Diagnostic radiology - Radiography

Question 1

How X-rays are produced?

Answer 1

tungsten filament is heated, electrons are ejected from the surface of the filament

Voltage (a large electrical potential) between the cathode and the anode forces electrons emitted from the filament to accelerate towards the anode, hit on tungsten target (e.g. titanium)

energy conversion when a fast-moving stream of electrons suddenly decelerates produces x-ray

Question 2

Special films for Pneumothorax, pleural effusion and wrist fracture?

Answer 2

Pneumothorax = inspiratory and expiratory film

Pleural effusion = decubitus film

Wrist fracture = scaphoid view

Question 3

Difference between conventional and digital radiography?

Advantage?

Answer 3

Digital = phosphor imaging plate connected to computer

• Complex image processing
• Electronic storage (easier to compare)
• Electronic image transmission

Question 4

Indications for mammography?

Answer 4

• Screening: asymptomatic, early detection of small breast cancers (e.g. DCIS)
• Diagnostic mammography: Symptomatic, detect mass

Question 5

3 views on mammography?

Answer 5

Medial lateral oblique view
Craniocaudal view
Special view: Compression paddle to spread out breast tissue, magnify to show small microcalcifications and lesions

Question 6

Mammography finding: Indications of lesion with

• Well-defined border, round?
• Speculated, irregular border?
• Large, clustered dots?
• Small specks that follow ducts?

Answer 6

Well defined border, round – cyst

Denser with speculated border and clumps of small
microcalcifications – breast cancer

Benign calcification = big, clustered

Malignant calcification (e.g. small dots that follow
ducts) – ductal carcinoma in situ

Question 7

Effect of age on mammography sensitivity?

Answer 7

Sensitivity decreases in dense breast:

Old: glands replaced by fat = easier to spot pathology
Young: glandular = whiter

mammogram are less sensitive in young patients (US more appropriate)

Question 8

Name of X-ray exam to Demonstrate the urinary tract for suspected urinary tract pathology

Answer 8

Intravenous urogram (IVU)

Question 9

Indications for Intravenous urogram (IVU)

Mechanism?

Answer 9

hematuria, loin pain

Uses intravenous nonionic contrast which are excreted in kidney to ‘contrast’ urinary system – looks white on X-ray

Question 10

Patient preparation for intravenous urogram

Answer 10

 Laxative (decrease fecal matter, can be mistaken as mass)
 Fast for 4 hours
 Hydration (increase distension of urinary collecting system)
 Vascular accesses

Question 11

Assessment before injection of IV contrast for intravenous urogram?

Patient preparation during exam?

Answer 11

Look for calcifications (e.g. ureteric stone) before injecting contrast

Compression band: presses down the top of bladder to adequately distend the pelvicalyceal system for evaluation

Question 12

How to assess for urinary retention on IVU?

Answer 12

Do 2 films:

Full bladder and post-micturition films

Question 13

Fluoroscopy

• Difference from X-ray
• Contrast medium used?

Answer 13

• Continuous exposure of X-ray gives dynamic view of moving body structures
• Barium, water-soluble contrast medium, Air

Question 14

Barium exam complications?

Answer 14

Perforation:
Barium peritonitis from peritoneal adhesions, granulomata

Aspiration into lung:
Barium pneumonia, need Physiotherapy

Question 15

Barium exam patient preparation

Answer 15

Fasting

Bowel prep: low residual diet for 3 days, laxatives

IV Buscopan: bowel relaxant, reduce bowel preistalsis, Increase distension for better assessment

Question 16

Procedure for barium enema

Answer 16

Barium release into rectum + air inflation for double contrast

Patient rolled around for different views

Question 17

Barium enema show:

• Outpouching of colon
• Apple core appearance of colon

Suggestive of what diseases?

Answer 17

Outpouching = diverticula

Apple core appearance = colorectal cancer

Question 18

5 symptoms and signs to indicate barium enema?

Answer 18

 Change in bowel habit
 Pain
 Mass
 Blood in stools
 Bowel obstruction

Question 19

Absolute precaution with barium studies

Answer 19

Must use water-soluble contrast instead of barium contrast for suspected intestinal obstruction

to avoid barium peritonitis after perforation

Question 20

2 types of small bowel barium studies?

Answer 20

Small bowel follow through: oral intake of barium

Small bowel enema: Catheter inserted through nostril (naso-gastric tube) through to duodenal-jejunum junction to inject barium and methylcellulose

Question 21

Small bowel follow through and small bowel enema.
Advantages
Disadvantages

Answer 21

Small bowel follow though
+ Easier oral intake of barium solution, less discomfort
- Delayed film for small bowel evaluation, single contrast, less wall detail

Small bowel enema
+ Better distension and double contrast, better detail
- Discomfort

Question 22

5 symptoms to indicate Barium meal?

What other visualization procedure has replaced most barium meal exams?

Answer 22

stomach, duodenum

 Dyspepsia, epigastric pain
 Weight loss
 Assessment for suspected stomach cancer
 Suspected perforation of peptic ulcer

Upper GI endoscopy

Question 23

Procedure of barium meal?

Answer 23

• Oral intake of barium solution
• Effervescent granules produce gas for double contrast - better mucosal detail
• Roll patient to different angles for views

Question 24

2 methods to visualize biliary tree?

Answer 24

1. Percutaneous cholangiogram

2. T-tube cholangiogram (skin to CBD)

Question 25

Percutaneous cholangiogram

• Indication
• Contraindication

Answer 25

 Indications:

• Biliary obstruction: stone, tumor, extrinsic compression
• Bile leak

 Contraindication: biliary sepsis

Question 26

Indications for Angiogram

Answer 26

 Assessment of arterial/venous disease, e.g. renal artery stenosis

 Localization of site of hemorrhage +/- embolization

 Fluoroscopic examination of vessels
(intravascular injection of contrast)

Question 27

Patient preparation for angiogram

Answer 27

 Fasting
 IV access
 Clotting profile, platelet

Question 28

Method to show vessels against a clearer background in angiogram?

Answer 28

digital subtraction angiogram

subtracts background structures e.g. bones

Question 29

Adverse reactions to intravascular water-soluble contrast medium for angiogram?

Answer 29

 Mild: sneezing, nausea

 Moderate: pruritis, flush, fever / chills, increased /
decreased blood pressure

 Severe: difficulty in breathing, periorbital edema,
cardiac arrhythmia, pulmonary edema, death

Question 30

5 ways to reduce radiation exposure

Answer 30

 Avoid unnecessary examination

 Use alternative: USG, MRI (particularly in pediatric, pregnant patients)

 Shielding of organs, e.g. gonad shield, lead apron, thyroid shield, glasses

 Filtration of X-ray beam

 Control of irradiation and recording of irradiation time