Reliability and validity of a new measurement of lumbar foraminal volume using a computed tomography

• Published in: Surgical and radiologic anatomy (English ed.) Vol. 37; no. 1; pp. 93 - 99
• Main Authors: Khiami, Frédéric, Aziria, Sid-Ali, Ragot, Stéphanie, Pascal-Moussellard, Hugues, Richer, Jean-Pierre, Scepi, Michel, Brèque, Cyril, Hirsch, Caroline
• Format: Journal Article
• Language: English
• Published: Paris Springer Paris 01.01.2015; Springer Nature B.V
• Subjects: Adult; Anatomy; Computers; Cross-Sectional Studies; Female; Humans; Imaging; Lumbar Vertebrae - diagnostic imaging; Male; Measurement techniques; Medical Imaging; Medicine; Medicine & Public Health; NMR; Nuclear magnetic resonance; Orthopedics; Prospective Studies; Radiology; Reference Values; Reliability; Reproducibility of Results; Surgery; Tomography; Tomography, X-Ray Computed; Validity; Young Adult; Foraminal stenosis; Lumbar foramen; Foraminal size; Low back pain; Degenerative intervertebral disk
• ISSN: 0930-1038; 1279-8517
• DOI: 10.1007/s00276-014-1324-4

Purpose Measuring foraminal stenosis is generally determined by an area calculation. It is difficult to know exactly where it is most appropriate to measure. No precise data are available on a method for calculating the foraminal volume using a CT. To develop a new method for measuring lumbar foraminal volume, we analyzed repeatability and reliability for measuring methods for foraminal volume using CT. Methods The measurements were performed using a CT scan from ten healthy patients, with a mean age of 26.3 years. L3–L4, L4–L5 and L5–S1 foramen were studied, to obtain 60 foraminal measurements. Inter- and intra-observer reproducibility was calculated. Each series was analyzed using the VitreaCore ® reconstruction software for volume calculation. Results Average volume measurements of 60 foramina and 20 L4–L5 foramina were, respectively, 1.17 and 1.25 mm 3 for observer 1 and 1.21 and 1.29 for observer 2. The intra-observer correlation coefficients for observer 1 when measuring all foramina and L4–L5 foramina were 0.98 and 0.99, respectively. For observer 2, coefficients were 0.90 and 0.92, respectively. The inter-observer correlation coefficients for observer 1 when measuring all foramina and L4–L5 foramina were 0.78 and 0.83, respectively. For observer 2, coefficients were 0.77 and 0.8, respectively. The average differences in intra- and inter-observer measurements regardless of the evaluator group were less than 0.2 mm 3 . Conclusions This is the first study measuring lumbar foraminal volume using CT. The excellent reproducibility of this simple measure can supplement a range of foramen measurement tools.