Forsberg Flemming, Stein Alan D, Liu Ji-Bin, Deng Xuedong, Ackerman William, Herzog Donald, Abend Kenneth, Needleman Laurence
Department of Radiology, Suite 763J Main Building, Thomas Jefferson University, 132 South 10th Street, Philadelphia, PA 19107, USA.
Acad Radiol. 2006 Oct;13(10):1204-10. doi: 10.1016/j.acra.2006.06.014.
Accurate measurement of blood volume flow (in ml/min) is an important clinical goal. This project compared in vitro and in vivo volume flow measurements obtained with a novel, real-time three-dimensional (i.e., four-dimensional) ultrasound scanner (Encore PV; Vuesonix Sensors, Wayne, PA) with those from an invasive transit time flowmeter.
A flow pump was used to generate pulsatile flow rates from 60 to 600 ml/min. The Encore detected absolute blood velocity vectors within a volume. The scanner determined the centerline of the vessel and volume flow was then automatically calculated. Results were compared with those of an invasive technique for volumetric blood flow measurements utilizing a transit-time flowmeter (TS420; Transonic Systems Inc., Ithaca, NY). In vivo, 10 second datasets of the volume flow in the distal aorta of six rabbits were obtained simultaneously with the Encore PV and the flowmeter. Data were compared using linear regression and Bland-Altman analysis (due to the lack of independence).
In vitro, Encore and flowmeter measurements both matched the flow pump (r2 > 0.99; P < .0001) with mean errors of -11.8% and -0.3%, respectively. Marked underestimation of the true flow rates was encountered with the Encore at the lowest pump setting. In vivo mean volume flows between 10.6 and 79.3 ml/min were measured. Mean and maximum volume flows obtained with the two techniques correlated significantly (P < .0001) with r2 values of 0.86 and 0.62, respectively. The corresponding root-mean-square errors were 6.9% for mean flow and 61.2% for maximum volume flow measurements.
A new semiautomated four-dimensional Doppler device has been tested in vitro and in vivo. Mean volume flow measurements with this unit are comparable to those of an invasive flowmeter.
准确测量血容量流量（毫升/分钟）是一项重要的临床目标。本项目将使用新型实时三维（即四维）超声扫描仪（Encore PV；Vuesonix Sensors，韦恩，宾夕法尼亚州）获得的体外和体内容量流量测量结果与侵入性渡越时间流量计的测量结果进行比较。
使用流量泵产生60至600毫升/分钟的脉动流速。Encore检测体积内的绝对血流速度矢量。扫描仪确定血管中心线，然后自动计算体积流量。将结果与使用渡越时间流量计（TS420；Transonic Systems Inc.，伊萨卡，纽约州）进行容积血流测量的侵入性技术结果进行比较。在体内，同时使用Encore PV和流量计获得六只兔子腹主动脉远端10秒的容量流量数据集。使用线性回归和布兰德-奥特曼分析（由于缺乏独立性）对数据进行比较。
在体外，Encore和流量计的测量结果均与流量泵匹配（r2>0.99；P<.0001），平均误差分别为-11.8%和-0.3%。在最低泵设置下，Encore明显低估了真实流速。在体内测量的平均容量流量在10.6至79.3毫升/分钟之间。两种技术获得的平均和最大容量流量显著相关（P<.0001），r2值分别为0.86和0.62。平均流量的相应均方根误差为6.9%，最大容量流量测量的均方根误差为61.2%。
一种新型半自动四维多普勒设备已在体外和体内进行了测试。该设备的平均容量流量测量结果与侵入性流量计相当。
