以颅骨体表骨性结构为配准标定点的方法在鼻内镜导航手术中的应用

目的　探讨颅骨体表骨性结构作为配准标定点的方法在鼻内镜导航手术中的应用价值。方法　回顾分析2017年5月～2018年11月行鼻内镜手术患者。骨性标志组以额骨颧突、中切牙根或鼻骨为配准标定点,对照组以外眦和人中软组织为配准标定点。分析两组导航误差、配准时间、配准标定点选择次数。结果　骨性标志组11例,软组织组9例;骨性标志组（中位数1 mm,四分位数间距0.5 mm）的导航误差小于面部软组织组（中位数2 mm,四分位数间距0.5 mm）,差异具有显著性（Z =3.51,P <0.05）;骨性标志组（中位数3.5 min,四分位数间距1 min）的导航配准时间小于面部软组织组（中位数7.5 min,四分位数间距1.5 min）,差异具有 显著性（Z =3.48,P <0.05）;骨性标志组（中位数1次,四分位数间距1次）配准标定点选择次数少于面部软组织组（中位数3次,四分位数间距1次）,差异具有显著性（Z =3.76,P <0.05）。相对于颅面软组织组,颅面骨性标志组在可操作性、误差大小和耗时方面更有优势。结论　使用颅骨体表骨性标志做为配准标定点的方法可操作性强、精确度高。     

影像导航系统在复杂鼻颅底内镜手术中的应用

目的 评价影像导航系统在复杂鼻颅底内镜手术中的作用。方法 26例中额窦复发性内翻性乳头状瘤2例,鼻腔鼻窦肿瘤侵及颅底5例,垂体腺瘤7例,创伤性视神经病12例,均应用影像导航系统行鼻内镜手术。结果 影像导航术前准备时间(包括配准、头架定位、常规器械注册等) 5～10min, 平均7min。手术区域影像标志与实体解剖标志间的误差≤1. 5mm,手术均顺利完成,术中、术后未出现并发症。结论 导航系统定位准确, 能帮助术者确定术区周围重要解剖结构,可以实时判定肿瘤切除程度, 能够最大限度地切除肿瘤, 减少并发症。尤其在有既往手术史或病变破坏了鼻鼻窦及颅底解剖标志的情况下,导航系统对术者的帮助更大,增强了术者自信心,提高了手术的安全因素,保证了肿瘤切除的彻底性。     

影像导航下鼻内镜手术58例临床分析

目的　探讨影像导航技术在鼻内镜手术中应用的有关问题。方法　回顾性分析 5 8例患者 ,其中慢性鼻窦炎、鼻息肉 39例、孤立性蝶窦炎 6例、坏死性上颌窦炎 3例、蝶窦囊肿 5例、鼻咽纤维血管瘤 2例 ;鼻颅沟通性脑膜瘤、外伤性脑脊液鼻漏、外伤性视神经损伤各 1例。所有病例均采用BrainLab影像导航系统及鼻内镜实施手术。结果　影像导航术前准备时间 (包括配准、头架定位、常规器械注册等 ) 10～ 2 0min ,平均 15min。 5 2例手术区域影像标志与实体解剖标志间的误差≤ 1 5mm ,6例 >3mm。影像导航可准确定位视神经等解剖标志 ,无手术并发症发生。结论　影像导航系统与内镜相驳接 ,不仅可以帮助术者在术中定位鼻腔、鼻窦、颅底的解剖结构 ,并可使手术视野扩展到内镜之外 ,使术者在术野中进行手术操作的同时 ,能顾及到术野周围的重要结构。特别是在复杂的手术中 ,可提高手术的精确性和安全性     

影像导航技术在鼻及颅底和鼻眼相关疾病内镜手术中的应用

目的 对影像导航技术在鼻及颅底和鼻眼相关疾病内镜手术中的实际应用进行评价。 方法 回顾性分析使用影像导航系统的751例实施鼻内镜手术的病例,其中565例应用美敦力Stealth Station^TM红外线导航系统,186例应用美敦力Fusion电磁导航系统。对导航系统的精确性、 术前导航准备时间、 术者对使用导航辅助的价值认知度、 导航手术中发生的不良事件,以及术中、 术后的并发症进行详细记录。 结果 红外线导航应用解剖标志法注册可提供0.5~2.0 mm的定位误差,电磁导航应用轮廓(Tracer)注册法均能达到<1 mm的注册误差。应用VAS评分评价术者对导航辅助的价值认知度为(8.3±1.2)分。其中,额窦、视神经管、颈内动脉管被认为是应用导航辅助价值最大的解剖部位。导航手术中发生的不良事件主要为影像漂移、定位器械无法实时定位、注册失败。全部病例均能顺利手术,无颅内和眶内并发症出现。 结论 影像导航与内镜手术的结合,为术者提供了更精确的解剖指引;能辅助提高内镜手术的准确性,消除内镜下可能出现的解剖错觉,尤其是在处理涉及额窦、视神经、颈内动脉的鼻颅底及眼眶手术中。导航手术中不良事件的发生率较低,此时术者的设备操作经验和内镜手术经验尤为重要。     

计算机辅助导航技术在鼻窦及鼻颅底手术中的应用

目的:探讨计算机辅助导航技术在鼻窦及鼻颅底手术中的应用价值。方法:49例患者(复发性鼻窦炎、鼻息肉25例,鼻腔鼻窦肿瘤9例,脑脊液鼻漏7例,脑膜脑膨出2例,先天性后鼻孔闭锁4例,垂体瘤1例,中颅窝底异物1例)均在计算机辅助导航下行鼻内镜手术。结果:计算机辅助导航术前准备时间为5～13min,平均7min,靶点误差≤1.5mm。49例患者均顺利完成手术,无并发症出现。结论:计算机辅助导航系统有助于术者正确判断鼻窦、颅底及相邻的解剖标志,可提高手术的精确性和安全性,减少术中及术后并发症的发生。     

影像导航系统在复杂鼻内镜手术中的作用和评价

目的：对影像导航系统在复杂鼻内镜手术中的作用进行评价。方法：使用影像导航系统对305例行鼻内镜手术的患者进行导航。对导航系统的精确性,总的手术时间,术者的满意程度,以及术中、术后的并发症进行详细记录分析。结果：305例患者中有301例（98．7％）影像导航系统提供了误差0.5～2．0mm（平均1．2mm）的解剖定位。术者增强了自信心,提高了手术的安全因素。未见术中及术后并发症发生。总的手术时间和常规鼻内镜手术时间基本相同。结论：影像导航系统是处理复杂鼻内镜手术很有价值的工具。     

影像导航引导经鼻内镜在鼻颅底肿瘤切除中的应用

目的:对影像导航引导经鼻内镜在鼻颅底肿瘤切除中作用进行评价。方法:在影像导航技术的引导下,采取鼻内镜手术治疗17例鼻颅底肿瘤患者。结果:术前影像导航配准时间平均25 min,导航提供了误差0.5~2.0mm(平均1.2mm)的准确定位,手术时间1.5~3h。手术均彻底切除肿瘤。1例并发脑脊液漏,2例损伤眶骨膜,2例术后半年复发。结论:影像导航系统结合鼻内镜手术治疗鼻颅底肿瘤具有定位准确、手术创伤小等优点,可有效提高手术疗效和避免并发症的发生。     

影像导航下的鼻内镜手术

目的　通过影像导航下进行的 5 3例鼻内镜手术分析 ,就不同类型耳鼻咽喉影像导航系统在鼻内镜手术中应用的有关问题进行探讨。方法　慢性鼻窦炎、鼻息肉 2 4例 ,鼻咽纤维血管瘤 4例 ,垂体腺瘤 8例 ,鼻窦骨化纤维瘤 9例 ,鼻咽混合瘤 2例 ,鼻腔平滑肌瘤 1例 ,霉菌性鼻窦炎 3例 ,鼻腔内翻性乳头状瘤 2例 ,分别在 3种类型的影像导航系统导航下进行鼻内镜手术。结果　影像导航术前准备时间 15～ 30min ,平均 2 6min。影像标志与实体指示之间误差 <1mm的范围包括鼻窦、颅底等手术区域。其中 3例患者术中出现较明显误差 ,均及时发现。 5 3例均手术过程顺利 ,无术中、术后并发症。手术时间与传统的鼻内镜手术相比无明显差异。结论　不同类型影像导航系统均能与鼻内镜配合 ,但各有优缺点。鼻腔、鼻窦及颅底解剖变异 ,肿物伴眶、颅底侵犯 ,有鼻科手术史解剖标志缺失的患者 ,是进行影像导航手术的指征。导航技术可以帮助医师在手术中确认鼻及颅底的局部及相邻解剖标志 ,提高手术的精确性 ,增加医师的信心 ,在未来鼻 颅底微创外科中有良好应用前景     

计算机智能导航系统在鼻科和耳科手术中的应用

目的：探讨计算机智能导航系统在鼻科和耳科手术中应用的有关问题。方法：霉菌性蝶窦炎1例，巨大额筛窦囊肿1例，先天性外耳道闭锁3例，均在影像导航系统下进行鼻内窥镜手术和显微镜手术。结果：术前准备时间16-30min，平均27min，配准系数在1.3-2.0之间，平均1.92。影像与实体指示之间误差小于1mm的是中耳，颅底，乳突，误差小于1.3mm的区域是鼻腔鼻窦，5例手术均顺利，无术中，术后并发症，手术时间与传统的鼻内窥镜手术和耳显微手术相比差异无显著性意义。结论：导航手术可以帮助医师在手术中确认鼻，耳及与之相连接的高危解剖区域的标志，即提高了手术的精确性，又提高了手术的安全性，是未来耳鼻咽喉微创外科的方向之一。     

影像导航系统在鼻内窥镜手术中的应用

目的 通过28例影像导航下进行的鼻内窥镜手术,探讨耳鼻咽喉影像导航系统在鼻内窥镜手术中的应用的有关问题。方法 慢性鼻突炎、鼻息肉10例,鼻咽血管纤维瘤4例,垂体腺瘤6例,鼻窦骨化纤维瘤3例,鼻咽混合瘤2例,鼻腔平滑肌瘤1例,霉菌笥鼻窦炎1例,鼻腔内翻性乳头状瘤1例,均在影像导航系统导航下进行鼻内窥镜手术。结果 术前准备时间15－30min,平均26min。配准系数在1.3-2.0之间,平均1.9;影像与实体指示之间误差小于1mm的范围包括算窦、颅底等手术区域。28例均手术过程顺利,无术中、要后并发症。手术时间与传统的鼻内窥镜手术相比差异无显著性。结论 影像导航系统能与鼻内窥镜配合。鼻腔、鼻窦及颅底解剖变异,肿瘤伴眶、颅底侵犯,有鼻科手术史正常解剖标志缺失的患者,是进行影像导航手术的指征。导航技术可以帮助医师在手术中确认鼻及颅底的局部及相邻解剖,提高手术 的精确性,在未来鼻－颅底微创外科中有良好的应用前景。     

Contour and paired-point registration in a model for image-guided surgery

OBJECTIVES/HYPOTHESIS: This study assesses target registration error (TRE) of contour-based registration (CBR) and paired-point registration (PPR) for endoscopic sinus surgery. STUDY DESIGN: The experimental registration model consisted of a replica of a human head (Sawbones #1345-27; Pacific Research Laboratories, Vashon, WA). Twelve surface fiducial markers were affixed to the simulated skin on the model, and titanium screws were placed in the regions of the anterior ethmoid (AE) and sphenoid face (SF). An axial computed tomography scan (1-mm slice thickness) was then obtained. METHODS: Registration was then performed on the InstaTrak 3500 Plus (GE Surgical Navigation & Visualization, Lawrence, MA) with the standard PPR protocol with 12 points and CBR protocol with 500, 250, 125, 50, and 4 points. TRE was then calculated at the AE and SF targets. RESULTS: Target registration error was significantly lower for paired-point registration compared with contour-based registration (AE, 0.5 mm vs. 1.5 mm, P < .0001; SF, 0.8 mm vs. 1.5 mm, P < .0001). Among contour-based registration protocols, target registration error at the sphenoid face was lowest with 50 points (1.5 mm, P < .02). At the anterior ethmoid, contour-based registration with 50 points produced a lower target registration error than contour-based registration with 125 points (1.5 vs. 1.8 mm, P < .01). Other target registration error values for CBR were similar at both regions. The target registration error interquartile range was lowest with CBR-125 at both regions. CONCLUSIONS: Paired-point registration provided significantly lower target registration error. Contour-based registration with 125 points (and possibly as few as 50 points) produces clinically acceptable target registration error. This registration model elucidates important concepts about registration for surgical navigation for sinus surgery.     

Use of anatomic or invasive markers in association with skin surface registration in image-guided surgery of the temporal bone

Conclusion: The use of an invasive marker in the ipsilateral temporal bone with mid-facial skin contouring for registration improved the position accuracy (PA) to levels required for otological and neuro-otological procedures. Objective: The aim of this study was to compare the PA after skin contouring with the combination of anatomic landmarks or a local invasive marker and skin surface registration for intratemporal computer-assisted navigation. Patients and methods: Thirty-three patients undergoing a lateral skull base procedure with the Digipointeur® system (Collin, Bagneux, France) based on CT scan were included in this study. Registration was obtained by a mid-facial skin contouring. In the first protocol (n=8), PA was evaluated and the position corrected for three intratemporal landmarks before evaluation of the target (round window). In a second protocol (n=25), a titanium screw was placed in the ipsilateral mastoid region before imaging. PA was measured before and after screw registration for five intratemporal landmarks. Results: In the first protocol, PA did not improve after the registration of the landmarks, and PA of the target was evaluated as 4.9±0.64 mm. In the second protocol, PA was reduced after screw registration for all landmarks with a mean PA ranging from 0 to 2.3 mm.     

Comparison of laser versus surface-touch registration for image-guided sinus surgery

BACKGROUND: Use of image-guidance systems has become more popular in endoscopic sinus surgery. The laser registration technique has been used previously; however, a less expensive surface-touch registration technique recently has been developed. We compared the accuracy and speed of laser and surface-touch registration techniques. METHODS: Localization accuracy after laser and surface-touch registration was examined after 15 endoscopic sinonasal procedures between July and September 2004. Compared anatomic locations included the nasofrontal angle, nasolabial angle, posterior maxillary wall, skull base, and posterior vomer. For each localization point, the degree of error (in millimeters) was measured in superior-inferior (SI), anterior-posterior (AP), and right-left (RL) dimensions. The length of time for each registration procedure was recorded for both techniques. RESULTS: Laser registration was significantly faster (mean, 20 seconds) than surface-touch registration (mean, 20 seconds versus 63 seconds, respectively; p < 0.05). Laser registration was accurate within 0.3 mm in the SI direction, 0.4 mm in the AP direction, and 0.4 mm in the RL direction. Surface-touch registration was accurate within 0.3 mm in the SI direction, 0.4 mm in the AP direction, and 0.3 mm in the RL direction. There was no significant difference between techniques for any anatomic point. In 97.7% of all points, accuracy was within 2 mm or less for both the laser and surface-touch registration. CONCLUSION: Surface-touch registration is significantly slower than laser registration but has virtually no difference in accuracy. Both techniques compare very favorably to the accuracy of other systems reported in the literature.     

Malleable registration mask: application of a novel registration method in image guided sinus surgery

Image-guided systems are becoming more widely used in endoscopic sinus and skull base surgery. All systems require initial registration to correlate the CT scan images to the patient's anatomy. Multiple registration techniques can be used. The ideal technique is one that is easy, reproducible, and provides the most accurate registration in the least amount of time. This study used an optical-based image-guided system (LandmarX) to test a unique mask registration technique and (compared it to a previously used anatomic registration technique. Twenty-one patients were scanned with the mask and underwent surgery. Registration was performed using both the registration mask and the anatomic landmarks. Mean registration error and time were recorded. Results are reported for 20 patients. Mean registration error for the mask technique was 0.96 mm and took a mean of 41 seconds. Anatomic registration error using five or six points resulted in a mean initial error of 2.08 mm and took 31.2 seconds. Mean final anatomic registration error was 1.53 mm, requiring reregistration of a mean of 4.6 points, and took 106 seconds. Statistically significant differences were obtained between the two techniques with regard to registration error and time to final registration. We found that the registration mask technique is a more reliable technique in ease, accuracy, and time of registration. This technique should be especially beneficial to the less experienced image-guided surgeon.     

A comparison of computer-aided surgery registration methods for endoscopic sinus surgery

BACKGROUND: Stereotactic computer-aided surgery has provided the surgeon with a means to navigate more safely through diseased or surgically altered sinus anatomy. Accurate registration is vital to successful image-guided surgery. This study compared the accuracy and performance of three registration methods: fiducial, anatomic landmarks, and surface registration. METHODS: Ten fixed cadaveric heads underwent endoscopic computed tomography scan followed by middle meatal antrostomy and sphenoidotomy. Each registration method was performed, and the time required and mean registration error were recorded. Five anatomic sites were then identified and compared with the preoperative computed tomography images. The true distances between the known anatomic sites and the crosshair locations on the images were measured. RESULTS: Statistically significant differences were noted for mean registration error and time for registration. The mean +/-SEM time for registration for the fiducial, surface, and landmark methods were 5 minutes 24 seconds +/-27 seconds, 1 minute 1 second +/-5 seconds, and 11 minutes 46 seconds +/-45 seconds, respectively. The mean +/-SEM registration error for the fiducial, surface, and landmark methods were 0.48 +/- 0.21 mm, 1.05 +/- 0.06 mm, and 3.1 +/- 0.25 mm, respectively. When the true accuracy of the three registration methods were compared, no significant difference was found between fiducial and surface registration. However, fiducial registration was significantly more accurate than landmark registration at all points. When compared with landmark registration, surface registration was statistically more accurate at all anatomic sites except for the sella turcica and optic nerve. CONCLUSION: When the true accuracies of these methods were compared in fixed cadaveric specimens,fiducial and surface registration were statistically similar but were found to be significantly more accurate than landmark registration. Furthermore, when time of registration, accuracy, and ease of use were considered, surface registration was found superior.     

A-mode ultrasound-based registration in computer-aided surgery of the skull

OBJECTIVE: To evaluate the integration and accuracy of A (amplitude)-mode ultrasound-based surface matching for noninvasive registration of the head into a frameless computer-aided surgery system for otorhinology and skull base surgery. DESIGN: Experimental study and case series. SETTING: Academic medical center. PATIENTS: Twelve patients underwent anterior and paranasal skull base surgery with the routine use of a computer-aided surgery system. INTERVENTIONS: A computer-aided surgery system, based on an optoelectronic localizer, was used to track the skull and the surgical tools, including the A-mode ultrasound probe. The A-mode probe was a 10-MHz immersion transducer. An acoustic lens attached to the transducer focused the ultrasonic beam to a depth of 1 to 10 mm. Accuracy tests were performed for the ultrasound setup. Different surface point distributions were evaluated with respect to matching accuracy on a human cadaver skull specimen equipped with fiducial markers. The matching comparison was based on the fiducial registration error. For the clinical evaluation, the laboratory setup was transferred to the operating room. MAIN OUTCOME MEASURES: Noninvasive registration of the skull by using A-mode ultrasound in computer-aided surgery (practical and clinical measurements). RESULTS: The accuracy tests on the human skull specimen revealed that the mean +/- SD fiducial registration error was 1.00 +/- 0.19 mm in the best series for A-mode ultrasound surface matchings and was robust with respect to different sets of surface points. The mean +/- SD root mean square error from the 12 A-mode ultrasound matchings in the patient study was 0.49 +/- 0.20 mm. CONCLUSION: A-mode ultrasound surface matching can be used as a noninvasive and accurate registration procedure in computer-aided surgery of the head.     

Asymmetrical surface scanning registration for image-guided otologic surgery: A phantom study

ObjectiveTo develop a registration procedure to achieve a higher degree of registration accuracy in image-guided otological surgery, paying particular attention to the registration centroid.MethodsA head phantom was used to measure the target registration error (TRE) at measurement points at various depth from the surface of the head. The surface-matching registration was performed using a commercially available surgical navigation system. We registered the phantom using only one ear of either side (right 100% - left 0%, or right 0% - left 100%) or using both ears with variable ratios (right 75% - left 25%, right 50% - left 50%, or right 25% - left 75%).ResultsThe overall TRE was the smallest when registration was performed equally on both sides. However, the TRE at 20–50 mm from the surface was the smallest when the fiducial points for the registration were collected asymmetrically at a ratio of 75:25 and weighed heavier on the operating side, and this difference was statistically significant.ConclusionThe accuracy of image-guided surgery can be improved by carefully planning the registration procedure without changing the procedure itself. Accurate image-guided surgery at the middle and inner ear was achieved using 75% of the point cloud for the operating side and 25% of that for the opposite side for the registration.     

Surface laser registration in ENT-surgery: accuracy in the paranasal sinuses--a cadaveric study

Over the past decade, surgical navigation systems have found widespread use in ENT-surgery. Navigational accuracy highly depends on the registration process. The objective of this study was to assess the accuracy in the paranasal sinuses and lateral skull base after surface laser registration using the navigation system VectorVisionCompact (BrainLab, Heimstetten, Germany). Repeated measurements were performed on two cadaver heads. Sixteen titanium screw fiducials per head were placed in facial bones, the paranasal sinuses and the lateral skull base, thereby serving as exactly identifiable measurement points. The respective influence on measurement accuracy depending on the localization and conformation of the registration area was evaluated by performing symmetrically bilateral as well as strictly unilateral registrations. The resulting overall accuracy for a symmetrically bilateral surface laser registration was 1.13 +/- 0.53 mm, ranging from 0.77 (sinus frontalis) to 1.76 (petrous bone) mm, and thus proved to be clinically sufficient. Increasing distance between target point and registration area went along with a decline in accuracy. Navigational accuracy was significantly influenced by the choice of the registration area. Best accuracy was detected after symmetrically bilateral registration.     

Preliminary report of real simultaneous record of auditory early,middle-latency and late potentials in man

Summary A new technique for the registration of the human early, middlelatency and late components, elicited by the same stimulus, is described and demonstrated by an example.With financial assistance of SFB 70 (Sonderforschungsbereich für Hirnforschung und Sinnesphysiologie der Deutschen Forschungsgemeinschaft)     

Diagnostic work-up of socially unacceptable snoring

Should all patients with socially unacceptable snoring (SUS) undergo polysomnography, or is history-taking sufficient to identify the presence of obstructive sleep apnoea syndrome (OSAS)? Three hundred and eighty consecutive patients with SUS who underwent sleep registration were evaluated retrospectively to determine the predictive value of a history of apnoea or excessive daytime somnolence (hypersomnia). Of the patients analysed, 54% had OSAS, defined as an apnoea / hypopnoea index (AHI) of >15. This is higher than previously reported in the literature (46.7%). (Incidental) apnoea was reported by 337 (89%) of the patients, with a sensitivity of 0.92 and a specificity of 0.13. The predictive value – as related to the gold standard, i.e. sleep registration, of a negative test and of a positive test for OSAS is low (0.56 and 0.59, respectively). Hypersomnia was reported by 280 (74%) of the patients, with a sensitivity of 0.29 and a specificity of 0.72. The predictive value of a negative test and a positive test for OSAS is also low, 0.45 and 0.56, respectively. These data confirm that apnoea and hypersomnia in the history do not have a reliable predictive value of an obstructive sleep apnoea syndrome. We conclude that sleep registration is indicated in all patients with SUS, to rule out or confirm the presence of OSAS.