A novel technique to measure splanchnic transit time using microbubble ultrasound.
OBJECTIVE
The objective of this study was to measure splanchnic transit time by intravenous injection of a microbubble.


METHODS
Ten volunteers were examined before and after eating. After Doppler indices of splanchnic circulation were obtained, the superior mesenteric artery (SMA) and vein (SMV) were simultaneously interrogated using power Doppler ultrasound after intravenous injection of a microbubble. Contrast arrival in the SMA and subsequently the SMV was recorded and splanchnic transit time calculated from differences in the time-intensity curves.


RESULTS
Splanchnic transit time decreased significantly after eating (mean 11 vs. 6.9 seconds; P = 0.007), reflecting splanchnic hemodynamics. Between-subject variability attributable to repeated measurements was least for the SMA resistive index (17%) but 56% for the new index, suggesting poor reproducibility.


CONCLUSIONS
Splanchnic transit time may be measured by microbubble injection but is subject to considerable measurement error. Newer microbubbles and imaging methods may allow more reproducible measurements.
Marshall
Michele
M
Intestinal Imaging Centre, St. Mark's Hospital, London, UK.
Halligan
Steve
S
Eckersley
Robert J
RJ
Williams
Andrew
A
Blomley
Martin J K
MJ
Cosgrove
David O
DO
Bartram
Clive I
CI
D000328:Adult; D000940:Antigenic Variation; D004435:Eating / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008638:Mesenteric Arteries / Q000000981:diagnostic imaging*; D008642:Mesenteric Veins / Q000000981:diagnostic imaging*; D045423:Microbubbles; D015203:Reproducibility of Results; D013152:Splanchnic Circulation / Q000502:physiology*; D014465:Ultrasonics; D014463:Ultrasonography