Nuclear medicine imaging
T or F •Unlike radiology, NM equipment does produce radiation.
false •Unlike radiology, NM equipment does not produce radiation.
•Octreotide radio labelled with Lutetium-177 (177Lu-DOTATATE) is used to treat ________ tumors.
neuroendocrine •Usually, the amount of emitted radiation is low. However, it may be detectable for few weeks.
•Radiopharmaceuticals are also used for therapy, to treat what?
overactive thyroids and some cancers
The_______travels through the area being examined Physiologic/metabolic processes in the body concentrate the tracers in specific tissues and organs The ______ give off radiation in the form of gamma rays which are detected by a special gamma camera and a computer to noninvasively image these processes or kill cells in regions where radionuclides have concentrated.
radiotracer radionuclides
what is the other names for HIDA scan?
cholescintigraphy and hepatobiliary scintigraphy
what are the radioisotopes typically used in nuclear studies to label tracers?
iodine-123, technetium-99m, xenon-133, thallium-201, and fluorine-18.
which can show abnormal cell activity first PET or CT scan ?
•Even when an abnormal growth is not yet visible on a CT scan, the PET scan can show the abnormal cell activity.
external contamination can be controlled by 1. 2. 3.
•External contamination can be controlled by consideration of time, distance, and shielding
reactive materials can come in all different forms 1 2 3 what are gases used for?
1.solids 2.liquids 3.gases gases are used for ventilation studies
Isotopes can be produced within the department via the ______ generator
99Mo/99Tc
how does PET image demonstrate levels of cell activity?
A PET image is color coded — different colors show various levels of cell activity.
PET Scan Imaging of Brain why is FDG used in PET scan of the Brain?
FDG is used in PET scan of the brain, because the brain uses glucose for its metabolism The image illustrates normal adult pattern of cerebral glucose metabolism measured with 18F-FDG
what are gamma rays a form of?
Gamma rays are a form of light that moves at a different wavelength than visible light.
when are gamma rays created?
Gamma rays are created during the emission of positrons by the radioactive tracer that has been injected into the patient
what does glucose utilization depend on ?
Glucose utilization depends on the intensity of cellular and tissue activity, so it is greatly increased in rapidly dividing cancer cells. In fact, the degree of aggressiveness for most cancers is roughly paralleled by their rate of glucose utilization.
what does NIBIB stand for ?
National Institute of Biomedical Imaging and Bioengineering
does nuclear medicine detect anatomical or functional properties of human tissues?
Nuclear imaging detects functional (vs. anatomical) properties of human tissues
what is nuclear medicine ?
Nuclear medicine is a medical specialty that utilizes radioactive substance and a special gamma camera to create 3-D pictures of organs at different angles
what is PET scan the best/most sensitive for?
PET scans are more sensitive than other tests in evaluating cancer patients for many types of cancer in regards to staging cancer, in detection of recurrent cancer, and response to treatment- a tumor cells are dying and thus using less sugar
what do PET scans with Tag radioactive glucose metabolism used to evaluate?
PET scans which tag radioactive glucose metabolism is used to evaluate the spread and activity of cancer.
how is technetium produced ?
Technetium is produced by bombarding molybdenum-98 with neutrons.
what is a widely used radioactive tracer isotope in nuclear medicine?
Technetium-99m
what is the actual does determined by?
The actual dosage is determined by the patient's body weight, the reason for the study and the body part being imaged. •The targeted nature of radiopharmaceuticals allows them to be delivered mostly to the organ of interest while maintaining a low whole body radiation exposure.
what does the color/ brightness of the image represent ?
The amount of the radionuclide collected in the tissue affects how brightly the tissue appears on the image (or what color), and indicates the level of organ or tissue function
how does the imaging process begin?
The imaging process begins by tracing the distribution of the pharmaceutical within the body with a gamma camera The PET scanner or the gamma camera is mounted on a rotating gantry that allows it to move in a tight circle around the patient who is lying motionless on a pallet
what is the major purpose of nuclear medicine scans?
The major purpose of nuclear medicine scans is to detect cancer and monitor its progression, response to treatment, and to detect recurrence and metastases
do all radiopharmaceutical concentrate the same?
The nuclear medicine physician will select the tracer that will provide the most specific and reliable information for a patient's particular problem. Certain radiopharmaceuticals concentrate selectively in body parts such as brain, bone, liver, or thyroid gland
what is a hot spot in nuclear medicine?
•Hot spot refers to any area in any organ where the concentrations of radioactivity are significantly greater than the surrounding tissues (eg. Hot nodules in the thyroid)
For example, a _____scan can show how blood flows to the heart or what areas of the brain are more active or less active
SPECT
which two are the most common imaging modalities in nuclear medicine that uses small amounts of radioactive material to diagnose diseases and determine its severity
SPECT scan PET scan
how do SPECT and PET scan differ?
SPECT scan differs from a PET scan in that the tracer stays in the blood stream rather than being absorbed by surrounding tissues, thereby limiting the images to areas where blood flows
what does SPECT scan images show? what information is provided?
SPECT scan produces images that show how organs work SPECT can give information about blood flow to tissues
are SPECT tracers have a long or short half life?
SPECT tracers have a relatively long half-life (technetium-99m has a half-life of six hours), whereas rubidium-82 is only 75 seconds. This short half-life is a limitation of the current front-line
how does scintigraphy get its name ?
Scintigraphy scans get their name from the ability of some crystals (such as sodium iodide) to scintillate (in other words, emit sparks) when exposed to radiation
what is sheilding ?
Shielding: Use syringe shields for the preparation and administration of radiopharmaceuticals. Leaded shields can help to reduce dose rates.
what does SPECT scan stand for?
Single Photon Emission Computed Tomography
what is FDG fluorodeoxyglucose
Slightly modified radiolabeled glucose molecules, a radioactive atom is applied to glucose (blood sugar) to create a radionuclide called fluorodeoxyglucose (FDG) have been shown to be the best available tracer for detecting cancer and its metastatic spread in the body.
_________scanning is also useful for pre-surgical evaluation of medically uncontrolled seizures. The test can be performed between seizures or during a seizure to determine blood flow to areas where the seizures originate
Spect scanning
IMAGE comparing 2 patients
Whole-body PET scans from two patients. The left scan is normal the right scan is from a patient with a lung tumor that spread from primary breast cancer. This scan shows increased fluorodeoxyglucose (FDG) uptake in the tumor (arrow) because a growing tumor has a higher rate of sugar metabolism than the surrounding normal tissue.
what is the big difference between PET and SPECT scan?
A big difference between the two technologies is the half-life of the isotope that each radiopharmaceutical tracer uses.
how does the computer analyze gamma rays?
A computer analyzes the gamma rays and uses the information to create an image with anatomic representation of the organ of interest aiding in evaluation of function
at what stages can scintigraphy identify diseases?
Because it is able to pinpoint molecular activity within the body, scintigraphy offers the potential to identify disease in its earliest stages
what kind imaging is nuclear medicine ?
Nuclear medicine is considered physiological imaging
what diseases can Nuclear medicine studies help determine which parts of the brain are being affected?
Nuclear medicine study can be helpful in determining which parts of the brain are being affected by Alzheimer's disease, and other types of dementia, Parkinson's disease, Huntington's disease, cerebrovascular accident (stroke)
who prepares the radiopharmaceutical?
Once a Pt has been referred to have a nuclear study, either a technologist within the nuclear department or the nuclear pharmacy prepares the specific radiopharmaceutical (the radioactive tracer)
what does PET scan stand for?
Positron Emission Tomography
what is a positron?
Positron is a subatomic particle with the same mass as an electron and a numerically equal but positive charge
what are the common organ systems that are routinely studied in the nuclear medicine department ?
Prominent organ systems that are currently studied routinely in the nuclear medicine department are: thyroid, brain, lungs, spleen, kidney, bone, and heart
how is the radioactive tracer administered into the body?
Pt is positioned on the imaging table, and the technologist injects the radioactive tracer into the patient's bloodstream in small amounts Sometimes the radioactive tracer is inhaled or swallowed, or directly injected in the organ depending on the study The radioactive tracer travels through the body
what is radioactive material also known as?
The radioactive material is also known as radiopharmaceutical since they must meet FDA's exacting standards for safety and appropriate performance for the approved clinical use.
how are radionuclides incorporated in the body?
These radionuclides are incorporated into radiopharmaceuticals and introduced into the body by injection, swallowing, or inhalation.
T or F Isotope has the same number of neutrons than the standard of that element; number of protons stays the same
a different Isotope has a different number of neutrons than the standard of that element; number of protons stays the same
•When a CT scan is laid over a PET scan, this is called PET/CT scan, doctors can pinpoint the exact location of ____ ____ ____
abnormal cell activity •They can also see the level and extent of that activity.
why do radiopharmacuticals become non-radioactive?
because of the short physical half-lives which means they decay quickly into non-radioactive forms
PET scan creates an image of the body's___________ activity.
biochemical
____PET scan creates an image of the body's biochemical activity.
biochemical
what is Skeletal Scintigraphy
bone scan
•Radioactive materials used to treat painful metastases to the______
bones
•The total radiation dose that the patient is exposed to by the majority of radiopharmaceuticals used in diagnostic nuclear medicine studies is no more than what is conferred during routine ____ ____ or ___ ___
chest Xrays or CT exams
what is the gamma camera also called ?
gamma camera is also called the scintillation camera
Each radiotracer is attracted to specific organs, bones, or tissues and gives off energy in the form of______ ______
gamma rays
PET shows the rate of metabolism at which the body's cells break down and use what?
glucose
•Radioactive iodine (I-131) therapy used to treat some causes of ____(Grave's disease and some types of thyroid cancer)
hyperthyroidism
________ is the radioactive form of an element
isotope
is nuclear medicine just used to diagnose?
its used to diagnoses and treat diseases
define physiological imaging?
physiological imaging indicates that the clinical studies are designed to tell whether a specific organ (e.g. heart, lungs, liver) is functioning properly
how are positrons admitted?
positrons are emitted by the breakdown of the radionuclide in the organ or tissue being examined
Some tracers employ molecules that interact with a specific ____ or ____in the body and can even employ the patient's own cells.
protein or sugar
Gamma camera is a large specially designed camera that is sensitive to _______and can detect gamma-ray
radiation
what is the radioactive substance referred to as?
radionuclides
•The radiation exposure from a nuclear scan comes from the ________used
radionuclides
what is the other name for nuclear medicine imaging?
scintigraphy
with NM what is the radiation source?
the patient
is radiation exposure higher in diagnostic or therapeutic uses? and why?
therapeutic is higher •This is because diagnostic imaging uses a low-energy isotope to see the target organ on the scan, while the therapy requires a higher energy isotope to target and kill the diseased cell.
Both SPECT and PET scan use radiopharmaceuticals to create __________images of the distribution of radioactive tracer molecules that have been introduced into the patient's body
three-dimensional
radioactive iodine is used to treat what type of cancer?
thyroid cancer
the______ that is used determines whether the patient receives a SPECT or PET scan
tracer
T or F Radioactive iodine is used both to obtain images of the thyroid and to treat thyroid cancer
true
T or F The radiotracers used in PET scans can be attached to a chemical substance or a carrier molecule that is used naturally by a particular organ or tissue during its metabolic processThese carrier molecules vary greatly depending on the purpose of the scan.
true
T or F nuclear medicine is used for diagnostic and therapeutic uses
true
T or F •A general simplified method is proposed to assess the skin dose after a contamination with 99mTc-labelled radiopharmaceuticals or 18F-fluorodeoxyglucose.
true
T or F •Like radiologists, nuclear medicine physicians are strongly committed to keeping radiation exposure to patients as low as possible, giving the least amount of radiotracer needed to provide a diagnostically useful examination •Nuclear medicine specialists use the ALARA principle (As Low As Reasonably Achievable) to carefully select the amount of radiopharmaceutical that will provide an accurate test with the least amount of radiation exposure to the patient.
true
T or F •The activities in radioiodine therapy are so large that the external exposure from the patient becomes significant
true
T or F •There are legitimate concerns about possible cancer induction even by low levels of radiation exposure from cumulative medical imaging examinations, but this risk is accepted to be quite small in contrast to the expected benefit derived from a medically needed diagnostic imaging study.
true
special techniques required for radiopharmaceutical preparation, most PET centers have been located near the production sites of radiopharmaceuticals T or F
true
what is I-131 MIBG (radioactive iodine labeled with metaiodobenzylguanidine) used for?
used to treat adrenal gland tumors in adults and adrenal gland/nerve tissue tumors in children
does the body react because the material is radioactive? give an example
when injected into the bloodstream, the body responds to the chemical composition of the pharmaceutical, not the fact that it is radioactive for ex., a pharmaceutical that behaves chemically like calcium is incorporated into bone.if the compound is radioactive and emits radiation, a "bone image" can be obtained with appropriate radiation detectors
Can nuclear medicine study used to locate the specific surgical site prior to surgical procedures of the brain?
yes
is HIDA scan a nuclear medicine study?
yes
can large doses of skin contamination e seen on nuclear technologists? how do you decontaminate?
yes •The use of a neutral hand soap should generally be preferred during decontamination.
what can CT demonstrate about organs?
•A CT scan shows the exact locations of the body's organs and also can show abnormal growths.
what happens after a radioactive patient leaves the hospital?
•After the patient leaves, the room must be thoroughly cleaned and monitored. •The room must be confirmed as being safe for use by the Radiation Protection Officer before being used again. •Clothes and materials handled by the patient must be handled separately and decontaminated •waste must be disposed of in a strictly controlled environment
what is bone scan used for?
•Areas of bone healing or cancer progression usually light up on SPECT scans, so this type of test is being used more frequently to help diagnose hidden bone fractures. SPECT scans can also diagnose and track bone metastasis •Also, it can detect stress fractures
what can cardiac nuclear medicine detect for?
•Because the radioactive tracer highlights areas of blood flow, SPECT can check for: •coronary arteries disease, cardiac infarction •Reduced cardiac pumping efficiency and cardiomyopathy •SPECT can show how completely the heart chambers empty during contractions.
what two types of scans are used to stage cancer these days? and why?
•By the combined matching of a CT scan with PET images, there is an improved capacity to discriminate normal from abnormal tissues •A combination instrument that produces both PET and CT scans of the same body regions in one examination (PET/CT scanner) has become the primary imaging tool for the staging of most cancers worldwide •because the combined images provide physicians with both functional and anatomical information on the body
what is a cold spot in nuclear medicine refer to?
•Cold spot in nuclear imaging refers to an area in any organ where the concentrations of radioactivity are significantly less than the surrounding tissue(eg. Thyroid cancer)
•in addition to using time, distance, and shielding to reduce radiation exposure, personnel must always be aware of potential contamination name some areas that may get contaminated?
•Contamination means spread of radioactive material to countertops, floors, personnel, imaging tables •Nuclear medicine technologists are exposed daily to the risk of skin contamination with radiopharmaceuticals
how can staff receive external exposure?
•External exposure to staff can occur from any exposure to a significant quantity of unshielded radioactive material. •When working with vials, syringes or transport boxes containing radioactive material. •During contact with a patient after radiopharmaceutical administration, e.g. after radioiodine therapy
•There are radiotracers to detect intestinal bleeding. how is it done ?
•For example, in cases where doctors need to know the exact source of intestinal bleeding, they may radiolabel (add radioactive atoms) a sample of red blood cells that is taken from the patient. •They then reinject the blood and use a SPECT scan to follow the path of the blood in the patient. •Any accumulation of radioactivity in the intestines informs doctors of where the bleeding occurs. •If blood flow and perfusion of an organ or tissue is of interest, the radionuclide may be a type of radioactive oxygen, carbon, nitrogen, or gallium
what is HIDA scan used to image?
•It uses radionuclides to image the biliary system to look for bile duct obstruction, bile leakage, congenital abnormalities in the bile ducts, cholecystitis, and gallstones •imaging is performed by injecting the Pt with an appropriate radiopharmaceutical
what are the two kinds of exposure?
•One can receive a radiation dose by exposure to nuclear medicine sources from outside the body (external exposure) or if the radioactive material enters the body (internal exposure).
what should patients do if they have to travel following a nuclear med provedure?
•Patients who plan to travel following a nuclear medicine procedure should carry a letter of explanation from their doctor that includes the patient's name, contact information for the testing facility, the name of the nuclear medicine procedure, the date of the treatment or test, the radionuclide that was used, its half-life, its administered activity and 24-hour contact information.
what are used to treat certain forms of lymphoma ?
•Radioactive antibodies are used to treat certain forms of lymphoma
how can radioactive material enter the body?
•Radioactive material can enter the body by inhalation, ingestion and by absorption through intact or damaged areas of the skin. •The presence of radioactive contamination presents an internal exposure risk to staff for each of these exposure route •There may be contamination: Where splashes or spills have occurred, on laboratory surfaces, trough the sweat, saliva and excreta of patients
what is used to treat some blood disorders?
•Radioactive phosphorus (P-32) used to treat certain blood disorders
what does it mean by radioactive tracers have a short half life?
•Radiotracers have very short physical half-lives, which means they decay quickly into non-radioactive forms.
describe how SPECT scan can be used with antibodies?
•SPECT scan can be used with antibodies •In this procedure, antibodies can be linked to a radioactive substance. •If a tumor is present, the antibodies will adhere to it. •Then, a SPECT scan can be done to detect the radioactive substance and reveal where the tumor is located. •High levels of antibody in pelvis and axilla (red) and uptake in skin of the thigh and right shoulder (green) showing areas of cutaneous T-cell lymphoma.
what does the staff do if a hospitalized patient is radioactive?
•Staff must wear protective clothing, limit their time in the room, and whenever possible, keep a shield between them and the patient. •Staff must wear personal dosimeters.
why is PET scan more sensitive to brain injury compared to Ct and MRI?
•Tests have shown that it might be more sensitive to brain injury than either MRI or CT scanning because it can detect reduced blood flow to injured sites.
why is radioactive iodine excellent for thyroid nuclear medicine?
•Thyroid Nuclear Medicine Study •radioactive iodine serves as an excellent method of evaluating the thyroid gland, since iodine is selectively removed from circulation by the thyroid gland
Pet scan is used to evaluate after trauma for what?
•To evaluate the brain after trauma to detect hematoma, bleeding, and/or perfusion (blood and oxygen flow) of the brain tissue
what happens if a radioactive patient is hospitalized?
•Whenever hospitalization is required, the patient must stay in a designated, shielded and isolated room. •Waste from the toilet and sink will be radioactive and must be carefully managed. •The area around the patient's toilet should be covered in absorbent paper to contain any contamination. Staff must have extra training.
what should you do if there is contamination?
•Where there is contamination, you should wear protective clothing, latex gloves and overshoes •Cover cuts and wounds. •Do not eat, drink or apply cosmetics. •Clean up spills, even minor splashes, as soon as practicable. •Do not touch things unnecessarily and wash your hands immediately •Shielding: Use syringe shields for the preparation and administration of radiopharmaceuticals. Leaded shields can help to reduce dose rates. •Use tongs to handle sources
what does a daily check do?
•daily checks are made to minimize the possibility of radioactive contamination •this is not a life-threatening problem, but contamination potentially may lead to misdiagnosis of a Pt
for personel what part of the body receives the most radiation? How can this be minimized?
•for personnel, the greatest radiation dose occurs to the hands as a result of preparing and injecting radiopharmaceuticals •minimize hand exposure, syringes can be inserted into syringe shields made of lead, tungsten or depleted uranium
who usually receieves the highest whole body dose? how had this been reduced?
•highest whole body doses are usually received by technologists who prepare radiopharmaceuticals •with the advent of pharmacies in almost every major city, this exposure has been greatly reduced
