Feasibility of small bowel flow rate measurement with MRI.
OBJECTIVE
To evaluate whether it is feasible to measure the segmental flux of small bowel content using MR phase-contrast (PC) pulse sequences.


METHODS
Using a phantom the accuracy of flux measurements was validated. Afterwards, 10 volunteers were included in a prospective clinical trial. To provide standardized small bowel distension, all volunteers ingested four equal portions of 400 mL of water doped with 5 mL gadoterate and 5.8 g Metamucil mite. The MR protocol covering the sagittal cross-sections of the small bowel included several two-dimensional (2D) PC sequences with a velocity encoding of 7 cm/second at a temporal resolution of 0.55 second. As proof of concept time-dependent flux was measured after intravenous (i.v.) administration of a spasmolytic agent in one volunteer.


RESULTS
Phantom measurements resulted in an excellent correlation between pump and PC measured flow rates (R = 0.999). Time-resolved small bowel flux was successfully measured in distended small bowel loops of all volunteers. A mean flow rate of 0.188 mL/second (standard deviation +/- 0.144 mL/second) was documented. The flux plots presented a sinus wave-like shape with regular aboral and oral flow. A spasmolytic effect both on flux and motility could be shown with residual flux despite complete arrest of small bowel motility.


CONCLUSIONS
PC MRI allows time-resolved in vivo measurement of small bowel flux in single well-distended bowel loops filled with gadolinium-doped aqueous solution.
Gutzeit
Andreas
A
Department of Radiology, Kantonsspital Winterthur, Winterthur, Switzerland. Andreas.Gutzeit@ksw.ch
Patak
Michael A
MA
von Weymarn
Constantin
C
Graf
Nicole
N
Doert
Aleksis
A
Willemse
Edwin
E
Binkert
Christoph A
CA
Froehlich
Johannes M
JM
D000328:Adult; D002086:Butylscopolammonium Bromide / Q000494:pharmacology; D005260:Female; D005682:Gadolinium / Q000494:pharmacology*; D005769:Gastrointestinal Motility; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007421:Intestine, Small / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010276:Parasympatholytics / Q000494:pharmacology; D010528:Peristalsis; D019047:Phantoms, Imaging; D013997:Time Factors
D010276:Parasympatholytics; D002086:Butylscopolammonium Bromide; D005682:Gadolinium