Impact of point spread function modeling and time-of-flight on myocardial blood flow and myocardial flow reserve measurements for rubidium-82 cardiac PET

Abstract Purpose The aim of this study was to assess the most reliable quantitative variable on Rubidium-82 (82Rb) cardiac PET/CT for predicting major adverse cardiovascular events (MACE), on the latest PET camera using silicon photomultipliers digital readout (SiPM) technology. Methods We prospectively enrolled 274 consecutive participants with suspected myocardial ischemia. Participants underwent 82Rb cardiac SiPM PET/CT and were followed-up for MACE over 652 days (interquartile range: 559 to 751 days). For each participant, global and regional myocardial flow reserve (MFR), stress myocardial blood flow (stress MBF) and their combination as myocardial flow capacity radius (MFC radius) were measured. Results On receiver operator curve analysis, MACE prediction was similar for global and regional MFR, stress MBF, and MFC radius (area under the curve; (i) Global: 0.70 vs. 0.71 and 0.73, and (ii) Regional: 0.71 vs. 0.71 and 0.73, respectively, p > 0.1 for all pairwise comparisons). On multivariable analysis, (i) Global: MFR < 1.98, stress MBF < 1.94 mL/g/min, and MFC radius < 3.12, as well as (ii) Regional: MFR < 1.75, stress MBF < 1.75 mL/g/min, and MFC radius < 2.7, emerged all as similar independent predictors of MACE (p < 0.001 for all). Conclusions Using the latest SiPM PET technology with 82Rb, global and regional MFR, stress MBF, and MFC radius are similar powerful predictors of cardiovascular event.

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Entropy-based myocardial blood flow measurements using PET: a way to improve reproducibility

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeab111.066 ◽

2021 ◽

Vol 22 (Supplement_3) ◽

Author(s):

J Van Dalen ◽

SS Koenders ◽

BN Vendel ◽

PL Jager ◽

JD Van Dijk

Keyword(s):

Blood Flow ◽

Myocardial Blood Flow ◽

Flow Parameter ◽

Myocardial Flow Reserve ◽

Flow Measurements ◽

Shannon's Entropy ◽

Flow Reserve ◽

The Mean ◽

Myocardial Flow ◽

Rubidium 82

Abstract Funding Acknowledgements Type of funding sources: None. Background and purpose Myocardial blood flow (MBF) measurements using PET are increasingly used to guide the management of patients with (suspected) coronary artery disease (CAD). Day-to-day variability of these measurements is poor with a 21% standard deviation or 40% 95%-confidence interval [Reference: JACC Cardiovasc Imaging, 2017;10(5):565]. This limits clinical applicability in diagnosis, risk stratification and follow-up as these all depend on comparison of flow values with fixed cut-off values. We expect that reproducibility can be improved by combining flow measurements with the variation of flow values within the myocardium. As entropy is a measure of variability of the associated distribution, we compared the reproducibility of an entropy-based flow parameter with that of conventional myocardial flow reserve (MFR) measurements. Methods We performed a study using intra-individual comparison in 24 patients who underwent rest and regadenoson-induced stress myocardial perfusion imaging using Rubidium-82 on two different PET systems (PET1: Discovery 690, GE Healthcare, and PET2: Vereos, Philips Healthcare) within 3 weeks. MBF for both rest and stress was calculated using Lortie’s one-tissue compartment model (Corridor4DM, INVIA). MFR (ratio of MBF stress/rest) was determined for the myocardial as a whole (MFRglobal), for the three vascular territories: LAD, LCX and RCA (MFRregional) and for the 17 segments. Next, we calculated Shannon’s entropy to measure the variation of the 17 MFR segmental values. We multiplied Shannon’s entropy by the mean of the MFR segmental values resulting in an entropy-based MFR (MFRentropy). For each patient MFRglobal, MFRregional and MRFentropy were compared between both PET systems. For each of the three parameters the test-retest precision was calculated as the SD of the relative difference between measurements. Results The mean difference in MFR measurements between both cameras did not differ from zero (p > 0.05). Mean values for PET1 were MFRglobal = 2.4, MFRregional = 2.4 (LAD), 2.4 (LCX) and 2.5 (RCA), and MFRentropy = 2.4. For PET2 we found MFRglobal = 2.5, MFRregional = 2.5 (LAD), 2.4 (LCX) and 2.6 (RCA), and MFRentropy = 2.5. Test-retest precision was lower for MFRentropy with 11% compared to that of MFRglobal (21%), MFRregional LAD (22%), MFRregional LCX (23%) and MFRregional RCA (24%) (p < 0.01). Conclusion The reproducibility of myocardial flow reserve measurements using Rubidium-82 PET improved by a factor of 2 when an entropy-based flow parameter instead of global or regional MFR parameters is used. This entropy-based flow-parameter may be used to better discriminate ischemia from non-ischemia and may therefore improve CAD management.

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Reduced myocardial flow reserve in anatomically normal coronary arteries due to elevated baseline myocardial blood flow in men with old myocardial infarction

Journal of Nuclear Cardiology ◽

10.1067/mnc.2002.119687 ◽

2002 ◽

Vol 9 (1) ◽

pp. 62-67 ◽

Cited By ~ 3

Author(s):

K Yonekura

Keyword(s):

Myocardial Infarction ◽

Blood Flow ◽

Myocardial Blood Flow ◽

Coronary Arteries ◽

Myocardial Flow Reserve ◽

Normal Coronary Arteries ◽

Flow Reserve ◽

Old Myocardial Infarction ◽

Myocardial Flow

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Evaluation of Myocardial Blood Flow and Myocardial Flow Reserve by Radionuclide Imaging

Nuclear Cardiology ◽

10.1007/978-3-030-62195-7_3 ◽

2021 ◽

pp. 107-123

Author(s):

Raffaele Giubbini ◽

Elisa Milan

Keyword(s):

Blood Flow ◽

Myocardial Blood Flow ◽

Radionuclide Imaging ◽

Myocardial Flow Reserve ◽

Flow Reserve ◽

Myocardial Flow

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Discordance between invasive coronary flow reserve (CFR) and non-invasive myocardial flow reserve (MFR) in diffuse coronary ectasia (DCE)

BJR|case reports ◽

10.1259/bjrcr.20190046 ◽

2020 ◽

Vol 6 (2) ◽

pp. 20190046

Author(s):

Mohammed Khalil ◽

Deniz Alibazoglu ◽

Cem Numan Balci ◽

Rawan Hussein ◽

Abraham Abuwadi ◽

...

Keyword(s):

Blood Flow ◽

Coronary Artery ◽

Myocardial Blood Flow ◽

Suspected Coronary Artery Disease ◽

Myocardial Flow Reserve ◽

Total Occlusion ◽

Flow Reserve ◽

Stress Myocardial Blood Flow ◽

Coronary Ectasia ◽

Myocardial Flow

Clinical use with evidence base for diagnostic and prognostic value of quantitative positron emission tomography(PET) myocardial perfusion imaging (MPI) in patients with known or suspected coronary artery disease has exponentially increased over the last decade. This case illustrates the very first time that stress myocardial blood flow(MBF) in absolute terms (ml/min/gram) and myocardial flow reserve(MFR) are augmented in three vessel diffuse coronary ectasia by N13-Ammonia PET MPI. Moreover, relative qualitative MPI demonstrated moderate-sized ischemia in right coronary artery territory with chronic total occlusion in middle segment; despite regional myocardial flow reserve remains above ischemic thresholds while regional stress myocardial blood flow is mildly reduced.

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