The Chest X-Ray

Patient Data Techniques CXR Interpretation Contents: Patient Data Techniques CXR Interpretation

Technical Details Type(PA/AP/Lat./decubitus/Lordotic) Rotation Inspiration/expiration Penetration

Densities 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

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

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

Techniques - Projection (continued) Lateral Decubitus

Lordotic view

Film Quality (cont) Was film taken under full inspiration? -10 posterior ribs should be visible. A really good film will show anterior ribs too, there should Be 6 to qualify as a good inspiratory film.

Ribs

Rotation

Rotation (continued)

TECHNIQUE, cont. Rotation Determined by distance between spinous process & medial clavicle Affects heart size & shape, aortic tortuosity, density of lung fields

Penetration Is the film over or under penetrated ? if under penetrated you will not be able to see the thoracic vertebrae. If overpenetrated you will see the thorasic vertebrae beyond the heart with details.

Anatomy

Lung Anatomy Right Lung Left Lung Superior lobe Middle lobe Inferior lobe Left Lung

Lung Anatomy on Chest X-ray These lobes can be separated from one another by two fissures. The minor fissure separates the RUL from the RML, and thus represents the visceral pleural surfaces of both of these lobes. Oriented obliquely, the major fissure extends posteriorly and superiorly approximately to the level of the fourth vertebral body. Grossly, these lobes can be separated from one another by two fissures which anatomically correspond to the visceral pleural surfaces of those lobes from which they are formed. The minor fissure separates the RUL from the RML, and thus represents the visceral pleural surfaces of both of these lobes. The minor fissure is oriented horizontally, extending ventrally from the chest wall, and extending posteriorly to meet the major fissure. Generally, the location of the minor fissure is approximately at the level of the fourth vertebral body and crosses the right sixth rib in the midaxillary line. The right major fissure is more expansive in size than the minor fissure, separating the right upper and middle lobes from the larger right lower lobe. Oriented obliquely, the major fissure extends posteriorly and superiorly approximately to the level of the fourth vertebral body. The major fissure extends anteroinferiorly, intersecting the diaphragm at the anterior cardiophrenic angle

Lobes Right upper lobe:

Lung Anatomy on Chest X-ray The right upper lobe (RUL) occupies the upper 1/3 of the right lung. The right upper lobe (RUL) occupies the upper 1/3 of the right lung. Posteriorly, the RUL is adjacent to the first three to five ribs. Anteriorly, the RUL extends inferiorly as far as the 4th right anterior rib.

Lobes (continued) Right middle lobe:

Lung Anatomy on Chest X-ray The right middle lobe is typically the smallest of the three, and appears triangular in shape, being narrowest near the hilum The right middle lobe is typically the smallest of the three, and appears triangular in shape, being narrowest near the hilum.

Lobes (continued) Right lower lobe:

Lung Anatomy on Chest X-ray These two lobes are separated by a major fissure, identical to that seen on the right side. The portion of the left lung that corresponds anatomically to the right middle lobe is incorporated into the left upper lobe. These two lobes are separated by a major fissure, identical to that seen on the right side, although often slightly more inferior in location. The portion of the left lung that corresponds anatomically to the right middle lobe is incorporated into the left upper lobe. It is important to understand that in most individuals, interlobar fissures are usually not completely formed; in some individuals there may be complete absence of a fissure thus losing the demarcation between lobes on gross examination. In general, fissures are not readily identifiable on plain films, with only small portions typically visualized at best. This is because fissures which are composed of only two layers of visceral pleura, may not present a significant radiographic interface and will not produce a shadow. However, if there is fluid within the pleural space or if the visceral pleura is thickened, fissures may be seen in their entirety.

Lobes (continued) Left lower lobe:

Left upper lobe with Lingula: Lobes (continued) Left upper lobe with Lingula:

Lung Anatomy on Chest X-ray The lobar architecture of the left lung is slightly different than the right. Because there is no defined left minor fissure, there are only two lobes on the left The lobar architecture of the left lung is slightly different than the right. Because there is no defined left minor fissure, there are only two lobes on the left; left upper

Lobes (continued) Lingula:

Left upper lobe - upper division: Lobes (continued) Left upper lobe - upper division:

Lateral CXR (continued)

Lateral CXR (continued)

The Silhouette Sign An intra-thoracic radio-opacity, if in anatomic contact with a border of heart or aorta, will obscure that border. An intra-thoracic lesion not anatomically contiguous with a border or a normal structure will not obliterate that border.

Systematic Approach Bony Framework Soft Tissues Diaphragm and Pleural Spaces Lung Fields and Hila Mediastinum and Heart Abdomen and Neck

Systematic Approach Bony Fragments Ribs Sternum Spine Shoulder girdle Clavicles First, inspect the BONY FRAMEWORK of the chest You should be able to count and number the ribs, inspect the capulae, humeri and shoulders, and clavicles, and seethe diaphragms overlying the posterior aspects of the 10th or 11th ribs (in a normal adult)> The spine and sternum are generally difficult to visualize in detail on standard PA films due to overlying shadows.

Systematic Approach Soft Tissues Mdiastinum Breast shadows Supraclavicular areas Axillae Mdiastinum Next, inspect the soft the SOFT TISSUES that overlie the thoracic cage Note the breast shadows,supraclavicular areas, axillae, and tissues along the sides of the chest.

Soft tissue

Now you are ready Look at the diaphram: for tenting free air abnormal elevation Margins should be sharp (the right hemidiaphram is usually slightly higher than the left)

Hilum Made of: 1. Pulmonary Art.+Veins The Bronchi L.N. Left Hilus higher (max 1-2,5 cm) Identical: size, shape, density

Check the hilar region The hilar – the large blood vessels going to and from the lung at the root of each lung where it meets the heart. Check for size and shape of aorta, nodes,enlarged vessels

Mediastinum & Heart

Check the Heart Size Shape Silhouette-margins should be sharp Diameter (>1/2 thoracic diameter is enlarged heart) Remember: AP views make heart appear larger than it actually is.

Heart Size:

Heart Size of heart Size of individual chambers of heart Size of pulmonary vessels Evidence of stents, clips, wires and valves

Systematic Approach Diaphragm and Pleural Surfaces Diaphragm Dome-shaped Costophrenic angles Normal pleural is not visible Interlobar fissures Next, examine the DIAPHRAGM and PLEURAL SURFACES Diaphragmatic images in the lung bases are dense, radiopaque shadows made principally by the liver on the left and the spleen on the right. The normal pleura is not visible on the chest x-ray, except where two layers come together to form the interlobar fissures.

Systematic Approach Abdomen and Neck Abdomen Neck Gastric bubble Air under diaphragm Neck Soft tissue mass Bone structure

Apices Behind the heart Behind the clavicles CP angles Parenchyma Lungs : Apices Behind the heart Behind the clavicles CP angles Parenchyma

Identify the lesion → localise the lesion → describe the lesion → give DD Never stop looking, carry on with your systematic approach!!

Consolidation Lobar consolidation: Alveolar space filled with inflammatory exudate Interstitium and architecture remain intact The airway is patent Radiologically: A density corresponding to a segment or lobe Airbronchogram, and No significant loss of lung volume Consolidation: In the lobar consolidation, a lobe is involved. The alveolar space is filled with inflammatory exudate made up of WBC, bacteria, plasma, and debris. In Pneumococcal pneumonia, the most common cause for lobar consolidation, the lobe goes through red hepatization and gray hepatization stage. In the stage of resolution, some secretions can be in the airway. The interstitium and architecture of the lung remain intact and complete recovery occurs. The lobe swells up initially and may shrink slightly later if there is significant secretions in the airway causing some obstruction. The airway is patent. Radiologically this transcribes to: 1. a density corresponding to a segment or lobe 2. airbronchogram, and 3. no significant loss of lung volume.

Atelectasis Loss of air Obstructive atelectasis: No ventilation to the lobe beyond obstruction Radiologically: Density corresponding to a segment or lobe Significant loss of volume Atelectasis: Atelectasis means loss of air. In absorptive Atelectasis there is an obstructive lesion on the bronchus. There is no ventilation to the lobe beyond the obstruction. Gradually the air gets absorbed by pulmonary circulation. The involved lobe eventually is devoid of air and becomes atelectatic. Radiologic criteria for absorptive Atelectasis is 1. a density corresponding to a segment or lobe, 2. significant signs of loss of volume, and 3. compensatory hyperinflation of normal lungs.

Left Sided Pneumothorax

Right Side Pleural Effusion

Right Lower Lobe Pneumonia

COPD

PLEURAL EFFUSION

TENSION PNEUMOTHORAX

SARCOIDOSIS Granulomatous Inflammation Bilateral & symmetrical hilar & mediastinal LAD Generalized fibrosis

ARDS Congestion Interstitial and alveolar edema Collapsed or distended alveoli Bilateral

CONSOLIDATION Alveolar space filled with inflammatory exudate WBC, bacteria, plasma, and debris

RLL pneumonia

LUL pneumonia

LLL pneumonia

Consolidation on CT

Hilar mass

The Enlarged Hila Causes: 1. Adenopathies (neoplasia, infection) 2. Primary Tumor 3. Vascular 4. Sarcoidosis

Multiple Masses

Pleural Effusion

?

Heart failure

Pneumothorax

Air under the diaphragm

Cavitating lesion

Hiatus hernia

Miliary shadowing

Chest Tube, NG Tube, Pulm. artery cath

Dextrocardia

A single, 3cm relatively thin-walled cavity is noted in the left midlung. This finding is most typical of squamous cell carcinoma (SCC). One-third of SCC masses show cavitation

Cavitation:cystic changes in the area of consolidation due to the bacterial destruction of lung tissue. Notice air fluid level.

Cavitation

Pseudotumor: fluid has filled the minor fissure creating a density that resembles a tumor (arrow). Recall that fluid and soft tissue are indistinguishable on plain film. Further analysis, however, reveals a classic pleural effusion in the right pleura. Note the right lateral gutter is blunted and the right diaphram is obscurred.

Pneumonia:a large pneumonia consolidation in the right lower lobe Pneumonia:a large pneumonia consolidation in the right lower lobe. Knowledge of lobar and segmental anatomy is important in identifying the location of the infection

CHF:a great deal of accentuated interstitial markings, Curly lines, and an enlarged heart. Normally indistinct upper lobe vessels are prominent but are also masked by interstitial edema.

24 hours after diuretic therapy

Pleural mass

Pleural effusion: Note loss of left hemidiaphragm Pleural effusion: Note loss of left hemidiaphragm. Fluid drained via thoracentesis

Lung Mass

Metastatic Lung Cancer: multiple nodules seen

Right upper lower lobe pulmonary nodule

Perihilar mass: Hodgkin’s disease