Section 7.18.450. Medical radiographic installation.

	(a)  A medical radiographic installation must use a diagnostic type protective x-ray tube housing and must meet the requirements of this section.  
	(b)  Medical radiographic equipment must define the useful beam with a diaphragm, cone, or adjustable collimator capable of restricting the beam to the area of clinical interest, providing the same degree of attenuation as is required of the protective tube housing.  These devices must be calibrated in terms of the size of the projected useful beam at specified source-film distances and must limit the target-to-skin distance to not less than 12 inches (30 centimeters).  
	(c)  Radiographic equipment must be equipped with adjustable collimators and light localizers to define the entire field and produce a visible indication of adequate collimation and alignment on the x-ray film.  Field size indication on adjustable collimators must be accurately aligned with the x-ray field to within two percent of the source-image receptor-distance (SID) at all possible positions of the x-ray tube, except when positive beam limitation is functional, in use, and a health physics survey confirms that the positive beam limitation confines the beam to within two percent of the SID.  
	(d)  Except when contraindicated for a particular medical purpose, the aluminum equivalent of the total filtration in the useful beam may not be less than 0.5 millimeters for equipment operating below 50 kVp;  may not be less than 1.5 millimeters for equipment operating from 50 kVp to 70 kVp;  and may not be less than 2.5 millimeters for equipment operating above 70 kVp.  If the filter in the machine is not accessible for examination or the total filtration is unknown, the requirements of this section are met if the half-value layer of the useful beam is not less than that listed for "Other X-Ray Systems" in Table I of 21 C.F.R. 1020.30(m), as revised as of April 1, 2008, and adopted by reference.  
	(e)  A device must automatically terminate the exposure after a preset time or exposure.  
	(f)  The exposure switch must be of a dead-man type switch and must be arranged in a manner that the switch cannot be operated outside a shielded area, except that exposure switches for spot film devices used in conjunction with fluoroscopic tables and for mobile diagnostic radiographic equipment are exempt from this shielding requirement.  
	(g)  The exposure switch for mobile equipment must be arranged in a manner that the operator can stand at least six feet from the patient and well away from the useful beam.  
	(h)  The control panel must include  
		(1) a device that will give positive indication of the production of x-rays whenever the x-ray tube is energized; and  
		(2) appropriate devices that will give positive indication of the physical factors used for the exposure, such as kVp, mA, and exposure time.  
	(i)  All wall, floor, and ceiling areas that may intercept the useful beam must have primary barriers.  
	(j)  A primary barrier in a wall must extend to a height of at least 84 inches or 210 centimeters above the floor.  
	(k)  A secondary barrier must be provided in all wall, floor, and ceiling areas not having a primary barrier or where the primary barrier requirements are lower than the secondary barrier requirements.  In a radiographic installation where the average radiographic workload is comparatively low, the conventional structural material in ordinary walls, floors, and ceilings may suffice as a primary barrier and secondary barrier without adding special shielding materials, particularly if the useful beam cannot be directed at occupied areas.  
	(l)  The operator's station must be behind a protective barrier that will intercept the entire useful beam and any radiation that has been scattered only once.  An operator must be unable to energize the tube while outside the protective barrier, except that spot film devices used in conjunction with fluoroscopic tables are exempted from this requirement.  
	(m)  A window of lead equivalent glass, equal to that required by the adjacent barrier, mirror system, or closed circuit television monitor, must be provided and it must be large enough and placed in a manner that the operator can see the patient during the exposure without having to leave the protective area.  
	(n)  If a patient must be held in position for radiography, a mechanical supporting, or restraining device must be used unless the device will interfere with the diagnosis.  
	(o)  If a patient must be held by an individual, that individual must be protected with appropriate shielding devices, such as protective gloves and apron, and that individual must be positioned in a manner that no part of that individual's body will be struck by the useful beam.  
	(p)  An individual occupationally exposed to radiation may not hold a patient during an exposure, except during an emergency.  An individual may not be regularly used for this service.  
	(q)  Only an individual required for the radiographic procedure may be in the radiographic room during exposure and, except for the patient, no unprotected parts of the individual's body may be in the useful beam.  
	(r)   The useful beam must be restricted to the area of the image receptor, and evidence of beam edges must show up on at least three sides of each radiographic image, except where a properly functioning positive beam limiting device is in place.  
	(s)  A patient must be provided with a shield to protect the gonadal area of the body, unless the use of a shield prohibits a proper diagnosis.  
	(t)  A protective apron and gloves must be tested at least annually to verify the continued integrity of radiation shielding properties sufficient to meet the standards of 7 AAC 18.440(l).  
	(u)  A chest photofluorographic installation does not meet radiation safety requirements and may not be used.  
	(v)   Mobile diagnostic radiographic equipment must meet the requirements of this section, except for the  
		(1) provisions of (q) of this section, if  
			(A) all individuals, except the patient being examined, are in shielded positions during exposure; and  
			(B)  personnel monitoring is required for all individuals operating mobile x-ray equipment; and  
		(2) shielding requirement of (f) of this section, except that if a mobile unit is used routinely for more than 30 days in one location, the unit is considered a fixed installation subject to the shielding requirements specified in this section and 7 AAC 18.430.  
	(w)  A registrant who uses film imaging and processing of the images shall establish processing quality control procedures at regular intervals that at least include  
		(1) documenting chemical change dates;  
		(2) documenting developer temperatures;  
		(3) processing a test strip that may be read by densitometer once weekly;  
		(4) documenting that chemical replenishment rates are maintained within plus or minus 15 percent once weekly;  
		(5) documenting that fixer retention does not exceed 0.05 milligrams per centimeter; and  
		(6) performing a two-minute fog test that demonstrates an optical density  of no more than 0.05 on film used for imaging individuals or a step wedge image that does not change more than one step, annually or following any changes in the structural integrity of the darkroom.  
	(x)  A registrant who uses electronic, digital, or computerized imaging methods shall establish quality control procedures that include at least  
		(1) a test of a phantom dose and density that approximates the most common  procedure performed in the facility;  
		(2) a record of exposure changes calculated at least once a month to evaluate potential exposure creep; and  
		(3) quality control procedures recommended by the manufacturer that are  performed on a schedule to verify that the operators are achieving the index or target values specified by the digital imaging manufacturer.  

Authorities

18.60.475;18.60.485

Notes

Reference

7 AAC 18.470

Authority

AS 18.60.475 AS 18.60.485

History

Eff. 4/9/2009, Register 190