Abstract
BACKGROUND AND PURPOSE: Preoperative hemodynamic impairment in the affected cerebral hemisphere is associated with the development of cerebral hyperperfusion following carotid endarterectomy. Cerebral oxygen extraction fraction images generated from 7T MR quantitative susceptibility mapping correlate with oxygen extraction fraction images on positron-emission tomography. The present study aimed to determine whether preoperative oxygen extraction fraction imaging generated from 7T MR quantitative susceptibility mapping could identify patients at risk for cerebral hyperperfusion following carotid endarterectomy.
MATERIALS AND METHODS: Seventy-seven patients with unilateral internal carotid artery stenosis (≥70%) underwent preoperative 3D T2*-weighted imaging using a multiple dipole-inversion algorithm with a 7T MR imager. Quantitative susceptibility mapping images were then obtained, and oxygen extraction fraction maps were generated. Quantitative brain perfusion single-photon emission CT was also performed before and immediately after carotid endarterectomy. ROIs were automatically placed in the bilateral middle cerebral artery territories in all images using a 3D stereotactic ROI template, and affected-to-contralateral ratios in the ROIs were calculated on quantitative susceptibility mapping–oxygen extraction fraction images.
RESULTS: Ten patients (13%) showed post-carotid endarterectomy hyperperfusion (cerebral blood flow increases of ≥100% compared with preoperative values in the ROIs on brain perfusion SPECT). Multivariate analysis showed that a high quantitative susceptibility mapping–oxygen extraction fraction ratio was significantly associated with the development of post-carotid endarterectomy hyperperfusion (95% confidence interval, 33.5–249.7; P = .002). Sensitivity, specificity, and positive- and negative-predictive values of the quantitative susceptibility mapping–oxygen extraction fraction ratio for the prediction of the development of post-carotid endarterectomy hyperperfusion were 90%, 84%, 45%, and 98%, respectively.
CONCLUSIONS: Preoperative oxygen extraction fraction imaging generated from 7T MR quantitative susceptibility mapping identifies patients at risk for cerebral hyperperfusion following carotid endarterectomy.
ABBREVIATIONS:
- CEA
- carotid endarterectomy
- OEF
- oxygen extraction fraction
- QSM
- quantitative susceptibility mapping
- ROC
- receiver operating characteristic
Footnotes
Disclosures: Ikuko Uwano—UNRELATED: Grants/Grants Pending: SENSHIN Medical Research Foundation. Makoto Sasaki—UNRELATED: Consultancy: Actelion Pharmaceuticals; Grants/Grants Pending: Hitachi, Japan Agency for Medical Research and Development, Japanese Ministries, Japanese Cabinet Office*; Payment for Lectures Including Service on Speakers Bureaus: Hitachi, Tanabe, Mediphysics, Eizai, FUJIFILM Pharmaceuticals, Daiichi Sankyo, Boehringer, Bayer AG, Otsuka Pharmaceutical, Chugai Pharma. Kohsuke Kudo—UNRELATED: Grants/Grants Pending: Japan Agency for Medical Research Development, Hitachi, Bayer, J-MAC SYSTEM, PSP Corporation*; Payment for Lectures Including Service on Speakers Bureaus: Hitachi, Bayer AG, Eizai, Daiichi Sankyo, FUJIFILM Pharmaceuticals. Kuniaki Ogasawara—RELATED: Grant: Grants-in-Aid for Strategic Medical Science Research (S1491001, 2014–2018) from the Ministry of Education, Culture, Sports, Science and Technology of Japan and a Grant-in-Aid for Scientific Research (15K10313) from the Japan Society for the Promotion of Science. *Money paid to the institution.
This work supported, in part, by Grants-in-Aid for Strategic Medical Science Research (S1491001, 2014–2018) from the Ministry of Education, Culture, Sports, Science and Technology of Japan and a Grant-in-Aid for Scientific Research (15K10313) from the Japan Society for the Promotion of Science.
- © 2017 by American Journal of Neuroradiology
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