Diagnostic Efficacy of Exercise Tc - 99m Tetrofosmin SPECT in Patients with Coronary Artery Disease / 대한내과학회지

OBJECTIVES: Tetrofosmin is a new Tc-99m labeled myocardial perfusion imaging agent that shows slow clearance from the myocardium and rapid clearance from background organs. The purpose of this study was to assess the ability of exercise Tc-99m tetrofosmin single photon emission computed tomography(SPECT) to identify and localize coronary artery disease. METHODS: The study population consists of 49 patients with suspected coronary artery disease who underwent both exercise Tc-99m tetrofosmin SPECT and coronary angiography within 2 weeks. Using the one day imaging protocol, 7-10mCi of Tc-99m tetrofosmin was injected at rest and 4 hours later, 25 mCi of Tc-99m tetrofosmin was injected at peak exercise. RESULTS: The sensitivity and specificity of exercise Tc-99m tetrofosmin SPECT was 94.9% and 60% for detection of coronary artery disease with luminal narrowing more than 50%, and 96.4% and 33.3% for detection of coronary artery disease with luminal narrowing more than 70%. The sensitivity of exercise Tc-99m tetrofosmin SPECT for detection of individual stenosed vessels(>or=50% and >or=70% coronary stenosis) was 79.2%, 100% for LAD, 55.6%, 55.6% for LCx and 85.0%, 92.9% for RCA and the specificity was 88.0%, 75.0% for LAD, 100%, 87.5% for LCx, 86.2%, 77.1% for RCA respectively. CONCLUSION: Exercise Tc-99m tetrofosmin SPECT appears to be an feasible and useful noninvasive test for the diagnosis of coronary artery disease

On-Line Assessment of Left Ventricular Cavity Area and Function by Automatic Border Detection Echocardiography

BACKGROUND: Assessment of left ventricular function with conventional 2-dimensional echocardiography (2D echo) remains largely qualitative and subjective because the manual tracing of endocardial borders is laborious and tedious. An automatic border detection (ABD) echo has been recently developed that permits real-time measurements of chamber areas and cardiac function. METHODS: To determine usefulness of ABD echo, left ventricular cross-sectional areas were automatically measured from the parasternal short-axis image in 25 cases including 9 cardiac patients, and compared with those by off-line analysis of the conventional 2D echo image. RESULTS: In on-line ABD analysis, short axis end-diastolic area averaged 13.1+/-2.2cm2, end-systolic area 5.3+/-1.3cm2 and fractional area change 59.4+/-9.0% and off-line manual analysis yielded corresponding values of 14.7+/-2.5cm2, 6.2+/-1.3cm2, and 57.1+/-7.1%. The end-diastolic and end-systolic areas by both methods were significantly different, respectively. Left ventricular end-diastolic and end-systolic area and fractional area change obtained from ABD echo correlated significantly with those of off-line measurements(r=0.897, p<0.001 ; r=0.505, p<0.01 ; r=0.427, p<0.05). CONCLUSION: Thus, these facts suggest that ABD echo is useful for on-line continuous measurement of chamber areas and cardiac function.