Term
| The spontaneous and random transformation of an unstable combination of nucelons (Parent) to a more stable combination of nucleons (daughter) |
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Definition
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Term
| How is radiation decay affected by each: temperature, pressure, chemical environment? |
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Definition
| unaffected by all of them |
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Term
| Radiation decay is always accompanied by ____. |
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Definition
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Term
| 3 intrinsic properties that can be used to differentiate various radionuclides |
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Definition
| type of radiation (a, B, or gamma) ... radiation energy ... rate of decay |
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Term
| alpha particles have what kind of charge? |
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Definition
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Term
| alpha particles are composed of __ neutrons and __ protons |
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Definition
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Term
| the number of atoms decaying per unit time |
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Definition
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Term
| the rate of radiation decay depends what two things? |
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Definition
| the number of atoms present and the type of radionuclide |
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Term
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Definition
| professional golfer that took radium drugs and proved that they are dangerous and need to be regulated |
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Term
| purpose of health physicists |
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Definition
| consider health effects of radiation exposure and ways to measure radation levels and limit exposure to personnel |
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Term
| the Radium Girls (radium dial painters) developed what problem? |
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Definition
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Term
| Excitation of radioactive particles |
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Definition
| electrostatic attraction of the particle raises an electron to a higher energy level, the electrons drop back to normal (stable) state and may emit electromagnetic radiation, such as fluorescent light |
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Term
| when ionization takes place, ___ is taken from the radioactive particle as it produces excitation and ionization |
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Definition
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Term
| when ionization takes place, what happens to the velocity of the radioactive particle, and why? |
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Definition
| it is reduced because it loses energy |
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Term
| in ionization of an a-particle takes place, it loses all its energy and forms ___ by combining with ____. |
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Definition
| helium by combining with 2 free electron |
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Term
| when a-particles ionize to helium, what happens to it's radioactivity? |
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Definition
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Term
| Due to electrostatic repulsion, electrons decelerate in the orbital and some of the energy may be converted to _____. |
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Definition
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Term
| Bremsstrahlung increases/decreases with higher atomic number absorbers. |
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Definition
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Term
| because bremsstrahlung increases with higher atomic number, ____ materials are better for pure beta emitters |
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Definition
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Term
| when gamma rays interact with matter, what mechanism is most important for gamma spectroscopy? |
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Definition
| photoelectric absorption - because it's predominate for low energy gamma rays |
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Term
| for GAMMA emitters, the mathematic relationship between the radiation exposure rate and the DISTANCE from the radiation source is governed by what law? |
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Definition
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Term
| how hazardous is exposure to alpha and low-energy beta particles from outside the body? |
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Definition
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Term
| how hazardous is exposure to high energy gamma rays? |
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Definition
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Term
| When are alpha and beta particles most hazardous? |
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Definition
| when they are ingested, inhaled, or contaminating a wound |
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Term
| radiation dose limit for the general public |
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Definition
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Term
| radiation dose limit for workers |
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Definition
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Term
| Acute Radiation Sickness (ARS) occurs when an individual is exposed to a large/small amount of radiation for a long/short period of time, occurs at doses greater than ___ rem (___ rad for gamma rays). |
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Definition
| large amount, short period of time ... 100 rem/100 rad |
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Term
| Acute Radiation sickness differs depending on the patient's ____, ____, ____, ___, and overall health |
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Definition
| age, sex, diet, body temp |
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Term
| CT contrast agents are ___-based |
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Definition
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Term
| why are CT contrast agents iodine-based? |
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Definition
| the are water solube, they absorb xrays to produce a "density map", their elimination is primarily via liver metabolism and intestinal excretion, they have no significant adverse reactions |
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Term
| _____ is a method for obtaining images of inside the human body through the use of high frequency sound waves. how does it work? |
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Definition
| ultrasound - the soundwave's echo are recorded and displayed as real-time images |
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Term
| T/F: no ionizing radiation is involved in ultrasound imaging |
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Definition
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Term
| ____ uses nuclear magnetic resonance technology in which the magnetic nuclei (especially protons) of a patient are aligned in a strong, uniform magnetic field, absorb/emit energy from tuned radiofrequency pulses, and absorb/emit radiofrequency signals as their excitation decays. |
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Definition
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Term
| Which imaging modality provides that BEST resolution for images of the brain |
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Definition
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Term
| what is the purpose of filtered backprojection? |
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Definition
| to make an image more clear |
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Term
| the concept of ____ is based on the application of a mathematical algorithm to remove blurriness from an image. |
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Definition
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Term
| In filtered backprojection, smaller/larger detectors allow you to see smaller objects |
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Definition
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Term
| 3 physical properties of spatial resolution |
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Definition
| geometry, positron range, non-collinearity |
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Term
| Coincidence is a property of what kind of imaging? |
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Definition
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|
Term
| True coincidence is based on what 3 things? |
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Definition
| activity of the source, geometric efficiency of detectors, and intrinsic efficiency of the detectors |
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Term
| Random coincidence is based on what 2 things? |
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Definition
| coincidence time window and single count rate for each detector pair |
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Term
| Scatter coincidence is based on a complicated equation of what 3 factors? |
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Definition
| dependencies, independent factors, and optimization factors |
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Term
| the ___ is based on a ratio of true coincidence to the background (random coincidence and scatter coincidence) |
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Definition
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Term
| purpose of a medical imaging agent |
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Definition
| to be clinically useful and provide accurate and reliable information that adds to the appropriateness of diagnostic or therapeutic patient management |
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Term
| 3 properties of a medical imaging agent |
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Definition
| contributes to a beneficial clinical outcome, provides accurate prognostic info, has no signficant adverse reactions |
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Term
| 3 advantages to using radiolabeled antibodies as radiotracers |
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Definition
| high binding affinity, high antigen population, high tumor uptake with long tumor retention |
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Term
| ___ are the most commonly used radiotracers |
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Definition
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Term
| advantages of using small peptides as radiotracers |
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Definition
| TOLERANCE of harsher chemical conditions for conjugation and radiolabeling, easy to SYNTHESIZE and modify, RAPIDLY CLEARED from the blood, less likely to be IMMUNOGENIC |
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Term
| why are extracellular receptors usually the molecular targets used for the development of target-specific radiotracers? |
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Definition
| they are OVEREXPRESSED IN DISEASED TISSUE while silent in normal tissue, changes in RECEPTOR CONCENTRATION are related to certain diseases, the RECEPTOR LIGAND will have better access without the need to penetrate cell membranes |
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Term
| 4 primary cancers that lead to metastatic bone disease |
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Definition
| breast, prostate, lung, thyroid |
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Term
| why is 153Sm-EDTMP used for bone pain treatment? |
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Definition
| it is able to deliver a large radiation dose over a short period of time, is has a SHORT HALF-LIFE so it can treat metabolically active tumors, its radiation DOSE TO BONE MARROW IS SMALL due to its low beta energy emission and "PATCHY" absorption by the bone marrow |
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Term
| why is 89SrCl2 able to localize in bone metastases? |
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Definition
| it's a calcium analog, it undergoes an ion exchange in bone tissue to Strontium Hydroxyapatite, it remains in metastatic sites for much longer than in normal bone, it can become more deeply embedded in the bone matrix |
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Term
| ____ is often used for bone pain treatment because it can localize in the bone metastases |
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Definition
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Term
| ___ is often used for thyroid cancer |
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Definition
|
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Term
| Goal of I-131 for thyroid cancer treatment |
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Definition
| to ablate the thyroid tissue remnants and improve treatment of the metastatic disease WITHOUT ablating the whole thyroid |
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Term
| 153Sm-EDTMP is used as a radiopharmaceutical for |
|
Definition
| metastatic bone disease pain |
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Term
| ___ can best be described as a philosophy to keep radiation exposures low |
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Definition
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Term
| the body that sets radation regulations is |
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Definition
| US NUclear Regulatory Commission |
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Term
| The probability that effects increase with dose |
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Definition
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|
Term
| the modifying factor that converts equivalent dose to effective dose is called the ___ factor |
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Definition
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Term
| 5 areas that use radioactivity |
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Definition
| nuclear pharmacy (making drugs), nuclear medicine (diagnosis/therapy), nuclear power, and research/idustry, food preservation |
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Term
| together, protons and neutrons are called ____ |
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Definition
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Term
| spontaneous emission of particulate and/or electromagnetic radiation |
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Definition
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Term
| a stream of matter or photons capable of causing electronic excitation |
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Definition
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Term
| alpha, beta, gamma, x-ray radiation -- how do their masses and distance traveled relate? |
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Definition
| alpha is heaviest and travels the shortest distance, gamma & x are lightest and travels the longest distance |
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Term
| what kind of charge do gamma and x-rays carry? |
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Definition
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Term
| energy in the form of particles or waves, given off by unstable (radioactive) atoms or by accelerated charged particles. does this type of radiation lose any particles? |
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Definition
| ionizing radiation. loses a particle |
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|
Term
| radioactive materials emit _____. |
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Definition
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|
Term
| T/F: during excitation, a particle (an electron) is lost from the atom |
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Definition
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|
Term
| negatrons and positrons are __ particles |
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Definition
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Term
| 2 properties of bremsstrahlung |
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Definition
| increases with higher atomic number absorbers, has a spectrum of energies (other rays do not) |
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Term
| 3 interaction mechanisms for gamma spectroscopy |
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Definition
| photoelectric absorption, compton scattering, pair production |
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Term
| coincidences (t, s, and r) are used in what kind of imaging? |
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Definition
|
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Term
| 3 cardinal rules of radiation monitoring |
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Definition
| time, distance, shielding |
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Term
| what unit is used to express the amount of gamma radiation exposure? |
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Definition
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|
Term
| what unit relates the different types of radiation to the energy they impart? it is the basic unit of absorbed dose of radiation |
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Definition
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|
Term
| What unit relates the dose of any radiation to the biological effect of that dose? |
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Definition
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|
Term
| removal of electrons is called ___ |
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Definition
|
|
Term
| 4 stages of acute radiation sickness |
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Definition
| prodromal phase, latent phase, manifest illness, recovery or death |
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|
Term
| what is the standard dose of irradiation used for total body irradiation? |
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Definition
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|
Term
| advantages of ultrasound imaging |
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Definition
| safe :: can differentiate between cysts and solid masses :: can tell how close masses are to vessels :: can detect changes in malignancy :: can measure dimensions and volume :: not very expensive |
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|
Term
| filtered backprojection is used in what imaging? |
|
Definition
|
|
Term
| 2 kind of non-ionizing imaging |
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Definition
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|
Term
| PET and CT can be used for imaging what 5 things (discussed in notes) |
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Definition
| spleen, kidney, and breast cancer, bone metastasis, and visualizing arteries |
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Term
| NEC stands for what? and is used in what kind of scanning? |
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Definition
| Noise equivalent count - has to do with coincidences - PET |
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Term
| the interaction of the proton magnetic moment (larmor frequency) with the lattice structure of the tissue, absorbing and dissipating energy into the environment. causes the magnetic moment to do what? |
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Definition
| spin-lattice interactions ... causes magnetic moment to relax back to equilibrium state |
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Term
| Spin-Lattice and spin-spin interactions have to do with what kind of imaging? |
|
Definition
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|
Term
| Spin-Spin interactions are T1/2 relaxivity, whereas spin-lattice are the opposite. |
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Definition
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|
Term
| ____ interactions cause the magnetic moments from the proon to spin at different frequencies because of small changies in the proton's larmor frequency. |
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Definition
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|
Term
| for imaging, it is best for a radioactive compound to have a low/high half life? |
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Definition
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|
Term
| coincidences - want to increase R,S,T and decrease R,S,t |
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Definition
| increase T, decrease R and S |
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|
Term
| 4 biomolecules that can be used as vectors |
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Definition
| antibodies, antibody fragments, small peptides, non-peptide heterocycles |
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|
Term
| advantages of using radiolabeled antibodies |
|
Definition
| high binding affinity, high antigen population, high tumor uptake, long tumor retention, good for radiotherapy |
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|
Term
| 4 primary sites where metastatic bone disease occurs |
|
Definition
| vertebrae, pelvis, femur, skull |
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Term
| an ideal drug for metastatic bone disease would have what 6 properties? |
|
Definition
| symptomatically treat pain, "cure" for cancer, rapid extraction from circulation, slow turnover from diseased site, rapid excretion, uptake only in diseased site |
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|
Term
| Side effects of Sr-89 for metastatic bone disease |
|
Definition
| myelosuppression, flare and flsuhing reactions |
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|
Term
| benefits of Sr-89 for metastatic bone diseas |
|
Definition
| single dose therapy, outpatient, long shelf life |
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|
Term
| side effects of Sm-153 for metastatic bone disease |
|
Definition
| myelosuppression, flare reaction, hypocalcemia, DIC |
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|
Term
| 3 therapeutic outcomes of thyroid treatment |
|
Definition
| euthyroid (desired), hyperthyroid (dose too small - overactivity of thyroid), hypothyroid (dose too big - underactivity of thyroid) |
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|
Term
| the usual treatment for thyroid cancer is? |
|
Definition
| surgical removal of entire thyroid |
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|
Term
| ___ occurs when an electron absorbs energy and is excited to the next orbital, then decays and loses energy. Are the electrons lost in this process? |
|
Definition
| excitation - electrons are not lost |
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Term
| 2 possible effects of radiation |
|
Definition
| somatic (effects on you) and genetic (effects on your children) |
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|
Term
| an effect in which the probability of occurrence increases with absorbed dose but the severity does not increase with the magnitude of the dose |
|
Definition
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|
Term
| a somatic effect which increases in severity with absorbed dose, owing to increased damage to cells and tissues (may have a threshold) |
|
Definition
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|
Term
| a small fraction (about 1%) of the radiation dose required to produce erythema |
|
Definition
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|
Term
| individual organs can be assigned weighting factors and converted to whole body ____ of radiation |
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Definition
|
|
Term
| stochastic/non-stochastic effects are usually due to low or chronic doses, and effects may take years to appear. there is also no observable threshold |
|
Definition
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|
Term
| ALARA is not a limit but a _____ to limit exposures |
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Definition
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|
Term
| what must be posted outside an area or room where licensed radioactive materials are stored? |
|
Definition
| "Caution Radioactive Materials" |
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|
Term
| fetuses are only at any risk from radiation if the dose is greater that ___mGy and during weeks __-__ of pregnancy |
|
Definition
|
|
Term
|
Definition
| conduct radiologic procedures only when necessary, conduct only the number of procedures needed to get the required information, and use good radiographic techniques |
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