Personnel Qualifications
Interpreting Physician Personnel Qualifications [1]
Must meet country’s qualification requirements
Must meet one of the following Continuing Experience requirements:
Currently meets the Maintenance of Certification (MOC) requirements for the ABR or the Osteopathic Continuous Certification (OCC) for AOBR.
Physicians reading CT examinations across multiple organ systems must have interpreted 200 CT exams over the prior 36 months.
Physicians reading organ-system-specific exams (i.e. body, abdominal, musculoskeletal, head) across multiple modalities must interpret a minimum of 60 organ-system-specific CT exams in 36 months; however, they must interpret a total of 200 cross-sectional imaging (MRI, CT, PET/CT and ultrasound) studies over the prior 36 months (the 60 organ-system-specific exams are included in the 200 cross-sectional imaging studies).
Cardiac CT Continuing Experience requirements [2]
Radiologists reading Cardiac CT examinations must have read 50 exams over the prior 24-month period. The cardiac exams interpreted will count toward the overall continuing experience for other CT modules.
Cardiologists reading Cardiac CT examinations must have continuing experience in accordance with level 2 requirements or higher - 50 examinations each year.
Must meet one of the following Continuing Education requirements:
Currently meets the Maintenance of Certification (MOC) requirements for the ABR or the Osteopathic Continuous Certification (OCC) for AOBR.
150 hours CME (including 75 hours category 1) in the prior 36 months pertinent to the physician's practice patterns (see the ACR Practice Parameter for Continuing Medical Education).
Cardiac CT Continuing Education requirements:
Radiologists interpreting CT Cardiac must have earned at least 15 CME hours in CT (half of which must be category 1) in the prior 36-month period and should include CME in Cardiac CT as is appropriate to the physician's practice needs.
Cardiologists interpreting CT Cardiac must have completed at least 30 hours of coursework in the prior 36-month period, in accordance with Level 2 requirements.
In addition, all physicians interpreting CT examinations must:
Have completed an accredited diagnostic radiology residency or 80 hours of documented, relevant classroom instruction including diagnostic radiology and radiation safety physics. Otherwise, physicians must demonstrate training in the principles of radiation protection, the hazards of radiation exposure to both patients and radiological personnel, and appropriate monitoring requirements.
Be thoroughly acquainted with the many morphologic and pathophysiologic manifestations and artifacts demonstrated on computed tomography. Additionally, supervising physicians should have appropriate knowledge of alternative imaging methods.
Be knowledgeable of patient preparation, and training in the recognition/treatment of adverse effects of contrast materials for these studies, as described in the ACR-SPR Practice Parameter for the Use of Intravascular Contrast Media.
Be responsible for reviewing all indications for the examination; specifying the use, dosage, and rate of administration of contrast agents (per the 2005 Clinical Competence Statement on Cardiac CT and MR), specifying the imaging technique, including appropriate windowing and leveling; interpreting images; generating written reports; and maintaining the quality of both the images and interpretations.
Be familiar with the meaning and importance to the practice of CT of total radiation dose to the patient; exposure factors; conscious sedation principles that are performed in the practice; and post-processing techniques and image manipulation on workstations.
Medical Physicist Personnel Qualifications
Must meet country qualification requirements
Must perform 2 CT unit surveys within 24 months
Must meet one of the following Continuing Education requirements:
Currently meets ABR Maintenance of Certification requirements for medical physics.
Complete 15 CEU/CME (1/2 Cat 1) in the prior 36 months (must include credits pertinent to the modality).
Must be familiar with the principles of imaging physics and of radiation protection; guidelines of the National Council on Radiation Protection and Measurements; laws and regulations pertaining to the performance of the equipment being tested; function, clinical uses, and performance specifications of imaging equipment; and calibration processes and limitations of instruments used for performance testing.
Is responsible for the conduct of all surveys of the equipment. The medical physicist may be assisted by properly trained individuals in obtaining data. The medical physicist is responsible for determining if the assisting individual is “properly trained.” These individuals must be approved by the medical physicist in the techniques of performing tests, the function and limitations of the imaging equipment and test instruments, the reasons for the tests, and the importance of the test results. Any assisting individual must be under the direct supervision of the medical physicist during the surveys (direct supervision means that the medical physicist must be present in the facility and immediately available to furnish assistance and direction throughout the performance of the procedure; direct supervision does not require that the medical physicist be present in the room when the procedure is being performed; teleconferencing does not constitute direct supervision).
Technologist Personnel Qualifications
Must meet country's qualification requirements.
Must have 24 hours of continuing education every 2 years.
CE must be relevant to imaging and the radiologic sciences, patient care.
CT must include credits pertinent to technologist's clinical practice.
CT Equipment Quality Control (QC)
CT equipment specification and performance must meet all local requirements and applicable ACR Practice Parameters and Technical Standards.
A quality control (QC) program must be established and implemented under the supervision of a qualified medical physicist (QMP). Initial performance testing (acceptance testing) is required upon installation. All facilities must maintain a documented QC program and must comply with the minimum frequencies of testing outlined in the 2012 ACR CT QC Manual, revised edition (2017).
Acceptance Testing
Acceptance testing is intended to measure quantifiable system parameters, which may then be compared to the manufacturer's specifications. A complete evaluation of system performance should be performed by a QMP after completion of installation and prior to patient imaging.
Acceptance testing encompasses the verification of the purchase specifications for a particular CT system. This testing should be conducted using the phantom, procedures, and specifications specified in the purchase contract. Discrepancies should be reported to the Service Engineer.
At the time of the acceptance testing, additional tests may be performed by the medical physicist. These tests are not used to determine whether the CT scanner meets the manufacturer's specification, but they may serve as the initial set of baseline results needed for future QC testing or they may be used to further characterize and optimize use of the CT scanner. Please note that additional testing outside of the vendor identified tests, methods, and acceptance criteria may not be supported by the manufacturer.
Annual Medical Physicist Survey
All facilities must demonstrate compliance with ACR QC requirements by including a copy of the facility’s most recent CT Annual System Performance Evaluation Summary Form (to include evaluation of the technologist QC) signed by a QMP (see attachment below). Your medical physicist must use the summary form provided by the ACR or one similar that itemizes pass-fail results of all the same tests using the same names and order as outlined on the ACR form.
The QMP must evaluate the performance of each CT unit at least annually. The ACR realizes that surveys cannot usually be scheduled exactly on the anniversary date of the previous survey. Therefore, a period of up to 14 months between surveys is acceptable. This evaluation must include, but not be limited to:
Participation in Review of Clinical Protocols with the CT Protocol Review & Management Team
Scout Prescription and Alignment Light Accuracy
Table Travel Accuracy
Radiation Beam Width [3]
Low-Contrast Performance
Spatial Resolution
CT Number Accuracy [4]
Artifact Evaluation
CT Number Uniformity
Dosimetry
CT Scanner Display Calibration
Other tests as required by state or local regulations
It is recommended that the Annual System Performance Evaluation include documentation of any corrective action taken (i.e. test failures or data outside of action limits).
In the case of dual source scanners, the primary and secondary tubes should both be evaluated in the annual system performance evaluations as the goal of the annual evaluations is to ensure that the scanner is functioning as designed in all respects and that it is being used optimally.
Continuous Quality Control
A continuous QC program must be established for all CT units with the assistance of a QMP. An on-site radiologic technologist should be identified to be responsible for conducting routine QC. The continuous QC program must include, but not be limited to, the following:
Water CT Number and Standard Deviation [5]- Daily
Artifact Evaluation- Daily
Wet Laser Printer Quality Control- Weekly (if applicable)
Visual Checklist- Monthly
Dry Laser Printer Quality Control- Monthly (if applicable)
Display Monitor Quality Control- Monthly
All QC testing must be carried out in accordance with written procedures and methods. The results of the QC program must be monitored annually by the QMP. If the results of a QC test fall outside the control limits, corrective action should be taken. A QMP should be available to assist in prescribing corrective actions for unresolved problems. All deficiencies must be documented and service records maintained by the CT facility.
Preventative Maintenace
Preventive maintenance must be scheduled, performed, and documented by a qualified service engineer on a regular basis. Service performed to correct system deficiencies must also be documented and service records maintained by the CT site.
QC Procedures Following Repairs
ACR 2017 CT QC manual indicates that QC procedures should be performed at acceptance testing, during an ongoing QC program following parameter specific frequencies and following major repairs. A major repair includes replacement or repair of components such as an x-ray tube or detector assembly. The evaluation should be determined by the qualified medical physicist based on the type of component repaired or replaced. A matrix of response is provided below for guidance for several major repairs or replacements:
Major repairs[6]
X-ray Tube Replacement
KV Generator Replacement
Detector Assembly Replacement
mA/kV Replacement
For all major repairs, the QMP must conduct the evaluation in person and technologist QC must be performed before clinical use. If results pass, then the QMP should complete appropriate evaluation as soon as possible within 30 days.
Other non-major repairs:
- CT Service Calibrations-Requires QMP oversight* and normal QC guidelines should be followed.
- HV Generator Service Calibration- Requires QMP oversight* and normal QC guidelines should be followed.
- Control Console Replacement- Requires QMP oversight* and normal QC guidelines should be followed.
- Collimator Adjustments- Requires QMP oversight* and normal QC guidelines should be followed.
- Software Upgrade- The QMP must discuss with the vendor for affected parameters.
- Protocol Change- Requires QMP oversight* with the radiologist and technologist and normal QC guidelines should be followed.
Clinical Image Evaluation and Labeling
Facilities must review 1 typical clinical examination from each module performed (including one pediatric exam if patient protocols are utilized) and attest to meeting the ACR clinical image quality and labeling requirements found in the links below.
Exam Requirements
Artifacts
Excessive motion artifacts that result in indistinct or "double" contours to organs should be repeated if they significantly degrade the examination quality.
The images should not exhibit excessive noise.
Streak artifacts that compromise diagnostic quality with sections not repeated may be a deficiency. However, internal metallic surgical clips may cause minor streak artifacts that will not be judged as deficient.
Exam Identification and Labeling
Patient and technical data must be displayed on the images or be available in the DICOM header.
Patient name (first and last)
Patient age (or date of birth)
Gender of patient, date of exam
Institution name
Left/right labeling
Technical parameters
kV
mA (or mAs or effective mAs or mAs/slice, as reported by scanner)
Rotation time
Pitch (if available)
Reconstructed image thickness (slice width)
Reconstructed filters/kernel
Display field of view (FOV)
Image number (numbered consecutively based on anatomic location)
Table position (scan location)
Presence of absence of IV contrast
Dose report
Policies and Procedures
In addition to the general policies and procedures noted in the instruction article, the facility must also have the following CT specific policies and procedures:
Specific pediatric examination protocols (if applicable)