Motion‐compensated b‐tensor encoding for in vivo cardiac diffusion‐weighted imaging

Motion is a major confound in diffusion‐weighted imaging (DWI) in the body, and it is a common cause of image artefacts. The effects are particularly severe in cardiac applications, due to the nonrigid cyclical deformation of the myocardium. Spin echo‐based DWI commonly employs gradient moment‐nulling techniques to desensitise the acquisition to velocity and acceleration, ie, nulling gradient moments up to the 2nd order (M2‐nulled). However, current M2‐nulled DWI scans are limited to encode diffusion along a single direction at a time. We propose a method for designing b‐tensors of arbitrary shapes, including planar, spherical, prolate and oblate tensors, while nulling gradient moments up to the 2nd order and beyond. The design strategy comprises initialising the diffusion encoding gradients in two encoding blocks about the refocusing pulse, followed by appropriate scaling and rotation, which further enables nulling undesired effects of concomitant gradients. Proof‐of‐concept assessment of in vivo mean diffusivity (MD) was performed using linear and spherical tensor encoding (LTE and STE, respectively) in the hearts of five healthy volunteers. The results of the M2‐nulled STE showed that (a) the sequence was robust to cardiac motion, and (b) MD was higher than that acquired using standard M2‐nulled LTE, where diffusion‐weighting was applied in three orthogonal directions, which may be attributed to the presence of restricted diffusion and microscopic diffusion anisotropy. Provided adequate signal‐to‐noise ratio, STE could significantly shorten estimation of MD compared with the conventional LTE approach. Importantly, our theoretical analysis and the proposed gradient waveform design may be useful in microstructure imaging beyond diffusion tensor imaging where the effects of motion must be suppressed.     

Immune checkpoint inhibitor-induced inflammatory arthritis: identification and management

ABSTRACT

Introduction

Immune checkpoint inhibitors (ICIs) have proved to be groundbreaking in the field of oncology. However, immune system overactivation from ICIs has introduced a novel medical entity known as immune-related adverse events (irAEs), that can affect any organ or tissue. ICI-induced inflammatory arthritis (ICI-IIA) is the most common musculoskeletal irAE and can lead to significant morbidity and limitation in anti-cancer therapy.     

探讨双重排粪造影对结肠功能性便秘的诊断价值

目的研究双重排粪造影方式应用在结肠功能性便秘诊断当中的效果。方法文章所选择的调查对象来自2017年10月-2018年12月,均为在此期间本院收治的60例经临床病理诊断确诊为结肠功能性便秘患者,分析双重排粪造影方式和排粪造影的符合性。结果采用双重排粪造影方式诊断结肠功能性便秘59例得到确诊,占98.33%,和排粪造影相比,差异有统计学意义(P<0.05)。结论通过双重排粪造影方式进行结肠功能性便秘诊断,可以有效的提升诊断的效率,对于具体症型的确认也具有重要意义。     

Gd-EOB-DTPA增强MRI评估功能性肝体积与肝功能Child-Pugh分级的相关性

目的：对比解剖性肝脏体积（ALV）和功能性肝脏体积（FLV）与肝功能Child-Pugh分级的相关性。方法：选择温州医科大学附属第二医院育英儿童医院2014年1月至2019年4月同时行增强CT和Gd-EOB-DTPA增强MRI扫描的肝硬化患者25例。对所有患者进行肝功能Child-Pugh评分，检测所有入组患者每个肝段的Gd-EOB-DTPA增强MRI平扫期和肝胆特异期的信号对比增强率（CER），以CT扫描的数据为基础利用MI-3DVS计算每个肝段的ALV和全肝的FLV。分析ALV和FLV与肝功能Child-Pugh分级的相关性。结果：肝功能Child-Pugh分级与ALV呈负相关（r=-0.792，P＜0.001），曲线拟合的决定系数（R2）=0.63；肝功能Child-Pugh分级与FLV亦呈负相关（r=-0.911，P＜0.001），曲线拟合的R2=0.80。FLV与肝功能Child-Pugh分级有更显著的负相关性。结论：结合Gd-EOB-DTPA增强MRI平扫期和肝胆特异期的信号CER和ALV计算所得的FLV较ALV能更好地反映肝脏的功能状态。     

不同影像检查在乳腺结构扭曲中的研究进展

我国乳腺癌的发病率占女性恶性肿瘤疾病的首位,结构扭曲病变(architectural distortion,AD)作为触诊阴性乳腺癌的第三最常见影像学表现,也是乳腺癌最早出现的征象,具有重要的临床价值。AD具有较高的漏诊率及假阳性率。本文通过查阅文献,针对超声、乳腺X线摄影、乳腺数字三维断层摄影技术及核磁共振成像技术在乳腺结构扭曲病变中的研究进展及优缺点进行分析,进一步指导科学研究及临床工作。     

基于机器学习的脑胶质瘤多模态影像分析

脑部胶质瘤是临床中常见的一种原发性脑肿瘤，具有复发率高、死亡率高以及治愈率低的特点。常规临床诊断主要依靠计算机断层扫描(CT)和磁共振成像(MRI)检查技术进行鉴别。随着成像技术和机器学习方法的不断发展，多模态影像智能分析技术已经逐步成为研究热点，在脑胶质瘤的病灶分割测量、肿瘤分级、预后生存周期预测和基因型辨别等方面具有重要的应用前景。本文重点介绍基于机器学习和多模态影像在脑胶质瘤临床辅助诊断和预后评估中的应用进展。     

The Relationship between Self-Efficacy,Functional Exercise Capacity and Physical Activity in People with COPD: A Systematic Review and Meta-Analyses

Abstract

The purpose of this study was to investigate the strength of the relationships between self-efficacy and (i) functional exercise capacity and (ii) physical activity in chronic obstructive pulmonary disease (COPD), and whether self-efficacy assessment type (i.e., COPD symptoms, exercise-task, exercise-barrier, general, falls) and physical activity assessment type (i.e., self-report vs. objective) are moderators. A systematic search of COPD and self-efficacy concepts was conducted using eight databases from inception to 23 January 2019. Studies were included if they provided correlation coefficients of the relationship between self-efficacy and functional exercise capacity or physical activity, were conducted in adults diagnosed with COPD, and were published in English-language journals. A total of 14 correlation coefficients were included in the self-efficacy and functional exercise capacity meta-analysis, and 16 in the self-efficacy and physical activity meta-analysis. Data were screened, reviewed, and extracted independently by two reviewers, with discrepancies resolved by a third reviewer. Stronger self-efficacy was associated with better functional exercise capacity (weighted r?=?0.38, 95%CI [0.25, 0.50]), and greater physical activity (weighted r?=?0.25, 95%CI [0.17, 0.34]). Exercise-task self-efficacy had the strongest relationship to functional exercise capacity (weighted r?=?0.64, 95% CI [0.51, 0.73]). For physical activity, the type of self-efficacy most strongly related was inconclusive. In COPD, self-efficacy has a relationship to functional exercise capacity and physical activity, the strength of which is influenced by the choice of self-efficacy measure. An understanding of these relationships will assist clinicians in selecting the self-efficacy measure most closely related to the outcome of interest.     

Real-time motion monitoring improves functional MRI data quality in infants

Imaging the infant brain with MRI has improved our understanding of early neurodevelopment. However, head motion during MRI acquisition is detrimental to both functional and structural MRI scan quality. Though infants are typically scanned while asleep, they commonly exhibit motion during scanning causing data loss. Our group has shown that providing MRI technicians with real-time motion estimates via Framewise Integrated Real-Time MRI Monitoring (FIRMM) software helps obtain high-quality, low motion fMRI data. By estimating head motion in real time and displaying motion metrics to the MR technician during an fMRI scan, FIRMM can improve scanning efficiency. Here, we compared average framewise displacement (FD), a proxy for head motion, and the amount of usable fMRI data (FD ≤ 0.2 mm) in infants scanned with (n = 407) and without FIRMM (n = 295). Using a mixed-effects model, we found that the addition of FIRMM to current state-of-the-art infant scanning protocols significantly increased the amount of usable fMRI data acquired per infant, demonstrating its value for research and clinical infant neuroimaging.     

Tears at the myotendinous junction of the infraspinatus: Ultrasound findings

PurposeTears involving the myotendinous junction (MTJ) of the infraspinatus (IS) have been recently described on MRI. These occur centrally in the muscle belly, and are not associated with full thickness tears of the distal infraspinatus tendon. They also induce a rapidly progressive fatty infiltration of the muscles and amyotrophy. The purpose of this study is to assess the accuracy of ultrasonography in diagnosing MTJ tears of the infraspinatus and to describe the usual ultrasonographic appearance compared with MRI.Materials and methodsRetrospective study of 2403 US examinations of the shoulder (over 5 years). Fifteen patients with a reported suspicion of infraspinatus MTJ tears were included. MRI examination was available in all cases, CT arthrography in 13 cases, and one patient underwent surgical confirmation.ResultsAll patients were sent for an ultrasound for suspect lesion of the tendons of the rotator cuff, with posterior pain in the infraspinatus fossa. All cases seen on ultrasonography were confirmed on MRI. CT arthrography confirmed the absence of tear of the IS tendon in all cases and did not reveal the MTJ tears. Two signs appeared to us as being of special interest: the “tadpole sign” on longitudinal views, and the “black eye sign” on sagittal views. The proximal retraction of the tendon at the MTJ is the anatomical explanation of both signs.ConclusionTears at the myotendinous junction of the infraspinatus are rare but can be diagnosed on US examination, provided that the sonographer pays attention to the infraspinatus fossa especially in cases of normality of the distal tendinous cuff.