Published online before print December 15, 2004, 10.1148/radiol.2342031002
MR Imaging of Apparent Small-Bowel Perfusion for Diagnosing Mesenteric Ischemia: Feasibility Study1
Thomas C. Lauenstein, MD,
Waleed Ajaj, MD,
Burcu Narin, MD,
Susanne C. Göhde, MD,
Knut Kröger, MD,
Jörg F. Debatin, MD, MBA and
Stefan G. Rühm, MD
1 From the Departments of Diagnostic and Interventional Radiology (T.C.L., W.A., B.N., S.C.G., J.F.D., S.G.R.) and Angiology (K.K.), University Hospital Essen, Hufelandstrasse 55, D-45122 Essen, Germany. Received June 25, 2003; revision requested September 4; final revision received March 16, 2004; accepted April 15. Address correspondence to T.C.L. (e-mail: thomas.lauenstein@uni-essen.de).
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Figure 1. Examination protocol for perfusion MR imaging. After intravenous (i.v.) administration of 0.05 mmol per kilogram of body weight (BW) of a paramagnetic contrast agent (Gadovist) at a flow rate of 2.0 mL/sec, 3D T1-weighted (T1w) data sets are acquired in blocks of five data sets each. The last acquisition was performed 125 seconds after intravenous contrast agent administration.
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Figure 2a. (a) Coronal source image from T1-weighted gradient-echo 3D MR imaging data set (3.1/1.2; flip angle, 15°). Owing to the oral ingestion of contrast agent before MR imaging, good bowel distention is achieved. (b) Enlargement of a. Signal-to-noise ratios (SNRs) in the small-bowel wall can be easily determined (circle).
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Figure 2b. (a) Coronal source image from T1-weighted gradient-echo 3D MR imaging data set (3.1/1.2; flip angle, 15°). Owing to the oral ingestion of contrast agent before MR imaging, good bowel distention is achieved. (b) Enlargement of a. Signal-to-noise ratios (SNRs) in the small-bowel wall can be easily determined (circle).
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Figure 3. Selected coronal source images from T1-weighted gradient-echo 3D MR imaging data set (3.1/1.2; flip angle, 15°) obtained at all 20 acquisition times in one healthy volunteer, a 24-year-old man. Increasing bowel wall enhancement can be observed within the first 70 seconds. Thereafter, the SNR values in the bowel wall are seen to be in a plateau phase. The numbers in the lower right hand corners of the images represent the time (in seconds) after contrast agent injection at which each image was obtained.
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Figure 4. Graph shows mean SNR values for the volunteer examinations performed with and those performed without caloric stimulation. The caloric stimulation leads to a significantly higher bowel wall perfusion compared with the baseline examination without caloric stimulation.
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Figure 5. Graph shows mean SNR values for the patient examinations performed with and those performed without caloric stimulation. As in the volunteer group, in the patient group, caloric stimulation leads to increased bowel wall perfusion. However, the increase is less compared with that in the volunteer group (Fig 4).
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Figure 6. Graph shows results of comparison between SNR values without caloric stimulation in the patient group and those in the volunteer group. Error bars indicate single standard deviations. In baseline conditions with no caloric stimulation, mean bowel wall perfusion is only slightly higher in the volunteer group than in the patient group.
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Figure 7. Graph shows results of comparison between SNR values with caloric stimulation in the patient group and those in the volunteer group. Error bars indicate single standard deviations. Bowel wall perfusion is significantly higher in the volunteer group than in the patient group when caloric stimulation is applied.
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Figure 8. Graph shows results of comparison between reserve capacity values in the patient group and those in the volunteer group. Error bars indicate single standard deviations. Reserve capacity proves to be a reliable parameter for the detection of mesenteric ischemia. Especially during the first pass of the intravenous contrast agent, reserve capacity is significantly higher in healthy volunteers than in patients.
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Copyright © 2005 by the Radiological Society of North America.
