Clinical usefulness of unsubtracted 3D digital angiography compared with rotational digital angiography in the pretreatment evaluation of intracranial aneurysms

BACKGROUND AND PURPOSE: Three-dimensional digital subtraction angiography (DSA) is useful as a supplement to 2D DSA in the pretreatment evaluation of intracranial aneurysms. However, the clinical efficacy of 3D digital angiography (DA) that is generated from unsubtracted rotational images has not been established. The purpose of this study was to assess whether 3D DA provides additional useful information to that of rotational DA in the preoperative evaluation of intracranial aneurysms. METHODS: This prospective study comprised 23 patients (age range, 37-83 years) with ruptured aneurysms who underwent angiography. Two radiologists independently evaluated the rotational DA images and the maximum intensity projection, shaded surface display, and volume-rendering 3D DA images, in combination with 2D DSA images. A four-point scoring system was used to evaluate aneurysm detection and delineation. Referring neurosurgeons were questioned as to whether the information obtained with 3D DA was useful for treatment decisions. RESULTS: Thirty aneurysms were confirmed by surgery or endovascular treatment. In detection and delineation of the 30 confirmed aneurysms, overall mean scores were highest with volume-rendering 3D DA and lowest with rotational DA. Compared with rotational DA, volume-rendering 3D DA demonstrated 27 additional findings in 14 (47%) of 30 aneurysms: detection of an aneurysm (n = 2), and delineation of aneurysm neck, shape, and relationship to adjacent arteries (n = 25). The information provided by 3D DA was useful for following treatment in five (22%) of 23 patients. CONCLUSION: In the preoperative evaluation of intracranial aneurysms, 3D DA can provide additional useful information to that of rotational DA.     

Preoperative evaluation of intracranial aneurysms: usefulness of intraarterial 3D CT angiography and conventional angiography with a combined unit--initial experience

PURPOSE: To assess the usefulness of intraarterial computed tomographic (CT) angiography in conjunction with digital subtraction angiography (DSA) by using a combined CT and angiographic unit in the preoperative evaluation of intracranial aneurysms. MATERIALS AND METHODS: Prospectively, 22 patients with or without subarachnoid hemorrhage underwent CT angiography in conjunction with DSA. Two radiologists independently evaluated DSA and CT angiographic images. Referring neurosurgeons were questioned as to how the additional information provided by CT angiography changed patient treatment. RESULTS: Intraarterial CT angiography was superior to DSA for use in aneurysm detection in three (12%) of 26 aneurysms and for delineation of aneurysm shape, neck, and location in more than half. In 14 (64%) of 22 patients, CT angiography demonstrated 18 additional findings: a very small aneurysm (n = 2), aneurysm shape and neck (n = 6), relationship of the aneurysm to adjacent arteries or bone structure (n = 8), and branches deriving from the aneurysm (n = 2). In four (27%) of 15 patients who underwent surgery or embolization, additional information obtained at CT angiography affected the treatment. CT angiography failed to clearly demonstrate an aneurysm adjacent to bone structures and small perforators, which were derived from the parent artery. CONCLUSION: Intraarterial CT angiography is useful for preoperative evaluation of intracranial aneurysms as a supplement to DSA.     

The role of MR angiography in the pretreatment assessment of intracranial aneurysms: a comparative study

BACKGROUND AND PURPOSE: With developments in coil technology, intracranial aneurysms are being treated increasingly by the endovascular route. Endovascular treatment of aneurysms requires an accurate depiction of the aneurysm neck and its relation to parent and branch vessels preoperatively. Our goal was to estimate the clinical efficacy of MR angiography (MRA) in the pretreatment assessment of ruptured and unruptured intracranial aneurysms. We compared MRA source data (axial acquired partitions), multiplanar reconstruction (MPR) of these data, as well as maximum intensity projection (MIP) and 3D-isosurface images with intraarterial digital subtraction angiography (IA-DSA). METHODS: The study was performed in 29 patients with 42 intracerebral aneurysms. The MRA data were examined in four different forms--as axial source data, MPR images of the source data, and MIP and 3D isosurface--rendered images. A composite standard of reference for each aneurysm was then constructed using this information together with the IA-DSA findings by looking at aneurysm detection rate, aneurysm morphology, neck interpretation, and branch vessel relationship to the aneurysm. All techniques, including conventional IA-DSA, were then scored independently on a five-point scale from 1 (non diagnostic) to 5 (excellent correlation with the standard of reference) for each of the aneurysm components as compared with the composite picture. An overall score for each technique was also obtained. RESULTS: Of the 42 aneurysms examined, 34 were small (<10 mm), six were large (10-25 mm), and two were giant (>25 mm). Three aneurysms were not detected with MRA. These were smaller than 3 mm and either in an anatomically difficult location (middle cerebral artery bifurcation) or obscured by adjacent hematoma. Two large aneurysms were depicted as undersized by IA-DSA owing to the presence of intramural thrombus shown by MRA axial source data. IA-DSA received the highest scores overall and in three of the four subgroups. Three-dimensional isosurface reconstructions scored higher than did IA-DSA for depiction of the aneurysm neck, although this difference was not significant. The MPR and 3D-isosurface images were comparable to those of IA-DSA in all categories. MPR images were particularly useful for defining branch vessels and the aneurysm neck. MIP images scored poorly in all subgroups (P < .005) compared with IA-DSA findings, except for in aneurysm detection. Source data images were significantly inferior to those of IA-DSA in all categories (P < .005). CONCLUSION: MRA is currently inferior to IA-DSA in pretreatment assessment of intracranial aneurysms, and can miss small lesions (<3 mm). It can, however, provide complementary information to IA-DSA, particularly in anatomically complex areas or in the presence of intramural thrombus. If MRA is used in aneurysm assessment, a meticulous technique with reference to both axial source data and MPR is mandatory. The axial source data should not be interpreted in isolation. Three-dimensional isosurface images are comparable to those of IA-DSA and are more reliable than are MIP images, which should be interpreted with caution.     

64层螺旋CT脑血管造影在颅内动脉瘤诊断中的应用

目的:与DSA相对照,探讨64层螺旋CT脑血管造影在颅内动脉瘤中的诊断价值。方法:对29例临床怀疑颅内动脉瘤的患者行64层螺旋CT脑血管造影(CTA)和DSA检查,使用GE64层Lightspeed VCT获得原始图像,所有病例均采用多层面重建(multiplanar reconstruction,MPR)、容积再现(volume rendering,VR)、薄层块最大密度投影(thin-slab maximumintensity projectjon,TS MIP)。后处理图像及DSA图像由2位放射科医生共同评估。结果:29例患者中,DSA证实25例共27个动脉瘤,其中2例为2个动脉瘤。与DSA结果相对照,CTA共检出25例26个动脉瘤,漏诊了1个颈出动脉瘤。CTA清晰显示了动脉瘤的形态、大小及载瘤动脉,3例动脉瘤瘤颈DSA未显示,CTA显示了全部动脉瘤的瘤颈。结论:64层CTA在颅内动脉瘤的诊断中具有极高价值,特别在显示动脉瘤瘤颈方面具有独特的优势,对临床治疗具有指导意义。     

Detection and characterization of intracranial aneurysms with 16-channel multidetector row CT angiography: a prospective comparison of volume-rendered images and digital subtraction angiography

BACKGROUND AND PURPOSE: The aim of our study was to compare multidetector row CT angiography (MDCTA) with digital subtraction angiography (DSA) in the detection and characterization of intracranial aneurysms. MATERIALS AND METHODS: In our blinded prospective study, 85 patients with suspected intracranial aneurysm (47 women, 38 men; age range, 19-83 years) underwent both 16-channel MDCTA and DSA. The MDCT angiograms were interpreted for the presence, location, size, ratio of the neck to the dome (N/D ratio), and lobularity of the aneurysms and relationship of the aneurysm with the adjacent arterial branches, by using volume-rendering techniques. MDCTA and DSA images (reference standard) were interpreted by 2 independent readers, and the results were compared. RESULTS: A total of 93 aneurysms were detected at DSA in 71 patients, whereas no aneurysms were detected in 14 patients. Compared with DSA, the overall sensitivity, specificity, and accuracy of MDCTA on a per-aneurysm basis were 92.5%, 93.3%, and 92.6%, respectively, for both independent readers. For aneurysms of <3 mm, however, MDCTA had a sensitivity of 74.1% for reader 1 and 77.8% for reader 2. There was excellent agreement between readers in the detection of aneurysms (kappa = 0.822). In addition, MDCTA was also accurate in determining N/D ratio of aneurysms, aneurysm lobularity, and adjacent arterial branches. CONCLUSION: MDCTA is accurate in the detection and characterization of intracranial aneurysms and can be used as a reliable alternative imaging technique to DSA in selected cases.     

MR angiography and surgery for unruptured familial intracranial aneurysms in persons with a family history of cerebral aneurysms.

OBJECTIVE: We used MR angiography to determine prevalence of unruptured familial intracranial aneurysms in a prepaid medical care program. We compared surgical outcomes and the cost of treating unruptured versus ruptured aneurysms. We compared the cost of MR angiography with the cost of screening mammography and with the cost of surgically treating a ruptured aneurysm. SUBJECTS AND METHODS: During a 30-month period, we performed MR angiography to show cerebral aneurysms in 63 surgical candidates who had one or more first-degree relatives with an aneurysm. Unruptured aneurysms seen on MR angiography were evaluated by digital subtraction angiography (DSA) and treated surgically. RESULTS: MR angiography showed nine unruptured aneurysms in six patients. Eight aneurysms were seen on MR angiography and nine were seen on DSA. Seven unruptured aneurysms were treated surgically. The mean treatment cost was 50% lower for an unruptured aneurysm than that for a ruptured aneurysm. No patient surgically treated for an unruptured aneurysm required rehabilitation, unlike 25% of patients with ruptured aneurysms. The annual total cost of MR angiography was equivalent to 2.9% of the annual cost of screening mammography. The annual cost of MR angiography equaled half the cost of treating one patient after aneurysm rupture. CONCLUSION: MR angiography showed a 9.5% prevalence of unruptured aneurysms among persons who had one or more first-degree relatives with a cerebral aneurysm. DSA confirmed 88% of aneurysms found on MR angiography. Persons with unruptured aneurysms had better treatment outcomes at lower cost than did patients treated for aneurysm rupture. The annual MR angiography cost was low compared with the cost of screening mammography and with the cost of treating one patient with aneurysm rupture.     

64层3D-CTA与3D-DSA对颅内动脉瘤评价的对比研究

目的 对比评价64层螺旋CT三维血管造影(3D-CTA)与三维数字减影血管造影(3D-DSA)对颅内动脉瘤的诊断价值.方法 28例临床怀疑颅内动脉瘤的患者均行64层螺旋CT血管造影和DSA,CT三维后处理主要包括容积重建(VR)及最大密度投影(MIP).常规二维DSA检查后,对可疑病变血管行旋转DSA检查,应用三维工作软件行3D后处理,比较3D-CTA与3D-DSA对动脉瘤显示的价值.结果 28例病例中22例CTA和DSA均显示动脉瘤并经手术或栓塞证实,其中1例CTA和DSA显示单个动脉瘤,手术证实为2个动脉瘤,1例CTA显示假阳性.3D-CTA与3D-DSA均能清楚显示动脉瘤形状、瘤径指向、瘤体直径、瘤颈、载瘤动脉、瘤体穿动脉情况,两者无明显差异.结论 64层3D-CTA在颅内动脉瘤诊断及细节显示上与3D-DSA无明显差异,一定程度上应能替代血管造影,指导临床治疗.     

螺旋CT血管造影在腹主动脉瘤诊断中的应用

目的 :评价螺旋 CT血管造影 (SCTA)在腹主动脉瘤诊断中的价值。方法 :13例腹主动脉瘤病人行螺旋 CT增强扫描 ,后进行各种重建 :表面阴影显示 (SSD)、多平面重建 (MPR)、最大密度投影 (MIP)。结果 :SSD明确显示动脉瘤的范围和周围血管的关系 ;MPR对瘤体内附壁血栓范围的显示较佳 ;而 MIP对瘤壁的钙化及对管腔各段的精确测量颇有价值。结论 :螺旋 CT血管造影操作简单、安全、诊断明确 ,能帮助和指导手术 ,可取代 DSA对腹主动脉瘤的诊断     

CT血管造影对脑动脉瘤的临床应用价值

目的 评价ＣＴ血管造影（ＣＡＴ）对脑动脉瘤的诊断价值。方法 脑动脉瘤,１９例行ＤＳＡ检查,１８例手术。用最大强度投影（ＭＩＰ）法进行血管重建。结果 ２０例患者中ＤＳＡ及手术发现２１个动脉瘤,ＣＴＡ发现０个。１９例为单发,１９例为单发,１例为多发（２个）,ＤＳＡ示位于基底动脉和左后交通动脉,ＣＴＡ未能显示后者动脉径为３～３３ｍｍ。１例有血管。靶重建、ＣＴＡ像与原始图像后交通动脉,ＣＴＡ像与原有显始图     

Comparison of 2D and 3D digital subtraction angiography in evaluation of intracranial aneurysms

BACKGROUND AND PURPOSE: Although digital subtraction angiography (DSA) is considered the criterion standard for depiction of intracranial aneurysms, it is often difficult to determine the relationship of overlapping vessels to aneurysms when using 2D DSA. We compared 2D and 3D DSA in evaluation of intracranial aneurysms. METHODS: Thirty-six consecutive patients with cerebral aneurysms underwent 2D and 3D DSA. After standard 2D DSA, rotational DSA was performed. Maximum intensity projection (MIP) and shaded surface display (SSD) images were created from the rotational DSA data sets. All images were assessed randomly for overall image quality, presence of aneurysm, presence of aneurysmal lobulation, visualization of aneurysmal neck, and relationship to adjacent vessels. Data analysis was conducted for 40 aneurysms treated by clip placement. RESULTS: One aneurysm that was not detected at 2D DSA was classified as uncertain on the basis of rotational DSA. All aneurysms were classified as probably or definitively present on the basis of MIP and SSD findings. Overall image quality of rotational DSA, MIP, and SSD was statistically inferior to that of the standard 2D DSA for visualization of distal arteries. However, MIP and SSD images were significantly superior to those of standard 2D DSA for all other evaluations. For detection of lobulation, SSD images were significantly superior to other images, and for visualization of aneurysmal neck and relationship to neighboring arteries, SSD images were significantly superior to those of rotational DSA. For evaluation of the relationship to neighboring arteries, MIP images were significantly superior to those of rotational DSA. CONCLUSION: Three-dimensional DSA, especially SSD, provided more detailed information for evaluating cerebral aneurysms than did standard 2D and rotational DSA.     

Spiral CT angiography and surgical correlations in the evaluation of intracranial aneurysms

We investigated the accuracy of spiral computed tomography angiography (CTA) in the detection and study of intracranial aneurysms by comparing CTA with selective angiograms and surgical findings. Twenty-six patients (9 men and 17 women; mean age 53.1 ± 1.8 years) with suspected intracranial aneurysms were submitted to CTA (1- to 2-mm slices, pitch 1:1, 24 s, RI = 1) after a conventional CT examination showing subarachnoid hemorrhage (SAH) in 19 cases and during neuroradiological investigations performed for other reasons in 7 cases. One hundred twenty to 150 ml iodate contrast agent (0.3–0.4 gI/ml) were injected intravenously at 5 ml/s rate and with 12- to 25-s delay calculated with a preliminary test bolus. Three-dimensional shaded surface display (3D SSD) and maximum intensity projection (MIP) reconstructions were obtained from axial images. Then, within 48 h, all patients were submitted to digital subtraction angiography (DSA), with separate assessment of CTA and DSA findings. Twenty-two aneurysms shown by CTA were confirmed at DSA and surgery (true positives), whereas the vascular lesion was not confirmed at DSA in 2 cases (false positives). The presence of intracranial aneurysms was excluded at both CTA and subsequent DSA in 7 cases (true negatives) and there were no false negatives; sensitivity was 100 %, specificity 77.8 %, and diagnostic accuracy 93.5 %. Computed tomography angiography aneurysm location was confirmed at surgery in all cases, with very high accuracy in assessing the presence of an aneurysm neck (100 %). Computed tomography angiography accurately depicted the aneurysm shape in 20 of 22 cases, but failed to depict its multilobed nature in 2 cases. The mean aneurysm diameter calculated at CTA was 0.99 ± 0.12 cm vs 1.09 ± 0.11 cm at surgery (p < 0.01). The present results suggest that the high sensitivity of CTA, if confirmed by further studies, might help in avoiding having to resort to arteriography after negative CTA in SAH patients. Received 15 July 1997; Revision received 30 September 1997; Accepted 5 November 1997     

Three-dimensional reconstructed rotational digital subtraction angiography in planning treatment of intracranial aneurysms

We evaluated three-dimensional (3D) reconstructions of 200 ° rotational digital subtraction angiography (DSA) images for their contributions to improving the safety of endovascular embolization of intracranial aneurysms. Standard DSA and 200 ° rotational DSA were performed in 40 adult patients (aged 21–77 years) with 45 intracranial aneurysms. Information obtainable from standard DSA and 3D-DSA images about aneurysm shape and size was compared. In 40 (89 %) of the 45 aneurysms 3D-DSA gave additional information about the anatomy of the aneurysm. In 17 (43 %) of these cases aneurysm anatomy could be visualized better on 3D-DSA than on standard DSA images. In three cases only 3D-DSA images showed blood vessels originating from the aneurysm. Reconstructed 3D images were also helpful in visualizing partially clipped aneurysms. On maximum-intensity projection images it was even possible to depict previously embolized aneurysms. Blood vessels originating from the aneurysm are visible on 3D-DSA images, and even previously clipped aneurysms can be visualized well. Rotational DSA with 3D reconstruction is a helpful tool in the assessment of intracranial aneurysms. Received: 7 September 1999; Revised: 26 November 1999; Accepted: 26 November 1999     

3D DSA在颅内动脉瘤介入诊疗中的应用价值

目的评价3D DSA在颅内动脉瘤诊疗中的作用,并与2D DSA比较。方法50个破裂的颅内动脉瘤均行2D DSA及3DDSA检查。观察2D DSA及3D DSA(VR)对颅内动脉瘤瘤颈和瘤体形态的显示,评估血管内栓塞治疗的可行性。获取血管内栓塞治疗的参考图像。通过对瘤颈和瘤体的测量,正确选择第1枚弹簧圈的直径及长度。结果50个破裂的颅内动脉瘤中,2D DSA能清楚显示14个动脉瘤的瘤颈;VR能清楚显示所有动脉瘤的瘤颈。2D DSA能清楚显示26个动脉瘤的形态;VR能清楚显示所有动脉瘤的形态。2D DSA认为6例不能行血管内栓塞治疗;3D DSA显示全部能行血管内栓塞治疗并栓塞成功。49个颅内动脉瘤行血管内栓塞治疗时均从3D DSA获取参考图像。48个第1枚弹簧圈选择正确。结论3D DSA在评估颅内动脉瘤血管内栓塞治疗的可行性、获得参考图像、动脉瘤精确测量等方面具有重要的临床价值。     

Intracranial aneurysms: clinical value of 3D digital subtraction angiography in the therapeutic decision and endovascular treatment

PURPOSE: To evaluate three-dimensional (3D) digital subtraction angiography (DSA) as a supplement to two-dimensional (2D) DSA in the endovascular treatment (EVT) of intracranial aneurysms. MATERIALS AND METHODS: In 22 ruptured aneurysms, neck visualization, aneurysm shape, and EVT feasibility were analyzed at 2D DSA (anteroposterior, lateral, and rotational views) and at maximum intensity projection (MIP) and surface shaded display (SSD) 3D DSA. The possibility of obtaining a working view for EVT at 3D DSA and the relevance of measurements in choosing the first coil also were assessed. RESULTS: Two-dimensional DSA images clearly depicted the aneurysm neck in four of 22 aneurysms; MIP images, in 10; and SSD images, in 21, but SSD led to overestimation of the neck size in one aneurysm. Aneurysm shape was precisely demonstrated in five of 22 aneurysms at 2D DSA, in eight at MIP, and in all cases at SSD. In two of 22 aneurysms, EVT seemed to be nonfeasible at 2D DSA; however, SSD demonstrated feasibility and EVT was successfully performed. In one aneurysm, only SSD demonstrated the extension of the neck to a parent vessel, which was proved at surgery. Working views for EVT were deduced from 3D DSA findings in 20 of 21 aneurysms. The choice of the first coil was correct in 19 of 21 aneurysms. CONCLUSION: Three-dimensional DSA is valuable for evaluating the potential for EVT, finding a working view, and performing accurate measurements.     

Magnetic Resonance Angiography of the Abdominal Aorta

Magnetic resonance angiography (MRA) of the abdominal aorta was performed in 36 patients using the "bright-blood" technique on the basis of a series of flow-compensated breath-hold 2 D-GE pulse sequences. Diverse diseases included complete occlusion, stenosis, atherosclerotic or dissecting aneurysm and renal artery stenosis. Coronal and axial projection angiograms [maximum intensity projection (MIP) algorithm] and individual GE images were compared with DSA and contrast-enhanced computed tomography (CT). Our data showed a good correlation of MR and digital subtraction arteriography (DSA) or CT resp. in all cases, when both rotating MIP angiograms and individual GE images were analyzed. Thus, MR is suggested to be a useful noninvasive diagnostic method for the abdominal aorta, particularly in preoperative staging of aneurysms, aortic occlusive disease, and stenosis of the proximal main renal artery. Drawbacks of the method are a signal loss in slow or turbulent flow conditions, and unsatisfactory spatial resolution in small vessels.     

多层螺旋CT三维血管成像在颅内动脉瘤评价中的初步应用--与DSA的对比研究

目的通过与数字减影血管造影(DSA)的对比研究,初步探讨三维CT血管成像(3D—CTA)在颅内动脉瘤评价中的应用价值。资料与方法对24例临床疑有颅内动脉瘤患者进行3D—CTA和DSA。3D—CTA后处理技术包括多平面重建(MPR)、最大信号强度投影(MIP)以及容积重建(VRT)。3D—CTA和DSA分别由相互独立的放射科医师实施和诊断,分别记录动脉瘤的位置、大小、形态以及与周围动脉分支等的关系。同时调查神经外科医师及患者对两种影像手段的认可度。结果3D—CTA发现13例15个动脉瘤,遗漏1个直径1．2mm的动脉瘤,发现的最小动脉瘤长径为1.8mm。DSA发现14例16个动脉瘤。CTA在显示瘤颈以及相邻骨质结构上明显优于DSA,而DSA空间分辨率较高。神经外科医师多认为CTA可以用作颅内动脉瘤的筛查和术前评估,而DSA仍是金标准。患者对CTA的接受度较高。结论3D—CTA是检查颅内动脉瘤高度敏感的无创影像手段,它可以作为颅内动脉瘤筛查和术前评估的首选技术。     

旋转血管造影技术对颅内动脉瘤的诊断价值

目的探讨旋转血管造影技术对颅内动脉瘤的诊断价值。方法对21例蛛网膜下腔出血（subarachnoid hemorrhage，SAH）患者的脑血管造影检查资料进行回顾性分析，所有患者均行常规数字减影血管造影（digital subtraction angiography，DSA）及旋转DSA检查，比较DSA和旋转DSA对动脉瘤瘤体、瘤颈和载瘤血管的显示情况。结果④21例患者共发现动脉瘤23个，常规DSA仅清晰显示16个，旋转DSA清晰显示23个。②DSA清晰显示瘤颈4个，载瘤血管11个，旋转DSA清晰显示瘤颈17个，载瘤血管21个。经统计学处理，差异均具有显著性（P〈0．01）。结论旋转DSA比常规DSA更容易发现动脉瘤．能更清晰显示动脉瘤形态、位置以及与周围血管的关系，是常规DSA不可缺少的补充。     

CT angiography,MR angiography and rotational digital subtraction angiography for volumetric assessment of intracranial aneurysms. An experimental study

The purpose of our experimental study was to assess the accuracy and precision of CT angiography (CTA), MR angiography (MRA) and rotational digital subtraction angiography (DSA) for measuring the volume of an in vitro aneurysm model. A rigid model of the anterior cerebral circulation harbouring an anterior communicating aneurysm was connected to a pulsatile circuit. It was studied using unenhanced 3D time-of-flight MRA, contrast-enhanced CTA and rotational DSA angiography. The source images were then postprocessed on dedicated workstations to calculate the volume of the aneurysm. CTA was more accurate than MRA (P=0.0019). Rotational DSA was more accurate than CTA, although the difference did not reach statistical significance (P=0.1605), and significantly more accurate than MRA (P<0.00001). CTA was more precise than MRA (P=0.12), although this did not reach statistical significance. Rotational DSA can be part of the diagnosis, treatment planning and support endovascular treatment of intracranial aneurysms. The emerging endovascular treatment techniques which consist of using liquid polymers as implants to exclude aneurysms from arterial circulation would certainly benefit from this precise measurement of the volume of aneurysms.     

Sixty-four-row multisection CT angiography for detection and evaluation of ruptured intracranial aneurysms: interobserver and intertechnique reproducibility

BACKGROUND AND PURPOSE: The purpose of this work was to assess intertechnique and interobserver reproducibility of 64-row multisection CT angiography (CTA) used to detect and evaluate intracranial aneurysms. MATERIALS AND METHODS: From October 2005 to November 2006, 54 consecutive patients with nontraumatic subarachnoid hemorrhage (SAH) underwent both CTA and digital substraction angiography (DSA). Four radiologists independently reviewed CT images, and 2 other radiologists reviewed DSA images. Aneurysm diameter (D), neck width (N), and the presence of a branch arising from the sac were assessed. RESULTS: DSA revealed 67 aneurysms in 48 patients and no aneurysm in 6 patients. Mean sensitivity and specificity of CTA for the detection of intracranial aneurysms were, respectively, 94% and 90.2%. For aneurysms less than 3 mm, CTA had a mean sensitivity of 70.4%. Intertechnique and interobserver agreements were good for the detection of aneurysms (mean kappa = 0.673 and 0.732, respectively) and for the measurement of their necks (mean kappa = 0.753 and 0.779, respectively). Intertechnique and interobserver agreements were excellent for the measurement of aneurysm diameters (mean kappa = 0.847 and 0.876, respectively). In addition, CTA was accurate in determining the N/D ratio of aneurysms and adjacent arterial branches. However, the N/D ratio was overestimated by all of the readers at CTA. CONCLUSION: Sixty-four-row multisection CTA is an imaging method with a good interobserver reproducibility and a high sensitivity and specificity for the detection and the morphologic evaluation of ruptured intracranial aneurysms. It may be used as an alternative to DSA as a first-intention imaging technique in patients with SAH.     

Intravenous 3D digital subtraction angiography in the diagnosis of unruptured intracranial aneurysms

Recent progress in digital subtraction angiography (DSA) devices makes it possible to perform rotational angiography with high resolution and high sensitivity. We tried intravenous (IV) 3D DSA in patients who had undergone MR angiography (MRA) suggestive of unruptured intracranial aneurysms. IV 3D DSA can be used as an alternative method for imaging unruptured intracranial aneurysms suggested on MRA.