Error analysis of table look-up method for cerebral blood flow measurement by123I-IMP brain SPECT: Comparison with conventional microsphere model method

Hiroshi Ito, Kiyoshi Ishii, Hiroto Atsumi, Toshifumi Kinoshita, Ryuta Kawashima, Shuichi Ono, Seiro Yoshioka, Hidehiro Iida, Kazuo Uemura, Hiroshi Fukuda

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14 Citations (Scopus)


While N-isopropyl-p-[123I]iodoamphetamine (IMP) is commonly used as a flow tracer, significant clearance from the brain causes underestimation of CBF as compared with true CBF when conventional microsphere model analysis is applied. We previously reported a simple "table lookup" method for CBF measurement using IMP taking into account this clearance effect. The method is based on a two-compartment model, the K1 (corresponding to CBF) and k2 constants being obtained from a table from the ratio of the 1st SPECT (40 min) to the 2nd SPECT (180 min) counts. Arterial input data used were obtained by one point blood sampling 10 min after IMP infusion against the standard input function. In the present study, this approach was compared with conventional microsphere model analysis. For 30 subjects, the latter method entailed 8 min continuous arterial blood sampling after IMP infusion and the use of SPECT data at the end of this period, calibrated by a count ratio of 8 min/40 min planar images of whole brains. A good correlation was observed between the two methods (r = 0.88), but an overestimation of table look-up method CBF as compared with microsphere model CBF was observed contrary to theoretical predictions. Limitations in the estimation of SPECT data at 8 min, obtained with SPECT data at 40 min for calibration of the count ratio of 8 min/40 min whole brain planar images, might be responsible for this.

Original languageEnglish
Pages (from-to)75-80
Number of pages6
JournalAnnals of Nuclear Medicine
Issue number2
Publication statusPublished - 1995 Jun


  • IMP
  • cerebral blood flow
  • table look-up method

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging


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