颈动脉磁共振血管成像对TIA病人短期并发急性脑梗死的预测价值

目的:探讨颈动脉磁共振血管成像(MRA)对短暂性脑缺血发作(TIA)病人短期并发急性脑梗死(ACI)的预测价值及意义。方法:选取2020年2月—2022年2月我院收治的187例TIA病人,根据6个月内是否并发ACI分为ACI组(90例)与无ACI组(97例),比较两组基线资料、颈动脉MRA检查结果(狭窄程度、斑块内出血、坏死脂核、纤维帽破裂、最小管腔面积、最大管壁厚度),采用Spearman或Pearson分析颈动脉MRA参数与ABCD3-I评分的相关性,分析TIA短期内并发ACI风险因素,采用受试者工作特征(ROC)曲线分析颈动脉MRA参数单独及联合预测TIA并发ACI的价值。结果:ACI组年龄大于无ACI组,糖尿病、高血压病人多于无ACI组,ABCD3-I评分高于无ACI组(P<0.001);ACI组狭窄程度重度、斑块内出血、坏死脂核、纤维帽破裂病人多于无ACI组,最小管腔面积小于无ACI组,最大管壁厚度大于无ACI组(P<0.05);狭窄程度、斑块内出血、坏死脂核、纤维帽破裂、最大管壁厚度与ABCD3-I评分呈正相关(r值分别为0.891,0.826,0.771,0....     

脑CT灌注成像联合颈动脉高分辨磁共振成像在颅外段颈动脉狭窄诊断及支架成形术中的应用

目的:探讨脑CT灌注成像(CTP)联合颈动脉高分辨磁共振成像(HR-MRI),在颈动脉狭窄诊断及支架置入术中的评估价值。方法:经颈动脉B超证实颅外段颈动脉重度狭窄90例患者,行脑CTP联合颈动脉HR-MRI检查,对结果分析、评估基础上,选取合适的颈动脉支架置入。结果:共筛查85例症状性颈动脉狭窄患者为颈动脉内膜剥脱术的高危患者,其中CTP异常75例。最终64例颈动脉狭窄患者存在易损斑块(含纤维帽破裂、斑块内出血),行闭环自膨支架治疗,余21例患者行开环自膨支架置入,术中所有患者使用保护伞装置。手术成功率97.6%,围手术期内出现1例脑叶出血、1例下肢静脉血栓,未发生缺血性脑血管病。结论:脑CTP联合颈动脉HR-MRI可充分评估颈动脉狭窄程度,并了解狭窄段管腔斑块成分,为颈动脉支架的选择及降低围手术期风险提供重要指导。     

弥散加权磁共振与磁共振血管成像在急性脑梗死诊断中的临床应用

目的　评价弥散加权磁共振成像 (Diffusion -weightedimaging ,DWI)及磁共振血管成像 (MagneticReso nanceAngiography ,MRA)在脑梗死早期的临床应用价值。 方法　对 3 0例急性脑梗死患者行DWI和MRA检查 ,并与CT、常规MRI的结果进行分析比较。结果　在超早期及早期急性脑梗死中DWI可显示CT及T2 WI不能显示的病灶 ,对于T2 WI能显示的病灶DWI能更清楚、更全面的显示该病灶 ,MRA能快速发现血管病变的部位和程度。结论　DWI与MRA对急性脑梗死的早期诊断十分敏感 ,联合检查可同时显示脑实质和脑血管情况 ,为早期溶栓治疗提供了切实可行的影像学资料     

颅内动脉狭窄的经颅多普勒超声与磁共振血管成像和(或)血管造影对比

目的 采用经颅多普勒超声研究颅内动脉狭窄的血流动力学改变,比较经颅多普勒超声与磁共振血管成像和(或)数字减影血管造影对脑动脉狭窄诊断的敏感性和特异性.方法分别对85例缺血性脑血管病患者进行经颅多普勒超声、磁共振血管成像和(或)数字减影血管造影检测,将经颅多普勒超声结果与磁共振血管成像和(或)数字减影血管造影进行对比分析.结果 以磁共振血管成像和(或)数字减影血管造影为标准,经颅多普勒超声诊断脑血管狭窄的灵敏度为88.2%,特异度为98.6%;以数字减影血管造影为标准,15例缺血性脑血管病患者经颅多普勒超声检测脑血管狭窄的灵敏度为90%,特异度为97.9%.结论 经颅多普勒可客观地反映脑血流动力学的改变.可作为脑血管狭窄预防性筛选方法之一.     

磁共振成像与磁共振血管造影在诊断颈动脉狭窄中的应用价值

目的探讨磁共振成像(MRI)与磁共振血管造影(MRA)在诊断颈动脉狭窄中的应用价值。方法对36例颈动脉狭窄患者行MRI及MRA,之后1周内行数字减影血管造影(DSA),从图像质量、血管狭窄程度及斑块成分三方面判断MRI联合MRA在诊断本病中的应用价值。结果经DSA证实共存在53支颈动脉狭窄,并对其中13支重度狭窄血管行手术治疗;以DSA结果为检验标准,MRI联合MRA诊断颈动脉狭窄的敏感度为92.98%,特异度为98.17%,准确性为92.45%,MRI联合MRA与DSA具有高度一致性,Kappa值为0.91;MRI及MRA图像质量优30例、良4例、差2例,优良比为94.44%;MRI联合MRA对斑块成分及软硬度的诊断与病理结果比较差异无统计学意义(P> 0.05)。结论 MRI对血管狭窄程度的判断准确客观,且能清晰显示脑出血及脑梗死等继发病变,MRA可有效减少信号噪音,直观显示血管整体情况。二者联合应用,对诊断斑块成分也具有一定临床应用价值。     

门静脉磁共振血管造影成像方法及临床应用研究

磁共振血管造影(magnetic resonance angiography,MRA)是一种非损伤性的血管成像检查方法[1]。20世纪80年代后期,此项技术已用于门静脉系统的检查,并将三维动态对比增强磁共振血管造影(three-dimensional dynamic contrast-enhanced MRA,3DDCE MRA)技术用于分流术或肝移植前后门静脉的评价。国内于上世纪90年代后期开展磁共振门静脉成像(MR portography,MRP)技术,目前其临床应用尚不普遍。现将MRP的成像方法、门脉解剖与变异及临床应用介绍如下。一、门静脉磁共振成像技术(一)时间飞逝法(time of flight,TOF)TOF的实质是伴有流动…     

颈部血管超声联合CT血管造影对脑梗死患者颈动脉斑块的诊断价值

目的 分析颈部血管超声联合CT血管造影（CTA）对脑梗死患者颈动脉斑块的诊断价值。方法 选择2020年1月至2021年8月北京市隆福医院收治的120例脑梗死患者,经数字减影血管造影检查证实,存在颈动脉斑块72例。所有患者行颈部血管超声和CTA检查,以数字减影血管造影为诊断颈动脉斑块的“金标准”,颈部血管超声、CTA及二者联合诊断脑梗死患者颈动脉斑块的灵敏度、特异度比较采用χ2检验。结果 颈部血管超声诊断颈动脉斑块的灵敏度、特异度、正确率分别为66.67%、91.67%、76.67%,CTA诊断颈动脉斑块的灵敏度、特异度、正确率分别为68.06%、89.58%、76.67%,二者联合诊断颈动脉斑块的灵敏度、特异度、正确率分别为88.89%、95.83%、91.67%。二者联合诊断颈动脉斑块的灵敏度分别高于颈部血管超声、CTA单独诊断（P<0.05）。结论 颈部血管超声联合CTA能在一定程度上降低脑梗死患者颈动脉斑块的误诊率,提高脑梗死患者颈动脉斑块的诊断正确率。     

颈内动脉颅外段严重狭窄和闭塞所致脑梗死病灶分布模式特征分析

目的 分析颈内动脉颅外段(extracranial internal carotid artery,EICA)严重狭窄和闭塞所致脑梗死的病灶分布模式,进而探讨两者导致脑梗死机制的差异,为个体化防治策略提供依据.方法 回顾性分析61例EICA粥样硬化性严重狭窄(狭窄程度70%～99%)或闭塞所致急性脑梗死患者的临床和影像...     

CT血管造影和磁共振血管成像在颅内动脉瘤诊治中的价值

目的 评价CT血管造影(CTA)、磁共振血管成像(MRA)在颅内动脉瘤诊断及治疗中的临床应用价值。方法 运用CTA、MRA和数字减影血管造影(DSA)影像学方法，对302例颅内动脉瘤患者及18例非动脉瘤自发性蛛网膜下腔出血患者进行了单独或联合检查。单独检查CTA、MRA或DSA的患者分别为203例、12例及88例，CTA DSA联合检查为11例，CTA MRA联合检查为4例，检测出的颅内动脉瘤均经手术证实；对18例非动脉瘤自发性蛛网膜下腔出血患者进行CTA DSA联合检查，并对CTA、MRA、DSA检查结果进行回顾性分析，结果 通过CTA、DSA检查单独确诊的动脉瘤分别为203个和88个，与术中结果相一致。仅行MRA检查的12例患者，其中10例与手术结果完全一致，1例术前MRA诊断为右侧大脑中动脉瘤，术中证实为右侧颈内后交通动脉瘤，1例术前MRA正常，术中证实为巨大前交通动脉瘤。10例先行CTA检查，怀疑为动脉瘤，后经DSA检查确诊，并经手术证实，1例DSA检查正常，后行CTA检查确诊并经手术证实。4例行MRA检查，怀疑为动脉瘤，后行CTA检查确诊，并经手术证实。另有18例自发性蛛网膜下腔出血患者，行CTA DSA检查均未见动脉瘤及其他脑血管病征象。CTA、MRA和DSA对颅内动脉瘤的检出率(与手术相比较)分别为100％、87．5％、98．9％。结论 CTA可以作为检查颅内动脉瘤的首选方法，MRA可以用于诊断颅内动脉瘤，但其检出率低于CTA、DSA。     

磁共振血管造影诊断脑梗死患者颅内动脉硬化程度的探讨

目的探讨脑梗死（CI）患者采取磁共振血管造影（MRA）诊断颅内动脉硬化程度的效果。方法将我院2012年1月至2014年1月接诊的CI患者112例作为研究对象,皆采取MRA进行诊断,诊断后的CI患者根据Adams分类法分为3组,其中大梗死42例,作为A组;小梗死39例,作为B组;腔隙性梗死31例,作为C组。对比分析3组诊断结果,包括动脉梗死程度与血管改变情况。结果 3组动脉硬化程度比较显示,动脉硬化程度差异均有统计学意义,其中C组重度率明显低于B组与A组,同时B组重度率也明显低于A组（P均〈0.05）;3组血管改变情况也有显著性差异,其中A组动脉闭塞率明显高于B组与C组,而且B组血管闭塞率也明显高于C组（P均〈0.05）。结论 MRA诊断CI患者,能通过动脉闭塞情况来反映出患者动脉硬化程度,有很高的临床诊断价值。     

彩色多普勒超声和数字减影血管造影检测颅外颈动脉狭窄的临床对比研究

目的 评价血管超声检查在颅外颈动脉粥样硬化斑块并狭窄检测中与全脑数字减影血管造影（digital subtraction angiography,DSA）检查的一致性.方法 对80例脑梗死或者有慢性脑供血不足包括短暂性脑缺血发作和高度怀疑有血管狭窄的患者颈部105条动脉颅外段同时进行血管超声及DSA检查,以DSA检查结果为金标准,分析血管超声检查对血管狭窄程度为轻度、中度、重度及闭塞的颈部动脉病变检出的敏感性、特异性及准确性.并分别对超声强回声组和非强回声组,有症状组和无症状组的敏感性、特异性及准确性进行比较.结果 血管超声检查对血管狭窄程度为轻、中度、重度及闭塞的颈部动脉病变检出的敏感性分别79.4％、47.2％、57.1％、92.9％,特异性分别为71.8％、85.5％、94.0％、98.9％,准确性分别为73％、72.4％、86.7％、98.1％.强回声组血管超声的一致性较非强回声组的好,症状性动脉狭窄组血管超声的一致性较无症状性动脉狭窄组好,差异有统计学意义（P＜0.05）.结论 血管超声技术对颈部动脉病变,特别是在严重狭窄或闭塞性病变的检测中有较高的准确性,可以应用于临床上动脉狭窄的筛查.     

血管超声与脑血管造影诊断颈动脉狭窄的对比研究

目的评价血管超声技术与脑血管造影诊断颈动脉狭窄的临床应用价值。方法回顾性分析130例缺血性脑血管病患者的颈部血管超声和数字减影血管造影术(DSA)检查结果 ,评价血管超声诊断颈动脉狭窄的价值。颈动脉狭窄率及狭窄程度分级按北美症状性颈动脉内膜剥脱术进行计算。结果 130例患者中,260支颈动脉行2种检查,DSA检查显示63例患者颈动脉狭窄,狭窄血管71支,血管超声检查显示56例患者颈动脉狭窄,狭窄血管70支。以DSA检查结果为金标准,血管超声诊断颈内动脉狭窄的敏感性、特异性和准确性分别为71.88%、94.47%和88.97%。血管超声诊断中、重度颈内动脉狭窄的敏感性、特异性和准确性分别为55.56%、99.20%和97.69%。以DSA诊断结果为标准,血管超声诊断颈总动脉狭窄的敏感性为100%,特异性为97.6%,准确性为97.69%。结论血管超声诊断颈动脉狭窄的敏感性较高,诊断颈总动脉狭窄的敏感性高于颈内动脉,可用于颈动脉狭窄的筛选和随访,但对于血管重度狭窄和闭塞诊断仍欠佳,尚不能取代DSA检查。     

Noninvasive investigation for renal artery stenosis: contrast-enhanced magnetic resonance angiography and color Doppler sonography as compared to digital subtraction angiography.

INTRODUCTION: The question about the most appropriate non-invasive method for detecting a renal artery stenosis (RAS) when comparing contrast enhanced magnetic resonance angiography (MRA) and color Doppler sonography (CDS) is still under discussion. Therefore we conducted a prospective study in order to evaluate both methods as compared to digital subtraction angiography (DSA). PATIENTS/METHODS: Thirtysix consecutive patients (53,9 +/- 13,7 years) with suspected RAS were investigated. MRA was performed using gadolinium for contrast enhancement. CDS was performed using a 2.5 and 3,5 MHz transducer. A peak systolic velocity (Vmax) >200 cm/sec within renal arteries and/or a side to side difference of the resistive index (RI) of >0,05 were used to discriminate stenosis. A diameter reduction of > or = 60% by DSA was considered a stenosis relevant to the patient. RESULTS: Sixty-eight main renal arteries and 9 accessory vessels were detected by DSA. Twenty main and 3 accessory arteries were found to be stenosed > or = 60%, while 4 main and 1 accessory artery presented with occlusion. MRA detected 70 renal vessels (65 main and 5 accessory arteries). Twenty-one stenosed arteries and 4 occluded vessels were correctly diagnosed by MRA. With CDS 68 renal vessels (62 main and 6 accessory arteries) could be visual- ized out of which 21 stenoses were diagnosed because of increased Vmax and 6 stenoses were detected because of a side to side difference of RI. For main renal arteries sensitivities and specificities were 96% and 86% for MRA and 96% and 89% for CDS. CONCLUSIONS: MRA and CDS are both comparable methods for detection of a renal artery stenosis > or = 60%. Despite several limitations, CDS can at the moment still be favored as a screening method.     

对比增强磁共振血管造影对椎动脉开口狭窄的诊断价值

目的评价对比增强MR血管造影（CE-MRA）在诊断椎动脉开口狭窄中的价值。方法对108例（216支椎动脉）有临床缺血症状的患者行CE-MRA检查,CE-MRA检查后1周内行DSA检查。以DSA为标准,评价CE-MRA诊断椎动脉开口狭窄的准确性。结果①216支血管中,CE-MRA与DSA检查结果一致的有188支（87.0%）。有24支（11.1%）CE-MRA判定狭窄程度高于DSA。有4支（1.9%）CE-MRA判定狭窄程度低于DSA。两种检查的Spearman秩相关系数rs=0.785,P〈0.001。②CE-MRA诊断为正常的有168支血管,DSA诊断有2支为轻度狭窄（狭窄率≤49%）,2支为中重度狭窄（狭窄率50%～99%）。CE-MRA诊断为轻度狭窄的8支血管中,DSA显示有6支为正常血管;在CE-MRA诊断为中重度狭窄的30支血管中,10支经DSA证实为轻度狭窄,8支为无狭窄。CE-MRA提示闭塞的10支血管,均与DSA显示的一致。③以DSA为金标准,CE-MRA检查的敏感性为89.5%（34/38）,特异性为92.1%（164/178）,假阳性率为7.9%（14/178）,假阴性率为10.5%（4/38）,阳性预测值为70.8%（34/48）,阴性预测值为97.6%（164/168）,诊断一致率为91.7%（198/216）,Youden指数=0.816。结论 CE-MRA诊断椎动脉开口狭窄的敏感性较高,可以作为一种筛查手段;但若准确评价椎动脉狭窄的程度,则需要联合多种检查手段。     

Doppler frequency spectrum analysis and digital subtraction angiography in carotid artery disease

The aim of the study was to evaluate the diagnostic accuracy of frequency spectrum analysis complementary to direct Doppler sonography in comparison to conventional biplane arteriography and transvenous digital subtraction angiography in internal carotid artery stenosis. In a group consisting of 229 carotid arteries visualized by conventional biplane arteriography, Doppler frequency spectrum analysis had a specificity of 97% and concerning all stenoses and occlusions, a sensitivity of 89%. In a second group consisting of 198 carotid arteries imaged by transvenous digital subtraction angiography, Doppler sonographic examination had a specificity of 65% only, and concerning all categories of stenoses and occlusions a sensitivity of 85%. These differences concerning specificity are not interpreted as false positive diagnoses in Doppler spectrum analysis but are considered to be due to false negative findings of digital subtraction angiography in stenoses of less than 50% vessel diameter reduction.     

Diagnosis of renal artery stenosis with magnetic resonance angiography and stenosis quantification

Atherosclerotic disease is the most common pathologic condition of renal artery stenosis, which typically compromises the ostium or the proximal 1-2 cm of renal arteries and is also usually present in the abdominal aorta. Fibromuscular dysplasia is the second most common cause of renal artery stenosis (RAS) which usually involves the distal two-third of the main renal artery with bed-like stenosis alternating with small fusiform or saccular aneurysms. Magnetic Resonance Angiography (MRA) was initially performed without contrast media injection using two- or three-dimensional Time-of-Flight (TOF) or Phase-Contrast (PC) techniques. Sensitivity and specificity of non-enhanced MRA in detection of proximal RAS are comprised between 53%-100% and 47%-97% respectively (table I). Main limitations of non-enhanced MRA are the long acquisition time, i.e. 5-8 min, the short field of view with lack of kidney visualization and major artifacts. Recent improvements allowed a three-dimensional acquisition during a single breath-hold (18-23 sec), associated to a bolus injection of a gadolinium chelate demonstrating a lack of nephrotoxicity. 3D gadolinium-enhanced ultrafast gradient-echo MRA techniques (3D enhanced-MRA) requires a precise technique. Firstly, kidney localization and morphologic imaging is performed before a 3D MRA data acquisition without injection (fig. 1). Secondly two successive 3D MRA sequences are performed synchronized with the gadolinium chelate bolus injection: the first acquisition corresponds to the arterial enhancement (fig. 4) and the second one to the venous enhancement. At last, a three-dimensional phase contrast could also be performed. After data acquisition, image post-processing is performed including image subtraction, maximum intensity projection (MIP) and reformation images of each renal artery, the abdominal aorta and its main branches (fig. 2, 3). The normal findings, pitfalls and anatomic variation are explained in detail. Particularly, when 3D enhanced MR angiography shows a normal artery, it is considered to be normal. It is also important to be aware of the existence of accessory or aberrant renal arteries that are well diagnosed by 3D enhanced MRA in 75% to 100% of the cases (fig. 2). 3D enhanced-MR angiography present several advantages in comparison to nonenhanced MRA: 1) a great field-of-view (30-36 cm) could be used allowing visualization of the abdominal aorta as well as its main branches; 2) the fast acquisition time allows an arterial imaging followed by a venous enhancement; 3) the kidneys are analyzed: kidney length, cortical thickness, corticomedullary differentiation and renal enhancement are well evaluated; 4) an accurate sensitivity and specificity in detection of proximal RAS comprised between 88%-100% and 71%-100% respectively (table II). Because a severe RAS (i.e. degree of stenosis > 50%) may cause renal ischemia leading to a blood pressure elevation that is often difficult to control with medical therapy, imaging has to assess the severity of RAS. MRA assessment of hemodynamic significance of RAS can be further refined by considering additional factors (fig. 4): arterial stop of signal, post stenotic dilatation, delayed renal enhancement and functional changes in the renal parenchyma (i.e. reduced kidney length and parenchymal thickness, loss of corticomedullary differentiation) (fig. 1). Precise evaluation of degree of stenosis requires the development of dedicated software such as MARACAS (MAgnetic Resonance Angiography Computer ASsisted analysis) software (fig. 5). In conclusions, 3D enhanced MRA allows an accurate diagnosis of proximal RAS, mainly due to atherosclerosis, without the risks associated with nephrotoxic contrast agents, ionizing radiation or arterial catheterization.     

Quantitative assessment of carotid stenosis: comparison between Doppler ultrasound, spiral computed tomography angiography, magnetic resonance angiography and digital angiography

BACKGROUND: The North American Symptomatic Carotid Endarterectomy Trial has confirmed the benefit of carotid endarterectomy in comparison to medical treatment in stroke prevention in symptomatic patients having a carotid stenosis of 70% or more. The Asymptomatic Carotid Atherosclerosis Study has concluded that the benefit of surgical treatment remains significant in asymptomatic patients with 60% (or more) stenosis of the ipsilateral internal carotid artery, when mortality rate remains inferior to 3%. In these two trials, angiography has been used to quantify the stenosis. Though this test is carrying some neurological and renal risks, replacing the angiography stenosis grading for a non or less invasive test, seems to be permissible. METHODS: In our retroprospective study, the assessments of the carotid stenosis by several non-invasive tests findings were compared to the angiography results. Nineteen carotid arteries of fifteen patients, both symptomatic and asymptomatic, having a carotid stenosis at least 60% or more and being detected by the Doppler ultrasound were explored either by magnetic resonance angiography (MRA), spiral computed tomography angiography (SCTA) and angiography. RESULTS: The ultrasonography and angiography findings were well correlated (r=0,88; p<0.002) according to the Spearman test. The assessments of the MRA were better correlated to the angiography than to the SCTA (respectively r=0.91, p<0.0001 and r=0,68, p<0.001). Using both ultrasonography and MRA as a confirmatory test, the rate of injustified carotid endarterectomy was 25%. And this rate rose up to 33% when the ultrasonography was used with the SCTA. It is noteworthy that negative predictive value of ARM was 100%. To reduce the mortality rate, several surgical teams managed the carotid stenosis without angiography. CONCLUSION: MRA could replace angiography, on condition that the rate of unjustified carotid endarterectomy lowers and becomes acceptable. Far reaching complementary studies are necessary to confirm the fiability of those non-invasive tests. In order to raise the benefit to carotid endarterectomy, the research studies should turn to the predictive score determination of a surgical international risk and towards the "High benefit" patients groups after endarterectomy.     

Comparison of auscultation, continuous wave Doppler imaging, intravenous digital subtraction angiography and conventional angiography in diagnosis of carotid artery disease

The reliability of auscultation, continuous wave (CW) Doppler imaging, and intravenous digital subtraction angiography (IV DSA) in the assessment of carotid artery disease has been evaluated in comparison with conventional angiography in 30 patients. With auscultation, specificity and sensitivity for internal carotid artery (ICA) stenosis of 50% or more were 81% and 67% respectively. CW Doppler imaging detected ICA stenosis of 50% or more with a sensitivity of 83% and a specificity of 92% and ICA occlusion with a sensitivity of 60%. The specificity of IV DSA was 95% and the sensitivity for ICA stenosis of 50% or more and ICA occlusion were 75% and 100% respectively. Combining CW Doppler and IV DSA findings raised sensitivity for ICA stenosis of 50% or more and ICA occlusion to 89% and 100% respectively and specificity to 95%. The combination of CW Doppler and IV DSA is a safe and accurate test battery in the detection and categorization of carotid disease.     

Analysis of digital subtraction angiography for estimating flow reserve in critical coronary artery stenosis

To assess the accuracy of digital subtraction angiography in evaluating coronary flow reserve in cases with critical coronary artery stenosis, time-density curves were obtained from digital subtraction coronary angiograms in the myocardial region of interest. Time to peak contrast (TPC) and time constant of the washout exponential curve (T) were measured in 14 patients with stable effort angina pectoris and critical one vessel lesion before and after percutaneous transluminal coronary angioplasty (PTCA). All patients had normal left ventricular ejection fraction (59 +/- 7%) and 201T1 myocardial images at rest. The values of TPC and T were significantly shortened from 5.4 +/- 1.3 to 4.5 +/- 1.0 sec (p less than 0.02) and from 10.9 +/- 3.8 to 5.3 +/- 1.3 sec (p less than 0.001) after PTCA, respectively. However, in 9 patients TPC values were approximately the same before and after PTCA. In five experimental dogs with critical circumflex coronary artery stenosis, coronary flow (CF; Doppler flowmeter) and systolic thickening of the posterior wall (by sonomicrometry) at rest did not differ from those of the controls. However, contrast media-induced reactive hyperemia was markedly attenuated, accompanied by a significant increase in T (7.7 +/- 4.5 vs 15.8 +/- 10.9 sec, p less than 0.01) and totally unchanged TPC (both 6.8 sec). With simultaneous tracings of CF and time-density curves, TPC and washout phases corresponded with contrast-induced transient CF reduction and hyperemic phases, respectively. We concluded that T may be more sensitive for estimating CF maintained nearly normal, e.g., in patients with stable effort angina pectoris having normal left ventricular wall motion at rest.