MR Arthrography of the Knee

The role of magnetic resonance imaging (MRI) in the evaluation of musculoskeletal injuries has been well documented during the last decade. There remain several important clinical situations in which noncontrast MRI has been disappointing. In the knee, magnetic resonance arthrography (MRA) can supplement noncontrast MRI in the evaluation of specific conditions, such as postoperative meniscus and osteochondritis dissecans. MRA significantly increases accuracy in the diagnosis of meniscal retear, as is seen in cases in which there has been a meniscal resection of more than 25% or after meniscal suturing. Also, in the evaluation of osteochondritis dissecans, the addition of intra-articular contrast has proved beneficial. Aside from assessing the integrity of the articular cartilage surface and documenting loose bodies, the contrast allows the clinician to distinguish fibrovascular granulation tissue from fluid partially or completely surrounding the osteochondritic fragment. These topics are discussed in this article.     

Gadolinium MR Arthrography of the Rotator Cuff

Conventional magnetic resonance imaging (MRI) of the rotator cuff has not done well in distinguishing partial-thickness tears from tendonitis or small, full-thickness tears. However, these are important distinctions for orthopedic surgeons who are deciding whether to operate and what type of surgery to perform on a patient with suspect rotator cuff pathology. Gadolinium magnetic resonance arthrography (MRA) involves injecting dilute gadolinium into the shoulder under fluoroscopy. Subsequent multiplanar T1-weighted fat-suppressed fast spin echo combined with T2-weighted fast spin echo and short tau inversion recovery (STIR) produces images that can accurately differentiate absence of tear from partial-thickness tear and from small, full-thickness tear; as a fringe benefit, this combination of sequences can identify the inflammation associated with tendonitis. Furthermore, the technique differentiates articular from bursal surface partial-thickness tears, and it accurately quantitates the size of full-thickness tears to help surgeons choose between arthroscopic versus open surgery.     

Normal Anatomy of the Elbow on Conventional MR Imaging and MR Arthrography

Conventional MR imaging allows clear depiction of the muscles, tendons, nerves, vessels, ligaments, bones, and cartilage that compose the elbow. MR arthrography can be a valuable supplementary technique for optimizing evaluation of intraarticular structures, including the undersurfaces of the collateral ligaments. Regardless of the imaging technique utilized, knowledge of normal anatomy-and normal anatomic variants-is fundamental for accurate assessment of normal and diseased states.     

CT and MR Arthrography of the Glenoid Labroligamentous Complex

Because they distend the shoulder joint and bathe the labrum with contrast, CT arthrography (CTa) and MR arthrography (MRA) are both excellent tests for evaluating the labrum. In this article, we discuss the advantages and disadvantages of each examination. We also describe techniques for performing CTa and MRA, including how to maximize image quality. The normal anatomy of the labrum and glenohumeral ligaments is described and demonstrated on both CTa and MRA images. To improve communication with orthopedic surgeons, the discussion of the pathology and normal variants of the labroligamentous complex is organized by functional anatomic regions. CTa and MRA images are then used to demonstrate a variety of pathologic and normal variant appearances of the labroligamentous complex.     

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。     

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.     

间接磁共振关节造影在色素沉着绒毛结节性滑膜炎中的应用

目的探讨间接磁共振关节造影在色素沉着绒毛结节性滑膜炎(pigmented villonodular synovitis,PVNS)中的诊断价值。资料与方法回顾性分析12例经手术及病理证实的PVNS患者的常规MRI、间接磁共振关节造影(indirect MR arthrography,I-MRa)资料。结果12例PVNS患者中关节滑膜呈弥漫性增生肥厚者10例,局限性2例。常规MR表现为T1WI等信号,T2WI高信号2例;T1WI、T2WI均为低信号9例。I-MRa表现为在关节积液的极高信号背景下增生肥厚滑膜呈中等强化的高信号,并对周围正常组织有不同程度的侵蚀。结论I-MRa与常规扫描序列相结合,不仅能更清晰地显示出病变累及的范围和程度,而且还可以显示滑膜对关节骨质的侵蚀、反映病变的血供等病理改变,从而可进一步提高PVNS定性及分期的准确性。     

磁共振关节腔造影诊断膝关节软骨磨损的价值

目的：通过比较各种磁共振检查方法和关节镜检查,探讨磁共振膝关节腔造影（ＭＲ－ＡＲ）应用于膝关节软骨磨损诊断和分级中的价值。材料和方法：１５例骨关节炎患者的软骨磨损磁共振表现与关节镜检查结果对照。磁共振成像包括矢状面和横断面常规ＳＥ序列成像和关节腔ＭＲ造影。采用三度分级法：Ⅰ度软骨磨损小于１ｍｍ,Ⅱ度病变软骨不同程度变薄。Ⅲ度局部软骨完全缺损。结果：常规ＭＲＩ／ＭＲ－ＡＲ诊断软骨缺损的敏感性为４５．１％／７４．２％,特异性为９０．９％／９３．２％,准确率为７２．０％／８５．３％。软骨缺损ＭＲＩ像表现表面毛糙征、软骨线变薄征、软骨线中断征、软骨信号改变和软骨下骨结构改变５种征象。结论：ＭＲ－ＡＲ虽为侵入性磁共振检查方法,但可显著提高软骨软骨磨损的检出率,尤其是发现早期的软骨磨损更具价值。     

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.     

间接磁共振膝关节腔内造影诊断膝关节半月板撕裂的价值

目的:通过比较临床检查、常规磁共振检查(MRI)、间接磁共振膝关节腔内造影检查(间接MRA)和膝关节镜术中所见,探讨间接MRA用于膝关节半月板撕裂诊断中的价值.材料和方法:本次研究中我们共收集125例曾行膝关节镜手术患者,全部患者都经过详细的病史采集和体格检查,其中57例患者术前行MRI检查,其中21例患者做MRI检查后立即做间接MRA,以膝关节镜为金标准,对各种检查发现进行互相比较.结果:①临床检查:敏感性75.47%、特异性69.44%、准确性72.00%.②MRI检查:敏感性82.86%、特异性54.55%、准确性71.93%.③间接MRA检查:敏感性100%、特异性90.00%、准确性95.23%.结论:间接MRA在诊断膝关节半月板撕裂方面具有很高的敏感性、特异性和准确性.     

弥散法MR膝关节造影在半月板损伤诊断中应用探讨

目的　用弥散法MR膝关节造影对半月板撕裂进行检查 ,探讨其临床应用价值。方法　检查 2 4例临床怀疑半月板撕裂的膝关节。采用常规检查技术进行扫描 ,然后进行弥散法膝关节造影检查 ,再经关节镜或手术证实。将常规扫描结果、弥散法关节腔造影结果与手术结果对照 ,分别算出常规扫描结果和弥散法结果的敏感性和特异性。结果　弥散法膝关节造影可使半月板撕裂处信号强度明显高于平扫时的信号 ,同时检查的敏感性从 74.2 %提高到 94.3 % ,特异性从 88%提高到 93 .4%。结论　弥散法膝关节造影在半月板撕裂检查上 ,从图像质量到检查的敏感性均优于常规MR检查     

Conventional 3-T MRI and 1.5-T MR Arthrography of Femoroacetabular Impingement

OBJECTIVE: This article provides a review of femoroacetabular impingement (FAI) and the role MRI is attempting to fulfill in this complex and sometimes controversial condition. A perspective on the current status and on the advantages of 1.5-T MR arthrography is presented, and its usefulness in this setting is compared with the potential of nonarthrographic 3-T MRI. CONCLUSION: With its increasing availability, 3-T MRI has the potential to provide routine, less invasive assessment of the hip for FAI.     

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.     

弥散法MR膝关节造影可行性研究

目的评价MR对比剂静脉内注射、膝关节腔内弥散关节造影的可行性研究并寻找最佳检查参数. 资料与方法选取膝关节正常者24名,按常规方法进行扫描后再将其分为运动组和未运动组.每组再分为3小组.3个小组分别从静脉注入不同剂量的Gd-DTPA.注射完后未运动组受检者静卧于检查床,进行延迟扫描;运动组步行10 min后再进行扫描,并进行延迟.扫描结束后,对平扫和增强图像中的关节腔周围组织及关节腔内信号进行测量.采集后的数据按组归类,并进行统计处理,观察对比剂注射后关节腔内信号增加程度并选取最佳检查方法. 结果弥散法膝关节造影可使关节腔信号强度明显增加,与周围组织产生明显信号差,以采用注射剂量为0.2 mmol/kg体重,注射后受检者正常步行10 min后造影效果最佳. 结论弥散法MR膝关节造影可起到关节造影的效果,造影效果良好,是一种操作简单、危险性小、并发症少的检查方法.     

Hip MR arthrography and femoroacetabular impingement

Hip pain is a common complaint among athletes of all ages. Advances in imaging and treatment are changing the paradigm of evaluation and management of hip pain. The role of abnormal femoral and acetabular morphology and lesions of the acetabular labrum and cartilage is increasingly recognized as being crucial in the development of degenerative change. In addition, femoroacetabular impingement is increasingly recognized as an etiologic factor in hip pain. This article discusses techniques of hip magnetic resonance (MR) arthrography, normal anatomy seen at hip MR arthrography, common intra-articular pathologies in patients with hip pain, and imaging findings of femoroacetabular impingement.