RENAL Scan
What is a Renal scan?
An exam used to evaluate the blood flow through the kidneys and to measure the amount of time it takes for the kidneys to remove the radioactive drug, collect urine, and drain it into the bladder. Kidney failure, kidney obstruction, follow up of kidney transplants, and diagnosing renovascular hypertensive disease (blocked kidney arteries) are examples of diseases a renal scan is used to evaluate. Numerous drugs are bound and or cleared by the kidneys. A number of technetium-99m labeled radiopharmaceuticals are also handled by the kidneys in ways useful for imaging, as their mode of excretion isolates certain elements of renal function. Tc-99m DMSA may be used to visualize and quantitate tubular function. Tc-99m Mag3 is used to quantify tubular secretion and glomerular filtration. There are different types of Renal scans:
Baseline Renal Scan (assess the blood flow and function of the kidneys),
Lasix Renal Scan (for obstruction), and
Captopril Renal Scan (for renal artery blockage).
What should I expect during the test?
Plan to arrive in Out Patient Registration 15 minutes before your scheduled exam time. A Nuclear Medicine technologist will start an IV (a needle in your vein in which fluids are given) and then inject a radioisotope-tagged medication into the IV that will follow the same path that blood flow and urine formation does in your kidneys. This IV stays in for the duration of the exam. You will lie on a padded imaging table. A specialized camera that is sensitive to the radioisotope will be placed under your lower back and multiple pictures will be taken continuously. You must remain still for the duration of the exam.
How long does the test take?
The study can take 45 minutes to 2 hours, depending on the type of kidney evaluation your physician has ordered. Sometimes additional medication may be needed to aid in the diagnosis of a kidney disorder. Captopril Renal scans take 2 hours; Lasix Renal scans and Baseline Renal scans take 45 minutes.
Is there any preparation for the Renal scan?
YES! You need to be well hydrated before any type of Renal Scan. Drink 8-16 ounces of fluid about an hour before the exam time. If you are having your renal arteries evaluated for blockage by the Captopril Renal scan, your must be off any ACE inhibitor (Capoten, captopril, Lotensin, beneazepril, Vasotec, enalapril, Prinivil, Vasotec, Altace, Zestril, Mavik, Aceon) or ARB medication (Atacand, Teveten, Avalide, Avapro, Cozaar, Hyzaar, Benicar, Micardis, Diovan) for 5 days prior to the exam. Do not stop taking these medicines on your own! Call your doctor in case an alternative medicine needs to be prescribed while you are off one of the medicines listed above. If you have questions, please contact the Nuclear Medicine Technologist at ext. 3305.
How safe is the Renal Scan?
Patients can resume their normal daily activities immediately after the test. Most radioactive tracers are excreted through the urinary system, so drinking fluids after a kidney scan can help flush the tracer out of the body more quickly. Any diagnostic procedure may have some risks, and you should consult your physician regarding the risks and benefits of this procedure. Allergic reactions are rare. The test and material are used routinely worldwide under physician supervision.
When will I get my results?
The Nuclear Medicine Physician will dictate a report on the results of your test. The report will be sent to your referring doctor. You should make an appointment with your referring doctor who will discuss with you the results of your Renal Scan.
Bone Scan
What is the purpose of the Bone Scan?
The most common reasons for performing a Bone Scan are to detect areas of abnormal bone growth or breakdown. It can be done to evaluate damage to the bones, find cancer that has spread (metastasized) to the bones, and monitor conditions that can affect the bones, including infection and trauma. The scan can help diagnose the cause or location of unexplained bone pain. A bone scan can often find an abnormality days to months earlier than a regular X-ray test. The radiopharmaceutical most commonly used is 99mTc-Medronate (MDP). MDP is injected into a vein, usually in the arm, where it is transported by the bloodstream to the bones.
What happens when I arrive in the Nuclear Medicine Department?
On the day of the exam, you will check in 15 minutes before your scheduled appointment time in Out Patient Registration. An injection of a small amount of radiopharmaceutical called 99mTc-Medronate (MDP) will be injected into one of your veins in your arm. There are no side effects to this medicine. You will also be asked several important questions about your health.
What happens after my injection?
Pictures of the blood supply going to your bones may be taken immediately after the injection for 10 minutes, depending on the disease your doctor is trying to assess. After the injection, there is a wait time of 3-4 hours. This delay is necessary to allow the material to accumulate into your bones. You will be told at what time to return for further pictures. When you return, you will lie on your back on a table and a large scanning camera will be positioned closely above you. It may move slowly above and around your body, scanning for radiation released by the tracer and producing pictures as the tracer moves into your bones. The camera does not produce any radiation, so you are not exposed to any additional radiation while the scan is being done. You may be asked to move into different positions so the area of interest can be viewed from other angles. You need to lie very still during each scan to avoid blurring the pictures. The length of time spent in the department when you return is approximately 30 minutes.
What do I have to do to prepare for the test?
There is no preparation prior to having a Bone Scan. You may continue to eat and drink normally prior to, and after, the scan. If you are on any medications, you may continue to take them. Drinking plenty of fluids before and after the injection of the MDP often helps to give better pictures of your bones. It is also recommended that you void frequently following injection.
How safe is the Bone Scan?
Any diagnostic procedure may have some risks, and you should consult your physician regarding the risks and benefits of the procedure. 99mTc-Medronate (MDP) causes minimal side effects. The test and material are used routinely worldwide under physician supervision.
What happens when I return to the Nuclear Medicine Department for the second part?
When you come back, empty your bladder before just before your scan time. The Technologist will position you on a bed under a machine called a Gamma camera. The scan time will vary depending on what your doctor is looking for. Typically, the scan images all the bones – head to toe, front and back.
Solid Phase Gastric Empty Scan
What is the purpose of a Gastric Empty Scan?
The test measures the speed with which food empties from the stomach and enters the small intestine. Gastric emptying studies are used for testing patients who are having symptoms that may be due to slow and, less commonly, rapid emptying (“dumping” syndrome) of the stomach. The symptoms of slow emptying are primarily nausea, vomiting, and abdominal fullness after eating (satiety). The symptoms of rapid emptying are diarrhea, weakness, or light-headedness after eating. A gastric emptying study is a procedure that is done using a small amount of a radioactive protein cooked in one egg.
What should I expect during the test?
Plan to arrive in Out Patient Registration 15 minutes before your scheduled exam time. You will be asked to eat one scrambled egg. The cooking process fuses the radioactive protein to the protein in the egg. This makes the test a solid phase study. The radioactive protein is odorless, colorless, and tasteless. Liquids can passively clear the stomach by gravity alone. This test evaluates stomach motility. Normal function of the stomach's muscles is necessary in order to propel food from the stomach and into the small intestine. If the muscles or the nerves that control the muscles are not working normally, food remains in the stomach.
How long does the test take?
The study takes about 90 minutes. A camera is placed over the patient's stomach to monitor the amount of radioactivity in the stomach after the test meal is eaten. Pictures are acquired continuously for the entire time. As the radioactively-labeled food empties from the stomach, the amount of radioactivity in the stomach decreases. The rate at which the radioactivity leaves the stomach reflects the rate at which food is emptying from the stomach.
Is there any preparation for the Gastric Empty scan?
YES! Do not eat or drink anything for at least 8 hours before this test. Do not take any narcotic drugs for 24 hours before the test. This includes most pain medications (Morphine, Demerol, Tylenol with Codeine, Vicodin, Lortab, Darvocet). Ibuprofen, regular Tylenol, and Toradol are acceptable. Medications such as metoclopramide (Reglan) and erythromycin can cause rapid emptying of the stomach. Please check with your doctor for instructions regarding these medicines.
How safe is the Gastric Empty Scan?
There are no side effects from a gastric emptying study. The radioactive material is not absorbed into the body and is eliminated in the stool. Any diagnostic procedure may have some risks, and you should consult your physician regarding the risks and benefits of this procedure. Allergic reactions are rare. The test and material are used routinely worldwide under physician supervision.
When will I get my results?
The Nuclear Medicine Physician will dictate a report on the results of your test. The report will be sent to your referring doctor. You should make an appointment with your referring doctor who will discuss with you the results of your Gastric Empty Scan.
HIDA Scan
What is the purpose of a HIDA Scan?
A HIDA scan is used to demonstrate gallbladder function. This may help in the diagnosis of several diseases and conditions, such as bile duct obstruction, bile leakage, congenital abnormalities in the bile ducts, gallbladder inflammation (cholecystitis), and gallstones. The scan helps your doctor track the production and flow of bile from your liver to your small intestine. Bile is a fluid produced by your liver that helps your digestive system break down fats in the foods you eat.
What should I expect during the test?
Plan to arrive in Out Patient Registration 15 minutes before your scheduled exam time. A Nuclear Medicine technologist will start an IV (a needle in your vein in which fluids are given) and then inject a radioisotope-tagged medication into the IV that will follow the same path that your body’s natural bilirubin would follow (bilirubin is a component of bile which is secreted by the liver and stored in the gallbladder). This IV stays in for the duration of the exam. You will lie on a padded imaging table. A specialized camera that is sensitive to the radioisotope will be placed over your abdomen and multiple pictures will be taken. You must remain still for the duration of the exam. Images are taken continuously.
How long does the test take?
The study can take at 60 minutes to 2 hours. The time is highly variable because the gallbladder and the ducts may not show up immediately. Sometimes additional medication may be needed to help obtain the necessary images. If you are severely jaundiced (yellowing of the skin), delayed images may be necessary. It is also important to evaluate how well the gallbladder contracts under normal stimulation. This is performed after the gallbladder and small bowel are visualized. A small amount of a hormone (cholecystekinen) is injected into the IV line to make the gallbladder contract. Pictures will be taken continuously for 30 minutes. As the gallbladder contracts, you may experience some nausea and abdominal pain which are normal side effects and usually on last for 2 minutes.
Is there any preparation for the HIDA scan?
YES! Do not eat or drink anything for at least 4 hours before this test. Do not take any narcotic drugs for 8 hours before the test. This includes most pain medications (Morphine, Demerol, Tylenol with Codeine, Vicodin, Lortab, Darvocet). Ibuprofen, regular Tylenol, and Toradol are acceptable. Be sure to have someone available to drive you home after the exam, as certain medicines may be used during the HIDA scan that may impair your ability to operate a motor vehicle.
How safe is the HIDA Scan?
Any diagnostic procedure may have some risks, and you should consult your physician regarding the risks and benefits of this procedure. Allergic reactions are rare. The test and material are used routinely worldwide under physician supervision.
When will I get my results?
The Nuclear Medicine Physician will dictate a report on the results of your test. The report will be sent to your referring doctor. You should make an appointment with your referring doctor who will discuss with you the results of your HIDA Scan.
LUNG Scan
What is the purpose of a LUNG Scan?
A lung perfusion scan is a nuclear medicine test that produces a picture of blood flow to the lungs. A lung ventilation scan measures the ability of the lungs to take in air and uses radiopharmaceuticals to produce a picture of how air is distributed in the lungs. Lung perfusion scans and lung ventilation scans are usually performed in the same session. They are done to detect pulmonary embolisms, determine how much blood is flowing to lungs, determine which areas of the lungs are capable of ventilation, and assess how well the lungs are functioning after surgery. These tests are called by different names, including perfusion lung scan, ventilation lung scan, xenon lung scan, ventilation/perfusion scanning (VPS), or, most commonly, V/Q scan. Calculation of the percent of blood flow to a given area of the lung may help your doctor predict lung function after lung surgery to remove a piece of lung or a whole lung.
What should I expect during the test?
Plan to arrive in Out Patient Registration 15 minutes before your scheduled exam time. In a lung ventilation scan, a mask is placed over the nose and mouth, and the patient is asked to inhale and exhale a combination of air and radioactive gas. Pictures are then taken that show the distribution of the gas in the lungs. If the airflow to the lungs is normal, radioactive gas will be evenly distributed throughout the lungs. Areas where no radioactive gas is seen may signal a mechanical obstruction to airflow. Areas that retain the radioactive gas for a prolonged period usually indicate areas of trapped gas, such as occurs in obstructive lung disease.
In a lung perfusion scan, a small amount of protein microspheres are labeled with a radioisotope and injected into the patient's arm vein. The patient is positioned under a special camera that can detect the radioactive microspheres, and a series of photographs are made of the chest. When these images are projected onto a screen, they show how the radioactive protein has been distributed by the blood vessels running through the lungs. If the blood flow through the lungs is normal, the radioactive material will be evenly distributed throughout the lungs. Areas where no radionuclide is seen may signal the presence of an abnormality, such as an obstruction to blood flow or a blood clot.
How long does the test take?
Each test takes 10-15 minutes.
Is there any preparation for the Lung scan?
There is little preparation needed for these tests. A regular chest X-ray is usually performed within 12 hours before this test or immediately afterward to identify any abnormalities that would alter the scan. The patient may eat and drink normally before the procedure. No special aftercare is needed. The patient may resume normal activities immediately.
How safe is the Lung Scan?
Any diagnostic procedure may have some risks, and you should consult your physician regarding the risks and benefits of this procedure. Allergic reactions are rare. The test and material are used routinely worldwide under physician supervision.
When will I get my results?
The Nuclear Medicine Physician will dictate a report on the results of your test. The report will be sent to your referring doctor. You should make an appointment with your referring doctor who will discuss with you the results of your Lung Scan.
Thyroid Uptake and Scan
What is the purpose of the Thyroid Uptake and Scan?
The Thyroid Scan serves two purposes. It will check the size of your gland, and it will check to see how well your gland is working. The Thyroid Scan must be performed over a period of two days in order to make these two measurements.
What happens when I arrive in the Nuclear Medicine Department?
Plan to arrive in Out Patient Registration 15 minutes before your scheduled exam time. You will be asked several questions with regards to the history of your health.
NOTE: This is important to know, as some procedures and medications will interfere with the results of the Thyroid Scan. On the first day, you will be given a capsule with a small amount of a radioactive iodine that will be taken up by your thyroid gland. You will be asked to come back approximately 24 hours later.
What happens on the second day?
On the second day, the Technologist will bring you into a room where a unit will be placed over your neck, and a measurement will be made of the amount of radioactive iodine that has been taken up by your thyroid gland. This procedure is called a Thyroid Uptake and will take aboutten minutes.
Am I finished after the Thyroid Uptake?
NO. After the Uptake Study, you will then be given an injection in your arm of another radioactive material which will again be taken up by your thyroid gland. After a period of 5-10 minutes, you will then be taken into a room and asked to lie down on a bed. A machine called a Gamma camera will be positioned over your neck which will take several pictures of your thyroid gland. This will take 20 minutes. When these pictures are finished, the Nuclear Medicine Physician may want to examine your neck.
Is there any preparation for the Thyroid Uptake?
YES! If your have had a CT scan with contrast in the past 6 weeks or are taking thyroid replacement hormones (Synthroid, Levothyroxine, Armour) or anti-thyroid medications (PTU, Tapazole), you must notify the technologist BEFORE the day of your exam.
IT IS IMPORTANT THAT YOU CHECK WITH THE DEPARTMENT FOR THE RECOMMENDED PREPARATIONS BEFORE THE TEST IF YOU ARE UNSURE.
How safe is the Thyroid Scan?
Any diagnostic procedure may have some risks, and you should consult your physician regarding the risks and benefits of this procedure. Technetium and the small amount of iodine ingested cause minimal side effects, and allergic reactions are extremely rare. The test and material are used routinely worldwide under physician supervision.
When will I get my results?
The Nuclear Medicine Physician will dictate a report on the results of your test. The report will be sent to your referring doctor. You should make an appointment with your referring doctor who will discuss with you the results of your Thyroid Scan.
Nuclear Stress Test
There are three types of Cardiolite stress tests:
1. Exercise Cardiolite stress test
2. Persantine Cardiolite stress test
3. Dobutamine Cardiolite stress test
What is Cardiolite?
Cardiolite is a radioactive medicine termed Technetium Tc99m Sestamibi. There are several commercially available radioactive medicines that can be used with equal results, but this is the agent of primary choice at this facility. Cardiolite (the brand name) is injected through an IV and it travels in the bloodstream and through the coronary arteries until it is picked up by living heart muscle cells. The areas of the heart that have an adequate blood supply pick up the tracer right away and more completely. Areas that do not have adequate blood supply or areas permanently damaged from previous heart attack pick up the tracer very slowly or not at all.
Cardiolite gives off a small amount of radiation that is detected with a nuclear scanning camera. A computer processes the information and produces the images of the radioactivity distributed in the heart. If an area receives less blood than the rest of the heart (because of a blocked or narrowed artery), it will pick up a lower level of radioactivity and will show up as a lighter area, called a "defect."
Cardiolite is injected while you are at rest and while your heart is under stress. By comparing rest and stress images side by side, the doctor can tell if there is significant, fixed coronary artery disease impeding blood flow through the heart muscle or if you have permanent heart muscle damage. The amount of radiation you will be exposed to is comparable to that from an X-ray or CAT (CT) scan.
Generally, Cardiolite is cleared from your body in 24 hours by natural processes. You won't feel any different after you are injected with Cardiolite. Most patients experience no side effects. Occasionally patients have a metallic taste in their mouth.
What is a Cardiolite Stress Test and what does it show?
A Cardiolite Stress Test is a diagnostic nuclear imaging study that uses a radioactive tracer, called Cardiolite, injected into a vein to produce images of the heart muscle. When combined with stress either through exercise or use of a pharmacological agent, the Cardiolite scan helps determine if there is adequate blood flow into the heart muscle.
As Coronary Artery Disease (CAD) progresses, the heart muscle may not receive enough blood when under stress. This can result in chest pain, shortness of breath, palpitations, etc. On the other hand, there may be no outward physical signs of the disease. If CAD is limiting blood flow to part of your heart, the stress test with Cardiolite may be useful in detecting the presence and significance of CAD by examination of the images obtained.
A Cardiolite Stress Test consists of two parts, rest and stress:
- Cardiolite will be administered by injection through your IV while you are at rest, and a special camera will take pictures of your heart.
- Cardiolite will be administered to you one other time by an IV injection during the stress portion of the test, and additional pictures will be taken of your heart.
This allows the doctor to compare the amount of blood flowing through the heart muscle during stress and at rest. Please allow approximately 4 hours for the exam.
How do I prepare for the test?
- Do not eat or drink after midnight the day of the test--this includes caffeined as well as de-caffeinated products! The pictures of your heart are clearer when the stomach is not full. If you are diabetic or need to eat/drink with your medication, get special instructions from your doctor.
- Avoid any strenuous physical activity on the day of the test because you will need to exert yourself maximally if you are doing an exercise test.
- Bring busy material. You will have periods of waiting throughout the test so bring a book, newspaper, knitting, etc. to keep you busy.
- No smoking 4 hours prior to the test. Smoking may interfere with the test results.
- Wear a comfortable two-piece outfit and comfortable shoes. A hospital gown may be provided and men may be asked to take off their shirt. Slacks or shorts are preferred if you are exercising. You should wear footwear appropriate for brisk exercise if you are doing an exercise test (no thong sandals or Crocs).
- Do not wear oils or lotions before your test. Small sticky patches (electrodes) will need to stick to your chest.
- Speak with your physician regarding heart medications you should or should not take on the day of your test. NOTE: Do not discontinue any medication without first talking with your physician.
What happens during the test?
After explaining the procedure, an IV will be started in a vein in your arm. The Nuclear Medicine Tech will put your first injection of Cardiolite through the IV. You will wait in the waiting room for at least 30 minutes to let the Cardiolite circulate to your heart.
Once your waiting period is over, the Nuclear Medicine Tech will put you under the camera for about 15 minutes. You will lay on your back on a table with your left hand behind your head. It is important for you to remain very still while the images are being taken. The camera will move about you but never come in contact with you during the scan. If you have extreme claustrophobia, inform your physician prior to the test day. A medication can be prescribed to help you relax during the imaging process. The majority of people tolerate the imaging procedure without the need for pre-medication. Following the completion of the resting scan, you will be escorted to a stress testing room. When you enter the stress testing room, the Cardiology Tech will have you sign a consent form and will make sure you understand the test. The Cardio Tech will have you lie on a stretcher while you are hooked up to the equipment. The chest will be abraded with alcohol and a cloth to create a good contact for the electrodes. If you have a hairy chest, patches will be shaven. Ten electrode patches are placed on your chest and torso. Wires will be attached to the electrodes in order to monitor your heart rate and EKG. A resting EKG and blood pressure are recorded. Once the Cardiologist arrives in the room, your test will begin. The treadmill is then started at a relatively slow "warm-up" speed. The treadmill speed and its slope, or incline, are increased every three minutes according to a Bruce protocol, the most common stress testing protocol used. It is this protocol that dictates the precise speed and slope. Each three minute interval is known as a Stage (Stage 1, Stage 2, Stage 3, etc. For example, a patient completing Stage 3 has exercised for 9 minutes). The patient's blood pressure is recorded during the second minute of each Stage. However, it may be recorded more frequently at the physician’s discretion.
The EKG is constantly displayed on the monitor. It is also recorded on paper at one minute intervals. The physician pays particular attention to the heart rate, blood pressure, changes in the EKG pattern, irregular heart rhythm, and the patient's appearance and symptoms. The treadmill is stopped when the patient achieves a target heart rate (this is 85% of the maximum heart rate predicted for the patient's age) or reaches his/her physical limitations . The test may also be stopped prior to achieving the target heart rate if the patient develops significant chest discomfort, shortness of breath, dizziness, unsteady gait, etc., or if the EKG shows alarming changes or serious abnormal heart rhythm. It may also be stopped if the blood pressure rises or falls beyond acceptable limits. (
NOTE: When sufficient exercise is not feasible due to musculoskeletal abnormalities, certain medications, or other reasons determined by your doctor, stress to the heart is obtained by pharmacological or chemical stimulation. See below for an explanation of these techniques.) You will have approximately an hour wait after completing the stress test before stress imaging can begin. The procedure is identical to the rest imaging process. Occasionally, patients are asked to lie prone (on the stomach) to gather additional imaging information. Please tell the Nuclear Medicine Technologist if you are unable to lie in this position.
Persantine Cardiolite Stress Test
For patients who are unable to have treadmill stress tesing, the drug Persantine may be given to produce an effect on the heart similar to exercise. Persantine works by increasing the blood vessel circumference of the coronary arteries (arteries that feed the heart) in order to increase blood flow to the heart. Persantine causes a 20% increase in heart rate and a mild but significant decrease in systolic and diastolic blood pressure. Persantine is metabolized in the liver. The amount of Persantine you will be given is based on your body weight. Some patients experience a burning or stinging sensation at their IV site because Persantine is more acidic than your blood. Persantine is contraindicated in patients who have a hypersensitivity to this drug. Persantine can also cause bronchospasm so your doctor may order a different test for you if you have a lung condition that will be worsened by using Persantine. Inform the technologist if you have asthma BEFORE starting the test. If you do develop side effects to Persantine, the Cardiologist will use the antidote Aminophylline to immediately reverse your side effects.
During the test, you will be lying on a stretcher and monitored with frequent blood pressures and EKGs in the same fashion as a walking stress test. The Persantine dosage you will be given is based on your body weight. Persantine is a vasodilator so you may feel warm, flushed, experience chest pressure, headache, dizziness, nausea or shortness of breath. These symptoms are perfectly normal, but make sure to let the Cardiologist know how you feel. The Persantine is infused over 4 minutes. Two to three minutes will lapse. Then you will be given another injection of Cardiolite. After the Cardiolite injection, you may receive the drug Aminophylline if you are experiencing any symptoms from the Persantine.
You will be allowed to resume your normal diet after completion of the stress test and take any medicines that were withheld for the test. You will need to wait at least 45 minutes to let the Cardiolite circulate to your heart before stress imaging can begin.
Dobutamine Cardiolite Stress Test
For patients who are unable to exercise adequately on the treadmill or have lung conditions worsened by Persantine, the drug Dobutamine may be given to produce an effect on the heart similar to exercise. Dobutamine both raises your heart rate and increases the pumping force and oxygen demand of the heart. During the test, you will be lying on a stretcher and monitored with frequent blood pressures and EKGs in the same fashion as a walking stress test. A line of normal saline will be connected to your IV. The drug Dobutamine will be infused through your IV. The Dobutamine dosage you will be given is based on your body weight. Dobutamine is infused slowly through your IV, and the dose is increased every 3 minutes. The Dobutamine continues until 85% of the maximum heart rate based on your age (target heart rate) is achieved. The Dobutamine may be turned off early if:
- You exceed the target heart rate based on your age
- The Cardiologist detects abnormal changes on your EKG You experience significant symptoms, such as shortness of breath, chest pain, chest tightness, dizziness, etc. that do not permit you to continue the Dobutamine infusion
- Your blood pressure goes up too high
If your heart rate has not reached your predicted target heart rate by 12 minutes, the Cardiologist will have a Nurse give you a drug called Atropine through your IV to stimulate the heart to beat faster. You will be given one more injection of Cardiolite once your heart rate is at or has exceeded your "target" heart rate. Sometimes after the test, the Cardiologist will have the Nurse give you a drug, known as a beta blocker, through your IV to slow your heart rate if it is taking a long time to decrease. You will be allowed to resume your normal diet after completion of the stress test and take any medicines that were withheld for the test. You will wait for at least 45 minutes to let the Cardiolite circulate to your heart before stress imaging can begin.