The reliability of low-dose chest CT for the initial imaging of COVID-19: comparison of structured findings, categorical diagnoses and dose levels

PURPOSEThe widespread use of computed tomography (CT) in COVID-19 may cause adverse biological effects. Many recommend to minimize radiation dose while maintaining diagnostic quality. This study was designed to evaluate the difference between findings of COVID-19 pneumonia on standard and low-dose protocols to provide data on the utility of the latter during initial imaging of COVID-19.METHODSPatients suspected of having COVID-19 were scanned with a 128-slices scanner using two consecutive protocols in the same session (standard-dose scan: 120 kV and 300 mA; low-dose scan: 80 kV and 40 mA). Dose data acquisition and analysis was performed using an automated software. High and low-dose examinations were anonymized, shuffled and read by two radiologist with consensus according to a highly structured reporting format that was primarily based on the consensus statement of the RSNA. Accordingly, 8 typical, 2 indeterminate, and 7 atypical findings were investigated. Cases were then assigned to one of the categories: (i) Cov19Typ, typical COVID-19; (ii) Cov19Ind, indeterminate COVID-19; (iii) Cov19Aty, atypical COVID-19; (iv) Cov19Neg, not COVID-19. McNemar test was used to analyze the number of disagreements between standard and low-dose scans regarding paired proportions of structured findings. Inter- test reliability was tested using kappa coefficient.RESULTSThe study included 740 patients with a mean age of 44.05±16.59 years. The median (minimum–maximum) dose level for standard protocol was 189.98 mGy•cm (98.20–493.54 mGy•cm) and for low-dose protocol was 15.59 mGy•cm (11.59–32.37 mGy•cm) differing by -80 and -254 mGy•cm from pan-European diagnostic reference levels. Only two findings for typical, one finding for indeterminate, and three findings for atypical categories were statistically similar (p > 0.05). The difference in other categories resulted in significantly different final diagnosis for COVID-19 (p < 0.001). Overall, 626 patients received matching diagnoses with the two protocols. According to intertest reliability analysis, kappa value was found to be 0.669 (p < 0.001) to indicate substantial match. CT with standard-dose had a sensitivity of 94% and a specificity of 72%, while CT with low-dose had a sensitivity of 90% and a specificity of 81%.CONCLUSIONLow kV and mA scans, as used in this study according to scanner manufacturer's global recommendations, may significantly lower exposure levels. However, these scans are significantly inferior in the detection of several individual CT findings of COVID-19 pneumonia, particularly the ones with GGO. Therefore, they should not be used as the protocol of choice in the initial imaging of COVID-19 patients during which higher sensitivity is required

Descriptive Features Related Works of COVID-19 and Contents of Randomized Controlled Trials: Systematic Review

Amaç: Bu araştırmada, COVID-19 ile ilgili yapılmış ulusal ve uluslararası yayınların sistematik olarak incelenmesi ve literatüre katkı sağlanması amaçlanmıştır. Gereç ve Yöntem: Çalışma sistematik derleme niteliğindedir ve 1 Aralık 2019 ve 24 Mayıs 2020 tarihleri arasında İngilizce literatür taranarak yapılmıştır. Veri tabanlarında “Coronavirus”, “COVID-19”, “Coronavirus COVID-19” anahtar kelimeleri sözcük grupları ile tarama yapılmıştır. Tarama raporları birinci aşamada çalışmaların genel özellikleri ve ikinci aşamada randomize kontrollü çalışmaların içerikleri olmak üzere iki aşamada sunulmuştur. Çalışmaya belirtilen tarihler arasında yapılmış ve yayımlanmış, tam metnine ulaşılabilen 8 randomize kontrollü çalışma dâhil edilmiştir. Bulgular: Bu sistematik derlemeye dâhil edilen çalışmalarda yayınların türleri ve 101 hemşirelik yayınının konu içerikleri incelendi. İkinci aşamada, incelenen toplam 8 randomize kontrollü çalışmada, Cohort study kalite değerlendirmesinde çoğunluğu düşük risk kategorisinde bulunmuştur. Sonuç: Bu sistematik derlemede, COVID-19 tedavisinde çalışmaların sonuçlarının uygulanabilir olduğuna dair güçlü kanıtlar elde edilmiştir. Kalite değerlendirmesinde altı çalışma düşük risk grubunda ve bir çalışma orta risk grubunda yer almakta idi. COVID-19’a yönelik tanı, tedavi ve mücadele çalışmalarına daha geniş kapsamda yer verilmelidir.Objective: It is aimed to investigate national and international studies systematically about COVID-19 and contribute for the literature. Material and Methods: The study is a systematic review and was conducted by searching the scientific literature in English between December 1, 2019 and May 24, 2020. In the databases, “Coronavirus”, “COVID-19”, “Coronavirus COVID-19” keywords were searched with phrases. Screening reports are presented in two stages: the general characteristics of the studies are presented in the first stage, and the contents of randomized controlled studies in the second. Eight randomized controlled trials, published between December 1, 2019 and May 24, 2020, were included in the study. Findings: In the selected studies, the types of publications and the subject matters of 101 nursing publications were examined. In the second stage, a total of 8 randomized controlled studies were examined and found that the majority of them are in the low-risk category according to the cohort study quality assessment. Conclusion: In this systematic review, strong evidence has been obtained that the results of studies are feasible in the treatment of COVID-19. In the quality assessment, six studies were in the low-risk group and one study in the mediumrisk group. Diagnosis, treatment, and fighting studies towards COVID-19 should be included in a wider scop