ABSTRACT
Aim/Introduction: Covid virosis can cause different injuries of lung parenchyma and vasculature. Viral pneumonia is considered to be a possible precursor to pulmonary fibrosis. There is also a risk for thromboembolism and in-situ thrombotic microangiopathy. V/Q pulmonary scintigraphy is an established procedure to detect acute as well as chronic thromboembolism including prognosis of chronic thromboembolic pulmonary hypertension, but it is not able to assess lung interstitium. The goal of our study was to assess possible pathology in patients sent to our department for lung scintigraphy after Covid-19 virosis. Material(s) and Method(s): We evaluated 27 patients, 15 female and 12 male, average age of 56 (34 to 85) year. All suffered Covid-19 virosis and was sent to exclude pulmonary embolism. The average time after virosis was 3 (0 to 8) months, 2 patients were actually ill. Clinical symptoms included resting or exertional dyspnea or chest pain. Several patients had increased D-dimer or signs of pulmonary hypertension on echocardiography. We performed V/Q pulmonary scintigraphy (99mTc MAA and 81mKr) on a dual head gamma camera together with a nondiagnostic low dose CT. We evaluated changes of perfusion in relation to embolism and parenchymal changes on CT portion of examination (increased or decreased density of parenchyma, effusion or combination). Result(s): No patient had typical signs of pulmonary embolism (V/Q mismatch). We detected no pathology in 10 patients. 9 patients had increased density of lung parenchyma consistent with fibrosis. It demonstrates the interstitial nature of lung damage from viral pneumonia, which can be expected in patients after Covid-19 pneumonia. 9 patients had decreased density of lung parenchyma consistent with emphysema and 3 patients had an effusion. 3 patients had fibrotic changes together with effusion, one patient had both fibrotic and emphysematous changes. Conclusion(s): Although the V/Q pulmonary scintigraphy is an established procedure to assess pulmonary embolism, it is, in principle, not able to assess lung parenchyma. This gap can be overcome by combination with a low-dose CT, which is especially useful in patients suffered Covid-19 virosis.