- Workshop presentation
- Open Access
Technique for retrospective respiratory and cardiac-gated phase contrast flow measurements
© Anderson et al; licensee BioMed Central Ltd. 2012
- Published: 1 February 2012
- Active Respiration
- Deep Breathing
- Respiratory Phasis
- Inspiration Phase
- Phase Contrast Flow Measurement
A technique for evaluation of respiratory impact on cardiac-gated phase contrast flow acquisitions is proposed. An example study was performed showing the effect of active respiration on CSF flow through the spinal canal.
The effect of the respiratory cycle on flow is well documented for cerebrospinal venous return  and CSF flow . However, cranial phase contrast (PC) MR flow measurements neglect the influence of respiration. Breath-held acquisitions are possible, but mask physiological flow changes that occur during active respiration. Here we demonstrate a technique to evaluate the effects of active respiration on CSF flow measurements throughout the cardiac cycle for 2 respiration states.
Three volunteers were scanned on a clinical 3T system with 2D radial PC acquisitions  between the C2 and C3 vertebrae: TR/TE = 9.4/6.1 ms, tip = 5°, resolution = 0.9x0.9x5 mm, and Venc = 8cm/s. Data were acquired during inspiration and expiration breath holds (1500 projections, 30 s), and during regular free and deep breathing (8000 projections, 2:32 min). Triggering was accomplished with pulse oximeter and bellow signals.
This study shows the feasibility of double retrospectively gated PC MR imaging for assessing flow in respiratory phases. The reconstruction scheme can be easily adjusted to capture additional respiratory phases at the expense of additional scan time. Our initial results demonstrate changes in CSF flow due to respirator phase, namely an overall increase in forward flow, as well as a decrease in reverse flow, leading to a significant increase in net flow during inspiration. This method can also be used to assessing venous and other flow affected by respiration.
NIH NHLBI R01HL072260.
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.