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Flashcards in *Radiology Deck (76):
1

How are x-rays formed?

The cathode directs a stream of electrons into a vacuum, which collects the electrons. When the electrons hit the anode, about 99% of the resulting energy is emitted as heat with the other 1% being emitted as x-rays.

2

How many mSv does an x-ray emit?
How many mSv does a chest CT emit?

0.02
10

3

What causes blunting of the costophrenic angle?

Usually a pleural effusion but it can also be caused by lung disease in the region of the costophrenic angle or hyper expansion

4

What is situs inversus?

an uncommon condition in which the heart and other organs of the body are transposed through the sagittal plane to lie on the opposite (left or right) side from the usual.

5

What is the cardiothoracic ratio (CTR)?
what is an abnormal ratio?

Cardiac width: thoracic width
A CTR of greater than 1;2 is abnormal (50%)

6

What can exaggerate the size of the heart?

if the patient doesn't breath fully

7

What kind of congenital malformation can be seen on the bronchial tree on imaging?

Hilar bronchogenic cysts

8

What lobes of the lung can be mainly seen on frontal radiography?

Right:
RUL
RML

Left:
LUL
Lingula

9

What lung lobes are seen in posterior radiography?

RLL
LLL

10

What type of fissure does both lungs have?

Oblique
Right lung also has a horizontal fissure

11

What allows the different types of tissue present on a CT scan to be compared?
Unit?

Each tissue has distinct densities
Hounsefield unit

12

What happens to a silhouette on imaging when you have 2 tissues of the same density together?

You lose the sillhouette

13

What are 2 other names for a mycetoma?
What is this?

Aspergilloma
Fungus ball
A clump of old which exists in a body cavity caused by fungi of the genus apergillus

14

What causes the appearance of lots of different dots in the lungs?

Miliary Tuberculosis (TB) - widespread dissemination of Mycobacterium tuberculosis via hematogenous spread

15

What lung disease is huge hillier lymph nodes a sign of?

Sarcoidosis

16

What is consolidation?

radiological sign that refers to non-specific air-space opacification on a chest radiograph or chest CT

17

What 2 questions regarding a PTE should be asked before a D-dimer is measured?

Is another diagnosis unlikely?
Is there a major risk factor?
Measure D-dimer if only 1 of the above answers is raised

18

What are the major risk factors for a PTE according to radiology form? (6)

Recent immobility
Pregnancy/ post partum
Major medical illness
Major surgery
Previous VTE
Lower limb trauma or surgery

19

what 3 questions should be considered when thinking about referring for a CTPA or V/Q scan (PTE)?
Results needed to get a scan

Is another diagnosis unlikely?
Is there a major risk factor?
Is the D-dimer raised? (only measure if only 1 of the above answers is YES)
CTPA or V/Q scan will only be done if 2 or more are YES

If

20

What does CTPA stand for?

CT pulmonary angiography

21

What is a V/Q scan?

Involves 2 types of radioisotope scans - patient inhales radioisotope gas and has radioisotopes infected into their veins - scan compares ventilation and blood flow in the lungs

22

What imaging is indicated for a PTE when CXR is normal?

V/Q scan

23

What imaging is indicated for PTE when radiation has tO be avoided/ left swollen?

Consider US leg for DVT

24

What imaging is indicated for PTE if CXR abnormal/ massive PE suspected?

CTPA

25

What is the usual isotope used for V/Q scan?

Tetnisium

26

If the patient has a PTE, what will a V/Q scan show?

Normal ventilation with abnormal perfusion

27

What are the 4 factors you have to look at to assess if a lung x-ray is technically adequate?

Penetration
Inspiration
Rotation
Angulation

28

How to check penetration?

You should be able to see the thoracic spine through the heart

29

How to check inspiration?

About 10 posterior ribs visible in an excellent inspiration, although in many hospitals 9 is adequate

30

How to check rotation?

Spinal process of the vertebral body is equidistant from the medial ends of each clavicle

31

How to check angulation?

A film which is angled up towards the head (apical lordotic) will have an unusually shaped heart and the sharp border of the left hemidiaphragm will be absent

32

Hamartoma?

a benign tumorlike nodule composed of an overgrowth of mature cells and tissues normally present in the affected part, but often with one element predominating (benign)

33

Are most lung masses benign or malignant?

Malignant

34

Are central or peripheral lung tumours likely to be more commonly asymptomatic?

Peripheral

35

what is lipoid pneumonia?

a specific form of lung inflammation (pneumonia) that develops when lipids enter the bronchial tree

36

Does scars form old TB predispose to lung cancer?

no

37

What are synchronous tumours?

Histologically distinct simultaneously deteted malignancies

38

What are metachronous tumours?

Not synchronous; multiple separate occurrences, such as multiple primary cancers developing at intervals.

39

What is bilateral calcified pleural plaque a marker of?

Asbestos exposure

40

What is asbestosis?

a lung disease resulting from the inhalation of asbestos particles, marked by severe fibrosis and a high risk of mesothelioma (cancer of the pleura).

41

What does HRCT stand for?

High resolution pulmonary fibrosis

42

What are peripheral tumours?

Tumours arising beyond the hilum

43

What are central tumours?

Tumours arising at or close to the hilum

44

Are peripheral tumours that are less than 1cm diameter visible on chest x-ray?

Rarely

45

Signs of a central tumour?

Hilar enlargement
Distal collapse/ consolidation
(not as easy to spot as a distal tumour as hidden by the mediastinum)

46

What is the international staging mechanism for lung cancer?

TNM

47

In terms of staging a tumour, what is contrast enhanced CT very good for? (3)

Assessing tumour size
Showing intracranial metastases
Guiding a biopsy of peripheral lesions

48

What is a PET scan very good for in terms of staging? (3)

Detecting:
Nodal metastases
Distant metastases (not brain)
Delineating tumour in an area of collapse

49

Is soft tissue differentiation better with MRI or CT?

MRI

50

Is spatial resolution better with MRI or CT?

CT

51

In the staging of lung cancer, what does M1a mean?

there are tumours in both lungs or fluid around the lung or heart that contains cancer cells

52

In the staging of lung cancer, what does M1b mean?

there are lung cancer cells in distant parts of the body, such as the liver or bones

53

What is adenopathy?

Another name for lymphadenopathy

54

In what type of lung cancer is mediastinal adenopathy often marked?

Small cell lung cancer - lottos nodal metastases

55

What is the main treatment for small cell lung cancer?

Chemotherapy (as it often spreads very quickly)

56

What is pulmonary lymphangitis carcinomatosis?

Tumour spread through the lymphatics of the lung

57

What is a complication of CT guided biopsy?

Pneumothorax

58

What is an US good for imaging?

Pleural effusion
Subphrenic collection
Movement of diaphragm
US guided drainage

59

What is a teratoma?

A tumour composed of tissues not normally present at the site (typically in the gonads)

60

What is radiation fibrosis?

abnormal production of the protein, fibrin, which accumulates in and damages the radiated tissue.

61

What is thoracoplasty?

the operation removing selected portions of the ribs to collapse part of the underlying lung or an abnormal pleural space, usually in the treatment of tuberculosis.

62

Why are the shoulders braced forward when taking a CXR?

To prevent the scapulae from obscuring the lungs

63

What does a PA radiograph mean?

The x-rays pass from posterior to anterior

64

When is an "AP radiograph" taken?

In patients who cannot stand

65

Why are AP radiographs not as good as PA radiographs?

The heart shadow is magnified so heart size can bot be accurately assessed
The scapulae overlie and partly obscure the lungs
It can be difficult for the patient to take an adequate inspiration

66

How much higher is the right diaphragm above the left diaphragm?

1.5cm

67

What colour should the retrosternal and retrocardiac spaces be on a lateral CXR?

Dark

68

CXR silhouette sign?

Loss of a borders edge may signify pathology

69

What are the names of the lung zones?

Each lung has an upper, middle and lower lobe

70

What could cause the left heart border to become obscured?

Infection of lingula

71

What causes a lobar collapse?

Obstruction of a lobar bronchus e/g/ tumours, food, mucus impaction

72

What lobar collapse causes displaced left oblique fissure and an obscured medial part of the left hemidiaphragm?

Left lower lobe collapse

73

What lobar collapse causes a displaced right horizontal fissure with a densnes superiorly to the fissure?

Right upper lobe collapse

74

What lobar collapse causes the left oblique fissure to be pulled anteriorly and obscures the left heart border?

Left upper lobe collapse

75

When is the pleural cavity visible on chest radiographs?

When it is filled with fluid (pleural effusion) or air (pneumothorax)

76

Where can dense pleural fluid be present on an erect CXR?

Seen to collect at the lung bases or tracking into the oblique and horizontal fissures