Chest xray -Lateral view radiology basics

Chest X-ray lateral view Radiology
Basics

1. Normal Chest Radiograph

-Lateral view

Dr.ANUPAMA S LAL

2. Preview

1. The need for lateral view

2. Lateral view positions

3. Radiological anatomy

4. Anatomical structure and their appearance

5. Checklist on lateral view

6. Pitfalls

3. Indications

1. To check whether equivocal frontal CXR shadow is actually

present

2. To position an abnormality shown on frontal CXR

a. Is it anterior or posterior

b. Which lobe is it in

c. Is it actually in a lobe

3. To check

a. Behind the heart

b. Hilar region

c. Domes of diaphragm

4. Positioning of patient and cassette

·The patient is turned to bring the side under

investigation in contact with the cassette.

·The median sagittal plane is adjusted parallel to

the image receptor.

· The arms are folded over the head or raised

above the head to rest on a horizontal bar support.

· The midaxillary line is coincident with the middle

of the film and the receptor is adjusted to include

the apices and the lower lobes upto the level of first

lumbar vertebrae

5. Technical Factors

● Normal full inspiration

● Centering point- midcoronal plane at the level of 7th thoracic vertebrae,

approximately the inferior angle of scapula

● Collimation- superiorly 5cm above the shoulder joint to allow proper

visualisation of upper airways. Inferiorly to the inferior border of 12th rib. AP

to the level of acromioclavicular joints.

● Detector size – 35x43cm

● Exposure- 100-110kVP , 8- 12 mAS

● SID- 180cm

6. Image technical evaluation

● The entire lung fields should be visible superiorly from the

apices inferiorly to the posterior costophrenic angle .

● The chin should not be superimposing any structures

● There is superimposition of the anterior ribs

● The sternum is seen in profile

● A minimum of ten posterior ribs are visualized above the

diaphragm

● The ribs and thoracic cage are seen only faintly over the

heart

● Clear vascular markings of the lungs should be visible

7. ● Routinely the left side is adjacent to the film because more

of the left lung than the right is obscured on the PA view
● If there is a specific lesion the side of interest is positioned

adjacent to the film.

9. ● Right lateral radiograph would project the posterior portion of

right hemidiaphragm higher than the left hemidiaphragm and

viceversa. This is due to beam divergence of the X-ray with

centering point above the diaphragm .

● Posterior ribs farther from the image receptor will be projected

more posteriorly, less sharp, and more magnified when

compared to the ribs located near the radiograph

10. MEDIASTINUM - FELSONS CLASSIFICATION

12. The clear spaces

There are two clear spaces
● These correspond to the sites where the lungs meet

behind the sternum and the heart.
● Loss of translucency of these areas indicates local

pathology

13. Retrosternal space

1. Normal : 2.5 – 3 cm

2. Increases in Emphysema and pectus carinatum

3. Decreases in Anterior mediastinal masses -Thymoma,aortic

aneurysms of ascending aorta & nodes.

14. Retrocardiac area

● The space between the posterior cardiac border and

vertebral column represents the retrocardiac space

● Lower lobe pneumonias may cause dense

retrocardiac region

15. RAIDER’S TRAINGLE
Boundaries: 

Anterior: Posterior tracheal strip

Posterior: Thoracic Vertebral bodies

Inferior: Aortic arch

Superior: Thoracic inlet

16. Diaphragm

● The right dome is visualised all the way from front to back.

● The shadow of the left dome only extends from the costophrenic recess

posteriorly to the back of the cardiac shadow anteriorly. This is because the

heart obliterates the lung / diaphragm interface anteriorly.

17. Hilum

● Contributed by pulmonary arteries and upper lobe veins

● The main pulmonary artery on the right side passes anterior to the right

main bronchus, whereas the main pulmonary artery on the left side passes

posteriorly and hooks over the left main bronchus.

18. Cardiac Anatomy

● The heart occupies most of mediastinum.:

● Anteriorly — right ventricle

● Posteriorly immediately behind the hila —

left atrium

● Posteriorly below the hila — left ventricle

19. Cardiac anatomy :right sided chambers

20. Cardiac Anatomy :left sided cambers

22. Lower 1/3rd of sternum

should be in contact with

right ventricle.

23. LUNG ANATOMY

Lobes are separated by fissures

☆ Right Lung :

● Upper Lobe

● Middle Lobe

● Lower Lobe

☆ Left Lung :

●Upper Lobe (includes lingula)

●Lower Lobe

24. Right side

25. Left side

26. Lung fissures

● Horizontal fissure :a line passing horizontally from

the midpoint of Hilum to anterior chest wall

●

● Oblique fissure :passes downwards from T4/T5

vertebrae through Hilum and ending at the anterior

third of diaphragm.

27. ● The left oblique fissure is steeper than the right and

terminates 5 cm behind the anterior cardiophrenic

angle.

● Loculated interlobar effusions are well shown and

displacement or thickening of the fissures should be

noted.

29. Trachea

● Slightly posterior direction to T6/T7 level of the

spine

● It is partly overlapped by the scapula and axillary

folds

30. Vertebral translucency

● The vertebral bodies become

progressively translucent caudally

(Spine sign).

● Loss of this translucency may be the

only sign of posterior basal

consolidation

● Other causes – pleural thickening

and posterior mediastinal masses

32. Pitfalls
1. FAKE MASS ANTERIORLY

Sometimes the shadow of a high right dome of the

diaphragm and the shadow of the posterior margin

of the heart overlap and create a well-defined

density that mimics an anterior mass.

2. AGE RELATED UNFOLDING OF AORTA

Where we can see the mid and distal part of descending aorta ,

which is not normally distinguished in young people.

33. 3.cardiac insicura

The apex of the heart and adjacent epicardial fat

intrudes into the left hemithorax and displaces the

most infero-medial and anterior aspect of the left

lung. This often produces a shadow which can

simulate a mass lesion. This appearance is often

referred to as the cardiac incisura.

34. Thank you