Radiology

Proper inspiratory film

- 7 anterior ribs should be visible above the right hemidiaphragm

Reticular CXR

- most common pattern seen is CHF The findings are: Normal old film on the left. Reticular pattern especially in the basal parts of the lung. Some Kerley B lines are seen. Increased heart size. Pleural fluid seen on the left side. Pulmonary vessels are somewhat more prominent compared to the old film. - normal vs. disease on rt

CHF CT

- thickened septae from fluid - pleural effusions - GGO CT will also demonstrate signs of congestive heart failure. On the image on the left notice the following: Thickened septal lines due to interstitial edema Subtle ground glass opacity in the dependent part of the lungs (HU difference of 100-150 between the dependent and non-dependent part of the lung). Bilateral pleural fluid.

bat-winging CHF

As pulmonary edema progresses, fluid begins to collect in alveoli, causing diffuse airspace disease often in a "bat-wing" or "butterfly" pattern, tending to spare the outermost lung fields. Pleural effusion may be a feature of pulmonary edema.

RML atelectasis

Blurring of the right heart border (silhouette sign) Triangular density on the lateral view as a result of collapse of the middle lobe Usually right middle lobe atelectasis does not result in noticable elevation of the right diaphragm. A pectus excavatum can mimick a middle lobe atelectasis on a frontal view, but the lateral view should solve this problem.

silicosis

Classical: eggshell calcification on CT

CHF fluid overload

Congestive heart failure (CHF) is the result of insufficient output because of cardiac failure, high resistance in the circulation or fluid overload. Left ventricle (LV) failure is the most common and results in decreased cardiac output and increased pulmonary venous pressure. In the lungs LV failure will lead to dilatation of pulmonary vessels, leakage of fluid into the interstitium and the pleural space and finally into the alveoli resulting in pulmonary edema. Right ventricle (RV) failure is usually the result of long standing LV failure or pulmonary disease and causes increased systemic venous pressure resulting in edema in dependent tissues and abdominal viscera. xray- (coarse) reticulation in CHF

Consolidation

Consolidation is the result of replacement of air in the alveoli by transudate, pus, blood, cells or other substances. Pneumonia is by far the most common cause of consolidation. The disease usually starts within the alveoli and spreads from one alveolus to another. When it reaches a fissure the spread stops there. The key-findings on the X-ray are: ill-defined homogeneous opacity obscuring vessels Silhouette sign: loss of lung/soft tissue interface Air-bronchogram Extention to the pleura or fissure, but not crossing it No volume loss

Diffuse consolidation

Diffuse consolidation The most common cause of diffuse consolidation is pulmonary edema due to heart failure. This is also called cardiogenic edema, to differentiate it from the various causes of non-cardiogenic edema. The increased heart size is usually what distinguishes between cardiogenic and non-cardiogenic. Look for other signs of heart failure like redistribution of pulmonary blood flow, Kerley B-lines and pleural fluid. However some patients, who have an acute cardiac infarction, may still have a normal heart size, while other patients who have a large heart due to a chronic heart disease, may have non-cardiac pulmonary edema due to a superimposed pulmonay infection, ARDS, near-drowning etc.

Traction bronchiectasis

Fibrosis causes traction on the walls of bronchi, resulting in irregular dilation.

Lobar consolidation CXR

Findings -increased density with ill-defined borders in the left lung -the heart silhouette is still visible, which means that the density is in the lower lobe -air-bronchogram Arrow: As the alveoli that surround the bronchi become more dense, the bronchi will become more visible, resulting in an air-bronchogram (arrow). Lobar consolidation is the result of disease that starts in the periphery and spreads from one alveolus to another through the pores of Kohn. At the borders of the disease some alveoli will be involved, while others are not, thus creating ill-defined borders. As the disease reaches a fissure, this will result in a sharp delineation, since consolidation will not cross a fissure. In consolidation there should be no or only minimal volume loss, which differentiates consolidation from atelectasis. Expansion of a consolidated lobe is not so common and is seen in Klebsiella pneumoniae and sometimes in Streptococcus pneumoniae, TB and lung cancer with obstructive pneumonia

CHF

Findings: loss of definition of pulmonary vasculature peribronchial cuffing Kerley B lines reticulonodular pattern thickening of interlobar fissures

GGO

Ground glass opacity is the first presentation of alveolar edema and a precursor of consolidation.

reticulonodular patter (restrictive LD)

IPF - lines and dots

reticular pattern CT

Innumerable small linear opacitiies that when put together form a 'net'. - usually ILD - better seen on CT - some components of reticular pattern are: - interlobular septal thickening - interlobular lines - cyst walls of honeycombing

Lobar atelectasis patterns

Lobar atelectasis or lobar collaps is an important finding on a chest x-ray and has a limited differential diagnosis. The most common causes of atelectasis are: Bronchial carcinoma in smokers Mucus plug in patients on mechanical ventilation or astmathics (ABPA) Malpositioned endotracheal tube Foreign body in children Sometimes lobar atelectasis produces only mild volume loss due to overinflation of the other lungparts.

left lower lobe pneumonia

Patchy consolidation left lower lobe with partial silhouetting of the left hemi-diaphragm. Remainder of the lungs are clear. No abdominal pathology.

CHF pleural effusion

Pleural effusion is bilateral in 70% of cases of CHF. When unilateral, it is slightly more often on the right side than on the left side. There has to be at least 175 ml of pleural fluid, before it will be visible on a PA image as a meniscus in the costophrenic angle. On a lateral image effusion of > 75 ml can be visible. If pleural effusion is seen on a supine chest film, it means that there is at least 500 ml present. On the left images of a patient who has bilateral pleural effusions. Notice that it is more evident on the lateral view.

Stage 2 CHF

Stage II - Interstitial edema Stage II of CHF is characterized by fluid leakage into the interlobular and peribronchial interstitium as a result of the increased pressure in the capillaries. When fluid leaks into the peripheral interlobular septa it is seen as Kerley B or septal lines. Kerley-B lines are seen as peripheral short 1-2 cm horizontal lines near the costophrenic angles. These lines run perpendicular to the pleura.

Stage 3- alveolar edema

Stage III - Alveolar edema This stage is characterized by continued fluid leakage into the interstitium, which cannot be compensated by lymphatic drainage. This eventually leads to fluid leakage in the alveoli (alveolar edema) and to leakage into the pleural space (pleural effusion). The distribution of the alveolar edema can be influenced by: Gravity: supine or erect position and right or left decubitus position Obstructive lung disease, i.e. fluid leakage into the less severe diseased areas of the lung On the left a patient who was admitted with severe dyspnoe due to acute heart failure. The following signs indicate heart failure: alveolar edema with perihilar consolidations and air bronchograms (yellow arrows); pleural fluid (blue arrow); prominent azygos vein and increased width of the vascular pedicle (red arrow) and an enlarged cardiac silhouette (arrow heads). After treatment we can still see an enlarged cardiac silhouette, pleural fluid and redistribution of the pulmonary blood flow, but the edema has resolved.

LLL atelectasis

There is a triangular density seen through the cardiac shadow. This must be an abnormality located posterior to the heart. This is confirmed on the lateral view. The contour of the left diaphragm is lost when you go from anterior to posterior. As the title suggests this is lower lobe atelectasis. We cannot see the lower lobe vessels, because they are surrounded by the atelectatic lobe. Normally when you follow the thoracic spine form top to bottom, the lower region becomes less opaque. Here we have the opposite (blue arrow).

Perihilar haze (in stage 2- interstitial)

When fluid leaks into the peribronchovascular interstitium it is seen as thickening of the bronchial walls (peribronchial cuffing) and as loss of definition of these vessels (perihilar haze). On the left a patient with congestive heart failure. There is an increase in the caliber of the pulmonary vessels and they have lost their definition because they are surrounded by edema.

4 pattern approach to lung patterns

Whenever you see an area of increased density within the lung, it must be the result of one of these four patterns. Consolidation - any pathologic process that fills the alveoli with fluid, pus, blood, cells (including tumor cells) or other substances resulting in lobar, diffuse or multifocal ill-defined opacities. Interstitial - involvement of the supporting tissue of the lung parenchyma resulting in fine or coarse reticular opacities or small nodules. Nodule or mass - any space occupying lesion either solitary or multiple. Atelectasis - collapse of a part of the lung due to a decrease in the amount of air in the alveoli resulting in volume loss and increased density.

RLL atelectasis

abnormal right border of the heart. The right interlobar artery is not visible, because it is not surrounded by aerated lung but by the collapsed lower lobe, which is adjacent to the right atrium. On a follow-up chest film the atelectasis has resolved. We assume that the atelectasis was a result of post-traumatic poor ventilation with mucus plugging. Notice the reappearance of the right interlobar artery (red arrow) and the normal right heart border (blue arrow).

Fine reticulation- sarcoidosis

chest x-ray shows subtle findings that could be described as fine reticulation. In many cases a HRCT is needed to determine the exact nature of the findings. The HRCT - not shown - demonstrated a fine nodular appearance as a result of sarcoidosis. Notice the subtle irregular thickening of the minor fissure. This is quite specific for sarcoidosis.

Right lung atelectasis

chest x-ray shows total atelectasis of the right lung due to mucus plugging. Notice the displacement of the mediastinum to the right. Re-aeration on follow-up chest film after treatment with a suction catheter. The mediastinum has regained its normal position. A common cause of total atelectasis of a lung is a ventilation tube that is positioned too deep and thus obstructing one of the main bronchi.

reticular cxr vs CT

chest x-ray with interstitial edema and Kerley B lines in a patient with congestive heart failure. The CT shows the septal thickening.

Stage 1 CHF

redistribution normal chest film with the patient standing erect, the pulmonary vessels supplying the upper lung fields are smaller and fewer in number than those supplying the lung bases. The pulmonary vascular bed has a significant reserve capacity and recruitment may open previously non-perfused vessels and causes distension of already perfused vessels. This results in redistribution of pulmonary blood flow. First there is equalisation of blood flow and subsequently redistribution of flow from the lower to the upper lobes. The term redistribution applies to chest x-rays taken in full inspiration in the erect position.

reticular pattern chest xray

subpleural reticulation