膝关节板股韧带MRI分析

目的 明确板股韧带正常MRI表现,鉴别板股韧带所致假撕裂与外侧半月板后角真撕裂.方法 对53例受检查者进行MRI扫描,观察板股韧带MRI表现.结果 前板股韧带显示率24.5%,后板股韧带显示率77.4%,前后板股韧带同时存在19%.板股韧带易误诊半月板撕裂13例,假撕裂在矢状位上仅有2种走行方式,即后下斜形及垂直方向,在冠状位上无线样高信号.结论 根据板股韧带形态、走行及假撕裂的方向、位置,可鉴别外侧半月板后角真假撕裂.     

膝关节外侧半月板后根部撕裂的MRI评价

目的:评价MRI对膝关节外侧半月板后根部撕裂的诊断价值,以提高对该病的认识,为临床诊疗提供帮助。方法:回顾性分析16例经关节镜或手术证实的外侧半月板后根部撕裂患者的MRI资料;在MRI冠状位、矢状位及横断位上评价外侧半月板后根部撕裂的直接征象及伴随征象;对冠状位"裂隙征"、矢状位"幽灵征"及横断位"裂隙征"的发生率行Fisher确切概率法检验,以P0.05为差异有统计学意义。结果:外侧半月板后根部撕裂冠状位"裂隙征"15例,矢状位"幽灵征"14例,横断位"裂隙征"4例;冠状位"裂隙征"与矢状位"幽灵征"发生率比较差异无统计学意义(P 0.05),冠状位"裂隙征"与横断位"裂隙征"显示率比较差异有统计学意义(P0.05),矢状位"幽灵征"与横断位"裂隙征"发生率比较差异有统计学意义(P0.05)。伴随征象中外侧半月板突出5例(5/16);外侧半月板后根部附着处软骨下骨水肿3例(3/16);胫骨外侧关节软骨损伤4例(4/16);合并外侧半月板其他节段撕裂4例(4/16);合并前交叉韧带撕裂6例(6/16),后交叉韧带撕裂1例(1/16),板股韧带缺失7例(7/16),其中外侧半月板突出5例中,4例板股韧带缺失或显示不清;合并胫骨平台骨折6例。结论:外侧半月板后根部撕裂MRI表现具有特征性;MRI对评价外侧半月板后根部撕裂具有重要价值。     

磁共振对膝板股韧带附着区半月板撕裂的诊断效果研究

目的探讨磁共振对膝板股韧带附着区半月板撕裂的诊断效果。方法回顾性分析2015年1月~2016年7月期间在我院接受治疗的膝板股韧带附着区半月板真性撕裂及伴发前交叉韧带(anterior cruciate ligament,ACL)损伤102例患者资料,作为实验组,选取在同一时间段内因ACL损伤患者来我院就诊的患者42例,作为对照组A组,选取同一时间段内在我院正常体检的人员42例,作为对照组B组。三组受试者均行膝关节MRI检查,观察比较三组患者的MRI表达状况、膝关节及其他结构损伤情况、高信号影连续显示的层数、长度等数据。结果实验组和对照组A组膝关节其他结构损伤情况比较无统计学意义;矢状面上,实验组MRI表达的主要特征为外侧半月板后角周缘部纵向线状高信号影;冠状面上,实验组MRI表达的主要特征有板股韧带起始部斑片状信号增高及局部形态不规则;其余部分的信号较为均匀;对照组MRI表达特点为:冠状面上,板股韧带起始部与外侧半月板后根部在同层面或相邻层面显示高信号;横断面上板股韧带的后上部起始部表现为小条状低信号,半月板后根部位于前下方,呈条片状低信号;实验组患者的横断面长度及矢状面连续显示层数均高于对照组A组、对照组B组,实验数据具有统计学意义;联合应用"连续线征"和"拉链征"诊断真性撕裂的敏感度为84.31%(86/102)、特异度为95.24%(80/84)、准确度为90.32%(168/186)。结论磁共振对膝板股韧带附着区半月板撕裂的诊断效果显著,联合应用"连续线征"和"拉链征"较易鉴别真、假性撕裂。     

膝板股韧带附着区外侧半月板后角撕裂的MRI表现及诊断价值

目的 探讨膝板股韧带附着区外侧半月板后角（PHLM）撕裂的MRI表现及鉴别诊断价值。 方法 选取2012年12月至2018年6月因前交叉韧带（ACL）损伤在南通市通州区中医院就诊的35例膝板股韧带附着区PHLM撕裂患者作为观察组,搜集同期30例ACL损伤但非PHLM撕裂患者作为对照A组,另选取同期例行体检的30名健康者作为对照B组。3组受试者均行膝关节MRI检查,观察3组受试者的MRI表现。分别应用χ 2检验、单因素方差分析和t检验分析膝关节MRI征象的发生率、膝关节周围结构的损伤情况及膝关节线状高信号影显示的层数和长度,并采用受试者工作特征（ROC）曲线分析鉴别诊断PHLM真、假性撕裂的效能。 结果 观察组患者在MRI矢状面和横断面图像上均表现为明显的PHLM周缘部线状高信号,矢状面上可连续检出（5.75±1.38）层（称“连续线征”）,横断面上自内向外延伸（15.06±5.02）mm（称“拉链征”）,与对照A组、B组比较差异均有统计学意义（F=43.231、36.113,均P<0.05）。以“连续线征”和“拉链征”作为阳性标准,MRI诊断膝板股韧带附着区PHLM撕裂的灵敏度为85.71%、特异度为95.00%、准确率为91.58%。 结论 膝板股韧带附着区PHLM撕裂在MRI上有明显的征象,辅以“连续线征”和“拉链征”进行鉴别诊断,可明显提升诊断效果。     

膝关节低场MRI最佳检查方法的回顾分析

目的:探讨膝关节低场磁共振的最佳检查方法。方法:在76例77个膝关节MRI检查中,冠状面图像的第一定位线是在横断面图像上内、外侧髁后缘连线的平行线;第二定位线是在矢状面图像上以胫骨髁间隆起的上缘为中心做股骨-胫骨长轴的平行线。矢状面图像的第一定位线是在冠状面图像上内、外侧半月板中心连线的垂线向外上内下倾斜,第二定位线是在横断面上内、外侧髁后缘连线的垂线向内前外后倾斜。结果:冠状面显示半月板、侧副韧带最佳,矢状面显示半月板、交叉韧带最佳,矢状面第一定位线平均倾斜角度(-x±s)为6.9°±1.3°,第二定位线倾斜角度平均为5.8°±1.4°。结论:在做膝关节MRI检查时,矢状面扫描双定位线的角度和方向要做适当调整,以便清晰显示前交叉韧带。     

半月板根部放射状撕裂MR表现

目的 探讨半月板根部放射状撕裂的MRI表现.方法 回顾性分析17例经关节镜证实半月板根部放射状撕裂MRI表现.结果 17例半月板根部放射状撕裂中,16例位于内侧半月板后角,1例位于外侧半月板后角.MRI表现为根部横断位和冠状位后角条状高信号和矢状位表现为后角弥漫性高信号.同时检出继发征象,包括半月板膨出11例,关节面下骨挫伤13例.17例患者均伴有膝关节退行性改变.结论 膝关节半月板根部放射状撕裂主要发生在内侧半月板后角,MRI可以依据多方位成像显示其多种征象,熟悉这些征象可以帮助放射诊断医师作出正确诊断指导临床治疗方案的实施.     

膝关节侧副韧带MRI显示方法分析

目的 探讨正常人膝关节侧副韧带MRI检查方法及表现. 方法 对55例成人选择矢状面、冠状面、后斜冠状面进行MR扫描,观察侧副韧带显示的情况,测量内、外侧副韧带的有关数据,并与解剖文献大体测量结果进行比较. 结果 (1)矢状面上内侧副韧带的定位线与胫骨干长轴的夹角为0.55°±0.25°;外侧副韧带的定位线与腓骨颈长轴的夹角为11.47°±1.61°.(2)内侧副韧带在常规冠状位1个层面上完整显示占96%,同时外侧副韧带在1个层面上完整显示占82%;外侧副韧带在11°后斜冠状位1个层面上完整显示占90%.(3)正常内、外侧副韧带在T1WI和PDWI上均呈扁平条状低信号,平均长度分别为11.53 cm和5.31 cm.结论选择完全显示胫骨干、腓骨颈的矢状面为基准面,层厚3 mm MR扫描能很好地显示内、外侧副韧带的解剖结构.     

膝关节盘状半月板的MRI诊断

目的　探讨膝关节盘状半月板的MRI表现以及MRI诊断盘状半月板的标准。材料与方法　对 2 6例经手术或关节镜证实的盘状半月板和 3 0例健康志愿者的膝关节进行MRI检查 ,对正常及盘状半月板的形态、大小及信号改变进行对照观察 ,包括半月板宽度和厚度的测量。结果　 2 6例盘状半月板中 ,2 5例为外侧盘状半月板 ,只有 1例为内侧盘状半月板 ,18例为厚板型 ,8例为楔型。冠状面上 ,盘状半月板体部平均宽度及厚度明显大于正常半月板 ,分别为 2 3 .4mm、11.5mm (P <0 .0 5 )和 3 .2mm、0mm(P <0 .0 1)。但盘状半月板边缘厚度与对侧半月板厚度差超过 2mm者只有 6例。矢状面上 ,连续 3层或 3层以上显示盘状半月板的前后角相连形成“领结”样改变 ,而正常半月板只有 2层有此表现。 2 6例盘状半月板中 ,2 4例并发半月板变性或撕裂。结论　盘状半月板多见于外侧半月板。盘状半月板特征性的MR表现是盘状半月板明显较正常半月板厚、大 ,MRI检查易于诊断。盘状半月板常并发半月板变性或撕裂。     

膝关节盘状半月板分型与撕裂类型相关性的MRI分析

目的:进行盘状半月板的流行病学研究,探讨膝关节盘状半月板的诊断标准、分型及其与年龄、撕裂类型的关系,以提高对盘状半月板及撕裂MRI表现的认识。方法:对842例诊断为盘状半月板的患者按年龄分为≤19岁、20³9岁、4039岁、40⁵9岁、≥60岁组。对全部患者冠状面髁间棘层面半月板宽度与胫骨平台宽度之比(板面比)、矢状面"领结样"改变层面中半月板后角最厚层面的厚度及矢状面"领结样"改变层数进行测量、分析。根据盘状半月板MRI表现,分为板型、楔型、肥角型。分析盘状半月板分型、年龄与撕裂类型的关系。结果:盘状半月板以外侧多见,女性发病率是男性的1.64倍。842例中,板型535例、楔型274例、肥角型33例。半月板撕裂354例,撕裂率为42.0%。842例板/面比均≥0.20,矢状面"领结样"改变层面中半月板后角最厚层面的厚度≥4.40mm。盘状半月板分型与撕裂类型及年龄分布有关系,而年龄分布与撕裂类型无明显相关。结论:盘状半月板多见于外侧,常伴半月板撕裂。板面比≥0.20、矢状面"领结样"改变层面中半月板后角最厚层面的厚度≥4.40mm、矢状面连续≥3层"领结样"改变,为盘状半月板的MRI诊断标准;盘状半月板分型与撕裂类型有关系;年龄可影响盘状半月板分型。     

外伤性膝关节前外侧韧带损伤的MR影像特征及相关性分析

目的探讨外伤所致膝关节前外侧韧带损伤病人的MR影像特征,并分析其与前交叉韧带撕裂、外侧半月板撕裂及骨挫伤的相关性,为深入研究前外侧韧带对膝关节稳定性的作用提供可靠依据。方法回顾性分析2016年1月—2017年2月间因外伤进行膝关节MRI检查的320例病人(共321膝)的影像资料。采用美国GE公司生产的Signa HDe 1.5 T MR扫描设备,分别行膝关节斜矢状面T1WI、质子密度加权成像(PDWI)和冠状面、横断面PDWI扫描。根据前外侧韧带的完整性和损伤部位对所有病人进行分类统计。采用独立性卡方检验对前外侧韧带撕裂与前交叉韧带撕裂、外侧半月板撕裂及骨挫伤的相关性进行分析。结果全部病人膝关节MR影像均可显示前外侧韧带,显示率为100%。151/321膝(47.0%;95%CI为41.6%~52.5%)存在前外侧韧带损伤,其中累及胫骨部、股骨部及半月板部的分别为97膝、96膝及65膝。前交叉韧带撕裂158膝,外侧半月板撕裂98膝,股骨外侧髁挫伤58膝,外侧胫骨平台挫伤71膝,分别与前外侧韧带撕裂具有相关性(均P0.001)。结论 MRI检查可以很好地显示前外侧韧带解剖及其损伤情况。膝关节前外侧韧带损伤与前交叉韧带撕裂、外侧半月板撕裂及膝外侧骨挫伤具有相关性。     

MR imaging of anterior cruciate ligament reconstruction graft

OBJECTIVE. The objective was to determine the MR imaging findings that differentiate intact anterior cruciate ligament reconstruction graft, partial-thickness tear, and full-thickness tear, using arthroscopy as the gold standard. MATERIALS AND METHODS. Sixteen consecutive MR imaging examinations were retrospectively and independently evaluated by two musculoskeletal radiologists for primary signs (graft signal, orientation, fiber continuity, complete discontinuity, and thickness) and secondary signs (anterior tibial translation, uncovered posterior horn lateral meniscus, posterior cruciate ligament hyperbuckling, and abnormal posterior cruciate ligament line) of anterior cruciate ligament reconstruction graft tear in 15 patients with follow-up arthroscopy. Results were compared with arthroscopy, and both receiver operating characteristic curves and kappa values for interobserver variability were calculated. RESULTS. Arthroscopy revealed four full-thickness graft tears, seven partial-thickness tears, and five intact grafts. Of the primary signs, graft fiber continuity in the coronal plane and 100% graft thickness in the sagittal or coronal plane were most valuable in excluding full-thickness tear. Complete discontinuous graft in the coronal plane also was valuable in diagnosis of full-thickness tear. Of the secondary signs, anterior tibial translation and uncovered posterior horn lateral meniscus assisted in differentiating graft tear (partial or full thickness) from intact graft. The other primary and secondary signs were less valuable. Kappa values were highest for graft fiber continuity and graft discontinuity in the coronal plane. CONCLUSION. Full-thickness anterior cruciate ligament graft tear can be differentiated from partial-thickness tear or intact graft by evaluating for graft fiber continuity (coronal plane), complete graft discontinuity (coronal plane), and graft thickness (coronal or sagittal plane).     

MR imaging of the knee: pseudotear of the lateral meniscus caused by the meniscofemoral ligament

Sagittal MR images of the knee often show a linear band of increased signal in the medial aspect of the posterior horn of the lateral meniscus that can be confused with a meniscal tear. This pseudotear is due to the meniscal insertion of the meniscofemoral ligament. To study the normal appearance of the medial aspect of the posterior horn of the lateral meniscus, we analyzed 109 MR examinations and correlated the findings with the results of arthroscopy. The meniscofemoral ligament was visualized in 54 cases (50%), and in 42 cases (39%) it caused the appearance of a pseudotear on sagittal images. The pseudotear had one of two orientations. The most common (35/42) was an oblique orientation coursing from the superior surface posteriorly and inferiorly. The other (7/42) was a more vertical orientation parallel to the base of the meniscus. Knowledge of the characteristic location and orientation of the meniscofemoral ligament should help to distinguish it from a true meniscal tear on MR images.     

Meniscal position on routine MR imaging of the knee

 Objective. To determine the prevalence of meniscal protrusion (i.e. location of the outer edge of a meniscus beyond the tibial articular surface), and to determine its relationship with internal derangement, joint effusion, and degenerative arthropathy. Design and patients. Sagittal and coronal MR images of 111 abnormal and 46 normal knees were evaluated for the presence of meniscal protrusion. We set 25% as the minimum amount of displacement considered abnormal because this was the smallest amount of displacement we could confidently discern. Presence of meniscal tear, anterior cruciate ligament (ACL) injury, joint effusion, or osteophytosis was also recorded. Results and conclusion. Normal examinations demonstrated protrusion of the medial meniscus in 6.5% of sagittal images and 15% of coronal images, and of the lateral meniscus in 2% and 13%, respectively. Fisher’s exact test demonstrated a statistically significant difference between the normal and abnormal groups for the medial meniscus on both sagittal (P<0.0001) and coronal (P=0.01) images, but not for the lateral meniscus in either plane (P>0.2). A protruding medial meniscus was associated with effusion and osteophytosis (P<0.05) but not with meniscal or ACL tear (P>0.1). Posterior protrusion of the lateral meniscus was only associated with ACL injury (P<0.0001); protruding anterior horns and bodies of lateral menisci were not associated with any of the four abnormalities. It is concluded that the medial meniscus may occasionally protrude more than 25% of its width, but protrusion is more often due to effusion and osteophytes. Protrusion of the posterior horn of the lateral meniscus is associated with ACL insufficiency, while protrusion of the body and anterior horn of the lateral meniscus is a normal variant.     

Pericruciate meniscal cysts arising from tears of the posterior horn of the medial meniscus: MR imaging features that simulate posterior cruciate ganglion cysts.

OBJECTIVE: The purpose of this study is to describe MR imaging features of an unusual type of meniscal cyst arising from tears of the posterior horn of the medial meniscus in 10 patients. MATERIALS AND METHODS: Retrospective review of MR examinations of the knee was performed of 10 patients (nine men, one woman; mean age, 39 years) in whom evidence of a meniscal tear and a cyst-like structure around the posterior cruciate ligament (PCL) was seen. RESULTS: An oval mass with low signal intensity on T1-weighted MR images and increased signal intensity on T2-weighted MR images posterior to the PCL, simulating a PCL ganglion cyst, was seen in all 10 patients. A tear of the posterior horn of the medial meniscus was also seen in all patients. The sites of communication between the cyst and meniscal tear were observed in sagittal MR images in eight patients. Septation within the cyst and associated joint effusion were seen in eight and four patients, respectively. Arthroscopy in eight patients and transmeniscal needle drainage in the other two patients confirmed both the meniscal tear and the pericruciate meniscal cyst. CONCLUSION: Pericruciate meniscal cysts cause fluid collections posterior to the PCL, simulating a PCL ganglion cyst. Careful analysis of the posterior horn of the medial meniscus should be performed when a cyst-like structure is seen adjacent to the PCL.     

MR imaging of displaced bucket-handle tear of the medial meniscus

A bucket-handle tear of the meniscus is a vertical or oblique tear with longitudinal extension toward the anterior horn in which the inner fragment is frequently displaced toward the intercondylar notch with resultant mechanical locking of the knee joint. A precise MR diagnosis requires identification of the centrally displaced fragment because the peripheral nondisplaced component may have only a subtle truncated or foreshortened appearance that may escape detection. Eighteen consecutive cases of displaced bucket-handle tears of the medial meniscus diagnosed by MR had a characteristic low-signal band extending across the joint and projecting over the medial tibial eminence. The posterior portion was parallel and beneath the posterior cruciate ligament on both sagittal and coronal images. Arthroscopy confirmed the presence and location of the displaced fragment in all 18 cases. Awareness of this characteristic MR finding may increase the sensitivity of MR imaging in the diagnosis of bucket-handle tears of the medial meniscus.     

MR imaging of the anterior intermeniscal ligament: classification according to insertion sites

Our objective was to study the frequency of anterior intermeniscal ligament on MR imaging and to make a classification according to its insertion sites on MR images. Sagittal T1-weighted and thin-section transverse T2*-weighted MR images of the knee were prospectively evaluated in 229 subjects without significant synovial effusion or total rupture of the anterior cruciate ligament. By using thin-section transverse images, the ligament was classified into three types according to its insertion sites (type A: between anterior horns of medial and lateral menisci; type B: between anterior horn of medial meniscus and anterior margin of lateral meniscus; type C: between anterior margins of medial and lateral menisci). On sagittal images location of the ligament was determined with respect to a line drawn between anterior of the tibial epiphysis and posterior of the intercondylar notch to look for a relation between its type on transverse images and location on sagittal images. Separately, arthroscopy was made in 36 patients to verify the MR assessment of the presence of the ligament. Anterior intermeniscal ligament was found in 53% of the subjects. Type B was the most common group (58%). Magnetic resonance imaging has a sensitivity and a specificity of 67 and 100%, respectively, in the detection of the ligament. Types A and C had a statistically significant location posterior and anterior, respectively, to the master line on sagittal images. In arthroscopy, the ligament was either cord-like (67%) or flat (33%) in appearance. Routine sagittal MR images can help identify anterior intermeniscal ligament.     

Posterior horn lateral meniscal tears simulating meniscofemoral ligament attachment in the setting of ACL tear: MRI findings

PURPOSE: We have noted apparent far lateral meniscal attachment of the meniscofemoral ligament (MFL) with an anterior cruciate ligament (ACL) tear. This study evaluates MFL attachment and association with posterior horn lateral meniscus (PHLM) tear. MATERIALS AND METHODS: Nine months of knee arthroscopy reports were reviewed to classify the PHLM and ACL as torn or normal. After excluding those with prior knee surgery, MR images were reviewed by two radiologists to determine the number of images lateral to PCL, which showed the ligaments of Humphrey and Wrisberg visible as structures separate from the PHLM. Any patient with abnormal PHLM surface signal not continuous with the MFL was excluded. MRI findings were compared with arthroscopy using Student's t test and Fisher's exact test. RESULTS: Of the 54 participants, 5 had PHLM tears and 49 were normal. Twenty-one had ACL tears; all those with an PHLM tear had an ACL tear. The ligament of Humphrey inserted on average 0.9 consecutive images lateral to the PCL without an PHLM tear and 4.7 with an PHLM tear; the ligament of Wrisberg inserted on average 3.0 consecutive images without an PHLM tear and 4.5 with an PHLM tear (slice thickness/gap = 3 mm/0.5 mm). There was a significant association between PHLM tear and number of images (p = 0.0028), and between ACL tear and this type of PHLM tear (p = 0.0064). CONCLUSION: Apparent far lateral meniscal extension of a meniscofemoral ligament (greater than or equal to four images lateral to the PCL) should be considered as a possible PHLM tear, especially in the setting of an ACL tear.     

Lateral meniscus root tear and meniscus extrusion with anterior cruciate ligament tear

PURPOSE: To retrospectively determine the prevalence of posterior lateral meniscus root tears (LMRTs), as depicted on magnetic resonance (MR) images, in patients with an anterior cruciate ligament (ACL) tear and to investigate the association of LMRTs with lateral meniscus extrusion and other ligament injuries. MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent was not required. This study was HIPAA compliant. MR images were obtained in 174 male and 119 female patients (mean age, 37 years; age range, 16-87 years) and retrospectively reviewed for LMRT, medial meniscus root tear (MMRT), nonroot meniscus tear, meniscus extrusion, and presence of meniscofemoral ligaments (MFLs). The chi2 and unpaired Student t tests were performed. RESULTS: In 33 patients, 34 meniscus root tears were identified. An LMRT was present in 26 (9.8%) of 264 patients, and an MMRT was present in eight (3.0%) (P=.008). Lateral meniscus extrusion was present in six (23%) of 26 LMRTs and five (2.2%) of 231 patients with normal meniscus roots (P<.001). Complex or deep radial tears were found in three of five cases of lateral meniscus extrusion and normal root. The MFL was not observed in five (19%) of 26 studies of an LMRT. Among these 26 studies of an LMRT, lateral meniscus extrusion was identified in three (14%) of 21 cases in which the MFL was intact and in three (60%) of five cases in which the MFL was not identified (P<.03). Prevalence of an extruded meniscus was seven (88%) of eight for an MMRT and six (23%) of 26 for an LMRT (P=.001). CONCLUSION: Prevalence of LMRTs is greater than that of MMRTs in patients with an ACL tear. LMRTs and complex and radial tears are associated with lateral meniscus extrusion; an absent MFL is more prevalent in patients with LMRTs and when the meniscus is extruded.