低场强MRI对膝关节半月板损伤的诊断价值探讨

目的评价低场强MRI对半月板损伤的诊断价值。方法对我院90例临床高度怀疑半月板损伤的患者行低场强MRI扫描和关节镜检查,并对其结果进行比较。结果本组90例患者的98个膝关节共累及103个半月板,经MRI诊断为真性撕裂者55个半月板．经父节镜证实为53个半月板;经MRI检查阴性而关节镜下见撕裂者2个半月板,MRI和父节镜检查均为阴性者30个半月板,其中有3个为盘状半月板。低场强MRI对半月板损伤的敏感性为9375％,特异性94．37％,准确性94．17％。结论低场强MRI是诊断半月板损伤无创性的极有价值的诊断疗法．是膝关节镜术前的重要榆查。     

MRI与关节镜诊断半月板损伤临床表现的对比分析

目的 探讨MRI和关节镜检查半月板损伤的诊断价值。方法 收集40例我院接受诊断与治疗的膝关节损伤患者的MRI图像,以关节镜诊断为标准,计算MRI诊断的敏感性、特异性、准确性。结果 本组40例膝关节,左膝18例,右膝22例,共80个半月板。MRI表现为Ⅰ度损伤9个,Ⅱ度损伤15个,Ⅲ度损伤56个。MRI诊断半月板撕裂56个,其中外侧半月板35,内侧半月板21个,关节镜证实半月板撕裂50个,其中外侧半月板32,内侧半月板18个,其余6个半月板关节镜下肉眼未见明显撕裂。24个半月板MRI诊断无撕裂者中,关节镜下证实有3个半月板撕裂并进行部分切除。以关节镜检查为标准,MRI对半月板撕裂诊断的敏感性为94.3%,特异性为77.8%,准确性为88.8%,MRI诊断与关节镜结果差异无统计学意义（x^2=0.44,P〉0.05）。结论 MRI对半月板撕裂具有较高的诊断价值。而关节镜检查为最终确诊半月板损伤提供了清晰的镜像和依据,两者相互补充才能得到更好的临床效果。     

MR与关节镜诊断半月板损伤的临床价值研究

目的探讨MR与关节镜诊断半月板损伤的临床价值。方法本组72例患者检查86个膝关节,共172例半月板,入院后进行MRI检查评价半月板损伤情况,2周内进行膝关节镜检查,MRI检查结果按Fischer分级标准分I级信号、II级信号、III级信号,关节镜检查结果分正常、退变、撕裂。结果 MRI与关节镜检查诊断半月板损伤结果比较,X~2=1.432,P=0.698,κ=0.694;MRI与关节镜检查诊断半月板撕裂结果比较,X~2=0.529,P=0.629,κ=0.767,MRI诊断半月板撕裂的敏感度86.27%、特异度91.73%、阳性预测值81.48%、阴性预测值94.07%、阳性似然比10.43、阴性似然比0.15、准确度90.12%、假阳性率8.27%、假阴性率13.73%。结论 MRI能够较好的诊断半月板损伤的程度,特别是对半月板撕裂的诊断,MRI的Ⅲ级信号可作为临床选择关节镜检查和手术治疗的一个重要指征。     

膝关节半月板撕裂的MRI诊断

目的探讨膝关节半月板撕裂的MR I表现及MR I诊断价值。方法行MR I检查并行关节镜检查或手术的患者98例,对其结果进行对照分析。结果在98例196个半月板中,与关节镜检查及手术结果比较,MR I诊断半月板撕裂的准确性为95.9%。结论MR I是诊断膝关节半月板撕裂理想的非创伤性的检查方法。     

MRI与关节镜诊断半月板损伤价值的对照研究

目的 分析MRI诊断半月板损伤的价值,为临床诊断和治疗半月板损伤提供依据.资料与方法 符合纳入标准的168例患者(均为单膝半月板受损),共336个半月板.对膝关节进行术前MRI检查,并于MRI检查后8周内行关节镜术.半月板损伤的MRI分级标准参考Fischer分级法,分为Ⅰ级损伤、Ⅱ级损伤、Ⅲ级损伤;关节镜分级,分为正常、纤毛化和撕裂.结果 与关节镜结果对照,MRI诊断半月板Ⅰ、Ⅱ级损伤的准确性分别为100%、92.9%.诊断半月板撕裂的敏感性、特异性、阳性似然比、准确性、Kappa值分别为93.1%、89.3%、8.7、91.1%、0.82.对半月板撕裂类型诊断总的灵敏性、特异性、阳性似然比、准确性、Kappa值分别为92.0%、79.8%、4.6、84.8%和0.70.结论 MRI不仅能够准确评价半月板损伤程度,而且还能对半月板撕裂进行准确分型.因此,MRI可广泛应用于半月板损伤性疾病的诊断,并进一步指导临床治疗方案的选择.     

MRI评价膝关节半月板的桶柄状撕裂

目的 明确5种MRI征象对膝关节半月板桶柄状撕裂的诊断价值。方法 回顾135例患者139个经关节镜证实的膝关节MR图像，其中19个存在半月板桶柄状撕裂。在均不告知关节镜结果的条件下，由2名有经验的放射医生对所有图像进行独立读片，差异协商解决。每个膝关节均记录如下5种MRI征象：双后交叉韧带征(双PCL征)、半月板翻转征、空领结征、碎块内移征和外周残半月板征。分别计算每种征象诊断半月板桶柄状撕裂的敏感度、特异度、阳性预测值、阴性预测值和准确度。结果 5种征象的诊断敏感度分布于52．6％和89．5％之间，特异度分布于83．3％和98．3％之间，阳性预测值分布于42．9％和88．2％之间，阴性预测值分布：于92．7％和98．3％之间，准确度分布于82．7％和96．4％之间。“碎块内移征”和“外周残半月板征”的诊断敏感度最高，“双PCL征”的诊断特异度和阳性预测值最高，而“碎块内移征”具有最高的阴性预测值和诊断准确度。结论 半月板桶柄状撕裂在MRI上可以有多种表现，各种征象对诊断的能力有所不同。     

MRI诊断膝关节半月板桶柄状撕裂

目的:总结分析半月板桶柄状撕裂的MRI征象和诊断价值.方法:回顾性分析146个经关节镜证实的膝关节MR图像,其中28个膝关节存在半月板桶柄状撕裂,记录如下5种MRI征象:碎块内移征、外周残半月板征、双PCL征、空领结征及双前角征,并分别计算每种征象诊断半月板桶柄状撕裂的敏感度、特异度、准确度、阳性预测值和阴性预测值.结...     

盘状半月板的磁共振成像诊断

目的探讨盘状半月板及其继发病变的磁共振诊断方法和价值。材料和方法23例盘状半月板病例中10例为关节镜证实,另收集23例非盘状半月板膝关节MRI作为对照组。结果MRI上外侧半月板中部宽度与外侧胫骨平台的比率超过50％为盘状半月板可靠的依据。板内Ⅲ级信号改变可为变性、板内撕裂或显性撕裂。结论MRI诊断盘状半月板及其继发病变具有很高的价值。     

超声检查在膝关节半月板损伤诊断中的应用价值

目的 探讨超声检查对膝关节半月板损伤的诊断价值。方法 对74例膝关节共148个半月板超声检查结果与关节镜检查结果进行对照分析。结果 148个半月板中，关节镜发现半月板损伤46个，超声检查准确作出半月板损伤诊断38个，漏诊8个，真阴性97个，假阳性5个。超声诊断半月板损伤的准确率91．2％，敏感性82．6％，特异性95．1％，阳性结果预测值88．4％，阴性结果预测值92．4％。结论 超声检查无创、方便、及时，诊断半月板损伤准确性较高，容易广泛开展，可作为诊断半月板损伤的一种重要检查方法。     

MRI水脂分离序列成像对膝关节半月板损伤的诊断价值

目的 :探讨MRI水脂分离技术——扰相梯度回波水脂分离T2WI(简称FatSepG-WFT2*)序列对膝关节半月板损伤的诊断价值。方法:回顾性分析MRI诊断的62例372个半月板区域的相关资料,以关节镜诊断为金标准,对结果行统计学分析。用χ2检验比较不同MRI序列对膝关节半月板损伤的差异。采用Kappa检验分析MRI诊断半月板撕裂与关节镜诊断的一致性。采用χ2检验分析MRI对内外侧半月板撕裂部位诊断准确性的差异。结果:以关节镜结果作为标准,MRI FatSepG-WFT2*序列诊断半月板撕裂的准确度为94%(350/372)、敏感度为93%(140/149),特异度为94%(210/223),对诊断半月板撕裂有较好的有效性(K=0.877)。结论 :MRI FatSepG-WFT2*序列较常规MRI序列具有更高的敏感性和特异性,两者结合可提高低场强MRI对膝关节病变的检出率。MRI是诊断膝关节半月板损伤的有效手段,与关节镜有较好的一致性,两者结合具有更好的诊断和治疗效果。     

Magnetic resonance diagnosis of meniscal tears in patients with acute anterior cruciate ligament tears

OBJECTIVE: To evaluate the accuracy of magnetic resonance imaging in the diagnosis of meniscal tear in patients with acute anterior cruciate ligament tears. METHODS: Magnetic resonance images obtained from 41 patients imaged within 6 weeks of injury who had acute anterior cruciate ligament tears identified at arthroscopy were retrospectively reviewed for meniscal tear. RESULTS: With MR imaging the sensitivity, specificity and accuracy for diagnosing meniscal tears in the presence of acute anterior cruciate ligament tears were 71%, 93%, and 88%; for the lateral meniscal tears were 57%, 100% and 85%; and for the medial meniscal tears were 100%, 88%, 90%. All false negative cases (n = 6) involved the posterior horn of the lateral meniscus. CONCLUSION: In the presence of acute anterior cruciate ligament tears, MRI imaging has relatively low sensitivity for detecting meniscal tears due to missed tears in the lateral meniscus.     

Meniscal tears on knee arthrography: Patterns of arthrographic abnormalities

The presence or absence of a meniscal tear was established in 340 out of 475 consecutive patients who had double contrast knee arthrograms. The accuracy in these 340 cases was 95% for both the medial and lateral menisci although the specificity for lateral tears was only 0.64. Analysis of the pattern of arthrographic abnormalities revealed that both medial and lateral tears usually involved the posterior horn of the meniscus. Posterior horn abnormalities rarely caused a false positive diagnosis of a meniscal tear. In contrast, isolated blunting of the anterior horn of either the lateral or medial meniscus was an unreliable sign of a tear and accounted for many of the false positive diagnoses. It is concluded that careful attention to the posterior horn of each meniscus is essential for accurate arthrographic diagnosis of a meniscal tear.     

Contribution of thin-slice (1 mm) axial proton density MR images for identification and classification of meniscal tears: correlative study with arthroscopy

Objective To evaluate the diagnostic efficacy of thin-slice (1 mm) axial proton density-weighted (PDW) MRI of the knee for meniscal tear detection and classification. Methods We prospectively assessed pre-operative MR images of 58 patients (41 males, 17 females; age range 18-62 years) with arthroscopically confirmed meniscal tear. First, we evaluated the performance of the sagittal and thin-slice axial MR images for the diagnosis of meniscal tears. Second, we compared the correlation of tear types presumed from sagittal and axial MRI with arthroscopy and tear classification from axial MRI. Tears were classified on the sagittal plane and the axial plane separately. The diagnostic performance and tear classification were compared statistically with arthroscopy results, which is accepted as the standard of reference. Results 8 of 58 patients were removed from the study group because they had complex or degenerative tears. A total of 62 tears were detected with arthroscopy in 50 patients. On the sagittal images, sensitivity and specificity values were 90.62% and 70.37%, respectively, for medial meniscus tears and 72.73% and 77.14%, respectively, for lateral meniscus tears. The corresponding values for axial images were 97.30% and 84.00%, respectively, for medial meniscus tears and 95.65% and 80.50%, respectively, for lateral meniscus tears. There was no significant difference in tear classification between the arthroscopy results and the thin-slice axial PDW MRI results (p>0.05). Conclusion thin-slice axial PDW MRI increases the sensitivity and specificity of meniscal tear detection and especially classification, which is important for surgical procedure decisions.     

Medial meniscocapsular separation: MR imaging criteria and diagnostic pitfalls

Various magnetic resonance imaging (MRI) signs can be used in the diagnosis of medial meniscocapsular separation. A thorough knowledge of the normal anatomy of the medial meniscocapsular junction is essential to understand these signs. MRI signs used in the diagnosis of meniscocapsular separation include meniscal displacement relative to the tibia, meniscal corner tear, perimeniscal fluid, irregular meniscal outline, meniscofemoral and meniscotibial extension tears, and interposition of contrast medium between the meniscus and the MCL. Potential causes of false positive diagnosis of meniscocapsular separation include MCL bursitis, meniscal cyst, MCL tear, joint effusion, and perimeniscal fat.     

Do physical diagnostic tests accurately detect meniscal tears?

Numerous physical tests have been described but their diagnostic accuracy is often questioned. Karachalios et al. described the new ‘Thessaly test’ and concluded that it could be safely used as a first line screening test for the selection of patients who need arthroscopic meniscal surgery. Our objective was to study the role of physical diagnostic tests in screening for meniscal tears and to validate the diagnostic accuracy of the Thessaly test. We examined 109 patients (80 male, 29 female; average age: 39 years; range: 16–56) who were presented with a history suggestive of a meniscal tear. Joint line tenderness, McMurray’s test, and the Thessaly test were assessed by an independent investigator blinded to any imaging data in all patients. MRI and subsequent arthroscopy results were then collated. Our study showed a much lower diagnostic accuracy for the Thessaly test (61% for medial meniscus and 80% for lateral meniscus). It is comparable to McMurray’s test (57% for medial meniscus and 77% for lateral meniscus). The Joint line tenderness test has a far superior diagnostic accuracy (81% for medial meniscus and 90% for lateral meniscus). However, combining the joint line tenderness test with McMurray’s test or the joint line tenderness test with Thessaly test further increased the accuracy of physical diagnosis of meniscal tears. Magnetic resonance imaging (MRI) detected 96% of meniscal tears. Physical tests may not always be diagnostic of meniscal tears. MRI and arthroscopy may be essential in dubious clinical presentations and especially where more than one pathology is suspected. Our study showed that the Thessaly test in isolation was not useful for the detection of meniscal tears but it helps to increase diagnostic certainty when combined with other standard tests.     

How I diagnose meniscal tears on knee MRI

OBJECTIVE: The goal of this article is to summarize the literature about the diagnosis of meniscal tears on MRI including the normal appearance of the meniscus and the appearance of the various types of meniscal tears. In addition, I discuss my experience with the causes of errors in the MR diagnosis of meniscal abnormalities and the nuances of meniscal abnormalities that can mimic a meniscal tear. CONCLUSION: MRI is a highly accurate imaging method for diagnosing meniscal tears. To avoid errors in diagnosing meniscal tears, those interpreting MR examinations of the knee need to be aware of the attachments of the menisci and the normal variations in meniscal anatomy that may resemble a meniscal tear. In addition, by being aware of the patterns of meniscal tears, it is easier to diagnose the less common tears.     

The value of magnetic resonance imaging in our current management of ACL and meniscal injuries

Magnetic resonance imaging (MRI) is frequently used in the diagnosis of anterior cruciate ligament (ACL) and meniscal injuries. The aim of this retrospective study was to determine the reliability and value of MRI in our management of ACL and meniscal tears. 138 patients who had undergone a MRI to confirm or refute the clinical diagnosis of an ACL or meniscal tear were identified. Those who had subsequently undergone arthroscopy were selected. MRI findings and clinical diagnosis were compared with those at arthroscopy. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy of clinical diagnosis and MRI were then calculated. The overall accuracy for MRI was 91, 68 and 86% for detecting ACL, medial meniscal and lateral meniscal tears, respectively. Accuracy for clinical diagnosis was 90 and 64% for ACL and meniscal tears, respectively. In contrast to other series, our results indicate a lower accuracy of MRI in detecting pathology, especially of the ACL and medial meniscus. We noted a low sensitivity, specificity and positive predictive value but a high negative predictive value rendering MRI most useful as a negative diagnostic tool. We suggest that where symptoms and clinical findings support one of these diagnoses and arthroscopic therapeutic intervention is contemplated, that MRI scanning is not always beneficial. Our current practice of requesting scans to routinely confirm the diagnosis should be altered. Unnecessary MRI scanning increases the financial burden and delays patient treatment. No funding has been received from any sources and no conflicts of interests are stated in the submission of this article.     

MRI of meniscal bucket-handle tears

Objective. A meniscal bucket-handle tear is a tear with an attached fragment displaced from the meniscus of the knee joint. Low sensitivity of MRI for detection of bucket-handle tears (64% as compared with arthroscopy) has been reported previously. We report increased sensitivity for detecting bucket-handle tears with the use of coronal short tau inversion recovery (STIR) images. Design and patients. Three hundred and twenty-seven patients who had MRI of the knee between October 1994 and December 1996 and subsequently underwent arthroscopy were included in the study. We prospectively and retrospectively reviewed the MR examinations of the 30 patients with arthroscopically proven bucket-handle tears. Each of two observers examined each scan for the three traditional findings of bucket-handle tears: a double posterior cruciate ligament sign, a flipped meniscus sign and/or a fragment in the intercondylar notch. We also assessed STIR images in the coronal plane through the menisci looking for an area of increased signal within either meniscus with a displaced meniscal fragment. Results. By using four criteria for diagnosis of meniscal bucket-handle tears, our overall sensitivity compared with arthroscopy was 93% (28 of 30 meniscal bucket-handle tears seen at arthroscopy were detected by MRI). The meniscal fragment was well visualized in all 28 cases on coronal STIR images. The double posterior cruciate ligament sign was seen in 8 of 30 cases, the flipped meniscus was seen in 10 of 30 cases and a fragment in the intercondylar notch was seen in 18 of 30 cases. Conclusion. By using four criteria for diagnosis of bucket-handle tears, overall diagnostic sensitivity of MRI compared with arthroscopy increased from the previously reported 64% to 93%. Coronal STIR images are useful for detecting small meniscal bucket-handle tears.     

Prevalence of meniscal radial tears of the knee revealed by MRI after surgery

OBJECTIVE: Meniscal resection decreases the ability of the meniscus to evenly distribute forces placed on it. These forces are oriented centrifugally on the meniscus by normal weight-bearing and are distributed by circumferentially oriented fibers. This alteration may predispose the knee to radial tears after surgery. SUBJECTS AND METHODS: One of three musculoskeletal radiologists prospectively interpreted 100 consecutive postoperative MRI examinations of the knee. A prospective MRI report was generated for the referring orthopedic surgeon, and prospective MRI interpretations were correlated with arthroscopic findings (n = 63). MRI examinations on those patients who underwent second-look arthroscopy were retrospectively reviewed by three musculoskeletal radiologists who reached a consensus on the prevalence of new postoperative meniscal radial tears. MRI criteria for radial tear diagnosis were used as outlined by Tuckman et al.: truncation, abnormal morphology, lack of continuity, absence of the meniscus, or any combination of those criteria on one or more MR images. An additional criterion used was abnormal increased signal in that area on T2-weighted images. RESULTS: Thirty-two of the 100 patients had meniscal radial tears on prospective MRI interpretations. In 29 of these 32 patients, second-look arthroscopy confirmed meniscal radial tears in the areas described on the MRI examinations. Five additional radial tears were shown on second-look arthroscopy that were not seen on prospective MRI interpretations. Two of those additional five radial tears were seen on consensus retrospective MRI review. CONCLUSION: In this study, a 32% prevalence of meniscal radial tears in the postoperative knee was present on prospective MRI interpretations as opposed to a reported 14% prevalence in the nonoperated knee. Meniscal resection decreases the ability of the meniscus to evenly distribute forces placed on it. This circumstance may increase the prevalence of meniscal radial tears in the postoperative knee. New meniscal radial tears are common in patients presenting with pain after knee surgery.     

Meniscal tears: role of axial MRI alone and in combination with other imaging planes

OBJECTIVE: The purpose of this study was to determine the reliability of standard axial MR images alone in the diagnosis of meniscal tears of the knee and in combination with other imaging planes. MATERIALS AND METHODS: Sixty-two patients (55 men, seven women; age range, 23-68 years) with a prior MRI examination who underwent arthroscopic surgery of the knee during a 1-year period were included in the study group. Images were independently reviewed for identification of meniscal tears by two musculoskeletal radiologists blinded to arthroscopic findings. Sequences for meniscal evaluation included axial fat-saturated fast spin-echo proton density, coronal fat-saturated fast spin-echo proton density, and sagittal fast spin-echo proton density with 4- to 5-mm slice thicknesses. Imaging groups for evaluation were axial, coronal, sagittal, axial and sagittal, axial and coronal, and coronal and sagittal. Observers reported a confidence level for the presence or absence of meniscal tear in all imaging groups based on a 5-point scale. Statistical analysis considered medial and lateral menisci separately. RESULTS: Forty patients had medial meniscal tears, and 16 had lateral meniscal tears at arthroscopy. For medial and lateral meniscal tears, the accuracy (79% and 71%, respectively) of imaging in the axial plane was comparable to other imaging groups but the mean confidence levels (2.82 and 3.00, respectively) were low. In one patient, the axial plane alone correctly showed that no tear was present. No statistically significant difference was observed between imaging plane groups of both menisci in the diagnosis of meniscal tears (p > 0.05). The axial plane increased the accuracy of sagittal and coronal planes of lateral meniscus when combined. CONCLUSION: In standard knee MRI examinations, the axial imaging plane may be valuable for the detection and characterization of meniscal tears.