Norihide Takaya MD, Presenter: Nothing to Disclose

Jianming Cai MD, Abstract Co-Author: Nothing to Disclose

Marina S. Ferguson MBBS, Abstract Co-Author: Nothing to Disclose

Baocheng Chu, Abstract Co-Author: Nothing to Disclose

Tobias Saam MD, Abstract Co-Author: Nothing to Disclose

Nayak L Polissar PhD, Abstract Co-Author: Nothing to Disclose

Jane Sherwood, Abstract Co-Author: Nothing to Disclose

Ricardo Caldeira Cury MD, Abstract Co-Author: Nothing to Disclose

Denise Hinton, Abstract Co-Author: Nothing to Disclose

Karen Furie, Abstract Co-Author: Nothing to Disclose

Thomas S Hatsukami MD, Abstract Co-Author: Nothing to Disclose

Chun Yuan PhD, Abstract Co-Author: Nothing to Disclose

Robert J Anders, Abstract Co-Author: Nothing to Disclose

Kay O Broschat, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Recent studies have shown that gadolinium contrast enhanced magnetic resonance imaging (CEMRI) can more accurately quantify critically important features of carotid atherosclerosis, such as the lipid-rich necrotic core (LR/NC), compared to non-contrast enhanced MRI (non-CEMRI). To use CEMRI in prospective serial studies, the reproducibility of the technique must be established. This study tests that hypothesis that intra-and inter-reader reproducibility for measuring LR/NC size is significantly improved with CEMRI, compared to non-CEMRI.

Thirty seven individuals with >50% carotid stenosis underwent carotid MRI at 1.5T (pre-contrast T1-, T2-, proton density-weighted, 3D time-of-flight [TOF], and post-contrast T1 weighted). Two independent readers measured the mean area of the LR/NC from the pre-contrast images only, followed by a second measurement using the additional the post-contrast images. One reader repeated the measurements after a washout interval of 5 months.

The coefficient of variation decreased from 33.7% to 8.8% for intra-observer measurements of the LR/NC and from 33.5% to 17.6% for inter-observer measurements. Standard deviation was significantly smaller with CEMRI than with non-CEMRI (P=0.003 and P=0.006, respectively). Intra-class correlation coefficients increased from 0.94 to 0.99 and from 0.85 to 0.93 for the intra- and the inter-observer measurements, respectively.

Reader reproducibility for in vivo MRI quantification of LR/NC size is significantly improved with the addition of gadolinium contrast in individuals with >50% carotid stenosis.

Takaya, N, Cai, J, Ferguson, M, Chu, B, Saam, T, Polissar, N, Sherwood, J, Cury, R, Hinton, D, Furie, K, Hatsukami, T, Yuan, C, Anders, R, Broschat, K, et al, , Intra-observer and Inter-observer Reproducibility of Magnetic Resonance Imaging for Quantifying the Lipid Rich Necrotic Core Is Improved with Gadolinium Contrast Enhancement.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4404618.html