Computed tomography reference dimensions for identification of stented surgical mitral bioprostheses valve size

BackgroundSelection of the transcatheter heart valve size for a mitral valve-in-valve procedure is based on the type and manufacturer’s labelled size. However, accurate information of surgical heart valve (SHV) size may not be available in the patient’s medical record. The purpose of this study is to establish reference data for computed tomography (CT) dimensions of commonly used mitral SHV in order to determine the manufacturer’s labelled size from a cardiac CT data set.MethodsCT datasets of 105 patients with surgical mitral bioprosthesis and available manufacturer labeled datasets were included in the analysis. CT derived valve dimensions were assessed by two observers using multiplanar reformats aligned with the basal sewing ring. A circular region of interest was used in a standardized fashion to minimize influence of image acquisition and reconstruction parameters. Interobserver variability was assessed by Bland-Altman analysis.ResultsThe CT-derived dimensions were stratified by valve size and type, and SHV properties were demonstrated for 5 common valve types. Variability of measurements was small and inter-observer limits of agreement were narrow. Stratified by SHV type, no overlap was noted for CT-derived dimensions among different SHV sizes . A reference table of CT characteristics of surgical mitral bioprosthesis types was created.ConclusionThe study provides reference CT data for determining the manufacturers’ labeled SHV size across a range of commonly used mitral SHVs. The findings will be important to help identify types of surgical mitral bioprosthesis utilizing CT characteristics for patients without SHV size documentation.     

基于人工智能的骨龄辅助评价系统对四川地区完全性生长激素缺乏症患儿骨龄研究

目的探讨采用基于"人工智能(AI)的骨龄辅助评价系统(上海初云医疗科技有限公司与四川大学华西第二医院合作开发)"(以下简称为AI系统)对完全性生长激素缺乏症(CGHD)患儿诊断及骨龄评价准确性。 方法选择2014年7月至2019年11月，于四川大学华西第二医院确诊的66例来自四川地区CGHD患儿为研究对象，纳入研究组。选择同期于病例收集医院儿童保健科进行骨龄测定的67例来自四川地区身高达标儿童作为对照，纳入对照组。对每例受试儿进行左手腕关节正位X射线摄片骨龄测定，由2位医师采用《TW₂骨龄评分法中国未成年人南方标准》(以下简称为TW₂CHN)》与《TW₃骨龄评分法标准》(以下简称为TW₃)，盲法评价受试儿TW₂CHN-桡、尺、掌指骨(RUS)与TW₂CHN-腕骨(carpal)、TW₂CHN-20、TW₃-RUS及TW₃-carpal骨龄(以下简称为5种传统骨龄)，以及以同性别、年龄身高达标儿童5种传统骨龄为标准，计算受试儿5种传统骨龄百分位数。同时，采用AI系统分别对每例受试儿采取TW₂CHN与TW₃法，评价其AI-TW₂CHN-RUS、AI-TW₂CHN-carpal、AI-TW₂CHN-20、AI-TW₃-RUS及AI-TW₃-carpal骨龄(以下简称为5种AI骨龄)及其相应百分位数。以上述5种传统骨龄＋5种AI骨龄(以下简称为10种骨龄)相应的P₅₀、P₂₅、P₁₀、P₃值(统称为P_n值)作为诊断CGHD患儿临界值，分别计算其诊断CGHD患儿的敏感度、特异度、约登(Youden)指数、准确率、阳性似然比、阴性似然比、阳性预测值、阴性预测值。采用Kappa值评价2组受试儿5种传统骨龄百分位数与对应的5种AI骨龄百分位数评价结果的一致性，以及2位医师对2组受试儿TW₂CHN-RUS骨龄百分位数评价结果一致性。绘制上述10种骨龄百分位数诊断CGHD患儿的受试者工作特征(ROC)曲线，并计算曲线下面积(AUC)。采用配对t检验，对2组受试儿TW₂CHN骨龄与TW₃骨龄进行比较。本研究遵循的程序符合2013年新修订的《世界医学协会赫尔辛基宣言》要求。2组受试儿年龄、性别构成比等一般临床资料比较，差异均无统计学意义(P>0.05)。 结果①采用10种骨龄的P_n值分别作为诊断CGHD临界值，对133例受试儿CGHD诊断结果显示，除了TW₃-RUS骨龄中，以骨龄≤P₁₀作为诊断CGHD患儿临界值时的诊断准确率最高(85.0%)，TW₂CHN-RUS、TW₂CHN-carpal、TW₂CHN-20、TW₃-carpal、AI-TW₂CHN-RUS、AI-TW₂CHN-carpal、AI-TW₂CHN-20、AI-TW₃-carpal、AI-TW₃-RUS骨龄中，均为以骨龄≤P₂₅作为临界值时，对CGHD的诊断准确率最高，分别为81.9%、75.2%、88.0%、78.2%、75.2%、73.6%、81.2%、72.9%、78.9%。②一致性检验结果显示，2组受试儿TW₂CHN-RUS与AI-TW₂CHN-RUS、TW₂CHN-carpal与AI-TW₂CHN-carpal、TW₂CHN-20与AI-TW₂CHN-20、TW₃-RUS与AI-TW₃-RUS、TW₃-carpal与AI-TW₃-carpal骨龄百分位数评价结果均为中等一致性，Kappa值分别为0.445、0.578、0.570、0.446、0.430(均为P<0.001)。③对2位医师对2组受试儿TW₂CHN-RUS骨龄百分位数评价结果进行一致性检验显示，其Kappa值为0.790(P<0.001)，一致性较高。④绘制10种骨龄百分位数评价结果诊断CGHD的ROC曲线分析结果显示，TW₂CHN-RUS、TW₂CHN-carpal、TW₂CHN-20、TW₃-carpal、TW₃-RUS、AI-TW₂CHN-RUS、AI-TW₂CHN-carpal、AI-TW₂CHN-20、AI-TW₃-carpal、AI-TW₃-RUS骨龄百分位数诊断CGHD患儿的AUC分别为0.932、0.859、0.915、0.895、0.844、0.823、0.805、0.866、0.860、0.764(均为P<0.001)。⑤133例受试儿的TW₃-RUS、TW₃-carpal、AI-TW₃-RUS、AI-TW₃-carpal骨龄，均分别显著低于TW₂CHN-RUS、TW₂CHN-carpal、AI-TW₂CHN-RUS、AI-TW₂CHN-carpal骨龄，并且差异均有统计学意义(t＝21.746、25.287、16.498、9.290，P<0.001)。 结论TW₂CHN法、TW₃法对CGHD患儿骨龄评价及诊断均有临床价值，TW₂CHN-RUS骨龄对于CGDH患儿诊断效能高。四川地区儿童TW₃骨龄较TW₂CHN骨龄低，TW₃法可能不完全适用于四川地区儿童骨龄评价。AI系统对于四川地区CGHD患儿骨龄评价结果与传统骨龄评价结果具有中等一致性，可为临床医师评价受试儿骨龄提供帮助。     

European consensus on patient contact shielding

Patient contact shielding has been in use for many years in radiology departments in order to reduce the effects and risks of ionising radiation on certain organs. New technologies in projection imaging and CT scanning such as digital receptors and automatic exposure control (AEC) systems have reduced doses and improved image consistency. These changes and a greater understanding of both the benefits and the risks from the use of shielding have led to a review of shielding use in radiology. A number of professional bodies have already issued guidance in this regard. This paper represents the current consensus view of the main bodies involved in radiation safety and imaging in Europe: European Federation of Organisations for Medical Physics, European Federation of Radiographer Societies, European Society of Radiology, European Society of Paediatric Radiology, EuroSafe Imaging, European Radiation Dosimetry Group (EURADOS), and European Academy of DentoMaxilloFacial Radiology (EADMFR). It is based on the expert recommendations of the Gonad and Patient Shielding (GAPS) Group formed with the purpose of developing consensus in this area. The recommendations are intended to be clear and easy to use. They are intended as guidance, and they are developed using a multidisciplinary team approach. It is recognised that regulations, custom and practice vary widely on the use of patient shielding in Europe and it is hoped that these recommendations will inform a change management program that will benefit patients and staff.     

Temporal changes in extra-axial brain hematoma's signal intensity in magnetic resonance images of trauma patients: A preliminary,technical study

IntroductionDating the exact or estimated time of trauma is an important issue facing forensic medicine. Several clinical and radiological methods were used to achieve this purpose. In the recent study, we aimed to track the changes in the signal intensity of the extra-axial brain hematoma using magnetic resonance imaging (MRI) conventional sequences as well as diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC).Materials and methodsConsidering inclusion and exclusion criteria, all patients with blunt head trauma were involved. After proper management., stabilization, and resuscitation, the participants were assessed using conventional sequences of MRI and DWI twenty-four hours, forty-eight hours, and three weeks after the injury. Temporal changes of signal intensity were compared by Wilcoxon ranged test.ResultsSixteen patients sustaining blunt head trauma were included in this study. The study showed that during the time, diffusion restriction could be seen in an extraaxial hematoma. At the first 24 hours, the signal of hematoma was void in 87.5% of DWI and 100% of ADC. On the second day, they were hypo-signal in 75% of DWI and 100% 0f ADCs, and after three weeks, 100% of cases were hyper-signal in DWI and hypo-signal ADCs.ConclusionThis preliminary study has shown that the DWI can be used to detect and track the extra-axial hematoma. The signal intensity was void during the first twentyfour hours, although it became hypo-signal after 48 hours. Of note, the diffusion restriction is noted after three weeks.     

儿童胰母细胞瘤的CT与MRI诊断

目的探讨儿童胰母细胞瘤的CT、MRI特征及临床表现,以提高对该病的认识。方法选取术后病理证实为胰母细胞瘤患儿7例,采用CT或MRI增强扫描,分析其影像学特点。结果7例均发生于胰头区,肿块大小1.0~7.5 cm,平均约4.3 cm,CT表现为与胰腺密度相仿或低密度结节影,密度均匀或欠均匀、呈分叶状,2例囊变,1例钙化,增强扫描动脉期5例病灶表现为不均匀轻度强化,2例表现为均匀强化;2例MRI表现为边界清楚结节影,T₁WI呈低或中等信号,T₂WI呈等信号或等高信号,增强后不均匀强化,1例主胰管扩张,3例胆总管扩张。结论儿童胰母细胞瘤作为罕见病,多发生于10岁以下儿童,具有胰头区低密度占位并增强后不均匀轻度强化等特点,偶合并胰胆管扩张可提高对该病的诊断。     

MSCT在对比剂外渗的急性腹部创伤性动脉损伤诊断中的应用价值

目的探讨MSCT在对比剂外渗的急性腹部创伤性动脉损伤诊断中的应用价值。方法回顾性分析本院2016年1月～2018年12月收治的44例急性创伤性腹部动脉损伤患者及58例腹部非创伤性动脉病变患者影像资料,分析急性腹部创伤性和非创伤性动脉病变所致对比剂外渗的相关性。结果 44例创伤性腹部损伤患者通过MSCT及图像后处理技术共检出59支动脉损伤,其中对比剂外渗34支、非对比剂外渗共25支;58例急性腹部非创伤组共检出58支动脉病变,其中8支存在对比剂外渗。对比剂外渗征象创伤组出现率明显高于非创伤性组(χ~2=24.42,P0.05)。结论与非创伤组相比,急性腹部创伤性动脉损伤对比剂外渗征象较为常见,MSCT可以较好地显示创伤性对比剂外渗的直接及间接征象。     

Cost-Effectiveness of Follow-Up for Subsolid Pulmonary Nodules in High-Risk Patients

ObjectiveTo evaluate the cost-effectiveness of a number of follow-up guidelines and variants for subsolid pulmonary nodules.MethodsWe used a simulation model informed by data from the literature and the National Lung Screening Trial to simulate patients with ground-glass nodules (GGNs) detected at baseline computed tomography undergoing follow-up. The nodules were allowed to grow and develop solid components over time. We tested the guidelines generated by varying follow-up recommendations for low-risk nodules, that is, pure GGNs or those stable over time. For each guideline, we computed average US costs and quality-adjusted life-years (QALYs) gained per patient and identified the incremental cost-effectiveness ratios of those on the efficient frontier. In addition, we compared the costs and effects of the most recently released version of the Lung Computed Tomography Screening Reporting and Data System (Lung-RADS), version 1.1, with those of the previous version, 1.0. Finally, we performed sensitivity analyses of our results by varying several relevant parameters.ResultsRelative to the no follow-up scenario, the follow-up guideline system that was cost-effective at a willingness-to-pay of $100,000/QALY and had the greatest QALY assigned low-risk nodules a 2-year follow-up interval and stopped follow-up after 2 years for GGNs and after 5 years for part-solid nodules; this strategy yielded an incremental cost-effectiveness ratio of $99,970. Lung-RADS version 1.1 was found to be less costly but no less effective than Lung-RADS version 1.0. These findings were essentially stable under a range of sensitivity analyses.ConclusionsCeasing follow-up for low-risk subsolid nodules after 2 to 5 years of stability is more cost-effective than perpetual follow-up. Lung-RADS version 1.1 was cheaper but similarly effective to version 1.0.     

New evidence supporting lung cancer screening with low dose CT & surgical implications

IntroductionLung cancer is the leading cause of cancer-death worldwide. The U.S. Preventative Services Task Force (USPTSF) approved screening for current or former smokers aged 55–80 based on the results of the National Lung Screening trial (NLST). Following the NLST, new evidence has emerged from clinical trials and updates to previous trials prior to the anticipated update to the USPSTF guideline. We review the new evidence on lung cancer screening with low dose computed tomography (LDCT) and the surgical implications.MethodsA review of new literature was performed pertaining to lung cancer screening since implementation of UPSTF guidelines. Articles for inclusion were identified by both authors’, then search of the Pubmed and Cochrane database was performed from January 1st, 2013 through February 4th, 2020 using the MeSH search terms: “lung cancer”; “screening”; “low dose CT”. The results of these studies are summarized.ResultsWe identified multiple prospective randomized control trials and meta-analysis since the NLST supporting lung cancer-specific mortality with screening. We identified new nodule classification systems and the development of risk-models which may reduce false positive rates and identify high risk patients not currently eligible for screening. Finally, we discussed the surgical implications of screening.ConclusionNew data supports NLST findings and show ongoing benefit to LDCT for lung cancer screening. Standardized LDCT screening classification has been shown to reduce harm and lower false positive rates. Further study is needed regarding use of risk-modeling. Screening will require an increase in the thoracic workforce to accommodate the amount of surgically operable cancers.     

Source imaging of seizure onset predicts surgical outcome in pediatric epilepsy

ObjectiveTo assess whether ictal electric source imaging (ESI) on low-density scalp EEG can approximate the seizure onset zone (SOZ) location and predict surgical outcome in children with refractory epilepsy undergoing surgery.MethodsWe examined 35 children with refractory epilepsy. We dichotomized surgical outcome into seizure- and non-seizure-free. We identified ictal onsets recorded with scalp and intracranial EEG and localized them using equivalent current dipoles and standardized low-resolution magnetic tomography (sLORETA). We estimated the localization accuracy of scalp EEG as distance of scalp dipoles from intracranial dipoles. We also calculated the distances of scalp dipoles from resection, as well as their resection percentage and compared between seizure-free and non-seizure-free patients. We built receiver operating characteristic curves to test whether resection percentage predicted outcome.ResultsResection distance was lower in seizure-free patients for both dipoles (p = 0.006) and sLORETA (p = 0.04). Resection percentage predicted outcome with a sensitivity of 57.1% (95% CI, 34–78.2%), a specificity of 85.7% (95% CI, 57.2–98.2%) and an accuracy of 68.6% (95% CI, 50.7–83.5%) (p = 0.01).ConclusionIctal ESI performed on low-density scalp EEG can delineate the SOZ and predict outcome.SignificanceSuch an application may increase the number of children who are referred for epilepsy surgery and improve their outcome.