Recommendations for additional imaging on emergency department CT examinations: comparison of emergency- and organ-based subspecialty radiologists

Comparing thoracic and abdominal subspecialists' follow-up recommendations for abdominal findings identified on chest CT

PURPOSE

To compare thoracic and abdominal radiologists' follow-up recommendations for abdominal findings identified on chest CT.

METHODS

This Institutional Review Board-exempt, retrospective study was performed at a large academic medical center with subspecialty radiology divisions. We used a combination of natural language processing and manual reviews to identify chest CT reports with and without abdominal findings that were interpreted by thoracic radiologists in 2019. Three random samples of reports were reviewed by two subspecialty trained abdominal radiologists for their agreement with thoracic radiologists' reporting: abdominal findings with follow-up recommendation (Group 1), abdominal findings without follow-up recommendation (Group 2), and no abdominal findings reported (Group 3). Primary outcome was agreement between thoracic and abdominal radiologists for the need for follow-up of abdominal findings. Secondary outcomes were agreement between subspecialists for the presence of abdominal findings and referring clinician adherence to recommendations. Fischer's exact test was used to compare proportions.

RESULTS

Abdominal radiologists agreed with need for follow-up in 48.5% (16/33) of Group 1 cases and agreed follow-up was not necessary for 100% (34/34) of Group 2 cases (p < 0.001). Abdominal radiologists identified abdominal findings in 31.4% (11/35) of Group 3 cases, none of which required follow-up. Referring clinician adherence to thoracic radiologist follow-up recommendations for abdominal findings was 13/33 (39.4%).

CONCLUSION

Abdominal radiologists frequently disagreed with thoracic radiologist recommendations for follow-up of abdominal findings on chest CT. Chest radiologists may consider abdominal subspecialty consultation or clinical decision support to reduce unnecessary imaging.

Incidental Radiology Findings on Computed Tomography Studies in Emergency Department Patients: A Systematic Review and Meta-Analysis

STUDY OBJECTIVE

An incidental finding is defined as a newly discovered mass or lesion detected on imaging performed for an unrelated reason. The identification of an incidental finding may be an opportunity for the early detection of a serious medical condition, including a malignancy. However, little is known about the prevalence of incidental findings in the emergency department (ED) setting and the strategies that can be used to mitigate the risk associated with them in the ED. This study aimed to estimate the overall prevalence of incidental findings and to summarize the currently described measures to mitigate the risks associated with incidental findings.

METHODS

On November 22, 2020, a systematic literature search of PubMed, EMBASE, and Scopus was performed for studies that were published in peer-reviewed journals and reported the prevalence of incidental findings in computed tomography (CT) scans in patients in the ED. Patients who received CT scans that included the head, neck, chest, or abdomen/pelvis were included. The study characteristics, overall prevalence of incidental findings, prevalence of incidental findings by body region, and prespecified subgroups were extracted. The criteria used for risk stratification within individual studies were also extracted. Pooled estimates were calculated using a random-effects meta-analysis.

RESULTS

A total of 1,385 studies were identified, and 69 studies met the inclusion criteria. The included studies represented 147,763 ED encounters or radiology reports across 16 countries, and 83% of studies were observational, cross-sectional studies. A total of 35 studies (50.7%) were in trauma patients. A large degree of heterogeneity was observed across the included studies. The overall pooled prevalence estimate for any incidental finding was 31.3% (95% confidence interval 24.4% to 39.1%). We found great variation in the methods described to mitigate the risk associated with incidental findings, including a lack of standardized risk stratification, inconsistent documentation practices, and only a small subset of studies describing prospective interventions aimed at improving the recognition and management of incidental findings from the ED.

CONCLUSION

In patients in the ED receiving CT scans, incidental findings are commonly encountered across a broad range of ED chief complaints. This review highlights the existence of great heterogeneity in the definitions used to classify incidental findings. Future studies are needed to determine a clinically feasible categorization standard or terminology for commonly encountered incidental findings in the ED setting to standardize classification and documentation.

Management of Incidental Pulmonary Nodules: Influencing Patient Care Through Subspecialized Imaging Review

OBJECTIVE

To evaluate whether thoracic radiologist review of computed tomography-detected incidental pulmonary nodules initially reported by non-thoracic imagers would change management recommendations.

MATERIALS AND METHODS

The Radiology Consultation Service identified 468 computed tomography scans (one per patient) performed through the adult emergency department from August 2018 through December 2020 that mentioned the presence of a pulmonary nodule. Forty percent (186/468) were read by thoracic radiologists and 60% (282/468) were read by non-thoracic radiologists. The Radiology Consultation Service contacted all patients in order to assess risk factors for lung malignancy. Sixty-seven patients were excluded because they were unreachable, declined participation, or were actively followed by a pulmonologist or oncologist. A thoracic radiologist assessed the nodule and follow up recommendations in all remaining cases.

RESULTS

A total of 215 cases were re-reviewed by thoracic radiologists. The thoracic radiologist disagreed with the initial nodule recommendations in 38% (82/215) of cases and agreed in 62% (133/215) of cases. All discordant cases resulted in a change in management by the thoracic radiologist with approximately one-third (33%, 27/82) decreasing imaging utilization and two-thirds (67%, 55/82) increasing imaging utilization. Nodules were deemed benign and follow up eliminated in 11% (9/82) of discordant cases.

DISCUSSION

Our study illustrates that nodule review by thoracic radiologists results in a change in management in a large percentage of patients. Continued research is needed to determine whether subspecialty imaging review results in increased or more timely lung cancer detection.

Radiologist Variation in the Rates of Follow-up Imaging Recommendations Made for Pulmonary Nodules

OBJECTIVE

Determine whether differences exist in rates of follow-up recommendations made for pulmonary nodules after accounting for multiple patient and radiologist factors.

METHODS

This Institutional Review Board-approved, retrospective study was performed at an urban academic quaternary care hospital. We analyzed 142,001 chest and abdominal CT reports from January 1, 2016, to December 31, 2018, from abdominal, thoracic, and emergency radiology subspecialty divisions. A previously validated natural language processing (NLP) tool identified 24,512 reports documenting pulmonary nodule(s), excluding reports NLP-positive for lung cancer. A second validated NLP tool identified reports with follow-up recommendations specifically for pulmonary nodules. Multivariable logistic regression was used to determine the likelihood of pulmonary nodule follow-up recommendation. Interradiologist variability was quantified within subspecialty divisions.

RESULTS

NLP classified 4,939 of 24,512 (20.1%) reports as having a follow-up recommendation for pulmonary nodule. Male patients comprised 45.3% (11,097) of the patient cohort; average patient age was 61.4 years (±14.1 years). The majority of reports were from outpatient studies (62.7%, 15,376 of 24,512), were chest CTs (75.9%, 18,615 of 24,512), and were interpreted by thoracic radiologists (63.7%, 15,614 of 24,512). In multivariable analysis, studies for male patients (odds ratio [OR]: 0.9 [0.8-0.9]) and abdominal CTs (OR: 0.6 [0.6-0.7] compared with chest CT) were less likely to have a pulmonary nodule follow-up recommendation. Older patients had higher rates of follow-up recommendation (OR: 1.01 for each additional year). Division-level analysis showed up to 4.3-fold difference between radiologists in the probability of making a follow-up recommendation for a pulmonary nodule.

DISCUSSION

Significant differences exist in the probability of making a follow-up recommendation for pulmonary nodules among radiologists within the same subspecialty division.

Lung Cancer Biopsies

Image-guided percutaneous transthoracic needle biopsy (PTNB) is a well-established and minimally invasive technique for evaluating pulmonary nodules. Implementation of a national lung screening program and increased use of chest computed tomography have contributed to the frequent identification of indeterminate pulmonary nodules that may require tissue sampling. The advent of biomarker-driven lung cancer therapy has led to increased use of repeat PTNB after diagnosis. Percutaneous insertion of markers for preoperative localization of small nodules can aid in minimally invasive surgery and radiation treatment planning. This article discusses PTNB, patient selection, and biopsy technique, including minimizing and managing complications.