Basics of PET Imaging

Sincethepublicationofthisbook in2005, thegrowthofpositron emission tomography(PET)andPET/CTmodalityhasbeenphenomenalwiththed- coveryofef?cientdetectorsandtheadditionofsophisticatedscannersand powerfulsoftware. Becauseofthevastadvancementandchangesintechn- ogy, andalso withgreatappreciationofthesuccess ofthe?rst edition, we thoughtasecondeditionofthebookwouldbeappropriate. Thebookisrevisedtoagainful?lltheneedsofnuclearmedicineprof- sionalssuchasphysicians, technologists, andresidents, alongwithstudents fortheirboardexaminationandtraining. Thecontentsofthebookhavebeen keptatthebasiclevelaswasinthe?rstedition. The organization of the book essentially has remained the same. Some chaptershavebeenrevisedvery extensively, while others haveonly minor changes. NochangehasbeenmadeinChap. 1asitisbasedonbasicphysics. Extensive revision has been made in Chaps. 2 and 3 to include up-to-date information on detectors, scanners, and data collection. Chapter 4 in the original edition has been divided into Chaps. 4 and 5 to allow for a se- ratechapteron“Storage,Display,andPACS. ”Chapter6hasbeenupdated withnewinformationonNEMAstandardsonacceptancetestsofPETsc- ners. NewPETradionuclidesandthelistofcurrentavailablecyclotronshave beenaddedtoChap. 7. Chapter8includesasectiononCompoundingofPET Radiopharmaceuticals,inadditiontoseveralnewPETradiopharmaceuticals. NewregulationsconcerningtheuseofPETradiopharmaceuticals,thelice- ingofphysiciansandtechnologists,andtheaccreditationofPETfacilitiesto beeligibleforreimbursementforPETproceduresareallincludedinChap. 9. Chapter10hasbeenrevised,focusingontheissuesofcurrentreimbursement issuesforPETstudies. OnlyminorchangeshavebeenmadeinChaps. 11and 12toincludeup-to-dateinformation. Questionshavebeenaddedattheend ofeachchapter,asappropriate,tore?ectthechangesincontents. IthankmycolleaguesattheClevelandClinicFoundationfortheirsupport in manywaysand Mrs. DianeGrif?s for kindly typingand completingthe manuscriptontime. vii viii Preface IsincerelythankAndrewMoyer,editorofradiologyandnuclearmedicine, atSpringerforsupportandencouragement,andS. GeethalakshmiSrinivasan, ProjectManager,atSPiTechnologiesIndiaPvtLtdforexcellentproduction ofthebook. Cleveland,OH GopalB. Saha Contents 1. RadioactiveDecayandInteractionofRadiationwithMatter . . . 1 AtomicStructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 RadioactiveDecay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ?Decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ? ? Decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 + Positron(?)Decay . . . . . . . . . . . . . . . . . . . . . . . . . 3 ElectronCapture . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 IsomericTransition . . . . . . . . . . . . . . . . . . . . . . . . . . 4 RadioactiveDecayEquations . . . . . . . . . . . . . . . . . . . . . 5 GeneralDecayEquations . . . . . . . . . . . . . . . . . . . . . . 5 SuccessiveDecayEquations . . . . . . . . . . . . . . . . . . . . . 7 UnitsofRadioactivity . . . . . . . . . . . . . . . . . . . . . . . . 9 UnitsofRadioactivityinSystemInternationale . . . . . . . . . 9 Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 InteractionofRadiationwithMatter . . . . . . . . . . . . . . . . . 10 InteractionofChargedParticleswithMatter . . . . . . . . . . . 10 Interactionof?RadiationwithMatter . . . . . . . . . . . . . . 12 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 ReferencesandSuggestedReading . . . . . . . . . . . . . . . . 17 2. PET ScanningSystems . . . . . . . . . . . . . . . . . . . . . . . . . 19 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 SolidScintillationDetectorsinPET . . . . . . . . . . . . . . . . . 20 PhotomultiplierTube . . . . . . . . . . . . . . . . . . . . . . . . . . 24 PulseHeightAnalyzer . . . . . . . . . . . . . . . . . . . . . . . . . 25 ArrangementofDetectors . . . . . . . . . . . . . . . . . . . . . . 25 PETScanners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 CoincidenceScintillationCameras . . . . . . . . . . . . . . . . . . 29 PET/CTScanners . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 SmallAnimalPETScanner . . . . . . . . . . . . . . . . . . . . . . 33 MobilePETorPET/CT . . . . . . . . . . . . . . . . . . . . . . . . 36 ix x Contents Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 ReferencesandSuggestedReading . . . . . . . . . . . . . . . . 39 3. DataAcquisition and Corrections . . . . . . . . . . . . . . . . . . . 41 PETDataAcquisition . . . . . . . . . . . . . . . . . . . . . . . . . . 41 TimeofFlightMethod . . . . . . . . . . . . . . . . . . . . . . . . 46 Two-Dimensionalvs. Three-Dimensional DataAcquisition . . . . . . . . . . . . . . . . . . . . . . . . 47 FactorsAffectingAcquiredPETData . . . . . . . . . . . . . . . . 49 Normalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 PhotonAttenuation . . . . . . . . . . . . . . . . . . . . . . . . . 50 AttenuationCorrectionMethods . . . . . . . . . . . . . . . . . . 52 RandomCoincidences . . . . . . . . . . . . . . . . . . . . . . . . 53 ScatterCoincidences . . . . . . . . . . . . . . . . . . . . . . . . . 55 CorrectionforScatterCoincidences . . . . . . . . . . . . . . . . 56 DeadTime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 RadialElongation . . . . . . . . . . . . . . . . . . . . . . . . . . 59 PET/CTDataAcquisition . . . . . . . . . . . . . . . . . . . . . . . 60 FactorsAffectingPET/CTData . . . . . . . . . . . . . . . . . . 62 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 ReferencesandSuggestedReading . . . . . . . . . . . . . . . . 68 4. ImageReconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . 71 SimpleBackprojection . . . . . . . . . . . . . . . . . . . . . . . . . 71 FilteredBackprojection . . . . . . . . . . . . . . . . . . . . . . . . . 72 TheFourierMethod . . . . . . . . . . . . . . . . . . . . . . . . . 73 TypesofFilters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 IterativeReconstruction . . . . . . . . . . . . . . . . . . . . . . . .