MRI Knee, Shoulder, Foot And Ankle Flashcards
Essential for examining menisci
Position?
Sagittal T1W
Externally rotated (5-10degrees)
Sequence to examine the cruciate ligaments and cartilage
T2 FSE and T2 GRASS
Used for confirming meniscal tear
Coronal images
Used for patellofemoral cartilage
Axial images
Normal menisci
T1
T2
Both low signal
Normal meniscus
Width
Thickness
9-12mm
4-5mm
Discoid meniscus
> 2 consecutive sagittal images that show bow tie appearance
Lateral meniscus often has what appears to be a tear on the anterior horn near its upper margin
Transverse ligament
Important for diagnosing ACL tear
T2WI
Normally seen in intercondylar notch as a linear, predominantly low signal structure on T1
Anterior Cruciate Ligament
Gently curved, homogenously low signal structure that is INfrequently torn
Posterior cruciate ligament
Normal PCL
<6mm
Low signal, round structure often seen anterior or posterior to PCL seen in sagittal views
Meniscofemoral ligament
Meniscofemoral ligament
In front of PCL
Behind PCL
Ligament of Humphry
Ligament of Wrisberg
Signal intensity of medial collateral ligament on
T1
T2
Both low signal
Injuries to medial collateral ligament
Valgus stress to lateral part of the knee
Lateral collateral ligament
Most posterior structure
Anterior to the biceps
Tendon of biceps femoris
Fibular collateral ligament
Insert onto the anteromedial aspect of tibia
Sartorius, gracilis and semitendinosus
-pes anserinus
Rotator cuff muscles
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Inserts onto greater tuberosity of humerus, superior to scapular, inferior to acromioclavicular jt
Supraspinatus
2-3 cm proximal to supraspinatus insertion
Critical zone (decreased vascularity)
Fibrocartilaginous ring that surrounds periphery of bony glenoid of the scapula
Glenoid labrum
Primary sequence for imaging rotator cuff
Fat suppresed fast spin echo T2 weighted oblique coronal
Most commonly seen cuff tear on MRI
Rim rent (anteriorly at insertion of supraspinatus)
Normal humeral head should be ____ on superior slices
Round
The glenoid labrum is best imaged on
Axial T2 or T2*
Normal labrum is _____ shaped and ____ signal
Triangular; low
Anterior vs posterior labrum
Anterior is larger
Normal variants in labrum that mimic torn/detached labrum
Sublabral foramen
Buford complex
Opening beneath anterosuperior labrum
Sublabral foramen
Absent anterosuperior labrum
Buford complex
Sublabral recess is seen only in ____ part of superior labrum
Anterior (thin and extends medially)
Long head of the biceps tendon runs in the ____
Bicipital groove
Made up of branches from C4, C5 and C6 roots of brachial plexus
Suprascapular nerve
Innervates supraspinatus
Suprascapular nerve
Teres minor has fatty atrophy
Quadrilateral space syndrome
Infraspinatus with fatty infiltration
Suprascapular nerve entrapment
Flexor tendons
Posteriorly in ankle
Extensor tendons
Anteriorly
Ankle tendon rupture seen best on
Axial images
Achilles tendon is best seen on
Sagittal image
Posterior tibial tendon
Tom - posterior tibial tendon
Dick - flexor digitorum longus
Harry - flexor hallucis longus
Flexor-
Extensor-
Posterior
Anterior
Most medial and largest
Posterior tibial tendon
Insertion of posterior tibial
Navicular, 2nd and 3rd cuneiform and bases of 2nd to 4th metatarsals
Runs deep to posterior tibialis, supports the talusband arch in PTT tears
Spring ligament
Only tendon at the distal level that has muscle still atached
Flexor hallucis longus tendon
Achilles tendon of the foot
Flexor hallucis longus tendon
Insertion of peroneus brevis
Base of 5th metatarsal
Insertion of peroneus longus
Base of 1st metatarsal
Strong fibrous band that extends across medial ankle joint for approximately ____ cm
Flexor retinaculum; 5-7cm
Most common accessory muscle encountered around the foot and ankle
Accessory soleus and peroneus brevis
Lies medially as a broad band beneath tendons
Deltoid ligament
Most commonly torn ankle ligament
Anterior talofibular ligament
Cone shaped space between talus and calcaneus
Sinus tarsi
Space between tibia and fibula
Lateral gutter