Reducing Exposure and Dose in Medical Radiology
Reading Time: 9 minutes read
Carestream solutions help improve patient safety and clinical outcomes.
A fundamental goal of radiographers is to complete an imaging exam that provides sufficient information for an accurate clinical diagnosis–and at the lowest possible dose. Fortunately, considerable progress has been made in reducing exposure in digital radiology without sacrificing image quality.
Continue reading to learn about Carestream’s suite of solutions to help you improve patient safety and clinical outcomes. To make it easier for readers, I’ve organized the available solutions into three exam types: general X-ray, chest imaging, and pediatric imaging.
Reducing dose in general X-ray exams
Capturing an image involves multiple steps that must be executed with precision. Thus, it is not surprising that human error is the biggest contributing factor to overexposure. In fact, incorrect exposure settings and patient positioning errors are the primary causes for retakes in general digital radiology; and 15% of retakes are due to exposure issues, according to a report by the American College of Radiology. (1)
This is why Carestream is automating many of these tasks with our Smart Room Assist Software. The features are specifically designed to dramatically reduce issues with patient positioning–which in turn reduces reject rates. In fact, during site evaluations, our DR Smart Room Assist features helped our customers realize an average reject rate reduction of 16% from their current rates. (2)
For example, Smart Technique automatically selects the appropriate acquisition technique based upon the patient’s size. This feature alone can eliminate up to 492 retakes every year. Additional Smart Room Assist features that help reduce exposure are Smart Patient Position, Video Assist, and Virtual Collimation.
Additional software features to help reduce exposure are embedded in our ImageView Software package. For example, IEC Exposure Index allows quick assessment of the amount of radiation used to create the image; while Deviation Index immediately compares the chosen exposure to your facility’s specific target goal.
We also have a Detector Verification alert that signals radiographers when they choose the wrong detector–which would result in the need to repeat the exam. The alert notifies the user when it senses physical movement of a non-selected detector. Exposure is disabled until the user confirms the correct detector. This feature is especially useful on mobile systems where multiple detectors are used.
Speaking of detectors, do you know that cesium iodide (Csl) detectors offer up to a 30% dose reduction when compared to gadolinium oxysulfide (GOS) detectors? Carestream’s broad family of detectors all use cesium iodide.
One last recommendation for reducing dose in general X-rays is to take advantage of Carestream Health’s groundbreaking Smart Noise Cancellation (SNC) technology. The artificial-intelligence (AI)-based software allows a user to reduce dose without loss of image quality.(3) SNC provides improved diagnostic quality, preservation of fine detail, and better contrast-to-noise ratio for images acquired at clinically nominal exposures.
Reducing dose in chest X-rays
Chest X-rays (CXRs) are one of the most difficult radiographs to interpret due to the dense structure of the heart, complex overlying and underlying patient anatomy, and the ever-present motions of the lungs and heart.
To help radiographers capture optimum images for radiologists to interpret–without a dose penalty–Carestream offers four impactful software technologies. I already mentioned Smart Noise Cancellation Software. The other three are Smart Grid Software, Dual Energy, and Digital Tomosynthesis.
SmartGrid Software: reduce scatter and dose
When imaging thicker areas of the body–such as the chest–there is the potential for degradation of image quality due to radiation scatter. The traditional solution to reduce scatter has been the use of anti-scatter grids.
Grids can be highly effective in reducing scatter; however, they typically require a higher dose of radiation exposure, as the X-ray beam is attenuated by the lead strips. Our SmartGrid Software uses an advanced algorithm that estimates low-frequency scatter distributed throughout an image and reduces it. The result: image quality comparable to images acquired with an anti-scatter grid but at a lower radiation dose.
Dual Energy: new standard of care for chest imaging
Ideally, radiologists would like to view separate images of the chest–one of soft tissue and another of bone–in order to make a more accurate diagnosis. In an effort to achieve this separation, imaging providers have explored dual-energy, image-capture technology that captures two radiographic images of a patient in rapid succession. However, the benefits of the technology also brought increased radiation dose. (Two exposures are required–one at a relatively lower energy X-ray exposure and a second at a relatively higher energy.) Also, imaging providers had difficulty overcoming the artifacts and misregistration resulting from patient motion (due to heartbeat and breathing) between the capture of the high- and low-energy image.
Fortunately, Carestream achieved a patented, technology breakthrough. Our Dual Energy method delivers excellent image quality at a similar entrance exposure as a standard PA chest X-ray. Our innovative differential filtration imaging subtracts rapidly acquired, low- and high-energy exposures for the generation of bone and soft tissue images–and it has automatic patient motion correction. We believe that Dual Energy has the potential to become the new standard of care in chest imaging.
Digital Tomosynthesis: a 3D extension of general radiography
Digital Tomosynthesis (DT) is a three-dimensional extension of general radiography. It uses a single sweep of X-ray exposures and streamlines operator workflow by separating the process of DT exposure acquisition from image volume formation. As a result, it can generate data from a series of low dose X-ray images of the same organ, taken at the same X-ray exposure, from different angles.
Carestream is currently partnering with Robarts Research Institute to explore further the clinical value of digital X-ray, Digital Tomosynthesis, and Dual Energy technologies to help improve the outcomes of patients with cardiothoracic and pulmonary diseases.
Pediatric imaging solutions for the smallest patients
Carestream’s pediatric X-ray solutions are tailored to support the special and specific requirements for imaging your smallest patients. Our right-sized cassettes and pediatric software meet the recommendations of government agencies, such as the Image Gently Alliance for Radiation Safety in Pediatric Imaging, and the safety principles of As Low As Reasonably Achievable (ALARA).
Let’s start with our detectors. The DRX Plus 2530C panel is a small-format, high-resolution (98 µm pixel spacing), high-detective quantum-efficiency (DQE) panel that fits easily into a neonatal incubator X-ray tray, and is also ideal for tabletop extremity exams. Its cesium scintillator layer helps to ensure the best possible image quality, while its right-sized fit lets you seamlessly incorporate it into your workflow in the NICU and pediatric ICU.
In addition, Carestream offers a single-shot detector for imaging pediatric patients with scoliosis. The single exposure capability of our DRX-LC Detector helps reduce patient dose for long-length imaging while delivering improved image quality—no more stitching. It also makes long-length imaging easier and more comfortable for both patient and radiographer by reducing hold time and the need for retakes.
In addition to using a highly efficient detector, it’s also essential to use the appropriate acquisition techniques (e.g., kVp, mAs, and filtration) across the wide range of pediatric body habitus. This range of body sizes–from the smallest neonatal patient to the largest adolescent–requires acquisition techniques tailored to each patient’s size and age. To help with this challenge, Carestream offers Pediatric Image Optimization and Enhancement Software that automatically adjusts and tailors the Carestream EVP Plus image-processing parameters for any one of the seven pediatric body-size categories. Pediatric optimization uses patient weight along with patient age to calculate exposure parameters.
A commitment to dose reduction
Capturing the best possible image at the lowest exposure requires constant monitoring and education. Our image-review capabilities are ideal for quality education programs and continuous improvement. Use them to measure and compare exposure and other key parameters for each exam performed. The tools include:
- Dose reporting collects and distributes comprehensive dose information to PACS–including DAP values, techniques, and exposure indices.
- Total Quality Tool uses a phantom and software to ensure your detector remains within the standards of Image Gently and government guidelines for pediatric imaging.
- Administrative Analysis and Reporting Software queries all Carestream systems in the facility and reports exposure levels per exam and per tech, repeat rates, repeat reasons, techniques used, and more.
I hope you found this overview of hardware and software features to help reduce dose and exposure in general X-ray helpful. Carestream has decades of imaging expertise, and we continually push the envelope on image quality to help you improve patient safety and clinical outcomes.
About the Author:
Renée Nichols RT(R)CT is a Worldwide Applications Engineer at Carestream Health. She is registered in X-ray and CT and has 39 years of experience in medical imaging. In her current role, she provides clinical and field support, develops end-user training, and commercialization and trade trial support.
1 Unified Database for Rejected Image Analysis Across Multiple Vendors in Radiography. Kevin J Little, Ingrid Reiser, Lili Liu, Tiffany Kinsey, Adrian A Sánchez, Kateland Haas, Florence Mallory, Carmen Froman, Zheng Feng Lu.
2 During customer site evaluations using Carestream DR Smart Room Assist features.
3 These statements were verified using Carestream detectors in a reader study performed by board certified radiologists comparing pairwise images taken at nominal dose (CsI ISO 400 speed/GOS ISO 320 speed) and reduced dose (CsI ISO 800 speed/GOS ISO 500 speed) with SNC.