Vascular & Stroke
Intracranial Hemorrhage: Name the Pattern & the Source
Fellowship-level neuroradiology teaching by E. Brooke Schrickel, MD. Open this topic in the interactive reading room →
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Core clinical idea
The clinician already knows there's blood — your job is to name the likely source, because each source drives a different treatment. Read it in order: compartment, then the company the blood keeps (shape, fracture, brain background, distribution), then the danger it's about to cause.
Bottom line
Blood is a question, not a diagnosis — name the compartment, read the company it keeps, and report the danger before the source.
Core workstation questions
- Which compartment is the blood in, and does its shape obey or cross sutures vs. dural attachments?
- Mixed density / swirl sign — is this actively bleeding and about to grow?
- Deep vs. lobar, young vs. old, clean vs. microangiopathic brain — hypertensive or amyloid?
- Is the SAH basal-cistern (aneurysm, get CTA) or perimesencephalic (benign venous, rule out then reassure)?
- Non-arterial patchy hemorrhage in edematous brain — have I looked for venous thrombosis (dense sinus / empty delta)?
- Could a tumor be hiding under this clot, and would delayed MR help?
- Post-arrest 'SAH' — is this pseudo-SAH (too-dark brain) rather than real blood?
What changes reporting / management
- Epidural = biconvex, fracture, arterial, crosses dural attachments not sutures, good prognosis if evacuated; subdural = crescentic, contrecoup, venous, crosses sutures not dural attachments, worse prognosis from compromised underlying brain.
- Swirl sign (mixed hyper-/hypodense extra-axial blood) = active hemorrhage; report expansion risk plus mass effect/midline shift/ventricular entrapment — this is the surgical case.
- Spontaneous parenchymal: deep (basal ganglia/thalamus/pons/cerebellum) + younger = hypertensive; lobar/peripheral + older + heavy white-matter disease = amyloid; add GRE/SWI to map microhemorrhage distribution.
- Aneurysmal SAH fills basal cisterns +/- IVH/IPH and needs CTA; perimesencephalic small-volume SAH with negative workup is benign nonaneurysmal venous (basal vein of Rosenthal draining straight to dural sinus), excellent prognosis.
- Patchy non-arterial hemorrhage in abnormal brain -> hunt for venous thrombosis (spontaneously dense sinus, triangular filling defect/empty delta on CTV).
- If a hemorrhagic tumor is possible, letting blood products evolve a few days improves MR sensitivity for an underlying enhancing mass.
Practical traps
- Reading swirl-sign mixed-density blood as 'acute-on-chronic' and being falsely reassured — it is hyperacute active bleeding that will expand.
- Trusting a near-normal CT/MR over a clinically devastated patient and missing traumatic axonal injury (GRE/SWI + diffusion are the tools).
- Anchoring on aneurysm for every SAH — trauma is the most common cause and trauma + SAH is usually just trauma.
- Calling pseudo-subarachnoid hemorrhage (too-dark post-arrest brain) a real bleed.
Teaching pearls
- Swirl sign means it's still bleeding — that's not acute-on-chronic, that's heading to the OR.
- Epidural crosses dural attachments not sutures; subdural crosses sutures not dural attachments.
- Deep and young is hypertensive; lobar and old with bad white matter is amyloid.
- Not every SAH is an aneurysm — perimesencephalic blood with a negative workup is benign venous.
- Bright on CT isn't always blood — a too-dark brain after arrest is pseudo-SAH.
- If the clot might be hiding a tumor, let the blood products age and re-image.
Teaching visuals
Source lectures
- Imaging of Intracranial Hemorrhages
Educational material for radiology residents and neuroradiology fellows. Nothing here drives individual patient care, and it contains no patient data.