An inflammatory process of the right femoral shaft showing a long intramedullary central linear track of fluid signal seen extending from the mid to lower femoral shaft, showing marginal post contrast enhancement and surrounding marrow edema signal. Diffuse cortical thickening is also noted.
A small sequestrum is seen within the mid femoral shaft, eliciting a persistent dark signal.
The track ends by breaching the posterior cortex of the lower femoral shaft by a draining sinus/ostium (cloaca).
A sinus tract extends from the cloaca along the posterior aspect of the thigh, reaching to the skin.
A small abscess collection is seen within the biceps femoris muscle, from which two sinus tracts extend and reach to the skin surface (one passes through the intermuscular fat plane) and the other tract reaches the skin via traversing the rectus femoris muscle).