Radiation dose management has become a “hot topic” as witnessed by several RSNA presentations about this subject and also obviously the attention it has gotten in the press because of several incidents causing people to be severely over-exposed with X-ray radiation.
The best known incident is probably the case in Cedars-Sinai in LA, California, where 269 patients were over-exposed as a result of CT exams, to the degree that they suffered hair loss, nausea and other symptoms associated with radiation over dose.
In addition to these incidents, there also has been an effort to reduce the dose to a level that provides images that are clinically acceptable albeit with added noise and reduced resolution. This is especially critical for pediatric applications. This has become even more important with the advent of digital radiography as there is a tendency for technologists to increase the dose, aka as the “dose creep” phenomena.
Both state and federal government is taking this issue seriously through new bills (notably in California), hearings and rules by the FDA. The MITA organization, representing imaging vendors, is also actively involved by defining guidelines and standards for dose reporting and registration. The most important factor is the definition of policies and procedure, technique charts, training and education as well as awareness. Healthcare IT can assist here as well, as an electronic health record could potentially be used to record radiation dose events and therefore alert a physician to have him potentially reconsider to perform yet another CT scan or conventional X-ray.
There are also technical solutions, as there is no question that the industry went a little bit overboard with their high volume multi-slice CT scans, fueled by a commercial drive by operators of clinics to come in for a “whole body scan”, which is in many cases not warranted based on clinical indication. Proper collimation, using different techniques to liite exposure for example for a head and give only the full exposure to the areas needed the most, such as for a pelvis and abdomen help a lot. Also, new solutions for dose recording and registration are implemented rapidly in the new devices.
Dose reporting is critical to allow for benchmarking against yet-to-be defined national standards and good practices. The ACR is setting up several trail centers to start recording this to allow for a database to be created. The IHE organization has stepped up and defined the so-called Radiation Exposure Monitoring profile that defines the use cases and DICOM transactions to implement this. There was actually a booth from the IHE at the recent RSNA showing the implementation of a modality simulator and an actual dose reporting system.
The IHE profile uses a so-called Dose Structured Report which is defined by the DICOM standard and has a template for both X-ray radiation dose and CT. These templates contain information about the observer/system, date/time and start and end of the event, the number of events that are recorded and the actual dose information. It also includes the method used to calculate and/or record the radiation event. This information can be sent to a PACS, RIS, or dose registry station, depending on the capabilities and architecture of the radiology imaging system. Dose reports can be sent, after anonymization, to an external registry.
There are other short-term solutions to record the dose, none of which are good solutions but might provide an interim approach. One could for example, capture a screen with the dose information, which can later be processed by an optical character recognition software package (OCR) to extract the information. Other solutions could be the use of the DICOM MPPS dose information, which migth not be as detailed and exact as the Structured Report (SR), but is better than nothing if the device does not (yet) support SR yet. Another solution that is used especially for digital mammography is to get this information from the DICOM image header.
In conclusion, there is no question that because of regulatory and consumer pressure, X-ray radiation devices will be required to be modified, upgraded and equipped with the capability to exchange dose information is a standard manner. Institutions will also have to store radiation events and dose details, most likely in the RIS, but also possibly in a PACS or separate application. Eventually, I would assume that these events will become part of an electronic and/or personal health record as well. Implementations are strongly suggest to use standards for the implementation, especially the IHE radiation dose profile.