Plain Radiology and Contrast Agents

Question 1

Which of the following marks the anterior limit of spinal canal?
● A. Anterior marginal line
● B. Middle marginal line
● C. Posterior marginal line
● D. Posterior spinal line
● E. Spinolaminar line

Answer 1

C. Posterior marginal line

Question 2

What is the average normal anterior dentate interval in adult male?
● A. < 3 mm
● B. 7 mm
● C. 9 mm
● D. 11 mm
● E. 15 mm

Answer 2

A. < 3 mm

Question 3

On cervical spine anteroposterior X-ray, a fracture-dislocation or ligament disruption may be diagnosed if the interspinous distance (measured from center of spinous processes) relative to that at both adjacent levels is what?
● A. 0.25 times
● B. 0.5 times
● C. Equal
● D. > 1.5 times
● E. Not related

Answer 3

D. > 1.5 times

Question 4

In C2 vertebra, how many primary ossification centers are there at birth?
● A. 1
● B. 2
● C. 3
● D. 4
● E. 5

Answer 4

D. 4

Question 5

Butterfly vertebra is an uncommon congenital anomaly thought to arise from failure of fusion of the lateral halves of the vertebral bodies due to persistent notochord tissue on AP X-rays or coronal CT scan reconstructions. On lateral views, what may it mimic?
● A. Locked facets
● B. Burst fracture
● C. Compression fracture
● D. Fracture dislocation
● E. Teardrop fracture

Answer 5

C. Compression fracture

Question 6

For basilar invagination, what is the line drawn across foramen magnum (basion to opisthion)?
● A. McRae’s line
● B. Chamberlain’s line
● C. McGregor’s baseline
● D. Wackenheim’s clivus-canal line
● E. Fischgold’s digastric line

Answer 6

A. McRae’s line

Question 7

For basilar invagination, posterior hard palate to posterior margin of foramen magnum-opisthion is what?
● A. McRae’s line
● B. Chamberlain’s line
● C. McGregor’s baseline
● D. Wackenheim’s clivus-canal line
● E. Fischgold’s digastric line

Answer 7

B. Chamberlain’s line

Question 8

What is the primary approved contrast agent for intrathecal use?
● A. Iohexol
● B. Iopromide
● C. Ioversol
● D. Iodixanol
● E. Ultravist

Answer 8

A. Iohexol

Question 9

What is the U.S. Nuclear Regulatory Commission (NRC) recommended maximal annual occupational dose limits for radiation (rem/y) for whole body?
● A. 5
● B. 10
● C. 15
● D. 20
● E. 50

Answer 9

A. 5

Question 10

For minimizing the occupational radiation exposure, ALARA (“As Low As Reasonably Achievable”) involves making every reasonable effort to keep radiation dose as far below the limits as possible and it is believed that lead aprons and shields may or may not work, but distance always works. What distance (ft) the American Association of Neurological Surgeons (AANS) has recommended to be kept?
● A. 1
● B. 2
● C. 3
● D. 5
● E. 10

Answer 10

E. 10

Question 11

On lateral c spine X-ray, there are four contour lines which normally form smooth gentle curve. Which of these four lines forms the anterior margin of spinal canal?
● A. Anterior marginal line along the anterior cortical surface
● B. Posterior marginal line along the posterior cortical surface
● C. Spinolaminar line
● D. Posterior spinous line
● E. None of above

Answer 11

B. Posterior marginal line along the posterior cortical surface

Question 12

According to the rule of Spence, the transverse atlantal ligament (TAL) is probably disrupted if the sum total overhang of both C1 lateral masses over C2 is more than or equal to what?
● A. 3 cm
● B. 5 cm
● C. 7 cm
● D. 9 cm
● E. 11 cm

Answer 12

C. 7 cm

Question 13

Posterior atlantodental interval, which is the distance from the back of odontoid to the anterior aspect of posterior C1 arch, forms the spinal canal diameter at this level. Stenosis of cervical spinal canal is present if the canal diameter is less than what?
● A. 10 mm
● B. 11 mm
● C. 12 mm
● D. 13 mm
● E. 15 mm

Answer 13

C. 12 mm

Question 14

Which of the following statements is true?
● A. On oblique X-ray view of lumbar sacral spine, discontinuation in the neck of scotty dog shows defect of spinous process
● B. AP X-ray view of lumbar sacral spine: nonvisualization of owl’s eyes shows pedicle erosion which is due to lytic tumor
● C. Butterfly vertebra is due to failure of fusion of two halves of posterior vertebral arches
● D. In axis vertebrae, the anterior synchondroses normally fuse between 6 and 9 years of age
● E. All of the above statements are correct

Answer 14

B. AP X-ray view of lumbar sacral spine: nonvisualization of owl’s eyes shows pedicle erosion which is due to lytic tumor

Question 15

The depth and length of the sella turcica on lateral view of normal skull X-ray are 8.1 and 10.6 mm, respectively. How does pituitary adenoma changes the dimensions of sella turcica?
● A. It tends to enlarge the sella
● B. It erodes posterior clinoids and does not enlarge sella
● C. It balloons the sella symmetrically
● D. It does not enlarge sella but causes enlargement of sphenoid sinus
● E. None of the above

Answer 15

A. It tends to enlarge the sella

Question 16

Basilar invagination/basilar impression (BI) is upward displacement of odontoid process through foramen magnum into the posterior fossa. Which of the following is best statement regarding BI?
● A. Basilar impression implies abnormal softening of skull base bones with atlantooccipital fusion
● B. Basilar invagination means normal skull base bones
● C. Platybasia is abnormal basal angle at skull base with > 145 degrees angle
● D. Type 1 BI means BI with Chiari malformation
● E. Type 2 BI denotes BI without Chiari malformation

Answer 16

C. Platybasia is abnormal basal angle at skull base with > 145 degrees angle

Question 17

McRae’s line is drawn from basion to opisthion and it is used in measurements in basilar invagination (BI). What is the relationship of odontoid tip with this line for excluding the diagnosis of BI?
● A. No part of odontoid tip should be above this line
● B. Dens should not be more than 3 mm above this line
● C. Dens should not be more than 4.5 mm above this line
● D. Odontoid tip should be 3 mm below this line
● E. None of the above

Answer 17

A. No part of odontoid tip should be above this line

Question 18

Which of the following conditions are associated with basilar invagination (BI)?
● A. Congenital conditions like Down syndrome, Klippel-Feil syndrome, Chiari malformation, or syringomyelia
● B. Acquired conditions like rheumatoid arthritis
● C. Post-traumatic
● D. Conditions with softening of bone like Paget’s disease, osteogenesis imperfecta, osteomalacia, rickets, or hyperparathyroidism
● E. All of the above

Answer 18

E. All of the above

Question 19

What medication can be used in a patient going to use intra-
venous contrast agent with previous history of mild reaction
with iodinated contrast medium for prevention of reaction
again?
● A. Prednisone 50 mg PO
● B. Solumedrol 25 mg IV
● C. Diphenhydramine 50 mg IM
● D. Hydrocortisone 100 mg IV
● E. All of the above

Answer 19

E. All of the above