Table 2.

Differential diagnosis table for panniculitis.

	Radiography	MRI	Ultrasound
Panniculitis	None or soft tissue swelling	Focal or nodular areas of T1w hypointense and T2w hyperintense signal in the subcutaneous fat tissue.	Nodular hypoechoic area in subcutaneous tissue
Cellulitis	None or soft tissue swelling	Diffuse skin thickening and subcutaneous oedema. Superficial fascial thickening or fluid may be seen.	Diffuse skin thickening and subcutaneous oedema (ill-defined anechoic area between subcutaneous fat)
Necrotizing fasciitis	Soft tissue gas	Involvement of deep fasciae with fluid collection, thickening and post contrast enhancement. Presence of fascial gas.	Difficult to visualized deep structure but if present it is seen as fluid between muscle plane or deep fascial gas.