Respiratory effects on phase contrast imaging of the jugular vein
© Schrauben et al; licensee BioMed Central Ltd. 2012
Published: 1 February 2012
An analysis of the effect of respiratory function on MR flow measures of the internal jugular vein (IJV) is presented. A novel 2D radial acquisition and reconstruction method allows for retrospective gating to both the cardiac and respiratory cycle. In-vivo scans of human volunteers verify the efficacy of the algorithm, showing increased IJV flow during inspiration and decreased flow during expiration for each cardiac time frame.
The introduction of the CCSVI hypothesis in the diagnosis of MS has recently caused interest in intra- and extracranial venous flow measurements (1). Due to structural complexity and individual variations, flow studies in cerebrospinal veins using phase-contrast (PC) MR are rarely conducted (2). Though it has long been confirmed a source of variability in venous drainage to the heart (3), respiratory motion effects have been largely ignored in PC-MR, partially due to the difficulty and longer scan times of gating the respiratory and cardiac cycles. The purpose of this pilot study was to implement a dual-gated PC-MR sequence and investigate the effect of respiratory motion during free breathing on cerebrospinal venous flow.
Data acquired using the radial PC sequence with a double-gated reconstruction scheme confirms respiratory motion affects venous flow waveforms in the IJV. As known from ultrasound studies, the negative thoracic pressure during inspiration decreases resistance to flow in the IJV, thus increasing flow in venous drainage. Based on our initial results, we recommend that the influence of respiratory motion should be considered for quantitative venous flow measurements in the neck.
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