Determining the Lumbar Vertebral Segments on Magnetic Resonance Imaging

Abstract

The addition of a cervicothoracic localizer scan in magnetic resonance imaging of the lumbosacral spine is highly recommended.

Lumbosacral Transitional Vertebrae: Classification, Imaging Findings, and Clinical Relevance

“…Using a sagittal cervicothoracic MR localizer alone assumes 7 cervical and 12 thoracic vertebrae and does not account for thoracolumbar transitions or allow differentiation of dysplastic ribs from lumbar transverse processes. The addition of a coronal MR cervicothoracic localizer increases the accuracy of enumerating lumbosacral transitional vertebrae 13 because it allows better differentiation at the thoracolumbar junction. However, given the large field of view and increased section thickness of these localizers, they still commonly do not provide enough reliable anatomic information to consistently number the segments of the lumbar spine correctly.…”

“…LSTVs are common in the general population, with a reported prevalence of 4%-30%. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] The degree of morphologic variation of these segments ranges from L5 vertebrae with broadened elongated transverse processes to complete fusion to the sacrum. Conversely, the S1 vertebral segment can show varying degrees of lumbarization, such as the formation of an anomalous articulation rather than fusion to the remainder of the sacrum, well-formed lumbar-type facet joints, a more squared appearance in the sagittal plane, as well as a well-formed fully-sized disk, rather than the smallersized disk typically seen between S1 and S2.…”

“…Additionally, although the relationship of low back pain and LSTV, termed "Bertolotti Syndrome," has been debated in the literature since its initial description in 1917, many support this association. [2][3][4]8,9,12,13,[15][16][17][18][19][20][21][22][23][24][25][26][27][28] Symptoms can originate from the anomalous articulation itself, the contralateral facet joint (when unilateral), instability and early degeneration of the level cephalad to the transitional vertebrae, and nerve root compression from hypertrophy of the transverse process. 2,3,5,8,9,12,20,24,[29][30][31] The symptoms associated with each of the above processes are treated differently, requiring reliable techniques to not only identify LSTVs but also determine the type and site of the pathology generated by the transitional segment.…”

Thoracolumbar junction: morphologic characteristics, various variants and significance

“…In the typical method of spinal enumeration, [1][2][3][4][5][6] the last thoracic vertebra is defined by counting down from the second cervical vertebra (C2) or the first thoracic vertebra (T1) under the assumption that there are 12 thoracic vertebra. However, this method may be prone to error because the number and distribution of thoracic and lumbar segments exhibit considerable variation, even though the cervical spine has a relatively stable morphology and a fixed vertebral count of seven.…”

Filum terminale lipomas: imaging prevalence, natural history, and conus position

“…20,21 We used the commonly accepted technique of labeling the most caudal of the rectangular-type vertebrae as the fifth lumbar level. 9,20,31,32 This technique does not readily take into account those with more than or fewer than 5 lumbar vertebrae.…”