Neuroradiology #28

A 24-year-old female patient with headache. What do you see?

Click here to see the answer

Multinodular and vacuolating neuronal tumor (MVNT): Cortical ribbon-juxtacortical T2 hyperintense (a-b) round to oval nodular lesions, not suppressed on FLAIR images (c) and usually no enhancement (d) may show fair enhancement rarely, without diffusion restriction (not shown)

Musculoskeletal #19

54-year-old man with dorsolumbar irradiated left leg pain and paresthesias

What are the imaging findings?

CT: Slightly insufflating lytic lesion in the left pedicle, with thickened vertical trabeculae (“polka dot sign”) 
MRI: The lesions show high signal on T2 and STIR sequences, with small foci of T1 hyperintensity within the lesions suggesting fatty component. Soft tissue component with the same characteristics and avidly enhancing. Note the spinal canal secondary stenosis, cord displacement and compression

What is the most likely diagnosis

Aggressive vertebral hemangioma with soft tissue component

Neuroradiology #27

48-year-old male patient, HIV (+); presented to emergency with headache, confusion, N/V.

What do you see?

Click here to see the answer

T2 hyperintense lesions of left caudate nucleus, left putaminal and right dentate nucleus , with perilesional edema.

Small corticomedullary T2 hyperintense lesions with faint enhancement.

Caudate and putaminal lesions demonstrates faint peripheric contrast enhancement whereas cerebeller lesion has strong peripheric and central nodular enhancement.

Caudate and cerebellar lesion have tiny microhemorrhages on SWI, a clue for diagnosis.

Toxoplasmosis

· Most common opportunistic CNS infection and most common cause of a mass lesion in AIDS
· Basal ganglia, thalamus, corticomedullary junction and cerebellum frequently involved
· Microhemorrhages can be seen on SWI, lesions may have ring or nodular enhancement
· Major ddx is lymphoma:
– Lymphoma is usually solitary whereas solitary lesions are uncommon in toxoplasmosis.
– Microhemorrhages are uncommon in lymphoma

Dr. Pepe’s Diploma Casebook 171 – SOLVED

Dear Friends,

presenting a new case of “Big little findings”. Radiographs belong to a 62-year-old man diagnosed of colon carcinoma one year ago. Talc pleurodesis performed after discovering right pleural implants.

What do you see? 

Click here to see the answer

Findings: PA radiograph (A) shows a right pleural effusion, secondary to talc pleurodesis. The lateral view shows D9 loss of height with erosion of the inferior vertebral plate (B, circle). The findings are partially obscured by the superimposed pleural effusion and are better seen in the insert (C).

Comparison with a sagittal CT taken six months earlier confirms that the chest radiograph findings were not present at that time (D and E, circles).

Coronal and sagittal CT show crumbling of D9 (A and B, circles). There is air in the intervertebral space, which goes against infection. MRI confirms the findings (C and D, circles). Final opinion was metastasis vs. compression fracture. Given the lack of trauma and the presence of metastases in other organs, metastasis was considered the best diagnosis. No further action was taken.

Final diagnosis: metastasis to D9 (unproven)

I am presenting this case to emphasize, once again, the importance of looking at the thoracic spine, an important landmark in the chest radiograph. Hidden by the mediastinal structures in the PA view, it is clearly depicted in the lateral radiograph.
It is important to check the spine in each lateral view because it can offer information that may be overlooked.

This case includes three basic points to remember when reading chest radiographs:

1. Satisfaction of search. The pleural effusion centers our attention and prevents examining other areas that may show important findings.
2. Comparison with previous films. Very useful to demonstrate that the finding is real and was not present previously.
3. Performing a thorough checklist. Discovering the abnormal vertebra takes a conscious effort of analysis of the lateral view, a routine that should not be forgotten.

Once the spinal abnormality is found, cross-sectional imaging (CT and/or MRI) is the method of choice to confirm the findings and reach a likely diagnosis.

To reinforce this concept, I am showing three more cases of spinal disease that might have been missed if we had not paid attention to subtle findings.

CASE 1. 73-year-old woman with back pain for one month. Lateral chest shows a compression fracture of D12 (A, circle), partially hidden by the diaphragm. The fractured vertebra is better seen in the cone-down view (B). Compression fractures of vertebral bodies are related to osteoporosis and common in advanced age. They cause significant pain, leading to inability to perform daily activities. If they are not recognized, they lead to a decline in the well-being of elderly patients.

CASE 2. 57-year-old man with back pain. Initial film shows D9 height loss that was overlooked (A, arrow). Three months later there is obvious collapse of D9 (B, arrow). CT confirms the collapsed vertebra and irregularity of the D10 upper plate (C, circle). Diagnosis: tuberculosis

CASE 3. 34-year-old man with back pain and fever. PA chest film (not shown) was uninformative.
Lateral view shows increased opacity of the middle third of the thoracic spine and an indistinct D7-D8 space (A, circle). Findings are more evident in the cone-down view (B).

Sagittal CT shows irregularity of the intervertebral disk and erosion of the end plates (C, circle).
Coronal and axial CTs show soft-tissue involvement, responsible for the increased opacity in the lateral chest film (D and E, arrows).
Diagnosis: infectious spondylitis


Follow Dr. Pepe’s advice:

Remember to look at the thoracic spine in the lateral radiograph. You may see subtle findings that portend relevant disease.

This is the way the world ends
Not with a bang but a whimper
(T S Eliot)

Dear friends,
This is our last case. For diverse circumstances Dr. Pepe and I have decided to abandon the EBR blog. We hope you’ve enjoyed the cases and that they’ve contributed to your education. Thanks for the interest you have shown over the years.
Our best wishes to you all.

Musculoskeletal #18 – Flashcard

27-year-old patient with neurofibromatosis-type 1 (NF-1). Bone lesions found on PET-CT

What are the imaging findings?

Multiple bilateral multiloculated eccentric metaphyseal lucent lesions with thin sclerotic rim

What is the most likely diagnosis?

Multiple non-ossifying fibromas in a patient with NF-1

Teaching points

Very common benign lesion in young adults. Tend to heal or involute. Vast majority asymptomatic. Large lesions may be painful or weaken the cortical predisposing to pathological fracture (rare). Multiple in NF-1

Cáceres’ Corner Case 256 – SOLVED

Dear Friends,

welcome to the second trimester of 2021! Showing today PA chest radiograph of a 66-year-old man with chest pain without any other symptoms.

What do you see?
More images will be shown on Tuesday and Wednesday.

Dear friends, showing today the lateral chest view.
Does it help?

Today I am showing an enhanced axial CT.
What would be your diagnosis?

Click here to see the answer

Findings: PA chest radiograph shows an increase in size and opacity of the left hilum
(A, arrow), due to superimposition of a well-defined posterior mass visible in the lateral view (B, arrow). At first glance, the appearance of the mass is compatible with an extrapulmonary lesion. However, there is retrocardiac nodule in the PA view (A, red arrow), suggesting a metastasis from an intrapulmonary mass.

Enhanced axial CT confirms an irregular pulmonary mass (C, arrow), which is invading the chest wall, as confirmed by the displaced intercostal artery (C, yellow arrow) and erosion of the underlying rib (D, circle).

Caudal slices confirm the retrocardiac nodule (E, white arrow) and additional nodules (E-F, red arrows) representing pleural implants.
Biopsy of the main mass returned as lung carcinoma.

Final diagnosis: Carcinoma of the lung simulating an enlarged hilum in the PA view.
 
Congratulations to Dr LeLam and thaf1212, who detected the retrocardiac nodule, which is the clue to determine that the main mass is intrapulmonary.
 
Teaching point: Remember that one of the three causes of unilateral enlarged hilum is superposition of a pulmonary opacity either in front or behind the hilum (the other two are enlarged hilar lymph nodes and increase in size of the pulmonary artery)

Neuroradiology #26 – Long case

Where is the abnormality?

Right temporal lobe

What is it like?

Effacement of the temporal horn of the right lateral ventricle and subtle hypodensity within the right temporal lobe

What would you do next?

CT with contrast and MRI

Click here to see more images

What are the MRI signal characteristics?

High-signal intensity lesion on FLAIR with significant edema and mass effect. Ring enhancement on post-contrast images

Dr. Pepe’s Diploma Casebook 170 – SOLVED

Dear Friends,

This week’s case follows the pattern of a “Meet the Examiner” presentation, with questions and answers similar to a real examination. Take your time before scrolling down for the answer.

There will be no new blog posts over the Easter period. The next case will be published on Monday, April 5, 2021.

The images belong to a 65-year-old woman with cough and low-grade fever. The referred physician demanded a chest CT.

What would be your diagnosis?

1. Pneumonia
2. Pulmonary infarction
3. Peripheral adenocarcinoma
4. Any of the above

Click here to see the answer

Findings: unenhanced axial and sagittal CTs show LLL airspace disease with a surrounding halo (B-C arrows). In my opinion, the sensible answer is 4. Any of the above, although I liked adenocarcinoma because of the peripheral halo and air bubbles within the infiltrate (A, circle).

Click here to see more images

Patient was diagnosed of pneumonia and treated with antibiotics, without improvement. Chest radiographs taken 13 days later shows progression of the LLL opacity (A and B, arrows).

A CT was recommended.

Click here to see the CT images

Two axial and one sagittal views are selected. What would your diagnosis be:

1. Peripheral adenocarcinoma
2. Tuberculosis
3. Covid pneumonia
4. None of the above

Click here to see the answer

In comparison with the previous CT, the LLL infiltrate has increased markedly in less than two weeks. An upper halo persists (A and C, arrows). A small infiltrate has appeared at the right lung base (B, arrow) In my opinion, this rapid progression rules out carcinoma and TB. A PCR was negative. Blood tests were not remarkable. It was considered that the patient had an unusual pneumonia, and the antibiotic was changed.

Click here to see more images

The fever disappeared with the new antibiotic and the patient improved moderately. A new CT was taken three weeks later. What would your diagnosis be?

1. Löffler syndrome
2. Goodpasture syndrome
3. Cryptogenic organizing pneumonia
4. Any of the above

Click here to see the answer

Findings: The most striking finding is the disappearance of the LLL infiltrate and the apparition of two new areas of airspace disease in RLL and LLL (A, arrows). There is a halo sign in the LUL infiltrate (B, arrows) and a negative halo in the RLL infiltrate (B and C, arrows).
This change of location of the opacities falls in the category of migratory infiltrates which are caused by several diseases, some of them listed in the previous questions.

The patient had no risk factors for parasitic infection and no peripheral eosinophilia, ruling out Löffler syndrome. Renal function was not altered, excluding Goodpasture’s syndrome

The combination of migratory infiltrates and a negative halo sign was very suggestive of a cryptogenetic organizing pneumonia, that was confirmed with BAL and an excellent response to corticosteroid treatment.

Final diagnosis: cryptogenic organizing pneumonia

Organizing pneumonia (OP) is a clinical, radiological and histological entity usually associated to other pathologies. The idiopathic form of OP is called cryptogenic organizing pneumonia (COP).
Clinical manifestations of COP begin with a mild flu-like illness with fever, cough and malaise.
In chest imaging it may appear as localized airspace opacity that may be confused with ordinary pneumonia, adenocarcinoma or aspiration, among others. The lack of response to antibiotic treatment and the peripheral location may help in suggesting the diagnosis.

I am presenting this case because it shows two features the help in the diagnosis: migratory infiltrates and the reverse halo sign.
Migratory infiltrates are not unique to COP, but they occur in a limited number of diseases (Loeffler syndrome, vasculitis, etc.) and their presence in the adequate clinical setting should suggest COP.
The reverse halo was originally described as specific of COP, but since then it has been seen in many other entities. It is defined as a central ground-glass opacity  surrounded by denser consolidation of crescentic shape or a complete ring. It is visible in about 20% of cases.

In this patient the combination of both signs strongly pointed towards COP, that was confirmed and responded brilliantly to corticoid treatment.

To complete the presentation, I am showing two more examples of reversed halo and migratory infiltrates (CASES 1 and 2, below).

CASE 1. 61-year-old woman with COP and basilar infiltrates (A, arrows). During treatment, coronal and axial CTs show bilateral and symmetrical reversed halo signs (B and C, arrows)

CASE 2. 51-year-old woman with COP and migratory pulmonary infiltrates (A and B). The second CT shows nice examples of reversed halo sign (B, circle), better seen in the cone down axial view (C, arrows).


Follow Dr. Pepe’s advice:

1. Localized cryptogenic organizing pneumonia may mimic other pulmonary processes

2. Migrating infiltrates and reverse halo sign (or both) are helpful in suspecting COP