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Interventional Neuroradiology

Welcome to the Neuro section of IR Bites, your go-to source for bite-sized interventional radiology education.

Neuroradiology is a subspecialty of diagnostic radiology that focuses on imaging and diagnosing conditions of the brain and nervous system. They use a variety of imaging techniques, including CT and MRI scans, to produce detailed images of the brain and identify any abnormalities.

Interventional neuroradiology, also known as neurointerventional surgery or endovascular neurosurgery, is a specialised branch of interventional radiology that focuses on treating conditions of the brain and nervous system through minimally invasive techniques.

Here, we explore the fascinating world of neurointerventional radiology, where minimally invasive techniques are used to treat a range of conditions affecting the brain. Our Aneurysms (intracranial) page covers coiling and stenting to treat intracranial aneurysms. Our Stroke thrombectomy page delves into acute ischemic stroke. We explore the minimally invasive technique of thrombectomy, where a catheter is used to remove the clot and restore blood flow to the affected area of the brain.

Intracranial aneurysms

Here, we will cover the critical role that the interventional neuroradiologist (INR) plays in the diagnosis and treatment of brain aneurysms.

Diagram of an intracranial aneurysm
Intracranial aneurysm

A brain aneurysm is a bulge in the wall of an artery in the brain. This bulge can cause the artery to weaken and possibly rupture, leading to a potentially life-threatening condition called subarachnoid haemorrhage. Because of the high risk associated with brain aneurysms, it is critical to diagnose and treat them as early as possible.

In the case of brain aneurysms, interventional neuroradiologists (INRs) can use a procedure called endovascular coiling to treat the aneurysm.

Diagram of coiling of a cerebral aneurysm
Coiling of a cerebral aneurysm
Diagram of coils within an aneurysm
Coils within an aneurysm

This involves inserting a thin, flexible tube called a catheter into an artery in the groin and guiding it through the blood vessels to the site of the aneurysm.

Once there, the catheter delivers small coils made of platinum or other materials to the aneurysm, which helps to block off the blood flow and prevent the aneurysm from rupturing.

Interventional neuroradiology also offers several other minimally invasive procedures to treat brain aneurysms, including stenting and flow diversion.

Stenting is a procedure that involves placing a small metal mesh tube, called a stent, across the neck of the aneurysm. This helps to prevent the aneurysm from rupturing by improving blood flow to the area and creating a barrier that prevents blood from entering the aneurysm. Stenting is often used in combination with other procedures, such as coiling, to provide additional support and stabilisation to the aneurysm.
Diagram of stenting an intracranial aneurysm
Stenting an intracranial aneurysm

Flow diversion is a technique that involves placing a stent-like device called a flow diverter across the neck of the aneurysm. This device is designed to divert blood flow away from the aneurysm and toward healthier blood vessels, which helps to reduce the risk of rupture. Over time, the flow diverter encourages the formation of new blood vessel tissue around the aneurysm, further reducing the risk of rupture.


  • Interventional radiology plays a critical role in the diagnosis and treatment of brain aneurysms.
  • By utilising advanced imaging techniques and minimally invasive procedures, interventional neuroradiologists can help to identify and treat these potentially life-threatening conditions in a safe and effective manner.

Stroke thrombectomy

Welcome to our comprehensive guide to stroke thrombectomy, an advanced interventional radiology procedure used to treat ischemic strokes.

Stroke Thrombectomy
Stroke thrombectomy is an interventional radiology procedure used to treat ischemic strokes.

Ischaemic strokes were traditionally treated by physicians using systemic medical agents such as antiplatelets (aspirin) or thrombolysis (clot-busting drugs). A 2020 Cochrane review of 19 studies concluded that “endovascular thrombectomy can increase the chance of survival with a good functional outcome without increasing the risk of intracerebral haemorrhage or death” for large artery occlusion ischaemic strokes in the anterior circulation.1

1. Roaldsen MB, JusufovicM, BergeE, LindekleivH. Endovascular thrombectomy and intra-arterial interventions for acute ischaemic stroke. Cochrane Database of Systematic Reviews 2021, Issue 6. Art. No.: CD007574. DOI: 10.1002/14651858.CD007574.pub3.

An ischemic stroke occurs when a blood clot blocks an artery in the brain, preventing oxygen and nutrients from reaching the affected area. This can cause damage to the brain tissue and lead to a variety of long-term disabilities or even death.

Along with symptoms of slurred speech, weakness down one side and facial droop a CT scan of the head can help diagnose an ischaemic stroke. Importantly it can exclude a hemorrhagic stroke, when the same symptoms are caused by a bleed on the brain, usually after an aneurysm rupture.
CT head scan
CT head scan
Many UK centres now use artificial intelligence to determine the patient’s Alberta stroke programme early CT score (ASPECTS). This 10-point score helps rapidly triage patients who may be suitable for mechanical thrombectomy. In hospitals without a thrombectomy service this can mean urgent patient transfer to a thrombectomy centre.
Thrombectomy is a minimally invasive procedure that can quickly and effectively remove blood clots from blocked arteries, restoring blood flow and reducing the risk of long-term damage.

The procedure is typically performed by an interventional neuroradiologist and involves the use of a thin, flexible tube called a catheter. The catheter is inserted into an artery, usually through the groin, and guided to the site of the clot in the brain.

Once in place, a specialised device (much like a hoover) is used to remove the clot from the vessel, allowing blood flow to be restored to the affected area of the brain.

Thrombectomy procedure
Thrombectomy procedure
Time is brain
Time is brain

Thrombectomy is most effective when performed within the first few hours after the onset of symptoms. Time is brain. It is often used in combination with other treatments such as thrombolysis (clot-busting drugs) to achieve the best possible outcome.

Thrombectomy is a safe and effective procedure with a high success rate in treating ischemic stroke. It is associated with lower rates of disability and mortality compared to other treatment options, and offers patients a quicker recovery time with fewer complications. However, it is important to note that not all patients are good candidates for thrombectomy, and the decision to undergo the procedure should be made in consultation with the patient or next of kin.


Stroke thrombectomy is a powerful tool for treating ischemic strokes, offering a minimally invasive and effective way to quickly remove blood clots from blocked blood vessels in the brain.


  • Thrombectomy is an effective and safe procedure performed by INRs to reduce disability and mortality associated with ischaemic stroke.
  • It is most effective when the clot is retrieved soon after symptom onset. ASPECT score helps identify suitable candidates.