| (82) Scan time--The period of time between the beginning
and end of x-ray transmission data accumulation for a single scan.
(83) Scattered radiation--Radiation that has been deviated
in direction during passage through matter.
(84) Secondary protective barrier (See definition for
protective barrier).
(85) Shutter--A device attached to the tube housing
assembly that can totally intercept the useful beam and that has a
lead equivalency not less than that of the tube housing assembly.
(86) Single tomogram system--CT system that obtains
x-ray transmission data during a scan to produce a single tomogram.
(87) Source--The focal spot of the x-ray tube.
(88) Source-to-image receptor distance--The distance
from the source to the center of the input surface of the image receptor.
(89) Source-to-skin distance (SSD)--The distance from
the source to the skin of the patient.
(90) Special purpose x-ray system--Any x-ray system
that is limited by design to radiographic examinations of specific
anatomical regions. Special purpose x-ray systems include, but are
not limited to, dedicated chest units, cystography units, and head
and skull units.
(91) Special procedures--The application of special
x-ray systems and specialized techniques to obtain required diagnostic
information. Special procedures include, but are not limited to, angiography,
cardiac catheterization, myelography, and surgery.
(92) Spot film--A radiograph that is made during a
fluoroscopic examination to permanently record conditions that exist
during that fluoroscopic procedure.
(93) Spot film device--A device intended to transport
and/or position a radiographic image receptor between the x-ray source
and fluoroscopic image receptor. It includes a device intended to
hold a cassette over the input end of an image intensifier for the
purpose of making a radiograph.
(94) Stationary x-ray system--A stationary x-ray system
that is installed in a fixed location.
(95) Stray radiation--The sum of leakage and scattered
radiation.
(96) Supervision--The delegating, by the practitioner,
of the task of applying radiation to persons who perform tasks under
the practitioner's control and who are certified under the Medical
Radiologic Technologist Act, Texas Occupations Code, Chapter 601.
The practitioner assumes full responsibility for these tasks and shall
assure that the tasks will be administered correctly.
(97) Target--The part of a radiation machine head that
by design intercepts a beam of accelerated particles with subsequent
emission of other radiation.
(98) Technique chart--A chart that provides technical
factors, anatomical examination, patient thickness for examination
being performed, and source-to-image distance needed to make clinical
radiographs when the radiographic system is in manual mode.
(99) Technique factors--The conditions of operation
that are specified as follows:
(A) for capacitor energy storage equipment, peak tube
potential in kV and quantity of charge in mAs.
(B) for field emission equipment rated for pulsed operation,
peak tube potential in kV and number of x-ray pulses;
(C) for CT systems designed for pulsed operations,
peak tube potential in kV, scan time in seconds, and either tube current
in mA, x-ray pulse width in seconds, and the number of x-ray pulses
per scan or the product of tube current, x-ray pulse width, and the
number of x-ray pulses in mAs;
(D) for CT systems not designed for pulsed operation,
peak tube potential in kV, and either tube current in mA and scan
time in seconds or the product of tube current and exposure time in
mAs when the scan time and exposure time are equivalent; and
(E) for all other x-ray systems, peak tube potential
in kV and either tube current in mA and exposure time in seconds or
the product of tube current and exposure time in mAs.
(100) Tomogram--The depiction of the x-ray attenuation
properties of a section through the body.
(101) Tomographic plane--The geometric plane that is
identified as corresponding to the output.
(102) Tomographic section--The volume of an object
whose x-ray attenuation properties are imaged in a tomogram.
(103) Traceable to a national standard--This indicates
that a quantity or a measurement has been compared to a national standard,
for example, the National Institute of Standards and Technology, directly
or indirectly through one or more intermediate steps and that all
comparisons have been documented.
(104) Tube--An x-ray tube, unless otherwise specified.
(105) Tube housing assembly--The tube housing with
tube installed. It includes high-voltage and/or filament transformers
and other appropriate elements when such are contained within the
tube housing.
(106) Useful beam--Radiation that passes through the
window, aperture, cone, or other collimating device of the source
housing. Also referred to as the primary beam.
(107) X-ray control panel--A device that controls input
power to the x-ray high-voltage generator and/or the x-ray tube. It
includes equipment such as timers, phototimers, automatic brightness
stabilizers, and similar devices that control the technique factors
of an x-ray exposure.
(108) X-ray field--That area of the intersection of
the useful beam and any one of the set of planes parallel to and including
the plane of the image receptor, whose perimeter is the locus of points
at which the exposure rate (air kerma rate) is 1/4th of the maximum
in the intersection.
(109) X-ray high-voltage generator--A device that transforms
electrical energy from the potential supplied by the x-ray control
to the tube operating potential. The device may also include means
for transforming alternating current to direct current, filament transformers
for the x-ray tubes, high-voltage switches, electrical protective
devices, and other appropriate elements.
(110) X-ray system--An assemblage of components for
the controlled production of x-rays and include a radiation machine.
It includes minimally an x-ray high-voltage generator, an x-ray control,
a tube housing assembly, a beam-limiting device, and the necessary
supporting structures. Additional components that function with the
system are considered integral parts of the system.
(111) X-ray tube--Any electron tube that is designed
to be used primarily for the production of x rays.
(f) Morgues, forensic medicine, and educational facilities.
(1) Morgues shall comply with the following requirements:
(A) subsection (b)(1) and (2) of this section concerning
scope;
(B) subsection (c) of this section concerning prohibitions;
(C) subsection (e) of this section concerning definitions,
as applicable;
(D) subsection (i)(2) of this section concerning operating
and safety procedures;
(E) subsection (i)(4) of this section concerning protective
devices;
(F) subsection (i)(11) of this section concerning holding
of tube;
(G) subsection (k)(1) of this section concerning warning
labels;
(H) subsection (m)(1)(A) of this section concerning
fluoroscopy; and
(I) subsection (s)(1)(A) - (I), and (R) of this section
concerning records.
(2) Facilities conducting training using non-humans
shall comply with all the requirements of this section except for
the following:
(A) subsection (i)(5) of this section concerning operator
credentialing;
(B) subsection (j) of this section concerning radiographic
entrance exposure (air kerma) limits;
(C) subsections (p), (q) and (r) of this section concerning
film processing; and
(D) subsection (o) of this section concerning equipment
performance evaluation.
(g) Requirements for bone densitometers. Bone densitometers
shall be exempt from this chapter except for the following:
(1) §289.203 of this title, §289.204 of this
title, §289.205 of this title, §289.226 of this title, and §289.231
of this title;
(2) healing arts screening and medical research in
accordance with §289.226(h) and (t) of this title;
(3) purpose and scope in accordance with subsections
(a) and (b) of this section;
(4) prohibitions in accordance with subsection (c)(1)
and (2) of this section;
(5) definitions in accordance with subsection (e) of
this section, as applicable;
(6) operating and safety procedures in accordance with
subsection (i)(2) of this section;
Cont'd... |
