Detection of intracranial aneurysms with two-dimensional and three-dimensional multislice helical computed tomographic angiography

OBJECTIVE: Computed tomographic angiography (CTA) has become a diagnostic method for the detection of intracranial aneurysms in cases of subarachnoid bleeding. We sought to evaluate the detection of aneurysms with CTA with a novel multislice helical computed tomographic scanner. METHODS: Prospectively, 179 patients underwent multislice CTA, followed by digital subtraction angiography (DSA) of both carotid arteries with or without the posterior circulation, DSA of one carotid artery with or without the posterior circulation, or DSA of the posterior circulation alone. The total number of carotid arteries studied was 298, and the number of vertebrobasilar arteries studied was 124. RESULTS: Of 178 aneurysms verified with DSA or intraoperatively, CTA failed to detect 7 aneurysms of 1 to 2 mm and 1 partially thrombosed, 4-mm aneurysm. The sensitivity and specificity of CTA for aneurysm detection were 0.96 and 0.97, respectively. CONCLUSION: The first generation of multislice computed tomographic technology does not improve CTA to surpass DSA for the detection of small aneurysms of 1 to 2 mm. In practice, however, CTA is superior as a fast noninvasive method without complications.     

Usefulness of multislice computerized tomographic angiography in the postoperative evaluation of patients with clipped aneurysms

Background  

The aim of our study was to evaluate the diagnostic efficacy of multislice computed tomographic angiography (MSCTA) regarding exclusion quality after aneurysm clipping.     

Sixteen-row multislice computerized tomography angiography in the postoperative evaluation of patients with intracranial aneurysms

The goal of this study was to assess the diagnostic accuracy of 16-row multislice computed tomography angiography (CTA) compared with digital subtraction angiography (DSA) in the detection of aneurysm remnants and arterial patency after clipping of intracranial aneurysms. Thirty-seven consecutive patients with 40 clipped aneurysms (39 of which had ruptured) were studied with the aid of postoperative CTA and DSA. CTA was performed with a 16-row multislice CT scanner by using collimation of 0.75 mm. Two neuroradiologists evaluated the image quality of CTA and the presence of the residual aneurysms with a 5-point rating scale. DSA was considered a reference standard. Two aneurysms with incomplete closure were identified by the 16-slice CTA reconstructions. With 16-slice CTA, there were no false-positive results of an aneurysm with incomplete closure in any patient. Arterial patency could be reliably evaluated close to the clip. The sensitivity, specificity, and accuracy of 16-slice CTA for aneurysm occlusion and arterial patency were 100%[97.5% confidence interval (CI): 15.8 - 100%], 100% (97.5% CI: 90.7 - 100%) and 100% (97.5% CI: 91.2 - 100%), respectively. The positive and negative predictive values were 100 and 100%, respectively. The mean duration of the examination was 12 min for CTA and 40 min for DSA (p < 0.05). Sixteen-slice CTA was highly cost effective (p < 0.05). Sixteen-slice CTA is a valuable non-invasive diagnostic modality for the assessment of aneurysm remnants and arterial patency in patients after aneurysm clipping. Its high sensitivity and low cost warrant its use for postoperative routine control examinations following clip placement on an aneurysm.     

骶骨肿瘤多层螺旋CT动脉造影对术前评估的意义

[目的]探讨多层螺旋CT动脉造影技术(multislice spiralcomputed tomographic angiography,MSCTA)及其后处理技术对骶骨肿瘤术前评估及临床手术的指导价值。[方法]对12例骨盆肿瘤患者进行薄层扫描,术前评估病变的性质、累及范围、肿瘤的血供状态和肿瘤周围的血管情况。[结果]83.3%的病例术前诊断性质与病理结果一致;81.8%的骶骨破坏情况与手术所见基本一致;72.7%的手术病例肿瘤的血供状态和肿瘤周围的血管情况与手术所见基本一致。[结论]MSCTA及后处理技术在术前能够准确地评估骨盆肿瘤的性质、累及范围、肿瘤的血供和肿瘤周围的血管状况,对选择治疗方案、手术方式及术后重建具有重要意义。     

16层螺旋CT成像在活体肾移植供体术前评价中的价值

目的 探讨16层螺旋CT成像在活体肾移植供体术前评价中的价值. 方法 36例肾移植供体行16层CT平扫、动脉期、静脉期和排泄期检查.采用最大密度投影和容积再现技术处理图像,2位放射科医师独立评价每个供体血管和集尿系统的解剖结构.活体肾移植术中所见作为标准,计算16层CT评价肾血管和集尿系统的特异性和准确性. 结果 16层CT检查发现变异肾动脉7支,1支外科手术中确诊的副肾动脉被漏诊.16层CT检查正确诊断了外科手术发现的全部肾静脉和输尿管解剖变异,诊断肾动脉、肾静脉和输尿管解剖变异的特异性为100%(29/29)、100%(32/32)和100%(35/35),准确性分别为97%(36/37)、100%(36/36)和100%(36/36). 结论 16层CT检查评价活体移植肾的血管和集尿系统准确性较高,是一种很好的术前评价活体移植肾的无创性检查方法.     

3-Dimensional computed tomographic angiography for use of surgery planning in patients with intracranial aneurysms

Summary Background. After subarachnoid haemorrhage (SAH) diagnostic evaluation of the underlying cause is warranted since the rebleeding rate is high. The objective of the study was to answer the question, whether 3-Dimensional computed tomographic angiography (3D-CTA) is able to accurately determine the surgical indications in patients with intracranial aneurysms. Methods. After performing 3D-CTA the size of the aneurysm, direction of the aneurysmal dome, neck position and variants of the circle of Willis were analysed. Surgery was performed solely on CTA data in those cases, where the aneurysm was clearly visible. If the findings were negative or inconclusive, intra-arterial digital subtraction angiography (DSA) was also done. Findings. Between January 2001 and December 2002 100 patients (68 F, 32 M) were examined and 123 aneurysms (86 ruptured and 37 unruptured) were diagnosed. All patients received CTA preoperatively and in 27 patients selective DSA was additionally performed. Postoperatively in 34 patients the operative result was checked by DSA. A good correlation between CTA and the intra-operative findings was present in 92 of 100 patients. One aneurysm was not seen on CTA, but was on DSA. In four cases we could confirm DSA findings in CTA after re-evaluation of the data. In three cases neither CTA nor DSA clearly showed an aneurysm, but it was confirmed during surgery. A good correlation between CTA and DSA was found in 60 of 61 patients (98%). The correlation between CTA and intra-operative findings was good as expected in 92 patients, in 5 patients an aneurysm was detected on re-evaluation. Only one aneurysm could not be demonstrated by CTA but in DSA. Conclusion. CTA is less invasive, less time consuming, cheaper and easier to demonstrate the essential information regarding the aneurysm than DSA. We therefore recommend that following a careful analysis most aneurysms – 92% – can be operated solely on CTA data. Contributed equally.     

Evaluation of multislice computed tomographic perfusion imaging and computed tomographic angiography on traumatic cerebral infarction

Objective： To evaluate the application value of multislice computed tomographic perfusion imaging （MSCTPI） and multislice computed tomographic angiography （MSCTA） on traumatic cerebral infarction.
Methods： MSCTA was performed on 10 patients who were initiailly diagnosed as traumatic cerebral infarction by normal conventional computed tomography （NCCT）, among whom, 3 patients were examined by MSCTPI simultaneously. Reconstructed images of the intracranial artery were made with techniques of maximum intensity projection （MIP） and volume rendering （VR） from MSCTA scanning data. Then the graph of function of four parameters, regional cerebral blood flow （rCBF）, regional cerebral blood volume （rCBV）, mean transit time （MTT）, and time to peak （TTP）, acquired by the perfusing analysis software was obtained.
Results： Among the 10 patients with traumatic cerebral infarction, 6 showed complex type on NCCT, which depicted abnormality on MSCTA, and 4 showed simple type on NCCT, which had negative results on MSCTA. Among the 4 patients with abnormal great vessels, 2 suffered from stenosis or occlusion of the middle cerebral artery, 1 from spasm of the anterior cerebral artery, and 1 from spasm of the vertebral-basal artery. The image of MSCTPI of 1 patient with massive cerebral infarction on the right cerebral hemisphere confirmed by CT was smaller than those of the other patients, which showed occlusion of the ipsilateral middle cerebral artery on MSCTA, Among the 6 patients whose MSCTA showed no abnormality, 4 showed simple infarction and 2 showed complex infarction. The infarction focus of 5 patients occurred in the basal ganglia and 1 in the splenium of corpus callosum. Among the 2 cases of small cerebral infarction volume on NCCT, one was normal, the other showed hypoperfusion on MSCTPI and was normal on MSCTA.
Conclusion： The combination of MSCTPI and MSCTA is very useful for evaluating the change of intracranial artery in ischemic regions and assessing the cerebral h     

Prospective evaluation of screening multislice helical computed tomographic angiography in the initial evaluation of penetrating neck injuries

BACKGROUND: The optimal management strategy for patients sustaining penetrating neck injury without an urgent indication for operative exploration remains controversial. The objective of this study was to prospectively assess multislice helical computed tomography angiography (MCTA) as a stand alone screening modality for the initial evaluation of hemodynamically stable patients with penetrating neck injuries. Our hypothesis was that MCTA is a sensitive diagnostic screening test that could noninvasively evaluate the vascular and aerodigestive structures of the neck. METHODS: After Institutional Review Board approval, all penetrating neck injuries assessed during a 16-month period were prospectively evaluated at a Level I trauma center. Patients without an indication for urgent neck exploration underwent MCTA screening. MCTA accuracy was tested against an aggregate gold standard of final diagnosis encompassing all imaging, surgical procedures and clinical follow-up obtained. RESULTS: In all, 106 injuries penetrated the platysma; 15 required urgent exploration and 91 underwent MCTA (34 gunshot wounds/57 stab wounds). Nineteen external wounds were in zone 1, 39 were in zone 2, 10 in zone 3, and 23 traversed multiple zones. MCTA was nondiagnostic in 2.2% secondary to artifact from retained missile fragments. Follow-up was achieved in 84.5% of patients for a mean of 33.3 days (range: 2-150). MCTA achieved 100% sensitivity and 93.5% specificity in detecting all vascular and aerodigestive injuries sustained. MCTA correctly identified two tracheal and two carotid artery injuries requiring operative or endovascular repair in asymptomatic patients. No injuries requiring intervention were missed by MCTA. CONCLUSION: In the initial evaluation of stable penetrating neck injuries, MCTA appears to be a sensitive and safe screening modality. Further investigation is warranted.     

Sixteen-row multislice computed tomography angiography in the diagnosis and characterization of intracranial aneurysms: comparison with conventional angiography and intraoperative findings

OBJECT: The goal of this study was to prospectively compare the effectiveness of 16-slice computed tomography (CT) angiography with that of conventional digital subtraction (DS) angiography and the surgical findings used to detect and characterize intracranial aneurysms. METHODS: Two hundred forty-four consecutive patients underwent both CT angiography and DS angiography no more than 3 days apart. Computed tomography angiography was performed with a 16-row multislice CT scanner in which a collimation of 0.75 mm was used. Two observers independently reviewed the CT images, and 1 of the 3 attending neuroradiologists reviewed the DS angiograms. They determined the presence, location, quantitation, and characterization of the intracranial aneurysms. Statistical results were calculated independently for the image interpretation performed by the 2 CT scan readers and the DS angiogram reader by using the combination of DS angiography or intraoperative findings or both as a reference standard. RESULTS: One hundred thirty-six patients harboring 153 intracranial aneurysms were included in this series. There was no statistically significant difference in sensitivity between 16-slice CT angiography and conventional DS angiography (p > 0.05). The sensitivities of 16-slice CT angiography for aneurysms < 5 mm, 5-10 mm, and > 10 mm were 94.8, 100, and 100%, respectively, on a per-aneurysm basis. The overall sensitivity and specificity of CT angiography for aneurysms were 98.0 and 99.1%, respectively. Sixteen-slice CT angiograms were clearer and more accurate in depicting the relationship of aneurysms to bone structures and adjacent branch vessels. CONCLUSIONS: Computed tomography angiography using a 16-slice scanner is an accurate tool for detecting and characterizing intracranial aneurysms, including small aneurysms. Noninvasive 16-slice CT angiography will become a viable replacement for conventional DS angiography in the diagnosis and characterization of aneurysms.     

The surgical treatment of intracranial aneurysms based on computer tomographic angiography alone--streamlining the acute mananagement of symptomatic aneurysms

BACKGROUND: We aimed to prospectively assess the usefulness of computer tomographic angiography (CTA) in streamlining the management of symptomatic intracranial aneurysms in a tertiary neurosurgical unit, from admission to surgery. METHODS: We performed a prospective evaluation over a 2-year period of all symptomatic intracranial aneurysms managed according to a standardized departmental protocol, to assess how CTA has impacted the decision-making process pertaining to the suitability of this investigation to proceed directly to surgery. FINDINGS: A total of 90 patients with intracranial aneurysms were treated over the 2-year period. 23 (26%) underwent endovascular occlusion while 67 (74%) patients underwent a surgical clipping procedure. In the surgical group, 22 (33%) patients had their aneurysms clipped based on CTA alone, while 45 (67%) required additional conventional angiography prior to surgery. Thus around one quarter of all patients treated for symptomatic intracranial aneurysms in our unit had their aneurysm secured surgically based solely on CTA. INTERPRETATION: CTA significantly influences the acute management of symptomatic intracranial aneurysms by streamlining the decision-making process during the early and acute management of these lesions.     

Comparison of multislice computerized tomography angiography and digital subtraction angiography in the postoperative evaluation of patients with clipped aneurysms

OBJECT: In this study the accuracy of multislice computerized tomography (MSCT) angiography in the postoperative examination of clip-occluded intracranial aneurysms was compared with that of intraarterial digital subtraction (DS) angiography METHODS: Forty-nine consecutive patients with 60 clipped aneurysms (41 of which had ruptured) were studied with the aid of postoperative MSCT and DS angiography. Both types of radiological studies were reviewed independently by two observers to assess the quality of the images, the artifacts left by the clips, the completeness of aneurysm occlusion, the patency of the parent vessel, and the duration and cost of the examination. The quality of MSCT angiography was good in 42 patients (86%). Poor-quality MSCT angiograms (14%) were a result of the late acquisition of images in three patients and the presence of clip or motion artifacts in four. Occlusion of the aneurysm on good-quality MSCT angiograms was confirmed in all but two patients in whom a small (2-mm) remnant was confirmed on DS angiograms. In one patient, occlusion of a parent vessel was seen on DS angiograms but missed on MSCT angiograms. The sensitivity and specificity for detecting neck remnants on MSCT angiography were both 100%, and the sensitivity and specificity for evaluating vessel patency were 80 and 100%, respectively (95% confidence interval 29.2-100%). Interobserver agreements were 0.765 and 0.86, respectively. The mean duration of the examination was 13 minutes for MSCT angiography and 75 minutes for DS angiography (p < 0.05). Multislice CT angiography was highly cost effective (p < 0.01). CONCLUSIONS: Current-generation MSCT angiography is an accurate noninvasive tool used for assessment of clipped aneurysms in the anterior circulation. Its high sensitivity and low cost warrant its use for postoperative routine control examinations following clip placement on an aneurysm. Digital subtraction angiography must be performed if the interpretation of MSCT angiograms is doubtful or if the aneurysm is located in the posterior circulation.     

Clinical utility of multislice computed tomographic angiography for detection of cerebral vasospasm in acute subarachnoid hemorrhage.

Digital subtraction angiography (DSA) has been used as the standard method for detecting cerebral vasospasm after subarachnoid hemorrhage (SAH). Multislice computed tomographic angiography (CTA) is a relatively recent method used for evaluating the vasculature of the intracranial arteries. The purpose of this study was to compare multislice CTA and DSA for the detection and quantification of cerebral vasospasm after SAH, and to analyze the usefulness of multislice CTA. Eight patients with SAH underwent initial CTA with DSA within 72 hours after the onset of symptoms and follow-up multislice CTA and DSA 8 to 48 days after SAH. Five arterial locations were established in the A1 and A2 segments of the anterior cerebral artery, the M1 and M2 segments of the middle cerebral artery and the posterior cerebral artery (PCA) on both multislice CTA and DSA images. Vasospasm was classified as none, mild (up to 30% reduction in luminal diameter), moderate (31-60% reduction), and marked (at least 60% reduction) using the scale of Schneck and Kricheff. The multislice CT system used the following parameters: 1.25 mm collimation and 3.75 pitch with a 4-channel system. The degree of vasospasm revealed by the multislice CTA was significantly correlated with the degree of vasospasm revealed by DSA. In general, most discrepancies between CTA and DSA were in the detection of mild and moderate vasospasm. We found that the consistency between multislice CTA and DSA was greater for mild (100%, n=3) or moderate (100%, n=3) vasospasm than none (n=1) or marked vasospasm (n=1). However, it was unclear whether multislice CTA was more specific for a proximal location (A1, M1, PCA) or distal location (A2, M2) for evaluation of cerebral arteries. Multislice CTA can detect angiographic vasospasm after SAH with an accuracy similar to that of DSA. Multislice CTA is highly sensitive, specific and accurate in detecting mild and moderate cerebral vasospasm. It is less accurate for detecting no vasospasm and marked vasospasm. Therefore, the authors propose that multislice CTA be considered as a useful tool for the detection and management of intracranial vasospasm after SAH.     

Simulation of clipping position for cerebral aneurysms using three-dimensional computed tomography angiography

A novel method for the simulation of the clipping position for cerebral aneurysms based on three-dimensional computed tomography (3D CT) angiography was evaluated. Rotating the regional 3D CT angiography images including the aneurysm provided the virtual intraoperative views of 36 cerebral aneurysms that were eligible for clipping through a pterional approach with a perpendicularly applied straight clip. The cut-along-trace function of the 3D CT workstation was used to simulate the clipping position. The presence or absence of aneurysm remnants was preoperatively evaluated by observing the clipping simulation image. Intraoperative endoscopy and postoperative cerebral angiography were routinely performed to confirm the completeness of obliterations. Nineteen of 21 aneurysms for which complete obliteration was preoperatively expected were confirmed to have no aneurysm remnant. Nine of 15 aneurysms which were expected to have aneurysm remnant were confirmed to persist. The clipping simulation images could correctly predict aneurysm remnant after the initial clipping with a sensitivity of 90.5% and specificity of 60%. The present simulation method can predict aneurysm remnants and improve the likelihood of complete obliteration by clipping.     

Preoperative and postoperative evaluation of airways compression in pediatric patients with 3-dimensional multislice computed tomographic scanning: effect on surgical management

OBJECTIVES: Surgical management of airway compression of vascular origin requires an accurate analysis of anatomy and various mechanisms of compression. This study assessed the usefulness of 3-dimensional computed tomographic scanning in the preoperative and postoperative evaluation of airways compression in a pediatric population. METHODS: Thirty-seven consecutive patients (median age, 4 months) were examined with multislice 3-dimensional computed tomographic scanning: 18 patients before surgical treatment of anomalies of vascular rings, 2 patients because of respiratory symptoms after repair of esophageal atresia, and 17 patients because of persisting respiratory symptoms or prolonged mechanical ventilation after cardiac surgery for congenital heart disease. RESULTS: The procedure was successful, with high-quality diagnostic imaging obtained in all cases without any complications. The anatomy and relationship between the vascular arches and airways was analyzed in all referred patients with vascular arch anomalies confirmed on the basis of the surgical findings, and this helped the surgeon to plan the procedure and choose the best approach. After cardiac surgery, the airway and vascular structures involved and the mechanism of compression were specified in all but one case, and the 3-dimensional computed tomographic scan serves as an important tool for deciding whether to perform reoperation on patients requiring prolonged mechanical ventilation. CONCLUSION: Three-dimensional computed tomographic scanning is a safe, fast, and noninvasive method useful for accurately analyzing the mechanisms of airway compression of vascular origin and thus possible improving the surgical management of pediatric patients.     

Comparison of multislice computed tomography angiography and digital subtraction angiography in the detection of residual or recurrent aneurysm after surgical clipping with titanium clips

Purpose  To determine the diagnostic accuracy of 3D-CTA using volume rendering (VR) in the detection of residual or recurrent cerebral aneurysms after clipping. Material and methods  Between January 2006 and November 2007, 45 patients (20 female, 25 male) with 50 intracranial aneurysms treated using titanium clips were enrolled in this study. IADSA and 3D-CTA were performed within 1 month after surgery in 27 (60%) patients, after 1 year in 12 (26%) patients and after 5 years in six (13%) patients. In blinded fashion, CTA and DSA images were independently interpreted by two senior neuroradiologists with 7 years of experience in vascular diagnostic neuroradiology. The diagnostic performance of MDCTA compared with DSA for the detection of aneurysm remnants was measured by receiver operating characteristic (ROC) analysis. The area under the ROC curve, 95% confidence interval (CI), sensitivity, and specificity were calculated. Results  For the detection of residue–recurrent aneurysm; the sensitivity and specificity of MDCTA were 87.5% (95% CI = 52.9–97.8%) and 97.4% (95% CI = 86.5–99.5%) for the first reader and 87.5% (95% CI = 52.9–97.8%) and 100% (95% CI = 90.8–100%) for the second reader respectively. Receiver operating characteristic (ROC) analysis revealed good diagnostic performance for 3D-CTA (mean area under ROC curve (Az) = 0.98 and 0.99 for the first and the second observer, respectively) The kappa values extracted from the interobserver concordance analysis for agreement observers regarding the use of MDCTA for assessment of a remnant neck was 0.62. Conclusion  Using MDCTA, it is possible to demonstrate the status of intracranial aneurysms after surgical clipping in the immediate postoperative period as well as long-term follow-up with an high sensitivity and specificity when comparing with the findings of DSA.