ABC | Volume 111, Nº4, Octuber 2018

Case Report Souza et al Coronary flow reserve in CZT gamma camera Arq Bras Cardiol. 2018; 111(4):635-637 Figure 1 – Evaluation of patient with suspected CAD. A) MPS showing small area of inferolateral ischemia. B and C) Time-activity curves in stress and rest phases, respectively, derived from the dynamic acquisition in CZT gamma camera. D, E, and F)Angiographic images showing 90% lesion in anterior descending artery, 75% lesion in circumflex artery and 50% in the middle third of right coronary artery, with 90% obstruction in posterior ventricular branch. G) Overall results of MBF quantification (in ml/min/g) and CFR in coronary territories (anterior descending artery, circumflex artery, and right coronary artery, respectively), followed by total values (last line). Reduced values of MBF and CFR are seen in all territories, which is compatible with the obstructive lesions found in coronary angiography. CAD: coronary artery disease; MPS: myocardial perfusion scintigraphy; MBF: myocardial blood flow; CFR: coronary flow reserve. in women and patients with metabolic syndrome. Previous PET studies have shown that CFR measurement can classify patients at low and high risk for cardiovascular events 9 and therefore be used as a new tool for risk stratification. New gamma cameras with solid and stationary CZT detectors have advantages when compared to traditional ones, with sodium-iodide detectors, as they allow for dynamic tomographic images and, theoretically, CFR quantification. Wells et al. 6 , in a pioneeringwork, have demonstrated a precise CFR quantification in a porcinemodel of resting and transitory occlusion upon stress using CZT gamma camera, paving the way for new possibilities of pilot studies with humans. Bouallègue et al. 7 evaluated CFR in 23 patients in comparison to their angiographic data, including fractional flow reserve (FFR), and found a good correlation between CFR and the number of obstructed vessels and reduced CFR values in obstructed territories. As seen in the present report, CFR quantification and the new methods of dynamic acquisition of myocardial blood flow constitute a current field of research that could generate knowledge about new applications of scintigraphy and bring improvements to diagnosis and management of coronary disease patients, including those with multivessel disease. Author contributions Conception and design of the research: Lima RSL; Acquisition of data: Souza ACAH, Gonçalves BKD, Tedeschi A, Lima RSL; Analysis and interpretation of the data, Statistical analysis and Writing of the manuscript: Souza ACAH; Critical revision of the manuscript for intellectual content: Tedeschi A, Lima RSL, Gonçalves, BKD. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding There were no external funding sources for this study. Study Association This article is part of the PhD project of Ana Carolina do Amaral Henrique de Souza at Universidade Federal do Rio de Janeiro. 636