积水潭膝关节MRI

nullPractical Interpretation of Knee MRIPractical Interpretation of Knee MRIRoutine MRI protocolRoutine MRI protocolSagittal,Coronal,Axial Spin echo(SE) FSE,STIR T1, T2, PDJSTCoronal: T2FFE T2 STIR Saggital: T1 T2 T2FFE T2 STIR TR和TE决定成像加权 TR和TE决定成像加权 短TE 长TE 短TR T1 无用途 长TR PD T2nullT1 weighted image (TR<1000msec,TE<40msec) “anatomy”T2 weighted image (TR>1500msec,TE>60msec) “pathology”Fat suppression Chemical saturation Short tau inversion recovery (STIR)Tissue characterizationTissue characterization T1 T2 Adipose tissue Fat white gray Yellow marrow Water dark white Cortical bone black black Cartilage gray gray Tendon / ligament/meniscus black/gray black/gray Muscle gray gray Hematoma white white Chronic hemorrhage dark dark nullnullAnterior Cruciate LigamentAnterior Cruciate Ligamentextension ER 15°— 20°extension ER 15°— 20°Normal MR appearance direct sign of torn ACL direct sign of torn ACLnull discontinuity nullnullnullnullabnornal orientation (fallen ACL)nullnonvisualizationnullAvulsion fxAvulsion fxIndirectIndirectBone bruise sign Deep sulcus sign Segond fx generalized increase in signal intensity thickness increase Anterior drawer sign Acute hemarthrosis Buckling of PCL pivot-shift pattern pivot-shift patternnullKissing signnullSegond signnullDeep sulcus sign > 2mmnullnull generalized increase in signal intensity thickness increasenullBuckling of PCL nonspecificAnt.drawer signAssociated soft tissue injuriesAssociated soft tissue injuriesPosterior horn of medial meniscus Bucket handle tear MCLPosterior Cruciate LigamentPosterior Cruciate LigamentnullNormal MR appearance nullnullMeniscus-Femoral ligamentnullnullPrimary sign of PCLPrimary sign of PCL complete tear partial tear “peel off ” injurynullComplete tearnullnullGrade1Grade3Grade2partial tearnullSecondary sign of PCL injurybone marrow edema(BME) avulsion fxnullDashboard injury signBone Marrow EdemanullTibial avulsion fxAssociated ligament injuryAssociated ligament injuryACL injury MCL injury PLC/LCL injuryCollateral ligamentCollateral ligamentnullNormal Anatomy of MCLnullGrading MCL InjuriesnullGrade 1 (sprain)Grade 2 (partial tear)Grade 3 (complete tear)nullNormal Anatomy of the LCL Complex/ Posterolateral Corner ComplexIliotibial bandIliotibial bandLCLnullPopliteal m.complexBiceps tendonBiceps tendonnullVisible disruption of one of the posterolateral capsule structures Extensive surrounding soft tissue edema Avulsion fracture or marrow edema involving the medial aspect of the fibular headSigns of Posterolateral Corner InjurynullnullMenisciMeniscinullbow ties < 2triangularrectangularnullCriterial to detect meniscal tearCriterial to detect meniscal teargrade 3 signal abnormal meniscal morphology displaced or missing meniscal tissue meniscocapsular separationnullGrade III meniscus tearnullmissing fragmentmissing fragmentnullDisplaced fragmentnullsmall PHMMnullMRI signsMRI signsabsent bow ties sign(1 or fewer) double PCL sign large anterior horn sign too many bow ties(3 or more) notch signnullnullLarge & degeneration ant.hornnull3 or more bow-tiesnullBucket handle tearnullnullnulldouble PCL signnulldiscoid meniscusnull3 or more bow-tiesnullnullnullPitfalls in meniscus diagnosisPitfalls in meniscus diagnosisGrade II signal Transverse meniscus lig. Popliteal hiatus Meniscofemoral lig. Bursa or fat plane of MCLnullnull nullnullPopliteal hiatusnull内侧半月板后角的上隐窝 垂直 光滑 不连通nullnullPostoperative Meniscus• Grade 3 signal on T1-weighted images only is indeterminate for tear: it may represent postoperative change or retear of the meniscus • Grade 3 signal on a T1-weighted image that is bright as fluid on a T2-weighted image is diagnostic of retear. • A displaced meniscal fragment is diagnostic of retear. • Grade 3 signal in new a location is diagnostic of retearnullBone Marrow Edema(BME)Bone Marrow Edema(BME)pivot-shift injury dashboard injury hyperextension injury: ”kissing sign” clip injury patellar dislocationnullclip injurynullpatellar dislocationOCDOCDnullpopliteal cystpopliteal cystnullMeniscus cystMeniscus cystPVNSPVNSnullnullcruciate cystcruciate cystACL cystACL cystPatellar dislocationPatellar dislocationnullnullpatellar tendonJumper’s kneeHousemaid’s knee Deep & Superficail infrapatellar bursa