Arterial spin labeling MR image denoising and reconstruction using unsupervised deep learning

Arterial spin labeling (ASL) imaging is a powerful magnetic resonance imaging technique that allows to quantitatively measure blood perfusion non-invasively, which has great potential for assessing tissue viability in various clinical settings. However, the clinical applications of ASL are currently limited by its low signal-to-noise ratio (SNR), limited spatial resolution, and long imaging time. In this work, we propose an unsupervised deep learning-based image denoising and reconstruction framework to improve the SNR and accelerate the imaging speed of high resolution ASL imaging. The unique feature of the proposed framework is that it does not require any prior training pairs but only the subject's own anatomical prior, such as T1-weighted images, as network input. The neural network was trained from scratch in the denoising or reconstruction process, with noisy images or sparely sampled k-space data as training labels. Performance of the proposed method was evaluated using in vivo experiment data obtained from 3 healthy subjects on a 3T MR scanner, using ASL images acquired with 44-min acquisition time as the ground truth. Both qualitative and quantitative analyses demonstrate the superior performance of the proposed txtc framework over the reference methods. In summary, our proposed unsupervised deep learning-based denoising and reconstruction framework can improve the image quality and accelerate the imaging speed of ASL imaging.     

Analysis of the correlation between P27 expression and Helicobacter pylori infection in gastric cancer

We aimed to explore the correlation between P27 expression and Helicobacter pylori (H. pylori) infection in gastric cancer, so as to provide evidence for understanding the pathogenesis of gastric cancer caused by H. pylori infection. A total of 82 samples of gastric cancer tissues and 56 samples of tumor-adjacent normal tissues collected from the gastrectomy were enrolled in this study. Then, 14C-urease breathing test was carried out to evaluate the infection of H. pylori in gastric cancer tissues, the expression of P27 in the tissue samples was detected by the immunohistochemistry staining, and the correlation between the H. pylori infection and P27 expression in gastric cancer was analyzed. Of 82 gastric cancer patients, there were 53 patients with H. pylori infection (64.63%). Among the patients with highly or moderately differentiated gastric cancer, the expression of P27 was much higher than that of patients with poorly differentiated gastric cancer (p < 0.01). Besides, comparison of the P27 expression between males and females, among different age groups, tumor sizes, TNM stages, tumor infiltration degrees, or lymph node metastasis, showed no significant differences (p > 0.05). Analysis of the correlation revealed that P27 expression was negatively correlated with the infection of H. pylori (p < 0.01). Multifactorial logistics regression analysis indicated that tumor differentiation was a risk factor of P27-positive expression in gastric cancer tissues (p < 0.01). In addition, P27 expression in the gastric cancer tissues was lower than that in the tumor-adjacent normal tissues (p < 0.01). In gastric cancer patients, expression of P27 is correlated with H. pylori infection which, via downregulating P27, can cause the cancerization of gastric mucosa, and P27, for its role in the development and progression of gastric cancer, is a potential auxiliary indicator for clinical diagnosis whether gastric cancer is complicated with H. pylori infection. So, P27 is a key indicator for diagnosis, treatment, and prognostic evaluation of disease in the advanced stage.     

Barrett食管伴滑动性食管裂孔疝腹腔镜治疗疗效观察

目的探究合并滑动性食管裂孔疝的Barrett食管患者经腹腔镜下治疗后生活质量和食管黏膜病变的改善情况。 方法回顾性收集首都医科大学宣武医院胃食管反流中心2016年1月至2020年12月诊断为Barrett食管伴滑动性食管裂孔疝患者23例，接受腹腔镜食管裂孔疝修补+胃底折叠术，于术前和术后12周时行胃镜、胃食管反流病自测量表（Gerd Q）评分、反流症状指数（RSI）评分、健康调查量表36（SF-36）调查问卷，评估患者术后生活质量和食管黏膜改善情况。 结果23例伴滑动性食管裂孔疝的Barrett患者术后12周随访显示3例患者黏膜病变部分消退。患者术后GerdQ、RSI相较术前均有明显改善（GerdQ：5.78±1.54 vs 11.65±1.50，P=0.00；RSI：9.70±1.92 vs 18.57±3.01，P=0.00），SF-36量表仅在生理功能方面改善不明显（85.87±4.16 vs 86.43±3.12，P=0.31），生理职能、情感职能、活力、精神健康、社会功能、躯体疼痛和总体健康方面均明显改善（生理职能：66.43±6.13 vs 35.48±2.86，P=0.00；情感职能：73.74±4.91 vs 65.22±2.58，P=0.00；活力：56.96±3.80 vs 50.30±4.56，P=0.00；精神健康：62.09±4.89 vs 53.26±2.07，P=0.00；社会功能：81.39±4.42 vs 74.00±3.59，P=0.00；躯体疼痛：80.00±6.84 vs 75.30±10.27，P=0.00；总体健康：69.17±5.68 vs 60.17±4.61，P=0.00）。 结论腹腔镜食管裂孔疝修补+胃底折叠术对伴滑动性食管裂孔疝的Barrett食管患者生活质量和黏膜病变均有一定改善。     

基于生物信息学的肥厚型心肌病易感基因TNNC1单核苷酸多态性致病表型分析

肥厚型心肌病(HCM)是一种常见的遗传性心脏病,是青少年及年轻运动员心源性猝死的最主要原因之一,其分子遗传学基础为基因突变。TNNC1是HCM的重要致病基因之一,目前仅发现其少量非同义单核苷酸多态性(nsSNPs)位点与HCM发病相关,但该基因其他nsSNPs数量较多,结合临床进行实验遗传检测其基因型与表型的关系,工作量巨大,尚不可行。因此,采用生物信息学方法,从dbSNP数据库中筛选出TNNC1基因全部的nsSNPs,联合4款(Mutation Taster、PolyPhen-2、PhD-SNP和MutPred)专业软件,进行有害性分级筛选和致病关联预测,最后进行突变蛋白三维结构建模及可视化分析。结果显示,首次从TNNC1基因102个nsSNPs位点中预测出疾病相关的18个(G159D、S69R、P52R、D149G、D3V、G140E、N51K、D151V、M47R、G110C、A23D、G140R、K158N、C35Y、R147C、L48P、F74C和V44G)高风险nsSNPs。基于生物信息学方法,以TNNC1基因的nsSNPs为示范,分析其nsSNPs与疾病表型的关系,这为其他遗传疾病致病基因nsSNPs的关联分析打下理论研究基础,具有重要的参考价值。     

A novel surgical technique to prevent post-enucleation conjunctival cyst:conjunctival staining with methylthioninium

Dear Editor,Conjunctival cyst of the orbit acquired from enucleation is an infrequent but serious complication;which can occur in 3%-7%of patients,more commonly after a secondary procedure;.The most common manifestations are the inability to retain the external prosthesis.