Abstract：
Previous studies have shown that the Valsalva maneuver (VM) causes spinal canal object movements. We hypothesized that this occurs because of cerebrospinal fluid (CSF) flow generated from intradural space reduction. Previous studies using myelograms reported lumbar CSF space changes during inspiration. However, no similar studies have been conducted using modern MRI. Therefore, this study analyzed intradural space reduction during the VM using cine magnetic resonance imaging (MRI).
The participant was a 39-year-old, healthy, male volunteer. Cine MRI involved fast imaging employing steady-state acquisition cine sequence during three resting and VM sets for 60 s each. The axial plane was at the intervertebral disc and vertebral body levels between Th12 and S1 during cine MRI. This examination was performed on 3 separate days; hence, data from nine resting and VM sets were available. Additionally, two-dimensional myelography was performed during rest and the VM.
Intradural space reduction was observed during the VM using cine MRI and myelography. The intradural space cross-sectional area during the VM (mean: 129.3 mm2; standard deviation [SD]: 27.4 mm2) was significantly lower than that during the resting period (mean: 169.8; SD: 24.8; Wilcoxon signed-rank test, P < 0.001). The reduction rate of the vertebral body level (mean: 26.7%; SD: 9.4%) was larger than that of the disc level (mean: 21.4%; SD: 9.5%; Wilcoxon rank sum test, P = 0.0014). Furthermore, the reduction was mainly observed on the ventral and bilateral intervertebral foramina sides at the vertebral body and intervertebral disc levels, respectively.
The intradural space was reduced during the VM, possibly because of venous dilatation. This phenomenon may be associated with CSF flow, intradural object movement, and nerve compression, potentially leading to back pain.
The participant was a 39-year-old, healthy, male volunteer. Cine MRI involved fast imaging employing steady-state acquisition cine sequence during three resting and VM sets for 60 s each. The axial plane was at the intervertebral disc and vertebral body levels between Th12 and S1 during cine MRI. This examination was performed on 3 separate days; hence, data from nine resting and VM sets were available. Additionally, two-dimensional myelography was performed during rest and the VM.
Intradural space reduction was observed during the VM using cine MRI and myelography. The intradural space cross-sectional area during the VM (mean: 129.3 mm2; standard deviation [SD]: 27.4 mm2) was significantly lower than that during the resting period (mean: 169.8; SD: 24.8; Wilcoxon signed-rank test, P < 0.001). The reduction rate of the vertebral body level (mean: 26.7%; SD: 9.4%) was larger than that of the disc level (mean: 21.4%; SD: 9.5%; Wilcoxon rank sum test, P = 0.0014). Furthermore, the reduction was mainly observed on the ventral and bilateral intervertebral foramina sides at the vertebral body and intervertebral disc levels, respectively.
The intradural space was reduced during the VM, possibly because of venous dilatation. This phenomenon may be associated with CSF flow, intradural object movement, and nerve compression, potentially leading to back pain.
摘要：
背景：先前的研究表明，Valsalva动作（VM）会导致椎管物体运动。我们假设这是由于硬膜内间隙减少产生的脑脊液（CSF）流所致。先前使用脊髓造影的研究报告了吸气过程中腰CSF空间的变化。然而,没有使用现代MRI进行过类似的研究.因此,这项研究使用电影磁共振成像（MRI）分析了VM期间硬膜内间隙的减少。
方法：参与者39岁，健康,男性志愿者电影MRI涉及在三个静息和VM设置期间使用稳态采集电影序列进行快速成像，每组60s。在电影MRI期间，轴向平面位于Th12和S1之间的椎间盘和椎体水平。此检查是在3天进行的；因此，可获得来自9个静息和VM集的数据.此外,在休息和VM期间进行二维脊髓造影.
结果：使用电影MRI和脊髓造影观察到VM期间硬膜外间隙减少。VM期间的硬脑膜内空间横截面积（平均值：129.3mm2；标准偏差[SD]：27.4mm2）显着低于静息期期间（平均值：169.8；SD：24.8；Wilcoxon符号秩检验，P<0.001)。椎体水平的降低率（平均值：26.7％；SD：9.4％）大于椎间盘水平的降低率（平均值：21.4％；SD：9.5％；Wilcoxon秩和检验，P=0.0014)。此外，主要在椎体和椎间盘水平的腹侧和双侧椎间孔侧观察到减少，分别。
结论：在VM期间硬膜内间隙减少，可能是因为静脉扩张.这种现象可能与脑脊液流动有关，硬膜内物体运动，神经压迫，可能导致背痛。
方法：参与者39岁，健康,男性志愿者电影MRI涉及在三个静息和VM设置期间使用稳态采集电影序列进行快速成像，每组60s。在电影MRI期间，轴向平面位于Th12和S1之间的椎间盘和椎体水平。此检查是在3天进行的；因此，可获得来自9个静息和VM集的数据.此外,在休息和VM期间进行二维脊髓造影.
结果：使用电影MRI和脊髓造影观察到VM期间硬膜外间隙减少。VM期间的硬脑膜内空间横截面积（平均值：129.3mm2；标准偏差[SD]：27.4mm2）显着低于静息期期间（平均值：169.8；SD：24.8；Wilcoxon符号秩检验，P<0.001)。椎体水平的降低率（平均值：26.7％；SD：9.4％）大于椎间盘水平的降低率（平均值：21.4％；SD：9.5％；Wilcoxon秩和检验，P=0.0014)。此外，主要在椎体和椎间盘水平的腹侧和双侧椎间孔侧观察到减少，分别。
结论：在VM期间硬膜内间隙减少，可能是因为静脉扩张.这种现象可能与脑脊液流动有关，硬膜内物体运动，神经压迫，可能导致背痛。
