Ventilation/perfusion SPECT/CT findings in different lung lesions associated with COVID-19: a case series

Abstract

The aim of this series of cases is to show the aspects of ventilation/perfusion single-photon emission computed tomography combined with computed tomography (V/Q SPECT/CT) in patients hospitalized for COVID-19 pneumonia, with the worsening of respiratory symptoms raising the suspicion of a pulmonary embolism. Patients did not benefit from CT angiography for various reasons: a contraindication, unavailability of the CT angiography, or a low clinical probability for pulmonary embolism. Methods We retrospectively describe the results of the V/Q SPECT/CT of five patients hospitalized for COVID-19 pneumonia in the nuclear medicine departments of the Centre Cardiologique du Nord and of the

Clinical utility of perfusion (Q)-single-photon emission computed tomography (SPECT)/CT for diagnosing pulmonary embolus (PE) in COVID-19 patients with a moderate to high pre-test probability of PE

“…In routine V/Q SPECT imaging studies, the ventilation component may improve the specificity of the perfusion study and there is already data showing that the addition of low-dose CT to the SPECT images, the corroborated reporting of the scans with the structural information leads to a higher sensitivity, comparable with that of CTPA [ 20 , 21 ]. Cobes et al retrospectively analyzed V/Q SPECT/CTs in 5 patients hospitalized with COVID-19 and determined that V/Q SPECT/CT could play a role diagnosing embolic complications while following meticulous hygiene [ 22 ]. However, combining a low-dose chest CT with Q-only SPECT can also satisfactorily demonstrate etiologies of potential non-embolic false positive results, such as pulmonary emphysema or bullous disease [ 23 ].…”

RETRACTED: Clinical and Scientific Rationale for the “MATH+” Hospital Treatment Protocol for COVID-19

“…Although reasons for lack of dyspnea are multiple, the largest contributors are; 1) early COVID-19 is an “organizing pneumonia” representing a cellular infiltration into the alveoli and ducts rather than alveolar fluid accumulation/edema as in classic ARDS making the lung “dry and light” versus “heavy and fluid-filled” and thus leads to less energy work to inflate and counter-act de-recruitment, 2) the as yet un-explained, paradoxical hyperperfusion of the foci of organizing pneumonia suggesting a failure of typical hypoxic pulmonary vasoconstriction and causing disproportionate hypoxemia (Figure 2), and 3) the likely early and extensive micro and/or macrovascular clotting not detected on routine imaging studies. 8,181,182…”

“…Although reasons for lack of dyspnea are multiple, the largest contributors are; 1) early COVID-19 is an "organizing pneumonia" representing a cellular infiltration into the alveoli and ducts rather than alveolar fluid accumulation/ edema as in classic ARDS making the lung "dry and light" versus "heavy and fluid-filled" and thus leads to less energy work to inflate and counter-act de-recruitment, 2) the as yet unexplained, paradoxical hyperperfusion of the foci of organizing pneumonia suggesting a failure of typical hypoxic pulmonary vasoconstriction and causing disproportionate hypoxemia (Figure 2), and 3) the likely early and extensive micro and/or macrovascular clotting not detected on routine imaging studies. 8,181,182 These differences from "traditional ARDS" were unfortunately both widely minimized and overlooked as evidenced by frequent recommendations for "early intubation" in what was an unfounded fear of the mechanically well-tolerated hypoxemia. Such approaches likely contributed to not only the unacceptably high mortality first reported but also the widespread shortages of ventilators, ICU beds, ventilators, nurses and medications in some of the earliest hard-hit areas.…”

Venous thromboembolism in the era of COVID-19

“…However, it cannot be routinely recommended over CTPA. 56,57 Ventilation-perfusion (V/Q) assessment appears to be a problematic alternative since pulmonary lesions secondary to COVID-19 would render it nondiagnostic in many cases. 58 Echocardiography with focused right ventricular windows could help for the evaluation and hemodynamic assessment but cannot confirm PE diagnosis alone.…”