Intraoperative ultrasonography: a tool for localizing small colonic polyps

Background and aims Small colonic polyps are difficult to palpate and thus difficult to localize during surgery. Preoperative injection of dyes and on-the-table colonoscopy are some of the methods used to allow the surgeon to find the polyps. The aim of the present study was to evaluate the value of intraoperative ultrasound as a tool that may allow detection of small colonic polyps during surgery.Results The study population consisted of nine consecutive patients referred to surgery for polyps of the large bowel that were not amenable to endoscopic removal. At surgery, the colon was filled with saline and than scanned by linear ultrasound probe. In 8 out of 9 patients, intraoperative ultrasound successfully detected all polyps, even those smaller than 0.5 cm. In one patient with two polyps, one in the right colon was easily localized, but a second flat, 0.4-cm tubular adenoma at the splenic flexure was missed. In three patients, intraoperative ultrasound showed penetration into the muscular coat. These polyps were found on pathology to be invasive cancer.Conclusion Intraoperative ultrasound makes it possible for surgeons to easily localize small nonpalpable polyps of the large bowel. Furthermore, it can determine the aggressive potential of these lesions with great accuracy.     

The representation of unattended, segmented sounds: A mismatch negativity (MMN) study

The detection of an irregular, potentially relevant change (deviance) in the regular, unattended acoustic environment is ensured by the automatic deviance detection mechanism. It underlies the formation of a regularity representation and a comparison of an incoming sound with this representation. A mismatch outcome of this comparison evokes the mismatch negativity (MMN) of the event-related potential. For unattended pure tones the automatic deviance detection mechanism operates most efficiently for initial sound parts, which is why these are suggested to contribute more to sound representation than later parts. A transient that physically segments the sound can overcome this temporal constraint in sound representation. Whether the resulting individual (initial and terminal) sound segments or the joined two-segments give rise to the regularity representation is addressed here. We took advantage that the MMN attenuation to the second of two successive deviances (deviance-repetition effect) is more pronounced when the deviances belong to the same unit of representation. We measured MMN for two deviances (frequency modulations) within segmented sounds that either occurred within the initial or the terminal segment, or that were split across both segments. Unexpectedly, we did not obtain a deviance-repetition effect. Instead, we obtained a temporal distance effect: With increasing temporal distance from deviance-onset relative to segment-onset the MMN amplitude decreased. Furthermore, this effect did not depend on whether the deviance occurred in the initial or in the terminal segment. Thus, (for the current approach) we suggest that the regularity representation is based on the individual rather than joined segments.     

便携式心音采集与处理系统的设计

目的:在心脏辅助泵血装置的研制过程中,需要一款携带方便、抗干扰能力强的心音采集与处理系统实现对心音的准确采集,同时能够将采集到的信号进行分析。方法:本文以单片机和Visual C++6.0为基础设计了一款便携式心音采集与处理系统;该系统通过随身携带的部件采集心音信号并利用蓝牙技术无线传输到PC机,实现信号的保存和和处理。结果:该系统能实现心音信号的采集、保存、波形的实时显示、采样频率设置、心音包络提取等。结论:采用该系统采集了二尖瓣区的心音信号并提取了其包络,通过与专业设备采集的数据和处理结果对比,证明该心音采集和处理系统采集的信号准确性高、可靠性强,提取的包络效果良好。     

CT三维重建在口腔埋伏牙定位中的临床应用

目的：探讨螺旋CT三维重建用于埋伏牙定位的临床效果。方法：对28例埋伏牙患者应用三维螺旋CT的图像处理功能,采用表面遮盖法（SSD）、多平面重建（MPR）、最大密度投影（MIP）获得牙体表面立体图像。结果：螺旋CT三维重建能清楚显示埋伏牙的形态、唇腭向位置、萌出方向及与邻牙的关系。结论：螺旋CT三维重建是一种能展示牙体表面立体形态影像的新技术,对埋伏牙的定性、定位准确,弥补了传统X线片及二位CT的不足,可作为骨内埋伏牙外科处理和正畸治疗的检查手段。     

术中实时超声定位在颅脑深部病变显微外科手术中的应用

目的：探讨术中实时超声定位在颅脑深部病变显微外科手术中的临床应用价值。方法对38例行外科手术的颅内病变患者,术中开颅后应用超声显示病变的位置、深度、范围、性质以及与毗邻血管的关系,对病灶进行定位;瘤体切除后再次探测有无残留。结果38例病变均在术中超声图像上清晰显示并准确定位,其中12例患者病灶较小或相对较深,超声引导下先行穿刺置入人工标志物后得以清除。结论术中超声检测可清晰显示颅内深部病变并进行准确定位,并可监控病变切除情况,缩短了手术时间,提高了手术成功率,具有较大临床应用价值。     

Analysis of the spectral envelope of sounds by the human brain

Spectral envelope is the shape of the power spectrum of sound. It is an important cue for the identification of sound sources such as voices or instruments, and particular classes of sounds such as vowels. In everyday life, sounds with similar spectral envelopes are perceived as similar: we recognize a voice or a vowel regardless of pitch and intensity variations, and we recognize the same vowel regardless of whether it is voiced (a spectral envelope applied to a harmonic series) or whispered (a spectral envelope applied to noise). In this functional magnetic resonance imaging (fMRI) experiment, we investigated the basis for analysis of spectral envelope by the human brain. Changing either the pitch or the spectral envelope of harmonic sounds produced similar activation within a bilateral network including Heschl's gyrus and adjacent cortical areas in the superior temporal lobe. Changing the spectral envelope of continuously alternating noise and harmonic sounds produced additional right-lateralized activation in superior temporal sulcus (STS). Our findings show that spectral shape is abstracted in superior temporal sulcus, suggesting that this region may have a generic role in the spectral analysis of sounds. These distinct levels of spectral analysis may represent early computational stages in a putative anteriorly directed stream for the categorization of sound.     

右房射频消融术治疗心房扑动

对５例阵发性心房扑动（简称房扑）患者行右房射频消融术。３例单型房扑消融成功，２例复合型房扑／房颤失败。３例成功者随访６个月无复发。房扑与右房内大折返运动有密切关系。射频消融结果与右房结构、房扑的类型及折返运动有关。右房射频消融的远期效果仍有待研究     

磁共振在中国——2014年中华医学会放射学分会全国磁共振学术大会高峰对话纪实

中华医学会放射学分会第十四届全国磁共振学术大会于2014年6月27日至29日在湖南省长沙市成功召开.来自海内外的磁共振领域专家、学者通过这一平台交流和探讨磁共振成像技术及临床应用的经验和成果,积极推动我国医学磁共振事业的发展.6月26日,由美国医学科学院(IOM)外籍院士、中华医学会副会长戴建平教授主持的“磁共振在中国”高峰对话提前拉开了这一盛会的序幕.本次高峰对话中,7位业内著名专家就磁共振设备在国内产学研用各方面的发展进行了深入的讨论,在建立磁共振诊疗的标准化流程,推动磁共振研发和生产的本土化,针对临床需求开展前沿领域科学研究等问题上达成了共识.     

Bone-Conducted Sound Lateralization of Interaural Time Difference and Interaural Intensity Difference in Children and a Young Adult with Bilateral Microtia and Atresia of the Ears

Objective—We used multi-slice helical computerized tomography (MSHCT) to evaluate the 3D characteristics of the laryngeal structures in patients with unilateral vocal fold paralysis (UVFP) during phonation, and compared the results with those obtained using an aerodynamic vocal function test. Material and methods—The subjects were 37 patients with UVFP. The region over the larynx was scanned during quiet phonation and again during inspiration using MSHCT, and 3D endoscopic and coronal reconstruction images were produced. Maximum phonation time (MPT) and mean airflow rate (MFR) during phonation were measured. Results—During phonation, the affected fold was thinner than the healthy fold in 30 subjects and located at a higher position than the healthy fold in 21 subjects. Abduction or thinning of the affected fold during phonation (paradoxical movement) was seen in seven subjects. MFR was significantly greater when the affected fold was thinner than the healthy fold during phonation, and MPT was significantly shorter when the affected fold showed paradoxical movement. Over-adduction of the healthy fold during phonation was present in 15 subjects. There were no significant differences in MPT or MFR between subjects with and without over-adduction. Conclusion—The combination of MSHCT endoscopic and coronal reconstruction images enables the 3D characteristics of the unilaterally paralyzed larynx to be visualized during phonation, and some of these characteristics are significantly correlated with vocal function in patients with UVFP.