OBJECTIVE: The purposes of this study were to (1) validate the accuracy of cine phase-contrast MR flow measurements within the portal vein, (2) develop a suitable protocol for using this method to measure volumetric flow rate in the portal venous system, and (3) use this protocol, with Doppler sonography as a reference, to measure portal venous flow in healthy volunteers and in patients with protal venous hypertension. SUBJECTS AND METHODS: Flow determinations were obtained in a model of fluid movement approximating blood-flow conditions in the portal venous system. A suitable protocol was based on consideration of the theoretical effects of (1) spatial resolution, (2) obliquity of the imaging plane to the direction of flow, and (3) signal-to-noise ratio of the signed quantitative velocity images (in three volunteers) on the accuracy and precision of flow measurements. This protocol was used to obtain cine phase-contrast MR images of the portal venous system in five volunteers and six patients. RESULTS: Values obtained with a flow phantom showed good accuracy of cine phase-contrast-measured vs actual volumetric flow rate (r = .995; p = .0001; MR rate = [0.94 x actual rate] + 65.6 ml/min; standard error of the y estimate = 67.3 ml/min). Velocity encoding and section thickness substantially influenced the signal-to-noise ratio of the velocity images, whereas flip angle and matrix size had only minimal effect. In volunteers and patients, portal volumetric flow rates determined by using MR images and Doppler sonography showed good correlation (r = .94; p = .0003). CONCLUSION: Our results indicate that cine phase-contrast MR imaging is a practical noninvasive method for measuring volumetric flow rates in the portal venous system.
OBJECTIVE: The purposes of this study were to (1) validate the accuracy of cine phase-contrast MR flow measurements within the portal vein, (2) develop a suitable protocol for using this method to measure volumetric flow rate in the portal venous system, and (3) use this protocol, with Doppler sonography as a reference, to measure portal venous flow in healthy volunteers and in patients with protal venous hypertension. SUBJECTS AND METHODS: Flow determinations were obtained in a model of fluid movement approximating blood-flow conditions in the portal venous system. A suitable protocol was based on consideration of the theoretical effects of (1) spatial resolution, (2) obliquity of the imaging plane to the direction of flow, and (3) signal-to-noise ratio of the signed quantitative velocity images (in three volunteers) on the accuracy and precision of flow measurements. This protocol was used to obtain cine phase-contrast MR images of the portal venous system in five volunteers and six patients. RESULTS: Values obtained with a flow phantom showed good accuracy of cine phase-contrast-measured vs actual volumetric flow rate (r = .995; p = .0001; MR rate = [0.94 x actual rate] + 65.6 ml/min; standard error of the y estimate = 67.3 ml/min). Velocity encoding and section thickness substantially influenced the signal-to-noise ratio of the velocity images, whereas flip angle and matrix size had only minimal effect. In volunteers and patients, portal volumetric flow rates determined by using MR images and Doppler sonography showed good correlation (r = .94; p = .0003). CONCLUSION: Our results indicate that cine phase-contrast MR imaging is a practical noninvasive method for measuring volumetric flow rates in the portal venous system.
Authors: A Frydrychowicz; B R Landgraf; E Niespodzany; R W Verma; A Roldán-Alzate; K M Johnson; O Wieben; S B Reeder Journal: J Magn Reson Imaging Date: 2011-07-12 Impact factor: 4.813
Authors: Zoran Stankovic; Bernd Jung; Jeremy Collins; Maximilian F Russe; James Carr; Wulf Euringer; Lena Stehlin; Zoltan Csatari; Peter C Strohm; Mathias Langer; Michael Markl Journal: Magn Reson Med Date: 2013-09-09 Impact factor: 4.668
Authors: El-Sayed H Ibrahim; Kevin R Johnson; Alan B Miller; Jean M Shaffer; Richard D White Journal: J Cardiovasc Magn Reson Date: 2010-05-11 Impact factor: 5.364
Authors: Benjamin E Levy; Md Murad Hossain; Justin M Sierchio; Diwash Thapa; Caterina M Gallippi; Amy L Oldenburg Journal: IEEE Trans Ultrason Ferroelectr Freq Control Date: 2018-05-28 Impact factor: 2.725