| AJNMMI Copyright © 2011-present, All rights reserved. Published by e-Century Publishing Corporation, Madison, WI 53711, USA 
 | 
          
         
        
Am J Nucl Med Mol Imaging 2012;2(1):77-87.
Original Article
Prediction of cerebral hyperperfusion following endarterectomy for unilateral 
cervical internal carotid artery stenosis using preoperative 123I-Iomazenil SPECT 
imaging
Yasushi Ogasawara, Kuniaki Ogasawara, Taro Suzuki, Takeshi Yamashita, Hiroki Kuroda, Kohei Chida, Shunrou Fujiwara, Kenta 
Aso, Masakazu Kobayashi, Kenji Yoshida, Kazunori Terasaki, Akira Ogawa
Department of Neurosurgery and Cyclotron Research Center, Iwate Medical University, Morioka, Japan.
Received October 9, 2011; accepted December 5, 2011; Epub December 15, 2011; Published January 1, 2012
Abstract: Purpose Cerebral hyperperfusion following carotid endarterectomy (CEA) occurs in patients with preoperative impairments 
in cerebral hemodynamics. The aim of the present study was to determine whether late images/early images on preoperative brain 
123I-iomazenil (IMZ) single-photon emission computed tomography (SPECT), which correlate with oxygen extraction fraction images 
on positron emission tomography, could identify patients at risk for cerebral hyperperfusion following endarterectomy for unilateral 
cervical internal carotid artery (ICA) stenosis. Methods In 80 patients, preoperative brain SPECT scans were initiated immediately 
after (early images) and 180 min after (late images) administration of 123I-IMZ. A region of interest (ROI) was automatically placed in 
the middle cerebral artery territory in both the cerebral hemispheres using a three-dimensional stereotaxic ROI template. 
Transcranial regional cerebral oxygen saturation (rSO2) was monitored using near-infrared spectroscope throughout carotid 
endarterectomy, and a patient was defined as having cerebral hyperperfusion when a ratio of rSO2 at the end of the surgery to rSO2 
before ICA clamping was ≥ 1.1. Results Cerebral hyperperfusion was observed on intraoperative rSO2 monitoring in eight patients 
(10%). Preoperative increase in affected side-to-contralateral side asymmetry on late/early 123I-IMZ value was the only significant 
independent predictor of cerebral hyperperfusion (95% confidence interval [CI], 1.606 to 8.710; P = 0.0010). The preoperative 
late/early 123I-IMZ asymmetry corresponded to an 88% sensitivity and 89% specificity, with 47% positive- and 98% negative-
predictive values for the development of cerebral hyperperfusion. Conclusions Preoperative late/early 123I-IMZ images can identify 
patients at risk for cerebral hyperperfusion following endarterectomy for unilateral cervical ICA stenosis. (ajnmmi1110001).
Keywords: 123I-iomazenil, brain SPECT, hyperperfusion, carotid endarterectomy
Full text PDF
Address all correspondence to:
Kuniaki Ogasawara, MD
Department of Neurosurgery
Iwate Medical University
19-1 Uchimaru, Morioka, 020-8505 Japan.
Tel: +81-19-651-5111, Fax: +81-19-625-8799
E-mail: kuogasa@iwate-med.ac.jp