Musculoskeletal Radiologists Research Articles

Poster 105: MRI Demonstrates Similar Diagnostic Value to MR Arthrogram for Determining Labral Tear Extent up to 2 Weeks Following Shoulder Dislocation

Objectives: The aim of this study was to determine the comparative accuracy and precision of routine Magnetic Resonance Imaging (MRI) versus magnetic resonance (MR) arthrogram in measuring labral tear size as function of time from shoulder dislocation, and to identify a time threshold after which MR arthrogram supersedes MRI in diagnostic utility. Methods: We retrospectively evaluated consecutive patients who underwent primary arthroscopic labral repair between 2012 and 2021 and completed a preoperative MRI or MR arthrogram of the shoulder within 60 days of injury, and subsequently underwent arthroscopic repair within 6 months of imaging. Arthroscopic labral tear size and location was used as standard comparison. Three musculoskeletal radiologists independently interpreted tear extent using clock-face convention. Accuracy and precision of MR labral tear measurements were defined by location and size of the tear, respectively. Accuracy and precision were compared between MRI and MR arthrogram, as a function of time from dislocation. Results: Thirty-two MRI and 65 MR arthrogram (total n=97) were independently assessed by radiologists. Multivariate analysis demonstrated that intraoperative tear size, early imaging, and arthrogram status were associated with increased MR accuracy and precision (p<0.05). Ordering surgeons preferred arthrogram for delayed imaging (p=0.018). For routine MRI, error in accuracy increased by 3.4° per day and error in precision increased by 2.3° per day (p<0.001) from time of injury. MR arthrogram, however, was not temporally influenced (Figure 1). Significant loss of accuracy and precision of routine MRI compared to MR arthrogram occurs at 2 weeks after acute shoulder dislocation. Conclusions: For determining shoulder labral tear size after acute dislocation, routine MRI has similar diagnostic value for measuring labral tear extent as MR arthrogram up to approximately 2 weeks postacute shoulder dislocation, after which it significantly loses accuracy and precision, possibly due to resolving posttraumatic effusion. MR arthrogram accuracy and precision were not temporally influenced.

The "Mustache sign:" An ancillary radiological sign for detecting L5/S1 spondylolisthesis.

Grade 1 spondylolisthesis can be challenging to detect on magnetic resonance imaging (MRI), particularly for spinal surgeons and radiologists with limited experience interpreting spinal MRIs. This study aims to describe a unique sign described as a "mustache sign," which may assist in detecting subtle Grade I spondylolisthesis on sagittal sequences on MRI of the spine. A retrospective review of 50 lumbar spine MRI scans of patients with Grade I spondylolisthesis of L5/S1 performed over 3 years was conducted at a tertiary orthopedic spinal center in the United Kingdom. The scans were assessed for the presence of the "mustache sign" and findings were independently recorded by one musculoskeletal radiology registrar and one fellowship trained musculoskeletal radiologist with over 10 years of experience. There were 35 females (70%) and 15 males (30%). The patient's mean age was 54.3 years (13-82). The "mustache sign" was present in 13 (26%) of these patients. Twelve of 13 scans (92%) positive for the sign also demonstrated pars interarticularis defects (P < 0.001, Fisher's Exact test), compared to those without the sign. There was excellent interobserver reliability with a kappa of 1. The "mustache sign" on MRI spine correlates well with the presence of Grade I spondylolisthesis. This ancillary sign can complement other previously described radiological findings on sagittal MRI sequences to confirm Grade I spondylolisthesis.

Poster 160: Preoperative MRI Underestimates Shoulder Labral Injuries Compared with Diagnostic Arthroscopy

Objectives: To compare the overall agreement in the magnitude of shoulder labral injuries between preoperative MRI and assessment at the time of diagnostic arthroscopy. Methods: A retrospective chart review was performed of patients undergoing primary arthroscopic labral repair procedures between February 2018 and February 2023. Exclusion criteria included prior ipsilateral shoulder surgery, MRI study performed at outside health system, and incomplete documentation of labral tear location. Age, gender, and dates of injury, imaging, and surgery were recorded. Radiology and operative reports were reviewed to record the location and extent of the labral tear using conventional clock-face coordinates. Tear locations were further classified as either anterior (2-6 o’clock), posterior (6-10 o’clock), or superior (10-2 o’clock). MRI studies were performed by 1.5-Tesla scanner and all radiology reports were performed by fellowship-trained musculoskeletal radiologists at a single health system. Subgroup analysis of labral tear size on radiology interpretation was performed between MRI arthrogram (MRA) and conventional MRI studies. Results: A total of 138 subjects (mean age 25.8 years, 73% male) met criteria for inclusion in this study. Of the included subjects, 105 underwent MRI arthrogram and 33 underwent conventional MRI studies. The average time from initial injury to MRI was 153.4 days and the average time from MRI to surgical intervention was 66.8 days. The average total recorded labral tear size in clock-face coordinates was significantly greater on diagnostic arthroscopy compared with the radiologist MRI interpretation (4.4 vs 3.6, p&lt;0.01). The average labral tear size in the posterior region was also significantly greater on diagnostic arthroscopy (2.4 vs 1.6, p&lt;0.01). The average labral tear size in the anterior (2.5 vs 2.2, p=0.08) and superior (1.6 vs 1.5, p=0.29) regions was greater on diagnostic arthroscopy but did not reach statistical significance. The difference in total and posterior tear size remained significant in both the arthrogram and conventional MRI subgroups. Subjects undergoing MRI arthrogram had a significantly greater reported size of anterior labral tears in clock-face coordinates compared with conventional MRI (2.7 vs 2.0, p=0.03), but did not reach significance for the posterior (p=0.40), superior (p=0.31), and the overall global labrum (p=0.29). Conclusions: MRI significantly underestimate the overall size of labral tears in setting of shoulder instability, particularly in the posterior labrum. Surgeons should account for potential underestimation of true labral injury during preoperative planning for surgical management of shoulder instability.

Paper 41: Does MR Arthrography Improve Evaluation of Patients with Posterior Shoulder Instability? An Analysis from the MOON Shoulder Instability Group

Objectives: Posterior shoulder instability is an uncommon injury, accounting for 2-12% of shoulder instability patients. Magnetic resonance imaging (MRI) is often utilized to non-invasively evaluate the joint for labral, cartilage, and bony injury. MR arthrography (MRA) may improve the evaluation of these intra-articular structures, but requires additional cost, time, and an invasive procedure. Moreover, its benefits for patients with posterior shoulder instability are unclear. Accurate imaging is critical in patients undergoing surgery because certain findings may influence the surgical approach. Thus, the purpose of this study is to compare the accuracy of MRA and non-enhanced MRI in detecting labral, chondral, and osseous lesions in patients with posterior shoulder instability. Methods: There were 291 patients with unilateral posterior shoulder instability who had preoperative MRA or MRI between 2006 and 2021 in the MOON database. Images were reviewed by a fellowship-trained musculoskeletal radiologist with 10+ years of experience and an orthopaedic surgeon. Evaluators were blinded to age, gender, medical history, MR report, and arthroscopic findings, but were aware of the patient's history of posterior shoulder instability. Examinations were evaluated for presence, location, morphology, and length of glenoid labral tears. Tear length and localization were noted using a standard clock face. The presence and size of humeral/glenoid osseous and cartilage lesions was also noted.Intraoperative findings from arthroscopic evaluation were documented by the surgeon using a standard response questionnaire. Diagnostic performance of standard MRA and MRI were evaluated using sensitivity and specificity with arthroscopic evaluation as the gold-standard. Chi-squared or Fisher’s exact tests were used to compare the sensitivities and specificities of MRA and MRI. Significance was defined as P &lt; 0.05. Results: 200 patients (69%) had MRA, while 91 patients had non-contrast MRIs of the shoulder. On imaging evaluation, 273 (94%) patients had labral tears with a mean tear size of 156º. 39 (13%) patients had humeral cartilage lesions, whereas 40 (14%) patients had glenoid cartilage lesions. 34 (12%) patients had glenoid bone loss greater than 5%. The mean glenoid bone loss was 12% (range, 5% - 26%). A reverse Hill-Sachs lesion was present in 35 (12%) patients. 16 (6%) patients had bipolar bone loss. The sensitivity for detection of labral tears was high for both MRA (0.95) and standard MRI (0.98) (Tables 1 and 2), though the specificity was low for both modalities (0.25 and 0.40, respectively). There was no difference in the sensitivities or specificities of the two imaging modalities in the detection of labral tears. MRA had a lower sensitivity than MRI in the detection of glenoid cartilage lesions (0.31 vs 0.88, p &lt; 0.001), but no difference was observed for specificity. There was no difference in the sensitivities and specificities of MRA and MRI for humeral cartilage lesions (p = 0.354).MRA had a higher sensitivity than MRI in assessing glenoid bone loss (0.78 vs 0.50, p &lt; 0.001), though there was no difference in specificity. There was no difference between imaging modalities in the evaluation of humeral bone loss (p = 1.000). Conclusions: In this multicenter study, MRA was the most commonly utilized preoperative advanced imaging study for patients with posterior shoulder instability. MRA had a higher sensitivity in detecting glenoid bone loss but lower sensitivity in detecting glenoid cartilage lesions compared to standard non-contrast MRI. There was no difference in diagnostic performance between MRA and MRI in the diagnosis of labral tears and humeral chondral and osseous lesions. MRA may provide an advantage over standard MRI in the evaluation of glenoid bone loss, which can influence the treatment plan for patients undergoing surgical management of posterior shoulder instability.

Interobserver Agreement and Performance of Concurrent AI Assistance for Radiographic Evaluation of Knee Osteoarthritis.

Background Due to conflicting findings in the literature, there are concerns about a lack of objectivity in grading knee osteoarthritis (KOA) on radiographs. Purpose To examine how artificial intelligence (AI) assistance affects the performance and interobserver agreement of radiologists and orthopedists of various experience levels when evaluating KOA on radiographs according to the established Kellgren-Lawrence (KL) grading system. Materials and Methods In this retrospective observer performance study, consecutive standing knee radiographs from patients with suspected KOA were collected from three participating European centers between April 2019 and May 2022. Each center recruited four readers across radiology and orthopedic surgery at in-training and board-certified experience levels. KL grading (KL-0 = no KOA, KL-4 = severe KOA) on the frontal view was assessed by readers with and without assistance from a commercial AI tool. The majority vote of three musculoskeletal radiology consultants established the reference standard. The ordinal receiver operating characteristic method was used to estimate grading performance. Light kappa was used to estimate interrater agreement, and bootstrapped t statistics were used to compare groups. Results Seventy-five studies were included from each center, totaling 225 studies (mean patient age, 55 years ± 15 [SD]; 113 female patients). The KL grades were KL-0, 24.0% (n = 54); KL-1, 28.0% (n = 63); KL-2, 21.8% (n = 49); KL-3, 18.7% (n = 42); and KL-4, 7.6% (n = 17). Eleven readers completed their readings. Three of the six junior readers showed higher KL grading performance with versus without AI assistance (area under the receiver operating characteristic curve, 0.81 ± 0.017 [SEM] vs 0.88 ± 0.011 [P < .001]; 0.76 ± 0.018 vs 0.86 ± 0.013 [P < .001]; and 0.89 ± 0.011 vs 0.91 ± 0.009 [P = .008]). Interobserver agreement for KL grading among all readers was higher with versus without AI assistance (κ = 0.77 ± 0.018 [SEM] vs 0.85 ± 0.013; P < .001). Board-certified radiologists achieved almost perfect agreement for KL grading when assisted by AI (κ = 0.90 ± 0.01), which was higher than that achieved by the reference readers independently (κ = 0.84 ± 0.017; P = .01). Conclusion AI assistance increased junior readers' radiographic KOA grading performance and increased interobserver agreement for osteoarthritis grading across all readers and experience levels. Published under a CC BY 4.0 license. Supplemental material is available for this article.

Extrapolating Caplan-Fisher rules for musculoskeletal radiologists

Extrapolating Caplan-Fisher rules for musculoskeletal radiologists

Exploring chat generated pre-trained transformer-3 ability to interpret MRI knee images and generate reports

Objectives: The study’s objective was to determine if Chat Generated Pre-Trained Transformer-3 (ChatGPT)-4V can interpret magnetic resonance imaging (MRI) knees and generate preliminary reports based on images and clinical history provided by the radiologist. Materials and Methods: This cross-sectional observational study involved selecting 10 MRI knees with representative imaging findings from the institution’s radiology reporting database. Key MRI images were then input into the ChatGPT-4V model, which was queried with four questions: (i) What does the image show?; (ii) What is the sequence?; (iii) What is the key finding?; and, (iv) Finally, the model generated a report based on the provided clinical history and key finding. Responses from ChatGPT-4 were documented and independently evaluated by two musculoskeletal radiologists through Likert scoring. Results: The mean scores for various questions in the assessment were as follows: 2 for “What does the image show?,” 2.10 for “What is the sequence?,” 1.15 for “What is the key finding?,” and the highest mean score of 4.10 for the command “Write a report of MRI of the…” Radiologists consistently gave mean scores ranging from 2.0 to 2.5 per case, with no significant differences observed between different cases (P &gt; 0.05). The interclass correlation coefficient between the two raters was 0.92 (95% Confidence interval: 0.85–0.96). Conclusion: ChatGPT-4V excelled in generating reports based on user-fed clinical information and key findings, with a mean score of 4.10 (good to excellent proficiency). However, its performance in interpreting medical images was subpar, scoring ≤2.10. ChatGPT-4V, as of now, cannot interpret medical images accurately and generate reports.

High-resolution ultrasound of the paratenon of the Achilles calcaneal tendon: anatomical study and description of the paratendinous injection technique.

The aim of this study is to determine if ultrasound (US) allows a precise assessment of the paratenon (PT) of the Achilles calcaneal tendon (AT), and to anatomically describe the US-guided paratendinous injection technique. This study was initially conducted on eight cadaveric specimens using high-resolution ultrasound (HRUS) to examine the PT appearance, thickness, and its relationships with the AT, plantaris tendon (PLT), Kager's fat pad (KFP), sural nerve (SN), and fascia cruris (FC). US-guided paratendinous injection of China ink was performed in all specimens, followed by anatomical dissection to assess injectate distribution. Then, HRUS study of the PT was carried out bilaterally in twenty asymptomatic volunteers (40 legs). Two musculoskeletal radiologists recorded all data in consensus except PT thickness in volunteers which was recorded independently in order to calculate intra and inter-observer reliability. The PT was consistently identified with HRUS along its entire course in both cadaveric specimens (8/8) and volunteers (40/40). The mean PT thickness was 0.54mm in cadavers and 0.39mm in vivo, without any correlation with the AT thickness. Intra- and inter observer reliability were respectively excellent and good for PT thickness. All eight (100%) ex vivo China ink injections were accurate, demonstrating a circumferential distribution of the injectate between the PT and the AT, associated with an anterior spread to the KFP. HRUS allows visualization of the PT along its entire length, and assessment of its relationships to adjacent structures. US-guided paratendinous injections can accurately and safely deliver injectates in the paratendinous sheath.

Automated weight-bearing foot measurements using an artificial intelligence-based software.

To assess the accuracy of an artificial intelligence (AI) software (BoneMetrics, Gleamer) in performing automated measurements on weight-bearing forefoot and lateral foot radiographs. Consecutive forefoot and lateral foot radiographs were retrospectively collected from three imaging institutions. Two senior musculoskeletal radiologists independently annotated key points to measure the hallux valgus, first-second metatarsal, and first-fifth metatarsal angles on forefoot radiographs and the talus-first metatarsal, medial arch, and calcaneus inclination angles on lateral foot radiographs. The ground truth was defined as the mean of their measurements. Statistical analysis included mean absolute error (MAE), bias assessed with Bland-Altman analysis between the ground truth and AI prediction, and intraclass coefficient (ICC) between the manual ratings. Eighty forefoot radiographs were included (53 ± 17years, 50 women), and 26 were excluded. Ninety-seven lateral foot radiographs were included (51 ± 20years, 46 women), and 21 were excluded. MAE for the hallux valgus, first-second metatarsal, and first-fifth metatarsal angles on forefoot radiographs were respectively 1.2° (95% CI [1; 1.4], bias = - 0.04°, ICC = 0.98), 0.7° (95% CI [0.6; 0.9], bias = - 0.19°, ICC = 0.91) and 0.9° (95% CI [0.7; 1.1], bias = 0.44°, ICC = 0.96). MAE for the talus-first, medial arch, and calcaneal inclination angles on the lateral foot radiographs were respectively 3.9° (95% CI [3.4; 4.5], bias = 0.61° ICC = 0.88), 1.5° (95% CI [1.2; 1.8], bias = - 0.18°, ICC = 0.95) and 1° (95% CI [0.8; 1.2], bias = 0.74°, ICC = 0.99). Bias and MAE between the ground truth and the AI prediction were low across all measurements. ICC between the two manual ratings was excellent, except for the talus-first metatarsal angle. AI demonstrated potential for accurate and automated measurements on weight-bearing forefoot and lateral foot radiographs.

Abnormal lateral meniscal signal in MRI after patellar dislocation does not indicate a meniscal tear: MR findings with surgical correlation

BackgroundCombined injuries observed with first-time lateral patellar dislocation (LPD) of the knee, particularly significant soft tissue injury, can inform surgical intervention criteria. PurposeThe purpose of this study was to compare MRI findings in LPD to surgical correlation concerning meniscal pathology as a guide for surgical management. Study designRetrospective case series, Level of evidence, 4. MethodsA retrospective review was conducted of 355 cases of patients with lateral patellar dislocation from 2012 to 2022. Imaging was reviewed by musculoskeletal radiologists blinded to surgical results for evidence of soft tissue injury, and associated arthroscopic data and operative reports were reviewed. ResultsOut of 44 cases of LPD in 42 patients who underwent MPFL reconstructive surgery, 27 (61%) cases had grade 2a or higher signal changes in the anterior horn of the lateral meniscus, of which 10 (23%) had grade 3 signal changes. There were zero cases of meniscal tear in these cases upon review of operative reports and arthroscopic images. ConclusionMRI findings of signal alterations in the lateral meniscus post-LPD may not indicate an actual tear. This could aid in surgical decision-making in primary LPD management.

Health technology assessment in musculoskeletal radiology: the case study of EOSedge™

ObjectivesHealth technology assessment (HTA) is a systematic process used to evaluate the properties and effects of healthcare technologies within their intended use context. This paper describes the adoption of HTA process to assess the adoption of the EOSedge™ system in clinical practice.MethodsThe EOSedge™ system is a digital radiography system that delivers whole-body, high-quality 2D/3D biplanar images covering the complete set of musculoskeletal and orthopedic exams. Full HTA model was chosen using the EUnetHTA Core Model® version 3.0. The HTA Core Model organizes the information into nine domains. Information was researched and obtained by consulting the manufacturers’ user manuals, scientific literature, and institutional sites for regulatory aspects.ResultsAll nine domains of the EUnetHTA Core Model® helped conduct the HTA of the EOSedge, including (1) description and technical characteristics of the technology; (2) health problem and current clinical practice; (3) safety; (4) clinical effectiveness; (5) organizational aspects; (6) economic evaluation; (7) impact on the patient; (8) ethical aspects; and (9) legal aspects.ConclusionsEOS technologies may be a viable alternative to conventional radiographs. EOSedge has the same intended use and similar indications for use, technological characteristics, and operation principles as the EOS System and provides significant dose reduction factors for whole spine imaging compared to the EOS System without compromising image quality. Regarding the impact of EOS imaging on patient outcomes, most studies aim to establish technical ability without evaluating their ability to improve patient outcomes; thus, more studies on this aspect are warranted.

Utilization trends for MR arthrography of the hip and shoulder: a retrospective cross-sectional analysis of 20-year data from a tertiary care academic medical center.

The purpose of this study is to analyze changes in the utilization of MRA of the hip and shoulder at a large tertiary care academic medical center during a period of significant technological advancements over the last 20 years. This retrospective cross-sectional analysis identified MRA of the hip and shoulder performed at our institution over a 20-year period (2/2003-2/2023) in relation to the total number of MR hip and shoulder examinations during the same period. Patient characteristics and referring provider demographic information were extracted. Descriptive statistics and trend analysis were performed. The total number of MRIs of the hip and shoulder increased overall, with small dips in 2020 and 2022. MRA of the hip increased significantly over the first 10 years of the study period (p = 0.0005), while MRA of the shoulder did not change significantly (p = 0.33). The proportion of both MRA of the hip and shoulder declined over the last 10 years (hip, p = 0.0056; shoulder, p = 0.0017). Over the same period, there was significant increase in the proportion of examinations performed at 3 Tesla versus 1.5 (p < 0.0001). Overall, there was a downward trend in MR shoulder and hip arthrogram utilization in the second half of this 20-year study period. However, utilization varied somewhat by referring specialties and credentials. These changes are likely reflective of both improvements in image quality and evolving practice recommendations. Awareness of such trends may be valuable in ensuring appropriate patient care, as well as for anticipating the needs of a musculoskeletal radiology practice.

Tumors of the Brachial Plexus: A Critical Analysis Review.

» Tumors of the brachial plexus are uncommon and can present as a mass, with or without neurological symptoms. At times, asymptomatic tumors are also picked up incidentally when imaging is performed for other reasons.» Magnetic resonance imaging is the main imaging modality used to evaluate tumors of the brachial plexus. Other imaging modalities can be used as required.» Benign tumors that are asymptomatic should be observed. Excision can be considered for those that are found to be growing over time.» Biopsies of tumors of the brachial plexus are associated with the risk of nerve injury. Despite this, they should be performed for tumors that are suspected to be malignant before starting definitive treatment.» For malignant tumors, treatment decisions should be discussed at multidisciplinary tumor boards, and include both the oncology and peripheral nerve surgical team, musculoskeletal radiology, neuroradiology, and general radiology.

An evaluation of AI generated literature reviews in musculoskeletal radiology

PurposeThe use of artificial intelligence (AI) tools to aid in summarizing information in medicine and research has recently garnered a huge amount of interest. While tools such as ChatGPT produce convincing and naturally sounding output, the answers are sometimes incorrect. Some of these drawbacks, it is hoped, can be avoided by using programmes trained for a more specific scope. In this study we compared the performance of a new AI tool (the-literature.com) to the latest version OpenAI's ChatGPT (GPT-4) in summarizing topics that the authors have significantly contributed to. MethodsThe AI tools were asked to produce a literature review on 7 topics. These were selected based on the research topics that the authors were intimately familiar with and have contributed to through their own publications. The output produced by the AI tools were graded on a 1–5 Likert scale for accuracy, comprehensiveness, and relevance by two fellowship trained consultant radiologists. ResultsThe-literature.com produced 3 excellent summaries, 3 very poor summaries not relevant to the prompt, and one summary, which was relevant but did not include all relevant papers. All of the summaries produced by GPT-4 were relevant, but fewer relevant papers were identified. The average Likert rating was for the-literature was 2.88 and 3.86 for GPT-4. There was good agreement between the ratings of both radiologists (ICC = 0.883). ConclusionSummaries produced by AI in its current state require careful human validation. GPT-4 on average provides higher quality summaries. Neither tool can reliably identify all relevant publications.

Artificial Intelligence in Musculoskeletal Radiographs: Scoliosis, Hip, Limb Length, and Lower Extremity Alignment Measurements

Artificial intelligence (AI) and machine learning approaches are increasingly being used in musculoskeletal (MSK) radiology with more articles involving AI published every year. A variety of length and angular measurements are used in the evaluation of MSK pathology. The purpose of this article is to discuss the current applications of AI in performing radiographic measurements pertaining to scoliosis, hip pathology, limb length, and lower extremity alignment. To that end, we identified a multitude of studies demonstrating that AI, in general, can accurately and efficiently generate automated measurements for diagnostic and management purposes. Current literature is reviewed, and future directions are highlighted.

Medial scapular body (MSB) Goutallier classification: MRI-based reliability and validity of evaluation of the Goutallier classification for grading fatty infiltration of the rotator cuff

IntroductionThe degree of atrophy and fatty infiltration of rotator cuff muscle belly is a key predictor for cuff repairability. Traditionally, Goutallier grading of fatty infiltration is assessed at sagittal scapular Y-view. Massive rotator cuff tears are associated with tendon retraction and medial retraction of cuff musculature, resulting in medialization of the muscle bulk. Thus, standard Y-view can misrepresent the region of interest and may misguide clinicians when assessing repairability. It is hypothesized that by assessing the muscle belly with multiple medial sagittal MRI sections at medial scapular body, the Medial Scapular Body - Goutallier Classification (MSB-GC) will improve reliability and repeatability giving a more representative approximation to the degree of fatty infiltration, as compared with original Y-view. MethodsFatty infiltration of the rotator cuff muscles were classified based on the Goutallier grade (0 to 4) at three defined sections section 1: original Y-view; section 2: level of suprascapular notch; section 3: three cm medial to suprascapular notch on MRI scans. Six sub-specialist fellowship trained shoulder surgeons, and three musculoskeletal radiologists independently evaluated deidentified MRI scans of included patients. ResultsOut of 80 scans, 78% (n=62) were massive cuff tears involving supraspinatus, infraspinatus and subscapularis tendon. Inter-observer reliability (consistency between observers) for Goutallier grade was excellent for all three predefined sections (range:0.87–0.95). Intra-observer reliability (repeatability) for Goutallier grade was excellent for all three sections and four rotator cuff muscles (range:0.83-0.97). There was a moderate to strong positive correlation of Goutallier grades between sections 1 and 3 and between sections 2 and 3 and these were statistically significant (p<0.001). There was a reduction in the severity of fatty infiltration on the Goutallier classification from sections 1 to 3 across all muscles. 42.5% of both supraspinatus and infraspinatus were downgraded by one, 20% of supraspinatus and 3.8% of infraspinatus were downgraded by 2 and 2.5% of supraspinatus were downgraded by 3. ConclusionThis study found that applying the Goutallier classification to more medial MRI sections (MSB-GC) resulted in assignment of lower grades for all rotator cuff muscles. Additionally, this method demonstrated excellent test-retest reliability and repeatability. Inclusion of a more medial view or whole scapula on MRI, especially in advanced levels of tear retraction, could be more reliable and representative for assessment of the degree of fatty infiltration within the muscle bulk that could help predict tear repairability and therefore improve clinical decision-making which should be studied further in clinical studies.

Presence of Additional Pathology in Low-Grade Acromioclavicular Joint Injuries.

To determine if additional pathology is present in low-grade acromioclavicular (AC) joint injuries. Prospective case series. Patients were assessed by primary care sports medicine physicians at a single institution between 2019 and 2023. Patients aged 18 to 65 years diagnosed with a type I to III AC injury based on clinical and radiographic evaluation. Consenting patients underwent magnetic resonance imaging (MRI) evaluation within 21 days of injury. All injuries were treated nonoperatively. Additional pathologies identified on MRI were reported in a standardized fashion by fellowship-trained musculoskeletal radiologists. Twenty-nine patients (26 men/3 women) were consented with a mean (±SD) age of 28.6 ± 9.5 years. The mean time from injury to MRI was 8.1 ± 5.9 days. Twenty-three injuries were sport related, and 6 were accidental traumas. Based on MRI, injury type was reclassified in 16 of 29 patients, and 13 remained unchanged. Additional pathologies identified included 14 muscle injuries, 5 rotator cuff tears, 5 labral tears, 1 nondisplaced fracture, and 1 intra-articular body. MRI evidence suggests that most AC joint injuries are more severe than clinically diagnosed. Identifying additional pathology may alter diagnostic and treatment guidelines for type I to III AC joint injuries.

Artificial Intelligence Quantification of Enhanced Synovium Throughout the Entire Hand in Rheumatoid Arthritis on Dynamic Contrast-Enhanced MRI.

Challenges persist in achieving automatic and efficient inflammation quantification using dynamic contrast-enhanced (DCE) MRI in rheumatoid arthritis (RA) patients. To investigate an automatic artificial intelligence (AI) approach and an optimized dynamic MRI protocol for quantifying disease activity in RA in whole hands while excluding arterial pixels. Retrospective. Twelve RA patients underwent DCE-MRI with 27 phases for creating the AI model and tested on images with a variable number of phases from 35 RA patients. 3.0 T/DCE T1-weighted gradient echo sequence (mDixon, water image). The model was trained with various DCE-MRI time-intensity number of phases. Evaluations were conducted for similarity between AI segmentation and manual outlining in 51 ROIs with synovitis. The relationship between synovial volume via AI segmentation with rheumatoid arthritis magnetic resonance imaging scoring (RAMRIS) across whole hands was then evaluated. The reference standard was determined by an experienced musculoskeletal radiologist. Area under the curve (AUC) of receiver operating characteristic (ROC), Dice and Spearman's rank correlation coefficients, and interclass correlation coefficient (ICC). A P-value <0.05 was considered statistically significant. A minimum of 15 phases (acquisition time at least 2.5 minutes) was found to be necessary. AUC ranged from 0.941 ± 0.009 to 0.965 ± 0.009. The Dice score was 0.557-0.615. Spearman's correlation coefficients between the AI model and ground truth were 0.884-0.927 and 0.736-0.831, for joint ROIs and whole hands, respectively. The Spearman's correlation coefficient for the additional test set between the model trained with 15 phases and RAMRIS was 0.768. The AI-based classification model effectively identified synovitis pixels while excluding arteries. The optimal performance was achieved with at least 15 phases, providing a quantitative assessment of inflammatory activity in RA while minimizing acquisition time. 3 TECHNICAL EFFICACY: Stage 2.

Photon-counting detector CT - first experiences in the field of musculoskeletal radiology.

The introduction of photon-counting detector CT (PCD-CT) marks a remarkable leap in innovation in CT imaging. The new detector technology allows X-rays to be converted directly into an electrical signal without an intermediate step via a scintillation layer and allows the energy of individual photons to be measured. Initial data show high spatial resolution, complete elimination of electronic noise, and steady availability of spectral image data sets. In particular, the new technology shows promise with respect to the imaging of osseous structures. Recently, PCD-CT was implemented in the clinical routine. The aim of this review was to summarize recent studies and to show our first experiences with photon-counting detector technology in the field of musculoskeletal radiology.We performed a literature search using Medline and included a total of 90 articles and reviews that covered recent experimental and clinical experiences with the new technology.In this review, we focus on (1) spatial resolution and delineation of fine anatomic structures, (2) reduction of radiation dose, (3) electronic noise, (4) techniques for metal artifact reduction, and (5) possibilities of spectral imaging. This article provides insight into our first experiences with photon-counting detector technology and shows results and images from experimental and clinical studies. · This review summarizes recent experimental and clinical studies in the field of photon-counting detector CT and musculoskeletal radiology.. · The potential of photon-counting detector technology in the field of musculoskeletal radiology includes improved spatial resolution, reduction in radiation dose, metal artifact reduction, and spectral imaging.. · PCD-CT enables imaging at lower radiation doses while maintaining or even enhancing spatial resolution, crucial for reducing patient exposure, especially in repeated or prolonged imaging scenarios.. · It offers promising results in reducing metal artifacts commonly encountered in orthopedic or dental implants, enhancing the interpretability of adjacent structures in postoperative and follow-up imaging.. · With its ability to routinely acquire spectral data, PCD-CT scans allow for material classification, such as detecting urate crystals in suspected gout or visualizing bone marrow edema, potentially reducing reliance on MRI in certain cases.. Bette S, Risch F, Becker J et al. Photon-counting detector CT - first experiences in the field of musculoskeletal radiology. Fortschr Röntgenstr 2024; DOI 10.1055/a-2312-6914.

Diagnosing periprosthetic hip joint infection with new-generation 0.55 T MRI

PurposeTo assess the accuracy of 0.55 T MRI in diagnosing periprosthetic joint infection (PJI) in patients with symptomatic total hip arthroplasty (THA). Material and methods0.55 T MRI of patients with THA PJI (Group A) and noninfected THA (Group B), including aseptic loosening (Group C, subgroup of B) performed between May 2021 and July 2023 were analysed retrospectively.Two musculoskeletal fellowship-trained radiologists independently identified MRI bone and soft tissue changes including: marrow oedema, periosteal reaction, osteolysis, joint effusion, capsule oedema and thickening, fluid collections, muscle oedema, bursitis, inguinal adenopathy, and muscle tears. The diagnostic performance of MRI discriminators of PJI was evaluated using Fisher’s exact test (p < 0.05) and interrater reliability was determined. 61 MRI scans from 60 THA patients (34 female, median age 68, range 41–93 years) in Group A (n = 9; female 4; median age 69, range 56–82 years), B (n = 51; 30; 67.5, 41–93 years), and C (10; 6; 67; 41–82 years) were included. ResultsCapsule oedema (sensitivity 89 %, specificity 92 %,), intramuscular oedema (89 %, 82 %) and joint effusion (89 %, 73 %) were the best performing discriminators for PJI diagnosis (p ≤ 0.001), when viewed individually and had combined 70 % sensitivity and 100 % specificity for PJI diagnosis in parallel testing. For the differentiation between PJI and aseptic loosening, intramuscular oedema (89 %, 80 %) and capsule oedema (89 %, 80 %) were significant discriminators (p ≤ 0.001) with combined 64 % sensitivity and 96 % specificity for PJI. ConclusionsNew generation 0.55 T MRI may aid in the detection of PJI in symptomatic patients. Oedema of the joint capsule, adjacent muscles as well as joint effusion were indicative of the presence of PJI.