SEGMENTATION OF SMALL STRUCTURES IN MR-IMAGES - SEMIAUTOMATED TISSUE HYDRATION MEASUREMENT

Segmentation of small anatomic structures in noisy magnetic resonance (MR) images is inherently challenging because the edge information is contained in the same high-frequency image component as the noise. The authors overcame this obstacle in the analysis of the sural nerve in the ankle by processing images to reduce noise and extracting edges wi th an edge detection algorithm less sensitive to noise. Anatomic accur acy of the segmentation was confirmed by a neuroradiologist. A nerve h ydration coefficient was determined from the signal intensity of the n erve in these segmented images. These semiautomated measurements of hy dration agreed closely with those obtained with a previously described manual method (n = 44, P = .76). Each image in the study was analyzed identically, with no modification of the computer algorithm parameter s. The data suggest that this robust method may be useful in a multice nter evaluation of diabetes treatment protocols.