Gastrointestinal stromal tumours of the upper gastrointestinal tract – imaging with contrast enhanced ultrasound

Aims: Gastrointestinal stromal tumours (GIST) show a distinct appearance in imaging methods such as computed tomography and sonography. In computed tomography it is reported that necrosis, bleeding and cystic degeneration appears predominantly in larger lesions. Modern contrast enhanced ultrasound (CEUS) techniques reveal high spatial resolution as well as real time imaging. However, there are few reports in the literature about the use of CEUS in the imaging of GIST of the upper gastrointestinal tract.

Methods: 12 patients with GIST of the stomach or the small bowel. Contrast enhanced ultrasound with 2.4ml BR1 (Bracco, Italy), Acuson Sequoia (Siemens, Erlangen), real time imaging up to 4 minutes after injection. We describe the features of the lesions in dependency of their size

Results: In all cases the investigation was technically feasible. All lesions showed a strong enhancement after injection of the contrast agent beginning at the periphery of the lesions. In contrast to published data small or large avascular areas, e.g. caused by necrosis or bleeding could be displayed even in lesions smaller than 3cm.

Conclusions: Using high spatial resolution contrast techniques the demarcation of avascular areas is a typical sign of GIST tumours of the upper gastrointestinal tract even in small tumours. This sign should be suggestive for this entity.