Imaging Flashcards
What is a Hill Sach deformity and Bankart lesion?
Anterior dislocation of gleno-humeral joint
→ impact injury of humeral head (Hill Sach deformity) against glenoid fossa (Bankart lesion)
What does a “light bulb” sign on a shoulder Xray indicate?
Posterior dislocation of glenohumeral joint
What are 2 causes of abnormal bony protuberance?
1) Exostosis
2) Osteochondroma
What is a possible physiological cause of a line of radiolucency within a adolescent’s bone on a radiograph.
Growth plate
What is a possible of easy fractures that show abnormal radiolucency of underlying bone?
Pathological fracture with cancerous replacement of bone matrix/material
What does a “fat pad” sign (presence of radiolucent shadows anterior and posterior to humerus) on an elbow xray indicate?
Elbow joint effusion
What is a “nightstick” fracture?
Fracture to ulnar shaft
What is a “Galeazzi fracture”.
Fracture @ distal 1/3 of radius
- a/w subluxation of distal radio-ulnar joint
What is “Colle’s fracture”?
Fracture of distal radius with dorsal displacement of wrist and hand
- presents with “Dinner fork deformity” of forearm
How does a scaphoid fracture lead to avascular necrosis?
Fracture → compression of radial artery → death of bone (avascular necrosis)
- chronic pain + l.o.f
What is the most commonly torn ligament in a rotator cuff tear?
Supraspinatus
How does a torn supraspinatus tendon differ from a normal one on ultrasound?
Normal tendon → hyperechoic
Tear → Fluid → Hypoechoic
What is a “Terry Thomas” sign?
Widening of Scaphoid-Lunate gap → Scapholunate ligament injury
What is an open mouth Xray used to assess?
C1 and 2 vertebrae
What is an EOS?
Low-dose, weight bearing X-ray
- can take whole body frontal and lateral images
- less radiation than conventional xray
- can produce both 2D and 3D images
- poor demonstration of bony features
What are 4 common imaging modalities used for back pain?
1) Radiograph
- good for 1st line
2) MRI
- good for soft tissue
3) CT
- goof for bony details
4) Nuclear medicine - bone scan
- good for bone metastasis
How is a T1-weighted MRI sequence differentiated from a T2-weighted MRI sequence?
T1: fluid is dark
T2: fluid is white
What is a bone scan?
Radioisotope injected IV → tracer incorporated into bone
- hot spots → ↑bone growth/repair
- cold spots → decreased/no uptake
When is imaging indicated for a suspected cervical spine trauma?
N - Neurological deficit
S - Spinal tenderness
A - Altered mental status
I - Intoxication
D - Distracting injury
How does one discern if there is an unstable injury after a suspected cervical spine injury?
All 4 lines of the neck vertebrae are straight/smooth.
1) Anterior vertebral
2) Posterior vertebral
3) Spinolaminar
4) Posterior spinous
Which imaging modality is most suited for a suspected cervical spine trauma?
CT
What are the 3 most common fractures of the thoracolumbar spine?
1) Compression
2) Burst
3) Chance
What are 2 common degenerative conditions of the thoracolumbar spine?
1) Spondylosis
2) Disc disease
What does an uneven iliopectineal or ilioischial line on a Xray pelvis indicated?
Hip fracture (relevant medial surface)
What is an “open book” fracture?
pelvic fracture is a specific type of open pelvic fracture where a person has: pelvic bones broken into two or more separate pieces.
What are the muscles visibile at the level of the anterior superior iliac spine?
Gluteal:
1) Gluteus maximus
2) Gluteus medius
3) Gluteus minimus
Pelvic:
4) Iliacus
5) Psoas
6) Iliopsoas
Where is the highest level at which the 3 thigh compartments can be seen?
Hip joint at greater trochanter
What are the muscles visible at the level of the lesser trochanter?
Medial compartment:
1-3) Adductor group (longus, brevis, magnus
4) Gracilis
5) Obturator externus
6) Pectineus
What are the the muscles are visible at the level of the proximal femur?
Posterior compartment (Hamstrings):
1) Semimembranosus
2) Semitendinosus
3) Biceps femoris
Anterior compartment:
4) Iliopsoas
5) Tensor fascia lata
6) Sartorius
7) Quadriceps femoris
Medial compartment:
8-10) Adductor group (longus, brevis, magnus)
11) Gracilis
12) Obturator externus
13) Pectineus
What are the arrangements of the muscles of the knee from medial to lateral?
1) Sartorius tendon
2) Gracilis tendon
3) Semimembranosus
4) Semitendinosus tendon
5) Gastrocnemius (Medial then lateral)
6) Biceps femoris
What are the structures at the level of the ankle?
Anterior group:
1) Tibialis anterior
2) Extensor Hallucis Longus
3) Dorsalis pedis Artery
4) Deep peroneal nerve
5) Extensor Digitorum longus
Posterior group:
6) Tibialis posterior
7) Flexor digitorum longus
8) Posterior tibial artery
9) Flexor Hallucis Longus
What are 4 imaging modalities that are used to visualise the lower limb arteries and veins?
1) US
2) CT angiogram
3) MR angiogram
4) Formal angiogram (invasive and allows intervention)
The sciatic nerve divides into the __________ at the ______________.
Common peroneal and tibial nerve at popliteal fossa
What are 2 imaging methods used to visualise the lower limb lymphatics?
1) PET
2) CT
