Axial resolution and the value of interpolating scan in multislice positron computed tomography

Conference · Wed May 01 04:00:00 EDT 1985 · J. Nucl. Med.; (United States)

OSTI ID:7031531

Senda, M; Yonekura, Y; Tamaki, N; Tanaka, Y; Komori, M; Minato, K; Torizuka, K

The authors have calculated the aperture function of a positron computed tomograph (PCT) with computer simulation and evaluated both theoretically and experimentally the axial resolution of a multislice PCT, Positologica III, which has 7 slices at the interval of 16mm. The axial point spread function (PSF) was approximately a triangle at or near the center of the field and the sensitivity for the slice decreased significantly as the source moved away off the image plane. Accordingly there are low sensitivity areas between an in-plane and the adjacent cross-plane. In experiments using a myocardial phantom, a small myocardial defect of 1cm diameter could not be detected when dropped into the gap between slices, although the machine had sufficiently high resolution to deliniate it if it was on the image plane. When long-axis images of the ''myocardium'' were reconstructed three-dimensionally from the images obtained in single object position, the ''inferior wall'' dropped into the gap and disappeared. In clinical myocardial scan with N-13 labeled ammonia in a normal volunteer, a false positive defect appeared in the inferior wall. However, when the object is slided half the slice interval to perform the ''interpolating'' scan and the two sets of images were interlaced with each other, no artifacts appeared. These results have suggested that the invisible regions between slices may be clinically significant if the object is thin enough in z-axis. In order to fill up the gaps between slices, it is valuable to perform the interpolating scan.

• Research Organization: Kyoto Univ., Kyoto
• OSTI ID: 7031531
• Report Number(s): CONF-850611-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 26:5
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
COMPUTERIZED SIMULATION
COMPUTERIZED TOMOGRAPHY
COUNTING TECHNIQUES
DIAGNOSTIC TECHNIQUES
EMISSION COMPUTED TOMOGRAPHY
EVALUATION
FUNCTIONS
IMAGE PROCESSING
IMAGES
POSITRON COMPUTED TOMOGRAPHY
PROCESSING
RESOLUTION
SENSITIVITY
SEQUENTIAL SCANNING
SIMULATION
TOMOGRAPHY