Reason: assess for L hip osteo History: pain, pressure ulcer There is a band of low signal intensity extending from the left lower buttock through the subcutaneous fat to the inferior margin of the left ischium, presumably representing ulceration with a sinus tract. The sinus tract itself is predominantly low signal intensity with minimal enhancement, although a small amount of increased signal intensity is seen within the tract on T2-weighted images adjacent to the ischium where there is also mild enhancement. There is slight irregularity of the cortical margin of the adjacent ischium that likely represents early cortical erosion. There is minimal increased signal intensity of the underlying marrow on fat-suppressed T2-weighted images and minimal enhancement following contrast administration, but the T1 signal intensity of the medullary bone is relatively preserved. This pattern supports reactive osteitis rather than medullary osteomyelitis. An additional small focus of abnormal signal intensity and enhancement is noted immediately distal to the terminal coccyx, which likely represents an additional small phlegmon that communicates with the skin surface. We see no drainable fluid collection and the marrow signal of the adjacent coccyx is normal. The remaining bone marrow signal intensity is unremarkable. There is atrophy of the musculature. A Foley catheter is noted in the bladder. A small amount of fluid is seen within both hip joints but there is no effusion. The sacroiliac joints are normal. There is mild degenerative disc disease at L5-S1.
Ulceration with sinus tract leading to the left ischium. Although there appears to be early erosion of the cortical margin of the bone, the signal intensity pattern of the underlying medullary bone suggests reactive osteitis rather than medullary osteomyelitis. A second small sinus is noted extending to the coccyx with no associated marrow signal abnormality.