What is CT Scanning?
A. A CT scanner is a doughnut-shaped machine that uses advanced X-RAY technology to obtain cross-sectional images of the body. The scanner rotates around the patient. Each revolution generates a number of “slices”. Sophisticated fast computer technology is employed to create high quality 3-dimensional diagnostic images.
A. You may be asked to drink a flavored liquid which highlights the intestine and helps to differentiate it from other internal organs. We also may ask you not to eat solid food or drink fluids less than four hours prior to your exam. Essential medication may be taken with a small amount of water.
Why do I need to take a medicine before my scan?
A. A slow heart rate allows us to get the best possible images. We would like your heart rate to be around 60 beats per minute. Many patients require a single dose of a medication to slightly slow their heart rate. This is administered 1 hour before the scan. It is well tolerated with minimal side effects. We will give you detailed instructions about the medication and ask that you precisely adhere to them. Occasionally a further dose is required. This will be administered through the IV by one of our physicians.
Will I need an injection?
A. Some CT scans are most informative when “dye” is used. Your physician and our radiologists make the decision for its use on a case by case basis to best meet your needs. The “dye” injection is a clear liquid contrast agent containing iodine. It enhances the soft tissues and helps to define abnormalities. It is essential in visualizing the blood supply to internal organs. The contrast is excreted by the kidneys within several hours. We use only non-ionic contrast, a safe agent with very few side effects. If you are being treated for asthma or have a history of a reaction to a previous iodine contrast injection, be sure to inform our scheduler.
How long does the exam take?
A. The MultiSlice helical CT scan is very fast. Once you are on the CT table, the scans are performed during a single breath hold, usually 20 – 30 seconds. The total exam time will be determined by the amount of anatomic coverage your particular exam requires. Typical examinations take between 15 minutes and one hour.
A. A 64 Slice Scanner is the fastest and most advanced CT scanner available today. It has 64 detectors which obtain 128 “slices” per rotation. It is the only CT scanner capable of imaging both soft and hard plaque in the coronary arteries long before the patient becomes symptomatic.
Why is a 64 Slice CT Scan better than traditional methods of diagnosing cardiac disease?
A. Traditional stress tests and echocardiograms identify coronary artery disease once it is already in a more serious advanced phase. Coronary angiography is more invasive than CT Scanning and is not used as a screening method for early diagnosis of coronary disease.
A. Asymptomatic patients with one or more of the following risk factors: Male over 40 years; female over 50 years Family history of coronary artery disease High blood pressure Past or present smoker – lung scan for early abnormalities also suggested Diabetes or pre-diabetes Elevated cholesterol levels or C-reactive protein (hs-CRP) levels Obesity
A. Calcification occurs in atherosclerotic plaques. Modern CT scanners are able to assess the amount of calcified plaque. This gives an estimate of the patient’s total plaque burden (calcified and non-calcified plaque). This can then be used to calculate the individual’s risk of having a significant cardiac event and to direct therapy.
A. A low radiation dose CT of the heart is obtained. No contrast is needed. A sophisticated computer program assesses the amount of calcified plaque in each of the coronary arteries.
What aspects of the cardiovascular system can be imaged by the 64 slice scanner?
A. The 64 Slice CT Scanner can image all the coronary arteries. It can also image carotid arteries in patients where there is risk of a stroke. Vessels of the lower extremities and other organs such as the kidneys can be successfully imaged. Extremity veins in patients with suspected deep vein thrombosis can also be imaged. The scanner can also produce high quality images of the heart in patients with suspected congenital heart disease, cardiac mass, or diseases of the pericardium.
Why do I need a Coronary CT Scan if I don’t have any symptoms?
A. Some patients fall into the category of an early form of coronary heart disease, which does not cause any symptoms. If left untreated and unmonitored, these patients are at an increased risk for a heart attack and sudden cardiac death. These patients usually have risk factors such as high cholesterol, high blood pressure, past or present smoking habit, obesity, diabetes, or family history. Many lives will be saved by early diagnosis with subsequent lifestyle modification and medication.
A. CCTA provides detailed images of the coronary arteries and chambers of the heart, revealing specific areas of cardiac disease if they exist.
What Is PET?
A. Positron Emission Tomography (PET) is a major diagnostic imaging modality used predominantly in determining the presence and severity of cancers, neurological conditions, and cardiovascular disease. It is currently the most effective way to check for cancer recurrences and metastatic disease, and it offers significant advantages over other forms of imaging such as CT or MRI scans. You may have recently undergone a CT scan which will be carefully compared with the PET scan to provide an accurate diagnosis.
What is PET/CT?
A. PET/CT is an imaging machine that combines a CT scanner with a PET scanner. Instead of undergoing a CT scan on one day and a PET scan on a different day, you will undergo both scans at the same time.
How does a PET scan work?
A. A tiny amount of radiopharmaceutical similar to glucose called FDG (fluorodeoxyglucose) is injected into your bloodstream and the radioactive glucose is taken up by all living tissue. This radioactivity is emitted from your body and is measured by the very sensitive detectors in the PET scanner. A computer reassembles this information into images that will be interpreted by the radiologist physician. Since cancerous cells can have a higher metabolic rate than normal tissue, signals coming from cancerous tissue can show up as hot spots on the images.
Why is my doctor ordering a PET/CT test?
A. Most of the time, a PET or PET/CT scan is ordered to evaluate a patient with cancer or suspected cancer. On occasion, these exams are ordered to evaluate non-cancerous conditions such as memory loss, certain neurological conditions and cardiovascular disease. Cancers for which PET scanning is considered particularly helpful include lung, head and neck, colorectal, esophageal, lymphoma, melanoma, breast, thyroid, cervical, pancreatic, and soft-tissue tumors, as well as other less-frequently occurring cancers. PET can help characterize a tumor as benign or malignant, thereby avoiding surgical biopsy when the PET scan is negative. PET is extremely sensitive in determining the full extent of disease. PET is very helpful in determining the response to chemotherapy and/or radiation therapy, and to help determine when a cancer is in remission.
What is the preparation for the PET/CT exam?
A. You will be asked to fast for about 6 hours and you should avoid strenuous exercise the day before and the day of the examination. If you are a diabetic or take chronic steroids, you will be given special instructions.
Are there any risks to the PET/CT exam?
A. There are virtually no risks to this examination. The amount of radiation that you will receive is equivalent to approximately two CT scans of the chest, abdomen and pelvis. The radiation from the injected FDG wears off very quickly because its half-life is less than two hours.
