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.     

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.     

Evaluation of vasospasm after subarachnoid hemorrhage by use of multislice computed tomographic angiography

OBJECTIVE: Multislice computed tomographic angiography (CTA) can provide clearer vascular images, even of the peripheral arteries, than conventional CTA. Multislice CTA was compared with digital subtraction angiography (DSA) for the detection of cerebral vasospasm in patients with acute aneurysmal subarachnoid hemorrhage (SAH) to analyze whether multislice CTA can replace DSA in the detection of vasospasm after SAH. METHODS: Within 72 hours after the onset of symptoms, multislice CTA and DSA were performed in 20 patients with SAH. Multislice CTA and DSA were repeated on Day 7 to assess cerebral vasospasm. Regions of interest were established in the proximal and distal segments of the anterior and middle cerebral arteries on both multislice CTA and DSA images, and the agreement between the severity of vasospasm on multislice CTA and DSA images was statistically compared. The multislice Aquilon computed tomography system (Toshiba, Inc., Tokyo, Japan) used the following parameters: 1 mm collimation and 3.5 mm per rotation table increment (pitch, 3.5). RESULTS: The degree of vasospasm as revealed by multislice CTA correlated significantly with the degree of vasospasm revealed by DSA (P < 0.0001). The agreement between the severity of vasospasm on multislice images obtained via CTA and DSA in the overall, proximal, and distal segments of the cerebral arteries was 91.6, 90.8, and 92.3%, respectively. CONCLUSION: Multislice CTA can detect angiographic vasospasm after SAH with accuracy equal to that of 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.     

Reliability of computed tomographic angiography in the diagnosis of brain death

OBJECTIVE: This study examined the validity of cerebral computed tomographic (CT) angiography in the diagnosis of brain death (BD) compared with conventional cerebral angiography. METHODS: This prospective, monocentric study was performed over a 24-month period and included 43 patients, at least 18 years of age, with clinical criteria of BD. All patients underwent cerebral CT angiography and then cerebral angiography. To confirm BD, the CT scan had to show the absence of perfusion of A2 anterior cerebral artery segments (A2-ACA), M4 middle cerebral artery segments (M4-MCA), P2 posterior cerebral artery segments (P2-PCA), basilar artery, internal cerebral veins, and finally the great cerebral vein. Cerebral angiography showed cerebral blood flow arrest at the level of the foramen magnum for posterior circulation and carotid siphon for anterior circulation. RESULTS: For 30 patients, BD was confirmed by both examinations. For 13 patients, cerebral angiography confirmed BD, whereas CT angiography still showed cerebral perfusion; the divergence rate was 30.2%. CONCLUSIONS: CT angiography seems to be a promising exam to confirm BD. However, the divergence with cerebral angiography is significant mainly concerning A2-ACA, which are proximal. It may be possible to only use the absence of opacification of M4-MCA, P2-PCA, basilar artery, and venous blood return to remain in conformity with the French law. In all cases, the international medical community should obtain a consensus for the interpretation of CT angiography to use it extensively as a complementary exam for BD.     

Three‐dimensional multislice spiral computed tomographic angiography: A potentially useful tool for safer free tissue transfer to complicated regions

Three‐dimensional multislice spiral computed tomographic angiography (3D‐MSCTA) is a minimally invasive method of vascular mapping. The aim of this study was to evaluate the clinical usefulness of this imaging technique in delineating the recipient vessels for safer free tissue transfer to complicated regions. 3D‐MSCTA was performed preoperatively in 26 patients scheduled for free tissue transfer, in whom the availability of the recipient vessels were considered to be uncertain, and 23 of these were operated on. Radiographic and operative findings regarding the availability of the recipient vessels for anastomosis were correlated in 21 of these 23 patients. 3D‐MSCTA yielded two false‐positive results; anastomosis was not possible because of widespread atherosclerotic plaques and poor flow observed in the recipient arteries despite the good caliber observed in 3D‐MSCTA images. 3D‐MSCTA provides a noninvasive means of preoperatively assessing recipient site vessels for anatomic variations and suitability before free tissue transfer and enables the surgeon to establish an appropriate treatment plan. But it is not 100% reliable yet and the possibility of false‐positive results should be kept in mind, especially inthe patients with peripheral vascular disease. 3D‐MSCTA has the potential to replace digital subtraction angiography for planning of microvascular reconstructions and newer devices with higher resolutions will probably increase the reliability of this technique. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.     

Association of hypovolemia after subarachnoid hemorrhage with computed tomographic scan evidence of raised intracranial pressure

Hypovolemic patients are more likely to suffer delayed cerebral ischemia and infarction after a subarachnoid hemorrhage (SAH). Prompt recognition and correction of hypovolemia may improve the outcome. We have identified computed tomographic (CT) scan findings that increase the probability of a patient presenting with hypovolemia soon after an SAH. The plasma volume (PV) of 25 patients admitted within 96 hours of an SAH was measured using radioiodinated serum albumin. The normal PVs were measured in an outpatient setting 6 months later or predicted from their total body water. Nine patients (36%) were found to be hypovolemic, defined as a fall in PV exceeding 10% of the normal PV (mean fall, 18 +/- 2%). Sixteen patients were normovolemic or hypervolemic (mean PV, +9 +/- 2%). The basal cisterns were compressed or obliterated on the CT scans of all hypovolemic patients compared with 12.5% of normovolemic patients (chi-square, 14.52; P less than 0.01). The probabilities of a patient being hypovolemic if the CT scan indicated raised intracranial pressure were high: hydrocephalus, P = 0.80; compression of the basal cisterns, P = 0.82; and compression of the basal cisterns associated with intracerebral hematoma or midline shift, P = 1.00. Patients with an SAH and radiological evidence of raised intracranial pressure should be considered at particular risk for systemic hypovolemia.     

Traumatic intracranial aneurysm in infancy

An anterior cerebral artery traumatic aneurysm in a 15-month-old infant is described. The diagnosis was confirmed by computed tomographic angiography. The patient recovered fully after successful clipping of the aneurysm. As the signs of traumatic intracranial aneurysm may be subtle especially in young children, a high degree of suspicion is essential in patients presenting with delayed neurological deterioration after head trauma.     

Magnetic resonance and computed tomographic image-directed stereotaxy for animal research

Current stereotactic frames for animal experimentation presume normal intracranial anatomy for atlas-directed probe placement. This is an invalid assumption for animal brain tumor models, where distortions of cerebral anatomy make image-directed stereotaxy necessary. To address this need, an accurate and reproducible magnetic resonance and computed tomographic compatible image-directed stereotactic apparatus for animal experimentation is presented.     

Computed tomographic angiography and perfusion in the diagnosis of brain death

IntroductionAccording to Polish brain death (BD) criteria, instrumental confirmatory tests should be used in certain clinical situations, particularly any case for which clinical examinations seem inadequate. Electrophysiological tests are often unavailable. Therefore, cerebral perfusion testing is the method of choice with four-vessel digital subtraction angiography (DSA), the gold standard. Unfortunately, DSA is an expensive and invasive examination that requires an experienced neuroradiologist and the availability of an angiography suite. Recently, multirow computed tomographic devices became available, even in smaller hospitals in Poland. Despite this fact, computed tomographic angiography (CTA) and computed tomographic perfusion (CTP) are not accepted in BD diagnosis protocols in Poland because of limited experience and a lack of widely accepted criteria. In this situation, we started a multicenter trial to determine the accuracy of CTA and CTP to confirm BD.MethodsWe examined 24 patients who fulfilled standard clinical BD criteria. We recognized the absence of brain perfusion in CTA examination following the criteria proposed by the French Society of Neuroradiology, namely, the absence of opacification of M4 middle cerebral artery segments (M4-MCA) and of deep cerebral veins.ResultsIn all of our patients, CTA showed absence of opacification of M4 segments and of deep cerebral veins. In addition, three patients had CTA showing weak opacification of A2 segments of the anterior cerebral artery (A2-ACA) and M2 or M3-MCA. Opacification of the basilar artery or of the posterior cerebral arteries was not noted in any case. In all patients, CTP revealed zero values of regional cerebral blood volume and regional cerebral blood flow. Conventional angiography confirmed cerebral circulatory arrest in all 24 cases.ConclusionCTA and CTP seem to be promising radiological examinations for the diagnosis of BD. They may be noninvasive alternatives to conventional cerebral angiography, and to the other instrumental confirmatory tests, that are unavailable or inadequate.     

多层螺旋CT血管成像在烟雾病诊断中的应用

目的探讨多层螺旋CT血管成像（MSCTA）在烟雾病诊断中的价值以及应用前景。方法回顾性分析10例烟雾病患者的MSCTA及数字减影血管造影（DSA）的影像学资料。结果MSCTA可清晰显示狭窄、闭塞以及异常增多的脑血管。容积重建有利于显示病变血管与周围结构的空间关系,综合最大密度投影法重建和多曲面重建图像分析可清晰显示异常增多的脑血管,即烟雾状血管。MSCTA对狭窄及闭塞血管的检出率为66．2％（53/80）;DSA对狭窄及闭塞血管的检出率为67．5％（54／80）,两者比较差异无统计学意义（P〉0．05）。MSCTA对颅底异常血管网的显示及分布情况与DSA大致相似。结论MSCTA诊断烟雾病的灵敏度高,是早期诊断烟雾病的重要依据,早期诊断、及时治疗是改善烟雾病患者预后的有效方法。     

Cognitive deficits related to computed tomographic findings after surgery for a ruptured intracranial aneurysm

A consecutive series of 118 patients operated on for ruptured intracranial arterial aneurysms was studied. Ninety-six of them could be adequately examined with a battery of psychological tests and computed tomographic scans 1 year after a subarachnoid hemorrhage. Seventeen orthopedic control patients with no history of brain damage were also tested. The pattern of cognitive deficits was strongly related to the findings on the computed tomographic scans. Patients with left lateral infarctions had deficits on performances requiring verbal efficiency, including memory and classification tasks, whereas patients who had right lateral infarctions were poor on a visuoconstructional task (the copying of Rey's Figure). These deficits were pronounced when lateral infarction was associated with diffuse brain damage. Patients with frontal medial infarctions had low scores on memory tests; the inefficiency in verbal fluency, categorical reasoning, and memory was related to diffuse brain damage. The patients who had no infarctions did not differ significantly from the control group. Cognitive impairments after left lateral and frontal medial infarctions, as well as diffuse brain damage, correlated with the Glasgow Outcome Scale.     

Screening for blunt cerebrovascular injury: evaluating the accuracy of multidetector computed tomographic angiography

BACKGROUND: Digital subtraction angiography (DSA) has been widely considered the "gold standard" for diagnosing blunt cerebral vascular injury, but recent advances in multidetector computed tomographic angiography (CTA) may have led to improved accuracy compared with DSA. METHODS: A retrospective study of patients who underwent CTA and DSA for suspected blunt cerebral vascular injury was performed. Two neuroradiologists and one radiology resident, blinded to the other test, independently reviewed CTA and DSA studies. Sensitivity and specificity of CTA were determined using DSA as the gold standard. RESULTS: Thirty-two patients met the study criteria. Consensus DSA interpretation identified 17 vascular injuries in 15 patients. Among the three radiologists, the sensitivity of CTA for carotid injury ranged from 83% (10 of 12) to 92% (11 of 12), and the specificity ranged from 88% (36 of 41) to 98% (40 of 41). The sensitivity for vertebral artery injury ranged from 40% (2 of 5) to 60% (3 of 5), and the specificity ranged from 90% (35 of 39) to 97% (38 of 39). CTA sensitivity rose to 80% (four of five) in the vertebral artery when a lower diagnostic threshold was used. CONCLUSION: The sensitivity of CTA for carotid artery injury at our center was higher than in previous studies. This might be attributable to the superior quality of multidetector CTA images. Our conclusions on CTA accuracy in the vertebral artery are limited by the small number of injuries.     

Positive-contrast computed cranial tomographic encephalography in children

Positive-contrast computed tomographic encephalography is a safe and effective technique for the evaluation of intraventricular, paraventricular, and cystic intracranial lesions in children. It provides dynamic as well as morphologic information not readily available by routine computed tomographic scanning alone. Our experience with the use of this technique in 21 children forms the basis for this paper.     

Evaluation of posttraumatic cerebral blood flow velocities by transcranial Doppler ultrasonography

Thirty-five patients were admitted to the hospital with Glasgow coma scale scores of 4 to 7 after severe, blunt head injury. Blood flow velocities of the middle cerebral artery (MCA) and the ipsilateral internal carotid artery (ICA), high in the neck, were recorded noninvasively by Doppler ultrasonography. Serial examinations were begun within 48 hours of trauma and continued until the patient either died or was discharged. Spasm of the MCA was assumed if the ratio of the velocity of blood flow in the MCA (VMCA) to the velocity of blood flow in the ICA (VICA) exceeded 3 (normal value, 1.7 +/- 0.4). In cases of severe MCA spasm, this ratio is higher because of increased flow velocity in the MCA and reduced flow in the ICA due to increased cerebrovascular resistance. Higher MCA velocities with VMCA/VICA above 3, consistent with MCA spasm, were found in 14 of the 35 patients (40%). The increase began as early as 48 hours after injury, reached a maximum between Days 5 and 7, and lasted until 2 weeks after injury. There was a significant correlation between the occurrence of vasospasm and the quantity of cisternal or intracerebral blood seen on a computed tomographic scan. No correlation was found with the age of the patients, the Glasgow coma scale score at admission, the intracranial pressure, or the functional outcome 6 months after injury. The occurrence of a secondary infarction in a patient with severe MCA spasm suggests that, at least in some cases, spasm may influence the prognosis.     

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。     

Multispiral computed tomographic angiography of renal arteries of live potential renal donors: a review of 118 cases

OBJECTIVES: Review of the angiographic data of 118 live kidney donors was performed to assess the renal vessel anatomy; compare the findings with the perioperative findings using multislice spiral (MS) computed tomographic angiography (CTA) with the use of 50 mL of intravenous contrast; determine the sensitivity of this technique in the workup of live potential renal donors; and finally to discuss and compare the results of the present study with the reported results using single-slice spiral (SS) CTA, magnetic resonance angiography (MRA), and conventional angiography (CA). METHODS: Retrospective analysis of the angiographic data of 118 of prospective live kidney donors was performed. All donors underwent renal angiography on MSCTA scanning using 50 mL of intravenous contrast with 1.25-mm slice thickness followed by maximum intensity projection and virtual rendering techniques postprocessing algorithms. Analysis was made on imaging and intraoperatively for the number of renal arteries as well as their bifurcation pattern, location, vessel caliber, length, and venous anatomy, and these were then compared with each other. RESULTS: MSCTA showed clear delineation of the main renal arteries in all the donors with detailed vessel morphology. The study also revealed a 100% sensitivity in the detection of accessory renal vessels, which had an overall incidence of 26.67%, with the most common distribution in the perihilar region. CONCLUSIONS: The present study showed a 100% sensitivity and specificity in the visualization and detection of main and accessory renal vessels with the use of only 50 mL of intravenous contrast with similar results seen with CA which has so far been considered the "gold standard." The results on MSCTA were also better than those with the use of SSCTA and MRA in the workup of liver renal donors, with the above technique also proving to be more cost effective. The overall incidence of supernumerary vessels was the same as reported in the literature; however, a higher incidence of single aberrant vessels was seen on the right side, contrary to what has been suggested so far and was attributable to improved detection of accessory vessels less then 2 mm in diameter.     

A middle cerebral artery dissecting aneurysm manifesting solely with pain, following a vertebral artery dissecting aneurysm

A 41-year-old male had presented with severe neck pain and was diagnosed as having a left vertebral artery (VA) dissecting aneurysm. During the observation period, he suddenly suffered from a pain on his left temple. MR imaging revealed neither SAH nor cerebral infarction. MR angiography, computed tomographic (CT) angiography and cerebral angiography showed fusiform dilatation of the M1 portion of the left middle cerebral artery (MCA) which had been normal in the former study. The abnormality of the left MCA normalized on both MR and CT angiography 6 months after the second onset. Because of the chronological change of radiological findings compatible with the symptom, we diagnosed the second episode as a MCA dissecting aneurysm manifesting with isolated pain. Among the previous forty-four MCA dissecting aneurysms, all but one case presented with hemorrhagic or ischemic event. In addition, this is the only case of multiple dissecting aneurysms of VA and MCA manifesting with isolated pain.     

Immediate postoperative seizures: Incidence and computed tomographic findings

Convulsive seizures within 48 hours after intracranial operations using a craniotomy were reviewed. Incidence was 8.9% (44 of 493 operations): 13.5% of brain tumor operations and 3.8% of aneurysmal operations. We demonstrated that preoperative seizures, sites of lesion, subtherapeutic anticonvulsant levels, and postoperative local organic lesions were important factors causing the immediate postoperative seizures. Among them, a survey of postoperative computed tomography scans disclosed nine intracerebral hemorrhages, eight cases of cerebral edema, and four cerebral infarctions in the 44 patients; such major complications had a significant correlation with postoperative seizures (p < 0.005).     

Contrast enhancement of cerebellar infarction on computed tomography

The author analyzed the appearance on computed tomography after infusion of contrast medium of cerebellar infarction in three patients, whose diagnosis was made on the basis of clinical presentation, cerebral angiography, and sequential computed tomographic scans. Their computed tomographic appearance was not always the same as seen in the supratentorial counterpart, in showing reminiscence of an arteriovenous malformation, a leptomeningeal dissemination of a tumor or meningitis, or a neoplasm, respectively. For these reasons, it was concluded that it is important to notice the contrast-enhanced computed tomographic appearance in cerebellar infarction, when making a differential diagnosis between various pathologies in the posterior fossa.