经颅彩色多普勒评价颅内动脉瘤夹闭术后脑血管痉挛患者大脑前循环脑血流量

我院对31例颅内动脉瘤患者利用经颅彩色多普勒进行术前、术后反复的大脑中动脉榆查,结合颈内动脉入颅段血流动力学参数,探讨经颅彩色多普勒对颅内动脉瘤夹闭术后脑血管痉挛及大脑前循环脑血流量变化的诊断价值.     

急性颈内动脉闭塞颅内循环的变化及临床意义

目的 分析急性颈内动脉闭塞后颅内血流动力学的变化及临床意义.方法 对68例经影像学检查证实急性单侧颈内动脉颅外段闭塞患者,采用经颅多普勒超声(TCD)检测颅内主要动脉的血流动力学变化.结果 患侧大脑中动脉峰值流速和搏动指数均显著低于健侧(P<0.001).在侧支循环开放中,前交通动脉开放占48.53%(33/68),后交通动脉开放为42.65%(29/68),眼动脉参与的侧支循环占32.35%(22/68),无交通支开放14.71%(10/68).患者颅内侧支循环开放,侧支途径两支以上者、患侧大脑中动脉峰值流速>60 cm/s者,临床预后相对较好.结论 TCD检测颅内主要动脉的血流状况,可以快速方便地评价颅内侧支循环状态,对急性颈内动脉闭塞患者治疗方法选择和预后判断具有重要的临床价值.     

经颅二维彩色多普勒超声对脑梗死患者大脑中动脉血流速度的研究

目的探讨经颅二维彩色多普勒超声(TCCS)对脑梗死患者大脑中动脉血流速度。方法应用经颅彩色多普勒超声对临床经血管造影确诊为脑梗死的患者48例(其中18例大脑中动脉主干梗死,14例大脑中动脉分支梗死,16例颅外单侧颈内动脉梗死)和50例健康成人分别采用经颅彩色多普勒血流显像(CDF I)进行探测,测量双侧大脑中动脉舒张末期血流速度(EDV),并计算舒张末期双侧大脑中动脉血流速度比率(健侧与患侧的比值)。结果在健康成人组中,舒张末期血流速度和舒张末期比率为:(42.79±13.72)cm/s、1.25±0.31;在大脑中动脉水平段主干梗死组及大脑中动脉分支梗死组舒张末期血流速度和舒张末期比率分别为:(17.20±5.65)cm/s、3.56±1.20,(20.14±4.35)cm/s、1.82±0.46;颅外单侧颈内动脉梗死组中,梗死侧的舒张末期血流速度和舒张末期比率为:28.70±11.21(cm/s)、1.68±0.57,所有梗死组舒张末期血流速度明显低于对照组,而舒张末期比率明显高于对照组。结论经颅二维彩色多普勒对大脑中动脉(MCA)水平段血流速度和舒张末期比率的检测,有助于大脑中动脉梗死的鉴别诊断。     

颅外段颈动脉狭窄支架植入术前后颅内外血流动力学变化的研究

目的 研究颅外段颈内动脉（EICA）狭窄支架植入术（CAS）治疗前后颅内、外动脉血流动力学的变化.方法 用彩色多普勒血流显像（CDFI）和经颅彩色多普勒血流显像（TCCD）分别对38例EICA狭窄患者CAS治疗前、后狭窄局部管径、收缩期峰值流速（PSV）及同侧大脑中动脉、眼动脉PSV、搏动指数（PI）和颅内侧支循环的建立情况进行分析.结果 CAS术后患侧原狭窄处内径较术前明显增宽（P＜0.001）,仍小于对侧（P＜0.001）;PSV较术前明显降低（P＜0.001）,仍大于对侧（P＜0.05）.CAS术后患侧大脑中动脉、眼动脉的PSV、PI较术前明显增高（P＜0.001）,与对侧比较差异无统计学意义（P＞0.05）.侧支循环全部关闭.结论 CDFI与TCCD结合可评价CAS治疗前、后颅内、外动脉的血流动力学变化,对判断CAS疗效具有重要的临床价值.CAS是治疗EICA狭窄安全而有效的方法,短期疗效令人满意.     

经颅多普勒对大脑中动脉血流速度改变的鉴别诊断

大脑中动脉是颈内动脉最大的分支 ,大脑半球 80 %的血液来自此动脉 ,它也是脑血管疾病发生最多的部位 ,相对于大脑前、后动脉 ,大脑中动脉的变异较小 ,因此 ,在经颅多普勒(TCD)诊断中 ,对大脑中动脉血流速度改变的鉴别诊断尤显重要。1　血流速度增高的鉴别诊断大脑中动脉血流速度增高主要有下述病因 :动静脉畸形 ,侧支循环代偿 ,血流量增高 (血流灌注增高 ) ,脑血管痉挛 ,脑血管狭窄 ,血管张力性血流速增高等。动静脉畸形因血液不经过毛细血管直接流入静脉所致 ,其病理基础决定了 TCD表现为血流速度显著增高 ,搏动指数明显降低以及频谱充…     

彩色多普勒对颈部肿块的术前应用价值

目的：探讨彩色多普勒对颈部肿块的术前应用价值。方法：对14例颈部肿块患者进行术前彩色多普勒检查，观察肿块二维超声表现及彩色多普勒因流；患侧颈总动脉压迫训练后测定健侧颈内动脉及双侧椎动脉的最大血流速度及速度时间积分，计算每分血流量及流速和流量增加率，并与手术结果对比。结果：颈部常见各种肿块超声表现有所不同。健侧颈内动脉及双侧椎动脉较压迫训练前血流速度及血流量显著增加（P＜0．01）。结论：应用彩色多普勒方法可诊断颈部肿瘤和判断侧支循环建立状况，可基本替代颈动脉造影的检查。     

彩色多普勒超声评价子宫肌瘤动脉栓塞术后血流动力学变化

目的　利用彩色及频谱多普勒显像技术对子宫肌瘤动脉栓塞术后的肌瘤的血供及子宫动脉血流动力学进行观察 ,评价子宫肌瘤动脉栓塞术治疗效果。方法　采用Sequoia 5 12型彩色多普勒超声诊断仪对 2 8例 48个子宫肌瘤动脉栓塞术前及术后 3天子宫动脉及肌瘤的血流动力学变化进行检测。结果　子宫肌瘤动脉栓塞治疗后 3天子宫动脉血流速度较术前明显降低 [(60 .86± 18.0 9)cm/svs(69.94± 17.0 1)cm /s ,P <0 .0 1] ,搏动指数增大 [(2 .63± 0 .90 )vs(2 .2 9± 0 .62 ) ,P <0 .0 5 ]、阻力指数增大 [(0 .84± 0 .10 )vs(0 .81± 0 .0 7) ,P <0 .0 1] ,血流量减少 [(2 92 .94± 2 0 6.17)ml/minvs (3 75 .0 7± 2 0 7.99)ml/min ,P <0 .0 1]。治疗前 2 8例患者 48个肌瘤全部可测及血流信号 ,以子宫动脉供血为主 ;治疗后 48个肌瘤中 2 9个血流完全消失 ,17个血流减少 ,2个无变化。结论　彩色及频谱多普勒是观察子宫肌瘤动脉栓塞治疗效果的较好方法     

彩色多普勒超声检测双侧颈内动脉闭塞患者侧支循环及血流动力学

目的 探讨彩色多普勒超声检测双侧颈内动脉闭塞患者颅内动脉侧支循环代偿途径及血流动力学状况的价值.方法 对7例双侧颈内动脉闭塞患者(患者组)和对照组7名健康成人,应用彩色多普勒超声检测双侧眼动脉(OA)及颅内动脉,分别根据患者OA反向血流及大脑后动脉(PCA)P1段峰值血流速度(Vs)大于对照组((-x)+2s)来判断OA、Willis环后交通动脉侧支循环代偿途径,并比较患者组与对照组大脑中动脉(MCA)、大脑前动脉(ACA)的平均血流速度(Vm).结果 7例患者均存在双侧OA反向血流,双侧椎动脉、基底动脉Vm明显高于对照组(P均＜0.05);4例左侧PCA P1段和3例右侧PCA P1段Vs大干对照组;MCA、ACA Vm较对照组明显降低(P均＜0.05).结论 双侧ICA闭塞患者存在OA及后交通动脉两种侧支循环代偿途径,但其颅内动脉仍供血不足.彩色多普勒超声能实时评价颅内动脉侧支循环血供和血流动力学变化.     

颈内动脉闭塞时经眼动脉侧支循环的彩色多普勒超声特征

目的 探讨单侧颈内动脉闭塞时经颈外-眼-颈内动脉侧支循环的彩色多普勒超声特征.方法 应用彩色多普勒超声前瞻性检查42例单侧颈内动脉闭塞患者的眼动脉、颈外动脉,并与30例颈内动脉正常的受试者比较,分析侧支循环的超声特征.结果 42条颈内动脉中,40条(95.2％)慢性闭塞由患侧颈外-眼-颈内动脉侧支循环代偿,与健侧和正常组比较,表现为眼动脉逆向血流,峰值后移,峰值血流速度增加,加速时间延长,阻力指数和搏动指数降低(P＜0.01).2条急性栓塞(4.8％)由健侧颈内-患侧颈内动脉侧支循环代偿,表现为眼动脉正向血流,血流速度降低,阻力指数和搏动指数降低.结论 颈内动脉慢性闭塞时患侧颈外-眼-颈内动脉侧支循环参与代偿,急性栓塞仅由健侧颈内-患侧颈内动脉侧支循环代偿.     

经颅多普勒超声在颈内动脉闭塞超早期的应用

目的：探讨经颅多普勒超声（TCD）在颈内动脉闭塞超早期的应用价值。方法：48例经磁共振血管成像或（和）数字减影血管造影确诊为颈内动脉闭塞患者，应用TCD监测颅内外各血管血流变化，分析血流变化与临床的关系。结果：患侧大脑中动脉血流受损程度与脑梗死轻重有直接的联系，侧支循环的建立及代偿在此种梗塞中起决定的作用。结论：低灌注是导致梗塞的主要原因，患侧大脑中动脉血流速度直接反映灌注情况，TCD可有效观测侧支循环及大脑中动脉血流速度。在颈内动脉闭塞超早期有独特的应用价值。     

Vector Doppler imaging of a spinning disc ultrasound Doppler phantom

Vector Doppler methods are used to obtain angle independent in-plane velocity information. Velocity magnitude as well as direction are reconstructed from regular steered colour flow and from split-aperture Doppler acquisitions. Spatially resolved in-plane velocity was obtained through Doppler colour flow mode and subsequent data triangulation. A depth-invariant constant Doppler angle was achieved by using a depth expanding transmit-receive Doppler aperture. Velocities of up to 50 cm s(-1) and 360 degrees vector velocity directions were measured. This was achieved by creating a spinning solid disc phantom. Such a phantom was built to allow underwater mounting and spinning of a solid disc-shaped ultrasound phantom (maximum velocity of 50 cm s-1). Doppler triangulation was realised by steered Doppler and by a split-aperture approach. Results of both imaging methods are shown. Split-aperture results showed errors of less then 10% for velocity magnitude estimation and less then 2.5 degrees for directional information.     

Doppler and color Doppler imaging in acute transplant failure.

Most renal transplants are lost by rejection. A method is required to identify and discriminate between this and acute tubular necrosis and cyclosporin toxicity. The sonogram of the normal renal transplant is characteristic. Early Doppler studies measuring a rise in vascular impedance in acute rejection showed a high sensitivity and specificity. This appears, at least in part, to have been due to patient selection. We conclude that Doppler studies cannot be used to differentiate between the main parenchymal causes of renal transplant failure, although it can be helpful, with other clinical information, in supporting a diagnosis and in monitoring the effects of treatment.     

Doppler ultrasound--basics revisited

Palpation of pedal pulses alone is known to be an unreliable indicator for the presence of arterial disease. Using portable Doppler ultrasound to measure the resting ankle brachial pressure index is superior to palpation of peripheral pulses as an assessment of the adequacy pf the arterial supply in the lower limb. Revisiting basics, this article aims to aid the clinician to understand and perform hand-held Doppler ultrasound effectively while involving the client or patient in the process. The author describes the basics of Doppler ultrasound, how to select correct equipment for the process, and interpretation of results to further enhance clinicians' knowledge.     

Pelvic Doppler.

This article reviews gray-scale and Doppler evaluation of the adexae and endometrium. Color Doppler is useful in distinguishing between cystic and solid masses. However, spectral Doppler is of limited utility in improving the gray-scale morphologic impression of a mass being either benign or malignant.     

Evaluation of joint effusion in rabbits by color Doppler, power Doppler, and contrast-enhanced power Doppler ultrasonography

PURPOSE: The aim of this prospective study was to evaluate the diagnostic value of power Doppler ultrasonography (PDUS) and contrast-enhanced PDUS (CEPDUS) in the depiction and characterization of experimentally induced arthritis in the rabbit. MATERIALS AND METHODS: Thirty rabbits were divided into three groups consisting of one control group (saline injection group) and two experimental groups: a suppurative arthritis group and a chemically induced synovitis group. The same amount (1 ml) of each agent was directly injected into the right hip joint. Serial color Doppler ultrasound (CDUS), PDUS, and CEPDUS images were obtained before and after injection. RESULTS: We observed that all of the infected knees in the suppurative arthritis group with Staphylococcus aureus demonstrated an increased signal on PDUS after inoculation. A minimal power Doppler signal was presented in the chemically induced synovitis group with talc injection, but none of the control knees demonstrated any increased signals. CEPDUS was the most sensitive imaging modality for evaluating the increase of blood flows in suppurative arthritis and was subsequently followed by PDUS and CDUS. CONCLUSION: The increased signals obtained with PDUS represent increased local blood flows; therefore, this technique can be used for evaluating the degree of inflammation. Furthermore, using the contrast agent enhances the sensitivity of PDUS, and it can even be useful for differentiating borderline cases.