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Fidex User Manual

Type of Document SpecificationsOperation DescriptionWork InstructionsS/W Version DocumentationTest PlanTest Reportsite ReportItem Selection ReportHazard AnalysisProduction ReleaseTechnical Report User Documentation

Product : Fidex

Document Number : ANI-80-300HFB09-0.7

Document Revision : 0.7

Revision Date : Oct 21, 2009

Author : Horst Bruning

File Path : Animage\User Manual

Number of pages in document :

Animage LLC Company Confidential

Animage, LLC Document # ANI-80-300HFB09-0.7FIDEX User Manual

Revision Description

Rev Date Comments Approved by

0.1 April 15, 2009 Document Creation – Horst Bruning0.4 July 8, 2009 Document expanded with CT, Fluoro, DR -

Dave Hill

0.5 July 24, 2009 Glossary, tests with Irene Bruning HB0.6 August 2, 2009 Guidelines for Section 2; editing0.7 October 21, 2009 Edits, fluoro playback, preview - Dave Hill

Document Revision: 0.7 Animage, LLC Company Confidential of 54October 21, 2009


Table of Contents

1 About this Manual............................................................................61.1 CONTENTS.............................................................................................................61.2 STYLISTIC CONVENTIONS..........................................................................................71.3 HOW TO USE THIS MANUAL......................................................................................8

2 Safety Information...........................................................................92.1 PRIMARY SAFETY RULES...........................................................................................92.2 SWITCHING THE SYSTEM OFF....................................................................................92.3 EMERGENCY SHUT-OFF............................................................................................92.4 GUIDELINES FOR OPERATOR AND PATIENT SAFETY........................................................9

2.4.1 Patient Positioning.........................................................................................92.4.2 Radiation Protection.....................................................................................102.4.3 Laser Exposure..............................................................................................102.4.4 Computer Connection...................................................................................10

3 Equipment Safety and Maintenance..............................................113.1 INSTALLATION SITE REQUIREMENTS..........................................................................113.2 SAFEGUARDS........................................................................................................123.3 SYSTEM MODIFICATIONS........................................................................................133.4 MAINTENANCE AND SERVICE...................................................................................133.5 FOOTSWITCH........................................................................................................153.6 CLEANING AND DISINFECTING..................................................................................15

3.6.1 Agents to avoid............................................................................................153.6.2 Cleaning........................................................................................................16

4 Getting Started..............................................................................174.1 SYSTEM INTRODUCTION.........................................................................................174.2 POWER ON..........................................................................................................174.3 MANUAL CONTROL FROM THE GANTRY - GCP............................................................174.4 MANUAL CONTROL FROM THE PATIENT TABLE............................................................194.5 FIDEX THE COMPUTER INTERFACE............................................................................194.6 EMERGENCY STOP.................................................................................................19

5 Daily Check....................................................................................205.1 AIR SCAN.............................................................................................................205.2 PHANTOM CHECK..................................................................................................21

5.2.1 DX check.......................................................................................................215.2.2 CT check....................................................................................................... 21

6 Scanning a Patient.........................................................................216.1 ENTERING A NEW PATIENT INTO THE DATA BASE........................................................22

6.1.1 Study............................................................................................................ 226.1.2 Patient already in data base.........................................................................236.1.3 Detector configuration.................................................................................24

6.2 PATIENT POSITIONING...........................................................................................24



7 Performing CR and DR...................................................................247.1 CR.....................................................................................................................257.2 DX.....................................................................................................................25

7.2.1 Basic mode...................................................................................................267.2.2 Advanced mode............................................................................................26

8 DR Visualization.............................................................................268.1 CR.....................................................................................................................278.2 DX.....................................................................................................................278.3 SAVING A VIEW.....................................................................................................27

9 Performing CT................................................................................289.1 HOW DOES CT WORK?..........................................................................................289.2 ANIMAL PREPARATION. POSITIONING AND SEDATION...................................................289.3 CHOOSING SCAN PARAMETERS.................................................................................29

9.3.1 Basic mode...................................................................................................299.3.2 Advanced mode............................................................................................31

9.4 TOTAL SCAN TIME.................................................................................................339.5 LOCALIZATION AND PREVIEW..................................................................................33

9.5.1 Field light......................................................................................................339.5.2 Center of rotation light.................................................................................339.5.3 Preview.........................................................................................................33

9.6 DATA ACQUISITION................................................................................................359.7 RECONSTRUCTION.................................................................................................36

10 CT Visualization..............................................................................3610.1 LABELING............................................................................................................ 3610.2 VOLUME RENDERING.............................................................................................37

10.2.1 Presets......................................................................................................3810.2.2 Rotation....................................................................................................3810.2.3 Clipping planes.........................................................................................3810.2.4 Scalpel......................................................................................................3810.2.5 Optimizing viewing...................................................................................38

10.3 SLICE DATA - MPR................................................................................................3910.3.1 SliceView..................................................................................................3910.3.2 MPR statistics and measurement.............................................................4010.3.3 Slab view..................................................................................................43

10.4 SAVING VISUALIZATIONS.........................................................................................4311 Acquiring Fluoroscopy....................................................................44

11.1 FLUOROSCOPY BASIC MODE....................................................................................4411.2 FLUOROSCOPY ADVANCED MODE.............................................................................44

12 Viewing a fluoroscopy study..........................................................4513 Creating a Report...........................................................................4614 Sending and receiving images externally......................................46

14.1 SENDING DATA TO AN EXTERNAL SITE........................................................................46



14.2 IMPORTING DATA FROM THE EXTERNAL SITE...............................................................4615 Quality Assurance..........................................................................4616 Appendix........................................................................................47

16.1 GLOSSARY........................................................................................................... 4716.2 TROUBLE SHOOTING..............................................................................................50

16.2.1 Restarting Fidex........................................................................................5016.2.2 Fault.........................................................................................................5016.2.3 Lock..........................................................................................................50

16.3 TECHNICAL SPECIFICATIONS.....................................................................................51



1 About this Manual This manual is distributed for the use of the equipment operator.Animage, LLC reserves the right to change the contents of this manual without notice.

The document may not, in whole or in part, be modified, copied, reproduced, distributed, translated, stored or published over networks, web sites or other on-line services, without express permission of Animage, LLC.

FIDEX is a registered trademark of Animage, LLC. All other product and brand names are trademarks of their respective companies.

FIDEX is manufactured by:

Animage, LLC3825 Hopyard RoadSuite 220Pleasanton, CA 94588Phone: +1 925 416 1900Fax: +1 925 369 0385

All rights reserved.

1.1 ContentsThis manual is intended to provide the end user with information and instructions regarding the use of the multiple-modality veterinary x-ray scanner FIDEX. It describes hardware, software, and operation.Prior to operating the scanner, this manual should be read and understood. Please keep this manual and other associated documentation for future reference and for new operators and qualified personnel.

The manual is organized as follows:

Section 1 (About this Manual), provides general information about structure and stylistic conventions of this manual.

Section 2 (Safety Information), includes primary safety information and procedures regarding the use of the scanner. Both operator and patient safety concerns are addressed.

Section 3 (Equipment Safety and Maintenance), provides more detailed safety information and operating procedures, and maintenance rules for the machine.



Section 4 (Getting Started), contains a general description of the main scanner components and their operation.

Section 5 (Performing checks), illustrates check to be performed by the user on a regular basis.

Section 6 (Entering a New Patient in the Data Base), describes the steps to ensure a patient is properly registered before scanning.

Section 7 (Performing CR), explains user actions necessary to obtain a digital overview radiograph (CR, computed radiography).

Section 8 (Performing CT), explains user actions necessary to obtain a volume CT acquisition.

Section 10 (CT Visualization), illustrates various ways to display the volume data on the screen.

Section 11 (Fluoroscopy), is a description of fluoroscopic imaging with associated safety instructions.

Section 12 (Working with a Study), gives examples of visualization tools to be used in the evaluation of images taken during a study.

Section 13 (Creating a Report), gives a template for a report as the result of a procedure or study.

Section 14 (Sending and receiving images externally) shows how to send images from Fidex to another data system or to receive images from another system, typicall over the internet.

Section 15 (Quality Assurance), contains the steps to run the FIDEX Quality Assurance process.

Section 16 (Appendix), lists glossary, technical specifications, suggestions for troubleshooting, standards and labeling.

1.2 Stylistic Conventions

Text Format Example MeaningBold Italic Menu or toolbar itemItalic Patient file Window titleBold underlined Apply Button command<text> <report template> Typed textCAPITAL LETTER ENTER Keyboard command

Important safety information and notes are highlighted in this manual as follows:

WARNING:Warn of the presence of a potential hazard, which may cause injury



CAUTION:Warns of the presence of a potential hazard, which may cause damage to the equipment.

NOTE:Draws attention to important but non-hazardous information.

1.3 How to use this manualThis manual should be read cover to cover. We recommend paying particular attention to the sections on safety and maintenance in Sections 2 and 3.



2 Safety InformationThis section includes all operational safety information relevant to the operator. Please familiarize yourself with this section before operating the scanner.

2.1 Primary Safety RulesThe safety rules concern the patient, the operating personnel and other persons in the vicinity of the scanner. Patient safety calls for sedation of the animal in most cases. For a CT procedure it is mandatory.Operating personnel should be trained in the use of Fidex. Radiation protection measures must be applied (see 2.4.1below). Mechanical motion of the scanner can be complex and sometimes unexpected, e.g. during system auto-calibration. The C-arm may rotate around its axis either clockwise or counter-clockwise before, during and after a scan. The patient table may move up or down. The table top may slide in or out of the scanner under computer control.The scanner should be located in a closed space to prevent unauthorized personnel interfering with its functions. Serious injury may occur if basic safety procedures are not followed.

2.2 Switching the system OFFTo prevent unauthorized use, the system should be switched off when not in use. Also, the computer should be shut down. The scanner will not be separated from the main power but will rather be in a sleep state, allowing it to come to stand-by easily.

2.3 Emergency Shut-offFidex comes with a small control box called CCP. It contains a mushroom-type emergency switch. Depressing it will stop x-rays but will not stop mechanical motion.

2.4 Guidelines for Operator and Patient Safety

2.4.1 Patient PositioningThe patient must always be positioned on the patient table. All body parts must be within a safe area extending about 30cm above the table top. When in doubt, rotate gantry to 12 o’clock (source on top), and check whether there is enough space between patient and collimator box. Repeat for horizontal gantry position if applicable.Fidex has a field light indicating the x-ray beam position. It can be turned on by pressing a button on the gantry control panel on the x-ray source cover.



Patient positioning depends on the type of image planned. For a CR, the patient table will be in low position if the x-ray source is at 12 o'clock, and the field of view will have maximal size. For CT, the patient should be centered around the isocenter of the scanner (laser light).

2.4.2 Radiation ProtectionFidex is capable of substantial radiation emission. The tube can be run at 120 kV and 10 kW. This requires good radiation protection measures for the operating personnel. In some states it is permissible to hold the animal on the table if proper aprons and gloves are used. This is not permissible for CT scanning. All personnel should be behind Pb barriers.

WARNING:FIDEX is designed for veterinary use. Scanning of humans is not permitted. The operator is responsible for proper use of the machine.

CAUTION:It is recommended that all personnel stay behind x-ray barriers during radiation. In some states it is permissible for the operator to hold the animal during a study, in which case proper precautions like lead aprons and gloves should be used. In particular, personnel should be shielded during CT studies.

2.4.3 Laser ExposureFidex uses a Class III laser to help with centering the patient. One should not look directly into the laser beam for any prolonged period.

2.4.4 Computer ConnectionFidex has at least one computer, the console computer. It is connected to a wall outlet, typically separate from the scanner. It will therefore not shut down automatically upon pressing the emergency button, or shutting the system off.

The PC has forced air circulation (fans), which must be checked from time to time to prevent obstruction of airflow through dust, animal hair etc.


Figure 1: Room layout


3 Equipment Safety and MaintenanceThis section includes all equipment and environment safety and maintenance information.The operator is responsible for the correct usage of the device, conforming to the instructions and procedures provided in the manual. In particular, the operator must observe the following:

The scanner can be operated only by authorized personnel with adequate knowledge of the usage, x-ray emission and local laws regulating the use of x-rays.

The device must never be used if any electrical, mechanical or radiological problems appear. It must never be used if it indicates malfunction of signal or emergency devices.

3.1 Installation Site RequirementsThe system must be installed and operated only in rooms designed for imaging use, according to recommendations of a qualified consultant. In particular, access to the scanner must be restricted during operation. Figure 1 shows a suggested room layout, with minimum room size 8 ft x 12 ft.

No exposure to acid, salt, or rain must occur.Operating temperature: 15oC to 350C.Operating humidity: 20% to 80%, non-condensing.

The equipment must be installed on a horizontal floor. If local regulations



require, the machine must be bolted to the floor to prevent tipping in case of an earthquake.

Power supplied must conform to local standards and regulations. In the US, a standard 115V/15Amp wall outlet is sufficient for the scanner. The computer should be powered from a separate circuit.

WARNING:Do not try to move the device after installation. Shifting the device could result in injury and could compromise the validity of the installation report.The provided wheels should be used only during installation, performed by authorized personnel.

NOTE:The computer must be installed outside the patient area. Only authorized personnel may handle connection cables between computer and scanner.

3.2 SafeguardsFluids and sprays.The device is not protected against dripping fluids and spray. No fluids should enter the scanner as this might result in damage to electrical and electronic components, and could be dangerous to the patient, the operator and the environment.

Fire safety.The device safety systems do not reduce the need for safety measures against fire in the working environment.

Fire Extinguisher.Use CO2 fire extinguisher only. It should be installed prominently and within easy reach.

Electrostatic discharge.Electrostatic discharge may result in damage to components. Flooring should therefore be constructed of anti-static material.

Radiation warning light.A Radiation ON light must be installed by the user to display emission status..

Door Interlocks.An interlock switch, preventing radiation when the door is open, may be installed by the user.



Electromagnetic Compatibility.For electromagnetic compatibility see APPENDIX Section 16.3, “Technical Specifications”.

3.3 System ModificationsModifications or upgrades to the system must comply with all required regulations.

WARNING:Opening the gantry back panel and tampering with the components is prohibited.

Improper and unauthorized modifications or upgrades of the system components (hardware or software) are prohibited as they can lead to improper functioning of the device, resulting in breakdown and/or accident and/or danger for patent, operator and equipment.

DISCLAIMER:The manufacturer is not responsible for safety, reliability and performance of the system if one of the following applies:

Installation, maintenance, modifications, repairs or upgrades are performed by personnel not directly authorized by the manufacturer or distributor.

Replacement parts have not been approved by the manufacturer or distributor. The environmental safety conditions do not reflect the ones described in this

manual, the regulation requirements or the advice of a qualified consultant. The system is used in a manner other than that specified in this manual.

3.4 Maintenance and Service

WARNING:Always switch power off before any maintenance of the device.

CAUTION:There are no user serviceable parts inside the unit. Do not remove the covers.

WARNING:



The only user-replaceable parts are the input accessible fuses, located at the rear interface panel. The replaced fuses must conform to the manufacturer’s specifications.

CAUTION:For continued protection against the risk of fire, replace only with the same type and rating of fuse.

Regular MaintenanceRegular maintenance is required in order to ensure the proper functioning of the device, as well as for safety of the patient, all personnel and third parties.

Maintenance and service of the device must be performed by personnel directly authorized by the manufacturer or distributor. All system components must be checked and, if necessary, replaced by qualified personnel.

WARNING:If the x-ray source is not used for three months or more, the tube must be conditioned as follows:

One pulse every 30 seconds at 120 kV, 15 mA, 0.1s (1.5 mAs) for 10 times.

Cleaning agent hazardsCertain cleaning agents should be avoided due to possible adverse effects on equipment and/or persons (see section 3.6 “Cleaning and Disinfecting”).

Preventive MaintenancePeriodically check the computer/device power and interface cables. Perform cable checks for the computer, monitors, keyboard, mouse according to manufacturer’s instructions. Device components must be installed and used according to provided technical documentation.

Storage of Components and AccessoriesComponents and accessories must be stored carefully.

MalfunctionsIf the system does not work as stated in this manual or defects arise, please contact customer service immediately.

Service ContractThe device must be serviced periodically. Please refer to the manufacturer or distributor to arrange for a maintenance contract.



Maintenance Interval ChecklistThe table below specifies time intervals for maintenance checking. For further details, please refer to local distributor.

Person in charge item activity intervalOperator system QA phantom scan

and analysisweekly

Service support Error log Check 12 monthsExternal components

Check for damage or dust

12 months

Emergency stop check 12 monthsElectrical parameters

Check 12 months

Mechanical parameters

Check 12 months

Patient table Motion test, visual check

12 months

3.5 FootswitchRadiographic and fluoroscopic functions can be controlled by a foot switch; CT cannot. Check regularly for damages to the cable.

3.6 Cleaning and Disinfecting

WARNING:Turn off the main power prior to cleaning and disinfecting.

Some ingredients of cleaning agents may be hazardous to your health. Concentration of such products in air should not exceed limits set by local ordinances. Adhere to all manufacturers’ recommendations on the use of these products, and ensure that the room is well ventilated.

3.6.1 Agents to avoid Do not use sprays as they may seep into components, possibly damaging

electrical parts, causing structural changes in various thermoplastics, or forming flammable mixtures of air and solution vapor.

Do not use abrasive fluids or organic solvents such as aldehyde, acetone, gasoline, spot remover or alcohol (except to clean the monitor screen, and aldehyde-based disinfectants for the table surfaces). These substances may



degrade components in the system, resulting in improper functioning of the device.

Avoid agents releasing ammonia by dissipation or decomposition. Ammonia causes corrosion.

Avoid agents containing silicone: this substance can accumulate causing problems with electrical contacts.

3.6.2 Cleaning

3.6.2.1 Gantry and Patient Table The device can be cleaned with a damp cloth, using mild cleaning solution. Moisten the cloth before applying to the device surface.

CAUTION:Never apply cleaning solution directly to the device.

3.6.2.2 Computer and Peripherals To clean the compute and peripherals, follow the manufacturer’s instructions. If no instructions are provided apply the same guidelines as for the scanner and patient table.

The monitors have a sensitive anti-reflective layer. Clean with a soft cloth. Pure alcohol or alcohol with 1/3 or 2/3 distilled water may be used. Do not use cleaning solution.

NOTE:For further information about safety and maintenance please refer to the local distributor.

3.6.2.3 Disinfecting Standard hydrous solutions of aldehyde-based and/or amphenolic surfactant-based disinfectants are recommended for disinfecting gantry and table top surfaces. (This conflicts with 3.6.1 above.)

3.6.2.4 Sterilization Sterilization is not required for the intended use of the device.



4 Getting StartedThis section provides an overview of the FIDEX multiple-modality scanner and its main components. It includes basic information of manual control from the gantry/patient as well as an overview of the available software packages.

4.1 System IntroductionFIDEX is a multiple-modality x-ray scanner for companion animals.

4.2 Power onThe control computer is ordinarily turned on first. In the typical computer fashion, press the power on button on the front of the computer and then turn on the display.

The power for the scanner is turned on using the on/off button on the CCP (Section 4.6). which sits beside the workstation controlling the scanner. Occasionally the two main switches in the pedestal holding the gantry are turned off as well; if so, turn them on.

The gantry will then move to the 12 o'clock position and adjust the collimation.

If you plan to use x-rays, pull out the emergency stop button (mushroom) on the CCP.

When all is working correctly, the lights on the CCP will show power on and ready.

WARNINGWhen powered up the gantry will move to the 12 o-clock position. Please be sure that there is no one or no thing that would impede it.

4.3 Manual control from the gantry - GCPThe x-ray source end of the rotating gantry holds the GCP (Gantry Control Panel), Figure 2.

On the left side in the center is a button which turns on the field light. The arrows surrounding the light adjust the 4 blades of the x-ray collimator and thus change the area irradiated by x-rays as shown by the changes in the area illuminated by the field light.

The display on the bottom right shows the state of the system; when not in use this is normally standby or ready. If fault occurs, the scanner is not operational until the fault is cleared; see Section 16.2.2.


Figure 2: Gantry Control Panel GCP


The light in the center is the x-ray on light; it is on whenever x-rays are being generated. The x-ray system also emits an audible beep when x-rays are being generated.

The display on the bottom left shows the type of scan selected: single x-ray with DX or CR, a fluoroscopic study,, or CT. The button on the left of this display toggles through the possible choices.

The functions on the left are possible choices of actions which have not yet been defined. (check this)

The presets on the right are suggested parameter combinations associated with the selected scan mode (these are very preliminary).

There is a foot switch supplied for initiating a DX, CR, or FL study. CT studies must be initiated from the console.



4.4 Manual control from the patient tableTable up/down, table in/out and gantry rotation can be manually controlled from switches mounted either at the end or the side of the patient table, depending upon the system configuration. Directions are clearly marked with the switches. (Figure 4).

Figure 4: Gantry and Table Control

4.5 Fidex the computer interface After the computer has been powered on, the standard Windows interface appears. Clicking on the Fidex icon causes the scanner to ready itself for use. The scanner will reset itself and do some mechanical calibration (no x-rays); the user interface will appear on the screen in the data base mode, ready for entry of patient information (Section 6.1)

4.6 Emergency StopThe Console Control Panel CCP (adjacent to the workstation) has a mushroom-shaped control for emergency stop. Pushing it in immediately turns off x-rays and stops all motions; it should be reserved for emergency use. The scanner goes into a fault state, and cannot be used until the button is pulled out to its normal position. (Figure 5)


Figure 5: Console Control Panel CCP


The CCP also includes a button which initiates an x-ray exposure. Usually, however, this is done either from the Fidex workstation or from the foot switch.

5 Daily CheckA daily check should be run to ensure that the scanner is function within its specifications. This should be done under patient “Daily Test” (Section 6.1).

5.1 Air scanRemove all objects from the patient table. Select Air Scan from the menu (not yet implemented). The C-arm will turn to 3 o’clock and a short x-ray pulse will be emitted. The software will check signal level and other conditions and proceed to the next step.


Figure 7: Data base choice

Figure 6: DX check


5.2 Phantom check

5.2.1 DX checkPlace the small soda bottle on the patient table, center it in the light field, and choose study “DX check”. Acquire a DX using the basic mode with standard image quality for a small animal (Section 7.2) A normal image should appear much like Figure 6 (except for the pen on the right side of the image).

5.2.2 CT checkTake a 15 cm diameter round plastic bottle filled with water (like a 1 gallon bottle with water or juice) and center it at isocenter. Raise or lower the patient table and put the bottle on the patient table centered using the cross hair coming from the gantry facing the patient table. Hold the bottle in place with tape or straps.

A scan of this water bottle is performed as patient named "Daily Test" with Study "water phantom". Section 6.1 discusses entering and using patient and study. Section 9.3 describes how to CT scan a patient. Run a large patient scan at 120 kV (This is a mode with 23 cm FOV.) in basic mode and high quality.

WARNINGThe top of the patient table must be at least 92 cm above the floor to avoid collision during a CT study. In case of doubt, run the gantry manually around the patient and check that a collision is not possible.

After reconstruction, when MPR slice appears (Section 10.3), set the window level to 0 and the window width to 300 and see that the water bottle is centered at a mid-gray with no gross artifacts or non-uniformities. Choose slab mode and create a 5.3 mm slab centered in the phantom. Select the circular ROI with a diameter of about ½ the image. The mean should be 0 ± 50 HU and the sigma 16±2 HU. (These numbers may be changed with experience.)


Figure 8: Data Base Patient entry


6 Scanning a PatientIn order to scan a patient, one has to go through a number of steps, which are detailed starting in Section 6.1 through Section 9.7:

1. Enter/find the patient in the Patient Data Base.2. Enter a new study in the DB (this includes e.g. the body part to be scanned, and

the scan mode (DR or CT).3. Position the patient on the table.4. Select scan parameters5. Scan the patient6. Generate viewable images (read the CR plate or reconstruct a CT volume)7. View images 8. Generate a report

6.1 Entering a New Patient into the Data Base

All imaging operations of FIDEX will be archived in the Patient Data Base DB. This provides easy access for evaluation, makes sure that studies do not get lost, and in general supports DICOM conventions.

A new patient with its relevant demographic and owner information should be entered before a study is set up. Enter all information your company requires; items preceded by a * are expected by the data base. (Figure 8) Weight is in pounds. After all the entries have been made, select Apply .

If the patient is already present in DB, its records may be accessed through the DB and PATIENT buttons.

6.1.1 StudyImages are stored in the DB for each patient under STUDY, which could contain CR images, a CT volume, or a fluoroscopy scene. A patient may be associated with several studies, which are kept in chronological sequence.


Figure 9: Data Base view


Select Study). Give a descriptive name to the study and then select Apply.

A scan can only be performed if the patient is registered in the DB, and a STUDY has been set up.

Once in the STUDY pane, choose the type of study from the top (DR (digital radiograph), CT (computed tomography) or FL (fluoroscopy)). Whatever you choose will be entered into the DB under the study name you had chosen.

6.1.2 Patient already in data baseIf the patient is already in the data base, then a new study is created by selecting the patient entry in the data base and then creating a new study. If the study is already created, then selection of that study will mean that any new acquisitions will be appended to it.

A new study can be created with a right click on the patient already in the DB.

To search in the data base for a particular patient or study, use the Search tab in the bottom right column. (This is not implemented yet.)



Figure 9 shows the expansion of an existing patient "salmon" with study "beautiful salmon" shown in the data base while patient "ME^Gabriele" in brown is the selected patient.

6.1.3 Detector configurationFIDEX has two detectors (x-ray receptors): the large, 14” x 17” CR plate, and the smaller CT/FL detector. The CT detector folds into the C-arm when not in use.

6.2 Patient PositioningPatient positioning is best done with the x-ray source at 12 o’clock (default gantry position). If the desired scan is a CR, the table should be in the low position, just above the CR plate. If the scan is a CT scan, the table must be in the CT position (50 mm below the isocenter and no lower than with the top of the table 92 cm above the floor).

The Gantry Control Panel (GCP) (Figure 2) has a push button for the field light. A high power LED projects a rectangular field onto the patient, visualizing the radiation field with its collimated edges.

The GCP also contains push buttons for moving the four collimator vanes in case not the full field is needed. Collimating the radiation field as much as possible is recommended in order to reduce exposure to the patient and scatter to the operator. If doing a CT, changing the collimator position from that chosen by the Fidex software may result in poor image quality.

Use the table in/out switch to move the region of interest close to the center cross in the illuminated rectangle.

If the study is a CT, care must be taken that no part of the animal extends beyond the patient table. See the warnings in Section 9.2.

7 Performing CR and DR

Fidex offers CR (Computed Radiography) as its way to deliver a large, 14” x 17” radiograph. The receptor is a CR plate positioned on the C-arm opposite of the x-ray source. If the scanner is in CR mode, the plate will sit safely in its plate holder, ready for exposure with the CT detector lowered. If the scanner is in CT mode, the CT detector is raised into position and the CR detector must not be present. Fidex can also do a DX, which is a 5" x 5" (13 cm x 13 cm) radiograph using the CT detector. Fluoroscopy (Section 11) also uses the CT detector.


Figure 10: CR acquisition


For both CR and DX, chose the DR tab at the top left. (Need recommendations for mAs, kV)

7.1 CRTo do a CR, after choosing the DR tab, select CR Exposure from the right side of the window (Figure 10). This should cause the CT detector to be lowered. Enter or modify the animal size and body part description as for CT (Section 9.3.1). Put a CR plate in the holder.

The patient table should be still in the up (CT) position. If the CR is to be taken at any angle other than 0° (12 o'clock), rotate the gantry manually to that angle. If the CR is to be taken at 0°, then lower the patient table to its lowest position, just above the CR plate. Choose the animal thickness at this body part (if the default is not approximately correct) and press ENABLE.

Select CR acquisition on the large button at the bottom right. The x-ray tube will warm up and then acquire the data.

Remove the CR plate and put it into the CR reader to acquire the data for further use.

7.2 DXTo do a DX, choose DX ACQUISITION from the right side of the DR tab (Figure 12). Enter or modify size and body part as described in Section 9.3.1. The information required is much the same as for CR (Section 7.1). Although the normal gantry position is with the source at 0°, it is possible to manually move the gantry to another angle.


Figure 12: DX advanced mode

Figure 11: DR Visualization


7.2.1 Basic modeFor the basic mode using the parameters suggested, click on the large Expose button at the bottom right.

7.2.2 Advanced modeChoosing the Advanced mode over the Basic mode allows the user to modify some parameters (Figure 12).

Advanced mode allows change of the detector acquisition mode (Section 9.3.2). the kV, mAs. tube current and also gantry angle, which will then rotate the gantry to the chosen angle before acquisition. Ordinarily 1x1 detector acquisition mode is used for DR for the best spatial resolution. Gantry position, in o'clock units for the position of the source, may be chosen with the down arrow to the side of the position indication.

WARNINGDo not change the gantry angle without checking that the patient table is raised at least to the CT position.

The default view is fullbeam. It is possible to get a view with the detector offcenter using half beam, or a larger field of view using extended. for which two acquisitions will be stitched together. If you change back to basic mode, the



detector will be moved to its fullbeam position but the gantry angle will stay at whatever angle you have set.

8 DR VisualizationOnce a CR or DX has been acquired, the software will automatically go to the DR view tab on the right hand side. If necessary, the DR view tab can be manually chosen. (Figure 11). This tab gives a number of possibilities:1. Change the zoom of the image using one of the four tabs under "Zoom":

- makes the image smaller; each click makes a factor of 2 change + makes the image large; each click makes a factor of 2 change the third icon shows a rectangle on the image. The part of the image included in

the rectangle is then enlarged to fill the screen. Type the desired magnification

2. Change the orientation of the image. Clicking Native on the upper right returns the orientation to its original state and resets the center and window.3. Change the center and window used to view the image. The upper slider is window with narrow to the left; the lower slider is the center of the window.4. To find the reading at any point, place the cursor on the image. The numbers appear under min and max.5. To find the mean and standard deviation of any region on the image, choose either the rectangle or the ellipse on the left of the window, use the cursor to draw a region, and find the results as mean and sigma.6. To find the readings along a line, choose profile, use the cursor to draw a line on the image. The profile is displayed on the right side.7. One can choose the data representation as raw (the intensity of the x-rays coming through the image; thin areas are white), the inverse of raw (thick areas are white) or filtered. The numbers given for mean and sigma will be, however, those of the raw representation.

To acquire another DX, choose DX Acquisition on the right hand side.

Sections 8.1 and 8.2 discuss capabilities which differ in visualizing CR and DX.

8.1 CR(this needs a discussion of available filters)filtersFor the use of CR for CT localization for CT localization, see Section 9.5

8.2 DXThe description above is basically for using a DX. I don't know how the CR will differ.



For the use of DR for CT localization (Preview), see Section 9.5.

8.3 Saving a viewThe data acquired has been saved in the DB. It is possible to acquire in addition two other records of the data using the buttons in the bottom right.

Screenshot saves a picture of the workstation screen including the right hand column in the DB. This image can only be viewed; no changes can be made.

Snapshot saves the entire data set as last viewed. including changes such as level and window. A snapshot view can be adjusted further.

9 Performing CT9.1 How does CT work?During CT an x-ray in every direction is acquired and then cross sectional data is reconstructed by untangling the data acquired in each direction. This works well if the subject being scanned does not move while the scan is underway; however, if the subject moves, then the data is inconsistent and streaks are the likely result. Cone beam CT, as used by Fidex, takes data over a 8 cm long region of the animal at once and reconstructs from that data a volume of cross sections covering 8 cm of the subject. Each element of this volume (voxel) has a numerical value which is proportional to the density of the subject at that point.

When the scanner is calibrated, these numbers proportional to the density are called Hounsfield numbers (HU) after Godfrey Hounsfield, Nobel Prize inventor of the CT scanner. Water has number 0 HU, air is -1000 HU, soft tissue ranges from -50 HU to +50 HU, and bone has numbers larger than 500 HU.

WARNINGThe HU numbers require both a good calibration of the scanner, as shown by the daily check (Section 5) and that the animal is fully within the FOV.

9.2 Animal preparation. positioning and sedationThe reconstruction algorithm assumes that the subject is always in the same place while the scan is underway. If the subject moves, artifacts such as streaks appear in the images, making interpretation of the images more difficult. Unlike a human, an animal cannot be told to hold its breath during the time of the scan; thus for a good CT the animal should be sedated, intubated if necessary, and strapped to the patient table. Any metal objects which will be in the region to be scanned, such as a collar, should be removed.


Figure 13: CT scan length options


WARNINGThe detector comes very close to the edge of the patient table when the gantry rotates. The animal's legs and feet should be positioned and strapped to that they do not hang over the edge of the patient table to avoid injury.

WARNINGAs the patient table pallet moves in, the front end can go as far as almost hitting the gantry. No part of the animal should extend beyond the front end of the pallet.

Straps supplied with Fidex can be wrapped around the patient table pallet; please be sure to wrap around only the flat pallet and not the metal structure below it.

For large animals, studies of the abdomen or hind quarters may require that the animal be positioned tail into the gantry.

WARNINGPlease be sure that the animal position icons in the basic mode screen are set properly; they are used to label the directions on the images.

The scanner software gives an estimate of how long the scan chosen will take (scan time in Figure 14), so that you can determine how much sedation is needed.

9.3 Choosing scan parametersChoose CT scan from the top right hand corner of the console. Choose the CT Acquisition tab on the right hand side. CT scans can only be started from the console; because of possible exposure, the technologist should not be standing with the animal for a CT scan.

There are two choices for types of scan mode: "basic" and "advanced". The basic mode (Figure 14) has Animage-recommended scan parameters based on the size and body part of the animal being scanned. The advanced mode gives more flexibility in changing the parameters, but must be used with care. For most purposes, choose "basic".

9.3.1 Basic modeChoose animal size (miniature, small, medium, large (we need weight recommendations here))


Figure 15: CT body part choices

Figure 14: CT basic mode


Use the drop down arrow to enter the length, which is the distance to be covered in the longitudinal direction (Figure 13) . The scanner covers only 8 cm longitudinally with each rotation; to cover more distance the scanner will automatically move the patient table and add additional rotations. To cover 8 cm no patient table movement is needed; to cover up to 13 cm one movement is need; to cover up to 18 cm 2 movements are needed, etc., up to approximately 50 cm. The table will move in to cover this distance, so if this distance is more than 8 cm be sure to start with the portion of the animal nearest to the gantry.

Flip the image of the animal head to tail or to the side to indicate how the animal is placed on the patient table. This will be used to label the images with the animal right, left, dorsal, ventral, head, tail.

Move the slider on the image of the body to the body part to be imaged (Figure 15)

The software will display four quantities (Figure 14):

o kVo total mAs in

the studyo field of view diameter in cm. o total elapsed time for the scan in seconds.

Select either the standard or high quality mode. The high quality mode uses more x-rays for lower noise but with additional dose.

The field-of-view has been chosen from the body part, animal size, and mode choice. Field of view is the diameter of the scanned field in cm in the transverse direction (in the plane of the scanner's rotation). The scanner has 3 possible fields of view (FOV): 8 cm, 15 cm, 23 cm. Typically the total scan time is smallest for the 8 cm FOV and largest for the 23 cm. The 23 cm FOV requires two rotations of the gantry (clockwise followed


Figure 16: CT advanced mode


by counterclockwise); the other two require only one rotation. Technically, the 8 cm FOV is called full beam, the 15 cm FOV is called half beam, and the 23 cm FOV is called extended mode.

The scan time required is a function of the specific parameters of the chosen modes. Under the "basic" choice, the user does not control these; they are set to give sufficient dose and acquire sufficient data for good images of the body part chosen. For example, a small animal requires less dose than a large one for the same image quality, and the scan time will be shorter.

9.3.2 Advanced modeThe advanced mode (Figure 16) requires that the basic mode be first used to choose animal size, body part, placement and length.

The advanced mode allows the user to change the parameters proposed in the basic mode to something else. The advanced mode gives access to most of the possible parameters affecting image quality, so these parameters are discussed here.

The concept of a projection or frame is useful in understanding these parameters. A projection or frame is the data which is acquired at one position of the x-ray source while the gantry rotates. Each projection is essentially a planar x-ray of the animal from a particular direction; for each of these the x-rays are on for 2-10 milliseconds; the scanner acquires from 30 to 60 projections/second.

The number of frames is the number of views of the subject taken as the scanner rotates through 360°. As each projection has the same kV and mAs, the total dose to the subject rises with the number of projections. The noise in the image is also inversely related to the square root of the amount of x-rays, so more projections mean lower noise in the image. Larger animals require more projections than smaller ones both for dose reasons and to make better images of the parts of the body near the edge of the FOV. However, the total scan time is also increases linearly with the number of projections. The allowed values are 256, 356, 512, and 745. Most exams should be done with 512 or 745 projections.



kV is the maximum potential of the x-rays; Fidex uses both 80 kV and 120 kV. 120 kV is more penetrating, and is necessary for larger animals.

mAs is the current (mA or milliamperes) used when the x-rays are on and s is the length of the exposure in seconds. kV times mAs is the energy given to the animal, and is thus proportional to the dose.

The tube current is current flowing in the x-ray tube; it is the mA in mAs.

Exposure time is not displayed; it is the length of time the x-rays are on for each projection (s in mAs) and is the quotient of mAs and mA. Exposure time is usually between 2 and 10 ms.

Quantity of volumes (we need a better name for this) is the number of patient table positions needed to cover the length specified; quantity of volumes is 1 for 8 cm, 2 for 13 cm, etc. The patient table moves in from its starting position.

The detector is divided into a matrix of 1024 x 1024 pixels in a 13 cm x 13 cm array. For most CT use, these are averaged (binned) into 2x2 or 4x4 pixels. 2x2 averaging gives the highest spatial resolution and is thus appropriate for the smallest animals and lung studies; it also gives 30 projections/second. 4x4 averaging gives sufficient spatial resolution for most studies and gives 60 projections/sec. 1x1 (no averaging) is slower, gives about 7 projections/second, and is almost never used with CT.

As noted above, the noise is related to the number of projections. It is also related to the average. Going to a 4x4 from a 2x2 causes the number of x-rays in each data point to go up by a factor of 4, so the noise will be lowered by a factor of 2 at a cost in spatial resolution.

For the description of full beam, half beam, and extended modes please see Section 9.3.1.

These parameters interact with each other and with the characteristics of the detector and x-ray source; thus the software limits the parameter combinations which can be chosen.

The parameter section of the advanced mode is divided into two parts; the input part and the suggested parameters. If you change one of the parameters, the suggested parameter section will give suggested values for other parameters which will meet the restrictions of the scanner. This gives the user the chance to see how these parameters



interact; however, the user must enter these suggested values into the parameter choice. If this is not done, the result may well be poor image quality.

Dose is increased by increasing the number of projections, increasing the mAs/projection, and changing the kV from 80 kV to 120 kV. In general, the images are less noisy with higher dose but the scan takes longer. The scanner is prevented from a user choice of parameters which has a significant chance of injuring the animal. In the advanced mode it is possible to select a set of parameters and define them as a user-defined mode which then becomes available in the basic mode. (This is not yet implemented.)

9.4 Total scan timeThe total scan time is dominated by the time for each component scan multiplied by the number of patient longitudinal positions on the animal scanned. For example, a single 512 projection scan using 2x2 binning takes 17 seconds for FOV 8 or 15 cm, and 35 seconds for a 23 cm FOV. Use of 4x4 binning reduces these times to 8 and 17 seconds. The total scan time given is the software estimate for the selected parameters.

9.5 Localization and Preview

9.5.1 Field lightThe field light is the primary indicator of position. With the x-ray source in the 12 o'clock position, a button on the gantry control panel turns on the field light. It shows where x-rays will hit the animal in that position once the scan mode has been chosen. For the 8 cm FOV it shows the region which will be scanned. For the 15 cm FOV, it shows half the FOV with the center of the region which will be scanned 1 cm in from the right hand edge. For the 23 cm FOV, it shows a centered 8 cm region. The total region scanned with the 23 cm FOV extends 8 cm more on each side perpendicular to the direction of patient table motion. The field of view shown by the light is about 1 cm larger on each edge than what the CT detector sees.

9.5.2 Center of rotation lightThere is a laser light mounted at the center of rotation of the scanner which indicates how the acquired volume will be centered about the scanner axis. The patient table should be raised or lowered so that the animal is centered in the volume, subject to the limitations of the table. The table maximum height is about 5 cm below the center of rotation; the 92 cm minimum height for CT is limited by the hardware and software to avoid the possibility of the detector hitting the patient table during rotation



9.5.3 PreviewThe imaging method of localization is called Preview, which is initiated by pressing the Preview button on the lower right.

9.5.3.1 Preview with a DX detector Preview with a DX detector is essentially a DR combining a DX data acquisition with patient table motion and fixed gantry angle to cover an 8 cm wide region centered on the axis of scanner rotation. The CT scan software then uses an area marked on this image as the area to be covered, thus setting both the length (basic CT acquisition mode) and the quantity of volumes (advanced mode) and then moving the patient table to the appropriate start position.

To set up a Preview, after placing the animal on the patient table, move the table so that the field light edge nearest the gantry strikes a position a few centimeters closer to the gantry than where the CT scan should start. Then set the CT basic mode length long enough to go a few centimeters at least beyond where you expect that the CT scan should stop.

Press the Preview button on the lower right, the x-rays will come on, the patient table will move, and a longitudinal DR image will appear on the screen. Hold down the left mouse button and adjust the window and level by moving the mouse left/right or up down until landmarks such as the spine or lungs are visible. (Figure 17)



Figure 17: Preview

The red lines on the Preview image mark the beginning and end of the area to be covered. Grab them one at a time and move them so that they then cover the region for the CT to cover.. As you move the red lines, the distance covered indicator will change to the distance between the red lines. Once you are satisfied with the result, and you have chosen the parameters of the CT scan you want, select the large CT acquisition button. The patient table will move to the appropriate start position and the CT scan will begin

A Preview may be taken at any gantry angle, although typically it is done with the x-ray tube at 6 o'clock. For some studies, the relevant information may be best found with the x-ray tube at 3 o'clock or 9 o'clock. Multiple previews and be taken; only the last one is used for the CT acquisition.

WARNINGIf the animal is moved on the table after a Preview and before the CT scan starts, the CT scan may be in the wrong place. Redo the Preview if you move the animal on the patient table. Moving the patient table with the animal does not cause a problem.

Currently, to save a copy of a Preview image one must use create a screen shot using the keyboard button prt scn



9.5.3.2 Preview with a large DR detector

If the scanner is equipped with a large DR detector, a region to be scanned is indicated on the DR image without patient table motion. The selection software indicates the region covered by each of the 3 possible fields of view. After the region has been chosen, the scanner selects the FOV and scan length and the automatically moves the patient table to the correct starting position for the CT scan. (This is not yet implemented. This is my guess as to how this will work; it may be possible to do this also with CR, but the workflow will be longer.)

9.6 Data acquisitionA CT scan is initiated by pressing START on the console (Figure 14) (the large button at the bottom right). The gantry (and patient table if using localization from a DR image) will move to start position, the anode on the x-ray source will begin to rotate, and a beep will occur while the x-rays are on.. During the course of the scan, the gantry and table will move when necessary and the x-rays will turn on and off until the total scan requested is compete. No operator intervention is needed.

During the course of the scan, the console screen will show a selection of the projections as they are acquired.

The scan sequence can be terminated at will by pushing the red emergency stop at the console or by pressing the cancel button on the console. If either of these is done, the x-rays turn off and motion stops. As the data is incomplete, it will not be reconstructed. After doing this, the animal will have to be rescanned.

When the scan is complete, the beeps will stop. the gantry will reset to the 12 o'clock position, and the console will say "starting reconstruction".9.7 ReconstructionReconstruction of the volume will take from 30 seconds to several minutes depending upon the volume covered. During reconstruction, partially reconstructed images will appear on the screen.

Once the reconstruction is complete, MPR of centered slices of the volume reconstructed (Section 10.3) will appear on the screen. By default, these slices will be the three perpendicular slices through the center of the volume scanned. The reconstructed data is then ready to be visualized, either on the scanner console or on an external work station. Use of this data is discussed in Section 10 following.



10 CT VisualizationCT visualization is called automatically at the end of reconstruction (Section 9.7). For animals scanned earlier and present in the data base, it is called when the cube of the relevant projection set (which contains the reconstructed images) is double clicked in the DB view.

10.1 LabelingBoth volume rendering (Section 10.2) and MPR (Section 10.3) use an image of a labeled cube to help orient you to what you are seeing. This cube has sides with the letters R (right), L (left), V (ventral), D (dorsal), H (head) and T (tail). These labels indicate the side of the animal being viewed. This information is determined from the positioning information entered when the patient is registered (Section 9.3.1).

WARNINGThese labels are only correct if the icon of how the animal is positioned is correctly chosen when the animal is placed.

10.2 Volume rendering


Figure 18: volume rendering without clipping planes


Volume rendering is a way of showing the entire 3D volume; in general, one sees the density in the direction one is looking which has been chosen to be opaque or partially opaque. If something is partially opaque, one can see through it somewhat to material behind it (Figure 18)

10.2.1 Presets

There are presets to automatically select certain types of views such as looking at the skin or bones or soft tissue. Make Preset and Save Preset in the upper right column allow the creation of such presets. Section 10.2.5 gives more information on how to choose parameters to best look at the data.

10.2.2 RotationThe volume can be rotated by placing the curser on the screen; the volume rotates with the motion of the curser.



10.2.3 Clipping planesClipping planes allow one to remove some part of the volume (such as a patient table) to look in more detail at the internal structure. In Figure 18,(new figure with clipping planes needed) a cut plane has been used to make visible a resolution phantom lying on the patient table. Select Clipping Planes on the upper right and move a given plane by selecting the green square in the middle of that plane.

10.2.4 ScalpelThe scalpel allows one to remove a piece of the outer layer of the volume to look at the data inside. Select Scalpel on the upper right and move the cursor to outline the area to be removed.

10.2.5 Optimizing viewingBelow the image is a histogram of the number of voxels (vertical direction) vs. the CT number (horizontal direction). In general, a peak near 0 HU represents soft tissue. On top of this histogram is a curve made of one or more line segments connected by small squares. If one of these squares is along the bottom, then any voxel with a CT number at that point will be complete transparent (i.e., not visible). On the other hand, if a square is at the top of this part of the window, then a voxel with a CT number at that position will be completely opaque (i.e., so visible that nothing beyond it will be visible). Points between the two squares will be partially opaque; a voxel at the point half way up the line will be 50% opaque. Viewing voxels in this way takes some practice.

To adjust the curve, click in the gray area under the curve and move it sideways to change which voxels are opaque and which are transparent.

The curve can have any number of line segments allowing a relatively complicated choice. To add a point, double click on the line where the point is wanted. A square appears there which can be moved using the curser to any desired opacity. To get rid of a square, click and hold on the point and press the delete key. If there are no points visible, double click on the gray area.

Color is used to help distinguish tissues. To select a color for a point, right click on the point and then choose a color from the choices presented. A bar at the top of the histogram display will show the chosen color as a function of CT number. For example, choosing a curve with white near 500 HU and red near 0 HU, both with high opacity, and 0 opacity under -100HU or so will show soft tissue as red, bone as white, and lung tissue and air will be transparent. Voxels with CT number between 0 HU and 500 HU will have a color with is a mixture of red and white as can be seen on the bar along the top.



10.3 slice data - MPRCT acquisition acquires a volume of data. MPR (MultiPlanar Reconstruction) shows slices through that data in the transverse, sagittal and coronal planes.

The data itself has been converted to Hounsfield numbers. Hounsfield numbers (HU) are approximately proportional to density and, by convention, water is 0 HU, air is -1000 HU, soft tissue ranges from -50 HU to +50 HU, and bone has numbers larger than 500 HU.

10.3.1 SliceViewFigure 23 shows the MPR display in slice view. When a single slice is shown, it has the voxel thickness as reconstructed, or between 0.16 mm and 0.46 mm depending upon the FOV.

The three primary views are indicated on the left side. The top (outlined in green) is the transaxial view, the center (outlined in blue) is the coronal view, and the bottom (outlined in red) is the sagittal view. The phantom in this figure is a DR resolution phantom lying on the patient table. This figure must be changed to get the labeling right. The enlarged view in the center is selected by clicking on one of the three views on the left; in this case it is a coronal view. The orientation cube will show the direction in the patient in which you are looking; that is, if it shows H (Head), you are looking at this transaxial slice from the head of the patient toward its feet. In addition, on the center view, small cubes on top, bottom, right and left sides of the image indicate which side of the patient is adjacent to the cube.

The location in the volume in the views is adjusted by moving the axial lines shown in the left views. For example, moving the red lines in sagittal or transaxial view will change the coronal view and thus the enlarged view in this example. By grabbing the end of one of the lines, you can change the angle of the view, thus creating a view in an oblique direction.

The slice in the large view in the center can be changed also by using the mouse wheel. When this done the location lines on the views on the left side change accordingly.

Window and level are adjusted using the sliders on the bottom, which has low numbers on the left. The window width is changed by varying the end points or selecting the width number and typing in a new number; the center is changed by moving the rectangular window indicator or selecting the center number and typing in a new number. The histogram is of number of pixels of a given CT number. Bumps in the



histogram indicate where the largest number of pixels are; this is typically around 0 HU, the value of water and near -1000 HU, the value of air.

The level and window can also be changed by holding down the left mouse button and moving from side to side (for the level) and up and down (for the window).

The image can be zoomed using the zoom tool under the MIP button (Figure 19).

Presets (Figure 19) for bone, soft tissue, or other tissue of interest can be created using make preset and saved using save preset. Available presets are shown in the area below the make and save preset buttons. Any presets which have been supplied or created (such as bone or soft tissue) are used to quickly look at an image in a standard way.

10.3.2 MPR statistics and measurementMoving the curser over the image gives the HU value of the point under the curser. One can select also a square or rectangular ROI (Figure 20 and Figure 19) and draw the ROI on the image. The result is the average HU value within the ROI under mean and the standard deviation under sigma. Min and max then give the maximum and minimum CT number within the ROI.



is of a soda bottle with top toward the gantry, one pencil on the side toward the ceiling, and two pencils on the right side as seen from the foot of the patient table.

Selection of Profile allows the drawing a line across the image; the CT numbers along that line will show below the Profile tab as a function of the pixel number along the line.

Selection of measure allows the measurement of distance between two points on the enlarged image using the curser. The length of the line in mm is given next to the line in the image.



(This figure should be changed to a more anatomic one; this requires also updating the previous text.)

10.3.3 Slab viewEach element of the volume (voxel) is a cube which has the dimensions on each side chosen in reconstruction. For Fidex, these are 0.15 mm for an 8 cm FOV, 0.25 mm for a 13 cm FOV, and 0.30 mm for an 18 cm FOV. As these slices are very thin, the image is likely to appear extremely noisy in a slice view as in Figure 23. MPR choice of slab view (Figure 22) allows the averaging of slices in one direction to, for example, give a slice width of 2 mm, which would add up 8 voxels in the direction perpendicular to the view seen. When the center view is the transaxial view, dotted green lines appear in sagittal and coronal view; the width is adjusted using the cursor. If the center view is the coronal, the dotted lines appear in the transaxial and the sagittal views. The dotted lines always appear in the two views which are not displayed in the center. Alternately, the desired new slice width can by typed in the upper left corner of the image where the current slice width is displayed. The image with the wider slice now has much less noise.

All the display and measurement capability in slice view is also available in slab view; the only difference is that in slab view the slice is thicker than that reconstructed.

10.4 Saving VisualizationsThe data acquired has been saved in the DB. It is possible to acquire in addition 3 other records of the data using the buttons in the bottom right.

Screenshot saves a picture of the workstation screen including the right hand column in the DB. This image can only be viewed; no changes can be made. A right click on the screenshot name in the DB view gives the location on disk where the screenshot can be found; this is useful for copying the screenshot to an external device for e-mailing or printing, for example.


Figure 24: Fluoroscopy basic mode


Snapshot saves the entire data set as last viewed. including changes such as level and window. A snapshot view can be adjusted further.

11 Acquiring FluoroscopyFluoroscopy uses the CT detector and can be performed at any gantry angle. To start fluoroscopy, choose the FL button on the top right pane (Figure 24) and then Live Fluoro on the right hand side.

Animal labeling is the same as for DR and CT (Section 9.3.1) In addition, the thickness of the animal in cm in the direction the x=rays will travel can be specified. This helps the system to optimize the acquisition parameters. To set the thickness manually, select enable and then adjust the object thickness slider to the right value in cm.

11.1 Fluoroscopy basic modeIn the basic mode, choose animal size, part and thickness in the same way as for other studies (Section 9.3.1). Frame rates of 5 fps or 10 fps can be chosen using the down arrow on the right side. By default a fluoroscopic study lasts 10 seconds.

11.2 Fluoroscopy advanced modeThe advanced fluoroscopy mode gives additional capability (Figure 25). With it the number of frames/second can be changed up to 30 fps for 2x2 detector averaging and up to 60 fps for 4x4 averaging. To change the length of the fluoroscopy, change the total number of frames. The gantry angle can also be changed from the user interface; the more likely situation is that you have adjusted the gantry angle manually while positioning the animal.


Figure 25: Fluoroscopy advanced mode


WARNINGThe gantry will move as soon as a gantry position is chosen in advanced mode. Please be sure that it will not be impeded.

Fluoroscopy studies are then begun either using the foot pedal at the gantry or the large start button at the bottom of the right hand panel. The study ends when the foot pedal is pressed again, the stop button on the panel is used, or the prescribed number of frames has been acquired.

Anyone performing a fluoroscopy study and standing by the animal should be wearing a leather apron and gloves, should stand back as far as possible from the animal, and should not put his or her hands in the x-ray beam.

To view a fluoroscopy study, choose the Playback tab on the right hand side and see Section 12 below. If difficulty, call up the study directly from the DB.

Images being acquired during a fluoroscopic study are visible on the monitor attached to the gantry as well as on the workstation.

12 Viewing a fluoroscopy studyTo view a fluoroscopy study, select the study in the DB and the FL screen with playback tab selected appears (Figure 26).

The analysis tools are the same as for DR, Section 8. The upper slider adjusts the window with which the data is viewed (narrow to the left) and the lower slider the center of the window.

The buttons on the bottom allow one to play, pause and stop the playback of the images.


Figure 26: Fluoroscopy playback


13 Creating a ReportThis section is still to be added.

14 Sending and receiving images externally

The exchange of addresses and technical details to allow the transmission of images must be set up before the following commands will work. The result of this will be a label for the external site such as "Dr Jones".

14.1 Sending data to an external siteTo send a study to an external site, in the DB view right click on the study to get a list of allowed external sites. Choose one and then click "export".

14.2 Importing data from the external siteTo import a study from an external site, in the DB choose the import/export tab on the right hand side, which will then present a list of the allowed external sites. Selection of the one of interest will give a list of the studies present on that site. Select the ones which you wish to import.

14.3 Creating a data DVD or CDSometimes it is desirable to go outside of the user interface and create a data DVD or CD as a step to sending an image to another computer system or user. To find the data, go to the DB view and right click on the patient, study, projection, or cube of interest. Select open data folder. The CT slice information has, for example, .slice as its extension. Figure xx is an example of what appears. Select the slices of interest and copy them to the DVD or CD writer supplied on the system. Put in a blank DVD or CD and press create in the writer software.



Figure 27: slice listing



15 Quality Assurance



16 Appendix16.1 GlossaryC-Arm

A C-Arm is a C-shaped radiographic device with x-ray source at one end of the C and x-ray detector at the other. It rotates about the center of the C.CCP

Console Control panelCollimator

A set of four blades mounted at the x-ray source which adjust the rectangular area of exposure to x-rays.Console Control Panel

A small panel adjacent to the user interface workstation containing the emergency stop switch and a start exposure button.CR

Computed Radiography.CR plate

The detector for CR; typically a 14" x 17" (35 cm x 43 cm) cassette which, after exposure, is converted by a reading device into a digital image.CT

Computed Tomography. It acquires an x-ray projection at each angle and uses software to reconstruct a cross section of the scanned object seen by the projections.CT detector

For Fidex, a 13 cm x 13 cm (5.3" x 5.3 ") solid state detector read directly by the Fidex system.DB

The Data Base, which for Fidex contains the descriptions of the animals studied and gives access to all studies performeddetector binning

The DX detector is constructed of 1024 x 1024 detector elements each 0.127 mm in size, giving a total size of 13 cm x 13 cm. The detector elements can be read individually, or binned by the detector system as the average of 2x2 elements (4 elements averaged together) or as the average of 4 x 4 elements (16 elements averaged together). Binning gives less noise and faster reading with a small cost in spatial resolution.DICOM

The Digital Imaging and Communication in Medicine Standard used to view medical images regardless of origin. DICOM is supported by Fidex.DR

Digital Radiography; for Fidex can refer to either a exposure taken as CR or DX with a fixed gantry angle. It can also refer to a 14" x 17" detector used in the place of the CR.



DXDigital X-ray; for Fidex DX refers to an exposure taken with the CT detector at a

fixed gantry angle.exposure time

The time the x-ray source is on for any projection.Field Light

The light mounted at the x-ray source which shines through the collimation and shows on the patient the approximate area which will be exposed to the x-rays.Field of View

The area at the patient seen by the imaging sequence. This is at isocenter for CT and for DR with gantry not at 0°; it is roughly at patient center for DR at 0°.FOV

Field of View.FL

Fluoroscopy.fluoroscopy

Fluoroscopy is a timed sequence of DX exposures at a given gantry angle. The number of exposures per second is determined by the user and the detector binning chosen. Fluoroscopy sequences can then be played back as a movie. Fluoroscopy may be used with contrast medium for angiographic studies or for swallowing or other motion studies.frame

A projection.GCP

Gantry Control Panel; GCP is the set of controls for field light, collimator, and scan mode mounted on the x-ray source end of the gantry.Hounsfield Units

Hounsfield Units are a CT standard for displaying density of CT images. Water is at 0 HU; air at -1000 HU, soft tissue is between -100 HU and 50 HU, and bone is >500 HU. Godfrey Hounsfield received a Nobel Prize for the invention of CT.HU

Hounsfield Units.isocenter

The isocenter is the center of the gantry about which the x-ray source revolves. In the coordinate system of CT images, it is (0,0)kV

Kilovoltage is the potential to which the electrons which cause the x-rays to be created are accelerated; it is also a measure of the maximum energy of the x-rays created. Fidex allows kilovoltages between 50 kV and 120 kV; lower kV tends to give better contrast and higher kV has better penetrating power for larger animals.level

In image display, the number at which the window is centered.



localizationLocalization is the process of finding where on the patient a CT or an FL is to be

performed. An outline of the proposed FOV is placed on a DR image of the patient, adjusted by the user, and when applied the patient table moves to the correct position. Localization only works properly if the patient does not move between DR and the later study.mAs

The mAs is an estimate of the amount of x-rays in a given study. The mA is the x-ray tube current which is multiplied by s, the exposure time. The mAs times the kV is an estimate of the total amount of energy used to create this exposure.mean

In Fidex use, mean is the average value of a selected set of pixels.MPR

MultiPlanar Reconstruction. MPR is the formation of an arbitrary planar slice through a volume of data by selecting the appropriate voxels from the volume and displaying them as a plane.Opacity

In volume rendering, opacity refers to how well one can see through a voxel. At full opacity, nothing behind that voxel can be seen.Patient

The patient is the animal studied. The name "Patient" is also used as the highest level of the data base directory, and is used to find the images associated with that animal.pixel

A pixel is the smallest element of a two dimensional data set - either of a radiograph, a detector, or a display screen.projection

A projection is the 2-dimensional data acquired during one x-ray exposure time and is typically at one gantry angle.reconstruction

Reconstruction is the process for CT which takes multiple projections passing through a volume and determines the densities of the individual voxels in the volume studied.region of interest

Region of interest is an elliptical or rectangular region selected on an image for which the mean and ROI are calculated.ROI

Region of Interest.sigma

The standard deviation, or a measure of the variation from constant, of a set of pixels. For a uniform object or organ, sigma is a measure of the noise coming from the number of x-rays going through that region



Study"Study" is the next lower level in the DB hierarchy after "Patient"; it contains

pointers to the individual CT, DR or FL studies performed.volume rendering

Volume rendering is the display process which allows the user to look at a volume of data, observe surfaces and density differences, cut away portions of the volume, etc.voxel

A voxel is the smallest element of a reconstructed volume data set; it is a 3 dimensional object which is essentially a pixel with thickness. Voxels for Fidex are typically isotropic; that is, all three sides are of the same dimension.window

In image display, window is the range of number displayed; all pixels whose value is smaller than the lower limit of the window are shown as black; all pixels whose value is larger than the upper limit are shown as white. Pixels with values in between are shown as varying shades of gray depending upon the difference from the limits.

16.2 Trouble shooting

16.2.1 Restarting FidexThe preferred method to close Fidex, especially if the software seems to require a restart, Is to go to the Windows start button on the lower left hand corner, choose Turn Off Computer, and then restart. When the computer has restarted click the Fidex icon on the desktop.

In the unlikely event that this does not work, then turn off the computer by holding the power button in for a few seconds, then power up the computer system and click on the Fidex icon.

16.2.2 FaultThere are several possible conditions which cause Fault to appear on the GCP and render the scanner inoperable. One is that the x-ray tube is overheated (should not occur); another is that there is a technical fault in the x-ray system; another is that the scanner controller will not start. Unless informed otherwise, you should call for service. (This requires a more detailed description of possible faults and responses.)

16.2.3 LockIf Lock appears on the GCP, it usually means that the mushroom emergency stop switch has been pushed; it must be pulled out to clear the lock.



16.3 Technical specifications ( to be added)


fidex user manual - exxim computing corporationexxim.com/fidex/documentation-fidex/dghill/fidex...

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