MAGNETIC-RESONANCE CHARACTERISTICS OF INTRAPELVIC HEMATOMAS

Although haematomas in the female pelvis are not rare, their magnetic resonance (MR) appearance has not been well characterized. Accordingly , we analysed the MR appearances of various stages of haematomas in th e female pelvis. A retrospective analysis of 35 haematomas in 28 patie nts sequentially imaged with a 1.5 T MR unit was performed. The time i nterval between the insult and MR imaging was determined and the appea rances of the haematoma were evaluated. The results were compared with those in the central nervous system. The evolution of haematomas in t he pelvis appeared similar to that of haematomas in the brain, and fou r stages (acute, early subacute, late subacute and chronic) were ident ified according to the signal intensity pattern on T-1 and T-2 weighte d images. Pelvic haematomas differed from intracranial haematomas in t he following features: (1) The speed of evolving pelvic haematomas was gradual. (2) In the centre of acute haematomas, slightly hyperintense areas were seen on both sequences, suggesting residual oxyhaemoglobin . (3) Haematomas evaluated in the early subacute stage had complex app earances; (4) In older haematomas; central intermediate signal intensi ty areas, presumably due to diamagnetic hemichromes, became predominan t on T-1 weighted images. In conclusion, although the evolution of a p elvic haematoma is similar to that of a brain haematoma, its speed is gradual and MR appearances are somewhat different due to environmental differences.