lec 3- 3D imaging principles

Question 1

what is geometric movement?

Answer 1

-If we move the II and X-ray tube, the objects move. But not all objects move in the same way

Question 2

if we move the II so it is in the position LPO45CR0, and there are two objects in the field of view, which object will move in the same direction as the II and which will move in the opposite direction?

Answer 2

the most proximal object: object closest to II (furthest from x-ray tube) will move in the opposite direction
the most distal object: object furthest from II (closest to x-ray tube) will move in the same direction as the II

Question 3

If the II moves to the position LAO45CR25, which object will be magnified? The object closest or furthest from the II
An which way will the two objects move

Answer 3

The most distal object (closest to x-ray tube) will be magnified
The most distal object will move in the same direction as the II and the proximal object will move in the opposite direction

Question 4

If the II is located anterior to the patient, will the transverse colon be more or less magnified than the ascending colon?

Answer 4

less magnified as it is closest to the II and the transverse colon is located anterior to the ascending colon

Question 5

If the II is located posterior to the patient, will the transverse colon be more or less magnified than the ascending colon?

Answer 5

more magnified as it is furthest from the II and located anteriorly to the ascending colon

Question 6

If a vascular surgeon is having trouble finding the right femoral vein what way will you move the II? (assume the x-ray tube is posterior to the patient_

Answer 6

LAO with caudal angulation to produce a profile projection
(minimal magnification distortion)
LAO25CAU20 to be exact

Question 7

what is a profile projection?

Answer 7

Where there is minimal magnification distortion in the anatomy visualised

Question 8

when imaging the renal system, what will the LPO/RAO position demonstrate?

Answer 8

• right kidney profile projection, left kidney axial view

- right ureter entry to bladder, left ureter in profile

Question 9

when imaging the renal system, what will the RPO/LAO position demonstrate?

Answer 9

• left kidney profile projection, right kidney axial view

- left ureter entry to bladder, right ureter in profile

Question 10

when imaging the renal system, what is the importance of performed LPO/RAO images as well as RPO/LAO images?

Answer 10

both projections demonstrate the kidneys/ ureters/ bladder in a difference projection. Tis enables a profile projection of all structures

Question 11

What is the radiographers responsibility?

Answer 11

• To produce quality images
• To be able to locate/ localise the object
• Describe extent of the pathology using images
• Ability to visualise with minimal interference from local near-by objects
• Know the shape of the anatomy to gain specialised views

Question 12

what are tangential views used for?

Answer 12

to determine the pathological extent

Question 13

what is an advantage of contrast media

Answer 13

can overcome the shadows of the surrounding anatomy

Question 14

what structures are examined in a barium swallow

Answer 14

oral cavity (naso/oro/laryngopharynx), oesophagus

Question 15

what structures do we need to be aware of when doing a barium swallow

Answer 15

spine, thyroid, trachea, sternum, motion artefact, oesophagus shape, heart, aorta

Question 16

what are the standard views when doing a barium swallow (upper GIT)

Answer 16

control AP, standard AP, lateral

Question 17

what are the views needed when doing a barium swallow when the
oesophagus enters the stomach, antrum, oesophagus entering stomach/ less curvature, fundus

Answer 17

• Oesophagus enters the stomach: control AP, standard AP
• Antrum: LPO/RAO
• Oesophagus entering stomach and lesser curvature: RPO/LAO
• Fundus: lateral

Question 18

when doing double contrast studies what do we need to be aware of

Answer 18

-The location of air and contrast media

Question 19

in a barium meal, when examining the stomach an duodenum, what structures do we want to view and what d we need to be mindful of?

Answer 19

need to be mindful of air/liquid filling
viewing:
- oesophageal sphincter
- fundus
- body
- greater and less curvature
- antrum
- pyloric sphincter

Question 20

in a barium meal, when examining the stomach an duodenum, what do we need to do to the greater curvature, and how do we do it?

Answer 20

need to coat with contrast, however, there is air in here

• Need the air to settle in the greater curvature, so that must be “elevated” with respect to other anatomy
• Roll the patient to coat the barium everywhere
• If the X-ray tube is under the table, patient is supine on the table, therefore, to raise curvature: LAO
• If the X-ray tube is over the table then the patient is in a RPO position

Question 21

in a barium meal, when examining the stomach an duodenum, what view could we do for the fundus?

Answer 21

: erect AP (any position erect will show air in the fundus and liquid contrast in the antrum and distal body of the stomach)