Skip Navigation LinksHome > May/June 2013 - Volume 37 - Issue 3 > Added Value of High-b-Value (b = 3000 s/mm2) Diffusion-Weigh...
Journal of Computer Assisted Tomography:
doi: 10.1097/RCT.0b013e318288a661

Added Value of High-b-Value (b = 3000 s/mm2) Diffusion-Weighted Imaging at 3 T in Relation to Fluid-Attenuated Inversion Recovery Images for the Evaluation of Cortical Lesions in Inflammatory Brain Diseases

Iwashita, Koya MD*; Hirai, Toshinori MD, PhD*; Kitajima, Mika MD*; Shigematsu, Yoshinori MD*; Uetani, Hiroyuki MD*; Iryo, Yasuhiko MD*; Azuma, Minako MD*; Hayashida, Eri MD*; Ando, Yukio MD; Murakami, Ryuji MD; Yamashita, Yasuyuki MD*

Collapse Box


Objective: The purpose of this study was to determine how the gray-to-white matter contrast in healthy subjects changes on high-b-value diffusion-weighted imaging (DWI) acquired at 3 T and evaluate whether high-b-value DWI at 3 T is useful for the detection of cortical lesions in inflammatory brain diseases.

Methods: Ten healthy volunteers underwent DWI at b = 1000, 2000, 3000, 4000, and 5000 s/mm2 on a 3-T MRI unit. On DW images, 1 radiologist performed region-of-interest measurements of the signal intensity of 8 gray matter structures. The gray-to-white matter contrast ratio (GWCR) was calculated. Ten patients with inflammatory cortical lesions were also included. All patients underwent conventional MRI and DWI at b = 1000 and 3000 s/mm2. Using a 4-point grading system, 2 radiologists independently assessed the presence of additional information on DW images compared with fluid-attenuated inversion recovery images. Interobserver agreement was assessed by κ statistics.

Results: In the healthy subjects, the b value increased as the GWCR decreased in all evaluated gray matter structures. On DW images acquired at b = 3000 s/mm2, mean GWCR was less than 1.0 in 7 of 8 structures. For both reviewers, DWI at b = 3000 s/mm2 yielded significantly more additional information than did DWI at b = 1000 s/mm2 (P < 0.05). Interobserver agreement for DWI at b = 1000 s/mm2 and b = 3000 s/mm2 was fair (κ = 0.35) and excellent (κ = 1.0), respectively.

Conclusions: At 3-T DWI, the gray-to-white matter contrast in most gray matter structures reverses at b = 3000 s/mm2. In the evaluation of cortical lesions in patients with inflammatory brain diseases, 3-T DWI at b = 3000 s/mm2 was more useful than b = 1000 s/mm2.

© 2013 by Lippincott Williams & Wilkins



Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.