Scintigraphic Patterns In Planar Pulmonary Perfusion-Only Studies In Patients With Dyspnea and Clinical Suspicion of COVID-19 Infection

ABSTRACT

Aim/Introduction: The purpose of this study is to perform a descriptive analysis of the scintigraphic patterns in pulmonary perfusion studies in patients with COVID-19 clinical suspicion, and its relation with biological (PCR positiviy) and biochemical parameters (D dimer plasmatic levels (DD)) as well as the presence of comorbidities. Material(s) and Method(s) 84 patients (44 male 52.4% and 40 female 47.6%, mean age 68.08+/-15.85), either outpatients or hospitalized, with clinical COVID-19 suspicion, with conduction of the study from the onset of symptoms to even 19 months after it, in case of clinical persistence, and their pulmonary perfusion studies have been analyzed by three nuclear medicine physicians. The different patterns observed have been categorized in homogeneous, heterogeneous and segmental, and independence test have been run, by means of Chi square test (X2) or Fisher's exact test (FET), to detect a possible association of the latter with laboratory confirmation of COVID-19 infection, DD plasmatic levels (normal <500ng/ml, high 500-1.000ng/ ml, and very high>1.000ng/ml) and the absence or presence of comorbidity (pulmonary disease, cardiovascular disease or both).Odds Ratio (OR) calculation has been run to estimate the probability of presenting a heterogeneous scintigraphic pattern in COVID infected vs. not infected patients, as well as in patients with very high vs. high DD levels. Result(s) Different scintigraphic patterns (31% homogeneous, 58.3% heterogeneous or 10,7% segmental) have been observed in patients with suspected COVID-19, of whom 65.5% were confirmed cases. Independence tests showed association between scintigraphic perfusion patterns and COVID-19 confirmation [X2= 8.0, p<0.05, Phi=0,324], while it did not in relation to DD levels [FET= 2.74, p>0.05]. The relative risk of presenting a heterogeneous scintigraphy in COVID+ patients is 0.16 ([0.043-0.595] %95 CI), thus infection can be considered a mild protector factor for heterogeneity. With regard to absence of previous disease (27.4%) or presence of pulmonary (4.8%), cardiac (57.1%) or coexistence of both diseases (10.7%), no significant association to the scintigraphic pattern could be found (chi2= 7.511, p>0.05]). Conclusion(s) Different scintigraphic patterns in pulmonary perfusion studies have been observed in patients with COVID-19 suspicion, being the heterogeneous one remarkably more frequent. It is significantly associated to positive microbiological test results but not to plasmatic DD levels or presence of comorbidity. Covid-infected patients have lower probability of presenting a heterogeneous scintigraphy pattern than not infected ones.