Patients' cough may also worsen after inhalation of radiopharmaceuticals, further increasing this risk.47, 48 As a result, multiple authors have suggested performing only a planar perfusion scan, perhaps at the bedside, or perfusion single-photon emission computed tomography (Q-SPECT), and forgo ventilation scintigraphy in COVID-19 patients.48 - 50 Zuckier et al proposed performing the perfusion portion of the scan if a CXR was clear and performing the ventilation portion only if clinically imperative; if perfusion defects are present, the scan should be interpreted as indeterminate, and the patient referred for alternate testing.48 However, this approach would exclude critically ill COVID-19 patients with extensive pulmonary consolidation and hence incorporating Q-SPECT and low-dose CT may be helpful.50 Similarly, Lu et al proposed obtaining planar perfusion images first to rule out PE and only if abnormal, performing Q - SPECT / CT to diagnose PE using the MSKCC Q-SPECT / CT criteria (≥1 wedge-shaped ≥ 50% segmental peripheral defect seen on all three orthogonal planes, without corresponding CT image abnormality) .49 It is unclear if negative perfusion-only scintigraphy can reliably rule out PE in COVID-19 patients.51 Also, Q-SPECT / CT without ventilation is reported to have high false-positive results that need to be weighed against the risks of anticoagulation.52 As the COVID-19 pandemic evolves differently across regions, the Society of Nuclear Medicine & Molecular Imaging has recently updated its guidance and recommends performing ventilation scans on a case-by-case basis while adhering to the local and institutional COVID-19 policies for aerosol-generating procedures.48 Chest computed tomography Chest CT helps evaluate patients with known COVID-19 pneumonia and related thoracic complications.53, 54 Semi-quantitate CT assessment of pneumonia severity and serial lung changes over time may correlate with disease severity and outcomes.55, 56 Typical imaging manifestations of COVID-19 pneumonia are bilateral peripheral ground-glass opacities without pleural effusions (Figure 1) .53, 54, 57, 58 Based on the illness state, consolidation and intralobular reticulations may also be present.53, 57, 59 Studies report abnormal pulmonary vascular thickening (thick vessel sign) within COVID-19 pneumonia opacities (Figure 2C) .60 Lang et al also observed extensive vascular changes (a study of 48 patients) demonstrating mosaic perfusion (94%), dilated and tortuous distal vascular enlargement (85%) present either within (79%) or outside (56%) the COVID-19 pneumonia opacities that extend to the pleura (83%) and along the lung fissures (63%) .61 Since these changes are usually not present in patients with non-COVID pneumonia, they hypothesised that abnormal vasoregulation in the lung might play a larger role in COVID-19 illness.