Assisting Scalable Diagnosis Automatically via CT Images in the Combat against COVID-19

Introductory paragraphThe pandemic of coronavirus Disease 2019 (COVID-19) caused enormous loss of life globally. 1-3 Case identification is critical. The reference method is using real-time reverse transcription PCR (rRT-PCR) assays, with limitations that may curb its prompt large-scale application. COVID-19 manifests with chest computed tomography (CT) abnormalities, some even before the onset of symptoms. We tested the hypothesis that application of deep learning (DL) to the 3D CT images could help identify COVID-19 infections. Using the data from 920 COVID-19 and 1,073 non-COVID-19 pneumonia patients, we developed a modified DenseNet-264 model, COVIDNet, to classify CT images to either class. When tested on an independent set of 233 COVID-19 and 289 non-COVID-19 patients. COVIDNet achieved an accuracy rate of 94.3% and an area under the curve (AUC) of 0.98. Application of DL to CT images may improve both the efficiency and capacity of case detection and long-term surveillance.

Multi-slice Spiral CT in Diagnosis of Lung Lesions with Cross Interlobar Fissure Symptom / 中国医学影像学杂志

Purpose To explore multi-slice spiral CT (MSCT) features of lesions with cross interlobar fissure symptom in the lung,and through pathological results,to study the differential diagnosis significance of cross interlobar fissure symptom.Materials and Methods Forty-nine patients who were confirmed with lesions in the lung with cross interlobar fissure symptom through surgery,pathological certification or clinical diagnosis from October,2015 to October,2016 were collected.Retrospective analysis was conducted on cross interlobar fissure symptom lesions and other representation in the lung on CT image.Results Sixteen cases were multiple lesions and 33 cases of single cross interlobar fissure lesions.9 cases in the multiple lesions (56.3％) were contagious lesions,including tubercle bacillus,fungus,staphylococcus aureus and klebsiella pneumoniae infection,in which 3 cases (18.7％) were adenocarcinoma,2 cases (12.5％) metastasis,1 case (6.3％) Wegener's granulomatosis and 1 case (6.3％) antineutrophil cytoplasmic anti-body (ANCA) related vasculitis.21 cases in single lesions (63.6％) had malignant tumor,including adenocarcinoma of lung,squamous carcinoma,lymphoma and metastasis,in which 6 cases (18.2％) were sclerosing pneumocytoma or hamartoma with smooth verge and without malignant symptom,and another 6 cases (18.2％) were inflammatory lesions.Conclusion Symptoms of lesions in the lung with cross interlobar fissure growth can be seen in malignant tumor,benign tumor and inflammatory lesions.Multiple lesions are accompanied with cross interlobar symptom which can be seen more often in benign lesions,but also can be seen in malignant tumor (metastasis and intrapulmonary metastasis of lung cancer).Single lesions are also accompanied with cross interlobar symptom which can be seen more often in malignant tumor,but also can be seen in cryptogenic organizing pneumonia and benign tumor.Sometimes,it's very difficult to identify malignant tumor with single cross interlobar distributed cryptogenic organizing pneumonia.When features of benign tumor are very clear,possibility of sclerosing pneumocytoma or hamartoma shall be taken into consideration.

Multi-slice Spiral CT in Differential Diagnosis of Esophageal Leiomyoma and Esophageal Carcinoma / 中国医学影像学杂志

Purpose To explore multi-slice spiral CT (MSCT) in differential diagnosis of esophageal leiomyoma and esophageal carcinoma.Material and Methods Plain chest CT scan and enhanced inspection image of 26 patients with esophageal leiomyoma and 68 patients with esophageal carcinoma at the same term which had been confirmed by surgery and pathology were retrospectively analyzed.Characteristics such as focus size,morphology,density and tumor-air surface,etc were recorded and compared.Results MSCT of esophageal leiomyoma showed uniform density,possible calcification,polylimited influence of esophageal wall,scarcity of depression in focus niche,smooth tumor-air surface,low degree of enhanced amplification,and cerioid expansion of related lumen of larger focus.However,MSCT in esophageal carcinoma was represented by thickened annulus of esophageal wall,no calcification of focus,familiarity of depression in focus niche,rough tumor-air surface and intermediate degree strengthening.Differences of contrast of calcification,polylimited influence of esophageal wall,scarcity of depression in focus niche,smooth tumor-air surface in sophageal leiomyoma with that of esophageal carcinoma were statistically significant (P＜0.05).Conclusion MSCT can accurately identify sophageal leiomyoma and esophageal carcinoma,offering evidence for clinical diagnosis and treatment.

Multi-slice Spiral CT Features of Lung Primary Invasive Mucinous Adenocarcinoma / 中国医学影像学杂志

PurposeTo investigate the multi-slice spiral CT features of lung primary invasive mucinous adenocarcinoma, a rare malignancy with few relevant literature. Materials and Methods Forty-one patients with pathology proven primary invasive mucinous adenocarcinoma of the lungs underwent MSCT examination, of which 27 patients received intravenous contrast. Imaging features were analyzed, and the patients were divided into groups according to morphology, density and enhancement.Results For 41 patients, 40 cases had one lesion, and one case had more than one lesion; the lesions were in the right upper lobe in 5 cases, right middle lobe in one case, right lower lobe in 17 cases, left upper lobe in 5 cases, and left lower lobe in 12 cases. There was solitary lesion in 40 cases. The other patient had multiple lesions. 29 cases showed nodules/masses, while non-mass lesions in 12 cases. Ground glass opacity was seen in 4 cases, single consolidation in 11 cases, and mixed consolidation in 26 cases. There was significant contrast enhancement in nodules/masses compared to non-mass lesions (t=5.00, 6.51 and 14.06,P<0.05).Conclusion MSCT shows a diversity of imaging features of primary invasive mucinous adenocarcinom, including single round lesion, lower lobe in both side; the density is lower than muscle on CT scan, and presents mild to moderate enhancement on enhancement scan round lesions has high density and enhancement range than irregular-shaped lesions.

Rationality of 16 or more multi-slice helical CT utilization for solitary pulmonary nodule / 中华放射学杂志

Objective To analyze the rationality of 16 or more multi-slice helical CT (MSCT) utilization for solitary pulmonary nodule (SPN) (<3 cm). Methods One hundred and fifty consultant cases with SPN from 133 different hospitals, examined with 16 or more MSCT, were selected in this study. The reconstructed slice thickness of routine CT scan, thin slice reconstruction thickness, 2D or 3D reconstruction, window wide and level setting, contrast enhancement effect were recorded from consultant films. Thoracic CT scan criteria for SPN were proposed according to the scan guidelines at Stanford University and PubMed articles. The rationality of 16 or more MSCT utilization in other hospitals for SPN was analyzed by two radiologists compared with scan criteria. The diagnostic accuracy in other hospitals was evaluated according to the pathologic and treatment results in our hospital. Results Sixteen-MSCT was performed in 92 cases, 64-MSCT in 54 cases and 40-MSCT in 4 cases. In routine thoracic CT scan, 9--10 mm reconstructed slice thickness was selected in 59 cases, 7--8 mm thickness in 12 cases and 5 mmthickness in 79 cases. Consecutive thin slice thickness (<3 mm) was used for SPN only in 46 cases. OnlyMPR and VR were filmed in 9 cases without thin slice reconstructed axial images. :53 cases (35.3%) were rescanned in our hospital due to the unsatisfied image quality. Of 150 cases, 78 cases had pathologic or treatment results in our hospital and 22 cases (14.7%) were proved to be misdiagnosed in other hospitals, and only 2 cases were misdiagnosed in our hospital. Conclusion There are many irrationalities of 16 or more MSCT utilization in our country which influence the diagnostic accuracy of SPN, Unified thoracic CT scan criteria in our country are needed.

Thoracic CT findings of Behcet disease / 中华放射学杂志

Objective To illustrate the thoracic CT findings of Behcet disease and to assess the CT diagnostic role in patients with Behcet disease. Methods Thoracic CT images and medical records were retrospectively reviewed in 13 patients with thoracic Behcet disease. The diagnosis was based on the criteria set by the international study group for Behcet disease. Results Of 13 patients, subpleural patchy consolidations were showed in 3, bilateral diffuse ground glass opacities in 3, left low lobe collapse with a right small nodule in 1, subpleural solitary pulmonary nodule in 1, bilateral pleural effusion in 2 ,mediastinal lymphoadenopathy in 2, diffuse bilateral miliary lung nodules in 1 during treatment. Thoracic vascular involvement was presented in 8 patients, two with superior vena cava thrombosis, one with left subclavicle artery aneurysm, one with left low pulmonary artery aneurysm and mural thrombosis, one with bilateral low pulmonary arteries and left basilar artery aneurysm, three with right pulmonary artery thrombosis in which there were two with left pulmonary artery occlusion and one with left basilar artery branch aneurysm. Conclusions Thoracic CT findings of Behcet disease are variable and nonspecific. Contrast-enhanced CT scan can be helpful by showing thrombosis of the superior vena cava and pulmonary artery as well aneurysm of the pulmonary artery.

Multislice helical CT imaging of coronary artery disease:primary experience / 中华放射学杂志

Objective To evaluate the efficacy of multislice helical CT(MSCT) in the diagnosis of coronary artery disease Methods 30 patients were studied with MSCT CT data were reconstructed to demonstrate the abnormalities of coronary artery and the results were compared with that of angiography Results In patients with heart rate less than 60 BPM, there was no difference to show the main branch of left coronary artery and left descending artery compared with more than 60 BPM( P =0 197 and 0 128,Fisher′exact);and obvious differences in showing left circumflex artery (? 2=5 88, P

Diagnosis of early central lung cancer with CT: correlation with bronchoscopic and histopathologic findings / 中华放射学杂志

Objective To study the CT findings of early central lung cancer and correlative pathologic basis, and to evaluate the role of CT in the differential diagnosis of central lung cancer Methods Seventeen patients with early central lung cancer and 10 patients with benign lesions resembling the central lung cancer were analyzed Thin section CT was performed with a section thickness of 3 mm or 1 5 mm at Philips SR 7000 or GE Lightspeed Plus scanner The visibility of the lesions was correlated with bronchoscopic and histopathologic findings Results All 17 lesions were visualized at CT Three lesions showed focal bronchial wall thickening and internal bronchial wall irregularity, bronchial mucous coarsening, redness and swollening at bronchoscopy Fourteen lesions showed focal narrowing or obliteration of the bronchial lumen, 4 complicated with subsegmental bronchial mucoid impaction, 10 with obstructive pneumonia or atelectasis Corresponding bronchoscopic view disclosed intraluminal polypoid protrusions The epithelia were involved in 1 case, subepithelia in 5, and cartilaginous involvement in 11 according to the depth of invasion of the bronchial wall at histopathology Among 10 patients with benign lesions, 6 cases were suspected as bronchogenic carcinoma and the possibility of bronchogenic carcinoma was not excluded at CT in 4 cases There were 5 patients with uneven thickening of internal bronchial wall, 2 with lumen blood clots, 1 with lumen nodule, and no abnormalities in 2 patients at bronchoscopy Conclusion Thin section CT has been proved to be a reliable method for demonstrating the mild changes of the bronchi and to be a valuable tool for the diagnosis of early central lung cancer

Early lung cancer baseline screening: preliminary study with low-dose spiral CT / 中华放射学杂志

Objective To evaluate the prevalence rate of pulmonary malignant disease detected by low dose spiral CT in people at high risk of lung cancer. Methods Low dose spiral CT scans and chest radiographs in 300 symptom free volunteers from an on going screening study were prospectively evaluated. The study has enrolled 240 smokers, aged 45 years or older, with at least 10 pack years of cigarette smoking and 60 individuals with chronic obstructive pulmonary disease, and without previous cancer history, who were medically fit to undergo thoracic surgery. Low dose CT scans were performed with SR 7000 scanner using spiral mode, 120 kV, 50 mA, pitch 2, 5mm thickness reconstruction and Lightspeed Plus multi slice scanner using spiral mode, 120 kV, 50 mA, pitch 6 to produce 2.5 mm thick image at 2.5 mm increments. All images were assessed with cine display mode on workstation monitor. Results Non calcified nodules were detected in 56 (19%) participants by low dose CT, compared with 9 (3%) by chest radiography. Malignant disease was detected in 4 (1.3%) by CT and 3 (1%) by chest radiography. All 4 cancers were stage I. Lobar or segmental bronchial abnormalities were detected in 9 (3%) participants by CT. Among them, 3 (1%) proved to be early central lung cancer. No bronchial abnormality was detected by chest radiography. The sensitivity and specificity of cancer screening was 43% and 89%, respectively for chest radiograph, 100% and 80%, respectively for CT. The sensitivity of CT was significantly higher than that of radiograph, whereas the specificity showed no statistical difference. Conclusion Preliminary screening study indicates that low dose CT can greatly improve the likelihood of detection for small non calcified nodules and mild bronchial abnormalities, and thus of peripheral and central lung cancer at an earlier stage.