Jonathan Hero Chung MD, Presenter: Nothing to Disclose

Emily Siegel, Abstract Co-Author: Nothing to Disclose

Ahmed El-Sherief MD, Abstract Co-Author: Nothing to Disclose

Brent Little MD, Abstract Co-Author: Nothing to Disclose

Carlos Andres Rojas MD, Abstract Co-Author: Nothing to Disclose

Suhny Abbara MD, Abstract Co-Author: Research funded, Bracco Group Consultant, Partners Imaging Consultant, Perceptive Informatics, Inc Consultant, Magellan Health Services, Inc

Quynh Truong MD, Abstract Co-Author: Nothing to Disclose

Udo Hoffmann MD, Abstract Co-Author: Research grant, Bayer AG Research grant, Bracco Group Advisory Board, Vital Images, Inc Advisory Board, Siemens AG Advisory Board, Bayer AG

The aim of this study was to determine the prevalence of incidental pulmonary nodules detected during cardiac CTA in a consecutive cohort of patients with suspected coronary artery disease and to project the test burden based on existing guidelines.

We included 2,989 consecutive patients referred to cardiac CTA from 2005-2007. Patients with incidental pulmonary nodules were identified through review of clinical CT reports. Patients with definitively benign or previously known nodules were excluded. The number of recommended follow up chest CT scans was projected based upon the Fleischner guidelines after review of data sets by radiologists. Cost of the subsequent CT exams was calculated using Medicare rates. Published estimates of radiation dose for standard chest CT (9.1 mSv) were used to calculate cumulative radiation exposure.

Overall, incidental pulmonary nodules were detected in 693 patients (23.2%, 63.8% male, 61±13 years-old). Average size of the largest nodule was 4.8±3.1 mm (range 2-26 mm). Follow-up recommendations for chest CT per Fleischner guidelines were: no follow-up in 195 patients (28.1%), one CT scan in 280 patients (40.4%), two CT scans in 130 (18.8%) patients, three CT scans in 59 (8.5%) patients, and further evaluation with FDG-PET or tissue sampling in 29 (4.2%) patients. With a total of 717 subsequent chest CT scans, the projected overall cost was $1,296,000 and projected increased radiation exposure was 6.5 Sieverts. If all highly suspicious nodules were biopsied rather than evaluated with FDG-PET, total cost would increase by $28,130. During follow-up 4 pathology-confirmed lung cancers were detected.

Pulmonary nodules are found in more than 20% of patients with suspected CAD referred for cardiac CTA. The application of the Fleischner guidelines for follow-up of these nodules results in substantial additional cost and radiation exposure. Formal cost effectiveness and quality of life analysis may need to be performed in order to define specific reporting guidelines in this setting.

Pulmonary nodules are commonly encountered on cardiac CTA; the benefits of detecting early lung cancer must be balanced with the extra cost and radiation dose from follow up CT scans.

Chung, J, Siegel, E, El-Sherief, A, Little, B, Rojas, C, Abbara, S, Truong, Q, Hoffmann, U, Incidental Pulmonary Nodules Detected on Cardiac CTA in the Setting of Non-acute Suspected or Known CAD: Projected Number, Cost, and Increased Radiation Dose.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9009122.html