Department of Radiology, Military Teaching Hospital Clermont-Tonnerre, Rue du colonel Fonferrier, 29240, Brest Cedex 9, France.
Department of Radiology, University Hospital La Cavale Blanche, Brest, France.
Eur Radiol. 2019 May;29(5):2608-2615. doi: 10.1007/s00330-018-5798-z. Epub 2018 Nov 9.
To evaluate the value of psoas muscle proximal insertion for correct numbering of the lumbar vertebrae in MRI, in particular in case of lumbosacral transitional vertebra (LSTV).
Two radiologists assessed 477 MRI scans of the lumbar spine with a sagittal localizer sequence on the whole spine for numbering vertebrae caudally from C2. Proximal insertion of the psoas was determined as the most proximal vertebra with psoas over half of its body on coronal T2 STIR sequence. The last lumbar vertebra was named considering both its number and the presence or absence of LSTV according to Castellvi classification. These same parameters were also assessed on 207 PET-CT scans of another cohort including the whole spine.
Proximal insertion of the psoas was L1 in 94.1% of cases: 98.5% in case of modal anatomy, 81.4% in case of LSTV, and 51.7% in case of missing or supernumerary lumbar vertebra without LSTV. There was no statistically significant difference between MRI and CT data. The inter-reader agreement for determination of psoas proximal insertion was excellent (kappa = 0.96).
Proximal insertion of the psoas muscle is a helpful marker for correct numbering of the lumbar vertebrae in MRI and to detect a complete lumbosacral segmentation anomaly.
• Proximal insertion of the psoas muscle can be easily identified on a coronal T2 STIR sequence. • Psoas proximal insertion on the spine almost always designates the first lumbar vertebra and is helpful to accurately number all lumbar vertebrae, especially in case of lumbosacral transitional vertebra. • Conversely, when psoas muscle does not insert five lumbar bodies above the apparent lumbosacral joint, the probability of variation in the number of lumbar vertebrae is high.
评估腰大肌近端附着点在 MRI 中正确标记腰椎的价值，特别是在腰骶移行椎（LSTV）的情况下。
两位放射科医生评估了 477 例腰骶部 MRI 扫描，在整个脊柱矢状定位序列上从 C2 向下对椎体进行编号。在冠状 T2 STIR 序列上，腰大肌近端附着点定义为具有超过一半身体被腰大肌覆盖的最接近椎体。最后一个腰椎的命名考虑了其编号以及根据 Castellvi 分类存在或不存在 LSTV。同样的参数也在另一组包括整个脊柱的 207 例 PET-CT 扫描中进行了评估。
腰大肌近端附着点在 94.1%的病例中为 L1：典型解剖结构为 98.5%，LSTV 为 81.4%，无 LSTV 时缺失或多腰椎为 51.7%。MRI 和 CT 数据之间无统计学差异。确定腰大肌近端附着点的两位读者之间的一致性非常好（kappa=0.96）。
腰大肌近端附着点是 MRI 中正确标记腰椎和检测完全腰骶分段异常的有用标记。
腰大肌在冠状 T2 STIR 序列上很容易识别。
脊柱上腰大肌的近端附着点几乎总是指定第一腰椎，有助于准确标记所有腰椎，特别是在腰骶移行椎的情况下。
相反，当腰大肌在明显的腰骶关节上方没有插入五个腰椎体时，腰椎数量变化的可能性很高。
