Lisette van Dam

CTPP for short-term clinical outcome prediction in acute PE 10 155 INTRODUCTION Computed tomography pulmonary angiography (CTPA) is the current imaging modality of choice for the diagnosis of pulmonary embolism (PE). 1 In recent years technical advances have been made in the diagnostic management of PE including the introduction of computed tomography pulmonary perfusion (CTPP) imaging. With CTPP additional information of hemodynamic and functional impact of the PE as expressed by measures of pulmonary perfusion can be assessed. 2 Available studies using CTPP havemostly focused on its diagnostic performance for acute PE. The addition of CTPP to CTPA has been reported to improve the specificity for a PE diagnosis 3 and to improve the detection rate of small, subsegmental emboli. 4,5 Also, perfusion defects on CTPP were found to be correlated to PE thrombus load and signs of right ventricular dysfunction on CTPA. 6-10 Therefore, perfusion defects on CTPP may be relevant for prognostication of PE patients as well, although this is less well studied. For instance, the quantification of perfusion defects may predict PE-related death, hemodynamic collapse or need for oxygen therapy. This information is relevant for initial risk stratification and treatment or to consider home treatment in patients with good prognosis. 11 In this study, we aimed to evaluate the correlation between perfusion defects on CTPP and clinical symptoms at presentation and its predictive value for adverse short-term outcome of acute PE. METHODS Study design and population This was a prospective observational study in a convenience sample of 100 consecutive hemodynamically stable adult patients ( ≥ 18 years) with CTPA- confirmed acute symptomatic PE, diagnosed between July 2017 and October 2019 in the Leiden University Medical Center (LUMC) in whom CTPP was performed as part of routine clinical practice. Patients were excluded in case of non-assessable CTPP scan due to imaging artefacts. The diagnostic management of patients with suspected acute PE started with assessment of the clinical pre-test probability in