Thallium-201 right lung/heart ratio during exercise in patients with coronary artery disease: relation to thallium-201 myocardial single-photon emission tomography, rest and exercise left ventricular function and coronary angiography

Abstract

The aim of this study was to correlate lung thallium-201 uptake on exercise with 201Tl single-photon emission tomography (SPET) myocardial perfusion imaging, rest and exercise equilibrium radionuclide angiographic and coronary angiographic findings in patients with coronary artery disease (CAD) using a simple, reproducible lung/heart (L/H) ratio that would be easy to use in clinical practice. L/H ratio was defined on the anterior planar image obtained during exercise 201Tl SPET acquisition as the mean counts per pixel in an entire right lung field region of interest divided by the mean counts per pixel in the hottest myocardial wall region of interest. We studied 103 patients. Fifty-nine patients (group I) with <5% likelihood of CAD were used as a reference group. In 44 CAD patients (group II), L/H ratio was compared with 201Tl SPET, radionuclide angiographic and coronary angiographic variables. The group I L/H ratio of 0.35+/-0.05 (mean +/-1 SD) was significantly lower (P<0.001) than the group II L/H ratio of 0. 45+/-0.10. An L/H ratio >0.45 (mean + 2 SD in group I) was considered abnormal. In group II, L/H ratio showed a significant correlation with stress and rest 201Tl perfusion defect size (r = 0. 39 and r = 0.42, P<0.01, respectively), but not with extent of ischaemic myocardium. The mean L/H ratio was 0.41+/-0.10 in patients with one-vessel disease (n = 15), 0.46+/-0.08 in those with two-vessel disease (n = 17) and 0.47+/-0.12 in those with three-vessel disease (n = 12), but no significant difference was found between the three subgroups. L/H ratio showed a significant inverse relation with rest and exercise left ventricular ejection fraction (r = -0.37 and r = -0.50, P<0.05 and P<0.001, respectively). Using stepwise multiple regression analysis, exercise left ventricular ejection fraction and previous history of hypertension were the sole two variables independently predictive of the L/H ratio. In conclusion, although lung thallium uptake is usually found to correlate with extent and severity of CAD, increased L/H ratio should primarily be considered as a marker of exercise-induced left ventricular systolic and perhaps diastolic dysfunction, probably independent of the underlying cardiac disease.

Optimized, Automated Striatal Uptake Analysis Applied to SPECT Brain Scans of Parkinson's Disease Patients

“…These ROIs do not assume a predefined volume for each structure and, in the case of the caudate and putamen, measure the maximum uptake of the structure. For cardiac applications (27,28), a method of measuring the hottest pixel with radiotracer techniques has been shown to be a reproducible and accurate way to evaluate physiologic function and is less prone to partial-volume effects resulting from the complex spatial geometry of the striatum or atrophic changes.…”

Clinical Significance of Tetrofosm in Extracardiac Uptake During Myocardial Perfusion Imaging

“…Abnormal pulmonary Tl-201 uptake during stress (treadmill or pharmacologic test) imaging has similar clinical significance to that noted during exercise. Thus, high uptake of Tl-201 in the lungs has an important prognostic value (Brown, 1997;Chin et al, 1996;Daou et al, 2000;Gill et al, 1987;Morel et al, 1999). Moreover, published data present an incremental prognostic value of increased Tl-201 pulmonary uptake over clinical, stress testing and other imaging findings, providing clinically useful risk assessment (Marcassa et al, 2000).…”

“…For Tl-201, LHR upper normal limits range in the literature from approximately 0.37 to 0.55 (Georgoulias et al, 2010a). Increased exercise Tl-201 uptake is associated with decreased left ventricular function, the presence of multiple-vessel CAD, and poor patient prognosis (Brown, 1997;Chin et al, 1996;Daou et al, 2000;Gill et al, 1987;Kurata et al, 1991;Morel et al, 1999). Kurata et al have found that patients with abnormal Tl-201 lung uptake had more extensive multiple-vessel CAD, more severe left ventricular dysfunction, and more perfusion defects than did patients with normal Tl-201 pulmonary activity (Kurata et al, 1991).…”

Sensitivity and specificity of stress cardiac gated SPECT imaging in the detection of coronary artery disease: validation of findings by coronary angiography.

“…), je nepřímou známkou dysfunkce levé komory srdeční a pojí se s vyšším rizikem kardiální příhody. (11,12) V současné éře stále častějšího užití 99m Tc značených radiofarmak (MIBI a tetrofosmin) však přicházíme o možnost zjištění plicní koncentrace radiofarmaka. Máme však k dispozici další důležitý parametr -poměr tranzientní ischemické dilatace (TID), který je kalkulován z "ungated" obrazů perfuze jako poměr velikosti dutiny levé komory po zátěži a v klidu.…”