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: Cortical hypodensity in the medial right occipital and right temporal regions, suspicious for acute infarct (coronal).
Region 2: Small wedge-shaped left lateral cerebellar infarct, age-indeterminate though likely chronic.
Deep gray nuclei: Subtle hypodensities are noted in the right more than left thalami.
Hyperdense vessels: None


Case Discussion:
1. Given the clinical history of visual field defects, scrutiny of the occipital lobe is essential. Although the occipital cortical hypodensity may best be noted on the coronal reconstruction, keen interpreters may note the cortical hypodensity also involves the right medial temporal in addition to the occipital regions on axial imaging.
2. Additional focused upon the deep gray nuclei reveals subtle thalamic hypodensities, right more than left.


Imaging follow up MRI (Scan 2)
Subsequent brain MRI demonstrates acute right medial temporal-occipital lobe and right thalamic infarcts (elevated DWI, low ADC signal) corresponding to the right posterior cerebral artery vascular territory. Additional small left thalamic acute/subacute infarct is present (elevated DWI, low/isointense ADC signal). Small chronic left cerebellar infarct.
Identification of this posterior cerebral artery infarct is best served with scrutiny of the medial temporal-occipital cortices on axial and coronal imaging, which can be easily overlooked. Once identification of a right posterior cerebral artery infarct is noted, the distal structures within this vascular territory should be interrogated, specifically the ipsilateral thalamus. In this case, the left thalamus also demonstrates an acute/subacute infarct. An artery of Percheron anatomic variant is possible given bilateral thalamic infarcts, though less favored as this infarct is usually symmetric and involves the paramedian thalamic portions. Also, other PCA distribution cortex is infarcted.
Recall that the thalami are supplied by posterior cerebral arteries. Otherwise the majority of the deep grey nuclei and capsular structures are supplied by anterior and middle cerebral arteries.
Recall that the posterior cerebral artery supplies the inferior temporal lobe, and the middle cerebral artery supplies the superior temporal lobe.
On axial imaging, note how this PCA infarct involves the temporal lobe parenchyma below the temporal horn of the lateral ventricle.


Primary teaching points:
1. Practical considerations for detecting temporal-occipital region infarcts.
2. Reviewing MRI signal characteristics for infarcts of varying ages.
3. Anatomic review of the posterior cerebral artery vascular territory.


Non-Contrast CT

In this case, what does the presence of bilateral thalamic infarcts indicate?