MSK MRI

Wrisberg-variant discoid lateral meniscus can be interpreted as peripheral longitudinal tear or popliteomeniscal fascicles tear. Watanabe classification recognizes three distinct variants of discoid meniscus, complete variant, partial variant, and Wrisberg variant. The Wrisberg-variant discoid lateral meniscus is an unstable type that lacks posterior ligament attachments, having only an attachme..

It is sometimes difficult to identify peripheral longitudinal tears in the posterior horn of the lateral meniscus because of the complex anatomy and posterior attachments of the capsule and popliteomeniscal fascicles. Far peripheral longitudinal tears can be more difficult to detect With an “extra” vertical line or layer in the meniscal periphery, it can be a subtle finding that indicates a tear..

On the left image, we can easily see the longitudinal tear, but on the right image it is very difficult to identify peripheral longitudinal tear. Like this, longitudinal tears that occur further peripherally can be more difficult to detect. When the tear extends through the meniscal substance it is readily identified against the contrast afforded by the low signal meniscal tissue. or, Identifica..

Here is a full-thickness peripheral longitudinal tear of the posterior horn of lateral meniscus. There is an extra vertical line or layer in the periphery of lateral meniscus, indicative of far peripheral longitudinal tear. The tear is parallel and adjacent to the popliteus tendon. It is sometimes difficult to identify peripheral longitudinal tears in the posterior horn of the lateral meniscus b..

Longitudinal tears are diagnosed on MRI by the presence of a vertical line of increased signal intensity contacting the superior, inferior, or both surfaces of the meniscus. The longitudinal tear extends to the inferior meniscal surface and courses parallel to the long axis of the meniscus on corresponding PD FSE axial image. [Tear_04] case demonstrates vertically oriented increased signal inten..

Longitudinal tears almost always involve the posterior horn in both the medial and lateral menisci. They are diagnosed on MRI by the presence of a vertical line of increased signal intensity contacting the superior, inferior, or both surfaces of the meniscus. MR images showing vertically oriented increased signal intensity contacting both articular surfaces of the body and posterior horn of the ..

Left drawing shows a typical longitudinal tear that divides the meniscus into inner and outer halves, and the right drawing shows the expected appearance of the tear. Longitudinal tear with peripheral vertical orientation through the circumferential collagen fibers. Longitudinal tears run perpendicular to the tibial plateau and parallel to the long axis of the meniscus. Unlike horizontal or radi..

Anomalous insertion of the medial meniscus (AIMM) into the anterior cruciate ligament (ACL) is rare.The AIMM has the same anatomical description as the anteromedial meniscofemoral ligament It appears as a linear band isointense to the ACL and meniscus, which runs parallel to the ACL and demonstrates a hyperintense gap between it and the ACL On MRI, this anomaly may be misinterpreted as an ACL te..

The medial OMML originates from the anterior horn of the medial meniscus and inserts onto the posterior horn of the lateral meniscus between the ACL and PCL. This structure should not be mistaken for a bucket handle meniscal tear A bucket-handle tear is a longitudinal tear with central migration of the inner “handle” fragment The correct diagnosis of an oblique meniscomeniscal ligament rather th..

The medial OMML originates from the anterior horn of the medial meniscus and extends through the intercondylar notch to insert onto the posterior horn of the lateral meniscus. This ligament passes between the ACL and PCL. This oblique meniscomeniscal ligament is kind of similar SI to meniscal tissue. The sagittal image near the midline demonstrates a linear low signal intensity structure atop th..