Werner Kenn MD, Presenter: Nothing to Disclose

Dirk Boehm, Abstract Co-Author: Nothing to Disclose

Herbert Koestler PhD, Abstract Co-Author: Nothing to Disclose

Dietbert Hahn MD, Abstract Co-Author: Nothing to Disclose

The degree of fatty degeneration of rotator cuff muscles is an important factor for the prognosis of rotator cuff repair.We established a new method that allows quantification of fatty degeneration in an arbitrarily shaped ROI using a clinical MR scanner.

A SPLASH sequence consisting of 19 complex 2D-FLASH images was implemented. The echo time was gradually increased from 5ms to 50ms. The spatial in plane resolution was 1.17mm, a spectral resolution of 0.33ppm was achieved in 3min.For calibration a fat/water phantom was used.20 patients (f/m 7/13) with rotator cuff tears (4 partial tears, 5 complete tears 5cm) were examined and the atrophy of the supraspinatus belly determined by the occupation ratio was correlated with the degree of fatty degeneration determined by SPLASH

The phantom study demonstrated a highly linear correlation between the volume percentages of water/aceton and the SPLASH measures. We found significant differences between different stages of rotator cuff disease, the fatty infiltration and the volume loss (determine by the occupation ratio) of the supraspinatus muscle. With increasing extent of rotator cuff disease, fatty infiltration increases significantly as well as the volume loss of the supraspinatus muscle. Comparing fatty infiltration and the occupation ratio individually there was only a moderate inverse correlation between fatty infiltration and the occupation ratio with considerable variation of data.

The SPLASH-sequence allows exact quantification of fatty infiltration in an arbitrarily shaped ROI. The extent of atrophy and fatty infiltration correlates with the size of tear. Atrophy and fatty infiltration correlate only moderate and should be evaluated separately.

Kenn, W, Boehm, D, Koestler, H, Hahn, D, 2D-SPLASH: A New Method to Determine the Fatty Infiltration of the Rotator Cuff Muscles.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4412825.html