Quality Control: Stereotactic Breast Biopsy (Revised 12-12-19)
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Modified on: Fri, 13 Dec, 2019 at 12:58 PM
Documentation of quality control (QC) is required as part of the application process. All facilities applying for accreditation must comply with the minimum frequencies listed below. Detailed instructions for each of the tests listed below are contained in the 1999 ACR Stereotactic Breast Biopsy Quality Control Manual. Upon acceptance of a facility’s initial application, the ACR will send a QC manual to the modality’s supervising physician at the practice site address.
Acceptance Testing
Initial performance testing should be performed upon installation of new stereotactic breast biopsy equipment. This testing should be more comprehensive than periodic performance and compliance testing and should be consistent with current acceptance testing practices.
Annual Medical Physicist Survey
The medical physicist must perform the QC tests listed in the table below when the equipment is installed and at least annually thereafter. 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. The medical physicist must provide a written report of findings of acceptance testing and performance evaluations to the responsible physician(s) and to the professional(s) responsible for service of the equipment. If appropriate, the medical physicist should inform the site supervisor of the required service. Written reports must be provided in a timely manner consistent with the importance of any adverse findings. If use of the equipment poses imminent danger to patients or staff, the medical physicist must take immediate action to preclude use of the equipment.
Annual Medical Physicist’s System Performance Evaluation |
QC Test | Description |
Stereotactic Breast Biopsy Unit Assembly | Ensures that the mechanical components of the system are reliable and safe for patient use |
Collimation Assessment | Ensures that the x-ray collimation does not allow significant radiation to extend beyond the edges of the image receptor and that the biopsy window aligns with the x-ray field (Collimation Test criteria requires "5 mm on any side” but per MQSA criteria, it is acceptable in upright systems if the collimation results fall within ±2% of the SID.) |
Focal Spot Performance and System Limiting Spatial Resolution | Ensures that the focal spot performance is adequate to minimize geometric blur in the image, and that the system-limiting resolution is adequate for the imaging requirements of the procedure |
kVp Accuracy and Reproducibility | Ensures that the indicated peak x-ray energy is accurate and reproducible, so that consistent contrast may be maintained |
Beam Quality Assessment (Half-Value Layer Measurement) | Ensures that the x-ray beam is sufficiently penetrating to minimize patient dose, but not so penetrating that contrast is reduced |
Automatic Exposure Control (AEC) System or Manual Exposure Performance Assessment | Assesses the performance of the system’s AEC or manual techniques regarding appropriate film optical density or detector signal levels over a range of breast thicknesses |
Receptor Speed Uniformity | Ensures that intensifying screens are adequately uniform in speed or that the digital detector is adequately uniform across its entire useful area |
Breast Entrance Exposure, Average Glandular Dose and Exposure Reproducibility | Ensures that breast radiation doses are adequately low to protect the patient and sufficient to maintain adequate image quality |
Image Quality Evaluation | Ensures that image quality is consistently high enough to meet the demands of the procedure |
Artifact Evaluation | Detects the presence of artifacts, isolates their sources and ensures that they are eliminated or minimized |
Localization Accuracy Test | Ensures the accuracy of the localization system, including needle position, stereo position calculations and the user interface |
Radiologic Technologist Quality Control Tests
A QC program must be implemented for all units and should be established with the assistance of a medical physicist. The radiologic technologist must perform the QC tests listed in the table below at the specified minimum frequencies. The medical physicist should identify the person responsible for performing the tests and may choose to increase the frequency of testing based on the facility and usage. If any QC parameter being monitored falls outside of the control limits, corrective action should be taken. A medical physicist should be available to assist in prescribing corrective actions for unresolved problems.
Radiologic Technologist's QC |
QC Test | Description | Frequency |
Localization Accuracy Test | Verifies system alignment and performance (procedure varies by manufacturer and system type) | Daily before patient exams |
Darkroom Cleanliness (N/A if digital used) | Minimizes artifacts on film images by maintaining the cleanest possible conditions in the darkroom | Daily |
Processor QC (N/A if digital used) | Ensures consistent performance of the film processor | Daily |
Phantom Images | Ensures that film density, contrast, uniformity, and image quality of the x-ray imaging system are optimal | Weekly |
Screen Cleanliness (N/A if digital used) | Ensures that cassettes and screens are free of dust and dirt particles that may degrade image quality or mimic calcifications | Weekly |
View boxes and Viewing Conditions (if film used) | Ensures that the view boxes and viewing conditions are optimized and maintained at optimal levels | Weekly |
Hardcopy Output Quality (if hardcopy produced from digital data) | Ensures that the quality of hardcopy output is consistent over time and matches the gray scales presented on the CRT monitor | Monthly |
Visual checklist | Ensures that the mammography x-ray system and, if applicable, the digital imaging system are working properly and that the mechanical rigidity and stability of the system are optimal | Monthly |
Analysis of Fixer Retention in Film (N/A if digital used) | Determines the quantity of residual fixer (hypo) in processed film as an indicator of keeping quality | Quarterly |
Compression | Ensures that the x-ray imaging system can provide adequate compression in the manual and automatic powered mode | Semiannually |
Repeat Analysis | Determines the number and causes of repeated patient exposures and identifies ways to improve efficiency, reduce patient breast dose, and cut costs | Semiannually |
Screen-Film Contact (N/A if digital used) | Ensures that optimum contact is maintained between the screen and the film in each cassette | Semiannually |
Darkroom Fog (N/A if digital used) | Ensures that darkroom safelights and other light sources inside and outside of the darkroom do not fog film | Semiannually |
Zero Alignment Test (if required by manufacturer) | Verifies that zero coordinate is accurate | Before each patient |
Additional tests if required by manufacturer |
| As required by manufacturer |
Preventive Maintenance
Preventive maintenance should be scheduled, performed, and documented by a qualified service engineer on a regular basis. Service performed to correct system deficiencies should also be documented and service records maintained by the facility.
Revision History for this Article |
Date | Section | Description of Revision(s) |
12-12-19 | All | Article created; FAQs incorporated; No criteria changes |
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