Fig. 13From: MRI and CT of anal carcinoma: a pictorial reviewA 46-year-old HIV-infected man with biopsy-proven SCAC. Initially, MDCT (a) shows left-sided thickening with involvement of the external sphincter (arrowheads). After chemo-radiotherapy, lesion regression is observed on MRI with appearance of T2-hypointense fibrosis (*) and hyperintense nodule (arrow) consistent with residual tumourBack to article page