髋关节MR造影检查对发育性髋关节发育不良病人髋臼盂唇损伤程度的评价

目的评价髋关节MR造影检查对发育性髋关节发育不良(DDH)病人髋臼盂唇损伤的诊断价值。方法选取2015年12月—2016年10月进行髋关节MR造影检查的DDH病人16例,其中男3例,女13例,年龄10~20岁,平均(14.88±2.60)岁。对每例病人的患侧髋臼行超声引导下髋关节MR造影检查,分别对前、外上及后盂唇进行观察,由2名影像诊断医师评价盂唇损伤的部位及程度,并以术中诊断结果作为金标准进行对比。采用Kappa检验计算髋关节MR造影检查与术中诊断的一致性。结果 16例病人共48处盂唇,无撕裂37处(0期32处,Ⅰ期损伤5处),髋臼实质部撕裂3处,髋臼盂唇-软骨连接区撕裂8处。术中所见无撕裂38处,髋臼实质部撕裂3处,髋臼盂唇-软骨连接区撕裂7处。髋关节MR造影诊断髋臼盂唇撕裂的敏感度为100%,特异度为97.37%,阳性预测值为90.91%,阴性预测值为100%。MR髋关节造影检查与术中诊断的一致性较好(Kappa=0.939,P0.001)。髋关节MR造影显示盂唇肥大、内翻2例,均为前盂唇,与术中所见相吻合。结论髋关节MR造影检查对DDH病人髋臼盂唇损伤诊断的敏感性和特异性均较高,可作为术前常规检查手段。     

髋关节MR造影在髋臼唇撕裂诊断中的应用

目的 探讨髋关节MR造影在髋臼唇撕裂诊断中的应用价值.方法 临床高度怀疑髋臼唇撕裂的15例20个髋关节在透视下行髋关节穿刺造影,采用SE T1WI加脂肪抑制技术,进行髋关节冠状面、矢状面、斜轴面及放射状位扫描.其中12例行关节镜检查.结果 在行髋关节镜检查的12例14个髋关节中,11例13个髋关节MR造影诊断为髋臼唇撕裂,与关节镜诊断相符;1例MR造影示正常,关节镜检查亦未发现髋臼唇撕裂.13个髋臼唇撕裂中位于前上象限12个髋关节,后上象限1个髋关节.在关节镜诊断髋臼唇撕裂的13个髋关节中,MR造影冠状面诊断髋臼唇撕裂3个髋关节,矢状面诊断10个髋关节,斜轴面及放射状位诊断髋臼唇撕裂均为13个髋关节.15例20个髋关节中有5例6个髋关节在后下象限有髋臼唇下沟表现.结论 MR髋关节造影是诊断髋臼唇撕裂的可靠方法,扫描方法应选择T1WI加脂肪抑制的矢状面及斜轴面或矢状面加放射状位.后下象限撕裂的诊断中应注意正常变异的存在.

Abstract：

Objective To investigate the application value of MR rthrography (MRA) in the diagnosis of acetabular labral tears. Methods Fifteen patients with a high degree of suspected acetabular labral tears received fluoroscope-guided injection of the contrast media into the hip joint ( hip arthrography) and fat-saturated spin-echo T1-weighted images were obtained in the coronal, sagittal, oblique-axial and radial planes. Hip arthroscopy was performed on 12 of them. Results Labral tears which were diagnosed in 11 patients by hip MRA were confirmed at hip arthroscopy. One patient showed no MRA indication of labral tear, also showed normal on arthroscopy. Tear in the anterior-superior quadrant 10 cases of 12 joints ( 12/13), posterior-superior quadrant 1 case of a joint (1/13). In 11 patients who underwent arthroscopy, hip MRA diagnosed 3 (3/13) joints labral tears in coronal planes, 10 (10/13) joints in sagittal planes and 13 (13/13) labral tears in axial-oblique and radial planes. In 15 patients with 20 hip joints, 5 cases 6 joints (6/20) with normal acetabular sublabral sulcus were performed. Conclusions MR arthrography of hip is a reliable method in the diagnosis of acetabular labral tears. Scanning method should be included fat-saturated spin-echo T1-weighted images in sagittal and oblique-axial planes or sagittal plus radial planes. The diagnosis of tor posterior-inferior quadrant should pay attention to the existence of a normal variation.     

常规MRI与MR关节造影诊断肩袖撕裂的初步对比研究

目的 比较3.0T常规MRI和MR关节造影检查对肩袖撕裂的诊断价值.方法 分析48例肩关节病变患者的常规MRI和MR关节造影检查资料,确定肩袖有无撕裂并进行分型.其中4例行肩关节镜检查.采用配对x2检验比较两种检查方法诊断肩袖撕裂的差异性.结果 常规MRI显示冈上肌腱全层撕裂6例,冈上肌腱部分撕裂9例;MR关节造影显示冈上肌腱全层撕裂7例,冈上肌腱部分撕裂8例.常规MRI和MR关节造影检查方法对肩袖全层撕裂诊断有6例相同,1例常规MRI诊断无撕裂MR关节造影诊断为撕裂;对肩袖部分撕裂的诊断有7例相同,3例不同,其中2例常规MRI诊断为撕裂而MR关节造影诊断为无撕裂,1例常规MRI诊断为无撕裂而MR关节造影诊断为撕裂;两种检查方法对肩袖全层撕裂(x2=0.000,P＞0.05)及部分撕裂(x2=o.000,P＞0.05)的诊断差异无统计学意义.结论 初步显示3.0T常规MRI对肩袖全层撕裂和肩袖部分撕裂的诊断能达到MR关节造影的诊断效果,同时可以显示肩袖撕裂伴发的各种异常.     

肩关节损伤的MR关节造影与MRI对比研究

目的探讨肩关节MR关节造影与常规MRI检查阳性率的敏感性及特异性,并探讨哪类患者更适用于MR关节造影。方法选取100例肩痛患者先后行肩关节常规MRI和MR关节造影检查,图像分别由两位有经验的放射医师盲法评价,评估盂唇撕裂和冈上肌肌腱撕裂;所有患者均行关节镜检查并与MRI及MR关节造影结果分别做对照分析。结果 100例患者中,在常规MRI检查评价者1中共有43例上盂唇前后(SLAP)撕裂,28例后盂唇撕裂,23例前盂唇撕裂和47例冈上肌肌腱撕裂;评价者2中有42例SLAP撕裂,26例后盂唇撕裂,24例前盂唇撕裂和47例冈上肌肌腱撕裂。在MR关节造影检查评价者1中有51例SLAP撕裂,33例后盂唇撕裂,29例前盂唇撕裂和49例冈上肌肌腱撕裂;评价者2中有50例SLAP撕裂,31例后盂唇撕裂,30例前盂唇撕裂和49例冈上肌肌腱撕裂。MR关节造影评价者1和2中均额外发现8例SLAP撕裂,5例后盂唇撕裂,6例前盂唇撕裂和2例冈上肌肌腱撕裂,而这些在常规MRI检查中均未发现。48例常规MRI检查正常中有21例在MR关节造影检查中发现额外异常;52例患者常规MR检查异常中仅有3例在MR关节造影检查中发现额外异常结果。结论常规MRI检查异常时再行MR关节造影检查能显示的额外阳性信息很少,这类患者可不需要MR关节造影检查;常规MRI检查为阴性患者再行MR关节造影检查可发现额外异常结果。     

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.     

3.0TMR肩关节造影在前下盂唇变异型损伤诊断中的应用

目的:探讨3.0TMR关节造影在肩关节前下盂唇变异型损伤诊断及分型价值.方法:搜集2016年1月-2019年12月疑似肩关节前下盂唇损伤患者79例,以关节镜或开放术后诊断为标准,回顾性对比分析其术前常规MR检查及MR关节造影检查资料,利用统计学计算两种检查术前诊断及分型的灵敏度、特异度、准确性.使用McNemar检验分...     

单髋高分辨力磁共振成像对髋臼盂唇及关节软骨损伤的诊断价值

目的 分析单髋高分辨率磁共振成像（MRI）扫描诊断髋臼盂唇及关节软骨损伤的临床意义。方法 选取2018年2月至2021年2月我院骨科骨关节病区接纳的100例临床髋部疼痛患者，所有患者分别实施常规髋关节MRI扫描与单髋高分辨率MRI扫描，对图像髋臼盂唇损伤显示情况进行盲评法评分，比较2种检查方法对都髋臼盂唇及关节软骨损伤的检查灵敏度。结果 关节镜结果证实表明，100例髋部疼痛患者有76例出现髋臼盂唇及关节软骨损伤，单髋高分辨率MRI扫描检查灵敏度要高于常规髋关节MRI扫描，差异有统计学意义（P<0.05）；且单髋高分辨率髋关节MRI扫描在图像得分上要明显高于常规髋关节MRI扫描，差异有统计学意义（P<0.05）。结论 单髋高分辨率MRI扫描对髋臼盂唇及关节软骨损伤能够做出清晰显示且灵敏度较高，能够为临床疾病确诊和治疗提供准确依据，保证治疗效果，值得推广应用。     

髋关节MR造影检测髋臼唇

髋部MRI为潜在的机械性髋疼痛提供了新的显示方法.对于髋部结构尤其是髋臼唇的显示,其它方法一直非常有限.通过MR关节造影术使髋关节膨胀起来,从而能够确认唇缘分离及撕裂,并与许多无症状的髋臼唇形态相鉴别.综述了髋的正常解剖、结构紊乱的临床表现以及MR关节造影,同时也总结了无症状髋臼唇的形态学改变及不正常髋臼唇的表现.     

髋关节撞击综合征影像表现的初步探讨

目的 探讨髋关节撞击综合征(FAI)的影像表现.方法 回顾性分析经手术证实的9例FAI患者的影像资料,9例患者均行髋关节正侧位X线检查及患髋MR检查,其中1例还接受了患髋关节MR关节造影检查,探讨其影像特征性改变.结果 9例患者X线表现均出现股骨头颈交界处骨性突起或髋臼过度覆盖.MR检查显示9例患者均出现不同程度的髋臼盂唇损伤,均出现在前上盂唇,ⅠA期损伤2例,ⅠB期损伤3例,ⅡA期损伤2例,ⅡB期损伤2例;1例患髋关节MR造影检查显示髋臼前上盂唇内线样裂隙,可见对比剂进入裂隙.2例的股骨头负重区软骨下骨内出现硬化囊变区,手术证实相应部位出现直径2 cm大小的软骨剥脱.结论 MRI可以显示FAI患者髋臼盂唇及关节软骨损伤,有助于早期诊断FAI.     

磁共振肩关节造影在肩袖完全撕裂诊断的临床应用

目的:探讨磁共振肩关节造影检查对肩袖完全撕裂的诊断价值.方法:回顾性分析54例肩袖完全撕裂MR关节造影及MRI表现,与肩关节镜手术结果对照.结果:54例肩袖完全撕裂病例,MRI诊断的敏感度、特异度及准确度分别是87.03％、50.00％和79.41％;MR关节造影诊断Ⅰ型9例、Ⅱ型21例,其敏感度分别为88.89％、95.24％;特异度分别为97.87％、97.14％;准确度分别为96.43％、96.43％;明显高于常规MRI诊断,差异均有统计学意义(P＜0.05);与关节镜结果对比,其一致性极佳(Kappa=0.841);而对于Ⅲ型肩袖完全撕裂,MR关节造影均不能显示.结论:MR关节造影能较准确判断Ⅰ型、Ⅱ型肩袖完全撕裂范围及程度,是MRI诊断肩袖损伤的有效补充,为临床诊断和治疗能提供更准确的依据,而对于Ⅲ型肩袖完全撕裂,MR关节造影不能显示其损伤部位及程度,无法对其进行诊断.     

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

Objective

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

Methods

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

Results

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

Conclusion

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

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

Objective:

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

Methods:

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

Results:

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

Conclusion:

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

Advances in knowledge:

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

Evaluation of the acetabular labrum at 3.0-T MR imaging compared with 1.5-T MR arthrography: preliminary experience

Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. The purpose of this study was to prospectively compare imaging of the acetabular labrum with 3.0-T magnetic resonance (MR) imaging and 1.5-T MR arthrography. Eight patients (four male, four female; mean age, 38 years) with hip pain suspicious for labral disease were examined at both MR arthrography and MR imaging. Presence of labral lesions, paralabral cysts, articular cartilage lesions, subchondral cysts, osteophytes, and synovial herniation pits was recorded. There was arthroscopic correlation of findings in five patients. MR imaging depicted four surgically confirmed labral tears that were identified at MR arthrography, as well as one that was not visualized at MR arthrography. MR imaging helped identify all other pathologic conditions that were diagnosed at MR arthrography and helped identify one additional surgically confirmed focal articular cartilage lesion. These results provide encouraging support for evaluation with 3.0-T MR imaging over 1.5-T MR arthrography.     

Sensitivity of MR arthrography in the evaluation of acetabular labral tears

OBJECTIVE: MRI has historically provided suboptimal visualization of tears of the acetabular labrum. Degenerative fraying and underlying cartilage abnormalities can often mimic tears of the labrum on conventional MRI. Administration of intraarticular gadolinium enhances the MRI appearance of the labrum to improve detection of labral abnormalities. This study examined the improved diagnostic sensitivity of MR arthrography compared with conventional MRI and the importance of confining the study to a small field of view. MATERIALS AND METHODS: Fifty-one hips were imaged in 48 patients. Fourteen hips underwent conventional MRI with a large field of view (30-38 cm). Seven hips underwent conventional MRI with a small field of view (14-20 cm). Thirty hips underwent MR arthrography with a small field of view (14-20 cm). Labral tears were diagnosed when contrast material was identified within the labrum or between the labrum and the acetabulum, when a displaced fragment was noted, or when a paralabral cyst was identified. All study results were compared with findings at the time of hip arthroscopy. RESULTS: Conventional MRI with a large field of view was 8% sensitive in detecting labral tears compared with findings at the time of arthroscopy. Diagnostic sensitivity was improved to 25% with a small field of view. MR arthrography with a small field of view was 92% sensitive in detecting labral tears. CONCLUSION: A combination of MR arthrography and a small field of view is more sensitive in detecting labral abnormalities than is conventional MRI with either a large or a small field of view.     

Evaluation of radial-sequence imaging in detecting acetabular labral tears at hip MR arthrography

Objective In recent years, radial imaging has been advocated for improved visualization of the acetabular labrum in magnetic resonance arthrography of the hip. The purpose of this study was to investigate whether radial imaging demonstrates labral tears not visible on standard imaging planes. Methods Fifty-four consecutive magnetic resonance (MR) arthrograms of the hip that included radial imaging over 2 years were retrospectively analyzed by two radiologists. Standard imaging planes and radial imaging were reviewed for identification of labral tears in four specific areas of the labrum: anterosuperior, posterosuperior, anteroinferior, and posteroinferior. The standard imaging sequences include fat-saturated spin-echo T1-weighted images in the coronal and oblique axial planes, non-fat-saturated T1-weighted images in the coronal and sagittal planes, and T2-weighted sequence in the axial plane. Radial imaging was performed as previously described using fat-saturated T1-weighted sequences. Results Using standard imaging planes, 50 anterosuperior, 31 posterosuperior, 10 anteroinferior, and 9 posteroinferior labral tears were detected in 54 MR arthrograms of the hip. Using radial sequences alone, 44 anterosuperior, 25 posterosuperior, 9 anteroinferior, and 5 posteroinferior labral tears were detected. In all four areas of the labrum, the radial imaging did not show any labral tear not seen on standard imaging planes. Discussion In MR arthrography of the hip, radial imaging did not reveal any additional labral tears. Standard imaging planes sufficiently demonstrate all acetabular labral tears.     

Ultrasound versus magnetic resonance arthrography in acetabular labral tear diagnostics: a prospective comparison in 20 dysplastic hips

Background: Acetabular labral tears are highly associated with hip dysplasia. Magnetic resonance arthrography (MR arthrography) is the expensive and time-consuming contemporary gold-standard method in the radiological assessment of acetabular labral tears.

Purpose: To assess the diagnostic ability of noninvasive ultrasound (US) examination compared to MR arthrography in diagnosing acetabular labral tears in dysplastic hip joints.

Material and Methods: The study compared US examination and MR arthrography diagnosis of labral tears in 20 consecutively referred dysplastic hip joints.

Results: The ability to diagnose acetabular labral tears upon US examination was calculated: sensitivity 44%, specificity 75%, positive predictive value 88%, and negative predictive value 25%.

Conclusion: The ability of US examination in diagnosing acetabular labral tears is not yet good enough. The technique is still to be developed, and more experience, especially with the interpretation of US examinations, is needed.     

Acetabular labral tears: contrast-enhanced MR imaging under continuous leg traction

 Objective. The objective of this study was to evaluate the effects of continuous leg traction on contrast-enhanced MR imaging of the hip joint and to determine whether MR imaging under these conditions is useful for demonstrating acetabular labral tears. Design and patients. Nineteen hips underwent MR imaging with a T1-weighted spin-echo sequence, followed by MR imaging under continuous leg traction after intravenous injection of gadolinium-DTPA. Joint fluid enhancement and labral contour detection were evaluated. Eleven hips had labral tears shown by conventional arthrography, arthroscopy and macroscopic surgical findings. Assessment of labral tears by MR imaging was correlated with the diagnosis based on these standard techniques. Results and conclusions. Joint fluid enhancement was obtained in all hips at 30 min after injection. Superior and inferior labral surfaces were completely delineated in 1 hip on the unenhanced MR images, and in 7 and 13 hips, respectively, on the enhanced images under traction. The enhanced images under traction depicted 9 of the 11 labral tears. Comparison between the unenhanced image and the enhanced image under traction avoided mistaking undercutting of the labrum for a tear in 4 hips. Contrast-enhanced MR imaging under traction was valuable for detecting labral tears non-invasively and without radiation. Follow-up examinations using this method in patients with acetabular dysplasia can help to clarify the natural course of labral disorders and enable better treatment planning.     

MR Arthrography of the Hip

Magnetic resonance imaging (MRI) of the hip has been valuable in the diagnosis of occult osseous abnormalities and of periarticular soft tissue disorders. MRI has been less useful in the evaluation of acetabular labral tears and other intra-articular abnormalities. Image optimization is more technically challenging in the hip than in smaller joints because the overlying soft tissues are thicker, resulting in decreased spatial and contrast resolutions that may not be adequate to distinguish the acetabular labrum from subchondral bone, articular cartilage, and joint capsule. MR arthrography (MRA) extends the capabilities of conventional MRI because contrast solution separates intra-articular structures and outlines abnormalities. In hips with suspected acetabular labral injury, arthrographic MR images demonstrate the location and length of tears and the presence of associated capsular defects. Arthrographic MR images may also enable the accurate diagnosis of cartilage lesions and intra-articular loose bodies. This article illustrates normal arthrographic MR features of the hip as well as pathologic disorders of the acetabular labrum, capsule, and articular cartilage     

Sublabral sulcus at the posteroinferior acetabulum: a potential pitfall in MR arthrography diagnosis of acetabular labral tears

OBJECTIVE: Our study correlated findings on hip MRI and MR arthrography with hip arthroscopy to assess the location, prevalence, and potential pitfall of a normal acetabular sublabral sulcus. MATERIALS AND METHODS: We retrospectively collected 58 hip MRI studies along with surgical reports in 58 patients who underwent hip arthroscopy over a 5-year period. Intraoperative photography (n = 23), radiography (n = 56), unenhanced MRI (n = 13), and MR arthrography (n = 54) studies were available for review. Two radiologists described hip anatomy on radiology studies with agreement by consensus. RESULTS: A normal posteroinferior sublabral groove was confirmed on available arthroscopy photographs in four (17.4%) of 23 hips. In each of these four patients, the anatomic sublabral groove correlated with apparent partial labral detachment on MR arthrography. On review of all studies, 13 hips (22.4%) without a posterior labral tear at surgery had imaging findings of a sublabral sulcus. The sulcus was not associated with acetabular dysplasia, which was radiographically noted in 12 cases (21.4%). Preoperatively, the sulcus was misdiagnosed as a tear in two cases. Labral tears were anterior or anterosuperior in 51 patients. CONCLUSION: A posteroinferior sublabral groove is a relatively common normal anatomic hip variation. If not recognized as normal, the sulcus may serve as a diagnostic pitfall on MR arthrography. Its location is distinct from most labral tears. We did not discover a sublabral sulcus at the anterior or anterosuperior acetabulum, the most common sites of labral injury.