While CT imaging has become an invaluable tool for expedited medical evaluation, its use has been associated with an increasing number of incidental findings, the handling of which creates both medical and logistical challenges.  Pulmonary nodules are among the most frequent and medically relevant incidental findings, but are easily overlooked – especially when discovered incidentally during hospitalization.  While hospital discharge summaries provide an opportunity to communicate such incidental findings to patients and their medical care providers, little data is currently available regarding the rate at which pulmonary nodules discovered incidentally on CT abdominal imaging during hospitalization are included in the discharge summary.   


A review of 7173 in-patient CT Abdominal studies done from 2012-2014 in patients aged 35 years or greater was performed to determine the prevalence of incidental pulmonary nodules mentioned in radiology reports and the factors associated with pulmonary nodule inclusion in the discharge summary.  Those patients with CT Chest imaging done during that hospitalization or within 30 days prior to admission were excluded to ensure that pulmonary nodules were incidental and asymptomatic.  Nodule size, characteristics, and stability compared to available prior imaging were noted in addition to patient age, gender, smoking status and prior history of malignancy.  Radiology reports were reviewed to determine if the pulmonary nodule(s) was mentioned in the summary headings of the report and whether specific follow up recommendations were provided.  Discharging service (medical/medical subspecialty vs. surgical/surgical subspecialty) was also noted.


Incidental pulmonary nodules were noted in 402 patients (5.6%), of whom 68.7% were ≥60 years old, 56.5% were men, and 46.3% were current or former smokers.  The majority of patients had solitary nodules (71.6%) and most had maximum nodule size of ≤4mm (58.5%).  Taking smoking status, nodule size, and reported size stability into account, 208 patients (2.9%) required follow-up surveillance as per 2005 Fleischner Society guidelines.  Among solitary pulmonary nodules requiring further surveillance (n=147), the mean risk of malignancy based on the Mayo Clinic Solitary Pulmonary Nodule Risk calculator was 7.9% (IQ range 3.0-10.5%) with 28% having a malignancy risk of ≥10%.  Of the total 208 nodules needing surveillance, 48 patients (23%) had some discharge summary documentation, 34 patients (16.4%) had discharge summaries recommending nodule follow-up and 19 patients (9.1%) had discharge summaries recommending a timeframe for repeat CT imaging.  Factors positively associated with inclusion of the pulmonary nodule in the discharge summary were 1) mention of the pulmonary nodule in the summary headings of the radiology report, 2) radiologist recommendation for further surveillance and 3) medical discharging service. 


Pulmonary incidental nodules mentioned in radiology reports from in-patient CT abdominal imaging are likely under-documented in the discharge summary, potentially contributing to poor follow-up rates and missed opportunities for early diagnosis.  While radiologist recommendation improves rates of nodule inclusion in discharge summaries, further system-based interventions are still required.