Right buttock ulceration There is a large ulceration along the posteromedial aspect of the proximal left thigh that extends to the ischial tuberosity. The wound contains foci of signal void representing gas and there is enhancement of the surrounding soft tissues indicating inflammation. There is mild marrow edema of the ischium and adjacent inferior pubic ramus on the fat-suppressed T2-weighted images as well as mild enhancement following contrast administration; however the marrow signal intensity on the corresponding T1 sequences is preserved. These findings are more suggestive of a reactive osteitis rather than true medullary osteomyelitis. There is diffuse subcutaneous edema of the visualized proximal left thigh but the marrow signal intensity of the visualized femur is normal. Again noted is a rectocutaneous fistula which is better appreciated on the comparison CT. There also appears to be a defect extending through the subcutaneous fat posterior to the sacrum which is associated with metallic susceptibility artifact from the surgical clip which is also better seen on the CT. The S5 segment as well as the upper coccyx is not well visualized either due to prior surgical resection or destruction from prior infection; however the signal intensity of the remaining sacrum is normal without evidence of osteomyelitis. There is edema within the soft tissues anterior to the sacrum but there is no rim-enhancing fluid collection to confirm an abscess. There is widening of the pubic symphysis and irregularity of its margins with mild alterations in signal intensity within the body of the pubic bones which may reflect prior trauma or chronic degeneration but does not have the typical appearance of infection.
Soft tissue ulceration and inflammation with signal abnormality of the left ischium demonstrating features more suggestive of reactive osteitis rather than true medullary osteomyelitis. Additional findings are described above.