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.     

64层螺旋CT头颈动脉联合成像诊断颅内动脉瘤的应用价值

 目的 评价64层螺旋CT诊断颅内动脉瘤的临床应用价值。方法 选取我院176例颅内动脉瘤患者的头颈CTA(computed tomographic angiography,CTA)检查资料,评价颅内动脉瘤的大小、形态、位置及术后情况。结果 176例均行数字减影血管造影(digital subtraction angiography,DSA)存在动脉瘤(157经手术治疗),共计 201个动脉瘤,其中19例为多发动脉瘤。首次CTA明确诊断动脉瘤171例(196个),漏诊5例,阳性诊断率97.5%(196/201)。171例(196个)中颈内动脉瘤112例,后交通动脉瘤10例,前交通动脉瘤26例,基底动脉瘤5例,大脑中动脉瘤13例,大脑前动脉瘤5例,对照DSA再次重组首次漏诊的5例CTA图像,又发现动脉瘤2例,阳性诊断率提高至98.5%。结论 应用多层螺旋CT头颈血管联合成像选择合理的后处理方法,有助于提高图像质量与诊断的准确性,对临床术前评估与术后评价有重要意义。     

16层螺旋CT血管成像在颅内动脉瘤诊断中的价值

目的:探讨16层螺旋CT血管成像(CTA)在颅内动脉瘤诊断中的价值.方法:对临床疑诊为颅内动脉瘤16例患者行CTA检查,其中8例同期行数字减影血管造影(DSA)检查.原始图像重建采用最大密度投影(MIP)和容积再现技术(VR).结果:16例患者经CTA检出动脉瘤17个.1例患者为多发动脉瘤(2个),15例为单发动脉瘤.瘤体以圆形或卵圆形居多(13个),也可以显示为肾形(2个)、葫芦形(1个)和串蛛状(1个).瘤体最大直径18 mm,最小直径1.5 mm.8例行DSA检查的患者中,7例DSA所见与CTA结果一致,1例DSA漏诊1个动脉瘤.结论:16层CTA检出动脉瘤准确率高,快速、无创,可以作为诊断动脉瘤首选影像学方法,尤其适合于急诊情况下,并能补充DSA诊断信息.     

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。     

Follow-up of intracranial aneurysms treated with detachable coils: comparison of gadolinium-enhanced 3D time-of-flight MR angiography and digital subtraction angiography

PURPOSE: To compare three-dimensional (3D) time-of-flight magnetic resonance (MR) angiography with digital subtraction angiography (DSA) in the follow-up of intracranial aneurysms treated with selective endovascular placement of detachable coils. MATERIALS AND METHODS: Sixty-eight consecutive patients with intracranial aneurysms were included in the prospective study. The goal was to evaluate 3D time-of-flight MR angiography versus DSA for the detection of a residual aneurysm neck or residual flow inside the coil mesh. RESULTS: Eighty-one MR angiographic and 83 DSA examinations were performed; 15 patients were examined with both modalities twice. MR angiography was not possible in two patients. In another patient, the quality of MR angiography was not sufficient to assess the treated aneurysm. In 72 of the remaining 80 MR angiographic and DSA examinations, there was good correlation between the two modalities. In 54 cases, neither image type showed remnants or recurrence, but in 18, both showed residual aneurysm. In eight cases, the MR angiographic and DSA results differed. In one of these cases, MR angiography depicted residual aneurysm but DSA depicted an arterial loop. In seven cases, a small (<3-mm) remnant was not detected at MR angiography. CONCLUSION: Because very small aneurysm remnants or recurrences probably are not clinically important, MR angiography is an option for following up intracranial aneurysms treated with detachable coils and may partly replace DSA.     

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.     

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。     

脑动脉瘤螺旋CT血管造影的评价

目的：探讨螺旋CT血管造影在脑动脉瘤诊断和治疗中的价值。方法：16例脑动脉瘤患者行SCTA和DSA检查，并进行对照研究，其中8例行MRI检查。4例行GDC栓塞治疗，2例巨大动脉瘤行球囊导管栓塞术，1例行外科手术，其余病例行内科保守治疗。结果：所有16例动脉瘤均在SCTA和DSA上清晰显示，瘤颈和瘤体大小2种方法测量统计学差异无显著性意义(P值均＞0.05)，对瘤壁钙化、瘤内情况如血栓、瘤颈情况、动脉瘤在颅内空间定位及动脉瘤与载瘤动脉的关系，SCTA较DSA具有优势，又对瘤体及瘤颈的测量SCTA较DSA方便、准确，SCTA操作简单、微创、无危险性，患者易于接受。结论：SCTA对动脉瘤具有诊断作用，可作为脑动脉瘤诊断的筛查技术，对其治疗有重要的指导作用，可作为动脉瘤术前常规检查。     

CT during selective arteriography: anatomical assessment of unruptured intracranial aneurysms before endovascular treatment

Our aim was to investigate the usefulness of helical CT during selective angiography (CT arteriography) in pretreatment assessment of unruptured intracranial aneurysms. We studied 47 unruptured aneurysms in 34 prospectively recruited patients for whom endovascular embolisation was initially considered. As pretreatment assessment, we performed rotational digital subtraction angiography (DSA) followed by CT arteriography. The findings on axial source images (axial images) and reconstructed three-dimensional CT angiography (3D-CTA) of CT arteriography were compared to those of rotational DSA, with particular attention to the neck of the aneurysm and arterial branches adjacent to it. Information provided by CT arteriography was more useful than that of rotational DSA as regards the neck in 25 (53 %) of 47 cases and as regards branches in 18 (49 %) of 37 aneurysms. On axial images, small arteries such as the anterior choroidal artery were seen in some cases. CT arteriography can provide valuable additional information about unruptured aneurysms, which cannot be obtained by rotational DSA alone. This technique is useful for obtaining anatomical information about aneurysm anatomy and for deciding the therapeutic strategy. Received: 22 May 2000/Accepted: 25 September 2000     

Detection of intracranial aneurysms: multi-detector row CT angiography compared with DSA

PURPOSE: To prospectively compare the effectiveness of multi-detector row computed tomographic (CT) angiography with that of conventional intraarterial digital subtraction angiography (DSA) used to detect intracranial aneurysms in patients with nontraumatic acute subarachnoid hemorrhage. MATERIALS AND METHODS: Thirty-five consecutive adult patients with acute subarachnoid hemorrhage were recruited into the institutional review board-approved study and gave informed consent. All patients underwent both multi-detector row CT angiography and DSA no more than 12 hours apart. CT angiography was performed with a multi-detector row scanner (four detector rows) by using collimation of 1.25 mm and pitch of 3. Images were interpreted at computer workstations in a blinded fashion. Two radiologists independently reviewed the CT images, and two other radiologists independently reviewed the DSA images. The presence and location of aneurysms were rated on a five-point scale for certainty. Sensitivity and specificity were calculated independently for image interpretation performed by the two CT image readers and the second DSA image reader by using the first DSA reader's interpretation as the reference standard. RESULTS: A total of 26 aneurysms were detected at DSA in 21 patients, and no aneurysms were detected in 14 patients. Sensitivity and specificity for CT angiography were, respectively, 90% and 93% for reader 1 and 81% and 93% for reader 2. The mean diameter of aneurysms detected on CT angiographic images was 4.4 mm, and the smallest aneurysm detected was 2.2 mm in diameter. Aneurysms that were missed at initial interpretation of CT angiographic images were identified at retrospective reading. CONCLUSION: Multi-detector row CT angiography has high sensitivity and specificity for detection of intracranial aneurysms, including small aneurysms, in patients with nontraumatic acute subarachnoid hemorrhage.     

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.     

颅内动脉瘤的MSCTA诊断

目的:探讨64层螺旋CT血管成像(64-MSCTA)对颅内动脉瘤的诊断价值。方法:搜集经DSA和手术证实的颅内动脉瘤18例,所有的病例均行64层螺旋CT血管成像。分别用最大密度投影(MIP)、容积再现(VR)、多平面重组(MPR)法进行图像重组。13例行手术治疗,5例行DSA检查。结果:18例患者中MSCTA发现动脉瘤17个,其中大脑中动脉7个,大脑前动脉6个,大脑后动脉2个,颈内动脉2个。1例左侧颈内动脉瘤MSCTA漏诊,经DSA检查发现。MSCTA上动脉瘤显示直径3～20mm。MSCTA所发现的17个动脉瘤与手术及DSA所见的动脉瘤位置、大小、形态基本一致。结论:MSCTA能清楚显示颅内动脉瘤的形态、位置及其与周围的解剖关系,为手术或介入治疗动脉瘤提供有价值的信息。     

Intracranial aneurysms: role of multidetector CT angiography in diagnosis and endovascular therapy planning

PURPOSE: To evaluate the sensitivity of 16-detector row computed tomographic (CT) angiography in diagnosis of intracranial aneurysms and to determine whether multidetector CT angiography provides sufficient diagnostic information to guide endovascular treatment, with combined imaging and clinical data as the reference standard. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. Eighty-seven patients clinically suspected of having subarachnoid hemorrhage underwent multidetector CT angiography and digital subtraction angiography (DSA). Aneurysm detection with multidetector CT angiography and DSA was analyzed on a per-patient and a per-aneurysm basis. For each aneurysm deemed ruptured on multidetector CT angiograms, the same multidetector CT angiography data set was used to determine whether the aneurysm was suitable for endovascular coil placement or whether a neurosurgical procedure was preferable. Criteria were based on neck width in relation to aneurysm size and the presence of vessels originating from the aneurysm. Results were compared with actual treatment that had been performed in each aneurysm after full diagnostic work-up, including DSA. Sensitivity, specificity, and positive and negative predictive values for aneurysm presence were determined. RESULTS: The reference standard revealed 84 aneurysms in 63 patients. Multidetector CT angiography was used to correctly identify 62 of 63 patients with 80 of 84 aneurysms and to correctly rule out aneurysms in 24 patients. DSA was used to correctly identify 62 of 63 patients with 79 of 84 aneurysms and to correctly rule out aneurysms in 23 patients. Per patient, the sensitivity, specificity, and positive and negative predictive values, respectively, for presence of aneurysm(s) were 98%, 100%, 100%, and 96% for multidetector CT angiography and 98%, 100%, 98%, and 96% for DSA. Per aneurysm, the possibility of coil embolization was correctly assessed with multidetector CT angiography in 69 (93%) of 74 target aneurysms for acute occlusive treatment. CONCLUSION: Multidetector CT angiography offers high diagnostic accuracy-equivalent to that of DSA-in the detection of intracranial aneurysms. Also, the possibility of coil embolization can be reliably determined with multidetector CT angiography.     

Three-dimensional time-of-flight MR angiography in the evaluation of intracranial aneurysms treated with Guglielmi detachable coils

BACKGROUND AND PURPOSE: Intravascular treatment of intracranial aneurysms is a relatively new therapeutic technique and long-term controlled angiographic trials are needed to assess persistence of aneurysm occlusion. Our purpose was to evaluate the effectiveness of 3D time-of-flight (3D-TOF) MR angiography as a noninvasive screening tool in the follow-up of cerebral aneurysms treated with Guglielmi detachable coils (GDCs). METHODS: Forty-nine patients with 50 intracranial aneurysms previously treated with GDCs were studied with both DSA and 3D-TOF MR angiography. In 14 cases, a second follow-up examination was performed, for a total of 64 aneurysms evaluated. In 25 aneurysms, both pre- and postcontrast MR angiographic studies were obtained. RESULTS: In seven of 64 aneurysms, the MR angiographic studies were considered to be unreliable owing to the presence of artifacts that obscured part of the parent artery and did not allow an accurate evaluation of the aneurysm neck. These seven aneurysms, however, all were shown to be completely occluded at digital subtraction angiography (DSA). In the remaining 57 aneurysms, DSA revealed complete occlusion in 39 and the presence of residual patency in 18, whereas MR angiography showed complete occlusion in 38 and residual patency in 19. Enhanced MR angiography proved to be useful in evaluating residual patency in large and giant aneurysms and in better depicting the distal branch arteries. CONCLUSION: Although artifacts related to the presence of coils are evident on a considerable number of imaging studies, our findings indicate that MR angiography is useful in the evaluation of residual patency of cerebral aneurysms treated with GDCs and may eventually prove valuable in the follow-up of those cases in which a good initial correlation with DSA was demonstrated.     

Intracranial aneurysms treated with Guglielmi detachable coils: usefulness of 6-month imaging follow-up with contrast-enhanced MR angiography

BACKGROUND AND PURPOSE: This study was undertaken to assess the utility of contrast-enhanced MR angiography at 6 months after endovascular treatment of intracranial aneurysms with Guglielmi detachable coils. METHODS: Contrast-enhanced MR angiography was performed in 47 patients at 6 and 12 months after endovascular treatment of intracranial aneurysms (48 aneurysms). Digital subtraction angiography (DSA) was used as reference and was performed at 12 months after the treatment in all patients. MR angiographs were analyzed independently by two senior radiologists. DSA and MR angiography findings were assigned into one of three categories: complete obliteration, residual neck, or residual aneurysm. RESULTS: All examinations were assessable. Interobserver agreement was judged as very good for contrast-enhanced MR angiography (kappa=0.96), with one discrepancy between examiners. Comparison between MR angiography at 6 months and DSA at 12 months showed an excellent agreement between techniques (kappa=0.93). Two cases of complete occlusion at DSA were misclassified as a residual neck at 6-month MR angiography. All aneurysm recanalizations at DSA already were detected on MR angiography at 6 months. The size of aneurysm recanalization did not increase between both MR angiographs performed at 6 and 12 months. CONCLUSION: Contrast-enhanced MR angiography after selective embolization of intracranial aneurysm seems to predict properly early aneurysm recanalizations.     

Comparison of three-dimensional rotational angiography with digital subtraction angiography in the assessment of ruptured cerebral aneurysms

BACKGROUND AND PURPOSE: Rotational angiography (RA) and digital subtraction angiography (DSA) together may depict more intracranial aneurysms than DSA alone. We compared the diagnostic value of 3D RA and biplanar DSA in detecting, classifying, and planning treatment for ruptured intracranial aneurysms. METHODS: A total of 53 patients with acute subarachnoid hemorrhage (Hunt and Hess grades I-V) underwent angiography with both methods. DSA was performed in two to six standard projections in every vascular territory. Three-dimensional RA datasets were evaluated by using surface-shaded display and maximum intensity projection. The usefulness of DSA images and 3D datasets in detecting aneurysms (number, configuration) and treatment planning were retrospectively analyzed in a blinded manner. RESULTS: In 42 patients, 56 aneurysms were detected, (one to five per patient; size, 0.6-20.4 mm); no aneurysm was found in 11 patients. RA revealed seven aneurysms not seen at conventional DSA. RA failed to depict one aneurysm visible only in a compression series. Delineation of the aneurysmal neck improved with RA in 71% of cases; the parent vessel and its relationship to adjacent vessels was demonstrated better with RA than with DSA in 45% and 50%, respectively. Endovascular treatment was proposed in nine patients; microsurgical therapy, in 26. In seven patients, both options were rated as being equal. Actual treatment consisted of eight endovascular procedures and 30 neurosurgical operations. Four patients died before therapy. CONCLUSION: Compared with DSA, 3D RA allows more exact depiction of anatomic details that are important in planning surgery and interventional therapy for intracranial aneurysms. RA depicted more aneurysms.     

Detection,characterization and endovascular therapy planning of intracranial aneurysms with 16-channel multidetector row CT angiography

Aim

To study the role of multidetector row CT angiography (MDCTA) in detection, characterization and endovascular therapy planning of intracranial aneurysms in comparison with digital subtraction angiography (DSA).

Material and methods

Between April 2011 and March 2012, prospective study of 43 patients with suspected cerebral aneurysms (27 females and 16 males) was done, their ages ranged from 40 to 74 years. Patients were referred to the Radiodiagnosis Department, from neurology and neuro-surgery departments for suspected cerebrovascular lesions. Aneurysm detection with multidetector CT angiography and DSA was analyzed.

Results

The MDCT angiograms were interpreted for the presence, location, size, ratios of the aneurysm (dome to neck ratio (D/N), aspect ratio), neck width, lobularity of the aneurysms and relationship of the aneurysm with the adjacent arterial branches, by using volume-rendering techniques.MDCT and DSA were done for all patients. Twenty-three patients had a single aneurysm, 4 had 2 aneurysms, 2 had 5 aneurysms and no aneurysms were detected in 14 patients presented with subarachnoid hemorrhage on unenhanced CT, the most common shape was saccular aneurysm (90%) and the most common size was medium size (43.9%). We determined the neck of 28 aneurysm (68%) and the remaining 13 could not be determined (32%).Among 41 cerebral aneurysms, 26 aneurysms were detected in anterior circulation (63.4%) and 15 in posterior circulation (36.5%). The middle cerebral artery (29.2%) was the most common site.In 55% of studied cases presented with aneurysmal rupture SAH was the commonest type of hemorrhage. According to Hunt and Hiss classification grades 2 and 3 were the most prevalent (17 patients and 6 patients respectively) followed by grade 4 (4 patients) and lastly grades 0 and 1 (one patient for each).

Conclusion

Sixteen channel Multidetector CT angiography offers high diagnostic accuracy nearly equivalent to that of DSA in the detection of intracranial aneurysms. However, 16 channel- MDCTA still has limited sensitivity in detecting aneurysms of 3 mm or less, despite its technical advances. MDCT can be used as a reliable alternative imaging technique to DSA in selected cases.     

Cerebral aneurysms: detection and delineation using 3-D-CT angiography.

PURPOSE: We compared three-dimensional image (3-D-CT) angiography with conventional angiography to determine the clinical usefulness of this technique. MATERIALS AND METHODS: We studied 15 patients with cerebral aneurysms using dynamic CT with intravenous injection of contrast material and reconstructed 3-D-CT angiography. RESULTS: 3-D-CT angiography could be performed in conjunction with standard axial high-resolution CT without any additional scanning time and within 10-30 minutes for the overall study. All aneurysms were clearly visualized by 3-D-CT angiography. 3-D-reconstruction was very helpful in demonstrating the neck, shape, and direction of aneurysms, and adjacent vascular and bony structures. One small aneurysm that was difficult to detect on axial images was clearly visualized on 3-D-reconstruction. CONCLUSION: 3-D-CT angiography of cerebral aneurysms could be performed routinely and was helpful in demonstrating the complex anatomy of cerebral aneurysms and surrounding structures. This technique will be of value in surgical planning.     

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     

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.