Multislice computerized tomography angiography in the evaluation of intracranial aneurysms: a comparison with intraarterial digital subtraction angiography

OBJECT: The goal of this study was to assess the diagnostic accuracy of computerized tomography (CT) angiography performed with the aid of multislice technology (MSCT angiography) in the investigation of intracranial aneurysms, by comparing this method with intraarterial digital subtraction (IADS) angiography. METHODS: Fifty consecutive adult patients, who successively underwent MSCT angiography (four rows) and IADS angiography of intracranial vessels, were prospectively identified. The MSCT angiography studies consisted of 1.25-mm slices, with 0.8-mm reconstruction intervals, a pitch of 0.75, and timing determined by a test bolus. Two neuroradiologists, who were blinded to the initial interpretation of the MSCT angiograms as well as to those of the IADS angiograms, independently reviewed the MSCT angiograms for the detection and characterization of intracranial aneurysms. Forty-nine intracranial aneurysms were identified in 40 patients; 33 of these lesions were responsible for subarachnoid hemorrhage. The sensitivity, specificity, and accuracy of MSCT angiography in the detection of intracranial aneurysms were 94.8, 95.2, and 94.9%, respectively, on a per-aneurysm basis and 99, 95.2, and 98.3%, respectively, on a per-patient basis. Interobserver agreement was 98%. There was an excellent correlation between aneurysm size assessed using MSCT angiography and that determined by IADS angiography (slope = 0.916, r = 0.877, p < 0.001); however, 2 mm stood as the cutoff size below which the sensitivity of MSCT angiography was statistically lower. That method displayed great accuracy in characterizing the morphological characteristics of the aneurysm. CONCLUSIONS: Multislice CT angiography is an accurate and robust noninvasive screening test for intracranial aneurysms. It performs better than that reported for single-slice CT angiography. Introduction of eight- and especially 16-row MSCT angiography will provide further progression through thinner slices, a lower pitch, and a purely arterial phase.     

Multislice computed tomography coronary angiography: risk stratification of patients in the perioperative period

Multislice computed tomography coronary angiography is emerging as a reliable non-invasive method for the assessment of coronary artery disease, coronary anatomy and cardiac function. Improvements in computed tomography technology hold the promise of replacing the standard invasive procedure of conventional coronary angiography in selected patient groups. The ability of a six-second scan to identify flow-limiting coronary artery stenoses as well as characterising coronary atheromatous plaque components provides valuable information that can assist in refining perioperative cardiovascular risk. Multislice computed tomography's high negative predictive value and high specificity for stenoses allows it to effectively rule out coronary artery disease in patients with cardiac risk factors who have non-diagnostic or equivocal non-invasive cardiac stress tests. Other uses include evaluating patients who are symptomatic following percutaneous coronary intervention, evaluating coronary artery bypass grafts and coronary stent patency, detecting coronary stenosis prior to valve surgery and assessing coronary anatomy in patients with technically difficult arterial access. Avoiding the small but definite risks of conventional coronary angiography makes cardiac computed tomography an appealing alternative. An overview of multislice computed tomography is presented with particular attention placed on its role in the risk stratification of selected patients in the perioperative period. A risk stratification algorithm is suggested.     

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.     

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.     

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.     

Early operations for ruptured intracranial aneurysms. Comparative study with computed tomography

Summary The authors have analyzed the correlation between the results of early operation for ruptured intracranial aneurysms (45 cases) and CT scan (54 cases) performed within the second week after subarachnoid haemorrhage (SAH).There was a good correlation between the results of early operation within one week after the haemorrhage and CT findings.Surgical results were closely correlated to the incidence of vasospasm in our cases.All cases with symptomatic vasospasm showed bilateral high density in the cistern or ventricles on CT scan performed within three days after initial bleeding.For the cases within 24 hours after haemorrhage, surgical operation is recommended as early as possible, including removal of blood clots in the basal cistern and Sylvian fissure, and ventriculo-cisternal drainage for improvement of cerebrospinal fluid (CSF) circulation. On the other hand, the cases in which operations were performed during the second to seventh days and where CT scan revealed bilateral high density in the cistern or ventricles resulted in poor outcome or death.     

全身骨扫描在肝癌术前筛查中的临床意义

目的：探讨全身骨扫描在肝癌术前筛查中的临床意义。方法：210例原发性肝癌患者术前行全身骨扫描检查,统计骨转移检出率,分别和整组患者中的检出率进行比较。最后对发生骨转移的患者的确诊依据进行分析。结果：全部210名肝癌患者中,骨转移的检出率为8.57%（18/210）,其中有症状组的检出率为18.75%（6/32）,无症状组中骨转移的检出率为6.74%（12/178）。有症状组的检出率和全组检出率比较有统计学意义（P〈0.05）,无症状组的检出率和全组检出率比较无统计学意义（P〉0.05）。结论：对于具有骨转移临床症状的肝癌患者行骨扫描是必要的,但尚需其他辅助检查确诊,无骨转移症状患者行全身骨扫描不能提高骨转移的早期发现率。     

Fusion of subarachnoid hemorrhage data and computed tomography angiography data is helpful to identify the rupture source in patients with multiple intracranial aneurysms

Neurosurgical Review - Determining the rupture source is imperative in patient with aneurysmal subarachnoid hemorrhage (SAH). About one third of SAH cases with multiple intracranial aneurysms...     

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.     

容积CT数字减影血管造影与同步匹配蒙片去骨法对颅内动脉瘤的诊断价值比较

目的探讨容积CT数字减影血管造影(VCTDSA)与同步匹配蒙片去骨(MMBE)法对颅内动脉瘤的诊断价值。方法分析临床怀疑颅内动脉瘤、并接受VCTDSA检查的57例患者资料,其中47例经3DDSA和/或手术证实,比较VCTDSA与MMBE的减影图像质量、对动脉瘤的检出率以及二者图像后处理时间。结果57例患者分别采用VCTDSA与同步MMBE的图像质量差异有统计学意义(P0.05)。经手术和/或3DDSA结果证实,47例患者共检出53个动脉瘤;VCTDSA对于IA的检出率为96.23%(51/53),高于MMBE(46/53,86.79%);VCTDSA对于颈内动脉瘤的检出率为94.12%(32/34),高于MMBE(27/34,79.41%)。VCTDSA对于3mm的动脉瘤的检出率为86.67%(13/15),高于MMBE(10/15,66.67%)。VCTDSA的平均后处理时间为(3.87±0.73)min,同步MMBE的平均后处理时间为(4.05±0.79)min,二者差异有统计学意义(P0.05)。结论 VCTDSA是一种方便、快速的检查方法,图像真实、可靠,对颅内动脉瘤的检出与诊断优于同步MMBE。     

Screening for unruptured asymptomatic intracranial aneurysms in patients undergoing coronary angiography

In screening for unruptured asymptomatic intracranial aneurysms, an intracranial intra-arterial digital subtraction angiography (IA-DSA), posteroanterior view, was obtained in 72 consecutive patients who underwent coronary angiography for workup of angina pectoris. In cases where an aneurysm was suspected from IA-DSA, conventional intracranial angiography was obtained. Five asymptomatic unruptured aneurysms were detected in four of these cases. The aneurysms ranged from 4 to 16 mm in diameter. There were no complications associated with the coronary angiography nor with the additional intracranial IA-DSA, which required less than 5 minutes to perform in all cases. The value of performing intracranial IA-DSA in patients undergoing coronary angiography to screen for unruptured asymptomatic aneurysm is discussed, as is the possible racial differences in the frequency of aneurysms.     

Volume-rendered helical computerized tomography angiography in the detection and characterization of intracranial aneurysms

OBJECT: The goal of this study was to evaluate the utility of volume-rendered helical computerized tomography (CT) angiography in patients with intracranial aneurysms. The authors compared the abilities of CT angiography, digital subtraction (DS) angiography, and three-dimensional time-of-flight magnetic resonance (MR) angiography to characterize aneurysms. METHODS: Helical CT angiography was performed in 45 patients with suspected intracranial aneurysms by using volume-rendered multiplanar reformatted (MPR) images. Digital subtraction angiography was performed using biplane angiography. These studies and those performed using MR angiography were interpreted in a blinded manner. Two neurosurgeons and two interventional neuroradiologists independently graded the utility of CT angiography with respect to aneurysm characterization. Fifty-five aneurysms were detected. Of these, 48 were evaluated for treatment. Computerized tomography angiography was judged to be superior to both DS and MR angiography in the evaluation of the arterial branching pattern at the aneurysm neck (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.007), aneurysm neck geometry (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.001), arterial branch incorporation (compared with DS angiography, p = 0.021, and with MR angiography, p = 0.001), mural thrombus (compared with DS angiography, p < 0.001), and mural calcification (compared with DS angiography, p < 0.001, and with MR angiography, p < 0.001). For surgical cases, CT angiography had a significant impact on treatment path (p = 0.001), operative approach (p = 0.001), and preoperative clip selection (p < 0.001). For endovascular cases, CT angiography had an impact on treatment path (p < 0.02), DS angiography study time (p = 0.01), contrast agent usage (p = 0.01), and coil selection (p = 0.02). Computerized tomography angiography provided unique information about 39 (81%) of 48 aneurysms, especially when compared with DS angiography (p = 0.003). The sensitivity and specificity of CT angiography compared with DS angiography was 1. The sensitivity and specificity of CT and DS angiography studies compared with operative findings were 0.98 and 1, respectively. CONCLUSIONS: Computerized tomography angiography is equal to DS angiography in the detection and superior to DS angiography and MR angiography in the characterization of brain aneurysms. Information contained in volume-rendered CT angiography images had a significant impact on case management.     

Classification of intertrochanteric fractures with computed tomography: a study of intraobserver and interobserver variability and prognostic value

The purpose of this prospective study was to determine the level of interobserver and intraobserver agreement among orthopedic surgeons and radiologists when computed tomography (CT) scans are used with plain radiographs to evaluate intertrochanteric fractures. In addition, the prognostic value of current classifications systems concerning quality of life was evaluated. Sixty-one patients who presented with intertrochanteric fractures received open reduction and internal fixation with compression hip screw. Three orthopedic surgeons and 2 radiologists independently classified the fractures according to 2 systems: Evans-Jensen and AO (Arbeitsgemeinschaft für Osteo-synthesefragen). Fractures were initially graded with plain radiographs and then again in conjunction with CT. Results were analyzed using the (kappa) kappa coefficient. The 36-item Short-Form Health Survey was administered at baseline, 3 months, and 1 year, and results were correlated with fracture grade. Mean kappa coefficients when comparing radiography alone with radiography and CT scan were 0.63 for the AO system and 0.59 for the Evans-Jensen system. Both represent "fair" agreements. Mean overall interobserver kappa coefficients were 0.67 for radiologists and 0.57 for orthopedic surgeons. Radiologists also had higher intraobserver kappa coefficients. No significant relationships were found between follow-up Short Form Health Survey results and intraoperative grading of fractures. When these classification schemes are compared, interobserver agreement does not appear to change dramatically when information from CT scans is added. This may suggest that (1) more data have been provided by CT with greater possibilities for misinterpretation and (2) these classification schemes may not be comprehensive in describing fracture pattern and displacement. Finally, both systems failed to provide any prognostic value.     

Renal imaging: duplex ultrasound,computed tomography angiography,magnetic resonance angiography,and angiography

Renal artery stenosis (RAS) is one of the most common causes of severe hypertension (approximately 1–5% of all patients with hypertension). Presently, there is no universally accepted screening test for RAS. However, most clinicians use renal duplex ultrasound (RDU) imaging; while others use magnetic resonance angiography (MRA) or contrast computed tomography angiography in selected patients. This review will highlight various imaging modalities and discuss the pros and cons of each.