Improved coronary disease detection with quantitative attenuation-corrected Tl-201 images

• Published in: Journal of nuclear cardiology 2002-01, Vol.9 (1), p.52-62
• Main Authors: Shotwell, Mathew, Singh, Balkrishna M., Fortman, Charlotte, Bauman, Brian D., Lukes, Jennifer, Gerson, Myron C.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Cardiovascular disease; Coronary Angiography; Coronary Stenosis - diagnostic imaging; Coronary vessels; Dipyridamole; Exercise Test; Female; Humans; Image Processing, Computer-Assisted - methods; Male; Middle Aged; Prospective Studies; Reference Values; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon - instrumentation; Tomography, Emission-Computed, Single-Photon - methods
• ISSN: 1071-3581; 1532-6551
• DOI: 10.1067/mnc.2002.119252

Background. The normal distribution of myocardial tracer activity is different in attenuation-corrected images compared with uncorrected images. We therefore postulated that quantitation of attenuation-corrected thallium 201 images with direct comparison to a database of healthy subjects could improve detection of coronary artery stenoses. Methods and Results. In 49 patients with angiographic evidence of coronary artery disease and 69 patients with a less than 5% likelihood of coronary artery disease, tomographic Tl-201 myocardial imaging was performed by means of a triple-headed camera with fan-beam collimators and the images were processed with attenuation correction, with attenuation and Compton scatter correction, and without correction. Images were subjectively interpreted in a blinded manner. From the group of 69 patients with a low likelihood of coronary disease, scintigraphic data from the first 20 men and the first 20 women were used to generate normal reference ranges for each of the 3 image-processing methods. Data from the 49 patients with angiographic coronary disease and from the remaining 29 patients with a low likelihood of coronary disease were then analyzed quantitatively in comparison to the gender-matched normal databases. With visual interpretation, attenuation-corrected images yielded an improved detection rate compared with uncorrected images (79% vs 46%, P = .008) for 70% or greater left anterior descending coronary artery stenoses. Attenuation-corrected images also provided an improved normalcy rate for the right coronary artery territory (91% vs 75%, P = .006) and an improved normalcy rate when the images were analyzed overall by patient (88% vs 74%, P = .009). With quantitative analysis, attenuation correction yielded an improved detection rate for patients with a significant coronary artery stenosis compared with uncorrected images (90% vs 71%, P = .016). Defect extent was also increased by attenuation correction. Compared with attenuation correction alone, the addition of scatter correction yielded no incremental improvement in detection rate or normalcy rate. Attenuation-scatter correction did produce a nonsignificant trend toward detection of more of the total number of stenotic arteries compared with uncorrected images (60 vs 48 of 79 arteries). Conclusions. With the use of a triple-headed camera with fan-beam collimation, visual analysis of attenuation-corrected Tl-201 images improved detection of left anterior descending c