Reason: please comment on the "lesion" in the midportion of the abd hallucis. Please compare to previous outside MRI in pacs History: pain medial arch There is a fusiform enhancing mass in the abductor hallucis muscle inferior to the medial cuneiform measuring approximately 1.5 x 1 cm in AP and transverse dimension. The longitudinal dimension is less well-defined but measures approximately 3 cm including a thin tail of enhancement that extends along the proximal tendon of the muscle. There is mild edema in the adjacent soft tissue. The lesion is predominantly isointense to skeletal muscle on T1 weighted images and heterogeneous on T2 weighted images with components that are hyperintense, isointense, and perhaps hypointense to skeletal muscle. The enhancement is likewise heterogeneous with a region of relative nonenhancement centrally. This mass has no appreciable effect on adjacent bones. Superficial to this mass are small foci of signal void, likely representing metallic susceptibility artifact from prior surgery. Proximal and distal to this mass there is mild fatty atrophy of the abductor hallucis muscle. The size of the mass is similar to that seen on outside MRI from 4/4/2016 accounting for technical differences. Of note, on this outside study the mass is of low to intermediate signal intensity on non-fat-saturated T2 weighted images. The mass has increased in size from the 9/3/2014 study, at which time the margins were less well defined.Slight irregularity of the medial navicular tuberosity is noted, which could conceivably be postoperative in nature, but this is equivocal. Only the distal posterior tibialis tendon is included on this study, but it appears to attach to the navicular tuberosity. The mass in question is clearly distal to the insertion of the posterior tibialis tendon, as is the most of the metallic susceptibility artifact. We see no additional masses. The remaining bones and soft tissues appear normal.
Enhancing mass within the abductor hallucis muscle as described above, which appears to underlie the site of prior surgery. Although nonspecific, the signal characteristics of this mass as well as tail-like extension along the tendon is a common feature of proliferating fibrous lesions.