Clinical application of 16-row multislice computed tomographic angiography in the preoperative and postoperative evaluation of intracranial aneurysms for surgical clipping

BACKGROUND: Sixteen-row multislice CTA has great potential for use in the studies of intracranial aneurysms. The aim of the study was to assess the clinical application of 16-row multislice CTA in the preoperative and postoperative evaluation of intracranial aneurysms for surgical clipping. METHODS: A total of 42 patients (45 aneurysms) underwent surgery using titanium clips. The CTA was performed with a 16-row multislice CT machine; detector slice, 0.75 mm; reconstruction interval, 0.40 mm; and timing determined by bolus trigger. The neuroradiologist independently evaluated the shape, size, and location of aneurysms; the relationship to other structures; and the presence of neck remnants and patency of the parent artery after clipping on MIP images, VR imaging, and thin-slab MIP and VR images. RESULTS: Sixteen-slice CTA clearly provided the shape and location of aneurysms, the size of the sac and the neck, and the relationship of aneurysms to bone structures and adjacent branch vessels; and this information would help the neurosurgeons find aneurysms and clip them successfully. Three clipped aneurysms with neck remnants were identified by the 16-slice CTA, and the parent artery could be reliably evaluated close to the clip. CONCLUSION: Sixteen-slice CTA is a useful reference for patients undergoing surgical clipping of aneurysms and can provide much effective information to clipped aneurysms.     

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     

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。     

CT三维血管造影诊断出血动脉瘤

目的 评价CT血管造影(CTA)在颅内动脉瘤破裂后蛛网膜下腔出血诊断中的价值及手术指导意义。方法 对63例急性蛛网膜下腔出血病人急诊行螺旋CT扫描,然后行脑血管三维成像。结果 发现颅内动脉瘤24例。有1例阴性经全脑血管造影(DSA)发现存在动脉瘤。诊断均以手术证实。结论 CTA对动脉瘤蛛网膜下腔出血是一种微创、快速、准确的诊断技术,对于急诊或危重病人应为首选。     

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.     

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.     

Distinction between paraclinoid and cavernous sinus aneurysms with computed tomographic angiography

OBJECTIVE: To examine the reliability of using the optic strut as a landmark in computed tomographic (CT) angiography, to differentiate between intradural and extradural (cavernous sinus) aneurysms involving the paraclinoid segment of the internal carotid artery (ICA). METHODS: Microanatomic dissections were performed with five cadaveric heads (10 sides), to establish the relationships of the optic strut to the cavernous sinus and the ICA. Results from these anatomic studies were compared with intraoperative and CT angiographic findings for four patients with nine intracranial aneurysms involving the paraclinoid segment of the ICA. RESULTS: The inferior boundary of the optic strut accurately localized the point at which the ICA pierced the oculomotor membrane (proximal dural ring) and exited the cavernous sinus. The optic strut and its relationship to the ICA could be well observed on CT angiograms. During surgery, six of six aneurysms that arose distal to the optic strut were identified intradurally and were successfully clipped. Conversely, all aneurysms that arose proximal to the optic strut were observed to lie within the cavernous sinus. An aneurysm at the optic strut was within the clinoid segment or interdural, between the proximal and distal rings. CONCLUSION: The optic strut, as identified with CT angiography, provided a reliable anatomic landmark for accurate discrimination between intradural and extradural (cavernous sinus) aneurysms.     

Clinical usefulness of multi-planar reconstruction images of three-dimensional computed tomographic angiography for internal carotid artery aneurysms

The usefulness of multi-planar reconstruction (MPR) images of three-dimensional computed tomographic angiography (3D-CTA) for the diagnosis of internal carotid artery (ICA) aneurysms is described. Eleven unruptured ICA aneurysms including six cases of IC-cavernous aneurysm, two cases of IC-ophthalmic artery aneurysm, two cases of IC-posterior communicating artery aneurysm and one cases of IC-anterior choroidal artery aneurysm, were examined by magnetic resonance angiography (MRA), digital subtraction angiography (DSA), 3D-CTA and its MPR images. 3D-CTA and DSA were useful to identify the aneurysmal neck in small aneurysms, but it was difficult to identify the aneurysmal neck in small aneurysms by 3D-CTA-MPR images. DSA and MRA were not useful for identifying the aneurysmal neck in aneurysms more than 10 mm in diameter, as a precise viewing of the neck could not be found due to their large size. For large aneurysms, neither was 3D-CTA useful for identifying the aneurysmal neck when their large size and surrounding bony structures overlapped the aneurysmal neck. On the other hand, 3D-CTA-MPR was very useful for identifying the aneurysmal neck without overlapping by surrounding bony structures. 3D-CTA-MPR images clearly visualized the calcification of the wall. 3D-CTA-MPR images are obtained from 3D-CTA source images without any additional stress to the patients, and they are more useful for the diagnosis as well as demonstration of the aneurysmal neck particularly in more than large aneurysms.     

多层螺旋CT血管成像诊断脑动脉瘤:与DSA对比研究

目的 探讨16层螺旋CT容积再现脑血管成像技术对脑动脉瘤的诊断价值。方法 对23例临床怀疑脑动脉瘤患者（其中蛛网膜下腔出血者20例）的16层螺旋CT三维血管后处理图像、DsA图像进行回顾性对比研究。CT后重建技术分别采用小视野容积再现技术（shutter volume rendering）、最大密度投影法（M1P）和多曲面重建（MPR），所有CT图像及DSA脑血管造影图像均由两位放射科医生和两位脑外科医生进行双盲法分析评价。结果 16层螺旋CT脑血管成像共检出动脉瘤25个，其中3例为多发性，1例CT血管成像（CTA）结果为阴性，阳性率95．7％（22／23），与DSA比较符合率95．7％（22／23）；16层CTA发现动脉瘤的敏感性为100％（24／24），特异性为100％（1／1），准确性为96．2％（25／26）。CTA对显示瘤体、瘤颈、载瘤动脉与周围血管关系与DSA相比更清晰、确切，并能显示病灶与颅骨结构间的关系，立体感强。结论 16层螺旋CT脑血管成像对脑动脉瘤具有极高的诊断价值，相对无创是诊断脑动脉瘤的最佳影像检查方法，有望替代DSA。     

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.     

Rebleeding of ruptured cerebral aneurysms during three-dimensional computed tomographic angiography: report of two cases and literature review

Although three-dimensional computed tomographic angiography (3D-CTA) is less complicated and time-consuming than conventional cerebral angiography (CCA) and represents a reliable alternative for evaluating cerebral aneurysms, some patients experience aneurysmal rerupture during 3D-CTA. Two women, 79 and 71 years old, who presented with severe subarachnoid hemorrhage (SAH) underwent 3D-CTA within 3 h after SAH onset. Their images clearly indicated extravasation from their aneurysms. Neither patient recovered from deep coma, and both died within 2 days. We reviewed the literature with special reference to the condition of SAH patients at admission and the interval between SAH onset and 3D-CTA, and discuss serious complications of 3D-CTA study. Although aneurysmal rerupture may reflect the natural course, rerupture during 3D-CTA, especially in SAH patients who are in poor clinical condition during the acute stage, should be recognized as a potentially fatal complication. Their blood pressure must be strictly controlled and factors such as their clinical condition and the interval from the ictus must be considered.     

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.