MR arthrography of the glenohumeral joint: a tailored approach

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.

[Postoperative Imaging of Rotator Cuff Tear]

Postoperative imaging of the rotator cuff may be performed routinely, even if pain or disability develops after surgery or if there are no symptoms. Postoperative images are obtained through MRI or US, and the purpose is to confirm the integrity of the restored tendon in general. Postoperative MRI has a relatively poor diagnostic accuracy compared to that of preoperative images because various materials used in surgeries deteriorate the image quality. US can dynamically check the condition of the restored tendon and avoid artifacts from the surgical instruments used for recovery. Although imaging findings are not always consistent with the clinical symptoms or prognosis, sub-deltoid fluid retention is more important for pain and functional recovery than the thickness of the reconstructed tendon. Strain elastography can also be a useful method for predicting the prognosis.

MRA improves sensitivity than MRI for the articular-sided partial-thickness rotator cuff tears

BACKGROUND

This study aims to compare the diagnostic accuracy of magnetic resonance imaging (MRI) and MR arthrography (MRA) for the articular-sided partial-thickness rotator cuff tear (PTRCT).

METHODS

Three electronic databases, PubMed/Medline, Embase and Cochrane Library, were utilized to retrieve articles comparing the diagnostic value of MRA and MRI for detecting articular-sided PTRCTs. The pooled statistical indexes included sensitivity, specificity, positive/negative predictive value, diagnostic odds ratio (DOR) and the area under the receiver operating characteristic curve (AUC).

RESULTS

Eleven studies involving 1703 patients and 1704 shoulders were included. The pooled sensitivity, specificity, DOR and AUC and their 95% CIs of MRA to diagnose articular-sided PTRCTs were 0.81 (95% CI, 0.65-0.90), 0.96 (95% CI, 0.91-0.98), 68.14 (95% CI, 33.20-139.84) and 0.96 (95% CI, 0.94-0.97), respectively. The pooled sensitivity, specificity, DOR and AUC and their 95% CIs of MRI were 0.78 (95% CI, 0.65-0.87) and 0.97 (95% CI, 0.84-0.99), 47.82 (95% CI, 8.29-275.89) and 0.89 (95% CI, 0.86-0.92), respectively.

CONCLUSIONS

This meta-analysis reveals that MRA has a better diagnostic value than that of MRI for the diagnosis of articular-sided partial-thickness rotator cuff tears because of an improvement of sensitivity.

A comparison of ultrasound-guided rotator interval and posterior glenohumeral injection techniques for MR shoulder arthrography

PURPOSE

The aim of this prospective, randomized study was to compare the performance of a rotator interval approach with the posterior glenohumeral approach for ultrasound-guided contrast injection prior to MR shoulder arthrography.

METHOD

This study was approved by the institutional review board. One hundred and twenty consecutive patients referred for MR shoulder arthrography were randomized into four groups: rotator interval approach in-plane (n = 30); rotator interval approach out-of-plane (n = 30); posterior approach in-plane (n = 30); and posterior approach out-of plane (n = 30). Outcome measures included procedure time, number of injection attempts, patient-reported pain score (0-10), and radiologist-reported technical difficulty (0-10). MR arthrograms were assessed for adequacy of joint distension, diagnostic utility, and extra-capsular contrast leakage.

RESULTS

All 120 patients had a successful ultrasound-guided injection with adequate joint distension and diagnostic utility for MR arthrography. In-plane needle guidance was less technically demanding, quicker, required fewer injection attempts, and had a lower frequency of contrast leakage than out-of-plane needle guidance. The posterior glenohumeral approach was less technically demanding though had a higher frequency of contrast leakage and caused more patient discomfort than the rotator interval approach.

CONCLUSION

For ultrasound-guided shoulder joint injection, an in-plane approach is preferable. The posterior glenohumeral approach is less technically demanding though causes more patients discomfort than the rotator interval approach possibly due to the longer needle path.

Detecting Rotator Cuff Tears: A Network Meta-analysis of 144 Diagnostic Studies

BACKGROUND

Many imaging techniques have been developed for the detection of rotator cuff tears (RCTs). Despite numerous quantitative diagnostic studies, their relative accuracy remains inconclusive.

PURPOSE

To determine which of 3 commonly used imaging modalities is optimal for the diagnosis of RCTs.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

Studies evaluating the performance of magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA), and ultrasound (US) used in the detection of RCTs were retrieved from the PubMed/MEDLINE and Embase databases. Diagnostic data were extracted from articles that met the inclusion/exclusion criteria. A network meta-analysis was performed using an arm-based model to pool the absolute sensitivity and specificity, relative sensitivity and specificity, and diagnostic odds ratio as well as the superiority index for ranking the probability of these techniques.

RESULTS

A total of 144 studies involving 14,059 patients (14,212 shoulders) were included in this network meta-analysis. For the detection of full-thickness (FT) tears, partial-thickness (PT) tears, or any tear, MRA had the highest sensitivity, specificity, and superiority index. For the detection of any tear, MRI had better performance than US (sensitivity: 0.84 vs 0.81, specificity: 0.86 vs 0.82, and superiority index: 0.98 vs 0.22, respectively). With regard to FT tears, MRI had a higher sensitivity and superiority index than US (0.91 vs 0.87 and 0.67 vs 0.28, respectively) and a similar specificity (0.88 vs 0.88, respectively). The results for PT tears were similar to the detection of FT tears. A sensitivity analysis was performed by removing studies involving only 1 arm for FT tears, PT tears, or any tear, and the results remained stable.

CONCLUSION

This network meta-analysis of diagnostic tests revealed that high-field MRA had the highest diagnostic value for detecting any tear, followed by low-field MRA, high-field MRI, high-frequency US, low-field MRI, and low-frequency US. These findings can help guide clinicians in deciding on the appropriate imaging modality.

Diagnostic accuracy of MRA and MRI for the bursal-sided partial-thickness rotator cuff tears: a meta-analysis

BACKGROUND

Numerous quantitatively studies have focused on the diagnosis of bursal-sided partial-thickness rotator cuff tears (RCTs); however, the accuracy of magnetic resonance imaging (MRI) and MR arthrography (MRA) remains inconclusive. This study was performed systematically to compare the diagnostic value of MRA and MRI for the bursal-sided partial-thickness RCTs.

METHODS

Three electronic databases, PubMed, Embase, and Cochrane Library, were utilized to retrieve articles comparing the diagnostic value of MRA and MRI for detecting bursal-sided partial-thickness RCTs. After screening and diluting out the articles that met the inclusion criteria to be used for statistical analysis, the pooled evaluation indexes include sensitivity, specificity, positive and negative predictive values, diagnostic odds ratio (DOR), and the area under the receiver operating characteristic curve (AUC).

RESULTS

Twelve studies involving 1740 patients and 1741 shoulders were identified. The pooled sensitivity, specificity, DOR, and AUC of MRA to diagnose bursal-sided partial-thickness RCTs were 0.77 (95% CI, 0.67-0.85), 0.98 (95% CI, 0.95-0.99), 73.01 (95% CI, 35.01-152.26), and 0.88 (95% CI, 0.85-0.91), respectively. The pooled sensitivity, specificity, DOR, and AUC of MRI were 0.77 (95% CI, 0.66-0.86) and 0.96 (95% CI, 0.81-0.99), and 37.12 (95% CI, 8.08-170.64) and 0.82 (95% CI, 0.78-0.85), respectively.

CONCLUSIONS

This meta-analysis reveals that MRA and MRI have similar diagnostic value for the diagnosis of bursal-sided partial-thickness rotator cuff tears.

[MR and CT arthrography in cartilage imaging : Indications and implementation]

BACKGROUND

The imaging of chondral pathologies is an essential part in the work-up of acute and chronic joint diseases. Besides conventional MR imaging, CT and MR arthrography are well-established methods in evaluating articular cartilage. The application of these techniques requires knowledge of indications and safe injection procedures by the performing radiologist.

PURPOSE

Our goal is to describe the techniques of cross-sectional arthrographies of different joints, give an overview of general and joint-specific considerations for practical application as well as provide typical indications for cartilage imaging.

MATERIALS AND METHODS

A selective PubMed literature search concerning "arthrography", "CT arthrography", "MR arthrography", "arthrography cartilage", "arthrography wrist", "arthrography elbow", "arthrography shoulder", "arthrography hip", "arthrography knee", "arthrography ankle", "arthrography complications", "arthrography imaging guidance" "osteochondral lesion", "cartilage imaging" and "cartilage lesion" was performed.

RESULTS AND CONCLUSION

CT and MR arthrography are valuable and safe tools in cartilage imaging. They are useful to verify and specify chondral pathologies, usually after conventional MR imaging, and have an important role in evaluating the stability and therefore in therapeutic decision making of osteochondral lesions. CT arthrography is not only a substitute technique in case of MR contraindications, it can be advantageous in small joints (wrist, elbow, ankle) compared to MR arthrography due to its higher image resolution. Fluoroscopic guided joint puncture is still the most commonly used image guidance method, but the role of ultrasound is steadily increasing. Joint traction in MR arthrography is a promising technique to improve cartilage visualization, though it is not yet used in clinical routine imaging.

Magnetic resonance arthrography of the shoulder: a painful procedure?

Objective

To compare the pain expected to that effectively caused by magnetic resonance arthrography of the shoulder and, secondarily, to describe a simplified approach to the technique for articular access.

Materials and Methods

We prospectively evaluated 40 participants who used a visual analog scale and a simplified categorical scale to indicate the level of pain expected and that experienced after the procedure, comparing the two with the Wilcoxon matched-pairs test. We also determined gender-related differences in pain conditions using the Mann-Whitney U test. In addition, we described a modified technique involving radiographic localization and the use of standard puncture needles for articular access.

Results

Analysis of the visual analog scales showed that the pain experienced was less than had been expected, with median scores of 1.75 and 3.75, respectively (p < 0.001). The level of pain expected was higher among women than among men, with median scores of 8.0 and 3.0, respectively (p = 0.014), as was the level of pain experienced, with median scores of 3.0 and 1.5, respectively (p = 0.139). The overall categorical evaluation corroborated that difference (p = 0.03). Articular access with the modified technique was successful in all patients.

Conclusion

Magnetic resonance arthrography of the shoulder is less painful than patients expect. In addition, digital radiographic guidance combined with the use of standard puncture needles appears to improve the efficiency of the method.

Correlation of Joint Volume and Passive Range of Motion With Capsulo-Synovial Thickness Measured by Contrast-Enhanced Magnetic Resonance Imaging in Adhesive Capsulitis

BACKGROUND

No study has investigated the relationship between the findings of contrast-enhanced magnetic resonance imaging (CE-MRI) and the joint volume of the shoulder, which has been considered the standard reference for diagnosis of adhesive capsulitis (AC).

OBJECTIVE

To investigate the relationships among the capsulo-synovial thickness measured by CE-MRI, joint volume, and passive range of motion (ROM) in patients with AC.

DESIGN

This was a retrospective study.

SETTING

The study took place at an institutional practice.

PATIENTS

Medical record of 103 patients (46 male and 57 female), who were treated with sonographically guided intra-articular injection with diagnosis of AC and underwent CE-MRI to rule out other concomitant shoulder disease, were retrospectively reviewed.

METHODS

Passive ROM and glenohumeral joint (GHJ) volume were measured before and during sonographically guided injection. The thickness of the enhancing portion of the capsulo-synovium was measured at the axillary recess and rotator interval on CE-MRI.

MAIN OUTCOME MEASUREMENTS

The relationship among the thickness of the enhancing portion on CE-MRI, GHJ volume, and passive ROM was analyzed using the Pearson correlation coefficient.

RESULTS

Capsulo-synovial thickness measured by CE-MRI at the enhancing portion of the axillary recess inversely correlated with GHJ volume (ρ = -0.444, P < .001), whereas at the rotator interval, this finding was not observed. At the axillary recess, the capsulo-synovial thickness inversely correlated with abduction (ρ = -0.400, P < .001), forward elevation (ρ = -0.378, P < .001), and external rotation (ρ = -0.297, P < .01), but at the rotator interval, such statistically significant correlations were not shown.

CONCLUSION

The capsulo-synovial thickness measured by CE-MRI at the enhancing portion of the axillary recess could represent obliterated joint capacity and clinical impairment (restricted passive ROM), which could help in diagnosing AC and in differentiating other shoulder diseases that may mimic this condition.

LEVEL OF EVIDENCE

III.

A prospective randomized study comparing three different approaches to fluoroscopy-guided shoulder arthrography according to the experience of practitioners

OBJECTIVE

To compare three approaches via the anterior and posterior glenohumeral joints, and the rotator interval in fluoroscopy-guided shoulder arthrography according to the experience of the practitioners.

MATERIALS AND METHODS

This prospective randomized study was originally designed to have 34 subjects for each approach, and finally evaluated 98 patients (mean age: 51.5 years; 55 men) from July to December 2014, who had shoulder arthrography via the anterior (n = 41) or posterior glenohumeral joint (n = 27) approaches, or via the rotator interval approach (n = 30) by residents (n=76) or fellows (n=22). The success rate, number of punctures, fluoroscopy time, radiation dose, and complications of the three methods were compared, and according to the practitioners.

RESULTS

The success rate was 100% for the anterior glenohumeral joint approach (34 out of 34), 90.0% for the posterior glenohumeral joint approach (23 out of 30), and 88.2% for the rotator interval approach (30 out of 34; p = 0.013). There was no difference in the success rate according to the practitioners' experience. Fluoroscopy time was longest for the posterior glenohumeral joint approach (mean: 95.44 s) and shortest for the rotator interval approach (mean: 31.57 s, p = 0.006). Radiation dose was larger by 1st- or 2nd-year residents (p = 0.014), with no difference among the three approaches. Only one patient who underwent arthrography using the posterior glenohumeral joint approach complained about post-procedural pain.

CONCLUSION

Fluoroscopy-guided shoulder arthrography via the posterior glenohumeral joint or rotator interval approach may be difficult for trainees, and the posterior glenohumeral joint approach may need a long fluoroscopy time.

Freehand direct arthrography of the shoulder using near real-time guidance in an open 1.0-T MRI scanner

OBJECTIVE

To assess the technical success and duration of magnetic resonance imaging (MRI)-guided freehand direct shoulder arthrography (FDSA) with near real-time imaging implemented in a routine shoulder MRI examination on an open 1.0-T MRI scanner, and to assess the learning curve of residents new to this technique.

METHODS

An experienced MRI interventionalist (the expert) performed 125 MRI-guided FDSA procedures, and 75 patients were treated by one of three residents without previous experience in MRI-guided FDSA. Technical success rate and duration of MRI-guided FDSA of the expert and the residents were compared. The residents' learning curves were assessed. The occurrence of extra-articular deposition and leakage of contrast media from the puncture site and the subsequent impairment of image interpretation were retrospectively analyzed.

RESULTS

Overall technical success was 97.5 %. The expert needed overall fewer puncture needle readjustments and was faster at puncture needle positioning (p < 0.01). The learning curve of the residents, however, was steep. They leveled with the performance of the expert after ≈ 15 interventions. With a minimal amount of training all steps of MRI-guided FDSA can be performed in ≤10 min.

CONCLUSION

Magnetic resonance-guided FDSA in an open 1.0-T MRI scanner can be performed with high technical success in a reasonably short amount of time. Only a short learning curve is necessary to achieve expert level.

Comparative analysis of anterior and posterior contrast injection approaches for shoulder MR arthrograms in adolescents

BACKGROUND

There is no consensus in the literature concerning the optimal approach for performing a fluoroscopically guided shoulder arthrogram injection in a pediatric population.

OBJECTIVE

To compare adequacy of capsular injection and radiation doses between fluoroscopically guided anterior and posterior glenohumeral joint contrast injections in adolescents.

MATERIALS AND METHODS

We evaluated imaging in 67 adolescents (39 boys, 28 girls; mean age 16.0 years; range 11.7-19.1 years) who underwent an anterior approach glenohumeral contrast injection with subsequent MR imaging, and 67 age- and gender-matched subjects (39 boys, 28 girls; mean age 16.0 years; range 11.1-19.2 years) who underwent a posterior approach injection during the period June 2010 to September 2015. Two pediatric radiologists independently evaluated all MR shoulder arthrograms to assess adequacy of capsular distention and degree of contrast extravasation. We recorded total fluoroscopic time, dose-area product (DAP) and cumulative air kerma (CAK).

RESULTS

There were no significant differences in age, gender, height, weight or body mass index between the populations (P-values > 0.6). The amount of contrast extravasation between the groups was not significantly different (P = 0.27). Three anterior injections (4.5%) and one posterior (1.5%) were suboptimal (P = 0.62). Fluoroscopy time was not different: 1.1 min anterior and 1.3 min posterior (P = 0.14). There was a significant difference in CAK (0.7 mGy anterior and 1.1 mGy posterior; P = 0.007) and DAP (5.3 μGym² anterior and 9.4 μGym² posterior; P = 0.008). Inter-rater agreement was excellent (Cohen kappa >0.81).

CONCLUSION

Both techniques were technically successful. There was no difference in the fluoroscopy time for either approach. The radiation dose was higher with the posterior approach but this is of questionable clinical significance.

Diagnostic Performance of MR Arthrography with Anterior Trans-Subscapularis versus Posterior Injection Approach for Subscapularis Tendon Tears at 3.0T

OBJECTIVES

To compare the diagnostic performance of shoulder magnetic resonance arthrography (MRA) with the anterior trans-subscapularis versus posterior injection approach to diagnose subscapularis tendon (SCT) tears.

METHODS

One hundred and sixty-seven arthroscopically confirmed patients (84 anterior and 83 posterior approaches) were included. Two readers retrospectively scored SCT tears. Proportions of correctly graded tears between MR arthrography and arthroscopy were calculated. Retrospective error analysis was performed.

RESULTS

The sensitivity and specificity were 80 % (24/30) and 72 % (39/54) by reader 1, 73 % (22/30) and 76 % (41/54) by reader 2 in the anterior approach, and 86 % (30/35) and 79 % (38/48) by reader 1, 80 % (28/35) and 88 % (42/48) by reader 2 in the posterior approach, respectively. There were no significant differences in sensitivity and specificity between the two groups. Proportions of correctly graded tears of both readers were 48 % and 36 % in the anterior approach, and 70 % and 68 % in the posterior approach, respectively. The intratendinous collection of contrast material was not statistically significantly different between anterior (n = 8) and posterior (n = 3) approach group.

CONCLUSIONS

For the MRA diagnosis of SCT tears, there was no significant difference between the anterior trans-subscapularis and the posterior approach.

KEY POINTS

• Anterior trans-subscapularis and posterior approaches showed no significant difference for SCT tears • Intratendinous collection of gadolinium is more frequent in anterior trans-subscapularis approach • Extent of SCT tears tends to be overestimated in anterior trans-subscapularis approach • Posterior approach should be considered for diagnosing SCT tear.

Beyond the Cuff: MR Imaging of Labroligamentous Injuries in the Athletic Shoulder

Shoulder disease is common in the athletic population and may arise as a consequence of a single traumatic episode or multiple repeated events. Associated labroligamentous injuries can result in substantial disability. Specific athletic and occupational activities result in predictable injury patterns. Imaging in general and magnetic resonance (MR) imaging, in particular, are vital in establishing the correct diagnosis and excluding common mimicking conditions, to ensure timely and appropriate management. In this review, the utility of MR imaging and MR arthrography will be explored in evaluation of shoulder disease, taking into account normal variants of the labroligamentous complex. Subsequently, broad categories of labral lesions and instability, external and internal impingement, as well as nerve entrapment syndromes, will be discussed, while emphasizing their imaging findings in the clinical context and illustrating key features. More recent concepts of internal impingement and secondary subacromial impingement will also be clarified.

A practical guide for performing arthrography under fluoroscopic or ultrasound guidance

Abstract

We propose a practical approach for performing arthrography with fluoroscopic or ultrasound guidance. Different approaches to the principal joints of the upper limb (shoulder, elbow, wrist and fingers), lower limb (hip, knee, ankle and foot) as well as the facet joints of the spine are discussed and illustrated with numerous drawings. Whenever possible, we emphasise the concept of targeting articular recesses, which offers many advantages over traditional techniques aiming at the joint space.

Teaching Points

• Arthrography remains a foremost technique in musculoskeletal radiology

• Most joints can be successfully accessed by targeting the articular recess

• Targeting the recess offers several advantages over traditional approaches

• Ultrasound-guidance is now favoured over fluoroscopy and targeting the recess is equally applicable

Magnetic resonance arthrography of the glenohumeral joint: ultrasonography-guided technique using a posterior approach

OBJECTIVE

The purpose of this study was to assess the efficacy and feasibility of ultrasound (US)-guided magnetic resonance (MR) arthrography of the glenohumeral joint via a posterior approach.

MATERIALS AND METHODS

Thirty-four patients (18 males and 16 females) who were suspected to have glenohumeral joint pathology were examined using MR arthrography. The patients ranged in age from 21 to 85 years, and the average age was 45±15.9 years. A Toshiba Xario US unit was utilized. Ultrasonography examinations were conducted using a broad-band 5-12 MHz linear array transducer. Gadolinium was injected into the shoulder joint using an 18-20 gauge needle. MR imaging was performed within the first 30 min after the injection.

RESULTS

The injection of gadolinium into the shoulder joint was successfully accomplished in all 34 patients. Major contrast media extravasation outside the joint was depicted in only two patients (5.9%). No major complications were encountered.

CONCLUSION

Ultrasonography is an effective alternate guidance technique for the injection of gadolinium into the glenohumeral joint for MR arthrography. US-guided arthrography via a posterior approach to the glenohumeral joint is safe, accurate, well tolerated by patients and easy to perform with minimal training.

Comparing the accuracy of ultrasound versus fluoroscopy in glenohumeral injections: a systematic review and meta-analysis

OBJECTIVE

We performed a systematic review with meta-analysis to compare the accuracy of fluoroscopic-guided glenohumeral injections with that of ultrasound-guided glenohumeral injections as reported in prior studies.

METHODS

We reviewed the databases of MEDLINE, PubMed, and Google Scholar using combinations of the keywords "ultrasound," "fluoroscopy," "injection," and "shoulder" for articles reporting the injection accuracy, confirmed by imaging, of the first attempt under either fluoroscopic or ultrasound guidance. A meta-analysis was performed to assess the accuracy of fluoroscopic-guided glenohumeral injections versus ultrasound-guided glenohumeral injections.

RESULTS

Five of 42 pertinent studies met our inclusion criteria for a total of 406 glenohumeral injections, of which 115 were fluoroscopy-guided and 291 were ultrasound-guided. The meta-effect estimates for the proportion of joints successfully injected with ultrasound and fluoroscopic guidance were 93% (95% CI, 86% to 98%) and 80% (95% CI, 63% to 93%), respectively, which did not reach statistical significance (Q[df] = 2.55 [1], p = 0.11).

CONCLUSIONS

Our meta-analysis indicates that glenohumeral injections guided by ultrasound are more accurate than injections guided by fluoroscopy but this difference did not reach statistical significance. As the use of ultrasound does not expose the patient or practitioner to radiation, its similar accuracy may make it the preferred modality for image-guided glenohumeral joint injections. Limitations to our analysis include the retrospective nature, limited number of studies included, and the potential generalizability of our findings to regions outside of those included in our study.

Ultrasound-guided shoulder MR arthrography: comparison of rotator interval and posterior approach

PURPOSE

The purpose of this study was to prospectively evaluate the two different ultrasound-guided injection techniques for magnetic resonance (MR) arthrography of the shoulder.

METHODS AND MATERIALS

This study included 100 patients [50 rotator interval group (n=50) vs. 50 posterior approach group (n=50)]. All procedures were performed by the same radiologist. The two injection techniques were compared. The discomfort during and after arthrography was evaluated. Extraarticular contrast media extravasation was graded according to the MRI findings. The number of injection attempts, effect of contrast media extravasation rate on diagnostic quality and procedure times were recorded.

RESULTS

There were no significant difference between the posterior and rotator interval puncture groups with regard to pain (P=.915), procedure times (P=.401) or attempt scores (P=.182). There were significantly more contrast media extravasations with rotator interval approach than posterior approach (P<.05).

CONCLUSION

Both techniques were successful and well tolerated by patients. Posterior injection technique provided a more effective route with decreased extravasation rate and easier approach compared to the rotator interval approach.

High origin of the anterior band of the inferior glenohumeral ligament: MR arthrography with anatomic and histologic correlation in cadavers

INTRODUCTION

The anterior band of the inferior glenohumeral ligament has been described to arise from the anteroinferior labrum, but we have observed that in some persons its origin is from the anterior or anterosuperior labrum, creating diagnostic difficulties.

MATERIALS AND METHODS

Ten fresh unembalmed cadaveric shoulders underwent magnetic resonance arthrography (MRA) using a posterior approach with a 1.5 T GE magnet, with the following sequences: T1-weighted fast spin-echo in axial, coronal and sagittal planes, and T1 fat-suppressed spin-echo in the axial plane (TR/TE 600/20, section thickness 2.5 mm, 0.5 mm interslice space, number of signals acquired, two, field of view 12 × 12 cm, and matrix 512 × 256 pixels). Following imaging, the shoulders were frozen and later sectioned using a band saw into 3-mm sections corresponding to the axial imaging plane. Histological analysis was also performed to determine the origin of the anterior band.

RESULTS

Four of the ten shoulders had an origin of the anterior band above or at the 3 o'clock position: one at the 1 o'clock position, two at the 2 o'clock position, and one at the 3 o'clock position. In another shoulder, the anterior band of the inferior glenohumeral ligament originated from the middle glenohumeral ligament, and in five other shoulders, the anterior band originated from the anteroinferior labrum as has been described in the literature.

CONCLUSIONS

This finding is of clinical significance as a high origin of the anterior band of the inferior glenohumeral ligament leads to MR arthrographic finding that can simulate those of labral tears or detachments.

Technical update on magnetic resonance imaging of the shoulder

Improvement in both hardware and software has opened up new opportunities in magnetic resonance (MR) imaging of the shoulder. MR imaging at 3-T has become a reality, with the prospect of 7-T imaging on the horizon. The art of MR arthrography continues to improve, aided by the use of novel imaging positions. New techniques for three-dimensional imaging, the reduction of metal artifact, and biochemical imaging of cartilage hold great promise.

Pictorial essay: pitfalls in magnetic resonance imaging of the shoulder

Numerous imaging pitfalls of normal variants due to imaging technique and artifacts can be seen on routine magnetic resonance imaging of the shoulder. Familiarity with these pitfalls is crucial to avoiding diagnostic errors. Understanding of the common causes of shoulder imaging artifacts will enable the radiologist to make rational changes in imaging technique to eliminate or reduce the effects of artifacts on magnetic resonance images. This pictorial essay highlights possible pitfalls that arise from imaging techniques, imaging artifacts, and normal variations, and how they may be recognized.

Magnetic resonance imaging in glenohumeral instability

The glenohumeral joint is the most commonly dislocated joint of the body and anterior instability is the most common type of shoulder instability. Magnetic resonance (MR) imaging, and more recently, MR arthrography, have become the essential investigation modalities of glenohumeral instability, especially for pre-procedure evaluation before arthroscopic surgery. Injuries associated with glenohumeral instability are variable, and can involve the bones, the labor-ligamentous components, or the rotator cuff. Anterior instability is associated with injuries of the anterior labrum and the anterior band of the inferior glenohumeral ligament, in the form of Bankart lesion and its variants; whereas posterior instability is associated with reverse Bankart and reverse Hill-Sachs lesion. Multidirectional instability often has no labral pathology on imaging but shows specific osseous changes such as increased chondrolabral retroversion. This article reviews the relevant anatomy in brief, the MR imaging technique and the arthrographic technique, and describes the MR findings in each type of instability as well as common imaging pitfalls.

Magnetic resonance-guided interventions of large and small joints

Magnetic resonance (MR)-guided interventions of large and small joints are feasible and safe procedures offering several advantages compared with standard guiding techniques. Nevertheless, MR-guided interventions are not routinely performed in daily practice apart from a few centers. Accurate injections are crucial for clinical outcome in diagnostic arthrography as well as therapeutic joint injections. In particular, palpatory joint puncture was shown to be inaccurate or uncertain in a substantial percentage of injections of the shoulder, the hip, and the knee. Magnetic resonance imaging offers respective merits of a cross-sectional technique with high soft-tissue contrast. Exact depiction of structures, which should be preserved, such as the labrum, should be aimed for. Areas with complex anatomy can be approached by adapting the right imaging plane(s) because of multiplanar capacity. Lack of ionizing radiation for patients is of growing interest particularly in young patients with repeated interventions. Magnetic resonance guidance alone allows an "all-in-one" MR arthrography combining precise targeting with high-field-strength imaging. Modern short-bore and open-bore high-field-strength systems offer a good comfort for patients as well as clinicians and enhance patient positioning options such as supine or prone position. Thus, a tailored approach such as a posterior technique for suspected anterior lesions in shoulder MR arthrography is possible.In this article, we describe the advantages and limitations of MR guidance in joint interventions with focus on shoulder and hip interventions. We review the requirements for needle material and MR sequences, discuss several different techniques developed to date, and present current results in clinical outcome.

Glenohumeral joint instability

Due to the configuration of its bony elements, the glenohumeral joint is the most mobile joint of the body, but also an inherently unstable articulation. Stabilization of the joint is linked to a complex balance between static and dynamic soft tissue stabilizers. Because of complex biomechanics, and the existence of numerous classifications and acronyms to describe shoulder instability lesions, this remains a daunting topic for most radiologists. In this article we provide a brief review of the anatomy of the glenohumeral joint, as well as the classifications and the pathogenesis of shoulder instability. Technical aspects related to the available imaging techniques (including computed tomography [CT] arthrography, magnetic resonance imaging [MRI], and MR arthrography) are reviewed. We then describe the imaging findings related to shoulder instability, focusing on those elements that are important to the clinician.

Efficacy of ultrasonography-guided shoulder MR arthrography using a posterior approach

AIM

Shoulder MR arthrography has an important role in the assessment of rotator cuff lesions, labral tears, glenohumeral ligaments, rotator interval lesions, and postoperative shoulder status. Injection in direct MR arthrography can be performed with palpation, fluoroscopy, ultrasonography (US), or MRI. Recently, the posterior approach is the preferred method due to the presence of fewer stabilizers, absence of important articular structures and less extravasation, has been advocated. Our aim was to assess the efficacy of US-guided MR arthrography via a posterior approach on the glenohumeral joint.

MATERIALS AND METHODS

Thirty MR arthrographies were performed on 29 patients. Ultrasonography (Xario, Toshiba) examinations were conducted by a wide-band 5-12 Mhz linear array transducer set to muscle-skeleton. Diluted contrast medium (1 ml gadolinium chelate and 100 ml saline, approximately 15 ml) was delivered into the glenohumeral joint space from between the humeral head and posterior labrum with a 20-gauge spinal needle. MRI examination was conducted by a 1.5 T scanner. Fat-saturated T1-weighted spin echo was applied on coronal, axial, and sagittal planes within the first 30 min after contrast material injection.

RESULTS

One (3.3%) arthrography was not successful due to technical reasons associated with obesity. Contrast extravasation around the infraspinatus and teres minör muscles was depicted in twelve examinations. One (3.3%) patient developed vasovagal collapse.

CONCLUSION

Ultrasonography-guided posterior approach is an easy, reliable, fast, and comfortable method in experienced hands. It may be an alternative for fluoroscopy-guided shoulder MR arthrography.

Accuracy of anterior glenohumeral injections: a cadaver study

PURPOSE

Intra-articular glenohumeral injections have an important role for therapeutic benefit and diagnostic information. Therefore, it is very important that the injected material should reach its desired target. This study assessed the accuracy of an anterior intra-articular injection in fresh cadavers.

METHODS

A total of 50 shoulders of 25 fresh cadavers were included in the study. Anterior placement of a spinal needle using a location just 1 cm lateral to the coracoid, without radiographic assistance were performed. After the needle was placed and estimated to be intra-articular 1 cc of acrylic dye was injected into the joint to determine accuracy of position.

RESULTS

Ninety-six percent of injections were accurately administered into the glenohumeral joint and 4% in the surrounding soft tissues and capsule.

CONCLUSION

Based on our cadaveric study, an unassisted anterior injection to the glenohumeral joint could be accurately placed.

Imaging shoulder instability in the athlete

Athletes who partake in overhead or throwing activities frequently suffer from shoulder pain. Glenohumeral instability plays an important role in sports-related shoulder pain. Shoulder instability can be traumatic, atraumatic, or microtraumatic in origin. In athletes, atraumatic and microtraumatic instabilities can lead to secondary impingement and chronic damage to intra-articular structures. MR arthrography is the modality of choice for assessing glenohumeral instability and diagnosing labroligamentous injuries. This article reviews imaging of instability-related injuries in athletes, with special emphasis on MR imaging.

Magnetic resonance arthrography

Magnetic resonance arthrography is widely used throughout the world for joint imaging. It extends the capabilities of conventional MR imaging because contrast solution distends the joint capsule, outlines intraarticular structures, and extends into soft tissue tears and defects. MR arthrography exploits the natural advantages gained from a joint effusion and can be performed on any joint.

The posterior transtriceps approach for elbow arthrography: a forgotten technique?

OBJECTIVE

To evaluate the technical feasibility of performing elbow MR arthrography via a posterior approach through the triceps.

MATERIALS AND METHODS

The images of 19 patients with elbow MR arthrography via a posterior transtriceps approach were retrospectively studied. The injections were performed by four musculoskeletal radiologists, using fluoroscopic guidance and a 22- or 25-gauge needle. The fluoroscopic and subsequent MR images were reviewed by two musculoskeletal radiologists and evaluated for adequacy of joint capsular distention, degree and location of contrast leakage, and presence of gas bubbles.

RESULTS

The injection was diagnostic in all 19 patients, with a sufficient amount of contrast agent seen in the elbow joint. No significant contrast leakage occurred in 12 patients who received injections of 8 cc or less of contrast agent, but moderate contrast leakage occurred in 6/7 patients who received injections of greater than 8 cc. Contrast leakage generally occurred within the triceps myotendinous junction. No gas bubbles were identified in the injected joints.

CONCLUSION

Patients often present for MR arthrography of the elbow with medial or lateral elbow pain. Contrast leakage during a radiocapitellar approach may complicate evaluation of the lateral collateral ligament or the common extensor tendon origin. Transtriceps MR arthrography offers an alternative to the more commonly used radiocapitellar approach. With injected volumes not exceeding 8 cc, the risk of significant contrast leakage is small. An advantage of the transtriceps injection is that contrast leakage through the posterior needle tract does not interfere with evaluation of the lateral structures.

Glenohumeral joint injection: a comparative study of ultrasound and fluoroscopically guided techniques before MR arthrography

To assess the variability in accuracy of contrast media introduction, leakage, required time and patient discomfort in four different centres, each using a different image-guided glenohumeral injection technique. Each centre included 25 consecutive patients. The ultrasound-guided anterior (USa) and posterior approach (USp), fluoroscopic-guided anterior (FLa) and posterior (FLp) approach were used. Number of injection attempts, effect of contrast leakage on diagnostic quality, and total room, radiologist and procedure times were measured. Pain was documented with a visual analogue scale (VAS) pain score. Access to the joint was achieved in all patients. A successful first attempt significantly occurred more often with US (94%) than with fluoroscopic guidance (72%). Leakage of contrast medium did not cause interpretative difficulties. With US guidance mean room, procedure and radiologist times were significantly shorter (p < 0.001). The USa approach was rated with the lowest pre- and post-injection VAS scores. The four image-guided injection techniques are successful in injection of contrast material into the glenohumeral joint. US-guided injections and especially the anterior approach are significantly less time consuming, more successful on the first attempt, cause less patient discomfort and obviate the need for radiation and iodine contrast.

MRI of shoulder instability

The most unstable joint in the body, the glenohumeral joint is subject to many insults including microinstability, subluxation and dislocation. During the last two decades, MRI has allowed for direct visualization of many of the lesions related to instability, aiding in diagnosis as well as therapeutic planning and follow-up. This article reviews the use of MRI for shoulder instability and describes the different types of lesions associated with this disorder. Topics include technical considerations, the use of MR arthrography, normal anatomy and variants, labral and glenohumeral ligament pathology, and osseous lesions related to instability.

MR Arthrography of the Glenohumeral Joint: Modified Posterior Approach without Imaging Guidance

Institutional review board approval and informed consent were obtained. The purpose of the study was to prospectively perform magnetic resonance (MR) arthrography of the glenohumeral joint by using modified posterior approach without ultrasonographic or fluoroscopic guidance. A solution containing 0.1 mL of gadolinium chelate, 15 mL of saline, and 5 mL of 2% lidocaine was subsequently injected into the glenohumeral joint in 147 patients (81 men, 66 women; age range, 20-79 years). A 21-gauge needle was advanced along a trajectory connecting a skin mark 3-4 cm below and 2 cm medially to the posterolateral margin of the acromion and the coracoid process, as assessed with palpation, proceeding in posteroanterior direction. The joint was successfully entered at first attempt in 125 (85%) patients, at second attempt in 19 (13%), and at third attempt in three (2%). Contrast material-enhanced images were evaluated for presence, site, and maximal extent of contrast material extravasation; route of diffusion of the extravasation; compromised or noncompromised diagnostic quality; and presence of gas bubbles. Extravasation occurred in seven patients: at the interval between the teres minor muscle and infraspinatus muscle in five and within the infraspinatus muscle belly in two; extravasation had diffused along the teres minor muscle and infraspinatus muscle in five (71%) and along the teres minor muscle in two (29%). The mean extension of extravasation was 15 mm. Image quality was not compromised, and no gas bubbles were detected. The procedure was successful in all patients, with no complications.

Magnetic resonance arthrography

For decades, fluoroscopic arthrography was the only method available to image a joint with contrast enhancement. Advances in CT led to the natural development of CT arthrography. Development of MRI and its capability for multiplanar imaging led to direct magnetic resonance arthrography (MRA). This technique has been performed since 1987 and has surpassed CT arthrography in popularity in the United States. Indirect MRA developed subsequently to offer a less invasive alternative. This article presents an overview of direct MRA and addresses joint-specific issues regarding direct MRA. An overview of indirect MRA also is provided.

An overview of MR arthrography with emphasis on the current technique and applicational hints and tips

Magnetic resonance (MR) arthrography has been investigated in every major peripheral joint of the body, and has been proven to be effective in determining the integrity of intraarticular ligamentous and fibrocartilaginous structures and in the detection or assessment of osteochondral lesions and loose bodies in selected cases. Several methods could be used to create arthrogram effect during MR imaging, however, direct MR arthrography using diluted gadolinium as the contrast agent is the most commonly used technique and is the most reliable of all. MR arthrography is useful for demonstrating labrocapsular-ligamentous abnormalities and distinguishing partial thickness rotator cuff tears from focal full thickness tears in the shoulder, identifying or excluding recurrent tears following meniscal operations in the knee, demonstrating perforations of the triangular fibrocartilage complex (TFCC) and ligaments in the wrist, showing labral tears in the hip, diagnosing ligament tears in the ankle and identifying osteochondral lesions or loose bodies in any of the aforementioned joints. In this article, an overview of techniques of MR arthrography is provided with emphasis on direct MR arthrography using diluted gadolinium as the contrast agent. The current applications of the technique in major peripheral joints are reviewed, with emphasis given to the shoulder joint where the role of this technique has become well established.