Case Challenge

Brain

Vascular

Daniel Cornfeld

Gain confidence interpreting Subtle Strokes Cases on CT and MRI with MRI Online. Quiz yourself using real-world, interactive scrollable cases &amp; earn CME. Try it free!

Case Review

Neuroradiology

Vascular Imaging

Case 1 - 60-year-old with double vision and dizziness.

Case 2 - 65-year-old with altered mental status.

Case 3 - 65-year-old. Altered mental status.

Case 4 - 68-year-old. Dysphagia and aphasia.

Case 5 - 82-year-old with right hemiparesis.

Case 6 - 70-year-old with confusion.

Case 7 - 60-year-old with right sided weakness.

Case 8 - 70-year-old with right-sided weakness.

Case 9 - 68-year old with aphasia.

Case 10 - 50-year-old with right-sided weakness.

Case 11 - 65-year-old with right visual field defects.

Case 12 - 65-year-old with right-sided weakness.

Case 13 - 60-year-old with left-sided weakness.

Case 14 - 60-year-old with left-sided stroke symptoms.

Case 15 - 60-year-old with bilateral weakness.

Case 16 - 50-year-old with right-sided weakness.

Case 17 - 65-year-old with right-sided weakness.

Case 18 - 60-year-old with altered mental status.

Case 19 - 55-year-old with aphasia.

Case 20 - 60-year-old with left-sided weakness.

Case 21 - 60-year-old with left hemiparesis.

Case 22 - 60-year-old with left visual field defects.

Case 23 - 68-year-old with weakness.

Case 24 - 60-year-old with bilateral weakness.

Case 25 - 90-year-old with acute left hemiplegia.

Subtle Stroke Case Challenge

Course Evaluation

Post-Course Activities

Learn to master subtle stroke cases on CT and MRI! Gain experience detecting strokes on CT by reviewing the 25 cases of subtle strokes presented in this module. The purpose is not to comprehensively explain the role of imaging in the evaluation of acute stroke or to teach a junior physician how to approach a CT scan of the brain. Instead, by reviewing these difficult cases, the reader will become better at detecting the subtle CT findings of acute stroke. Some of these cases were initially interpreted correctly. Many were not.

Subtle Strokes Case Challenge

Case Findings (Scan 1)
Hemorrhage: No
Hydrocephalus: No
Herniation: No
Gray-white differentiation/wedge-shaped hypodensity/cortical involvement: Yes.
Region 1: Loss of gray-white matter differentiation in the right frontoparietal and right posterior insular regions, suspicious for acute/subacute infarct. No acute hemorrhage.
Region 2: Small subtle area of cortical hypoattenuation in the left parietal region, suspicious for acute infarct.
Deep gray nuclei: Preserved
Hyperdense vessels: None

Case Discussion:
1. Methodical, focused review of the cortex and subcortical white matter on stroke window should result in detection of hypoattenuation most pronounced in the right posterior subinsular region. Finding is suspicious for an acute/subacute infarct.
2. An additional region of cortical hypoattenuation is also noted in the left parietal lobe, though to a much lesser extent compared to the right and difficult to see. When assessing for cortical abnormalities on the stroke window, finally adjusting the window to best assess the cortical density relative to the adjacent white matter for each case is an essential skill for detecting subtle cortical infarcts. (Note: This is very subtle, really only noticeable in retrospect, but hey, these are supposed to be difficult cases!)

Imaging follow up MRI 12 hours later (Scan 2)
MRI was performed 12 hours later showing acute infarcts (low ADC, high FLAIR signal) in the bilateral parietal and posterior right insular regions, corresponding to the middle cerebral artery vascular territories. Multifocality suggests embolic etiology.

Brief review:
1. Hyperacute infarcts are suggested with high diffusion, low ADC, and normal FLAIR signal.
2. Acute infarcts are suggested with high diffusion, low ADC, and elevated FLAIR signal.
3. Subacute infarcts are suggested with high diffusion, isointense ADC, and elevated FLAIR signal.
4. Chronic infarcts are suggested with normal diffusion signal, elevated FLAIR signal, and volume loss.


Primary teaching points:

1. Reinforcing importance of custom windowing on each case to best accentuate the cortical density relative to the subcortical white matter when assessing for subtle cortical infarcts.
2. Review of MRI signal characteristics when assessing infarct age.


Non-Contrast CT

Based on the MRI, the strokes can be described as which of the following?