digital radiography (dr) system - dphu · digital radiography has only been around since 1970....

Digital Radiography (DR) system Medical Diagnostic X-ray

Equipment

Lin muyan

[email protected]

Presented by:CocticaUwititonze

Email: [email protected]:+250 (0)7888 44764 ISSN 2313-285X = University without

borders for the open society Volume: 4

mailto:[email protected]

Content

1. Goals

2. Introduction

3. X-ray machine structure

4. Fundamental condition emerge x-ray

5. Digital radiography innovative

6. Installation and calibration

7. Troubleshooting procedure

8. Conclusion ISSN 2313-285X = University without


The goals

Goals:

1. To understand the Digital radiograph system

2. General structure of x-ray machine

3. Fundamental condition emerge x-ray

3. Installation and calibration process

4. Troubleshooting procedure

ISSN 2313-285X = University without


Introduction

Medical imaging play a big role to study the human anatomy and physiology

body

X-ray based methods of medical imaging include conventional General

X-ray radiography machine , computer tomography (CT),mammography and angiography

Molecular imaging such as : leaner accelerator , gamma used in nuclear medicine and uses a variety of methods to visualize biological processes taking place in the cells of organisms. Small amounts of radioactive markers used



Introduction

Other types of medical imaging are magnetic resonance imaging (MRI) and ultrasound imaging. MRI and ultrasound operate without ionizing radiation.

MRI uses strong magnetic fields, which produce no known irreversible biological effects in humans.

ultrasound systems use the propagation of acoustic wavesin attenuating media. high-frequency sound waves toproduce images of soft tissue and internal body organs.



X-ray machine structure

Quick questions

1. Major components of x-ray machine

2. which role of each part

3.What role of filament in the x-ray and which material

4. How the x-ray tube works

5. State three components of x-ray tube

6. What is CR

7. What is IP cassette



Answer

X-Ray machine structure

X-Ray Tube: X-Ray : to generate x-ray and shut

High-Voltage Generator: Provide power to X-ray tube

Controller: Control kv、mA、s

The role of filament is to generate electrons

Peripheral: Machinery and auxiliary device

DR : computer Radiographer

IP cassette: Image Plate store the image in form of energy.ISSN 2313-285X = University without


ANALOGUE X-RAY machine structure



filament220/380 volts

3-5 or 12 volts

80,000 to

125,000 volts

65-190 volts

kVp

Selector



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X-ray Tube Components

berylliumwindow

5 9

x-ray tube structure




x-section

of

filament

hot

filament

The hotter the filament,

the greater the quantity of electrons that are

released, hence the higher the mA

Space charge

electrons

Thermionic EmissionRelease of electrons from hot filament

when current flows after depressing

exposure switch




3

X-ray Production




Incoming 220 Volt line

65 V

cu

rren

t flow

Autotransformer

80 V

Volts per

turn is the

same

across all

turns




Step-Up Transformer

Primary

Secondary

220 volts

cu

rren

t flow

65,000 to

90,000 volts

cu

rren

t flow

Volts/turn

in the

primary

Will always

equal

Volts/turn

in the

secondary




Step-Down Transformer

Primary

Secondary

220 volts

cu

rren

t flow

3-5 volts

cu

rren

t flow

Volts/turn

in the

primary

Volts/turn

in the

secondary

Will always

equal




• Higher average energy of x-rays

• Greater maximum energy x-rays

• More x-rays

Increasing kVp results in:




mA (milliamperes)

X-ray Energy (keV)

Qu

an

tity

of

X-r

ays

70

10 mA

5 mA

maximum energy

average energy

(no change)

(no change)




Quality

Quantity

penetrating ability

number of x-rays




How to determine mAsmilliamperes (mA) x seconds (s)

50 cycles/impulses = 1 second

10 mA x .5 seconds = 5 mAs

20 mA x .25 seconds = 5 mAs

50 mA x .1 second = 5 mAs




Increasing mA or Exposure

Time results in:

• An increase in the quantity of

x-rays produced

• No change in the quality of the

x-ray beam




Automatic expose control

Ion chamber Advantages

Ionization chambers are used

with digital imaging systems

(DR or CR) as well as

standard film systems.

Ionization chambers are the

sensors used in Automatic

Exposure Control (AEC)

systems for x-ray generators.

AEC systems provide proper,

reproducible film densities by

automatically compensating

for variables such as patient

size, anatomy, pathology and

positioning.



X-ray emission system



Digital Radiography innovative

Although X-rays have been in existence since the early 1900s,

digital radiography has only been around since 1970. However,

since that time,. Popular imaging systems in use today include the

CR and DR systems.

CR, or computed radiography, uses an imaging cassette of

phosphor to create digital images, and DR systems, or direct digital

radiography, uses a collection plate for image capture.

These two systems, along with related hardware and software units

such as the DICOM digital format, PACS and RIS, have brought

many medical facilities up to the modern age with state-of-the-art

digital radiography capabilities. ISSN 2313-285X = University without


Digital Radiography innovative

In the 1990s, a shift in digital radiography was made.

X-ray images, it was discovered, could be stored on

phosphor screens, and this formed the basis of today's

CR imaging systems.

Complementary PACS systems had their debut in 1982,

in the DICOM imaging format, similar to the common

JPEG format, can be stored on a server for archival

purposes,ISSN 2313-285X = University without


What is DR(Digital Radiography)?

Digital radiography is a form of X-ray imaging, where

digital X-ray sensors are used instead of traditional

photographic film.

Advantages include time efficiency through bypassing

chemical processing and the ability to digitally transfer

and enhance images.

Also less radiation can be used to produce an image of

similar contrast to conventional radiography



What is DR(Digital Radiography)?

Instead of X-ray film, digital radiography uses a digital image capture device.

Advantages

1. Immediate image preview and availability

2. Elimination of costly film processing steps

3. Ability to apply special image processing techniques that enhance overall display of the image.



self stand RD with flat panel detector



Differents DR design (U arm )

Depend on the user request the manufacture are able to customize

the stand goes along with detector and tube



Top mounting DR



Type of Digital Radiograph

In X-ray radiography There are two different way to obtaining the Digital Image

1. Computer Radiography : (CR) by using IP cassette and reader

2. Digital Radiograph :(DR) by using Image detector and processed by CPU and review immediately

NOTE:

So far the DR has two different types

Direct image detector : plat panel detector

Indirect detector :by using Charge-Coupled Device (CCD)ISSN 2313-285X = University without


What is CCD

A charge-coupled device (CCD) is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value.

CCDs move charge between capacitive bins in the device, with the shift allowing for the transfer of charge between bins

The CCD is a major piece of technology in digital imaging sensor

to achieve a high pixel the apply Metal Oxide Semiconductor (MOS) Capacitor

CCD image sensors are widely used in professional, medical, and scientific applications where high-quality image data is required



CR PROCESSOR ( IP -READER)

The manage is captured on the Imaging Plate (IP) cassette

and being processed by IP reader which is connected to the CPU with monitor in order to review the image and share with group of people (PACS )

Condition having DICOM protocol is required



CR (Computed Radiography)

Stimulable phosphor

detetor

Semiconductor

laser

A/D

converter

controller

CRT

The Host computer

Schematic showing formation of the latent image on the CR imaging

plate (1) the plate being scanned by the laser beam (2) light photons

being converted to electrical signal (3) and electrical signals being

converted to digital signals, which form a CR image ISSN 2313-285X = University without


IP Cassette processing

X-ray photons

Laser-Beam Scanning

Light

X-ray Eeposure

BaFX

Crystals

Support

Reading

Erasing

Unused Imaging Plate

Recording the X-ray Imaging

The Laser Beams Extracts the X-ray Image

from the plate by Converting to Light Photo,

which from a Light Image

The Small Amount of Residual Image on the

Plate is Thoroughly Erased by Flooding the

Plate with Light

The Erase Plate Can Be Used AgainISSN 2313-285X = University without


Mobile X-ray machine with DR/ CR

Today ‘s technology mobile

x-ray comes with DR option

: wireless cassette ,

and CR , IP cassette option

with screen which allow

you review edit and send

the image to the server !

ISSN 2313-285X = University

without borders for the open

society Volume: 4

Different type of x-ray detector

Different type of x-ray

director

FLAT PANEL DETECTOR

CCD detector

ISSN 2313-285X = University

without borders for the open

society Volume: 4

Different type of detectors

Flat panel detector CCD detector



Indirect CCD detector * X-Ray → CSI (a fluorescent substance) → visible radiation → focusing

lens → CCD Camera → DATA

(2) Expense is cheaper than FPD method but image processing speed

is slow

(3) Image quality is low than FPD method and require high dose

(4) Geometric false occurs after change light during focusing process



* Indirect measuring method (CSI-FPD)

CSI changes X-ray to light. a-Si: H changes strength of light to

electronic signal and send TFT array. It is sensitive to light.

(1) X-Ray →CSI (a fluorescent substance) → visible radiation

→ P h o t o d i o d e

→ electronic signal → TFT → DATA



1. Hardware structure

Detector – Technology (Indirect / Direct)

* Direct measuring method (a-Se-FPD)

a-Se absorbs X-ray photon and high voltage is approved to make

ionized Selenium

collector electrode collects ionized Selenium and sends TFT array.

(1) X-Ray → A-Se → electronic signal → TFT → DATA(no light

transforming procedure) (2) Comparing indirect DR method,

X-ray image is good because it

h a s

no diffusion of light

(3) It needs high voltage approval

because of Selenium physical

feature.

(4) Image reproducibility is not good

by ghost effect

(5) A manufacturing process is

s i m p l e

and than indirect DR method but

need high irradiation condition.ISSN 2313-285X = University without


3) Strength and Weakness

Strength(DR) Weakness (CR)

- Availability of various

diagnosis

- Obtain same image quality

- Improve work efficiency

- low radiation dosage

- Easy data base

- Easy application to PACS

- Need clinical study

- Smaller image than real size

- Heavy error possibility by wrong

set up

- Increase clinical expense

- low examination efficiency by

radiologist work load increase

- Slow speed than conventional

system

2. CR and DR comparison to get X-ray image



Film(Analog Radiography) Digital Radiography

Information

Capacity10^2.5(=300; 8 bit) ~ 10^3.5(=3000; 12bit) 14bit(16384) ~ 16bit(65536)

Detector

•Limited information capacity depending on

brightness of view box.

•1500cd/m^2 viewbox brightness: 10^2.8=630

(9 bit) at least

•3000cd/m^2 viewbox brightness(mamo):

•max. 10^3.1=1260(10bit)

•* The eyes of human can be reading up to 6 bit,

therefore after covering up reading area for

adjusting the eyes, then reading a image.

•Current maximum monitor brightness: 700cd/m^2

= possibly reading 10^2.5=316(8bit)

•Brightness/Contrast adjustment requires for reading

remain information.

Storage

• storage film wareroom

• Large area requires

• easy to lose

• contaminate easily by moisture.

•Digital storage through hard disk or CD-ROM

Copy • 30% lose of information for 1 copy. •Unlimited

Maintenance

• film cost + developing cost + waste water

treatment cost+ developing room rental cost/film

wareroom rental/maintain cost

+ film management (storage/find) cost

•basic storage device + backup cost

(CD-ROM/labor cost) + storage device extension cost

Retaking rate

• abnormality of exposure condition+ film

+ abnormality of film development

•contamination and lost

•Retaking rate is very low.

System price USD10,000~USD50,000 USD100,000~USD500,000ISSN 2313-285X = University without


X-ray hard ware system

CCD Detector, tube, generator and console



DR SOFTWARE REQUEREMENT

IN ORDER TO ACHIEVE THE COMUNICATION

BETWEEN THE Detector , Generator and the tube, you

must have a communication software compatible with

detector

the software also communicate with DICOM in order to

form digital image format for send and save to Picture

Achieving System (PACS) and RIS system



X-ray generator: Hv transformer and capacity tank



DR software system

SOFTWARE COMUNICATION AND REVIEW

IMAGE ACQUISITION AND REVIEW



X-RAY INSTALLATION /MOUNTING THE TUBE

I self have never assemble the x-ray machine before, but I fund it easy

spent 5 hours You Just need to know the procedures

repair should be …..less



X-ray Generator

Bucky tray

X-ray tube

X-ray Procedure ROOM

4

2 1265

3

13

9

Film viewing and

Diagnosis area

(light box)

Un- Exposed

Film screen

Cassette

storage

Film processing

Area (dark room)

X-ray Requisition

Dispatcher and

patient

Escort Area

1

1110

87

Diagnostic Area



Engineers at work / installation and adjusting



X-RAY TUBE WIRE CONNECTIONS



Installation

X-ray tube wire connection

-With rotating anode

connection wires(x2)

small & larger

Filaments wire

connection wires(4)

Ground wire (x1)

X-ray tube wire connection



Connecting the flat panel detector to the HV generator



plat panel installation

plat panel installation

following wire need to be connected

Ethernet cable , power supply ,cable to the generator

data transportation cable

once the Flat panel communicated with software

there is green light indication



Flat panel and generator calibration

After each installation

you have to align the

flat panel

and mA calibration

follow the manufacture

instructions



X-ray calibration

Ma calibration

mA calibration procedure From low dose to the

maximum select

mA and kvp -~ dose to the maximum mA and

measure the mA output by using oscilloscope



How can you upgrade your Analogue x-ray machine to DR

It is quite simple and cheep

Even you x-ray in 15 years old it is possible to upgrade

1. you need a professional camera and Image intensifier to detect x-ray , it package with software

And small modification on Generator

The cost is aloud 7,000~12,000 $

wherever you have a limited funds for new DR system you can upgrade Digital is an engineer responsibility to bring the innovative in your envelopment

DE

TE

CT

OR

C

AM

ER

A



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Troubleshooting procedure

Wait a second !!!

it is very important that you fulfill following skills

understand the schematic system : image acquisition chain

Basic computer communication system : check software , IP address, internet skills ??

Electronics or electrical skills ??

Do you have test tools such as: voltmeter and oscilloscope



RD common error

software problem

Error sending image to server check the internet connection /speed

CPU overheat check the fan / dust, heat dismiss ,

IP address conflict check internet protocol

Wire disconnection check the wire disconnect/ loosen

CPU memory crashed Replace memory



DR- common error

X-ray generator

Error on console : consult the service manual board number , error number

Power supply error measure on generator test point

try to hear the burn smell easy to find components or wire burned

generator gives error :blinking LED check the board connection / insert property

generator gives error :blinking LED check incoming power supply fuses

Identify the defective board see if you can measure the components lever specially power supply board there is chance to repair



RD common error

x-ray tube

Error code …. filament open the cup mesure both filament independently

in case one filament gone use the second one with limited exposure : filament board / transformer

error… the anode is not rotating check the anode wire for power supply

tube over heat check anode rotation : bearing problem

System is normal , but no x-ray emitted check the collimator sliding plate/



common error / analogue machines

user interface setting

film /photo is too blight Auto exposure ( no) / if not increase KVp,mA

film /photo is too dark Auto exposure(no) / if not decrease KVp, &mA

Patient table is not moving : check the ac motor : coil , fuse , power supply , belt,….

no communication with Generator check the wire disconnect/ loosen

Automatic expose not function check the expose ionization chamber



Troubleshooting principal

Precautions !

Playing With 120,000Volts~ and 500~ kgs of gear

No guessing !!

I know you can handle but be careful !!!

The role

( KISS)



The questions we should ask our self

Is there any hospital : private public which need to digitizer they x-ray machine

Can we fix the issue for them by transforming the ANALOGUE TO DIGITAL

Do you know where to buy camera ?

do you know how to install ?



THANK YOU FOR YOUR ATTENTION !!

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digital radiography (dr) system - dphu · digital radiography has only been around since 1970....

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