螺旋CT扫描的深部剂量研究

目的 研究多层螺旋CT扫描的深部剂量分布,并导出剂量随受照深度变化的拟合方程。方法 用热释光剂量计和改进后的CT标准剂量监测模体,在MX-8000多层CT机上,按4层常规扫描参数,分别在模体径向方向的中心轴0,37.5,75,112.5和150mm处测量了辐射的平均剂量。结果 CT扫描的辐射剂量随入射深度的增加而减小,呈指数衰减规律。结论 若已知扫描器官对应的体表剂量A,则可根据剂量随深度变化的拟合方程,求得该器官的吸收剂量D=Ae^-0.0044x。     

鹰视眼前段分析仪对前房的测量分析

目的应用鹰视眼前段分析仪（Oculyser）对前房角宽度（ACAW）和前房深度（ACD）进行定量测量,探讨Oculyser在前房测量的应用价值以及多种仪器眼前房生物学参数的关系。方法应用Oculyser对闭角型青光眼和老年性白内障ACAW和ACD进行定量测量,并对各组参数进行统计分析。结果与老年性白内障组相比,闭角青光眼急性发作组和临床前期组ACAW、ACD差异均具有统计学意义。而闭角青光眼急性发作组和临床前期组间比较,ACAW、ACD差异无统计学意义。男女性别间ACAW、ACD差异无统计学意义。结论Oculyser具有客观、准确、非接触和避免人为干扰等优点,可应用于前房角的测量。     

立体视觉相关皮层的研究进展

立体视觉是视觉器官分辨周围物体三维空间位置的感知能力,是建立在双眼同时视和融合基础上的高级视功能。双眼视差是产生立体视的生理基础,是形成立体视觉的主要机制,但立体视觉的中枢神经机制至今仍不明确。     

深部脑电图在七氟醚麻醉条件下的(痫)样放电波幅变异

目的:比较七氟醚在不同麻醉深度下对颞叶癫(痫)手术术中深部电极描记的EEG的影响.方法:颞叶癫(痫)行射频热凝毁损手术患者68例,在七氟醚吸入麻醉,最小肺泡浓度(MAC) =0.6时监测额叶皮质EEG和颞叶深部EEG,再加深麻醉至MAC=1.2时再监测.EEG数据应用快速傅里叶处理(FFT),计算额叶背景平均波幅,测量10个颞叶内侧棘波的波幅,取平均值后确定为该患者的棘波波幅,对MAC=0.6和MAC=1.2两组进行统计.结果:MAC=0.6时颞叶内侧棘波放电波幅平均为(426.2±63.1)μV,额叶10～12 Hz(80.3±16.4)μV背景波幅显著;MAC=1.2时颞叶内侧棘波放电波幅平均为(171.2±32.6)μV,额叶10～12 Hz(550.3±126.8)μV背景波幅显著,两组间的(痫)样放电波幅和额叶背景波幅比较差异均有统计学意义(P＜0.05).MAC≤1.2时,七氟醚吸入麻醉影响背景节律和(痫)样放电的波幅,对频率和波形无明显影响.结论:七氟醚麻醉对深部电极EEG的影响呈剂量依赖性,麻醉过深则可能导致(痫)样放电鉴别困难.     

NIRS系统在生物组织中的探测深度研究

在均一生物组织模型下,研究近红外光谱测量系统的探测深度。根据漫射近似理论模拟生物组织中不同位置的吸收体对探测信号衰减量的分布,由数据处理计算出光子在其中的最大穿透深度约为15mm;基于Lambert-Beer定律,利用近红外光谱系统探测模型实验中光强信号的变化,得到该系统的最大探测深度约为14mm。比较模型实验与理论模拟的结果,表明近红外光谱测量系统可以探测均一生物组织中的最大探测深度约为14mm。     

Memory function during low intensity hippocampal electrical stimulation in patients with temporal lobe epilepsy

Hippocampal memory dysfunction is a main symptom of mesiotemporal lobe epilepsy (TLE). It may increase after temporal lobectomy for seizure relief. The aim of this study was to assess the ability of psychometry during hippocampal electrical stimulation to predict post-operative memory deficits and thereby to contribute to lateralization of the epileptogenic zone. A computerized memory test was performed during low intensity hippocampal stimulation in nine patients with TLE during invasive presurgical evaluation. The following results were obtained: speech dominant hippocampal stimulation induced subtle verbal memory deficits in patients with the epileptogenic zone in the speech dominant hemisphere and normal baseline memory performance. Verbal memory deficits could not be induced in patients with the epileptogenic zone in the speech dominant hemisphere and pre-existing memory deficits, or if the seizure origin was contralateral to speech dominance. Thus it was possible to lateralize the epileptogenic zone in patients with normal baseline memory performance by revealing hippocampal dysfunction only during electrical stimulation. Post-operative psychometric testing demonstrated that the individual risk for impairment of verbal memory performance following temporal lobectomy could be predicted correctly. In conclusion, psychometry during hippocampal stimulation may allow prediction of memory deficits following temporal lobectomy and improve determination of the epileptogenic zone.     

一种基于深度残差网络模型的睡眠呼吸暂停识别方法

目的:睡眠呼吸暂停综合征是由于睡眠时上气道通气不畅或堵塞等引起呼吸暂停和低通气,严重影响了人类的健康和正常生活.目前,相关检测的金标准是多导睡眠监测,但因诸多限制不能有效推广,因此,设计一种使用方便、准确性高的睡眠呼吸暂停监测方法显得尤为迫切和重要.方法:本方案设计了一种基于深度残差网络(ResNet)模型的算法,实现...     

Time-lapse between periodontal regeneration surgery and root canal therapy in sever combined periodontal-endodontic lesions

ObjectiveThe purpose of this study was to evaluate the time-lapse of periodontal regeneration surgery of combined periodontal-endodontic lesions (PEL) after root canal therapy (RCT) to guide the clinical treatment.Methods26 patients (28 teeth) with severe combined PEL were equally divided into 4 groups (n = 7); the control group included patients who underwent periodontal regeneration surgery with no prior RCT and the remaining three experimental groups including patients who received periodontal regeneration surgery post-RCT either immediately or after 3 and 6 months. The probing depth, clinical attachment loss, and periodontal bone density were measured before or after 3, 6, and 12 months post-RCT, respectively.ResultsPeriodontal regeneration surgery could improve the PD (Probing Depth), CAL (Clinical Attachment Loss), BD (Bone Mineral Density) values irrespective of whether the RCT was performed within 12 months or not. However, obviously improved PD, CAL and BD were observed when surgery was performed post-RCT. The time lapse between RCT and periodontal regeneration surgery had no obvious effects on the periodontal index in 3 months after the surgery. Moreover, these periodontal indexes tend to stabilize in 3 to 6 months after the surgery with no significant differences.ConclusionAlthough there were no obvious impacts of time lapse between RCT and periodontal regeneration surgery on the severe PEL, an earlier periodontal surgery might contribute to the healing of periodontal lesions.     

Should an elective contralateral neck dissection be performed in midline-reaching squamous cell carcinomas of the oral cavity and oropharynx?

Objectiveto compare the rate of occult contralateral neck metastases (OCNM) in oral and oropharyngeal squamous cell carcinomas (SCC) reaching or crossing the midline and to identify risk factors for OCNM.Materials and methodswe conducted a single-center retrospective study of oral and oropharyngeal SCC with contralateral cN0 neck. The cohort was divided into a midline-reaching (MR; approaching the midline from up to 10 mm) group and a midline-crossing (MC; exceeding the midline by up to 10 mm) group. Clinical N-status was assessed by a radiologist specializing in head and neck imaging. All patients underwent contralateral elective neck dissection (END).ResultsA total of 98 patients were included in this study, 59 in the MR group and 39 in the MC group. OCNM were present in 17.3% of patients, 20.3% in the MR group and 12.8% in the MC group (p = 0.336). In multivariable analysis, MR/MC status as well as distance from the midline (in mm) were not identified as risk factors for OCNM. Conversely, oropharyngeal primary and clinical N-status above N1 were significantly associated with a higher risk of OCNM, with odds ratios (OR) of 3.98 (95% CI = 1.08–14.60; p = 0.037) and 3.41 (95% CI = 1.07–10.85; p = 0.038) respectively.Conclusionin patients with oral and oropharyngeal SCC extending close to or beyond the midline, tumor origin and clinical N-status should carry the most weight when dictating the indications for contralateral END, rather than the midline involvement in itself.