Lung Ventilation-Perfusion Scan in COVID-19: Various Patterns of Perfusion Defects.

ABSTRACT: Although COVID-19 infection is associated with the increased risk of pulmonary thromboembolism (PTE), COVID-19 pulmonary lesions cause ventilation-perfusion (V/Q) patterns other than PTE. Although extensive research has been done to address different anatomical patterns of COVID-19, there is a knowledge gap in terms of V/Q lung scintigraphy in these patients. The purpose of this study is to demonstrate these patterns and to show how important it is to use SPECT/CT in addition to planar images to differentiate between these patterns from PTE. In the current collection, we presented various patterns of V/Q SPECT/CT abnormalities in COVID-19 patients.

Functional Alterations Due to COVID-19 Lung Lesions-Lessons From a Multicenter V/Q Scan-Based Registry.

PURPOSE: In coronavirus disease 2019 (COVID-19) patients, clinical manifestations as well as chest CT lesions are variable. Lung scintigraphy allows to assess and compare the regional distribution of ventilation and perfusion throughout the lungs. Our main objective was to describe ventilation and perfusion injury by type of chest CT lesions of COVID-19 infection using V/Q SPECT/CT imaging. PATIENTS AND METHODS: We explored a national registry including V/Q SPECT/CT performed during a proven acute SARS-CoV-2 infection. Chest CT findings of COVID-19 disease were classified in 3 elementary lesions: ground-glass opacities, crazy-paving (CP), and consolidation. For each type of chest CT lesions, a semiquantitative evaluation of ventilation and perfusion was visually performed using a 5-point scale score (0 = normal to 4 = absent function). RESULTS: V/Q SPECT/CT was performed in 145 patients recruited in 9 nuclear medicine departments. Parenchymal lesions were visible in 126 patients (86.9%). Ground-glass opacities were visible in 33 patients (22.8%) and were responsible for minimal perfusion impairment (perfusion score [mean ± SD], 0.9 ± 0.6) and moderate ventilation impairment (ventilation score, 1.7 ± 1); CP was visible in 43 patients (29.7%) and caused moderate perfusion impairment (2.1 ± 1.1) and moderate-to-severe ventilation impairment (2.5 ± 1.1); consolidation was visible in 89 patients (61.4%) and was associated with moderate perfusion impairment (2.1 ± 1) and severe ventilation impairment (3.0 ± 0.9). CONCLUSIONS: In COVID-19 patients assessed with V/Q SPECT/CT, a large proportion demonstrated parenchymal lung lesions on CT, responsible for ventilation and perfusion injury. COVID-19-related pulmonary lesions were, in order of frequency and functional impairment, consolidations, CP, and ground-glass opacity, with typically a reverse mismatched or matched pattern.

Revisiting One of the Dreaded Outcomes of the Current Pandemic: Pulmonary Embolism in COVID-19.

Pulmonary embolism (PE) is a commonly encountered clinical entity in patients with coronavirus disease 2019 (COVID-19). Up to 1/3 of patients have been found to have PE in the setting of COVID-19. Given the novelty of the virus causing this pandemic, it has not been easy to address diagnostic and management issues in PE. Ongoing research and publications of the scientific literature have helped in dealing with COVID-19 lately and this applies to PE as well. In this article, we attempt to succinctly yet comprehensively discuss PE in patients with COVID-19 with a review of the prevailing literature.

Beyond the clot: perfusion imaging of the pulmonary vasculature after COVID-19.

A compelling body of evidence points to pulmonary thrombosis and thromboembolism as a key feature of COVID-19. As the pandemic spread across the globe over the past few months, a timely call to arms was issued by a team of clinicians to consider the prospect of long-lasting pulmonary fibrotic damage and plan for structured follow-up. However, the component of post-thrombotic sequelae has been less widely considered. Although the long-term outcomes of COVID-19 are not known, should pulmonary vascular sequelae prove to be clinically significant, these have the potential to become a public health problem. In this Personal View, we propose a proactive follow-up strategy to evaluate residual clot burden, small vessel injury, and potential haemodynamic sequelae. A nuanced and physiological approach to follow-up imaging that looks beyond the clot, at the state of perfusion of lung tissue, is proposed as a key triage tool, with the potential to inform therapeutic strategies.

It's a small world after all: A Canadian resident's perspective on COVID-19.

COVID-19 has infected millions of people, with an estimated total dead in the hundreds of thousands. This has significantly impacted health care, including who is delivering it, how it is delivered, and how it is taught. This article describes challenges of the COVID-19 pandemic from the perspective of a Canadian nuclear medicine resident, including new risks with nuclear imaging, navigating new and sometimes challenging guidelines, as well as working and living within the confines of social distancing.

Lung Scintigraphy Imaging Features in a Young Patient With COVID-19.

A 31-year-old man developed diarrhea, fatigue, and intermittent fever for 2 weeks. The past few days he had experienced increasing dyspnea and dry cough. Ambulatory reverse transcriptase-polymerase chain reaction testing was positive for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Because of elevated D-dimer (1.5 mg/L), a lung scintigraphy (V/Q scan) was performed as SPECT/CT. Ventilation SPECT showed reduced ventilation with central nuclide deposition, whereas perfusion SPECT was inconspicuous, excluding pulmonary embolism. However, the low-dose CT revealed bilateral ground-glass opacities as previously described in COVID-19. This case highlights the procedure and findings of V/Q scanning (without embolism) in COVID-19.