Dave’s: Nuclear Medicine Board Review 5 – Flashcards
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TCM-99 DISIDA
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HEPATOBILIARY
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TCM-99 DMSA
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RENAL CORTICAL SCANNING
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TCM-99 DTPA AEROSOL
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LUNG
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TCM-99 DTPA IV
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BRAIN RENAL (GFR)
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TCM-99 DTPA (ORAL)
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LIQUID GASTRIC EMPTYING
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TCM-99 ECD
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BRAIN SCAN
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TCM-99 HMPAO
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BRAIN
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TCM-99 LABELED RBC
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GI BLEEDING SCAN
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TCM-99 MAA
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LUNG
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TCM-99 MAG3
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RENAL BLOOD FLOW AND FUNCTION
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TCM-99 MDP
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BONE SCAN
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TCM-99 PERTECHNETATE (ORAL)
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THYROID MECKELS TESTICLE
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TCM-99 PERTECHNETATE (URETRHA)
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CYSTOGRAM
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TCM-99 SESTIMIBI
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PARATHYROID MYOCARDIAL PERFUSION
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TCM-99 SULFUR COLLOID (INTRADERMAL)
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LYMPHOSCINTIGRAPHY
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TCM-99 SULFUR COLLOID (IV)
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LIVER/SPLEEN SCAN BONE MARROW SCAN
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TCM-99 SULFUR COLLOID (ORAL)
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ESOPHAGEAL TRANSIT GE REFLUX GASTRIC EMPTYING
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F 18 FDG
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BRAIN CARDIAC TUMOR
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GA 67
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GALLIUM SCAN
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IN 111 DTPA
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CISTERNOGRAM
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IN 111 WBC
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WBC SCAN
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IN 111 PENTREOTIDE
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SOMATOSTATIN SCAN
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Tl 201
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MYOCARDIAL PERFUSION
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XE 133
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LUNG VENTILATION
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Tl 201 keV
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69-81 keV
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Tl 201 half life
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73h
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XE 133 keV
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81 keV
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XE 133 half life
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5.3 days
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Rb 82 keV
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511
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Rb 82 half life
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1.3 minutes
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Pinhole collimator
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Very small opening Poor sensitivity Placed close to region of interest Very good resolution Used w/small body parts: thyroid and pediatric hip
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Is there a low, medium and high energy parallel hole collimator
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yes, these are categorized based on the thickness of the lead.
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Is there a size change when bringing a parallel collimator close to an object
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No, since the holes are paralell there will be no effect
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How does change in distance effect the resolution of a parallel hole collimator
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Increased distance =worse resolution
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Advantage and disadvantage of a diverging collimator
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Advantage: increased imaged area Disadvantage: minified image
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What characteristics are worsened as you move away from a divering collimator
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Resolution Sensitivity
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What is a diverging collimator used to image
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large organs like the lungs
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Does a converging collimator magnify or minify an image
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magnify
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What happens to the senisitivity as an object moves away from a converging and diverging collimator
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Sensitivity increases as the object moves further from a converging collimator Sensitivity decreases as the object moves further from a diverging collimator
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What happens to the resolution as an object moves away from any collimator
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decreased resolution
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Is a converging collimator used for small or large areas
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Small and will magnify. Diverging can be used for large and will minify.
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What happens to the resolution of all collimators as an object is moved away
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decrease
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What does intrinsic resolution refer to
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Intrinsic spatial resolution refers to the limit of spatial resolution achievable by the detector and the electronics NOTE: IGNORE IMAGE. RESOLUTION WILL DECREASE WITH INCREASING CRYSTAL THICKNESS
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What factors will increase the resolution of a camera
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INCREASED CRYST THICK = DECREASED RESOLUTION INCREASED RAY ENERGY = DECREASED RESOLUTION Larger number of PM tubes and improvement of light collection efficiency result in better resolution.
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What is used to determine intrinsic resolution
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bar phantom
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What is non-linearity
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Non-linearity refers to that a straight line object appear as curved line image. This occurs when when the X and Y positional signals do not change linearly with the displacement distance
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What is pincushion distortion
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"Pincushion" distortion is an inward "bowing" image and "Barrel" distortion is an outward "bowing" image
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What is image non-uniformity
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Non-Uniformity refers to the intensity variation from a uniform flood source. The causes could be the non-uniform detection efficiency (small differences in pulse height spectrum) and non-linearity of PM tubes (more server) or instrument malfunctions.
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What are 4 diagnostic reportable events
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1)Incorrect radiopharmaceutical administered 2)Diagnostic dose differing from prescribed dose by > 20% 3)Administration by unprescribed route 4)Whole body dose > 5 rem or single organ dose > 50 rem
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What is the required action if there is a reportable incident
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1)Document details 2)Notify NRC/state in writing of misadministration, giving pertinent details and plans for preventing recurrence
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What is the whole body radiation limit for a year
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5 rem 5000 mrem
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What is the eye lens radiation limit for a year
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15 rem 15000 mrem
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What is the extremity radiation limit for a year
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50 rem 50000 mrem
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What is the maximum dose allowed to the general public (not counting background radiation and studies)
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Whole body: 0.1 rem/y (1 mSv/y) 100 mrem/y
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What is the radiation limit for a place to be an unrestricted radiation area
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< 2 mrem/h 100 mrem/y Note: The categories of radiation areas Radiation area 5 mrem High radiation area 100 mrem Very high radiation area 500 mrem
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What is the radiation limit allowed in a radiation area
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greater than 5 mrem/h at 30 cm
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What dose of radiation is the limit when an area is a high radiation area
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> 100 mrem in 1 h at 30 cm from source
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What is a very high radiation area
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> 500 rad in 1 h at 1 m from source
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If there is a major radiation exposure in the first 10 days of gestation is fetal demise likely
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yes
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First trimester, 20 to 40 days after conception
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Radiation-induced congenital abnormalities
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Result of radiation exposure 50 to 70 days of gestation
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Radiation-induced microcephaly (1%/rem up to 16 w)
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Result of radiation exposure 70 to 150 days of gestation
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Growth and mental retardation
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What is considered the threshold underwich radiation effects are considered negligible
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Risks of congenital abnormalities are negligible below 10 mGy Exposure allowed throughout pregnancy: 5 mSv =0.05 Sv = .5 rem = 500 mrem = 5 mGy Exposure allowed each individual month of pregnancy 0.5 mSv = .005 Sv = 10 mGy = .01 Gy = 1 rad = 1000 mrad 10 mSv = .01 Sv = 1 rem = 1000 mrem
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For doses up to 100 mGy (0.1 Gy) , any radiation risks are deemed to be low when compared with normal risks of pregnancy
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yes Exposure allowed throughout pregnancy = 500 mrem = 5 mGy 10 mGy = .01 Gy = 1 rad = 1000 mrad 10 mSv = .01 Sv = 1 rem = 1000 mrem
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At doses > 0.1 Gy, risk of congenital malformation increases (abortion to avoid possible radiation-induced congenital anomalies considered only for > 0.1 Gy)
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yes
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For dose of 10 mGy in second or third trimester, risk of childhood leukemia may be increased by as much as 40%
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yes
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What are 5 quality control parameters of a gamma camera
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peaking (window setting) uniformity spatial resolution linearity Annual test (misc)
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How often is the camera peaking evaluated
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Peaking (window setting) of camera for a particular isotope is done before every exam
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How often is uniformity inspected
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Uniformity: daily using either solid cobalt-57 source or liquid Tc-99m source With collimator on for extrinsic uniformity, and intrinsic flood with collimator off using planar or point source
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What parameter of the gamma cammera is checked daily
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uniformity
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What is intrinsic uniformity
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uniformity without the collimator on
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What quality controls on the gamma camera are done weekly
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Spatial resolution: weekly with a resolution phantom (quadrant bar phantom) Linearity: weekly with bar phantom
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What test are done annually
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Annual tests: energy resolution, count rate response, sensitivity, collimator integrity, formatter performance, whole body accessory
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What quality control measures are done for a SPECT
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Uniformity and center of rotation checks weekly Gantry and table alignment quarterly
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How often is the gantry and table alignment checked on a SPECT
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Gantry and table alignment quarterly
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What is a dose calibrator
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A dose calibrator is a well-type ionization chamber that is used for assaying gamma ray emitting radioactivity.
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What are dose calibrators used for 3
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these are use for 1) measuring the dosage of radionuclides given to patients 2) measuring Technicium elutes made in a generator 3) measuring dosage of radiation that are shipped from suppliers
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How does the detector part of the dose calibrator work
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The detector element for a dose calibrator is a gas-filled ionization chamber, sealed to avoid variations in response with changes in ambient temperature and atmospheric pressure.
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How is the radioactivity of a radionuclide determined
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by measuring the current produced in an ionizing chamber
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Why is important to know what radionuclide you are testing
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different radionuclides with the same amount of activity will produce different amounts of electrical current in the ionization chamber because they emit different energy gamma rays. This makes it important to know what type of radionuclide you are analyzing.
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What 4 test are performed to ensure a properly working dose calibrator
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Linearity (totally different from linearity of a detector) Constancy Accuracy Geometry
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How is linearity measured
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High activity Tc-99m source (50-300 mCi) measured at T0 and at 48 h (or other predetermined time but must be less than 48h) Then the expected and actual measurements are compared. From this comparison it is determined if the instrument is linear throughout the activity range. : the test passed because the activity decreased with time as expected
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What is the linearity of a dose calibrator
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The linearity (i.e., the relationship between current and radioactivity) and stability of a dose calibrator must be checked periodically. NOTE: not to be confused with detector linearity. : the test passed because the activity decreased with time as expected
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When is linearity of a dose calibrator tested
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Initial installation and then quarterly : the test passed because the activity decreased with time as expected
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Is linearity the same for all dose calibrators
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no, it is different based on geometrical set-up, volume, and type of container and therefore is different for different : the test passed because the activity decreased with time as expected
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What is constancy (in terms of dose colibrators)
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Constancy means reproducibility in measuring the same source, over a period of time, with a decay correction : the test passed because the activity is generally the same from day to day
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What radionuclide is recommended in measuring constancy
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Cs-137 (100 μCi) is strongly recommended because the 30 year half-life will assure use of the same source throughout the life of the calibrator, and is readily available (remember there is a decay correction so even though it has a half life the decay is still accounted for) : the test passed because the activity is generally the same from day to day
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How often is constancy measured (besides at instillation)
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each day prior to using the calibrator. (Cs-137) : the test passed because the activity is generally the same from day to day
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What is the purpose of an dose calibrator accuracy test
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An Accuracy test is designed to show that the calibrator is giving correct readings throughout the entire energy scale that we are likely to encounter ; the expected and measured dose match at different keV
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What radionuclides must be used in order to perform a proper accuracy test
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Low, medium, and high energy standards (usually Co-57, Ba-133 or Cs-137, and Co-60, respectively), are measured in the dose calibrator using appropriate settings. ; the expected and measured dose match at different keV
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Are constancy, linearity, accuracy and geometry all performed at initial instillation
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yes
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Why is a geometry test performed
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The Geometry Test, is designed to show that correct readings can be obtained regardless of the sample size or geometry
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How is a geometry test done
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0.5 ml of Tc-99m in a 10 ml syringe (activity 25 mCi) is measured in the dose calibrator and the value obtained is recorded. The activity is then diluted with sterile water to 1 ml, 2 ml, 3 ml, 4 ml, etc.
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Passing Geometry test
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Not the activity does not change regardless of the sample volume
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What dose calibrator test is only done during instaliation
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geometry
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What dose calibrator test is done at instillation and then daily
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constancy
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What dose calibrator test is done at instillation and then annually
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accuracy
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What dose calibrator test is done at instillation and then quarterly
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linearity
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For all of the test measured what is the margin of error for a test to pass
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Expected and measured values must be +/- 10%
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For all of the test measured what is the margin of error for a test to pass
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Expected and measured values must be +/- 10%
