Larsen J L, Olsen K O
Department of Diagnostic Radiology, Haukeland Hospital, University of Bergen, Norway.
Acta Radiol. 1991 May;32(3):214-9.
A radio-anatomical study was performed of the distal dural sac (DS) in 121 patients subjected to myelography. In 83.4% the termination of the DS was located from the upper half of the S1-segment to the lower half of the S2-segment. In the remaining patients the dural terminations were more distally located. The average location of the DS-termination was higher than that found in a previous anatomic study. The inference is that in patients with low-back pain and sciatica, the DS tends to terminate at a higher spinal level than in a non-selected anatomic material. The caudal reduction in sagittal diameter of the DS was less than that of the frontal diameter of the sac. The linear diminution in cross-sectional area of the DS from the level of L3 towards the lumbo-sacral junction was not correlated with the degree of caudal extension of the DS into the sacrum. Thus the length of the DS and its transverse diameters are independent of each other. These results supported the view that the location of the termination of the DS (and hence that of the spinal cord) is not related to stenosis of the central spinal canal.
对121例行脊髓造影的患者进行了硬膜囊远端（DS）的放射解剖学研究。83.4%的患者硬膜囊终止于S1节段上半部分至S2节段下半部分。其余患者的硬膜终止位置更靠下。硬膜囊终止的平均位置高于先前解剖学研究中的发现。由此推断，在患有腰痛和坐骨神经痛的患者中，硬膜囊往往比在非选择性解剖材料中终止于更高的脊髓节段水平。硬膜囊矢状径的尾侧缩小小于其额径缩小。从L3水平至腰骶交界处，硬膜囊横截面积的线性减小与硬膜囊向骶骨尾侧延伸的程度无关。因此，硬膜囊的长度及其横径彼此独立。这些结果支持了硬膜囊（以及脊髓）终止位置与中央椎管狭窄无关的观点。
