Imaging Features of Gastrointestinal Stromal Tumour: Diagnosis and Evaluation of Treatment Response

RISK STRATIFICATION OF GASTROINTESTINAL STROMAL TUMOURS There are several guidelines for assessing the malignant potential of GISTs; the most common are the modified National Institutes of Health criteria and the Armed Forces Institute of Pathology criteria. Rectal gastrointestinal stromal tumour in a 48-year-old man. (a) Contrast-enhanced computed tomography showing aheterogeneously enhancing mass with smooth margin arising from the right mesorectum with possible invasion into the mesorectal fasciaand right pelvic floor (arrow). (b) T1-weighted and (c) T2-weighted magnetic resonance imaging showing a well-defined eccentric muralmass at right mesorectum. [11] In addition, the presence of haemorrhage on magnetic resonance imaging is a feature that favours GISTs. Rectal adenocarcinoma in a 69-year-old woman. (a) Contrast-enhanced computed tomography showing eccentric muralthickening with irregular margin involving the mid rectum (white arrow). (b) T1-weighted and (c) T2-weighted magnetic resonance imagingshowing an irregular eccentric mural mass (white arrow) that is T1 isointense and mildly T2 hyperintense relative to muscle.