Basic Imaging

Question 1

What is the most common imaging modality for bone structure?

Answer 1

X-ray.

Question 2

Which scan best measures bone mass/density?

Answer 2

DEXA (Dual energy X-ray absorptiometry).

Question 3

What does a T-score < -2.5 on DEXA indicate?

Answer 3

Osteoporosis.

Question 4

What is the hallmark fracture site in osteoporosis?

Answer 4

Vertebral compression fractures.

Question 5

What are classic spine X-ray findings in osteoporosis?

Answer 5

Osteopaenia, anterior wedging, biconcave vertebra.

Question 6

Radiologic features of wrist in osteoporosis?

Answer 6

Increased radiolucency, cortical thinning.

Question 7

What causes osteomalacia?

Answer 7

Vitamin D deficiency causing unmineralized osteoid.

Question 8

What are Looser’s zones?

Answer 8

Unicortical insufficiency fractures pathognomonic for osteomalacia.

Question 9

What differentiates rickets from osteomalacia?

Answer 9

Rickets affects growth plate in children; osteomalacia affects mineralized bone in adults.

Question 10

Radiographic signs of rickets?

Answer 10

Cupping, fraying, metaphyseal widening, rachitic rosary.

Question 11

What hormone increases serum calcium and stabilizes phosphate?

Answer 11

Parathyroid hormone (PTH).

Question 12

Key radiological sign in hyperparathyroidism?

Answer 12

Subperiosteal bone resorption, especially in 2nd/3rd finger phalanges.

Question 13

What is a ‘rugger-jersey spine’?

Answer 13

Sclerotic bands along vertebral endplates seen in secondary hyperparathyroidism.

Question 14

Radiologic features of advanced hyperparathyroidism?

Answer 14

Brown tumors, terminal tuft erosion, salt and pepper skull.

Question 15

What is thalassaemia’s skeletal hallmark on skull X-ray?

Answer 15

Hair-on-end appearance.

Question 16

What is a ‘rib-within-a-rib’ sign?

Answer 16

Thalassaemia radiologic sign in ribs.

Question 17

What is avascular necrosis (AVN)?

Answer 17

Bone death due to disrupted blood supply.

Question 18

Common AVN sites?

Answer 18

Femoral head, scaphoid, talus.

Question 19

Best imaging modality for early AVN?

Answer 19

MRI.

Question 20

Ficat stage I AVN radiograph?

Answer 20

Normal X-ray, positive MRI/bone scan.

Question 21

Ficat stage IV AVN feature?

Answer 21

Joint space narrowing, acetabular changes.

Question 22

What is a medullary bone infarct?

Answer 22

Ischemic necrosis in the medullary cavity with serpiginous sclerosis.

Question 23

What joint is most affected in haemophilia?

Answer 23

Large joints, especially knees.

Question 24

Radiologic features of haemophilic arthropathy?

Answer 24

Joint effusion, widened intercondylar notch, osteoporosis.

Question 25

What is spondylodiscitis?

Answer 25

Infection of intervertebral disc and adjacent vertebra.

Question 26

Radiologic signs of spondylodiscitis?

Answer 26

Disc space narrowing, endplate irregularity.

Question 27

Best modality for early spondylodiscitis?

Answer 27

MRI.

Question 28

Common site for TB spondylitis?

Answer 28

Lower thoracic and upper lumbar spine.

Question 29

Key radiological sign in TB spondylitis?

Answer 29

Vertebral body collapse with anterior wedging and gibbus formation.

Question 30

What are the 5 D’s in Charcot’s arthropathy?

Answer 30

Debris, Destruction, Dense, Deformity, Dislocation.

Question 31

Main cause of Charcot arthropathy in foot?

Answer 31

Diabetes.

Question 32

Radiographic signs of osteoarthritis?

Answer 32

Joint space narrowing, osteophytes, subchondral sclerosis, cysts.

Question 33

Common joint spared in RA?

Answer 33

DIP joints.

Question 34

Radiologic deformities in RA?

Answer 34

Swan neck, boutonniere, ulnar deviation.

Question 35

Radiographic signs of gout?

Answer 35

Juxta-articular erosions with overhanging edge, late joint narrowing.

Question 36

Most affected joint in gout?

Answer 36

First MTP joint.

Question 37

Radiologic sign of pseudogout?

Answer 37

Chondrocalcinosis.

Question 38

What is ankylosing spondylitis?

Answer 38

Chronic axial arthritis causing spinal ankylosis.

Question 39

Radiologic feature of ankylosing spondylitis?

Answer 39

Bamboo spine.

Question 40

What is assessed on lateral cervical spine X-ray?

Answer 40

Alignment, vertebral bodies, prevertebral soft tissue.

Question 41

Normal prevertebral soft tissue width at C2 and C6?

Answer 41

C2 = 6 mm; C6 = 22 mm.

Question 42

Odontoid view importance?

Answer 42

Assess C1-C2 alignment; detect Jefferson fracture.

Question 43

Hangman’s fracture location?

Answer 43

Fracture of the C2 pedicles.

Question 44

What does an open book pelvic fracture result from?

Answer 44

Anteroposterior compression.

Question 45

What is a Malgaigne fracture?

Answer 45

Vertical shear pelvic fracture.

Question 46

What is assessed in AP hip radiograph?

Answer 46

Comparison of both hips; cortical integrity; trabecular pattern.

Question 47

Common types of proximal femur fractures?

Answer 47

Subcapital, transcervical, intertrochanteric, subtrochanteric.

Question 48

Define pathologic fracture.

Answer 48

Fracture in bone weakened by disease.

Question 49

Radiographic clues for pathologic fracture?

Answer 49

Transverse pattern, bone lesion, soft tissue mass, endosteal scalloping.

Question 50

Common causes of pathologic fractures?

Answer 50

Malignancy, benign bone lesions, metabolic bone disease.

Question 51

Best modality to detect underlying lesion in pathological fracture?

Answer 51

MRI or CT.

Question 52

Where are pathological fractures commonly seen?

Answer 52

Subtrochanteric femur, humeral head, vertebral bodies.