Magnetic resonance arthrography with positional manoeuvre for the diagnosis of synovial fold of posterior shoulder joint capsule.

OBJECTIVES: The objective of this study is to prospectively assess the effectiveness of shoulder magnetic resonance (MR) arthrograms with positional manoeuvres in detecting posterior synovial folds. METHODS: Two radiologists independently assessed all axial MR arthrograms in internal rotation, neutral position, and external rotation for the presence of a posterior synovial fold. The diagnostic performances of the MR arthrograms were then compared, with results validated through arthroscopy. RESULTS: Arthroscopy was performed on 81 of the 150 patients included in the study. A posterior synovial fold was identified arthroscopically in eleven of these patients. Measurements of the posterior synovial fold obtained in external rotation and the neutral position of the arm showed a significant correlation with arthroscopic results (p < 0.05). For detecting the posterior synovial fold with arthroscopic correlation, the sensitivity and specificity values for observer 1 and observer 2 were 100-81.4% and 100-88.6%, respectively, for MR arthrograms in the neutral position; 100-52.9% and 100-62.9% for MR arthrograms in external rotation; and 100-95.7% and 81.8-98.6% for MR arthrograms in internal rotation. There was a fair agreement for MR arthrography in external rotation for detecting posterior synovial folds, while MR arthrograms in internal rotation and neutral position showed near-perfect and significant interobserver agreement. CONCLUSION: The rotational positions of the humeral neck during MR arthrographic examination can influence the diagnostic specificity and sensitivity of axial MR arthrograms in detecting the posterior synovial fold. CLINICAL RELEVANCE STATEMENT: The posterior synovial fold can mimic a posterior labral detachment. Therefore, its correct identification is crucial in order to avoid unnecessary surgical procedures. KEY POINTS: Movement of the shoulder may introduce variability in MR arthrography appearance. Rotation of the humeral neck during MR arthrography can affect diagnoses in posterior synovial fold detection. Given that posterior synovial folds can imitate posterior labral detachment, their correct identification is crucial to avoid unnecessary surgical procedures.

Semiquantitative index of symptomatic minor instability of the lateral elbow at CT arthrography (SMILE index): clinical applicability and reproducibility study.

OBJECTIVE: To assess the applicability of a semiquantitative index for symptomatic minor instability of the lateral elbow (SMILE). MATERIALS AND METHODS: CT arthrograms of consecutive patients with lateral elbow pain who underwent ultrasound-guided CT arthrography at our orthopedic center between April 2019 and May 2022 were included. Images were acquired at 100 kVp and 80 mAs. An expert radiologist (R1) and a radiology resident (R2) retrospectively performed an independent, blinded evaluation of the arthrograms to assess the presence of imaging findings suggestive of elbow instability. The SMILE index (0-8) was obtained adding (I) radial head chondromalacia (0 - 1); (II) humeral capitellum chondromalacia (0 - 1); (III) humeral trochlear ridge chondromalacia (0 - 1); (IV) annular ligament laxity (0 - 2); (V) synovial thickening (0 - 1); (VI) humeroradial joint asymmetry (0 - 1); and (VII) capsular tear (0 - 1). R1 repeated the assessment after 14 days. Cohen's weighted κ statistic and raw concordance were used to appraise reproducibility. RESULTS: Eighty patients (median age 49 years, interquartile range 40-53 years, 49, 61% males) underwent CT arthrography at our center, and 10 (12%) of them underwent bilateral elbow examination, leading to 90 included CT arthrograms. Median SMILE index was 4 (IQR: 2-5) for R1, 4 (IQR: 2-5) for R2, and 4 (IQR: 2-5) for the second assessment by R1. Intra-reader agreement was excellent (κ = 0.94, concordance 87%), while inter-reader agreement was substantial (κ = 0.75, concordance 67%). CONCLUSION: The proposed SMILE index showed good reproducibility; further studies are warranted to correlate our index with clinical and surgical data. CLINICAL RELEVANCE STATEMENT: Our scoring system allows a standardized evaluation of patients with lateral elbow pain and instability suitable for application into clinical practice, complementing the orthopedic surgeon's clinical diagnosis with imaging findings that may aid treatment choices. KEY POINTS: • Lateral elbow pain is often interpreted clinically as lateral epicondylitis, but it can also encompass intra-articular pathology. • The proposed arthrographic index allows comprehensive quantification of lateral elbow pathology with good reproducibility and application times. • Our index provides the orthopedic surgeon with information regarding intra-articular findings, aiding treatment choices.

Diagnostic performance of long head of biceps tendon tears on MRI: systematic review and meta-analysis.

OBJECTIVES: The purpose of this meta-analysis was to determine the diagnostic performance of conventional MRI and MR arthrography for tendinosis, and partial and complete tears of the long head of the biceps tendon (LHBT) using arthroscopy as the reference standard. MATERIALS AND METHODS: A systematic review was performed using predefined data fields in PubMed, and all articles published from January 2000 up to April 2022 were retrospectively pooled and reviewed. Six MRI studies on complete tear (n = 555) and ten studies on partial tear/tendinosis (n = 2487) were included in the analysis. Two of the included studies in each group investigated the use of MR arthrography. The data sets were analyzed using a univariate approach with the DerSimonian and Laird random effects model and the proportional hazards model. RESULTS: MRI shows high specificities in diagnosing complete tears of the LHBT ranging from 93.0 to 99.0%. Diagnostic sensitivity was more heterogeneous ranging from 55.9 to 90.0%. The overall negative likelihood ratio was 0.29 (95% CI: 0.17-0.50) and the overall positive likelihood ratio was 37.3 (95% CI: 11.9-117.4). The mean sensitivity in diagnosing partial tear/tendinosis of the LHBT was 67.8% (95% CI: 54.3-78.9%) and the specificity was 75.9% (95% CI: 63.6-85.0%), resulting in a balanced accuracy of 71.9%. The overall negative likelihood ratio was 0.44 (95% CI: 0.32-0.59) and the overall positive likelihood ratio was 2.64 (95% CI: 1.91-3.65). CONCLUSION: MRI is highly specific for the diagnosis of complete tears of the LHBT, whereas diagnostic sensitivity was more heterogeneous. The diagnosis of partial tears and/or tendinosis of the LHBT remains challenging on MRI, which may warrant complementary clinical examination or other imaging modalities to increase diagnostic confidence in equivocal cases. CLINICAL RELEVANCE STATEMENT: Conventional MRI and MR arthrography have high diagnostic performance for complete tendon tear when compared to arthroscopy. The diagnosis of tendinosis/partial tears remains challenging and may require comparison with clinical tests and other imaging modalities. KEY POINTS: •There is no clear consensus regarding the primary imaging modality for the evaluation of LHBT disorders. •Conventional MRI and MR arthrography are highly specific in diagnosing complete tears of the LHBT. •Diagnosis of partial tears/tendinosis of the LHBT on conventional MRI and MR arthrography remains a diagnostic challenge.

Comparison of conventional MR arthrography and 3D volumetric MR arthrography in detection of cartilage defects accompanying glenoid labrum pathologies.

OBJECTIVES: In this study, we aimed to compare conventional and T1-weighted volumetric magnetic resonance arthrography (MRA) in the diagnosis and grading of glenoid cartilage defects that accompany labral pathologies. MATERIALS AND METHODS: A total of 79 patients who were prediagnosed with labrum pathologies based on shoulder magnetic resonance imaging (MRI) had MRA and CTA between December 2021 and May 2022. CTA was regarded as reference standard. CTA images were examined by a radiologist experienced in musculoskeletal radiology, and MRA images were examined by two radiologists independently to determine presence, grade, and localization of any glenoid cartilage defect, if present. Sensitivity, specificity, and accuracy were calculated separately for conventional and T1-weighted volumetric MRA. In addition, at the last stage, two observers examined all MRAs together, and the presence of a cartilage defect was decided by consensus, and the overall sensitivity, specificity, and accuracy were calculated. RESULTS: Cartilage defect was detected on CTAs of 48 (60.75%) cases of among 79 patients with labrum pathology. The sensitivity, specificity, and accuracy of conventional MRA for two examiners were 17-19%, 100-100%, and 49-51%, respectively, while those values were 67-65%, 92-97%, and 84-77%, respectively, for T1-weighted volumetric MRA. Inter-examiner agreement was excellent for diagnosis of cartilage defects on all MRAs. The overall sensitivity, specificity, and accuracy for detection of glenoid cartilage lesions by MRA were 69%, 97%, and 80%, respectively. CONCLUSION: T1-weighted volumetric MRA seems to demonstrate cartilage defects accompanied with labrum pathologies accurately with high sensitivity, specificity, and excellent inter-examiner agreement.

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.

OBJECTIVE: 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. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Direct MR arthrography of the hip joint: anterior approach without imaging guidance.

PURPOSE: The purpose of this study is to describe the anterior injection approach, with anatomical landmark guidance, for direct MR arthrography (dMRA) of the hip joint, and to evaluate the effectiveness in joint distension and the security of the technique. MATERIAL AND METHODS: Retrospective review of hip dMRAs was conducted on patients with suspected intra-articular pathology from two MR outpatient centers, performed by two radiologists with 25 and 5 years of experience, respectively. The analysis included assessing the presence of intra-articular contrast material (gadolinium-based solution), the number of injections performed, the degree of joint distension, and the degree of contrast extravasation. A multi-variant analysis was carried out to determine if the procedure success depend on any of the demographic variants or on the radiologist experience. Additionally, the presence of immediate and medium-term post-puncture complications was evaluated. RESULTS: One hundred patients with 104 hip dMRA were included; 60 were men, with mean age of 38 years (16-63 years). Contrast material was successfully introduced intra-articularly in 100% of patients, being necessary a second puncture only in 6% of procedures. The capsular distension was considered optimal for diagnosis in 97% of cases. Different degrees of contrast extravasation were found in 30% of dMRA. There was no statistically significant relationship observed between patient variables and the performance of dMRA, nor did it show any correlation with the experience of the radiologists. No puncture-derived complications were found. CONCLUSION: Hip dMRA through anterior injection guided by anatomical references is an effective and safe alternative for patients with suspected intra-articular pathology.

Ankle, knee, and elbow arthrography: 2022 survey of Society of Skeletal Radiology members.

OBJECTIVE: To determine the preferred ankle, knee, and elbow arthrography injection techniques for Society of Skeletal Radiology (SSR) members and whether more recently described techniques are gaining acceptance. We also sought to determine whether the concept of knowledge translation might explain differences between the preferred technique, year of fellowship graduation, and year the newer technique was described. MATERIALS AND METHODS: A 29-question survey was created in Qualtrics and submitted to current SSR members to determine if they perform knee, elbow, and ankle arthrography, and if so, the year of fellowship completion and preferred approaches. Survey respondents indicated the starting and ending needle tip positions for three knee, two elbow, and three ankle arthrography approaches using grids placed over provided frontal and lateral radiographs. RESULTS: Two hundred seventy-four SSR members (mean post-fellowship 13 years; range 0-38) completed the survey and performed fluoroscopic-guided knee (93%), elbow (95%), and ankle (75%) arthrography. Preferred approaches included the following: knee lateral subpatellar (43%), anterior (40%); elbow radiocapitellar (74%); ankle anterior/peritendon (70%), lateral mortise (24%). Preference of newer technique was related to fellowship graduation year and publication year for the ankle mortise (26% before, 42% after; p = 0.03) and posterior trans-triceps elbow articles (19% before, 33% after; p < 0.01). The anterior knee approach preference increased from 11% in 2008 to 40% (p ≤ 0.001). CONCLUSION: Nearly twice as many SSR members who graduated after the posterior trans-triceps and ankle mortise techniques were published prefer them for performing arthrography, possibly due to knowledge translation. The preference of the anterior knee arthrography approach has increased nearly fourfold since 2008.

The 2D and 3D MR arthrographic description of aponeurotic expansion of supraspinatus tendon and biceps tendon anomaly in a large patient cohort.

OBJECTIVE: To describe the aponeurotic expansion of supraspinatus tendon (AEST) and biceps tendon abnormalities with magnetic resonance (MR) arthrographic examinations and determine their prevalence in patients, we performed a high-resolution 3D direct MR arthrography. MATERIALS AND METHODS: This was a retrospective study of 700 shoulder MR arthrograms performed between May 2010 and January 2022. Extension in the coronal plane of an AEST on 3D fat-suppressed T1-weighted volumetric interpolated breath-hold examination (VIBE) MR arthrography was identified. Based on its morphology, the AEST on MR arthrography was divided into four subtypes: absence of tendinous thickness in the bicipital synovial surface or intra-synovial tendon-like structure in the bicipital groove, thin and flat tendinous thickness ≥1 mm of bicipital synovium, oval tendinous structure less than half the size of the adjacent biceps tendon, oval tendinous structure more than half the size of the adjacent biceps tendon, and oval tendinous structure larger than the adjacent biceps tendon. Based on its origin and termination, aponeurotic expansions can be divided into three subtypes: proximal pulley zone, middle humeral neck zone, and distal myotendinous junction zone. Association with the biceps synovium of the AEST was categorized into three types: intra-synovial, extra-synovial, and trans-synovial. RESULTS: An AEST in the anterior shoulder joint in 3D VIBE MR arthrography images was identified in 63 (9%) of 700 arthrograms. The most common arthrographic type of AEST was type 1-this was detected in 39 of 63 patients. The most common course type of the AEST was anteriorly midline. The most common distal insertion type was at the tenosynovial sheath of the long head of the biceps tendon (LHBT) in the middle humeral neck zone-this was detected in 31 of 63 patients. There were only 10 MR arthrograms biceps tendon abnormality, including 4 biceps agenesis and 6 split ruptures. CONCLUSION: A 2D and high-resolution 3D MR arthrography can demonstrate the anatomical detail around the bicipital groove and facilitate the differentiation between a biceps tendon anomaly and an AEST. On high-resolution 3D MR arthrographic images, the AEST tends to be in the anterior midline and anteromedial portions of the biceps synovium with intra-synovial, extra-synovial, and trans-synovial courses and its three different insertion types.

Direct MR arthrography without image guidance: a practical guide, joint-by-joint.

Direct MR arthrography (dMRA) is a fundamental technique in diagnosing pathology in major peripheral joints, allowing for precise evaluation of intra-articular structures. Although injection guidance is typically performed using imaging techniques such as ultrasound or fluoroscopy, puncture via anatomical landmarks may be useful in certain circumstances where it has been proven to be a safe and effective procedure. This paper describes the indications and injection technique of dMRA, joint by joint, focusing on the different technical details, from the most common locations, like the shoulder or hip, to those with more restricted clinical indications, such as the wrist, knee, elbow, or ankle. The most relevant anatomical landmarks are detailed for each joint, aiding in the intra-articular introduction of diluted contrast, highlighting the most accessible trajectories and structures to avoid when inserting the needle. Additionally, tips are provided to facilitate proper joint distension. With all this information, this paper aims to serve as a suitable reference guide for performing dMRA without image guidance if needed.

SSR white paper: guidelines for utilization and performance of direct MR arthrography.

OBJECTIVE: Direct magnetic resonance arthrography (dMRA) is often considered the most accurate imaging modality for the evaluation of intra-articular structures, but utilization and performance vary widely without consensus. The purpose of this white paper is to develop consensus recommendations on behalf of the Society of Skeletal Radiology (SSR) based on published literature and expert opinion. MATERIALS AND METHODS: The Standards and Guidelines Committee of the SSR identified guidelines for utilization and performance of dMRA as an important topic for study and invited all SSR members with expertise and interest to volunteer for the white paper panel. This panel was tasked with determining an outline, reviewing the relevant literature, preparing a written document summarizing the issues and controversies, and providing recommendations. RESULTS: Twelve SSR members with expertise in dMRA formed the ad hoc white paper authorship committee. The published literature on dMRA was reviewed and summarized, focusing on clinical indications, technical considerations, safety, imaging protocols, complications, controversies, and gaps in knowledge. Recommendations for the utilization and performance of dMRA in the shoulder, elbow, wrist, hip, knee, and ankle/foot regions were developed in group consensus. CONCLUSION: Although direct MR arthrography has been previously used for a wide variety of clinical indications, the authorship panel recommends more selective application of this minimally invasive procedure. At present, direct MR arthrography remains an important procedure in the armamentarium of the musculoskeletal radiologist and is especially valuable when conventional MRI is indeterminant or results are discrepant with clinical evaluation.

Preliminary exploration of deep learning-assisted recognition of superior labrum anterior and posterior lesions in shoulder MR arthrography.

PURPOSE: MR arthrography (MRA) is the most accurate method for preoperatively diagnosing superior labrum anterior-posterior (SLAP) lesions, but diagnostic results can vary considerably due to factors such as experience. In this study, deep learning was used to facilitate the preliminary identification of SLAP lesions and compared with radiologists of different seniority. METHODS: MRA data from 636 patients were retrospectively collected, and all patients were classified as having/not having SLAP lesions according to shoulder arthroscopy. The SLAP-Net model was built and tested on 514 patients (dataset 1) and independently tested on data from two other MRI devices (122 patients, dataset 2). Manual diagnosis was performed by three radiologists with different seniority levels and compared with SLAP-Net outputs. Model performance was evaluated by the receiver operating characteristic (ROC) curve, area under the ROC curve (AUC), etc. McNemar's test was used to compare performance among models and between radiologists' models. The intraclass correlation coefficient (ICC) was used to assess the radiologists' reliability. p < 0.05 was considered statistically significant. RESULTS: SLAP-Net had AUC = 0.98 and accuracy = 0.96 for classification in dataset 1 and AUC = 0.92 and accuracy = 0.85 in dataset 2. In dataset 1, SLAP-Net had diagnostic performance similar to that of senior radiologists (p = 0.055) but higher than that of early- and mid-career radiologists (p = 0.025 and 0.011). In dataset 2, SLAP-Net had similar diagnostic performance to radiologists of all three seniority levels (p = 0.468, 0.289, and 0.495, respectively). CONCLUSIONS: Deep learning can be used to identify SLAP lesions upon initial MR arthrography examination. SLAP-Net performs comparably to senior radiologists.

The value of combined ultrasound contrast arthrography and subacromial-subdeltoid bursography for detecting and differentiating the rotator cuff tear subtypes in patients with the uncertain rotator cuff tear.

OBJECTIVES: In this study, ultrasound (US) contrast arthrography and subacromial-subdeltoid bursography with the contrast agent of SonoVue were performed to evaluate their value for detecting and differentiating the rotator cuff tear (RCT) subtypes in patients with the uncertain RCT. METHODS: A total of 102 patients with the clinically suspected RCTs in the orthopedic clinic were prospectively recruited and underwent conventional high-frequency US for the category of undoubted full-thickness RCT, uncertain RCT, and intact rotator cuff. Among these patients, the patients with uncertain RCT underwent the subsequent US contrast arthrography and subacromial-subdeltoid bursography. The arthroscopic findings were used as the gold standard in this study. RESULTS: After the conventional US screening, 62 patients with uncertain RCT underwent the subsequent US contrast arthrography and subacromial-subdeltoid bursography. All the US contrast arthrography and subacromial-subdeltoid bursography were successfully performed and no severe side effects were observed in all the patients. For full-thickness tears, the sensitivity and specificity of the combined US contrast arthrography and subacromial-subdeltoid bursography were 94.7% (CI: 0.72-1.0) and 81.4% (CI: 0.66-0.91), respectively, and for articular-side tears 100% (CI: 0.51-1) and 100% (CI: 0.92-1), respectively, and for the bursal-side tears 84.6% (CI: 0.54-0.97) and 97.9% (CI: 0.88-1.0), respectively. The main inconsistency between the contrast-enhanced US and arthroscopy was that 7 patients with arthroscopic proved concurrent articular- and bursal-side tears were indicated as full-thickness RCTs on contrast-enhanced US. CONCLUSIONS: Combined US contrast arthrography and subacromial-subdeltoid bursography are useful for detecting the RCT subtypes in patients with the uncertain RCTs. CLINICAL RELEVANCE STATEMENT: When conventional high-frequency US has some difficulty in differentiating the full-thickness from partial-thickness RCTs, combined US contrast arthrography and subacromial-subdeltoid bursography could be used to improve the detection accuracy of RCT subtypes. KEY POINTS: • This is the first study by injection of the US contrast agent SonoVue into the shoulder joint cavity and subacromial-subdeltoid bursa for the detection and differentiation of the RCT subtypes among the people with the uncertain RCT by conventional US screening. • The SonoVue was injected into the glenohumeral joint cavity under US guidance to differentiate the full-thickness RCTs from partial-thickness RCTs. • Combined US contrast arthrography and subacromial-subdeltoid bursography are useful for detecting the RCT subtypes in patients with the uncertain RCTs.

Can gadolinium contrast agents be replaced with saline for direct MR arthrography of the hip? A pilot study with arthroscopic comparison.

OBJECTIVE: To compare image quality and diagnostic performance of preoperative direct hip magnetic resonance arthrography (MRA) performed with gadolinium contrast agent and saline solution. METHODS: IRB-approved retrospective study of 140 age and sex-matched symptomatic patients with femoroacetabular impingement, who either underwent intra-articular injection of 15-20 mL gadopentetate dimeglumine (GBCA), 2.0 mmol/L ("GBCA-MRA" group, n = 70), or 0.9% saline solution ("Saline-MRA" group, n = 70) for preoperative hip MRA and subsequent hip arthroscopy. 1.5 T hip MRA was performed including leg traction. Two readers assessed image quality using a 5-point Likert scale (1-5, excellent-poor), labrum and femoroacetabular cartilage lesions. Arthroscopic diagnosis was used to calculate diagnostic accuracy which was compared between groups with Fisher's exact tests. Image quality was compared with the Mann-Whitney U tests. RESULTS: Mean age was 33 years ± 9, 21% female patients. Image quality was excellent (GBCA-MRA mean range, 1.1-1.3 vs 1.1-1.2 points for Saline-MRA) and not different between groups (all p > 0.05) except for image contrast which was lower for Saline-MRA group (GBCA-MRA 1.1 ± 0.4 vs Saline-MRA 1.8 ± 0.5; p < 0.001). Accuracy was high for both groups for reader 1/reader 2 for labrum (GBCA-MRA 94%/ 96% versus Saline-MRA 96%/93%; p > 0.999/p = 0.904) and acetabular (GBCA-MRA 86%/ 83% versus Saline-MRA 89%/87%; p = 0.902/p = 0.901) and femoral cartilage lesions (GBCA-MRA 97%/ 99% versus Saline-MRA 97%/97%; both p > 0.999). CONCLUSION: Diagnostic accuracy and image quality of Saline-MRA and GBCA-MRA is high in assessing chondrolabral lesions underlining the potential role of non-gadolinium-based hip MRA. KEY POINTS: • Image quality of Saline-MRA and GBCA-MRA was excellent for labrum, acetabular and femoral cartilage, ligamentum teres, and the capsule (all p > 0.18). • The overall image contrast was lower for Saline-MRA (Saline-MRA 1.8 ± 0.5 vs. GBCA-MRA 1.1 ± 0.4; p < 0.001). • Diagnostic accuracy was high for Saline-MRA and GBCA-MRA for labrum (96% vs. 94%; p > 0.999), acetabular cartilage damage (89% vs. 86%; p = 0.902), femoral cartilage damage (97% vs. 97%; p > 0.999), and extensive cartilage damage (97% vs. 93%; p = 0.904).

Detection of the glenoid bare spot by non-arthrographic MR imaging, conventional MR arthrography, and 3D high-resolution T1-weighted VIBE MR arthrography: comparison with CT arthrography.

OBJECTIVES: To determine the diagnostic accuracy of non-arthrographic MR imaging, conventional MR arthrography, and 3D T1-weighted volumetric interpolated breath-hold examination (VIBE) MR arthrography sequences as compared with a CT arthrography in the diagnosis of glenoid bare spot. METHODS: A retrospective study of 216 patients who underwent non-arthrographic MR imaging, conventional MR arthrography, VIBE MRI arthrography, and CT arthrogram between January 2011 and March 2022 was conducted. The diagnostic accuracy of non-arthrographic MR imaging, direct MR arthrography, and VIBE MRI arthrography in the detection of glenoid bare spot was compared with that of CT arthrography. All studies were reviewed by 2 MSK radiologists. Interobserver agreement for MR imaging and MR arthrographic findings was calculated. RESULTS: Sixteen of 216 patients were excluded. Twenty-three of 200 shoulders had glenoid bare spot on CT arthrographic images. The glenoid bare spot was detected in 11 (47.8%) and 7 (30.4%) patients on conventional non-arthrographic MR images and in 18 (78.3%) and 16 (69.6%) patients on conventional MR arthrograms by observers 1 and 2, respectively. Both observers separately described the bare spot in 22 of 23 patients (95.7%) on 3D volumetric MR arthrograms. Interobserver variabilities were fair agreement for conventional non-arthrographic MR imaging (κ = 0.35, p < 0.05), moderate agreement for conventional MR arthrogram (κ = 0.50, p < 0.05), and near-perfect agreement for 3D volumetric MR arthrogram reading (κ = 0.87, p < 0.05). CONCLUSIONS: A 3D high-resolution T1-weighted VIBE MR arthrography sequence may yield diagnostic performance that is comparable with that of CT arthrography in the diagnosis of glenoid bare spot. KEY POINTS: •Glenoid bare spot should not be misdiagnosed as a transchondral defect of the glenoid surface by radiologists. •A 3D high-resolution T1-weighted VIBE MR arthrography sequence may be used as a high-sensitivity imaging technique in the diagnosis of glenoid bare spot.

Are degenerative findings detected on traction MR arthrography of the hip associated with failure of arthroscopic femoroacetabular impingement surgery?

OBJECTIVES: To identify preoperative degenerative features on traction MR arthrography associated with failure after arthroscopic femoroacetabular impingement (FAI) surgery. METHODS: Retrospective study including 102 patients (107 hips) undergoing traction magnetic resonance arthrography (MRA) of the hip at 1.5 T and subsequent hip arthroscopic FAI surgery performed (01/2016 to 02/2020) with complete follow-up. Clinical outcomes were assessed using the International Hip Outcome Tool (iHOT-12) score. Clinical endpoint for failure was defined as an iHOT-12 of < 60 points or conversion to total hip arthroplasty. MR images were assessed by two radiologists for presence of 9 degenerative lesions including osseous, chondrolabral/ligamentum teres lesions. Uni- and multivariate Cox regression analysis was performed to assess the association between MRI findings and failure of FAI surgery. RESULTS: Of the 107 hips, 27 hips (25%) met at least one endpoint at a mean 3.7 ± 0.9 years follow-up. Osteophytic changes of femur or acetabulum (hazard ratio [HR] 2.5-5.0), acetabular cysts (HR 3.4) and extensive cartilage (HR 5.1) and labral damage (HR 5.5) > 2 h on the clockface were univariate risk factors (all p < 0.05) for failure. Three risk factors for failure were identified in multivariate analysis: Acetabular cartilage damage > 2 h on the clockface (HR 3.2, p = 0.01), central femoral osteophyte (HR 3.1, p = 0.02), and femoral cartilage damage with ligamentum teres damage (HR 3.0, p = 0.04). CONCLUSION: Joint damage detected by preoperative traction MRA is associated with failure 4 years following arthroscopic FAI surgery and yields promise in preoperative risk stratification. CLINICAL RELEVANCE STATEMENT: Evaluation of negative predictors on preoperative traction MR arthrography holds the potential to improve risk stratification based on the already present joint degeneration ahead of FAI surgery. KEY POINTS: • Osteophytes, acetabular cysts, and extensive chondrolabral damage are risk factors for failure of FAI surgery. • Extensive acetabular cartilage damage, central femoral osteophytes, and combined femoral cartilage and ligamentum teres damage represent independent negative predictors. • Survival rates following hip arthroscopy progressively decrease with increasing prevalence of these three degenerative findings.

An assessment of SLAP type 5 lesions using proton density oblique sagittal imaging in magnetic resonance arthrography.

BACKGROUND: Bankart lesions accompany superior labrum anteroposterior (SLAP) lesions; these are called SLAP type 5. PURPOSE: To compare SLAP type 5 lesions using routine magnetic resonance arthrography (MRA) and thin-slice oblique sagittal proton density (PDW) sequences and correlation operation results. MATERIAL AND METHODS: In total, 181 patients were admitted with shoulder instability. The study was completed with 44 patients. The presence or absence of isolated Bankart and SLAP type 5 lesions in routine MRA and PDW oblique sagittal images were evaluated separately. Absence of rupture scored 0 points, suspected ruptures scored 1 point, and apparent ruptures scored 2 points. The two scores were compared with the shoulder arthroscopy findings. RESULTS: According to the findings in the shoulder arthroscopy, 40 patients had Bankart lesions and 17 patients had accompanying SLAP type 5 lesions. To detect a Bankart lesion, there was no significant difference between routine MRA sequences and PDW oblique sagittal images (P = 0.061). Routine MRA sensitivity was 95%, specificity 25%, positive predictive value (PPV) 92%, negative predictive value (NPV) 33%, while for PDW oblique sagittal images, sensitivity was 75%, specificity 100%, PPV 100%, and NPV 28.5%. In 8/17 type 5 SLAP lesions, routine MRA detected sensitivity 47%, specificity 92.6%, PPV 80%, and NPV 73.5%; in 14/17 SLAP type 5 lesions, PDW oblique sagittal images detected sensitivity 82%, specificity 100%, PPV 100%, and NPV 90% (P = 0.015). CONCLUSION: The PDW oblique sagittal images may play a significant role in assessing the anterior and superior extent of the tears.

Dual-layer spectral detector CT arthrography of the shoulder: assessment of image quality and value in differentiating calcium from iodine.

BACKGROUND: Dual-layer spectral detector computed tomography (DLCT) may potentially improve CT arthrography through enhanced image quality and analysis of the chemical composition of tissue. PURPOSE: To evaluate the image quality of monoenergetic reconstructions from DLCT arthrography of the shoulder and assess the additional diagnostic value in differentiating calcium from iodine. MATERIAL AND METHODS: Images from consecutive shoulder DLCT arthrography examinations performed between December 2016 and February 2018 were retrospectively reviewed for hyperattenuating lesions within the labrum and tendons. The mean attenuation of the target lesion, noise, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of the virtual monoenergetic images obtained at 40-200 keV were compared with conventional 140-kVp images. Two evaluators independently classified each target lesion as contrast media or calcification, without and with DLCT spectral data. Receiver operating curve (ROC) analysis was performed to assess the diagnostic performance of shoulder DLCT arthrography, without and with the aid of spectral data. RESULTS: The study included 20 target lesions (18 DLCT arthrography examinations of 17 patients). The SNRs of the monoenergetic images at 40-60 keV were significantly higher than those of conventional images (P < 0.05). The CNRs of the monoenergetic images at 40-70 keV were significantly higher than those of conventional images (P < 0.001). The ability to differentiate calcium from iodine, without and with DLCT spectral data, did not significantly differ (P = 0.441 and P = 0.257 for reviewers 1 and 2, respectively). CONCLUSION: DLCT had no additive value in differentiating calcium from iodine in small, hyperattenuating lesions in the labrum and tendons.

Influence of joint volume on range of motion after arthroscopic rotator cuff repair.

BACKGROUND: Capsular contracture is a well-known etiology in the primary stiff shoulder; thus capsular contracture and resultant decreased joint volume could lead to postoperative stiffness, which is a commonly reported morbidity after arthroscopic rotator cuff repair (ARCR). The purpose of this study was (1) to quantify the joint volume (total joint volume and each quadrant compartmental volume) using computed tomography arthrography (CTA) and (2) to demonstrate the relationship between joint volume and postoperative range of motion (ROM) after ARCR. MATERIALS AND METHODS: Eighty-three patients (60 ± 5.11 years, men = 26, women = 57) who had undergone ARCR between January 2015 to December 2020 due to small to medium full-thickness tear and followed by CTA 6 months postoperatively were retrospectively reviewed. An image reconstruction program (3D Slicer, version 4.11.2 software) was used to calculate the joint volume (total joint volume and quadrant compartment joint volumes; anteroinferior, anterosuperior, posterosuperior and posteroinferior). For shoulder ROM, data including scaption (Sc), external rotation on side (ERs), external rotation at 90° (ER90), and internal rotation on back (IRb) were collected 6 months postoperatively. An evaluation of the correlation between joint volume and each shoulder motion was performed. RESULTS: There were moderate correlations between the total joint volume and each motion (Sc: Pearson coefficient, 0.32, p = 0.0047; ERs: Pearson coefficient, 0.24, p = 0.0296; ER90: Pearson coefficient, 0.33, p = 0.0023; IRb: Pearson coefficient, 0.23, p = 0.0336). Among the quadrant compartments, the anteroinferior (Sc: Pearson coefficient, 0.26, p = 0.0199; ERs: Pearson coefficient, 0.23, p = 0.0336; ER90: Pearson coefficient, 0.25, p = 0.0246; IRb: Pearson coefficient, 0.26, p = 0.0168) and posterosuperior (Sc: Pearson coefficient, 0.24, p = 0.029; ER90: Pearson coefficient, 0.29, p = 0.008; IRb: Pearson coefficient, 0.22, p = 0.0491) and posteroinferior (Sc: Pearson coefficient, 0.30, p = 0.0064; ER90: Pearson coefficient, 0.29, p = 0.0072) showed moderate correlations with each shoulder motion. CONCLUSION: Total joint volume, anteroinferior compartment joint volume, posterosuperior compartment joint volume and posteroinferior compartment joint volume were related to postoperative ROM after ARCR. Perioperative methods to increase the joint volume, especially the anteroinferior, posterosuperior and posteroinferior parts of the capsule may prevent postoperative stiffness after ARCR. LEVEL OF EVIDENCE: Level III; Retrospective Case-Control Study.

Frequency of technical success of ultrasound-guided arthrogram injections in children.

BACKGROUND: MR arthrography is an essential diagnostic tool to assess and guide management of labral, ligamentous, fibrocartilaginous, and capsular abnormalities in children. While fluoroscopy is traditionally used for intra-articular contrast administration, ultrasound offers advantages of portability and lack of ionizing radiation exposure for both the patient and proceduralist. OBJECTIVE: The purpose of this retrospective study is to quantify technical success and frequency of complications of ultrasound-guided arthrogram injections at our institution. MATERIALS AND METHODS: This retrospective analysis investigates the results of 217 ultrasound-guided arthrograms of the shoulder, elbow, and hip in patients aged 5-18 years. Successful injection of contrast into the target joint, clinical indication for MR arthrography, and complications were reviewed. RESULTS: Accurate ultrasound-guided intra-articular administration of contrast into the target joint was successful for 100% of shoulder cases (90/90), 97% of elbow cases (77/79), and 98% of hip cases (47/48). Leak of contrast outside the target joint occurred in 1.4% (3/217) of cases. No major side effects including excessive bleeding, paresthesia, allergic reactions, or infection occurred during or after the procedure. Additionally, no major vessel, nerve, or tendon complications were observed on MR images. CONCLUSION: Ultrasound guidance is a reliable, effective, and safe approach to arthrography in children.

Factors affecting satisfaction in patients with a rotator cuff retear: CT arthrography-based study.

PURPOSE: The relationship between retear that may occur after rotator cuff repair and patient satisfaction is not well established. This study aimed to determine whether the types and size of the retear evaluated by computed tomography arthrography (CTA) influenced patient satisfaction. We also analyzed the patient factors that could affect patient satisfaction. PATIENTS AND METHODS: A total of 50 patients who were diagnosed with rotator cuff retear after undergoing arthroscopic rotator cuff repair were included in this study. All the patients were dichotomously classified into the satisfactory or dissatisfactory groups according to the patients' self-classifications. CTA was used to assess the attachment status of the footprint, detect retear on the medial side of the footprint of the repaired cuff, and determine the retear size. Demographic factors, including sex, age, occupation, dominant upper extremity, duration of pain, presence of diabetes mellitus, trauma history, history of ipsilateral shoulder surgery, repair technique, worker's compensation status, and functional shoulder score, were investigated. RESULTS: Thirty-nine patients were classified into the satisfactory group and 11 patients were classified into the dissatisfactory group. There were no differences in age, sex, occupation, dominant hand, duration of pain, presence of diabetes mellitus, trauma history, history of ipsilateral shoulder surgery, repair technique, worker's compensation, and duration of follow-up between the two groups. However, the postoperative American Shoulder and Elbow Surgeon (ASES) score (P < 0.01), visual analog scale (VAS) pain level (P < 0.01), anteroposterior (AP) length (P < 0.01), and area of the retear site (P < 0.01) were significantly different. CONCLUSION: The AP length and area of the retear site estimated using CTA were confirmed as the significant risk factors for dissatisfaction. However, the type of repaired rotator cuff judged by the attachment status of the footprint did not correlate with patient satisfaction. In addition, the postoperative VAS pain scale and ASES score was correlated with patient satisfaction.