Normative MRI for Lumbar Spinal Canal and Vertebral Body Dimensions in a Jordanian Population Sample

Aim: To provide normal values for the lumbar spinal canal, lumbar vertebral body and dural sac dimensions and canal body ratio by MRI for a Jordanian population sample. Material and methods: Three well trained observers reviewed 218 lumbar MRI scans performed between 2019–2021 (1090 lumbar levels) and obtained from the central computerized medical archive of three main governmental hospitals in north, central and south Jordan. All MRIs with alignment abnormalities (scoliosis and kyphosis), canal compression, vertebral disease (including fractures) or technical artifacts were excluded. The following were measured from L1 to L5 levels: the midsagittal diameters of the spinal canal and vertebral body, axial anteroposterior (AP), and transverse diameter of the vertebral body, dural canal and dural canal area. Data on sex and age were also documented. Results: The studied MRI scans included 113 males (51.8%) and 105 females (48.2%). Age ranged between 23–86 years old (mean 52.23 ± 13.125). The mid sagittal mid vertebral AP diameter of the lumbar spine range was 2.8–3.1 cm. The mid sagittal spinal canal diameter range was 1.3–1.5 cm. Canal body ratio was 3.3–3.6. The AP, transverse dural sac diameter ranges were 1.2–1.4 cm and 1.5–1.9 cm, respectively. Finally, the dural sac area ranged from 331–362 mm2. Conclusion: The dimensions of the lumbar spinal canal, vertebral bodies, and vertebral canal ratio at all levels were documented for a Jordanian population sample. Dimensions varied according to sex and when compared with other ethnic groups (Asian and African). The findings suggest that canal stenosis criteria should take these differences into consideration.