Whole-brain dynamic CT angiography and perfusion imaging

The availability of whole brain computed tomography (CT) perfusion has expanded the opportunities for analysing the haemodynamic parameters associated with varied neurological conditions. Examples demonstrating the clinical utility of whole-brain CT perfusion imaging in selected acute and chronic ischaemic arterial neurovascular conditions are presented. Whole-brain CT perfusion enables the detection and focused haemodynamic analyses of acute and chronic arterial conditions in the central nervous system without the limitation of partial anatomical coverage of the brain.     

动态数字减影CT血管成像在脑血管病诊断中的应用

目的 探讨动态数字减影CT血管成像(DSCTA) 在脑血管病诊断中的应用.方法 收集110例拟诊脑血管病患者动态数字减影CT血管成像检查的影像资料,并结合临床病史、DSA检查、手术结果进行回顾性分析.结果 110例患者经DSCTA检出动脉硬化、狭窄72例,动脉瘤9例,动静脉畸形4例,烟雾病3例,脑静脉畸形2例.DSCTA能良好显示脑内动脉主干及主要分支充盈过程及管腔情况,发现狭窄血管,明确动脉瘤位置、大小、形态、以及与周围血管和颅骨的关系,并能清晰显示脑动静脉畸形的供血动脉和引流静脉.结论 动态数字减影CT血管成像对多种脑血管病的诊断能提供详尽客观的影像依据,具有肯定的临床应用价值.     

CT血管成像在心脑血管一站式成像中的研究进展

心脑血管疾病是我国因病致死的首要死因,其发病率逐年上升。CT血管成像（CTA）检查心脑血管疾病逐渐广泛应用于临床,它能够全方位地观察心脑血管,清晰显示血管的解剖结构及病变部位。传统的心脑血管扫描分为两次,辐射剂量大且操作复杂。近年来,许多学者对心脑血管联合扫描一站式成像进行了研究,其简便、快捷、无创、辐射剂量低、对比剂使用少、准确性高等优点使其被广泛应用。笔者就CTA在心脑血管一站式成像中的研究进展进行综述。     

Helical CT angiography of thoracic outlet syndrome: functional anatomy

OBJECTIVE: The objective of this study is to determine the anatomic characteristics of the thoracic outlet in symptomatic patients before and after postural maneuver. SUBJECTS AND METHODS: Seventy-nine symptomatic patients (61 female patients [group 1]; 18 male patients [group 2]; mean age, 38 years) underwent helical CT angiography of the thoracic apices in the neutral position and after a postural maneuver, enabling the evaluation of the functional anatomy of the musculoskeletal and arterial structures of the ipsilateral thoracic outlet. RESULTS: A statistically significant difference was found between the distribution of the distances (maximum and costosubclavian) measured in the neutral position and after postural maneuver in groups 1 and 2. The median value of these distances was smaller after postural maneuver in groups 1 and 2. A statistically significant difference was found between the distribution of the distances (maximum and costosubclavian) measured in patients of group 1 with arterial stenosis and in patients of group 1 without arterial stenosis. A slight indentation of the anterior wall of the subclavian artery when it arches around the anterior scalene muscle was observed in 39 patients (64%) in group 1 and in 11 patients (61%) in group 2 in the neutral position, in 19 patients (31%) in group 1 and in six patients (33%) in group 2 after the postural maneuver. The predominant positional changes of the vascular structures were the posteroanterior displacement of the subclavian vessels observed in groups 1 and 2, the arch made by the subclavian artery above the first rib in 40 patients (66%) in group 1 and nine patients (50%) in group 2, and the posterior displacement of the axillary artery observed in 36 patients (59%) in group 1 and in 12 patients (67%) in group 2. CONCLUSION: Helical CT shows significant narrowing of the costoclavicular space after postural maneuver in symptomatic patients.     

Helical CT with CT angiography in assessing periampullary neoplasms: identification of vascular invasion

PURPOSE: To determine the accuracy of helical computed tomography (CT) with CT angiography in identifying vascular invasion by periampullary neoplasms and to assess the added value of CT angiography. MATERIALS AND METHODS: Sixty-nine patients suspected of having periampullary neoplasms were examined. Images from dual phase helical CT with CT angiography were compared with surgical findings in 36 patients. Arterial and venous invasion were assessed separately. Accuracy, positive predictive value (PPV), and negative predictive value (NPV) were determined for CT alone and for CT supplemented with CT angiography. RESULTS: The accuracy, PPV, and NPV of helical CT with CT angiography in identifying venous invasion was 92% (33 of 36 patients), 86% (12 of 14 patients), and 95% (21 of 22 patients), respectively. When transverse CT images alone were analyzed, accuracy decreased to 69% (25 of 36 patients) (P =.005); PPV and NPV were 63% (five of eight patients) and 71% (20 of 28 patients), respectively. When identifying arterial invasion, the accuracy of CT with CT angiography and of CT alone was 86% (31 of 36 patients). PPV and NPV also were identical at 71% (five of seven patients) and 90% (26 of 29 patients), respectively. CONCLUSION: CT angiography significantly increases the ability to identify venous invasion when compared with CT alone but does not improve detection of arterial invasion.     

MSCT血管造影在颅内血管性疾病中的诊断价值

目的探讨16层螺旋CT血管造影(MSCTA)在颅内血管性疾病中的诊断价值。方法对339例患者行16排螺旋CT血管造影,同时采用容积重建(VR)、多平面重建(MPR)、最大密度投影(MIP)显示血管,其中45例动脉瘤、22例动静脉畸形、4例烟雾病和18例脑动脉狭窄随后进行了DSA检查或手术治疗。结果CTA诊断为动脉瘤的患者83例,动静脉畸形22例,静脉瘤2例,海绵状血管瘤3例,海绵窦动静脉瘘3例,单纯烟雾病3例,烟雾病合并动脉瘤1例,缺血性脑血管病22例,先天性变异等32例,正常病例186例,其中CTA诊断的45例动脉瘤、22例动静脉畸形、4例烟雾病和18例脑动脉狭窄与DSA检测结果及手术结果基本一致。结论MSCTA对头部血管性疾病的诊断,具有微创、快速、安全、准确性高的特点,可作为头部血管性疾病的首选影像学筛查。     

Encephalopathic cerebrovascular steal: dynamic CT of arteriovenous malformations

Summary Arteriovenous maloformations and the clinical symptoms they engender are due in large part to the cerebrovascular steal intimately associated with these lesions. Intravenous dynamic computed tomography was utilized in a series of 10 patients harboring cranial vascular malformations of varying size and location in an effort to further elucidate the pathophysiology and extent of the arteriovenous shunt in pre-hemorrhagic (8 subjects) and posthemorrhagic (2 subjects) clinical situations. Perfusion abnormalities were identified locally as well as distant from the nidus of the lesion, both intra- and extra-axially. The technique of dynamic computed tomography in this study group confirms past observations regarding the steal phenomenon and reveals aberrant perfusion states which were previously unknown.     

64层螺旋CT血管造影在脑血管疾病中的应用

目的 探讨64层螺旋CT血管造影在脑血管疾病诊断中的应用价值.方法 53例脑血管病变患者行64层螺旋CT脑血管造影检查.先行平扫,后行CTA扫描,并用减影法进行后处理,重建得到VR、MIP、MPR及CPR图像,综合分析多种图像评价脑血管病变.结果 动脉瘤患者11例,其中颈内动脉至大脑中动脉瘤1例,颈内动脉瘤2例,大脑中动脉瘤2例,小脑上动脉瘤1例,后交通动脉瘤2例,前交通动脉瘤2例,基底动脉瘤1例,所有瘤体及瘤颈均得到清晰显示.动静脉畸形2例,均能显示畸形血管团,其中1例清晰显示供血动脉及引流静脉,另1例仅能显示引流静脉,供血动脉显示不清.脑血管狭窄或闭塞40例,均显示脑血管不同程度节段性、局限性狭窄或闭塞.结论 64层螺旋CT血管造影运用减影技术并综合多种重建方法能快速、准确诊断脑血管病变,有良好的临床应用价值.     

Helical CT of calcaneal fractures: technique and imaging features

 Since the degree of comminution, fracture alignment, and articular congruity of intra-articular calcaneal fractures are important determinants in surgical treatment and patient prognosis, we review helical computed tomographic (CT) technique and features for detecting and assessing the extent of acute calcaneal fractures. Helical CT can be used to classify these fractures and facilitate the surgeon’s understanding of the anatomy and position of the fracture components in all orthogonal planes independently of the patient’s condition, foot placement in the CT gantry, or other injuries.     

颅颈联合减影CT血管成像对脑缺血的诊断价值

目的 探讨减影CTA在缺血性脑血管病诊断中的应用价值.方法 83例临床拟诊短暂性脑缺血发作(TIA)或脑梗死患者行颅颈部CT血管成像检查,在同一序列依次进行平扫和增强扫描,增强延迟16～20整数秒,重建层 厚0.625 mm,间隔0.45 mm,通过Image Combination V7.01软件自动处理获得减影图像.由1名有经验的操作者间隔30 d以上对同一病例常规CTA和减影CTA图像分别进行去骨处理并记录消耗时间.由2名资深放射科医师以商讨形式对去骨效果、血管边缘清晰度评级,血管狭窄程度按NASCET标准分级.结果 2组去骨时间有统计学差异,减影CTA时间为(16.0±0.23)min vs (19.9±0.18)min(t=19.10,P<0.001);减影CTA去骨效果优于常规CTA(χ2=12.6,P=0.006),虽然减影与常规CTA对血管狭窄程度分级差异没有统计学意义(χ2=0.06,P=0.972),但减影CTA血管边缘清晰度不如常规CTA(χ2=15.0,P=0.002).结论 减影CTA去骨快,血管连续性好,能整体显示血管走行、狭窄部位及程度,但血管边缘清晰度稍差,且不适用于斑块性质准确评估.     

脑血管病变115例CT血管成像分析

目的：探讨64层螺旋CT脑血管成像（MSCTA）对脑血管病变的诊断价值。方法：经64层螺旋CT脑血管成像检查的病例,使用减影方法进行后处理,得到VR、MIP图像,原始图像重建得到MPR、CPR图像,综合四种图像诊断脑血管病变,并与DSA诊断进行对照分析。结果：115例脑血管病变中,动脉瘤62例（53.91%）、动静脉畸形（AVM）6例（5.21%）、脑静脉畸形（CVM）3例（2.61%）,脑动脉狭窄或闭塞38例（33.04%）、烟雾病3例（2.61%）、海绵窦动静脉瘘2例（1.74%）、海绵状血管瘤1例（0.87%）。其中46例DSA检查结果均与MSCTA一致。结论：64层螺旋CT脑血管成像是一种安全、快速、无创的检查方法,可作为颅内血管性病变筛查和术前评估的首选检查技术。     

Helical CT imaging of clinically suspected appendicitis: correlation of CT and histological findings

PURPOSE: The diagnosis of appendicitis is traditionally made on the basis of clinical findings supported by laboratory results. The aim of our study was to determine the accuracy and feasibility of using a relatively new technique of computed tomography (CT) using only colonic contrast medium. MATERIALS AND METHODS: A total of 50 patients clinically diagnosed as having appendicitis were prospectively examined before surgery with thin-collimation helical CT from the L3 level to the acetabular roof with only rectally administered colon contrast medium. The hard copy CT images were reviewed jointly by two radiologists and a consensus was reached for each patient. The results were then compared with the surgical and histological findings at appendicectomy. RESULTS: There were 35 true-positives, one false-positive, 12 true-negatives and two false-negatives for CT. This yielded an accuracy of 94%, sensitivity of 95%, specificity of 92%, positive predictive value of 97% and negative predictive value of 86%. The appendix was identified in 45 patients (90%) and obscured by an inflammatory mass in the remaining five. An alternative diagnosis was found in 10 of 12 normal CT examinations (83%). CONCLUSION: Helical CT with rectal contrast medium is a quick, well tolerated and accurate test to diagnose appendicitis. It can offer alternative, possibly non-surgical diagnosis in patients who would otherwise have undergone laparotomy.     

64层螺旋CT血管成像在脑血管疾病中的应用

目的:评价64例螺旋CT血管成像对脑血管病的诊断及临床应用价值.方法:64层螺旋CT血管成像检查确诊脑血管疾病患者60例,50例在1周内行DSA检查.采用减影方法进行后处理,分别得到VR,MIP,ISMIP图像,利用这三种方法重建图像综合评价脑血管病变.结果:①脑动脉狭窄或闭塞者46例,其中36例有DSA对照,98.8%的狭窄或闭塞的脑血管与DSA诊断一致,CT血管成像的敏感性,特异性,准确性分别为100%、98.5%、98.8%;②烟雾病3例,均有DSA对照,表现为单侧或双侧大脑中动脉重度狭窄,远端分支异常增多;③脑动脉瘤患者12例,均有DSA对照,后交通动脉瘤7例,前交通动脉瘤3例,大脑中动脉瘤1例,大脑后动脉瘤1例,CT血管成像与DSA显示一致.结论:64层螺旋CT层血管成像能快速,准确地诊断各种脑血管疾病,结合减影处理方法提高了诊断的效率和准确性,为临床提供了全面的信息,可作为脑血管疾病患者的首选诊断方法.     

Takayasu arteritis: imaging spectrum at multidetector CT angiography

Takayasu arteritis is a chronic, idiopathic, inflammatory disease that primarily affects large vessels, such as the aorta and its major branches and the pulmonary and coronary arteries. The non-specific inflammation of involved vessels usually leads to concentric wall thickening, fibrosis and thrombus formation. Diseased arteries become stenotic or occluded, undergo vascular remodelling or develop aneurysms. According to the involvement of arteries, six types of Takayasu arteritis are documented. The purpose of this pictorial review is to illustrate the various multidetector CT angiography appearances of Takayasu arteritis and to discuss the differential diagnosis.Takayasu arteritis (TA) is a chronic, idiopathic, inflammatory disease that primarily affects large vessels, such as the aorta and its major branches, pulmonary and coronary arteries. Because of considerable morbidity and mortality, accurate and early diagnosis plays a crucial role in improving the outcomes for patients with TA [1]. Unfortunately, the non-specific clinical presentations and laboratory test results frequently contribute to late diagnosis and delayed treatment [1]. Since large-artery biopsies cannot easily be done, imaging examination is essential for providing the diagnosis and differential diagnoses in patients with suspected TA.Conventional angiography has been traditionally considered the gold standard for the diagnosis of TA [2]. However, multidetector CT angiography (CTA) is emerging as a reliable tool in non-invasively depicting both luminal and mural lesions in the aorta and its main branches, which may facilitate the detection of vasculitis during the early phase of TA.In this article, we will review the CTA findings in TA and how this non-invasive method impacts patient care.