Musculoskeletal (MSK) lesions include a wide range of neoplastic, non-neoplastic, and tumor-like conditions that frequently require imaging for diagnosis. However, unnecessary imaging is commonly performed because clinicians may be unfamiliar with the characteristic clinical and radiographic features of these lesions and with appropriate diagnostic pathways. As a result, patients are often subjected to multiple imaging studies—radiographs, ultrasound, CT, MRI, PET, and bone scans—many of which may not contribute meaningfully to diagnosis or treatment [1]. Excessive imaging increases healthcare costs, exposes patients to avoidable radiation, and may delay definitive management. Radiography remains the recommended first-line modality for evaluating bone tumors because of its high diagnostic value [1]. Ultrasound helps assess superficial soft-tissue lesions, CT is useful in complex anatomical regions and for identifying cortical breach or calcification [2], and MRI is superior for local staging and evaluating marrow, joint, and neurovascular involvement. PET and angiography also play selective roles, though PET uptake may occur in non-malignant conditions [3]. Despite advances in imaging and surgical management, inappropriate imaging continues to be reported. Western studies have shown wide variation in unnecessary MRI and CT use, with inappropriate rates ranging from 6% to over 40% [2-6]. However, no similar evaluation has been conducted in the Indian setting. This study therefore aims to assess the usefulness of commonly used imaging modalities in MSK lesions and to determine inter-observer agreement regarding their utility.

Study Design and Setting A prospective analytical study was conducted at the Department of Radiodiagnosis, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi. Patients referred between 1 January 2021 and 30 August 2022 for evaluation of suspected MSK lesions were included. Sample Size Twenty-one patients comprising 58 imaging investigations were evaluated. Inclusion Criteria Patients of any age or gender with suspected MSK neoplastic, tumor-like, or infective lesions. Exclusion Criteria • Primary joint or ligament involvement • Extra skeletal soft-tissue tumors • Fresh fractures or superficial abscesses of diffuse inflammation Data Collection For each patient, clinical details, prior imaging, laboratory investigations, and referral notes were recorded. All imaging studies were independently reviewed by two radiologists with 30 and 18 years of experience. Assessment of Usefulness An imaging study was considered useful if it contributed meaningfully to diagnosis, narrowed the differential diagnosis, assisted in staging, or influenced management. The reasons for an imaging study being judged unnecessary were also documented. Statistical Analysis Usefulness was expressed as proportions. Agreement between the two reviewers was assessed using Cohen’s kappa statistic. A p-value <0.05 was considered significant.

Table 1. Age and Gender Distribution of Study Participants (n = 21) Age Group (years) Male (n) Female (n) Total (n) Percentage (%) 0–10 1 1 2 9.5 11–20 5 5 10 47.6 21–30 2 1 3 14.3 31–40 1 1 2 9.5 41–50 1 1 2 9.5 >50 1 1 2 9.5 Total 11 10 21 100 The study included 21 patients, comprising 11 males and 10 females. The majority (47.6%) were between 11 and 20 years of age. Smaller proportions were observed in the 0–10 years (9.5%), 21–30 years (14.3%), 31–40 years (9.5%), 41–50 years (9.5%), and above 50 years (9.5%) groups. Overall, the sample showed an almost equal gender distribution across age categories. Table 2 shows the distribution of musculoskeletal lesions among 21 patients. Non-neoplastic lesions were most common, with tubercular osteomyelitis (28.6%) and fibrous dysplasia (19%). Benign bone tumors and malignant tumors each accounted for smaller proportions, with all individual tumor types contributing 4.8% each. Table 2. Distribution of Musculoskeletal Lesions (n = 21) Type of Lesion Specific Diagnosis Number of Cases Percentage (%) Non-neoplastic lesions Fibrous dysplasia 4 19.0 Tubercular osteomyelitis 6 28.6 Benign bone tumors Aneurysmal bone cyst 1 4.8 Chondroblastoma 1 4.8 Chondromyxoid fibroma 1 4.8 Recurrent giant cell tumor with extramedullary GCT 1 4.8 Malignant tumors Ewing’s sarcoma 1 4.8 Osteosarcoma 1 4.8 Chondrosarcoma (skull base) 1 4.8 Soft tissue sarcoma (scapula) 1 4.8 Metastasis—prostate carcinoma 1 4.8 Metastatic cervical mass 1 4.8 Table 3. Imaging Modalities Evaluated (n = 58) Imaging Modality Number Percentage (%) Radiographs 27 47.3 MRI 15 26.3 CT scans 12 21.0 Skeletal survey 2 3.4 Sonography 1 1.7 18F-FDG PET CT 1 1.7 Table 3 summarizes the 58 imaging investigations performed. Radiographs were the most frequently used modality (47.3%), followed by MRI (26.3%) and CT (21%), while skeletal survey, sonography, and PET-CT were rarely used. Table 4. Usefulness of Imaging Modalities (Reviewer 1 vs Reviewer 2) Imaging Modality Useful (R1) Useful (R2) Agreement (κ) Interpretation Radiographs 25/27 27/27 0.92 Almost perfect MRI 8/15 10/15 0.76 Moderate CT 2/12 4/12 0.57 Weak Skeletal survey 2/2 2/2 1.0 Perfect Sonography 1/1 1/1 1.0 Perfect PET CT 1/1 1/1 1.0 Perfect Table 4 compares the usefulness of each imaging modality between two radiologists. Radiographs showed almost perfect agreement (κ = 0.92) and were useful in most cases. MRI showed moderate agreement, while CT had weak agreement. Skeletal survey, sonography, and PET-CT demonstrated perfect agreement due to limited but clear usefulness. Table 5. Imaging Features Associated with Benign vs Malignant Lesions Imaging Feature Benign Lesions Malignant Lesions p-value Well-defined margin (narrow zone of transition) 82% 0% 0.004 Cortical breach 42.8% 100% <0.05 Soft-tissue mass 1 case 80–100% 0.001 Table 5 highlights imaging features associated with benign versus malignant lesions. Well-defined margins strongly indicated benignity (p = 0.004), whereas cortical breach and soft-tissue mass were significantly associated with malignant lesions (p < 0.05).

In this prospective study evaluating the appropriateness and usefulness of imaging modalities in musculoskeletal (MSK) lesions, radiography emerged as the most valuable initial investigation, demonstrating both high diagnostic utility and strong inter-observer agreement. Radiographs were useful in nearly all cases (92.5% by Reviewer 1 and 100% by Reviewer 2), yielding an almost perfect kappa value (κ = 0.92). These findings reinforce existing literature stating that plain radiography remains the cornerstone of MSK lesion evaluation due to its ability to depict matrix mineralization, cortical integrity, periosteal reaction, and lesion margins with high specificity [3,8,11]. Prior studies have shown that up to 70–80% of bone lesions can be confidently diagnosed with radiographs alone, which mirrors the 80% benign and 75% malignant lesion identification rates reported in this study [8,11] MRI demonstrated moderate agreement (κ = 0.76) and was useful primarily for local staging and assessment of marrow involvement, soft-tissue extension, and neurovascular relations. Its limited contribution to establishing a primary diagnosis is consistent with earlier research, which emphasizes MRI’s role in staging rather than initial characterization [5,12,13]. CT showed weak agreement (κ = 0.57) and limited usefulness except in anatomically complex regions or for evaluating calcification and cortical breach. Similar trends have been reported by Aboulafia et al. and Martin et al., who noted that CT is frequently overutilized in MSK tumor work-up without adding substantial diagnostic value [4,7]. The study also identified key imaging features differentiating benign from malignant lesions. A well-defined margin with a narrow zone of transition was strongly associated with benignity (82%; p = 0.004), while cortical breach and soft-tissue mass were strongly associated with malignancy (p < 0.05). These findings are consistent with classical radiologic criteria described by Lodwick and later validated by multiple tumor-imaging studies [11,12]. Malignant lesions in this study showed cortical destruction in 100% of cases, supporting prior evidence that cortical breach is a reliable marker of aggressiveness [11]. The overall diagnostic concordance (90.4%) between radiological diagnosis and final diagnosis indicates that a systematic approach beginning with radiographs, followed by selective use of MRI or CT, is both efficient and clinically sound. This is particularly important in the Indian healthcare setting, where resource optimization is necessary. The present study fills a major gap in regional literature, as no prior Indian study has systematically evaluated the usefulness of various imaging modalities across a spectrum of MSK lesions. The results also highlight the concerns of unnecessary advanced imaging seen in Western studies. Aboulafia et al. reported inappropriate MRI, CT, and bone scan use in 34.2%, 36.1%, and 42.5% of cases, respectively [7], whereas Martin et al. reported only 6.25% inappropriate MRI use [4]. The variability underscores the need for institution-specific guidelines. The present findings support international recommendations advocating proper review of radiographs before requesting further tests, and limiting advanced imaing to cases where staging, biopsy planning, or assessment of complications is required. Overall, the study emphasizes that rational imaging—starting with radiographs and reserving advanced modalities for select indications—can significantly reduce unnecessary investigations, healthcare costs, and patient burden without compromising diagnostic accuracy.

Radiography should remain the first-line imaging modality in MSK lesion evaluation due to its high diagnostic value and excellent inter-observer agreement. MRI should be reserved for staging and complex cases, while CT should be judiciously used. This study highlights the need for structured imaging algorithms to prevent unnecessary investigations and optimize patient care.

1. Nystrom LM, Reimer NB, Dean CW, Bush CH, Scarborough MT, Gibbs CP Jr. Evaluation of imaging utilization prior to referral of musculoskeletal tumors: a prospective study. J Bone Joint Surg Am. 2015;97(1):5-10. 2. Yiu-Chiu VS, Chiu LC. Complementary values of ultrasound and computed tomography in the evaluation of musculoskeletal masses. Radiographics. 1983;3(1):46-82. 3. Miwa S, Otsuka T. Practical use of imaging technique for management of bone and soft tissue tumors. J Orthop Sci. 2017;22(3):391-400. 4. Martin CT, Morcuende J, Buckwalter JA, Miller BJ. Prereferral MRI use in patients with musculoskeletal tumors is not excessive. Clin Orthop Relat Res. 2012;470(11):3240-5. 5. De Schepper AM, De Beuckeleer L, Vandevenne J, Somville J. Magnetic resonance imaging of soft tissue tumors. Eur Radiol. 2000;10(2):213-23. 6. Crone-Münzebrock W, Baake S, Thoma G, Müller P, Rehder U. Comparison of computed tomography and digital subtraction angiography for preoperative evaluation of soft-tissue tumors of the limbs. Arch Orthop Trauma Surg. 1988;107(6):357-63. 7. Aboulafia AJ, et al. Inappropriate use of MRI and CT in musculoskeletal tumors. (Cited in thesis.) 8. Priolo F, Cerase A. The current role of radiography in the assessment of skeletal tumors and tumor-like lesions. European journal of radiology. 1998;27:S77-85. 9. Costelloe CM, Madewell JE. Radiography in the initial diagnosis of primary bone tumors. American Journal of Roentgenology. 2013;200(1):3-7. 10. Miller BJ, Avedian RS, Rajani R, Leddy L, White JR, Cummings J, Balach T, MacDonald K. What is the use of imaging before referral to an orthopaedic oncologist? A prospective, multicenter investigation. Clinical Orthopaedics and Related Research®. 2015;473(3):868-74. 11. Lodwick GS. The bones and joints. Chicago, IL: Year Book Medical Publishers; 1971. 12. Kransdorf MJ, Jelinek JS, Moser RP Jr. Imaging of soft tissue tumors. Radiol Clin North Am. 1993 Mar;31(2):359-72. PMID: 8446754. 13. O'Donnell, Paul. “Evaluation of focal bone lesions: basic principles and clinical scenarios.” Imaging 15 (2003): 298-323.