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• Quantification of myocardial blood flow is possible using a cadmium-zinc-telluride (CZT) camera. • Myocardial perfusion reserve is associated with number of coronary artery disease. • Dynamic single-photon emission computed tomography using a CZT camera can identify occult coronary artery disease. Relative myocardial perfusion imaging can misdiagnose "balanced" ischemia caused by coronary artery disease (CAD). We assessed the feasibility of myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) using dynamic single-photon emission computed tomography (SPECT) with a cadmium-zinc-telluride (CZT) camera for estimating underlying CAD in patients with normal stress myocardial perfusion SPECT (MPS). 125 patients with normal stress MPS (summed stress score ≤3) were enrolled. All patients underwent coronary angiography (CAG) and stress/rest 201Tl dynamic SPECT for MBF and MPR calculation. The diagnostic accuracy of both these quantitative values and other clinical risk factors for predicting occult CAD were validated by CAG. MPR was 2.85 in patients with no CAD, 2.47 with 1-, 1.98 with 2-, and 1.76 with 3-vessel CAD. The patient's age, morbidity of diabetes mellitus (DM), chronic kidney disease (CKD), stress MBF, and MPR were significantly associated with the presence of CAD (age, p = 0.02; DM, p = 0.005; CKD, p = 0.005; creatinine level, p = 0.012, stress MBF, p = 0.019, and MPR, p < 0.001). Independent predictors in the multivariate regression analysis were as follows: DM, p = 0.011, CKD, p = 0.028, and MPR, p < 0.001. The combined index was calculated from three independent predictors. Area under the receiver operating characteristic curve was 0.75 for MPR and 0.81 for the combined index. To identify CAD, sensitivity, and specificity for MPR were 77% and 66%, and for the combined index they were 79% and 66%, respectively. Quantification of MPR and MBF using dynamic SPECT with a CZT camera can be useful to identify balanced ischemia caused by occult CAD in patients with normal stress MPS findings. [ABSTRACT FROM AUTHOR]

Background Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disorders. The aim of this study was to examine whether the quantitatively measured myocardial blood flow (MBF) or myocardial perfusion reserve (MPR), calculated by dynamic single photon emission computed tomography (SPECT) analysis using a cardiac cadmium zinc telluride (CZT) gamma camera, was related to renal dysfunction in patients with normal myocardial perfusion imaging (MPI) findings. Methods The study population consisted of 46 patients with CKD and 46 individuals without CKD (controls). Their MPR index was quantitatively measured using adenosine MPI with a cardiac CZT gamma camera. All assessments were with a single tissue compartment kinetic model. The K1 value was calculated on stress and at-rest images. To obtain the MPR index we divided K1 stress-by K1 at-rest values. Results The at-rest K1 value was significantly higher and the MPR index was significantly lower in patients with CKD than those without CKD [CKD vs. controls: at-rest K1 value, 0.21 (0.17–0.25) vs. 0.19 (0.16–0.22), p = 0.040; MPR index, 1.86 (1.69–2.22) vs. 2.19 (1.93–2.41), p < 0.001]. The stress K1 values were not significantly different. Conclusion The MPR index is significantly lower in CKD patients; this is considered as being mainly due to an increase in the at-rest K1 value. [ABSTRACT FROM AUTHOR]