Figure 13.

MR images of an intramuscular lipoma of the forearm (A–D) and a perineural ganglion cyst of the leg (E–G) of two different patients. The lipoma (asterisk) shows a homogeneous high signal on coronal T2w (A) and a low signal on axial fat-suppressed T1w (B), b = 800 DWI (C); the corresponding ADC map (D). Note the absence of diffusion restriction and the intrinsically low ADC values of this benign lipomatous lesion. The ganglion cyst (arrows) displays high signal intensity on coronal fat-suppressed T2w (E), axial b = 800 DWI (F), and axial ADC map (G). High b-value DWI shows high signal due to T2 shine-through effect; the ADC map confirms the absence of diffusion restriction and the cystic nature of the lesion (ADC: 2.603 × 10⁻³ mm²/s).