Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Application of imaging > Imaging of the thorax > Flashcards

Imaging of the thorax Flashcards

1
Q

Basic anatomy of the thorax region

A

Lungs – How many? Regions? Right lobe has 3 regions, left has 2 because of the heart.

Mediastinum & Hilum- What does this comprise of? trachea, aorta. Hilum- start point of the lungs.

Heart and Major Vessels- Where and how?

Ribs – How many? Function?

Diaphragm – Where? Bottom of the chest x ray. Function? Aids with inspiration and expiration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Lung anatomy

A

There are two lungs – right and left.

The left lung is smaller to accommodate the heart within the thoracic cavity and has 2 lobes

The right lung has 3 lobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is Mediastinum?

A
  • A cavity between the lungs containing the heart, trachea, oesophagus, major vessels and lymph nodes
  • It extends from the sternum to the vertebrae posteriorly
  • Top to bottom it extends from the thoracic inlet to the diaphragm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Hilum?

A
  • The Hilum (Hila): - or lung root mainly consist of the major bronchi and pulmonary veins and arteries
  • It is the point in which the bronchi, pulmonary arteries and veins, nerves and lymphatic vessels enter/leave to lung
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ABCDEFGHI

A
  • A. Airways
  • B. Bones and Soft tissues
  • C. Cardiac
  • D. Diaphragm
  • E. Effusions (buildup of fluid where it shouldn’t be) /soft tissue
  • F. Fields, fissures and soft tissue
  • G. Great Vessels/ Gastric bubble
  • H. Hilum
  • I. Impression?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Chest criteria

A

-Patient Name
-Patient DOB
-Date
-Correct anatomical marker
-Medial ends of clavicle equidistant from spinous processes
-Clavicles horizontal
-Scapula clear of lung fields
-Lung Markings evident
-Apices shown
-Bases shown

-Collimation evident
-Intervertebral spaces seen through heart
-Bony trabeculae shown
-Spine to T4 clear
-Carina shown
-Spinous processes central
-Gas bubble under left diaphragm
-8-10 posterior ribs visible
-Cardio-phrenic / costo-phrenic angles
-CTR?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Cardio-Thoracic ratio?

A
  • Way of measuring heart size
  • CTR – the cardiac diameter should be 50% or less the width of the chest.
  • If any greater than 50% - underlying cardiac disease/masses
  • Diagnosis relies upon a non rotated image
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Respiration: Breathing

A

o Air is drawn in and moistened/filtered via nasal passages/mouth
o Drawn then into the trachea (windpipe)-then the 2 main bronchi (left/right)
o Travels to bronchioles-finally ending at the alveoli
o Gas exchange takes place-02 passes into the bloodstream from the warmed air and CO2 passes out of the blood into the air filled alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Respiration: On inspiration

A

intercostal muscles contract, thorax expands, diaphragm also contracts, lung volume increases, lung pressure drops & air is drawn into the lungs (think bellows!); this is why we expose on arrested inspiration with chest radiography

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Respiration: On expiration

A

intercostal muscles relax, thoracic cage reduces in volume, diaphragm relaxes and moves upwards-this reduces lung volume; pressure then increases and air is expelled
Under voluntary & autonomic control-we can control our breathing-but we do it without thinking. Cannot stop our breathing; the autonomic system takes over.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the diaphragm?

A

The diaphragm is a muscular sheet between the thorax and the abdomen. It is supplied by the phrenic nerve. The diaphragm is an important muscle in respiration and is responsible for most of the quiet breathing at rest.
* It is divided into 2: the left and right hemi-diaphragm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What legislation is involved in the justification of a mobile chest radiograph?

A
  • Ionising Radiation Regulations – (IRR 17)
  • Ionising Radiation (Medical Exposure) Regulations – IR(ME)R 17
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which key principle of IR(ME)R 17 is applied?

A
  • ALARP – As low as reasonably practicable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Information on a request card

A

-Symptoms e.g decreased air entry
-What the clinical question is that they want answering- what they’re looking for. E.g PE (pleural effusion).

-Do you understand the request? (Terminology or abbreviations)
-Has the request been signed by a medical practitioner or authorized nurse practitioner?
-Is the clinical history, correct? – how can you check this?
-Have you checked previous imaging? How may this affect justification?
-Is the request in date?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Patient preparation

A

-Remove patient’s clothing/objects down to the waist – patients will require a radiolucent hospital gown.
-Investigate if the patient has any individual communication needs
-Explain clearly the procedure to the patient – this aids the examination performance and helps put the patient at ease.
-Inform patient of breathing technique required and rehearse, if necessary, prior to exposure being taken – WHY?
-Move/ remove any monitor lines or dressings if necessary… What should you do before you move these?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Chest x ray projections

A

Erect PA (postero-anterior) – This is the gold standard
Alternative projections
* Lateral - Usually a secondary view to better locate a structure
* Erect AP – If the patient is too unsteady to stand for a PA projection
* Supine AP – If it is unsafe or inappropriate to sit up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Positioning and technique

A

Posterior-Anterior projection (PA)
-Anterior-Posterior projection (AP)
-Lateral Projection

18
Q

Erect PA projection

A

-For a routine examination of the chest – the patient should always be positioned (if possible) in the ERECT POSTERO-ANTERIOR position.

-Exposure should be made at the end of the deep arrested inspiration
Why do we take the radiograph on arrested inspiration?

19
Q

Erect PA projection-positioning

A
  • Patient stands facing the erect image receptor (wall stand)
    -Patient’s arms should be either:
  • Rotated medially with the dorsal aspects of the hands resting on the back of the hips or
    Rotated from the shoulder joint with the hands and forearms against the sides of the wall stand or encircling the imaging receptor (best for elderly/ patients with reduced mobility)
  • Patient must be positioned without rotation – if rotated, this causes distortion of the heart shadow
  • Chin is extended and if possible, placed on the image receptor support (top of the image receptor should be 5cm above the level of the shoulders) to ensure chin and neck do not superimpose apices of lungs.
20
Q

What should the distance be between the x-ray source and image receptor?

A

180cm

21
Q

ERECT PA Projection – Centering points

A
  • Central ray - horizontal (parallel to floor) & 90 degrees to the image receptor in the patients’ midline at the level of T8
  • This is best found by finding the inferior angle of scapula
  • T7 spinous process is palpable and lies on same level as thoracic vertebra 8.
  • In practice: vital to ensure entire region on the image
  • Patients’ median-sagittal plane at 90 degrees to the image receptor.
  • MS plane divides the body into left and right halves.
22
Q

Benefits of the erect PA projection summary

A
  • Standardised (simplified positioning)
  • Gravity effect on abdominal organs discloses max lung fields
  • Fluid levels, if present are best demonstrated
  • Easier for patients to take the required (adequate) breath in- especially for patients with breathing difficulties
  • Stability for the patient due to positioning
  • Reduces magnification of the heart
  • Reduction of dose to the eyes, breast tissue, thyroid
  • Scapula are cleared from the lung field
23
Q

Image criteria

A

§ Ends of clavicles equidistant from spine
§ Thorax should be symmetrical, distance from mid-vertebral column to the lateral borders of ribs should be equal
§ Trachea visible in the midline
§ Scapulae projected away from lung fields
§ Sharp outline of diaphragm and cost-phrenic angles – can be obscured by breast tissue in females
§ Sharp outline of heart
§ Arrested inspiration – look for clear outline of the diaphragm – which should be below level of 10th ribs
§ Count 8-10 posterior ends of ribs

24
Q

AP Erect- patient positioning

A
  • Patient sits as upright as possible with their back
    against the image receptor
  • Their chin is raised to ensure it is out of the image field
  • If possible, the hands are placed by the patient’s side (try not to irradiate the humerus)
  • Shoulders are depressed/relaxed to ensure the clavicles
    do not overly/obscure the apices
    consider Image Receptor orientation for patient’s body habitus
25
Q

AP erect Centring and angulation

A
  • Level of the 7th thoracic vertebra, approx. 7 cm below the suprasternal notch
  • Central ray is angled to be perpendicular to the long axis of the patient’s sternum & the IR.
  • Usually there is some degree of caudal angulation
  • Collimate to include: AC & GH joints laterally, Some c-spine & upper airways superiorly, inferior border of 12th rib inferiorly.
26
Q

The Mobile/Portable Chest Examination

A

-Chest x-rays performed portably will almost always be undertaken AP. This is as patients will usually be sedated and ventilated and have reduced mobility
-Where possible, Portable AP Chests should be performed as erect as possible allow gravity to force abdominal contents downwards away from the chest and give us best visualisation of the lung fields

27
Q

Lateral Projection – Positioning/Centring

A

ü Normally a left lateral projection is taken - it places the heart nearer to the film resulting in less magnification
ü If known pathology is present, then the affected side should be positioned against the image receptor
ü Used to localise and demonstrate the extent of a lesion

28
Q

Lateral Projection – Positioning

A

ü In this projection, the patients’ MS plane is parallel to the
image receptor.
ü Centre through the axilla (arm pit) at T8 mid way
between anterior and posterior thoracic walls.
ü Will not demonstrate the apical areas due to shoulders
ü As for PA, on deep arrested inspiration
ü Older/immobile patients may not be able to arms-use
a drip stand with arms extended forwards
ü Ensure the chin is raised!

29
Q

Lateral projection image criteria

A

§ Left hemi-diaphragm seems to disappear at heart border.
§ Pleural effusions are sometimes more obvious on this view – causes blunting of costo-phrenic angle(s).
§ Anterior, central and posterior areas should be of relatively equal density.
§ Look for evidence of a mass – white/denser areas.
§ Look for different densities.

30
Q

Where should annotation be placed?

A
  • Where it isn’t overlying any diagnostic information.
  • This includes MSK anatomy and upper abdominal area.
31
Q

What factors can affect image quality that the radiographer should be aware of an avoid where possible?

A
  • Artefact
  • Patient movement
  • Rotation
  • Lordosis
  • Kyphosis
32
Q

What is lordosis?

A
  • The patient is leaning too far backwards/there is insufficient caudal angulation (Horizontal beam is NOT perpendicular to long axis of sternum)
33
Q

How can you correct a lordotic image?

A
  • Apply more caudal angulation
  • Sit patient more upright if possible.
34
Q

What is kyphosis?

A
  • Patient is leaning too far forwards or there is too much caudal angulation (Horizontal beam is NOT perpendicular to the long axis sternum)
35
Q

How can you correct a kyphotic image?

A
  • You can attempt to sit patient more upright (by leaning back) and ask them to lift their chin high.
  • You can reduce caudal angle of the beam- sometimes requires either straight tube or even cranial angulation of horizontal beam to achieve a diagnostic image.
36
Q

What may cause axial rotation?

A
  • Patients with comorbidities may struggle to support themselves in upright, straight position
  • Stroke patients/paraplegic patients/muscular dystrophy/dementia/general weakness
37
Q

Patient aftercare

A

§ Allow the patient to dress
§ Ensure the patient has clear instructions of how to obtain results i.e. back to a clinic or GP
§ Replace any dressings, lines etc removed prior to examination
§ As with any examination do not discuss with the patient what you have seen on the radiograph!

38
Q

Sternum: indications? and lateral view

A

Indications –usually trauma
Lateral View
§ Patient in lateral position
§ Shoulders and arms rotated posteriorly
§ Centre to mid sternum
PA Oblique occasionally taken.

39
Q

Sterno-clavicular joints: indications

A

§ Subluxation-minor dislocation
§ pathology at medial end of clavicle
§ PA & Oblique views taken
§ However rarely done now; CT is the usual imaging pathway.

40
Q
A

Application of imaging (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions