Orbit-related variation in spatial resolution as a source of artifactual defects in thallium-201 SPECT

Journal Article · Wed May 01 04:00:00 EDT 1991 · Journal of Nuclear Medicine; (USA)

OSTI ID:5544993

Maniawski, P J; Morgan, H T; Wackers, F J ^[1]

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1. Yale Univ. School of Medicine, New Haven, CT (USA)

The cause of 180-degree diametrical artifactual defects in clinical thallium-201 SPECT imaging was investigated using phantom simulation. This artifact was observed on SPECT images acquired with a 'body contour' or 'peanut' orbit. It was hypothesized that this artifact was caused by differences in spatial resolution that occur when the heart-to-detector distance changes employing noncircular orbits. To test this hypothesis, a series of planar static images of a normal cylindrical phantom was obtained at varying distances from the camera detector head. From these images, tomographic acquisition files were created that simulated tomographic data acquired with circular orbits and elliptical orbits. The reconstructed phantom short-axis slices showed no artifacts for circular orbits. However, for various elliptical orbits, significant regional nonuniformity, similar to the artifacts noted in patients, was observed. The degree of nonuniformity correlated with the long-short axis ratio of elliptical orbits (r = 0.98). In addition, circular orbits with the phantom in an eccentric position resulted in similar nonuniformities. It is concluded that a noncircular tomographic orbit can create characteristic artifacts on thallium-201 SPECT images. For rotational thallium 201 SPECT, a circular orbit with the heart in the center of rotation should be employed.

• OSTI ID: 5544993
• Journal Information: Journal of Nuclear Medicine; (USA), Journal Name: Journal of Nuclear Medicine; (USA) Vol. 32:5; ISSN 0161-5505; ISSN JNMEA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
BETA DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
COMPUTERIZED TOMOGRAPHY
COUNTING TECHNIQUES
DATA COVARIANCES
DAYS LIVING RADIOISOTOPES
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
EMISSION COMPUTED TOMOGRAPHY
HEART
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MOCKUP
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PHANTOMS
RADIOISOTOPE SCANNING
RADIOISOTOPES
RESOLUTION
SCINTISCANNING
SECONDS LIVING RADIOISOTOPES
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
SPATIAL RESOLUTION
STRUCTURAL MODELS
THALLIUM 201
THALLIUM ISOTOPES
TOMOGRAPHY