Anatomy and imaging

Question 1

Name the three planes which pass through the body in anatomical position, and describe their location

Answer 1

Coronal - vertical, divides body into anterior and posterior
Sagittal - vertical, through nose (if median sagittal plane)
Transverse/horizontal/axial - divides body into superior and inferior

Question 2

What does the word ‘ventral’ describe?

Answer 2

Structures relative to the front of the body (anterior)

Question 3

What does the word ‘dorsal’ describe?

Answer 3

Structures relative to the back of the body (posterior)

Question 4

What does the word ‘cranial’ mean?

Answer 4

Towards the head (superior)

Question 5

What does the word ‘caudal’ mean?

Answer 5

Towards the tail (inferior)

Question 6

What does the word ‘rostral’ mean?

Answer 6

Towards the nose (eg. forebrain is rostral to hindbrain)

Question 7

Who invented the X-ray machine?

Answer 7

Wilhelm Roentgen, in 1895, produced the first radiographic exposure of his wife’s hand

Question 8

How much do air, bone, water and fat attenuate X-rays in relation to each other?

Answer 8

Air attenuates them a little
Then, in increasing order;
Fat, water, bone

Question 9

Suggest a substance that could be used to demonstrate the gastrointestinal tract on an X-ray

Answer 9

Barium sulphate (suspension), as it is an insoluble, relatively high-density, non-toxic salt
Air can be added to the suspension which is called a double-contrast study

Question 10

What contrast agent could be used intravenously or intra-arterially to visualise the arteries, veins, and other structures and why? What other structures can be visualised by this method?

Answer 10

Iodine, as it has a relatively high atomic mass and is naturally excreted via the urinary system. This is why it can also be used to visualise the kidneys, bladder and ureter in intravenous urography

Question 11

What is subtraction angiography?

Answer 11

It is used to get around the issue of overlying bony structures. Two images are taken, one before the injection of the contrast media and one after, and the images are combined to create a solitary image of contrast only

Question 12

Which plane does a CT scanner obtain images in?

Answer 12

Axial

Question 13

What is the difference in the appearance of fat and fluids in T1 and T2 weighted MRI images?

Answer 13

T1 - dark fluid, bright fat

T2 - bright fluid, intermediate fat

Question 14

What type of radiation is used in nuclear medicine imaging?

Answer 14

Gamma rays

Question 15

Suggest a radiopharmaceutical commonly used in nuclear medicine imaging?

Answer 15

Technetium 99m, often combined with other complex molecules

Question 16

In simple terms, how does a PET scanner work?

Answer 16

Tissues that actively metabolise glucose take up more of an injected radioactive compound such as FDG, so they produce a ‘hot spot’; this is often used in the detection of cancer.

Question 17

Which direction are most chest radiographs taken in?

Answer 17

PA

AP is sometimes used if the patient is too unwell to stand

Question 18

Which direction are most abdominal radiographs taken in?

Answer 18

AP supine position

Erect plain abdominal radiograph sometimes used if small bowel obstruction is suspected

Question 19

How are most CT images orientated?

Answer 19

In the axial plane
Observer looks from feet upwards towards head
The uppermost border of the image is anterior
The patient’s left is on the observer’s right