Hypoplasia of the internal carotid artery: a noninvasive diagnosis

We present the characteristic imaging findings of hypoplasia of the internal carotid artery (ICA) in two cases, one accompanied by an intracranial aneurysm. Finding of a diffuse luminal narrowing of the ICA on MR angiography or digital subtraction angiography (DSA) could wrongly evoke severe acquired diseases such as dissection or atherosclerosis. Absence of associated wall thickening and flow disturbances on color Doppler sonography (CDS) should suggest carotid hypoplasia. Confirmation of the diagnosis is obtained by CT of the skull showing a small carotid canal. Non-invasive procedures are sufficient to differentiate this rare congenital anomaly from acquired string signs. Received: 25 October 1999; Revised: 27 January 2000; Accepted: 30 March 2000     

Serial MRI of a mycotic aneurysm of the cavernous carotid artery

Cerebral mycotic or infective aneurysms are a rare complication of infectious illness, and such aneurysms of the intracavernous portion of the internal carotid artery are rare. They have been described as a consequence of cavernous sinus infection in an immunocompromised host, but not previously in a renal transplant recipient. We present such a case with serial MRI showing progression from arterial narrowing to aneurysm formation. Transcranial Doppler sonography of the middle cerebral artery showed distal asymptomatic embolisation from the aneurysm.     

Duplex and color Doppler flow sonography of occlusion and near occlusion of the carotid artery.

PURPOSETo determine whether color Doppler flow imaging with the use of slow-flow sensitivity improves sensitivity and specificity in the differentiation of occlusion and near occlusion of the internal carotid artery.METHODSColor Doppler and duplex sonography were performed in symptomatic patients who had angiographically confirmed occlusion and/or near occlusion of the internal carotid artery. The study consisted of two phases: in the first, we assessed the usefulness of color Doppler flow imaging by retrospectively reviewing the records of 35 patients with 36 angiographically confirmed occlusions or near occlusions of the internal carotid artery who were examined with color Doppler flow imaging at our institution during a period of 4 years; in the second phase, we incorporated color Doppler sonography into the routine scanning protocols of 39 patients with 41 occluded or nearly occluded internal carotid arteries seen over a period of 2 1/2 years.RESULTSOverall, color Doppler imaging correctly showed all 34 of the near occlusions (sensitivity, 100%) and 36 of the 43 occlusions (specificity, 84%). Seven patients with angiographically confirmed occlusion had sonographic findings that suggested near occlusion. In the first phase, eight near occlusions were misinterpreted as occlusions with conventional duplex sonography, but were correctly shown with color Doppler flow imaging. In the second phase, sensitivity increased from 50% to 100% (18 or 18) because of better detection of the nearly occluded lumen. This was at the expense of a decrease in specificity (from 100% to 78%). owing to identification of apparent flow in the internal carotid artery on color Doppler flow images in five of 23 occlusions.CONCLUSIONBecause of its ability to depict slow flow, color Doppler imaging with slow-flow sensitivity is superior to conventional duplex sonography for the noninvasive discrimination of occlusion from near occlusion of the internal carotid artery.     

颅外颈动脉螺旋CT血管造影的临床意义(附45例报告)

目的 报告颅外颈动脉ＣＴ血管造影（ＣＴＡ）的初步经验,探讨该技术对各种颅外颈动脉病变的诊断意义,并在可能范围内与数字减影血管造影（ＤＳＡ）作小样本的对照。方法 ４５例颈动脉ＣＴＡ,经最大密度投影（ＭａｘＩＰ）及表面灰度成像法（ＳＳＤ）行三维重建,其中５例在１周内作了ＤＳＡ检查。结果 ４５例颈动脉ＣＴＡ检查,共得到９０支血管图像。其中正常血管５５支,狭窄血管３１支,闭塞血管２支,颈内动脉动脉瘤１支,     

脑梗死患者颈动脉超声检查及血流阻力指数的临床意义

目的:探讨脑梗死患者超声检查时颅外段颈动脉狭窄、闭塞及RI的临床意义。方法:对89例脑梗死患者(脑梗死组)及68例非脑梗死患者(对照组)行颅外段颈部动脉的彩色多普勒超声检查,观察动脉有无狭窄、狭窄程度及RI。结果:脑梗死组患者颅外段颈动脉狭窄的发生率、≥50%狭窄的发生率及闭塞发生率均明显高于对照组;脑梗死组中双侧颈动脉狭窄的发生率也高于对照组;脑梗死组的狭窄部位以颈内动脉最多见,但2组间RI差异无统计学意义。结论:脑梗死与颅外段颈动脉狭窄或闭塞有关;双侧颈动脉尤其是颈内动脉的严重狭窄或闭塞更易导致脑梗死;颅外段动脉RI测量无助于脑梗死的诊断。     

Diagnostics and characterisation of preocclusive stenoses and occlusions of the internal carotid artery with B-flow

The purpose was to evaluate whether B-flow can improve the ultrasonographic diagnosis of preocclusive stenosis and occlusion of the internal carotid artery (ICA) compared with colour-coded Doppler and power Doppler. Ninety patients with occlusions or preocclusive stenoses of the ICA suspected by Doppler sonography were examined with B-flow in comparison with colour-coded Doppler sonography (CCDS), power Doppler (PD) and intra-arterial digital subtraction angiography (DSA). Intrastenotic flow detection and lengths of stenoses were the main criteria. Ulcerated plaques found by surgery in 42/90 patients were compared by ultrasonography (US). Diagnosis of ICA occlusion with CCDS, PD and B-flow was correct in all 42 cases. A preocclusive ICA stenosis in DSA was detected correctly in all 48/48 cases (100%) for B-flow, in 44/48 (92%) for PD and in 39/48 (81%) for CCDS. Surgical findings showed in 17/42 cases ulcerated plaques; 15/17 (89%) of these cases were detected with B-flow, 12/17 (71%) with PD, 10/17 (59%) with CCDS, and 8/17 (47%) with DSA. With B-flow the extent of stenosis was appraised more precisely than with PD and CCDS (P<0.0001). In conclusion, B-flow is a reliable method for preocclusive stenosis of the ICA with less intrastenotic flow artefacts. B-flow facilitates the characterization of plaque morphologies.     

颅外颈内动脉损伤诊治方法的探讨

目的　探讨颅外颈内动脉损伤的早期诊断和治疗方法。方法　 1982～ 2 0 0 2年共收治颅外颈内动脉损伤 8例 ,其中颈内动脉破裂并休克 3例 ,并发栓塞 4例 ,假性动脉瘤 2例。行颈内动脉修补 2例 ,颈内动脉 -颈外动脉端端吻合 1例 ,颅内 -外动脉搭桥 2例 ,手术取栓 1例 ,瘤体切除加动脉修补 2例。结果无死亡 ,4例出现偏瘫失语等神经系统并发症 ,1例经颅内 -外动脉搭桥后完全康复 ,1例经取栓术后改善 ,2例经保守治疗症状轻度改善。余 4例除 1例遗有颈内动脉假性动脉瘤外 ,均痊愈。结论　早期诊断及颈内动脉修复重建是降低死亡率 ,减少神经系统并发症的关键     

Maximum stenosis of extracranial internal carotid artery: effect of luminal morphology on stenosis measurement by using CT angiography and conventional DSA.

PURPOSE: To assess the luminal morphology of the extracranial internal carotid artery at three-dimensional (3D) computed tomographic (CT) angiography and how this factor affects measurement of maximum carotid arterial stenoses at conventional intraarterial digital subtraction angiography (DSA). MATERIALS AND METHODS: Prospectively, conventional intraarterial DSA and 3D CT angiography were performed in 42 carotid arteries in 21 patients with suspected carotid artery disease. The longest axis length-perpendicular axis length (L/P) ratios of the arterial lumen on the cross-sectional images at the most stenotic area and distal nonstenotic area were analyzed by acquiring multiplanar reconstruction (MPR) images at 3D CT angiography. The maximum stenosis was measured at each modality with North American Symptomatic Carotid Endarterectomy Trial criteria. RESULTS: The L/P ratios in the most stenotic areas ranged from 1.0 to 3.2 (mean, 1.5 +/- 0.5 [SD]). The mean difference in maximum percentage of stenosis between the two modalities for L/P ratios of 2.0 or greater was significantly greater than that for L/P ratios of less than 1.5 (P < .05). Three carotid arteries with 70%-99% stenosis, with grades determined only with 3D CT angiography, had L/P ratios of 2.0 or greater. CONCLUSION: On MPR images at 3D CT angiography, the lumen of extracranial internal carotid artery stenosis showed a wide range of shapes. When a carotid artery has a high L/P ratio, the luminal morphology of the carotid artery stenosis may affect the assessment of maximum stenosis of the internal carotid artery at conventional DSA.     

Duplex Doppler sonography of the carotid artery: false-positive results in an artery contralateral to an artery with marked stenosis

Anecdotal reports have described a false-positive "jet effect" or velocity increase in the carotid artery contralateral to an artery with significant stenosis or occlusion when using duplex Doppler sonography. In this study, the frequency, significance, and possible reasons for this finding were evaluated by a retrospective comparison of duplex sonography and angiography. Twenty-three patients with unilateral 81-100% carotid artery stenosis who underwent both duplex sonography (16 Acuson, seven Quantum) and angiography were evaluated. In 14 patients, there was an accurate or slight underestimate (less than 20%) of stenosis present in the internal carotid artery contralateral to an artery with tight stenosis/occlusion. In nine, a velocity increase in the internal carotid artery resulted in overestimation (10-80%) of the actual degree of stenosis. In one of these nine patients, real-time images were sufficient to explain the velocity increase on the basis of vessel tortuosity. In one, falsely elevated velocity resulted from inaccurate assignment of the Doppler angle of incidence in a patient in whom real-time visualization of a distal internal carotid lesion was poor. In four of the nine patients, cross filling via the circle of Willis toward the side of greater stenosis occurred. However, seven of 14 patients in whom there was duplex sonography/angiography agreement or slight duplex sonography underestimation also had cross filling. Vertebral artery patency did not correlate well with the presence of a "jet effect." These findings suggest that an increase in blood flow velocity with duplex Doppler sonography in the internal carotid artery on the side opposite an artery with a tight stenosis is a common source of error and is not readily explained by angiographic evidence of collateral flow.     

Duplex Doppler sonography of the carotid artery: false-positive results in an artery contralateral to an artery with marked stenosis

Anecdotal reports have described a false-positive "jet effect" or velocity increase in the carotid artery contralateral to an artery with significant stenosis or occlusion when using duplex Doppler sonography. In this study, the frequency, significance, and possible reasons for this finding were evaluated by a retrospective comparison of duplex sonography and angiography. Twenty-three patients with unilateral 81-100% carotid artery stenosis who underwent both duplex sonography (16 Acuson, seven Quantum) and angiography were evaluated. In 14 patients, there was an accurate or slight underestimate (less than 20%) of stenosis present in the internal carotid artery contralateral to an artery with tight stenosis/occlusion. In nine, a velocity increase in the internal carotid artery resulted in overestimation (10-80%) of the actual degree of stenosis. In one of these nine patients, real-time images were sufficient to explain the velocity increase on the basis of vessel tortuosity. In one, falsely elevated velocity resulted from inaccurate assignment of the Doppler angle of incidence in a patient in whom real-time visualization of a distal internal carotid lesion was poor. In four of the nine patients, cross filling via the circle of Willis toward the side of greater stenosis occurred. However, seven of 14 patients in whom there was duplex sonography/angiography agreement or slight duplex sonography underestimation also had cross filling. Vertebral artery patency did not correlate well with the presence of a "jet effect."(ABSTRACT TRUNCATED AT 250 WORDS)     

Post-traumatic dissecting aneurysm of extracranial internal carotid artery: endovascular treatment with stenting

Traumatic internal carotid dissection occurs frequently in motor vehicle accidents, typically extracranially, close to the skull base. Dissection may lead to stenosis or occlusion of the vessel, possibly with a pseudoaneurysm, symptoms ranging from neck pain to neurological deficits. In symptomatic patients and in cases of pseudoaneurysm, when conservative medical treatment fails, surgery or endovascular treatment are indicated. We report a post-traumatic dissecting aneurysm of the extracranial internal carotid artery successfully treated with stenting via a transfemoral approach. Received: 5 November 1998 Accepted: 5 December 1998     

Spontaneous dissection of both extracranial internal carotid arteries

Summary Neurological examination and Doppler sonography of a 50-year-old patient were suggestive of a spontaneous dissection of the left internal carotid artery (left-sided headaches, amaurosis fugax, Horner's syndrome and hemispheric stroke). Four-vessel angiogram performed several days after the onset of the symptoms showed dissection of both extracranial carotid arteries, more pronounced on right side where the dissection was clinically asymptomatic. Angiogram follow-up demonstrated a recanalization of both carotid arteries. A review of 15 other documented reports indicates that bilateral internal carotid dissection is usually associated with fibromuscular dysplasia. A large majority of cases does not clinically differ from unilateral carotid artery dissection.     

Non-visualization of the internal carotid artery with a normal ipsilateral common carotid artery Doppler waveform: a finding suggesting congenital absence of the ICA on colour Doppler ultrasound

We report a case of congenital absence of the left internal carotid artery (ICA) that presented with left-sided facial numbness. On MRI of the brain, occlusion of the left cavernous ICA was suggested. On colour Doppler ultrasound (CDS), the left ICA was not visualized and the ipsilateral common carotid artery (CCA) showed normal flow in systole and diastole. Combined with the correct identification of the left external carotid artery (ECA), these findings were suggestive of congenital absence of the ICA rather than occlusion. The final diagnosis of congenital absence of the ICA was confirmed with CT of the skull base.     

Pseudoaneurysm of the cervical internal carotid artery with associated hypoglossal nerve paralysis

Summary A case of pseudoaneurysm of the cervical internal carotid artery with associated hypoglossal nerve paralysis resulting from trauma is presented. CT and angiographic manifestations of this pseudoaneurysm and the resulting hypoglossal nerve paralysis are discussed. Correlative CT and angiographic findings of this association have not previously been described in the literature.     

Spontaneous thrombosis of a giant intracavernous internal carotid artery aneurysm and ipsilateral internal carotid artery occlusion

A 75-year-old man who had suffered from right visual disturbance for 10 years suddenly experienced right cavernous sinus syndrome. Magnetic resonance imaging revealed a giant thrombosed aneurysm in the right cavernous sinus extending to the right middle cranial fossa. Digital subtraction angiography disclosed occlusion of the right internal carotid artery at the petrous portion and good cross filling in the right-sided circulation through the anterior communicating artery. There was no filling of the aneurysm. In this case, the mechanism of parent artery occlusion is unclear, but direct compression and stretching of the parent artery by the aneurysm may be involved.     

彩色多普勒超声在颈动脉病变诊治中的应用

目的彩色多普勒超声在颈动脉病变诊治中的应用。方法应用彩色多普勒超声筛选出颈动脉粥样硬化斑块狭窄甚至闭塞的患者。超声检查内容包括斑块的大小、回声以及稳定性,斑块造成狭窄时,计算狭窄率,同时记录血管内径及血流动力学指标。重度狭窄及闭塞患者要评估颅内侧支循环的建立情况,并与磁共振血管成像(MRA)和血管造影(DSA)对比分析。最后经过临床筛选54例患者共56条颈动脉接受内膜剥脱术(CEA)或颈动脉扩张成形加支架植入(CAS)手术治疗(包括1例无症状颈动脉狭窄患者)。结果超声对斑块回声及其稳定性评价优于其它影像学,狭窄程度判断与其它影像基本相符合;对颅内侧支循环的评估与DSA相同但优于MRA;术后颈内动脉内径及血流速度较术前有明显改善,内径〔(4.1±0.5)mm VS(1.4±0.5)mm,P<0.01〕;流速〔(74.2±13.1)cm/s VS(205±132.4)cm/s,P<0.01〕。结论彩色多普勒超声对颈动脉病变的部位、范围、动脉硬化斑块的稳定性以及狭窄的程度诊断率高,能够客观反映血流动力学改变,评估颅内侧支循环的建立情况,为是否需要手术治疗提供科学依据。同时为评价治疗效果以及术后随访和临床无症状的健康筛查提供有效便捷的手段。     

Detection of internal carotid artery stenosis: comparison of MR angiography, color Doppler sonography, and arteriography.

Findings of two-dimensional time-of-flight magnetic resonance (MR) angiography projection angiograms were prospectively compared with those of color Doppler sonography by using angiography as a standard in 23 consecutive patients (42 carotid bifurcations) to evaluate their utility in determining the presence of carotid artery stenosis. MR angiography helped detect 50% or greater lumen diameter stenosis (sensitivity, 0.96; specificity, 0.64). Color Doppler sonography with 1.25 m/sec peak systolic velocity as a threshold had a sensitivity of 0.96 and a specificity of 0.71. Statistical analysis showed a correlation between percentage of lumen diameter narrowing and the length of the zone of signal intensity loss with MR angiography (r = .69; P less than .0001). A stronger relationship was obtained between angiographic narrowing and peak systolic velocity derived from color Doppler sonography (r = .80; P less than .0001). Two-dimensional time-of-flight MR angiography displayed as projection angiograms and combined with carotid artery and combined with carotid artery sonography is a useful approach for helping detect and potentially grade the severity of stenoses of the carotid artery.     

Use of intravascular stents in the treatment of internal carotid and extracranial vertebral artery pseudoaneurysms.

The management of extracranial carotid or vertebral artery pseudoaneurysms is controversial. Although some of these lesions resolve spontaneously, many clinicians opt to treat them with trapping procedures that result in vessel sacrifice. We describe two cases in which an intravascular stent was used to obliterate an aneurysm of the extracranial vertebral artery and the internal carotid artery, respectively, while maintaining the patency of the parent vessel. The technique, which has been successful in experimental animal models, shows promise for application in humans.     

颈内动脉纤维肌肉发育不良的MSCT血管造影诊断(附9例报告)

目的:探讨颈内动脉纤维肌肉发育不良的多层螺旋CT血管造影(MSCTA)表现及诊断。方法:收集本院2003年~2005年6月经多层螺旋CT血管造影检查确诊的纤维肌肉发育不良9例。结果:9例中发生在颈内动脉颅内段5例,其中3例同时合并前、中动脉病变;岩骨段1例;单一中动脉3例。合并颈内动脉颅外整段狭窄、闭锁者2例,椎动脉整段性狭窄者2例,累计病灶17处。血管改变有:血管对称性狭窄,局限性偏心性狭窄,串珠样扭结状改变,狭窄伴动脉瘤。脑实质表现有:脑实质正常,脑梗塞,蛛网膜下腔出血。结论:本病无特异性临床症状,诊断依靠对本病的警惕,影像学特点是节段性血管腔狭窄及串珠样改变,使用MSCTA是生前诊断本病的简便有效方法。     

Spontaneous bilateral internal carotid artery dissection with hypoglossal nerve palsy.

Spontaneous dissection of the extracranial internal carotid artery (ICA) is increasingly being recognized as a common vascular disease. We report on a 52-year-old-male presented with bilateral extracranial internal artery dissection and twelfth nerve palsy and review the previous literature.