1. MR Imaging of the knee
Dr.Ajai Perti MD.
Chief Radiologist & Medical Director
Vita Diagnostics Ltd.
MR & CT Imaging Centers,
Cochin, Thrissur, Vaikom,Calicut
7. Grading of meniscal signal
Grade I : Globular intrasubstance increased
signal intensity, not extending to
articular surface.
Grade II : Linear , may communicate with
capsular margin.
Grade III : Sharp linear, extending to articular
surface
40. MCL injury
Grade I : Edema & hemorrhage superficial to lig.
Grade II : Displacement of lig. fibres from bone
Grade III : Complete lig. discontinuity.
47. Chondromalacia patella
⢠Softening of articular cartilage
⢠Common in young adults, can mimic meniscal tear
⢠Predisposing â Trauma, patellar malalignment,
subluxation , PCL injury etc.
48.
49. ⢠Primarily affects male patients -
10 to 20 yrs
⢠Typically involves the lateral
surface of med.fem.condyle.
⢠H/o trauma in 50%
Osteochondritis dissecans
50. Osteochondritis dissecans - Staging
Stage I : lesion 1-3cm ; intact cartilage
Stage II : Cartilage defect ; no loose body
Stage III : Partially detached ost.chond fragment
Stage IV : Complete separation ; loose body +
56. ⢠Grade-2 vs grade 3 signals â
⢠To distinguish articular surface extension of
the tears.
⢠Intrasubstance tear âat scopy - may need
probing.
⢠Effusion- If present â disrupted menisceal
surface.
57. ContdâŚ.
⢠Transverse ligament-
⢠Anterior horns of medial & lateral
meniscus.
⢠Antero-lateral to LM - between tibial
attachment of ACL and Infra patellar fat
pad.
⢠Seen in 40% pts.
⢠Simulates an oblique tear of LM.
58. contdâŚ.
⢠Fibrillation- Fraying of the free edge.
⢠Use fat sat images.
⢠Frayingď Macerationď Imbibes synovial
fluidď High signal on T2WIď Mimics a
tear.
59. contâŚ
⢠Popliteus tendon-
⢠Sheath near the Posterior horn of LM ď
Grade-3 signal ď Tear.
⢠After lat. meniscectomyď Popliteus
ď Retained post.horn remnant.
60. contd. âŚ
⢠Menisco-Femoral Ligaments-Anterior -Lig.
Of Humphrey- ant. to PCL-34%.
⢠Posterior -Lig. Of Wrisberg- post. to PCL-
60%.
⢠Fat bet. Post horn of LM and MF ligament
ď Mimics vertical tear in post.horn of LM.
61. Pseudo bucket-handle tearâŚ.
⢠Separate portions of PHLM-In corona
sections.
⢠Not seen with Medial meniscus.
⢠Look at Sagittal images.
62. Lax meniscal signâŚ.
⢠Lax or redundant meniscus- MMď with
asso. Effusionď Mimics menisceal tear.
⢠Disappears with joint manipulation.
64. Final RequestâŚ.
⢠What the mind doesnât know the eyesâŚâŚ.
⢠Radiologists do make mistakes even after
years of MR interpretationâŚ.
⢠Follow ups are of great help to improve the
diagnostic accuracyâŚ..!!!!