Supraspinatus tendon tears: comparison of 3D US and MR arthrography with surgical correlation

Objective

The objective of the study was to compare the diagnostic reliability of 3D US with MR arthrography in diagnosing supraspinatus tendon tears, with arthroscopic findings used as the standard.

Materials and methods

In a prospective study 50 patients who later underwent arthroscopic surgery of the rotator cuff were examined pre-operatively by 3D US with MR arthrography. The presence or absence of a full- or partial-thickness supraspinatus tendon tear and the tear size as demonstrated by each imaging and arthroscopy was recorded. The tear size was divided into three grades: small (<1 cm), medium (1-3 cm), and large (>3 cm).

Results

The arthroscopic diagnosis was a full-thickness tear in 40 patients, partial-thickness tears in 5, and intact supraspinatus tendon in 5. 3D US correctly diagnosed 35 out of 40 full-thickness tears and MR arthrography 39 out of 40 full-thickness tears. Regarding partial-thickness tears, 3D US underestimated 2 cases as no tear and overestimated 1 case as a full-thickness tear. MR arthrography underestimated 1 case as a partial-thickness tear and overestimated 2 cases as full-thickness and partial-thickness tears respectively. 3D US and MR arthrography yield a sensitivity for full-thickness tears of 87.5% and 97.5% with specificity of 90.0% and 90.0%. Based on the grading system, 3D US measurements correctly predicted the tear size of 23 (65.7%) of the 35 full-thickness tears and MR arthrography 30 (75.0%) of the 39 full-thickness tears.

Conclusion

Three-dimensional ultrasound seems to be a promising imaging modality comparable to MR arthrography for the assessment of the supraspinatus tendon tears.     

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.     

Prevalence of HAGL lesions and associated abnormalities on shoulder MR examination

Objective

Humeral avulsion of the glenohumeral ligament (HAGL) is an uncommon shoulder injury. We report the prevalence of HAGL lesions and other associated shoulder injuries in a large series of shoulder MR examinations. All results were correlated with surgery.

Materials and methods

MR reports of 1,000 consecutive conventional shoulder MR exams performed on patients with shoulder pain were reviewed in our information system for the word HAGL. A total of 743 patients went on to surgery. There were 23 HAGL lesions reported at surgery. Those 23 examinations were reviewed retrospectively in consensus by two musculoskeletal radiologists. Scans were assessed for HAGL lesions, full or partial thickness supraspinatus, infraspinatus or subscapularis tendon tears, superior labral anterior posterior (SLAP) tears, anterior or posterior labral tears, and Hill–Sachs lesions.

Results

All 23 patients had HAGL lesions at surgery. Sixteen HAGL lesions were seen on prospective MR reading and 17 HAGL lesions were seen on retrospective MR consensus reading. Six HAGL lesions were not seen on retrospective consensus reading. Sixteen patients had Hill–Sachs deformities, ten had subscapularis tendon tears, five had supraspinatus tendon tears, six had superior labral tearing, and six had anterior labral tears. The above findings were confirmed on arthroscopy.

Conclusions

In this series, there was a 1.6 % prevalence on all MR examinations, and prevalence of 2.1 % seen on MR examination for those who went to surgery. Common injuries associated with HAGL lesions are Hill–Sachs deformities and subscapularis tendon tears. Anterior labral tears were seen in only six cases despite Hill–Sachs deformities in 16 patients. In patients with Hill–Sachs deformities without anterior labral tears, one must carefully assess for the presence of a HAGL lesion.     

Can isotropic fast gradient echo imaging be substituted for conventional T1 weighted sequences in shoulder MR arthrography at 3 Tesla?

PURPOSE: To assess the practical utility of isotropic shoulder imaging in patients undergoing MR arthrography. Isotropic shoulder imaging can be performed in less than three minutes with use of fast gradients. MATERIALS AND METHODS: Two experienced musculoskeletal radiologists retrospectively interpreted MR images of the shoulder in 100 consecutive patients undergoing MR arthrography of the shoulder. All patients underwent MRI of the shoulder in oblique coronal, oblique sagittal, and axial planes on a 3.0-Tesla MRI system. All patients had conventional fast spin-echo T1-weighted imaging. All patients also had thin section (0.4 mm) isotropic spoiled gradient echo images performed. A total of 67 of the 100 patients underwent subsequent arthroscopy and results were compared with MR interpretations. RESULTS: There were 41 full-thickness supraspinatus tendon tears, nine partial-thickness supraspinatus tendon tears (seven articular surface and two bursal surface), 21 superior labral, 18 anterior labral, and seven posterior labral tears demonstrated by consensus retrospective reading of the 100 shoulder MR exams. There was no difference in interpretation of the isotropic images as compared to the conventionally acquired images in the oblique coronal, oblique sagittal, and axial planes. Some patients had more than one finding on each exam. A total of 67 patients went on to arthroscopy. There were 41 full-thickness supraspinatus tendon tears, nine partial-thickness supraspinatus tendon tears, 21 superior labral, 18 anterior labral, and seven posterior labral tears demonstrated on arthroscopy. All full- and partial-thickness supraspinatus tendon tears seen at arthroscopy were seen on consensus MR reading. A total of 19 out of the 21 patients with superior labral anterior posterior (SLAP) tears at arthroscopy were seen on consensus MR reading. A total of 16 of the 18 anterior labral tears and six of the seven posterior labral tears seen at arthroscopy were seen on consensus MR reading. Some of the 67 patients had more than one finding on arthroscopy. CONCLUSION: Isotropic imaging of the shoulder is practical in clinical imaging when performed with use of fast gradients on a 3-Tesla system. Isotropic imaging provides the same clinical information as conventional imaging and can be acquired in less than three minutes.     

Shoulder MR arthrography: which patient group benefits most?

OBJECTIVE: We sought to compare the diagnostic accuracy of conventional MRI versus MR arthrography of the shoulder in the assessment of high-performance athletes (professional baseball players) and to compare our findings in these patients with the conventional MRI and MR arthrographic findings in an age-matched control group of nonprofessional athletes. MATERIALS AND METHODS: Conventional MRI and MR arthrographic examinations of the shoulder in 20 consecutive professional baseball players with shoulder pain were reviewed retrospectively by two musculoskeletal radiologists in consensus. These interpretations were compared with retrospective consensus interpretations of conventional MRI and MR arthrographic examinations of the shoulder obtained in a control group of 50 consecutive nonprofessional athletes with shoulder pain. MR images were assessed for full- or partial-thickness supraspinatus tendon tears, superior labral anteroposterior (SLAP) tears, and anterior or posterior labral tears. RESULTS: In the 20 consecutive professional athlete patients, two full-thickness and six partial-thickness undersurface supraspinatus tendon tears were seen on MR arthrography but not seen on conventional MRI as well as six SLAP tears, two anterior labral tears, and one posterior labral tear. Three patients had both SLAP tears and full- or partial-thickness supraspinatus tendon tears. Of 14 patients with findings on MR arthrography that were not seen on MRI, 11 had arthroscopic correlation. In all 11, arthroscopic findings confirmed findings on MR arthrography. In the group of 50 nonprofessional athlete patients, five had additional findings on MR arthrography not seen on conventional MRI: two anterior labral tears, two partial-thickness supraspinatus tendon tears, and two SLAP tears. One patient had both a partial-thickness supraspinatus tendon tear and a SLAP tear seen on MR arthrography. The five patients with additional findings on MR arthrography had arthroscopy. In all five, arthroscopic findings confirmed the findings on MR arthrography. CONCLUSION: MR arthrography is considerably more sensitive for detection of partial-thickness supraspinatus tears and labral tears than conventional MRI. MR arthrography showed injuries in addition to those seen on conventional MRI in 14 of 20 patients in the high-performance athlete group. These results suggest high-performance athletes may be a subgroup of patients for whom MR arthrography yields considerably more diagnostic information than conventional MRI.     

Accuracy of 3-Tesla MR and MR arthrography in diagnosis of meniscal retear in the post-operative knee

Purpose

This study assesses the accuracy of 3-Tesla (3-T) conventional MR imaging, 3-T MR arthrography, and the combined use of conventional MR and MR arthrography in the diagnosis of meniscal retears as compared with arthroscopy. The study also assess whether there are false-negative cases in which injected contrast does not extend into the meniscus despite a meniscal retear being seen on arthroscopy.

Materials and methods

One hundred consecutive knee MR arthrograms performed on patients with previous knee surgery were reviewed retrospectively. 3-T conventional MR imaging, 3-T MR arthrography, and the combined use of conventional MR and MR arthrography were assessed for meniscal retears as compared with arthroscopy. The criterion used to diagnose a meniscal retear on MR arthrogram was injected contrast tracking into the meniscus. All patients underwent second-look arthroscopy.

Results

Seventy-four patients had conventional MR findings consistent with a meniscal retear. In 83 of the 100 patients, intraarticular contrast helped in demonstrating a retear. In ten patients, there were MR findings consistent with a meniscal retear despite intra-articular contrast not tracking into the meniscus. Ninety-four of the 100 patients had meniscal retears on second-look arthroscopy. Three-Tesla conventional MR examination was 78 % sensitive and 75 % specific, MR arthrogram examination was 88 % sensitive and 100 % specific, and the combined use of MR and MR arthrogram imaging was 98 % sensitive and 75 % specific in the diagnosis of a meniscal retear.

Conclusions

The combined use of 3-T MR and MR arthrography allows for high sensitivity and specificity in meniscal retear detection. In some patients, intraarticular contrast will not track into a meniscal retear. When MR findings are consistent with a meniscal retear but contrast does not extend into the meniscus, a meniscal retear is likely.     

Comparison of 3.0-T MR vs 3.0-T MR arthrography of the hip for detection of acetabular labral tears and chondral defects in the same patient population

Objective:

We report our experience in diagnostic sensitivity of 3.0-T conventional MR vs 3.0-T MR arthrography of the hip for detection of acetabular labral tears and chondral defects in the same patient population.

Methods:

43 consecutive patients had both conventional hip MR and MR arthrography examinations performed. These examinations were reviewed retrospectively by independent reading of two musculoskeletal radiologists who read the MR and MR arthrogram examinations in a randomized fashion (i.e. MR and MR arthrogram examinations were read at separate sittings and in a randomized fashion so as not to bias reviewers). Scans were assessed for acetabular labral tears and chondral defects. All patients went on to arthroscopy.

Results:

Of these 43 patients, 40 had acetabular labral tears read by Reader 1 and 39 had acetabular labral tears read by Reader 2 on MR arthrogram, 39 had acetabular labral tears read by Reader 1 and 38 had acetabular labral tears read by Reader 2 on conventional MR examination. There were 42 labral tears in 43 patients at arthroscopy. There were four false-negative labral tears compared with arthroscopy on MR and three false negatives on MR arthrography for Reader 1 and five false negatives on MR and four false negatives on MR arthrography for Reader 2. Each reader had one false-positive labral tear compared with arthroscopy on both MR and MR arthrography. There were 32 acetabular chondral defects at arthroscopy. Reader 1 saw 21 acetabular chondral defects on conventional MR and 27 chondral defects at MR arthrography. Reader 2 saw 19 acetabular chondral defects at conventional MR and 25 acetabular chondral defects on MR arthrography. There were no false-positive readings of chondral defects compared with arthroscopy on MR and one false positive for Reader 1 and two false positives for Reader 2 on MR arthrography as compared with arthroscopy. On conventional MR examination, sensitivities and specificities as compared with arthroscopy were as follows: Reader 1 acetabular labral tear (90% sensitivity, 0% specificity) and Reader 2 acetabular labral tear (88% sensitivity, 0% sensitivity). On MR arthrogram, sensitivities and specificities as compared with arthroscopy for Reader 1 were 93%, 0% and for Reader 2 were 90%, 0%, respectively. Sensitivities and specificities for detection of acetabular chondral defects as compared with arthroscopy were Reader 1 conventional MR (65% sensitivity, 100% specificity), Reader 1 MR arthrography (81% sensitivity, 91% specificity), Reader 2 conventional MR (59% sensitivity, 100% specificity) and Reader 2 MR arthrography (71% sensitivity, 82% specificity).

Conclusion:

In this series, 3.0-T MR demonstrated sensitivity for detection of acetabular labral tears that rivals the sensitivity of 3.0-T MR arthrography of the hip. In this series, 3.0-T MR arthrography was more sensitive than conventional 3.0-T MR for detection of acetabular chondral defects.

Advances in knowledge:

3.0-T MR and MR arthrography are near equivalent in the diagnosis of acetabular labral tears. This information is useful for pre-operative planning.MR arthrography has been reported to be more sensitive and specific for detection of acetabular labral tears in the hip than conventional MRI.^1–10 MR arthrography has also been reported to be superior in detection of acetabular cartilage defects as compared with conventional MRI.¹¹ To our knowledge 3.0-T MR vs 3.0-T MR arthrography sensitivity for detection of acetabular labral tears and chondral defects has not been specifically assessed.To our knowledge, Petersilge et al¹ first reported the utility of hip MR arthrography in the diagnosis of acetabular labral tears. Toomayan et al² compared MR arthrography of the hip with conventional MRI of the hip in different patient populations. He found MR arthrography with a small field of view to be substantially more sensitive for detection of acetabular labral tears than conventional MRI. Sutter et al¹¹ found 1.5 T MR arthrography to be superior to conventional MRI for detecting labral tears and acetabular cartilage defects.Patients with acetabular labral tears present with symptoms of persistent pain, clicking, locking and decreased range of motion. With the availability of hip arthroscopy, labral tears can more easily be addressed with minimally invasive surgery. Accurate pre-operative identification of labral tears is needed.² Based on previous studies demonstrating the accuracy of MR arthrography in detection of acetabular labral tears, surgeons often request MR arthrography of the hip to characterize labral tears prior to surgery.^1–10 The purpose of this study is to assess 3.0-T MR vs MR arthrography diagnostic performance in detection of acetabular labral tears and chondral defects in the same patient population using arthroscopy as a reference standard.     

Detection of partial-thickness supraspinatus tendon tears: is a single direct MR arthrography series in ABER position as accurate as conventional MR arthrography?

Purpose  

The purpose of this study was to retrospectively evaluate sensitivity and specificity of a single magnetic resonance (MR) arthrography series in abduction external rotation (ABER) position compared with conventional MR arthrography for detection of supraspinatus tendon tears, with arthroscopy as gold standard, and to assess interobserver variability.     

MR-arthrography in superior instability of the shoulder: correlation with arthroscopy

Purpose

This study was undertaken to evaluate magnetic resonance (MR) arthrography in the detection and classification of lesions that may cause superior instability.

Materials and methods

Forty-two consecutive patients with clinical signs of chronic superior instability of the shoulder underwent MR arthrography followed by arthroscopic surgery. For each patient we retrospectively reviewed the MR arthrography and surgical findings.

Results

We detected 31 superior labral anterior posterior (SLAP) lesions, all confirmed on arthroscopy with three cases of underestimation: in the detection of SLAP lesions, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of MR arthrography were 100%; in the evaluation of the type of SLAP lesion, sensitivity was 100%, specificity was 78.5%, accuracy was 92.8%, PPV was 71.7% and NPV was 100%. All cases of capsular laxity (13/42) and biceps tendon lesions (3/42) were confirmed on arthroscopy with sensitivity, specificity, accuracy, PPV and NPV of 100%. Eleven cuff lesions were detected on MR arthrography, 10 of which confirmed at arthroscopy: sensitivity was 100%, specificity was 96.8%, accuracy was 97.6%, PPV was 90.9% and NPV was 100%. Associated lesions were found in 38/42 patients.

Conclusions

Superior instability is frequently associated with different anatomical variants or pathological conditions, such as SLAP lesions. The role of MR arthrography is to describe the key features of lesions affecting the superior portion of the shoulder, including location, morphology, extent, and associated injuries and leanatomical variants and to correlate these features with clinical symptoms.     

Rotator cable at MR imaging: considerations on morphological aspects and biomechanical role

Purpose

The rotator cable (RC) is a thickening of the coracohumeral ligament. It extends from the coracohumeral ligament to the inferior border of the infraspinatus tendon, with fibres running perpendicularly to the rotator cuff fibres. According to some authors, the RC tends to thicken with age, thus allowing some individuals with a cuff lesion to preserve normal shoulder function. We evaluated the RC with magnetic resonance (MR) imaging and investigated its possible role in the biomechanics of the shoulder affected by cuff lesions.

Materials and methods

Between November 2007 and May 2008, we performed shoulder MR examinations for shoulder pain or disability on 94 patients (46 males, 48 females; age range 16?C79 years; mean age 54.09±15.09 years) for a total of 104 shoulders (62 right, 42 left).

Results

RC was more easily detectable in oblique coronal scans where it appeared as a crescent-shaped, regularly marginated structure adjacent to the articular surface of the supraspinatus tendon and medial to the insertion point of this tendon on the greater tuberosity. Its thickness was 2.8±0.3 mm. The structure was identified in 62% of cases (mean patient age 55.3±14.9 years). No statistically significant difference in age was found between patients with and without evidence of RC (Student??s t test=0.05; p=0.82). Among patients with partial- or full-thickness supraspinatus tendon lesions at MR imaging, no statistically significant difference was found between the presence or absence of RC and disability on Jobe??s test (??²=1.17; p>0.05).

Conclusions

RC can be observed at MR imaging in >60% cases. In our sample it did not seem to influence shoulder function in patients with cuff lesions.     

Rotator cuff tears: assessment with MR arthrography in 275 patients with arthroscopic correlation

We assessed the diagnostic performance of magnetic resonance (MR) arthrography in the diagnosis of articular-sided partial-thickness and full-thickness rotator cuff tears in a large symptomatic population. MR arthrograms obtained in 275 patients including a study group of 139 patients with rotator cuff tears proved by arthroscopy and a control group of 136 patients with arthroscopically intact rotator cuff tendons were reviewed in random order. MR imaging was performed on a 1.0 T system (Magnetom Expert, Siemens). MR arthrograms were analyzed by two radiologists in consensus for articular-sided partial-thickness and full-thickness tears of the supraspinatus, infraspinatus, and subscapularis tendons. At arthroscopy, 197 rotator cuff tears were diagnosed, including 105 partial-thickness (93 supraspinatus, nine infraspinatus, three subscapularis) and 92 full-thickness (43 supraspinatus, 20 infraspinatus, 29 subscapularis) tendon tears. For full-thickness tears, sensitivity, specificity, and accuracy were 96%, 99%, and 98%, respectively, and for partial tears 80%, 97%, and 95%, respectively. False negative and positive assessments in the diagnosis of articular-sided partial-thickness tears were predominantly [78% (35/45)] observed with small articular-sided (Ellman grade1) tendon tears. MR arthrography is highly accurate in the diagnosis of full-thickness rotator cuff tears and is accurate in the diagnosis of articular-sided partial-thickness tears. Limitations in the diagnosis of partial-thickness tears are mainly restricted to small articular-sided tears (Ellman grade 1) due to difficulties in differentiation between fiber tearing, tendinitis, synovitic changes, and superficial fraying at tendon margins.     

Comparison of Three-Dimensional Isotropic and Two-Dimensional Conventional Indirect MR Arthrography for the Diagnosis of Rotator Cuff Tears

Objective

To compare the accuracy between a three-dimensional (3D) indirect isotropic T1-weighted fast spin-echo (FSE) magnetic resonance (MR) arthrography and a conventional two-dimensional (2D) T1-weighted sequences of indirect MR arthrography for diagnosing rotator cuff tears.

Materials and Methods

The study was approved by our Institutional Review Board. In total, 205 patients who had undergone indirect shoulder MR arthrography followed by arthroscopic surgery for 206 shoulders were included in this study. Both conventional 2D T1-weighted FSE sequences and 3D isotropic T1-weighted FSE sequence were performed in all patients. Two radiologists evaluated the images for the presence of full- or partial-thickness tears in the supraspinatus-infraspinatus (SSP-ISP) tendons and tears in the subscapularis (SSC) tendons. Using the arthroscopic findings as the reference standard, the diagnostic performances of both methods were analyzed by the area under the receiver operating characteristic curve (AUC).

Results

Arthroscopy confirmed 165 SSP-ISP tendon tears and 103 SSC tendon tears. For diagnosing SSP-ISP tendon tears, the AUC values were 0.964 and 0.989 for the 2D sequences and 3D T1-weighted FSE sequence, respectively, in reader I and 0.947 and 0.963, respectively, in reader II. The AUC values for diagnosing SSC tendon tears were 0.921 and 0.925, respectively, for reader I and 0.856 and 0.860, respectively, for reader II. There was no significant difference between the AUC values of the 2D and 3D sequences in either reader for either type of tear.

Conclusion

3D indirect isotropic MR arthrography with FSE sequence and the conventional 2D arthrography are not significantly different in terms of accuracy for diagnosing rotator cuff tears.     

Ultrasonography of symptomatic rotator cuff tears compared with MR imaging and surgery

Purpose

To compare the accuracy of ultrasonography and magnetic resonance imaging in the detection of rotator cuff tears.

Materials and methods

Ninety-six patients with clinically suspected rotator cuff pathology underwent ultrasonography and magnetic resonance imaging of the shoulder. The findings in 88 patients were compared with arthroscopy or open surgery.

Results

Full-thickness tear was confirmed in 57 cases, partial-thickness tear in 30 cases and degenerative changes without tear in 1. In all 57 cases of full-thickness tear and in 28 out of 30 cases of partial-thickness tear the supraspinatus tendon was involved. The accuracy in the detection of full-thickness tears was 98 and 100% for ultrasonography and magnetic resonance imaging, respectively. The accuracy in the detection of bursal or articular partial-thickness tears was 87 and 90% for ultrasonography and magnetic resonance imaging, respectively.

Conclusions

In experienced hands ultrasonography should be considered as an accurate modality for the initial investigation of rotator cuff, especially supraspinatus, tears.     

MR arthrographic assessment of suspected posteroinferior labral lesions using flexion, adduction, and internal rotation positioning of the arm: preliminary experience

Objective

Imaging the shoulder in the position of flexion, adduction, and internal rotation (FADIR) may be useful in characterizing lesions of the posteroinferior labrum. The purpose of this preliminary study is to illustrate the diagnostic utility of FADIR positioning in the assessment and characterization of posteroinferior labral tears.

Materials and Methods

In the FADIR position, the arm is placed across the chest, with the hand on the contralateral shoulder and palm facing outwards. FADIR positioning was performed if there was a subtle or equivocal abnormality of the posteroinferior labrum on conventional MR arthrography sequences. A retrospective review of the charts of 9 people who were imaged using FADIR positioning in addition to routine MR arthrographic sequences of the shoulder was performed. The review included the indication for the study, documentation of presence of clinical posterior instability, and surgical correlation, where available.

Results

In all 9 patients, FADIR positioning helped confirm, exclude, or better characterize a posteroinferior labral abnormality by increasing the diagnostic confidence.

Conclusion

Flexion, adduction, and internal rotation positioning appears to be a useful adjunct in evaluating patients with equivocal or subtle posteroinferior labral abnormalities on conventional MR arthrography sequences.     

3.0 T conventional hip MR and hip MR arthrography for the acetabular labral tears confirmed by arthroscopy

Objective

To evaluate the value of hip MR for diagnosing acetabular labrum tears, and to further compare the diagnostic performances of conventional MR with MR arthrography in acetabular labrum tears.

Methods

90 patients undergoing both hip MR examination and subsequent hip arthroscopy were retrospectively evaluated. Of these patients, 34 accepted both conventional MR and MR arthrography; while the other 56 only underwent conventional MR examination. All hip MR images were independently reviewed by two radiologists, and further compared with the results of hip arthroscopy.

Results

59 of 90 patients were confirmed with acetabular labral tears by hip arthroscopy and 31 without tears. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of conventional MR for evaluating the acetabular labral tears were 61.0%, 77.4%, 83.7% and 51.1% (radiologist A), and 66.1%, 74.2%, 82.9% and 53.4% (radiologist B), respectively, with good consistency between the two observers (K = 0.645). The sensitivity, specificity, PPV and NPV of MR arthrography for assessing the acetabular labral tears were 90.5%, 84.6%, 90.5% and 84.6% (radiologist A), and 95.2%, 84.6%, 90.9% and 91.7% (radiologist B), respectively, with excellent good consistency between the two observers (K = 0.810). The sensitivity and NPV of MR arthrography for diagnosing the acetabular labral tears were significantly higher than those of conventional MR (both P < 0.05).

Conclusion

Hip MR arthrography is a reliable evaluation modality for diagnosing the acetabular labral tears, and its diagnostic performance is superior to that of conventional MR at 3.0 T.     

Moderate value of non-contrast magnetic resonance imaging after non-dislocating shoulder trauma

Purpose

The purpose of the present study was to determine the value of shoulder magnetic resonance imaging (MRI) obtained in the community setting interpreted by musculoskeletal radiologists in patients with shoulder pain initiated by a single non-dislocating shoulder trauma.

Methods

In 56 of 61 consecutive patients who underwent shoulder arthroscopy due to pain after a single non-dislocating shoulder trauma, the data sets of non-contrast MRI were complete. These were retrospectively interpreted by three radiologists specialized on musculoskeletal MRI who were blinded for patients’ history and who did not have access to the reports of arthroscopy. Standard evaluation forms were used to assess the MRIs for superior labrum anterior and posterior (SLAP) lesions, anterior or posterior labrum lesions, lesions of the long head of biceps tendon (LHB) and for partial tears of the supraspinatus tendon and the upper quarter of the subscapularis tendon. Quality of the MRI was assessed by each radiologist on a four-point scale.

Results

The pooled sensitivity for the three radiologists for the detection of SLAP lesions was 45.0 %, for anterior or posterior labrum tears 77.8 and 66.7 %, for lesions of the LHB 63.2 % and for partial tears of the supraspinatus or subscapularis tendon tears 84.8 and 33.3 %. Corresponding inter-rater reliabilities were poor (SLAP lesions) to substantial (anterior labrum tears). Quality of MRI only influenced the accuracy for the detection of posterior labrum tears.

Conclusion

A non-contrast shoulder MRI obtained in the community setting after non-dislocating shoulder trauma has a moderate sensitivity for most intraarticular pathologies when interpreted by musculoskeletal radiologists. Accuracy is dependent on the observer and not on the assessed quality.

Level of evidence

Case series, Level IV.

     

Correlation of MRI with arthroscopy for the evaluation of the subscapularis tendon: a musculoskeletal division’s experience

Objective

To determine the accuracy of MR imaging for the evaluation of the subscapularis tendon as well as define imaging findings that will increase accuracy.

Materials and methods

Retrospective review of the MR and operative (OR) reports of 286 patients was conducted and reviewed for the presence/degree (partial (PT)/full-thickness (FT)) of tearing; only PT articular tears were included. The presence of a supraspinatus tear and time interval between surgery and MRI were also documented. All of the PT tears called on MRI were also reviewed to see if there was a statistically significant association between certain imaging characteristics and the presence of a tear in surgery. Statistical analysis included 95 % confidence intervals, Fisher’s exact, and exact Mann–Whitney tests.

Results

A total of 244 patients were included in the study with a total of 25 subscapularis tears, 16 PT and nine FT, and 219 intact tendons in arthroscopy; 20/25 tears and 200 intact tendons were diagnosed correctly on MRI, resulting in sensitivity of 80 %, specificity of 91 %, accuracy of 90 %, positive predictive value of 51 %, and negative predictive value of 98 %. There was a significant association between the presence of a PT tear during arthroscopy and fluid-like signal within the tendon on more than one imaging plane (p?<?0.001) with an accuracy of 90 %.

Conclusions

This study reflects a musculoskeletal radiology section’s experience with the diagnosis of subscapularis tendon pathology, demonstrating that MRI could be used to accurately evaluate the subscapularis tendon. An understanding of certain imaging pitfalls and the presence of fluid-like signal on multiple imaging planes should increase the diagnostic accuracy of the radiologist evaluating the subscapularis tendon for the presence of a tear.     

Intrinsic ligament and triangular fibrocartilage complex tears of the wrist: comparison of MDCT arthrography, conventional 3-T MRI, and MR arthrography

Purpose

This study compares the diagnostic performance of multidetector CT arthrography (CTA), conventional 3-T MR and MR arthrography (MRA) in detecting intrinsic ligament and triangular fibrocartilage complex (TFCC) tears of the wrist.

Materials and methods

Ten cadaveric wrists of five male subjects with an average age 49.6 years (range 26–59 years) were evaluated using CTA, conventional 3-T MR and MRA. We assessed the presence of scapholunate ligament (SLL), lunotriquetral ligament (LTL), and TFCC tears using a combination of conventional arthrography and arthroscopy as a gold standard. All images were evaluated in consensus by two musculoskeletal radiologists with sensitivity, specificity, and accuracy being calculated.

Results

Sensitivities/specificity/accuracy of CTA, conventional MRI, and MRA were 100 %/100 %/100 %, 66 %/86 %/80 %, 100 %/86 %/90 % for the detection of SLL tear, 100 %/80 %/90 %, 60 %/80 %/70 %, 100 %/80 %/90 % for the detection of LTL tear, and 100 %/100 %/100 %, 100 %/86 %/90 %, 100 %/100 %/100 % for the detection of TFCC tear. Overall CTA had the highest sensitivity, specificity, and accuracy among the three investigations while MRA performed better than conventional MR. CTA also had the highest sensitivity, specificity, and accuracy for identifying which component of the SLL and LTL was torn. Membranous tears of both SLL and LTL were better visualized than dorsal or volar tears on all three imaging modalities.

Conclusion

Both CT and MR arthrography have a very high degree of accuracy for diagnosing tears of the SLL, LTL, and TFCC with both being more accurate than conventional MR imaging.     

MR imaging of subscapularis tendon injury in the setting of anterior shoulder dislocation

Objective

To evaluate the degree and location patterns of subscapularis tendon injury in patients with prior anterior shoulder dislocation (ASD).

Material and methods

Forty-five consecutive MR shoulder examinations in patients with a history of ASD and 20 consecutive MR examinations in patients without prior dislocation were reviewed. Two readers assessed for the presence and location of tendinosis and tearing in the subscapularis tendon, which was divided into three segments: superior, middle, and inferior. The readers also documented the presence of anterior labral tears, osseous Bankart defects and Hill–Sachs lesions. Fisher’s exact tests were performed to analyze the different types of pathology and their locations.

Results

Subscapularis tendinosis, and partial thickness and full thickness tears were more common in patients with a history of ASD. Tendinosis was found in 60-64.4% of the dislocation patients compared with 40% of the non-dislocation group. When stratified by location, the middle and inferior thirds were the most commonly affected with statistical significance (p?p?Conclusion Our study suggests an association between middle and inferior subscapularis tendon pathology and prior anterior shoulder dislocation. Based on our results, careful MR assessment of the subscapularis tendon by the radiologist is indicated in the setting of ASD as injury of this structure can be symptomatic and may be amenable to treatment.     

Extra-articular contrast material leaks into locations unrelated to the injection path in shoulder MR arthrography

Objectives

To evaluate the localisation, frequency and amount of extravasation in patients with extra-articular contrast material leak into locations unrelated to the injection path in shoulder magnetic resonance (MR) arthrography and associated shoulder disorders.

Methods

The sites of extravasation were determined on the shoulder MR arthrography of 40 patients. The extravasations were measured on three vertical planes of the MR arthrography. Sufficient joint distension was assessed according to the transverse diameters of the axillary recess on coronal MR images.

Results

Extravasation of the contrast material occurred through the subscapular recess, the synovium of the biceps, and the axillary recess. In four cases, extravasations were observed in more than one anatomic location. The most common site of extravasation was along the subscapularis muscle. Superior labrum anterior-posterior (SLAP) lesions were found to be most frequently associated with extravasations. The amount of extravasation was significantly higher in patients with adhesive capsulitis compared with the patients with a different diagnosis (p?=?0.022).

Conclusions

The extravasations adjacent to the axillary recess do not always indicate glenohumeral ligament pathology. Massive subscapular extravasations were most frequently associated with adhesive capsulitis and SLAP lesions, and might be considered in the MR arthrography report.

Key Points

? Contrast material extravasation may reduce the diagnostic value of shoulder MR arthrography. ? The extravasations may occur into locations unrelated to the injection path. ? The extravasations adjacent to axillary recess can be misleading for HAGL lesion. ? Massive subscapular extravasations were frequently associated with adhesive capsulitis and SLAP lesions.