European Journal of Radiology 85 (2016) 150–157 Contents lists available at ScienceDirect European Journal of Radiology j ourna l h o mepage: www.elsevier.com/locate/ejrad Pulmonary arteriovenous malformation (PAVM) reperfusion after percutaneous embolization: Sensitivity and specificity of non-enhanced CT Chantale Bélanger a , Carl Chartrand-Lefebvre a,b , Gilles Soulez a,b , Marie E. Faughnan c,d,e , Muhammad Ramzan Tahir b , Marie-France Giroux a , Patrick Gilbert a , Pierre Perreault a , Louis Bouchard a , Vincent L. Oliva a , Eric Therasse a,b,∗ a Department of Radiology, Centre hospitalier de l’Université de Montréal (CHUM), Montreal, QC, Canada b Centre de recherche, Centre hospitalier de l’Université de Montreal (CRCHUM), Montreal, QC, Canada c Respirology Division, Department of Medicine, St. Michael’s Hospital, University of Toronto, Toronto, ON, Canada d Li Ka Shing Knowledge Institute, St. Michael’s Hospital, University of Toronto, Toronto, ON, Canada e Montreal HHT Centre, Pneumology Division, CHUM, Montreal, QC, Canada a r t i c l e i n f o Article history: Received 28 July 2015 Received in revised form 4 November 2015 Accepted 5 November 2015 Keywords: Pulmonary arteriovenous malformation Reperfusion CT a b s t r a c t Purpose: To evaluate the sensitivity and specificity of non-enhanced chest CT to detect reperfusion after pulmonary arteriovenous malformation (PAVM) embolization. Materials and methods: The Institutional Review Board approved this retrospective HIPAA-compliant study and waived the need for patient consent. All consecutive patients who underwent PAVM emboliza- tion between January 2000 and April 2011 were included. Complex PAVMs and patients without available pre- and/or post-embolization CT were excluded. PAVM artery, aneurysm and vein diameters were measured on non-enhanced chest CT before and after PAVM embolization. Pulmonary angiography (PA) was the reference standard to assess PAVM reperfusion. Reperfusion detection was analyzed with receiver operating characteristic (ROC) curves according to percentage of diameter reduction cut-off. Inter-observer concordance was ascertained with intra-class correlation coefficients (ICCs). Results: Out of 68 patients with PAVM embolizations, 42 (62%) had 108 PAVMs that met inclu- sion/exclusion criteria. Areas under the ROC curves for PAVM reperfusion detection were 0.84, 0.87, and 0.78, respectively, for PAVM artery, aneurysm and vein (p > 0.05). Sensitivity varied between 51% and 56%, and specificity between 86% and 98% for the <30% diameter reduction cut-off. Sensitivity was between 98% and 100%, and specificity, between 20% and 47% for the <70% diameter reduction cut-off. ICCs for inter-observer concordance were 0.58, 0.88 and 0.68 for percentage reduction of PAVM artery, aneurysm and vein, respectively. Conclusion: PAVM diameter reduction cut-offs of <30% and <70%, to detect PAVM reperfusion on non- enhanced CT reported in the literature, would respectively result in low sensitivity and specificity. © 2015 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Pulmonary arteriovenous malformations (PAVMs) represent direct communications between the pulmonary artery and vein, with these right-left shunts resulting in hemorrhagic complications and paradoxical embolization leading to stroke and brain abscesses ∗ Corresponding author at: Department of Radiology, CHUM, 3840, rue Saint- Urbain, Montréal, QC H2W 1T8, Canada. Fax: +1 514 412 7193. E-mail address: eric.therasse.chum@ssss.gouv.qc.ca (E. Therasse). [1–6]. Percutaneous PAVM embolization is technically very suc- cessful and is now the standard of care for the treatment of these lesions [7,8]. However, PAVM reperfusion rates after embolization are estimated to be between 2 and 25% [9,10] due most often to the recanalization of embolized vessels [11,12]. Pulmonary angiogra- phy (PA) is the imaging reference standard for PAVM reperfusion assessment [7,13] but, given its cost and invasive nature, CT is the preferred follow-up imaging modality. CT detection of PAVM reperfusion after embolization is based on either PAVM enhancement on contrast-enhanced CT or PAVM diameter reduction on non-enhanced CT [9,10,14–17]. Today novel http://dx.doi.org/10.1016/j.ejrad.2015.11.014 0720-048X/© 2015 Elsevier Ireland Ltd. All rights reserved.