CT Scan
MRI
PET Scan
Pulmonary Function Test
Cardio-Pulmonary Exercise Test
Cardiac Stress Test
CT Scan
A CT (computed tomography) scan uses special equipment to obtain images of multiple cross-sections of the body. CT images are more detailed than a conventional chest x-ray. It can show different types of tissue, including lungs, bones, soft tissue, muscle, and blood vessels. Modern CT scans use a method called spiral (helical) CT that takes pictures from different angles and, through the aid of a computer, produces cross-sectional images.
All the CT scanners at Stony Brook are helical and multi-detector scanners. These technologies allow us to take images incredibly fast, so your study will be finished quicker. Additionally, these technologies allow us to see extremely fine detail, far better than older CT scanners.
Sometimes a CT scan is ordered with contrast. Contrast material is injected into a vein to help blood vessels stand out more on images. Contrast helps the doctors interpreting the images to distinguish blood vessels from surrounding soft tissue. This is particularly helpful when looking in the middle of the chest.
If you are asked to have a CT scan with contrast, you will be asked if you have any allergies to iodine, and you may need to have blood drawn to check your kidney function.
When contrast material is injected, people may experience a flush of heat or a metallic taste in the mouth; this lasts for only a few minutes. If you experience itching, hives, swelling of the throat, or shortness of breath, let the technician know immediately, as this could be an allergic reaction to the contrast. The technician has medication to deal with this.
Please dress comfortably. Avoid clothes with metal, and take off jewelry, which can show up on the images. You will be asked to lie flat on your back, and periodically hold your breath. The CT scanner is a large machine with a padded table that slides through a large doughnut-shaped hole.
A CT scan is not invasive and involves relatively low radiation. It can give the doctors more information than a routine x-ray, and is often useful in guidance during biopsy procedures.
MRI
Magnetic resonance imaging, known as MRI, uses strong magnets to generate images of the body. This technology is currently the best way for radiologists to diagnose tumors of the brain.
MRI uses a very strong magnetic field; thus, any metal object will be pulled into the magnet. The technician who performs the MRI will ask if you have any metal implanted in your body, such as a heart pacemaker, implanted port/infusion catheter, prosthetic joints, metal plates, pins, or surgical staples.
You will also be asked if you have a bullet or shrapnel in your body or have ever worked with metal. If there is any question of metal fragments, you may be asked to have an x-ray to detect their possible presence. You will be asked to remove hairpins, jewelry, eyeglasses, hearing aids, and removable dental work.
The conventional MRI unit is a closed cylindrical magnet in which the patient needs to lie completely still for several minutes at a time. The patient is placed on a sliding table and a radio antenna device, called a surface coil, is positioned around the upper part of the head. The technician will leave the room, but is able to communicate with you by using an intercom system.
In general, the test can take 15-45 minutes, depending on how detailed the requested study must be. Some people may feel confined or claustrophobic. If this is a concern for you, please ask your primary care doctor to give you a sedative. Most bothersome to many people is the loud tapping or knocking noises heard at certain times during the test.
The technician will offer you ear plugs to help.
Sometimes an injection of contrast material through an IV line (intra-venous; into a vein) is needed. MRI contrast material is less likely to produce an allergic reaction than the iodine-based material used during CT (computed tomography) scans, and the potential for kidney damage is not a concern. Some people may experience a cool sensation at the injection site.
PET Scan
1. You have been scheduled for a PET scan. The weight limit for the machine is 375lbs.
2. If you have problems keeping this appointment, please call (631) 638-2121 to cancel or reschedule the appointment.
3. Please have your doctor's office fax your prescription immediately to us at (631) 638-2323. If you have a copy of your prescription please bring it with you. Note that your insurance company may require preauthorization for this test. Check with your doctor's office to make sure they have obtained you authorization.
4. You need to fast for 6 hours prior to the study. The test is very sensitive. If you eat candy, gum, nutrasweet, sugar, ice cream or any other food, you may need to repeat the test. You may only drink plain water during the 6 hours of fasting prior to the test.
5. Your last meal should be at least 6 hours prior to the exam. If possible, eat a high protein meal, such as chicken, meat, fish, bacon, eggs, ham. You should avoid carbohydrates, such as bread, rice, pasta, potatoes, chips or any sweet foods. If you are a vegetarian you may eat vegetables up to 6 hours before your exam.
6. It is recommended that you drink at least ½ quart of plain water prior to the study. You should begin drinking water at least an hour before your exam. You may drink water at any time prior to this. (Please do not drink flavored water.) If you have kidney or heart problems, do not drink water if your doctor has advised you not to drink additional fluids.
7. Please take all regularly prescribed medications. There are no restrictions on medications, as they will not interfere with the test. There is a special preparation for diabetic patients. If you are taking insulin or oral diabetic medication, please consult the information sheet for Diabetic Patients (click here to view).
8. We start the test by placing an IV in your arm. The medication is injected through the IV. After the injection, you must wait 60 minutes to allow the medicine to circulate prior to the imaging. You may be asked to drink oral contrast. The total procedure time is approximately 3 hours.
9. If you are anxious, tense, or claustrophobic, please ask your doctor to prescribe a sedative for you to take prior to coming for you PET scan. Only your regular physician is allowed to give you this type of medication. If you will take a sedative, you must arrange to have a responsible adult drive you home form the exam.
10. Please bring copies of your latest CT and MRI films, as well as the reports.
11. Exam location: Imaging Center in the Ambulatory Care Pavilion on Edmund D. Pellegrino Road. Click here for Directions.
12. After the procedure, please stay away (at least 3 feet) from any children or pregnant women for 6 hours.
For patients with diabetes, click here.
Pulmonary function test
The pulmonary function test (PFT) compares the function of your lungs to predictions based on your height, age, and weight. Abnormal test results can be caused by lung diseases, such as emphysema, scarring, and asthma, and also by abnormalities in your rib cage, abdominal diseases, and heart failure.
The test measures the amount and speed of air moved in and out of your lungs. Nose clips are used to prevent air from escaping through your nose. You will need to be able to follow directions during the test. Please inform the technician if you expect problems related to hearing loss or need for an interpreter.
Please wear comfortable clothes that do not restrict your breathing. You will be asked to perform these breathing techniques several times. Sometimes a drug (broncho-dilator) is used that widens the air passages of the lungs and eases breathing; and you then repeat the test. The value of this test depends on your effort, so please try your best.
The results are given in both raw data and as a percent of "predicted values" based on height, weight, and age. Your doctor may ask for blood to be drawn at the time of your test, to determine how much oxygen and carbon dioxide is in your blood.
All this information is used to determine what type of treatment you are a candidate for. If surgery is being discussed, a PFT will tell the surgeon how much lung can be removed or whether surgery is a good option at all. PFT's are often done for patients periodically during treatments to give the doctor an indication of how they are tolerating the treatment.
Cardio-Pulmonary Exercise Test
Breathing problems may begin in the lungs, heart, or the system that circulates your blood. Sometimes your doctors will ask you to have a cardio-pulmonary stress test if they are unsure of why you are short of breath or they are concerned about the results of your pulmonary function test.
During the test you will be asked to walk on a treadmill or ride a stationary bicycle. Small pads (electrodes) will be placed on your body to monitor your heart. You will also wear nose clips and breathe through a mouthpiece.
Before you start to exercise, your heart rate, breathing, and blood pressure will be monitored. You will exercise as long as you can. Before the test and at the end of the test, a blood sample from an artery may be taken.
The cardio-pulmonary stress test measures your exercise capacity and identifies the cause of shortness of breath. This information may be useful in determining your operative risk and predicting how you will feel after lung resection.
For a list of instructions, please click here.
Cardiac Stress Test
Often a cardiac stress test is indicated prior to any surgically procedure to assess your heart function and determine operative risk. There are numerous ways for this to be performed. If you are able, you may be asked to run on a treadmill to elevate your heart rate. If you are not able to exercise, then a medication can be injected through an IV line (intra-venous; into a vein) to mimic exercise.
For instance, dobutamine (Dobutrex) can be used to elevate your heart rate. This medication is also the preferred drug for patients with chronic obstructive pulmonary disease (COPD), asthma, or an active wheeze. Other options are adenosine (Adenoscan) or dipyridamole (Persantine) which act as vasodilators, that is, they make your blood vessels open wider and thus increase blood flow.
If you take theophylline (Bronkodyl; Elixophyllin; Slo-bid; Slo-Phyllin; Theo-24; Theo-Dur; Theolair; Uniphyl), you cannot take it 24 hours prior to the test. This test is not recommended for patients who actively wheeze.
Exercise treadmills and dobutamine stress tests depend on your heart rate. If you take medication such as a beta blocker, you may be asked to not take it for a few dosages. Often a nuclear stress test is ordered, in which images of your heart are taken at rest and during stress. These images give an indication of whether there are areas of poor blood flow to the heart muscle (perfusion ) and overall heart function.
For a list of instructions, please click here.