WBCT has been used frequently for major trauma patients worldwide. In addition to traumatic findings that require immediate management, Sierink et al. reported an incidental finding rate of 44.5% (143/321) with traumatic WBCT in 2013.5 Seah et al. also showed that 57/104 trauma patients (54.8%) had incidental findings identified on the WBCT radiologist report.6 Overall, the incidental finding rate in the previous literature ranged from 31 to 54%.5–13 The results of the current study are consistent with those of previous studies (89/217, 41.0%). However, owing to the critical condition of trauma patients who require WBCT, the images are usually read for traumatic findings. Thus, nontraumatic findings may be overlooked by first-line trauma surgeons or ED physicians. Some of these nontraumatic findings could be life-threatening or require further evaluation and treatment. The nontraumatic findings on WBCT for trauma patients generally have poor follow-up rates.5,6,9,10,15,16
Although it is difficult to identify and treat all WBCT findings, a comprehensive interpretation and follow-up plan is important for such nontraumatic findings. However, the distribution of nontraumatic findings is diverse among body regions and patients (Table 3). Some findings indicate an immediate need for treatment, some indicate close follow-up or continuous monitoring, some could not be identified by the primary imaging examination and needed further examinations, and some are harmless and do not indicate the need for any intervention. Patients might benefit from an early diagnosis of malignancies; on the other hand, these findings may increase anxiety and create extra medical costs for a series of additional examinations, and ultimately, the lesion might not affect the patient’s health. The fundamental and perhaps most important question is which patients have a higher probability of having nontraumatic findings that may indicate the need for early treatment?
Compared with patients without nontraumatic findings, patients with nontraumatic findings were significantly older (57.3 vs. 38.9, p < 0.001). This aging effect is especially significant for findings in the abdomen (57.9 vs. 41.3, p < 0.001). In addition to several intra-abdominal malignancies, gallstone disease is one of the leading causes of digestion-related hospital admissions for elderly patients.17,18 The frequency of gallstone disease varies among different countries and ethnic populations as well as various regions of each country.19 In most developed countries, the overall prevalence of gallstone disease has been reported to be between 10% and 20%.20,21 Furthermore, previous studies have shown that the occurrence of gallstone disease increases with age, with a high prevalence rate at 50–60 years in both men and women.21–25 Renal stones are also a common disease with a significant healthcare burden worldwide. Epidemiological studies show that the prevalence rate ranges between 4% and 20% in developed countries.26–27 In Taiwan, the prevalence of upper urinary tract stones has been reported to range from 2.85–9.6%.28–30 Age is a risk factor for urolithiasis, especially in people who are 50–60 years old.31–34 Nontraumatic findings are significantly more common in patients older than 40 years of age, as reported by previous studies.10,15 As the average age of the modern population continues to increase and a corresponding increase in the average age of injured patients occurs, nontraumatic findings will become even more common and a greater patient-care and medical-legal dilemma. Therefore, more attention should be paid to the interpretation of WBCT images of elderly patients. Furthermore, an alert notification system for important incidental findings on WBCT may be needed. Even after admission, most physicians focus on a patient’s traumatic findings and treat the major problems first. Some incidental findings noted on the WBCT performed prior to admission could be overlooked, causing patients to lose the clinical benefit. It was reported that an alert notification of critical test results improved patient care35,36. The implementation of a similar system for the interpretation of incidental findings on WBCT could be feasible and beneficial.
Another point of interest is that female patients had more important nontraumatic findings in the head and neck than male patients (15.0% vs. 4.0%, p = 0.015). Among the 10 patients with thyroid nodules who were diagnosed incidentally with WBCT, 7 were female (11.9%), and only 3 were male (1.9%). Thyroid nodules are predominantly found in females.37–39 Although most thyroid nodules are benign, thyroid cancer occurs in 4 to 15% of patients with thyroid nodules.40–45 In the current guidelines, it is suggested that people with thyroid nodules receive follow-up care.46 These findings suggest that WBCT images of the head and neck regions should be read carefully for females.
Approximately 2.8% (6/217) of patients had nontraumatic findings that were potentially severe and needed further follow-up. Chronic aortic dissection (Stanford type B) was diagnosed incidentally with WBCT in a patient with a traumatic brain injury. After his trauma was treated, a thoracic endovascular aortic repair procedure was performed smoothly. There was one patient with abrupt tapering of the distal common bile duct and atrophy of the left liver on WBCT. This nontraumatic finding was recorded on the medical chart, and magnetic resonance imaging was performed accordingly by an outpatient department physician after discharge. Then, an intraductal papillary mucinous neoplasm with biliary obstruction was diagnosed. Except for the above two patients, the other patients had no follow-up records of potentially severe incidental findings, even after discharge. ED physicians or trauma surgeons usually focus on patients’ traumatic findings, so subacute lesions are overlooked. Prior literature has noted the poor follow-up of such nontraumatic findings in trauma patients.5,6,9,10,15,16 In regard to the management of nontraumatic findings, a previous study has looked at the use of midlevel providers to perform tertiary trauma surveys once the patients are admitted and to notify those patients prior to discharge with appropriate follow-up plans.16 Another study implemented a dedicated incidental finding coordinator for the detection and follow-up of nontraumatic findings, which resulted in a more than 2.5-fold higher rate for the identification of incidental findings and adequate follow-up both in the hospital and after discharge.15 This seems to represent a potential solution to this patient-care and medical-legal dilemma in the future. This approach will rely on collaborative efforts between radiologists, trauma and emergency physicians, and primary care physicians. Primary care physicians should value those nontraumatic findings more and arrange examinations, interventions or outpatient department follow-up examinations when the patients are discharged from the ward. More immediately, however, front-line trauma staff need to be vigilant about discussing the nontraumatic findings with their discharged patients to ensure that all patients have appropriate follow-up care arranged.
The limitations of this study include its retrospective nature and limited patient sample from a single institution. Although there are a large number of trauma patients in our ED per year, only a small proportion of patients with major trauma were enrolled in the current study. Thus, possible selection bias may have limited our conclusions. The WBCT protocol was designed for trauma patients. Therefore, the images of the head and neck were non-contrast enhanced. Under this condition, some lesions that need contrast enhancement for diagnosis could not be detected. In addition, the general use of WBCT for all trauma patients is infeasible because of biohazards of radiation exposure and expanded medical cost. Another concern is that some findings were difficult to define, making it challenging to determine whether they should be included in this study. For example, spinal degenerative changes were only reported in severe cases that could be observed on imaging. A reporting threshold might be needed for minor cases. Further studies with larger sample sizes and prospective designs are needed to establish an accurate interpretation system for a comprehensive evaluation of both traumatic findings and nontraumatic findings.