Abstract No. 399 - Multidisciplinary interrater reliability of ventricle ratio screening for submassive pulmonary embolism on axial non-EKG-gated CT pulmonary angiography

Abstract

No. 399 Multidisciplinary interrater reliability of ventricle ratio screening for submassive pulmonary embolism on axial non-EKG-gated CT pulmonary angiography Z.L. Bercu, V.V. Patil, L. Azour, V.L. Bishay, M. Salvatore, J. Oropello, R.A. Lookstein, A.M. Fischman, E. Kim, S.F. Nowakowski, R.S. Patel; Division of Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York, NY; Department of Radiology, Mount Sinai School of Medicine, New York, NY; Department of Surgical Critical Care, Icahn School of Medicine at Mount Sinai, New York, NY Purpose: A right ventricle (RV) to left ventricle (LV) ratio 40.9 and positive pulmonary embolism (PE) on computerized tomography pulmonary angiography (CTPA) is associated with doubled 30-day mortality [1]. If confirmed on echocardiography, patients may benefit from more aggressive therapy. RV:LV ratios on axial imaging may be comparable to reformated 4-chamber views [2]. The purpose is to assess the interrater reliability (IRR) of ventricle measurements for RV: LV ratio calculation among diverse readers. Materials and Methods: 17 patients with PE underwent axial non-gated CTPA between November 1, 2013 and March 31, 2014. Patient charts and imaging were reviewed for demographics, treatment, and PE burden using the Modified Miller Score (MMS). 4 readers measured maximum RV/LV diameters following a 5 minute training session. Reader 1 was a radiology resident with 1.5 years imaging experience. Reader 2 was a chest radiologist with 14 years experience. Reader 3 was an interventional radiologist with 7 years experience. Reader 4 was a critical care physician with 24 years experience treating PE. IRR was assessed using intra-class correlation (ICC). Results: 5 patients had malignancy. 5 had deep venous thrombosis. Average MMS was 4.6 (range: 0-16). 4 of 10 patients had right cardiac dysfunction on echocardiogram. 5, 2, and 1 received low molecular weight heparin, rivaroxiban, and warfarin, respectively. 6 received combination therapy either for bridging or complication. 2 were ineligible for anticoagulation. 1 underwent peripheral thrombolysis. 4 underwent filter placement. ICC was 0.870 (CI: 0.728-0.948) for the RV and 0.870 (CI: 0.728-0.948) for the LV. Readers 1, 2, 3, and 4 found 13, 9, 15, and 12 patients with RV:LV40.9, respectively. Conclusion: Detection of patients who may have submassive PE requires diverse physician coordination. The study population included a full spectrum of disease burden. High ICCs among multidisciplinary readers confers high accuracy. Slightly more patients were found with RV:LV40.9 than with right heart dysfunction on echo, suggesting its utility for screening for sicker patients.