Administrative Rules of Montana › Department 37 - PUBLIC HEALTH AND HUMAN SERVICES › Chapter 37.14 - RADIATION CONTROL › Subchapter 37.14.10 - X-Rays in the Healing Arts › Rule 37.14.1006 - FLUOROSCOPIC INSTALLATIONS

Current through Register Vol. 13, July 5, 2024
(1) The
				equipment used in fluoroscopic installation shall be as follows:
(a) The tube housing shall be of a diagnostic
				type.
(b) During fluoroscopy and
				cinefluorography, the kV and the mA shall be continuously indicated.
(c) The source to skin distance shall not be
				less than:
(i) 38 centimeters on stationary
				fluoroscopes installed after March 28, 1980.
(ii) 35.5 centimeters on stationary
				fluoroscopes which are in operation prior to March 28, 1980;
(iii) 30 centimeters on all mobile
				fluoroscopes; and
(iv) 20
				centimeters for image intensified fluoroscopes used for specific surgical
				application. The users operating manual must provide precautionary measures to
				be adhered to during the use of this device.
(d) The total filtration permanently in the
				useful beam shall be at least 2.5 millimeters aluminum equivalent.
(e) The equipment shall be so constructed
				that, under conditions of normal use, the entire cross section of the useful
				beam is attenuated by a primary protective barrier, permanently incorporated
				into the equipment and the exposure shall automatically terminate when the
				barrier is removed from the useful beam.
(i)
				The lead equivalent of the barrier of conventional fluoroscopes shall be at
				least 1.5 millimeters for equipment capable of operating up to 100 kVp, at
				least 1.8 millimeters for equipment capable of operating between 100 kVp and
				125 kVp, and at least 2 millimeters for equipment capable of operating between
				125 kVp and 150 kVp.
(ii) With the
				fluorescent screen 14 inches (35 cm) from the panel or table top, the exposure
				rate 2 inches (5 cm) beyond the viewing surface of the screen shall not exceed
				30 mR/hr. for each R per minute at the table top with the screen in the useful
				beam without a patient and with the fluoroscope operating at its highest
				possible potential.
(iii) A
				collimator shall be provided to restrict the size of the useful beam to less
				than the area of the barrier. The x-ray tube and collimating system shall be
				linked with the fluorescent screen assembly so that the useful beam at the
				fluorescent screen is confined within the barrier irrespective of the
				panel-screen distance. For all new fluoroscopic units with image intensifiers
				sold in Montana after July 1, 1969, the useful beam shall be centered on the
				input phosphor and during fluoroscopy or cine recording shall not exceed the
				diameter of the input phosphor.
(iv) When the adjustable diaphragm is opened
				to its fullest extent, an unilluminated margin shall exist at all edges of the
				fluorescent screen when the screen is 14 inches (35 cm) from the panel surface
				or table top or at the fixed screen position in equipment such as
				orthodiascopes. In equipment used solely for image intensified fluoroscopy, the
				shutter shall restrict the useful beam within the diameter of the input
				phosphor.
(v) Collimators,
				adjustable diaphragms and shutters shall provide the same degree of attenuation
				as is required of the tube housing.
(f) The fluoroscopic exposure switch shall be
				a dead-man switch type.
(g) A
				shielding device of at least 0.25 millimeters lead equivalent for covering the
				Bucky slot during fluoroscopy shall be provided on all new units sold in
				Montana after July 1, 1969.
(h) A
				shield of at least 0.25 millimeters lead equivalent such as overlapping
				protective drapes or hinged or sliding panels shall be provided on all new
				units sold in Montana after July 1, 1969, to intercept scattered radiation
				which would otherwise reach the fluoroscopist and others near the
				machine.
(i) A cumulative timing
				device activated by the fluoroscope exposure switch shall be provided. It shall
				indicate the passage of a predetermined period of irradiation either by an
				audible signal or by temporary interruption of the irradiation when the
				increment of exposure time reaches a predetermined limit not exceeding 5
				minutes.
(j) Image intensification
				shall always be provided on mobile fluoroscopic equipment. It shall be
				impossible to operate mobile fluoroscopic equipment unless the useful beam is
				intercepted by the image intensifier.
(k) Provision shall be made to intercept the
				scattered x-rays from the undersurface of the table top and other structures
				under the table. The shieldings shall provide the same degree of attenuation as
				is required of the tube housing, with the incident angle of the useful beam
				taken into consideration.
(l)
				Equipment to be operated in areas where explosive gases may be used shall have
				the approval of underwriters laboratory for such use.