PT  - JOURNAL ARTICLE
AU  - Kenya Murase
AU  - Hiroyoshi Fujioka
AU  - Takeshi Inoue
AU  - Yoshihiro Ishimaru
AU  - Akihisa Akamune
AU  - Yuji Yamamoto
AU  - Junpei Ikezoe
TI  - Measurement of Blood Radioactivity for Quantification of Cerebral Blood Flow Using a Gamma Camera
DP  - 1998 Sep 01
TA  - Journal of Nuclear Medicine Technology
PG  - 191--195
VI  - 26
IP  - 3
4099  - http://tech.snmjournals.org/content/26/3/191.short
4100  - http://tech.snmjournals.org/content/26/3/191.full
SO  - J. Nucl. Med. Technol.1998 Sep 01; 26
AB  - Objective: This study was designed to determine whether gamma cameras can be substituted for well-type scintillation counters in measuring blood radioactivity counts to be used as an input function for the quantitative measurement of cerebral blood flow (CBF). Methods: Twelve different aqueous 123I solutions were prepared by serial dilution of the original concentration of 281.9 kBq/ml, and the radioactivity count of each dilution was measured with a gamma camera with the collimator removed, and with a well-type scintillation counter. When measuring the radioactivity counts with a gamma camera, static images were acquired using a 128 × 128 matrix for 5 min, and the regions of interest with 14 × 14 pixels (21 mm × 21 mm) were defined. Results: There was a good correlation between the results obtained by these two procedures in the range of concentration between 0.008 kBq/ml and 281.9 kBq/ml (y = 4.245x – 2.549, r = 1.0, n = 12, s.e.e. = 7.217 kcpm). There was good agreement between the CBF values (ml/100 g/min) obtained using the cross-calibration factor (CCF) and blood radioactivity counts measured with the two procedures (y = 0.990x + 0.552, r = 0.990, n = 231, s.e.e. = 1.340 ml/100 g/min). Conclusion: The results suggest that gamma cameras can be substituted for well-type scintillation counters in the quantitative measurement of CBF, and make it unnecessary to measure CCF after routine calibration of a SPECT apparatus.