Contribution of full-thickness supraspinatus tendon tears to acquired subcoracoid impingement

AIM: To assess the relationship between the severity of full-thickness supraspinatus tendon tears and the development of subcoracoid impingement. MATERIALS AND METHODS: Fifty-one magnetic resonance imaging (MRI) shoulder examination reports with full-thickness supraspinatus tears were retrospectively identified and reviewed by two dedicated musculoskeletal radiologists. The appearances of the rotator cuff muscles, biceps tendon and the lesser tubercle were recorded. The acromio-humeral distance and the axial coraco-humeral distance were measured. The data were recorded and analysed electronically. RESULTS: The kappa values for inter-observer agreement were: 0.91 for acromio-humeral distance and 0.85 for coraco-humeral distance measurements. Twenty-six patients had significant retraction of the supraspinatus tendon, 85% (22 cases) of this group had imaging evidence of tear or tendonopathy of the subscapularis tendon. Twenty-five patients had no significant retraction of the supraspinatus, 56% (14 cases) of this group had imaging evidence of a subscapularis tear or tendonopathy. The acromio-humeral distance was significantly less in patients with supraspinatus tears and retraction (p<0.05). The subscapularis tendon was significantly more likely to be abnormal if the supraspinatus was retracted than if no retraction was present (p<0.05). There were no significant differences in coraco-humeral distances between the groups. CONCLUSION: Subscapularis tendon signal and structural changes are frequently associated with full-thickness supraspinatus tendon tears, particularly if the supraspinatus is significantly retracted. In this static MRI series, the data do not support the occurrence of classical subcoracoid impingement as an aetiology; however, they may support the possibility of a dynamic mechanism, to which future studies could be directed.     

Subscapularis tendon tear: primary and associated signs on MRI

PURPOSE: The purpose of this work was to investigate signs of subscapularis tendon tear on MRI. METHOD: Preoperative written interpretations of high field (n = 9) and low field (n = 7) MRI of 16 patients with tears confirmed at surgery or arthroscopy were reviewed, followed by retrospective review of these studies. RESULTS: A preoperative diagnosis of subscapularis tear was made in five (31%) cases. On retrospective review, primary signs of tear were present in 15 (94%) cases and in two-thirds were limited to the cranial third of the tendon. Supraspinatus tears were present in 69% of cases. Associated findings included medial dislocation (n = 4) or subluxation (n = 3) of biceps tendon, biceps tendinopathy (n = 2), superior labral tear (n = 5), and effusions of superior subscapularis recess (n = 6), subcoracoid bursa (n = 2), or both (n = 5). One or more associated signs were present in 94% of cases. CONCLUSION: Subscapularis tear is frequently missed on MRI. Recognizing that primary signs of tear may be limited to the cranial third of the subscapularis tendon and identifying associated signs should facilitate diagnosis.     

Full-thickness and partial-thickness supraspinatus tendon tears: value of US signs in diagnosis

PURPOSE: To determine which US signs are important in the diagnosis of a surgically identifiable supraspinatus tendon tear. MATERIALS AND METHODS: Fifty consecutive ultrasonographic (US) studies of the shoulder in patients who underwent arthroscopic follow-up were retrospectively reviewed by a musculoskeletal radiologist. US images of the supraspinatus tendon were evaluated for tendon nonvisualization, abnormal tendon echogenicity, tendon thinning, greater tuberosity cortical irregularity, cartilage interface sign, joint fluid, and subacromial-subdeltoid bursal fluid. US findings were compared with arthroscopic results. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for each US sign in the diagnosis of full-thickness tendon tear and again for any type of supraspinatus tendon tear. RESULTS: Arthroscopy revealed 21 full-thickness tears, five bursal surface partial-thickness tears, 10 articular surface partial-thickness tears, and 14 patients without tear of the supraspinatus tendon. The presence of greater tuberosity cortical irregularity and joint fluid was most important in the diagnosis of full-thickness supraspinatus tendon tear (sensitivity, 60%; specificity, 100%; positive predictive value, 100%; negative predictive value, 78%; accuracy, 84%). For diagnosis of any type of supraspinatus tendon tear (partial or full thickness), tendon nonvisualization, greater tuberosity cortical irregularity, and cartilage interface sign are most important, although a combination of signs did not improve accuracy. CONCLUSION: Secondary US signs, such as greater tuberosity cortical irregularity and joint fluid, are most valuable in the diagnosis of supraspinatus tendon tear.     

肩关节肱二头肌肌腱损伤的MRI表现

目的:探讨MRI对肩关节肱二头肌长头肌腱损伤的诊断价值。方法:收集2006年1月～2010年8月共12例肩关节肱二头肌长头肌腱损伤的病例资料,回顾性分析患者的肩关节MR扫描图像,所有病例均经肩关节手术证实。结果:①12例肱二头肌长头肌腱断裂,其中部分撕裂4例,表现为肱二头肌长头腱增粗,T2W上可见局部高信号影,肌腱连续性存在;完全撕裂8例,表现为横断面上,结节间沟内未见肱二头肌长头腱显示,斜冠状面可见撕裂肌腱近端或远端呈波浪状。肱二头肌长头肌腱半脱位1例,表现为横断面上,肱二头肌长头肌腱向内侧移位,位于肱骨小结节前方;脱位2例,表现为横断面示空置的结节间沟,肱二头肌长头腱向内侧移位、位于肩胛下肌腱前方;②肱二头肌长头腱损伤伴随腱鞘积液2例,表现为横断面上肌腱被液性高信号影所环绕;伴随肩关节腔内积液12例;③12例肱骨结节间沟宽度≥8mm;深度<3mm、结节间沟变浅3例;3例内壁角<30°;④合并肩袖损伤7例,其中冈上肌腱撕裂5例,冈下肌腱撕裂1例,肩胛下肌肌腱撕裂1例;合并喙肱韧带损伤11例。出现肩峰撞击综合征10例。结论:MRI能够准确的诊断肩关节肱二头肌长头肌腱损伤,从而有助于临床手术方案的制定。     

Isolated and combined tears of the subscapularis tendon

BACKGROUND: Isolated and combined subscapularis tendon tears are rare and are described in the literature only in small numbers. HYPOTHESIS: The outcome of surgical intervention for isolated and combined subscapularis tendon tears may be influenced by the tear pattern of the anterior rotator cuff and the period of time between trauma and surgical procedure. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 1994 and 1999, 34 shoulders with isolated traumatic tears (16 shoulders) or subscapularis tendon rupture combined with a supraspinatus tendon tear were treated operatively. The average patient age was 51 years, and the mean follow-up period was 37 months. For statistical analyses, the Friedman and Mann-Whitney tests were used. RESULTS: In patients with isolated tears, the Constant score rose from an average of 43.9 to 88.7 points (P < .01), and in patients with combined tears, it rose from an average of 40.6 to 74.7 points (P <.01). Isolated tears improved 14 points more than combined tears (P <.05). The delay between trauma and surgical intervention was inversely proportional to the improvement in the Constant score. The Spearman coefficient of correlation was -0.97 in isolated tears and -0.89 in combined tears. CONCLUSIONS: Young patients with isolated traumatic tears of the subscapularis tendon and immediate repair have the best prognostic factors for treatment. Accuracy in the trauma history and the clinical and radiographic examination is demanded.     

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.     

Subscapularis tendon tears: detection and grading at MR arthrography

PURPOSE: To assess diagnostic accuracy in the detection and grading of subscapularis tendon lesions at magnetic resonance (MR) arthrography. MATERIALS AND METHODS: MR arthrograms in 50 consecutive patients (29 with normal subscapularis tendons, 11 with a lesion in the cranial quarter, seven with a major tear but not complete detachment, three with complete detachment) with arthroscopic or surgical confirmation were evaluated independently by two radiologists. Diagnosis was established on findings from transverse and/or parasagittal images. RESULTS: With transverse images alone, sensitivity was 95%/100% (reader 1/reader 2); specificity was 55%/62%. With parasagittal images alone, sensitivity was 91%/91%; specificity was 76%/90%. With combined images, sensitivity was 91%/91%; specificity was 86%/79%. Interobserver agreement was substantial (kappa = 0.67). Forty-one of 50 (82%) grades for subscapularis abnormalities matched at MR imaging and surgery; nine mismatches differed by only one degree. Several signs were specific (90%-100%) but insensitive (29%-62%); these included leakage of contrast material onto the lesser tuberosity, fatty degeneration of the subscapularis muscle, and abnormality in the course of the long biceps tendon (luxation, subluxation). CONCLUSION: MR arthrography is accurate in the detection and grading of subscapularis tendon lesions. Specificity of findings on transverse images for this diagnosis can be improved by including indirect signs and findings on parasagittal images.     

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.     

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 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.     

MR assessment of the repaired rotator cuff: prevalence, size, location, and clinical relevance of tendon rerupture

The objectives of this study were to use magnetic resonance (MR) imaging to evaluate the prevalence, size, location, and clinical relevance of tendon rerupture following complete repair of full-thickness rotator cuff tear (RCT). A total of 78 surgically proven full-thickness rotator cuff tears in 74 patients were retrospectively included in the study. Clinical assessment was performed using the University of California at Los Angeles score. Postoperative MR imaging was evaluated to determine prevalence, size, and location of tendon rerupture. At a mean 48.4 months’ follow-up, 62 shoulders (79.5%) had favorable outcomes and 45 shoulders (57.6%) showed rerupture on MR imaging studies. Reruptures were significantly more prevalent among patients with intermediate-to-bad outcomes (81.3%), with surgically demonstrated two-tendon tears (78.9%) or three-tendon tears (100%), and with preoperative fatty degeneration of the supraspinatus muscle greater than 1 (91.6%). Reruptures were also significantly larger in those subgroups. Complete repair of RCT of all sizes may have favorable outcomes in a significant proportion of patients in spite of a high prevalence of reruptures. Preoperative tear size and degree of muscle fatty degeneration influence the prevalence and rerupture size. After repair of supraspinatus tears, reruptures tend to invade the posterior aspect of the tendon.     

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.     

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.     

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.     

Severe atrophy and fatty degeneration of the infraspinatus muscle due to isolated infraspinatus tendon tear

Atrophy of both the supraspinatus and infraspinatus muscles is usually caused by chronic rotator cuff tear, but may also derive from suprascapular nerve entrapment at the spinoglenoid notch. Isolated infraspinatus muscle atrophy is uncommon, and typically associates with suprascapular nerve entrapment occurring distal to the spinoglenoid notch. However, isolated atrophy of the infraspinatus muscle due to insertional tear of the infraspinatus tendon may also occur. We present a case of a 43-year-old male with isolated infraspinatus muscle atrophy and fatty degeneration following an isolated full-thickness infraspinatus tendon tear at the insertion site on the humerus. While it is important to rule out other causes of infraspinatus muscle atrophy, such as concomitant rotator cuff tendon/muscle pathology or suprascapular nerve palsy, we present this case to increase awareness of this uncommon clinical presentation and the potential implications for treatment.     

Ultrasonographic rotator-cuff changes in veteran tennis players: the effect of hand dominance and comparison with clinical findings

The aim of this study was to correlate sonographic abnormalities of the rotator cuff with clinical findings in veteran tennis players. One hundred fifty individuals playing competition-level tennis, aged from 35 to 77 years (mean age 55 years), underwent physical and US examinations of their shoulders. The US abnormalities found in the dominant shoulder were compared with those observed in the non-dominant shoulder and in different subsets of players defined by the absence or presence of former and/or current pain. Tears of the long head of the biceps tendon were seen only in dominant shoulders (n=8), and tears (23 complete and 20 partial) of the supraspinatus tendon were observed in 43 dominant vs 16 (3 complete and 13 partial) contralateral shoulders (p<0.001). Subscapularis tendon calcifications were depicted in 23 dominant vs 12 contralateral shoulders (p<0.05). Seventy players had no pain, 49 had former-but-not-current pain, and 31 had current pain. Abnormal thickening (>2 mm) and effusion of the subacromial–subdeltoid bursa and complete tear of the supraspinatus tendon were more frequent in the latter two groups (p<0.001 and p<0.05), respectively. Although 90% of the players with a complete supraspinatus tear had experienced former pain, no relationship was found between current pain and the presence of a supraspinatus tear or tendon calcification. The rotator cuff may present important asymptomatic lesions, such as complete tears of the supraspinatus tendon or calcifications, that do not prevent the playing competitive tennis. The only US abnormality associated with pain was subacromial–subdeltoid bursa effusion.     

Transosseous arthroscopic repair of partial articular-surface supraspinatus tendon tears

Partial articular-surface tendon avulsion (PASTA) lesions of the supraspinatus muscle represent a common cause for shoulder impairment and a preceding pathology for full-thickness tendon tears. Arthroscopic tendon repair is a possible surgical method of treatment. The purposes of cuff repair are anatomical tendon healing, prevention of tear size progression to completion and reduction of shoulder pain. In this report, we describe a transtendon arthroscopic technique of transosseous refixation of articular-side partial tears leaving the bursal layer of the supraspinatus tendon intact. A curved hollow needle is used to perform an all arthroscopic transosseous mattress suture. Thus, anatomical tendon-to-bone contact of the rotator cuff to the footprint is restored. Preliminary clinical results of 16 patients are convincing with significant pain relief and functional improvement.     

Arthroscopic management of calcific tendinitis of the subscapularis tendon

Calcific tendinitis is a common disorder of the rotator cuff. Conservative treatment is frequently successful. For the patients remaining symptomatic after conservative treatment, excision of the calcium deposits offers a generally reliable pain relief. While calcific tendinitis is seen commonly affecting the supraspinatus tendon, it has been rarely reported involving the subscapularis tendon. We report on the clinical features, radiographic findings, arthroscopic treatment and results of one patient who presented a calcific tendonitis involving the subscapularis tendon of the left shoulder unresponsive to conservative treatment and associated subcoracoid stenosis and coracoid impingement.     

Repair of tears of the subscapularis tendon

Tears of the subscapularis are much less common than tears of the supraspinatus and infraspinatus. Subscapularislesions are usually traumatic in etiology and occur in younger patients. These lesions can be complete or limited to the superior insertion of the subscapularis, and they may be isolated or occur with other rotator cuff lesions. In most instances, treatment of subscapularis tears is surgical. In this article, we present the clinical and radiographic findings, discuss operative indications, and illustrate our preferred surgical technique for tears of the subscapularis tendon.     

慢性冈上肌腱损伤肌肉萎缩及脂肪浸润的定量研究

目的应用mDIXON-Quant技术定量测量肌肉脂肪含量,研究慢性冈上肌脂肪浸润、肌肉萎缩及肌腱损伤程度(TTS)之间的关系。方法选取85例肩关节有临床症状者纳入本研究,对其进行MRI检查(包括mDIXON-Quant)。通过mDIXON-Quant获取脂肪分数(FF)图。用冈上肌的相对大小(RSS)作为冈上肌萎缩的指标。根据常规MRI显示的冈上肌TTS将其分为正常组、退变组、部分撕裂组和完全撕裂组。RSS多组间比较采用单因素方差分析,组间进一步两两比较采用Scheffe检验;FF多组间比较采用Welch近似F检验,组间进一步两两比较采用Dunnett’s T_3法。采用Spearman相关分析FF、RSS与TTS之间的相关性。结果各组间RSS及FF差异均有统计学意义(均P0.05)。完全撕裂组RSS明显低于正常组及退变组(均P0.05);FF完全撕裂组明显高于部分撕裂组、退变组和正常组,部分撕裂组高于退变组和正常组,退变组高于正常组(均P0.05)。RSS和TTS呈负相关(r_s=-0.384,P0.001)。FF和TTS呈正相关(r_s=0.808,P0.001)。FF和RSS呈负相关(r_s=-0.495,P0.001)。结论mDIXON-Quant可定量评价不同程度冈上肌腱损伤后脂肪浸润程度。