Interventional Radiology is an innovative branch of medicine in which physicians treat diseases non-operatively through small catheters guided to target sites by fluoroscopic and other imaging methods. The Radiology and Imaging Services Laboratory at Saint Francis Hospital and Medical Center is accredited by the Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL) to perform angiography for the diagnosis of vascular disease.
"By utilizing noninvasive vascular testing techniques, we can detect early on life-threatening vascular diseases.
It's a vital role, given the statistics of cardiovascular disease, the leading cause of death in the United States,"
-Michael Twohig, M.D., director of Radiology and Imaging Services, Saint Francis Hospital and Medical Center.
What is Angiography?
Angiography is performed using catheters and sophisticated imaging techniques including computed tomography (CT) and magnetic resonance imaging (MRI) to examine the condition and flow of blood through the vessels. CT angiography (CTA), uses contrast material, specialized x-ray equipment and a computer to produce multidimensional views of the vessels. In magnetic resonance angiography (MRA), a powerful magnetic field, radio waves and a computer produce the detailed images. MR angiography does not use x-rays.
Vascular surgeons use these procedures to:
- Identify disease or aneurysms in the aorta, in the chest, abdomen, or other major blood vessels
- Detect atherosclerosis in the carotid artery of the neck
- Detect atherosclerotic disease that has narrowed the arteries to the legs
- Reveal the severity of atherosclerosis in the coronary arteries
Saint Francis has the first-in-the-state Siemens Definition system with Dual Source 128-slice capability. It is the latest breakthrough in computed tomography (CT) technology, employing two x-rays to give physicians precise images of the beating heart in a matter of seconds. The 'dual source consists of two x-ray tubes and two detectors that rotate simultaneously, capturing image data in half the time required by conventional CT technology. The scanner can also produce images with increased resolution over the popular 64-single-source CT systems. The greatest advantage of this new technology is providing critical care in emergency situations. Patients with chest pain, abdominal pain and suspicion of stroke can be diagnosed faster with pinpoint analysis, thanks to the superior imaging and dual energy method of the Definition CT. A patient experiencing chest pains would previously be required to take beta-blockers to slow the heart rate for the 64-slice scanner to capture images, and that takes precious minutes. But with two x-ray tubes, the 128-slice scanner can produce diagnostic images of a patient's coronary arteries without the need for medications to reduce the heart rate. The benefits are even more far-reaching to a patient population once precluded from the 64-slice scanner because of complicated medical conditions. Patients who were overweight could not be imaged well on the prior generation of scanners because of power limitations of single-tube units. The addition of an extra x-ray tube on the Siemens Definition system allows doctors to obtain outstanding images on patients of any size. Acutely ill patients who could not tolerate having their heart rate slowed can also be imaged using the 128-slice scanner, a real advantage in the acute care setting. When time is of the essence, our radiologists can diagnose critical conditions much faster with this latest CT technology.
What to Expect...
The exam begins with an intravenous (IV) line inserted into a small vein in the arm or hand. A small dose of contrast material may be injected through the IV. During scanning, the table will move to the start point and then move through the opening of the machine as the scanning begins. You may be asked to hold your breath during this process. When you enter the CT scanner, special lights may be used to ensure that you are properly positioned. You may hear a slight buzzing and clicking sound as the CT scanner revolves. A patient is alone in the exam room during the CT scan, however, the technologist will be able to see, hear and speak with you at all times. Once the process is completed, the IV line will be removed. Scanning can take from 5 to 20 minutes from the time you enter the room. After a CT exam, you can return to your normal activities. If you received contrast material, you may be given special instructions.
Most CT exams are painless, fast and easy. However, there may be some discomfort from having to remain still for several minutes. A mild sedative may be administered to help tolerate the CT scanning procedure. If an intravenous contrast material is used, a slight pin prick can be felt when the needle is inserted into the vein. A warm, flushed sensation during the injection of the contrast materials and a metallic taste in the mouth can last a few minutes. If light-headedness or difficulty breathing occurs, please notify the technologist or nurse immediately.
PREPARING FOR AN EXAM
Wear comfortable, loose-fitting clothing
Remove jewelry, eyeglasses, dentures, hearing aids before the exam
Do not eat or drink for several hours prior to the exam
Inform your physician about medications or allergies you may have
Disclose any recent illnesses or other medical conditions
Women should inform the physician if they are pregnant or breastfeeding at the time of the exam
In magnetic resonance angiography (MRA), a powerful magnetic field, radio waves and a computer produce the detailed images of blood flowing through the vessels. Signals produced by the magnets and the waves are transmitted to a computer, which processes the signals and generates a series of images, each of which shows a thin slice of the body. When a contrast material is introduced to the bloodstream during the procedure, it clearly defines the blood vessels by making them appear bright white. The traditional MRA unit is a large cylinder-shaped tube surrounded by a circular magnet. You will lie on a moveable examination table that slides into the center of the magnetized tube. Some MRA units are designed so that the magnet does not completely surround you; others are open on all sides (open MRI). These units are especially helpful for examining patients who are fearful of being in a closed space and for those who are very obese. Newer open MRI units provide very high-quality images for many types of exams.
What to expect...
An MRI is usually done on an outpatient basis.
Grips may be used to help a patient remain still and maintain the correct position during imaging.
Small devices that contain coils capable of sending and receiving radio waves may be placed around or adjacent to the area of the body being studied.
If a contrast material is used during the MRI exam, a nurse or technologist will insert an intravenous (IV) line into a vein in the hand or arm. Saline solution will drip through the IV to prevent blockage of the IV line until the contrast material is injected.
The patient will be moved into the magnet of the MRI unit and the radiologist and technologist will leave the room while the MRI examination is performed.
If a contrast material is used during the examination, it will be injected into the intravenous line (IV) after an initial series of scans. Additional series of images will be taken following the injection.
MRI exams generally include multiple runs (sequences), some of which may last several minutes. The entire examination is usually completed within 30 to 60 minutes.
Most MRI exams are painless. Some patients, however, find it uncomfortable to remain still during MR imaging. Others experience a sense of being closed-in (claustrophobia). Therefore, sedation can be arranged for those patients who experience anxiety.
It is normal for the area of the body being imaged to feel slightly warm. It is important that the patient remain perfectly still while the images are being recorded, which is typically only a few seconds to a few minutes at a time. For some types of exams, patients may be required to hold their breath. Similar to a CT scan, a patient will be alone in the exam room during the MR imaging, however, the technologist will be able to see, hear and speak with you at all times. Earplugs to reduce the noise of the MRI scanner are sometimes provided.
When the contrast material is injected, it is normal to feel coolness and a flushing for a minute or two. The intravenous needle may cause some discomfort when it is inserted and when it is removed. There is also a very small chance of irritation to the skin at the site of the IV tube insertion.
If a patient is not sedated, no recovery period is necessary and normal activities may be resumed immediately. A few patients experience side effects from the contrast material, including nausea and local pain.
It is recommended that nursing mothers not breastfeed for 36 to 48 hours after an MRI with a contrast material.