180 Neb. Admin. Code, ch. 6, § 008

Current through September 17, 2024

Section 180-6-008 - COMPUTED TOMOGRAPHY (CT) AND CONE BEAM COMPUTED TOMOGRAPHY (CBCT) SYSTEMS

This section applies to registrants using computed tomography (CT) systems and cone beam computed tomography (CBCT) systems.

008.01 DEFINITIONS. In addition to the definitions provided in 180 NAC 1-002 and 180 NAC 6-002, the following definitions apply to 180 NAC 6-008.

008.01(A) CONTRAST SCALE. Contrast scale has the same meaning as 21 CFR § 1020.33(b).

008.01(B)COMPUTED TOMOGRAPHY (CT) CONDITIONS OF OPERATION. Computed tomography (CT) conditions of operation are all selectable parameters governing the operation of a computed tomography (CT) system including, but not limited to, nominal tomographic section thickness, filtration, and the technique factors as defined in this chapter.

008.01(C) COMPUTED TOMOGRAPHY (CT) NUMBER. Computed tomography (CT) number has the same meaning as set out in 21 CFR § 1020.33(b). 008.01(D) NOISE. Noise has the same meaning as set out in 21 CFR § 1020.33(b).

008.01(E) NOMINAL TOMOGRAPHIC SECTION THICKNESS. Nominal tomographic section thickness has the same meaning as set out in 21 CFR § 1020.33(b).

008.01(F)REFERENCE PLANE. Reference plane is a plane which is displaced from and parallel to the tomographic plane.

008.01(G) SCAN. Scan is the complete process of collecting x-ray transmission data for the production of a tomogram. Data can be collected simultaneously during a single scan for the production of one or more tomograms.

008.01(H) SCAN INCREMENT. Scan increment has the same meaning as set out in 21 CFR § 1020.33(b).

008.01(I) SCAN SEQUENCE. Scan sequence has the same meaning as set out in 21 CFR § 1020.33(b).

008.01(J)TOMOGRAPHIC PLANE. Tomographic plane has the same meaning as set out in 21 CFR § 1020.33(b).

008.01(K) TOMOGRAPHIC SECTION. Tomographic section has the same meaning as set out in 21 CFR § 1020.33(b).

008.02 COMPUTED TOMOGRAPHY (CT) AND CONE BEAM COMPUTED TOMOGRAPHY (CBCT) EQUIPMENT REQUIREMENTS. Computed tomography (CT) and cone beam computed tomography (CBCT) equipment must meet the following requirements, except for fluoroscopic systems capable of performing cone beam computed tomography (CBCT).

008.02(A)TERMINATION OF EXPOSURE. The timer must meet the specifications of 21 CFR § 1020.33(f)(2).

008.02(B) TOMOGRAPHIC PLANE INDICATION AND ALIGNMENT. Tomographic plane indication and alignment must meet the specifications of 21 CFR § 1020.33(g).

008.02(C) BEAM-ON AND SHUTTER STATUS INDICATORS AND CONTROL SWITCHES. Visual indication of x-ray production and shutter status must meet the specifications of 21 CFR § 1020.33(h). Each emergency button or switch must be clearly labeled as to its function.

008.02(D) INDICATION OF CONDITIONS OF OPERATION. Visual indication of the conditions of operation to be used during a scan or scan sequence must meet the specifications of 21 CFR § 1020.33(f).

008.02(E) SCAN INCREMENT ACCURACY. The accuracy of scanning increments must meet the specifications of 21 CFR § 1020.33(i).

008.02(F) MEAN AND STANDARD DEVIATION. The method used to calculate the mean and standard deviation must meet the specifications of 21 CFR § 1020.33(j).

008.03 FACILITY DESIGN REQUIREMENTS. Registrants using computed tomography (CT) equipment must meet facility design specifications.

008.03(A) AURAL COMMUNICATION. There must be two-way aural communication between the patient and the operator at the control panel.

008.03(B) VIEWING SYSTEMS. Viewing systems must include the following:

(i) Windows, mirrors, closed-circuit television, or an equivalent must be provided to permit continuous observation of the patient during irradiation and must be located so the operator can observe the patient from the control panel; and

(ii) When the primary viewing system is by electronic means, an alternate viewing system, which may be electronic, must be available for use in the event of failure of the primary viewing system.

008.04 PLAN REVIEWS, CALIBRATIONS, SPOT CHECKS, AND OPERATING PROCEDURES. Plan reviews, calibration, spot checks and operating procedures for computed tomography (CT) and cone beam computed tomography (CBCT) systems must meet the following requirements..

008.04(A) PLAN REVIEWS. For computed tomography (CT) and cone beam computed tomography (CBCT) x-ray systems, the plan review required by 180 NAC 6-003.19 must be performed by, or under the direction of, a radiological medical physicist or radiological health physicist meeting the requirements of 180 NAC 2-005.04(C)(ii). In addition, radiation surveys must be performed after any change in the registrant's facility or equipment that might cause an individual to receive a dose in excess of the limits prescribed in 180 NAC 4-005, 4-011 or 4-013.

008.04(B) PLAN REVIEW RESULTS. The registrant must obtain a written report of the results of the plan review from the radiological medical physicist or radiological health physicist. A copy of the report must be maintained for inspection by the Department.

008.04(C) RADIATION CALIBRATIONS OF COMPUTED TOMOGRAPHY (CT) AND CONE BEAM COMPUTED TOMOGRAPHY (CBCT) SYSTEMS. The calibration of radiation output of computed tomography (CT) or cone beam computed tomography (CBCT) system must be performed by, or under the direction of, a radiological medical physicist or radiological health physicist meeting the requirements of 180 NAC 2-005.04(C)(ii) who is physically present at the registrant's facility during the calibration. Calibration procedures must be in writing.

008.04(C)(i)FREQUENCY OF CALIBRATION. The calibration of a computed tomography (CT) or cone beam computed tomography (CBCT) system must be performed after initial installation, prior to the first use on a patient, and at intervals specified by a radiological medical physicist or radiological health physicist, not to exceed two years. Additionally, a calibration must be performed by a radiological medical physicist or radiological health physicist within 30 days after any change or replacement of components that, in the opinion of the radiological medical physicist or radiological health physicist, could cause a change in the radiation output. Calibration of a computed tomography (CT) system must include the spot-checks specified in 180 NAC 6-008.05(A)(ii). Calibration of a cone beam computed tomography (CBCT) system must include the quality control checks specified in 180 NAC 6-008.07(C).

008.04(C)(ii) DOSIMETRY SYSTEM. The measurement of the radiation output of a computed tomography (CT) or cone beam computed tomography (CBCT) system must be performed with a calibrated dosimetry system. The calibration of that system must be traceable to a national standard. The dosimetry system must have been calibrated within the preceding two years.

008.04(C)(iii) DOSIMETRY PHANTOMS. Computed tomography (CT) dosimetry phantom or phantoms must be used to ensure the computed tomography (CT) system meets the specifications of 21 CFR § 1020.33(b)(6).

008.04(C)(iv) HEAD, BODY, OR WHOLE-BODY SCANS. A computed tomography (CT) system must be calibrated for each type of head, body, or whole-body scan or scans performed at the registrant's facility to ensure that the system meets the specifications of 21 CFR § 1020.33(c)(2).

008.04(C)(v) RECORDS OF COMPUTED TOMOGRAPHY (CT) CALIBRATIONS AND CONE BEAM COMPUTED TOMOGRAPHY (CBCT). Records of calibrations performed must be maintained for inspection by the Department.

008.05 SPOT CHECKS OF COMPUTED TOMOGRAPHY (CT) EQUIPMENT. Spot-check procedures must be in writing and must be developed by a radiological medical physicist or radiological health physicist.

008.05(A) SPOT-CHECK PROCEDURES. Spot-check procedures must include the following:

(i) Use of a computed tomography (CT) phantom or phantoms that meets the requirements of 21 CFR § 1020.33(d)(1);

(ii) A check of the contrast scale, noise, nominal tomographic section thickness, spatial resolution of the system for low and high contrast objects, and a measurement of the mean computed tomography (CT) number of water or a reference material; and

(iii) Acquisition of images must be obtained with the computed tomography (CT) phantom or phantoms using the same processing mode and computed tomography (CT) conditions of operation used to perform calibrations required by this chapter.

008.05(B) FREQUENCY OF SPOT-CHECKS. All spot checks must be performed at the frequency and under system conditions specified by a radiological medical physicist or radiological health physicist.

008.05(C) SPOT-CHECK RECORDS. Records of the spot-checks performed must be maintained for inspection by the Department.

008.06 OPERATING PROCEDURES FOR COMPUTED TOMOGRAPHY (CT) SYSTEMS. Registrants must develop written operating procedures for computed tomography (CT) systems as follows.

008.06(A) OPERATION OF THE COMPUTED TOMOGRAPHY (CT) SYSTEM. The system must only be operated by an individual who has been specifically trained in its operation and meets the requirements of 180 NAC 6-003.05.

008.06(B) INFORMATION ON OPERATION AND CALIBRATION. Information must be available in the operator control area regarding the operation and calibration of the system. The information must include:

(i) Dates of the latest calibration and spot-checks and the location where the results of those tests may be found;

(ii) Instructions on the use of the computed tomography (CT) phantom or phantoms including a schedule of spot-checks appropriate for the system, allowable variations for the indicated parameters, and the results of the most recent spot-checks performed on the system;

(iii) The distance in millimeters between the tomographic plane and the reference plane if a reference plane is utilized; and

(iv) A current technique chart available at the control panel which specifies, for each routine examination, the computed tomography (CT) conditions of operation and the number of scans for each examination.

008.06(C) OPERATING PARAMETERS. If the calibration or spot-check of the computed tomography (CT) system identifies that a system operating parameter has exceeded a tolerance established by the radiological medical physicist or radiological health physicist, use of the system on patients must be limited to those permitted by written instructions of the radiological medical physicist or radiological health physicist.

008.07 CONE BEAM COMPUTED TOMOGRAPHY (CBCT) SYSTEMS. In addition to other requirements of this chapter, this section applies to registrants using with cone beam computed tomography (CBCT) systems.

008.07(A) OPERATION OF THE CONE BEAM COMPUTED TOMOGRAPHY (CBCT) SYSTEM. The cone beam computed tomography (CBCT) system must only be operated by an individual who has been specifically trained in its operation and meets the requirements of 180 NAC 6-003.05.

008.07(B) BEAM ALIGNMENT. The x-ray field in the plane of the image receptor must not exceed beyond the edge of the image receptor by more than two percent of the source-to-image distance (SID) when the axis of the x-ray beam is perpendicular to the plane of the image receptor. In addition, the center of the x-ray field must be aligned with the center of the image receptor to within 2 percent of the source-to-image distance (SID).

008.07(C) QUALITY CONTROL. The registrant must follow the quality control recommendations of the manufacturer. If manufacturer recommendations are not obtainable, the registrant must perform quality control on the cone beam computed tomography (CBCT) system that has been developed by a radiological medical physicist or radiological health physicist.

008.07(D) INFORMATION FOR THE CONE BEAM COMPUTED TOMOGRAPHY (CBCT) OPERATOR. The following information must be readily available to the operator of the cone beam computed tomography (CBCT) system:

(i) Instructions on performing quality control on the cone beam computed tomography (CBCT) system;

(ii) The time interval for performing quality control on the cone beam computed tomography (CBCT) system;

(iii) The allowable uses of the cone beam computed tomography (CBCT) system if a quality control check identifies a system operating parameter has exceeded a tolerance established by the manufacturer. If tolerances from the manufacturer are not obtainable, a radiological medical physicist or radiological health physicist must establish the tolerances and the cone beam computed tomography (CBCT) system must be limited to those uses allowed by the radiological medical physicist or radiological health physicist; and (iv) The results of the most recent quality control completed on the cone beam computed tomography (CBCT) system.

180 Neb. Admin. Code, ch. 6, § 008

Amended effective 11/4/2020