scholarly journals Value of regional myocardial flow measurements using Rubidium-82 PET

2021 ◽  
Vol 22 (Supplement_3) ◽  
Author(s):  
SS Koenders ◽  
JA Van Dalen ◽  
PL Jager ◽  
M Mouden ◽  
CH Slump ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Visual Assessment ◽  
Diagnostic Value ◽  
Myocardial Flow Reserve ◽  
Flow Measurements ◽  
Regional Flow ◽  
Flow Reserve ◽  
Myocardial Flow ◽  
Rubidium 82

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The combination of myocardial blood flow (MBF) measurements using Rubidium-82 (Rb-82) PET and visual assessment of the PET images is increasingly used due to its high diagnostic and prognostic value. Typically, flow measurements are calculated and used for the myocardium as a whole (global). However, small regional flow deficits may go unnoticed when only looking at global flow values. Purpose To compare the diagnostic value of regional and global myocardial flow measurements using Rb-82 PET in the detection of obstructive CAD. Methods  We retrospectively included 1034 patients with no history of coronary artery disease (CAD) referred for rest and regadenoson-induced stress Rb-82 PET/CT. MBFs were calculated using Lortie’s one-tissue compartment model. Myocardial flow reserve (MFR) was calculated as the ratio of MBF during stress and rest. Regional flow was determined per vessel and per segment. Vessel MFR was defined as the lowest flow reserve of LAD, LCX and RCA territories and segmental MFR as the lowest flow reserve in all 17 segments. Follow-up data were obtained from medical records. Patients were classified to have obstructive CAD if follow-up included a positive invasive coronary angiography (ICA), percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) or all cause death. Receiver-operating characteristic (ROC) analyses were constructed to compare the diagnostic value of global and regional flow values. Results Follow-up was obtained in all 1034 patients and the median follow-up time was 2.1 years. Myocardial flow reserve values were significantly lower (p < 0.001) in the 128 patients classified with obstructive CAD than in the 906 patients without obstructive CAD: global MFR  (median 1.9 [interquartile range 1.6-2.4] vs. 2.5 [2.1-2.9]); vessel MFR (1.6 [1.3-2.1]  vs. 2.3 [1.9-2.6]); Segmental MFR (1.3 [0.9-1.7] vs. 1.9 [1.6-2.2]). The area under the curve of vessel MFR (0.79 ± 0.02) and segmental MFR (0.81 ± 0.02) were similar but significantly (p < 0.001) larger than the area of global MFR (0.75 ± 0.03), as shown in the Figure. Conclusion The diagnostic value improved with the use of regional MFR instead of global MFR measurements in the detection of obstructive CAD. Therefore, it seems that visual assessment of PET images can best be combined with regional flow measurements either on a per vessel or a per segment basis in Rubidium-82 PET myocardial perfusion imaging.

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

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.

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

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.

P3354Papillary muscle ischemia and global myocardial flow reserve: assessment by high-resolution cine imaging of 13N ammonia PET

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Nakao ◽  
M Nagao ◽  
M Momose ◽  
N Kasuga ◽  
Y Matsuo ◽  
...  
Keyword(s):  
Coronary Artery ◽  
High Resolution ◽  
Myocardial Ischemia ◽  
Papillary Muscle ◽  
Myocardial Flow Reserve ◽  
Cine Imaging ◽  
Ischemic Group ◽  
Flow Reserve ◽  
Muscle Ischemia ◽  
Myocardial Flow

Abstract Purpose Papillary muscle ischemia (PMI) is caused by micro-vessels' occlusion in the broad endocardium because papillary muscle perfusion is supply from micro-vessels of peripheral coronary arteries and is easy to fail by the increase in peripheral vascular resistance. However, the clinical significant is not understood because PMI could not be detected by existing perfusion imaging such as SPECT and MRI. We propose the detection method of PMI using 13N-ammonia PET (NH3-PET), and investigate the association with the global myocardial flow reserve (Global-MFR) reflecting coronary microvascular dysfunction. Methods Data of adenosine-stress NH3-PET for consecutive 260 patients with coronary artery disease (CAD) or suspected CAD was retrospectively analyzed. Using high-resolution cine imaging derived from NH3-PET, PMI was defined as the absence of the PM accumulation at stress conditions. Myocardial flow was generated from the time activity curve of left ventricle input and myocardial uptake using 3-compartment model and the first 2 minutes' dataset of list mode images. Global-MFR was calculated by stress to rest flow ratio. Summed stress score (SSS) was used as an estimate of the extent of myocardial ischemia. 150 out of 260 patients (58%) with SSS ≥4 or with the past history of coronary artery diseases were classified as ischemic group, and 110 patients (42%) with SSS<4 were classified as non-ischemic group. Results PMI was seen in 68 of 260 patients (26.6%). The frequency of PMI was higher in the ischemic group than the non-ischemic group (37.8% vs. 10.1%, p<0.0001). Global-MFR was significantly lower in patients with PMI than those without (1.87±0.55 vs. 2.39±0.80, p<0.0001). In both ischemic and non-ischemic group, global-MFR was significantly reduced in patients with PMI. (Ischemic group: 1.83±0.56 vs. 2.12±0.52, p=0.0043, Non-ischemic group: 2.06±0.45 vs. 2.63±0.91, p=0.040). Typical case of PMI Conclusion High-resolution cine imaging derived from NH3-PET makes it possible to detect PMI in about a quarter of patients with CAD or suspected CAD. PMI associates with reduced Global-MFR regardless of the presence of myocardial ischemia, suggesting that PMI is an important sign of early ischemia confined to the papillary muscle or the broad microvascular injury.

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