Delineation of unruptured cerebral aneurysms by computerized angiotomography

[Cerebral aneurysms diagnosis by three-dimensional CT angiography]

Three-dimensional computerized tomography angiography is a fast diagnosis method and low invasive that passed to be used recently in the cases of intracranial aneurysms. This method presents a 100% specificity and can reach 95% of sensibility in the evaluation of the aneurysms in the circle of Willis, substituting the digital angiography but not in all of the cases. We report our experience in evaluation of the three-dimensional angiotomography exams in a period of 2 years between June of 1997 and June of 1999, were accomplished for detection of intracranial aneurysms in 136 patients, being 118 just with three-dimensional angiotomography and in 18 cases they were accomplished besides three-dimensional angiotomography also the conventional digital angiography. The exam of three-dimensional angiotomography possesses low risk being used better in the detection of the aneurysms when possess higher diameter than 3mm, with some limitations as in the very small aneurysms when smaller than 3mm, carotid intern cavarnous aneurysms, posterior circulation aneurysms as well as the non accomplishment of the dynamic exam.

Computerized tomography angiography in isolated third nerve palsies

OBJECT

The goal of this study was to assess the value of computerized tomography (CT) angiography as a diagnostic tool in isolated oculomotor nerve palsies.

METHODS

One hundred consecutive patients who presented with an isolated third nerve palsy were examined by CT angiography. This procedure was followed by conventional cerebral angiography in most patients in whom a vascular abnormality was noted on the CT angiography. Thus, all patients whose symptoms were caused by a compressive aneurysm were identified. The remaining patients were observed clinically to exclude the possibility that a missed cerebral aneurysm caused the isolated third nerve palsy. Eighteen patients harbored a cerebral aneurysm responsible for causing the isolated third nerve palsy. Most of the remaining patients experienced some degree of spontaneous recovery. There was no clinical evidence to indicate that a case of compressive cerebral aneurysm causing the isolated third nerve palsy had been missed on CT angiography.

CONCLUSIONS

Computerized tomography angiography is a reliable diagnostic tool for use in the assessment of patients with an isolated third nerve palsy; it can identify the minority of patients in whom conventional cerebral angiography may be required.

Long-term outcome of surgically treated unruptured cerebral aneurysms

We report the surgical morbidity and mortality and the results of statistical analysis based on the long-term outcome (average 50.1 months) of 69 patients with unruptured cerebral aneurysms. These patients harbored a total of 76 unruptured cerebral aneurysms, 72 larger than 3 mm in diameter. All the latter were surgically treated. There was no operative mortality. Operative morbidity occurred in 5 patients (7.2%), including hemiplegia in 2 from obliteration of perforator vessels, transient memory impairment in 2 due to brain retraction, and transient oculomotor nerve palsy in 1 patient resulting from an unknown etiology. During the observation period, 53 patients (76.8%) had a good or fair outcome, 11 (15.9%) had a poor outcome, and 5 (7.3%) died from causes unrelated to the aneurysms, such as pneumonia, gastrointestinal bleeding, and heart failure. The 5-year survival rate was 94%. Statistical analysis of the long-term outcome of all patients showed no significantly important factor influencing long-term morbidity. Prophylactic surgery of aneurysm is recommended for low-risk patients who may develop eventual rupture of an aneurysm, but perforator vessels around the aneurysm should be preserved, clips should be properly placed, and brain retraction should be minimized.

Detection of intracranial aneurysms by three-dimensional time-of-flight magnetic resonance angiography

The purpose of this study was to investigate the reliability of magnetic resonance angiography (MRA) for detection of intracranial aneurysms. Ninety-six consecutive patients who underwent both MRA using the three-dimensional time-of-flight technique (3D TOF) with the rephase/dephase subtraction method and conventional angiography were reviewed. MRA showed 22 aneurysms in 19 patients, and conventional angiography 28 aneurysms in 23 patients. The sensitivity of MRA was thus 79% for aneurysms in 83% of patients. MRA showed no aneurysm in 67 of 73 patients without aneurysms; its specificity was therefore 92%. The 6 false positive interpretations were suspected internal carotid artery aneurysms.

Clinical utility of three-dimensional time-of-flight magnetic resonance angiography for the evaluation of intracranial aneurysms

Magnetic resonance (MR) angiographic studies of 14 patients with intracranial aneurysms (AN) were analyzed retrospectively as compared with contrast angiographic studies. Eighteen of 19 (95%) lesions were detected, and the relation between AN and their parent vessels was precisely assessed. The diameter of the smallest aneurysm detected in our case was 3 mm. However, small vessels around AN were not visualized. Therefore, MR angiography (MRA) is definitely not a substitute for preoperative contrast angiography. MRA is a useful screening tool for nonruptured AN, but further refinement is required to evaluate emergency ruptured AN.

Natural history and risk factors of unruptured cerebral aneurysms

We report the results of a statistical analysis of the long-term outcome of 54 patients with 72 unruptured cerebral aneurysms, and identify the factors for predicting subsequent ruptures. Twenty-two patients died during the observation period, which averaged 43.7 months. The 5-year survival rate was 56%. Aneurysms ruptured in 11 patients (20.4%), 10 of whom died without undergoing surgery. The annual bleeding rate was 1.92%. The average size of the 11 ruptured aneurysms was 13.1 mm. In 4 patients, however, bleeding occurred in unruptured cerebral aneurysms of 4 and 5 mm, which suggests that leaving unruptured cerebral aneurysms of less than 10 mm in size untreated is hazardous. According to the Cox proportional hazards model, the shape and location of the aneurysm and the presence of hypertension were the most important factors for predicting a subsequent rupture. Our data suggest that unruptured cerebral aneurysms arising from the vertebrobasilar and middle cerebral arteries of 10-19 mm size and of multilobes had a statistically high probability of subsequent bleeding. Although 20 patients with 28 unruptured cerebral aneurysms were followed through repeated examinations, we could not correlate the risk of subsequent bleeding with changes in the size of the aneurysm.

Transient oculomotor nerve paresis in congenital distal basilar artery aneurysm

The clinical and pathologic findings of a 10-month-old girl with congenital heart disease who died after rupture of a congenital distal basilar artery aneurysm are reported. The patient developed transient minimal oculomotor nerve paresis 7 days prior to suffering a massive subarachnoid hemorrhage. The finding of transient third nerve dysfunction, particularly in the context of recurrent syncope, should prompt investigation for an intracranial arterial aneurysm.

Acute subdural hematoma after aneurysmal rupture; evacuation with aneurysmal clipping after emergent infusion computed tomography: case report

A 74-year-old woman sought treatment after an initial subarachnoid hemorrhage verified on computed tomographic scan with no focal neurological deficit. Shortly after admission, she sustained a second subarachnoid hemorrhage with acute neurological decompensation. A repeat computed tomographic scan revealed increased blood along the right medial temporal region, as well as in the interhemispheric fissure and bilateral sylvian cisterns. Also evident was a right hemispheric acute subdural hematoma. The patient's rapidly deteriorating neurological status precluded a cerebral angiogram; therefore, a double-dose infusion computed tomographic scan was performed. This revealed a cerebral artery aneurysm adjacent to the right medial temporal hematoma. She was taken to the operating room on the basis of this study. After evacuation of the right hemispheric subdural hematoma and clipping of the right posterior communicating artery aneurysm, the patient made a rapid, full neurological recovery.

Three-dimensional computerized tomography angiography in the diagnosis of cerebrovascular disease

Computer-generated three-dimensional reconstruction of the intracranial vascular system obtained by contrast-enhanced computerized tomography (CT) has been used in the diagnosis of 20 patients with known or suspected intracranial cerebrovascular disease. This technique allows visualization of the intracranial vasculature without exposing patients to the risks associated with intra-arterial angiography. The color prints and videotape images generated have been used to diagnose the presence of intracranial aneurysms, arteriovenous malformations, and venous angiomas. They have also been used to rule out structural abnormalities in patients with suspected intracranial vascular pathology and to screen patients with a strong family history of intracranial aneurysm. In 11 patients who underwent both three-dimensional CT angiography and intra-arterial angiography, the diagnostic correlation was 100%. No complications from the procedures or from incorrect diagnosis have been encountered. Although this technique requires further development and clinical evaluation, the authors' early experience with three-dimensional CT angiography suggests that this may become a valuable tool in the diagnosis of patients with cerebrovascular disease.

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.

CT infusion scanning for the detection of cerebral aneurysms

Computerized tomography (CT) infusion scanning can confirm the presence or absence of an aneurysm as a cause of spontaneous intracerebral hemorrhage. Eight patients who presented with spontaneous hemorrhage were examined using this technique. In five patients the CT scan showed an aneurysm which was later confirmed by angiography or surgery; angiography confirmed the absence of an aneurysm in the remaining three patients. This method is an easy effective way to detect whether an aneurysm is the cause of spontaneous intracerebral hemorrhage.

Obstructive hydrocephalus due to a giant aneurysm of the internal carotid bifurcation

A rare case of obstructive hydrocephalus associated with a giant aneurysm of the internal carotid artery is presented. The giant aneurysm, which was located in the prepontine cistern, was initially thought to be of basilar artery origin. Cerebral computed angiotomography had the most diagnostic value in disclosing the partially thrombosed giant aneurysm and its relationship with the surrounding arteries. After undergoing a ventriculoperitoneal shunt operation, the patient's clinical symptoms markedly improved.

Dynamic CT of micro- and macroangiopathic states of the cerebrum

Dynamic computed tomography utilizing intravenous contrast agents affords a unique opportunity to evaluate pathologic vascular states of the cerebrum in cross-section with an imaging system which is more contrast-sensitive than either conventional film-screen or digital subtraction angiography. Dynamic scanning therefore routinely allows the non-invasive detection of pathologic vascularity in-vivo in lesions that could previously only be detected reliably primarily with in-vitro techniques. The first section of this two part report examines the microscopic vascularity observed in active demyelination, inflammatory states, trauma, infarction and other forms of acquired cerebral disease. In the second section, the ability of intravenous dynamic cranial computed tomography to detect macroscopic pathologic vascularity is reviewed. The diagnostic principles of conventional angiography apply in this technique except that the lesion is viewed in cross-section, rather than in-toto with all structures superimposed. The method therefore yields a true tomographic angiogram. Abnormal vascular states associated with malignancies, vascular malformations, aneurysms, and vascular occlusions are simply evaluated and correlate precisely with the aberrant vascular patterns revealed angiographically.

Port wine nevus associated with ipsilateral saccular aneurysms: treatment by intraarterial balloon trapping

A 21-year-old woman with a port wine nevus presented with ipsilateral monocular visual loss. A computed tomography scan of the brain revealed a round suprasellar mass. Angiography demonstrated aneurysm of the right external carotid artery, and petrous, cavernous, and giant ophthalmic internal carotid aneurysms. Four detachable balloons were deployed with arteriographic guidance, resulting in occlusion of the right carotid artery. The association of aneurysms and phakomatoses is discussed. The use of detachable balloons in the treatment of nonresectable aneurysms represents a safe and advantageous option. The use of detachable balloons for carotid occlusion has proven to be an effective modality in the treatment of giant supraclinoid and carotid-cavernous aneurysms. Giant intracranial aneurysms have been surgically treated with carotid ligation proximal to the aneurysm and by direct approach using microsurgical technique. In cases in which direct ligation is not possible balloon occlusion represents an effective alternative. This case illustrates treatment by carotid trapping performed entirely with intraarterial balloons. In addition the association of saccular aneurysms in a patient with a port wine facial nevus is reported.