Extravasation of intracranial aneurysm during computed tomography angiography: mimicking a blood vessel

Two cases of contrast media extravasation of a ruptured aneurysm during computed tomography angiography (CTA) are described. The contrast media extravasation appeared as a highly attenuated twisted ribbon-like structure originating from the aneurysmal dome, and this mimicked a vascular structure. Because rebleeding of an aneurysm is accompanied by disastrous consequences, it is important to understand the imaging feature of active bleeding on CTA.     

Demonstration of an actively bleeding aneurysm by CT angiography

We describe a case of an actively bleeding aneurysm demonstrated by CT angiography (CTA). The active hemorrhage was characterized by a nebulous attenuation in the subarachnoid space adjacent to the aneurysm. The measurements (HU) of the hemorrhage were equal to or slightly less than those of the contrast material in the arteries and diminished as one moved further from the aneurysm. As CTA is used more frequently in the diagnosis of cerebral aneurysms, it is important to understand imaging features of this potentially lethal condition.     

Extravasation on three-dimensional CT angiography in patients with acute subarachnoid hemorrhage and ruptured aneurysm

Three-dimensional computed tomographic angiography (CTA) is a noninvasive technique for detecting lesions after acute subarachnoid hemorrhage. We encountered extravasation on CTA, a finding that has not been reported previously. Three patients with saccular aneurysms showed extravasation on CTA performed within 3 h of the onset of hemorrhage, and all three patients died within 2 weeks. At autopsy, the site of rupture of the aneurysm was confirmed in all three cases. There were two patterns of extravasation shown by CTA, which seemed to depend on the direction of rupture. Extravasation on CTA might represent the natural progression of ruptured aneurysm and may indicate a poor prognosis.     

Nonhelical acquisition CT angiogram after aneurysmal clipping: in vitro testing shows diminished artifact

Imaging of the cerebral vessels with use of CT angiogram (CTA) after placement of aneurysmal clips is often limited by clip artifacts. We used a phantom to demonstrate a visible reduction in metal artifact when using the axial technique, compared with the usual CTA helical acquisition. This approach may have some advantage when used for CTA with 64-section scanners in the specific circumstance of immediate postoperative imaging after placement of cerebral aneurysmal clips.     

肝脏16层螺旋CT增强多期相扫描及血管成像的综合应用

目的:探索16层螺旋CT在肝脏多期相扫描设置的优化及血管成像的综合应用技术,以期提高肝脏疾病的诊断准确率.方法:参照肝脏增强时间密度曲线,选择兼顾肝动脉、门静脉成像及肝内病变检出的最佳时间段设置扫描期相.采用此期相设置对40例经B超发现肝脏有病变的患者进行16层CT增强检查.将所得双期血管成像与其中12例行数字减影血管造影(DSA)检查的患者进行比较,作出前瞻性诊断后追踪病理及临床综合资料并作比较.结果:在注射对比剂后40例患者病变均能检出,且前瞻性诊断符合率达95%,双期血管成像与DSA比较有较好的相似性.结论:肝脏16层CT多期相设置及血管成像的综合技术有较高的临床应用价值.     

Active hemorrhage into a postresection cavity detected by neuro-CT angiography

We describe a case demonstrating active extravasation of contrast material into a hematoma resection cavity during CT angiography (CTA) that necessitated emergent reexploration, decompression, and hemostatic control. Our case highlights the value of neuro-CTA in the immediate postoperative setting and describes another scenario where CTA has added value. Prompt recognition of contrast extravasation is critical to the diagnosis and ultimately affects the quality of patient care.     

CT angiography of intracranial aneurysms related to arteriovenous malformations: a cautionary tale

Computed tomographic angiography (CTA) has a high sensitivity and specificity for the detection of intracranial aneurysms and is increasingly used as the primary imaging modality in the investigation and pretreatment planning of patients presenting with acute subarachnoid haemorrhage. We present two cases in which CTA failed to demonstrate arteriovenous malformations associated with intracranial aneurysms.     

Detection of cerebral aneurysms in nontraumatic subarachnoid haemorrhage: role of multislice CT angiography in 130 consecutive patients

PURPOSE: The leading cause of a nontraumatic subarachnoid haemorrhage is rupture of an intracranial aneurysm. The aim of this study was to assess the usefulness of multislice computed tomography angiography (CTA) in identifying and evaluating cerebral aneurysms by comparing it with intra-arterial digital subtraction angiography (DSA) and intraoperative findings. MATERIALS AND METHODS: During a 20-month period (June 2004 and February 2006), 130 patients with a CT diagnosis of nontraumatic acute subarachnoid haemorrhage were prospectively recruited to this study and underwent 16-detector CTA and DSA (57 men, 73 women; mean age 59.5 years). Twenty-five patients who underwent DSA alone postclipping were excluded. CTA and DSA were evaluated by the performing radiologist to assess the presence of one or more aneurysms and their morphological characteristics. RESULTS: CTA detected 133 aneurysms, whereas DSA identified 134: the aneurysm missed by CTA was 2 mm in size. CONCLUSIONS: CTA is fast and relatively noninvasive, and its sensitivity appears similar to that of DSA in detecting and evaluating intracranial aneurysms, even those smaller than 3 mm. This study confirms the value of CTA as the primary imaging technique in subarachnoid haemorrhage, with DSA reserved for selected patients.     

Contrast extravasation on CT predicts mortality in primary intracerebral hemorrhage

BACKGROUND AND PURPOSE: Recent studies of intracerebral hemorrhage (ICH) treatments have highlighted the need to identify reliable predictors of hematoma expansion. The goal of this study was to determine whether contrast extravasation on multisection CT angiography (CTA) and/or contrast-enhanced CT (CECT) of the brain is associated with hematoma expansion and increased mortality in patients with primary ICH.MATERIALS AND METHODS: All patients with primary ICH who underwent CTA and CECT, as well as follow-up noncontrast CT (NCCT) before discharge/death from January 1, 2003, to September 30, 2005, were retrospectively identified. One neuroradiologist reviewed admission and follow-up NCCT for hematoma size and growth. A second neuroradiologist independently reviewed CTA and CECT for active contrast extravasation. Univariate and multivariate logistic regression analyses were performed to evaluate the significance of clinical and radiologic variables in predicting 30-day mortality, designated as the primary outcome. Hematoma growth was considered as a secondary outcome.RESULTS: Of 56 patients, contrast extravasation was seen in 17.9% of patients on initial CTA and in 23.2% of patients on initial CECT following CTA. Univariate analysis showed that the presence of extravasation on CT, large initial hematoma size (>30 mL), the presence of “swirl sign” on NCCT, the Glasgow Coma Scale and ICH scores, and international normalized ratio were associated with increased mortality. On multivariate analysis, only contrast extravasation on CT (P = .017) independently predicted mortality. Contrast extravasation on CT (P < .001) was also an independent predictor of hematoma growth on multivariate analysis.CONCLUSION: Active contrast extravasation on CT in patients with primary ICH independently predicts mortality and hematoma growth.

Primary intracerebral hemorrhage (ICH) is one of the most devastating forms of stroke, with 30-day mortality rates ranging from 35% to 44%.^1–3 Recent studies of hemostatic treatments such as recombinant activated factor VII as a means to reduce hematoma growth and impact clinical outcome in patients with primary ICH have highlighted the need to identify reliable predictors of hematoma expansion.^4–6 A number of clinical and radiologic variables have been associated with poor outcome following ICH, including age; blood glucose level; Glasgow Coma Scale (GCS) score; and hemorrhage location, size, and intraventricular extension.^7–12 Several prognostic models for ICH have been developed incorporating both clinical and radiologic variables, among them the ICH score, which includes the GCS score, advanced age, hematoma location, ICH volume, and the presence of intraventricular hemorrhage, to predict 30-day mortality.¹³Nearly all studies of prognostic variables with respect to imaging have focused exclusively on noncontrast CT (NCCT). One study by Becker et al from 1999¹⁴ examined the role of iodinated contrast administration in primary ICH, concluding that contrast extravasation was independently associated with increased mortality. However, CT technology has evolved considerably since 1999, primarily due to the introduction of multisection CT scanners. High-quality CT angiography (CTA) and contrast-enhanced CT (CECT) studies of the brain are now routinely performed following contrast administration. The respective roles of CTA and CECT were not separately defined in Becker''s study, in which single-section CT scanner technology was used.¹⁴ A recent study by Goldstein et al¹⁵ demonstrated an independent association between contrast extravasation and hematoma expansion but did not explore the relationship with mortality.The goal of this study was to determine whether contrast extravasation as visualized on multisection CTA and/or CECT is associated with hematoma expansion and increased mortality in patients with primary ICH.     

CT angiography of extremity trauma

With the advent of multi-detector computed tomography, CT angiography (CTA) has rapidly become the first line imaging modality for detecting extremity arterial injuries in blunt and penetrating trauma patients. A variety of significant injuries are detected with high sensitivity and specificity. The information provided by CTAs in this patient population is often sufficient for making therapeutic decisions, such as the need for and type of surgical or endovascular interventions. Technological advances have allowed for isotropic imaging and improved quality of multi-planar and three-dimensional reformations, which aid in diagnosis and surgical planning. The rapid acquisition speed of 64 multi-detector CT scanners has facilitated integration of CTA into routine trauma CT imaging using a single contrast bolus injection.     

64层MSCTA对蛛网膜下腔出血病因的诊断

目的：探讨64层螺旋CT血管成像（MSCTA）在自发性蛛网膜下腔出血的临床应用价值。方法：搜集临床拟诊为蛛网膜下腔出血患者76例,行64层螺旋CT血管成像检查,并将结果与DSA结果、手术结果相对照。结果：本组76例患者中CTA诊断动脉瘤28例,DSA发现29例,手术证实29例;诊断为动静脉畸形3倒,DSA发现3例,手术证实3例。有45例CTA检查未见异常发现,其中1例动脉瘤CTA漏诊。结论：64层螺旋CT血管成像可作为自发性蛛网膜下腔出血病因诊断方法之一。     

Intracranial vascular calcifications mimicking small saccular aneurysms on CT angiography: a technical note and case description

The authors describe a case of intracranial vascular calcifications that mimicked small saccular aneurysms on CT angiography (CTA). The density of two vascular calcifications was visually similar to that of contrast in the parent vessel, making them indistinguishable from aneurysmal outpouchings. Comparison of the CTA with the non-contrast head CT (NCCT) was critical to distinguish low-density calcifications from tiny aneurysms.     

脑血管CTA预测高血压脑出血患者血肿扩大的临床分析

 目的 分析脑血管CTA检查中造影剂外渗与急性期高血压脑出血血肿扩大的关系。 方法 63例急性期高血压脑出血患者入院后行头颅CT及脑血管CTA检查,24 h后复查头颅CT,观察造影剂外渗情况,分析脑 血管CTA检查过程中造影剂外渗与血肿扩大的关系。 结果 血肿扩大组11例(17.46%),血肿无扩大组52例 (82.54%)。血肿扩大11例患者中造影剂外渗者9例,CTA阳性预测血肿扩大准确率81.82%,造影剂外渗患者血肿量增加（27.63 ±11.52）ml,造影剂无外渗患者血肿量增加（3.12±1.48）ml（ P =0.006）,血肿扩大组血肿量增加（20.18±12.27） ml,血肿无扩大组出血量增加（1.59±1.05） ml（ P =0.027）。 结论 在脑血管CTA检查中,造影剂外 渗与急性期高血压脑出血血肿扩大有明显相关性,可预测高血压脑出血血肿扩大情况。     

64层MSCTA对急性自发性蛛网膜下腔出血病因诊断价值分析

目的：探讨64层螺旋CT血管成像在急性自发性蛛网膜下腔出血病因的诊断价值和临床应用。方法：收集临床拟诊急性自发性蛛网膜下腔出血患者进行64层螺旋CT血管造影检查,并将检查结果与DSA或手术结果进行对照研究。结果：本组69例患者中CTA诊断动脉瘤53例59个,其中5例为多发,DSA发现53例动脉瘤共59个,CTA漏诊、误诊动脉瘤各1例;诊断动静脉畸形5例,DSA和手术均证实为5例,另外还有3例烟雾病得到DSA证实。其中8例为阴性。MSCTA蛛网膜下腔出血病因诊断敏感性、特异性、阳性预测值和阴性预测值分别为98.6%,88.9%,98.6%,88.9%;MSCTA和DSA对动脉瘤长径、囊颈比（瘤体短轴/瘤颈）的评价方面无统计学差异（P〉0.05）,但对囊颈比整体存在评价过低情况,易把窄颈动脉瘤评价为宽颈动脉瘤。结论：64层CTA能准确、迅速地评价急性自发性SAH,为临床诊治提供科学的依据和指导,降低患者的致残率和死亡率。     

CT-angiographic evaluation of intracranial aneurysms - a review of the literature and first experiences with 4- and 16-slice multi detector CT scanners

Intracranial aneurysms are a common pathology faced by the diagnostic radiologist in daily practice. They can present as symptomatic aneurysms with a subarachnoid hemorrhage or as an incidental finding in another radiological study. Moreover, clipped or coiled aneurysms sometimes require a postinterventional work-up to exclude residual perfusion.Previous studies assessing the value of CT angiography in the diagnosis of intracranial aneurysms have been conducted using single slice spiral CT-scanners. They have shown a limited sensitivity in the diagnosis of small aneuryms with a diameter of equal to or smaller than 3 mm.Presently, there is only limited experience regarding the use of multi-detector row CT (MDCT) in the diagnosis of intracranial aneurysms. We have examined eight patients with a total of eleven aneurysms with MDCT technology, five patients with a 4-slice MDCT and three with a 16-slice MDCT. Of these, five were untreated aneurysms and six posttherapeutic with a status post surgical clipping. The mean diameter of the aneurysms was 5 mm (range 2 to 13 mm, median 3 mm). Of the treated aneuryms, two showed residual perfusion of the aneurysmal neck with a diameter of 2 and 6 mm respectively. In all cases, MDCT-angiography was in full agreement with the DSA diagnosis.Studies on larger patient populations will need to demonstrate the value of CTA in the diagnosis of intracranial aneurysms compared to the reference standard DSA.     

An investigation into current protocols and radiographer opinions on contrast extravasation in Irish CT departments

BackgroundIodinated contrast extravasation is a serious complication associated with intravenous administration in radiology. Departmental protocols and the radiographer's approach on both prevention techniques and treatment will affect the prevalence of extravasation, and the eventual outcome for the patient when it does occur.AimsTo examine contrast extravasation protocols in place in Irish CT departments for alignment with European Society of Urogenital Radiology (ESUR) Guidelines (2014); to establish radiographer's opinions on contrast extravasation; and to examine radiographer adherence to protocols.MethodsContrast extravasation protocols from a purposively selected sample of CT departments across Ireland (n = 6) were compared to ESUR guidelines, followed by an online survey of CT radiographers practicing in the participating centres.ResultsAll participating CT departments (n = 5) had written protocols in place. High risk patients, such as elderly or unconscious, were identified in most protocols, however, children were mentioned in just one protocol and obese patients were not specified in any. The response rate of CT radiographers was 23% (n = 24). 58% (n = 14) of respondents indicated that contrast extravasation was more likely during CTA examinations. While high levels of confidence in managing extravasation were reported, suggested treatment approaches, and confidence in same, was more variable. Clinical workload in CT departments was also identified as a factor impacting on patient care and management.ConclusionWhile contrast extravasation protocols were generally in line with ESUR Guidelines, high risk patients may not be getting sufficient attention. More radiographer awareness of patient monitoring needs, particularly in busy departments with a heavy workload may also reduce extravasation risk, and improve management of same.     

Spiral CT angiography of aortic dissection

Spiral CT angiography (CTA) is one of the newest imaging techniques used for the evaluation of aortic dissection. Current spiral CT scanners with high-performance tubes and subsecond scanning allow increased regions of coverage. Large volumes of data are rapidly acquired through the aorta during maximum contrast enhancement. Multiplanar reformat (MPR), curved planar reformat (CPR), and 3-D rendering techniques including shaded surface display (SSD) and maximum intensity projection (MIP) are then applied to the data to generate CT angiographic images of the aorta. Emergent spiral CTA may be performed in patients with suspected aortic dissection who are hemodynamically stable. Postprocessing is performed immediately following data acquisition and can provide additional information for aortic dissection diagnosis and clinical management. The technique, applications, and limitations of spiral CTA for the evaluation of aortic dissection will be discussed relative to the role of other imaging modalities.     

CT angiography for evaluation of cerebral vasospasm following acute subarachnoid haemorrhage

Introduction  

Cerebral vasospasm (CV) is one of the most dreaded complications in patients who survive acute subarachnoid haemorrhage (SAH), and conventional cerebral angiography (DSA) is the gold standard for its diagnosis. We evaluated CT angiography (CTA) as a non-invasive alternative for diagnosis of CV and assessed if CTA could have a role in choosing appropriate treatment.     

Modern cross-sectional imaging in the diagnosis and follow-up of intracranial aneurysms

Digital subtraction angiography (DSA) is still considered the gold standard for most applications in neurovascular imaging. However, with the ongoing development of cross-sectional imaging modalities DSA is increasingly being replaced by less invasive methods. This contribution describes the diagnostic value and the increasing potential of computed tomography angiography (CTA) and magnetic resonance angiography (MRA) in the diagnosis and follow-up of intracranial aneurysms. The main role of CTA is in the diagnosis and therapy planning of ruptured aneurysms; in contrast, MRA plays an increasingly important role in the screening for asymptomatic aneurysms (especially in cases of familial subarachnoid hemorrhage) and in the follow-up after endovascular therapy with coils and/or intracranial stents. Technical issues concerning examination technique are covered here as well as an approach to advanced postprocessing of the image data. Furthermore, a brief outlook on the impact of new developments (MRA with parallel imaging and at 3.0 T) is given.     

颅内动脉瘤的CTA术前诊断

评价CT血管造影(CTA)在颅内动脉瘤的术前诊断价值及对最大密度投影(MIP)、表面遮盖显示(SSD)和容积显示技术(VRT)作用的比较.材料和方法:对36例CT平扫怀疑患有颅内动脉瘤的患者进行CTA检查,初选27例动脉瘤患者分别进行MIP、SSD及VRT成像,观察动脉瘤的部位、形态、生长方向及载瘤动脉;进行瘤体大小及瘤颈宽度的测量,部分病例与术中结果比较.结果:27例动脉瘤患者中,动脉瘤大小:5～60mm.瘤颈呈蒂状(颈宽＜10mm)18例、宽颈(颈宽≥10mm)9例.载瘤动脉分别为:大脑中动脉(12例)、大脑前交通动脉(7例)、颈内动脉虹吸部(6例)、基底动脉(2例).蒂状窄颈动脉瘤均行手术治疗,术后恢复良好;1例瘤颈宽为10mm手术后患者所在中动脉闭塞,脑组织缺血性梗死,9例均放弃手术.结论:CTA可作为动脉瘤的有效术前筛选诊断,可作为神经外科医师手术前的重要指导方法之一.