A ruptured aneurysm results in subarachnoid hemorrhage, which is a severe complication with high mortality rates. To prevent this risk, unruptured intracranial aneurysms (UIA) are managed endovascularly or surgically. However, these treatment options may have their own set of side effects.
So, patients are selected for these treatment options only when the benefits outweigh the risk. Your doctor will make this decision for you based on the aneurysm rupture risk. The risk can be predicted based on the patient’s age, size of the aneurysm, hypertension, location of the aneurysm, and history of subarachnoid hemorrhage.
This aneurysm rupture risk can be further refined using high-resolution vessel wall magnetic resonance imaging (HRVWI-MRI). For instance, usually, aneurysms smaller than 7mm are less prone to rupture. However, some patients with small aneurysms do report SAH from aneurysm rupture. So the HRVWI-MRI can detect the aneurysms which need urgent treatment.
Aneurysm wall enhancement on vessel wall imagining indicates arterial instability and an increased risk factor for aneurysm rupture.
Silent saccular aneurysms are observed in about 4% of the normal population. A high-resolution vessel wall magnetic resonance imaging can help differentiate an unstable aneurysm from a stable one to decide the urgency for the treatment.
A thick circumferential pattern of aneurysmal wall enhancement has the highest specificity for differentiating between stable and unstable aneurysms (Circumferential aneurysmal wall enhancement is observed in almost 90% of the unstable aneurysms, allowing refined prediction of the aneurysm rupture risk).
It also aids in identifying the culprit aneurysm for SAH when multiple aneurysms are present.
It also aids in diagnosing the following conditions:
- Eccentric wall thickening in atherosclerotic plaque
- Concentric wall thickening in vasculitis
- Minimally enhancing wall thickening in reversible cerebral vasoconstriction syndrome
- Non-enhancing intracranial carotid stenosis in Moyamoya disease (non-atherosclerotic progressive vasculo-occlusive condition)
As the investigation involves high-resolution imaging, additional time and money are involved.
Normal enhancement in large intracranial blood vessels near the skull base can be mistaken as arterial wall enhancement.
Brain Imaging Techniques for Stroke (Banner)
Imaging techniques are used to:
- Detect or Exclude hemorrhage
- Understand the extent of brain injury
- Identify the underlying cause for stroke
- Ruling out conditions that mimic stroke such as tumors
Imaging techniques commonly used are:
- Computed tomography (CT)
- Magnetic resonance imaging (MRI)
- CT/MR angiography
- CT Perfusion Imaging
- Digital Subtraction Angiography (DSA)