Today’s radiographs belong to a 46-year-old man.
Preoperative for knee surgery.
What do you see?
Leave your thoughts on the comments and come back on Friday to see the answer!
There are some things which cannot be learned quickly, and time, which is all we have, must be paid heavily for their acquiring. They are the simplest things; and, because it takes a man’s life to know them, the little new that each man gets from life is very costly and the only heritage he has to leave
Dear friends, this quote from Ernest Hemingway serves as introduction to the next series of webinars. From October to March I intend to give a webinar every two weeks describing my basic approach to interpreting the chest radiograph. The subject is ample, and will continue with a second series in 2021.
To start, I am showing a preoperative PA chest radiograph for varices in a 60-year-old woman. The chest was read as normal, but there is an abnormality, difficult to detect.
Do you see it?
The answer was given during a webinar. You can watch the webinar here
Findings: PA radiograph shows a small nodule overlapping the left cardiac border (A-B, arrows). The nodule was overlooked, and the chest was read as normal.
A chest radiograph taken four years later shows a marked increase in size of the nodule (C, arrow). Enhanced axial CT shows a non-enhancing low-density nodule (-30 H.U.)
(D, arrow). Needle biopsy confirmed the diagnosis of hamartoma.
Final diagnosis: Pulmonary hamartoma, overlooked in the initial film
Congratulations to Uve, who discovered the nodule with a little help.
Teaching point: Remember that overlooking visible findings accounts for 50% of our errors. Using checklists is an excellent way to change an error into a discovery.
Today’s radiographs belong to a 53-year-old man with dysphagia.
What do you see?
Come back on Friday to see the answer!
Findings: PA radiograph (A) is unremarkable. The lateral view shows a slight anterior bowing of the trachea (B, arrow) with an apparently dilated upper esophagus with an air/solid interface (B, red arrow).
These findings are well seen in the cone down view, which better shows a thickened retrotracheal stripe (C, red arrows), a sign that suggests esophageal pathology, among others.
For all of you who diagnosed achalasia there is a negative finding: the lack of occupation of the retrocardiac space (D, circle) which practically rules out dilatation of the lower esophagus.
Sorry to say that I do not have additional images. After receiving the possible diagnosis of esophageal tumor, the patient went to another hospital, where esophagoscopy and biopsy confirmed upper esophageal dilatation by a carcinoma of the middle third.
Final diagnosis: Carcinoma of the middle third of the esophagus with proximal dilatation and food retention.
Congratulations to Dr Ahmad who was the first to describe the findings.
Teaching point: this case emphasizes the value of clinical information in selected cases. I suspect that some of you would not have discovered the dilated esophagus in the lateral view if I had withheld the history of dysphagia :).
Today I’m showing chest radiographs of a 50-year-old woman with cough and sputum production.
What do you see?
You will have more images on Wednesday.
showing today CT images of the patient. What do you see?
Findings: PA chest shows a small right lung, with a triangular opacity occupying the lower lung (A, arrow). The right heart border is not seen. The trachea and mediastinum are displaced to the right. In the lateral view the lower opacity occupies the lower lung from front to back (B, arrows).
This appearance is typical of combined RLL and RML collapse (obliteration of right heart border) and the most likely diagnosis is an obstructing lesion in the intermediary bronchus.
Enhanced axial CT shows marked narrowing of the intermediary bronchus (C, arrow). A caudal image shows marked dilatation of mucous-filled bronchi (D, arrows). This appearance indicates a long-standing obstruction and goes against a malignant process
Comparison with a previous radiograph (F) shows that the chest has not changed in comparison with the recent one (E). Bronchoscopy performed three years earlier demonstrated chronic stenosis of intermediate bronchus secondary to previous TB
Final diagnosis: Chronic TB changes of intermediary bronchus causing collapse of RML and RLL.
Congratulations to Maged Shaban and Yelgha who made the correct diagnosis of RLL and RML collapse
Teaching point: remember that central lobar collapse with bronchiectasis is rarely caused by malignancy.
Today I am presenting another “Art of interpretation case”, from last August.
Radiographs belong to a 22-year-old Spanish national with fever and dry cough for the last seven days. He had visited South Korea during the month of July. Chest radiographs read as normal by the Emergency Room physician.
What do you see?
More images will be shown on Wednesday.
showing several images of the enhanced CT.
What do you see?
Findings: PA radiograph shows convexity of the aortopulmonary window (A, white arrow) and increased opacity of the left hilum (A, red arrow). The lateral view shows a faint opacity projected over the middle third of the thoracic spine (B, circle) that was overlooked in the initial reading.
The convexity of the APW suggested mediastinal lymphadenopathy, and CT was performed.
Coronal enhanced CT shows an enlarged lymph node in the APW (A, arrow). Axial CT depicts enlarged lymph nodes in the left hilum (B, circle). Lung window demonstrates air-space disease in the apical segment of the LLL (C, arrow), which explains the posterior faint opacity in the lateral view.
Summary of CT findings:
– Unilateral enlarged hilar lymph nodes
– Lymph node in APW
– Air-space disease in the apical segment of LLL
The most significant finding is the presence of unilateral hilar lymph nodes which have a limited differential diagnosis: in the great majority of patients they are due either to lung carcinoma or active tuberculosis. As this particular patient is 27 y.o., carcinoma is unlikely. Therefore, our tentative diagnosis should be active TB, which is also supported by disease in the apical segment of the LLL, a common location for TB.
The patient was placed in isolation, bronchoscopy was performed, and Mycobacterium tuberculosis was found in the aspirate.
Final diagnosis: active tuberculosis
Active pulmonary tuberculosis is not uncommon, and the chest radiograph plays an important role in its detection. Findings that help to suspect TB in the plain film are:
Location of the parenchymal disease. Involvement of the apices or the apical segment of either lower lobe should raise the possibility of a tuberculous infiltrate, although TB can affect any area of the lung.
Cavitation. The presence of cavities within a pulmonary infiltrate suggest tuberculosis or necrotic pneumonia.
Visible lymphadenopathies. Tuberculous lymph nodes are usually unilateral and located in the hilum and homolateral mediastinum. In about one third of patients they are bilateral. In such cases, lymphoma and sarcoidosis, among others, should also be considered.
CT refines these parameters by discovering cavitation or lymphadenopathy that is not evident in the plain film. The presence of low-attenuation lymph nodes due to caseous necrosis is highly suggestive of TB, although it is not pathognomonic. Other conditions can also show these features. However, normal-density lymph nodes do not exclude TB, as was seen in the present case.
Below, I show a few nice images of active TB in which low-attenuation lymph nodes
suggested the correct diagnosis.
23-year-old woman with cough and low-grade fever. Chest radiographs shows air-space disease in the RLL (A and B, white arrows). There is obvious widening of the right paratracheal line (A, red arrow), indicating mediastinal lymphadenopathy.
Enhanced axial CT confirms the RLL disease which is non-specific (C, arrow). No cavitations are visible. The mediastinal window shows numerous enlarged lymph nodes, some with a hypodense center (D and E, arrows) and others with peripheral enhancement (ring sign) (F, arrows).
Abdominal CT also shows enlarged mesenteric lymph nodes with the ring sign (G and H, circles).
It is interesting to note that lower lobe TB occurs in only 5% of patients. In this particular case the diagnosis of TB was suggested by the CT appearance of the affected lymph nodes. Mycobacterium tuberculosis was recovered from sputum.
Final diagnosis: active TB
Dr. Pepe’s teaching points:
1. Think of TB in unilateral hilar adenopathy in a young person.
2. Low-density lymph nodes on CT are highly suggestive of active TB, although normal-density nodes do not exclude it.
showing another case seen during this summer. Preoperative chest radiography for knee surgery in a 57-year-old man. More images will be shown on Wednesday.
What do you see?
New images are shown:
Findings: PA radiographs shows a right mediastinal mass at the level of the tracheal bifurcation (A, arrow), which has not changed significantly in comparison with a chest film taken for pneumonia one year earlier (B, arrow).
Several of you have mentioned a triangular shadow at the right cardiophrenic angle
(A-B, red arrows). This appearance should suggest paracardial fat pad as the first choice.
The differential diagnosis of a right mediastinal mass at the level of the tracheal bifurcation is simple: most of the times it is either an enlarged azygos vein or lymphadenopathy.
CT shows a dilated azygos vein with a prominent azygos arch (C-D, arrows), suggesting a impeded blood flood either in the inferior or superior vena cava. Considering that the patient is asymptomatic, the most likely diagnosis is congenital interruption of the inferior vena cava, with azygos continuation. The diagnosis is confirmed noting the absence of the suprarenal portion of the IVC (C, circle) and the association of other congenital anomalies, such as polisplenia (C, red arrows) and abnormal bifurcation of the bronchial tree (E, arrows).
Coronal CT confirms that the triangular paracardial shadow represents paracardiac fat.
Final diagnosis: Congenital absence of IVC with azygos continuation
Congratulations to MK, who made a late (and accurate) diagnosis of prominent azygos vein
Teaching point: remember that the most common right lower paratracheal masses are either an enlarged azygos vein or mediastinal lymph nodes.
as I told you last week, my plan for September is to show interesting cases seen during this summer.
Today I have prepared an Art of Interpretation case that I saw in July. Radiographs belong to a 90-year-old man with cardiac arrhythmia.
Most likely diagnosis:
1. Aortic aneurysm
2. Duplication cyst
3. Thymic tumor
4. Any of the above
Leave your thoughts in the comments and come back on Friday to see the answer!
Findings: PA and lateral radiographs show a left superior middle mediastinal mass adjacent to the aortic knob (A and B, white arrows). Healed fractures of the right clavicle and second left rib are visible (A, red arrows). Pacemaker in the left hemithorax.
Analysis of relevant findings:
1. Left middle mediastinal mass adjacent to the aortic knob
2. Old fracture right clavicle
3. Old fracture second left rib
Summing up the findings: Although the appearance of the mediastinal mass is non-specific, the proximity to the aortic arch raises the possibility of an aortic aneurysm.
The bone fractures indicate previous trauma. Especially relevant is the fractured second rib. The first and second ribs are well protected by the thoracic cage and breaking either of them needs a strong impact, significant enough to shear the thoracic aorta and lead to pseudoaneurysm formation.
Therefore, our tentative diagnosis should be traumatic pseudoaneurysm of aorta, followed by a request for enhanced CT to confirm the diagnosis.
Enhanced CT confirms a partially thrombosed aneurysm with a connection to the inferior aspect of the aortic arch (A-C, red arrows). On questioning, the patient mentioned an automobile accident fifteen years earlier. Because of his age, it was decided to control the aneurysm in six months’ time.
Final diagnosis: traumatic aortic pseudoaneurysm
Rupture of the thoracic aorta is not uncommon in severe blunt trauma, usually after high impact accidents or falls from a height of more than three meters (see case 1, below). About 85% of affected patients die immediately. The remaining 15% may survive if they arrive to the hospital in time to be treated.
A small percentage of cases are overlooked and patients survive without treatment. Over time a pseudoaneurysm develops at the point of rupture, most commonly the aortic arch.
About half these cases are discovered in routine chest examinations because of the typical location of the pseudoaneurysm around the aortic arch. Another diagnostic tip is that the patients are usually younger than patients with atherosclerotic aneurysms (see Case 2).
Discovering signs of previous trauma facilitates the diagnosis, especially when the first or second ribs are affected. After a history of severe trauma is elicited, the diagnosis is confirmed with enhanced CT. The pseudoaneurysm is usually located in the inferior aspect of the aortic arch, distal to the origin of the left subclavian artery.
Traumatic aortic pseudoaneurysms are infrequent, but I have seen several cases during my professional life. I am showing two representative cases to familiarize you with their radiographic appearance.
Chest radiographs of a 75-year-old male tourist with chest pain . A peripherally calcified mediastinal mass is projected over the aortic knob in the PA radiograph (A, arrow). The lateral view shows that the mass arises from the inferior aspect of the aortic arch (B, arrow).
Coronal and sagittal enhanced CT images demonstrate a calcified aneurysm arising from the inferior aspect of the aortic arch (C and D, arrows), distal to the origin of the left subclavian artery (E, circle). On questioning, the patient mentioned surviving a helicopter crash six years earlier. A diagnosis of traumatic pseudoaneurysm was made. The patient returned to his country of origin and was lost to follow-up.
42-year-old man with vague chest symptoms. A chest radiograph from another center (unavailable) showed a mediastinal mass with peripheral calcification. CT scout view yields the same finding (A, arrow).
Enhanced CT shows a large calcified aneurysm distal to the origin of the left subclavian artery (B and C, arrows). The rest of the aorta is normal. The patient had experienced an automobile accident ten years earlier. Traumatic pseudoaneurysm was proven at surgery.
Dr. Pepe’s teaching points:
Tips to suspect a traumatic aortic pseudoaneurysm in the chest radiograph:
1. Mediastinal mass around the aortic arch
2. Signs of previous trauma, especially fractures of the first or second ribs.