Diagnostic performance of MR arthrography after rotator cuff repair

OBJECTIVE: The objective of this study was to investigate the diagnostic performance of MR arthrography after rotator cuff repair. MATERIALS AND METHODS: MR arthrographic examinations of the shoulder performed after rotator cuff repair and before revision surgery were retrospectively analyzed in 48 patients (31 males, 17 females; mean age, 50.3 years; age range, 17-69 years). Full-thickness and partial-thickness defects of the supraspinatus, infraspinatus, and subscapularis tendons were diagnosed independently by two radiologists. Revision surgery served as the standard of reference. RESULTS: Observer 1 correctly recognized five of eight intact supraspinatus tendons, 10 of 19 partial-thickness defects, and 19 of 21 full-thickness defects. For observer 2, the numbers were three of eight, eight of 19, and 18 of 21. The corresponding numbers for the infraspinatus tendon for observer 1 were 28 of 31, 0 of three, and 14 of 14 tendons. For observer 2, they were 28 of 31, two of three, and 11 of 14. For the subscapularis tendon, observer 1 made the correct diagnosis in 18 of 31, five of six, and nine of 11 tendons. The results for observer 2 were 26 of 31, one of six, and 10 of 11 tendons. Interobserver agreement (weighted kappa) was 0.47 for the supraspinatus, 0.64 for the infraspinatus, and 0.20 for the subscapularis tendons, respectively. CONCLUSION: Postoperative full-thickness defects of the rotator cuff are reliably diagnosed with MR arthrography. The diagnostic performance for partial-thickness defects is only moderate.     

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.     

Comparisons of the Various Partial-Thickness Rotator Cuff Tears on MR Arthrography and Arthroscopic Correlation

Objective

To assess the diagnostic performance of MR arthrography in the diagnosis of the various types of partial-thickness rotator cuff tears by comparing the MR imaging findings with the arthroscopic findings.

Materials and Methods

The series of MR arthrography studies included 202 patients consisting of 100 patients with partial-thickness rotator cuff tears proved by arthroscopy and a control group of 102 patients with arthroscopically intact rotator cuffs, which were reviewed in random order. At arthroscopy, 54 articular-sided, 26 bursal-sided, 20 both articular- and bursal-sided partial-thickness tears were diagnosed. The MR arthrographies were analyzed by two radiologists for articular-sided tears, bursal-sided tears, and both articular- and bursal-sided tears of the rotator cuff. The sensitivity and specificity of each type of partial-thickness tears were determined. Kappa statistics was calculated to determine the inter- and intra-observer agreement of the diagnosis of partial-thickness rotator cuff tears.

Results

The sensitivity and specificity of the various types of rotator cuff tears were 85% and 90%, respectively for articular-sided tears, 62% and 95% for bursal-sided tears, as well as 45% and 99% for both articular- and bursal-sided tears. False-negative assessments were primarily observed in the diagnosis of bursal-sided tears. Conversely, both articular- and bursal-sided tears were overestimated as full-thickness tears. Inter-observer agreement was excellent for the diagnosis of articular-sided tears (k = 0.70), moderate (k = 0.59) for bursal-sided tears, and fair (k = 0.34) for both articular- and bursal-sided tears, respectively. Intra-observer agreement for the interpretation of articular- and bursal-sided tears was excellent and good, respectively, whereas intra-observer agreement for both articular- and bursal-sided tears was moderate.

Conclusion

MR arthrography is a useful diagnostic tool for partial-thickness rotator cuff tears, but has limitations in that it has low sensitivity in bursal- and both articular- and bursal-sided tears. In addition, it shows only fair inter-observer agreement when it comes to predicting both articular- and bursal-sided tears.     

Imaging of degenerative and posttraumatic disease in the shoulder joint with ultrasound

This article reviews the examination technique of shoulder ultrasound, normal and abnormal ultrasound findings in acute (posttraumatic) and chronic (degenerative) lesions. Moreover, it reviews the effectiveness of ultrasound in relation to magnetic resonance (MR) imaging. Most authors report that full-thickness tears of the supraspinatus can reliably be diagnosed by ultrasound. However, the simple diagnosis of a full-thickness rotator cuff tear is no longer sufficient for surgical management. The precise localization and size of rotator cuff tears as well as the extent of muscle degeneration is important for surgical planning. For this aspect and for partial-thickness tears of the supraspinatus, for subscapularis lesions as well as for lesions of the long biceps tendons there is no consensus regarding the diagnostic value of ultrasound. To the present, ultrasound (contrary to MR imaging) has failed to demonstrate that it consistently influences the clinician's degree of confidence in the clinical diagnosis or the treatment plan. Therefore, some orthopedic surgeons prefer MR imaging to ultrasound in the evaluation of rotator cuff tears and other abnormalities of the glenohumeral joint. Moreover, MR imaging, especially when combined with arthrography, represents a one-step investigation, which not only allows for assessment of rotator cuff lesion but also of lesions of the labrum (Bankart lesions, SLAP lesions), the joint capsule and the biceps tendon. It also demonstrates muscle atrophy, which represents an important predictor of surgical outcome in rotator cuff repair.     

Full-thickness tears of the rotator cuff of the shoulder: diagnosis with MR imaging.

The purpose of this study was to describe MR findings in full-thickness tears of the rotator cuff. Of 102 shoulders examined by MR imaging, 31 were found to have a full-thickness tendon tear at arthroscopy/bursoscopy (five shoulders) or open surgery (26 shoulders). All shoulders were imaged in oblique coronal and axial planes. MR images of the 102 shoulders were evaluated for (1) the presence of fluid in the subacromial and subdeltoid bursae; (2) abnormal signal of the supraspinatus, subscapularis, infraspinatus, and teres minor tendons; (3) interruption of tendon continuity and thinning of the tendon; and (4) proximal retraction of the junction of the muscle and tendon. The presence or absence of each finding was determined by consensus of two radiologists, who interpreted the images without knowledge of the surgical findings. Results in those 31 shoulders with proved full-thickness tears were: fluid in the subacromial bursae (29 shoulders), interruption of tendinous continuity (22 shoulders), focally increased signal of the tendon equivalent to that of water (27 shoulders), and musculotendinous retraction (24 shoulders). The finding of subacromial fluid was a sensitive indicator (93%) of a full-thickness tear, and interruption of tendinous continuity was a specific finding (96%) in diagnosing a full-thickness tear. Our experience shows interruption of tendon continuity is the most specific MR finding of full-thickness rotator cuff tears, while subacromial fluid is the most common finding.     

Evaluation of Rotator Cuff Tendon Tears: Comparison of Multidetector CT Arthrography and 1.5-T MR Arthrography

Purpose: To compare the diagnostic performance of multidetector computed tomographic (CT) arthrography and 1.5-T magnetic resonance (MR) arthrography in the evaluation of rotator cuff lesions, with arthroscopic correlation. Materials and Methods: This study was approved by the institutional ethical committee, and informed consent was obtained from all patients. CT and MR arthrographic images prospectively obtained in 56 consecutive patients, following the same arthrographic procedure, were independently evaluated by two radiologists. Arthroscopy, performed within 1 month of the imaging, was used as the reference standard. Sensitivity and specificity of CT and MR arthrography were compared by using the McNemar test. Interobserver and intertechnique agreement for detecting rotator cuff lesions were measured and compared with κ and Z statistics. The Bland-Altman method was used to determine interobserver and intertechnique agreement for measuring tendon tears. For grading fatty infiltration of rotator cuff muscles, κ and Z statistics were used. Results: There was no statistically significant difference in sensitivity and specificity between CT arthrography and MR arthrography in depiction of rotator cuff lesions. The respective sensitivity and specificity of CT arthrography were 92% and 93%-97% for the supraspinatus, 100% and 77%-79% for the infraspinatus, 75%-88% and 85%-90% for the subscapularis, and 55%-65% and 100% for the biceps tendon. The respective sensitivity and specificity of MR arthrography were 96% and 83%-93% for the supraspinatus, 88%-100% and 81%-83% for the infraspinatus, 75%-88% and 90%-100% for the subscapularis, and 65%-85% and 100% for the biceps tendon. Interobserver agreement was substantial to almost perfect (κ = 0.744-0.964 for CT arthrography; κ = 0.641-0.893 for MR arthrography), and intertechnique agreement was almost perfect (κ > 0.819). CT and MR arthrography both yielded moderate interobserver and intertechnique agreement for measuring rotator cuff tears and grading muscle fatty infiltration. Conclusion: Data suggest that CT and MR arthrography have similar diagnostic performance for the evaluation of rotator cuff tendon tears. ? RSNA, 2012.     

MR evaluation of subscapularis tears.

PURPOSE: The purpose of this work was to describe the MR appearance of tears of the subscapularis tendon and compare the usefulness of different imaging planes as well as note the association of subscapularis tears with other rotator cuff tears and biceps tendon dislocations. METHOD: MR studies at 1.5 T over an 8 year interval were retrospectively assessed for the presence of a rotator cuff tear and/or tear of the subscapularis tendon. Images that showed a subscapularis tear were reviewed for the presence of a visible tear separately on the axial, coronal, and sagittal images. The MR studies were also evaluated for associated tears of the supraspinatus, infraspinatus, and teres minor muscles as well as biceps tendon dislocation and the "naked humerus sign" on coronal images. Last, clinical records and surgical reports were reviewed. RESULTS: Forty-five (2%) of 2,167 rotator cuff tears involved the subscapularis; 27% were partial and 73% were complete tears. Tears were best seen in the sagittal oblique plane. Almost all subscapularis tears were an extension of typical rotator cuff tears: supraspinatus in 35 patients (79%), extending into infraspinatus tears in 25 (56%) and into teres minor tears in 2 patients (4%). Bicipital dislocations were seen in 22 patients (49%), and three complete tears of the biceps (7%) were noted as well. The naked humerus sign was demonstrated in 31 patients (69%). Surgical reports that confirmed the MR findings were available for 15 patients. CONCLUSION: About 2% of rotator cuff tears involve the subscapularis tendon. Most subscapularis tears are extensions of supraspinatus tears and frequently involve the biceps tendon.     

Diagnosis of tears in rotator-cuff-injuries

Pathology of the rotator cuff is the cause of most common problems at the shoulder joint. Acute injuries are not as frequent as chronic cuff disease, but often they aggravate inflammatory or degenerative tendon alterations, even if they are of minor severity. Traumatic rotator cuff tears predominantly affect the supraspinatus tendon or the rotator interval. The subscapularis tendon is involved in anterior dislocations of the glenohumeral joint or in direct trauma. Plain film radiography still remains the base of all further imaging studies. If only full-thickness tears must be ruled out, double-contrast arthrography and ultrasound are acceptable imaging modalities. However, the former has a drawback in being invasive and does not detect partial tears at the bursal site of the cuff or rotator cuff tendinopathy, whereas the latter heavily depends on the experience of the radiologist and is restricted to the rotator cuff. Nowadays the most comprehensive imaging method is magnetic resonance (MR) imaging. MR imaging enables the detection or exclusion of complete rotator cuff tears with a reasonable accuracy and is also suitable to diagnose further pathologies of the shoulder joint. MR arthrography is valuable in the detection of subtle anatomic details and further improves the differentiation of rotator cuff diseases. Although in comparison MR imaging is still the most expensive imaging method, its high negative predictive value for the diagnosis of complete rotator cuff tears and its reliability evaluating different shoulder joint pathologies make it the preferred imaging modality.     

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.     

Clinical impact of MR arthrography of the shoulder.

PURPOSE: To evaluate the effect of MR arthrography of the shoulder on diagnostic thinking and therapeutic decisions by orthopedic shoulder surgeons. MATERIAL AND METHODS: Orthopedic surgeons completed a questionnaire before and after MR arthrography for 73 consecutive patients. The main indications were suspected rotator cuff abnormalities. The clinical diagnosis, the degree of confidence in this diagnosis, and the therapeutic decision were noted before and after MR imaging. Surgical reports were available for 34 patients. RESULTS: Thirty-four percent of the pre-MR imaging diagnoses were withdrawn after MR imaging, and new diagnoses were made after MR imaging in 13% of the cases. Confidence in the diagnosis increased significantly after MR imaging for supraspinatus and infraspinatus lesions (p<0.05). Changes of therapeutic decision after MR imaging were noted in 36 of the 73 patients (49%). In 23 patients, more invasive therapeutic procedures were initiated after MR imaging, and a more conservative treatment was implemented for 13 patients. Agreement of MR diagnoses with surgery was 94% for supraspinatus tears, 87% for infraspinatus tears, 77% for subscapularis tears, and 81% for biceps tendon lesions. Agreement of clinical diagnoses with surgery was 56%, 83%, 50%, and 64%, respectively. CONCLUSION: MR arthrography of the shoulder has a major effect on diagnostic thinking and therapeutic decisions by orthopedic shoulder surgeons.     

肩袖损伤的MRI诊断比较研究

目的:比较常规MRI和MRI间接关节造影检查对肩袖撕裂伤的诊断价值.方法:搜集2002年11月～2006年8月共40例肩袖损伤病例,20例行常规MRI检查,20例行MRI间接关节造影检查.以肩关节镜作为诊断标准,比较两种影像学方法诊断肩袖损伤的敏感性和特异性.结果:肩袖完全撕裂中,常规MRI检查的敏感度为45.5%,特异度为66.7%,准确度为55%;MRI间接关节造影的敏感度为92.3%,特异度为85.7%,准确度为90%.肩袖不全撕裂中,常规MRI检查敏感度为57.1%,特异度为53.8%,准确度为55%;而间接关节造影敏感度为83.3%,特异度为92.8%,准确度则为90%.经Fisher确切概率统计法统计,MRI间接关节造影诊断肩袖全层撕裂敏感性及准确性明显高于常规MRI(P＜0.05),在诊断肩袖部分撕裂时,MRI间接关节造影的特异性及准确性明显高于MRI(P＜0.05).结论:MRI间接关节造影较常规MRI诊断肩袖撕裂准确性较高.同时对盂唇等其它病变诊断有帮助.     

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.     

Association of biceps tendon tears with rotator cuff abnormalities: degree of correlation with tears of the anterior and superior portions of the rotator cuff

OBJECTIVE: This study was performed to examine the relationship and association of abnormalities seen in the long head of the biceps brachii tendon to abnormal findings in the rotator cuff. MATERIALS AND METHODS: One hundred eleven patients underwent MR imaging for shoulder pain followed by arthroscopic or open shoulder surgery from January 1997 to December 2000. Patients were identified by a retrospective search, and all consecutive patients having undergone both MR imaging and surgery were included in the patient cohort. Official MR imaging interpretations were compared with operative reports, and all findings were recorded. RESULTS: Twenty-three patients were identified with partial- or full-thickness tears of the long head of the biceps tendon. The sensitivity, specificity, and accuracy of unenhanced MR imaging of the shoulder for detecting these bicipital tears were 52%, 86%, and 79%, respectively. When a tear was present in the biceps tendon, the prevalence of supraspinatous, infraspinatus, and subscapularis tendon tears was 96.2%, 34.6%, and 47.1%, respectively. Patients with biceps tendon tears were significantly more likely to also have subscapularis tendon tears (p < 0.0001) and supraspinatous tendon tears (p < 0.008) than those patients who did not have biceps tendon tears. No significant relationship was found between the presence or absence of a biceps tendon tear and the presence or absence of a infraspinatus or teres minor tendon tear (p = 0.17). CONCLUSION: Tears of the long head of the biceps tendon have a statistically significant association with tears of the anterior and superior rotator cuff and are highly correlated with tears of the supraspinatous and subscapularis tendons. When tears of these tendons are detected, specific attention directed toward the long biceps tendon is warranted to characterize the status of this structure that provides additional stability to the shoulder joint.     

MR versus MR arthrography in detection of supraspinatus tendon tears in patients without previous shoulder surgery

Purpose

We report the prevalence of supraspinatus tendon tears seen on MR arthrography that are not seen on conventional MR exam in the same patient population.

Materials and methods

A total of 150 consecutive conventional shoulder MR and MR arthrography exams performed on the same patients who went on to arthroscopy were reviewed retrospectively by consensus reading of two musculoskeletal radiologists. Full-thickness supraspinatus tendon tears were assessed. None of the patients had previous shoulder surgery.

Results

There were 113 full-thickness supraspinatus tendon tears seen on conventional MR exam while there were 119 full-thickness supraspinatus tendon tears seen on MR arthrography. The six additional full-thickness supraspinatus tendon tears seen on MR arthrography but not seen on conventional MR exam were confirmed at arthroscopy.

Conclusions

Some full-thickness supraspinatus tendon tears are not seen on conventional MR exam but are seen on MR arthrography. This is most likely due to fibrosis at the supraspinatus tendon tear site simulating an intact tendon on conventional MR.     

Imaging findings in the dominant shoulder of throwing athletes: comparison of radiography, arthrography, CT arthrography, and MR arthrography with arthroscopic correlation

OBJECTIVE: Conventional radiography, arthrography, CT arthrography, and MR arthrography--including use of the abduction and external rotation position--were compared, with arthroscopic correlation, to determine the spectrum of abnormalities encountered and the relative benefits of each imaging method in the evaluation of shoulder lesions occurring in 17 throwing athletes. SUBJECTS AND METHODS: Each of 36 athletes with shoulder pain aggravated by abduction and external rotation was examined in a single visit during which conventional radiography, arthrography, CT arthrography, and MR arthrography were performed. In 17 of these athletes, imaging findings were compared with those at arthroscopy. All images were independently evaluated by two groups of musculoskeletal radiologists. RESULTS: Structures found to be affected were, in decreasing order of frequency, the following: the posterosuperior labrum, supraspinatus tendon, infraspinatus tendon, humeral head, glenoid cavity and rim, acromioclavicular joint, anteroinferior capsulolabral complex, biceps tendon, and subscapularis tendon. MR arthrography without and with abduction and external rotation yielded the highest sensitivity and specificity for all lesions with the exceptions of bone sclerosis and enthesophytes (which were best seen with CT arthrography). MR arthrography with abduction and external rotation was most accurate for diagnosis of rotator cuff and anteroinferior capsulolabral complex tears. CONCLUSION: On the basis of these preliminary results, we believe that MR arthrography with abduction and external rotation should be part of the imaging evaluation of shoulder pain in throwing athletes, owing to the high sensitivity of this imaging technique.     

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.     

Findings of the subcoracoid bursa on MR arthrography and their clinical significance

We studied visualization of the subcoracoid bursa by conducting a retrospective analysis of the MR arthrograms of 101 shoulders with surgical confirmation. MR arthrography showed the subcoracoid bursa in 28 shoulders, among which the bursa was revealed by inadvertent direct injection of contrast material into the bursa in 10 shoulders. Of the remaining 18 shoulders, 16 shoulders had rotator cuff tears, one had shoulder instability, and one had dislocation of the long head of the biceps tendon. Both the subcoracoid and subscapularis bursae are located in the subcoracoid space. The subcoracoid bursa does not communicate with the subscapularis bursa, but occasionally communicates with the subacromial-subdeltoid bursa. On MR arthrography, contrast material in the subcoracoid bursa indicates a pathologic condition such as rotator cuff tear. Careful examination of the subcoracoid bursa on MR arthrography helps to achieve better assessment of the rotator cuff.     

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 arthrography in calcific tendinitis of the shoulder: diagnostic performance and pitfalls

The purpose was to assess the diagnostic performance of MR arthrography to diagnose calcific tendinitis of the shoulder and to assess the reasons for diagnostic errors. Standard MR arthrograms of 22 patients with calcific tendinitis and 61 controls were retrospectively analyzed by two independent and blinded radiologists. All cases were consecutively collected from a database. Conventional radiographs were available in all cases serving as gold standard. The supraspinatus was involved in 16, the infraspinatus in four and the subscapularis in two patients. All diagnostic errors were analyzed by two additional readers. Reader 1 correctly detected 12 of the 22 shoulders with and 42 of the 61 shoulders without calcific tendinitis (sensitivity 0.55, specificity 0.66). The corresponding values for reader 2 were 13 of 22 and 40 of 61 cases (sensitivity 0.59, specificity 0.69). Inter-rater agreement (kappa-value) was 0.42. Small size of the calcific deposits and isointensity compared to the surrounding tissue were the most important reasons for false negative results. Normal hypointense areas within the supraspinatus tendon substance and attachment were the main reason for false positive results. In conclusion, MR arthrography is insufficient in the diagnosis of calcific tendinitis. Normal hypointense parts of the rotator cuff may mimic calcific deposits and calcifications may not be detected when they are isointense compared to the rotator cuff. Therefore, MR imaging should not be interpreted without corresponding radiographs.     

MR imaging of the shoulder: diagnosis of rotator cuff tears

Twenty-five patients with known or suspected tears of the rotator cuff in 26 shoulders underwent MR imaging. All patients also underwent arthrography or surgery. MR visualized abnormalities consistent with a tear in 20 of the 22 tears diagnosed by arthrography or surgery. In most cases, tears were seen as regions of increased signal intensity within the cuff on long-TR pulse sequences, although two cases simply showed an almost complete absence of normal cuff. The MR appearance of the two cases with partial tears was similar to that of full-thickness tears. Of the four cases with normal arthrograms, one case had MR findings consistent with a tear. We conclude that MR has good potential for the noninvasive diagnosis of rotator cuff tears. Its ultimate role in this diagnosis must await prospective studies comparing its accuracy with that of sonography, CT, and arthrography.