Duerk J L, Pattany P M
Cleveland Metropolitan General Hospital, Radiology Dept., Ohio 44109.
Magn Reson Imaging. 1988 May-Jun;6(3):321-33. doi: 10.1016/0730-725x(88)90409-2.
In-plane flow quantification in MRI offers the potential for assessing vessel patency, and both volume flow rate and flow velocity. These techniques will have definite future impact on MR angiography. The method used in this paper employs motion artifact suppression technique (MAST) gradients to refocus spins travelling along any of the three imaging axes while encoding the velocity component along the phase encoding axis. This method has several advantages over in-plane flow quantification along the read axis. Primarily, flow voids due to complete spin dephasing can be eliminated (or reduced), wider velocity limits can be measured, and gradients can be designed which are sensitive to only velocity along the phase axis with no additional effect from higher order derivatives, or motion along the read axis. Flow phantom studies, carried out on 19 mm inside diameter glass tubes, have produced accurate results for flow rates ranging from 0.6 gallons per minute (GPM) to 2.5 GPM, corresponding to a mean velocity range from 13.2 cm/sec to 55.3 cm/sec. Reynolds numbers varied from 2,700 to 11,500. Errors were less than or equal to 8% over the range of flow rates studied.
磁共振成像（MRI）中的平面内血流定量为评估血管通畅性、体积流速和流速提供了可能。这些技术将对磁共振血管造影产生明确的未来影响。本文所采用的方法利用运动伪影抑制技术（MAST）梯度，在对沿相位编码轴的速度分量进行编码时，使沿三个成像轴中任何一个轴行进的自旋重新聚焦。与沿读出轴进行平面内血流定量相比，该方法具有多个优点。主要优点包括：由于完全自旋去相而产生的血流空洞可以消除（或减少），可以测量更宽的速度范围，并且可以设计仅对沿相位轴的速度敏感的梯度，而不受高阶导数或沿读出轴的运动的额外影响。在内径为19毫米的玻璃管上进行的血流模型研究，对于流速范围从每分钟0.6加仑（GPM）到2.5 GPM（对应平均速度范围从13.2厘米/秒到55.3厘米/秒）产生了准确的结果。雷诺数在2700到11500之间变化。在所研究的流速范围内，误差小于或等于8%。
