Interventional Neuroradiology

Diseases We Treat

Acute Stroke Treatment

Stroke is the third leading cause of death in the United States and is responsible for high rates of disability. It results from blockage to blood flow in one or more of the arteries supplying the brain.

The blockage may start in one of the arteries supplying the brain, or it may result from blood clot that formed in the heart and floated up into one of these arteries. When the blockage is complete and lasts long enough a portion of the brain may die unless the artery is re-opened rapidly.

Conditions such as diabetes, high blood pressure, high cholesterol levels in the blood and smoking can predispose a person to having a stroke.

Symptoms of a stroke can include weakness or numbness in a part of the body, difficulty seeing, or difficulty speaking.

There are treatments to open the blockages, but they must be given quickly. Giving a clot-busting drug through a vein can treat some strokes. Some centers are also using the clot-busting medication by giving it directly into the clot by placing a catheter into the arteries that are blocked up.

In addition there are some centers that are using newer more experimental techniques to mechanically remove or break up the clot.

Stroke pretreatment: 

Angiogram of a woman within hours of an acute stroke showing no flow of blood to the right middle cerebral artery due to a blood clot.

Stroke post treatment: 

Angiogram after endovascular stroke treatment with a small catheter placed into the blood clot shows complete opening of the artery and normal blood flow to the brain.


An aneurysm is an abnormal ballooning out of an artery. When this occurs the wall of the artery weakens and this puts a patient at risk of rupturing or bleeding from the aneurysm. Bleeding from an aneurysm represents a serious medical problem that can cause stroke or death.

Aneurysms are usually acquired, although there is an increased incidence in family members related directly to a person with aneurysms. The average age when a person has symptoms from an aneurysm is usually 40-60 years old, although this can be quite variable. It may be associated with other medical conditions like hypertension. Aneurysms occur slightly more frequently in women. About 20% of patients with aneurysms will have multiple (two or more) aneurysms at the same time.

Many patients have no symptoms until the aneurysm ruptures. In some cases, there may be symptoms suggesting that an aneurysm is present before there is bleeding. Aneurysms can cause headache or neurologic symptoms before bleeding. Some aneurysms are found prior to rupturing using CT (computed tomography) or MRI (magnetic resonance imaging). While CT and MR can show many aneurysms, most patients with aneurysms need a cerebral angiogram for definitive diagnosis and to determine the best treatment.

The treatment goal with aneurysms is to exclude the aneurysm from the circulation, thereby eliminating the chance of rupture. This can be done with a surgical procedure to "clip" the aneurysm or an endovascular procedure to "coil" the aneurysm. Clipping an aneurysm is done by opening the skull and placing a clip over the aneurysm.

Coiling of the aneurysm is done by placing a catheter (a hollow plastic tube) into the aneurysm. The catheter is started out in a little nick in the artery going to the leg, the femoral artery. The procedure is monitored by the interventional neuroradiologist using fluoroscopy so they can see the exact location of the catheter at all times.

Once positioned, tiny detachable platinum micro coils are placed into the aneurysm. Controlled angiography is done during the procedure to monitor the occlusion of the aneurysm. If the aneurysm has not ruptured prior to coiling, the patient will generally spend one night in the intensive care unit for monitoring and then go to the general ward overnight.

The only restriction after the procedure is to refrain from heavy lifting for a period of a few days. If the patient has already suffered from a rupture, the recovery will be determined by the extent of the initial bleed and any deficits that was caused.

Sometimes after an aneurysm bleeds there is a reaction of the blood vessels near the rupture called vasospasm (narrowing of the blood vessel). This after-effect can be life-threatening and must be treated aggressively to prevent further neurologic deficits.

Treatment can include IV fluids, elevating the patient's blood pressure, and sometimes an angioplasty. Interventional neuroradiologists treat patients that have had clipping or coiling of the aneurysm for this problem. Angioplasty consists of placing a special balloon-tipped catheter into the cerebral blood vessels that are narrowed. The balloon is then blown up which pushes the walls of the blood vessel open, and blood flow is restored to the brain. At times medication is also infused to assist with opening the vessel.

Aneurysm pretreatment:  Angiogram of a patient with a ruptured aneurysm prior  to treatment.

 Aneurysm post treatment: 
Angiogram following coiling shows complete closure of the aneurysm

Arteriovenous Malformations (AVMs)

Blood normally flows through arteries under high pressure to supply all the organs including the brain. From the arteries it passes through thin-walled capillaries to supply the tissue of the brain and then enters the veins under low pressure to be carried back to the heart and lungs.

Arteriovenous malformations are abnormal collections of blood vessels that directly connect arteries to veins and bypass the capillary bed. Without a capillary bed the AVM blood vessels see an increase in flow and blood pressure. Over the years this causes them to dilate and become thin-walled, and more likely to rupture. AVMs are thought to be congenital in nature. AVMs are usually not inherited and other members of the family are not at increased risk for having an AVM.

An AVM can cause headache, weakness, numbness, visual problems, or seizures. They often first show symptoms when there is a bleed or rupture from one of the blood vessels making up the AVM.

An AVM is usually diagnosed with a CT (computed tomography) scan or MRI (magnetic resonance imaging). A patient usually requires an angiogram to then fully identify the anatomy of the AVM and make decisions about treatment. AVMs can be treated using three different techniques. Often more than one technique is used to treat the same AVM because the combination of techniques may prove safer or more successful than one technique alone. These techniques are embolization, surgery and radiation therapy or radiosurgery. Surgery is done by opening the skull and removing the blood vessels that make up the AVM.

Radiosurgery involves using beams of focused radiation to injure the blood vessels of the AVM and cause them to close off. Embolization is done by placing a tiny catheter directly into the AVM vessels within the brain. Material is then injected into the blood vessel to block them up. The material that is usually used is a glue-like material that leaves the catheter as liquid and solidifies within the AVM blood vessel to block it up. Embolization of an AVM is often done in advance of surgery or radiosurgery to help improve the likelihood these techniques will be successful.

AVM pretreatment: 

Angiogram of a patient with a large AVM involving the temporal and parietal lobes of the brain.

AVM post treatment: 

Angiogram of the same patient after treatment with embolization and radiosurgery shows complete obliteration of the AVM.

Atherosclerosis (Carotid, Vertebral, Intracranial)

Atherosclerosis is hardening of the arteries that can result in narrowing (stenosis) or blockage (occlusion) of an artery. This can occur in any artery in the body.

When an interventional neuroradiologist is involved in treating this problem it involves the larger arteries going to the brain (carotid or vertebral arteries) or the arteries inside the head (intracranial arteries).

Atherosclerosis of the carotid arteries often causes transient ischemic attacks (TIAs) because the blood flow may be interrupted to the point that a portion of the brain is not working. Typical symptoms include weakness or numbness on one side of the body, inability to speak or understand speech, and changes in vision. If the blood flow is only decreased for a short time a TIA occurs, but if the interruption is sufficiently long a stroke occurs.

Medical treatment may be recommended if the narrowing is not severe. If the narrowing is greater than 70% surgery or endovascular therapy may be recommended. Surgery involves opening the artery and removing the atherosclerotic plaque that is narrowing it.

Endovascular therapy involves using a balloon or stent to push open the wall of the artery from within. Surgery is often done on the carotid artery in the neck, but endovascular treatment may be recommended. Endovascular therapy is often in other location such as the vertebral artery and the intracranial arteries.

Carotid Stenting pretreatment: 

Angiogram of a patient with frequent transient ischemic attacks demonstrates a severe narrowing of the internal carotid artery.

Carotid Stenting post treatment:

Angiogram following carotid stent placement shows opening of the narrowing by the stent with improved blood flow to the brain.

Carotid-Cavernous Fistula

Carotid-cavernous fistulae are a specific kind of dural fistula that involves the carotid artery (or its branches) and a large vein (cavernous sinus) behind the eye. These fistulae can occur because of trauma, if there is an aneursym in the carotid that breaks and causes the communication, or they can happen spontaneously without a definite reason.

Symptoms can include eye pain, swelling and redness of the eye, double vision or loss of vision if untreated. These fistulae are usually difficult to treat surgically. They are often treated by an endovascular approach, putting a catheter in the artery or vein and using material to block up the connection between the artery and vein. This material can include balloons, coils, and liquid glue.

CC Fistula pretreatment: 

Angiogram from a patient who fell at a construction site causing a tear in the carotid artery and a carotid cavernous fistula.  Arrows and arrowheads show the veins draining the fistula.
CC Fistula post treatment:

Angiogram after treatment with a small balloon placed at the site of the arrow shows complete closure of the fistula.

Dural Arteriovenous Fistulas

Dural arteriovenous fistulae are blood vessels that represent abnormal connections between arteries veins that are found in the covering of the brain. This covering is known as the dura, hence the name. There is a direct connection between the arteries and the sinus without any vessels between.

These fistulae or connections are usually acquired and can occur after trauma, infection or thrombosis (clotting-off) of veins in the dura. The fistula may cause abnormal noises in the head due to the high flow of blood. They can also cause headaches or result in bleeding into the brain.

The treatment is similar to those available for AVMs and can include embolization, surgery and in some cases radiosurgery. Embolization is often used as the primary therapy to treat this problem.

Dural AVF pretreatment:

Angiogram from a young woman with a dural AVF causing increasing pressure in the brain and headaches.

Dural AVF post treatment:

Angiogram following treatment with embolization shows complete closure of the fistula.

Spinal Compression Fractures

The spinal column is made up of thirty-one individual bones called vertebrae. When they become weakened either because of disease or secondary to medications, they can break or collapse. This is called a compression fracture.

Since it is not possible to immobilize the vertebra completely, patients can have severe pain with any patient movement or secondary to nerve compression. Until the late 1980’s, the only way that this problem was treated was with bed rest, narcotic medication and in some cases back bracing.

Now we are able to offer a procedure called percutaneous vertebroplasty. This procedure is done with high tech x-ray equipment to provide optimal visualization. The physician then inserts a small needle directly into the vertebral body that is compressed. Once needle placement has been confirmed, Polymethylmethacrylate, a type of bone cement, is injected. This essentially strengthens the bone from within.

This procedure has been very effective in decreasing pain, decreasing medication usage, and increasing patient mobility, and is also very safe.

Vertebroplasy pretreatment:

CT scan of a patient with a painful compression fracture of the lumber spine. Patient had failed treatment with pain medicine and bed rest.

Vertebroplasty post treatment:   

CT scan after vertebroplasty treatment shows bone cement stabilizing the fracture.  Patient experienced complete pain relief several hours after treatment.

Vascular Tumors

(Hemangioblastomas, Juvenile, Nasoangiofibromas, Meningiomas, Metastatic Tumors)  
Vascular tumors that come to the attention of the Interventional Neuroradiologist may be inside the skull (intracranial) or outside, in the head and neck region (extracranial). 

Endovascular embolization of vascular tumors is often done as a pre-operative procedure. The goal of this embolization is to reduce the amount of blood loss that is experienced at the time of surgery and also to make the removal of the tumor easier and potentially more complete. 

The types of tumors that may respond favorably to this technique include: 

The embolization is performed by placing a catheter directly into the blood supply of the tumor (this is also done by starting at the femoral artery as in most interventional procedures).  Embolic material is then injected through the catheter to close off the blood vessels supplying the tumor and embolize the capillary bed of the tumor. This embolic material can include particles such as polyvinyl alcohol as well liquid glue, which leaves the catheter as a liquid and solidifies within the blood vessel. 

Tumor pretreatment: 

Angiogram of a patient with a large vascular brain tumor.  Arrows and arrowhead point to prominent blood vessels feeding this tumor.

Tumor post treatment:   

Angiogram following embolization shows complete removal of blood flow to the tumor.  Patient then underwent an uncomplicated resection of the tumor.

Vein of Galen Malformations

The Vein of Galen malformation is a congenital communication between arteries and veins.  In this case the communication specifically occurs between a set of deep arteries in the brain called the choroidal arteries and a deep midline vein, the Vein of Galen. 

Often a Vein of Galen Malformation will present with symptoms in early infancy or in childhood.  In early infancy these symptoms can include congestive heart failure.  Symptoms may occur somewhat later in childhood and the child can manifest enlargement of the head (macrocrania) or a neurocognitive development delay. 

In general, the treatment of this disease depends upon the size of the Vein of Galen malformation and the symptoms experienced by the patient. Endovascular therapy is often a mainstay of treatment.  This usually involves embolization, often with liquid embolic material (glue) or platinum coils to help occlude the abnormal communications between the arteries and the veins. 

Vein of Galen Malformation pretreatment:

Angiogram of a young child who presented with enlarging head size shows a large vein of Galen malformation.

VOG post treatment: 

Angiogram following treatment with embolization shows obliteration of the malformation. 

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