Feasibility of dual radionuclide brain imaging with I-123 and Tc-99[ital m]

Journal Article · Sun May 01 00:00:00 EDT 1994 · Medical Physics; (United States)

OSTI ID:7207164

Ivanovic, M; Weber, D A ^[1]; Loncaric, S ^[2]; Franceschi, D ^[1]

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1. Medical Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)
2. Medical Physics, Rush-Presbyterian St. Lukes Medical Center, Chicago, Illinois 60612 (United States)

A study was conducted to evaluate the feasibility of simultaneous dual radionuclide brain imaging with [sup 123]I and [sup 99[ital m]]Tc using photopeak image subtraction techniques or offset photopeak image acquisition. The contribution of the photons from one radionuclide to a second radionuclide's photopeak energy window (crosstalk) was evaluated for SPECT and planar imaging of a brain phantom containing [sup 123]I and [sup 99[ital m]]Tc for a range of activity levels and distribution properties approximating those in rCBF images of the adult human brain. Crosstalk was evaluated for 10% symmetrical energy windows centered on the [sup 123]I and [sup 99[ital m]]Tc photopeaks and for 10% energy windows asymmetrically placed to the left and right of the center of the respective photopeaks. It was observed that the centered photopeak windows, [sup 99[ital m]]Tc crosstalk in the [sup 123]I window is 8.9% of the [sup 99[ital m]]Tc seen in the [sup 99[ital m]]Tc window and ranges from 37.5% to 75.0% of the [sup 123]I in the [sup 123]I window. [sup 123]I crosstalk is 37.8% of the [sup 123]I seen in the [sup 123]I window and ranges from 4.4% to 8.9% of the [sup 99[ital m]]Tc seen in the [sup 99[ital m]]Tc window. The spatial distribution of a radionuclide's crosstalk photons differs from that observed in the radionuclide's photopeak window. A [sup 99[ital m]]Tc photopeak window offset to the left does not decrease [sup 123]I crosstalk, and the percentage of [sup 99[ital m]]Tc scattered photons is significantly increased in the window. Offsetting the [sup 123]I window to the right decreases [sup 99[ital m]]Tc crosstalk to 9.0% to 17.9% of the [sup 123]I counts, but decreases [sup 123]I sensitivity by 39.9%. Offsetting both photopeak windows to the right decreases the [sup 99[ital m]]Tc scattered photons in the [sup 99[ital m]]Tc window, but increases [sup 123]I crosstalk to 17.0% to 33.8% of the [sup 99[ital m]]Tc counts.

• OSTI ID: 7207164
• Journal Information: Medical Physics; (United States), Vol. 21:5; ISSN 0094-2405
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BRAIN
RADIOISOTOPE SCANNING
FEASIBILITY STUDIES
ACCURACY
DUAL-ISOTOPE SUBTRACTION TECHNIQUE
IODINE 123
PHANTOMS
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
SPATIAL RESOLUTION
TECHNETIUM 99
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CENTRAL NERVOUS SYSTEM
COMPUTERIZED TOMOGRAPHY
COUNTING TECHNIQUES
DIAGNOSTIC TECHNIQUES
ELECTRON CAPTURE RADIOISOTOPES
EMISSION COMPUTED TOMOGRAPHY
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE ISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MOCKUP
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANS
RADIOISOTOPES
RESOLUTION
STRUCTURAL MODELS
TECHNETIUM ISOTOPES
TOMOGRAPHY
TRACER TECHNIQUES
YEARS LIVING RADIOI
550601* - Medicine- Unsealed Radionuclides in Diagnostics