Ley Sebastian, Kreitner Karl-Friedrich, Morgenstern Iris, Thelen Manfred, Kauczor Hans-Ulrich
Department of Radiology, Langenbeckstr. 1, 55131 Mainz, Germany.
AJR Am J Roentgenol. 2002 Nov;179(5):1209-15. doi: 10.2214/ajr.179.5.1791209.
The purpose of our study was to compare differences in flow between the pulmonary and systemic circulations by assessing MR phase-contrast flow measurements and CT measurements of dilated bronchial arteries in patients with chronic thromboembolic pulmonary hypertension.
Seventeen patients were included in this study. MR phase-contrast flow measurements were used to calculate the net forward volumes in the right and left pulmonary arteries and in the ascending aorta. Single-detector helical CT scans were assessed for the presence of dilated bronchial arteries that could be delineated from the descending aorta to the mainstem bronchi. Their perpendicular cross-sectional area at the level of the main bronchi was measured using a double-threshold region of interest (> or =100-3072 H).
The mean net forward volume in the aorta was 44.6 mL per heartbeat (R-R interval) and in the pulmonary arteries, 30 mL per R-R interval. Thus, the mean difference was 14.6 mL per R-R interval; this value represents the shunt volume between the systemic arterial and pulmonary venous circulations. On CT, dilated bronchial arteries were depicted in all patients (mean, three arteries per patient). The mean cross-sectional area of the bronchial arteries was 0.19 cm(2). Pearson's correlation coefficient (r) between cross-sectional area and shunt volume was 0.86 (p < 0.01).
MR imaging was able to reveal substantial differences in flow between the systemic arterial and pulmonary venous circulations in patients with chronic thromboembolic pulmonary hypertension. These differences correlated well with the diameters of the bronchial arteries seen on helical CT. Furthermore, these differences resolved after pulmonary thromboendarterectomy. MR imaging enables the accurate estimation of flow in the bronchial arteries in patients with chronic thromboembolic pulmonary hypertension.
我们研究的目的是通过评估慢性血栓栓塞性肺动脉高压患者的磁共振相位对比血流测量结果和扩张支气管动脉的CT测量结果，比较肺循环和体循环之间的血流差异。
本研究纳入了17例患者。采用磁共振相位对比血流测量法计算右、左肺动脉及升主动脉的净向前流量。对单排螺旋CT扫描进行评估，以确定是否存在可从降主动脉至主支气管清晰显示的扩张支气管动脉。在主支气管水平测量其垂直截面积，采用双阈值感兴趣区（≥100-3072 H）。
主动脉的平均净向前流量为每心跳（R-R间期）44.6 mL，肺动脉为每R-R间期30 mL。因此，平均差值为每R-R间期14.6 mL；该值代表体循环动脉和肺静脉循环之间的分流体积。在CT上，所有患者均显示有扩张的支气管动脉（平均每位患者3条动脉）。支气管动脉的平均截面积为0.19 cm²。截面积与分流体积之间的Pearson相关系数（r）为0.86（p<0.01）。
磁共振成像能够揭示慢性血栓栓塞性肺动脉高压患者体循环动脉和肺静脉循环之间的血流存在显著差异。这些差异与螺旋CT上所见支气管动脉的直径密切相关。此外，这些差异在肺动脉血栓内膜剥脱术后消失。磁共振成像能够准确估计慢性血栓栓塞性肺动脉高压患者支气管动脉的血流情况。
