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Respiratory and postprandial changes in portal flow rate: Assessment by phase contrast MR imaging
Author(s) -
Sadek Ahmed G.,
Mohamed Feroze B.,
Outwater Eric K.,
ElEssawy Saleh S.,
Mitchell Donald G.
Publication year - 1996
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.1880060118
Subject(s) - postprandial , phase contrast microscopy , medicine , radiology , contrast (vision) , nuclear medicine , computer science , physics , artificial intelligence , insulin , optics
Abstract The objective of this study was to investigate the variability of several different phase contrast (PC) magnetic resonance techniques and duplex Doppler imaging (DDI) for measuring portal flow rate (PFR) with different patterns of respiration before and after a standard meal. PFR was measured in nine normal volunteers in both fasting and postprandial states, using both 2D and cine PC MR techniques. Two‐dimensional PC technique was performed with and without breathhold (BH). Four different patterns of BH (relaxed maximal inspiration, expiration, Valsalva maneuver, and Müller or reversed Valsalva) were used. Cine PC technique was performed without BH. DDI measurement of PFR was done in the fasting state with relaxed inspiration. PFR measurements made by means of PC MR techniques varied, depending on BH method, and were systematically less than those obtained by DDI. PFR measured during inspiration was significantly less than that measured during expiration and other respiratory maneuvers ( P < .03). PFR increased significantly after a meal for PC and Doppler measurements, with a range of mean increases of 24 to 74%. Two‐dimensional PC MR imaging techniques yielded differing measurements of PFR, depending on whether they were done with or without BH, as well as on the pattern of BH. PC mean measures of PFR were consistently less than those of DDI. The physiologic inspiratory decreases and postprandial increases of the PFR were evident from 2D and cine PC MRI techniques, as well as with DDI.