Magnetic Resonance Imaging and GeneXpert: A Rapid and Accurate Diagnostic Tool for the Management of Tuberculosis of the Spine

Sharma, Ayush; Chhabra, Harvinder Singh; Mahajan, Rajat; Chabra, Tarun; Batra, Sahil

Abstract

STUDY DESIGN: Retrospective study. PURPOSE: The aim of this study was to analyze various diagnostic tools, including GeneXpert, for the management of tuberculosis of the spine. OVERVIEW OF LITERATURE: Traditional diagnostic methods of microscopy, histology, and culture have low sensitivity and specificity for the management of tuberculosis of the spine.
METHODS
Of the 262 treated cases of spinal tuberculosis, data on 1 year follow-up was available for 217 cases. Of these, only 145 cases with a confirmed diagnosis were selected for retrospective analysis.
RESULTS
In 145 of the 217 patients (66.80%), diagnosis was confirmed on the basis of a culture. Of the 145 patients with a confirmed diagnosis, 98 (66.20%) patients were diagnosed on the basis of clinical presentation, whereas 123 (84.8%) exhibited a typical magnetic resonance imaging (MRI) picture. In 99 surgically treated patients, the diagnosis was confirmed on the basis of an intraoperative tissue biopsy. Among the 46 patients treated conservatively, 35 underwent a transpedicular biopsy, 4 patients underwent computed tomography-guided biopsy, 6 patients were diagnosed on the basis of material obtained from a cold abscess, and 1 patient underwent an open biopsy. The sensitivity of the culture for the detection of Mycobacterium tuberculosis was 66.80% (145/217) in our patients. Among the cases in which GeneXpert was used, the sensitivity for the detection of Mycobacterium tuberculosis was 93.4% (43/46). Moreover, the sensitivity of GeneXpert to detect rifampicin resistance was 100% (7/7) in our study.
CONCLUSIONS
Majority of the patients with tuberculosis of the spine can be diagnosed on the basis of a typical radiological presentation via MRI. In our study, 84.8% cases exhibited typical MRI findings. For patients presenting with atypical MRI features, a rapid and accurate diagnosis is possible by combining GeneXpert with MRI. The combined use of MRI and GeneXpert is a rapid and highly sensitive tool to diagnose tuberculosis and rifampicin resistance in patients with tuberculosis of the spine. Furthermore, we achieved a 97.9% sensitivity for the detection of Mycobacterium tuberculosis and 100% sensitivity for the detection of rifampicin resistance in our study.