Background
Analysis of portal venous flow (PVF) is important when evaluating the severity and prognosis of liver disease. PVF might be altered by postural changes (ie, difference in the effects of gravity).
Purpose
To evaluate the effect of gravity on PVF using a novel MRI system, which can obtain abdominal MRIs in both the supine and the upright positions.
Study Type
Prospective self control.
Subjects
Twelve healthy young male volunteers.
Field Strength/Sequence
Caval velocity‐mapped images were obtained using the electrocardiography‐triggered cine phase‐contrast technique in the supine and upright positions with multiposture MRI (paired 0.4 T permanent magnets).
Assessment
The mean PVF velocity in the region of interest in each cardiac phase was determined. A PVF curve in the cardiac cycle was also obtained from the PVF velocity multiplied by the cross‐sectional area. The mean PVF velocity, maximum PVF velocity, cross‐sectional area of the PV, mean PVF, maximum PVF, and heart rate in the supine and upright positions were assessed.
Statistical Tests
Wilcoxon signed‐rank tests were applied. P < 0.05 was considered statistically significant.
Results
The mean PVF velocity, maximum PVF velocity, cross‐sectional area of the PV, and maximum PVF were all significantly lower in the upright position compared with the supine position (P = 0.002 for all), with differences of 42% ± 15%, 38% ± 12%, 60% ± 17%, 24% ± 11%, and 22% ± 9.3%, respectively. However, heart rate was significantly higher (116% ± 9.2%, P = 0.003) in the upright position compared with the supine position.
Data Conclusion
The effect of gravity during postural change from a supine to an upright position significantly decreases the PVF. Multiposture MRI allows acquisition of more detailed information on liver function.
Level of Evidence: 2
Technical Efficacy Stage: 1
J. Magn. Reson. Imaging 2019;50:83–87.
Background Inferior vena cava flow (IVCF) and abdominal aortic flow (AAF) are essential components of the systemic circulation. Although postural changes might alter IVCF and AAF by the gravity effect, the exact details are unknown. Purpose To evaluate the effect of gravity on IVCF and AAF using a novel magnetic resonance imaging (MRI) system that can image in any position. Material and Methods Caval velocity-mapped images were obtained using the cine phase-contrast technique in the upright and supine positions with multi-posture MRI (n = 12). The mean IVCF/AAF velocity, maximum IVCF/AAF velocity, cross-sectional area of IVC/AA, mean IVCF/AAF, maximum IVCF/AAF, and heart rate in the two positions were assessed. Results The mean IVCF velocity, maximum IVCF velocity, cross-sectional area of IVC, mean IVCF, maximum IVCF, mean AAF velocity, maximum AAF velocity, mean AAF, and maximum AAF were significantly lower in the upright position compared with the supine position ( P < 0.05 for all), with differences of 52% ± 33%, 36% ± 19%, 56% ± 18%, 26% ± 18%, 19% ± 11%, 33% ± 13%, 33% ± 22%, 42% ± 21%, and 37% ± 28%, respectively. Heart rate was significantly higher in the upright position compared with the supine position (116% ± 9.2%; P = 0.003). There were no differences in cross-sectional area of AA between the two positions (108% ± 22%; P = 0.583). Conclusion The effect of gravity decreases IVCF and AAF. Clarifying the effect of gravity on IVCF and AAF during a postural change may help to improve the management of patients with circulatory disease.
In this study, we report two cases of transcatheter arterial embolization for intramammary hemorrhage caused by seat belt injuries. All patients were female drivers involved in traffic accidents. In each case, we accessed the hemorrhage through the left brachial artery and embolized the perforating branch of the left internal mammary artery with N-butyl-2-cyanoacrylate, obtaining effective hemostasis. Transcatheter arterial embolization is considered effective for breast hemorrhage because of rare but dangerous seat belt injuries.
Intravascular large B-cell lymphoma (IVLBCL) is a very rare subtype of malignant lymphoma that is difficult to diagnose. Cases of myocardial infarction caused by IVLBCL are even rarer. Herein, we report a case presenting with heart failure and delayed enhancement in the hypokinetic cardiac septum on contrast-enhanced cardiac magnetic resonance imaging. Myocardial biopsy showed large B-cell lymphoma cells in the microvessels within the myocardium. To the best of our knowledge, this is the first report of imaging findings of cardiac involvement in IVLBCL.
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