DIAGNOSTIC ACCURACY OF TUFFIER’S LINE IN DETECTION OF TRANSITIONAL VERTEBRAE KEEPING MRI AS GOLD STANDARD

Abstract

Objective:
To evaluate and compare the diagnostic accuracy of Tuffier’s line identified via clinical palpation and on MRI for detecting lumbosacral transitional vertebrae (LSTV), using full lumbar spine MRI as the gold standard.

Methodology:
This prospective diagnostic accuracy study was conducted over six months in the Radiology Department of [Hospital Name]. A total of 150 adult patients undergoing lumbar spine MRI for any clinical indication were enrolled. Participants were divided into two groups: (1) Tuffier’s line localization via clinical palpation by two blinded clinicians, and (2) Tuffier’s line localization directly on MRI by two blinded musculoskeletal radiologists. Final diagnosis of LSTV was confirmed through consensus MRI review. Sensitivity, specificity, predictive values, and overall accuracy were calculated for both groups. Inter-rater reliability was assessed using Cohen’s kappa, and subgroup analysis was conducted based on BMI, age, and sex.

Results:
LSTV was confirmed in 28 patients (18.7%) on MRI. For palpation, sensitivity was 64.3%, specificity 91.8%, and overall accuracy 86.0%. For MRI-based identification, sensitivity was 85.7%, specificity 95.1%, and accuracy 93.3%. Inter-rater agreement was substantial for palpation (κ = 0.78) and almost perfect for MRI assessment (κ = 0.89). Diagnostic accuracy of palpation decreased significantly in obese individuals (BMI ≥30), whereas MRI accuracy remained consistently high across all subgroups.

Conclusion:
Tuffier’s line palpation demonstrated high specificity but only moderate sensitivity in identifying LSTV, limiting its standalone diagnostic value. MRI-based identification of Tuffier’s line offers superior accuracy and should be considered in cases where precise vertebral localization is critical, particularly in patients with higher BMI or suspected spinal anomalies