Semiquantitative Assessment of Cerebral Blood Flow: Comparison of Region of Interest Method and A Commercial Semiautomatic Analysis Program

Son, Hye Kyung; Song, Ho Cheon; Bom, Hee Seung; Jeong, Hwan Jeong; Min, Jung Jun; Kim, Ji Yeul

Abstract

PURPOSE
Region of interest (ROI) method is a standard tool to measure regional cerebral blood flow (rCBF) semiquantitatively. Recent vendor provided semiautomatic assessment programs (SAP) for semiquantitative measurement of rCBF are convenient to use. The purpose of this study was to evaluate a commerical SAP by comparing it with ROI method.
MATERIALS AND METHODS
Twenty eight normal controls (15 males and 13 females) and eleven patients (10 males and a female) with middle cerebral artery disease comfirmed by cerebral angiography were studied. All subjects underwent SPECT study using two head gamma camera following injection of 925 MBq 99mTc-HMPAO. ROIs were defined at cortical areas on transaxial slices. The coefficient of variation of region to whole brain ratio measured by two methods, intra- and inter-observer studies of measurement were calculated. To evaluate the discriminative ability between normal and diseased brain of ROI and SAP methods, receiver operating characteristics (ROC) curves were acquired.
RESULTS
There was no significant differences between SAP and ROI methods in normal controls and patients with cerebrovascular disease (p>0.05). The coefficients of variation of region to whole brain ratio between intra- and inter- observer studies by ROI and SAP methods were 3.65%, 3.43%, 3.92%, 4.74%, respectively. ROC curve plotted for identification of diseased brain cortex in all patients showed no difference of area under curves between the two methods (0.97 for ROI method and 0.87 for SAP method, p=0.20).
CONCLUSION
Both methods showed reproducible quantitative results. Therefore, SAP method could be used conveniently for semiquantitative measurement of rCBF as ROI method.