目的　探讨腰骶移行椎与骶骨之间椎间盘的MRI影像特点。　方法　对52例腰骶移行椎患者的MRI及X线片影像学进行分析。　结果　Ⅰ型23.1%（12例）、Ⅱ型17.3%（9例）、Ⅲ型48.1%（25例）、Ⅳ型11.5%（6例）。Ⅰ型腰骶移行椎与骶骨间椎间盘的形态与正常腰椎的L5/S1椎间盘相同；Ⅱ型与正常相近，但有发育不良现象；Ⅲ型和Ⅳ型则明显发育不良。　结论　Ⅰ型的椎间盘具备与正常L5/S1椎间盘相同的功能；Ⅱ型其椎间盘接近正常L5/S1椎间盘；Ⅲ型和Ⅳ型则为残存椎间盘，几乎不具备椎间盘功能，无退变发生。

Objective　To explore MRI features and clinic significance of the disc between the lumbosacral transitional vertebrae (LSTV) and the sacrum.　Methods　The MRI and X-ray data from 52 patients with lumbosacral transitional vertebrae, and the average age of 49.3 years, were analyzed. 　Results　 The LSTV types of Ⅰ, Ⅱ, Ⅲ and Ⅳ were 23.1%（12 cases）, 17.3% (9 cases), 48.1% (25 cases) and 11.5% (6 cases) respectively according to the Castellvis classification. The disc between LSTV Ⅰ and the sacrum were significantly less degenerative than the disc immediately above the LSTV, more like the remnant compared with the disc at the other levels. However, the lumbar discs immediately above the LSTV were more significantly degenerative than the disc at the other levels.　Conclusions　The disc between the LSTV and the sacrum is a kind of remnant and less degenerative, especially in the Ⅲ and Ⅳ types, for its' stability between the transitional vertebrae and the sacrum could be preserved by the articulation or bony union between the LSTV and the sacrum through its transverse process, which protect the disc from the degeneration in the long term.