Evaluating the use of anti-scatter grids in adult knee radiography

IntroductionAnti-scatter grids efficiently reduce scatter radiation from reaching the imaging receptor, enhancing image quality; however, the patient radiation dose increases in the process. There is disagreement regarding the thickness thresholds for which anti-scatter grids are beneficial. This study aims to establish a thickness threshold for the use of anti-scatter grids to optimise adult knee radiography.MethodsThe study consisted of two phases. In Phase 1 phantom knee radiographs were acquired at varying thicknesses (10–16 cm) and tube voltages (60–80 kV). For each thickness and tube voltage, images with and without an anti-scatter grid were obtained. In Phase 2, two radiologists and three radiographers, evaluated the image quality of these images. Visual Grading Analysis (VGA) scores were analysed using Visual Grading Characteristics (VGC) based on the visualisation of five anatomic criteria.ResultsThe average DAP decreased by 72.1% and mAs by 73.1% when removing the anti-scatter grid. The VGC revealed that overall images taken with an anti-scatter grid have better image quality (AUC ≥0.5 for all comparisons). However, the anti-scatter grids could be removed for thicknesses 10, 12 and 14 cm in conjunction with using 80 kVp,.ConclusionAnti-scatter grids can be removed when imaging adult knees between 10 and 12 cm using any kVp setting since the radiation dose is reduced without significantly affecting image quality. For thicknesses >12 cm, the use of anti-scatter grids significantly improves image quality; however, the radiation dose to the patient is increased. The exception is at 14 cm used with 80 kVp, where changes in image quality were insignificant.Implications for practiceOptimisation by removing anti-scatter grids in adult knee radiography seems beneficial below 12 cm thickness with any kVp value. Since the average knee thickness ranges between 10 and 13 cm, anti-scatter grid can be removed for most patients. Nevertheless, further studies are recommended to test if this phantom-based threshold applies to human subjects.     

577 nm激光光凝联合玻璃体内注射康柏西普治疗糖尿病性黄斑水肿的效果观察

目的　探讨577 nm激光光凝联合玻璃体内注射康柏西普治疗糖尿病性黄斑水肿的效果。方法　选取2016年1月至2017年3月在我院治疗的糖尿病性黄斑水肿患者81例81眼，根据患者最终选取的治疗方案分为观察组43例43眼和对照组38例38眼，观察组给予577 nm激光光凝联合玻璃体内注射康柏西普治疗，对照组仅给予577 nm激光光凝，观察两组治疗前后最佳矫正视力（best corrected visual acuity，BCVA）和黄斑中心凹厚度（central fovea of macula thickness，CMT），分析观察组BCVA和CMT变化值与初始因素的相关性。结果　随治疗时间延长，观察组和对照组BCVA、CMT相应改善（均为P＜0.05）；观察组治疗后1个月、3个月和6个月BCVA分别为0.37±0.09、0.44±0.10和0.52±0.13，均明显高于对照组（均为P＜0.05）；观察组治疗后1个月、3个月和6个月CMT分别为（351.03±41.43）μm、（270.32±40.03）μm和（220.01±32.91）μm，均明显低于对照组（均为P＜0.05）；BCVA变化值与糖尿病性黄斑水肿病程、治疗前BCVA呈负相关（r=-0.422、-0.410，均为P＜0.05）；CMT变化值与糖尿病性黄斑水肿病程、治疗前CMT呈负相关（r=-0.430、-0.415，均为P＜0.05）。结论　577 nm激光光凝联合玻璃体内注射康柏西普治疗糖尿病性黄斑水肿效果较好，其效果与患者基线BCVA、糖尿病性黄斑水肿病程有一定相关性。     

Hailey–Hailey disease improved by fractional CO2 laser

Hailey–Hailey disease (HHD), also known as benign familial pemphigus, is an autosomal dominant skin condition that affects the adhesion of epidermal keratinocytes. Although the initial manifestation of flaccid vesicles on erythematous or normal skin in flexure sites frequently goes unnoticed, large, macerated, exudative plaques of superficial erosions with crusting are observed at the time of diagnosis. There is no specific treatment for HHD, and most cases are symptomatically supported. However, infrared laser ablation has been somewhat helpful. We present a case successfully treated with fractional CO₂ laser showing a long-term favourable outcome and no adverse effects. Thus, this modality could be an alternative to full ablation for this condition.     

Er:YAG激光桩道预处理的研究进展

本文回顾了Er:YAG激光活化根管冲洗技术的最新研究进展,包括光子诱导光声流(photon initiated photoacoustic streaming,PIPS)技术和冲击波增强发射光声流(shock wave enhanced emission photoacoustic streaming,SWEEPS)技术,探讨Er:YAG激光预处理桩道的原理、优点以及对纤维桩粘接强度的影响,以期为临床选择适宜的桩道处理方法提供新思路。     

Advance in Functional Restoration of Injured Nerve with Low Level Laser and its Utilization in the Dental and Maxillofacial Region

The inferior alveolar nerve and facial nerve are the two most important nerves in the dental and maxillofacial region. The injury to them is one of the major postoperative complications after alveolar surgery and orthognathic surgery. However, recovering the nerve function after injury takes a long time and the recovery effect tends to be unsatisfactory. In recent years, an intensively investigated technique, low level laser which has been applying in assisting the recovery of nerve function, has been gradually proved to be effective in clinically treating postoperative nerve injury. In this article we review in terms of the mechanisms involved in low level laser-assisted functional restoration of nerve injury and its clinical application in the recovery of nerve function in the dental and maxillofacial area as well.