Radiology

Question 1

AXR Tox Ingestions

Answer 1

Radio-dense Tablets
- Iron tablets
- Potassium Chloride (KCL Tablets)
Metals
- Mercury
Iatrogenic
- Barium

Question 2

Aortic Dissection CXR

Answer 2

1. Widened mediastinum > 8cm aortic arch
2. Abnormal aortic contour - Aortic knuckle deformity/irregular or indistinct
3. Calcium sign >5mm (separation of intiminal calcification from vessel wall)
4. Pleural effusion L>R
5. Tracheal shift to RHS
6. Left apical cap
7. NGT deviation to RHS at T4
8. Widening of Right paratracheal-stripe >5mm
9. Normal in 11-16%

Apical cap is formed when blood dissects above the lung on either side Left more sensitive than Right

Question 3

CXR

Answer 3

ADV
Readily available
Bedside
Fast
Low radiation
May see other pathologies

CONS
Low sensitivity for some pathologies
May miss other diagnoses

Question 4

AXR / XR KUB

Answer 4

ADV

Readily Available

Fast

Low radiation - monitoring renal stone

CONS

Low sensitivity

Unable to assess complications of pathology

Question 5

USS

Answer 5

ADV

Readily available

Non-invasive

No radiation

Preferred mode for pregnant patient

Bedside procedure

CONS

Operator dependent

Formal may not be available 24/7

Difficult with large body habitus

Question 6

Echo

Answer 6

ADV

Readily available

Non-invasive

No radiation

Bedside procedure

CONS

Operator dependent

Formal may not be available 24/7

Difficult with large body habitus

Limited by pt positioning or SC emphysema

Question 7

Ct angio

Question 8

CT A/P

Question 9

MRI

Answer 9

ADV

Non-invasive

No radiation

Other causes identified

CONs

Not easily available

Time consuming

Expensive

Accuracy may be less than IVP

Question 10

IR

Question 11

USS Duplex

Answer 11

ADV

Non-invasive

Avoids contrast

Bedside

Monitor in ED for deterioration

CONS

Not always available 24/7

Operator dependent

Less sensitive below knee for DVT/embolism

Question 12

CT KUB

Answer 12

ADV

High sensitivity for renal calculi

Measure size

Location

Detect obstruction

ID other causes of flank pain

Avoid contrast

CONS

Radiation

Higher cost

Question 13

IVP

Answer 13

ADV

Size and location stone

Measures renal function

CONS

Contrast nephropathy

Contrast allergy

More time consuming than CT

Unable to exclue other diagnoses

Radiation

Question 14

CXR - Foreign Body aspiration

Answer 14

• Radio-opaque FB
• Hyperinflation affected side
• +/- atelectasis on affected side
• Lobar atelectasis
• Whole lung atelectasis
• Shift of mediastinal shadow
• Aeration within area of atelectasis

Question 15

C-spine Soft Tissue Swelling

Answer 15

Question 16

USS Causes No Lung Slide

Answer 16

1. Loss of pleural apposition
   a. PTx / Pleural
   b. Bullae
2. Increased adhesion between pleural layers
   a. Pleural adhesions
   b. ARDS
   c. Pulmonary fibrosis
   d. Pneumonia
   e. VATS / pleurodesis
3. Absent local ventilation
   a. Mainstem bronchial intubation
   b. Atelectasis

Question 17

C-spine XR

Answer 17

1. Adequate views - C1-T1
2. Alignment
   
   • Ant Longitudinal Line
   • Post Longitudinal Line
   • Spinolaminal Line
   • Spinous Process Line
3. Bones
   
   • Assess each vertebra for Fracture / Collapse / Avulsion
4. Cartilage
5. Soft tissue - Prevertebral ST swelling
   
   • 6mm at C2 or 22mm at C6
   • 6mm C2 or 14mm at C6 - kids
6. Spaces
   
   • Predental space - betw/ C1 tubercle and anterior face of dens
     * <3mm adults
     * <5mm children
   • Basion Dental interval
     * <12mm XR
     * <8.5mm CT
   • Power’s Ratio (atlanto-occipital dislocation
     * AB/CD should be < 1
   • Line of Swischuck - line from anterior aspect C1 to C3 spinous processes
     * Anterior aspect of C2 should be < 2mm of this line
     * Deviated > 2mm ? subluxation
     * Deviated < 2mm ? pseudosubluxation
7. Scan base skull, airway, sinuses
8. AP and Odontoid views

[https://www.nyp.org/professionals/emergency-medicine/how-to-read-emergency-images/how-to-read-a-c-spine-film]
[https://dontforgetthebubbles.com/c-spine-x-ray-interpretation/

Question 18

Power’s Ratio

Answer 18

Marker of atlanto-occipital dissociation BC/AO <1 A = Ant arch atlas B = Basion C = Post spinolaminar line C1 O = Opisthion

Question 19

Basion Dental Interval

Answer 19

Marker of antlanto-occipital dissociation <12mm on XR < 8.5mm CT

Question 20

Line of Swischuck

Answer 20

Anterior aspect of C2 should be within 2mm of this line >2mm true subluxation <2mm ?psuedosubluxation

Question 21

Pre-Dental Space

Answer 21

Normal < 3mm >2mm ? damage transverse ligament > 5mm implies rupture to transverse ligament

Question 22

CXR Cavitating Lesions

Answer 22

Infection
Bacterial - Abscess, infected bullae, TB, Empyema
Fungal - Coccidiomycosis, Apergillis, Cryptococcus
Parasitic - Amebiasis, Entomaeba histolytica

Neoplastic
Bronchogenic - SCC or Adenocarcinoma
Metastatic
Lymphoma

Inflammatory
Sarcoidosis
Wegner’s
RA nodules

Vascular - (both bland and septic pulmonary emboli)

Trauma - pneumatoceles

Other
FB aspiration
Younger pts -
CPAM (congenital pulmonary airway malformation)
pulmonary sequestration
Bronchogenic cyst

Question 23

CXR Solitary Nodules

Answer 23

Only 30-40% malignant

Malignant - Primary Lung or lymphoma
Benign - Hamartoma, chrondroma
Infection - Tuberculoma, Aspergilloma, Abscess, round pneumonia, hydatid disease
Autoimmune - RA, Wegeners
Vasc - AV malformation, infarct, haematoma
Congenital - bronchial atresia, sequestration

Question 24

CXR in Pneumonia

Answer 24

Segmental or lobar opacity with air bronchogram – Strep. pneumonia

Cavitation - Klebsiella, Staph aureus

Cavitation + Pleural effusion:
- Staph aureus
- Anaerobes
- Gram negatives
- TB

Lower zones: Legionella

Upper Zones: Klebsiella

*​multifocal peripheral ground glass appearance - COVID -19

*​round pneumonia (solitary pulmonary nodule)

-​C Burnetti

-​S pneumoniae

-​L pneumophilia

-​S aureus

Question 25

Urogenital injury imaging

Answer 25

USS ADV- scrotal or penile trauma may be seen DISADV not sensitive enough for renal/ureteric injury CT KUB - not helpful CT IVP RUG

Question 26

Foetal Exposure with Imaging

Answer 26

Question 27

USS Cholecystitis

Answer 27

GB wall > 3mm Pericholecystic fluid Enlarged GB Sonogrpahic Murphy's sign Gallstones Dilated CBD > 10mm (usually less than 6mm) Gas in biliary tree Gas in gall bladder - acalculus or gangrenous cholecystitis

Question 28

USS pleural effusion

Answer 28

Hypoechoic region above diaphragm Sinusoid sign - atelectic lung moving with respirations Thoracic psine sign - see spine aobve vlevel of diaphragm Effusions > 5cm depth usually indicates at least 500ml of pleural fluid

Question 29

CXR in TB

Answer 29

- Consolidation upper and mid-zone prevelance - Hilar lymphadenopathy - Cavitating lesions - Ghon focus - subpleural calcifcation remains after inital infection - Fibrosis calcification - Tuberculoma - well defined mass - Miliar Pattern - small nodules throughout the lungs

Question 30

USS Features appendicitis

Answer 30

Appendiceal diameter >6mm Appendiceal wall thickness >3mm Non-compressible Hyperaemia Surrounding oedema or fat stranding Appendicolith

Question 31

ECHO PE

Answer 31

RV dilation Septal bowing Apical hypokinesis IVC dilation