§ 175.55 — Computed Tomography (CT) Equipment

§ 175.55 Computed Tomography (CT) Equipment.

Except for dental registrants possessing cone beam computed tomography, each facility utilizing computed tomography equipment must comply with the requirements of this section. (a) CT x-ray system equipment requirements. (1) Each control panel and gantry of a CT x-ray system must include visual signals that indicate to the operator of the CT x-ray system whenever x-rays are being produced and when x-ray production is terminated, and, if applicable, whether the shutter is open or closed. (2) Each CT x-ray system must be equipped with a control that allows the operator of the CT x-ray system to terminate the x-ray exposure at any time during a scan, or series of scans, when the exposure time is greater than one-half second duration. (3) Each CT x- ray system must be designed such that the CT conditions of operation to be used during a scan or a scan sequence are indicated prior to the initiation of a scan or a scan sequence. (4) Each CT x-ray system must include a clearly and conspicuously labeled emergency shutoff button or switch. (5) Premature termination of the x-ray exposure by the operator must require resetting of the CT conditions of operation by the operator prior to the initiation of another scan. (b) Patient communication and viewing requirements. (1) Each CT x-ray system must be equipped to allow two-way aural communication between the patient and the operator at the control panel. (2) Each CT x-ray system must be equipped with windows, mirrors, closed- circuit television, or an equivalent to permit continuous visual observation of the patient during CT scanning by the CT operator from the control panel. (3) When the primary viewing system is by electronic means, an alternate viewing system (which may be electronic) must be available for if the primary viewing system fails. (c) Determination of the CT unit radiation output. (1) Each registrant must ensure that the measurement of the radiation output of each CT x-ray system that it operates is performed by, or under the direction of, a QMP and the output measurement must be conducted following the guidelines of the facility's accreditation as to methodology and as to setting scan techniques and CT unit technique settings. (2) Each registrant must maintain and make available for review by the Department, on the premises of its radiation installation where a CT x-ray system is located, written procedures for the appropriate output measurement of the CT x-ray system. (3) After initial installation, the CT x-ray system radiation output must be determined prior to its use on human beings and re-measured at least every 12 months thereafter. Any change or replacement of components of a CT x-ray system which could cause a change in the radiation output will require a re-measurement within 30 days of component installation under the supervision of a QMP operating within their scope of practice. If the accreditation body does not dictate the criteria for re-measurement based upon CT component replacement, then the facility must establish these criteria in conjunction with the QMP and CT service engineer, including the list of components that dictate a re-measurement, and this protocol must be documented in the facility's QA Manual. (4) The measurement of the radiation output of a CT x-ray system must be performed with a calibrated dosimetry system. This system must have been calibrated either by the National Institute of Standards and Technology (NIST) or traceable to NIST or equivalent standards organization. The calibration must have been performed within the previous 12 months and after any servicing that might have affected system calibration, (5) The CT dosimetry phantoms must meet the following specifications and conditions of use: (i) any effects on the doses measured because of the removal of phantom material to accommodate dosimeters must be accounted for through appropriate corrections to the reported data or included in the statement of maximum deviation for the values obtained using the phantom; and (ii) all dose measurements must be performed with the CT dosimetry phantom simulating an adult abdomen or adult head placed on the patient couch or support device without additional attenuation materials present. (iii) the requirements of subparagraphs (i) and (ii) of this paragraph can also be met by using an alternative method of radiation measurement and calculation published in the peer-reviewed scientific literature and acceptable to the Department. (6) Records of radiation output determinations performed must be maintained for 3 years at the radiation installation where the CT is located. (d) Quality assurance testing. (1) Each registrant possessing one or more CT units shall be deemed a large facility. (2) Regardless of the number of patient exams conducted per year all Quality Assurance (QA) tests for existing x-ray equipment on site must be done on a frequency for a large facility. As such, each registrant must have a QA committee that meets at least semi-annually and such committee must be comprised of the medical professionals associated with the registrant's facility, including the QMP or a representative conducting the accreditation for the facility, the Radiation Safety Officer for the facility, and whatever additional facility titles that the accreditation body mandates to be present for such meetings. (3) Each registrant must maintain a QA manual that contains written procedures for all testing and meet the requirements of the facility's accreditation body for maintaining a QA program as to what QA must be done and their mandated testing frequency. The CT Quality Assurance procedures must have been developed under the direction of a QMP and radiologist and be approved by the registrant's QA committee. (4) The QA procedures must incorporate the use of one or more phantoms approved by the facility's accreditation body and must be imaged according to the accreditation body's recommendations. If the accreditation body does not provides tolerances for daily CT QA tests, then the facility must follow the manufacturer's specifications for daily CT QA tests and utilization of the manufacturer's phantom for such daily testing. The QA testing of the phantom must have the capability of providing an indication of contrast scale, noise, the resolution capability of the system for low and high contrast objects, and measuring the mean CT Number for water or other reference material and uniformity. All of the aforementioned image quality parameters must be evaluated at least semi-annually by a QMP and presented to the QA Committee for their review and approval. (5) Written records of the QA checks performed by the registrant must be maintained for review by the Department for at least 5 years. (6) QA checks must include the following: (i) images obtained from x-ray scanning of the CT phantom pursuant to 24 RCNY Health Code § 175.55(d)(4) must be retained as electronic copies stored within the CT x-ray system or stored in the facility's Picture Archiving and Communication (PACS) system, if these images are available based on the CT system. (ii) dose assessment for the most common CT examinations that are performed on the system for which reference levels have been published by the American College of Radiology (ACR), the American Association of Physicists in Medicine (AAPM) or the National Council on Radiation Protection and Measurements (NCRP) for pediatric head, pediatric abdomen, adult head and adult abdomen. (iii) for brain perfusion studies clinically conducted at the registrant's facility, the registrant must have on an annual basis the clinical dose measured by a QMP and an annual evaluation and approval of the clinical protocols for such brain perfusion studies by the registrant's Radiation Protocol Committee (RPC), or Radiation Safety Committee (RSC), if the RSC assumes the responsibilities of the RPC. The facility must investigate and document the clinical necessity of brain perfusion CTDIvol doses greater than 100 rads (1 Gray) or whatever guidance dose is so stated in the ACR-ASNR-SPR Practice Parameters for the Performance of CT Perfusion in Neurological Imaging (Amended 2014) or superseding documents. (iv) for each CT unit possessing dose adjustment software features for dose adjustment in clinical patient scans: (A) the facility must conduct measurements to determine that the dose adjustment software is functioning as the manufacturer specified to adjust the CT imaging techniques so as to maintain image quality. (B) this must be conducted at least annually or whenever there is a software upgrade or change to the dose adjustment software of the CT software. (C) for verification testing as required by clause (A) of this subparagraph (iv) of paragraph (6) of this subdivision, manufacturer test results with documentation and formal report shall be acceptable to verify compliance. (7) For CT units used for treatment planning simulation, the registrant must conduct the following QA testing, in addition to daily QA tests mandated by the accreditation agency, if the site is accredited: (i) daily measurements to verify that image reconstruction dimensions or scaling accuracy are accurate to manufacturer's tolerances. (ii) daily verification of the CT number uniformity for the manufacturer's water phantom and verify compliance with the manufacturer's tolerances. In this context, CT number uniformity must be conducted for the four quadrants of the water phantom image and compliance shall be determined by comparison between the outer four quadrants and the center of the water phantom as per manufacturer's tolerances. (iii) measure each month the CT number uniformity for a variety of materials with densities above and below that of water and verify compliance with the accreditation body standards or manufacturer specifications. (iv) the registrant can follow the accreditation body's guidelines for the conduct of such measurements and tolerances for such, but the frequency of conduct must be as stated in subparagraphs (i) through (iii) of this paragraph. (e) Operating procedures and policies. (1) All diagnostic CT and CBCT units for human use must be accredited by an accrediting organization recognized by the Department. This requirement does not apply to CBCT units used at dental facilities and to CT units used solely for simulation of patients for radiation therapy. (i) Effective January 1, 2021, new registrants must be accredited but must demonstrate that they have initiated the accreditation process within 90 days of the start of operations. (ii) Registrants, possessing CT units that have been notified by accrediting agencies that their CT units do not meet minimum standards to be accredited, must notify the Department within 30 days of such notice. (iii) A facility performing CT that has an existing accreditation revoked, repealed, or otherwise terminated for any reason, must report such occurrence to the Department within 30 days. (2) The CT x-ray system must not be operated on a human being except by a physician or by a licensed radiologic technologist who has been specifically trained in the operation of the CT system. To meet compliance with this section, each facility must maintain documentation that each physician or LRT operator of the facility's CT units have received training on the specific manufacturer model that the facility possesses. (3) The registrant must ensure that each CT x-ray system has a radiation protection survey for assessment of exposure to persons in controlled and non-controlled areas made at the time of installation. Any change in the installation that compromises the original integrity of the facility's shielding and installation of a new CT unit shall require an additional radiation protection survey to verify compliance with Article standards for radiation protection doses to the public and radiation workers. (4) Each CT x-ray system must have available at the control panel the operation and output determination of the CT x-ray system which must include: (i) dates of the latest output determination and QA checks and the location within the facility where the results of those tests may be obtained; (ii) instructions on the use of the CT image quality phantoms including a schedule of QA tests that are appropriate for the system as determined by the manufacturer, allowable variations for the indicated parameters. (5) For each CT scanner in a facility, a current set of default protocols are available at the control panel (either electronically or as a document) which specifies for each routine examination the CT conditions of operation and the slice thickness, spacing between slices or pitch. The default protocols need not be the same as the clinically used scan protocols at the facility, but the clinically used protocols must be derived from the default protocols. (6) If the QA testing on the CT x-ray system identifies that a system operating parameter has exceeded a tolerance as specified in the Quality Assurance manual, use of the CT x-ray system on patients must be limited to those exceptions permitted by established written instructions of the licensed QMP or radiologist. Upon completion of corrective action, the QA testing must be repeated to verify that the system is back within tolerance. (7) All clinical CT scans must be free of any and all imaging artifacts that the CT facility discovers upon daily QA phantom testing. Upon discovery of any and all imaging artifacts by way of daily QA phantoms testing, the facility must cease clinical scans until corrective action has removed such artifacts being present in clinical scans, exception for all patient CT scans conducted on emergency cases such as in hospital emergency rooms or hospital trauma centers. All corrective actions must be documented by the registrant for review by the Department. (8) Effective July 1, 2020, each registrant performing CT scans on human beings must ensure that for each scan, the radiation dose delivered by the scanner to a reference phantom or the dose received by the patient or other dose metric is saved and recorded. The dose delivered must be recorded as Computed Tomography Dose Index volume (CTDIvol), dose length product (DLP) or other dosimetry metric published in the peer reviewed scientific literature and acceptable to the Department. (9) The displayed dose must be verified on an annual basis by or under the supervision of a QMP to ensure that the equipment manufacturer's displayed dose is within 20percent of the measured dose. To accomplish the latter, a phantom must be used for this measurement. (10) Each registrant that performs CT scans on human beings must establish and implement a policy and a procedure to ensure that a request for a CT scan originates from a licensed physician or other authorized professional practitioner familiar with the patient's clinical condition. The request must include sufficient information to demonstrate the medical indication for the CT examination and allow for the proper performance and interpretation of the CT scan. (11) Each facility must maintain a patient logbook of all patients undergoing CT exams at the facility. The logbook must contain the following information: (i) patient identification information, (ii) CT scans performed along with the imaging parameters, (iii) the CT manufacturer's patient dose assessment, and (iv) whether the study was conducted with contrast media. (v) The logbook can be in electronic format provided all information is readily available to the Department during periodic inspections. (f) CT Radiation Protocol Committee (RPC). (1) The registrant must develop and maintain a CT RPC, or must allow its Radiation Safety Committee to assume such responsibility. Members of the RPC must include but not be limited to the: (i) lead CT radiologist; (ii) lead CT technologist; (iii) QMP; and (iv) other individuals as deemed necessary by the registrant (e.g., Radiation Safety Officer, Chief Medical or Administrative Officer, Radiology Department Administrator/Manager). (2) The RPC must: (i) review existing CT protocols along with the evaluation and implementation of new and innovative technologies that can improve image quality and lower patient dose in comparison with the older protocol. (ii) review the capabilities of the individual CT scanner to ensure maximum performance is achieved. (iii) determine and review the protocols used frequently or which could result in significant doses. This review must include acquisition and reconstruction parameters and radiation dose. At a minimum, the facility must review the following clinical protocols, if performed, at intervals at least every 12 months: (A) Pediatric Head; (B) Pediatric Abdomen; (C) Adult Head; (D) Adult Abdomen; (E) Adult Chest; (F) Brain Perfusion. (iv) establish and implement written protocols, or protocols documented in an electronic reporting system, that include but are not limited to the following: (A) a method to be used to monitor the CT radiation output. (B) a standardized protocol naming policy. (C) an alert dose value for CT procedures reviewed in clause (iii) of this paragraph must be established by the QMP. (D) actions to be taken for cases when the alert dose value was exceeded, which may include patient follow-up. (E) a process determining who has access and authority to make changes to the protocol management systems, including a method to prevent inadvertent or unauthorized modifications to a CT protocol. (v) if CT fluoroscopy is performed, the RPC must establish and implement operating procedures and training designed to minimize patient and occupational radiation exposure. (vi) provide an annual report to the radiation safety committee or radiation safety officer, in the absence of a radiation safety committee, (vii) At a minimum the RPC members must meet as often as necessary to conduct business but at intervals not to exceed 12 months. (viii) A record of each RPC meeting must be maintained. The record must include the date, names of individuals in attendance, minutes of the meeting, and any action taken. (g) PET CT and SPECT CT systems. Registrants of CT systems used solely to calculate attenuation coefficients in nuclear medicine studies are exempt from the accreditation and quality assurance requirements of subdivisions (c) through (f) of this section. The registrant must follow the manufacturer's recommendations for the quality assurance tests to be conducted at the manufacturer's recommended frequency. (h) CT and CBCT units utilized in podiatry and veterinary offices. CT systems, including CBCT systems, solely used for podiatry imaging or non-human imaging must meet the requirements of radiation protection surveys as indicated in 24 RCNY Health Code § 175.16, and are otherwise exempt from the accreditation and quality assurance requirements of subdivisions (c) through (f) of this section. Facilities must follow the manufacturer recommended testing protocols and frequency as stated in the manufacturer's manual, and if any tests are shown to exceed manufacturer tolerances, the registrant must complete all required corrective actions within 30 days of such test. (Added City Record 4/24/2019, eff. 5/24/2019)