Objective Myocardial perfusion imaging (MPI) by gated single-photon emission computed tomography (SPECT) is a feasible method in the evaluation of left ventricular perfusion and function. The purpose of this study was to determine the threshold and grading of left ventricular (LV) diastolic dysfunction (LVDD) using gated SPECT MPI. Methods A total of 149 patients were recruited in the study. All of the patients underwent a standard 2-day stress/rest gated MPI study and transthoracic echocardiography within 2 weeks. The reconstructed rest-only images were analyzed by Cedar-Sinai’s quantitative gated SPECT and the LV diastolic parameters, including peak filling rate (PFR), time to PFR (TTPF) and secondary PFR (PFR2) to PFR ratio were provided and compared to echocardiographic data. Results 68 (45.6%) and 81 (54.4%) of patients were categorized in LVDD-absent and LVDD-present groups on the basis of LVDD evidence in echocardiography, respectively. receiver-operating-characteristic analysis for PFR and TTPF was performed, resulting in diagnostic sensitivities of 70 and 57% and specificities of 60 and 75% for PFR <2.6 end-diastolic volumes (EDV)/s and TTPF>160.5 ms, respectively. Applying our previously used thresholds of <1.70 EDV/s for PFR, >208 ms for TTPF and >1 for PFR2/PFR, sensitivities and specificities of 9.9 and 96.6%, 9.9 and 95.6% and 13.8 and 88% were resulted, respectively. Grading of LVDD on the basis of MPI-obtained diastolic parameters showed considerable overlapping data by interquartile range. Conclusion Gated SPECT MPI can be used as a highly specific means for detection of LV diastolic dysfunction when compared to echocardiography. However, grading of severity of diastolic heart failure appears to be impracticable.

Quantitative analysis of myocardial perfusion Single photon emission computerized tomography (SPECT) images is increasingly applied in modern nuclear cardiology practice, assisting in the interpretation of myocardial perfusion images (MPI). There are different extensively validated state-of-the-art software packages, including QPS (cedars-Sinai), Corridor 4DM (University of Michigan) and Emory cardiac toolbox (Emory university), providing highly accurate and reproducible data. However, these software packages may suffer from potential artifacts related to patient or technical factors. By recognizing the source of such artifacts, the interpreting physician can avoid misinterpretation of MPI study. In this review, we discuss some of technical pitfalls that may occur in Quantitative Perfusion SPECT software (QPS, cedars-Sinai Medical center).

The coronavirus disease is due to Acute Respiratory Syndrome Coronavirus2 (SARS-CoV-2). COVID-19 mainly affects the respiratory and immune systems and other organs like the cardiovascular and nervous systems, lungs, and kidneys (1). Several studies have reported COVID-19 patients with persistent symptoms for months after the initial phase. The most common symptoms are fatigue, headaches, cough, anosmia, arthralgia, and chest pain (2). Studies have shown this modality to diagnose, follow up, and evaluate response to treatment in chronic COVID-19 complications using 99mTc-MIBI myocardial perfusion single photon emission computed tomography (SPECT), pulmonary involvement with  99mTc-MAA perfusion lung scan, renal involvement with 99mTc-DTPA, and 99mTc-DMSA renal scintigraphy (3). Myocardial perfusion imaging with 99mTc-MIBI provides meaningful data to predict prognosis, risk of annual cardiac events, and evaluation of myocardium viability (4). Conventional SPECT Myocardial Perfusion Imaging (MPI) needs a viable metabolically active myocardial cell to extract the radiotracer. A review of articles shows that 99mTc-MIBI myocardial perfusion scintigraphy could be helpful in the timely acute myocardial infarction (MI) diagnosis and myocardial viability in COVID-19 patients. It is also beneficial in managing COVID-19 patients with heart failure by myocardial injury evaluation and choosing the best therapeutic choice, prognosis, and treatment response.