MSKI-RADS: An MRI-based Musculoskeletal Infection Reporting and Data System for the Diagnosis of Extremity Infections.

Background Current terms used to describe the MRI findings for musculoskeletal infections are nonspecific and inconsistent. Purpose To develop and validate an MRI-based musculoskeletal infection classification and scoring system. Materials and Methods In this retrospective cross-sectional internal validation study, a Musculoskeletal Infection Reporting and Data System (MSKI-RADS) was designed. Adult patients with radiographs and MRI scans of suspected extremity infections with a known reference standard obtained between June 2015 and May 2019 were included. The scoring categories were as follows: 0, incomplete imaging; I, negative for infection; II, superficial soft-tissue infection; III, deeper soft-tissue infection; IV, possible osteomyelitis (OM); V, highly suggestive of OM and/or septic arthritis; VI, known OM; and NOS (not otherwise specified), nonspecific bone lesions. Interreader agreement for 20 radiologists from 13 institutions (intraclass correlation coefficient [ICC]) and true-positive rates of MSKI-RADS were calculated and the accuracy of final diagnoses rendered by the readers was compared using generalized estimating equations for clustered data. Results Among paired radiographs and MRI scans from 208 patients (133 male, 75 female; mean age, 55 years ± 13 [SD]), 20 were category I; 34, II; 35, III; 30, IV; 35, V; 18, VI; and 36, NOS. Moderate interreader agreement was observed among the 20 readers (ICC, 0.70; 95% CI: 0.66, 0.75). There was no evidence of correlation between reader experience and overall accuracy (P = .94). The highest true-positive rate was for MSKI-RADS I and NOS at 88.7% (95% CI: 84.6, 91.7). The true-positive rate was 73% (95% CI: 63, 80) for MSKI-RADS V. Overall reader accuracy using MSKI-RADS across all patients was 65% ± 5, higher than final reader diagnoses at 55% ± 7 (P < .001). Conclusion MSKI-RADS is a valid system for standardized terminology and recommended management of imaging findings of peripheral extremity infections across various musculoskeletal-fellowship-trained reader experience levels. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Schweitzer in this issue.

CT-based comprehensive scoring system for assessing hip arthropathy in ankylosing spondylitis: feasibility study with clinical correlation.

OBJECTIVE: To develop a CT-based scoring system for assessment of hip arthropathy in AS. METHODS: All AS patients were prospectively recruited, consented, and underwent whole-body stereoradiographs and pelvis CT, which were assessed by two independent radiologists. Stereoradiographs were assessed according to Kellgreen-Lawrence and BASRI-h. For the Hip arthropathy CT score in AS (HACTSAS), joints were divided into 7 segments and scored for joint space, osteophytes, subchondral cysts/erosions. Patients were clinically assessed for range of motion (ROM), pain, and clinical scores (BASMI, BASFI, ASQol, BASDAI and ASDAS). Radiological scores correlations with clinical parameters were compared. ROM sensitivity and specificity for hip arthropathy (BASRI-h ≥ 2) were calculated. RESULTS: Sample included 112 patients, with 36/112 females and 76/112 males. Average age was 51.0 ± 11.2 years and mean duration of AS was 20.9 ± 9.6 years. ICC for HACTSAS, Kellgreen-Lawrence and BASRI-h were 0.89, 0.89 and 0.82 respectively. HACTSAS showed moderate absolute correlation with ROM (ρ=-0.41) and BASMI (ρ = 0.45), and weak with pain (ρ = 0.18) and BASFI (ρ = 0.25). BASRI-h and Kellgreen-Lawrence exhibited moderate correlation with ROM (ρ=-0.44 and ρ=-0.40, respectively), weak with pain (ρ=-.27and ρ=-0.23, respectively) and BASFI (ρ=-0.16 and ρ=-0.18, respectively), but only weak with BASMI (ρ=-0.34 and ρ=-0.36, respectively). Internal rotation <15°, abduction <31°, and intermalleolar distance <75cm were, respectively, 73%, 70% and 73% sensitivity and 81%, 65% and 68% specific for hip arthropathy. CONCLUSION: HACTSAS exhibited higher correlation with BASMI and BASFI when compared with BASRI-h, but less correlation with pain and ROM. Internal rotation was the best clinical discriminator for hip arthropathy.

MRI-based Neuropathy Score Reporting And Data System (NS-RADS): multi-institutional wider-experience usability study of peripheral neuropathy conditions among 32 radiology readers.

OBJECTIVE: To determine the inter-reader reliability and diagnostic performance of classification and severity scales of Neuropathy Score Reporting And Data System (NS-RADS) among readers of differing experience levels after limited teaching of the scoring system. METHODS: This is a multi-institutional, cross-sectional, retrospective study of MRI cases of proven peripheral neuropathy (PN) conditions. Thirty-two radiology readers with varying experience levels were recruited from different institutions. Each reader attended and received a structured presentation that described the NS-RADS classification system containing examples and reviewed published articles on this subject. The readers were then asked to perform NS-RADS scoring with recording of category, subcategory, and most likely diagnosis. Inter-reader agreements were evaluated by Conger's kappa and diagnostic accuracy was calculated for each reader as percent correct diagnosis. A linear mixed model was used to estimate and compare accuracy between trainees and attendings. RESULTS: Across all readers, agreement was good for NS-RADS category and moderate for subcategory. Inter-reader agreement of trainees was comparable to attendings (0.65 vs 0.65). Reader accuracy for attendings was 75% (95% CI 73%, 77%), slightly higher than for trainees (71% (69%, 72%), p = 0.0006) for nerves and comparable for muscles (attendings, 87.5% (95% CI 86.1-88.8%) and trainees, 86.6% (95% CI 85.2-87.9%), p = 0.4). NS-RADS accuracy was also higher than average accuracy for the most plausible diagnosis for attending radiologists at 67% (95% CI 63%, 71%) and for trainees at 65% (95% CI 60%, 69%) (p = 0.036). CONCLUSION: Non-expert radiologists interpreted PN conditions with good accuracy and moderate-to-good inter-reader reliability using the NS-RADS scoring system. CLINICAL RELEVANCE STATEMENT: The Neuropathy Score Reporting And Data System (NS-RADS) is an accurate and reliable MRI-based image scoring system for practical use for the diagnosis and grading of severity of peripheral neuromuscular disorders by both experienced and general radiologists. KEY POINTS: • The Neuropathy Score Reporting And Data System (NS-RADS) can be used effectively by non-expert radiologists to categorize peripheral neuropathy. • Across 32 different experience-level readers, the agreement was good for NS-RADS category and moderate for NS-RADS subcategory. • NS-RADS accuracy was higher than the average accuracy for the most plausible diagnosis for both attending radiologists and trainees (at 75%, 71% and 65%, 65%, respectively).

Diagnostic efficacy of posterior tibialis tendon dysfunction: a systematic review of literature.

OBJECTIVE: To perform a systematic review to examine the diagnostic accuracy of magnetic resonance imaging, ultrasonography, and radiography in the evaluation of posterior tibial tendon dysfunction (PTTD). MATERIALS AND METHODS: Medline, Scopus, Embase, and The Cochrane Central Register of Controlled Trials (CENTRAL) were searched for relevant studies through April 2023. The study quality was assessed using the QUADAS-2 scoring system. RESULTS: Of the initial 634 studies, 12 studies met the quality criteria and were included, with 645 PTTs evaluated with MRI, 133 with US, and 97 with radiography. MRI was found to be more sensitive and specific than ultrasound, radiography, and clinical evaluation for detecting PTTD, with a sensitivity of up to 95%, specificity of up to 100%, and accuracy of 96% for detecting PTT tears. US showed a sensitivity of 80% and specificity of 90% for diagnosing tendinopathy, and a sensitivity of 90% and specificity of 80% for diagnosing peritendinosis when compared to MRI. Weight-bearing radiographs had a sensitivity of 71.4%, specificity of 88.9%, and diagnostic accuracy of 81.3% when diagnosing PTT ruptures. Various radiologic measurements were also found to have a significant relationship with PTT tears but were poorly correlated with PTT tendinosis and isolated tenosynovitis. CONCLUSION: Magnetic resonance imaging is the preferred imaging tool for evaluating patients with posterior tibial tendon dysfunction, with higher diagnostic accuracy, sensitivity, and specificity compared to ultrasound and radiographic imaging. However, initial imaging with ultrasound and radiographs may be used due to their availability and cost-effectiveness. CLINICAL RELEVANCE: PTTD affects 3% of women ≥ 40 years and 10% of adults ≥ 65 years globally. Using the appropriate imaging study, MRI ensures that patients suffering from PTTD are diagnosed and treated in a timely manner. KEY POINTS: • This review aimed to determine the diagnostic accuracy of MRI, ultrasonography, and radiography in evaluating PTTD. • MRI outperformed ultrasound and radiography, with higher sensitivity, specificity, and accuracy in detecting PTT tears. • MRI is the preferred imaging modality for the initial diagnosis of PTTD.