Sagital FSE PD:
Cruciate ligaments
Anterior Cruciate Ligament (3.0T) (pd fat sat)
Pitfalls
- - Partial volume averaging with lat fem condyle
- - ACL myxoid degeneration/cyst (2)
- - Proximal tear (ACL anterior fibers should make an acute angle with the intercondylar notch roof
- - Partial/chronic tear
Associations:
- - Typical bone marrow edema pattern(lat fem condyle at trochlear sulcus and post-lat tibial plateau)
- - Deep lat notch sign (lat fem condyle trochlear sulcus) (pf)
- - Lat meniscus tears > Med meniscus tears
- - O'Donoghue's Triad (ACL, MMT, MCL) (rare)
- - Segond Fx
- - Avulsion of the medial tibial spine (peds>adult)
Posterior Cruciate Ligament
Extensor mechanism
- Patellar tendon
- Quadriceps tendon
Sagital CSE PD fat saturation:
Menisci (Longitudinal, Horizontal/Oblique tears, Bucket handle, Radial/Parrot beak)
Medial Meniscus
Pitfalls
- - Myxoid degeneration
- - Intrasubstance tear not extending to an articular surface
- - Magic angle
- - Transverse meniscal/transgeniculate ligament (ant horn)
Associations:
- - Post horn >2x ant horn
- - PHMM undersurface may be an arthroscopic blind spot.
- - Meniscal ossicle (extremely rare)
Lateral Meniscus
Pitfalls
- - Meniscofemoral ligaments
- - Humphrey's may mimic a meniscal fragment
- - Wrisberg (post horn)
- - Popliteus tendon mimicking a vertical tear (post horn)
- - Transverse meniscal/transgeniculate ligament (ant horn)
Associations:
- - Post horn = ant horn
- - Discoid Meniscus
- - Meniscal cyst (lat>med)
Cartilage (chondromalacia, osteo-cohondral defect)
Bone marrow edema pattern
Coronal FSE PD fat saturation:
Medial supporting structures:
Tibial collateral ligament
Pitfalls
- - Fibrofatty tissue/bursa between superficial/deep layers of MCL
- - Chronic/healed MCL tears
Associations:
- - Meniscocapsular separation
- - Pellegrini-Steida dz
Lateral supporting structures: (and posterior lateral corner)
Fibular collateral ligament (pd w/o fatsat)
Associations:
- - ACL and PCL injuries (very rarely an isolated injury)
Arcuate ligament and posterior lateral capsule
Associations:
- - Arcuate sign/fibular head avulsion fx
Popliteus tendon
Biceps Femoris tendon (T1 for anatomy)
Iliotibial band (T1 for anatomy)
Bone marrow edema
Axial STIR or 3.0T Axial FSE PD fat sat:
Cartilage Medial Meniscus (3.0T pd fatsat)
Associations:
- - Chondromalacia patella
Effusion/Baker's cyst
Associations:
- - loose boodies, hemorrhage, ruptured/dissecting
Med/Lat retinacula/patello-femoral ligaments
Associations:
Pes Anserinus: Sartorius, Gracillus, Semitendinosis
Associations:
- - Pes Anserinus bursitis
