Sung Hyun Baik, Presenter: Nothing to Disclose

Eun Hae Park, Abstract Co-Author: Nothing to Disclose

Chun Ai Lee, Abstract Co-Author: Nothing to Disclose

Kyu Yoon Jang, Abstract Co-Author: Nothing to Disclose

In-Hwan Kim, Abstract Co-Author: Nothing to Disclose

Sang Y Lee MD,PhD, Abstract Co-Author: Nothing to Disclose

To document the causes of signal intensity changes of the meniscus on MR images using the correlation between the MR images and histologic findings.

This study protocol was approved by the institutional review board, and written informed consent was obtained from all patients. For the correlation between the MR images and histology, we obtained 31 meniscal specimens from 21 patients (one man, 20 women). Proton density-weighted turbo spin-echo (PD-TSE) MR images were used. Minimal tears on the surface of the meniscus, thinning of the lamellar layer, radial tie fibers, crystals and degeneration of the central layer were correlated with the corresponding MR images.

Minimal tears of the lamellar layers were seen in 60 zones out of 100 slides. On MR images, 38 (63.3%) out of these 60 zones had surface irregularities (M1), and 29 zones (48.3%) had abnormally high signal intensities (S1). Surface thinning of the lamellar layer was seen in 24 zones, with 7 (29.2%) having increased signal intensities (S1). 57 central zones showed degenerative changes in the central layer and abnormally high signal intensity (S1, 100%). Six cases with meniscal crystals did not show any abnormal signal intensity on MR images. Radial tie fibers in the central layer appeared as high signal intensity (S1) areas.

Relatively large proportion of minimal tears in the lamellar layer or on the apical surface can cause (abnomally HIS) on MR images due to (only by) surface irregularity (and abnormally high signal intensity on MR images,) which might lead radiologists to false positive meniscal tears.

High signal intensity of meniscus in MR is caused by not only definite meniscal tear but also caused by minimal tear, surface thinning, degeneration and radial tie fibers in the central layer    

Baik, S, Park, E, Lee, C, Jang, K, Kim, I, Lee, S, Causes of High Signal Intensity Changes of the Meniscus on MR Images: Correlation with Histologic Examination.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11013327.html