Cerebral angiographic risk in mild cerebrovascular disease

Can contrast-enhanced ultrasound with second-generation contrast agents replace computed tomography angiography for distinguishing between occlusion and pseudo-occlusion of the internal carotid artery?

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of contrast-enhanced ultrasound with a second-generation contrast agent in distinguishing between occlusion and pseudo-occlusion of the cervical internal carotid artery, comparing it with that of conventional Doppler ultrasound and the gold standard, computed tomography angiography.

METHOD

Between June 2006 and June 2012, we screened 72 symptomatic vascular surgery outpatients at a public hospital. Among those patients, 78 cervical internal carotid arteries were previously classified as occluded by Doppler ultrasound (without contrast). The patients were examined again with Doppler ultrasound, as well as with contrast-enhanced ultrasound and computed tomography angiography. The diagnosis was based on the presence or absence of flow.

RESULTS

Among the 78 cervical internal carotid arteries identified as occluded by Doppler ultrasound, occlusion was confirmed by computed tomography angiography in only 57 (73.1%), compared with 59 (77.5%) for which occlusion was confirmed by contrast-enhanced ultrasound (p>0.5 vs. computed tomography angiography). Comparing contrast-enhanced ultrasound with Doppler ultrasound, we found that the proportion of cervical internal carotid arteries classified as occluded was 24.4% higher when the latter was used (p<0.001).

CONCLUSIONS

We conclude that, in making the differential diagnosis between occlusion and pseudo-occlusion of the cervical internal carotid artery, contrast-enhanced ultrasound with a second-generation contrast agent is significantly more effective than conventional Doppler ultrasound and is equally as effective as the gold standard (computed tomography angiography). Our findings suggest that contrast-enhanced ultrasound could replace computed tomography angiography in this regard.

Balloon test occlusion of internal carotid artery: Angiographic findings predictive of results

AIM: To reveal angiographic findings to predict the result of balloon test occlusion (BTO).

METHODS: The cerebral angiograms of 42 consecutive patients who underwent cerebral angiography including both the Matas and Allcock maneuvers and BTO were retrospectively analyzed. Visualization of the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) by the cross flow on the tested side during the Matas or Allcock maneuver was graded on a 5-point scale. Circle of Willis (COW) anatomy with respect to the presence/absence of a collateral path to reach the tested internal carotid artery (ICA) was classified into four categories. A univariate logistic analysis was used to analyze the associations between each angiographic finding and the BTO result. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for each finding were calculated.

RESULTS: Five patients (12%) were BTO-positive and the remaining 37 patients (88%) were BTO-negative. Visualizations of the ACA and MCA as well as the COW anatomy were significantly associated with the BTO result (P = 0.0051 for ACA, P = 0.0002 for MCA, and P < 0.0001 for COW anatomy). In particular, good MCA visualization and the presence of an anterior connection (collateral path to the tested ICA from the contralateral ICA via the anterior communicating artery) in the COW were highly predictive for negative BTO (negative predictive value = 100% for both).

CONCLUSION: A BTO result may be predicted by angiographic findings including ACA/MCA visualization and COW anatomy.

Whole body magnetic resonance angiography and computed tomography angiography in the vascular mapping of head and neck: an intraindividual comparison

Introduction

The aim of the study was to compare the detectability of neck vessels with contrast enhanced magnetic resonance angiography (MRA) in the setting of a whole-body MRA and multislice computed tomography angiography (CTA) for preoperative vascular mapping of head and neck.

Methods

In 20 patients MRA was performed prior to microvascular reconstruction of the mandible with osteomyocutaneous flaps. CTA of the neck served as the method of reference.

1.5 T contrast enhanced magnetic resonance angiograms were acquired to visualize the vascular structures of the neck in the setting of a whole-body MRA examination. 64-slice spiral computed tomography was performed with a dual-phase protocol, using the arterial phase images for 3D CTA reconstruction. Maximum intensity projection was employed to visualize MRA and CTA data. To retrieve differences in the detectability of vessel branches between MRA and CTA, a McNemar test was performed.

Results

All angiograms were of diagnostic quality. There were no statistically significant differences between MRA and CTA for the detection of branches of the external carotid artery that are relevant host vessels for microsurgery (p = 0.118). CTA was superior to MRA if all the external carotid artery branches were included (p < 0.001).

Conclusions

MRA is a reliable alternative to CTA in vascular mapping of the cervical vasculature for planning of microvascular reconstruction of the mandible. In the setting of whole-body MRA it could serve as a radiation free one-stop-shop tool for preoperative assessment of the arterial system, potentially covering both, the donor and host site in one single examination.

Risk factors of ischemic lesions related to cerebral angiography and neuro-interventional procedures

Embolic stroke is not a rare complication of cerebral angiography. The risk factors for incidental embolism after cerebral angiography were retrospectively examined using diffusion-weighted magnetic resonance imaging (DWI) in 180 patients who underwent 247 angiography procedures, consisting of 174 diagnostic angiography and 73 interventional procedures, and magnetic resonance imaging including DWI within 72 hours after angiography. The two neuroradiologists in our hospital detected embolism after cerebral angiography as high-intensity lesions (HIL) on DWI. The relationships between HIL on DWI and procedural factors were evaluated. DWI after cerebral angiography revealed HIL related to the procedure in 72 of 247 angiographies. In all procedures, age (p < 0.01), past history of cerebral infarction (p < 0.05), anti-platelet therapy (p < 0.05), neuro-intervention (p < 0.01), and total amount of contrast medium (odds ratio [OR] 2.125, 95% confidence interval [CI] 1.045-4.321) were significantly correlated with HIL. In diagnostic angiography, the performance of the procedure by a resident operator (OR 2.526, 95% CI 1.214-5.254) was significantly correlated with HIL. Age, past history of cerebral infarction, and previous anti-platelet therapy determined the risk of atherosclerotic changes in patients. The neuro-intervention and total amount of contrast medium used could predict the risk of time limitations for angiography. Resident operator is also a risk factor. This study demonstrates the importance of improving the risk of time limitations for angiography and the risk due to operator inexperience. Further training of residents may be needed to reduce the occurrence of embolic complications.

Endovascular treatment of carotid occlusive disease

Carotid occlusive disease is one of several etiologic factors for stroke. Of all strokes, an estimated 88% are ischemic in nature. Less than 20% of these are caused by atheroma in the carotid bifurcation. Traditionally, carotid artery stenosis has been treated with carotid endarterectomy (CEA); however, carotid artery balloon angioplasty and stent placement has enjoyed significant technological advances over the last decade and can now offer a comparable treatment alternative to CEA. In this review, the authors concentrate their discussion on the treatment of carotid atherosclerotic disease with particular attention on the endovascular treatment.

Usefulness of acceleration time for internal carotid artery origin stenosis

Calcification of the internal carotid artery (ICA) hinders accurate evaluation of the stenosis by conventional ultrasonography due to acoustic shadow. We examined the relationship between acceleration time (AcT) and ICA origin stenosis. One hundred thrity seven samples (266 vessels) that enforced duplex ultrasonography in our hospital were targeted. The results have shown that there is a significant relationship between AcT and stenosis. AcT of more than 110 msec suggests that the stenosis is more than 60% by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method. AcT is thought to be useful for the diagnosis of ICA stenosis with calcification. (English Translation of J Jpn Coll Angiol 2011; 51: 365-371).

Extent of spontaneous cross-flow via the anterior communicating artery in steno-occlusive carotid artery disease

PURPOSE

Our purpose was to evaluate the agreement of transcranial color-coded duplex sonography (TCCS) measurements and intra-arterial digital subtraction angiography (DSA) findings in determining the extent of spontaneous cross-flow via the anterior communicating artery (AcoA) in patients with internal carotid artery (ICA) stenosis.

METHODS

Thirty adult patients with suspected uni- or bilateral high-grade carotid artery stenosis were prospectively examined by DSA and angle-corrected TCCS. The extent of cross-flow was determined considering retrograde flow in the ipsilateral anterior cerebral artery (ACA) and sideto-side differences of the A1-segments of the ACA and middle cerebral arteries (MCAs) by both techniques. Cross-flow was angiographically categorized by means of a four-step scale. DSA findings were correlated with side-to-side differences in mean blood flow velocity as well as flow direction measured by TCCS.

RESULTS

Twenty-seven of 30 patients had a uni- or bilateral ICA stenosis of >49%. Excellent agreement between TCCS and DSA was evaluated for the detection of lack (grades 0 and 1) or presence (grades 2 and 3) of reversed flow in the ACA (sensitivity 100%, specificity 93%, positive predictive value 94%). Post hoc analysis of the mean velocities in the ACA and MCA revealed a side-to-side difference of 25 cm/s as a cutting point allowing for definition of a corresponding four-grade scale for ultrasound. However, full agreement, i.e.same grade of cross-flow detected by both techniques, was only found in 17(57%) of 30 cases.

CONCLUSIONS

Non-invasive TCCS is reliable for detecting reversed flow in the ACA in patients with ICA stenosis. However, there is only a moderate agreement between angiography and TCCS in quantifying the extent of spontaneous anterior cross-flow because different information on the intracranial hemodynamics may be obtained.

Accuracy of vessel-encoded pseudocontinuous arterial spin-labeling in identification of feeding arteries in patients with intracranial arteriovenous malformations

BACKGROUND AND PURPOSE

Identifying feeding arteries of intracranial AVMs is very important for preoperative evaluation. DSA remains the reference standard for diagnosis but is invasive. Our aim was to evaluate the diagnostic accuracy of vessel-encoded pseudocontinuous arterial spin-labeling in identifying feeding arteries of intracranial AVMs by using DSA as the criterion standard.

MATERIALS AND METHODS

Eighteen patients with AVMs were examined with vessel-encoded pseudocontinuous arterial spin-labeling and DSA. Three postlabeling delays (postlabeling delay = 1, 1.3, and 1.6 seconds) were applied in 6 patients, and a single postlabeling delay (1 second) was applied in the remainder. Perfusion-weighted images were decoded into individual vascular territories with standard and relative tagging efficiencies, respectively. The supply fraction of each feeding artery to the AVM was calculated. The within-subject ANOVA was applied to compare supply fractions acquired across 3 postlabeling delays. Receiver operating characteristic analysis curves were calculated to evaluate the diagnostic accuracy of vessel-encoded pseudocontinuous arterial spin-labeling for identifying the feeding arteries of AVMs.

RESULTS

There were no significant differences in supply fractions of the 3 major arteries to AVMs acquired with 3 postlabeling delays (P > .05). For vessel-encoded pseudocontinuous arterial spin-labeling with standard labeling efficiencies, the area under the receiver operating characteristic analysis curve was 0.942. The optimal cutoff of the supply fraction for identifying feeding arteries was 15.17%, and the resulting sensitivity and specificity were 84.62% and 93.33%, respectively. For vessel-encoded pseudocontinuous arterial spin-labeling with relative labeling efficiencies, the area under the receiver operating characteristic analysis curve was 0.957. The optimal cutoff of the supply fraction was 11.73%, which yielded an 89.74% sensitivity and 93.33% specificity.

CONCLUSIONS

The contribution fraction of each feeding artery of the AVM can be reliably estimated by using vessel-encoded pseudocontinuous arterial spin-labeling. Vessel-encoded pseudocontinuous arterial spin-labeling with either standard or relative labeling efficiencies offers a high level of diagnostic accuracy compared with DSA for identifying feeding arteries.

A Quantitative Comparison of the Vertebral Artery and Transverse Foramen Using CT Angiography

Background and Purpose

The vertebral artery (VA) is important for the development of the transverse foramen (TF). Most studies of these structures have focused on anatomical anomalies. Therefore, we investigated quantitatively the association between the relative sizes of the TF and VA.

Methods

We recruited a consecutive series of subjects who underwent CT angiography to estimate the relative sizes of the VA and TF in axial source images. Two neurologists independently reviewed the axial CT images of 208 patients who had no history of transient ischemic attack or stroke. Averaged areas of the VA and TF were defined by the sum of the areas at each level from C3 to C6, divided by 4. Correlation analyses were adjusted for age, sex, and vascular risk factors.

Results

The mean age of the subjects was 53 years. The interobserver and intraobserver reliabilities of TF size were good. There was a linear relationship between the sizes of the VA and TF on each side (right side: r²=0.58, p<0.001; left side: r²=0.62, p<0.001). The area of the VA was significantly associated with that of the TF after adjusting for vascular risk factors.

Conclusions

The size of the VA is strongly and linearly correlated with the size of the TF. These findings suggest that measurement of the TF and VA with CT angiography is a reliable method for evaluating VA diseases, and may provide new insight into the differentiation between VA hypoplasia and atherosclerosis of the VA.

Endovascular treatment of extracranial vertebral artery stenosis

Percutaneous angioplasty and stenting for the treatment of extracranial vertebral artery (VA) stenosis seems a safe, effective and useful technique for resolving symptoms and improving blood flow to the posterior circulation, with a low complication rate and good long-term results. In patients with severe tortuosity of the vessel, stent placement is a real challenge. The new coronary balloon-expandable stents may be preferred. A large variability of restenosis rates has been reported. Drug-eluting stents may be the solution. After a comprehensive review of the literature, it can be concluded that percutaneous angioplasty and stenting of extracranial VA stenosis is technically feasible, but there is insufficient evidence from randomized trials to demonstrate that endovascular management is superior to best medical management.

Contrast-enhanced magnetic resonance angiography

Magnetic resonance (MR) angiography is a powerful tool for the evaluation of cervical and intracranial vasculature. Both noncontrast and contrast-enhanced MR angiography can provide exquisite vascular contrast and detail without the use of ionizing radiation. More advanced techniques such as time-resolved MR angiography and parallel imaging provide dynamic information in rapid fashion. This article describes the basic principles and techniques of MR angiography image acquisition.

State of the art in managing nontraumatic intracerebral hemorrhage

Nontraumatic intracerebral hemorrhage constitutes a major public health problem worldwide. Intracerebral hemorrhage leads to a high rate of morbidity and mortality. To date, no medical or surgical trials have clearly attested to the benefit of a particular therapy. The aim of this review was to summarize the best evidence for management decision-making in intracerebral hemorrhage.

Risk of cerebral angiography in patients with symptomatic intracranial atherosclerotic stenosis

BACKGROUND

A well-defined rate of adverse events following cerebral angiography in patients with symptomatic intracranial atherosclerosis would be useful to physicians making decisions regarding imaging and treatment of these patients. We report the adverse events associated with angiography in patients who underwent single-vessel cerebral angiography as part of the study protocol in the Warfarin-Aspirin for Symptomatic Intracranial Arterial Stenosis trial.

METHODS

Single-vessel cerebral angiography was performed to specifically define the degree of stenosis in 196 patients suspected of having intracranial atherosclerotic stenosis on noninvasive tests. Adverse events that occurred within 24 h of cerebral angiography were reported by the sites performing the angiography.

RESULTS

Overall, neurological adverse events occurred in 4 patients (2.0%; 95% CI: 0.6-5.1%), and nonneurological adverse events occurred in 12 patients (6.1%; 95% CI: 3.2-10.5%). All of the neurological adverse events were transient.

CONCLUSIONS

The risk of permanent neurological adverse events associated with single-vessel cerebral angiography in patients with symptomatic intracranial atherosclerosis is relatively low. The quantification of the risk of cerebral angiography in patients with intracranial atherosclerosis provides useful information to consider when evaluating noninvasive imaging techniques for their relative value.

Assessing cost-effectiveness and value as imaging grows:the case of carotid artery CT

Computed tomographic (CT) angiography is an imaging test that is safer and less expensive than an older test in diagnosing narrowing of the carotid arteries-the most common cause of stroke in US adults. Our examination of Medicare data between 2001 and 2005 found that about 20 percent of the time this test was used, it substituted for the older test. The majority of new use, however, constituted "incremental" use, in cases where patients previously would not have received any test. We found no evidence that the growth in CT angiography led to more patients' being treated for carotid artery disease. The value of the test as a substitute for the older procedure may be enough to still justify expanding use. Tracking the uses of emerging technologies to encourage efficient use is essential, but it can be challenging in cases where new tools have multiple uses and information is incomplete.

[Ocular ischemic syndrome]

Ocular ischemic syndrome (OIS) is a group of ocular diseases caused by chronic artery occlusion usually involving the internal carotid artery. Patients suffer from visual loss and pain. OIS is a rare disease which can be confounded with diabetic retinopathy or an older central retinal vein occlusion. The only therapy is to treat the neovascular complications. Due to the high mortality of OIS patients, medical and neurological examinations are mandatory. We discuss the clinical findings and diagnostic and therapeutic options of OIS patients in this paper.

Evaluation framework for carotid bifurcation lumen segmentation and stenosis grading

This paper describes an evaluation framework that allows a standardized and objective quantitative comparison of carotid artery lumen segmentation and stenosis grading algorithms. We describe the data repository comprising 56 multi-center, multi-vendor CTA datasets, their acquisition, the creation of the reference standard and the evaluation measures. This framework has been introduced at the MICCAI 2009 workshop 3D Segmentation in the Clinic: A Grand Challenge III, and we compare the results of eight teams that participated. These results show that automated segmentation of the vessel lumen is possible with a precision that is comparable to manual annotation. The framework is open for new submissions through the website http://cls2009.bigr.nl.

Doppler criteria for identifying proximal vertebral artery stenosis of 50% or more

OBJECTIVES

The proximal segment of the vertebral artery is a frequent site of obstructive atherosclerosis. The purpose of this study was to determine Doppler criteria for identifying proximal vertebral artery stenosis of 50% or more by comparison with digital subtraction angiography.

METHODS

Forty-eight patients with vertebral artery stenosis were examined prospectively with color Doppler sonography and digital subtraction angiography. The peak systolic velocity (PSV), end-diastolic velocity (EDV), peak systolic velocity ratio (PSVr), and end-diastolic velocity ratio (EDVr) were evaluated by receiver operating characteristic curve analysis for their ability to detect vertebral artery stenosis of 50% or more. The optimal criteria for identifying proximal vertebral artery stenosis of 50% or more were determined.

RESULTS

For identifying vertebral artery stenosis, the parameter with the highest accuracy was the PSVr (area under the receiver operating characteristic curve, 0.967 [95% confidence interval, 0.899-0.994]). A PSVr of greater than 2.2 was found to be the optimal criterion for identifying proximal vertebral artery stenosis of 50% or more, with sensitivity and specificity of 96% and 89%, respectively. The optimal thresholds for the other Doppler parameters in identifying proximal vertebral artery stenosis of 50% or more were as follows: PSV, greater than 108 cm/s; EDV, greater than 36 cm/s; and EDVr, greater than 1.7.

CONCLUSIONS

Color Doppler sonography is an accurate method for identifying proximal vertebral artery stenosis. The PSVr is superior to other Doppler parameters for detecting vertebral artery stenosis.

Whole-body magnetic resonance angiography for presurgical planning of free-flap head and neck reconstruction

OBJECTIVES

Aim of the study was to evaluate if a whole-body magnetic resonance angiography (MRA) protocol meets the requirements to evaluate the donor and host site target vessels for planning of microvascular head and neck reconstructions.

PATIENTS AND METHODS

In 20 patients, scheduled for reconstruction of the mandible with fibular free flaps, contrast-enhanced whole-body MRA was performed prior to surgery. 32-Channel 1.5-T MR angiograms were acquired using a 2-step contrast (gadobutrol) injection scheme to visualize the arterial vasculature from head to feet. Maximum intensity projection and multiplanar reconstruction technique was employed to visualize MRA data. For image evaluation the arterial tree was divided into 51 segments. The presence of artefacts impairing diagnostic quality was noted. Evaluable segments were assessed regarding the presence of stenoses >50% diameter reduction, occlusions or aneurysms.

RESULTS

No adverse reactions or complications occurred. Of 1020 vessel segments 1003 (98.3%) were evaluable. 36 stenoses >50%, 50 occlusions and one aneurysm were observed. In 21 of 40 lower limbs relevant atherosclerotic changes were depicted.

CONCLUSION

Whole-body MRA proved to be a suitable three-dimensional, noninvasive, nonionising modality for preoperative evaluation of the entire arterial vasculature.

Decision analysis and carotid endarterectomy

A data base and a framework for clinical decision analysis are provided to enable the clinician to determine the value of carotid endarterectomy in patients with transient ischemic attacks. This approach permits optimal utilization of available data, maximizes the value of informed consent by clearly delineating areas of physician and patient expertise, and permits a quantitative assessment of the impact of uncertainty regarding underlying variables on decision outcome. The results of the analysis indicate that (a) the late nonstroke death rate has little effect on the value of endarterectomy, (b) the patient's relative valuation of stroke and immediate versus delayed death are among the most crucial variables underlying the value of endarterectomy, and (c) endarterectomy may be indicated in certain patients with transient ischemic attacks, but when its utility is measured in terms of value rendered to the patient, its relative cost may be greater than that of certain life-saving operations such as heart or liver transplant.

Diagnosis of intracranial atherosclerosis

IMPORTANCE OF THE FIELD

Intracranial atherosclerosis is quickly becoming the most common stroke mechanism worldwide. Accurate diagnosis is important in making treatment decisions.

AREAS COVERED IN THE REVIEW

In this article the clinical and radiographic diagnosis of intracranial atherosclerosis is reviewed. An overview is provided of widely available invasive and non-invasive methods for the detection of intracranial atherosclerosis, including transcranial Doppler, magnetic resonance and computed tomography angiography, as well as conventional angiography.

WHAT THE READER WILL GAIN

The reader will become familiar with the advantages and limitations of various imaging modalities used in the diagnosis of intracranial atherosclerosis.

TAKE HOME MESSAGE

Non-invasive imaging modalities have a high negative predictive value in detecting intracranial atherosclerosis. The gold standard for confirmation of the diagnosis remains catheter angiography.

Periprocedural MRI perfusion imaging to assess and monitor the hemodynamic impact of intracranial angioplasty and stenting for symptomatic atherosclerotic stenosis

We aimed to assess the clinical value of MRI perfusion imaging in the periprocedural management of intracranial atherosclerosis, analyzing if changes in mean transit time (MTT), cerebral blood volume (CBV) and cerebral blood flow (CBF) correlated with angiographic outcomes. Pre-procedural and post-procedural MRI perfusion was performed on six patients who underwent angioplasty and/or stenting for symptomatic intracranial atherosclerosis. MTT, CBV and CBF were analyzed and graded. In 83% of patients, perfusion imaging correlated with angiographic outcomes. Perfusion parameters improved to normal in two patients. Two showed marked improvement and one showed mild improvement. In one patient, the results of the post-procedural MRI perfusion prompted an angiogram, which confirmed stent occlusion. Semi-quantitative scores of MTT and CBF changed over time (p=0.05, p=0.03) whereas CBV did not change significantly (p>0.05). We conclude that MRI perfusion appears a promising technique for analyzing the impact of intracranial stenosis on cerebral hemodynamics before and after treatment.

Comparison of dual-source CT angiography and MR angiography in preoperative evaluation of intra- and extracranial vessels: a pilot study

Besides the assessment of carotid artery stenosis, evaluation of the vascular anatomy and lesions within both the extra- and intracranial arteries is crucial for proper clinical evaluation, treatment choice and planning. The purpose of our study was to evaluate the potential of dual-source CTA and 3T-MRA. In 16 symptomatic CAS patients, contrast-enhanced DSCT and 3T-MRA examinations were performed. For DSCT a dual-energy protocol with a 64 x 0.6-mm collimation was applied. In 3T-MRA intracranial high-resolution unenhanced TOF and extracranial contrast-enhanced MRA were performed. All examinations were analyzed for relevant morphologic and pathologic features or anomalies, and a total of 624 vessel segments were scored. All examinations were of diagnostic image quality with good to excellent vessel visibility. Almost all intracranial arteries were significantly better visualized by MRA compared to CTA (five of six vessels, p < 0.05). DSCT however allowed for further morphological carotid stenosis description, especially with respect to calcification. Although MRA proved to be superior in visualization of smaller intracranial arteries, all pre-interventionally relevant information could be perceived from DSCT. DSCT and MRA may both be regarded as a reliable, fast, pre-interventional imaging investigation in patients with carotid artery stenosis.

Assessment of cerebral arteriovenous malformations with high temporal and spatial resolution contrast-enhanced magnetic resonance angiography: a review from protocol to clinical application

The combination of high spatial and high temporal resolution contrast-enhanced magnetic resonance angiography (MRA) at 3.0 T has enabled the detailed evaluation of functional vascular anatomy and hemodynamics of cerebral arteriovenous malformations (AVMs). Key contributory technical factors for the successful implementation of MRA in patients with different vascular pathologies are multicoil and multichannel receiver arrays, which enable higher parallel acquisition at 3.0 T over a uniform and a large field of view for highly temporally and spatially resolved MRA. Magnetic resonance angiography enables both screening of patients with suspected AVMs and follow-up of patients after therapy. It allows the characterization of AVMs with respect to nidus configuration, size, venous drainage, and so on, according to the Spetzler-Martin classification.

Imaging in endovascular therapy: our future

The endovascular therapist now has many modern imaging techniques available to plan and execute treatment, whereas in the past vascular surgeons relied mostly on clinical examination and arteriography. Advances in computer technology have enabled fast acquisition and processing of the large amounts of digital data essential to capture the dynamic information from fast-flowing blood at high resolution. Functional imaging has begun to play a role in predicting stability of progressive vascular disease and the need for and risks of intervention. Computing power now affords the interventionist the ability to handle imaging data in powerful 3-dimensional programs and electronically "in-lay" a variety of devices to plan complex endovascular procedures from the familiar platform of a laptop. In four major clinical areas, carotid intervention, peripheral intervention, endoluminal grafting, and cardiac imaging, we review the latest advances and changes with an eye toward how we should best be using imaging in our patients undergoing endovascular treatment...now and into the future.

Endovascular retrograde suction decompression as an adjunct to surgical treatment of ophthalmic aneurysms: analysis of risks and clinical outcomes

OBJECTIVE

Endovascular retrograde suction decompression with balloon occlusion of the internal carotid artery is a useful adjunct in the surgical treatment of ophthalmic aneurysms. This technique helps establish proximal control, facilitates intraoperative angiography, and may aid dissection by evacuating blood and softening the aneurysm. Although the technical aspects of this procedure have been described, the published data on its safety are scant. This study analyzed 2 groups of patients who underwent craniotomies for treatment of ophthalmic aneurysms, comparing a group who received suction decompression with a group who did not.

METHODS

A retrospective analysis of prospectively collected data on 118 craniotomies for ophthalmic aneurysms performed from 1990 to 2005 is presented. A group of 63 patients treated with endovascular suction decompression during surgery is compared with 55 patients who did not undergo this technique.

RESULTS

In our overall analysis of ophthalmic aneurysms, the clinical outcome was statistically related to aneurysm size (P = 0.046). The endovascular suction decompression group in this study had overall larger aneurysms (P < 0.0001) compared with the other group. There was no statistical difference between the 2 groups in rates of complications, stroke, new visual deficit, or death. The clinical outcomes were statistically similar at discharge and at 1 year.

CONCLUSION

Endovascular balloon occlusion and suction decompression did not increase the complication rate in a large cohort of craniotomy patients with ophthalmic aneurysms. This technique may be used to augment surgical capabilities without significantly increasing the operative risk.

Moyamoya disease: a clinical spectrum, literature review and case series from a tertiary care hospital in Pakistan

Background

Moyamoya is a rare cerebrovascular disease of unknown etiology. The data on moyamoya disease from Pakistan is sparse. We report a case series of 13 patients who presented with moyamoya disease to a tertiary care hospital in Pakistan with a national referral base.

Methods

We conducted a retrospective review of thirteen patients who presented to The Aga Khan University and diagnosed with "Moyamoya Disease" during the period 1988 – 2006. These patients were identified from existing hospital database via ICD-9 codes. A predesigned questionnaire containing information about clinical presentation, management and neuroimaging was administered to all identified patients.

Results

There were seven males and six females. Mean age at presentation was 16.5 years and a female predominance was found in the pediatric age group (n = 10, 71.4%). Stroke (n = 11, 84.2%) was the most common presentation with motor deficit being the universal cortical symptom. Fever was a common symptom in the lower age groups (n = 4, 51.7%). Cerebral Angiography and Magnetic Resonance Angiography showed bilateral involvement of the vessels in eleven patients while unilateral in two. Subarachnoid and interventricular haemorrhage appeared in 2(15.4%) adults. Twelve (92.3%) patients were discharged as independent with minor deficits regardless of therapeutic modality. Only three (23.0%) patients underwent surgery whereas the remaining were managed conservatively.

Conclusion

Physicians when dealing with childhood strokes and characteristic deficits in adult population should consider Moyamoya disease.

Multidetector row CT angiography in spontaneous lobar intracerebral hemorrhage: a prospective comparison with conventional angiography

BACKGROUND AND PURPOSE

The aim of our study was to assess the accuracy of multidetector row CT angiography (MDCTA) in the detection of the underlying vascular abnormalities causing spontaneous lobar intracerebral hemorrhage (ICH) compared with conventional digital subtraction angiography (DSA).

MATERIALS AND METHODS

Seventy-eight patients who underwent MDCTA with use of a 16-detector row scanner and DSA were prospectively included in this study. Each study was assessed by 2 independent blinded neuroradiologists; decisions were made in consensus. Findings on CT angiograms, including the original axial data, multiplanar reformations, and volume-rendered images with and without automated bone segmentation, were used to identify the underlying causes of ICH.

RESULTS

Twenty-two of the 78 patients (28.2%) exhibited angiographic abnormalities, including aneurysms of the proximal arteries (n = 9), arteriovenous malformations (n = 7), Moyamoya disease (n = 4), and aneurysms of the distal arteries (n = 2). MDCTA detected the underlying vascular abnormalities in 21 patients except 1 case of small arteriovenous malformation. Overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCTA for detection of underlying vascular abnormalities were 95.5%, 100%, 100%, 98.2%, and 98.7%, respectively.

CONCLUSIONS

MDCTA is a highly accurate imaging technique in the diagnosis of underlying vascular abnormalities in patients with spontaneous lobar ICH.