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: Focal cortical/subcortical hypodensity and cystic encephalomalacia in the right parietal region, likely a chronic infarct.
Region 2: Small focal cortical/subcortical left occipital hypodensity, age-indeterminate though possibly subacute/chronic infarct.
Deep gray nuclei: Tiny hypodensities in the right striatum, possibly chronic lacunar infarcts.
Hyperdense vessels: None

Case Discussion:
This is an incredibly challenging case and highlights the difficulty of assessing for acute infarcts when extensive chronic ischemic changes are present throughout the subcortical white matter. Initial attention turns to the right parietal region, though the degree of encephalomalacia and volume loss overall favors a chronic infarct. Keen eyed clinicians may note a small focal hypodensity in the posterior left occipital region, which raises concern for an age-indeterminate though possibly subacute/chronic infarct given the degree of hypoattenuation. Ultimately, a clinical impression of "No definite acute infarct. MRI would be more sensitive for detection of acute ischemia" would be reasonable.

Imaging follow up MRI (Scan 2)
Subsequent brain MRI demonstrates extensive acute infarcts in the left occipital and inferior left temporal corresponding to the left posterior cerebral artery vascular territory (high DWI, low ADC, and abnormal FLAIR signal). This infarct is very subtle on the CT examination. See these coronal and axial images.
Additionally, note difficulties with assessing the occipital-temporal regions on the coronal reconstruction related to beam hardening artifact from the skull base. In clinical practice, these cases illustrate MRI improved sensitivity for detecting acute infarcts over unenhanced CT examinations.

Upon further review of the brain MRI, the previously seen hypodensities in the right parietal and left occipital regions are chronic (no diffusion signal, high T2 signal). There is also a right frontal subacute infarct in the right middle cerebral artery M2 superior division vascular territory (high DWI signal, low/isointense ADC signal). Multifocal infarcts in different vascular distributions of varying ages suggest embolic etiology.
Probable chronic lacunar infarct in the right putamen are noted with MRI given trace surrounding FLAIR signal, though prominent perivascular spaces could have a similar appearance.

Primary teaching points:
1. Review MRI signal characteristics for assessing infarct chronicity
2. Review of posterior cerebral artery and middle cerebral artery M2 superior division vascular territories.


Non-Contrast CT

Given the history, where might this stroke be (assuming a stroke is present because this is a module on subtle strokes)?