Presented by: Dr Nikhil Bansal

The Normal Chest: Methods Of Investigation & DD

Part-1

Plain films:• PA, Lateral• AP, Decubitus, Supine, Oblique• Inspiratory-Expiratory• Lordotic, Apical, Penetrated• Portable radiographsTomographyCT scanning

Methods of Investigation

Radionuclide studiesNeedle biopsyUltrasoundFloroscopyBronchographyPulmonary angiographyBronchial arteriographyMRIDigital radiographyLymphangiography

THE PLAIN FILM• The PA (postero-anterior) view:It is the most frequently required radiological

examination. Comparison of current film with old films is valuable.

Position: Patient facing the film, chin up with the shoulders rotated forwards to displaced the scapulae from the lungs. Exposure is made on full inspiration, centering at T5.

kVp

kVp = Energy of x-rays = higher penetrability, it moves through tissue.

The energy determines the QUALITY of x-ray produced.1. increase in kVp = electrons gain high energy2. higher the energy of electrons = greater quality of x-rays3. greater quality = greater penetrability

kVp Low kVp (60-80 kV)

High kVp (120-170kV)

Produces High contrast films Low contrast films

Better •Miliary shadowing •Calcification

•Hidden areas

Lateral view:

Comparison with PA view:

Advantages : Anterior mediastinal massesEncysted pleural fluidsPosterior basal consolidation

Disadvantages : Lung collapseLarge pleural effusion.

Collapse of the Left lung. Only the right hemidiaphragm is visible.

PA View Lateral View

This is a PA film on the left compared with a AP supine film on the right.  The AP shows magnification of the heart and widening of the mediastinum.AP film is taken mostly in very ill patients who cannot stand erect.

Other views: Oblique view is better for: • Retrocardiac area• Posterior costophrenic angles• Chest wall• Pleural plaques

Lateral decubitus position: It is helpful to assess the volume of pleural

effusion and demonstrate whether a pleural effusion is mobile or loculated.

Lateral decubitus position film showing mobile pleural effusion (arrows)

Viewing the PA film:

Technical aspects:• Well centered• Clavicles should be equidistant from the vertebral body's at T4/5 level.• Side markers should be place.

Poor inspiration can crowd lung markings producing pseudo-airspace disease

With better inspiration, the

“disease process” at the lung bases has

cleared

About 8 posterior ribs are showing

8

9-10 posterior ribs are showing

9

If spinous process appears closer to the right clavicle (red arrow),

the patient is rotated toward their own left side

If spinous process appears closer to the left clavicle (red arrow),

the patient is rotated toward their own right side

Trachea:• It should be examined for narrowing,

displacement, caliber and intraluminal lesions.

It is in midline in upper part, then deviates slightly to the right around the aortic knuckle.

The mediastinum and heart:• Two-third of the cardiac shadow lies to the

left of midline and one-third to the right.• CT ratio is less then 50% on PA film & 60% in

AP film.• In young children triangular sail shaped

‘Thymus’ makes ‘wave sign of Mulvey’.

Soft Tissues Breast shadows Supraclavicular areas Axillae Tissues along side of breasts Abdomen Gastric bubble Air under diaphragm Neck Soft tissue mass

Bones: Check the bones for any fracture , lesions, density or mineralization.

Bony FragmentsRibsSternumSpineShoulder girdleClavicles

Cardiac Heart size on PARight side

Inferior vena cavaRight atriumAscending aortaSuperior vena cava

Left sideLeft ventricleLeft atriumPulmonary arteryAortic archSubclavian artery and vein

Right LungSuperior lobeMiddle lobeInferior lobe

Left LungSuperior lobeInferior lobe

The right middle lobe is typically the smallest of the three, and appears triangular in shape, being narrowest near the hilum.

The right lower lobe is the largest of all three lobes, separated from the others by the major fissure.

Posteriorly, the RLL extend as far superiorly as the 6th thoracic vertebral body, and extends inferiorly to the diaphragm.

Review of the lateral plain film surprisingly shows the superior extent of the RLL.

Diaphragm:• On inspiration the domes of the diaphragms

are at the level of the 6th rib anteriorly and 10th rib posteriorly.

• Check sharpness of borders.• Right is normally higher than left.• Check for free air, gastric bubble, pleural

effusions.

The Fissures:The main fissures:Horizontal fissure: On the PA film it running

from the hilum to the 6th rib in the axillary line.

Oblique fissure: It separates the three lobes of right side with horizontal fissure and two lobes of left side.

Accessory fissures:• Azygos fissure: It is a comma shaped fissure.• The superior accessory fissure• The inferior accessory fissure• The left-sided horizontal fissureThe hidden areas:• The apices• Mediastinum and hila• Diaphragm• Bones

Hila: Look for nodes and masses in the hila of both lungs. On the frontal view, most of the hilar shadows represent the left and right pulmonary arteries. The left pulmonary artery is always more superior than the right, making the left hilum higher. Look for calcified lymph nodes in the hilar, which may be caused by an old tuberculosis infection.

The Lungs:Lung anatomy:• Trachea• Carina• Right and Left Pulmonary Bronchi• Secondary Bronchi• Tertiary Bronchi• Bronchioles• Alveolar Duct• Alveoli

Anatomy of main bronchi and segmental division

Viewing the lateral film: