肩关节损伤的MR影像诊断

目的 探讨常规MRI和MR间接关节造影对肩关节损伤的诊断价值.方法 回顾分析经关节镜证实的90例肩关节损伤患者肩关节常规MRI和MR问接关节造影表现,其中肩袖病变组57例、盂肱关节不稳组33例.对常规MRI和MR间接关节造影诊断结果进行Fisher确切概率法比较.结果 (1)肩袖病变组中MR间接关节造影37例,显示部分撕裂10例,1例漏诊;显示完全撕裂17例,2例误诊,7例肩袖无撕裂.MR间接关节造影显示部分撕裂的敏感度、特异度、准确度分别为90.9%(10/11)、92.3%(24/26)、91.9%(34/37);显示完全撕裂的敏感度、特异度、准确度分别为89.5%(17/19)、94.4%(17/18)、91.9%(34/37).MR间接关节造影诊断肩袖部分及完全撕裂的敏感度及准确度均高于常规MRI(P<0.05).(2)盂肱关节不稳组中,盂唇损伤26例,Hill-sachs病变27例、反Hill-sachs病变2例、骨陛Bankart损伤7例、关节囊损伤18例.间接关节造影20例,显示盂唇损伤14例,1例漏诊,5例正常.MR间接关节造影显示盂唇损伤的敏感度、特异度、准确度分别为93.3%(14/15)、100.0%(5/5)、95.0%(19/20).前者诊断盂唇损伤的敏感度及准确度明显高于常规MRI(P<0.05).结论 MR检查特别是MR间接关节造影能够准确显示肩关节常见病变及相关组织的病理发展过程,为临床诊断及治疗提供影像学依据.     

Shoulder instability: accuracy of MR imaging performed after surgery in depicting recurrent injury--initial findings.

PURPOSE: To analyze a series of postoperative magnetic resonance (MR) images obtained in patients with recurrent signs or symptoms of instability in whom subsequent surgical correlation was performed to determine the accuracy in diagnosing recurrent injury. MATERIALS AND METHODS: The authors identified 24 patients who underwent MR imaging after shoulder instability surgery and had recurrent instability requiring repeat surgery. Twelve nonenhanced MR images and six indirect and six direct MR arthrograms were retrospectively reviewed with consensus to determine the presence or absence of recurrent labral or rotator cuff tear. Operative reports were reviewed to confirm the presence or absence of labral or rotator cuff tear. The mean interval between initial surgery and MR imaging was 10 months. The mean interval until repeat surgery was 2 months. RESULTS: Overall, the accuracy of postoperative MR imaging was 79% in depicting recurrent labral tear and 88% in depicting recurrent rotator cuff tear. Indirect MR arthrography had 100% accuracy for recurrent labral tear detection, whereas direct MR arthrography and nonenhanced MR imaging had accuracies of 67% and 75%, respectively. Direct MR arthrography was more sensitive, 100% versus 71%, but less specific, 60% versus 80%, than nonenhanced MR imaging in depicting recurrent labral tears. Direct MR arthrography had 100% accuracy in depicting rotator cuff tear, whereas both indirect MR arthrography and nonenhanced MR imaging had 83% accuracy. CONCLUSION: MR imaging, indirect MR arthrography in particular, appears to be an accurate means of evaluating the shoulder following instability surgery.     

肩关节造影和MRI诊断肩袖损伤

目的评定肩关节造影、MRI诊断肩袖损伤的价值.材料和方法将33例临床诊断肩袖损伤患者的术前关节造影和MRI检查结果与术中观察结果的比较.另有13例复发性肩关节不稳、无肩袖损伤症状和体征的年轻患者术前的关节造影和MRI结果以及术中观察结果作为正常肩袖对照.结果在诊断肩袖完全断裂中,肩关节造影的敏感性为91%,特异性为100%;MRI的敏感性为95%,特异性为88%.结论关节造影诊断肩袖完全撕裂方法简单、迅速且费用低,易于广泛开展.但不能直接显示病变部位.MRI不但能够准确显示断裂的部位,反映肩袖病变的病理过程,而且能同时显示相邻组织的病理改变,更利于诊断和鉴别诊断.     

肩袖撕裂的肩关节MR造影评价

目的 评价肩关节MR造影对肩袖撕裂的诊断价值。方法 分析32例病人的肩关节MR造影图像,评价内容包括肩袖肌腱、盂唇、肱二头肌长头腱,结果与肩关节镜及肩部开放手术比较。结果 以肩关节镜和手术结果为标准,32例病人包括14例全层撕裂,6例下表面部分撕裂,12例无撕裂。肩关节MR造影判定有无肩袖撕裂的敏感性、特异性和准确性都为100％;诊断全层撕裂的敏感性、特异性和准确性分别为100％、94％和97％。同时,肩关节MR造影还正确诊断了所有的多肌腱撕裂、合并的盂唇异常及肱二头肌长头腱异常。结论 肩关节MR造影可以准确、全面地评价肩袖撕裂。     

MR shoulder arthrography in patients younger than 40 years of age: frequency of rotator cuff tear versus labroligamentous pathology

The purpose of this study was to compare the frequency of rotator cuff pathology versus labroligamentous pathology in patients younger than 40 years and to determine whether routine MR arthrography is justified in all patients in this age group, regardless of the clinical symptoms. The MR arthrography was carried out on 332 patients 40 years of age and younger. Two hundred and forty-three patients had clinical history of instability and possible labroligamentous pathology. Eighty-nine patients had no history or physical signs of instability and were referred for reasons other than instability, such as assessment for rotator cuff tear. In the 243 patients younger than 40 years with clinical history of potential labral pathology, 39% (95/243) showed a labral tear and 2.1% (5/243) had a full-thickness rotator cuff tendon tear. In the 89 patients with no history suggesting labral pathology, 19% (17/89) showed an unsuspected labral tear and 4.5% (4/89) had a full-thickness rotator cuff tear. These findings suggest that, regardless of the clinical indication for referral, patients aged 40 and less referred for shoulder MRI should be imaged using MR arthrography because of the significant risk that symptoms are related to unsuspected labral pathology.     

Ultrasonics of the shoulder. Diagnostic possibilities in lesions of the rotator cuff

Twenty five healthy people and 25 patients with shoulder pain underwent US control over a 12-month period: 24 patients with shoulder pain had rotator cuff and/or biceps tendon lesions. The US findings on rotator cuff and biceps tendon lesions are compared with those of arthrography and/or surgery (96% sensitivity). US is rapid, safe, non invasive, inexpensive and often more accurate, and its use is recommended for the routine examination of the shoulder joint instead of arthrography.     

Capsulo-labro-ligamentous lesions of the shoulder: evaluation with MR arthrography

PURPOSE: The aim of the study was to analyse the accuracy of MR arthrography in the evaluation of capsulo-labro-ligamentous lesions of the shoulder in patients with glenohumeral joint instability. MATERIALS AND METHODS: From 1999 to 2001 fifty-eight patients with glenohumeral joint instability were studied by MR arthrography. Twenty-seven patients underwent surgical repair: 11 by arthroscopic and 16 by arthrotomic approach. All shoulder evaluations were performed with T1 and T2 weighted axial, coronal and sagittal oblique images, before and after intra-articular injection of gadolinium contrast. RESULTS: Forty capsulo-ligamentous lesions (including 14 capsular ruptures with extravasation of the contrast medium) were detected by MR arthrography. Fifty-two labral tears (36 of the anterior, 13 of the superior and 3 of the posterior glenoid labrum) were identified: 11 out of 52 were not recognized before gadolinium contrast injection. Five rotator cuff tears were identified, one of which was not shown in the pre-injection examination. Surgical results confirmed the MR arthrographic findings in 25/27 patients. In one case MR arthrography did not recognize a SLAP lesion; in another case it identified a tear of the capsule but not of the glenoid labrum. CONCLUSIONS: In many cases of subacute glenohumeral joint lesions with intracapsular fluid, MR may accurately evaluate capsulo-labral-ligamentous lesions. Indeed, the examination of lesions is limited by the absence of the natural contrast determined by fluid; in such cases, intra-articular injection of gadolinium contrast is necessary. MR arthrography evaluates the degree of capsulo-labro-ligamentous tears and may guide the surgical approach.     

常规MRI及MRI肩关节造影在肩袖撕裂中的应用

目的:探讨常规MRI及MRI肩关节造影在肩袖撕裂诊断中的价值。方法:226例肩关节损伤的患者,分别行常规MRI及MRI肩关节造影检查,以近期肩关节镜检查为金标准,对比2种检查方法的敏感性及特异性。结果:常规MRI对肩袖撕裂诊断的敏感性为70.8%(17/24),特异性100%(2/2),准确性65.4%(17/26);MRI肩关节造影对肩袖撕裂的敏感性为95.8%(23/24),特异性100%(2/2),准确性88.5%(23/26)。两者的诊断敏感性差异有统计学意义(P=0.016)。结论:MRI肩关节造影可以显著提高肩袖撕裂诊断的敏感性。     

MRI和MR关节造影在肩部损伤中的诊断价值

目的 :探讨MRI(核磁共振成像 )和MR关节造影在肩部损伤中的诊断价值。方法 :自 1999年 3月至 1999年11月 ,共有 73个患者 75例肩关节接受了肩部MRI检查 ,其中 16例经关节镜或手术证实。对手术中所见与核磁共振表现进行比较。结果 :对肩袖完全撕裂 ,MRI和MR关节造影对全层撕裂诊断阳性率分别为 90 .6 %和 10 0 % ,特异性分别为 96 %和 97.6 %。MRI对肩袖部分撕裂诊断正确率低 ,可靠性差 ;MR关节造影诊断正确率达 80 % ,是肩袖部分撕裂诊断的可靠方法。MRI对急性Bankart损伤诊断阳性率 10 0 % ,对慢性或陈旧损伤 ,阳性率低 ,只有 33.3% ;而MR关节造影对慢性或陈旧损伤诊断阳性率达 10 0 %。对SLAP损伤 ,MR关节造影较MRI诊断阳性率高 ,但目前关节镜仍是SLAP损伤更可靠的定性诊断手段。     

US of the shoulder: non-rotator cuff disorders.

The most common indication for shoulder ultrasonography (US) is the diagnosis of rotator cuff disease. However, there is a spectrum of non-rotator cuff abnormalities that are amenable to US examination, including instability of the biceps tendon, glenohumeral joint, and acromioclavicular joint; arthropathies and bursites (inflammatory diseases, degenerative and infiltrative disorders, infections); nerve entrapment syndromes; and space-occupying lesions. Many of these conditions may be overlooked clinically or can even mimic rotator cuff tears, and US can help redirect the diagnosis if a complete shoulder examination rather than a simple rotator cuff assessment is performed. In addition, US can be remarkably helpful in guiding either needle aspiration procedures or local injection therapy in patients with synovial processes. Although radiography, magnetic resonance (MR) imaging, and computed tomographic and MR arthrography are effective modalities for the evaluation of non-rotator cuff disorders, US is both less costly and less invasive and will likely be used more frequently in this setting as experience increases. Once adequate radiographs have been obtained to exclude apparent bone disorders, high-resolution US should be the first-line imaging modality in the assessment of non-rotator cuff disorders of the shoulder, assuming the study is performed with high-end equipment by an experienced examiner.     

MR arthrography of the shoulder: comparison with conventional MR imaging

Twenty-three patients underwent both conventional MR imaging of the shoulder and MR shoulder arthrography for clinically suspected labral or rotator cuff abnormalities. Images obtained before and after contrast administration were studied independently, and without knowledge of clinical findings, by two radiologists for the presence of abnormalities of the glenoid labrum or rotator cuff. Results were correlated with surgical findings in all patients. Nine patients had surgically proved labral tears. MR arthrography detected all nine labral abnormalities, while six of the nine were missed on conventional MR imaging. Fourteen patients had surgically proved rotator cuff tears. MR arthrography detected 11 of the 14 tears and missed three partial tears on the bursal surface. Conventional MR imaging detected nine cuff tears and missed five tears; two of these were complete rotator cuff tears and three were partial tears of the undersurface of the rotator cuff. Our results suggest that MR arthrography enhances the accuracy of MR in the evaluation of the glenoid labrum and rotator cuff tendon.     

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

The aim of this study was to compare the diagnostic reliability of US with MR arthrography in diagnosing supraspinatus tendon tears. Surgical findings were used as the gold standard in detecting tears. A total of 44 patients were assessed with transverse and longitudinal US scans with respect to the long axis of the rotator cuff tendons and then examined with MR arthrography. This technique involved free-hand injection of contrast medium into the shoulder joint. At surgery 20 incomplete and 24 complete tears were observed. Ultrasound offered good results for the large tears, but its sensitivity decreased proportionally with the size of the tears. Magnetic resonance arthrography correctly diagnosed 43 tears, whereas only one false-negative diagnosis of tendinosis was made for a partial tear on the bursal side. Since it improves the diagnosis of small tears, MR arthrography must be performed on all patients for whom surgical repair is necessary in order to restore normal functions.     

Shoulder impingement syndrome: MR findings in 53 shoulders

The shoulder impingement syndrome refers to a condition in which the supraspinatus tendon and subacromial bursa are chronically entrapped between the humeral head inferiorly and either the anterior acromion itself, spurs of the anterior acromion or acromioclavicular joint, or the coracoacromial ligament superiorly. As a result, the space for the bursa and tendon is reduced, and repeated trauma to these structures leads to bursitis and rotator cuff injury. Although pain and limitation of motion are common early findings, the diagnosis is often delayed until a complete tear of the rotator cuff has occurred. In an attempt to determine if MR can be used to depict the abnormalities associated with impingement syndrome (subacromial bursitis, supraspinatus tendinitis, and rotator cuff tear), we reviewed 107 MR scans of painful shoulders. Changes consistent with impingement syndrome were found in 53 patients (50%), 32 of whom underwent subsequent arthrography or surgery. MR was found capable of depicting several soft-tissue and bony abnormalities that have been clinically described in impingement syndrome. In regions of inflammation, we found that the supraspinatus tendon and/or the subacromial bursa were compressed by spurs (25 shoulders), capsular hypertrophy of the acromioclavicular joint (six shoulders), and/or low-lying acromion (14 shoulders). While T1-weighted MR imaging was highly sensitive to abnormalities of the supraspinatus tendon, tendinitis could be differentiated from a small tear of the supraspinatus tendon only with T2-weighted imaging. Large, full-thickness tears, especially if chronic, produced characteristic MR findings on both T1- and T2-weighted images. We conclude that MR can be used to detect several abnormalities associated with the shoulder impingement syndrome.     

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 imaging diagnosis of rotator cuff tears

Thirty-one symptomatic patients were studied with MR imaging to evaluate the sensitivity and specificity of shoulder MR in the diagnosis of rotator cuff tears. Correlative studies included arthroscopy in 19 patients and arthrography in 12 patients. Images were obtained on either a 0.5- or 1.5-T Philips superconducting magnet using spin-echo pulse sequences (650-850/30 [TR, TE], 2000/30, 100) with 5-mm slices oriented in an oblique coronal plane perpendicular to the glenohumeral joint. The MR studies were initially interpreted without knowledge of the results of other diagnostic procedures. The MR diagnosis of cuff tear was made when irregularity, discontinuity, and increased signal were identified in the rotator cuff. MR images showed tears in 10 patients (32%) and were negative for tear in 21 patients (68%). MR correlated with arthroscopy and arthrography in 17 of 18 normal patients, in eight of 10 patients with complete tears, and in one of three patients with partial tears. For complete rotator cuff tears, the sensitivity, specificity, and accuracy were 80%, 94%, and 89%, respectively. For all tears (partial and complete), the sensitivity, specificity, and accuracy were 69%, 94%, and 84%, respectively. These data suggest that MR imaging is an accurate procedure for the diagnosis of complete rotator cuff tears. The number of partial tears (three) in this series is too small to evaluate the value of MR imaging in the diagnosis of partial tears.     

Direct MR arthrography of the shoulder: is exercise prior to imaging beneficial or detrimental?

PURPOSE: To define the beneficial and detrimental effects of adding exercise to direct magnetic resonance (MR) shoulder arthrography. MATERIALS AND METHODS: Direct, intraarticular, gadolinium arthrography of the shoulder was performed in 41 patients, who underwent 1.5-T MR imaging before and after 1 minute of arm swinging. Fourteen milliliters of dilute gadolinium solution was injected. Two readers blinded to exercise independently graded the randomly distributed images with a five-point scale for capsular contrast material resorption; extraarticular contrast material leakage; rotator cuff, glenoid labrum, and anterior capsule conspicuity; and partial-thickness or full-thickness rotator cuff tear and labral tear detectability. The sign test was performed to evaluate the significance of differences between preexercise and postexercise grading for each reader. A second review was performed, with direct side-by-side comparison of preexercise and postexercise images. RESULTS: There was evidence of increased capsular resorption after exercise but no alteration in the depiction of the rotator cuff tendons or glenoid labrum. There was no significant extraarticular contrast material leakage after exercise and no alteration in depiction of the anterior capsule. There was no difference in the detectability of rotator cuff or labral tears. CONCLUSION: Exercise with direct shoulder MR arthrography has no beneficial or detrimental effect on image quality or on the depiction of rotator cuff or labral 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.     

MR imaging of the shoulder after surgery

This review article describes postoperative MR findings relating to surgery in shoulder impingement syndrome, including rotator cuff lesions, shoulder instability, and arthroplasty. Potentially misleading postoperative findings are emphasized. Because standard MR imaging may not always be the method of choice for post operative imaging, alternative imaging techniques have been included (MR arthrography, CT arthrography, and sonography).     

MR imaging of rotator cuff tears]

A total of 115 patients with clinical symptoms and signs suggesting rotator cuff tears underwent MR imaging with a 1.5-Tesla system. The body coil was used as the receiver coil in 24 patients and a single 10 cm surface coil in 91. Arthrography or MR imaging with intra-articular Gd-DTPA (MR arthrography) was performed in 95 of the 115. T2-weighted images with the body coil showed high signal intensity lesions in rotator cuffs in only seven of the 10 patients who had tears demonstrated by arthrography or MR arthrography. On the other hand, T2-weighted images with the surface coil demonstrated high signal intensity lesions in cuffs in all 27 patients who were diagnosed to have tears by arthrography or MR arthrography. In 12 patients, T2-weighted images with the surface coil showed high signal intensity lesions in cuffs, while arthrography and MR arthrography did not show tears. Surgery was performed in four of the 12 patients and partial tears were confirmed. A single 10 cm surface coil, 3 mm slice thickness and 2.5 second repetition time seem to account for the fine visualization of cuff tears by the T2-weighted images. These results suggest that T2-weighted images obtained with the surface coil are superior to arthrography and MR arthrography.     

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.