Abdominal surgery and imaging

Question 1

medium used for intravasular contrast medium

Answer 1

iodine

Question 1

what is the principle of radioisotope imaging

Answer 1

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

Question 2

distribution of iodine when injected into the body

Answer 2

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

Question 2

principle of ultrasound imaging

Answer 2

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

Question 2

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

Answer 2

if the high frequency ultrasound hits air it bounces back

Question 3

principle of MRI

Answer 3

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”

Question 4

what are the main reasons for surgery of the small bowel

Answer 4

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

Question 5

what are the main reasons for surgery of the stomach

Answer 5

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

Question 6

principle of radioisotope biliary imaging

Answer 6

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

Question 7

doppler effect

Answer 7

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

Question 9

types of diagnostic radiology (5)

Answer 9

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

Question 11

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

Answer 11

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

Question 12

what physiological and pathological features cause a shadow on ultrasound

Answer 12

physiological - lungs pathological - gall stones

Question 13

how do we improve on the natural differences in Xray absorption

Answer 13

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

Question 14

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

Answer 14

30,000

Question 15

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

Answer 15

• COLORECTAL CANCER - diverticular disease - ulcerative colitis and Chron’s colitis

Question 17

wave length and energy of xrays

Answer 17

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

Question 18

common reason for surgery on the gallbladder

Answer 18

gall stones +/- inflammation