Related Experiment Video
Updated: Feb 3, 2026
Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery
Published on: September 5, 2018
The Feasibility of Using Volumetric Phase-Contrast MR Imaging (4D Flow) to Assess for Transjugular Intrahepatic
Joseph W Owen1, Nael E Saad2, Glenn Foster3
1Department of Radiology, University of Kentucky College of Medicine, 800 Rose Street, HX315A, Lexington, KY 40536-0293.
Purpose:
To demonstrate the feasibility of detecting patency, stenosis, or occlusion of transjugular intrahepatic portosystemic shunt (TIPS) with four-dimensional (4D) flow MR imaging.
Materials And Methods:
Sequential adult patients with TIPS were eligible for enrollment. Volumetric phase-contrast sequence was used to image TIPS. Particle tracing cine images were used for qualitative assessment of stenosis. TIPS was segmented to generate quantitative data sets of peak velocity. Segmentation and quantitative measurement of flow throughout an entire TIPS defined technical success. Doppler US was used for comparison. Venography, when available, and 6-month clinical follow-up were used as reference standards.
Results:
4D flow MR imaging was performed in 23 patient encounters and was technically successful in 16/23 (69.6%) encounters. Three cases demonstrated both focal turbulence and abnormal velocities (> 190 cm/s or < 90 cm/s) on 4D flow and had venography-confirmed stenosis (true-positive cases). Seven cases had normal velocities and no turbulence on 4D flow, and all were confirmed negative with clinical follow-up or venography (true-negative cases). Six cases had discordant 4D flow results, with abnormal velocities but no turbulence or focal turbulence but normal velocities. All 6 discordant cases had no evidence of dysfunction during 6-month follow-up.
Conclusion:
4D flow MR imaging can detect TIPS patency and stenosis, but further investigation is required before it can be used to assess for TIPS dysfunction.
Related Concept Videos
01:26Phase Contrast and Differential Interference Contrast Microscopy
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
01:26Shunt Admittances
To model this effect, the method of images is employed. This method involves replacing the Earth with an image conductor that mirrors the original...
02:31Phase Transitions
02:39Phase Diagrams
01:28Inductance: Single-Phase And Three-Phase Line
Single-Phase Two-Wire Line:
A single-phase line consists of two solid cylindrical conductors, denoted as x and y. Each conductor carries phasor currents ix and iy, respectively. Given that the sum of these currents is...
01:25Capacitance: Single-Phase And Three-Phase Line
Single-Phase Lines
Consider a single-phase, two-wire transmission line with equal phase spacing energized by a voltage source. One conductor carries a uniform positive charge, while the other carries an equal negative charge. The capacitance C of the line can be derived from the voltage V between the conductors. For a one-meter section of the line, the capacitance is given...