CT-Volumetry of lumbar vertebral bodies: analysis in normal patients and patients with hypoplasia of lumbar vertebra L5 and spondylolysis. 2010
General Spine
Guido, E, Wilms, MD, PhD
Endry, Willems, MD, Non ASSR Member
Bart, De Dobbelaer, Non ASSR Member
Frederik, De Keyzer, Non ASSR Member
Paper/Non-Mentor
Purpose
To get numerical information on the volume of vertebral bodies L3, L4 and L5 in normal patients and patients with suspected hypoplasia L5.
Methods & Materials
We performed CT of the lumbar spinal canal in 51 consecutive normal controls and in 8 patients with bilateral spondylolysis and visually hypoplastic appearance of lumbar vertebra L5, with reduction of the anteroposterior diameter and wedging. Lumbar vertebral body volume of L3, L4 and L5 was measured by CT volumetry with a semi-automated program, created with MeVisLab.
Results
In the control group the average vertebral body volume of L3 was 39.3+/-7.3 cm3, 40.2+/-7.2 cm3 for L4 and 38.1+/-6.8 cm3 for L5. In patients with suspected hypoplasia L5 the average body volume was 41.8+/-7.9 cm3 for L3, 42.0+/-7.3 cm3 for L4 and 36.4+/-5.8 cm3 for L5.
There was a significant difference between the ratio L5/L4 (P<0.0001) between both groups. The mean ratio L5/L4 in the control group was 94.7+/-4.4%, the ratio for the hypoplastic L5 group was 86.9+/-2.4%.
However the difference in mean vertebral body volume for L3, L4 and L5 between both groups was not significant.
Conclusion
There is no significant difference in the vertebral body volume for L3, L4 and L5 between patients in the control group and patients with suspected hypoplasia, due to variations in body constitution.
However the relation between the body volume of L5 and L4 is significantly different between both groups. L5 proved to be on average 13% smaller than L4 in the group with bilateral spondylolysis and visually hypoplastic L5 whereas the difference in the control group was only 5%.
References/Financial Disclosures
Wilms G, Maldague B, Parizel P, Meylaerts L, Vanneste D, Peluso J. Hypoplasia of L5 and wedging and pseudospondylolisthesis in patients with spondylolysis: study with MR imaging. AJNR Am J Neuroradiol. 2009 30(4):674-80. Epub 2009 Jan 15.