正常及异常腰段后韧带的MR表现

MR Imaging of Normal and Abnormal Lumbar Posterier Longitudinal Ligament

目的：分析腰段后纵韧带的形态、结构及在不同ＭＲ序列上的表现，测量正常值。探讨后纵韧带破裂的依据和病理基础以及后纵韧带改变的原因。材料及方法：腰段标本四具，分析解剖结构，腰椎ＭＲ检查正常者４０例，手术病理证实穿韧带型髓核突出２６例，后纵韧带增厚钙化１例，结核脓肿３例及转移瘤４例。ＳＥ序列Ｔ１ＷＩ，Ｔ２ＷＩ矢状、轴位检查。结果：正常后纵韧带在ＳＥ序列上呈线状低信号，矢状位厚度为１２±０２ｍｍ，破裂时表现为低信号线中断、移位，脓肿及转移瘤者后纵韧带无或部份破坏，注ＧｄＤＴＰＡ后有助于鉴别后纵韧带有无浸润和破坏。结论：ＭＲ是测量正常。

Purpose: To analyse the shapes、 structures and the MR appearance of lumbar posterieer longitudinal ligament (PLL) at the different SE sequence, to measure it's normal size; to verify the patterns and pathological basis of the disrupted lumbar PLL and the common reasons of lumbar PLL changes. Materials and Methods: Sagittal section of two lumbar spines in the midline plane and coronal section of two lumbar spines at the roots of pedicles were dissected for analysing the lumbar PLL. MRI of 40 normal lumbar spines, 26 transligament herniation patients, 1 case of calcification and thinckness of PLL, 3 tuberculous abscess and 4 metastasis were confirmed by operation, SE sequence on T 1WI and T 2WI with 2 acquisition, sagittal and axial imaging and FOV 18cm. Results: Normal PLL showed linear low signal intensity in SE sequence. The thick of PLL was 1.2±0.2mm on sagittal plane. The appearance of disrupted lumbar PLL presented disconnected low signal and movement with the side of herniation. But the abscess and metastasis showed partial or non destruction of PLL. It is useful to determine the infiltration and destruction of PLL after injection of Gd DTPA. Conclusion: MRI is a reliable method in showing a normal and abnormal lumbar PLL.