N.M. Admin. Code § 20.3.6.603

Current through Register Vol. 35, No. 21, November 5, 2024

Section 20.3.6.603 - GENERAL REQUIREMENTS FOR ALL DIAGNOSTIC X-RAY SYSTEMS

In addition to other requirements of this Subpart, all diagnostic x-ray systems shall meet the following requirements:

A. Warning Label: The control panel containing the main power switch shall bear the warning statement, legible and accessible to view: "WARNING: This X-ray Unit May Be Dangerous To Patient and Operator Unless Safe Exposure Factors and Operating Instructions Are Observed";

B. Battery Charge Indicator: On battery-powered generators, visual means shall be provided on the control panel to indicate whether the battery is in a state of charge adequate for proper operation;

C. Leakage Radiation from the Diagnostic Source Assembly: The leakage radiation from the diagnostic source assembly measured at a distance of 1 m in any direction from the source shall not exceed 100 mR (1 mSv) in 1 hour when the x-ray tube is operated at its leakage technique factor. Compliance shall be determined by measurements averaged over an area of 100 sq cm (39.37 inches) with no linear dimension greater than 20 cm (7.87 inches); and

D. Radiation from Components other than the Diagnostic Source Assembly: The radiation emitted by a component other than the diagnostic source assembly shall not exceed 2 mR (2 mSv) in 1 hour at 5 cm from any accessible surface of the component when it is operated in an assembled x-ray system under any conditions for which it was designed. Compliance shall be determined by measurements averaged over an area of 100 sq cm (39.37 inches) with no linear dimension greater than 20 cm (7.87 inches).

E. Beam Quality:

(1) Half-value layer:

(a) The half-value layer (HVL) of the useful beam for a given x-ray tube potential shall not be less than the values shown in Table 603.1 [Table 1, Section 603 of 20.3.6.603 NMAC]. If it is necessary to determine such half-value layer at an x-ray tube potential which is not listed in Table 603.1 [Table I, Section 603 of 20.3.6.603 NMAC], linear interpolation or extrapolation may be made.

TABLE I

Design operating range Measured potential Half-value layer

(Kilovolts peak) (Kilovolts peak) aluminum) (Millimeters of)

Below 50 30 0.3

40 0.4

49 0.5

50 to 70 50 1.2

60 1.3

70 1.5

Above 70 71 2.1

80 2.3

90 2.5

100 2.7

110 3.0

120 3.2

130 3.5

140 3.8

150 4.1

(b) The above HVL criteria will be considered to have been met if it can be demonstrated that the aluminum equivalent of the total filtration in the primary beam is not less than that shown in Table 603.2 [Table II of Section 603, 20.3.6.603 NMAC].

TABLE II

FILTRATION REQUIRED vs. OPERATING VOLTAGE

Total Filtration (inherent plus added)

Operating Voltage (millimeters aluminum

(kVp)equivalent)

Below 50 0.5 mm

50 - 70 1.5 mm

Above 70 2.5 mm

(c) Beryllium window tubes shall have a minimum of 0.5 mm aluminum equivalent filtration permanently mounted in the useful beam.

(d) For capacitor energy storage equipment, compliance shall be determined with the maximum quantity of charge per exposure.

(e) The required minimal aluminum equivalent filtration shall include the filtration contributed by all materials which are always present between the focal spot of the tube and the patient (e.g., a tabletop when the tube is mounted "under the table" and inherent filtration of the tube).

(2) Filtration control: For x-ray systems manufactured after August 1, 1974, which have variable kVPand variable filtration for the useful beam, a device shall link the kVPselector with the filter(s) and will prevent an exposure unless the minimum required amount of filtration (see Table 603.1 or Table 603.2 above [Table I or II, Section 603 of 20.3.6.603 NMAC]) is in the useful beam for the given kVPwhich has been selected.

F. Multiple Tubes: Where two or more radiographic tubes are controlled by one exposure switch, the tube or tubes which have been selected shall be clearly indicated prior to initiation of the exposure. This indication shall be both on the x-ray control and at or near the tube housing assembly which has been selected.

G. Mechanical Support of Tube Head: The tube housing assembly supports shall be adjusted such that the tube housing assembly will remain stable during an exposure unless the tube housing movement is a designed function of the x-ray system.

H. Technique Indicators:

(1) The technique factors to be used during an exposure shall be indicated before the exposure begins, except when automatic exposure controls are used, in which case the technique factors which are set prior to the exposure shall be indicated.

(2) On equipment having fixed technique factors, the requirement, 603.H.1 [Paragraph (1), Subsection H., Section 603 of 20.3.6.603 NMAC], may be met by permanent markings. Indication of technique factors shall be visible from the operator's position except in the case of spot films by the fluoroscopist.

N.M. Admin. Code § 20.3.6.603

5-3-95; 20.3.6.603 NMAC - Rn, 20 NMAC 3.1.6.603, Recompiled xx/xx/xx