[Clinical features and chest CT findings of coronavirus disease 2019 in infants and young children].

OBJECTIVE: To study the clinical features and chest CT findings of coronavirus disease 2019 (COVID-19) in infants and young children. METHODS: A retrospective analysis was performed for the clinical data and chest CT images of 9 children, aged 0 to 3 years, who were diagnosed with COVID-19 by nucleic acid detection between January 20 and February 10, 2020. RESULTS: All 9 children had an epidemiological history, and family clustering was observed for all infected children. Among the 9 children with COVID-19, 5 had no symptoms, 4 had fever, 2 had cough, and 1 had rhinorrhea. There were only symptoms of the respiratory system. Laboratory examination showed no reductions in leukocyte or lymphocyte count. Among the 9 children, 6 had an increase in lymphocyte count and 2 had an increase in leukocyte count. CT examination showed that among the 9 children, 8 had pulmonary inflammation located below the pleura or near the interlobar fissure and 3 had lesions distributed along the bronchovascular bundles. As for the morphology of the lesions, 6 had nodular lesions and 7 had patchy lesions; ground glass opacity with consolidation was observed in 6 children, among whom 3 had halo sign, and there was no typical paving stone sign. CONCLUSIONS: Infants and young children with COVID-19 tend to have mild clinical symptoms and imaging findings not as typical as those of adults, and therefore, the diagnosis of COVID-19 should be made based on imaging findings along with epidemiological history and nucleic acid detection. Chest CT has guiding significance for the early diagnosis of asymptomatic children.

IDEAL-IQ measurement can distinguish dysplastic nodule from early hepatocellular carcinoma: a case-control study.

Background: Previous studies have confirmed that malignant transformation of dysplastic nodule (DN) into hepatocellular carcinoma (HCC) is accompanied by reduction of iron content in nodules. This pathological abnormality can serve as the basis for magnetic resonance imaging (MRI). This study was designed to identify the feasibility of iterative decomposition of water and fat with echo asymmetry and least squares estimation-iron quantitative (IDEAL-IQ) measurement to distinguish early hepatocellular carcinoma (eHCC) from DN. Methods: We reviewed MRI studies of 35 eHCC and 23 DN lesions (46 participants with 58 lesions total, 37 males, 9 females, 31-80 years old). The exams include IDEAL-IQ sequence and 3.0T MR conventional scan [including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and Gadopentic acid (Gd-GDPA)-enhanced]. Then, 3 readers independently diagnosed eHCC, DN, or were unable to distinguish eHCC from DN using conventional MRI (CMRI), and then assessed R2* value of nodules [R2* value represents the nodule iron content (NIC)] and R2* value of liver background [R2* value represents the liver background iron content (LBIC)] with IDEAL-IQ. Statistical analysis was conducted using the t-test for comparison of means, the Mann-Whitney test for comparison of medians, the chi-square test for comparison of frequencies, and diagnostic efficacy was evaluated by using receiver operating characteristic (ROC) curve. Results: This study evaluated 35 eHCC participants (17 males, 6 females, 34-81 years old, nodule size: 10.5-27.6 mm, median 18.0 mm) and 23 DN participants (20 males, 3 females, 31-76 years old, nodule size: 16.30±4.095 mm). The NIC and ratio of NIC to LIBC (NIC/LBIC) of the eHCC group (35.926±12.806 sec-1, 0.327±0.107) was lower than that of the DN group (176.635±87.686 sec-1, 1.799±0.629) (P<0.001). Using NIC and NIC/LBIC to distinguish eHCC from DN, the true positive/false positive rates were 91.3%/94.3% and 87.0%/97.1%, respectively. The rates of CMRI, NIC and NIC/LBIC in diagnosis of eHCC were 77.1%, and 94.3%, 97.1%, respectively, and those of DN were 65.2%, 91.3%, and 87.0%, respectively. The diagnosis rate of eHCC and DN by CMRI was lower than that of NIC and NIC/LBIC (eHCC: P=0.03, 0.04, DN: P=0.02, 0.04). Conclusions: Using IDEAL-IQ measurement can distinguish DN from eHCC.

Case Report: Mycobacterium kansasii causing infective endocarditis explored by metagenomic next-generation sequencing.

In this report, we describe the first case of infective endocarditis caused by Mycobacterium kansasii in a 45-year-old male patient who presented with a 10-day fever and decompensated cirrhosis. Despite negative results in blood culture and pathology, we employed metagenomic next-generation sequencing (mNGS) to analyze the genome sequences of both the host and microbe. The copy number variation (CNV) indicated a high risk of liver disease in the patient, which correlated with biochemical examination findings. Notably, M. kansasii sequences were detected in peripheral blood samples and confirmed through Sanger sequencing. Unfortunately, the patient's condition deteriorated, leading to his demise prior to heart surgery. Nevertheless, we propose that mNGS could be a novel approach for diagnosing M. kansasii infection, particularly in cases where blood culture and pathology results are unavailable. It is important to consider M. kansasii infection as a potential cause of endocarditis and initiate appropriate anti-infection treatment.

Chest X-ray imaging of patients with SARS.

OBJECTIVE: To investigate the chest X-ray manifestations of SARS cases. METHODS: A retrospective study was conducted among 52 clinically confirmed SARS patients from February 9 to May 10, 2003. Chest X-ray scanning was performed at a interval of 1 - 3 days according to the requirements. The manifestations and special features of SARS in X-ray were analyzed. RESULTS: Small or large patchy shadows with intensive density in both lungs were observed in 31 cases, ground-glass like opacification in 16, small patchy shadows in one lung lobe or one lung segment in 18, nodular shadows in one lung segment in 1, and increased lung marking in lung interstitial tissues in 2. Rapidly changing consolidations revealed in chest X-ray images were found to be associated with SARS infections, and they were not affected by treatment with antibiotics. CONCLUSION: Chest X-ray provides a sensitive and specific method for the diagnosis and treatment of SARS, and those present with symptoms and signs should undergo chest X-ray scanning every 1 - 3 days.

Radiologic diagnosis for AIDS patients complicated with candidal esophagitis.

BACKGROUND: Candidal esophagitis is the primary infection among all digestive tract opportunistic ones in acquired immunodeficiency syndrome (AIDS) cases. X-ray manifestation reports of it are still rare. This study aimed to conduct a retrospective analysis on the X-ray data of 6 AIDS cases complicated with candidal esophagitis, and to study the X-ray characteristics of it combined with the findings from gastroscopy. METHODS: Among 6 cases in this series, all cases were confirmed by Shenzhen Center for Disease Control and Prevention (CDC) to be HIV positive and all of them had CD4 cell counts less than 150 × 10(6)/L. All cases underwent X-ray and gastroscopy, and mycelium were found in the mucous membrane of the esophagus. RESULTS: In this series, the findings of the X-ray were as follows: (1) Affected areas: Four cases in the whole esophagus, 2 cases in the middle and lower part of esophagus; (2) Abnormal motivity: Six cases had decreased tension, loose walls, weakened peristalsis, decreased number of peristalsis waves and delayed emptying of barium; (3) Abnormal contour: Six cases had the sign of "decorative border" or "brush", two cases had narrowed canal; (4) Abnormal membrane and "cobblestone sign": Six cases had thickened membrane and "cobblestone sign" on the surface of the abnormal membrane. The hyperemia of mucosa was covered tightly with yellow-white pseudomembrane spots. This was in accordance with the small cobblestone-like filling defect found by X-ray. CONCLUSIONS: If the AIDS cases have dysphagia, and X-ray shows that more than two sections of the esophagus are affected, with decreased motility, the walls in the sign of "brush" or "decorative edges", thickened membrane with "cobblestone sign", candidal esophagitis is highly possible.

[Clinical and chest X-ray characteristics of 5 cases with severe acute respiratory syndrome in children in Shenzhen area].

OBJECTIVE: To explore clinical and chest X-ray features of SARS in children to facilitate correct diagnosis. METHODS: Clinical manifestations and chest X-ray findings in five children suffering from SARS admitted for treatment in the hospital between February and May, 2003 in Shenzhen area were analyzed. The diagnosis was confirmed by epidemiological, clinical, laboratory and radiological examinations. Among the 5 cases, 1 was a boy and the others were girls at the age of 4 to 13 years. RESULTS: Of the 5 SARS children, 3 presented a history of close contact with SARS patients. Fever was the initiative symptom, 4 had a body temperature of over 38 degrees C with the highest being 40 degrees C; fever sustained from 4 to 7 days with an average of 5.6 days. All the 5 cases developed nonproductive cough; on auscultation, both moist and dry rales could be heard in 3 out of the 5 cases. Mean total white count of peripheral blood was (2.96 - 6.9) x 10(9)/L, and was < 5.0 x 10(9)/L in 4 cases. SARS associated coronavirus specific RNA fragment was found positive by RT-PCR in 1 case; 1 case was positive for both IgM and IgG antibodies to the virus; 1 case was positive for only IgM antibody and another 2 cases were positive for only IgG antibody. IgG and IgM antibodies to Mycoplasma pneumoniae and Chlamydia pneumoniae as well as blood culture for bacteria were all negative. Findings on chest X-ray examination: 4 cases showed presence of patchy or macular opacities with cord-like shadows in unilateral lung plates while 1 case each showed ground-glass-like opacity and migratory changes; 1 case showed interstitial changes in the lungs in the form of irregular reticular lattice and cord-like shadows. Two cases received CT scanning and macular-patchy or spotty shadows were seen all over the lung. The shortest time for absorption of foci in the lungs was 7 days while the longest was 33 days with a mean of 15 +/- 6 days. None of the cases had any signs of fibrosis in the lungs. All the 5 cases were completely cured and discharged 7 to 40 days (mean 18 +/- 11 days) after admission. CONCLUSION: Compared with adult cases with SARS, children with SARS had milder symptoms and signs. Presence of unilateral patchy shadow in lungs represented the main chest X-ray findings.