MRI of Knee joint-- DR. ABDUL LATIF
MRI of knee joint
Presented by- Dr. Abdul Latif
Ligaments & minisci: (picture)
KNEE JOINT:
The largest synovial hinge type of joint allowing flexion and extension
Articulation between femur and tibia is weight bearing
Articulation between patella and femur is not weight bearing
Articular surfaces are covered by articualr cartilage
MINISCUS:
Two fibrocartilaginous C –shaped structures located in the tibial plateau separated by tibial eminences
The minisci, one in each side between the femoral and tibial condyles accommodate the changes of femoral articular surfaces during the joint movements
Posterior horn of medial miniscus is the most common site of injury
Medial miniscus is attached at its margin to the joint capsule and to the tibial collateral ligament
Lateral miniscus has no such attachment with the fibular collateral ligament or joint capsule
So lateral collateral ligament is more mobile than the medial miniscus and is less subjected to injury
The minisci are interconnected anteriorly by a transverse ligament of the knee
But the lateral miniscus is connected to the tendon of the popliteas which passes superolaterally between this miniscus and the joint capsule to insert on the femur. In MRI section it may mimic LCL
LIGAMENTS
Patellar ligament:
- attached to tibial tuberosity
Tibial (medial collateral) ligament:
-Medial femoral epicondyle to medial tibial margin
Fibular (lateral collateral)ligament:
-lateral femoral epicondyle just above the groove for
popliteal tendon to lateral surface of fibular head
Anterior cruciate ligament:
Ant. part of inter condylar area of tibia, ascends
posterosuperiorly to attach to the lateral surface
of intercondylar fossa of femur
Posterior cruciate ligament:
Attaches to the posterior aspect of the intercondylar area of tibia and ascends anterosuperiorly to attaches the medial surface of the intercondylar fossa of the femur.
Anterior cruciate ligament prevents anterior dislocation of the tibia relative to the femur and posterior cruciate ligament prevents the posterior dislocation of tibia relative to the femur.
MRI PLANES:
Coronal
Sagittal
Axial
IMAGES:
T1WI (long TE, long TR)
T2WI (short TE, short TR)
PDWI (short TE long TR)
. Protocol have been designed for assessing the knee using
knee coils & 1.5 T (MFS) for yielding imaging with good
contrast and spatial resolution of osseous and soft tissue
structures of the knee in reasonable time.
. knee coils reduces the SNR
. Small field of view (FOV) in the range of 10-14 cm greatly
improves the spatial resolution for the optimal assessment
of the small anatomical structures.
.Acquisition of images in three orthogonal planes is very
helpful in defining and characterizing abnormalities.
. Short echo time (TE) conventional spin-echo (CSE) images
provides best contrast for anatomical evaluation.
. Three dimensional Fourier transformation (3D FT) imaging
provides the height spatial resolution with acceptable SNR
while allowing image reconstruction in any plane.
. The minisci can be evaluated with various techniques
including 3 D volumetric acquisition and radial imaging.
. Fast-spin FSE) pulse sequence are less sensitive than CSE
technique for assessment of miniscal tear.
. Bone contusions and other marrow abnormalities are best
evaluated with short tau inversion recovary (STIR) and fat s
saturated FSE sequences.
. Intravenous gadolinium (Gd) may be useful in the
assessment of inflammatory arthritides as a consequence of
the enhancement of pannus.
. MR arthrography with intraarticular injects of Gd-DTPA is
helpful i the evaluation of post operative knee for defining
recent tears in minisci.
. Sagittal images with the knee externally rotated at 10-15
degrees allow optimal depiction of the ACL.
. Knee should be in neutral in position for coronal scans.
NORMAL IMAGES:
T1WIs:
T2WIs:
PDWIs:
MINISCUS TEAR:
Sagittal plane images
Slice thickness is 4 – 5 mm
MRI Findings:
Increased signal intensity within the normally signal free miniscus.
Grade 1 Tear:
. Increased signal intensity within the miniscus appears
globular, irregular in outline and does not extend to any of
the articualr surfaces.
. Histologically it represents early degenerative changes.
Corresponding surgical findings normal.
Grade 2 Tear:
. Linear signal intensity within the signal free miniscus not
extending to any articular surfaces but may communicate
with the capsular margin of the miniscus.
. Pathologically it corresponds to more sever degenerative
change.
. Arthroscopically tear is detected rarely.
Grade 3 Tear:
Signal intensity within the signal free miniscus extends to any of the articular surfaces.
Grade 4 Tear:
Signal intensity of miniscal fragmentation or peripheral rim tear.
LIGAMENT TEAR:
Types :
Complete tear
Partial tear
Interstial tear
MRI findings for ACL:
Direct evidences:
.Increased signal intensity
.Empty notch sign
.Abnormal laxity along the course of ACL
Indirect evidences:
. Ant. translation or subluxation of tibia with laxity of PCL
. Evidence of miniscal or other injury
. Evidence of edema around the torn ACL
MRI findings for PCL:
. Less common injury
. Increased signal intensity in PCL
. Posterior subluxation of tibia
. Evidence of associated injury
. Evidence of edema around the torn PCL
Presented by- Dr. Abdul Latif
Ligaments & minisci: (picture)
KNEE JOINT:
The largest synovial hinge type of joint allowing flexion and extension
Articulation between femur and tibia is weight bearing
Articulation between patella and femur is not weight bearing
Articular surfaces are covered by articualr cartilage
MINISCUS:
Two fibrocartilaginous C –shaped structures located in the tibial plateau separated by tibial eminences
The minisci, one in each side between the femoral and tibial condyles accommodate the changes of femoral articular surfaces during the joint movements
Posterior horn of medial miniscus is the most common site of injury
Medial miniscus is attached at its margin to the joint capsule and to the tibial collateral ligament
Lateral miniscus has no such attachment with the fibular collateral ligament or joint capsule
So lateral collateral ligament is more mobile than the medial miniscus and is less subjected to injury
The minisci are interconnected anteriorly by a transverse ligament of the knee
But the lateral miniscus is connected to the tendon of the popliteas which passes superolaterally between this miniscus and the joint capsule to insert on the femur. In MRI section it may mimic LCL
LIGAMENTS
Patellar ligament:
- attached to tibial tuberosity
Tibial (medial collateral) ligament:
-Medial femoral epicondyle to medial tibial margin
Fibular (lateral collateral)ligament:
-lateral femoral epicondyle just above the groove for
popliteal tendon to lateral surface of fibular head
Anterior cruciate ligament:
Ant. part of inter condylar area of tibia, ascends
posterosuperiorly to attach to the lateral surface
of intercondylar fossa of femur
Posterior cruciate ligament:
Attaches to the posterior aspect of the intercondylar area of tibia and ascends anterosuperiorly to attaches the medial surface of the intercondylar fossa of the femur.
Anterior cruciate ligament prevents anterior dislocation of the tibia relative to the femur and posterior cruciate ligament prevents the posterior dislocation of tibia relative to the femur.
MRI PLANES:
Coronal
Sagittal
Axial
IMAGES:
T1WI (long TE, long TR)
T2WI (short TE, short TR)
PDWI (short TE long TR)
. Protocol have been designed for assessing the knee using
knee coils & 1.5 T (MFS) for yielding imaging with good
contrast and spatial resolution of osseous and soft tissue
structures of the knee in reasonable time.
. knee coils reduces the SNR
. Small field of view (FOV) in the range of 10-14 cm greatly
improves the spatial resolution for the optimal assessment
of the small anatomical structures.
.Acquisition of images in three orthogonal planes is very
helpful in defining and characterizing abnormalities.
. Short echo time (TE) conventional spin-echo (CSE) images
provides best contrast for anatomical evaluation.
. Three dimensional Fourier transformation (3D FT) imaging
provides the height spatial resolution with acceptable SNR
while allowing image reconstruction in any plane.
. The minisci can be evaluated with various techniques
including 3 D volumetric acquisition and radial imaging.
. Fast-spin FSE) pulse sequence are less sensitive than CSE
technique for assessment of miniscal tear.
. Bone contusions and other marrow abnormalities are best
evaluated with short tau inversion recovary (STIR) and fat s
saturated FSE sequences.
. Intravenous gadolinium (Gd) may be useful in the
assessment of inflammatory arthritides as a consequence of
the enhancement of pannus.
. MR arthrography with intraarticular injects of Gd-DTPA is
helpful i the evaluation of post operative knee for defining
recent tears in minisci.
. Sagittal images with the knee externally rotated at 10-15
degrees allow optimal depiction of the ACL.
. Knee should be in neutral in position for coronal scans.
NORMAL IMAGES:
T1WIs:
T2WIs:
PDWIs:
MINISCUS TEAR:
Sagittal plane images
Slice thickness is 4 – 5 mm
MRI Findings:
Increased signal intensity within the normally signal free miniscus.
Grade 1 Tear:
. Increased signal intensity within the miniscus appears
globular, irregular in outline and does not extend to any of
the articualr surfaces.
. Histologically it represents early degenerative changes.
Corresponding surgical findings normal.
Grade 2 Tear:
. Linear signal intensity within the signal free miniscus not
extending to any articular surfaces but may communicate
with the capsular margin of the miniscus.
. Pathologically it corresponds to more sever degenerative
change.
. Arthroscopically tear is detected rarely.
Grade 3 Tear:
Signal intensity within the signal free miniscus extends to any of the articular surfaces.
Grade 4 Tear:
Signal intensity of miniscal fragmentation or peripheral rim tear.
LIGAMENT TEAR:
Types :
Complete tear
Partial tear
Interstial tear
MRI findings for ACL:
Direct evidences:
.Increased signal intensity
.Empty notch sign
.Abnormal laxity along the course of ACL
Indirect evidences:
. Ant. translation or subluxation of tibia with laxity of PCL
. Evidence of miniscal or other injury
. Evidence of edema around the torn ACL
MRI findings for PCL:
. Less common injury
. Increased signal intensity in PCL
. Posterior subluxation of tibia
. Evidence of associated injury
. Evidence of edema around the torn PCL
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