磁共振3D-Tricks技术在评估舌动脉解剖中的应用

目的 评价MR血管成像技术－三维时间分辨力对比剂动力成像(Three-dimenstional 　time-resolved imaging of contrast Kinetics,3D-Tricks)对舌动脉形态显示能力。 方法　纳入研究对象43例进行3D-Tricks序列扫描,其均无颈部和脑部血管性疾病;利用容积再现(VR)、多平面重组(MPR)及最大强度投影(MIP)技术对舌动脉进行三维重建,观察舌动脉起源、形态、走行,并测量舌动脉起始点、舌骨大角段距颈动脉分叉距离以及舌动脉起始点距舌骨大角段的距离。 结果　43例研究对象共显示86侧舌动脉,其中58侧直接起始于颈外动脉,27侧与面动脉、1侧与甲状腺上动脉共干且起始于颈外动脉。舌动脉在舌骨大角处较恒定,以颈动脉分叉为标志,舌骨大角段舌动脉位于颈动脉分叉上方45侧,平行于颈动脉分叉9侧,低于颈动脉分叉32侧。86侧舌动脉起始部内径为 (2.88±0.46) mm,距离颈动脉分叉处为 (1.33±0.62) cm,距离舌动脉舌骨大角段为 (1.28±0.61) cm。 结论　3D-Tricks技术能无创性显示舌动脉形态,并能获得活体的解剖学资料,在临床应用中具有重要的指导意义。     

颈内动静脉与颅底骨三维空间关系

目的 :显示对比正常侧和病变侧颈内动静脉与周围骨结构的解剖关系 ,以完善术前准备。方法 :10例颌颈部肿瘤患者 ,术前行颈动脉三维CT血管成像 (CTA) ,同步注射造影剂 ,螺旋CT对病变区血管段进行重点薄层螺旋扫描 ,由EasyVision工作站三维重建。结果 :5例颈外动脉和颈内静脉受压狭窄 ,其中 3例出现颈总动脉、颈内动脉向内侧移位 ,另 1例左侧颈内动脉动脉瘤清晰定位。CTA能够显示病变区血管段 (包括颈总动脉、颈内动脉、颈外动脉、颈内静脉 )与下颌骨、舌骨、颈椎、颅底骨结构的三维解剖关系 ,进行旋转、放大 ,三维测量 ,多视角观察 ,无重叠干扰。结论 :对颌颈、口咽部肿瘤患者术前CTA检查 ,能够判断颈部大血管的情况及颈部巨大肿瘤造成颈内动脉移位 ,CTA可显示血管性肿瘤的三维形状和与颅底骨空间关系 ,为手术入路及术式提供参考 ,有助于降低手术风险     

颈内静脉与颅底骨三维空间关系

】目的显示对比正常侧和病变侧颈内动静脉与周围骨结构的解剖关系，以完善术前准备。方法10例颌颈部肿瘤患者，术前行颈动脉三维CT血管成像(CTA)，同步注射造影剂，螺旋CT对病变区血管段进行重点薄层螺旋扫描，由Easy Vision工作站三维重建。结果5例颈外动脉和颈内静脉受压狭窄，其中3例出现颈总动脉、颈内动脉向内侧移位。CTA能够显示病变区血管段(包括颈总动脉、颈内动脉、颈外动脉、颈内静脉)与下颌骨、舌骨、颈椎、颅底骨结构的三维解剖关系，进行旋转、放大，三维测量，多视角观察，无重叠干扰。结论对颌颈、口咽部肿瘤患者术前CTA检查，能够判断颈部大血管的情况及颈部巨大肿瘤造成项内动脉移位，CTA可显示血管性肿瘤的三维形状和与颅底骨空间关系，为手术入路及术式提供参考，有助于降低手术风险。     

颈动脉分叉区域的神经血管解剖及其对颈动脉内膜剥脱术的临床意义

目的　通过对尸体标本的颈动脉分叉区域内的神经、血管进行解剖研究,为安全有效地开展颈动脉内膜剥脱术提供形态学依据及解剖学基础。 方法 选取20例（40侧）无明确心、脑血管疾患的尸体解剖标本（男11例、女9例）,采取颈动脉内膜剥脱术式入路对颈动脉分叉区域内的神经、血管进行解剖研究,明确血管和神经的形态学及结构特点。 结果 颈总动脉分叉部形态可分为Ⅰ、Ⅱ、Ⅲ型,分别占比为10%、52.5%、37.5%。分叉位置以甲状软骨为界,左侧颈总动脉分叉部高度在其上缘以上、平上缘和上缘以下的占比分别为55%、37.5%、7.5%;相较之下右侧分别为62.5%、27.5%、10%。男性颈总、颈内、颈外动脉内径均大于女性（P<0.05）;男性颈动脉分叉角度大于女性（P<0.05 ）。双侧颈总、颈内、颈外动脉内径相比无统计学意义（P>0.0 5）;左侧颈动脉分叉角度大于右侧（P<0.05）。 结论　通过对颈动脉分叉区域内的神经、血管进行解剖研究,对颈动脉内膜剥脱术术中血管与神经的保护具有重要的临床意义。     

咽升动脉分支的解剖分组及其临床意义

目的探讨咽升动脉及其主要分支在颈部颅底区域走行规律及其在血管内外治疗中的临床意义。方法选择以10%甲醛固定并用乳胶灌注的8具(16侧)成人颅颈部标本, 自颈总动脉分叉水平向上解剖至颅底骨质, 分离显露咽升动脉及周围相关结构, 观察咽升动脉的起源部位及主要分支, 测量相关解剖学参数。依据咽升动脉主要分支与颈动脉鞘的位置关系分为颈动脉鞘内、外2组, 观察2组分支血管的走行规律及解剖分布特点。结果 8具16侧标本中:咽升动脉13侧自面动脉起始点平面以下的颈外动脉发出, 2侧起源于枕动脉, 1侧与枕动脉共干起源于颈外动脉;14侧咽升动脉沿颈内动脉腹侧上行(15.39 ± 3.20)mm后发出主要分支咽干和脑膜干, 2侧变异。脑膜干自咽升动脉主干发出(9.32 ± 3.20)mm后均穿入颈动脉鞘, 上行分叉后经舌下神经管或颈静脉孔或鼓室小管下口或枕大孔入颅;咽干则在颈动脉鞘外走行并分布于咽旁、椎旁等区域。颈动脉鞘内组包括脑膜干和鼓室下动脉, 均穿入颈动脉鞘后沿颈内动脉内侧上行;颈动脉鞘外组包括咽干和肌支, 于鞘外走行。结论咽升动脉及其分支变异显著、走行复杂, 可按照咽升动脉各主要分支与颈动脉鞘的...     

股骨远端微创锁定内固定钢板固定参数的三维数字化测量

背景：有研究表明股骨远端微创锁定内固定钢板治疗股骨远端骨折具有较好的疗效,但其设计参数多为参照西方人种数据,且其产品规格有限。 目的：对成年中国人中远端股骨微创锁定内固定钢板手术相关解剖CT数据进行数字化测量。 方法：选自内蒙古医学院第二附属医院影像科非膝关节疾患的成人CT连续扫描数据15例,利用Mimics 10.01软件进行三维重建,在三维立体图形中测量股骨远端宽;股骨外侧髁前后径;股骨外侧髁基底部宽;股骨外侧髁干角;自股骨大转子下缘5 cm至外上髁每隔5 cm划分为1段,共分为5段,分别测量每段中部股骨内外侧皮质及髓腔横径。 结果与结论：成年中国人中远端股骨微创锁定内固定钢板固定后,股骨远端左右侧宽分别为(84.80±1.27) mm和(84.60± 1.40) mm;股骨外侧髁前后径分别为(67.36±1.41) mm和(66.27±1.42) mm;股骨外侧髁基底部宽分别为(42.53±3.42) mm和(42.98±1.25) mm;股骨外侧髁干角分别为(7.58±0.69)°和(7.66±0.79)°,左右侧别间差异均无显著性意义。 关键词：微创锁定内固定钢板;股骨远端;三维重建;设计参数;数字化骨科 doi:10.3969/j.issn.1673-8225.2012.13.003     

小鼠颈动脉系解剖与测量在局灶性脑缺血模型中的应用

目的　系统解剖与测量小鼠颈动脉系统 ,为小鼠局灶性脑缺血模型的制作提供参数。方法　在手术显微镜下 ,解剖小鼠颈动脉系后 ,用油标卡尺测定从颈总动脉分叉至各部的长度 ,结果以均数表示。并对尼龙单丝线末端的处理进行了较详细的研究。结果　小鼠颈总动脉分叉至大脑前中动脉分叉处的长度较恒定 ,具体为 (8 2 9± 0 5 4 )mm。尼龙单丝线末端经高温处理后 ,缩短的距离不同 ,所形成的球径不同 ,以缩短 1mm效果较好。结论　小鼠局灶性脑缺血模型制作时 ,从颈总动脉分叉至大脑前中动脉分叉处插线的深度不能超过 8 2 9mm。     

成年中国人第5腰椎峡部Micro CT扫描的显微影像特点

背景：目前国内外学者对成年中国人第5腰椎峡部作了大量的应用解剖学研究,但研究结果各不相同,并且观测参数不系统、不完整,而对成年中国人第5腰椎峡部进行较系统的临床应用解剖与Micro CT扫描显微影像解剖对照研究国内外文献未见报道。 目的：观测成年中国人第5腰椎峡部Micro CT扫描显微影像解剖学及应用解剖学特点,以期为成年中国人第5腰椎峡部易患病性提供形态学依据。 方法：实验从成都医学院局解实验室随机选取60例成年中国人干燥、无破损第5腰椎标本,应用游标卡尺测量第5腰椎峡部的相关数据,并应用Micro CT的三维重建系统分析第5腰椎标本三维骨结构,并逐一测量与第5腰椎左、右侧峡部临床应用解剖观测的指标相对应的Micro CT扫描显微影像解剖参数。 结果与结论：在成年中国人第5腰椎标本观测： ①左、右侧峡部上缘厚度分别为(4.27±0.99) mm,(4.25± 0.98) mm。②左、右侧峡部下缘厚度分别为(7.31±1.23) mm,(7.29±1.25) mm。③左、右侧峡部内缘厚度分别为(6.61±0.33) mm,(6.59±0.36) mm。④左、右侧峡部外缘厚度分别为(8.65±0.27) mm,(8.59±0.33) mm。⑤左、右侧峡部上下缘距离分别为(11.10±3.14) mm,(11.07±3.11) mm。⑥左、右侧峡部上缘长度分别为(8.37±0.99) mm,(8.40±0.96) mm。⑦左、右侧峡部下缘长度分别为(4.71±0.71) mm,(4.73±0.62) mm。⑧左、右侧峡部内缘长度分别为(13.01±1.38) mm,(13.04±1.36) mm。⑨左、右侧峡部外缘长度分别为(10.75±1.11) mm,(10.78±1.06) mm。游标卡尺与Micro CT所测的第5腰椎峡部左右侧的三维数值之间均差异无显著性意义。结果证实,对成年中国人第5腰椎峡部临床应用解剖测量值与Micro CT测量值之间具有统一性,左右侧腰椎峡部解剖值没有差异,Micro CT能为临床上第5腰椎的易患病性提供更为详尽准确的参考数据。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

基于64-MSCTA左半肝肝动脉的应用解剖

目的　应用64排螺旋CT血管成像探讨活体左半肝肝动脉在肝内配布情况,为肝脏疾病的诊疗提供形态学资料。  方法　采集120例受试者肝脏CT图像,经容积再现(VR)技术重建肝动脉。测量左半肝肝动脉相关数据进行统计分析。  结果　肝左动脉主干长度为（42.37±26.58）mm;肝左动脉主干起始处、中点（1/2处）、分叉处内径分别为（3.06±0.70 ）、（2.82±0.68）、（2.78±0.65）mm;肝左动脉在左半肝内的主要分支呈1支、2支、3支、4支型者分别为4.2%、63.3%、28.3%、2.5%,其中,左外叶支与左内叶支的夹角为（80.21±23.36）°,左外叶支主干长度和起始处内径分别为（42.80±29.11）mm、（2.25±0.70）mm,左内叶支长度和起始处内径分别为（42.90±22.70）mm、（1.66±0.64）mm;肝左动脉供应Ⅱ、Ⅲ、Ⅳ段者占64.1%,供应Ⅱ、Ⅲ段者占28.3%,迷走肝左动脉供应Ⅱ、Ⅲ段,Ⅱ段,Ⅱ、Ⅲ、Ⅳ段者分别占5.0%,3.3%,0.8%。  结论　64-MSCTA可真实、准确的提供活体肝左动脉的形态学资料;肝左动脉在肝内的分支分布较为复杂,在左半肝内以二分支（左外叶支和左内叶支）为主,主要参与Ⅱ、Ⅲ、Ⅳ肝段供血。     

颈动脉的形态与动脉粥样硬化的解剖学观测

目的研究颈动脉的形态与动脉粥样硬化的情况,为颈总、颈内动脉狭窄的诊治提供形态学基础。方法解剖观测成尸30(男24、女6)侧颈动脉,观测颈动脉的形态及动脉粥样硬化情况。结果①颈总动脉中段外径,左侧(8.75±1.56)mm;右侧(8.31±0.99)mm。②颈内动脉根部外径,左侧(8.15±1.42)mm;右侧(7.51±1.63)mm。③颈外动脉中段外径,左侧(4.87±1.09)mm;右侧(4.39±0.89)mm。④颈动脉粥样硬化发生率占60%(18侧),其中颈内动脉根部四壁明显动脉硬化,内腔直径1.6mm严重狭窄1侧,占总数的3.33%。结论颈动脉粥样硬化发生率最高为颈动脉窦,占颈动脉硬化标本的100%,可致颈内动脉内腔狭窄。     

Occipital artery arising from the superior aspect of the carotid bifurcation identified by three-dimensional computed tomography angiography

Variation of the branches of the external carotid artery is well known, but it is extremely rare for the occipital artery (OA) to arise from the carotid bifurcation (CB). A 73-year-old man was found to have this anatomical variation on the right side by three-dimensional CT angiography for vascular mapping of the carotid arteries before superselective intra-arterial catheterization. The OA arose from the CB and the inner diameter of the origin of the OA was 1.5 mm. The CB was located at the level of C3–C4 and 7.9 mm above the tip of the greater horn of the hyoid bone.     

Anomalous artery directly connecting the external and internal carotid arteries

An anomalous artery directly connecting the external with the internal carotid artery was encountered on the right side of a 68-year-old Japanese female cadaver. This anomalous artery (5 mm in diameter, 12 mm in length) branched out from the posterior aspect of the external carotid at the level of the origin of the lingual artery, ran obliquely upward posteriorly along the course of the hypoglossal nerve, and was confluent with the anterior aspect of the internal carotid artery. No other variations were found in the morphological aspects of, or in the anatomical relationships between, the carotid arteries and their surrounding structures on either side. The carotid body-like structure was observed at the carotid bifurcation and was innervated by small branches of the glossopharyngeal, the vagus and the sympathetic trunk. Embryologically, it is conceivable that this anomalous artery may have derived from the right second branchial arch artery, although there is no abnormality in other derivative structures of the second pharyngeal arch. There may have been no effect from this anomaly on the functions of the arterial blood flow and blood supply under normal circumstances in the present case, but this report may be of embryological significance and contribute some insight into the mechanisms of the formation of the carotid circulation systems.     

大隐静脉重建颈动脉在头颈部恶性肿瘤手术治疗中的应用

目的 探讨大隐静脉在颈动脉重建手术中的应用以及对恶性肿瘤侵犯颈动脉的患者行颈动脉重建手术的临床疗效和安全性。方法 回顾性研究。纳入中国医学科学院肿瘤医院头颈外科2017年11月-2019年9月18例行肿瘤切除颈动脉重建的恶性肿瘤患者,其中男10例、女8例,年龄47～72(58.8±6.6)岁;甲状腺乳头状癌11例,头颈部鳞癌7例,其中5名患者在术前接受过放射治疗。完成综合术前检查后,术中完整切除肿物及受侵的部分颈动脉,并以自体大隐静脉重建颈动脉。观察患者术前颈部超声及颈部CT提示肿瘤包绕角度、下肢静脉超声所提示的大隐静脉情况及距汇入股静脉远心端5 cm处内径,手术时间、术中出血量、移植大隐静脉侧别、供体大隐静脉长度、术中颈动脉阻断时间、肿瘤包绕颈动脉角度、受体颈动脉吻合处内径,术后病理组织学检查结果、患者住院时间、重建血管的通畅情况、有无出现神经系统及下肢供区并发症,随访期间有无局部复发及远处转移病例。结果 术前超声探查及颈部CT示,18例患者大隐静脉在距汇入股静脉远心端5 cm处内径(0.53±0.14)cm;颈部CT扫描见肿瘤对颈动脉的包绕角度均超过180°,其中超过270° 15例、全部包绕颈动脉9例。术中大隐静脉取材长度(7.3±1.1)cm,取用左侧大隐静脉9例、右侧大隐静脉9例。颈动脉近心端吻合处均为颈总动脉,内径(0.74±0.06)cm;远心端吻合处位于颈总动脉14例,颈内动脉4例,内径(0.71±0.17)cm。术中颈动脉阻断时间(640±117)s。术中观察颈动脉受侵角度190°～360°(317°±56°),与术前影像学检查一致。18例患者手术时间4～6 h,术中出血200～500 mL,住院时间7～28 d(平均13.13 d)。术后病理提示侵犯颈动脉血管壁组织13例。术后随访时间3～24个月,平均11.06个月。18例中,死亡2例、局部复发1例,余15例无瘤生存;术后颈动脉CT血管成像示重建血管均通畅,未见移植血管破裂、感染、狭窄及假性动脉瘤形成,供区下肢均未见水肿、跛行等血液循环障碍并发症。结论 在头颈部肿瘤患者的颈动脉重建手术中,大隐静脉具有易于取材、移植物感染率低等优势,同时该手术能在低神经系统并发症风险下安全、完整地切除肿瘤,值得推广应用。     

Topography of carotid bifurcation: considerations for neck examination

Clinical examination and surgical procedures require the knowledge of anatomical structures of such a complex area as neck, especially the developmental anomalies in vascular drainage may occur. The aim of this study was to describe the common carotid artery bifurcation to its surrounding structures to locate it properly by using external and internal landmarks. Measurements were performed on 43 Thai cadavers by the direct inspection method. Carotid bifurcation level was compared to the level of cervical vertebra, isthmus of thyroid cartilage, angle of mandible and origins of superior thyroid artery, and lingual artery. Most of carotid bifurcations were found at the level of C3, between C3 and C4, and C4 vertebra, as well as the tendency to lower position in men was noted. Measurements to the angle of mandible on the left sides were significantly different in studied groups (P = 0.02), also with lower position of bifurcation in men. The mean level of carotid bifurcation was approximately 6 mm above ITC, which literally is at the level of the superior border of thyroid cartilage. Moreover, in four cases, common carotid artery did not bifurcate bilaterally, and in four cases, no bifurcations were found at the right side of neck. Further, many superior thyroid arteries originated from common carotid artery. To sum up, during the clinical procedures, the level of thyroid cartilage is mostly advised to follow to locate the carotid sinus. Further, the described variations in topography of carotid bifurcation and arteries origins may have important clinical implications.     

Anatomic evaluation of the carotid artery bifurcation in cadavers: implications for open and endovascular therapy

Knowledge of carotid bifurcation (CB), common carotid artery (CCA) and its branches and their recognition during diagnostic imaging are also important for vascular surgical procedures in the region, such as carotid endarterectomy or radical neck dissection, catheterization and aneurysms. The surgical anatomy of the carotid arteries was studied in 20 cadavers. Micrometric values of the CB and its relation with surrounding structures, measurements belonging to the external carotid artery (ECA) and internal carotid artery (ICA), and metric data, such as lower face including the greater horn, laryngeal prominence have been evaluated by making linear measures. The diameter of the CCA at the CB under 2 cm and CB diameter was measured as 8.1 +/- 2.24 mm and 12.79 +/- 2.87 mm, respectively. Evaluating data related to the ICA and the ECA in samples, the aspect was measured the ICA and the ECA in the CB discrimination point as 21.52 +/- 20.53 degrees . In the most location of the ECA origin according to the ICA has been determined as medial position in 35 specimens. The origin of the superior thyroid artery (STA) was found to be at the same level with the CB in 40% and below it in 25% specimens. This study has provided measured objective criteria for the arterial features of the neck region, which are crucial during surgery. The origins of the branches of the CCA act as key landmarks for adequate and appropriate placement of the cross-clamp on the carotid arteries.     

The diameters of common carotid artery and its branches in newborns

The common carotid artery (CCA) bifurcation is of clinical importance due to its vascular access site for intravascular intervention. Additionally, it is also one of the most common sites of atherosclerotic plaque formation. There are numerous studies on the diameters of CCA, internal carotid artery (ICA), and external carotid artery (ECA) in adults, but few studies on newborns. Cadaver and angiographic studies have shown dimensional variations in the carotid arteries within/between individuals and also between different sexes. It is well known that the initial lesions of atherosclerosis begin very early in fetal life. Therefore, it is important to know the anatomical details of the CCA and its branches. In the present study, the neck regions of 20 (11 males and 9 females) fixed newborn cadavers were dissected. The CCAs were cut below the bulb of the carotid bifurcation further; ICA and ECA were cut above the bulb of the carotid bifurcation. The internal diameters of the CCA, ICA, and ECA were measured using a light microscopy. ECA/CCA, ICA/CCA, ICA/ECA ratios, and outflow to inflow area ratio were calculated. The mean outflow to inflow area ratio was 1.14±0.28. Our results highly correlated with the defined optimal ratio (1.15). The ECA/CCA, ICA/CCA, and ICA/ECA ratios were 0.78±0.12, 0.71±0.13, and 0.93±0.16, respectively. There were no statistically significant differences between male and female and also between right and left sides. These findings are of importance in understanding the anatomy of carotid artery during newborn period.     

锁骨下动脉、颈总动脉和椎动脉分叉处血流动力学数值模拟

目的:探讨锁骨下动脉、颈总动脉和椎动脉分叉处的血流动力学特性,分析该处发生血管狭窄引起大脑供血不足的 血流动力学原因。方法:采用内蒙古民族大学附属医院神经内科提供的CT数据,应用医学建模软件MIMICS20.0将患者 二维CT数据进行三维血管重建,经过网格划分及边界条件设置后导入计算流体力学软件FLUENT14.5中。计算和分析 不同血液入口速度的锁骨下动脉、颈总动脉和椎动脉分叉处的血流动力学特性。结果:在血液入口速度不同的情况下,锁 骨下动脉、颈总动脉和椎动脉分叉处的血液流场分布、血液压力分布和血管壁面切应力分布有显著变化。在血液入口速 度增大时,锁骨下动脉分叉处和颈总动脉分叉处的血液流速快、血管壁压力大,颈总动脉内侧血管壁面切应力大,但锁骨 下动脉分叉处和颈总动脉分叉处血管壁面切应力数值和变化幅度小,属于低切应力区。结论:通过血流动力学数值模拟 研究,分析锁骨下动脉、颈总动脉和椎动脉分叉处易发生粥样斑块病变导致大脑供血不足的血流动力学原因。     

Association between internal carotid artery morphometry and posterior communicating artery aneurysm

PURPOSE: The goal of this study was to directly measure the association between the internal carotid artery (ICA) morphometry and the presence of ICA-posterior communicating artery (PCOM) aneurysm. MATERIALS AND METHODS: The authors intraoperatively measured the length of the supraclinoid ICA because it is impossible to radiologically determine the exact location of the anterior clinoid process. We used an image analyzer with a CT angiogram to measure the angle between the skull midline and the terminal segment of the ICA (ICA angle), as well as the diameter of the ICA. The lengths and diameters of the supraclinoid ICA and the ICA angle were compared among PCOM aneurysms, anterior communicating artery (ACOM) aneurysms, and middle cerebral artery (MCA) bifurcation aneurysms (n=27 each). Additionally, the lengths and the diameters of M1 and A1 were compared for each aneurysm. RESULTS: The lengths of the supraclinoid ICA were 11.9+/-2.3 mm. The lengths of the supraclinoid ICA in patients with ICA-PCOM aneurysms (9.7+/-2.8 mm) were shorter than those of patients with ACOM aneurysms (13.8+/-2.2 mm, Student's t-test, p<0.001) and with MCA bifurcation aneurysms (12.2+/-1.9 mm, Student's t-test, p<0.001). The diameters of the supraclinoid ICA and A1 in patients with ACOM aneurysms were larger than those in patients with MCA bifurcation aneurysms (Student's t-test, p<0.05). There were no significant differences in the lengths of M1 and A1, ICA angle, or diameter of M1 for each aneurysm. CONCLUSION: These results suggest that the relatively shorter length of the supraclinoid ICA may be a novel risk factor for the development of ICA-PCOM aneurysm with higher hemodynamic stress.