COMPARISON OF 180-DEGREES AND 360-DEGREES DATA-COLLECTION IN TL-201 IMAGING USING SINGLE-PHOTON EMISSION COMPUTERIZED-TOMOGRAPHY (SPECT) - CONCISE COMMUNICATION

  • 1 January 1982
    • journal article
    • research article
    • Vol. 23  (8) , 655-660
Abstract
201Tl imaging using SPECT [single-photon emission computerized tomography] is being done with 180.degree. (RAO[right anterior oblique]-LPO [left posterior oblique]) data collection in some centers with single-.gamma.-camera systems. Using a SPECT system with 2 .gamma.-cameras, the effects of 180.degree. data collection without attenuation correction were compared against 360.degree. collection with attenuation correction, using phantoms and patients. With a heart phantom in a chest phantom, 201Tl activities simulating normal myocardium, ischemia, infarction and background were placed in object contrast ratios (with respect to background) of 5.0, 2.0 and -1.0, respectively. The 180.degree. data gave image contrast ratios of 1.6, 0.2 and -0.8, and the 360.degree. data gave ratios of 1.5, 0.8 and -0.3, respectively. Uniform activity throughout the heart gave similar image contrast with both data-collection methods, but there was more variability with the 180.degree. collection than with 360.degree. collection. Since attenuation correction is available with the 360.degree. collection, the effects of attenuation are seen only on the 180.degree. collection images. In 8 patients the image contrasts from the 180.degree. and 360.degree. collection are similar. For the 2-camera SPECT system, the 360.degree. collection permits attenuation correction, has less variability in counting statistics and gives contrast ratios like those of 180.degree. collection.