Background: Analysis of rejected radiographs is an important quality indicator of any radiology department. At King Abdulaziz Medical City (KAMC), about 185,000 radiographs are performed annually. Methods: The rejected radiographs over a period of 5 years were analyzed using a dedicated electronic rejection system. The rejection is performed by a certified radiologist and communicated electronically to the concerned technologist. Results: A total of 455 rejected radiographs were reviewed and analyzed. Of the reviewed rejected radiographs, 247 were adults (60%) whereas 166 were pediatrics (40%). In terms of sex, 231 (56%) of the rejected radiographs were for men and 182 (44%) were for women. The most common reason for rejection was labeling (22%), followed by procedure protocol (20%). Other reasons included positioning (14%), processing (14%), artifacts (13%), wrong documentation (9%), and exposure error (6%). The rejection due to exposure error was very low (6%) owing to the utilization of digital systems that offer a wide exposure latitude. Reported data at hospitals that use analog systems show up to 67% of rejections were due to exposure error. In terms of body parts, the highest rejection was for extremities (43%) followed by chest (31%). The remaining rejected radiographs includes abdomen (9%), spine (8%), pelvis (5%), and head and neck (4%).Conclusion: The outcome of this study can be used to set up training programs to improve radiological services and reduce the unnecessary radiation exposure to the patients.
In diagnostic imaging, one of the main goals of a quality assurance (QA) program is to produce consistent high-quality radiographs at a minimum exposure to the patient. Reject analysis is a complementary part of QA program in radiology department.[2–4] A considerable number of radiographs taken may be rejected because of quality issues. In the USA, 8% of radiographs that are performed annually are rejected due to different reasons. Patients might undergo repeated x-ray examinations after their initial x-ray radiographs are rejected due to different reasons such as poor image quality, artifact, anatomy cutoff, patient motion, and equipment malfunction. Rejected radiographs that are repeated may lead to extra radiation dose to the patient; reduction in the lifetime of the x-ray machines, which added expenses on the health care system; and long waiting list.[5,6] In the analog system era, rejected radiographs were counted by the number of wasted radiographs that were physically collected from a waste container. Nowadays, rejected digital radiographs are counted by the number of deleted radiographs from the modality.[5,7] There has been a general belief that the rejection with the analog systems was significant because of the relatively narrow exposure latitude. On the other hand, digital systems were assumed to have reduced the rejection due to more forgiving exposure latitude. In addition to the wider exposure latitude, the advantages of digital over analog systems include processing capabilities and manipulation, which allow technologists to adjust radiographs' quality. In digital systems, radiographs are more likely to be rejected due to positioning errors or artifacts. On the other hand, in analog systems, exposure error has been reported as the most common reason for rejection, accounting for as high as 67%.[10,11] In terms of body parts, the most frequently rejected radiographs are extremities and chest, followed by spine, pelvis, head and neck, and abdomen.[9,12,13] This is expected due to the fact that extremities and chest are the most common body parts radiographed in imaging department. The purpose of this study was to evaluate the radiographs reject rate and to identify the causes of rejection. This study is the first of its kind and scale to be conducted at King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia. The results of this study help to improve radiological services and reduce the unnecessary radiation exposure to the patients.
Material and Methods
KAMC is a large tertiary care hospital in Riyadh, Saudi Arabia with a bed capacity of 1600. A retrospective cross-sectional study of rejected radiographs was conducted in the radiology department at KAMC. The department has 22 digital radiography and six computed radiography units. About 185,000 radiographs are performed annually. Rejected radiographs over a period of approximately 5 years (from January 2013 to August 2017) were retrieved and analyzed using a dedicated electronic rejection system “Peervue” (Change Healthcare Company, Nashville, Tennessee, USA). This system is an intelligent software that helps in automating and simplifying workflow and communication within diagnostic imaging department. The rejection is performed by a certified radiologist and communicated electronically through the Peervue system to the concerned technologist. The radiologist submits feedback through the system. Cases are then presented on work lists for the supervisors. The supervisors will review cases with performing technologists. Radiographic examinations, reasons for rejection, body parts, sex, and age were recorded. When rejecting a radiograph, the reason for rejection had to be selected among eight predefined reasons in Peervue system. All plain radiographs performed during that period were included. Magnetic resonance imaging, computed tomography, nuclear medicine, ultrasound, fluoroscopy, and mammography were excluded from the study. A total of 455 rejected radiographs were collected, reviewed, and analyzed. Forty-two radiographs were excluded from the total because they were rejected due to documentation issues and not quality reasons. Cases were categorized according to reason for rejection. The categories include labeling, procedure protocol, positioning, processing, artifacts, wrong documentation, exposure errors, and others. Internal Review Board approval was obtained from King Abdullah International Medical Research Center. Descriptive statistics was used with Microsoft Excel 2010 to calculate the frequency and percentage of reject rates.
A total of 247 rejected radiographs were for adult patients and 166 for pediatric patients (60% and 40%, respectively). It is worth noting that KAMC classifies patients younger than 14 years as pediatrics. In terms of sex, 231 (56%) of the rejected radiographs were for male patients and 182 (44%) were for female patients. There is no standard method of categorizing the reasons for rejection in the literature. For example, patient motion is sometimes considered as positioning error and other times as artifact. This may explain variations in the reported data on reasons for rejection. In our study, we assigned the rejected radiographs into eight different reasons, namely, labeling, procedure protocol, positioning, processing, artifacts, wrong documentation, exposure error, and others.
The most common reason for rejection in our study was labeling with a total of 101 radiographs (22%), followed by procedure protocol, 92 (20%). Positioning error, on the other hand, accounted for 14% of the rejections. Figure 1 shows the distribution of reasons for rejection. In the figure, the rejections classified under “other” included lack of proper protection (four radiographs) and missing clinical information (three radiographs). In terms of body parts, majority of the rejected radiographs were extremities 180 (43%) and chest 127 (31%). Other rejected radiographs included abdomen 36 (9%), spine 33 (8%), pelvis 22 (5%), and head and neck 15 (4%) [Figure 2].
Reject analysis is an important quality measure of modern radiology department. There is currently lack of sufficient reported data of reject analysis in the Kingdom of Saudi Arabia. Number and type of rejected radiographs will vary depending on whether it is a teaching hospital or not, and whether it is a specialized or general hospital. It will also depend on whether the hospital is equipped with digital or analog units. KAMC is a tertiary care hospital comprising large general hospital, surgical trauma center, advanced cardiac center, and a dedicated specialized children hospital. In our study, among the various reasons for rejection, labeling constitutes the highest percentage of rejected radiographs (22%). It has been reported that the introduction of digital markers causes technologists to ignore using the physical markers, which is considered unacceptable and a reason for rejection. A number of studies reported positioning and exposure errors as the most important reasons for rejection. Table 1 compares positioning and exposure errors in our study with similar studies in the literature. A wide variation in the percentage of positioning errors can be seen. This might be due to the variability in defining positioning error. For instance, some researchers include labeling as part of positioning error whereas others do not.[14–19] American Association of Physicists in Medicine (AAPM) Task Group 151 reported up to three-fold variation in the percentage of rejection among different hospitals, depending on type of practice and setting. Rejections due to exposure errors (over and under exposure) were comparable with results from other studies [Table 1]. The relatively low rejection rate due to exposure error is a result of the utilization of digital systems that offer extended dynamic range. Although constituting 40–60% of all rejects in the analog systems, the relative contribution of exposure errors in the digital systems has been reduced to less than 15%. In KAMC, the rejection due to artifact is 13%. Comparable studies show rejection due to artifact ranging from 7% up to 11% depending on the type of hospital. The slightly higher percentage was probably due to the fact that we included patient motion under artifact (motion artifact). Artifacts were seen more frequently with female patients compared with males (57% and 43%, respectively). This is anticipated because artifacts are more likely to be seen on female patients due to presence of hair pins, hair clips, and accessories. The introduction of picture archiving and communication systems has generated new type of rejects such as the incorrect choice of processing algorithm. Processing errors accounted for 14% of the total reject rate in our study. There is, however, lack of published data on processing errors to compare our results with. In terms of examination type, extremities and chest counted for over 70% of the number of images rejected. Our results were consistent with published data [Table 2].[9,12,18] Traditionally, the decision to reject an image for quality reason is made by the radiographer. The causes of rejects are in many cases defined and reported with reference to radiographer's subjective evaluations.[7,19–27] Unnecessary repeats were found to have been caused by poor technical judgment and no availability of radiologist for advice. The utilization of the Peervue system has allowed the radiologist to review the images, assess the quality, and reject those images that do not add diagnostic information. The rejection is based on a more consistent quality standard. The radiologists are therefore taking a more active role in the guidance and training of the radiographers. The system is integrated with the Radiology Information System so that the radiologist decision and reason for rejection are communicated electronically to the appropriate radiographer immediately. This process significantly enhances the image quality discussion between radiologists and radiographers and enlightened the radiographers on the image quality criteria expected by the radiologists.
The AAPM recommend rejection analysis to be performed on at least a quarterly basis, but preferably monthly. The automation of the process of rejection allows us to continuously monitor rejection rate and take necessary action in a timely manner. Results of the analysis of the rejection can be utilized to plan for training programs and continuous education and as a baseline for need assessment.
Radiograph reject analysis has been used to assess the quality of radiographic examinations in the KAMC radiology department. In our study, we have identified that the most common reason for rejection is labeling followed by procedure protocol and positioning errors. The utilization of digital radiography systems helped keep the exposure errors minimal. Chest and extremities radiographs constitute the highest body part subject for rejection. The proposed method of electronic communication of the rejection reasons provides an efficient method for collecting and analyzing the reject rate. It is recommended that a review of the rejected radiographs should be made on periodic basis as part of the overall QA program of the hospital to identify staff competency gaps and plan for appropriate training.
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Conflicts of interest
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