Lung perfusion assessed by SPECT/CT after a minimum of three months anticoagulation therapy in patients with SARS-CoV-2-associated acute pulmonary embolism: a retrospective observational study.

BACKGROUND: Anticoagulant treatment is recommended for at least three months after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related acute pulmonary embolism (PE), but the persistent pulmonary clot burden after that time is unknown. METHODS: Lung perfusion was assessed by ventilation-perfusion (V/Q) SPECT/CT in 20 consecutive patients with SARS-CoV-2-associated acute PE after a minimum of three months anticoagulation therapy in a retrospective observational study. RESULTS: Remaining perfusion defects after a median treatment period of six months were observed in only two patients. All patients (13 men, seven women, mean age 55.6 ± 14.5 years) were on non-vitamin K direct oral anticoagulants (DOACs). No recurrent venous thromboembolism or anticoagulant-related bleeding complications were observed. Among patients with partial clinical recovery, high-risk PE and persistent pulmonary infiltrates were significantly more frequent (p < 0.001, respectively). INTERPRETATION: Temporary DOAC treatment seems to be safe and efficacious for resolving pulmonary clot burden in SARS-CoV-2-associated acute PE. Partial clinical recovery is more likely caused by prolonged SARS-CoV-2-related parenchymal lung damage rather than by persistent pulmonary perfusion defects.

Findings in [99mTc]MAA SPECT/CT in the diagnosis and follow-up of pulmonary embolism after infection by SARS-CoV-2 (COVID-19).

SARS-CoV-2 (COVID-19) infection is a current public health problem that has been shown to cause multiple complications, including pulmonary thromboembolism. The first presented case is a 59-year-old woman with a history of COPD, paroxysmal atrial fibrillation and COVID-19 infection in September 2020, consultation in December 2020 for atypical chest pain with suspected PE, AngioCT of pulmonary vessels was performed negative for emboli, subsequently [99mTc]Tc MAA SPECT/CT was indicated with a report of multiple triangular defects concerning acute pulmonary thromboembolism. A second case is a 70-year-old man with a history of dyslipidaemia, presented COVID-19 infection in September 2020 with a complication of PE with involvement of the left pulmonary artery, followed by [99mTc]Tc MAA SPECT/CT report multiple triangular and not triangles defects concerning pulmonary thromboembolism with signs of reperfusion.

Investigation of perfusion defects by Q-SPECT/CT in patients with mild-to-moderate course of COVID-19 and low clinical probability for pulmonary embolism.

OBJECTIVE: Pulmonary embolism is a severe source of mortality and morbidity in patients with severe and critical coronavirus disease 2019. It is not yet clear whether the tendency to thrombosis is increased in the mild-to-moderate course of COVID-19. Our research aims to show the clinical benefit of Q-SPECT/CT in diagnosing PD in outpatients treated with mild-to-moderate course of COVID-19 and to determine the frequency of perfusion defects in these patients having relatively lower risk. METHODS: All patients who underwent Q-SPECT/CT with suspicion of embolism were examined retrospectively. Only patients with low clinical probability and mild-to-moderate course of COVID-19 for PE were included in the study. The patients were evaluated comparatively as those with and without perfusion defects. Patients were divided into laboratory suspicion, clinical suspicion, or clinical and laboratory suspicion. RESULTS: In outpatients with mild-to-moderate COVID-19 with low clinical probability for PE, PD without CT abnormality was detected with a rate of 36.6% with Q-SPECT/CT performed for complaints of high D-dimer and/or dyspnea. None of the patients had PD at more proximal level than the segment level. PD with no concomitant CT abnormality was observed with a rate of 56.5% in patients with both clinical and laboratory suspicion. For D-dimer = 0.5 mg/dL cut-off sensitivity is 85%, for D-dimer = 1.5 mg/dL cut-off specificity 81%. CONCLUSION: Thrombosis tendency is also present in outpatients with mild-to-moderate COVID-19, and these patients should also be offered anticoagulant prophylaxis during the COVID-19 period.

Pulmonary Embolism in an Asymptomatic COVID-19 Patient Detected on Ventilation/Perfusion SPECT/CT.

ABSTRACT: Severe COVID-19 infection is associated with significant coagulopathy. We would like share a case of an asymptomatic 26-year-old man who tested positive for COVID-19 and had elevated d-dimer levels. Because of inconclusive CTPA findings, V/Q (ventilation/perfusion) SPECT/CT was performed, which confirmed the presence of pulmonary embolism. This case highlights the fact that pulmonary embolism should not be overlooked in a COVID-19 patient who has raised d-dimer levels, even in the absence of symptoms. It also highlights the importance of performing a V/Q study when CTPA results are inconclusive or when there are contraindications for iodinated contrast media.

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

PURPOSE: 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 Delafontaine hospital in Saint-Denis (Ile-de-France, France) between April 2, 2020, and April 10, 2020. These patients had persistent dyspnea or chest pain suggesting pulmonary embolism. RESULTS: The V/Q SPECT/CT allowed to diagnose a pulmonary embolism in one of these five patients. We also noted several characteristics of the perfusion and ventilation depending on the lung lesions on the CT scan. The areas affected by COVID-19 were most often responsible for ventilatory anomalies with a relatively preserved perfusion. In more advanced cases of pneumonia, with alveolar fillings, the perfusion was also reduced or absent in accordance with large ventilation defects. In addition, the healthy parenchyma appeared to benefit from an uptake in ventilation and perfusion. CONCLUSION: V/Q SPECT/CT can play a role in the management of patients hospitalized for COVID-19 for the diagnosis of embolic complications with meticulous hygienic precautions. The different characteristics of the ventilatory and perfusion anomalies related to COVID-19 pneumonia will be confirmed with the next cases. In addition, in this pandemic context and facing a significant infectious risk, the utility of ventilation will also have to be specified.

Incidental CT Findings Suspicious for COVID-19-Associated Pneumonia on Nuclear Medicine Examinations: Recognition and Management Plan.

Some patients undergoing routine SPECT/CT and PET/CT examinations during the COVID-19 pandemic may incidentally reveal findings of COVID-19-associated pneumonia (C-19AP) on localizing CT. It is critical for nuclear medicine physicians to develop diagnostic skills for timely recognition of typical findings of C-19AP on a localizing CT. Furthermore, it is our responsibility to know the optimal practices for safely isolating and managing such patients while protecting the staff, other patients at the facility, family and/or friend accompanying the patients, and the public in general from risky exposure to COVID-19 sources. We offer several steps following an encounter suspicious of C-19AP.

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.