翼管、圆孔和蝶腭孔的CT三维重建解剖学观察

目的 使用三维高分辨率CT（HRCT）重建的方法,观察经鼻内镜至翼腭窝（PPF）的手术入路中的重要解剖结构,探讨翼管（VC）、圆孔（FR）和蝶腭孔（SPF）这些重要解剖标志的三维立体空间关系。方法 回顾性分析17例患者及1例尸体标本的HRCT扫描数据。在CT三维重建的影像中,观察 SPF、VC和FR的形态以及SPF和VC之间的三维立体空间关系。 结果 三维测量SPF,VC,和FR的平均直径分别为（6.26±1.59）mm,(2.35±0.77)mm和(2.75±0.77)mm。VC和SPF后下缘之间的平均距离为(4.03±1.15)mm。三维立体CT重建影像中VC和FR之间的平均垂直和水平距离分别为(4.94±1.35)mm和(9.22±3.07)mm。VC的全部或部分边缘92%(33/36)位于SPF的下缘以上,97%（35/36）位于SPF内缘外侧。结论 深入理解SPF、VC和FR之间的三维空间立体关系,有助于安全实行内镜下经鼻至翼腭窝的手术。     

Trigeminal neuralgia is caused by maxillary and mandibular nerve entrapment: greater incidence of right-sided facial symptoms is due to the foramen rotundum and foramen ovale being narrower on the right side of the cranium

Trigeminal neuralgia (TN) is the most important disease of the trigeminal nerve. Vascular compression of the dorsal root of the trigeminal nerve by aberrant loop of blood vessels is currently accepted as the most common cause of TN. The right side of the face is affected by TN twice as often as the left side, but there are no anatomical reasons for the blood vessels loop to be more frequent on the right side of the cranial fossa. Additionally, vascular compression in asymptomatic patients and in TN patients without aberrant blood vessels has been reported, thereby arguing against the idea that vascular compression alone is responsible for TN. Anatomical and radiological studies have shown that the rotundum and ovale foramens on the right side of the human cranium are significantly narrower than on the left side. The rotundum and ovale foramens are crossed by the maxillary and mandibular nerves, respectively, and are the nerves most affected in TN. Based on demographic and epidemiological data of TN patients, and on anatomical findings in the foramens, we hypothesized that entrapment of the maxillary and mandibular nerves when they cross the ovale and rotundum foramens is a primary cause of TN and accounts for the higher incidence of TN on the right sided.     

蝶腭孔、翼管前口的应用解剖及临床意义

目的 为鼻内窥镜翼管神经切断术等临床应用提供解剖学依据。方法 用15个30侧经防腐处理的成人头颅标本，经正中矢状面剖开，解剖观察测量蝶腭孔、翼管前口及穿过的血管、神经。结果 19例(63．33％)蝶腭孔位于中鼻甲后端前方平均8．09mm；11例(36．67％)位于在中鼻甲后端前上方平均7．24min。蝶腭孔呈圆形24例，直径平均3．25mm；呈卵圆形6例，最大径平均4．92mm穿过蝶腭孔的动脉有蝶腭动脉，或其分支鼻后外侧动脉和鼻中隔后动脉。翼管前口位于蝶腭孔后方约7mm，呈圆形漏斗状，横径约3mm，略向外下方开口，距离鼻小柱平均71．72mm，有翼管神经和翼管动脉穿过。结论 经鼻腔暴露翼管前口及翼管神经，以及进入翼腭窝处理上颌动脉末端的分支时，蝶腭孔及其周围骨质菲薄的部位是理想的手术入路部位。     

The neglected anatomical and clinical aspects of pterygoid canal: CT scan study

Purpose  

To present the variable positions of pterygoid canal (PC) relative to sphenoid sinus floor and cavity, which may be helpful for understanding pathologic and surgical conditions related to sphenoid sinus region.     

Postnatal enlargement of the foramina rotundum, ovale et spinosum and their topographical changes

In the newborn the Canalis (Foramen) rotundus is about 2.5 mm and in 15-til 17-year-old about 3 mm in length. The Apertura interna postnatal develops in width from 2.06 to 3.50 mm and in height from 1.8 to 2.73 mm. From the median sagittal plane the medial rim of the Apertura interna is distant about 11.0 mm in newborns and in adults 16.47 mm on the right side and 17.63 mm on the left side. Moreover the angular distance of the axis of the Canalis rotundus just across the median plane and also just across the frankfurt plane were determined. In the newborn the Foramen ovale is about 3.85 mm and in the adults about 7.2 mm in length. The width extend from 1.81 mm in the newborn to 3.7 mm in adults. In the newborn the distance from the medial rim to the median sagittal plane is about 3.9 mm, in the adults at the right side 20.9 mm and at the left side 22.5 mm in length. In the newborn the Foramen venosum (Vesalii) is about 1.0 mm in length and in the adults at the right side about 2 mm and at the left side 1.4 mm. The width increases from 1.0 to 1.14 mm at the right side and to 1.3 mm at the left side. The mean distance opposite to the median sagittal plane increases between newborn time and the adults from 10.0 mm at the right side to 15.78 mm and at the left side from 10.75 to 17.62 mm. In the newborn the Foramen spinosum is about 2.25 mm and in the adults about 2.56 mm in length. The width extends from 1.05 mm to about 2.1 mm in the adults. The distance opposite to the median sagittal plane in the newborn run to about 18.2 mm and in the adults 28.08 mm at the right side and 29.76 mm at the left side. The maximum length of the "Canalis spinosus" increases from 2.85 mm in the newborn to 7.35 mm in the adults. The lateral rim of the Foramen rotundum has a mean distance of 20.0 mm opposite to the upper edge of the Processus zygomaticus above the Tuberculum articulare in the newborn and about 43.5 mm in the adults. The mean distance from the cited reference area to the lateral rim of the Foramen ovale increases from about 15 to 34.33 mm, and from that of the Foramen spinosum from 15.3 to 31.4 mm.(ABSTRACT TRUNCATED AT 400 WORDS)     

Anatomy of greater palatine foramen and canal and pterygopalatine fossa in Thais: considerations for maxillary nerve block

This study aims to investigate the anatomy of the greater palatine foramen (GPF), greater palatine canal (GPC) and pterygopalatine fossa (PPF) with special reference to the blockage of the maxillary nerve. A correlation between the length of GPC and PPF and the heights of the orbit and the maxilla was also studied using simple linear regression analysis. The morphology of the GPF, GPC and PPF as well as heights of the orbit and the maxilla were assessed in 105 Thai skulls. The thickness of the mucosa over the GPF was also measured from the dissection of 55 cadavers. The results showed that most GPF appeared as an oval foramen located at the palatal aspect of the upper third molar. The GPF was 16.2±1.3 mm lateral to the median sagittal plane of the hard palate, 2.1±1.3 mm anterior to the posterior border of the hard palate and 5.1±1.3 mm from the greatest concavity of the distolateral margin of the hard palate. The mean length of GPC and PPF was 29.7±4.2 mm. The mean angles of the GPC in relation to the hard palate and the vertical plane were 57.9±5.8° and 6.7±5.2°, respectively. In attempting to insert a needle to reach the foramen rotundum through the GPF, 31.7% passed into the orbit while 8.7% passed into the brain. The mean thickness of the mucosa over GPF was 6.7±2.3 mm. Two models for estimating the depth of needle injection in maxillary nerve block have been developed as follows: Length of GPC and PPF=19.038+0.314 (orbital height) and length of GPC and PPF=21.204+0.187 (maxillary height). The calculated length combined with the mucosal thickness was the estimated depth of needle injection. In conclusion, our results concerning the GPF, GPC and PPF will provide the useful reference for clinicians to anesthetize the maxillary nerve with a greater degree of success.     

The anatomical and clinical details of the pterygoid canal: a three-dimensional reconstructive virtual anatomic evaluation based on CT

Purpose

To delineate the pterygoid canal (PC) configuration and its position in relation to surrounding important anatomical landmarks using three-dimensional reconstructive technology based on CT for the Chinese.

Methods

The computerized tomography arteriography (CTA) data of 137 patients were retrospectively evaluated using neuroimaging three-dimensional reconstructive software. The morphological parameters of the PC as well as the spatial relationship and distance between the PC relative to internal carotid artery (ICA) and the foramen rotundum were evaluated.

Results

83.9 % of the PC can be identified by our neuroimaging three-dimensional reconstructive software. The mean distance from the PC to the ICA was 2.6 ± 1.2 mm. The mean distance between medial aspects of bilateral ICA was 19.6 ± 2.7 mm. The distal vertical and horizontal distances between the PC and foramen rotundum were 5.2 ± 3.2 and 6.1 ± 2.8 mm, respectively. All the proximal end of the PC were inferior-lateral to the ICA. The PC mainly (92.9 %) ran posteriorly with a medial to lateral direction. The distance from the PC to ICA was positively correlated with the distance between bilateral ICA and the distal diameter of the PC. The vertical distance between the PC and foramen rotundum was positively correlated with the length of the PC and the horizontal distance between the PC and foramen rotundum.

Conclusions

Understanding the configuration and spatial relationship of the PC may be helpful to improve the accuracy and safety of operation during the expanded transnasal endoscopic approaches to skull base. The three-dimensional reconstructive virtual anatomic technology may be a useful tool to delineate the PC configuration and its position to surrounding important anatomical landmarks.     

Connections between the facial, vestibular and cochlear nerve bundles within the internal auditory canal

The vestibular, cochlear and facial nerves have a common course in the internal auditory canal (IAC). In this study we investigated the average number of nerve fibres, the average cross-sectional areas of the nerves and nerve fibres, and the apparent connections between the facial, cochlear and vestibular nerve bundles within the IAC, using light and scanning electron microscopy. The anatomical localization of the nerves within the IAC was not straightforward. The general course showed that the nerves rotated anticlockwise in the right ear from the inner ear end towards the brainstem end and vice versa for the left ear. The average number of fibres forming vestibular, cochlear, and facial nerves was not constant during their courses within the IAC. The superior and the inferior vestibular nerves showed an increase in the number of nerve fibres from the inner ear end towards the brainstem end of the IAC, whereas the facial and the cochlear nerves showed a reduction in the number of fibres. This suggests that some of the superior and inferior vestibular nerve bundles may receive fibres from the facial and/or cochlear nerves. Scanning electron microscopic evaluations showed superior vestibular-facial and inferior vestibular-cochlear connections within the IAC, but no facial-cochlear connections were observed. Connections between the nerves of the IAC can explain the unexpected vestibular disturbances in facial paralysis or persistence of tinnitus after cochlear neurectomy in intractable tinnitus cases. The present study offers morphometric and scanning electron microscopic data on the fibre connections of the nerves of the IAC.     

Original landmarks for intraoperative localization of the foramen ovale: a radio-anatomical study

Purpose

Radiofrequency lesioning is one of the frequently used modalities for the treatment of trigeminal neuralgia. Easily identifiable radiological landmarks are necessary for correct intra-operative localization of foramen ovale.

Methods

One hundred and seventy sides of dry skulls were studied for the following measurements. D-1: the transverse distance between the apex of the petrous temporal and the centre of the foramen ovale. D-2: the transverse distance from the midline to the centre of the foramen ovale. The distances between the centre of the foramen ovale and, D-3: the anterior margin of mandibular fossa, D-4: centre of the mandibular fossa and D-5: point at the junction of posterior margin and floor of the sella. D-6: the vertical distance between the centre of the foramen ovale and point at the junction of posterior margin and floor of the sella.

Results

The mean values measured were D-1: 13.9?mm, D-2: 24.5?mm, D-3: 3.1?mm, D-4: 11.4?mm, D-5: 0.75 and D-6: 12.42?mm. In majority of cases the centre of foramen was around 25?mm from midline. Additionally the centre of the foramen was at the level of the junction of the posterior wall and floor of the sella or within 2?mm of this point in the antero-posterior direction. In most (81%) cases the vertical displacement of the foramen was 1–1.5?cm inferior to this point.

Conclusion

During intra-operative imaging, the midline of the skull and the junction of the posterior wall and floor of the sella can be used as reliable landmarks for the identification of foramen ovale.     

Landmarks of the facial nerve: implications for parotidectomy

Facial nerve paralysis is a daunting potential complication of parotid surgery and is widely reported. Knowledge of the key landmarks of the facial nerve trunk is essential for safe and effective surgical intervention in the region of the parotid gland. In current practice, wide ranges of landmarks are used to identify the facial nerve trunk, however, there is much debate in the literature about the safety and reliability of each of these landmarks. The aim of this study, therefore, was to evaluate the relation of the surrounding anatomical structures and surgical landmarks to the facial nerve trunk. The anatomical relationship of the facial nerve trunk to the surrounding structures was determined after micro-dissection on 40 adult cadavers. The shortest distances between the facial nerve and the “tragal pointer”, attachment of the posterior belly of digastric muscle, tympanomastoid suture, external auditory canal, transverse process of the axis, angle of the mandible and the styloid process were measured. In addition, these distances were compared in the right and left sides, males and females and edentulous and non-edentulous mandibles. The distance of the facial nerve trunk from each of the surrounding landmarks ranged from (mm): tragal pointer, 24.3 to 49.2 (mean 34); posterior belly of digastric, 9.7 to 24.3 (mean 14.6); external auditory canal, 7.3 to 21.9 (mean 13.4); tympanomastoid suture, 4.9 to 18.6 (mean 10.0); styloid process, 4.3 to 18.6 (mean 9.8); transverse process of the axis, 9.7 to 36.8 (mean 16.9); angle of the mandible, 25.3 to 48.69 (mean 38.1). The length of the facial nerve trunk from its point of exit from the stylomastoid foramen to its bifurcation into upper and lower divisions ranged from (mm) 8.6 to 22.8 (mean 14.0). The results demonstrated that the posterior belly of digastric, tragal pointer and transverse process of the axis are consistent landmarks to the facial nerve trunk. However, it should be noted that the tragal pointer is cartilaginous, mobile, asymmetrical and has a blunt, irregular tip. This study advocates the use of the transverse process of the axis as it is easily palpated, does not require a complex dissection and ensures minimum risk of injury to the facial nerve trunk.     

A study of the lateral pterygoid muscle: anatomic sections and CT appearances

Summary The authors have studied the relationship between anatomic and CT sections of the lateral pterygoid muscle in 39 anatomic specimens. Good superimposition of the images was found, which seems important in neoplastic invasion of the infratemporal fossa and which may lead to a pathogenic interpretation of the algo-dysfunctional syndrome of the masticatory apparatus.

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Etude anatomo-radiologique (TDM) du muscle ptérygoïdien latéral

Résumé Les auteurs ont étudié, sur 39 pièces anatomiques, la corrélation entre coupes anatomiques et tomodensitométriques (TDM) du muscle ptérygoïdien latéral. Il apparaît une bonne superposition des images ce qui semble intéressant dans les envahissements de la fosse infratemporale en carcinologie et qui pourrait déboucher sur une interprétation pathogénique du syndrome algo dysfonctionnel de l'appareil manducateur.

     

颞骨CT内面神经、迷路、听骨结构深度学习的自动化分割方法

目的 探讨神经网络的深度学习方法,进行颞骨CT内面神经、迷路及听骨结构的自动化分割的可行性和精确性。方法 选择常规颞骨CT检查患者的数据,随机分为两组,一组为训练集（20例）,另一组为测试集（5例）。在上述颞骨CT中采用手工分割的方法,分割出迷路、听骨及面神经结构。选择三维卷积神经网络3D U-Net作为深度学习中的神经网络结构部分,通过对训练集的训练,得到该网络的平均精度。用该网络模型对5组测试集中的不同解剖标志自动分割的结果与手工分割的结果进行测试,分别获得面神经、迷路及听小骨的测试精度。并将上述精度与另一种基于三维卷积神经网络结构的V-Net网络模型获得的精度进行比较。结果 在颞骨CT标本中,采用面神经、迷路及听小骨分别对3D U-Net-plus和V-Net网络结构的自动分割进行训练,在训练样本中,3D U-Net-plus网络结构的平均误差为0.016,V-Net网络结构的平均误差为0.035,两者差异有统计学意义（P<0.05）;利用3D U-Net-plus神经网络自动分割的迷路、听小骨及面神经与手工分割图像的Dice相似指数分别为0.618±0.107、0.584±0.089和0.313±0.069, 利用V-Net神经网络自动分割的迷路、听小骨、面神经与手工分割图像的Dice相似指数分别为0.322±0.089、0.176±0.100和0.128± 0.077,两者差异有统计学意义（P<0.001）。结论 采用3D U-Net-plus神经网络,在颞骨内听骨、迷路及面神经的自动识别和分割方面具有可行性,该方法优于V-Net神经网络。随着网络结构的优化和学习样本的扩大,其将更加接近人工分割的效果。     

利用多层螺旋CT进行面神经管迷路段与面神经膝定位

目的探讨面神经管迷路段与面神经膝的位置关系,以及多层螺旋CT影像测量方法的可信性。方法对15例颅底标本面神经膝至内耳道底、弓状隆起、面神经管裂孔、棘孔、岩大神经与下颌神经交点、颈动脉管膝间的直线距离进行直接测量,并进行64层螺旋CT扫描。对颅底标本的扫描影像及118例病例的头颅CT影像资料进行相同项目的测量。对颅底标本两种测量方法,以及男女患者头颅CT影像资料的测量结果进行比较分析。结果标本直接测量与CT影像测量,两种方法所得结果差异无统计学意义（P〉0．05）。男女性问的差异有统计学意义（P〈0．05）,左右两侧的差异没有统计学意义（P〉0．05）。结论多层螺旋CT影像测量方法可靠,测得值可信,有助于医生对面神经管迷路段、面神经膝及耳蜗等解剖结构进行定位和保护。     

Morphometric analysis of the infraorbital groove, canal, and foramen on three-dimensional reconstruction of computed tomography scans

Purpose

This study aimed to investigate the anatomy of the infraorbital foramen (IOF), infraorbital canal (IOC), and infraorbital groove (IOG) with regard to surgical and invasive procedures using three-dimensional reconstruction of CT scans.

Methods

The CT scans of 100 patients were evaluated retrospectively. The morphology of the IOF, IOC, and IOG as well as their relationships to different anatomic landmarks was assessed in a three-dimensional model.

Results

The mean length of the IOC and IOG and the angle of the IOC relative to IOG were 11.7 ± 1.9, 16.7 ± 2.4 mm, and 145.5° ± 8.5°, respectively. The mean angles of the IOC relative to vertical and horizontal planes were 13.2° ± 6.4° and 46.7° ± 7.6°, respectively. In the relationships between the IOF and different anatomic landmarks, the mean distances from the IOF to supraorbital notch/foramen, facial midline, and infraorbital rim were 5.6 ± 3.1 mm laterally, 26.5 ± 1.9 mm laterally, and 9.6 ± 1.7 mm inferiorly, respectively. The mean distance from the IOF to anterior nasal spine (ANS) was 35.0 ± 2.6 mm, and the mean angle of the axis that passed the IOF and ANS relative to horizontal plane was 28.8° ± 4.1°. In addition, the mean soft tissue thickness overlying the IOF was 11.4 ± 1.9 mm.

Conclusions

These results provide detailed knowledge of the anatomical characteristics and clinical importance of the IOF. Such knowledge is of paramount importance for surgeons when performing maxillofacial surgery and regional block anesthesia.     

面神经颞骨内段在横断薄层和CT上的定位及临床意义

目的：为面神经及耳科病变的影像诊断和手术治疗提供解剖学基础。方法：15例成人头部标本，以眦耳线(CML)为基线，获得间隔为1．0mm，厚度为1．0mm的CT图像，扫描后的头部标本按原定位截取以耳颞区为中心的组织块并将其制成厚为1．0mm的连续横断薄层切片。标本切片与CT图像对照，对颞骨内面神经、听小骨、骨半规管、前庭、耳蜗等结构进行观测。结果：(1)面神经膝状神经节(GG)多位于外半规管层面。(2)匙突多与锤砧关节位于同一层面。(3)锥隆起多位于鼓岬层面。结论：面神经水平段起始部，GG，面神经迷路段三者在外半规管层面内呈倒“V”字型排列；面神经垂直段位于面神经隐窝深面，面神经隐窝、锥隆起、锥隐窝三者在鼓岬层面内从内向外呈“ω”字型排列。     

Alternative explanations to the differences of femoral and brachial saline contrast injections for echocardiographic detection of patent foramen ovale

Patent foramen ovale (PFO) of the interatrial septum is a cardiac foetal remnant, which frequent persistence in adulthood has important implications in a variety of clinical conditions. Echographic diagnosis of PFO is based on detection of interatrial shunt by means of contrast microbubbles identification after venous injection of a first-generation echographic contrast agent. Current recommendations propose venous femoral injection of contrast for enhanced echographic detection of PFO instead of venous brachial administration, as femoral injection has been shown to have higher sensitivity for PFO detection. Inferior vena cava inflow directed toward interatrial septum has been considered the explanation for increased sensitivity of femoral delivery of contrast. In the present paper, it is hypothesised that the main determinants of these differences between injection sites are technical factors related to right atrial contrast opacification and proper transient right atrial pressure rise, rather than intraatrial flow streaming. Effects of inferior vena cava inflow stream, although significant during foetal life, would be negligible after birth. Rationale and evidence, basis for further research, and practical implications leading to a simpler and safer routine technique for echographic detection of PFO are presented and discussed.     

正常人面神经管垂直部与外耳道解剖位置关系的影像与临床研究

目的 观察、测量面神经管垂直部毗邻解剖关系及乳突的形态学指标,分析面神经管垂直部和外耳道后壁、外耳门后缘位置变化的相关性,探讨乳突气化程度与面神经管垂直部之间的关系及临床意义。 方法 1. 评价CT影像测量相关结构的正确性,采用64层螺旋CT对4具干颅标本进行扫描,在横断位测量面神经管垂直部至外耳道后壁、外耳门后缘的距离,在矢状平面上测量乳突的前后径（外耳道下壁最低点至乳突后缘的水平距离）和高度（外耳道下壁至乳突尖的垂直距离）;按影像层面锯开标本,对上述距离行实体测量。影像测量均值与实体测量均值的差异行显著性检验。2. 在体研究：随机入选无耳部疾患的118人（236侧）,其中男性55例（110侧）,女性63例（126侧）,行颌面部CT扫描。如上选择层面,并测量面神经管垂直部至外耳道后壁、外耳门后缘及乳突前后径和高度的距离,以乳突前后径与高度乘积的1/2定义为乳突面积,以乳突面积的大小来定义乳突气化程度,同时将乳突面积分别与面神经管垂直部至外耳道后壁、外耳门后缘距离分别进行相关和回归分析。 结果 1. 标本部分：各项指标的影像测量值与实体测量值差异无统计学意义（P>0.05）。2. 在体研究：各项指标测量结果侧别差异无统计学意义（P>0.05）,性别差异有统计学意义（P<0.05）。乳突面积与面神经管垂直部至外耳道后壁距离之间呈负相关性,且相关性有统计学意义;乳突面积与面神经管垂直部至外耳门后缘有相关性,但相关性无统计学意义。 结论 乳突发育气化好,面神经垂直部位置偏前。 CT检查可以明确面神经管垂直部与外耳道后壁的关系,有助于耳外科手术术式的选择以及对术中重要结构损伤的控制。