Photon count, image resolution, and contrast-detail detection potential of SPECT

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

OSTI ID:5873040

Lim, C B; Kim, K I; King, S E

A detectable lesion or picture element in a noisy image is specified by its area size and contrast. Lesion detection in an image is determined by the ratio of its image contrast and the relative statistical noise the background defined over the equivalent size area. The SPECT resolution is formed by the detector and reconstruction resolutions. Scatter photons affect local background level. The SPECT image pixel noise relative to the background level is proportional to the three halves power of the linear sample number spanning the object and inversely to the square root of the total photon count. This analysis reveals that the detectable lesion size splits into the photon-limited region and the resolution-limited region divided by the resolution distance. For a 20 cm diameter object with the S/N ratio K=3.5, FWHM=10 mm, SF=30% for 10% ER and 20% EW, the detectable lesion sizes of object contrast .5 are 35 mm, 23 mm, 17 mm and 14 mm respectively for the total counts 50K, 200K, 800K, and 3.2M. This trend potentially suggests a new collimator design criteria for SPECT imaging from lesion detectability standpoint depending on the specific photon availability in clinical procedures.

• Research Organization: Technicare Corp., Solon, OH
• OSTI ID: 5873040
• 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

550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
61 RADIATION PROTECTION AND DOSIMETRY
62 RADIOLOGY AND NUCLEAR MEDICINE
655003 -- Medical Physics-- Dosimetry
COLLIMATORS
COMPARATIVE EVALUATIONS
COMPUTERIZED TOMOGRAPHY
COUNTING RATES
DESIGN
DIAGNOSTIC TECHNIQUES
EMISSION COMPUTED TOMOGRAPHY
IMAGE PROCESSING
MATHEMATICAL MODELS
PERFORMANCE
PROCESSING
RESOLUTION
SENSITIVITY
SIGNAL-TO-NOISE RATIO
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
TOMOGRAPHY