Joint Dual Photopeak Image Reconstruction in Lu-177 SPECT · 2019-12-17 · Energy Spectrum of...

JointDualPhotopeak ImageReconstructioninLu-177SPECT

2018EANM

HongkiLim,JeffreyFessler,YuniDewarajaUniversityofMichigan,AnnArbor

EANMDisclosure Statement

1) I or one of my co-authors hold a position as an employee, consultant, assessor or advisor for a pharmaceutical, deviceor biotechnology company. If yes, please specify name/position/company:Nothing to disclose

2) I or one of my co-authors receive support from a pharmaceutical, device or biotechnology company. If yes, pleasespecify name/position/company/which project and whether support is in kind or monetary:Yuni Dewaraja is paid consultants forMIM Software Inc., Cleveland, USA

3) I or one of my co-authors hold property rights/patents for (radio)pharmaceuticals, medical devices or medicalconsulting firms. If yes, please specify name/position/company:Nothing to disclose

4)Ioroneofmyco-authorshavewrittenarticlesfor(radio)pharmaceutical,medicaldevice,biotechnologyorconsultingcompaniesduringthelast5years.Ifyes,pleasespecifyname/position/company/article/journalandco-authors:Nothing to disclose

2/21JointdualphotopeakimagereconstructioninLu-177SPECT

HongkiLim(Universityof Michigan)

EnergySpectrumof177Lu

3/21JointdualphotopeakimagereconstructioninLu-177SPECT

1. Ljungberg et al. "MIRD pamphlet no. 26" J Nucl Med 57.1 (2016): 151-62.

q Generalrecommendation1

• MEcollimator+208keV

q Anotheroption

• MEcollimator+113&208keV

0 300Re

lativeCo

Energy(keV)

Simulationwithpointsourceinwaterphantom&MEcollimator

Totalevents PrimaryEvents Total- Primary

EnergySpectrumofLu-177

q Generalrecommendation

• MEcollimator+208keVàClinicallyadoptedoption

q Anotheroption

• MEcollimator+113&208keV

0 300Re

lativeCo

Energy(keV)

JointdualphotopeakimagereconstructioninLu-177SPECT

q Generalrecommendation

• MEcollimator+208keV

q Anotheroption

• MEcollimator+113&208keVàGoodtousewhen#ofcountsis

insufficient(imagingatlatertimepointorpretherapydiagnosticimaging)

0 300Re

lativeCo

Energy(keV)

113 208

q Comparedto208-keV,113-keV has

! ~60%ofYield! ~70%PrimaryCounts(cps/MBq)forMEcollimator

0 300Re

lativeCo

Energy(keV)

113 208

Optionsforusingbothphotopeaks- 113&208keV

q Twooptions1) Reconstructtwoimagesseparately andmakesum

𝑦#~Poisson 𝐴#𝑥# + 𝑠# ,𝑥/# = argmin𝑥#𝑓(𝑥#; 𝑦#, 𝑠#)𝑦8~Poisson 𝐴8𝑥8 + 𝑠8 ,𝑥/8 = argmin𝑥8𝑓(𝑥8; 𝑦8, 𝑠8)𝑥/ = 𝑥/#+𝑥/8

2)Reconstructoneimagejointly

𝑦 =𝑦#𝑦8 ~Poisson( 𝐴#𝐴8

𝑥 +𝑠#𝑠8 )

𝑥/ = argmin𝑥𝑓(𝑥; 𝑦, 𝑠)

• 𝒚#(𝒚8) ismainenergywindowand𝒔#(𝒔8) isscatterenergywindowacquisitionaround208(113)-keV• 𝑓(𝑥)denotesnegativePoisson likelihood function• Forscatterestimation,weusedtriple-energy-window(TEW)technique

Optionsforusingbothphotopeaks- 113&208keV

àMorealignedwithactualPoissonnatureofmulti-windowacquisition

• 𝒚#(𝒚8) ismainenergywindowand𝒔#(𝒔8) isscatterenergywindowacquisitionaround208(113)-keV• 𝑓(𝑥)denotesnegativePoisson likelihood function• Forscatterestimation,weusedtriple-energy-window(TEW)technique

q Twooptions1) Reconstructtwoimagesseparately andmakesum

𝑦#~Poisson 𝐴#𝑥# + 𝑠# ,𝑥/# = argmin𝑥#𝑓(𝑥#; 𝑦#, 𝑠#)𝑦8~Poisson 𝐴8𝑥8 + 𝑠8 ,𝑥/8 = argmin𝑥8𝑓(𝑥8; 𝑦8, 𝑠8)𝑥/ = 𝑥/#+𝑥/8

2)Reconstructoneimagejointly

𝑦 =𝑦#𝑦8 ~Poisson( 𝐴#𝐴8

𝑥 +𝑠#𝑠8 )

𝑥/ = argmin𝑥𝑓(𝑥; 𝑦, 𝑠)

Whatfactorsneedtobeconsideredforjointreconstruction?

q SystemModel𝑦#𝑦8 ~Poisson(

𝐴#𝐴8

𝑥 +𝑠#𝑠8 ),

where𝑎EFG = 𝛼G𝑝EFG𝑔EFG

𝑎EFG: elementofsystemmodel(𝐴G) at𝑖-th rowand𝑗-th column in𝑘-th energywindow

𝛼G:Relativecameradetection efficiency × branchingratio𝑝EFG :depth-dependentandenergy-dependenteffectofattenuation𝑔EFG:depth-dependentandenergy-dependent3D-collimator detectorresponse

Experimentalsetting

q 2measurements+1simulation+1patientscan

I. Spherephantommeasurement(4scans)

II. Liver-torsophantommeasurement(4scanswithhigh/low-counts)

III. XCATphantomsimulation (10realizationswithhigh/low-counts)

IV. Patientscan

Physicalphantommeasurement1

q Spherephantommeasurement(4scanstoassessnoise)- Sphere-to-backgroundratiowas6:1 ,30minutesacquisition- Mainwindowwidth:20%,scatterwindowwidth:10%

208-keVmainwindow 208-keVscatterwindow

Physicalphantommeasurement2

q Liver-torsophantommeasurement- 4scanstoassessnoise:

4scanof35 min(mimickingDay3post177Lu-DOTATATE)4scansof3 min(mimickingDay3pre-therapydiagnosticimaging)

- Lesion-to-liverratiowas4:1

35 minutesscan

208-keVmainwindow

113-keVmainwindow

208-keVmainwindow

113-keVmainwindow

3 minutesscanJointdualphotopeakimagereconstructioninLu-177SPECT

XCATsimulation

q XCATcoupledwithSIMIND2 simulation(10realizationstoassessnoise)- Realisticactivitydistributionfor177Lu-DOTATATE

2. Ljungberg M. Monte Carlo Calculation in Nuclear Medicine: Application in Diagnostic Imaging, 2nd edn, 2012.

OrganRelativeactivity

concentration

Lesioninliver 1.00

Spleen 0.59

Kidney 0.48

Liver 0.16

Gallbladder 0.02

Renalpelvis 0.02

Post-therapyDay1count-level Pre-therapyDay1count-level

208-keVmain 208-keVscatter

177Lu-DOTATATEPatientscan

q Day5 acquisition- 1clinicalscanwith208-keV (Scannedfor25minutes)- 3researchscanswithboth photopeaks (Scannedfor2 minutestomimicpre-therapy)

25minutesscanatDay5

2minutesscanatDay5

ReconstructionandEvaluationmethods

I. Activity-recovery

II. Contrast-recovery

III. Image-ensemble-noise(variabilityacrossmultipleacquisitions)

q Reconstructiondetails(forbothsingleandjoint)• AppliedGaussiansmoothingtoTEWscatterestimate• EMalgorithm+50iteration(1subset)

q Evaluationmetrics

Calibrationfactorforabsolutequantification

1. NISTrecommendation3 (0.9%uncertainty)• 3mL177Luina10mLSchottvial:CRC-15Rdialsetting449x10

2. TransferringCalibrationtoanewgeometry(10mLsyringe)• Activity insyringe=activityinvial- residual

3. Withthesyringe inthedosecalibratoradjustsetting• Settingtogetcorrectreadingfor3mLinsyringe:480x10

Syringe tapedtoSourceholder

q Imagingforcalibrationfactor• planar with20%mainwindow&10%TEWSC

q 208keV(head1):12.9cps/MBq(head2):13.4cps/MBq

à (within1%ofmanuf.specifiedvalue for5/8”xtal)q 113keV(head1): 9.2cps/Mbq (70%ofabove)

(head2):9.3cps/MBq

‘NISTgeometry’fordosecalibrator

Transfertosyringeforfillingphantomandcamerasensitivity

3. Bergeron DE, Cessna JT. Nucl Med Commun. 2018 Jun;39(6):500-504

Result:Spherephantommeasurement

Single208-keV Single113-keV Joint

0 200 400 600x-axis

ity (B

TRUESIR 208SIR 113JIR

Profileacrosscoldspot

Profile

Result:Spherephantommeasurement

0 50 100 150

ContrastRecoverytoNoiseRatio

SphereSize(ml)

SinglePhotopeakRecon@208-keV

JointPhotopeakRecon

0 20 40 60 80 100 120

ContrastRecovery

SphereSize(ml)

JointPhotopeakRecon

0 20 40 60 80 100 120

ActivityRecovery

SphereSize(ml)

JointPhotopeakRecon

Result:Liver-torsophantommeasurement(axialview)

Single208-keV Single113-keV Joint

HighCountsà

LowCountsà

Result:Liver-torsophantommeasurement

Noise ContrastRecovery CRNR29mlovoid 16mlsphere 29mlovoid 16mlsphere

208-keV 11.4 75.3 70.4 6.6 6.2113-keV 16.4 72.4 66.6 4.4 4.1Joint 9.5 74.4 69.1 7.8 7.2

208-keV 36.4 65.2 63.7 1.8 1.8113-keV 48.5 58.7 51.8 1.2 1.1Joint 29.3 62.1 58.1 2.1 2.0

35 minutesscan

3 minutesscan

Result:XCATphantomsimulation

208keV 10.1 76.3 92.9 7.5 9.2113keV 12.9 73.3 90.4 5.7 7.0Joint 8.0 75.0 91.8 9.4 11.5

208keV 65.2 75.8 91.7 1.2 1.4113keV 85.5 68.7 91.5 0.8 1.1Joint 52.2 72.8 91.6 1.4 1.8

Post-therapyDay1count-level

Pre-therapycount-level

208-keV 113-keV Joint

Kidneys

Result:Patientscan

25minutes scan,208-keVSPECT/CT

Single208-keVShortScan

Single113-keVShortScan

JointShortScan

Recon(unit:Bq/ml) RMSD* Noise*208-keV 1.47e4 332.9113-keV 1.90e4 278.6Joint 1.45e4 260.4*RMSDrelativetolongscan*Imageensemblenoisebetween3repeatshortscans

Spleen

Single208-keVLongScan

Summary

q Jointreconstructionw/E-dependentsystemmodel&TEWSCiseasytoimplementq Comparedtosinglephotopeak(208-keV)reconstruction,jointreconstruction- Gavecomparableactivity/contrastrecovery- Improvednoisesignificantlyevenforhigh-countsdataà Importantforvoxel-leveldosimetry- Improvedcontrastrecoverytonoiseratio: 16.7-27.3%

q Jointreconstructioncanbebeneficialforreducingscantime

ExperimentsSpherephantom Liverphantom XCAT

Count-level High Low High Low

Improvement(%) 20.9-23.2 16.7-17.5 17.3-21.5 25.4-25.8 24.7-27.3

Improvement(%)ofContrastRecoverytoNoiseRatiooversingle208-keV

Thank You

Weacknowledge• UofMichiganRadiologySeedGrant• JeremyNiedbala,Gerrid Rosebushforallhelpinmeasurementsandcalibration

Contact:hongki@umich.edu

Joint Dual Photopeak Image Reconstruction in Lu-177 SPECT · 2019-12-17 · Energy Spectrum of...

Documents

Transcript of Joint Dual Photopeak Image Reconstruction in Lu-177 SPECT · 2019-12-17 · Energy Spectrum of...

Early SPECT Studies

Spect in parkinsonism

SPECT, PEC Corregido

QUALITY ASSURANCE TESTS FOR SPECT-CT /SPECT/GAMMA CAMERA ...

Processing SPECT VQ Studies - krypton81m.org.uk SPECT VQ Processing J OBrien Kr… · Processing SPECT VQ Studies Joseph O'Brien joseph.o'brien@nhs.net Clinical Scientist ... Operator

SL Mass Spect

Introduction to SPECT/CT - UP · Siemens Symbia T series Siemens SPECT/CT: Symbia T series MPI: IQ SPECT Technology Partially Converging Collimation 4 min cardiac SPECT, 1 min CT

Medical Image Denoising And Fusion Using Cross Bilateral ... · imaging quality and includes PET-CT, PET-MRI-CT, SPECT-CT, MR-SPECT, MRI-CT-SPECT MRI/CT-PET-SPECT etc. Usually, the

Spect hardware

8.- Gammacamara SPECT

SPECT/PET Scans

Spect Rm Tutorial

SPECT - Protocolos Tecnicos

Con Spect Gc

spect and pet

Aula SPECT

Determination of the photopeak detection efficiency of a ... · Determination of the photopeak detection efficiency of a HPGe detector, for volume sources, via Monte Carlo simulations

J U S N E D annual meeting issue...Mouse Cardiac SPECT Mouse Oncology SPECT Mouse Knee SPECT PET, SPECT, CT & Optical ... This categorical seminar will present ways that medical ...

Mass Spect

Gated Spect