Findings: PA radiograph shows a curvilinear opacity in the right middle/lower lung (A, arrows). The right lung is slightly smaller than the left and the hilum looks abnormal (A, circle). Aside from slight elevation of the right hemidiaphragm, the lateral view (B) is unremarkable.

Coronal CT shows that the curvilinear line represents a scimitar vein draining below the diaphragm (C, arrow). The right pulmonary artery describes an unusual path (D, circle) and there is abnormal branching of the right main bronchus (D, circle).

An unexpected finding is an oblique band in the lower right lung (E and F, arrows). The bronchi and RLL vessels pass through an opening in the center (E and F, circles).

Final diagnosis: hypogenetic right lung with duplicated diaphragm

The reason I’m presenting this case is to discuss duplication of the diaphragm, an uncommon congenital malformation associated with hypogenetic lung.

As you all know, hypogenetic lung is a congenital malformation characterized by absence of one or two lobes of the right lung, with abnormal lower lung venous drainage (scimitar vein) in 80% of cases. It is asymptomatic and almost always occurs on the right side. Because it is symptomless, it is usually found incidentally in adults .

Typical signs in the PA chest radiograph (Fig. 1) reflect the small size of the lung:

1. Small right hemithorax with secondary dextrocardia
2. Small right hilum
3. Anomalous vein in RLL (scimitar sign), not always present

Occasionally, hypogenetic lung occurs with minimal hypoplasia, a normal-sized right lung, and absent dextrocardia. In these patients (such as the initial one), the scimitar vein and abnormal right hilum are the clues to the diagnosis.

In my experience, these cases are the ones most commonly associated with duplicated diaphragm, an infrequent malformation resulting from an alteration of caudal migration of the embryonic diaphragm.

Anatomically it appears as a band running obliquely from the chest wall to the right hemidiaphragm (Fig. 3, drawing).

If we’re lucky, we might see it as an oblique line in PA and lateral radiographs (Fig. 4), but it is usually not visible or overlooked (Fig. 5). An additional sign is blurring of the central part of the right hemidiaphragm, where the duplication ends (Figs. 4 and 5).

My hard-learned experience tells me it is very difficult to suspect duplicated diaphragm on plain films. It is usually discovered in a CT performed to confirm a hypogenetic right lung or for other reasons.
The good news is that the CT findings are pathognomonic and consist of:

1. An oblique band with a central opening
2. RLL bronchi and vessels passing through the opening and fanning out thereafter

You may wonder why I present such a rare condition, but the answer is simple:

a) It is easily recognized because of the distinctive findings. Once recognized, advise against surgery or other invasive procedures.

b) I don’t believe it’s that rare. In my career I have seen a dozen cases, the last three in this century and at the same institution. The last, seen in 2015, is the one that headed this Diploma. Two more were seen in 2004 and 2008 (Cases 1 and 2, below).

I am due to see a new case soon. Perhaps in a COVID patient, allowing me to write a useless paper about the relationship between COVID and duplicated diaphragm 🙂

Follow Dr. Pepe’s advice:
1. Duplicated diaphragm is an infrequent malformation associated with hypogenetic right lung

2. Difficult to detect in the chest radiograph

3. Easy to diagnose in CT images by the following signs:

a) Oblique band with a central hiatus in the right lower lung

b) Central hiatus that constricts RLL bronchi and vessels

Findings: the most important feature is a negative finding: absence of air in the gastric fornix (A, circle). Although this is sometimes seen in healthy persons, it is more frequent in distal esophageal obstruction. A careful look discovers that the left mediastinum has a double contour, actually the left wall of the dilated esophagus (A, blue arrow) and the descending aorta (A, red arrow). There is bulging of the right paraesophageal line (A, yellow arrow). A dilated air-filled upper esophagus is visible in the lateral view (B, arrows).

The findings are typical of lower esophageal obstruction with dilatation of the esophagus. The double contour of the left mediastinum is better seen in the cone down view (C, arrows) and confirmed with CT (D, arrows).

The air-filled dilated esophagus in the lateral view (E, arrows) is confirmed with sagittal CT (F, arrows) (T= trachea).

Final diagnosis: unsuspected esophageal achalasia

To my eternal shame, I confess that when I read the initial radiographs I overlooked the findings (nobody’s perfect!). Achalasia was discovered in a routine follow-up CT taken one year later. I redeemed myself in a subsequent pre-op PA radiograph of the patient, in which I saw a double contour of the descending aorta (A and B, red and blue arrows) and bulging of the paraesophageal line (A and B, yellow arrows). I missed the absent air in the gastric fornix, again!

Esophageal achalasia is not an uncommon condition, and early stages can be suspected in the chest radiograph if we pay attention to the telltale signs. Note that these signs are not specific for achalasia and can be secondary to any obstructive process of the distal esophagus. The most revealing findings are:

Absent gastric bubble
Displaced lower mediastinal lines
Air-fluid level in the mediastinum

ABSENT GASTRIC BUBBLE

Occurs in about 10% of the normal population and 50% of achalasia patients, and is due to failure of swallowed air to cross the distal esophageal sphincter. It is a negative finding and therefore, difficult to recognize. When it is detected, we should examine the lower mediastinum, looking for signs of esophageal dilatation (Fig. 1).

DISPLACED LOWER MEDIASTINAL LINES

A dilated esophagus displaces the paraesophageal line toward the right, making it convex. The left wall of the esophagus moves outward, and is sometimes seen as a double contour with the descending aorta (Figs. 2 and 3). Convexity of the paraesophageal line is the most reliable sign and the easiest to detect.

AIR-FLUID LEVEL IN MEDIASTINUM

Excluding hiatal hernia, an air-fluid level in the mediastinum is usually located in the esophagus. It is seen as a straight horizontal line in the middle/upper mediastinum. It is usually related to esophageal obstruction of any cause, the most common being achalasia. Discovery of an air-fluid level should lead us to investigate other signs of esophageal dilatation (Figs. 4 and 5).

Aspiration pneumonia is a complication of achalasia. I’m showing two cases in which the signs mentioned helped to suggest the correct diagnosis (Figs. 6 and 7).

CASE 1.

55-year-old man with pancreatic carcinoma and known achalasia who presented with marked cough. Chest radiographs show bilateral airspace infiltrates. In the PA view there is also dilatation of the upper esophagus (A, white arrows) with an air-fluid level (A, red arrow). The lateral view shows a retrocardiac mass (B, white arrow), suggestive of a dilated lower esophagus. The trachea is displaced forward (B, red arrow). These signs were overlooked by the radiologist, whose diagnosis was widespread pneumonia.

Coronal CT demonstrates widespread air-space disease. It also shows a dilated esophagus (C, arrow). Axial CT images confirm dilatation of the esophagus, which is full of residue
(D and E, arrows).
Final diagnosis: esophageal achalasia with secondary aspiration pneumonia.

CASE 2.

This an old case of a 27-year-old woman with a chronic RUL opacity suspected to be TB (disregard the opacities in both middle lung fields, caused by superimposed breast implants).
PA chest radiograph shows an opacity in the right upper lobe (A, circle). A right paramediastinal line extends from top to bottom (A, arrows). The lateral view shows anterior displacement of the trachea by a tubular structure (B, arrows), which occupies the upper and middle mediastinum. Both findings suggest a dilated esophagus.
Barium swallow confirms the dilated esophagus, secondary to narrowing at the esophagogastric junction (insert, arrow). Considering the age of the patient, achalasia with aspiration pneumonia was the most likely diagnosis, confirmed later.
(Remember that aspiration pneumonia goes to the right upper lobe when the patient is recumbent at night).

Follow Dr. Pepe’s advice:

Subtle findings of distal esophageal obstruction (achalasia) that should not be overlooked:

1. Absent gastric bubble

2. Displaced lower mediastinal lines

3. Air-fluid level in mediastinum

Findings: AP chest radiograph shows a poorly defined opacity in the RUL (A, circle).

Axial and coronal enhanced CT show that the opacity corresponds to a tortuous brachiocephalic artery (B and C, arrow). There is no pulmonary infiltrate.

Final diagnosis: Tortuous brachiocephalic artery simulating a pulmonary infiltrate.

The aim of this Diploma is to continue discussing chest imaging in the older population.

Today I will comment about the main manifestations of aging in the mediastinum and heart, discussing variants that may simulate disease, followed by the most common conditions affecting these regions in elderly patients.

NORMAL VARIANTS

The standard PA radiograph in aging adults usually shows a somewhat enlarged mediastinum, due to poor inspiratory effort combined with an elongated aorta and mediastinal fat accumulation (Fig. 1) .

A common variant in older patients is a tortuous brachiocephalic artery, which may project into the lung, simulating a pulmonary lesion (Fig. 2), as was shown in the initial case.

Sometimes the tortuous artery simulates a mediastinal mass. In these cases, the diagnosis is easy because a mediastinal mass pushes the trachea toward the left (Fig. 3A), whereas an elongated artery does not; instead, the associated elongated aorta displaces the trachea to the right (Fig. 3B).

The aorta is elongated in most older adults. A kink in the distal descending aorta often casts a posterior shadow in the lateral view that should not be confused with disease (Fig. 4).

Calcification of the annulus fibrosus of the mitral valve is common in elderly individuals. It does not cause symptoms and should not be confused with other conditions. It has a pathognomonic appearance in the chest radiographs (Fig. 5).

A variant of calcified annulus fibrosus is a condition termed caseous necrosis of the mitral annulus. It appears as an ovoid intracardiac calcification, visible in chest radiographs (Fig. 6) and confirmed with CT. It is also symptomless.

PATHOLOGY

The most common mediastinal pathology in the older population is hiatus hernia, easily identifiable when it contains air. An airless hernia should not be confused with a lower mediastinal mass. The best way to diagnose hiatus hernia is by looking at previous films (Fig. 7). If none are available, a barium swallow is sufficient (Fig. 8).

At times, too much air in a hernia may be misleading, as occurred in the case below, which was initially diagnosed as a possible pneumopericardium (Fig. 9).

Pneumopericardium was suspected. Enhanced CT coronal and sagittal images
show that the apparent pneumopericardium was actually a large hiatus hernia (B and C, arrows). On retrospective review of the patient’s chest radiograph, bowel air can be seen projected over the heart.

Mediastinal mass in patients of advanced age are commonly due to metastasis. Lymphoma is an alternative diagnosis, as around 50% of non-Hodgkin lymphomas occur in patients older than 65 years (Fig. 10).

Differentiating aortic aneurysm from a tortuous aorta is difficult in chest radiographs, because the medial aortic wall is obscured by the mediastinum. Sometimes the inner wall is outlined by air, allowing detection of aortic dilation in the plain film (Fig. 11).

The incidence of atrial fibrillation increases after the age of 65, and up to 9% of octogenarians are affected with this condition. Detecting a prominent left atrium in the chest radiograph of an elderly person should suggest this diagnosis (Fig. 12).

Ventricular aneurysm is a complication of myocardial infarction. In an elderly patient, the aneurysm may calcify and appear as curvilinear calcium projected over the left heart (Fig. 13).

Follow Dr. Pepe’s advice:

1. Tortuous brachiocephalic artery and calcification of the mitral annulus are common variants in persons of advanced age.

2. Hiatus hernia occurs frequently in older individuals.

3. Enlarged left atrium in this age group should raise the possibility of atrial fibrillation.

This is the last case on 2020 and we will be back on January 11, 2021!

Findings: PA radiograph shows a bulge in the left paraspinal line (A, arrow), suggestive of a posterior mediastinal mass. A rounded posterior opacity is seen in the lateral view (B, arrow).

Unenhanced coronal and sagittal CT show large osteophytes displacing the paraspinal line (C, circle) pushing the aorta forward in the sagittal view(D, circle). Incidental gas is visible in the intervertebral disk.

Final diagnosis: large osteophytes simulating a pulmonary/mediastinal mass

The aim of this Diploma is to discuss chest imaging in the elderly. As patients get older the appearance of their chest radiographs changes in comparison with young persons. I intend to discuss changes associated to aging as well as the most common pathologies in the old.

I have divided the presentation into three separate chapters:

1- Bony structures of the chest
2- Heart and mediastinum
3- Lungs and diaphragm

Today I will comment on the main manifestations of aging in the chest skeleton, discussing variations that may simulate disease, followed by the most common bone pathologies in the elderly.

NORMAL VARIANTS IN THE AGED

Degenerative changes are the hallmark of the aging skeleton.Vertebral osteophytes are common and large ones should not be confused with pulmonary nodules (Fig 1) or mediastinal masses (Fig 2), as shown in the initial case. The diagnosis is easily made with chest CT.

Calcification of the first costal cartilage may happen in the young but it is more common in the elderly. When asymmetrical, it may be confused with a pulmonary nodule (Fig 3). Exuberant cartilage calcification may simulate an upper lobe infiltrate (Fig 4).

Aging causes brittle bones and explains the increased incidence of costal fractures in the elderly. The callus of a healed fracture should not be confused with a pulmonary nodule (Fig. 6).

Resuscitation maneuvers, not uncommon in advanced age, may cause bilateral rib fractures, that should be recognized as such (fig 7).

SKELETAL PATHOLOGY

The most common bone pathology in the elderly are fractures. Acute rib fractures are common, most of them secondary to falls (Fig 8). Detection is important because they cause respiratory impairment that may end in pneumonia with the subsequent increase of morbidity and mortality.

Compression fractures of vertebral bodies are related to osteoporosis and common in the elderly. They cause significant pain, leading to inability to perform daily activities. If they are not recognized they cause a decline of the quality of life in elderly patients (Fig 9).

Lytic bone lesions in the elderly are usually related to metastases or multiple myeloma. Sclerotic metastases are common in old males. Given the prevalence of prostate carcinoma this should be our first diagnostic consideration in widespread sclerotic lesions (Fig 10). The differential diagnosis includes myelofibrosis (fig 11) and chronic renal failure (Fig 12).

Myelofibrosis is a myeloproliferative neoplasm which cause osteosclerosis. The association of an enlarged spleen should alert us to this possible diagnosis.

Solitary sclerotic lesions of the skeleton raises the possibility of metastasis vs. Paget disease. In the spine, Paget disease usually increases the size of the vertebra whereas metastases do not (Fig 13). In the peripheral skeleton the increase in width of the cortical bone is characteristic of Paget disease (Figs 14-15) .

Follow Dr. Pepe’s advice:

1. Osteophytes and healed rib fractures may simulate pulmonary nodules in the elderly

2. It is important to detect rib or vertebral fractures in the elderly because they may be the source of complications

3. Sclerotic bone lesions in the elderly are usually due to prostate metastases or Paget disease