Abdominal surgery and imaging Flashcards Preview

Z MD1 GI block > Abdominal surgery and imaging > Flashcards

Flashcards in Abdominal surgery and imaging Deck (18)
1

medium used for intravasular contrast medium

iodine

1

what is the principle of radioisotope imaging

- attached to particular molecules that are introduced into the body - emit gamma rays that are recorded by a gamma camera

2

distribution of iodine when injected into the body

distributed through the blood vessels --> some becomes extravascular --> then goes to kidneys --> excreted

2

principle of ultrasound imaging

machine produces thin sectional images using echoes returned form tissue interfaces (some will reflect and some will go to reflect at other surfaces)

2

why do you need gel between the probe and the skin when using Ultrasound

if the high frequency ultrasound hits air it bounces back

3

principle of MRI

put patient in a very strong magnetic field - aligns the atoms of the body momentarily to the same direction. Then stop the magnitism and listen for the resulting signal from the change in magnitism back to "normal"

4

what are the main reasons for surgery of the small bowel

- obstruction due to adhesions, herniae - utility of small bowel - ileal pouch operation, ileostomy - Meckel's diverticulum - Ileal Crohn's disease

5

what are the main reasons for surgery of the stomach

- hiatus hernia - Barrett's oesophagus - helicobacter in antrum - duodenal ulcers - CD in duodenum - achalasia

6

principle of radioisotope biliary imaging

radioisotope is attached to a molecule which is recognized as like bilirubin --> excreted to liver and then into the gall bladder --> duodeum

7

doppler effect

a perceived change in frequency of waves when there is relative movement between the generator of the sound and the observer of the sound

9

types of diagnostic radiology (5)

x-ray -gamm rays - ulrasound - MRI -PET

11

absorption of an x-ray beam in tissues depends on:

- thickness of the tissue - density of the tissue - atomic number of the tissue (to the 4th power)

12

what physiological and pathological features cause a shadow on ultrasound

physiological - lungs pathological - gall stones

13

how do we improve on the natural differences in Xray absorption

- alter the absorption (use a radiographic medium) - measure the absorption by a more sensitive method

14

how many times stronger is the MRI magnetism compared to earths gravity

30,000

15

what are the main reasons for surgery of the colon and rectum

- COLORECTAL CANCER - diverticular disease - ulcerative colitis and Chron's colitis

17

wave length and energy of xrays

short wavelength and high energy ( in between UV and gamma rays)

18

common reason for surgery on the gallbladder

gall stones +/- inflammation