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: Yes. Subtle linear subarachnoid hemorrhage in the left frontal lobe. (This is also seen on the followup MRI 24 hours later.)
Hydrocephalus: No
Herniation: No
Gray-white differentiation/wedge-shaped hypodensity/cortical involvement: Yes.
Region 1: Focal hypodensity in the left frontal cortical/subcortical regions, suspicious for acute/subacute infarct.
Region 2: Subtle loss of gray-white matter differentiation and cortical hypodensity in the inferior left occipital lobe, suspicious for acute infarct.
Deep gray nuclei: Preserved
Hyperdense vessels: None

Case Discussion:
1. Systematic slice by slice review of the axial stroke windows should reveal a focal hypodensity in the left frontal cortical/subcortical region, predominantly centered in the left middle frontal gyrus. In the absence of prior imaging and encephalomalacia, this suspicious for an acute/subacute infarct. Of note, the sagittal reformats can often be of use when scrutinizing this region.
2. Keen readers may also note subtle medial left occipital cortical hypodensity. The occipital region is often best scrutinized with coronal reformats, though calvarial beam hardening artifact could potentially mimic or superior pathology. Fortunately the more readily apparent left frontal abnormality will hopefully result in the patient receiving appropriate treatment. It can be easy to miss a second subtle infarct after finding the first one. However, given a history of right visual field defects you should have scrutinized the left medial occipital lobe. Don't give into "search satisfaction."


Imaging follow up MRI 24 hours later (Scan 2)
MRI was performed 24 hours later.
1. Acute left posterior cerebral artery vascular territory infarct (high DWI, low ADC, FLAIR signal abnormality) in the medial-inferior left occipital lobe, splenium of the left corpus callosum, left hippocampus, posterior medial left temporal lobe).
2. Acute/subacute posterior left frontal infarct in the left middle cerebral artery vascular territory with regions of petechial hemorrhage (high DWI, low to isointense ADC signal, and susceptibility on gradient echo sequences).
3. Tiny acute/subacute infarct in the right parietal-occipital subcortical white matter (high DWI, low to isointense ADC signal).
Given multifocal infarcts of varying ages in multiple vascular territories, an embolic etiology is suspected. Should you review brain MRIs in your daily practice, a slice-by-slice approach to the diffusion weighted sequence is suggested as sometimes tiny clinically relevant infarcts may be visible on only one slice. This tiny infarct is not seen on CT.
4. Small chronic left cerebellar infarct, better seen on MRI than CT.
5. Incidental 8 mm extra-axial right frontal lesion abutting the frontal parenchyma, likely a meningioma. No parenchymal edema (FLAIR, CT).


Primary teaching points:

1. Although detecting a single focal infarct is often enough for appropriate clinical care, a conscientious appropriate to exclude for multifocal infarcts are unenhanced head CT may be of use, particularly in the setting of patient's unable to obtain MRI.
2. Increased detection of infarcts is often aided by multiplanar reformats, with some reformats better able to highlight pathology within certain regions of the brain.
3. Review infarct aging and hemorrhage assessment with multiple MRI sequences.
4. Suggestion for detecting tiny clinically relevant infarcts on DWI with a slice-by-slice approach.


Non-Contrast CT

Multiple infarcts of varying ages and in different vascular territories are suggestive of which of the following?