Bowel MR imaging with oral Gastrografin: an experimental study with healthy volunteers

Abstract

Our objective was to evaluate Gastrografin for MR bowel imaging. Twenty-three healthy volunteers in two randomised groups received 300 or 400 ml 50% Gastrografin, drunk continuously during 2 and 3 h, respectively. Images were applied during breath-hold in three orthogonal orientations. The balanced fast-field echo (BFFE) and balanced turbo field-echo (BTFE) sequences, with acquisition times from 13 to 25 s, were used before gadolinium (Gd) DTPA implying 1-to 2-mm-thick slices locally or 6-mm-thick slices through the entire gastrointestinal tract. The Gd-enhanced images were performed using a 3D T1-weighted FFE sequence with water selective excitation (Proset). Image quality, including bowel distention, homogeneity of opacification and wall conspicuity, were evaluated by two experienced reviewers, and the adverse reactions were recorded. Very good or excellent distention, homogeneity and wall conspicuity were achieved in the central segments from the ileum to the left colon flexure in 83-96% of cases, due to the adequate contrast media supply in these regions. Distention, homogeneity and delineation were good in the central segments of the remaining bowels. Diarrhoea was a major problem affecting all participants, followed by nausea. Provided that there is modern fast sequential technology, excellent MR imaging of the bowel can be achieved by the oral administration 50% diluted Gastrografin. Further studies are needed to refine the technique and optimise the quantity and concentration of Gastrografin in order to avoid or reduce adverse reactions.

Usefulness of Three Dimensional Proset MR Images for Diagnosis of Symptomatic L5-S1 Foraminal and Extraforaminal Stenosis

“…Proset-MRI was first suggested by Borthne et al1) to obtain excellent bowel image. The principle of this modality is a selective excitation to suppress either fat or water by exploiting the difference between the water and fat resonance frequencies.…”

Practical applications of balanced steady-state free-precession (bSSFP) imaging in the abdomen and pelvis

“…Fat-suppressed bSSFP images can now be generated on most commercial scanners by applying frequency selective RF preparatory pulses within a given TR or magnetization preparation. 23,24 India ink (etching) artifact occurring at fat-water interfaces should be recognized on bSSFP imaging. This artifact can be exploited to identify fat-containing structures and also, in our experience, can be used in conjunction with other sequences to determine whether an expected fat-water interface may be obscured/ invaded.…”

Do radiologists agree on the quality of computed tomography enterography?

“…Images were displayed with window level 60 Hounsfield Units (HU) and width setting 360 HU; the radiologists could adjust both values as preferred. They assessed the quality variables detailed in Table 1 in the following order: bowel filling (length of adequately filled bowel), bowel distension (lumen diameters), bowel wall delineation, 20 subjective bowel wall enhancement, artefacts, 18 total quality, and measured enhancement (HU) in the superior mesenteric vein and in presumed normal jejunal wall. Bowel filling, bowel distension, and bowel wall delineation were evaluated separately for the duodenum (distal to bulb), jejunum (defined as small bowel left of midline and cranial to aortic bifurcation), ileum (right of midline/caudal to aortic bifurcation) and terminal ileum (distal 10 cm).…”

“…Rated as 0 = bowel segment not seen, 1 = parts of the segment seen, 2 = bowel wall seen but not in the entire length of the segment, 3 = wall seen in its entire length, 4 = wall optimally delineated. 20…”