open gantry cone-beam ct - i-star...planmed verity curvebeam pedcat carestream onsight *errors and...

Jeff Siewerdsen, PhDJeff Siewerdsen, PhDDepartment of Biomedical EngineeringDepartment of Biomedical Engineering

Department of Computer ScienceDepartment of Computer ScienceRussell H. Morgan Department of RadiologyRussell H. Morgan Department of Radiology

Department of NeurosurgeryDepartment of NeurosurgeryArmstrong Institute for Patient Safety and QualityArmstrong Institute for Patient Safety and Quality

Johns Armstrong Institute for Patient Safety and QualityArmstrong Institute for Patient Safety and Quality

Johns Johns Hopkins University

Carnegie Center for Surgical Innovation / carnegie.jhu.eduCarnegie Center for Surgical Innovation / The I

Carnegie Center for Surgical Innovation / The I-

Carnegie Center for Surgical Innovation / carnegie.jhu.educarnegie.jhu.eduCarnegie Center for Surgical Innovation / Carnegie Center for Surgical Innovation / The I-STAR Lab / istar.jhu.edu

Open GantryCone-Beam CT

Now You C It

DisclosuresFunding SupportFunding SupportNational Institutes of HealthNational Institutes of HealthNational Institutes of Health

R01National Institutes of HealthNational Institutes of Health

R01R01-National Institutes of HealthNational Institutes of Health

R01R01--EBNational Institutes of HealthNational Institutes of HealthNational Institutes of HealthNational Institutes of Health

EBEBEBEB-National Institutes of HealthNational Institutes of HealthNational Institutes of HealthNational Institutes of HealthNational Institutes of HealthNational Institutes of HealthNational Institutes of HealthNational Institutes of Health

EBEBEBEB--017226 (Imaging for OR Safety and QA)R01R01R01R01R01-

EBR01 EBEBR01R01--CA

EBEBEBCACACACACA-

017226 (Imaging for OR Safety and QA)017226 (Imaging for OR Safety and QA)017226 (Imaging for OR Safety and QA)EB 017226 (Imaging for OR Safety and QA)017226 (Imaging for OR Safety and QA)CACA--112163 (Dual

017226 (Imaging for OR Safety and QA)112163 (Dual112163 (Dual-017226 (Imaging for OR Safety and QA)017226 (Imaging for OR Safety and QA)017226 (Imaging for OR Safety and QA)112163 (Dual112163 (Dual--Energy CT)R01

R01R01R01R01-R01 CAR01R01--EB

CACACAEBEBEBEBEB-

112163 (Dual112163 (Dual112163 (Dual112163 (DualCACA 112163 (DualCAEBEBEBEBEB--018896

112163 (Dual112163 (Dual018896 018896 (High112163 (Dual112163 (Dual

(High(High(High-Energy CT)Energy CT)Energy CT)Energy CT)112163 (Dual112163 (Dual Energy CT)

(High(High(High--Resolution CBCT Resolution CBCT –– W W ZbijewskiZbijewski, PI)R01R01U01R01R01U01U01U01-R01 EBEBEBU01U01--EB

EBEBEBEBEBEBEBEBEBEB-

018896 018896 018896 018896 EB 018896 018896 EBEBEBEBEB--018758

(High018896 (High(High018758 018758 (Sub

(High(High(Sub(Sub(Sub-

Resolution CBCT Resolution CBCT Resolution CBCT Resolution CBCT (High(High Resolution CBCT (Sub(Sub(Sub--mSv

Resolution CBCT Resolution CBCT mSvmSv CT Resolution CBCT

CT CT –Resolution CBCT Resolution CBCT Resolution CBCT

– JW Resolution CBCT Resolution CBCT W Resolution CBCT

JW JW StaymanZbijewskiZbijewskiW W Zbijewski

StaymanStaymanStayman, PI)U01U01U01Siemens

018758 018758 018758 018758 (SubEBEBEBEBEBSiemens Siemens Healthineers

mSvmSvmSvmSv CT CT CT (Sub(Sub(Sub(SubHealthineersHealthineersHealthineers (XP, AT)Siemens Siemens HealthineersHealthineersHealthineers (XP, AT)

Mobile and Robotic C(XP, AT)(XP, AT)

Mobile and Robotic CMobile and Robotic CMobile and Robotic C-(XP, AT)(XP, AT)(XP, AT)

Mobile and Robotic CMobile and Robotic C--arm CBCTMobile and Robotic CMedtronicMedtronic

Intraoperative 3D Imaging and RegistrationIntraoperative 3D Imaging and RegistrationCarestream

Intraoperative 3D Imaging and RegistrationIntraoperative 3D Imaging and RegistrationCarestreamCarestream HealthCarestreamCarestream HealthHealth

Extremity CBCTExtremity CBCTPointExtremity CBCTPointPoint-Extremity CBCTPointPoint--ofExtremity CBCTExtremity CBCT

ofofofof-Extremity CBCTExtremity CBCTExtremity CBCTExtremity CBCT

ofofofof--Care CBCT of the Head

Advisory BoardAdvisory BoardSiemens

Advisory BoardAdvisory BoardSiemens HealthineersSiemens Siemens Siemens Siemens HealthineersHealthineersCarestream

HealthineersHealthineersHealthineersHealthineersHealthineersHealthineersCarestreamCarestreamCarestream Health

Licensing AgreementLicensing AgreementCarestream

Licensing AgreementLicensing AgreementCarestream HealthCarestreamCarestreamElektaCarestreamCarestreamCarestreamCarestream HealthHealthHealthHealthCarestreamCarestreamElektaElekta Oncology

*This presentation includes research systems and off*This presentation includes research systems and off-*This presentation includes research systems and off-label use.

Physical configurationsImage acquisition and reconstruction

Handouts for this presentation available after RSNA at:http://istar.jhu.edu/talks

Overview / Learning Objectives

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Diversity of system platformsDiversity of applications – from IGRT to diagnostic imaging

Spatial resolution, contrast resolution, …ArtifactsRadiation dose

New systems and applicationsAdvanced imaging techniques

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Physical configurationsPhysical configurationsPhysical configurationsPhysical configurationsPhysical configurationsPhysical configurationsPhysical configurationsImage acquisition and reconstructionPhysical configurationsImage acquisition and reconstructionImage acquisition and reconstructionPhysical configurationsPhysical configurationsPhysical configurationsPhysical configurationsImage acquisition and reconstruction

Diversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of applications Diversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of applications Diversity of applications Diversity of applications Diversity of applications Diversity of applications –Diversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of applications Diversity of applications Diversity of applications Diversity of applications Diversity of applications Diversity of applications Diversity of applications Diversity of applications Diversity of applications Diversity of applications –– from IGRT to diagnostic imagingfrom IGRT to diagnostic imagingfrom IGRT to diagnostic imagingDiversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platforms

from IGRT to diagnostic imagingfrom IGRT to diagnostic imagingfrom IGRT to diagnostic imagingDiversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platforms

–Diversity of system platformsDiversity of system platformsDiversity of system platformsDiversity of system platforms

–––– from IGRT to diagnostic imaging

Spatial resolution, contrast resolution, …Spatial resolution, contrast resolution, …Spatial resolution, contrast resolution, …Spatial resolution, contrast resolution, …ArtifactsArtifactsArtifactsArtifactsSpatial resolution, contrast resolution, …Spatial resolution, contrast resolution, …Spatial resolution, contrast resolution, …Spatial resolution, contrast resolution, …ArtifactsArtifactsArtifactsArtifactsArtifactsRadiation doseRadiation doseArtifactsRadiation doseRadiation doseArtifactsArtifactsArtifactsArtifactsRadiation dose

New systems and applicationsNew systems and applicationsNew systems and applicationsNew systems and applicationsNew systems and applicationsAdvanced imaging techniquesNew systems and applicationsAdvanced imaging techniquesAdvanced imaging techniquesNew systems and applicationsNew systems and applicationsNew systems and applicationsNew systems and applicationsAdvanced imaging techniques

Physical Configuration

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

X

Det

*Large-area detector (typically 25-43 cm)2D projections (typically hundreds, circular orbit)3-D Volume (from a single rotation)Many, varied configurations / applications

Multi-Detector CT Open Gantry / Cone-Beam CT

~Typical CharacteristicsMulti-Detector CT Open Gantry / Cone-Beam CT

X-ray Source High Power (100-240 kW)Continuous mA

Lower Power (3-100 kW)Pulsed mA

Detector 1-64 rows (up to 256-320 rows)~few cm Z coverage (up to 16 cm)

>1024 – 2048 rows>20 cm Z coverage

Acquisition Speed and Orbit

FastCircular / Helical~3-5 rotations / sec

Fast table feed (>10-50 cm / sec)(1000s of projections / rotation)

SlowCircular (semi-circular) or Non-Circular

~1 rotation / 5-60 secNo table motion

(100s of projections / rotation)

Image Quality Good(bone + soft tissues)

(CE-enhanced scans; DE protocols)

Moderate(CNR challenged by scatter)

(isotropic sub-mm spatial resolution)(artifacts)

Applications Diagnostic Radiology(some interventional)

Image-Guided Procedures(specialty diagnostic applications)

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

ConeCone-Cone-Beam System Geometry

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Cosine Weighting(Feldkamp Weights)

u

v

Siewerdsen, Stayman, and Noo (Chapter 13 in Image Processing in Radiation Therapy, K. K. Brock, Ed, CRC Press 2013)

3D Filtered Back3D Filtered Back-3D Filtered Back-Projection

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

3D Filtered Back3D Filtered Back-3D Filtered Back-Projection

Siewerdsen, Stayman, and Noo (Chapter 13 in Image Processing in Radiation Therapy, K. K. Brock, Ed, CRC Press 2013)

3D Back-Projection

# of voxels# of projections

Repeat

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

IGRT Image-Guided Surgery ENT Breast MSK

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

System Configurations and Applications

ImageImage-Image Guided Radiation Therapy (IGRT)ImageImageImage Guided Radiation Therapy (IGRT)Guided Radiation Therapy (IGRT)Guided Radiation Therapy (IGRT)CBCT on a linear acceleratorCBCT on a linear acceleratorCBCT on a linear acceleratorCBCT on a linear acceleratorCBCT on a linear accelerator

ElektaCBCT on a linear acceleratorCBCT on a linear acceleratorCBCT on a linear acceleratorCBCT on a linear acceleratorCBCT on a linear acceleratorCBCT on a linear accelerator

ElektaElekta SynergyElektaElekta SynergySynergyVarian OBIVarian OBI

New systems for proton / heavy ion New systems for proton / heavy ion TxNew systems for proton / heavy ion New systems for proton / heavy ion

IG Surgery / Interventional RadiologyIG Surgery / Interventional RadiologyFIXED

IG Surgery / Interventional RadiologyFIXED-

IG Surgery / Interventional RadiologyIG Surgery / Interventional RadiologyIG Surgery / Interventional RadiologyFIXED-ROOM:FIXEDFIXEDFIXED ROOM:ROOM:ROOM:ROOM:ROOM:ROOM:

Siemens ROOM:ROOM:

Siemens Siemens ArtisArtis (Artis (PhenoPheno, Pheno, ZeegoZeego, Zee, …), Philips , Zee, …), Philips AlluraAllura, Toshiba , Toshiba InfinixSiemens MOBILE:MOBILE:

Medtronic OMedtronic O-Medtronic O-arm, Siemens arm, Siemens CiosCios Spin, Spin, ZiehmZiehm VarioVario, Vario, XoranXoran Xcat

Diagnostic SpecialtiesDiagnostic SpecialtiesBreast CT:Breast CT:Breast CT:

KoningBreast CT:Breast CT:

KoningKoning (Ning), UC(Ning), UC-(Ning), UC-Davis (Boone)KoningKoning (Ning), UC(Ning), UC(Ning), UC(Ning), UCENT / Maxillofacial:ENT / Maxillofacial:

CarestreamENT / Maxillofacial:ENT / Maxillofacial:

CarestreamCarestream CS9300, CS9300, XoranXoran MiniCATMiniCAT, MiniCAT, MiniCAT, MiniCAT TeraReconTeraRecon PreXionPreXion, …CarestreamCarestream CS9300, CS9300, CS9300, Musculoskeletal (MSK) /

XoranXoran MiniCATMiniCATCS9300, XoranXoranMusculoskeletal (MSK) / Musculoskeletal (MSK) / Orthopaedics

TeraReconMiniCATMiniCATMiniCAT, MiniCAT, MiniCATOrthopaedicsOrthopaedicsOrthopaedics:Musculoskeletal (MSK) /

PlanMedMusculoskeletal (MSK) / Musculoskeletal (MSK) /

PlanMedPlanMed VerityPlanMedPlanMed VerityCurveBeam

VerityVerityVerityCurveBeamCurveBeamCurveBeam pedCATCurveBeamCarestream

pedCATpedCATCurveBeamCurveBeam pedCATCarestreamCarestreamCarestream OnSight

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

ImageImageImage-Guided Radiation Therapy (IGRT)Guided Radiation Therapy (IGRT)Guided Radiation Therapy (IGRT)


*Errors and omissions are responsibility of the author.




New systems for proton / heavy ion New systems for proton / heavy ion TxNew systems for proton / heavy ion New systems for proton / heavy ion




Siemens ROOM:ROOM:

Siemens Siemens ArtisArtis (Artis (PhenoPheno, Pheno, ZeegoZeego, Zee, …), Philips , Zee, …), Philips AlluraAllura, Toshiba , Toshiba InfinixSiemens MOBILE:MOBILE:

Medtronic OMedtronic O-Medtronic O-arm, Siemens arm, Siemens CiosCios Spin, Spin, ZiehmZiehm VarioVario, Vario, XoranXoran Xcat












Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections



Images courtesy of J.-J. Sonke (NKI Amsterdam)





New systems for New systems for New systems for proton / heavy ion proton / heavy ion TxNew systems for New systems for proton / heavy ion proton / heavy ion proton / heavy ion




Siemens ROOM:ROOM:

Siemens Siemens ArtisArtis (Artis (PhenoPheno, Pheno, ZeegoZeego, Zee, …), , Zee, …), Philips Philips AlluraAllura, Toshiba , Toshiba InfinixSiemens MOBILE:MOBILE:

Medtronic OMedtronic O-Medtronic O-arm, arm, Siemens Siemens CiosCios Spin, Spin, ZiehmZiehm VarioVario, Vario, XoranXoran Xcat













Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections










Siemens ROOM:ROOM:















Tognolini et al.Acad Radiol 2011

Batra et al.,Int For All Rhin 2011

Image courtesy ofBoulder Neurosurg. Spine Assoc.

Wang et al.Phys Med Biol 2014

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

ImageImageImage-Guided Radiation Therapy (IGRT)Guided Radiation Therapy (IGRT)Guided Radiation Therapy (IGRT) TognoliniTognolini et al.AcadAcad Radiol 2011









Siemens ROOM:ROOM:















Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections










Siemens ROOM:ROOM:














S. Demehri and W. Zbijewski (Johns Hopkins University)

J. Boone (UC Davis)


Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections



The AAPM Task Group 2383D C-Arms with Volumetric Imaging Capability

Charge: Assessment of 3D C-Arm Cone Beam CT (CBCT) technology for applications in image-guided interventions. …

… characteristics of 3D C-arm systems, quantitative metrics, sources of uncertainty, and quality assurance measures, including dose and image quality.

Also:G. J. GangP. A. HelmL. RitschlM. D. SilverJ. TimmerY. Trousset

M. Supanich

R. R. Fahrig A. K. Jones J. Zhang

S. Schafer C. Riddell K. K. Farahani

A. A. KuhlsKuhls-Kuhls-Gilchrist M. Lin B. B. SchuelerJ. Y. J. Siewerdsen

ApplicationsApplicationsNomenclatureNomenclatureSystem CalibrationSystem Calibration3D Image Reconstruction3D Image ReconstructionImage QualityImage QualityDosimetryDosimetryTraining Issues for Medical Physicists

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

asdfasdf

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Spatial Resolution

Contrast Resolution

Temporal Resolution

TaskTask-Task-Based Based Performance

Artifacts

Siewerdsen, Zbijewski, and Xu (Chapter 4 in Cone Beam Computed Tomography, C. Shaw, Ed, CRC Press 2014)

avox = 0.39 mm

avox = 0.26 mm

avox = 0.13 mm

14

15161718

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Spatial ResolutionSpatial ResolutionSmallest discernible feature sizeSmallest discernible feature sizeSmallest discernible feature size(in the absence of noise)

Governed by:Governed by:Geometric calibrationGeometric calibrationFocal spot sizeFocal spot sizeScintillatorScintillatorDetector pixel sizeDetector pixel sizeReconstruction (smoothing filters)

Metrics:Metrics:Qualitative (lineQualitative (line-Qualitative (line-pair patterns)Qualitative (lineQualitative (lineQualitative (line pair patterns)pair patterns)pair patterns)Spread function width (PSF, ESF)Spread function width (PSF, ESF)Modulation Transfer Function (MTF)Modulation Transfer Function (MTF)NoteModulation Transfer Function (MTF)NoteNote: Modulation Transfer Function (MTF)Modulation Transfer Function (MTF)Modulation Transfer Function (MTF)NoteNote: : shift variance / stationarityNote: shift variance / stationarityshift variance / stationarityshift variance / stationarity

shift variance / stationarityshift variance / stationarityshift variance / stationarity localshift variance / stationarityshift variance / stationarity

locallocal approximations

Caveat:locallocallocal approximationsapproximations local

Caveat:Caveat: nonlinear reconstruction / processing algorithmsCaveat:Caveat: nonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithms

nonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithms contrast

nonlinear reconstruction / processing algorithmscontrastcontrast-

nonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithmscontrastcontrast--dependent

Sign

al (m

m-1

)

Axial Image Signal (thin steel wire)


Four

ier T

rans

form

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Spatial ResolutionSpatial ResolutionSmallest discernible feature sizeSmallest discernible feature sizeSmallest discernible feature size(in the absence of noise)

Governed by:Governed by:Geometric calibrationGeometric calibrationFocal spot sizeFocal spot sizeScintillatorScintillatorDetector pixel sizeDetector pixel sizeReconstruction (smoothing filters)

Metrics:Metrics:Qualitative (lineQualitative (line-Qualitative (line-pair patterns)Qualitative (lineQualitative (lineQualitative (line pair patterns)pair patterns)pair patterns)Spread function width (PSF, ESF)Spread function width (PSF, ESF)Modulation Transfer Function (MTF)Modulation Transfer Function (MTF)NoteModulation Transfer Function (MTF)NoteNote: Modulation Transfer Function (MTF)Modulation Transfer Function (MTF)Modulation Transfer Function (MTF)NoteNote: : shift variance / stationarityNote: shift variance / stationarityshift variance / stationarityshift variance / stationarity



Caveat:locallocallocal approximationsapproximations local

Caveat:Caveat: nonlinear reconstruction / processing algorithmsCaveat:Caveat: nonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithms

nonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithms contrast

nonlinear reconstruction / processing algorithmscontrastcontrast-

nonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithmsnonlinear reconstruction / processing algorithmscontrastcontrast--dependent

Contrast ResolutionContrast ResolutionSmallest discernible signal differenceSmallest discernible signal differenceSmallest discernible signal difference(large stimulus)

Governed by:Governed by:DoseDoseElectronic noiseXElectronic noiseXX-Electronic noiseElectronic noiseElectronic noiseXX--ray scatter

Metrics:Metrics:ContrastContrastNoise, NoiseNoise, Noise-Noise, Noise-Power SpectrumNoise, NoiseNoteNoise, NoiseNoteNote: Noise, NoiseNoise, NoiseNoise, Noise Power SpectrumPower SpectrumPower SpectrumNoise, NoiseNoise, NoiseNoteNote: : shift variance / stationarityNote: shift variance / stationarityshift variance / stationarityshift variance / stationarity



s

bb

b

bb

b

𝑪𝒐𝒏𝒕𝒓𝒂𝒔𝒕 = |𝝁𝒔 − 𝝁𝒃|

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 20 40 60 80 100 120 140

Cont

rast

(mm

-1)

SPR (%)

BR-SR1 Breast in Water


Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

FOVz~24 cm

FOVz~5 cm






60 mAs30 mAs 120 mAs

Axial m(x,y) ssmsm(m((x,yx,yx,y)

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

20 40 60 80 100 1200

2

4

6

8

10

12

14

16

mAs

CN

R

mAs20 40 60 80 100 120

CNR

(Kid

ney-

Fat)

10

8

6

4

2

0

𝐶𝑁𝑅 = ∆𝜇′ 𝐷𝑜𝐷𝑄𝐸(0)

𝑘𝐸

𝑎𝑥𝑦3 𝑎𝑧

𝐵𝑊𝐼

(A) Uncorrelated

(C) Mid-Pass

(B) Low-Pass

(D) High-Pass

Noi

se-P

ower

Spe

ctru

m

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections






(A) Uncorrelated

(C) Mid-Pass

(B) Low-Pass

(D) High-Pass

Noi

se-P

ower

Spe

ctru

m

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

𝑁𝑃𝑆 𝑓𝑥, 𝑓𝑦, 𝑓𝑧 =𝑎𝑥𝑎𝑦𝑎𝑧𝑁𝑥𝑁𝑦𝑁𝑧

𝐹𝑇 ∆ 𝑥, 𝑦, 𝑧 2






zyxtask dfdfdffWfNPSfMTFd

' 2

22

TaskTask-Task-Based Imaging PerformanceBased Imaging PerformanceBased Imaging PerformanceBased Imaging PerformanceConsiders:Considers:Considers:Considers:Considers:Considers:Considers:Fidelity of signal transfer (MTF)Fidelity of signal transfer (MTF)Correlation of noise (NPS)Correlation of noise (NPS)Spatial frequencies of interest (Spatial frequencies of interest (WWWtasktasktask)

Variations in Observer Model:Variations in Observer Model:Prewhitening

Variations in Observer Model:Variations in Observer Model:PrewhiteningPrewhitening (PW /

Variations in Observer Model:Variations in Observer Model:(PW / (PW / HotellingHotellingHotelling)PrewhiteningPrewhitening (PW / (PW /

PW with eye filter (HotellingHotelling(PW / (PW / Hotelling

PW with eye filter (PW with eye filter (PW with eye filter (PWEiHotellingHotelling

PWEiPWEi)PW with eye filter (NonPW with eye filter (NonNon-PW with eye filter (PW with eye filter (PW with eye filter (NonNon--prewhitening

PWEiPWEiPWEi)PW with eye filter (PW with eye filter (PWEiprewhiteningprewhiteningprewhitening (NPW)NonNonNon prewhiteningprewhiteningprewhiteningprewhitening (NPW)(NPW)

Channelized Hoteling (CHO)

Useful for:Useful for:ObserverObserverObserver-ObserverObserver--independent performanceObserverObserverObserver independent performanceindependent performanceindependent performanceSystem design, optimizationSystem design, optimizationLowSystem design, optimizationLowLow-System design, optimizationSystem design, optimizationSystem design, optimizationLowLow--dose performance System design, optimizationSystem design, optimization

dose performance dose performance limits

NoteNote: Note: linearity, shift variance / stationarityNote: linearity, shift variance / stationaritylinearity, shift variance / stationaritylinearity, shift variance / stationarity

linearity, shift variance / stationaritylinearity, shift variance / stationaritylinearity, shift variance / stationarity locallinearity, shift variance / stationaritylinearity, shift variance / stationarity


P. Prakash et al. Med Phys 2011

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Mag

nific

atio

n

Pixel Size (mm)0.1 0.2 0.3 0.4

1.2

1.4

1.6

1.8

2

0.8

1

1.2

1.4

1.6

1.8

2

High-Frequency Task(Bone Edge) 0.194 mm pixels

1x1 Readoutd'

TaskTask-Task-Based Imaging PerformanceBased Imaging PerformanceBased Imaging PerformanceBased Imaging PerformanceConsiders:Considers:Considers:Considers:Considers:Considers:Considers:Fidelity of signal transfer (MTF)Fidelity of signal transfer (MTF)Correlation of noise (NPS)Correlation of noise (NPS)Spatial frequencies of interest (Spatial frequencies of interest (WWWtasktasktask)















Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Low-Frequency Task(Muscle-Fat)

0.1 0.2 0.3 0.4

1.2

1.4

1.6

1.8

2

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

Pixel Size (mm)

Mag

nific

atio

n

0.388 mm pixels

2x2 Binningd'

TaskTask-Task-Based Imaging PerformanceBased Imaging PerformanceBased Imaging PerformanceBased Imaging PerformanceConsiders:Considers:Considers:Considers:Considers:Considers:Considers:Fidelity of signal transfer (MTF)Fidelity of signal transfer (MTF)Correlation of noise (NPS)Correlation of noise (NPS)Spatial frequencies of interest (Spatial frequencies of interest (WWWtasktasktasktasktask)















Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Basic Principles

CBCTSystems

Imaging Performance

FutureDirections

ArtifactsRing ArtifactsRing ArtifactsRing Artifacts

DRing ArtifactsRing ArtifactsRing ArtifactsRing Artifacts

DDefective pixel elementsDefective pixel elementsefective pixel elementsGeometric CalibrationGeometric Calibration

Irreproducible orbitIrreproducible orbitLateral

Irreproducible orbitIrreproducible orbitLateral Lateral TruncationLateral Lateral TruncationTruncation

Limited detector FOVLimited detector FOVShort Scan (<180Short Scan (<180Short Scan (<180o

Limited detector FOVLimited detector FOVShort Scan (<180Short Scan (<180o+fan)Short Scan (<180Short Scan (<180Short Scan (<180 +fan)+fan)+fan)

Insufficient data, Parker weightsXX-

Insufficient data, Parker weightsInsufficient data, Parker weightsX--ray Scatterray Scatterray Scatterray Scatter

Large volumetric FOVLarge volumetric FOVBeam HardeningBeam Hardening

(as with MDCT)(as with MDCT)Image LagImage Lag

Residual signal from previous framesResidual signal from previous framesCone

Residual signal from previous framesConeCone-

Residual signal from previous framesResidual signal from previous framesResidual signal from previous framesConeCone--Beam ArtifactConeConeCone Beam ArtifactBeam ArtifactBeam Artifact

Circular orbit, divergent beamCircular orbit, divergent beamPatient

Circular orbit, divergent beamCircular orbit, divergent beamPatient Patient MotionPatient Patient MotionMotion

Slow scan Motion

Slow scan Slow scan time

DosimetryDosimetrySee also:See also:See also:AAPM Task Group 111 (Dixon et al.)AAPM Task Group 111 (Dixon et al.)AAPM Task Group 200 (AAPM Task Group 111 (Dixon et al.)AAPM Task Group 111 (Dixon et al.)AAPM Task Group 200 (AAPM Task Group 200 (BakalyarAAPM Task Group 111 (Dixon et al.)AAPM Task Group 111 (Dixon et al.)

BakalyarBakalyar et al.)AAPM Task Group 200 (AAPM Task Group 200 (BakalyarBakalyarExtended CTDI PhantomsExtended CTDI PhantomsLongitudinal stack (3 cylinders ~45 cm)Longitudinal stack (3 cylinders ~45 cm)Long xLongitudinal stack (3 cylinders ~45 cm)Long xLong x-Longitudinal stack (3 cylinders ~45 cm)Longitudinal stack (3 cylinders ~45 cm)Longitudinal stack (3 cylinders ~45 cm)Long xLong x--ray scatter tailsLong x

Point ray scatter tailsray scatter tailsray scatter tailsLong xLong xLong x

Point Point Dose MeasurementsPoint Point Dose MeasurementsDose MeasurementsFarmer chamber (0.6 cmFarmer chamber (0.6 cmFarmer chamber (0.6 cm3

Dose Measurements3 air volume)Farmer chamber (0.6 cm

Central dose (DCentral dose (DCentral dose (Do

Farmer chamber (0.6 cmFarmer chamber (0.6 cmCentral dose (DCentral dose (DCentral dose (D )Central dose (DCentral dose (DCentral dose (DPeripheral dose (

o)Peripheral dose (Peripheral dose (Peripheral dose (DDDDpDDD )Peripheral dose (Peripheral dose (DDDpp)

Short scans and object truncationShort scans and object truncationNonuniform

Short scans and object truncationShort scans and object truncationNonuniformNonuniform dose distributions

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Peripheral

Central


BakalyarBakalyar et al.)AAPM Task Group 200 (AAPM Task Group 200 (BakalyarBakalyarExtended CTDI PhantomsExtended CTDI PhantomsLongitudinal stack (3 cylinders ~45 cm)Longitudinal stack (3 cylinders ~45 cm)Long xLongitudinal stack (3 cylinders ~45 cm)Long xLong x-Longitudinal stack (3 cylinders ~45 cm)Longitudinal stack (3 cylinders ~45 cm)Longitudinal stack (3 cylinders ~45 cm)Long xLong x--ray scatter tailsLong xLong xLong x ray scatter tailsray scatter tailsray scatter tails

Point Dose MeasurementsPoint Dose MeasurementsFarmer chamber (0.6 cmFarmer chamber (0.6 cmFarmer chamber (0.6 cm3

Point Dose Measurements3 air volume)Farmer chamber (0.6 cm

Central dose Farmer chamber (0.6 cmCentral dose Central dose (D(D(Do

Farmer chamber (0.6 cmFarmer chamber (0.6 cmFarmer chamber (0.6 cm(D(D(D(D(D(D )Central dose Central dose (D(D

Peripheral dose (D(D(D

Peripheral dose Peripheral dose Peripheral dose Peripheral dose Peripheral dose Peripheral dose Peripheral dose (o)

Peripheral dose Peripheral dose Peripheral dose (((DDDDpDDDDDD )Peripheral dose Peripheral dose Peripheral dose (DDDDpp)Short scans and object truncationShort scans and object truncationNonuniform


𝐷𝑤 =1

3𝐷0 +2

3𝐷𝑃

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

mGy

Half-scan (200◦)


BakalyarBakalyar et al.)AAPM Task Group 200 (AAPM Task Group 200 (BakalyarBakalyarExtended CTDI PhantomsExtended CTDI PhantomsLongitudinal stack (3 cylinders ~45 cm)Longitudinal stack (3 cylinders ~45 cm)Long xLongitudinal stack (3 cylinders ~45 cm)Long xLong x-Longitudinal stack (3 cylinders ~45 cm)Longitudinal stack (3 cylinders ~45 cm)Longitudinal stack (3 cylinders ~45 cm)Long xLong x--ray scatter tailsLong xLong xLong x ray scatter tailsray scatter tailsray scatter tails

Point Dose MeasurementsPoint Dose MeasurementsFarmer chamber (0.6 cmFarmer chamber (0.6 cmFarmer chamber (0.6 cm3

Point Dose Measurements3 air volume)Farmer chamber (0.6 cm

Central dose Farmer chamber (0.6 cmCentral dose Central dose (D(D(Do

Farmer chamber (0.6 cmFarmer chamber (0.6 cmFarmer chamber (0.6 cm(D(D(D(D(D(D )Central dose Central dose (D(D

Peripheral dose (D(D(D

Peripheral dose Peripheral dose Peripheral dose Peripheral dose Peripheral dose Peripheral dose Peripheral dose (o)

Peripheral dose Peripheral dose Peripheral dose (((DDDDpDDDDDD )Peripheral dose Peripheral dose Peripheral dose (DDDDpp)Short scans and object truncationShort scans and object truncationNonuniform


Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Dlens = 5.5 mGy

D0 = 20 mGy

Half-scan (200◦)

0

5

10

15

20

25

mGy

𝐷𝑤 =1

3𝐷0 +2

3𝐷𝑃

0 10 20 30Position, z (cm)

0

5

10

15

20

25

Dose

(mG

y)

Peripheral

Central

Pheno Robotic C-arm (Siemens)Basic

Principles

CBCTSystems

ImagingPerformance

FutureDirections

Head Scanner (Prototype) J. Xu et al. Med Phys 2016

New SystemsNew Systemsand Acquisition Techniquesand Acquisition TechniquesRobotic gantryRobotic gantryRobotic gantryNoncircular orbitsNoncircular orbitsSpecialty systems (pointSpecialty systems (point-Specialty systems (point-ofofof-ofof-care)Specialty systems (point

New DetectorsCMOS, CMOS, Variable gain modesCMOS, CMOS, CMOS, CMOS, Variable gain modesVariable gain modesVariable gain modesVariable gain modesHigher resolutionHigher resolutionLower electronic noise

Improved Artifact CorrectionsImproved Artifact CorrectionsLag + GlareLag + GlareLag + GlareScatter + BeamScatter + Beam-Scatter + Beam-HardeningScatter + BeamScatter + BeamScatter + Beam HardeningPatient Motion

New Reconstruction MethodsNew Reconstruction MethodsModel

New Reconstruction MethodsModel-

New Reconstruction MethodsNew Reconstruction MethodsNew Reconstruction MethodsModel-based image reconstruction (MBIR)ModelModelModelModelModelModel based image reconstruction (MBIR)based image reconstruction (MBIR)based image reconstruction (MBIR)based image reconstruction (MBIR)based image reconstruction (MBIR)based image reconstruction (MBIR)Prior information (patient and devices)Prior information (patient and devices)Accelerated reconstruction

Multitom RAX(Siemens)

Imaging Ring(Imaging RingImaging Ring((medPhotonImaging RingmedPhotonmedPhoton)

InReach(CurveBeam)

Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

apix = 0. 099 mmσadd = 304 electrons

FOV = 29.5 x 29.5 cm2

Dalsa3030HR

Varian4343CB

apix = 0. 138 mmσadd = 5968 electrons

FOV = 43 x 43 cm2

CMOS DetectorFlat Panel Detector

Extremity CT (Hi-Res pQCT Prototype)W. Zbijewski, Johns Hopkins University

CMOSCMOSDalsaCMOSDalsaDalsa Xineos

Flat PanelFlat PanelVarian 4030


New DetectorsCMOS, Variable gain modesCMOS, Variable gain modesCMOS, Variable gain modesHigher resolutionHigher resolutionLower electronic noise





Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Varian4343CB


Glare PSFShort range PSF

Sisniega et al., Phys Med Biol 2015

Veiling Glare Deconvolution

MC Scatter + Beam Hardening

*-1

Detector Lag Deconvolution

+

-

Joseph Spital

MC

*-11 − 𝑐1 𝑒𝑥𝑝

−𝑥2

2𝑐22 +

𝑐1𝜋𝑐3

1

1 + 𝑥2 𝑐32

𝑛=1

𝑁

𝑏𝑛 ⋅ 𝑒−𝑎𝑛𝑘𝑢(𝑘)

𝑆𝑖

𝜇𝑖 𝜇𝐵𝐻 𝜇i𝐵𝐻

𝑦𝑖𝜇𝑖+1







Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Varian4343CB






*-1


+

-

Joseph Spital

MC

*-11 − 𝑐1 𝑒𝑥𝑝

−𝑥2

2𝑐22 +

𝑐1𝜋𝑐3

1

1 + 𝑥2 𝑐32

𝑛=1

𝑁


𝑆𝑖


𝑦𝑖𝜇𝑖+1

Glare Deconvolution


Lag Deconvolution

*

No Corrections

Scatter Correction All All CCorrections







Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Varian4343CB






*-1


+

-

Joseph Spital

MC

*-11 − 𝑐1 𝑒𝑥𝑝

−𝑥2

2𝑐22 +

𝑐1𝜋𝑐3

1

1 + 𝑥2 𝑐32

𝑛=1

𝑁


𝑆𝑖


𝑦𝑖𝜇𝑖+1No Corrections

Scatter Correction All Corrections







MotionMotion-Motion CorrectedPatient Motion

CMA-ESmin𝑇6𝐷𝑜𝐹𝑺𝛁 FDK (pq,T)

Patient Motion‘Auto

Patient Motion‘Auto‘Auto-

MotionMotionMotion-CorrectedCorrectedCorrectedPatient MotionPatient MotionPatient Motion‘Auto‘Auto-Focus’ Image Domain Motion Compensation








Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

Filtered Backprojection Penalized Likelihood

Penalty

Log-Likelihood 𝝁 =

𝟎

𝟐𝝅 𝑹𝟐

𝑼𝟐 𝒙, 𝒚, 𝜽𝒑′ 𝝃, 𝜽 ∗ 𝒌𝒓𝒂𝒎𝒑 𝝃 𝒅𝜽

Conventional MBIR







Basic Principles

CBCTSystems

ImagingPerformance

FutureDirections

FBP PLH

6.6 mGy1.0 mm

2.113 s

3.3 mGy1.0 mm

2.74 hr 19 s

DoseSpatial Res. (ESF)

CNRRecon Time

Wang et al. Med Wang et al. Med PhysPhys (2015)

LargeLarge-Large area detectorLargeLargeLarge area detectorarea detectorarea detectorCircular (or non

area detectorCircular (or nonCircular (or non-

area detectorarea detectorarea detectorCircular (or nonCircular (or non--circular) orbit circular) orbit Volumetric FOV

Handouts for this presentation available after RSNA at:http://istar.jhu.edu/talks

LargeLargeLarge-area detectorarea detectorarea detector

In SummaryBasic

Principles

CBCTSystems

Imaging Performance

FutureDirections

Rich diversity of system configurationsRich diversity of system configurationsIGRT Rich diversity of system configurationsRich diversity of system configurationsIGRT IGRT Rich diversity of system configurationsRich diversity of system configurations

IR Rich diversity of system configurationsRich diversity of system configurationsRich diversity of system configurationsRich diversity of system configurations

IR IR IR IR Rich diversity of system configurationsRich diversity of system configurationsRich diversity of system configurations

IG surgery Rich diversity of system configurationsRich diversity of system configurations

IG surgery IG surgery Rich diversity of system configurationsRich diversity of system configurationsRich diversity of system configurations

Specialty diagnostics (breast, MSK, …)

Good (nearly isotropic) spatial resolutionGood (nearly isotropic) spatial resolutionModest softGood (nearly isotropic) spatial resolutionModest softModest soft-Good (nearly isotropic) spatial resolutionGood (nearly isotropic) spatial resolutionGood (nearly isotropic) spatial resolutionModest softModest soft--tissue contrast resolutionModest softArtifacts

New systems, detectors, and acquisition techniquesNew systems, detectors, and acquisition techniquesModelNew systems, detectors, and acquisition techniquesModelModel-New systems, detectors, and acquisition techniquesNew systems, detectors, and acquisition techniquesNew systems, detectors, and acquisition techniquesModelModel--based image reconstruction

Basic Principles

CBCTSystems

Imaging Performance

FutureDirections

Sheth

Weiss Thawait

Zhang

Osgood

De Silva

Taylor

KhannaOuadah Uneri Jacobson

Tilley

Reaungamornrat

Prince

Stevens

Goerres

Aygun

AcknowledgmentsBiomedical EngineeringThe I-STAR LabThe Carnegie Center for Surgical Innovation

RadiologyN Aygun, C Weiss, K Hong, S Demehri, J Carrino

NeuroscienceR Stevens, V Koliatsos

NeurosurgeryJP Wolinsky, N Theodore, D Sciubba, T WithamA Cohen, M Luciano, G Gallia, X Ye, H Brem

Orthopaedic SurgeryG Osgood, B Shafiq, J FickeJ Khanna, L Riley

Computer Science and ECER Taylor, G Hager, P KazanzidesJ Prince

ZbijewskiSiewerdsen Brem TheodoreStayman

Sisniega

HanWu

istar.jhu.educarnegie.jhu.edu

Xu Cao

Dang

Ketcha

Brehler

open gantry cone-beam ct - i-star...planmed verity curvebeam pedcat carestream onsight *errors and...

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