EXII reading part 1

Question 1

what is conventional radiology? what are the pros and cons?

Answer 1

ionizing radiation & light → photosensitive surface

pros: cheap, can use anywhere
cons: physical storage, limited densities, ionizing rad

Question 2

what is the cornerstone of cross-sectional imaging?

Answer 2

CT

Question 3

what is a con of fluoroscopy?

Answer 3

more radiation

Question 4

what sources of the body’s radiation does nuclear medicine use?

Answer 4

iodine in thyroid
glucose in brain
phosphate in bones
PET: positron emission tomography for biochemical and metabolic processes (for cancer mets)

Question 5

what kind of imaging has the least patient exposure?

Answer 5

nuclear medicine

Question 6

what is the underlying principle of nuclear med?

Answer 6

artificial radioactive isotopes emit radiation from nuclear as it decays. (gamma camera and SPECT)

Question 7

what are the 2 dangers of under penetration?

Answer 7

causes you to overcall: 
mimics or hides true disease in left lower lung 
pulmonary markings (vessels) appear more prominent

Question 8

what is the danger of over penetration?

Answer 8

lung markings may seem ↓ or absent cay accidentally thing pt has emphysema or pneumothorax

Question 9

what is the danger of poor inspiration in a chest film?

Answer 9

compresses lower lung → lower lobe pneumonia appearance

Question 10

what is the rotation if the midline appears close to the right clavicle?

Answer 10

pt is rotated to his let

Question 11

what 2 errors can occur with a rotated xray?

Answer 11

hilum appears larger on further away side

hemidiaphragm may appear higher on rotated side

Question 12

what is apical lordotic angling?

Answer 12

xray beam angled towards patient’s head

Question 13

what is the difference between vessels at different heights in the lung?

Answer 13

lower vessels are larger than at apex

Question 14

which 5 areas are seen on a lateral chest xray?

Answer 14

retrosternal clear space
hilar region
fissure
thoracic spine 
diaphragm and posterior costophrenic sulci

Question 15

what does a thickened fissure indicate?

Answer 15

fluid or fibrosis

Question 16

what is an indication of disc degeneration on xray?

Answer 16

bony spurs at margins of vertebral bodies

Question 17

what is the cardiothoracic ratio? what is a normal ratio?

Answer 17

widest transverse diameter of the heart compared to the widest internal diameter of the ribcage

<50% in normal adult

Question 18

what is the first step of compensation when ventricular outflow is blocked?

Answer 18

hypertrophy

Question 19

what is chamber enlargement usually the result of?

Answer 19

volume overload >pressure overload

Question 20

what is the pleural space?

Answer 20

between visceral and parietal

Question 21

what are the 2 steps for detecting pleural effusion?

Answer 21

1. conventional radiology

2. CT/US

Question 22

what are 6 causes of pleural effusion?

Answer 22

↑ hydrostatic pressure (L HF)
↓ colloid pressire (hypoproteinemia)
↑ capillary permeability (Pneumonia)
↓ lymph absorption (↑ venous pressure)
↓ pleural pressure
fluid from abdomen → thorax

Question 23

what are the 2 kinds of pleural effusion with examples?

Answer 23

1. transudate (↑ capillary pressure or ↓ colloid pressure)
   - CHF
   - hypoalbuminemia
   - cirrhosis
   - nephrotic syndrome
2. Exudate (inflammation)
   - malignancy**
   - empyema
   - hemothorax
   - chylothorax

Question 24

which 2 diseases commonly cause bilateral pleural effusion?

Answer 24

CHF

SLE