Brain imaging capstone course

Patients often present in the clinic and hospital settings with neurologic symptoms including headache, dizziness, seizure, weakness, and numbness. For this reason, brain imaging with either computed tomography (CT) or magnetic resonance imaging (MRI) is one of the most common radiology exams, and every physician is likely to encounter imaging of the brain. But where do you begin? What’s the best test for your patient, a CT or an MRI? Do I need to order contrast? What kind of history helps the radiologist get the test right? Once your patient has gotten the test, then what? There may be anywhere from 100 to 3000 images, and if you want to have a chance of seeing the abnormality when you review the imaging yourself you need a good strategy. In this course, we’ll answer these common questions about imaging of the brain and provide background about relevant indications for brain imaging, the most frequently ordered exams, and most common imaging findings encountered on CT and MRI.

After an introductory session to brain imaging, we will teach you how to review imaging on your own with confidence and develop your own search pattern so you can recognize important findings. In this interactive session, you will have a series of scrollable cases that you can evaluate through a web-based PACS and we will guide you through as you identify some common diagnoses, such as stroke, hemorrhage, brain tumors, and infection. At the end of this course, you will have gained a deeper understanding of how to use brain imaging to answer different clinical questions and tangible skills about how to review imaging on your own as a resident. 

The learning objectives for this course are:

  1. Gain familiarity with the basic concepts of brain imaging including anatomy, how to review images, and answers to common questions about brain imaging.
  2. Learn appropriate uses for each imaging type and how to order the best imaging study of the brain like a pro.
  3. Work through hands on examples of sample brain imaging to learn a strategic way to review your own imaging and recognize common imaging abnormalities on your own.

The following links will help you get access to the cases you need to scroll through the course and give you some additional information.

Before you start with the cases on your own, this first lecture describes some of the common imaging modalities you’ll encounter when doing brain imaging, including CT, CT angiography, MRI, and MR angiography. This lecture has some of the basics of these imaging modalities and the next video will go into greater detail about why you might choose a given modality for a specific purpose.

 

In this video, we talk about when to order different types of imaging and the relative advantages of each type of imaging. This includes head CT, brain MRI, and the different types of vascular imaging like CT angiography and MR angiography.

In this video, we talk about basics of how to review brain cases on your own, including some tips for how to get effective at finding abnormalities and learning your on your own.

Normal case

This is a case of a 47 year-old man with facial droop. This is an example of a normal case.

Head CT

Top left – axial brain window

Top right – axial bone window

Bottom left – coronal brain window

Bottom right – sagittal brain window

Brain MRI

Top row (left to right) – diffusion (DWI), FLAIR, and gradient

Bottom row (left to right) – T2 fat-saturated, T1 precontrast, T2 postcontrast

Explanation video

If you’d like to check out a video explanation of how to explore a normal case, check out the video here.

Now that you know general concepts about brain imaging, we will talk about some of the common pathology you may encounter in the brain. This includes:

  • Stroke
  • Hemorrhage
  • Hydrocephalus
  • Tumor
  • Infection

Sample cases

Now you are ready to try to interpret some cases on your own. Each of the following cases has images you can browse as well as questions you can answer about each case.

 

 

Case 1

83-year-old female with h/o hypertension presents with altered mental status, slurred speech, left hemiplegia and right sided gaze

Head CT/CTA

Top left – axial brain window

Top right – axial bone window

Bottom left – axial CTA

Brain MRI

Top row (left to right) – diffusion (DWI), ADC

Bottom row (left to right) – FLAIR, T1 postcontrast

 

Questions

1a. What study should be performed first in evaluating stroke?

Answer 1a
CT head without contrast to exclude hemorrhage prior to therapy

1b. Which intracranial artery supplies the largest vascular territory of the major cerebral arteries?

Answer 1b
Middle cerebral artery

Explanation video – Case 1

The video explanation for the brain course case 1 is here.

 

 

Case 2

60 year-old man with personality changes and lack of motivation with flat affect for 1-2 months

Brain MRI

Top row (left to right) – diffusion (DWI), FLAIR, T2, SWI

Bottom row (left to right) – sagittal T1 precontrast, axial T1 precontrast, axial T1 postcontrast, coronal T1 postcontrast

Questions

2a. What imaging characteristics in this case make this tumor appear higher grade?

Answer 2a
Central necrosis, thick nodular rind of enhancement, multifocal enhancement, restricted diffusion, crosses midline (corpus callosum) 

Explanation video – Case 2

The video explanation for the brain course case 1 is here.

link to brain imaging case 2

 

 

Case 3

62 year-old male with new onset of  left sided weakness, left facial droop and right eye pain

Head CT

Top left – axial brain window

Top right – axial bone window

Bottom left – coronal brain window

Bottom right – sagittal brain window

Questions

3a. CTA is negative for aneurysm or arteriovenous malformation. What is your next step in management?

Answer 3a
Neurosurgical consultation for potential decompression

3b. In a patient with intraventricular extension of hemorrhage, what major complication are they likely to experience?

Answer 3b
Acute hydrocephalus

 

 

Case 4

65 year-old male with possible ground level fall found to be altered. On Coumadin for DVT.

Head CT

Top left – axial brain window

Top right – axial bone window

Bottom left – coronal brain window

Bottom right – sagittal brain window

Questions

4a. What additional complications do you see in this case?

Answer 4a
Multiple, including midline shift, uncal herniation, infarct, and ventricular entrapment.

4b. What territory is the infarct in?

Answer 4b
Left PCA

 

 

Case 5

52 year-old with left sided weakness and numbness

Head CT

left – axial brain window

right – axial bone window

Brain MRI

Top row (left to right) – diffusion (DWI), FLAIR, T2

Bottom row (left to right) – T1 axial precontrast, T1 axial postcontrast, T1 coronal postcontrast

Questions

5a. Is this lesion intra-axial or extra-axial?How do you know?

Answer 5a
Extra-axial​. CSF cleft sign on T2 images.

 

 

Case 6

69 year-old-female with h/o autoimmune hepatitis admitted for hyponatremia. Hospital course complicated by vision changes.

Brain MRI

Top row (left to right) – diffusion (DWI), ADC, FLAIR

Bottom row (left to right) – T2 fat-saturated, T1 precontrast, T1 postcontrast

Questions

6a. How would you describe the restricted diffusion pattern and what is it concerning for?

Answer 6a
There is central restricted diffusion concerning for pus

 

 

Case 7

37 year-old-male presents with worst headache of life (WHOL)

Head CT/CTA

Top left – axial brain window

Top right – coronal brain window

Bottom left – axial CTA

Bottom right – coronal MIP CTA

Questions

7a. What is the cause of this hemorrhage?

Answer 7a
Ruptured aneurysm

7b. What is a well-known complication of subarachnoid hemorrhage (SAH)?​When does it usually occur?

Answer 7b
Vasospasm, 4-10 days from onset of hemorrhage

 

 

Summary

Hopefully by working through this course, you have learned:

  • Modalities used in brain imaging
  • Choosing an appropriate imaging modality
  • Basics of reviewing brain cases
  • Common imaging pathology of the brain

Remember, when considering imaging modalities

  • CT – screening exam, good for finding major pathology
  • MRI – more detailed for soft tissue of the brain parenchyma

Then, you were able to apply those principles in a case-based review. Now hopefully you can now recognize some of the key imaging findings of:

  • Stroke
  • Hemorrhage
  • Tumor
  • Infection
  • Hydrocephalus

Thanks for joining us for this course, and please be sure to revisit the site and check out the YouTube Channel for additional learning resources.

If you haven’t already checked it out, there is a similar course for vascular imaging of the head and neck, so check it out as well.