Introduction to evaluation of shoulder and knee joints on mr imaging with examples of routinely seen pathologies and approach to diagnosis making

3. MRI Rules
T1 T2
Fat Hyperintense Hyperintense
Water Hypointense hyperintense
Cortical bone Hypointense Hypointense
Fibrous tissue Hypointense Hypointense
Cartilage Isointense Isointense

4. Indications of MRI
Occult fracture
Marrow abnormality
Ligament pathology
Tendon pathology
Muscular injury
Infection
Bone and soft tissue tumour

6. Meniscal Tear
Imaging Criteria
1. Presence of linear signal intensity weather
reaching superior or inferior articular surface or
not
2. Abnormal meniscal morphology

7. Meniscal Tear
 Grade
Grade 1- Globular signal within the meniscus
Grade 2- Linear signal within the meniscus
not reaching the articular surface
Grade 3- Linear signal within the meniscus
reaching the articular surface

9. Grade I
Grade II
Grade III

11. Radial tear- Tear perpendicular to free
edge of meniscus

12. Longitudinal tear

13.  Bucket Handle Tear- Longitudinal tear
along the length of the meniscus and the
inner rim flips into the intercondylar
notch while remaining attached to the
anterior and posterior horns.
 Double-PCL sign -The flipped fragment
lies inferior and anterior to the PCL

14. Bucket Handle tear

15. Anterior flipped horn

16. Meniscal cyst
 Joint fluid is expressed
into adjacent soft
tissue through the tear
 Mostly occur in medial
compartment
 Most common
associated tear is
horizontal cleavage
tear

17. Discoid Meniscus-
 More common on lateral side
 High incidence of tear than normal meniscus
 Complete- Meniscus is a large slab of fibrocartilage
instead of a crescent shaped wedge
 Incomplete- If lateral meniscus has wedge shaped but
wedging is larger than that of medial meniscus
 Instability is more in complete discoid meniscus

19. Complete discoid menscus

20. Meniscocapsular separation
 Fluid signal between
posterior portion of
medial meniscus and
joint capsule

24. 1. Grade I sprain (Low-Grade partial tear)
• Signal around ACL
• The fibres of the ligament are stretched,
and we can see more than 50% of its
fibres intact.
2. Grade II sprain (High-Grade partial tear)
• Signal within ACL
• We can see less than 50% of fibres intact.
3. Grade III tear (Complete ACL tear)

25. Grade I sprain
(Low-Grade partial tear)

26. Grade II sprain
(High-Grade partial tear)

27. Grade III tear (Complete ACL tear)
1. Discontinuous fibers
2. Non-visible fibers
3. Abnormal slope of the
ligament
4. Empty notch sign

28. Grade III tear
(Complete ACL tear)
Discontinuous fibers

29. Grade III tear
(Complete ACL tear)
Non-visible fibers

30. Grade III tear
(Complete ACL tear)
Abnormal slope of the
ligament

31. Grade III tear
(Complete ACL tear)
Abnormal slope of the
ligament

32. Grade III tear
(Complete ACL tear)
Abnormal slope
of the
ligament

33. Grade III tear
(Complete ACL tear)
Abnormal slope of the
ligament

36. Grade III tear
(Complete ACL tear)
Empty notch sign

39. Deep lateral femoral notch sign
 Indicator of chronic ACL
insufficiency but may also
be seen in acute tear

40. Associated injuries with ACL
 O’Donoghue’s triad-
 ACL rupture
 MCL injury
 Medial meniscal tear

41. O’Donoghue’s triad

42. Segond Fracture

43. Other bony injuries with ACL tear
 Bruise in weight bearing
portion of lateral femoral
condyle and posterior
aspect of lateral tibial
plateu due to internal
rotation of tibia and
valgus angulation of knee

44. Normal PCL
PCL injury
• Less common – 5-
20%
• Associated with
other injuries

45. Partial PCL tear Complete PCL tear

46. PCL avulsion

47. Medial Collateral Ligament
 Grade I- Mild partial interstitial tear ,appears as edema
along superficial aspect
 Grade II- Extensive interstitial partial tear ,appears as
thickening of ligament with internal signal abnormality
or frank thining due to extensive partial tear
 Grade III- Complete rupture of ligament

48. Grade I Grade II Grade III

49. Lateral Collateral Ligament tear

50. Iliotibial Band Injury
 Overuse injury usually
seen in runners and
bicyclists
 Iliotibial band Friction
syndrome- Due to rubbing
of ITB against lateral
femoral condyle

51. Quadriceps rupture
 Appears as balled up and
mildly retracted tendon
edge with edema in
surrounding soft tissue
and tendon gap

52. Jumper knee/Patellar tendinitis
 Overuse injury to proximal
aspect of patellar tendon
 Usually seen in
basket/volleyball players
 Misnomer, mucoid
degeneration of collagen fibres
of tendon
 MRI- Swelling of proximal
aspect of tendon with internal
high signal intensity.
Fusiform swelling
Edema in Hoffas fat pad

53. Osgood Schlatter disease
 Degeneration of distal
aspect of patellar tendon
 Triad- Pain, soft tissue
swelling, ossification in
distal aspect of patellar
tendon
 MRI- Enlarged distal
tendon with low signal
intensity foci of
heterotopic ossification

54. Lateral dislocation of patella
 Bony bruise in medial
aspect of patella and
lateral aspect of lateral
femoral condyle
 Tear of medial
retinaculum appears as
thickening and internal
high signal intensity on T2
weighed image
 Tear of vastus medialis
oblique muscle appear as
high signal intensity on T2
weighed image

60. Complete medial plica
 Plicae are remnants of fetal
synovial tissue
 Symptomatic only if complete
 Forms a shelf from medial side of
joint capsule to infrapatella fat
pad
 Overuse injury in sports like
running,bicycling
 MRI- Thickened low signal
intensity on T2 weighed image

69. Pes Anserinus Bursitis
 Pes anserinus bursa is located
between tendon of pes
anserinus and medial collateral
ligament
 MRI- High signal intensity fluid
filled bursa with low signal
intensity internal debris

70. Superficial infrapatellar bursitis/Preacher’s
knee
 Present anterior to tibial
tubercle and distal aspect of
patellar tendon
 Named so because it gets
compressed between tibial
tubercle and wooden bench
on which a preacher sit
 MRI- Low signal intensity on
T1 sequence and high
intensity on T2 sequence

71. Synovitis
 Fat suppressed T1
weighed image after iv
contrast shows
thickened synovium

72. Bones and Cartilage

73. Sequence Bone Cartilage Fluid
T1 Signal Void Iso Hypo
T2 Signal Void Hypo Bright
PDFS Signal Void Hyper Bright
Gradient Signal Void Hyper Bright

90. Grade MRI finding
I Focal signal intensity changes without contour deformity
(difficult to assess on MRI)
II Focal signal intensity change and contour bulge (partial
thickness)
III Focal signal intensity change, contour irregularities,
cartilage thinning and fluid extension into cartilage (full
thickness)
IV Similar to stage III with defects extending to the cortical
bone (with subchondral bony changes)

94. Osteochondritis dissecans
 Occur due to blood
deprivation
Cracks forms in
cartilage and subchondral
bone
Fragmentation of
cartilage and bone in the
joint

95. 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 +

96. Avascular Necrosis
 Initial ischemia- Large area of ill defined marrow edema
 If ischemia persists- avascular necrosis of bone occur in
subchondral portion manifested as single or double rim
of demarcation and may have appearance of fat,
edema,blood or sclerosis

97. Initial ischemia Avascular necrosis
(demarcated zone )

98. Spontaneous Osteonecrosis of knee(SONK)/
Subchondral insufficiency fracture of knee(SIFK)
 Subchondral fracture
followed by osteonecrosis
 MRI- Subchondral linear
component representing
fracture with low signal
intensity and surrounding
marrow edema with high
signal intensity

99. MRI
SHOULDER

101. Normal Shoulder MRI
Coronal Oblique
Sagital Oblique
Axial Cuts

102. Normal Coronal Oblique
Parallel to plane of
Supraspinatus
• Supraspinatus
• A-CJoint
• Sub-acromial &
Sub-Deltoid bursa
• Labrum- Sup & Inf
• BicepsTendon

103. Normal Coronal Oblique
• d

104. Normal Coronal Oblique
• Parallels the central tendon of supraspinatus

105. Normal Sagittal Oblique
Perpendicular to the
plane of Supraspinatus
• Medial to Lateral
• Coraco-acromial arch
• Rotator cuff
• Shape of Acromion

106. Normal Sagittal Oblique
• a

107. Normal Axial Cuts
• Labrum- Ant & Post
• Gleno-humeral ligament
• Gleno-humeral cartilage
• Biceps Tendon
• Subscapularis & Teres
Minor

108. CAPSULE AND LIGAMENTS

112. LABRUM

115. CARTILAGE

116. 116BURSAE

117. 117
SUBSCAPULAR BURSA

118. 118
 On the fat-suppressed T2-weighted image a large bursal effusion has high
signal intensity. Near the greater tuberosity a partial, bursa-sided tear is
seen. The bone marrow edema in the degenerated acromioclavicular joint
and the bone appositions at the undersurface of the acromion

119. Arthrogram
Sequence
• Distension of joints, crowded
structures seen separately -
Labrum, G-H ligaments, biceps
anchors
• Partial articular surface RC
tears
• SLAP tears

120. Pathological processShoulder
• Impingement
• Rotator cuff pathology
• Instability
• Miscellaneous- Biceps, Infection,Adhesive
Capulitis

121. Osseous Acromial Outlet
A-C joint
Acromion
Humeral Head

122. Extrinsic Impingement
• A-C osteophytes
• Sub-acromial
Enthesophytes
• Acromion Shape

123. 123
 Synovitis and fi brovascular tissue in the subacromial–subdeltoid
bursa and the acromioclavicular joint. T1-weighted fat-suppressed
coronal (a) and axial (b) images after gadolinium application.
 Mechanical stress in subacromial impingement is translated to the
acromioclavicular joint

124.  Acromioclavicular joint degeneration in a patient suffering from
impingement syndrome. Oblique coronal T1- weighted (a) and STIR
image (b). Erosions and irregularities in the acromioclavicular joint in
combination with bone marrow edema adjacent to the joint space are
present. Fluid in the subacromial–subdeltoid bursa and subacromial
bone appositions are also identifi ed

125. 125
 Acromioclavicular joint degeneration. The caudal
orientated spurs are in contact with the rotator cuff

126. Acromion Shape
3 types
Type1 Type 2 Type 3

127. Rotator Cuff Pathology
• Tendinosis
• Partial thickness Cuff Tears
• Full thickness Cuff Tears

128. Tendinosis
• Thickened tendon with
degeneration
• Intrasubstance
degeneration
• Normal to intermediate
SI changes

129. Partial Cuff Tears
Three types
• Articular side- FP, CZ
• Interstitial
• Bursal side

130. Partial RC Tear
• Intrasubstance tear
• Bursal sided RC Tear
Bursal Tear Intra-Substance Tear

131. Full thickness RC tears
• Tear extending from bursal to articular
surface
• Fluid in SA-SD bursa
• Retraction of tendon
• Muscle undergoes
- Atrophy
Degeneration
Fatty Infiltration

132. Full Thickness RC Tears

133. Full Thickness RC Tears
• Muscle Atrophy

134. Instability
Spectrum ranging from subtle instability to frank
dislocation
• Anterior Instability
• Posterior Instability
• SLAP tear

135. Anterior
Instability
• Bankart Lesion
• Bony Bankart
• Glenoid Erosion
• Hill Sach's lesion

136. Anterior Instability
• Bankart Lesion

137. Anterior Instability
• Bony Bankart Glenoid Erosion
Bony Bankart Glenoid Erosion

138. Anterior Instability
• Hill Sach's Lesion-
Postero-Sup aspect
of Humeral Head

139. Anterior Instability
• Hill Sach's Lesion

140. BANKART’S

141. BONY BANKART’S

142. Posterior Instability
• Posterior Labral
Lesion
• Reverse Hill Sach's

143. SLAP Tear
• Superior Labrum
Antero-Posterior
Tear
• Avulsion Biceps
Anchor

144. SLAP Tear
• Normal Biceps Anchor

145. SLAP Tear
• Torn labral

146. Biceps Pathology
• Tendinosis
• Rupture
• Dislocation

147. Miscellaneous

148. Osteonecrosis
Infection

149. AVN
T1 T2
“Double Line” Sign- Seen On T2 Images

150. Coracoid impingement.
The subscapularis
tendon becomes
impinged between the
coracoid process and
themedial humeral
head. Bone marrow
edema is present
medialto the lesser
tuberosity

151. Trauma
-24 y.o. Female: Persistent Painful Shoulder After Skiing
Accident

152. Nonspecific Marrow Signal
-DDX: Infection, Tumor, Trauma
-T1 Image: Use Muscle as Internal Standard
-T1 Signal Darker than Muscle: Pathologic

153. Tumor
-Osteosarcoma Proximal Humerus
-Mass with Cortical Destruction
-Low Signal T1; High Signal T2 Images

154. ACRONYMS
 ALPSA
 Anterior labroligamentous periosteal sleeve avulsion
 HAGL
 Humeral avulsion of glenohumeral ligaments
 BHAGL
 Bony humeral avulsion of glenohumeral ligaments
 GLAD
 Glenolabral articular disruption
 Undisplaced Bankart’s lesion
 BENNETT’S
 Mineralisation of posterior band of IGHL & posterior capsule

155. REVERSE BANKART’S

156. ALPSA

157. HAGL

158. GLAD

159.  Calcifying tendonitis. The calcified deposits are
of low signal intensity

160. PARALABRAL CYSTS

161. • Shoulder is a complex joint with many normal
variants
• Proper clinical examination and probable clinical
diagnosis
• MRI - very sensitive test for diagnosing shoulder
problems
• MRI findings should corroborate clinical findings