Alessandro Furlan MD, Presenter: Nothing to Disclose

Amol Patil, Abstract Co-Author: Nothing to Disclose

Bum-Woo Park, Abstract Co-Author: Nothing to Disclose

Chung-Chou H. Chang, Abstract Co-Author: Nothing to Disclose

Mark S. Roberts, Abstract Co-Author: Nothing to Disclose

Kyongtae Tyler Bae MD, PhD, Abstract Co-Author: Patent agreement, Covidien AG, Saint Louis, MO Patent agreement, Bayer AG, Pittsburgh, PA Expert Advisory Committee, Bracco Group, Princeton, NJ

To assess accuracy and reproducibility of clot burden quantification with CT pulmonary angiographic (CTPA) imaging.

This retrospective, HIPAA-compliant study was institutional review board-approved. A semi-automated program was developed for segmentation and volumetric quantification of pulmonary embolus with CTPA. Accuracy of measurement method was assessed using two pulmonary embolus phantoms. Reproducibility of measurement method was assessed using clinical CTPA of 30 patients (16 women, 14 men; mean age, 62 years) with pulmonary embolism (PE). Two observers segmented and measured the volume of blood clot from CTPA images twice at two separate sessions. Accuracy was evaluated by the relative volume measurement error. Intra- and inter-observer reliability was evaluated using intraclass correlation coefficient (ICC); agreement between measurements within and between the two observers was assessed using Bland-Altman analysis.

Mean relative measurement error from the two phantoms was less than 1% for both observers. A total of 60 emboli were measured from the 30 patients. Intra-observer ICC was 0.990 for observer 1 and 0.999 for observer 2; inter-observers ICC was 0.994 for session 1 and 0.989 for session 2. ICC for all four clot measurements was 0.988. Mean volume measurement difference for the intra-observers agreement was 0.9% for observer 1 and 0.3% for observer 2, while that for inter-observers agreement was -5.1% for session 1 and -5.8% for session 2.

Blood clot burden can be quantified with a high degree of accuracy and reproducibility from CTPA images using a semi-automated segmentation method.

Blood clot burden quantifiable from CTPA may serve as an important imaging biomarker for assessing the prognosis and treatment response for patients with pulmonary embolism.

Furlan, A, Patil, A, Park, B, Chang, C, Roberts, M, Bae, K, Accuracy and Reproducibility of Blood Clot Burden Quantification with CT Pulmonary Angiographic Imaging.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9004207.html