Uptake of F-18 FDG and ultrasound analysis of carotid plaque

Objectives

To elucidate the relation between the echolucent plaque on carotid ultrasound and acute inflammation on F-18 FDG carotid PET/CT.

Methods

Thirty nine patients (M:F ratio = 23:16, mean age = 63 ± 11 years) that underwent coronary angiography and carotid ultrasound were divided into three groups—echolucent plaque (n = 22), calcified (n = 10), and no plaque(n = 7). All the patients underwent F-18 FDG carotid PET/CT. The mean standardized uptake values (SUV), namely target to background ratio (TBR) on 180 minutes delayed F-18 FDG carotid PET/CT images were compared with levels of serum inflammatory markers and lipid profiles, and in terms of the presence of carotid plaque on carotid US.

Results

180 minutes TBR of carotid arterial wall at echolucent plaque, calcified plaque, and no plaque were 1.40 ± 0.05, 1.23 ± 0.03, 1.17 ± 0.03 in both carotid artery. TBR of carotid arterial walls for echolucent plaque were significantly larger than TBR for calcified, and no plaque respectively at the both side of carotid artery (P < .05). Serum HDL levels were found to be inversely correlated with F-18 FDG uptake at both carotid arteries (r = ?0.43, P = .005) on 180 minutes delayed phase images. Also serum hs-CRP levels were found to be correlated with F-18 FDG TBR values of right carotid arteries (r = 0.41, P = .04).

Conclusions

Our results show that F-18 FDG carotid PET/CT can depict metabolically active atherosclerotic plaques, and suggest that F-18 FDG carotid PET/CT can be used as a noninvasive imaging modality for functional evaluation of atherosclerosis.     

Imaging Atherosclerosis in the Carotid Arteries with F-18-Fluoro-2-deoxy-D-glucose Positron Emission Tomography: Effect of Imaging Time after Injection on Quantitative Measurement

Purpose

To compare F-18-fluoro-2-deoxy-D-glucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) imaging at two different circulation times after injection of F-18 FDG in order to measure atherosclerosis in carotid arteries.

Methods

We assessed 12 patients with recent symptomatic plaques in the carotid arteries. F-18 FDG PET/CT carotid plaque imaging was performed for 20 min at 2 h after F-18 FDG injection in five patients and at 3 h in seven patients. We measured vessel wall uptake using the maximal standardized uptake value (SUV), and the mean and maximal blood target-to-background ratios (TBR) of the symptomatic carotid arteries. Blood pool activity (BPA) was measured as the mean SUV of the superior vena cava (SVC) and jugular vein of these 12 patients, and in 14 age- and gender-matched patients who underwent whole-body F-18 FDG PET/CT examinations 1 h after injection.

Results

F-18 FDG PET/CT revealed visible F-18 FDG uptake in all patients with symptomatic carotid plaques. Maximal SUV did not differ between groups evaluated at 2 h and 3 h (2.62 ± 0.45 vs 3.00 ± 0.85, p = 0.335). However, mean (2.04 ± 0.22 vs 3.54 ± 0.62, p < 0.05) and maximal (1.65 ± 0.15 vs 2.70 ± 0.42, p < 0.05) TBR values that were normalized to BPA in the SVC differ significantly.

Conclusions

Symptomatic carotid plaques are visualized for a relatively short period of imaging time on ≥1-h PET/CT images. Quantitative parameters of atherosclerotic carotid arteries are preserved or even increased over time, whereas those of blood pools are decreased.     

Value of F-18 FDG hybrid camera PET and MRI in early takayasu aortitis

Takayasu aortitis (TA) is a chronic inflammatory and fibrotic vasculitis of large- and medium-sized arteries. Early stages of the disease show a panarteritis and inflammatory wall thickening of the aorta and its branches, whereas advanced (fibrotic) stages comprise stenosis, aneurismatic transformation and occlusion. Magnetic resonance imaging visualises early-stage disease with high accuracy and is considered to be the method of choice in the diagnosis of TA. The aim of this article is the detailed comparison of FDG-PET performed with a hybrid camera and MR imaging in five patients with early TA. Five patients (median age 60 years) were enrolled during an ongoing prospective study on [18F]2'-deoxy-2-fluoro-D-glucose (FDG) hybrid camera PET in patients with fever of unknown origin (FUO). These patients underwent MR imaging after establishing the diagnosis of TA. Abnormal FDG uptake in the wall of the aorta was noted in all patients. The bracheocephalic artery and the common carotid arteries were visualized in 3 cases. Increased uptake of the subclavian artery was found in 3 patients and in 4 patients pathological uptake was noted in the ilio-femoral vessels. Of 34 vascular regions studied, 26 (76%) showed elevated FDG uptake. On transversal MR images vessel wall thickening and contrast enhancement of the thoracic aorta was found in 4 patients (ascending aorta/aortic arch: n=2; descending aorta: n=3; abdominal aorta: n=1). Additionally, vessel wall pathologies of the subclavian and the common carotid arteries could be shown in 1 patient and in another patient in the ilio-femoral arteries. No abnormalities were found using contrast-enhanced MR angiography. Of 28 vascular regions studied, 9 (32%) showed vasculitis on MRI. The FDG-PET is a suitable whole-body screening method in the primary diagnosis of early TA, especially in those cases with early disease that present with uncharacteristic symptoms such as FUO. Both MRI and MRA remain indispensable in the exact determination of the pathomorphological changes and in the documentation of complications such as stenosis, aneurismatic transformation and occlusion. Electronic Publication     

Time-to-time correlation of high-risk atherosclerotic lesions identified with [18F]-FDG-PET/CT

Objective  It has been shown that [¹⁸F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) can identify macrophage-rich high-risk atherosclerotic plaques in animal models as well as in patients with atherosclerotic plaques in the carotid arteries. The development of inflamed macrophage-rich plaques over time is not well known. This study was performed to determine the variability of such FDG-accumulating plaques between consecutive PET/CT examinations. Methods  Twenty-eight patients who underwent two whole-body FDG-PET/CT examinations within 7 months for malignant diseases were re-evaluated for atherosclerotic lesions in major arterial segments. The plaques were identified as active, inactive, or mixed depending on their appearance on PET and CT. Every identified plaque was compared with that of the other examination to evaluate the time-to-time correlation. Results  The time-to-time correlation was close to 100% for calcified inactive plaques and about 50% for FDG-accumulating active plaques, with a high consistency between all examined arterial segments in this material. Conclusions  A large proportion of FDG-accumulating plaques can be identified on consecutive FDG-PET/CT examinations within 7 months.     

Non-specific binding of [18F]FDG to calcifications in atherosclerotic plaques: experimental study of mouse and human arteries

Purpose [¹⁸F]FDG has been used as an inflammation marker and shown to accumulate in inflammatory atherosclerotic plaques. The aim of this study was to investigate the uptake and location of [¹⁸F]FDG in atherosclerotic plaque compartments. Methods The biodistribution of intravenously administered [¹⁸F]FDG was analysed in atherosclerotic LDLR/ApoB48 mice (n=11) and control mice (n=9). Digital autoradiography was used to detect the ex vivo distribution in frozen aortic sections. In vitro binding of [¹⁸F]FDG in human atherosclerotic arteries was also examined. Results The uptake of [¹⁸F]FDG was significantly higher in the aorta of atherosclerotic mice as compared with the control mice. Autoradiography of excised arteries showed higher [¹⁸F]FDG uptake in the plaques than in the healthy vessel wall (mean ratio ±SD 2.7±1.1). The uptake of [¹⁸F]FDG in the necrotic, calcified sites of the advanced atherosclerotic lesions was 6.2±3.2 times higher than that in the healthy vessel wall. The in vitro studies of human arterial sections showed marked binding of [¹⁸F]FDG to the calcifications but not to other structures of the artery wall. Conclusion In agreement with previous studies, we observed [¹⁸F]FDG uptake in atherosclerotic plaques. However, prominent non-specific binding to calcified structures was found. This finding warrants further studies to clarify the significance of this non-specific binding in human plaques in vivo.     

Direct quantitative in vivo comparison of calcified atherosclerotic plaque on vascular MRI and CT by multimodality image registration

PURPOSE: To investigate direct volumetric in vivo correspondence of calcified atherosclerotic plaque lesions in MRI and CT images of the thoracic aorta by multimodality image registration and fusion. MATERIALS AND METHODS: Twelve CT (11 noncontrast and one contrast) and MRI (TruFISP, contrast T1-weighted volumetric interpolated breath-hold examination (VIBE)) data sets were co-registered by approximate segmentation of the aorta and subsequent automatic co-registration by maximization of mutual information (MI). We quantitatively assessed 22 co-registered calcified plaque lesions on CT and MRI. RESULTS: The three-dimensional registration consistency and accuracy were 1.74 +/- 1.3 mm, and 2.42 +/- 1.65 mm, respectively. The ratio of CT/MRI calcified plaque volume decreased asymptotically with MRI volume, and correlated with average CT lesion density (r = 0.72) for small lesions (<25 mm(3)). The average calcified plaque volume, circumferential extent, and maximal radial width by MRI were significantly smaller compared to CT (35%, 68%, and 53%, respectively; P < 0.05). CONCLUSION: Software co-registration allowed precise, direct, and voxel-based comparison of calcified atherosclerotic plaque lesions imaged by MRI and CT. In comparison with co-registered MRI, overestimation of calcified plaque in aortic CT due to "blooming" correlates with the average lesion density for small plaques, and is greater for small plaques.     

Atherosclerotic plaque features and distribution in bilateral carotid arteries of asymptomatic elderly population: A 3D multicontrast MR vessel wall imaging study

PurposeThis study sought to investigate the characteristics of morphology, compositions and distribution of carotid atherosclerotic plaques in asymptomatic elderly population using three dimensional (3D) multicontrast magnetic resonance vessel wall imaging.Materials and methods146 asymptomatic elderly subjects (≥ 60 years) were recruited and underwent 3D multicontrast MR vessel wall imaging for bilateral carotid arteries on a 3.0T MR scanner. The presence of carotid atherosclerotic plaque was determined and the stenosis was measured. The characteristics of plaque morphology and compositions were evaluated and compared among distal internal carotid artery (D-ICA), proximal-ICA (P-ICA), carotid bulb (CB), distal common carotid artery (D-CCA) and proximal-CCA (P-CCA).ResultsOf all recruited 140 subjects (72.1 ± 5.7 years, 63 males), 87 (62.1%) had carotid plaques, 17 (12.1%) had high-risk plaques and 51 (36.4%) had multiple plaques. Of all 280 carotid arteries, only 16 (5.7%) had luminal stenosis (21.1% ± 11.4%). Among carotid arteries without luminal stenosis, the prevalence of plaque and high-risk plaques was 43.2% and 8.3%, respectively. Carotid plaques were mostly found in CB segment (33.9%), followed by P-ICA (13.6%), P-CCA (11.1%), D-CCA (4.6%) and D-ICA (3.6%). Age was independently associated with presence of multiple carotid plaques (odds ratio, 1.835; 95% confidence interval, 1.196–2.815; P = 0.005).ConclusionCarotid artery atherosclerotic plaques are prevalent and a substantial number of high-risk plaques can be found in the asymptomatic elderly subjects. Longitudinal studies are warranted to investigate the risk of having ischemic stroke for asymptomatic elderly individuals with carotid artery high risk plaques.     

Emerging role of FDG-PET/CT in assessing atherosclerosis in large arteries

Atherosclerosis is a dynamic inflammatory disorder. The biological composition and inflammatory state of an atherosclerotic plaque, rather than the degree of stenosis or its size are the major determinants of acute clinical events. A noninvasive technique to detect vulnerable atherosclerotic plaque is critically needed. FDG-PET/CT, a combined functional and structural whole-body imaging modality, holds great potential for this purpose. FDG uptake in large arteries has been frequently observed and is associated with cardiovascular risk factors. FDG accumulates in plaque macrophages and uptake is correlated with macrophage density. It is known that vascular FDG uptake and calcification do not overlap significantly and changes of FDG uptake are common, suggesting that FDG uptake may represent a dynamic inflammatory process. It has been reported that vascular FDG uptake can be attenuated by simvastatin in patients, and by the antiinflammatory drug probucol in rabbits. Vascular FDG uptake has been linked to cardiovascular events in some preliminary studies. Data from basic sciences, and animal and clinical studies support the emerging role of FDG-PET/CT in assessing atherosclerosis in large arteries in humans.     

Delayed 18F-fluorodeoxyglucose PET/CT imaging improves quantitation of atherosclerotic plaque inflammation: Results from the CAMONA study

Background

This study aimed to determine if delayed ¹⁸F-fluorodeoxyglucose (¹⁸FDG) PET/CT imaging improves quantitation of atherosclerotic plaque inflammation. Blood-pool activity can disturb the arterial ¹⁸FDG signal. With time, blood-pool activity declines. Therefore, delayed imaging can potentially improve quantitation of vascular inflammation.

Methods and Results

40 subjects were prospectively assessed by dual-time-point PET/CT imaging at approximately 90 and 180 minutes after ¹⁸FDG administration. For both time-points, global uptake of ¹⁸FDG was determined in the carotid arteries and thoracic aorta by calculating the blood-pool corrected maximum standardized uptake value (cSUV_MAX). A target-to-background ratio (TBR) was calculated to determine the contrast resolution at 90 and 180 minutes. Furthermore, we assessed whether the acquisition time-point affected the relation between cSUV_MAX and the estimated 10-year risk for fatal cardiovascular disease (SCORE %). A significant increase in carotid cSUV_MAX (23%, P < .0001), carotid TBR (20%, P < .0001), aortic cSUV_MAX (14%, P < .0001), and aortic TBR (20%, P < .0001) was observed with time. At 90 minutes, cSUV_MAX did not relate to SCORE %, whereas at 180 minutes significant positive relations were observed between SCORE % and carotid (τ = 0.25, P = .045) and aortic (τ = 0.33, P = .008) cSUV_MAX.

Conclusions

Delayed ¹⁸FDG PET/CT imaging at 180 minutes improves quantitation of atherosclerotic plaque inflammation over imaging at 90 minutes. Therefore, the optimal acquisition time-point to assess atherosclerotic plaque inflammation lies beyond the advocated time-point of 90 minutes after ¹⁸FDG administration.     

Behcet病的胸部CT表现

目的 分析Behcet病的胸部CT表现,评价其在诊断中的作用.方法 回顾性分析13例有胸部病变的Behcet病的临床病历记录及CT影像资料,所有患者的诊断根据Behcet病国际研究小组诊断标准.结果 13例中3例表现为胸膜下斑片状实变影,3例为双肺弥漫磨玻璃密度影,1例左下叶塌陷伴有右下叶结节影,1例胸膜下孤立结节影,2例双侧少量胸水,2例伴有纵隔淋巴结增大,1例在治疗过程中CT表现为双肺弥漫性粟粒状结节.13例中8例有胸部血管病变,2例为上腔静脉栓塞;1例左锁骨下动脉瘤;1例左下肺动脉瘤伴附壁血栓;1例双下肺动脉瘤及左侧基底动脉瘤;3例右下肺动脉栓塞,其中2例伴有左肺动脉闭塞,1例伴有左侧基底动脉分支动脉瘤.结论 Behcet病的胸部CT表现多种多样,增强CT可显示胸部血管病变如上腔静脉或肺动脉栓塞、肺动脉瘤等,有助于对病变的评价.     

High-resolution imaging of human atherosclerotic carotid plaques with micro<Superscript>18</Superscript>F-FDG PET scanning exploring plaque vulnerability

Aims  

FDG-PET can be used to identify vulnerable plaques in atherosclerotic disease. Clinical FDG-PET camera systems are restricted in terms of resolution for the visualization of detailed inflammation patterns in smaller vascular structures. The aim of the study is to evaluate the possible added value of a high-resolution microPET system in excised carotid plaques using FDG.     

Thoracic involvement in Behçet's vasculitis

Thoracic involvement of Behcet's disease is unusual but serious. It is related to the well known vascular tropism of the disease. It may involve the superior vena cava, pulmonary arteries, aorta and subclavian vessels. Imaging is useful for diagnosis and assess the degree of thoracic involvement. CT scan and MRI are obviously more accurate than angiography. The spectrum of thoracic manifestations of the disease is presented based on a review of 22 cases.     

A study of plaque vascularization and inflammation using quantitative contrast-enhanced US and PET/CT

Background

Contrast-enhanced ultrasound (CEUS) is an in vivo methodology to quantify carotid plaque vascularization. Increased metabolism in plaques, measured as FDG uptake in PET/CT examination, has been associated with markers of inflammation in histological samples. In this study, we tested the association between FDG uptake and vascularization measured by CEUS to assess whether CEUS can be used as an in vivo marker of plaque vulnerability.

Methods

After informed consent, subjects aged >60 years with carotid plaque height exceeding 2.5 mm were recruited. CEUS was performed and analyzed using earlier described protocol and software, Contrast Quantification Program, which calculates the fraction of the plaque being contrast positive (CQP value). PET/CT examination was performed within 3 months of CEUS (median time 7 days). PET/CT images were acquired 90 min after FDG injection (2.7 MBq/kg). FDG uptake was measured as tissue background index (TBI), calculated using Spearman's rho as mean standard uptake value (SUV) of the plaque divided by mean SUV in the jugular vein (mean of 7 measuring points). Local ethics committee approved the study.

Results

We recruited 13 subjects (5 women) with a mean age of 71 years, 6 had a history of stroke or TIA, 1 had a history of ipsilateral stroke. CQP values showed a significant, positive correlation with TBI of carotid plaques, r = 0.67, p < 0.02.

Conclusions

Plaque vascularization measured by CEUS correlates positively with FDG uptake measured by PET/CT in humans. This indicates an association between vascularization and inflammation and/or hypoxia, supporting the use of CEUS as a non-invasive method to detect plaque vulnerability.     

Atherosclerotic plaque volume and composition in symptomatic carotid arteries assessed with multidetector CT angiography; relationship with severity of stenosis and cardiovascular risk factors

The purpose of this study was to examine the volume and the composition of atherosclerotic plaque in symptomatic carotid arteries and to investigate the relationship between these plaque features and the severity of stenosis and the presence of cardiovascular risk factors. One hundred patients with cerebrovascular symptoms underwent CT angiography. We measured plaque volume (PV) and the relative contribution of plaque components (calcifications, fibrous tissue, and lipid) in the symptomatic artery. The contribution of different components was measured as the number of voxels within defined ranges of HU values (calcification >130 HU, fibrous tissue 60–130 HU, lipid core <60 HU). Fifty-seven patients had atherosclerotic plaque in the symptomatic carotid artery. The severity of stenosis and PV were moderately correlated. Age and smoking were independently related to PV. Patients with hypercholesterolemia had significantly less lipid and more calcium in their plaques than patients without hypercholesterolemia. Other cardiovascular risk factors were not significantly related to PV or plaque composition. Luminal stenosis of the carotid artery partly reflects the amount of atherosclerotic carotid disease. Plaque volume and plaque composition are associated with cardiovascular risk factors.     

64层螺旋CT血管造影及超声造影评价颈动脉斑块

目的 探讨64层螺旋CT血管造影(MSCTA)及超声造影(CEUS)在评价颈动脉斑块中的价值.资料与方法 37例颈动脉斑块狭窄患者于1周内分别行MSCTA及CEUS检查,分析颈动脉内中膜厚度/颈动脉管壁厚度、狭窄比率、斑块表面形态,采用CEUS观察斑块内新生血管情况,将斑块分为内中膜增厚型、稳定型及易损斑块.结果 37例共51处病变血管,MSCTA:颈动脉管壁增厚9处;斑块42处,其中稳定斑块27处,易损斑块15处.CEUS:颈动脉内中膜增厚11处;斑块40处,其中稳定斑块23处,易损斑块17处.MSCTA:轻度狭窄21处,中度狭窄15处,重度狭窄12处,闭塞3处;CEUS:轻度狭窄20处,中度狭窄16处,重度狭窄13处,闭塞2处.MSCTA与CEUS对颈动脉斑块狭窄(Kappa=0.71,P＜ 0.05)及斑块稳定性(Kappa=0.69,P＜0.05)评价一致性较好.结论 MSCTA与CEUS对评价颈动脉斑块狭窄及斑块稳定性具有较好的一致性.     

Spectral CT of carotid atherosclerotic plaque: comparison with histology

Objective

To distinguish components of vulnerable atherosclerotic plaque by imaging their energy response using spectral CT and comparing images with histology.

Methods

After spectroscopic calibration using phantoms of plaque surrogates, excised human carotid atherosclerotic plaques were imaged using MARS CT using a photon-processing detector with a silicon sensor layer and microfocus X-ray tube (50?kVp, 0.5?mA) at 38-μm voxel size. The plaques were imaged, sectioned and re-imaged using four threshold energies: 10, 16, 22 and 28?keV; then sequentially stained with modified Von Kossa, Perl’s Prussian blue and Oil-Red O, and photographed. Relative Hounsfield units across the energies were entered into a linear algebraic material decomposition model to identify the unknown plaque components.

Results

Lipid, calcium, iron and water-like components of plaque have distinguishable energy responses to X-ray, visible on spectral CT images. CT images of the plaque surface correlated very well with histological photographs. Calcium deposits (>1,000?μm) in plaque are larger than iron deposits (<100?μm), but could not be distinguished from each other within the same voxel using the energy range available.

Conclusions

Spectral CT displays energy information in image form at high spatial resolution, enhancing the intrinsic contrast of lipid, calcium and iron within atheroma.

Key Points

? Spectral computed tomography offers new insights into tissue characterisation. ? Components of vulnerable atherosclerotic plaque are spectrally distinct with intrinsic contrast. ? Spectral CT of excised atherosclerotic plaques can display iron, calcium and lipid. ? Calcium deposits are larger than iron deposits in atheroma. ? Spectral CT may help in the non-invasive detection of vulnerable plaques.     

Aberrant right common carotid and subclavian arteries causing tracheoesophageal compression combined with persistent left superior vena cava—case report

Vascular rings are a rare group of congenital thoracic vascular anomalies which are characterized by abnormal vascular structures that completely or incompletely encircle the trachea, esophagus, or both. We report the case of a vascular ring formed around the trachea and esophagus by aberrant right subclavian artery and aberrant right common carotid artery, associated with persistent left superior vena cava, complete absence of azygos vein, and with multiple nonvascular abnormalities. Recurrent pulmonary infections were the only clinical manifestation of this complex vascular anomaly. Our report represents a so-far-undescribed anatomic variation of the vascular ring that clinicians should be aware of.     

颈部CTA图像后处理的临床应用

目的:比较颈部CTA图像后处理方法的优缺点。方法:25例病人,经四排螺旋CT扫描后得到50支颈动脉和椎动脉,分别用3mm、5mm和15mm薄层MIP和SSD方法进行重建。结果:1侧椎动脉闭塞,1侧椎动脉全程较细,32支颈总动脉或颈内、外动脉有斑块,1支颈动脉2级狭窄、11支颈动脉1级狭窄。结论:颈部CTA可以准确地评估颈部动脉粥样硬化,层厚为15mm的薄层MIP可以几乎显示颈总动脉及其分支的全程,显示椎动脉需用3mm的薄层MIP,SSD不能鉴别钙化斑块和增强后的动脉,评估颈动脉需结合重建后的图像和原始的轴位图像。     

不同部位注射对比剂对颈动脉血管CT造影图像质量的影响

 目的 探讨通过左、右肘注射对比剂对颈动脉CT造影(CTA)成像图像质量的影响。方法 回顾性分析2019-09至2021-06在武警北京总队医院医学影像科行头颈部CTA检查的100例患者,其中50例经右臂肘正中静脉注射对比剂的为右臂组,50例经左臂肘正中静脉注射对比剂的为左臂组;对比两组患者两侧颈动脉CT值及静脉显影优良率。结果 右臂组及左臂组的左颈总动脉CT值分别为(335.25±20.67)Hu、(315.78±20.67)Hu,右颈总动脉CT值分别为(330.28±18.45)Hu、(313.56±19.45)Hu,差异无统计学意义(P＞0.05);右臂组静脉显影优良率为86.00%,高于左臂组的63.00%,差异有统计学意义(P＜0.05)。结论 颈动脉CT血管造影采用右臂静脉注射对比剂,可减少上腔静脉、头臂静脉、锁骨下静脉伪影及对比剂反流。     

缺血性脑血管病患者多层螺旋CT血管造影情况分析

目的根据螺旋CT血管造影（CTA）情况,探讨缺血性脑血管病患者颅内外血管粥样硬化斑块的性质、成分和动脉管腔狭窄程度与缺血性脑血管病的关系。方法选择缺血性脑血管病患者45例,经头颈部螺旋CT血管造影（CTA）,分析脑动脉管腔狭窄程度及动脉粥样斑块的性质、成分。结果45例患者中,CTA检出各种斑块（钙化斑、软斑、混合斑）33例（73．3％）,22例（48．8％）有动脉狭窄,血管闭塞5例。颅外动脉狭窄最常见的部位是颈内动脉起始部,颅内动脉狭窄最常见的部位是大脑中动脉M1段。结论缺血性脑血管病患者的颅内外动脉斑块发生率均较高,动脉粥样硬化致血管狭窄前循环发生率高于后循环,Ⅲ、Ⅳ级狭窄动脉相应供血区域大多出现缺血病灶,头颈动脉多层CTA可以准确评价颅内外动脉的病变情况,对脑卒中的二级预防具有重要指导意义。