Dual-energy ct pulmonary angiography quantifies vasculopathy in severe covid-19 pneumonia

Abstract

Purpose: To evaluate the relationship between dual-energy CT pulmonary angiography (DECTPA) and disease duration, right ventricular dysfunction (RVD), lung compliance, d-dimer, and obstruction index in coronavirus disease 2019 (COVID-19) pneumonia. Materials and Methods: This institutional review board approved this retrospective study and waived the informed consent requirement. Between March and May 2020, 27 consecutive ventilated patients with severe COVID-19 pneumonia underwent DECTPA to diagnose pulmonary thrombus (PT). Eleven underwent surveillance DECTPA 14 days 6 11.6 (standard deviation) later. Qualitative and quantitative analysis of perfused blood volume (PBV) maps recorded: (a) perfusion defect “pattern” (wedge-shaped, mottled, or amorphous), (b) presence of PT and CT obstruction index, and (c) PBV relative to pulmonary artery enhancement (PBV/PAenh); PBV/ PAenh was also compared with seven healthy volunteers and correlated with d-dimer and CT obstruction index. Results: Amorphous (n = 21), mottled (n = 4), and wedge-shaped (n = 2) perfusion defects were observed (men = 20; mean age = 56 years 6 8.7). Mean extent of perfusion defects was 36.1% 6 17.2. Acute PT was present in 11 of 27 (40.7%) patients. Only wedge-shaped defects corresponded with PT (two of 27, 7.4%). Mean CT obstruction index was 2.6 6 5.4 out of 40. PBV/PAenh (18.2% 6 4.2) was lower than in healthy volunteers (27% 6 13.9, P = .002). PBV/PAenh correlated with disease duration (β = 0.13, P = .04) and inversely correlated with RVD (β = −7.2, P = .001), persisting after controlling for confounders. There were no linkages between PBV/PAenh and d-dimer or CT obstruction index. Conclusion: Perfusion defects and decreased PBV/PAenh are prevalent in severe COVID-19 pneumonia. PBV/PAenh correlates with disease duration and inversely correlates with RVD. PBV/PAenh may be an important marker of vasculopathy in severe COVID-19 pneumonia even in the absence of arterial thrombus.