This document discusses MRI imaging of the knee, focusing on the meniscus. It provides details on different MRI sequences that can be used to image the knee, including T1, proton density, T2, and fat suppression sequences. It outlines criteria for diagnosing a meniscal tear based on MRI findings. Specific types of meniscal tears are described, such as bucket-handle tears and cleavage tears. Other knee structures discussed include the ligaments, popliteus tendon, and transverse ligament. Factors that can complicate interpretation, such as normal meniscal vascularity and postoperative changes, are also covered. Accuracy rates of MRI for diagnosing meniscal tears are provided.

2. Professor of Orthopaedic Surgery
Benha Faculty of Medicine
BY

11. T1 sequence.

12. Proton Density sequence.

13. T2 sequence.

14. Fat suppression sequence.

16. Gradient echo image.

17. Normal meniscus.

18. Sagital image. Coronal image. Axial image.

30. PCLLine

37. Criteria of Meniscal tear:Criteria of Meniscal tear:
(1) Linear or complex intrameniscal
signal extending to the superior or
inferior surface of the meniscus.
(2) Gross disruption of the normal
meniscal contour with obvious
foreshortening.
 (3) complete absence of any meniscal
structure.

38. Criteria of Meniscal tearCriteria of Meniscal tear
 Linear or complex
intrameniscal
signal extending to
the superior or
inferior surface of
the meniscus

39. Linear or complex intrameniscal signalLinear or complex intrameniscal signal

40. Gross disruption

41. Foreshortening.

42. Criteria of Meniscal tearCriteria of Meniscal tear
Absence of any
meniscal
structure.

45. Ant.

46. Bucket-handle tearsBucket-handle tears
There are four traditional findings for bucket-handle tears:
1- Fragment in the intercondylar notch
2- Flipped meniscus sign
3- Double posterior cruciate ligament sign
4- Absent bow tie sign
Resnick, 2002

47. Fragment in the intercondylar notch

48. Flipped meniscus sign

49. Double posterior cruciate ligament sign

51. Absent bow tie sign

52. Bucket-handle tears.Bucket-handle tears.
Lat. M. Med.M.

53. Bucket-handle tear lat.M.Bucket-handle tear lat.M.

54. Bucket Handle TearBucket Handle Tear

55. Bucket Handle TearBucket Handle Tear

57. Bucket handle tear lat.M.

60. Watanabe's classification ofWatanabe's classification of
Discoid meniscus.Discoid meniscus.

61. Discoid MeniscusDiscoid Meniscus

63. Discoid MeniscusDiscoid Meniscus

64. Discoid meniscus.Discoid meniscus.

65. Discoid Meniscus.Discoid Meniscus.

66. Discoid MeniscusDiscoid Meniscus

67. Cleavage TearCleavage Tear

68. Flap TearFlap Tear

69. Flap TearFlap Tear

70. Radial TearRadial Tear

71. Deg. TearDeg. Tear

72. Meniscal cyst.Meniscal cyst.

73. Meniscal ossicle.

86. Normal vascularity.Normal vascularity.
In children there is frequently a high
signal within the meniscus which reflects
the normal vascularity which decreases
with age.
 This may confuse the diagnosis of
meniscal abnormality.
(Takeda et al.1998)

87. Normal vascularity.Normal vascularity.

88. Normal vascularity.Normal vascularity.

89. Grade2 versus grade3.

93. Transverse ligament.Transverse ligament.

94. Transverse ligament.Transverse ligament.

96. PopliteusPopliteus tendontendon

97. PopliteusPopliteus tendon.tendon.

98. Ligament of HumphreyLigament of Humphrey
 An intra-articular
loose body may be
simulated by a branch
of the
 meniscofemoral
ligament

99. Ligament of Wrisberg.Ligament of Wrisberg.

102. POSTOPERATIVE MRI.POSTOPERATIVE MRI.
A knee which has been operated on
is always a diagnostic challenge and
false-positive MRI results may
occur. Surgical trimming of a
meniscus may have extended almost
to an area of myxoid degeneration,
and MRI may erroneously suggest a
persisting defect. .

106. Accuracy of MRIAccuracy of MRI
A multicentre review of 2000
patients assessed by both MRI and
arthroscopy showed an overall
accuracy for the medial meniscus of
0.89 with a sensitivity of 0.93 and a
specificity of 0.84 . Overall accuracy
for the lateral meniscus was similar,
but the sensitivity was much lower
(0.76) and the specificity was higher