Figure 2. A 21-year-old man with normal menisci: (a) Pre ultrashort echo time (UTE), (b) post UTE, (c) pre TE=5.95 ms echo image, (d) post TE=5.95 ms image, (e) pre difference image (c subtracted from a) and (f) post difference image (d subtracted from b). In (a) the menisci and the outer layer of the articular cartilage are almost isointense. Joint fluid has a slightly lower signal. In (c) the menisci are seen as low signal areas with the outer aspects slightly lower in signal intensity. In (e) (the subtracted image) the menisci are seen with moderate signal intensity with slightly higher signal on their outer aspects. In (b) enhancement is seen but it is not possible to define the extent of the menisci. In (d) the menisci are of low signal except for a small linear area (arrow) with features consistent with a collagen tie. In (f) generally higher signal is seen in the menisci together with obvious enhancement (arrows). This area of enhancement was designated the intermediate region, the lower signal area within the meniscus central to it was designated as the central region and the area just peripheral to it was designated as the peripheral region. Regions of interest were then placed in these regions on (f) and transferred to (b) and (c) etc. for corresponding measurements of signal intensity.