Background: Myocardial blood flow (MBF) and flow reserve (MFR) examination, especially useful in the diagnosis of multivessel coronary artery disease (CAD), can be assessed with a cadmium-zinc-telluride (CZT) SPECT gamma camera, as an alternative to the expensive and less available PET. However, study processing is not free from subjective factors. Therefore, this paper aims to evaluate intra- and interobserver repeatability of MBF and MFR values obtained by the same operator and two independent operators. Methods: This study included 57 adult patients. MBF and MFR were assessed using a Discovery NM530c camera in a two-day, rest/dipyridamople protocol, using 99mTc-MIBI. Data were processed using Corridor4DM software, twice by one operator and once by another operator. Results: The repeatability of the assessed values was quite good in the whole myocardium, LAD and LCX vascular territories, but was poor in the RCA territory. Conclusions: The poor repeatability of MBF and MFR in RCA vascular territory can be explained by poor automatic orientation of the heart axis during post-processing and a so-called “cardiac creep” phenomenon. Better automatic heart orientation and introduction of automatic motion correction is likely to drastically improve this repeatability. In the present state of the software, PET is better for patients requiring assessment of MFR in the RCA territory.

No abstract

This paper presents a review of the literature concerning the clinical application of modern semiconductor (CZT) gamma cameras in the radioinuclide diagnosis of coronary artery disease. It contains information on the diagnostic efficacy of myocardial perfusion studies performed with those cameras compared with the widely used scintillation (Anger) cameras, an overview of their effectiveness in comparison with coronary angiography (also fractional flow reserve) and currently available clinical results of a myocardial flow reserve measured with a dynamic SPECT study. Introduction of this imaging modality to the measurement of a myocardial flow reserve aims to facilitate access to this type of study compared to the less available and more expensive PET method used so far.

Background Speckle tracking echocardiography (STE) may be useful for the detection of subclinical systolic function abnormalities. Dynamic acquisition of myocardial blood flow using 99mTc-MIBI SPECT-CZT gamma camera allows the calculation of coronary flow reserve (CFR). Purpose The aim of our study is to assess the relationship between left ventricular longitudinal strain (LS) and CFR in patients with suspected coronary artery disease (CAD). Methods 55 patients (pts) (43.6% females, mean age 64.6±8.4 years) with suspected CAD underwent transthoracic echocardiography with assessment global and local LS by STE. We calculated mean global left ventricular LS (GLS), as well as LS of individual coronary artery territories (LAD LS, LCx LS and RCA LS). All pts underwent myocardial perfusion study with novel solid-state CZT nuclear camera (dipyridamole stress protocol). We measured CFR of the left ventricle and individual coronary territories. Results Mean absolute GLS in pts with total CFR <2 was significantly lower than in pts with CFR >2 (median value −13.9 vs −18.3; p<0.001). Similar differences were observed in all three coronary territories (p≤0.01). Modest but significant correlations were detected between total CFR and GLS values (r=−0.56; p<0.001), LAD CFR and LAD LS (r=−0.54; p<0.001), RCA CFR and RCA LS (r=−0.36; p=0.007), LCx CFR and LCx LS (r=−0.53; p<0.001). GLS at rest had good diagnostic value for detecting total CFR <2 (AUC=0.767; p<0.001). The criterion with the highest diagnostic accuracy was GLS > (−15.8) – its sensitivity was 68%, specificity 77.7%, and overall accuracy 73%. Conclusions Indices of left ventricular longitudinal function obtained by speckle tracking echocardiography correlate with SPECT-derived CFR in patients with suspected CAD. FUNDunding Acknowledgement Type of funding sources: None.