Diagnostic Accuracy of Magnetic Resonance Spectroscopy (MRS) in differentiating Malignant and Benign Musculoskeletal Tumours, Taking Histopathology as Gold Standard

Abstract

Background: Magnetic Resonance Spectroscopy is a noninvasive imaging modality that provides biochemical information useful for characterizing musculoskeletal tumors. Early differentiation between benign and malignant lesions is essential for guiding treatment decisions. Histopathology remains the reference standard, yet it is invasive and may be delayed. This study evaluated the diagnostic accuracy of Magnetic Resonance Spectroscopy for distinguishing malignant from benign musculoskeletal tumors using histopathology as the gold standard.

Objective: To determine the sensitivity, specificity, predictive values, and overall diagnostic accuracy of Magnetic Resonance Spectroscopy in differentiating malignant and benign musculoskeletal tumors, taking histopathology as the reference.

Methods: A descriptive cross-sectional study was conducted over six months in the Radiology Department of Jinnah Hospital, Lahore. A total of 111 patients aged 20 to 60 years with suspected musculoskeletal tumors larger than 5 cm and symptoms exceeding three months were included through consecutive nonprobability sampling. Routine MRI was followed by single-voxel Magnetic Resonance Spectroscopy using PRESS sequences at TE 135 ms and TR 1500 ms. Spectral patterns were categorized as malignant or benign based on predefined metabolic criteria. Histopathology served as the gold standard. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were calculated, along with stratified analysis by age, gender, disease duration, and lesion size.

Results: Of 111 patients, the mean age was 38.64 years (SD 11.35), and 69.4% were male. Magnetic Resonance Spectroscopy identified 73 malignant cases, while histopathology confirmed 75 malignant lesions. The sensitivity of Magnetic Resonance Spectroscopy was 90.7 percent, and the specificity was 86.1 percent. The positive predictive value was 93.2 percent, and the negative predictive value was 81.6 percent. The overall diagnostic accuracy was 89.2 percent. Stratified analysis showed consistently high diagnostic performance across all subgroups of age, gender, disease duration, and lesion size.

Conclusion: Magnetic Resonance Spectroscopy demonstrated high diagnostic accuracy for differentiating malignant from benign musculoskeletal tumors. Its strong sensitivity and specificity across demographic and clinical subgroups indicate that it is a reliable noninvasive adjunct to MRI and can support early diagnostic decision-making. Incorporating Magnetic Resonance Spectroscopy into routine musculoskeletal tumor evaluation may improve diagnostic precision and reduce dependence on invasive procedures.

Keywords: Magnetic Resonance Spectroscopy, musculoskeletal tumors, malignancy, diagnostic accuracy, histopathology, MRI.