PT  - JOURNAL ARTICLE
AU  - Kouris, Kypros
AU  - Elgazzar, Abdelhamid
AU  - Affana, Raid
AU  - Higazi, Ezzat
AU  - Awdeh, Maha
AU  - Mahmoud, Abdelrahman
AU  - Abdel-Dayem, Hussein M.
TI  - Methodology and Performance Assessment of Zoom SPECT
DP  - 1990 Sep 01
TA  - Journal of Nuclear Medicine Technology
PG  - 198--203
VI  - 18
IP  - 3
4099  - http://tech.snmjournals.org/content/18/3/198.short
4100  - http://tech.snmjournals.org/content/18/3/198.full
SO  - J. Nucl. Med. Technol.1990 Sep 01; 18
AB  - The methodology of zoom single-photon emission computed tomography (Z SPECT) imaging and its performance was assessed using two tomographic gamma cameras, systems A* and B†, fitted with high resolution collimators. The center of rotation (COR) varied linearly for zoom factors (ZF) from 1.0 to 4.0. It was more stable and reproducible in system B and its variation with ZF was significantly smaller. Z SPECT acquisitions were done using projection matrix sizes 64 × 64 and 128 × 128, 64 projections over 360 degrees and ZF equal to 1.0, 1.6 and 2.0. Point source acquisitions demonstrated the superior performance of system B. Two small phantoms were constructed (10 × 10 × 5 cm each) containing cold rods and hot rods. The use of zoom improved both contrast and resolution. The Nowak reconstruction algorithm provided better contrast than the conventional filtered backprojection algorithm. The 2 mm hot rod was visible using system B with projection matrix 64 × 64 and ZF = 1.6. The use of zoom in SPECT leads to improved contrast and resolution; the application of Z SPECT to small organs is recommended.