Evaluation of sensitivity, specificity and diagnostic accuracy of MRI image of proton density weight along with T1 and T2 weight images in intervertebral disc herniation and its comparison with routine T1 and T2 weight images

Abstract

ABSTRACT Background and Aim: Disc herniation is the main causes of back pain with the origin of spinal cord. Although MRI is the preferred method with high diagnostic sensitivity, definitive diagnosis based on MRI image interpretation is still a major challenge. The aim of this study is to evaluate the clinical and morphological findings on different MRI sequences and then assessment of the agreement between different observers. Materials and Methods: In this study, MRI images at T1, T2, and PD sequences of 224 patients with disc herniation were analyzed and diagnosed separately by two radiologists. The morphological type of disc herniation and the location of the involved disc were diagnosed by physicians and recorded with demographic information and patient history. In this study, the prevalence of disc in terms of age, sex, anatomical involvement, and morphological type of involvement were analyzed and finally, the agreement between observers in the diagnosis was examined. Results: 40% of the cases were bulge, 38% protrusion, 13% extrusion and 9% sequestration. Bulge was further diagnosed at T1 sequence, protrusion and sequestration at T2 and PD sequences, and extrusion was diagnosed similar at three sequences. There was complete agreement between the observers in determination of anatomical location, but in terms of morphological type, the agreement between observers kappa coefficient was 0.45. All agreements were observed in the diagnosis of bulge and protrusion, no agreement was observed in the extrusion and sequestration stages. Conclusion: Although MRI imaging is highly sensitive in the diagnosis of disc herniation, definitive diagnosis of disc herniation is now a diagnostic challenge among physicians. In order to increase agreement between observers, the use of other diagnostic methods beside MRI, as well as integrated and continuous training of methods for interpreting MRI images based on Best Evidence Medical Education (EBM) may be recommended.

Keywords: Disc Herniation, MRI sequences, Observer agreement, Disc location, disc level