As a result of his extensive clinical experience, his dedication to patients' welfare, and his sense of scientific inquiry, several inventions and many landmark clinical observations were made in the first few years after the discovery of the X-ray. These included 1 the invention of a "densitometer" for standardized measurements of relative X-ray attenuation of the lung, 2 the invention of a "seehear" device to correlate auscultative findings and fluoroscopic observations, 3 the recognition that fluoroscopy was more accurate than percussion for estimating mediastinal displacement, 4 the discovery that clinically occult tuberculosis and congestive heart failure could be detected with fluoroscopy, 5 the documentation that unilateral chest disease caused decreased ipsilateral ventilatory compliance and increased contralateral ventilation, 6 the identification of the classical imaging characteristics of tuberculosis, pneumonia, pneumothorax, tension pneumothorax, pleural effusion, hydropneumothorax, emphysema, congestive heart failure, and air trapping.
In April , Dr.
Williams described the "air bronchogram" in a radiograph of a patient with pneumonia. National Center for Biotechnology Information , U. Didn't get the message? Add to My Bibliography. They are characterized by linear shadows of increased density at the lung bases. They are usually horizontal, measure mm in thickness and are only a few cm long. In most cases these findings have no clinical significance and are seen in smokers and elderly. They are seen in patients, that are in a poor condition and who breathe superficially, for instance after abdominal surgery figure.
Platelike atelectasis is also frequently seen in pulmonary embolism, but since it is non-specific, it is not a helpful sign in making the diagnosis of pulmonary embolism. Atelectasis can be the result of fibrosis of lungtissue. This is seen after radiotherapy and in chronic infection, especially TB. Here we have a patient who was treated with radiotherapy for lungcancer. Notice the increased density of the lung tissue and the volume loss.
Notice the deviation of the trachea. There is also some atelectasis of the left upper lobe, which results in a high position of the left pulmonary artery as seen on the lateral view red arrow. Click here for more detailed information about Solitary Pulmonary Nodule. A solitary pulmonary nodule or SPN is defined as a discrete, well-marginated, rounded opacity less than or equal to 3 cm in diameter.
It has to be completely surrounded by lung parenchyma, does not touch the hilum or mediastinum and is not associated with adenopathy, atelectasis or pleural effusion. The differential diagnosis of SPN is basically the same as of a mass except that the chance of malignancy increases with the size of the lesion. Lesions smaller than 3 cm, i. SPN's are most commonly benign granulomas, while lesions larger than 3 cm are treated as malignancies until proven otherwise and are called masses. The tabel is adapted from chest x-ray - a survival guide. In lesions that do not respond to antibiotics, probably the most important non-invasive diagnostic tool is nowadays the PET-CT.
False-positive findings in the lung are seen in granulomatous disease and rheumatoid disease.
False negatives are seen in low grade malignant tumors like carcinoid and alveolar cell carcinoma and lesions of less than 1 cm. Previous chest radiographs should be reviewed to determine if the lesion has been stable over 2 years. If so, no further follow up is necessary, with the exception of pure ground-glass lesions on CT scans, which can be slower growing. Management of indeterminate lesions greater than mm depends on clinical probability of malignancy, as follows:.
Any unequivocal growth noted during follow up means that a definitive tissue diagnosis is needed. The differential diagnostic list of multiple masses is very long. The most important diagnoses are listed in the table. Metastases Metastases are the most common cause of multiple pulmonary masses. Usually they vary in size and are well-defined. They predominate in the lower lobes and in the subpleural region.
HRCT will demonstrate the random distribution unlike other diseases that have a perilymphatic or centrilobular distribution. The images show a renal cell carcinoma that has invaded the inferior vena cava with subsequent spread of disease to the lungs. Here another patient with widespread pulmonary metastases of a cancer, that was located in the tongue. Mucus plugs or mucoid impaction can mimick the appearance of lung nodules or a mass. Sometimes differentiating mucus impaction from a lungcancer can be difficult.
Mucoid impaction is commonly seen in patients with bronchiectasis, as in cystic fibrosis CF and allergic bronchopulmonary aspergillosis ABPA. It is also seen in bronchial obstruction caused by an obstructing tumor or bronchial atresia. In this case there are some mass-like structures in the right lung. CT demonstrated bronchiectasis with mucoid impaction. Bronchial atresia is a congenital abnormality resulting from interruption of a bronchus with associated peripheral mucus impaction and associated hyperinflation of the obstructed lung The hyperinflation of the affected lungsegment is caused by collateral ventilation through the pores of Kohn.
The characteristic finding is a hyperlucent area of the lung surrounding a branching or nodular opacity that extends from the hilum. Radiologists use many terms to describe areas of decreased density or lucencies within the lung, like cyst, cavity, pneumatocele, emphysema, bulla, honeycombing, bleb etc. Many of these terms are based on the pathogenesis of the abnormality. This makes it difficult to use these terms, since in many cases when we describe a chest X-ray, we are trying to figger out what the pathology could be.
Cavities frequently arise within a mass or an area of consolidation as a result of necrosis. We will discuss them here, because the prominent feature is the lucency. In the differential diagnosis there is overlap between cavities and cysts. Cavities can heal and end up as lungcysts and lungcysts can become infected and turn into thick walled cavities. Sometimes emphysematous bullae have visible walls that measure less than 1 mm. To differentiate them from cysts, is to look at the surrounding lung parenchyma.
Cysts occur without associated pulmonary emphysema. Cysts usually contain air, but occasionally contain fluid or solid material. The term is mostly used to describe enlarged thin-walled airspaces in patients with lymphangioleiomyomatosis or Langerhans cell histiocytosis. Thicker-walled honeycomb cysts are seen in patients with end-stage fibrosis In virulent pyogenic infections an abscess may form within the consolidated lung as a result of necrosis due to vasculitis and thrombosis.
When some of the pus is coughed up, a cavity can be seen on the chest film. These patients are usually very ill. In granulomatous infection like TB, cavities may form, but these patients are usually not that ill. These images are of a young patient with pneumonia. No micro-organism could be isolated. Within one month after treatment with antibiotics, there was almost complete resolution of the consolidation and the cavity.
Primairy TB is usually clinically silent. On the CXR it is seen as consolidation with cavitation in the apical segments of the upper and lower lobes. This patient presented first with the CXR on the left. First study the images. We can assume that this is reactivation of a latent TB. Culture was positive for TB. Notice the cavitation especially on the right. In the left upper lobe there is probably some traction-bronchiectasis due to the fibrosis. Nontuberculous mycobacteria, also known as atypical mycobacteria, are all the other mycobacteria which can cause pulmonary disease resembling TB.
Here a patient with active disease in both upper lobes due to infection with atypical mycobacterium. Notice the air-fluid level indicating pus within the cavity arrow. Septic emboli usually present as multiple ill-defined nodules. CT demonstrates more lesions than the chest film and can suggest the diagnosis in the proper clinical setting by demonstrating wegde-shaped peripheral lesions abutting the pleura, air-bronchograms within the ill-defined nodules and a feeding vessel sign 7.
Category:Respiratory system imaging
Some argue whether there is really something like a feeding vessel sign 8. Here a patient with septic emboli. The chest film shows two ill-defined densities iin the left lung, which are probably consolidations. On the CT cavitation is seen and another density with cavitation in the right lung. Small cell lungcancer does not cavitate. Bronchoalveolar carcinoma, or now called adenocarcinoma in situ, may occasionally cavitate and sometimes present as multiple lesions. In pulmonar embolism it is not common to see consolidation.
The consolidation is a result of lunginfarction and bleeding into the alveoli. Here we see an old chest film, which is normal. The pulmonary embolus has caused a triangular density on the chest film arrow. On the CT we can see, that it is a segmental consolidation. On follow up films first a cyst is seen.
One year later there is a thick wall probably as a result of secondary infection. The term pneumatocele is used to describe a lungcyst, which is most frequently caused by acute pneumonia, trauma, or aspiration of hydrocarbon fluid and is usually transient.
The mechanism is believed to be a combination of parenchymal necrosis and check-valve airway obstruction The illustration shows a pneumatocele as a result of a trauma. When it fills with fluid, it may resemble a solitary pulmonar nodule. 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. The key-findings on the X-ray are: Differential diagnosis The table summarizes the most common diseases, that present with consolidation.
A way to think of the differential diagnosis is to think of the possible content of the alveoli: Cells - tumor, chronic inflammation.
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Another way to think of consolidation, is to look at the pattern of distribution: Diffuse - perihilar batwing or peripheral reversed batwing. Multiple - usually multiple ill-defined densities. The new name for BAC - bronchoalveolar carcinoma is adenocarcinoma in situ. In chronic disease we think of: Neoplasm with lobar or segmental post-obstructive pneumonia. Lung neoplasms like bronchoalveolar carcinoma and lymphoma.
Chronic post-infection diseases like organizing pneumonia OP or chronic eosinophilic pneumonia, which both present with multiple peripheral consolidations. Sarcoidosis is the great mimicker and sometimes the granulomatous noduli are so small and diffuse that they can present as consolidation.
This is known as alveolar sarcoidosis. Alveolar proteinosis is a rare chronic disease that is characterized by filling of the alveoli with proteinaceous material.
The Radiology Assistant : Chest X-Ray - Lung disease
Lobar consolidation The most common presentation of consolidation is lobar or segmental. Here a typical lobar consolidation. First study the images, then continue reading. Lobar pneumonia On the chest x-ray there is an ill-defined area of increased density in the right upper lobe without volume loss. The right hilus is in a normal position.
Notice the air-bronchogram arrow. This was an acute lobar pneumonia caused by Streptcoccus pneumoniae. Lobar pneumonia - in a patient with cough and fever. Pulmonary hemorrhage - in a patient with hemoptoe. Organizing pneumonia OP - multiple chronic consolidations. Infarction - peripheral consolidation in a patient with acute shortness of breath with low oxygen level and high D-dimer.
Pumonary cardiogenic edema - filling of the alveoli with transudate in a patient with congestive heart failure. This would be more obvious if you were shown the whole image.
Sarcoidosis - at first glanse this looks like consolidation, but in fact this is nodular interstitial lung disease, that is so wide-spread that it looks like consolidation. Hemorrhage In this case there was a solitary nodule in the right upper lobe and a biopsy was performed.
Hemorrhage is seen in: Pulmonary contusion Pulmonary infarction Bleeding disorders: Lung infarction The radiographic features of acute pulmonary thromboembolism are insensitive and nonspecific. In most cases of pulmonary emboli the chest x-ray is normal. Pulmonary sequestration This is an uncommon cause of lobar consolidation. Notice the feeding artery, that branches off from the aorta blue arrow. Diffuse consolidation The most common cause of diffuse consolidation is pulmonary edema due to heart failure.
Congestive heart failure First study the images, then continue reading. Diffuse consolidation in bronchopneumonia Here another case of diffuse consolidation. This patient had fever and cough. This was thought to be a diffuse bronchopneumonia. Diffuse consolidation in bronchoalveolar carcinoma The chest x-ray shows diffuse consolidation with 'white out' of the left lung with an air-bronchogram. Continue with the CT. Finally the diagnosis non Hodgkin's disease was made based on biopsy.
Multifocal Multifocal consolidations are also described as multifocal ill-defined opacities or densities. First study the chest x-ray. What are the findings and what is the differential diagnosis? Wegener's granulomatosis Wegener's is a collagen vascular disease with vasculitis involving the lung, kidney and sinuses. Cystic versus Reticular It can be difficult to determine whether we are dealing with a reticular pattern or a cystic pattern.
Reticular pattern in Congestive heart failure Study the images and then continue reading. Normal old film on the left. Reticular pattern especially in the basal parts of the lung. Some Kerley B lines are seen.
Pleural fluid seen on the left side. Pulmonary vessels are somewhat more prominent compared to the old film. Based on these findings we can conclude that we are dealing with congestive heart failure. This is the most common interstitial pattern on a CXR. The main differential diagnosis of Kerley B lines is: Sometimes the reticulation is more coarse like in this case of congestive heart failure.
Sarcoidosis In this case the chest x-ray shows subtle findings that could be described as fine reticulation. Longstanding Sarcoidosis Here a typical chest film in a patient with long standing Sarcoidosis stage IV. Here another patient with sarcoidosis. The HRCT demonstrates honeycombing and traction bronchiectasis. Interstitial pneumonias An acute reticular pattern is most frequently caused by interstitial edema due to cardiac heart failure.
The other cause is interstitial pneumonia: Viral PCP Mycoplasma pneumonia. Sarcoidosis On a CXR sarcoidosis usually first presents with hilar and mediastinal lymphadenopathy example. Here a typical case. When these small nodules coalesce, they may resemble consolidation. Lymphangitis carcinomatosis Lymphangitis carcinomatosis also produces a reticular pattern. Sharply-defined opacity obscuring vessels without air-bronchogram Volume loss resulting in displacement of diafragm, fissures, hili or mediastinum. Lobar atelectasis 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. The illustration summarizes the findings of the different types of lobar atelectasis. Right upper lobe atelectasis First study the images, then continue reading. This patient had a centrally located lungcarcinoma with metastases in both lungs red arrows.
Right middle lobe atelectasis First study the x-rays and then continue reading. What are the findings? 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. Right lower lobe atelectasis Chest x-rays of a year old male who fell from the stairs and has severe pain on the right flank.
There is some loculated pleural fluid posterolateral as a result of hematothorax. What are the pulmonary findings? There is a right lower lobe atelectasis. Left upper lobe atelectasis First study the x-rays, then continue reading. Minimal volume loss with elevation of the left diaphragm Band of increased density in the retrosternal space, which is the collapsed left upper lobe Abnormal left hilus, i. This is called the luft sichel sign. First study the x-rays, then continue reading. Large density on the left with loss of cardiac silhouette.
High position left diaphragm with tenting. Low position minor fissure Low position right hilum These findings indicate a total atelectasis of the left upper lobe and possibly also partial atelectasis on the right. There were mutiple bone metastases. One rib metastasis is indicated by the arrow.
Luft sichel means a sickle of air blue arrow. Study the images and then continue reading. Left lower lobe atelectasis First study the x-rays then continue reading. Where is the abnormality located? We cannot see the lower lobe vessels, because they are surrounded by the atelectatic lobe. Total atelectasis The chest x-ray shows total atelectasis of the right lung due to mucus plugging.
These images are of a patient who had widespread bronchopneumonia and was on ventilation. Rounded atelectasis The typical findings of rounded atelectasis on CT are pleural thickening, pleural-based mass and comet tail sign. First study the images and then continue reading. A CT was performed - see next images. The CT-images show the typical features of a rounded atelectasis. There is an oval mass, pleural thickening and a comet tail sign arrow. This lesion did not change in a two-year follow up.
Plate-like atelectasis Plate-like atelectasis is a common finding on chest x-rays and detected almost every day. Plate-like atelectasis is frequently seen in patients in the ICU due to poor ventilation. Cicacitration atelectasis Atelectasis can be the result of fibrosis of lungtissue. Here we have a patient with atelectasis of the right upper lobe as a result of TB.
Solitary Pulmonary Nodule Click here for more detailed information about Solitary Pulmonary Nodule A solitary pulmonary nodule or SPN is defined as a discrete, well-marginated, rounded opacity less than or equal to 3 cm in diameter. Fleischner Society recommendations for follow-up of nodules Previous chest radiographs should be reviewed to determine if the lesion has been stable over 2 years.
For lesions with a benign pattern of calcification, further testing is not necessary. Management of indeterminate lesions greater than mm depends on clinical probability of malignancy, as follows: Serial CT scanning at 3, 6, 12, and 24 months Intermediate probability: Surgical resection Any unequivocal growth noted during follow up means that a definitive tissue diagnosis is needed. Multiple masses The differential diagnostic list of multiple masses is very long. Sometimes it is difficult to differentiate multifocal consolidations from masses. Mucoid impaction Mucus plugs or mucoid impaction can mimick the appearance of lung nodules or a mass.
A more common presentation of mucoid impaction in seen here. This is the typical 'finger-in-glove' appearance of mucoid impaction. The mucus in the dilated bronchi looks like the fingers in a glove. Bronchial atresia Bronchial atresia is a congenital abnormality resulting from interruption of a bronchus with associated peripheral mucus impaction and associated hyperinflation of the obstructed lung Notice the central mass surrounded by hyperlucent lung blue arrow.
A more practical approach is to describe areas of decreased density in the lung as: Cavity - lucency with a thick wall Cyst - lucency with a thin wall Emphysema - lucency without a visible wall. Cavitation Pneumonia In virulent pyogenic infections an abscess may form within the consolidated lung as a result of necrosis due to vasculitis and thrombosis.
Cavitation is not seen in viral pneumonia, mycoplasma and rarely in streptococcus pneumoniae. Pneumonia Here another example of a pneumonia with cavitation. Notice the destruction of lung parenchyma as seen on the CT. At one year follow up only minimal changes are seen on the CXR. TB Primairy TB is usually clinically silent. Miliary TB is the result of hematogenous spread.