Densities Techniques Anatomy CXR Interpretation

The big two densities are: (1) WHITE - Bone (2) BLACK - Air The others are: (3) DARK GREY- Fat (4) GREY- Soft tissue/water And if anything Man-made is on the film, it is: (5) BRIGHT WHITE - Man-made

Routine chest radiograph Air — least dense; most transparent or radiolucent; unobstructed beam or air-filled densities appear black Lungs, gastric bubble, trachea, ? bifurcation of bronchi Air — least dense; most transparent or radiolucent; unobstructed beam or air-filled densities appear black Lungs, gastric bubble, trachea, ? bifurcation of bronchi

Routine chest radiograph Fat — breasts

Routine chest radiograph Fat — breasts Note: breast least opaque on the lung field, moderate lateral to lung. Fully opaque over the liver. Fat — breasts Note: breast least opaque on the lung field, moderate lateral to lung. Fully opaque over the liver.

Non-pendulous breast producing impression on the lung field.

Routine chest radiograph Blood: heart most opaque, hilar vessels less opaque. Opacity in the hilar vessels decreases distally.

 The patient should be examined in full inspiration.  This greatly helps the radiologist to determine if there are intrapulmonary abnormalities.  The diaphragm should be found at about the level of the 8 th - 10 th posterior rib or 5 th - 6 th anterior rib on good inspiration.  A patient can appear to have a very abnormal chest if the film is taken during expiration.

 If there is rotation of the patient, the mediastinum may look very unusual.  One can access patient rotation by observing the clavicular heads and determining whether they are equal distance from the spinous process of the thoracic vertebral bodies.

P-A (relation of x-ray beam to patient)

Routine chest radiograph PA view – film is placed anteriorly, X-ray beam passes from posterior aspect to anterior side.

Lateral

Lateral Decubitus The right is an example of a decubitus film in this case showing a mobile pleural effusion (arrows).

AP view An AP film, enlarges the shadow of the heart and makes the posterior ribs appear more horizontal.

Lung lobes Anteriorly most area is represented by left upper lobe

Lung lobes In the lateral view upper lobe occupies upper and anterior portions.

Lung lobes Posteriorly maximum portion is occupied by lower lobe

Right upper lobe:

Right middle lobe:

Right lower lobe:

Left lower lobe:

Left upper lobe with Lingula:

Position of the fissure rt lt

The level of the left diaphragm is About 2.5cm below the right one. The level of the left diaphragm is About 2.5cm below the right one. DIAPHRAGM

In chest PA view, mediastinum has Two borders, left and right In chest PA view, mediastinum has Two borders, left and right MEDIASTINUM

MEDIASTINAL BORDER Right border is formed by - Form above downwards Right bracheocephalic vessels Ascending aorta and superimposed SVC Right atrium Inferior vena cava Right border is formed by - Form above downwards Right bracheocephalic vessels Ascending aorta and superimposed SVC Right atrium Inferior vena cava

MEDIASTINAL BORDER Left border is formed by - from above downwards Left bracheocephalic vessels Aortic arch Pulmonary trunk Left atrial appendage Left ventricle Left border is formed by - from above downwards Left bracheocephalic vessels Aortic arch Pulmonary trunk Left atrial appendage Left ventricle