Diagnosis: Pilonidal cyst without mention of abscessClinical question: Sacral dimple, evaluate for communication with the spinal canalSigns and Symptoms: Sacral dimple, pain with clear drainage Within the subcutaneous tissues to the right of the coccyx and the posterior to it. It is bright on T2 and dark on T1 It is associated with contrast enhancement. There is infiltration of the fat planes surrounding it. The fluid like portion measures approximately 11 mm x 6 mm axial dimensions. There is a small amount of enhancement of the adjacent bony marrow at the tip of the coccyx, as well as the adjacent periosteum and tissues immediately adjacent to the coccygeal bone. The spinal canal is approximately 3 bone segments above the level of the inflamed marrow.Five lumbar type vertebral bodies are presumed to be present, which are appropriate in overall alignment and height. The conus medullaris on sagittal imaging is grossly intact.At L5-S1 there is no significant compromise to spinal canal or neural foramina.At L4-5 there is no significant compromise to spinal canal or neural foramina.At L3-4 there is no significant compromise to spinal canal or neural foramina.At L2-3 there is no significant compromise to spinal canal or neural foramina.
There is a small fluid collection associated with inflammatory changes presumably representing a small abscess located in the subcutaneous tissues adjacent to the coccygeal bone. There is some associated involvement of the distal tip of the coccyx compatible with osteomyelitis. There is no involvement of the spinal canal appreciated.