U-turn speed is a valid and reliable smartphone-based measure of multiple sclerosis-related gait and balance impairment

BackgroundPeople living with multiple sclerosis (MS) experience impairments in gait and mobility, that are not fully captured with manually timed walking tests or rating scales administered during periodic clinical visits. We have developed a smartphone-based assessment of ambulation performance, the 5 U-Turn Test (5UTT), a quantitative self-administered test of U-turn ability while walking, for people with MS (PwMS).Research questionWhat is the test-retest reliability and concurrent validity of U-turn speed, an unsupervised self-assessment of gait and balance impairment, measured using a body-worn smartphone during the 5UTT?Methods76 PwMS and 25 healthy controls (HCs) participated in a cross-sectional non-randomised interventional feasibility study. The 5UTT was self-administered daily and the median U-turn speed, measured during a 14-day session, was compared against existing validated in-clinic measures of MS-related disability.ResultsU-turn speed, measured during a 14-day session from the 5UTT, demonstrated good-to-excellent test-retest reliability in PwMS alone and combined with HCs (intraclass correlation coefficient [ICC] = 0.87 [95 % CI: 0.80–0.92]) and moderate-to-excellent reliability in HCs alone (ICC = 0.88 [95 % CI: 0.69–0.96]). U-turn speed was significantly correlated with in-clinic measures of walking speed, physical fatigue, ambulation impairment, overall MS-related disability and patients’ self-perception of quality of life, at baseline, Week 12 and Week 24. The minimal detectable change of the U-turn speed from the 5UTT was low (19.42 %) in PwMS and indicates a good precision of this measurement tool when compared with conventional in-clinic measures of walking performance.SignificanceThe frequent self-assessment of turn speed, as an outcome measure from a smartphone-based U-turn test, may represent an ecologically valid digital solution to remotely and reliably monitor gait and balance impairment in a home environment during MS clinical trials and practice.     

The Potential of Digital Microscopy in Breast Pathology

The rapidly evolving field of digital microscopy supports the efficient exploitation of inherent information from stained glass slides to offer widespread utilization in breast histopathology. Digital image signals can be accurately measured, integrated into databases and shared through computer networks. Therefore, digital microscopy can boost telepathology-consultation, gradual- and postgradual teaching, proficiency testing, intra- and interlaboratory validation of biomarker screening interpretation, and automated image analysis of biomarker expression for both diagnostics and research applications. This is a brief highlight of the potential of digital microscopy in breast pathology applications.     

CR与非晶体硅DR胸部摄影曝光剂量优化的探讨

目的 比较CR与非晶体硅DR在胸部摄影中入射剂量的差异,探讨两者最优化曝光剂量.方法 应用CR、DR分别别胸部模体行不同入射剂量曝光成像,记录模体表面入射剂量,用CDRAD2.0评估软件计算模体影像图像质量因子反数值IQFinv.CR组、DR组图像IQFinv差异用两独立样本t检验;CR组、DR组各自图像IQFinv与入射剂量的关系应用pearson相关;应用ROC曲线分析获取两组最佳图像IQFinv值,并换算曝光剂量.结果 CR和DR组入射剂量和图像质量IQFinv值之间呈明显的正相关(r=0.893、0.848,P<0.01),并存在线性回归.CR和DR组IQFinv值差异有统计学意义(t=5.455,P<0.05).ROC曲线分析(曲线下面积AUC=0.893,P<0.001),最佳IQFinv值为3.55.结论 CR、DR系统对于低对比度细节的检测能力均随着入射剂量的增加而增加.入射剂量相同时,DR系统对于低对比度细节的检测能力优于CR;在获得相同的图像质量时,与CR相比应用DR可大大降低被榆者辐射剂量.     

CAD-CAM construction of an auricular template for craniofacial implant positioning: a novel approach to diagnosis

A novel approach to the diagnosis of bone available for craniofacial implant positioning is discussed in a case that required ear ablation for tumor removal. A mirrored volume of the healthy ear was rapidly prototyped for a clinical trial in an appropriate position relative to the patient's face. Three ideal positions for the implant were chosen in the inner of the volume of the mirrored ear. The same positions were transferred to a diagnostic template that was rapidly prototyped with a positioning arm extending to the zygomatic arch. Computed tomography (CT) revealed errors in the planning of the implant position and, as a clinical consequence, an implant site was excluded from surgical planning. A virtual elaboration for maxillofacial implant positioning was used to define the correct implant site in relation to the available bone, and two craniofacial implants were correctly positioned in the temporal bone.     

Digital mammography: An update

Digital mammography has increasingly replaced conventional film-screen mammography and has become the gold standard in combination with soft copy reading in diagnostic as well as screening settings. Large international multi-center trials were able to demonstrate at least equivalence and for some aspects superiority of digital over conventional mammography with regard to detectability of breast cancer, especially in pre/perimenopausal women, women younger than 50 years and generally in dense breasts. Especially the experienced reader may benefit form CAD with an increase of specificity. Additionally digital mammography offers options of advanced processing such as digital tomosynthesis and contrast enhanced mammography. The future of breast imaging will be fusion of different imaging systems (hybrid systems).     

Contrast-enhanced digital mammography

CEDM is a recent development of digital mammography using the intra-venous injection of an iodinated contrast agent in conjunction with a mammography examination. Two techniques have been developed to perform CEDM examinations: the temporal subtraction technique with acquisition of high-energy images before and after contrast medium injection and the dual energy technique with acquisition of a pair of low and high-energy images only after contrast medium injection. The temporal subtraction technique offered the possibility to analyze the kinetic curve of enhancement of breast lesions, similarly to breast MRI. The dual energy technique do not provide information about the kinetic of tumor enhancement but allows the acquisition of multiples views of the same breast or bilateral examination and is less sensitive to patient motion than temporal CEDM. Initial clinical experience has shown the ability of CEDM to map the distribution of neovasculature induced by cancer using mammography. Moreover, previous studies have shown a superiority of MX+CEDM, either for the assessment of the probability of malignancy than for BIRADS assessment comparing to MX alone. The potential clinical applications are the clarification of mammographically equivocal lesions, the detection of occult lesions on standard mammography, particularly in dense breast, the determination of the extent of disease, the assessment of recurrent disease and the monitoring of the response to chemotherapy. CEDM should result in a simple way to enhance the detection and the characterization of breast lesions.     

Should previous mammograms be digitised in the transition to digital mammography?

Breast screening specificity is improved if previous mammograms are available, which presents a challenge when converting to digital mammography. Two display options were investigated: mounting previous film mammograms on a multiviewer adjacent to the workstation, or digitising them for soft copy display. Eight qualified screen readers were videotaped undertaking routine screen reading for two 45-min sessions in each scenario. Analysis of gross eye and head movements showed that when digitised, previous mammograms were examined a greater number of times per case (p = 0.03), due to a combination of being used in 19% more cases (p = 0.04) and where used, looked at a greater number of times (28% increase, p = 0.04). Digitising previous mammograms reduced both the average time taken per case by 18% (p = 0.04) and the participants’ perceptions of workload (p < 0.05). Digitising previous analogue mammograms may be advantageous, in particular in increasing their level of use.     

Characterization of microcalcification: can digital monitor zooming replace magnification mammography in full-field digital mammography?

The aim of this study was to compare the diagnostic accuracy and image quality of microcalcifications in zoomed digital contact mammography with digital magnification mammography. Three radiologists with different levels of experience in mammography reviewed 120 microcalcification clusters in 111 patients with a full-field digital mammography system relying on digital magnification mammogram (MAG) images and zoomed images from contact mammography (ZOOM) using commercially available zooming systems on monitors. Each radiologist estimated the probability of malignancy and rated the image quality and confidence rate. Performance was evaluated by sensitivity, specificity, positive predictive value, negative predictive value, and receiver operating characteristic (ROC) analysis. All three radiologists rated MAG images higher than ZOOM images for sensitivity with statistical significance (average value, 92% vs. 87%, P < 0.05) and performance by ROC analysis improved with MAG imaging. The confidence rate for diagnosis decision and the assessment of lesion characteristics were also better in MAG images than in ZOOM images with statistical significance (P < 0.0001). Digital magnification mammography can enhance diagnostic performance when characterizing microcalcifications. Images zoomed from digital contact mammography cannot serve as an alternative to direct magnification digital mammography. This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2007-313-E00363).     

64层螺旋CT血管造影在诊断颅颈部血管病变中的应用

目的：探讨64层螺旋CT用于颅颈部血管成像的技术操作要点,分析影响成像质量的因素,评价64层螺旋CT无创性颅颈部血管造影在诊断颅颈部血管疾病中的临床应用价值。方法：对进行了CTA检查的50例怀疑颅颈部血管疾病患者的资料进行回顾性分析,以DSA及手术结果为金标准,评价CTA在颅颈部血管病变的诊断敏感性与准确性。结果：64层螺旋CT利用CTA显示动脉280节段,其中动脉狭窄235节段。与DSA或手术结果比较,符合的有260节段,不符合有20节段,不相符处主要表现在动脉狭窄的评估方面。CTA显示正常37节段,与DSA比较,符合31节段,不符合6节段。在所有检查结果中,以DSA或手术结果为金标准,经计算,其敏感性为97．4％。采用X^2检验统计学分析,CTA检查结果与DSA或手术结果之间差别无统计学意义。结论：64层螺旋CT颅颈部CTA成像无创、经济,简单易行,既能显示管腔又能显示管壁情况,弥补了DSA的不足。在颅颈部血管病变的诊断中具有较高的敏感性,可作为一种有效的无创性检测手段广泛用于颅颈部血管疾病的筛查、诊断和随访中。     

小脑上动脉解剖变异的DSA研究

目的：研究数字减影血管造影（DSA）下小脑上动脉的解剖变异。方法：回顾分析我院从2007年8月~2008年12月的137份,常规脑血管造影的DSA片。结果：本组病例SCA重复变异发生率右侧为4.4%,左侧为5.8%,双侧重复变异为0.7%。小脑上动脉起源于大脑后动脉发生率右侧为2.2%,左侧为1.5%,双侧为0.7%。小脑上动脉提前分岔发生率右侧为1.5%,双侧为0.7%。结论：DSA了解小脑上动脉的解剖变异对指导脑血管疾病的介入治疗以及神经外科临床具有重要的意义。