Radiology

Question 1

Name 4 radiological modalities that use radiation

Answer 1

• Xray
.Ct scan (ct Angio highest)
• mammogram (least)
• pet scan

Question 2

Name 2 radiological modalities that don’t use radiation and therefore is safe for pregnancy and paeds

Answer 2

• Ultrasound
• MRI

Question 3

List radiological modalities from least to most expensive (5)

Answer 3

• Xray
.Ct and US
• MRI
• Ct Angio
• pet scan

Question 4

What is the ALARA principle

Answer 4

As low as reasonably achievable dose of radiation and still provide detailed exams

Question 5

Define the stochastic effect of radiation

Answer 5

Likelihood that effect/cancer will occur in long term, there is no threshold (not dose dependent)
More time dependent

Question 6

Define the deterministic effect of radiation

Answer 6

Effects vary with dose, there is a threshold below which the effect does not occur (dose dependent)
Eg skin cancer occur from dose 2-5 Gy, not below that.

Question 7

Name 1o uses ultrasound

Answer 7

Trauma:
• fast: free fluid in abdomen, pericardium, haemothorax, pneumothorax
• Doppler: vascular injury

Paediatrics
• solid abdominal organ exam

Neonates
• hip dislocation
• intracranial haemorrhage!

• General exam: gallstones, kidney stones, liver disease, thyroid, testicular torsion
• obstetrics: intrauterine foetus development and other complications eg abruptio
• Heart echo: ejection fraction, pericardial effusion
• MSK: tendon rupture/tear
• breast: lesions, biopsies

Question 8

What is fluoroscopy and what is it used for (4)

Answer 8

Uses x ray to view anatomy as it functions in real time.
• gastrointestinal: barium swallow and meal, barium enema
• genitourinary: vesicoureterogram vcug (inject urographin contraSt in bladder), intravenous pyelogram IVP (inject ultraVist contrast iv )
• Arthrogram’s: joint space
• hysterOgrams: uterus and fallopian tubes

Question 9

Name 3 considerations before giving patient Ct contrast

Answer 9

• Iodine allergy
• penicillin allergy
• if patient has taken glucophage - if given with contrast → lactic acidosis

Question 10

Name 6 uses MRI

Answer 10

Best for soft tissue
. Brain: tumours, stroke, abscesses, nerve compression
• chest: heart, valves, coronary blood vessels
• Blood vessel magnetic resonance angiography MRA: aneurysm, stricture, dissection
• abdomen, pelvis: liver, gallbladder, pancreas, kidneys, prostates bladder; blockage, ambiguous genitalia, tumours, bleeding, infection
• bones and joints: bone marrow, bone tumours, cartilage, torn ligaments or tendons, infection
. Spine: discs, nerves for spinal stenosis, disc bulge, spine tumour

Question 11

Nb name 2 contraindications MRI

Answer 11

• Pacemakers, metal implants, metal chips or clips
• claustrophobia

Question 12

How can physician reduce radiation doses (5)

Answer 12

• Order appropriate investigation for relevant clinical presentation
• do not unnecessarily repeat
• always check previous imaging before order new
• have all pre-ct scan pre-requisites checked before request investigation eg have relevant blood results ready in case of post contrasted imaging or angiography
• check if allergy to iodine, penicillin, opioids

Question 13

How much radiation can pregnant woman receive

Answer 13

<50 mGy (5 rads)

Question 14

How can irradiation in unknown early pregnancy be prevented

Answer 14

Ten day rule:
Women of childbearing age: non-urgent diagnostic radiography of abdo should be confined to pre-ovulatory phase of menstrual cycle ie 10 days following first day of last period

Question 15

First choice study for head trauma?

Answer 15

Ct brain

Question 16

First choice study for long bone fracture??

Answer 16

Xray

Question 17

First choice study for symptoms cholecystitis?

Answer 17

Ultrasound

Question 18

First choice study for chronically ill with metastasis presenting with confusion, slurred speech, herriparesis?

Answer 18

Only pre and contrast Ct brain
Not staging Ct

Question 19

First choice study for trauma to exclude tension pneumo, widened mediastinum, location ETT and ICD?

Answer 19

Ap chest radiograph

Question 20

First choice study for suspected vascular injury in trauma?

Answer 20

Doppler

Question 21

First choice study for evidence vascular injury in trauma?

Answer 21

CTA

Question 22

Imaging Approach to widened mediastinum? (3)

Answer 22

• Chest xray ideally with head up, NGT
. If abnormal, Ct scan with contrast
. If abnormal or equivocal, angiography

Question 23

First choice study for suspected intracranial bleed adult?

Answer 23

Pre contrast Ct

Question 24

First choice study for suspected intracranial bleed neonate?

Answer 24

Ultrasound

Question 25

First choice study for suspected Gallstones adult?

Answer 25

Ultrasound

Question 26

First choice study for suspected intracranial aneurysm?

Answer 26

Ct Angie

Question 27

First choice study for sudden paraparesis and incontinence?

Answer 27

MRI spire

Question 28

First choice study for suspected interstitial lung disease?

Answer 28

High resolution Ct chest

Question 29

First choice study for suspected neonate hip dislocation?

Answer 29

Ultrasound

Question 30

First choice study for suspected intra peritoneal abscesses adult?

Answer 30

Contrasted Ct scan

Question 31

First choice study for suspected hyperacute infarct with normal Ct?

Answer 31

MRI hyper acute sequence

Question 32

First choice study for suspected brain abscess or metastasis with known renal failure?

Answer 32

MRI special sequence not needing contrast

Question 33

First choice study for suspected diverticulitis adult?

Answer 33

Barium enema

Question 34

First choice study for adult fell and present with suspected knee dislocation and cold limb?

Answer 34

Doppler then xray
If absent pulses and stable: Ct Angio lower limb to plan surgery

Question 35

First choice study for unstable hypotensive with abdominal and head injures?

Answer 35

Ultrasound abdomen
Ct abdo, Ct brain

Question 36

First choice study for blunt abdo trauma with suspected haemorrhage from pelvic #?

Answer 36

Ct angio abdo and pelvis

Question 37

First choice study for suspected appendicitis adult?

Answer 37

Contrasted Ct abdomen
Ultrasound if obese

Question 38

What does pneumoperitoneum indicate?

Answer 38

• Bowel perforation
• surgical emergency

Question 39

Name 2 causes pneumoperitoneum

Answer 39

. Gastric ulcer perforation
• colonic diverticulitis perforation
Not seen in perforated appendicitis

Question 40

Symptoms ruptured aneurysm?

Answer 40

Triad:
• hypotension
• pulsating mass
• back pain

Question 41

Most common site ruptured aneurysm?

Answer 41

Left retroperitoneum

Question 42

Name 2 git complications ruptured aneurysm

Answer 42

• Sigmoid diverticulitis
• renal colic
Due to impingements haematoma on adjacent structure

Question 43

First choice study for suspected ruptured aneurysm in stable patient?-

Answer 43

Ct angiogram

Question 44

First choice study for suspected ruptured aneurysm in unstable patient?-

Answer 44

Ultrasound

Question 45

Name 2 uses plain abdominal radiograph in acute abdomen

Answer 45

• Kidney stone detection
• pneumoperitorium detection

(If don’t find these, do more investigations )

Question 46

Define positive fast in RUQ

Answer 46

Fluid in morrison’s pouch between liver and kidney

Question 47

Top 3 scans for chest emergency?

Answer 47

. CXR first
• then ultrasound
• then Ct if still in doubt

Question 48

First choice study for suspected bladder injury?-

Answer 48

Ct cystogram

Question 49

First choice study for suspected pancreatitis?-

Answer 49

Ultrasound
If in doubt, Ct (fat stranding)