Thoracic paravertebral abscess and osteomyelitis

Mediastinal opacity at the level of the right hilum. 

Within the superior segment of the right lower lobe, together with the pleural surface, and at the level of T4-T7, there is a well-defined mass characterized by a thick enhancing capsule and homogeneous hypoattenuating content, with an estimated volume of -60 ml. It causes mild surrounding ground glass opacities and adjacent pleural thickening. The surrounding inflammatory process appears to spare the fat in between the parietal pleura and the thoracic spine. No evidence of vertebral periosteal reaction, thoracic disc spaces are preserved. A few small peripheral and subpleural nodules measuring up to 4 mm are identified scattered and are of low suspicion. The lungs and pleural spaces are otherwise clear. The airways are normal. There is no mediastinal abnormality. No lymph node enlargement. No suspicious bony abnormality identified.

There is abnormal marrow signal within the T5 and T6 vertebral bodies, with adjacent discontinuity of endplates adjacent to the T5/6 intervertebral disc as well as abnormal enhancement. Abnormal enhancement also involves the anterior T5-6 disc and this is contiguous with a peripherally enhancing linear low signal tract which extends outward beyond adjacent T5-6 anterior osteophytes into the prevertebral tissues and then tracks into the right pleural cavity as a larger, centrally non-enhancing collection. This right paravertebral/pleural collection is similar in size to the prior CT. The adjacent lung parenchyma is collapsed and hyperenhancing, favored to reflect a reactive change. Small focus of altered marrow signal and enhancement within the adjacent right inferolateral aspect of T4, possibly a further focus of infection secondary to subligamentous spread. No other abnormal focus of enhancement. The imaged thoracic cord maintains normal signal and contour. Partially imaged renal cysts.