Imagerie en coupes de l’estomac et du duodénum

[Imaging of gastrointestinal stromal tumors]

Gastrointestinal stromal tumors (GIST) arising from interstitial cells of Cajal, represent the first type of solid tumor, which is very sensitive to a specific molecularly targeted tyrosine kinase receptor blocker (i. e., imatinib). On CT, which is considered as the reference technique, GISTs typically present as large, well-delineated, heterogeneous and sometimes exophytic masses. In contrast with the absence of lymph node involvement, hepatic metastasis as well as mesenteric involvement can be observed. MR-enteroclysis is indicated to investigate the local extent of the disease in specific cases whereas MR imaging is used to detect hepatic metastasis. Because of a specific treatment, contrast-enhanced imaging is needed for the follow-up of treated tumors. Evaluation of tumor response to treatment is best assessed with CT which still remains the reference imaging technique whereas FDG-PET imaging is used in specific cases.

Le scanner multi détecteurs améliore la détection des perforations d’ulcères gastro duodénaux

OBJECTIVE

To determine whether multidetector computed tomography (MDCT) is helpful for early detection of gastroduodenal perforation.

MATERIAL AND METHODS

Fifteen consecutive gastroduodenal perforations for ulcer were recorded in the HIS of a single institution. Reports were analyzed and classified according to the following signs: Was a pneumoperitoneum detected? Was there mention of a perforation site, and how was it depicted (axial or reformatted slices, thin or thick slices)? What were the other described features, including peritoneal fluid, abdominal fat blurring, and bowel wall thickening?

RESULTS

All patients had a gastroduodenal perforation. MDCT identified pneumoperitoneum in 15 of 15 cases as compared with three of nine cases for plain films. The perforation site was seen in eight of 15: it was identified as a defect in the parietal wall (gastroduodenal). Six of eight cases were depicted in axial view. Two of them were only seen on MPR, coronal or sagittal view.

CONCLUSION

MDCT improves the detection rate of pneumoperitoneum and provides critical data for locating the perforation using direct and indirect signs. Multiplanar images seem to improve radiologists' confidence.