Basic and clinical studies of single photon emission computed tomography of the liver

The value of single photon emission computed tomography (SPECT) in the detection of small space occupying lesions (SOL) was basically and clinically evaluated. Phantom studies based on optimal conditions, including sampling time and attenuation coefficient, revealed that SPECT can detect SOL 1.2 - 1.6 cm in diameter. From clinical studies with 127 patients in whom defect was visualized on SPECT and lesions were confirmed by other methods, the detectability and accuracy of SPECT were 66 % and 83 %, respectively, when images in transaxial, sagittal and coronal planes were combined. False negative rate and false positive rate of SPECT for SOL were 8 % and 24 %, respectively. SPECT visualized SOL larger than 4 cm in diameter in 100 %, SOL 2 - 4 cm in 91 %, and SOL smaller than 2 cm in 40 %. The smallest SOL visualized was 1.5 cm. (Namekawa, K.)