Opacities in the Lung

Solitary, Circumscribed Opacity of the Lung

Checklist:

Singular, Circumscribed Opacity of the Lung

• Is the radiographic appearance of the lesion homogeneous or inhomogeneous?

• Is the margin to the surrounding parenchyma sharp or unsharp?

• Is its contour smooth or irregular, straight or lobulated?

• Are any interfaces to adjacent structures (diaphragm, heart contour, aortic arch) obscured?

• Does the lesion displace its neighboring tissues or cause loss of volume with resulting shift of adjacent structures toward the lesion?

All of a sudden—a spot in the lung

Sidel Zastro (78) has come into the hospital to get his inguinal hernia repaired. Since he has not really felt well for the past months (he has not enjoyed his cigars the way he used to) and since he has got some mileage on him, a preoperative chest radiograph is performed. With a patient of this age, Paul anticipates seeing some traces of a life gone by—long, exhaustive work, war, malnutrition, diseases, smoking, surgery, and vice of any kind may leave their traces in the thorax of an individual. He expects apical (Fig. 6.6a) and possibly basal pleural adhesions, irregular vascular markings such as in old age emphysema, and possibly some scarring due to past pneumonias (Fig. 6.6b). Mr. Zastro did not, of course, bring previous films—why on earth should he have bothered? He last saw the inside of a hospital 30 years ago. Paul and Joey study the CXR (Fig. 6.7) together, following the analysis scheme outlined above (see p. 40, 43-46).

^ What Is Your Diagnosis? Paul has discovered that the right basal lung isn't as radiolucent as it should be. Or could that be a delusion? In a woman, removal of the breast on the other side could sometimes give rise to this appearance, argues Joey. How about a chest wall anomaly? The x-ray technician says the patient's chest looked normal to her. Should one consider an emphyse-matous overinflation of the left basal lung in a patient of this age? In that case the vessel markings should be irregular and decreased, which is not what Paul and Joey see. Both finally agree that the true abnormality is at the right lung base. They go ahead and answer all the key checklist questions one by one:

Is the internal structure of the lesion homogeneous or inhomogeneous? Lesions with homogeneous internal structure: In this case the parenchyma is devoid of air. A solid tumor will replace alveoli and bronchi with tumor tissue (Fig. 6.8). In a pleural effusion, whether mobile (Fig. 6.9a) or loculated (Fig. 6.9b), the lung is intact but displaced away from the abnormality. In endobronchial obstruction, the air distal to the point of obstruction is resorbed—a postobstructive atelectasis results (Fig. 6.10).

I A Chest Radiograph Appropriate for Age

Postobstructive Pneumonia RadiologyPostobstructive Pneumonia Radiology

Fig. 6.6a During the course of the usual pulmonary infections of a long life, this patient has developed apical pleural scarring with some calcifications (arrows). No need to get exited—this finding is appropriate for age. b This elderly gentleman must have experienced a severe pneumonia that left a large area of scarring (arrows). Could a bronchial carcinoma hide in there? Of course! Any pulmonary scar may turn malignant ("scar cancer"). It is only the careful comparison with previous films that gives you sufficient certainty. The patient will possibly reassure you by telling you that he has had a scar in his lung for years. He may, however, not realize that there has been a change in size or appearance since the previous radiographs.

I The Case of Sidel Zastro

I The Case of Sidel Zastro

Aortic Nipple Looking
Fig. 6.7 Have a look at the CXRs of Sidel Zastro. Anything remarkable?

I Bronchial

Carcinoma

I Bronchial

Carcinoma

Scar Lung Adenocarcinoma

Fig. 6.8a The tumor has a relatively homogeneous internal structure because there are no aerated components. Its margins are irregular. You appreciate the pulmonary parenchyma overlying the tumor. Where is the tumor? In the lower or middle lobe? b On the lateral view of the patient you recognize the complete situation: the middle lobe (search for the minor and major fissure!) is homogeneously opacified and shows volume loss—the minor fissure ascends too steeply and runs too far inferiorly. This configuration is typical of atelectasis. Superiorly to the minor fissure the opacity continues, however. There it has an unsharp and irregular margin. In this patient a carcinoma developed in the middle lobe, led to atelectasis, and then continued to invade the neighboring lung tissue.

Fig. 6.8a The tumor has a relatively homogeneous internal structure because there are no aerated components. Its margins are irregular. You appreciate the pulmonary parenchyma overlying the tumor. Where is the tumor? In the lower or middle lobe? b On the lateral view of the patient you recognize the complete situation: the middle lobe (search for the minor and major fissure!) is homogeneously opacified and shows volume loss—the minor fissure ascends too steeply and runs too far inferiorly. This configuration is typical of atelectasis. Superiorly to the minor fissure the opacity continues, however. There it has an unsharp and irregular margin. In this patient a carcinoma developed in the middle lobe, led to atelectasis, and then continued to invade the neighboring lung tissue.

Compressed Lobes Lung

I Pleural Effusion a

Right Sided Pleural Effusion

Fig. 6.9a Note the large right-sided pleural effusion, which obscures any internal structures (it is homogeneous). The middle lobe floats in it; the upper and middle lobes are compressed by the fluid in the pleural cavity. In the left mid-lung close to the hilum (left) you see a dark branching structure—that is the air bronchogram of the middle lobe bronchus surrounded by compressive atelectasis.

Fig. 6.9a Note the large right-sided pleural effusion, which obscures any internal structures (it is homogeneous). The middle lobe floats in it; the upper and middle lobes are compressed by the fluid in the pleural cavity. In the left mid-lung close to the hilum (left) you see a dark branching structure—that is the air bronchogram of the middle lobe bronchus surrounded by compressive atelectasis.

Scar Atelectasis
b In this patient a previous large pleural effusion has been absorbed except for some residual fluid at the base (left) and some loculated fluid along the course of the minor fissure (right). This interlobar effusion can persist and scar down over time.

Lesions with inhomogeneous internal structure: These must be analyzed further. Do you see tubular, branching structures of radiolucency, that is, air bronchograms (Fig. 6.11a)? In pneumonia the alveoli fill with pus and exudate while the larger bronchi remain air-filled in the initial phase. For that reason they suddenly become visible against the backdrop of the airless surrounding alveoli (Fig. 6.11b). If the alveoli are filled with fluid from the interstitium, for example, in edema (Fig. 6.12), or with blood, for example, in a lung contusion (see Fig. 14.6, p. 313), the same phenomenon develops. If the lung is compressed from the outside, for example, by a large pleural effusion, the alveoli collapse while the bronchi stay open owing to the relative rigidity of their walls: compression atelectasis is the end result (Fig. 6.9a).

I Postobstructive Atelectasis

Atelektasis Radiology

Fig. 6.10 The opacity of the right upper lobe has a homogeneous internal structure. The minor fissure and the hilum are displaced superiorly, which points to a volume loss. The upper lobe bronchus is obstructed and a postobstructive atelectasis has developed. The air in the alveoli and the bronchi has been absorbed.

Fig. 6.10 The opacity of the right upper lobe has a homogeneous internal structure. The minor fissure and the hilum are displaced superiorly, which points to a volume loss. The upper lobe bronchus is obstructed and a postobstructive atelectasis has developed. The air in the alveoli and the bronchi has been absorbed.

Pneumonia

Treatment For Atelectasis

Fig. 6.11 a An air bronchogram in a lower lobe pneumonia (arrows). Could a cancer look like that? Unfortunately yes! The bronchoalveolar carcinoma tends to destroy the alveoli first and leaves the bronchi open initially. The complete resolution of any "pneumonia" type infiltration must therefore be docu-

Alveoli Filled With Pus

Fig. 6.11 a An air bronchogram in a lower lobe pneumonia (arrows). Could a cancer look like that? Unfortunately yes! The bronchoalveolar carcinoma tends to destroy the alveoli first and leaves the bronchi open initially. The complete resolution of any "pneumonia" type infiltration must therefore be docu-

mented radiologically once treatment has been completed, especially in the elderly. b In this boy a severe pneumococcal pneumonia has necessitated treatment in the intensive care unit. The alveoli are filled with pus; the bronchi can be traced far into the periphery.

Space-occupying lesions of the lung can also become partially necrotic. If necrosis reaches the bronchial tree, some of the necrotic tissue may be coughed up and air may enter the ensuing cavity (Fig. 6.13a). The contents of a necrotic lesion can be spread along the bronchial tree (Fig. 6.13b). Almost all infections, especially tuberculosis, can form cavities. But malignant tumors may do the same thing (Fig. 6.14). If the infectious cavities heal, their wall thickness may decrease and they can turn into cysts. Naturally these dark, warm, and humid spaces provide

I Alveolar Lung Edema

Infectious Opacities Lungs

Fig. 6.12 This is the CXR of a polytrauma-tized patient who received large quantities of intravenous fluid replacement within a short period of time to treat his severe blood loss. It ended up being a little too much of a good thing: The symmetrical opacification of both central lungs with air bronchograms indicates an alveolar pulmonary edema. The minor fissure is prominent, the bronchial walls are thickened, and the interlobular septae, particularly in the periphery of the right base, are well appreciated (Kerley B lines). This is an indication that there is also fluid deposition in the pulmonary interstitium. Conclusion: They'd better get the kidneys to work quickly.

I Tuberculosis

I Tuberculosis

Tuberculosis Radiology

Fig. 6.13 a Here we see a consolidation with a central lucency (arrows), indicative of a cavity. This radiograph of a young prison inmate sent the whole chest unit team into a flurry. Before the urgently summoned Gregory had a chance to declare "Hey, mates, this is one hell of a full-blown tuberculosis," the chest unit room had already been sealed and the disinfector been called by the young tech in charge. A rather typical finding,

Fig. 6.13 a Here we see a consolidation with a central lucency (arrows), indicative of a cavity. This radiograph of a young prison inmate sent the whole chest unit team into a flurry. Before the urgently summoned Gregory had a chance to declare "Hey, mates, this is one hell of a full-blown tuberculosis," the chest unit room had already been sealed and the disinfector been called by the young tech in charge. A rather typical finding, indeed. The prison guards who accompanied the man immediately got themselves an appointment for a check-up with their own physicians.

b This CT demonstrates beautifully what else happens when the cavity erodes into the bronchial system: Infectious material is distributed all over the bronchial system and initiates satellite lesions.

I Bronchial

Carcinoma

I Bronchial

Carcinoma

What Satilite Lesion The Lung
Fig. 6.14 This bronchial carcinoma (arrows) has turned necrotic in its center and eroded a bronchial wall vessel. The patient is coughing up blood—that was his first symptom.

Does the lesion have a sharp or unsharp border? The margin tells us something about the localization and type of the lesion. Borders that are smooth and straight at the same time are often formed by an adjacent fissure (see Fig. 6.10). If you recognize the involved fissure, you know which lobe the lesion most probably occupies. If the lesion has a smooth interface with the thoracic wall, first check whether there is a pleural effusion or whether the ribs are destroyed. If the borders toward the thoracic wall and toward the lung are smooth, a pleural process such as a loculated pleural effusion or a lipoma (Fig. 6.16) might be present.

Is the contour regular or irregular, straight, or lobulated?

A lobulated, relatively sharp contour is found in many pulmonary nodules, for example, in metastases (Fig. 6.17). An irregular, pointed, and jagged margin implies a disturbance of the surrounding pulmonary parenchymal architecture and is seen not only in primary pulmonary tumors, for example in bronchial carcinoma (Fig. 6.18), but also in infections.

perfect growing conditions for fungi (Fig. 6.15), which can superinfect a preexisting cavity.

Finally one has to realize that a CXR is a two-dimensional projectional image of a three-dimensional object. Several superimposed anterior and posterior pulmonary opacities can create the visual impression of a single inhomo-geneous infiltrate when in fact there are multiple focal ones. This can be the case in inflammatory and neoplastic processes.

Are any of the physiological air-soft tissue interfaces (diaphragm, heart border, aortic arch) obliterated? Normal interfaces between soft tissue structures like the diaphragm, the heart and the aortic arch on the one hand and the air-filled lung on the other hand disappear if the adjacent lung loses its air content at the site of contact (see p. 23-24, 44). This phenomenon, also called "silhouette sign," allows assignment of the location of underlying radiopaque lesions to certain areas of the chest:

I Aspergilloma a

Aspergillus Lung Disease

Fig. 6.15a This patient has interstitial lung disease associated with bullae due to previous asbestos exposure. One of the bullae has been colonized by Aspergillus.

b Under fluoroscopy the fungus ball (arrow) can be seen rolling around in the bulla! A stellar moment for any radiologist and the pathognomonic sign of an aspergilloma.

Fluoroscopy Diaphragm

I Pleural Lipoma

I Pleural Lipoma

Pleural Lipoma

Fig. 6.16a This tumor (arrows) adjacent to the diaphragm (left or right hemidiaphragm?) was found on the occasion of a preoperative chest check-up. It has a smooth margin and is not associated with a pleural effusion. It looks pretty benign.

•jujod sim saAOjd qjeau -japun A|paj|p uo|co aqj ui jib ai|i 'UjBBJL|dB|p|UjaL| ya| aqj si }|

Fig. 6.16a This tumor (arrows) adjacent to the diaphragm (left or right hemidiaphragm?) was found on the occasion of a preoperative chest check-up. It has a smooth margin and is not associated with a pleural effusion. It looks pretty benign.

•jujod sim saAOjd qjeau -japun A|paj|p uo|co aqj ui jib ai|i 'UjBBJL|dB|p|UjaL| ya| aqj si }|

b CT confirms the benign character of the lesion: The tumor (arrows) clearly exhibits fat density (compare the density of the subcutaneous fat!). It is a lipoma.

I Metastases

I Bronchial Carcinoma

I Metastases

I Bronchial Carcinoma

What Lung Nodules Look Like
Fig. 6.17 This is what typical metastases (arrows) look like: multiple round nodules with relatively sharp margins surrounded by pulmonary parenchyma.

Fig. 6.18 This bronchial carcinoma (arrows) has a spiculated border. The tumor invades and distorts the surrounding pulmonary parenchyma in the process (see also Fig. 6.8a).

I Atelectasis

I Atelectasis

Spiculated The Heart

Fig. 6.19 a The opacity seen on the CXR obliterates the interface between the left heart and the left lung—which means that it is located in the upper lobe. It demonstrates a homogeneous internal structure indicating that it is airless and it shows asso ciated volume loss in the affected lung (the left hemidiaphragm is elevated). b The lateral view confirms a dense stripe retroster-nally (arrows). This is compatible with left upper lobe collapse (complete lobar atelectasis).

Fig. 6.19 a The opacity seen on the CXR obliterates the interface between the left heart and the left lung—which means that it is located in the upper lobe. It demonstrates a homogeneous internal structure indicating that it is airless and it shows asso ciated volume loss in the affected lung (the left hemidiaphragm is elevated). b The lateral view confirms a dense stripe retroster-nally (arrows). This is compatible with left upper lobe collapse (complete lobar atelectasis).

• Loss of the left or right lower heart border: anterior location, middle lobe (right) or lingula (left)

• Loss of definition of the aortic arch contour: mid chest, left upper lobe

• Loss of the contour of the descending aorta and/or the paravertebral soft tissue shadow: dorsal location, lower lobe.

Now you can go ahead and apply your new knowledge to Fig. 6.19a. Where is the pathological finding?

What is the volume effect of the lesion? The volume effect is of special relevance. The displacement of surrounding structures (for example, the fissures, the diaphragm, the mediastinum) toward the lesion implies a loss of volume: a loss of lung aeration (atelectasis, Fig. 6.19) or scarring (see Fig. 6.6b) causes this behavior, but a slow-growing tumor or a chronic infection may also lead to this phenomenon. An increase in volume would point toward an acute infection or a quickly growing tumor (see Fig. 6.8a).

• Diagnosis: Paul and Joey have got it all figured out. Mr. Zastro's temperature is normal. The internal structure of the lesion is homogeneous in their opinion. The contour is sharp and straight: it is the minor fissure. The right heart contour is obliterated. The lesion seems to decrease volume rather than increase it. They have made up their mind: it is obstructive atelectasis of the middle lobe. As they want to go ahead and call up Mr. Zastro's doctor, Greg, the senior resident in neuroradiology, trots by in his search for Giufeng and stops the students: "Do you think you're done just because Mr. Zastro has an atelec-tasis? Always think of a bronchial carcinoma in this age group! Look at the hilum again and analyze it carefully, then go ahead and search the lymph node stations." Together they scrutinize the aortopulmonary window, the azygos angle, and the carina underneath the tracheal bifurcation. Nothing! Greg leaves them grumbling. A bronchoscopy will be necessary to find the cause of the obstruction and to verify it histologically. Should a bronchial carcinoma be the cause a chest CT would be needed to stage the tumor correctly following the TNM system and to determine operability as well as the optimal chemotherapy regimen (Fig. 6.20a, b). Some will have this CT done even before the bronchoscopy is performed in order to give better orientation to the bro-choscopist. In any case, this CT should—as a rule—include the upper abdomen to the adrenal glands (Fig. 6.20c) because they are a frequent and early location of metastases. Rarely a special MR study is necessary (Fig. 6.20d). If tumor tissue cannot be gathered at bronchoscopy, a core needle biopsy may be attempted under CT guidance (Fig. 6.20e).

I Staging in Bronchial Carcinoma

Mri Pancoast Tumor

Fig. 6.20a Lung windows in this CT illustrate the spiculated contour and the size of the tumor. The cancer does not appear to infiltrate the mediastinum— thus it is not a T4 stage. b Soft tissue windows of a CT obtained from a different patient shows enlarged lymph nodes along the course of the azygos vein and ventral to the trachea (arrows). They correspond to an N2 stage of a right-sided bronchial carcinoma. c Bronchial carcinoma frequently metastasizes into the adrenal glands (arrows). d This MRI in a third patient depicts a bronchial carcinoma (T4 stage). This Pancoast tumor extends cranially and into the spinal canal. e If blood clotting tests are normal, CT-guided biopsy with a core needle is the fastest, least invasive, and for the patient perhaps the most comfortable way to obtain a tissue biopsy for histological diagnosis.

Fig. 6.20a Lung windows in this CT illustrate the spiculated contour and the size of the tumor. The cancer does not appear to infiltrate the mediastinum— thus it is not a T4 stage. b Soft tissue windows of a CT obtained from a different patient shows enlarged lymph nodes along the course of the azygos vein and ventral to the trachea (arrows). They correspond to an N2 stage of a right-sided bronchial carcinoma. c Bronchial carcinoma frequently metastasizes into the adrenal glands (arrows). d This MRI in a third patient depicts a bronchial carcinoma (T4 stage). This Pancoast tumor extends cranially and into the spinal canal. e If blood clotting tests are normal, CT-guided biopsy with a core needle is the fastest, least invasive, and for the patient perhaps the most comfortable way to obtain a tissue biopsy for histological diagnosis.

Obstructive Atelectasis in Children

Children also develop postobstructive atelectasis. Causes differ from the adult population, however: foreign bodies and mucous plugs are more common. Typical foreign bodies in toddlers are glass eyes chewed off of the favorite teddy bear or aspirated peanuts that have just the right caliber to block the trachea or a main bronchus. By the way, children in the Netherlands know just what to do to decrease this risk: As a rule of thumb, any kid who manages to reach over his or her head and insert a finger into the opposite external ear canal may eat peanuts. As you can see, Philipp may enjoy peanuts, but Paula is not ready for them yet. Her airways do not have a large enough caliber.

Opacity The Head

The times of a purely "contemplative" radiology have definitely passed. The analysis of a finding is essential, but the next diagnostic or therapeutic step should always be considered. Try to reach conclusions that directly improve the patient's management in terms of time needed to diagnosis and recovery. Getting the patient back on the right track with minimally invasive diagnosis and therapy—that is the goal!

Multiple Lesions in the Lung

Multiple Lesions in the Lung

Checklist:

• Do the lesions have sharp or unsharp margins?

• Are they calcified or ossified?

• Are they solid or necrotic?

• Do you know the age, history, and symptoms of the patient?

And There Are More and More Every Month

Isadora Pumpkin (65) has been feeling unwell and depressed for a few months. She has lost some weight and her primary care physician has diagnosed anemia. He has sent her for a thorough diagnostic check-up. The ultrasound of the abdomen has been unremarkable. Joey and Ajay are hanging out in the chest imaging unit and are the first to review Mrs. Pumpkin's CXR (Fig. 6.21). The finding is obvious: multiple nodules in both lungs. They discuss the relevant differential diagnoses.

^ What Is Your Diagnosis?

Metastases: The most frequent multiple lesions in the lung are, of course, metastases (Fig. 6.22). They tend to be round and sharply demarcated (see Fig. 6.17). Breast, kidney, and colon cancers as well as carcinomas of the head and neck region are the most frequent primary tumors to give rise to metastatic involvement of the lung; in young men testicular cancer takes the lead as source of pulmonary metastases. Some types of tumors show specific characteristics: osteosarcomas, for example, have a tendency to ossify, not only at the primary site but also their metastases. Multiple ossifying pulmonary nodules are therefore almost pathognomonic for this tumor in the respective—unfortunately often young—patient group (Fig. 6.23).

I The Case of Isadora Pumpkin

Testicular Nodules
Fig. 6.21 This is the CXR of Mrs. Pumpkin. Which diagnoses do you consider?

I Metastases of Testicular Carcinoma

Cxr Contours

Fig. 6.22a You see the horrific findings on a CXR of a young man with a history of testicular carcinoma. Metastases of up to walnut size are observed scattered throughout the lungs. Take note of the nodules projecting over the heart shadow and underneath the diaphragmatic contour. You have to search there, too! Have you noticed the widening of the upper mediastinum? The aortopulmonary window and theazygos angle are filled with enlarged lymph nodes. The paratracheal stripe is widened considerably for the same reason (compare Fig. 6.1). b With just a little luck these masses will all but disappear with modern combination therapy and only a few scattered scars will remain.

Fig. 6.22a You see the horrific findings on a CXR of a young man with a history of testicular carcinoma. Metastases of up to walnut size are observed scattered throughout the lungs. Take note of the nodules projecting over the heart shadow and underneath the diaphragmatic contour. You have to search there, too! Have you noticed the widening of the upper mediastinum? The aortopulmonary window and theazygos angle are filled with enlarged lymph nodes. The paratracheal stripe is widened considerably for the same reason (compare Fig. 6.1). b With just a little luck these masses will all but disappear with modern combination therapy and only a few scattered scars will remain.

I Metastases of an Osteosarcoma

I Metastases of an Osteosarcoma

Can Lung Nodules Disappear

Fig. 6.23 The nodules in this lung are rather dense—denser than the rib intersections! The increased density suggests ossification; in a 17-year-old an osteosarcoma is an unfortunate but likely diagnosis. Of course, calcified granulomas following an infection with tuberculosis can also be very dense. However, we tend to expect them in older patients or in patients from endemic areas.

Fig. 6.23 The nodules in this lung are rather dense—denser than the rib intersections! The increased density suggests ossification; in a 17-year-old an osteosarcoma is an unfortunate but likely diagnosis. Of course, calcified granulomas following an infection with tuberculosis can also be very dense. However, we tend to expect them in older patients or in patients from endemic areas.

b
Calcified Lung NoduleFungal Infection Lungs During Chemo

Fig. 6.24a This patient has become neutropenic during the course of chemotherapy for his chronic myelogenous leukemia (CML). The aspergillus hy-phae ubiquitous in his bronchial system have subsequently overwhelmed the immune system and have infiltrated through the bronchial walls into the pulmonary arterial system. Here they have become dislodged by the bloodstream into the pulmonary capillaries, where they have induced small-vessel obstruction, "fungal" infarctions. b The "fungal" infarctions eventually lead to necrosis of lung tissue and resulting cavitation (arrows). c Vessels may also be eroded. This patient developed a mycotic aneurysm (arrow) and died of a severe pulmonary hemorrhage.

Fig. 6.24a This patient has become neutropenic during the course of chemotherapy for his chronic myelogenous leukemia (CML). The aspergillus hy-phae ubiquitous in his bronchial system have subsequently overwhelmed the immune system and have infiltrated through the bronchial walls into the pulmonary arterial system. Here they have become dislodged by the bloodstream into the pulmonary capillaries, where they have induced small-vessel obstruction, "fungal" infarctions. b The "fungal" infarctions eventually lead to necrosis of lung tissue and resulting cavitation (arrows). c Vessels may also be eroded. This patient developed a mycotic aneurysm (arrow) and died of a severe pulmonary hemorrhage.

Septic emboli: Septic emboli can also give rise to multiple nodules in the lungs. They tend to become necrotic centrally. If, for example, the mitral valve is colonized with bacteria in endocarditis, some of the vegetations can be dislodged into the lung vasculature and settle in the pulmonary parenchyma. In immunosuppressed patients (cancer, transplantation, long-lasting corticosteroid therapy, HIV infection), ubiquitous fungi such as Candida albicans and Aspergillus can invade the vessels and settle in the parenchymal periphery, causing life-threatening infections of the lung (Fig. 6.24). The reasons for septic emboli can be bizarre. In drug addicts the injection of contaminated material can cause multiple infections and abscess formations in the lung (Fig. 6.25). Whether you will see them in your life greatly depends on the type of community you work in (inner cities, etc.) and the existence of clean needle programs in that community.

I Septic Emboli in Intravenous Drug Abuse

Septic Emboli

Fig. 6.25 This young drug addict was brought into the emergency ward absolutely run-down and severely sick, straight from some abandoned harbor shack. A lot of lesions are visible in the lung, the majority of which appear centrally necrotic—septic emboli. Can metastases look like that? Yes, but infrequently. If you are looking for reasons in favor of methadone substitution therapy for intravenous drug addicts, here is one.

Fig. 6.25 This young drug addict was brought into the emergency ward absolutely run-down and severely sick, straight from some abandoned harbor shack. A lot of lesions are visible in the lung, the majority of which appear centrally necrotic—septic emboli. Can metastases look like that? Yes, but infrequently. If you are looking for reasons in favor of methadone substitution therapy for intravenous drug addicts, here is one.

Wegener disease: Solitary or multiple pulmonary lesions Skin tumors, nipples: As an exception, skin tumors may

(granulomata) can occur in Wegener disease, an autoimmune vasculitis that is frequently associated with glomerulonephritis. They tend to necrotize centrally (Fig. 6.26).

I Wegener Disease look like multiple lung nodules—just think of neurofibromatosis (Fig. 6.27). Nipples can also look suspicious. In some departments small lead markers are taped onto them to facilitate their differentiation from lung lesions. In other instances a quick fluoroscopy with a metal paper-clip taped to the areola will solve the problem.

I Wegener Disease

Wegener Disease

Fig. 6.26 This pulmonary lesion is centrally necrotic. If the clinicians do not consider all of this patient's findings, diagnosis and therapy may go awry. A bright radiologist might include Wegener disease in the differential diagnosis and prompt a search for the respective clinical signs (sinus and joint problems, glomerulonephritis, and the presence of antineutrophilic cytoplasmic antibodies [c-ANCA]).

Fig. 6.26 This pulmonary lesion is centrally necrotic. If the clinicians do not consider all of this patient's findings, diagnosis and therapy may go awry. A bright radiologist might include Wegener disease in the differential diagnosis and prompt a search for the respective clinical signs (sinus and joint problems, glomerulonephritis, and the presence of antineutrophilic cytoplasmic antibodies [c-ANCA]).

• Diagnosis: Joey and Ajay have talked to Mrs. Pumpkin. She has been pretty healthy up to now and is not the adventurous, easy-going type. For these reasons the lesions are metastases until proven otherwise. Ajay suggests an examination of the breast physically and mammographi-cally, which would certainly be a good next step as breast cancer is a common malignancy in women of her age; someone should also take a look at her colon. If this and other tests fail to find the primary tumor, a CT-guided biopsy of one of the metastases would be the way to go (see Fig. 6.20e) because the appearance of the tumor cells under the microscope may provide a clue as to their origin. Bronchoscopy, perhaps with bronchial lavage, would be the next step in an immunosuppressed patient with a suspicion of a fungal infection of the lung that needs specific therapy urgently. Of course, CT-guided biopsies should only be performed if blood clotting is normal and if bronchoscopy does not provide the material with more ease.

I Skin Tumors

Neurofibromatosis Physical Appearance
Fig. 6.27a The cutaneous tumors in neurofibromatosis may certainly become visible on the CXR just as prominently as nipple shadows. A precise physical inspection and perhaps a short fluoroscopic examination after marking the nipple or any cutaneous tumors will clarify the situation.
b If the CXR becomes too complex, a CT may be necessary. In patients with neurofibromatosis it frequently also shows pulmonary emphysema.

Diffuse, Homogeneous Opacity of the Lung

Diffuse, Homogeneous Opacity of the Lung

Checklist:

Unilateral

• Is the patient well positioned?

• Has the contralateral breast been resected?

• Is there any volume loss? Bilateral

• Has the patient taken a deep breath?

• Has the film been adequately exposed?

• Is the patient exceptionally adipose?

Shortness of Breath in Search of a Cause

Jonathan Bootleg (53) has developed shortness of breath while on dialysis for his terminal renal insufficiency. The internist in charge has requested a CXR (Fig. 6.28). Hannah is alone this late morning in the chest unit and takes a close look at the film. She considers the list of differential diagnoses.

I The Case of Jonathan Bootleg

Abnormal Cxr Causes
Fig. 6.28 Analyze the CXR of Mr. Bootleg. Does anything appear abnormal?

• What Is Your Diagnosis?

Pleural effusion: A multitude of diseases, for example, pleural tumors (metastases, mesotheliomas) can result in a unilateral effusion. A homogeneous opacity of both lung fields can naturally also be caused by bilateral pleural effusions. The bilateral effusions may be different in quantity (Fig. 6.29), especially in cardiac decompensation and subsequent pulmonary venous congestion.

Do You Know Other Causes for a Diffuse Homogeneous Opacity of the Lung?

Portable CXRs are frequently performed without a scatter grid. The scattered radiation reaches the detector and uniformly increases the image density. If a grid is used it may not be properly aligned with the tube and may partially block diagnostic x-rays in one half of the chest causing an asymmetric exposure of the film. In insufficient inspiration, the density of the lung parenchyma also increases bilaterally owing to low lung volumes. Finally, any imaging technology may fail because the wrong exposure parameters have been chosen or because the patient simply was not built for imaging: patients who weigh more than 140 kg/300 pounds may need to be imaged with dedicated veterinarian equipment.

Posttraumatic loss of radiolucency: Trauma can result in a diffuse unilateral opacity of the thorax; a chest wall hematoma, possibly due to a serial rib fracture, or a hemothorax (Fig. 6.30) after an injury of intrathoracic vessels (intercostal arteries or the aorta) may be the cause.

Atelectasis: An atelectasis of the left upper lobe or of a total lung can increase the density of a complete hemithor-ax (see also Fig. 6.19a).

Swyer-James syndrome: Sometimes it is difficult to differentiate between an opacity on one side and an increase in radiolucency on the other. An early childhood pneumonia causes a circumscribed hypoplasia of the lung in Swyer-James syndrome. The change is characterized by a decreased vascularity and an increased aeration due to air trapping (Fig. 6.31).

• Diagnosis: Initially Hannah was going to report a pleural effusion in Mr. Bootleg's chest, but the dark stripe along the right thoracic wall has made her hesitant: Could this also be a pneumothorax? Sitting in front of the viewbox, she scratches her head as Joey, Giufeng, and Ajay come by to pick her up for lunch. "It's a skin fold," Giufeng declares, "the density slowly increases laterally and then suddenly falls off. Above the aortic arch on the left side you can see two more of those folds." "That does not explain it all, Giufeng," Joey throws in, "the patient is rotated to the right quite a bit. Just have a look at the trachea and the unfolded aortic arch! This is one poorly taken radiograph. The rotation is another reason for the increase in density." "OK, OK, I've got the message," mumbles Hannah, "and which one of you smart alecs can tell me now why the patient is short of breath?" A long silence ensues, then Ajay replies softly: "Hannah, I would worry about that large air-filled structure in the heart shadow. How about this being a large hiatal hernia or even an 'upside-down-stomach'! That could explain the dyspnea."

I Pleural Effusion

Pleural Effusion Recumbent

Fig. 6.29 This large right-sided and smaller left-sided pleural effusion extends far superiorly in this portable chest film obtained from a recumbent patient in bed. For this reason the complete lung appears homogeneously opacified. The interface between diaphragm and lower lobe is obliterated on the right side—go ahead and compare it to the left side. The vessels close to the hilum are enlarged and their margins are unsharp. The bronchi can be traced far into the lung core. The heart appears enlarged, even for a portable supine study. This is compatible with cardiogenic pulmonary venous congestion with subsequent edema.

I Hemothorax

I Hemothorax

Hyperinflation The Lungs
Fig. 6.31 These CXRs in inspiration (left) and expiration (right) show decrease in vasculature in the right hemithorax (also compare both hila) and hyperinflation of the right lung (also called "air trapping"). The right hemidiaphragm does not move at all.

All are impressed—a real team effort. Hannah jots down the preliminary report. "Well, I should be depressed. But thanks anyway. Talking about gastrointestinal stuff," she goes "I'm starving. Let's go for lunch!"

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Responses

  • Debra
    Does prominence in the left hilum have anything to do with left diaphragm paralysis?
    4 years ago
  • Anna
    How likely is opacity with central lucency due to artifact?
    4 years ago
  • Arabella
    What is dense inhomogeneous opacity?
    3 years ago
  • Bernd
    Can lung nodules disappear in osteosarcoma?
    2 years ago
  • steffen
    Can opacity on chest xray turn out to be nothing?
    2 years ago

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