The classical appearance of an endometrioma would be a cyst that is hyperintense on T1WI and hyperintense on T2WI with fat suppression. T2 shading (signal loss) may occur secondary to repeated haemorrhage into the cyst. The fibrous wall is of low signal. Where the mass may be appreciated by the patient, a cyclical increase in size and symptoms may help indicate the diagnosis. In these cases MR and US would be superior to CT in the evaluation.