FASTSPECT: A four-dimensional brain imager
- Univ. of Arizona, Tuscon, AZ (United States)
The exact location of a lesion in the brain is most critical. High-resolution quantitative 4-dimensional brain imaging would offer improvement in detecting and characterizing brain lesions over state-of-the-art SPECT systems. We report the first clinical brain images on FASTSPECT (Four-dimensional Arizona Stationary SPECT), a fixed imaging system based on 24 modular 10 cm x 10 cm gamma cameras in 2 rings (13+11) about the bead. Each module views the entire brain continuously from a different perspective through one or more pinhole apertures. The system gathers true 3-dimensional whole-brain data it 1-2 frame/sec, fully adequate for vascular dynamics, and is therefore a 4-dimensional imaging system (dynamic SPECT). To calibrate the system a (3.3 mm){sup 3} point source of Tc-99m is stepped through each voxel in the object space. We measure the response of each detector element on each modular camera to the source at each position. The resulting system matrix (dimensions approximately 100,000 x 160,000) is compressed, stored and used in the iterative reconstruction algorithm. Three volunteers, blindfolded for 20 min to suppress visual cortical uptake, were imaged after bolus IV injection of 30 mCi (1.11 GBq) Tc-99m HMPAO. Dynamic images at 2 sec/frame clearly showed common and internal carotid arteries, and anterior and middle cerebral artery groups. Static images (11 million counts in 20 min imaging time) clearly showed the cerebral cortex and white matter, cerebellar cortex and white matter, thalami, caudate, lentiform nuclei, cingulate gyrus, brain stem, and brachium pontis. Distinguishable only with difficulty were putamen from globus pallidus, ventral from dorsal thalamus, and cerebrospinal fluid from white matter. Comparison with concurrent conventional single-headed SPECT images in the same subjects showed significantly better anatomic definition in the FASTSPECT images. Conventional SPECT is incapable of full-brain dynamic imaging.
- OSTI ID:
- 197965
- Report Number(s):
- CONF-940605-; ISSN 0161-5505; TRN: 95:007029-0105
- Journal Information:
- Journal of Nuclear Medicine, Vol. 35, Issue Suppl.5; Conference: 41. annual meeting of the Society of Nuclear Medicine, Orlando, FL (United States), 5-8 Jun 1994; Other Information: PBD: May 1994
- Country of Publication:
- United States
- Language:
- English
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