The prevalence and clinical significance of transitional vertebrae: a radiologic investigation using whole spine spiral three-dimensional computed tomographic images

Abstract

Background Errors in counting spinal segments are common during interventional procedures when there are transitional vertebrae. In this study, we investigated the prevalence of the transitional vertebrae including thoracolumbar transitional vertebra (TLTV) and lumbosacral transitional vertebrae (LSTV). The relationship between the existence of TLTV and abnormal rib count or the existence of LSTV were also evaluated. Methods The vertebral levels were counted craniocaudally, starting from C1, based on the assumption of 7 cervical, 12 thoracic, and 5 lumbar vertebrae, using whole spine spiral three-dimensional computed tomographic images. The 20th and 25th vertebrae were defined as L1 and S1, respectively. Results In total, 150 patients had TLTV, with a prevalence of 11.2% (150/1,340). LSTV was observed in 111 of 1,340 cases (8.3%). Sacralization was observed in 68 of 1,340 cases (5.1%) and lumbarization in 43 of 1,340 cases (3.2%). There was a significant relationship between the existence of TLTV and the abnormal rib count (odds ratio [OR]: 117.26, 95% confidence interval [95% CI]: 60.77–226.27; P < 0.001) and LSTV (OR: 7.38, 95% CI: 3.99–13.63; P < 0.001). Conclusions Our study results suggest that patients with TLTV are more likely to have an abnormal rib count or LSTV. If a TLTV or LSTV is seen on the fluoroscopic image, a whole spine image is necessary to permit accurate numbering of the lumbar vertebra.

An Automated Treatment Planning Framework for Spinal Radiation Therapy and Vertebral-Level Second Check

“…These three criteria signify important considerations for clinical practice. As noted by many authors, an imaging protocol which allows for -whole spine imaging‖ or contains C1 or T1 in the scan allows for the correct method of enumeration 14,44,45 . For most clinics with 3-dimensional treatment planning capability, a slice thickness of 2.5mm or 3.0 mm for simulation of conformal EBRT treatments is common.…”

“…Thus, the use case of the framework for the typical 3-D based clinical simulation procedure is supported. Given that the incidence of numerical variants is 7.7% 44 , transitional thoracolumbar vertebrae is 12.6% 46 , lumbosacral transitional vertebrae is 4%-35.9% 15,45 , and twelve normal rib bearing vertebrae is 91.6% 45 , proper image protocol or access to prior imaging is essential to prevent mislabeling errors.…”

Prediction of successful caudal epidural injection using color Doppler ultrasonography in the paramedian sagittal oblique view of the lumbosacral spine

“…Third, the possibility that the vertebra, which Yoo, et al is expected to be L5 on ultrasound, is actually S1, due to lumbarization of S1, cannot be excluded. Although accurate lumbar vertebra numbering is possible through whole spine images [25], preoperative whole spine images of all patients were not obtained uniformly.…”

Vertebrae at the thoracolumbar junction: A quantitative assessment using CT scans

“…Vertebrae at the thoracolumbar junction can potentially be either thoracic, lumbar, or thoracolumbar transitional vertebrae (TLTV). Transitional vertebrae are defined as vertebrae that result from overlapping somites resulting in blended regional features of adjacent vertebrae in the spine (Doo et al, 2020;Oostra et al, 2005). Controversy regarding the classification of TLTV however still exists, with some authors rooting their findings by using the articulation of hypoplastic ribs to the vertebra as the identifying feature of TLTV (Carrino et al, 2011;Park et al, 2016aPark et al, , 2016b.…”

“…Differentiation of vertebrae between anatomical regions of the spine can be done through assessment of vertebral morphology using radio‐imaging modalities (Dias, 2007; Zaneb et al, 2013). (Doo et al, 2020; Lewis et al, 2009; McLain, 2006; Park et al, 2020; Wu et al, 2021). Features that are commonly examined to differentiate between the respective regions include the spinous process, vertebral body, and direction of joint facets along with unique features for each region such as transverse foramina, costal facets or anterior sacral foramina.…”