Hawaii Administrative Rules › Title 11 - DEPARTMENT OF HEALTH › Subtitle 1 - GENERAL DEPARTMENTAL PROVISIONS › Chapter 45 - RADIATION CONTROL › Subchapter 6 - X-RAYS IN THE HEALING ARTS › Section 11-45-121 - Computed tomography x-ray systems

Current through June, 2024
(a) General
				  requirements:
(1) Means shall be provided to
				  terminate the x-ray exposure automatically by either de-energizing the x-ray
				  source or shuttering the x-ray beam in the event of equipment failure affecting
				  data collection. Such termination shall occur within an interval that limits
				  the total scan time to no more than one hundred ten percent of its preset value
				  through the use of either a backup timer or devices which monitor equipment
				  function.
(2) A visible signal
				  shall indicate when the x-ray exposure has been terminated through the means
				  required by paragraph (1).
(3) The
				  operator shall be able to terminate the x-ray exposure at any time during a
				  scan, or series of scans under computed tomography x-ray system control, of
				  greater than one-half second duration.
(4) For any single tomogram system, means
				  shall be provided to permit visual determination of the tomographic plane or a
				  reference plane offset from the tomographic plane.
(5) For any multiple tomogram system, means
				  shall be provided to permit visual determination of the location of a reference
				  plane. This reference plane can be offset from the location of the tomographic
				  planes.
(6) If a device using a
				  light source is used to satisfy paragraphs (4) and (5), the light source shall
				  provide illumination levels sufficient to permit visual determination of the
				  location of the tomographic plane or reference plane under ambient light
				  conditions of up to five hundred lux.
(7) The computed tomography x-ray control and
				  gantry shall provide visual indication whenever x-rays are produced and, if
				  applicable, whether the shutter is open or closed.
(8) Each emergency button or switch shall be
				  clearly labeled as to its function.
(9) The computed tomography x-ray system
				  shall be designed such that the computed tomography conditions of operation to
				  be used during a scan or a scan sequence shall be indicated before the
				  initiation of a scan or a scan sequence. On equipment having all or some of
				  these conditions of operation at fixed values, this requirement may be met by
				  permanent markings. Indication of computed tomography conditions of operation
				  shall be visible from any position from which scan initiation is
				  possible.
(10) When data are not
				  being collected for image production, the radiation adjacent to the tube port
				  shall not exceed that permitted by section 11-45-117(c).
(11) The angular position where the maximum
				  surface computed tomography dose index occurs shall be identified to allow for
				  reproducible positioning of a computed tomography dosimetry phantom.
(12) Additional requirements applicable to
				  computed tomography x-ray systems containing a gantry manufactured after
				  September 3, 1985:
(A) The total error in the
				  indicated location of the tomographic plane or reference plane shall not exceed
				  five millimeters.
(B) If the x-ray
				  production period is less than one-half second, the indication of x-ray
				  production shall be actuated for at least one-half second. Indicators at or
				  near the gantry shall be discernible from any point external to the patient
				  opening where insertion of any part of the human body into the primary beam is
				  possible.
(C) The deviation of
				  indicated scan increment versus actual increment shall not exceed plus or minus
				  one millimeter with any mass from zero to one hundred kilograms resting on the
				  support device. The patient support device shall be incremented from a typical
				  starting position to the maximum incremented distance or thirty centimeters,
				  whichever is less, and then returned to the starting position. Measurement of
				  actual versus indicated scan increment may be taken anywhere along this
				  travel.
(D) Premature termination
				  of the x-ray exposure by the operator shall necessitate resetting of the
				  computerized tomography conditions of operation before the initiation of
				  another scan.