Oregon Administrative Rules › Chapter 333 - OREGON HEALTH AUTHORITY, PUBLIC HEALTH DIVISION › Division 106 - X-RAYS IN THE HEALING ARTS › Section 333-106-0350 - Definitions

Current through Register Vol. 63, No. 7, July 1, 2024
In addition to the definitions provided in division 100 and 106
				of these rules, the following definitions shall be applicable to OAR
				333-106-0350  through
				333-106-0369.
(1) "Annual" means a period of 12
			 consecutive months, not to exceed a period of 14 months.
(2) "Computed tomography (CT)" means the
			 production of a tomogram by the acquisition and computer processing of X-ray
			 transmission data. Computed tomography includes the capability of producing
			 axial tomograms.
(3) "Computed
			 Tomography Dose Index" means the integral from -7T to +7T of the dose profile
			 along a line perpendicular to the tomographic plane divided by the product of
			 the nominal tomographic section thickness and the number of tomograms produced
			 in a single scan. This definition assumes that the dose profile is centered
			 around z = 0 and that, for a multiple tomogram system, the scan increment
			 between adjacent scans is nT.
(4)
			 "Contrast scale" or "CS" means the change in the linear attenuation coefficient
			 per CTN relative to water.
(5) "CT
			 conditions of operation" means all selectable parameters governing the
			 operation of a CT X-ray system including, but not limited to, nominal
			 tomographic section thickness, filtration, and the technique factors as defined
			 in OAR
			 333-106-0005.
(6) "CT gantry" means the tube
			 housing assemblies, beam-limiting devices, detectors, and the supporting
			 structures and frames which hold these components.
(7) "CT number" means the number used to
			 represent the X-ray attenuation associated with each elemental area of the CT
			 image.
(8) "CT scanner" means a CT
			 machine capable of performing CT scans of the head, other body parts, or full
			 body patient procedures including PET/CT and SPECT/CT hybrid scanners if used
			 for diagnostic CT procedures.
(9)
			 "CTDIvol" (see computed tomography dose index).
(10) CTN (see CT number).
(11) "Dose-length product (DLP)" is the
			 CTDIvol multiplied by the scan length (image thickness multiplied by the number
			 of adjacent, non-overlapped images in the acquisition in centimeters.
(12) "Dose profile" means the dose
			 as a function of position along a line.
(13) "Elemental area" means the smallest area
			 within a tomogram for which the X-ray attenuation properties of a body are
			 depicted (see also picture element.)
(14) "Multiple tomogram system" means a
			 computed tomography X-ray system which obtains X-ray transmission data
			 simultaneously during a single scan to produce more than one tomogram.
(15) "Noise" means the standard
			 deviation of the fluctuations in CTN expressed as a percentage of the
			 attenuation coefficient of water.
(16) "Nominal tomographic section thickness"
			 means the full width at half-maximum of the sensitivity profile taken at the
			 center of the cross-sectional volume over which X-ray transmission data are
			 collected.
(17) "Picture element"
			 means an elemental area of a tomogram.
(18) "Positron emission tomography (PET)"
			 means an imaging technique that uses positron-emitting radionuclides to produce
			 3-dimensional images of functional processes in the body.
(19) "Qualified CT medical physicist" means
			 an individual qualified in accordance with OAR
			 333-106-0367.
(20) "Reference plane" means a
			 plane which is displaced from and parallel to the tomographic plane.
(21) "Scan" means the complete process of
			 collecting X-ray transmission data for the production of a tomogram. Data can
			 be collected simultaneously during a single scan for the production of one or
			 more tomograms.
(22) "Scan
			 increment" means the amount of relative displacement of the patient with
			 respect to the CT X-ray system between successive scans measured along the
			 direction of such displacement.
(23) "Scan sequence" means a preselected set
			 of two or more scans performed consecutively under preselected CT conditions of
			 operation.
(24) "Scan time" means
			 the period of time between the beginning and end of X-ray transmission data
			 accumulation for a single scan.
(25) "Single photon emission computed
			 tomography (SPECT)" means an imaging technique that uses radionuclides to
			 produce 3-dimensional images of functional processes in the body.
(26) "Single Tomogram System" means a CT
			 X-ray system which obtains X-ray transmission data during a scan to produce a
			 single tomogram.
(27) "Tomogram"
			 means the depiction of the attenuation properties of a section through a body.
(28) "Tomographic plane" means
			 that geometric plane which is identified as corresponding to the output
			 tomogram.
(29) "Tomographic
			 section" means the volume of an object whose X-ray attenuation properties are
			 imaged in a tomogram.
(30)
			 "Traceable to a national standard" means an instrument is calibrated at either
			 the National Institute of Standards and Technology (NIST) or at a calibration
			 laboratory that participates in a proficiency program with the NIST at least
			 once every two years and the results of the proficiency test conducted within
			 24 months of calibration show agreement within plus or minus three percent of
			 the national standard in the appropriate energy range.
Stat. Auth.: ORS 453.605 - 453.807
Stats. Implemented: ORS 453.605 -
				  453.807