Song Yunsun, Kim Joong-Goo, Cho Hong-Jun, Kim Jae Kyun, Suh Dae Chul
Departments of Radiology and Research Institute of Radiology, University of Ulsan, College of Medicine, Asan Medical Center, Seoul, Korea.
Department of Family Medicine, University of Ulsan, College of Medicine, Asan Medical Center, Seoul, Korea.
PLoS One. 2017 Sep 27;12(9):e0184551. doi: 10.1371/journal.pone.0184551. eCollection 2017.
Changes in cerebral blood flow (CBF) immediately after cigarette smoking (CS) are still unclear. Our purpose was to evaluate the hemodynamic changes in each intracranial vessel after CS by using quantitative magnetic resonance angiography (MRA).
Fifteen healthy male smokers less than 45 years old with more than 3 pack-year smoking history were enrolled in this study. The hemodynamic change in the vessels, represented by cerebral flow rate (CFR, ml/s) and flow velocity (FV, cm/s), was quantitatively measured in eleven vascular segments of the brain using phase-contrast MRA. Two sets of data at each vessel before and after CS were statistically analyzed by paired t-test. Three of 15 participants, as a control group, followed all the procedures but did not smoke.
Total CFR of the distal intracranial vessels (anterior, middle, and posterior cerebral arteries; ACA, MCA, and PCA) was significantly reduced after CS by 7.3% (847 vs. 785 ml/s, p = 0.024). Such flow changes were statistically more significant in the anterior circulation (ACA and MCA) compared to the posterior circulation (PCA). All distal intracranial vessels did not have significant FV change while peak systolic velocity and mean velocity dropped 7.4 and 4.3% and pulsatility index decreased 10.9% in the internal carotid artery. Regarding cross-sectional areas, all distal intracranial vessels showed diminished, and only MCA had a statistical significance (9.9 vs. 9.3 mm2, p = 0.016).
There was a significant decrease of CFR after CS especially in the anterior circulation of twelve young male smokers. Considering the changes of FV and cross-sectional area all together, it can be suggested that cerebrovascular impedance increased after CS especially at the main trunk level of the distal intracranial vessels (ACA, MCA, and PCA).
吸烟后即刻脑血流量（CBF）的变化仍不明确。我们的目的是通过定量磁共振血管造影（MRA）评估吸烟后各颅内血管的血流动力学变化。
本研究纳入了15名年龄小于45岁、吸烟史超过3包年的健康男性吸烟者。使用相位对比MRA定量测量大脑11个血管节段中以脑血流速率（CFR，ml/s）和血流速度（FV，cm/s）表示的血管血流动力学变化。对15名参与者中的3名作为对照组，遵循所有程序但不吸烟。对每位参与者吸烟前后各血管的两组数据进行配对t检验统计分析。
吸烟后颅内远端血管（大脑前动脉、大脑中动脉和大脑后动脉；ACA、MCA和PCA）的总CFR显著降低了7.3%（847 vs. 785 ml/s，p = 0.024）。与后循环（PCA）相比，这种血流变化在前循环（ACA和MCA）中在统计学上更显著。所有颅内远端血管的FV没有显著变化，而颈内动脉的收缩期峰值速度和平均速度分别下降了7.4%和4.3%，搏动指数下降了10.9%。关于横截面积，所有颅内远端血管均减小，只有MCA具有统计学意义（9.9 vs. 9.3 mm2，p = 0.016）。
吸烟后CFR显著降低，尤其是在12名年轻男性吸烟者的前循环中。综合考虑FV和横截面积的变化，可以认为吸烟后脑血管阻抗增加，尤其是在颅内远端血管（ACA、MCA和PCA）的主干水平。
