Riduzione della dose nella SPECT cardiaca : apparecchiature e software

Transcription

1 Riduzione della dose nella SPECT cardiaca : apparecchiature e software Optimization of procedures in Nuclear Cardiology A.Ghilardi Nuclear Medicine Department AO Papa Giovanni XXIII Bergamo Italy Io c ero

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4 Iterative Filtering New Collimators Iterative RR Filtering New Detectors Attenuation / Scatter Correction New Tracers

5 Advantages and disadvantages of PET and SPECT in a busy clinical practice. Bateman TM. Cardiovascular Radiologic Imaging, Mid-America Heart and Vascular Institute, Kansas City, MO 64111, USA. tbateman@saint-lukes.org The continued high utilization of rest-stress single-photon emission computed tomographic (SPECT) myocardial perfusion imaging (MPI) is supported by its known clinical benefits, established reimbursement, and wide availability of cameras and radiopharmaceuticals. However, traditional rest-stress SPECT protocols tend to be lengthy and inefficient, and the prevalence of equivocal studies continues to be a problem. The use of stress-only SPECT protocols in selected patients, and a new generation of ultrafast SPECT cameras have led to improved image quality, reduced dosimetry and shorter, more efficient MPI protocols. The utilization of positron emission tomographic (PET) MPI has been accelerated by the availability of radiopharmaceuticals that can be generated on-site, and by the availability of more PET cameras. Emerging evidence consistently demonstrates that PET provides improved image quality, greater interpretive certainty, higher diagnostic accuracy, lower patient dosimetry, and shorter imaging protocols as compared to SPECT. Importantly, PET imaging allows assessment of left ventricular function at peak-stress, and evaluation of microvascular function through the measurement of absolute myocardial blood flow at rest and at peak-stress. Wider utilization of PET MPI is hindered by a high cost of entry, high on-going costs, and an immature reimbursement structure.

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7 apoptosis Irreversible Infarction Regional myocardial innervation Recovery Ischaemia hybernation Angina Reversible Ischemic ST depression Regional myocardial dysfunction Regional myocardial anaerobic activation Flow Flow heterogeneity heterogeneity= = Perfusion Perfusion Defect Defect = aerobic suppression Ischaemic Ischaemic cascade cascade

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9 From Thallium201 to Tc99m-Sestamibi / Tetrofosmin Planar SPECT myocardial perfusion Gated-SPEC T myocardial perfusion + LV function

10 Nuclear cardiology = standardization = optimization Natural history of new ideas Innovation Umbridled enthusiasm Harsh reality Ultimate applicability Thoughtful adaptation TIME

11 Nuclear cardiology = standardization = optimization Radiopharmacy Uniformity Quality Control Acquisition Processing Report

12 optimization of procedures Imaging quality less dosimetry reduced acquisition time

13 optimization of procedures Sestamibi Tetrofosmin MIBG Tc99m PET radiopharmaceutical F18lupiridaz Rb82 D S P E C T G S P E C T I123 F18DG NH13 instrumentation G-PET_CT software - processing CZT

14 Tc99mSestamibi \ Tetrofosmin Tracers no side effects Thallium201 Chloride potassium-mimetic flurpirida z avaibility dosimetry imaging quality

15 Acquisition Protocols Tc99m-Sestamibi / Tetrofosmin ev 30 ( Two separate days or 1 day ) min min G-Spect no defects STOP ev stress double head geometry 90 body contour high resolution collimator MTX 64 x X frames / detector Zoom 1.45 [ resolution pxl 3.3 mm ] frame/time sec ECG trigger 12 frames / cycle G-Spect rest

16 From Gated-SPECT to SPECT evolution Gated-SPECT Attenuation correction myocardial perfusion + LV function Scatter correction Cardio Focusing Collimator SPECT / CT Activity administered Dosimetry Full Time Acquisition Processing

17 Gated-SPECT Pazienti con probabilità di evento grave: > 4% a 20 mesi Dose per esame: 9 15 msv Indice di rischio: induzione di tumore 0.02% 0.05% a anni dall esposizione Sul 50% circa dei pazienti cui si è evitata la coronarografia si è evitato: Rischio equivalente da irradiazione Rischio aggiuntivo di complicazioni gravi dell ordine dello 0.1% 0.2%

18 MAJOR ACHIEVEMENTS IN NUCLEAR CARDIOLOGY Advances in technical aspects of myocardial perfusion SPECT imaging Piotr J. Slomka, PhD,a James A. Patton, PhD,b Daniel S. Berman, MD,a and Guido Germano, PhDa Although myocardial perfusion SPECT (MPS) imaging is widely used in current clinical practice, it suffers from some fundamental limitations including long image acquisition, low image resolution, and patient radiation dose.

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22 Abstract EANM BS Poliambulanza Goteborg 2014

23 Old town Cardiac Focusing Collimator [IQSPECT] in Myocardial imaging as a new diagnostic tool: eight months experience A.Ghilardi, G.Medolago, L.Pozzi, MT Caloiero, C.Bianchi, A, Bruno AO Papa Giovanni XXIII Bergamo, Italy SNM Vancouver 2013

24 Acquisition Parameters Symbia SPECT Siemens LEHR Smartzoom [IQSPECT] Imaging quality MTX 128x x128 Zoom 1,45 1 Starting angle Global rotation Views /detector # Time/view 30sec sec Distance Body-countour 28cm

25 Acquisition Parameters Symbia SPECT Siemens Smartzoom [IQSPECT] Imaging quality SIEMENS Bergamo MTX 128x x128 Zoom 1 1 Starting angle Global rotation Views /detector # Time/view 10 sec sec Distance 28 cm 28cm

26 LEHR SMARTZOOM IQ SPECT Sensitivity Acquisition Time: 5 min PSF LEHR Smartzoom [IQSPECT] Mean counts Totall counts Mean counts Totall counts Detector 1 7, ,316 14, ,84 Detector 2 6, ,133 14, ,24 Efficiency Ratio [smartzoom/lehr] Detector 1 : 1.90 Detector

27 Attenuation correction

28 Normal patient

29 LEHR Smartzoom [IQSPECT] normal ischemia

30 LEHR MPI SSS 23 SRS 22 SDS 1 Tc99m TF Smartzoom [IQSPECT] SSS 23 SRS 20 SDS 3 #A

31 LEHR Smartzoom [IQSPECT] LEHR Smartzoom IQSPECT Rest Stress Rest Stress EDV LVEF WMS

32 Smartzoom [IQSPECT] MIBG SPECT vs MPI Tetrofosmin SLICES 4hrs MIBG MPI 4hrs MIBG MPI 4hrs MIBG MPI

33 MIBG SPECT [ IQ collimator ] quantification MIBG 28 MPI 26 MIBG% 41 MPI% 30 SD 2 precoci SD 3 tardive MIBG MPI

34 Scintigraphic Patterns: Perfusion Defect

35 CONCLUSION 18F-FDG has been shown to be a sensitive noninvasive marker of myocardial ischemia. The finding of a persistent metabolic switch from fatty acid to glucose, 24 h after the resolution of transient myocardial ischemia on a treadmill, provides the potential for diagnosing myocardial ischemia in the acute-care setting. thus, metabolism plays a critical role in sustaining myocellular viability by adapting quickly to the ischemic injury response,

36 Multimaging evaluation of stress induced myocardial ischemia with stress PET/CT [F18-DG] and stress/rest gated SPECT [Tc 99m-Tetrofosmin]: Preliminary data SNM 2014 St Louis A.Ghilardi, G.Medolago, A Bruno, M.Carminati, C.Bianchi*, L.Pozzi, N.Brambati, M.T.Caloiero Nuclear Medicine Department *Medical Physics AO Papa Giovanni XXIII Bergamo Italy Io c ero

37 Imaging Protocol Tc99m-Tetrofosmin 7.5 MBq / Kg 9 MBq / Kg 230 MBq STRESS G_SPECT 5 min Tc99m-Tetrofosmin F18-DG REST G_SPECT PET 45 min // 60 min glycaemia 1st day 2nd day

38 Gated_SPECT Symbia_S Siemens Smartzoom Collimator ACQUISITION PARAMETERS Collimator Smart Zoom [IQ SPECT] Matrix 128 x128 pxls Zoom 1.00 Views views [20-30 sec view] Mode Orbit Step & shoot Circular cardiac focusing [28cm] Total Arc 105 [from RAO 59 to LLO 163 ] ECG Trigger Frames / Cycle Frame mode 12 Reconstruction PARAMETERS FLASH 3D filtering Iterations Subsets Gauss SPECT Gated SPECT

39 PET_CT Biograph 6 Siemens CT Parameters mas Kv Slice Thickness Pitch FOV mm mm PET Acquisition Parameters # Beds 1 Scan time 15min Patient position supine Position Cranio_caudal Scan Modality List Mode [32 bit] PET Reconstruction Parameters Sampling List Mode 16 frames/cycle Zoom 1,4 Static Imaging Iterative OSEM filtering Position Cranio_caudal Scan Modality List Mode [32 bit] Reconstruction Parameters Filtering Iterations 8 Subsets 4 Gaussian 5 Matrix 128x128pxls

40 Case Report Fusione PET-SPECT stress PET SPECT Stress ED gated ED-stress SPECT No-Gated ED-PET

41 Myocardial 18F-FDG Uptake After Exercise-Induced Myocardial Ischemia in Patients with Coronary Artery Disease Ke-Fei Dou*1, Min-Fu Yang*2, Yue-Jin Yang1, Diwakar Jain3, and Zuo-Xiang He Exercise 18FDG imaging seems to be well suited for direct imaging of exercise-induced myocardial ischemia Direct Imaging of Exercise-Induced Myocardial Ischemia With Fluorine-18 Labeled Deoxyglucose and Tc-99m-Sestamibi in Coronary Artery Disease Zuo-Xiang He, MD; Rong-Fang Shi, MD et al 2003 Exercise-induced myocardial ischemia can be imaged directly with 18FDG. Combined exercise 18FDG-99mTc-sestamibi imaging provides a better assessment of exercise-induced myocardial ischemia compared with exercise-rest perfusion imaging. Direct ischemia imaging eliminates some of the limitations of presently used myocardial perfusion imaging

42 SPECT attenuation correction Stress NAC Rest NAC Stress AC Rest AC

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44 Filtering BPF BT 0.2;5 BT 0.5;5 Limiti Aumento del rumore Apparente ispessimento della parete miocardica Body-contour non sempre compensa gli algoritmi di ricostruzione Zoccarato O

45 Filtering iterativo Vantaggi Compensazione per non stazionarietà della risposta del collimatore Modellizzazione dell emissione e del rumore Corregge per la variazione della distanza paziente detector modellando sia orbite fisse che variabili Indipendente dall operatore Incorpora le mappe di attenuazione (in progress) Zoccarato O

46 Left Ventricle iterative Filtering Iterativo Resolution Recovery BPF Right Ventricle TOF surgical corrected TGA Arterial Switch CMD HPG23 Bergamo

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48 D-SPECT D-SPECT

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50 Quantification Blood flow and Coronary Reserve 4 min D-SPECT 6 min CdZnTe [detector] 16 min SPECT 24 min Dynamic-SPECT Time activity curves LAD #6 : 75% occlusion FFR=0.86

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52 Improvement in PET myocardial perfusion image quality and quantification with flurpiridaz F 18 Daniel S. Berman, MDGuido Germano, PhDand Piotr J. Slomka, PhD J Nucl Cardiol 2012 resolution recovery in the reconstruction technique and correction for Respiratory and cardiac motion.

53 Why Nuclear Cardiology? accuracy of diagnosis FN, FP prognostic evaluation monitoring therapy efficacy unnecessary invasive procedure

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55 SPECT + MSCT

56 Noninvasive assessment myocardial viability: Current status and future directions Kevin C. Allman, MBBS, FRACP, FACC, FCSANZ, FAANMS, FASNC Sydney JNC june2013 CMR shows subendocardial anterior wall and apical enhancement. Fusion Imaging reduced metabolic uptake at these sites on FDG PET

57 The decision whether cardiac imaging is reasonable or not should be based on how the information gained will influence subsequent patient care and patient outcomes including health status and survival. Patel MR, Spertus JA, Brindis RG, et al. ACCF proposed method for evaluating the appropriateness of cardiovascular imaging. J Am Coll Cardiol. 2005;46:

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59 2012 CHANGING PATTERNS OF APPROPRIATENESS Impact of Education (n=862) ,0% 10,0% 5,0% 12,0% Appropriate Uncertain Inappropriate 76,0% 85,0% Ayyad et al AHA 2007

60 Nuclear Cardiology Imaging >>>>> Clinical data Clinical Stress Test Decision Making Imaging Final Report

61 Technologists as students Do exist any priorities for technologists? excellent diagnostic patient care development of the department and hospital as a whole teaching and developing others in the field ALL techs experience ongoing learning and receive education from : physicians, techs, program directors, PhDs, secretaries and patients so we re what we ve been taught Technologists teaching patients Technologists as teachers MOST techs were not trained to teach. teaching is but one facet of their job function SOME techs present scientific lectures techs perform diagnostic procedures on patients must provide information about radiation, NM procedure at hand to gain inform consent Some patients may want to be instructed beyond the boundaries of techs education or responsibility: scan results.

62 v'rybody's talking about agism, Shagism, Dragism, Madism, Ragism, Tagism >> SPECT, PET his-ism, that-ism, is-m, is-m, is-m. l we are saying is give peace a chance l we are saying is give peace a chance mon v'rybody's talking about Ministers, nisters, Banisters and canisters shops and Fishops and Rabbis and Pop eyes, nd bye bye, bye byes. l we are saying is give peace a chance Give Nuclear Cardiology. more than a chance!

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64 X V I C O R S O D I A G G I O R N A M E N T O G I C N GICN 2015 GruppoItaliano di CardiologiaNucleare XVI Corso di Aggiornamento Lucca 5-7 novembre 2015