Matakazu Furukawa MD, Presenter: Nothing to Disclose

Etsushi Iida, Abstract Co-Author: Nothing to Disclose

Naofumi Matsunaga MD, PhD, Abstract Co-Author: Nothing to Disclose

Although arterial spin labeling (ASL) MR imaging is an emerging technique for noninvasive measurement of cerebral blood flow (CBF), intravascular signal (IVS) often complicates the calculation of quantitative CBF. We assessed whether ASL with single post-label delay time and IVS on fluid attenuated inversion recovery (FLAIR) image could identify the CBF deficiency in patients with chronic cerebrovascular diseases, using 123I-IMP SPECT as a standard reference.

Fifty-three patients with unilateral (n=35) or bilateral (n=18) cerebrovascular stenosis underwent CBF evaluation by 3D-GRASE ASL (FOV 256 mm, matrix 64 x 64, 32 slices, TR/TE/TI 5,000/16/1,800 msec) and 123I-IMP SPECT within a mean interval of four days (range: 0-28 days). Quantitative CBF and cerebrovascular reserve (CVR) measurement by 123I-IMP-SPECT was used as a standard reference. Side-by-side difference on 3D-ASL and IVS on FLAIR image were evaluated visually by two radiologists, and those were compared with the SPECT findings for the middle cerebral artery (MCA) territory.

The agreement between readers for ASL and IVS on FLAIR was strong, with a weighted Kappa value of 0.73 and 0.87, respectively. When a cut-off value of 10% was used on rest 123I-IMP-SPECT, 22 of 53 patients showed CBF difference between bilateral MCA territories. On 3D-ASL, 45 patients showed visual CBF difference, and the sensitivity, specificity, diagnostic accuracy of 3D-ASL were 91%, 19%, and 49%, respectively. Although the sensitivity was poor, 16 of 25 false-positive patients on 3D-ASL showed >10% CBF difference on post-acetazolamide 123I-IMP-SPECT, predicting the CVR impairment. IVS on FLAIR image was seen in 19 patients, and the sensitivity, specificity, diagnostic accuracy to rest 123I-IMP-SPECT were 55%, 77%, and 68%, respectively. The specificity and PPV of IVS on FLAIR was both 100% with a sensitivity of 49% to post-acetazolamide 123I-IMP-SPECT.

Although 3D-ASL MR imaging showed a low specificity, 3D-ASL and IVS on FLAIR imaging would potentially provide valuable information regarding the impaired vasoreactivity. ASL perfusion MR imaging showed high sensitivity and would be clinically applicable, especially for a screening of cerebral hypoperfusion.

3D-ASL perfusion MR imaging combined with intravascular signal on FLAIR imaging would be clinically applicable, especially for a screening of chronic cerebral hypoperfusion.  

Furukawa, M, Iida, E, Matsunaga, N, Evaluation of Cerebral Perfusion by Using 3D-arterial Spin Labeling and FLAIR MR Imaging in Patients with Chronic Cerebrovascular Stenosis: A Comparative Study with I-123-Iodoamphetamine Single Photon Emission CT.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044282.html