AbstractThe been adopted from screen-film technology without further
AbstractThe introduction of PACS, computed radiography, and digital radiography, has brought many changes to the radiology department.
It has impacted the service received by patients, and it has also changed the way the front office staff, straight across to the radiologist operates. The integration of RIS, HIS, PACS, HL7 and DICOM, workflow and throughput has been improved. Creating a paperless wastage system that is cost effective and efficient for radiographers, physicians and also office management.
Although the transition from conventional screen-film imaging to digital image acquisition has been almost completed during the last couple of years, examination parameters, such as tube voltage, tube current, and filtration have been adopted from screen-film technology without further adjustments. Digital systems, however, are characterised by their flexibility and productivityOther advantages of digital radiography include higher patient throughput, increased dose efficiency, and the greater dynamic range of digital detectors with possible reduction of radiation exposure to the patient. The future of radiography will be digital, and it pushes radiologists to be familiar with the technical principles, image quality criteria, and radiation exposure issues associated with the various digital radiography systems that are currently available.IntroductionThe more technology changes, the more it changes. The introduction of computed radiography (CR), have advanced to improve film-based radiography systems. As the population grew, healthcare improvements needed to be made. Efficiency and Image quality was the main factor in patient diagnosis.
Hence, computed radiography (CR) was created to fill the gap within the radiology department. Advancement in photostimulable storage phosphor (PSP) and new processing units that were capable of reducing acquisition time and generate diagnostic quality X-rays. Though this improvement has been managed by a worldwide software, a system called picture archiving and communication system (PACS), it seems that the quality of X-rays and workflow needed to be the main priority for modern radiological health care. Hence, digital radiography (DR) was introduced. The name computed radiography (CR) and digital radiography (DR) has been used interchangeably, however, digital radiography (DR) focuses on a complete process.
Thus, digital radiography (DR) systems have been touted as a totally integrated X-ray source-generator-detector solution with images displayed for review within the room shortly after the X-ray exposure. Whereas, computed radiography (CR) is an offline process that integrates the technologist in-process handling. As a result, this seems to be the future. “In any equipment purchase, you need to look at the clinical utility of what you are trying to achieve. Then you must brace that against the quality of the product and the quality of the outcome you are trying to achieve: in this case, image and imaging” said Steven Metcalf, BS, CRA, Manager of Radiology Services, Altru Health System, Grand Forks, ND. An equipped radiography department must have greater workflow, managing imaging systems, patient information efficiency, image quality and consistency with an ease-of-use. Since the introduction of the digital era, it has impacted the productivity of the radiology department immensely.
ObjectivesThere are six (6) primary objectives; 1. Digital Radiography systems have increased workflow by reducing patient exam times.2.
Digital Radiography produce better image quality, which aid in proper diagnosis.3. Picture Archiving and Communication System (PACS) is used as a communication tool for digital systems and reduce wastage.4. Integrated system such as Registered Information Systems (RIS) and Hospital Information Systems (HIS) helps in paperless patient information storage and efficiency between front office to technologist. 5.
Highlight some of the improvements from film-based technology to digital radiographic technology. 6. Radiation dose to the patient with Digital Systems are significantly lower than film-screen systems.
ApproachFor this assignment, I used Google Search Engine, EBSCOHOST and Google Scholar to find articles, journals and websites that had information based on various subjects. What was most interesting was Google Search Engine and not Google Scholar or EBSCOHOST. They both had many “Subscribe” and “paid” options to read articles or even an abstract. Below are materials frequently used:Journals;• HIS/RIS/PACS Integration: Getting to the Gold Standard by Radiology Management (2004)• Digital Radiography Image Quality: Image Processing and Display by American College of Radiology (2007)• ACR-AAPM-SIIM practice guideline for digital radiography by Journal of Digital Imaging ( 2013)Article;• Image Acquisition and Quality in Digital Radiography by ASRT Essential Education • The evolution of Digital Radiography by Imaging Technology News (2014)• Computed Radiography (CR) and Digital Radiography (DR): Which Should You Choose? : by VAREX imaging ( 2016)Findings and DiscussionsFindings; DR Systems and WorkflowAs we shift from film-screen to digital radiography (DR), workflow in the x-ray department have shown to decrease workload on the system and the technologist.
According to (Bookchever, 2004), the push towards enterprise-wide image management solutions, where digital images from radiology are seamlessly linked with information from clinical information systems and other databases, and they are accessed seamlessly from a single point of end-user interaction. Therefore the “gold standard” of system integration would provide the platform for improved workflow, patient throughput and patient safety, as well as decreased cost. Hence system the integration of radiology information system (RIS), hospital information system (HIS), and picture archiving and communication systems (PACS) was needed to sync with Health Level-7 and DICOM.The highlight of this new technology according to (Colbeth, 2016) is that digital radiography (DR) offers throughput compared to computed radiography (CR) because it embeds the imaging processing cycle in the acquisition task, images can appear as quickly as five (5) seconds. Computed radiography (CR) involves more steps because cassettes processing takes longer. Consequently, digital radiography (DR), improves workflow because more images can be taken and processed in the same amount of time, allowing imaging facilities to handle more patients in a given period of time and consequently lower the cost per image. (Shannon Alexander, 2016) Also said that image accessibility is improved because the need to physically track down a hard copy image no longer exist.
The physical space and resources to store hardcopy images are eliminated as image viewing typically occurs via a computer monitor. Also the cost to copy and distribute the images decrease significantly as transport expenses are nearly eliminated with PACS, and the cost of materials needed to copy the images is minimal. Discussion; DR Systems and WorkflowThe digital workflow is incredible fast and efficient with digital radiography (DR). Once the x-rays is taken, the images are acquired on mere seconds. Using PACS, the technologist can pre-program the anatomy information so the machine is ready to go before the patient enters the room, all the technologist needs to position the patient. The technologist makes sure that the anatomy is accurately in position, and without having to change cassettes, can take all the images needed. Less time and attention is spent on the equipment, and more time an attention engaged with the patient.
The one-on-one time and connection from more human contact and less machine work can make a difference about how the patient perceives his or her care experience. For example within the clinical setting, the technologist pre-programs, carries cassette and then call in the patient and runs off with the cassette to process and returns with another cassette. That disconnect with the patient can make the patient feel uneasy and unsure. Also with digital technology, film wastage is almost obsolete. Many is sent via the computer. Though the printed films can be lost and damage, it can also add dose to some patients when they come in for a check-up, having to redo the examination.
Findings; DR Systems and Image QualityPhysical parameters of radiographic systems, such as contrast, sharpness, and noise, act in unison in determining the final appearance of a radiograph and affect not only the portrayal of the expected pathologic condition but also that of the normal anatomy. According to (Dallessio, 2018), in terms of image quality, the fact that digital radiography (DR) is a closed system; therefore the risk of artefacts due to contamination with dirt or dust is reduced. Optimal image quality remains essential for radiologists evaluating diagnostic radiographs. As mentioned by (Shannon Alexander, 2016), spatial resolution for indirect and direct digital radiography systems is higher that of images required with CR detectors but lower than spatial resolution on film-screen radiographs. Spatial resolution refers to the visible sharpness of images and the ability to present fine details that help the radiologist differentiate between objects. However, one factor that should take into consideration in digital radiography (DR) is “Exposure factor creep”. “Exposure factor creep” is a well-known phenomenon related to the wide latitude of digital radiography (DR).
Artifacts are not apparent until exposure exceeds 10 times the appropriate level, (Charles E. Willis, 2014). According to the study, (SpahnM., 2005) dynamic range is a measure of the signal response of a detector that is exposed to x-rays. In conventional screen-film combinations, the dynamic range gradation curve is S shaped within a narrow exposure range for optimal film blackening (Fig 1); thus, the film has a low tolerance for an exposure that is higher or lower than required, resulting in failed exposures or insufficient image quality.
For digital detectors, dynamic range is the range of x-ray exposure over which a meaningful image can be obtained (Fig 2). Digital detectors have a wider and linear dynamic range, which, in clinical practice, virtually eliminates the risk of a failed exposure. Another positive effect of a wide dynamic range is that differences between specific tissue absorptions (eg, bone vs soft tissue) can be displayed in one image without the need for additional images. Discussion; DR Systems and Image QualityOptimal image quality remains essential for radiologists evaluating diagnostic radiographs. Image acquisition, image presentation, and image archiving used to be bundled on a single film sheet. With digital detectors, these main functions of radiography have been uncoupled, which is a prerequisite condition for PACS.
The inverse correlation between dose and image contrast is eliminated with digital systems. Image contrast and brightness can be optimised independently. Digital systems, however, are characterised by their flexibility: the acquisition dose can be reduced at the expense of image quality and vice versa. The imaging parameters must be optimised according to the best performance of a particular system. The traditional means of dose containment, such as positioning and collimation, are as valid for digital techniques as they were for conventional techniques. Digital techniques increasingly offer options for dose reduction.
At the same time, there is a risk of substantially increasing the patient dose, possibly unawares, due to the lack of visual control. Therefore, implementation of dose indicators and dose monitoring is mandatory for digital radiography. The use of image quality classes according to the dose requirements of given clinical indications are a further step toward modern radiation protection. With an inadequate image, diagnoses of medical conditions are in jeopardy and leave the radiologist and corresponding health care facility legally responsible. Therefore, understanding the factors that go into creating a quality image using digital radiography while maintaining the ALARA principle is essential.Findings; DR Systems and Dose Efficiency According to (Colbeth, 2016), both GOS (gadolinium oxysulfide) and CsI (cesium iodide )-based DR detectors have higher dose efficiency than CR. When DR with CsI is used, DR systems are two to three times more efficient at converting dose to signal than CR.
Automatic exposure control is another method used to lower patient exposure and prevent dose creep, (Euclid Seeram, 2014) Automatic exposure control units are designed to turn off the x-ray generator when an appropriate exposure level has been received at the image receptor during an exposure, (Andriole, et al., 2013). This is done through the use of 3 to 5 radiation detectors, or ionization chambers, (Euclid Seeram, 2014). “In conventional screen-film radiography, inadequate images were easily identified. The majority of these images were subsequently re-taken. With digital techniques, however, image processing can compensate for acquisition errors. Appropriate collimation of the X-ray beam is important for both radiation protection and image quality in a DR/CR setting” said (MacMahon, 2003).
By controlling patient dose (Martin Uffmann, 2009) states that the inverse correlation between dose and image contrast is eliminated with digital systems. Therefore, “film blackening” as an indicator of overexposure, no longer exists. In digital radiography, there is a reciprocal relationship between dose and signal-to-noise ratio: a lower acquisition dose is associated with increased image noise and vice versa. Thus, images will be hardly ever rejected by the radiologist when overexposed.
Discussion; DR Systems and Dose EfficiencyAnother trend that is affecting every area of medical imaging is the development of products that aid in decreasing and managing radiation dose exposure. The use of CsI (cesium iodide ) increased dose utilization means that DR can produce the same image quality as CR at a lower dose or that DR can produce higher contrast resolution images than CR using the same dose. Also, optimal collimation area depends on the individual patient and is the responsibility of the radiographer, taking into account the patient body size, the diagnostic question, and the individual requirements of the examination type. This becomes especially important when using systems that are not cassette-based (some CR systems, all DR systems) and that use large-area detectors. Implementing the use of radiographic technique charts can keep technologists’ settings more consistent between examinations. Technique charts should take into account the anatomical area under study as well as patient size. As radiographers are trained to use technical charts in CR settings, AEC should be used to help reduce the dose to the patient.
It is not taught in the practice environment but it should be encouraged. Recommendations• Even though the cost to switch from Computed Radiography to Digital Radiography is high, it is a better closed system that reduces artifacts and provides better image quality that reduces dose to the patient. • Since public health institutions are moving towards digital radiography, in order to make it work efficiently, is to integrate all software applications that aid in the processing and transmission of patient information and digital x-rays. • Also, by creating a system that allow patient information to be shared on a private network from hospital to hospital. Reduces the need for CD’s and paper if installed.
• Workshops need to be implemented to update and train older and new radiographers. Since this technology is Information Technology based, a required knowledge of computer systems should be mandatory for applicants. • Based on the education aspect, institutions should focus on Computed and Digital Radiography. Therefore, students are aware of new development in x-ray technology. • The use of a “Tablet” interface to review and receive digital X-rays using a web based platform for mobility. This can be an in-hospital program for better efficiency. • For radiation safety, the department should create a protocol of technical factors that are standard and non-standard patient based.
This will help decrease the assurance of dose creep in digital radiography systems. • For quality assurance purposes, enlist a weekly log to check for image quality testing, using a phantom, to check for image degradation. ConclusionDigital imaging brings a significant technological advancement to the radiology profession. Although the physical elements used to obtain a radiograph have not changed from the standard method of film-screen radiography, the mechanism used to capture x-rays and convert them into an image is mostly digital. Digital radiography provides advantages for department workflow, efficiency, and image quality.
Although digital radiography introduces the problem of dose creep, a technologist’s commitment and adherence to departmental and organizational policies decreases the risk of unnecessary radiation exposure to the patient and possible litigation as it relates to this emerging technology.Yes I do agree that an integrated digital system will increase work efficiency practice form the front desk clerks to radiographers and physicians. Plus the use of digital technology in a large institution or a growing population is applicable for the modern age. I do agree that digital systems have a wider dynamic range than that of computerized radiography that allows for image manipulation when post processing and allows fewer repeats. However, I do agree that both systems are capable of increasing dose to the patient if a proper protocol or quality assurance isn’t kept within the department. Also reduce not having to repeat is by proper positioning and communication to the patient.
I do agree that the less radiographers spent using the machine rather than paying more focus to the patient can make the patient feel more intuitive and connect. Giving the impression radiographers are providing proper health care. ReferencesAndriole, K.
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