INTRODUCTION

Nuclear medicine is that branch of medicine which uses radioactive materials (radioisotopes and radiopharmaceuticals) to diagnose and treat diseases. Images obtained with a gamma camera represent the quantitative distribution of a radiopharmaceutical in the body. These examinations are particularly suited to examine the functions of the major organ systems in the body, as well as detect sites of inflammation/infection and tumor growth. Nuclear medicine procedures are also valuable aids to high resolution radiological techniques (i.e., CT and MRI) as they provide unique physiologic information about the patient while using small amounts of radioactivity with yield low total body radiation burdens.

The most common type of radioactive material used in nuclear medicine are gamma ray (g) emitters such as technetium-99m, indium-111, thallium-201, gallium-67, iodine-123, etc. These radionuclides can be easily detected, quantified, and localized within the body with modern instrumentation. Scintillation gamma camera systems have attached dedicated computers which convert collected radioactive counts to functional images that allow visualization of functioning organs that are not routinely seen on X ray exams. Radionuclides (radiopharmaceuticals) can be administered orally, intravenously, or through intracavitary routes and they usually deliver lower doses of ionizing radiation than alternative radiographic techniques.

Both diagnostic examinations and radiotherapeutic treatments may be performed using radioactive materials. Many radionuclides emit negatively charged beta particles (electrons) with and without g rays (i.e., I-131, Sr-89, Re-186, P-32) and are used in nuclear medicine as therapeutic agents. Beta emitters when localized to a particular site such as the thyroid or a malignant tumor, can deposit energy and kill the offending tissue. Site specific therapy with beta emitters is presently an area of great interest in nuclear medicine.

The purpose of this booklet is to provide a guide of how nuclear medicine procedures can be cost effectively used by the clinician. The most commonly available tests are described along with their rationale and other considerations to assist you in properly requesting Nuclear Medicine services at the University of Illinois Hospital.

There are a variety of ways in which each procedure can be performed depending on the clinical indication and equipment available. For this reason the referring physician should communicate the clinical details of each patient to the nuclear medicine physician. If this is not possible, a good description of the clinical history and test indication on the nuclear medicine order form is essential. Having a clear picture of the patient and the clinical question(s) being asked, the nuclear medicine physician can insure that the procedure is appropriately performed. In all cases, the patient should be informed about the nature of the study and the reason(s) for requesting the exam. Requests for exams on pregnant patients can be performed in many cases as fetal exposure from diagnostic doses is extremely low.

GENERAL CONSIDERATIONS:

1. Studies included in The Guide are listed alphabetically in the table of contents. Once you find the study you want, please indicate on the Nuclear Medicine Order Form the clinical question you want answered. Often additional views can be taken, or occasionally, an alternative radiopharmaceutical can be used which will better provide the information you seek. The staff of the Nuclear Medicine section welcomes and encourages consultations and is anxious to help you choose the most appropriate study.

We can be reached at extensions 6-3965 or pager (312) 812-0241.

2. Routine studies are performed 8:00 -5:30 P.M. Monday through Friday. Attending staff and/or a resident are continuously available during this time.

3. Acquiring results. Telephone access to dictated reports is available 24 hours a day. Telephone access enables the physician to acquire the results of scans promptly without the need to call the Section of Nuclear Medicine.

1. Dial (312) 413-8788 outside the hospital, or Ext. 3-8788 inside the hospital.
2. When prompted for "ID Number", enter the first three letters of your last name on the telephone keypad. (note: Q=7 and Z=9), then press(#).
3. When prompted for "Subject" enter the patient's 8 digit Medical Record Number.
4. You will hear the most recent radiology/nuclear medicine report for the patient. NOTE: Previous reports for the same patient will automatically play out following current report, or you may press [8]any time during the dictation to skip to the previous report for the same patient.
5. To select another patient, press[*] then enter another patient's 8-digit Medical Record Number.

6. To advance to the to the impression of the report, press [4][9].

7. To end your listening session, hang up.

For additional information, call Ext. 6-0231 and ask for information about the dictation system. Convenient instruction cards are available in the section of nuclear medicine.

4. In general, studies are performed within 24 hours of being requested. Preliminary readings are available shortly after scanning is completed and a final report is dictated the same day in most cases.

5. Keep in mind that not all radiopharmaceuticals are available in the laboratory. One example is Indium-111 which takes 24 hours to obtain from the supplier (although shorter times are occasionally possible).

6. Pregnancy and nursing are relative contraindications to the administration of any radioactive substance. Some will only delay nursing (eg. Technetium) while others preclude nursing because of their prolonged retention in the body (Gallium, I-123 and I-131).

7. In this guide you'll find references to critical organ. This is the organ which is expected to receive the highest significant dose from administration of a radiopharmaceutical.

8. Unless otherwise stated, doses quoted are for adults. Pediatric doses are calculated based on the child's weight or body surface area.

9. For the pediatric patient, the child's weight should be included with each requisition. If sedation will be needed, please arrange this prior to scanning.

EMERGENCY SCANS:

Nuclear Medicine services are available 24 hours a day, 7 days a week. A resident physician is always on call to assist you with emergency scans. An Attending Physician is also available. In the appropriate clinical setting the following studies are available:

1. Hepatobiliary - to rule R/O acute cholecystitis.
2. Pulmonary V/Q scan - to R/O embolus.
3. Testicular Scan - R/O torsion.
4. GI Bleeding Study.
5. Renal in transplant patients - R/O acute rejection.
6. Cerebral radionuclide angiogram to confirm brain death.

ORDERING AN EMERGENCY SCAN:

1. Page the radiology resident on call - 6-0275. The resident will notify the technologist on call if a scan is to be done.
2. Have the appropriate information available; patient name, room number, clinical information, reason for study, physician responsible for obtaining results, etc.
3. A physician, nurse, or attendant must be available to accompany the patient for after hours scanning, and may be required to remain with the patient. Discuss this with the radiology resident.
4. All patients for a V/Q study must have a recent (<24 hours) chest film which must be available to the Nuclear Medicine physician for interpretation of the scan.
5. Specific requirements for each study are listed under "Patient Preparation" in the text.

LEGAL DISCLAIMER

This text has been paraphrased from many sources. It is intended to be a study and review guide, not a comprehensive text.

The instructions, indications, dosage schedules, and adverse reactions listed in this text were as accurate as possible at the time of publication. It is possible that typographical errors exist, or that currently accepted medical practice may change. The reader is urged to review the package information data of the manufacturers of the radiopharmaceuticals and medications mentioned.

Neither the authors, their respective institutions, nor any other individual or institution except the person using this text is responsible or liable for any consequences of its use.

The authors actively encourage your comments. We will annotate the text with hypertext links to any valid, well-documented corrections or addenda, and give full credit to those who submit them.