Diagnostic performance and interreader agreement of individual and combined non-enhanced and contrast-enhanced MR imaging parameters in adhesive capsulitis of the shoulder

OBJECTIVE

The aims of our study were to analyze agreement among readers with different levels of expertise and diagnostic performance of individual and combined imaging signs for the diagnosis of adhesive capsulitis of the shoulder.

METHODS

In a retrospective study, contrast-enhanced shoulder MRIs of 60 patients with and 120 without clinically diagnosed adhesive capsulitis were evaluated by three readers independently. As non-enhanced imaging signs, readers evaluated signal intensity and thickness of the axillary recess capsule, thickness of the rotator interval capsule and the coracohumeral ligament as well as obliteration of subcoracoid fat. Furthermore, contrast enhancement of axillary recess and rotator interval capsule were evaluated. Data analysis included interreader reliability, ROC analysis, and logistic regression (p < 0.05).

RESULTS

Contrast-enhanced parameters showed substantially higher agreement among readers (ICC 0.79-0.80) than non-enhanced parameters (0.37-0.45). AUCs of contrast-enhanced signs (95.1-96.6%) were significantly higher (p < 0.01) than of non-enhanced imaging signs (61.5-85.9%) when considered individually. Combined evaluation of axillary recess signal intensity and thicknesses of axillary recess or rotator interval-when at least one of two signs was rated positive-increased accuracy compared to individual imaging signs, however not statistically significant.

CONCLUSION

Contrast-enhanced imaging signs show both distinctly higher agreement among readers and distinctly higher diagnostic performance compared to non-enhanced imaging signs based on the imaging protocol used in this study. Combined evaluation of parameters showed a tendency to increase discrimination; however, the effect on diagnosis of ACS was not statistically significant.

MR imaging detection of adhesive capsulitis of the shoulder: impact of intravenous contrast administration and reader's experience on diagnostic performance

OBJECTIVE

Correct identification of adhesive capsulitis of the shoulder (ACS) has an important impact on adequate therapy. The aim of our study was to investigate the influence of intravenous contrast administration and of reader's experience on sensitivity and specificity of MRI in diagnosing ACS.

MATERIALS AND METHODS

A total of 180 patients were included in a retrospective study: 60 subjects with at least 4 of 5 clinical signs of adhesive capsulitis of the shoulder and 120 patients with other shoulder diseases who underwent contrast-enhanced MRI. In a first session, only non-enhanced images and in a second session also contrast-enhanced (CE) series were independently evaluated by three radiologists with various levels of professional experience. Readers were blinded to all clinical information and had to rate the shoulder MRIs for absence or presence of adhesive capsulitis. Data analysis included McNemar's test, t test, and U test (p < .05).

RESULTS

Using non-enhanced MRI, readers achieved a mean sensitivity of 63.9% and a mean specificity of 86.4%. By additional use of CE sequences, the mean sensitivity (85.5%) and the sensitivity for each reader increased significantly (p = .046, p < .01, p < .001, p = .045) while the improvement in mean specificity was not significant. Reader's experience had a positive effect on sensitivity and specificity, which was in part but not consistently significant.

CONCLUSION

The addition of CE sequences can significantly increase the sensitivity of MRI in the diagnosis of ACS. Reader's experience has shown to be another important factor for the diagnostic outcome.

Correlation of magnetic resonance and arthroscopy in the diagnosis of shoulder injury

BACKGROUND

Advances in shoulder magnetic resonance imaging (MRI) and arthrography (MRA) have revolutionised musculoskeletal diagnosis and surgical planning. Despite this, the overall accuracy of MRI, with or without intra-articular contrast, can be variable.

METHODS

In this prospective non-randomised analysis, 200 participants (74.5% males) with suspected shoulder injuries underwent MRI (41.0%) or MRA followed by arthroscopy. A study specific proforma was developed to ensure consistency of reporting by radiologists and surgeons. The reports were compared to assess the predictive power of MRI/MRA. Specific assessment of rotator cuff tendon appearance, long head of biceps (LHB) tendon appearance, position and anchor, subacromial space, glenoid labrum and humeral cartilage grade were included.

RESULTS

Shoulder MRA demonstrated a higher agreement with arthroscopy than MRI for supraspinatus, infraspinatus and subscapularis tendon appearance (κ = 0.77 vs. κ = 0.61, κ = 0.55 vs. κ = 0.53 and κ = 0.58 vs. κ = 0.46 respectively). There were also superior agreement rates with MRA compared to MRI for LHB tendon appearance (κ = 0.70 vs. κ =0.54) and position (κ = 0.89 vs. κ = 0.72). As an overall assessor of shoulder pathology we found significantly higher total agreement scores when MRA was used (p = 0.002).

DISCUSSION

Whilst magnetic resonance imaging with arthrography is an extremely useful tool to assess underlying pathological shoulder states it does not confer 100% accuracy. In cases whereby this modality is inconclusive, an examination under anaesthesia and diagnostic arthroscopic assessment for the detection of intra-articular shoulder pathology may be considered.

Thrower's Shoulder: An Approach to MR Imaging Interpretation

In this article, the authors aim to focus on the challenges of interpreting shoulder MR imaging in the throwing athlete with an approach formed by evidence-based literature and clinical experience, with a particular focus on superior labrum tears.

7-T clinical MRI of the shoulder in patients with suspected lesions of the rotator cuff

Background

To evaluate feasibility and diagnostic performance of clinical 7-T magnetic resonance imaging (MRI) of the shoulder.

Methods

Eight patients with suspected lesions of the rotator cuff underwent 7-T MRI before arthroscopy. Image quality was scored for artifacts, B₁⁺ inhomogeneities, and assessability of anatomical structures. A structured radiological report was compared to arthroscopy. In four patients, a visual comparison with pre-existing 1.5-T examinations was performed.

Results

Regarding image quality, the majority of the sequences reached values above the middle of each scoring scale. Fat-saturated proton density sequences showed least artifacts and best structure assessability. The most homogenous B₁⁺ field was reached with gradient-echo sequences. Arthroscopy did not confirm tendinopathy/partial tear of supraspinatus in 5/8 patients, of subscapularis in 5/6, and of infraspinatus in one patient; only a partial lesion of the subscapularis tendon was missed. Pathologic findings of long bicipital tendon, acromioclavicular joint, glenohumeral cartilage, labrum, and subacromial subdeltoideal bursa were mainly confirmed; exceptions were one lesion of the long bicipital tendon, one subacromial bursitis, and one superior glenoid labrum anterior-to-posterior lesion, missed on 7-T MRI. Evaluating all structures together, sensitivity was 86%, and specificity 74%. A better contrast and higher image resolution was noted in comparison to previous 1.5-T examinations.

Conclusions

7-T MRI of the shoulder with diagnostic image quality is feasible. Overrating of tendon signal alterations was the main limitation. Although the diagnostic performance did not reach the current results of 3-T MRI, our study marks the way to implement clinical 7-T MRI of the shoulder.

Effect of patient age on accuracy of primary MRI signs of long head of biceps tearing and instability in the shoulder: an MRI-arthroscopy correlation study

OBJECTIVE

To determine the effect of patient age on the accuracy of primary MRI signs of long head of biceps (LHB) tendon tearing and instability in the shoulder using arthroscopy as a reference standard.

MATERIALS AND METHODS

Subjects with MRI studies and subsequent arthroscopy documenting LHB tendon pathology were identified and organized into three age groups (18-40, 41-60, 61-87). Normal and tendinopathic tendons were labeled grade 0, partial tears grade 1 and full tears grade 2. Two radiologists blinded to arthroscopic data graded MRI studies independently. Prevalence of disease, MRI accuracy for outcomes of interest, and inter-reader agreement were calculated.

RESULTS

Eighty-nine subjects fulfilled inclusion criteria with 36 grade 0, 36 grade 1 and 17 grade 2 tendons found at arthroscopy. MRI sensitivity, regardless of age, ranged between 67-86% for grade 0, 72-94% for grade 1 and 82-94% for grade 2 tendons. Specificity ranged between 83-96% for grade 0, 75-85% for grade 1 and 99-100% for grade 2 tendons. MRI accuracy for detection of each LHB category was calculated for each age group. MRI was found to be least sensitive for grade 0 and 1 LHB tendons in the middle-aged group with sensitivity between 55-85% for grade 0 and 53-88% for grade 1 tendons. Agreement between MRI readers was moderate with an unweighted kappa statistic of 62%.

CONCLUSION

MRI accuracy was moderate to excellent and agreement between MRI readers was moderate. MRI appears to be less accurate in characterizing lower grades of LHB tendon disease in middle-aged subjects.

Detour sign in the diagnosis of subluxation of the long head of the biceps tendon with arthroscopic correlation

OBJECTIVE

To determine whether detection of the detour sign via MRI indicates subluxation of the long head of the biceps tendon (SLBT) in the shoulder joint and to investigate the association of SLBT with the degeneration of the long head of the biceps tendon (LBT) and rotator cuff tears.

METHODS

This retrospective study included 65 patients with shoulder pain who underwent shoulder MRI and arthroscopic surgery. When axial images revealed that the LBT was displaced over the inner rim of the bicipital groove with some remaining contact with the groove (Criterion 1), or demonstrated a "detour sign" of the biceps tendon (Criterion 2), the lesion was diagnosed as an SLBT. Shoulder arthroscopy was used as the reference standard.

RESULTS

Arthroscopy identified SLBT in 18 patients. When the MRI diagnosis was based on Criterion 1 alone, SLBT was diagnosed with a sensitivity of 44.4-55.6% and 75.4-80% accuracy. However, when the MRI diagnosis was based on Criteria 1 plus 2, SLBT was diagnosed with a sensitivity of 83.3-94.4% and 78.5-81.5% accuracy. There was a significant difference (p < 0.05) in the diagnostic sensitivity of Criteria 1 and 2.

CONCLUSION

The detour sign based on axial MRI may be regarded an additional useful anatomical feature that improves the diagnostic performance of MRI in the identification of SLBT lesions. Advances in knowledge: Recognition of the detour sign may enhance the diagnostic performance of the conventional MRI protocol over the MR arthrography protocol for SLBT.

Correlation between MRI and Arthroscopy in Diagnosis of Shoulder Pathology

INTRODUCTION

Shoulder pain can cause significant pain, discomfort and reduce the ability to perform activities of daily living, thus making it the third most common cause of musculoskeletal consultation. The current gold standard diagnostic investigation is arthroscopy. MRI is a proved sensitive and accurate non-invasive tool in investigating shoulder pathology, but false and misleading results are equally reported.

AIM

The aim of the study is to compare the efficacy of MRI in diagnosing shoulder pathologies in comparison to arthroscopy, considering arthroscopy as the gold standard.

MATERIALS AND METHODS

Thirty nine consecutive patients, between 18-80 years of age, presenting with chronic shoulder pain or instability of more than 6 weeks, or with clinical signs of impingement or tear were included in the study. MRI of the shoulder joint was done followed by shoulder arthroscopy. The data collected was analysed for the significant correlation between MRI of shoulder and arthroscopic findings by kappa statistics.

RESULTS

Out of 39 patients, Rotator cuff (RC) tear was the most common pathology. MRI showed excellent sensitivity in the diagnosis of rotator cuff tears (0.91) and osteochondral defects (OCD), very good sensitivity for Bankart's lesion (0.8) and had poor sensitivity to detect SLAP tear (0.15). MRI was specific for all shoulder pathologies. MRI detected RC tears with kappa score of 0.73, Bankart's tear and OCD's with kappa score of 0.83 and 1.0 respectively and SLAP lesion with kappa score of 0.14. The accuracy of MRI was highest in diagnosing OCD's (1.0), followed by RC tear (0.9), Bankart's tear (0.9) and accuracy was least in diagnosing SLAP lesion (0.7). False negative results were more than false positives.

CONCLUSION

The present study supports that MRI is effective in diagnosing rotator cuff tears, Bankart's tear and ostechondral defects but was not found to be helpful in diagnosing SLAP lesions. MRI and arthroscopy have complimentary roles in the diagnosis of shoulder pathology.

[Systematics of injuries of the rotator cuff and biceps tendon]

PERFORMANCE

Injuries of the rotator cuff and the biceps tendon demonstrate different patterns, which can be recognized clinically and radiologically.

ACHIEVEMENTS

These patterns are impingement syndrome with additional trauma, isolated trauma of the rotator cuff and shoulder dislocation causing rotator cuff tears. Furthermore, it is clinically crucial to evaluate the extent of a rotator cuff injury.

PRACTICAL RECOMMENDATION

Magnetic resonance imaging (MRI) is the modality of choice to differentiate these patterns.

[Clinical or radiological diagnosis of impingement]

CLINICAL/METHODICAL ISSUE

Shoulder impingement syndrome is a clinically common entity involving trapping of tendons or bursa with typical clinical findings.

STANDARD RADIOLOGICAL METHODS

Important radiological procedures are ultrasound, magnetic resonance imaging (MRI) and MR arthrography. Projection radiography and computed tomography (CT) are ideal to identify bony changes and CT arthrography also serves as an alternative method in cases of contraindications for MRI. These modalities support the clinically suspected diagnosis of impingement syndrome and may identify its cause in primary diagnosis. In addition, effects of impingement are determined by imaging. Therapy decisions are based on a synopsis of radiological and clinical findings.

PERFORMANCE

The sensitivity and specificity of these imaging modalities with regard to the diagnostics of a clinically evident impingement syndrome are given in this review article.

PRACTICAL RECOMMENDATIONS

Orthopedic and trauma surgeons express the suspicion of an impingement syndrome based on patient history and physical examination and radiologists confirm structural changes and damage of intra-articular structures using dedicated imaging techniques.

Clinical application of radial magnetic resonance imaging for evaluation of rotator cuff tear

BACKGROUND

Magnetic resonance imaging is useful for evaluating the rotator cuff, but some tendinous insertions cannot be assessed using oblique sagittal, oblique coronal, and axial magnetic resonance (MR) images because of the presence of the partial volume effect.

HYPOTHESIS

The purpose of this study was to determine whether radial-slice MR images could reveal normal rotator cuff insertions and rotator cuff tears more clearly than conventional MR images.

PATIENTS AND METHODS

The study included 18 subjects with normal rotator cuffs and 30 with rotator cuff tears. MR images of rotator cuff insertions sliced into radial, oblique coronal, and axial sections were obtained. The extent to which normal rotator cuff insertions and rotator cuff tears were visualized in each of the three MR images was evaluated.

RESULTS

The top to posterior portions of the rotator cuff insertions from 0° to 120° could be visualized in the radial MR images. In comparison, the posterior portions of the rotator cuff insertions could not be visualized around 45° in both the oblique coronal and axial MR images.

DISCUSSION

These findings demonstrate that radial MR images are superior to the oblique coronal and axial MR images regarding their ability to accurately visualize rotator cuff insertions. Radial MR images also revealed greater detail around 45° in the posterior area of the rotator cuff tears than the oblique coronal and axial MR images. Radial MR images are particularly useful for visualizing clinically important posterosuperior rotator cuff tears.

LEVEL OF EVIDENCE

Level III - Diagnostic study.

Long head of the biceps brachii tendon: unenhanced MRI versus direct MR arthrography

OBJECTIVE

We sought to determine the diagnostic accuracy of unenhanced MRI and direct MR arthrography (MRA) for evaluation of the intra-articular long head of the biceps brachii tendon (LHBT) using arthroscopy as the gold standard.

MATERIALS AND METHODS

A retrospective review of patients who underwent shoulder MRI (n = 132) and MRA (n = 67) within 12 months prior to arthroscopy was performed. MR images were independently reviewed by two blinded musculoskeletal radiologists. Routinely recorded arthroscopic photos/videos were reviewed by an orthopedic surgeon. The LHBT was graded as normal, tendinosis, partial thickness tear less or greater than 50%, and complete tear. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for tendinosis and tear detection were calculated.

RESULTS

MRI correctly diagnosed fewer normal LHBTs compared to MRA (39-54% versus 74-84%, respectively; p < 0.005). MRI and MRA did not differ significantly in the diagnosis of tendinosis (18-36% and 15-38%, respectively; p > 0.05) and tears (75-83% and 64-73%, respectively; p > 0.05). For tendinosis, MRI versus MRA showed 18-36% and 15-38% sensitivity, 69-79% and 83-91% specificity, 22-28% and 18-50% PPV, 74-76% and 80-86% NPV, and 61-64% and 70-81% accuracy; respectively. For tears, MRI versus MRA showed 75-83% and 64-73% sensitivity, 73-75% and 82-91% specificity, 66-69% and 41-62% PPV, 82-87% and 92-94% NPV, and 74-78% and 79-88% accuracy; respectively.

CONCLUSIONS

No significant difference was found between unenhanced MRI and direct MRA for the detection of tendinosis and tears of LHBTs.

MRI-Arthroscopy Correlation for Shoulder Anatomy and Pathology: A Teaching Guide

OBJECTIVE

The objectives of the article are to improve the radiologist's understanding of shoulder arthroscopy and see how it correlates with MRI. We review the basic principles of arthroscopy followed by a comparison of its strengths and weaknesses relative to MRI. This discussion is supplemented by a series of cases that show the relationship between arthroscopy and MRI in terms of the visualization of normal and abnormal anatomy in the diagnosis of common shoulder abnormalities.

CONCLUSION

By understanding what our orthopedic colleagues are seeing (and not seeing) during arthroscopic shoulder surgery, we can better understand the strengths and weaknesses of MRI, which provides us the opportunity to improve our imaging interpretations and produce valuable management-guiding diagnostic reports.

[Traumatic bone and cartilage injuries of the shoulder]

BACKGROUND

Traumatic injuries to the shoulder joint occur both as isolated, especially to the humerus and clavicle, as well as accompanying glenohumeral dislocations.

AIM

To give an overview of the main approach of diagnostic imaging of the more common traumatic injuries to bone and/or cartilage of the shoulder joint. Only the scapula, proximal humerus and lateral clavicle are covered.

METHODS

In this overview radiography (RG), computed tomography (CT) and magnetic resonance imaging (MRI) are considered. Sonography is not included.

CONCLUSION

The radiological report has to correctly identify injuries and describe their extent but the use of classification schemes is strongly dependent on local procedural practices.

Contribution of MRI and CT arthrography to the diagnosis of intra-articular tendinopathy of the long head of the biceps

INTRODUCTION

Clinical diagnosis of biceps tendinopathy is difficult to make because of the poor sensitivity of existing clinical tests. The goal of this study was to determine whether MRI or CT arthrogram could contribute to the diagnosis of tendinopathy in the intra-articular portion of the long head of biceps (LHB), while using macroscopic findings during shoulder arthroscopy as a reference.

MATERIAL AND METHODS

A prospective, single-centre study was performed over a 4-month period. The radiology part of the study was carried out by a radiologist experienced in shoulder imaging. The arthroscopy part of the study was conducted while the biceps was being evaluated for treatment purposes. The study included 87 patients having an average age of 45.7 years (range 17-78). Fifty-eight patients underwent CT arthrography and 38 underwent an MRI. Seven patients underwent both imaging exams. One patient was removed from the study because of a spontaneous LHB rupture. The demographics of the two study populations were equivalent.

RESULTS

For the diagnosis of tendinopathy of the intra-articular portion of the long head of biceps, the CT arthrogram had a sensitivity of 71.43%, specificity of 100%, positive predictive value of 100% but a negative predictive value of 67.74%. For the diagnosis of tendinopathy of the intra-articular portion of the long head of biceps, the MRI had a sensitivity of 42.85%, specificity of 75%, positive predictive value of 50% but a negative predictive value of 69.23%.

CONCLUSION

This study showed that radiological diagnosis of tendinopathy of the long head of biceps remains challenging. Nevertheless, CT arthrography is more sensitive and specific than MRI in identifying this disorder.

LEVEL OF EVIDENCE

III (case-control study).

The added value of ABER position for the detection and classification of anteroinferior labroligamentous lesions in MR arthrography of the shoulder

PURPOSE

The purpose of this study is to compare MR arthrography in abduction and external rotation (ABER) position with conventional MR arthrography in neutral position for the detection and further classification of anteroinferior labroligamentous lesions.

MATERIALS AND METHODS

Two hundred and twenty-nine cases of shoulder MR arthrography with subsequent arthroscopy were retrospectively evaluated. All MR arthrograms in ABER position and neutral position were independently assessed by two radiologists who were blinded to the arthroscopic findings. Sensitivities and specificities of both positions for detection and further categorization of anteroinferior labroligamentous lesions were calculated and compared using paired McNemar test. K values were calculated to quantify the level of interobserver agreement.

RESULTS

At arthroscopy, 24 Bankart lesions, 59 ALPSA lesions, 39 Perthes lesions, 8 GLAD lesions, 4 ALIPSA lesions, 31 nonclassifiable lesions and 60 intact anteroinferior complexes were found. The sensitivity of MR arthrography in ABER position for detecting anteroinferior labroligamentous lesions was significantly higher than that of in neutral position (92.7-94.5% versus 81.8-83%, P<0.05). For the detection rate of the mentioned 6 subtypes of lesions, only the Perthes lesions had significant improvement in ABER position when compared with conventional MR arthrography (observer 1, 61.5-87.2%, P=0.006; observer 2, 69.2-92.3%, P=0.004). MR arthrography in ABER position was more effective in identifying of Perthes lesions (66.7-74.4% versus 35.9-40%, P<0.05) while the conventional MR arthrography was more effective in accurate diagnose of ALPSA lesions (74.6-78.0% versus 54.2-55.9%, P<0.05). No statistically significant difference of the diagnostic accuracy was found between the two positions for Bankart lesions, GLAD lesions, and ALIPSA lesions.

CONCLUSION

MR arthrography in ABER position has more added value on detection of Perthes lesions in evaluation of anteroinferior labroligamentous complex tear.

MRI of selected abnormalities at the anterior superior aspect of the shoulder: potential pitfalls and subtle diagnoses

OBJECTIVE

MRI has proven to be a helpful tool in the detection and description of pathologic changes of the rotator cuff, biceps tendon, and glenoid labrum and has thus become a mainstay in the evaluation of patients with shoulder pain. This review seeks to illustrate some of the more subtle abnormalities that can be detected on shoulder MRI and to highlight some normal anatomic variants that may mimic pathologic processes, concentrating on structures at the anterior superior aspect of the shoulder.

CONCLUSION

Shoulder MRI can provide a very accurate evaluation of shoulder pathologic processes and can assist in elucidating abnormalities that can be difficult to diagnose clinically. Awareness of the known anatomic variants and the sometimes subtle potential pain generators at the anterior superior aspect of the shoulder will allow a more accurate interpretation and can therefore increase the diagnostic yield of shoulder MRI.

Supraspinatus tendon tears at 3.0 T shoulder MR arthrography: diagnosis with 3D isotropic turbo spin-echo SPACE sequence versus 2D conventional sequences

OBJECTIVE

To assess the diagnostic performance of shoulder MR arthrography with 3D isotropic fat-suppressed (FS) turbo spin-echo sequence (TSE-SPACE) for supraspinatus tendon tears in comparison with 2D conventional sequences at 3.0 T.

MATERIALS AND METHODS

The study was HIPAA-compliant and approved by the institutional review board with a waiver of informed consent. Eighty-seven arthroscopically confirmed patients who underwent 3.0 T shoulder MR arthrography with 2D sequences and 3D TSE-SPACE were included in a consecutive fashion from March 2009 to February 2010. Two reviewers independently analyzed 2D sequences and 3D TSE-SPACE. Sensitivity, specificity, accuracy, and interobserver agreement (κ) were compared between 2D sequences and 3D TSE-SPACE for full-thickness and partial-thickness supraspinatus tendon tears together and for partial-thickness supraspinatus tendon tears alone.

RESULTS

There were 33 full-thickness tears and 28 partial-thickness tears of supraspinatus tendons. For full-thickness and partial-thickness supraspinatus tendon tears together, the mean sensitivity, specificity, and accuracy of both readers were 96, 92, and 94% on 2D sequences and 91, 84, and 89% on 3D TSE-SPACE. For partial-thickness supraspinatus tendon tears alone, the mean sensitivity, specificity, and accuracy were 95, 92, and 94% on 2D sequences and 84, 85, and 84% on 3D TSE-SPACE. There was no statistical difference between 2D sequences and 3D TSE-SPACE. Interobserver agreements were almost perfect on 2D conventional sequences and substantial on 3D TSE-SPACE.

CONCLUSION

Compared with 2D conventional sequences, MR arthrography using 3D TSE-SPACE was comparable for diagnosing supraspinatus tendon tears despite limitations in detecting small partial-thickness tears and in discriminating between full-thickness and deep partial-thickness tears.

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.

Comparison of three-dimensional isotropic T1-weighted fast spin-echo MR arthrography with two-dimensional MR arthrography of the shoulder

PURPOSE

To determine the accuracy of a three-dimensional (3D) isotropic T1-weighted fast spin-echo (FSE) magnetic resonance (MR) sequence as compared with a conventional two-dimensional (2D) sequence in the diagnosis of rotator cuff tears and labral lesions.

MATERIALS AND METHODS

Institutional review board approval was obtained, and the informed consent requirement was waived. Forty-nine patients who had undergone direct or indirect shoulder MR arthrography with the 2D T1-weighted FSE sequence and the 3D isotropic T1-weighted FSE sequence and subsequent arthroscopy were included. Each MR imaging sequence was independently scored by two readers retrospectively for the presence of full- or partial-thickness tears of the supraspinatus (SST) and infraspinatus (IST) tendons and the subscapularis tendon (SCT) and labral lesions. Diagnostic performance based on each sequence type was compared by using the area under the receiver operating characteristic curve (AUC).

RESULTS

Arthroscopic findings enabled confirmation of the presence of 17 full-thickness SST-IST tears, 18 partial-thickness SST-IST tears, four full-thickness SCT tears, 17 partial-thickness SCT tears, and 17 labral lesions. The AUCs for the readers using the 3D T1-weighted FSE sequence versus those obtained with the 2D sequence were 0.771-0.989 versus 0.837-0.998 for reader A and 0.771-0.989 versus 0.797-0.989 for reader B in the detection of rotator cuff tears and 0.885 versus 0.897 for reader A and 0.895 versus 0.895 for reader B in the detection of labral lesions. The mean AUCs between the 2D and 3D sequences were not significantly different, with the exception of partial-thickness SCT tears for one reader.

CONCLUSION

The accuracy of 3D isotropic FSE MR arthrography may be comparable with that of conventional 2D MR arthrography in the diagnosis of rotator cuff tears and labral lesions with a shorter imaging time.