Quantitative Tc-99m myocardial perfusion SPECT with 180[degree] acquisition

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:5346587

Ye, J

Myocardial perfusion single photon emission computed tomography (SPECT) images using 180[degrees] acquisition are degraded by the effects of scatter, nonuniform attenuation and system geometric resolution variation with source depth. Using a 180[degrees] scan orbit which is closer to the heart may provide higher image resolution, signal-to-noise ratio and defect-to-normal contrast than using a 360[degrees] orbit, however, significant object shape distortion has been observed in the 180[degrees] reconstructed images. A method has been developed that combines filtered back-projection (FBP) with iterative attenuation and three-dimensional (3-D) resolution compensation for Tc-99m myocardial perfusion imaging, data. The non-uniform attenuation coefficient distribution is obtained by a quick transmission scan using a flood source and segmentation of the reconstructed transmission image to define areas of significantly different attenuation. A priori attenuation coefficients are assigned to the areas to form the attenuation distribution map. The 3-D correction is accomplished by including both the non-uniform attenuation and depth-dependent resolution variation in the reprojection procedure of an iterative correction algorithm. The method was evaluated with both simulated and experimental data using clinical protocols with a cardiac phantom. A significant improvement in image resolution was observed with line source images was reduced from approximately 10 mm to 7.l5 mm after 7 iterations of the 3-D correction. The contrast of two perfusion defects to the surrounding normally perfused regions was significantly improved with the correction. Significant improvement in uniformity at different positions in the 100% perfused areas in the myocardium was also observed. The normalized root squared error (NRSE) of one transaxial image from the original source distribution in the simulation study was reduced from 0.8 to 0.2 after 5 iterations of the 3-D correction.

• Research Organization: Georgia Inst. of Tech., Atlanta, GA (United States)
• OSTI ID: 5346587
• Country of Publication: United States
• Language: English

Related Subjects

550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
BODY
CARDIOVASCULAR SYSTEM
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
EMISSION COMPUTED TOMOGRAPHY
HEART
MUSCLES
MYOCARDIUM
NOISE
ORGANS
RESOLUTION
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
TOMOGRAPHY