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: None
Hydrocephalus: None
Herniation: None
Gray-white differentiation/wedge-shaped hypodensity/cortical involvement: Yes.
Subtle loss of gray-white matter differentiation in the left frontal operculum. Axial image. Stroke windows.
Deep gray nuclei: Preserved.
Hyperdense vessels: None.


Case Discussion:

1. Very subtle loss of gray-white matter differentiation in the left frontal opercular cortical region. This region is best assessed with sagittal reconstructions, and the clinical history of aphasia should be a clue to scrutinize this region. Most people are language left-brain dominant. Functionally speaking, the operculum is defined as 'roof' or 'cover', and anatomically the operculum of the brain 'covers' the insula: there is a frontal, temporal, and parietal operculum -- portions of brain bordering the lateral sulcus -- knowing the name of a structure means you are more likely to look at said structure.
2. Upon slow slice by slice review of the axial imaging, you may note this subtle hypoattenuation in the subcortical frontoparietal white matter. These are generally related to chronic small vessel ischemic disease, though in the presence of acute infarct symptoms and no prior imaging, these should be viewed with suspicion.
3. Age-indeterminate right occipital infarct. Given the absence of prior imaging and no clear cortical volume loss, an age-indeterminate infarct is appropriate for the unenhanced CT. The degree of hypoattenuation may suggest an acute/subacute or subacute/chronic infarct in age. Of note, just as the opercular regions are best assessed with sagittal reconstruction, the occipital/cerebellar regions are best assessed with coronals - it's all about the orthogonal view relative to the region of concern!

Imaging follow up MRI 24 hours later (Scan 2)
Subsequent review of an MRI performed 24 hours later demonstrates high DWI signal in the left frontoparietal cortex corresponding to low ADC signal, overall suggestion acute/early subacute left frontoparietal cortical and subcortical infarcts. Note the absence of DWI abnormality indicating the right occipital infarct is subacute or chronic, as well as the tiny chronic cortical infarct in the right precentral gyrus. Cortical/subcortical infarcts of varying ages in multiple vascular territories should raise suspicion for an embolic etiology of the infarcts.

Primary teaching points:
1. Orthogonal view for insular and occipital/cerebellar regions.
2. Clue into the clinical history to scrutinize areas of concern.
3. Inability to accurately age infarcts with a single unenhanced CT exam.
4. Subsequent MRI demonstrating infarcts of varying ages in multiple vascular territories should raise suspicion for an embolic etiology.


Non-Contrast CT

What structure(s) is/are surrounded by the operculum?