Objective:To evaluate the effects of different low-dose CT scanning protocols on the screening and evaluation of pulmonary ground-glass nodules in healthy physical examination subjects.Methods:The study was a prospective cohort study. A total of 805 healthy subjects who underwent pulmonary CT examinations at Huadong Hospital from March 2016 to December 2021 were included. The first examination was performed using the American GE Discovery CT750 (HDCT), with a tube current of 50 mA (voltage 120 kV), and 41 subjects with pulmonary ground-glass nodules were identified. A follow-up examination was conducted three months later with a tube current of 25 mA, while all other parameters remained consistent. The CT volume dose index (CTDIvol) and effective dose (ED) were recorded for each scan. Two radiologists statistically analyzed the pulmonary ground-glass nodules observed in each scan. The Wilcoxon signed-rank test was used to compare the differences in the detection of ground-glass nodules, diagnostic image acceptance rate, and subjective image quality scores between the two different tube current (I) values.Results:When I was 50 mA, the average CTDIvol and ED were (3.71±0.35) mGy and (1.94±0.24) mSv; When I was 25 mA, the average CTDIvol and ED were (1.84±0.20) mGy and (0.97±0.11) mSv (both P<0.05). Compared with the 50 mA, there was 50% intrinsic dose reduction when I was 25 mA. All the ground-glass nodules detected under the 50 mA circumstance were also detected when I was 25 mA. The diagnostic acceptability and image noise score with I of 25 mA were (4.77±0.42), (4.62±0.49), (4.81±0.39) and (4.63±0.48), (4.17±0.62), (4.84±0.37) and these were (4.82±0.39), (4.78±0.42), (4.84±0.37) and (4.70±0.46), (4.55±0.59), (4.88±0.33) (all P>0.05) with I of 50 mA. The Kappa values for the detection of pulmonary ground-glass nodules, diagnostic image acceptance rate, and subjective noise assessment by the two radiologists were 1.000, 0.706, and 0.885, respectively (all P<0.05). Conclusion:Different low-dose CT scanning protocols can meet the screening and diagnostic requirements for pulmonary ground-glass nodules in the healthy physical examination subjects, but the CT scanning protocol with tube current of 25 mA has a lower radiation dose.

Objective:To evaluate the effects of different low-dose CT scanning protocols on the screening and evaluation of pulmonary ground-glass nodules in healthy physical examination subjects.Methods:The study was a prospective cohort study. A total of 805 healthy subjects who underwent pulmonary CT examinations at Huadong Hospital from March 2016 to December 2021 were included. The first examination was performed using the American GE Discovery CT750 (HDCT), with a tube current of 50 mA (voltage 120 kV), and 41 subjects with pulmonary ground-glass nodules were identified. A follow-up examination was conducted three months later with a tube current of 25 mA, while all other parameters remained consistent. The CT volume dose index (CTDIvol) and effective dose (ED) were recorded for each scan. Two radiologists statistically analyzed the pulmonary ground-glass nodules observed in each scan. The Wilcoxon signed-rank test was used to compare the differences in the detection of ground-glass nodules, diagnostic image acceptance rate, and subjective image quality scores between the two different tube current (I) values.Results:When I was 50 mA, the average CTDIvol and ED were (3.71±0.35) mGy and (1.94±0.24) mSv; When I was 25 mA, the average CTDIvol and ED were (1.84±0.20) mGy and (0.97±0.11) mSv (both P<0.05). Compared with the 50 mA, there was 50% intrinsic dose reduction when I was 25 mA. All the ground-glass nodules detected under the 50 mA circumstance were also detected when I was 25 mA. The diagnostic acceptability and image noise score with I of 25 mA were (4.77±0.42), (4.62±0.49), (4.81±0.39) and (4.63±0.48), (4.17±0.62), (4.84±0.37) and these were (4.82±0.39), (4.78±0.42), (4.84±0.37) and (4.70±0.46), (4.55±0.59), (4.88±0.33) (all P>0.05) with I of 50 mA. The Kappa values for the detection of pulmonary ground-glass nodules, diagnostic image acceptance rate, and subjective noise assessment by the two radiologists were 1.000, 0.706, and 0.885, respectively (all P<0.05). Conclusion:Different low-dose CT scanning protocols can meet the screening and diagnostic requirements for pulmonary ground-glass nodules in the healthy physical examination subjects, but the CT scanning protocol with tube current of 25 mA has a lower radiation dose.

Objective To evaluate the findings of computerized tomography (CT) imaging in patients with primary pulmonary fungal infections.Methods CT findings and clinical data of 18 cases of primary pulmonary fungal infections from 2004 to 2012 were retrospectively analyzed.The diagnoses of all patients were confirmed by pathology or serology.Results The CT of primary pulmonary fungal infections showed soft tissue density nodules in 15 out of 18 cases,and masses in 3 out of 18.By pathology or serological examination,there were 12 cases of Aspergillus infections,3 cases of cryptococcal infections and 3 cases of coccidioidomycosis.The CT findings of all of the 12 cases of Aspergillus infection showed quasi-circular shaped lesions,with lobulation and spiculation (6/12),bronchial through syndrome (3/12),the air crescent sign (6/12),or mediastinal/hilar lymphadenopathies (3/12).Six cases presenting air crescent sign were all diagnosed with primary pulmonary aspergillosis.Among 12 aspergillosis cases,6 cases underwent CT enhancement scan,among which 3 showed no enhancement and 3 showed slight enhancements.The CT findings of all eases of Cryptococcus neoformans infections were cauliflower-like shape,with lobulation,spiculation,and no focal point calcification or mediastinal/hilar lymphadenopathies.After enhancement,all of the lesions were enhanced heterogeneously.The CT findings of all the coccidioidomycosis were irregular shaped lesions with halo sign and mediastinal/hilar lymphadenopathies.All 3 cases of halo signs were diagnosed with primary coccidioidal infections.Conclusions The CT findings of primary pulmonary fungal infections have certain characteristics.Diagnosis could be made based on CT imaging together with clinical manifestations before pathological results are available.