Is Reject Analysis Necessary after Converting to Computed Radiography?

Abstract

Reject analysis is an accepted standard of practice for quality assurance in conventional radiology. The need for reject analysis has been challenged by the introduction of computed radiography (CR) because of low reported reject rates and because criteria for improperly exposed images were lacking. Most CR systems include quality control (QC) workstations that are capable of modifying the appearance of images before release, and also of deleting poor images before they are analyzed. Texas Children's Hospital has been using computed radiography since October 1995, and now conducts essentially filmless imaging operations using a large-scale picture archival and communications system (PACS) with fourteen CR units. The QC workstation is a key element of our CR operation; however, the extensive software tools of the workstation are limited in terms of avoiding repeated examinations. Neither the QC workstation nor the PACS itself is designed to support reject analysis, so our task was to design a system that accommodates identification, isolation, and archiving of repeated examinations, making use of our electronic imaging systems. We had already developed transcription codes for our radiologist's examination critique, so we adopted these as codes for rejected images. The technologist at the QC workstation appends the critique code to patient demographic information, modifies other fields to indicate that the image is rejected, and archives as usual. Modified routing tables prevent the release of rejected images but ensure they are available for review. Our frequency and reasons for repeated examinations are comparable to other reports of reject analysis in the literature. The most frequent cause of a repeated examination is mis-positioning. The process of developing the method for capturing repeat, collecting the data, and analyzing it is only one-half of the battle; to achieve an improvement in services, it is necessary to feed back the results to management and staff and to implement training as indicated. It is our intention to share our results with PACS and CR vendors in the hope that they will incorporate some mechanisms for reject analysis into the design of their systems.

Image Retake Analysis in Digital Radiography Using DICOM Header Information

“…Other studies 10,16,17 have described that most film-screen retakes were exposure and processing issues, while most digital retakes were due to a mispositioning of the patient, as it has happened in our case. The causes of repetition and the relative rates were similar in the abdomen and the chest images.…”

“…Image retake analysis is a method of identifying image faults, sources of error, and in general, inappropriate practices. It is a key aspect in any quality assurance program, 2,4-9 a basic tool to avoid unnecessary doses to patients in radiology departments, 10,11 and a way to save time in services already suffering from a substantial scheduling backlog, improving efficiency in the use of X-ray equipment and saving space in local picture archiving and communication system (PACS). This could result eventually in better patient care.…”

One Year’s Results from a Server-Based System for Performing Reject Analysis and Exposure Analysis in Computed Radiography

“…6 During early clinical experience with digital radiography, it was proposed that this new technology might eliminate repeated images and render any RAP obsolete. 7 However, imaging departments quickly realized that this was not the case 8 and that a RAP was still a vital part of a QA program. In fact, digital radiography has made reject analysis more complicated and, ironically, may facilitate the repetition of images owing to the ease of acquisition, especially with cassette-less systems where no manual intervention occurs between receptor exposure and image readout.…”

“…Physical evidence of rejected images no longer exists for tallying, and on many early digital imaging systems, radiographers can simply delete unwanted images, which are ultimately never accounted for. 8,9 This is still a problem today, and one manufacturer of indirect digital radiography (iDR) equipment whose equipment is installed at our institution allows the user to select "Delete" from a right-click pop-up menu during an active examination unless the function is locked by the administrator. Even if deletion is not an option, rejected images often simply reside in the system until they are deleted to make room for more images.…”

Maintaining Quality Control Using a Radiological Digital X-ray Dashboard

“…[1][2][3][4][5][6][7][8] There are several peer-reviewed articles addressing the question or need for a form of higher level quality assessment in the digital Xray department, but none is offering a software solution or a simple means of supporting managers and those responsible for overseeing the quality of digital X-ray imaging in becoming more effective and efficient in delivering the intended service. [9][10][11][12][13] At the beginning of digital projection radiography, repeats, dose, and usage were only manageable by manually scribing ledgers or by printing to film and keeping every exposure as in the traditional workflow fashion. Both methods sacrificed workflow at the department level to enable digital radiographic imaging.…”