Cerebral Aneurysm Size and Distal Intracranial Hemodynamics: An Assessment of Flow and Pulsatility Index Using Quantitative Magnetic Resonance Angiography

Neurosurgery ◽  
2017 ◽  
Vol 83 (4) ◽  
pp. 660-665 ◽  
Author(s):  
Ahmed E Hussein ◽  
Denise Brunozzi ◽  
Sophia F Shakur ◽  
Rahim Ismail ◽  
Fady T Charbel ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Flow Velocity ◽  
Cerebral Aneurysm ◽  
Pulsatility Index ◽  
Quantitative Magnetic Resonance ◽  
Aneurysm Size ◽  
Risk Of Rupture ◽  
The Impact ◽  
The Relationship

Abstract BACKGROUND The relationship between cerebral aneurysm size and risk of rupture is well documented, but the impact of aneurysms on distal intracranial hemodynamics is unknown. OBJECTIVE To examine the relationship between aneurysm size and distal intracranial hemodynamics prior to treatment. METHODS Patients seen at our institution between 2006 and 2015 with cerebral aneurysms within the internal carotid artery (ICA) segments (proximal to ICA terminus) were retrospectively reviewed. Patients were included if the aneurysm was unruptured, and were excluded if a contralateral aneurysm was present. Flows within bilateral ICAs and middle cerebral arteries (MCA) were measured prior to any treatment using quantitative magnetic resonance angiography. Pulsatility index (PI = [systolic − diastolic flow velocity]/mean flow velocity) within each vessel was then calculated. Hemodynamic parameters were analyzed with respect to aneurysm size. RESULTS Forty-two patients were included. Mean aneurysm size was 13.5 mm (range 2-40 mm). There was a significant correlation between aneurysm size and ipsilateral MCA PI (P = .006; r = 0.441), MCAipsilateral/ICAipsilateral PI ratio (P = .003; r = 0.57), and MCAipsilateral/MCAcontralateral PI ratio (P = .008; r = 0.43). Mean PI in the ipsilateral ICA was 0.38 (range 0.17-0.77) and ipsilateral MCA was 0.31 (range 0.08-0.83), and mean PI in contralateral ICA was 0.35 (range 0.19-0.57) and MCA was 0.30 (range 0.07-0.89). CONCLUSION Larger aneurysm size correlates with higher ipsilateral MCA PI, demonstrating that aneurysms affect distal intracranial hemodynamics.

Abstract WP88: Relationship Between Aneurysm Size and Distal Cerebral Hemodynamics

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Ahmed E Hussein ◽  
Denise Brunozzi ◽  
Sophia F Shakur ◽  
Fady T Charbel ◽  
Ali Alaraj
Keyword(s):  
Flow Velocity ◽  
Cerebral Hemodynamics ◽  
Flow Volume ◽  
Hemodynamic Parameters ◽  
Mean Flow ◽  
Anterior Circulation ◽  
Aneurysm Size ◽  
The Impact ◽  
The Relationship ◽  
Anterior Circulation Aneurysms

Introduction: The impact of aneurysms on distal cerebral hemodynamics is unknown. Here we examine the relationship between aneurysm size and distal hemodynamics prior to treatment. Methods: Patients seen at our institution between 2006-2015 with aneurysms within the cavernous or supraclinoid ICA segment (proximal to ICA terminus) were retrospectively reviewed. Only un-ruptured proximal anterior circulation aneurysms were included, patients with contralateral aneurysms were excluded. Patients were included if they had flow volume rate and flow velocities measured prior to any treatment using Quantitative MRA. Pulsatility index (PI) = [(systolic - diastolic flow velocity)/mean flow velocity] was calculated for ipsilateral and contralateral MCA and ICA. Hemodynamic parameters were analyzed with respect to aneurysm size. Results: 42 patients were included. Mean aneurysm size was 13.5 mm (range 2-40mm). There was significant correlation (Pearson’s) between aneurysm size and ipsilateral MCA PI ( P =0.006; r=0.441), MCA ipsilateral /ICA ipsilateral PI ratio ( P =0.003; r=0.57), and MCA ipsilateral /MCA contralateral PI ratio ( P =0.008; r=0.43). Conclusions: Larger aneurysm size is significantly associated with higher ipsilateral MCA PI, demonstrating that aneurysms change distal cerebral hemodynamics. Aneurysm treatment may thus acutely change those altered hemodynamics.

Impact of cerebral aneurysm size on distal intracranial hemodynamics and changes following flow diversion

2021 ◽  
pp. 159101992110324
Author(s):  
Denise Brunozzi ◽  
Alfred See ◽  
Mark Rizko ◽  
Jason Choi ◽  
Gursant Atwal ◽  
...  
Keyword(s):  
Cerebral Aneurysm ◽  
Pulsatility Index ◽  
Pressure Ratio ◽  
Systolic Pressure ◽  
Flow Diversion ◽  
Aneurysm Size ◽  
Before And After ◽  
Mean Pressure ◽  
The Mean ◽  
The Impact

Background The impact of cerebral aneurysm size on distal intracranial hemodynamics such as arterial pressure and Pulsatility Index is not completely understood, either before or after flow diversion. Objective The aim of the study is to assess the impact of aneurysm size on distal Pulsatility Index and pressure before and after flow diversion. Methods From December 2015, prospective measurement of middle cerebral artery pressure and Pulsatility Index was performed in consecutive patients with unruptured cerebral aneurysms in the cavernous to communicating segments of the internal carotid artery, which were treated with single flow diversion. Pressure and Pulsatility Index were recorded at the M1-segment ipsilateral to the cerebral aneurysm. Ratio of middle cerebral artery to radial arterial pressure (pressure ratio) was calculated to control for variations in systemic blood pressure. Correlations between aneurysm size and pressure ratio and Pulsatility Index were assessed before and after treatment. Results A total of 28 aneurysms were treated. The mean aneurysm size was 7.2 mm. Aneurysm size correlated linearly with systolic pressure ratio (1% pressure ratio increase per mm aneurysm size increase, P = 0.002, r2 = 0.33), mean pressure ratio (0.6% per mm, P = 0.03, r2 = 0.17) and Pulsatility Index (5% Pulsatility Index increase per mm, P = 0.003, r2 = 0.43). After flow diversion, aneurysm size preserved a linear correlation with the systolic pressure ratio (1% per mm, P = 0.004, r2  =  0.28), but not with the mean pressure ratio (0.4% per mm, P = 0.15, r2 < 0.1) or Pulsatility Index (0.3% per mm, P = 0.78, r2 < 0.1). Conclusion Aneurysm size affects distal hemodynamics: patients with larger aneurysms have increased systolic and mean pressure ratio, and increased Pulsatility Index. After flow diversion, mean pressure ratio and Pulsatility Index no longer associate with the aneurysm size, suggesting an effect of the flow diversion also on distal intracranial hemodynamics.

Validation of cerebral arteriovenous malformation hemodynamics assessed by DSA using quantitative magnetic resonance angiography: preliminary study

2017 ◽  
Vol 10 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Sophia F Shakur ◽  
Denise Brunozzi ◽  
Ahmed E Hussein ◽  
Andreas Linninger ◽  
Chih-Yang Hsu ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Transit Time ◽  
Internal Carotid ◽  
Flow Measurements ◽  
Quantitative Magnetic Resonance ◽  
Transit Times ◽  
Before And After ◽  
Preliminary Study ◽  
The Difference

BackgroundThe hemodynamic evaluation of cerebral arteriovenous malformations (AVMs) using DSA has not been validated against true flow measurements.ObjectiveTo validate AVM hemodynamics assessed by DSA using quantitative magnetic resonance angiography (QMRA).Materials and methodsPatients seen at our institution between 2007 and 2016 with a supratentorial AVM and DSA and QMRA obtained before any treatment were retrospectively reviewed. DSA assessment of AVM flow comprised AVM arterial-to-venous time (A-Vt) and iFlow transit time. A-Vt was defined as the difference between peak contrast intensity in the cavernous internal carotid artery and peak contrast intensity in the draining vein. iFlow transit times were determined using syngo iFlow software. A-Vt and iFlow transit times were correlated with total AVM flow measured using QMRA and AVM angioarchitectural and clinical features.Results33 patients (mean age 33 years) were included. Nine patients presented with hemorrhage. Mean AVM volume was 9.8 mL (range 0.3–57.7 mL). Both A-Vt (r=−0.47, p=0.01) and iFlow (r=−0.44, p=0.01) correlated significantly with total AVM flow. iFlow transit time was significantly shorter in patients who presented with seizure but A-Vt and iFlow did not vary with other AVM angioarchitectural features such as venous stenosis or hemorrhagic presentation.ConclusionsA-Vt and iFlow transit times on DSA correlate with cerebral AVM flow measured using QMRA. Thus, these parameters may be used to indirectly estimate AVM flow before and after embolization during angiography in real time.

The influence of aneurysm morphology on the volume of hemorrhage after rupture

2021 ◽  
pp. 1-9
Author(s):  
Pablo M. Munarriz ◽  
Blanca Navarro-Main ◽  
Jose F. Alén ◽  
Luis Jiménez-Roldán ◽  
Ana M. Castaño-Leon ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Univariate Analysis ◽  
Size Ratio ◽  
Computer Assisted ◽  
Data Set ◽  
Aneurysm Size ◽  
Risk Of Rupture ◽  
Morphological Variables ◽  
Hemorrhage Volume ◽  
The Impact

OBJECTIVE Factors determining the risk of rupture of intracranial aneurysms have been extensively studied; however, little attention is paid to variables influencing the volume of bleeding after rupture. In this study the authors aimed to evaluate the impact of aneurysm morphological variables on the amount of hemorrhage. METHODS This was a retrospective cohort analysis of a prospectively collected data set of 116 patients presenting at a single center with subarachnoid hemorrhage due to aneurysmal rupture. A volumetric assessment of the total hemorrhage volume was performed from the initial noncontrast CT. Aneurysms were segmented and reproduced from the initial CT angiography study, and morphology indexes were calculated with a computer-assisted approach. Clinical and demographic characteristics of the patients were included in the study. Factors influencing the volume of hemorrhage were explored with univariate correlations, multiple linear regression analysis, and graphical probabilistic modeling. RESULTS The univariate analysis demonstrated that several of the morphological variables but only the patient’s age from the clinical-demographic variables correlated (p < 0.05) with the volume of bleeding. Nine morphological variables correlated positively (absolute height, perpendicular height, maximum width, sac surface area, sac volume, size ratio, bottleneck factor, neck-to-vessel ratio, and width-to-vessel ratio) and two correlated negatively (parent vessel average diameter and the aneurysm angle). After multivariate analysis, only the aneurysm size ratio (p < 0.001) and the patient’s age (p = 0.023) remained statistically significant. The graphical probabilistic model confirmed the size ratio and the patient’s age as the variables most related to the total hemorrhage volume. CONCLUSIONS A greater aneurysm size ratio and an older patient age are likely to entail a greater volume of bleeding after subarachnoid hemorrhage.

Combined Direct and Indirect Bypass for Moyamoya

Neurosurgery ◽  
2013 ◽  
Vol 73 (6) ◽  
pp. 962-968 ◽  
Author(s):  
Sepideh Amin-Hanjani ◽  
Amritha Singh ◽  
Hashem Rifai ◽  
Keith R. Thulborn ◽  
Ali Alaraj ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Superficial Temporal Artery ◽  
Temporal Artery ◽  
Reciprocal Relationship ◽  
Bypass Flow ◽  
Similar Time ◽  
Quantitative Magnetic Resonance ◽  
Small Cohort ◽  
Direct Bypass

Abstract BACKGROUND: The optimal revascularization strategy for symptomatic adult moyamoya remains controversial. Whereas direct bypass offers immediate revascularization, indirect bypass can effectively induce collaterals over time. OBJECTIVE: Using angiography and quantitative magnetic resonance angiography, we examined the relative contributions of direct and indirect bypass in moyamoya patients after combined direct superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass and indirect encephaloduroarteriosynangiosis (EDAS). METHODS: A retrospective review of moyamoya patients undergoing combined STA-MCA bypass and EDAS was conducted, excluding pediatric patients and hemorrhagic presentation. Patients with quantitative magnetic resonance angiography measurements of the direct bypass immediately and &gt; 6 months postoperatively were included. Angiographic follow-up, when available, was used to assess EDAS collaterals at similar time intervals. RESULTS: Of 16 hemispheres in 13 patients, 11 (69%) demonstrated a significant (&gt; 50%) decline in direct bypass flow at &gt; 6 months compared with baseline, averaging a drop from 99 ± 35 to12 ± 7 mL/min. Conversely, angiography in these hemispheres demonstrated prominent indirect collaterals, in concert with shrinkage of the STA graft. Decline in flow was apparent at a median of 9 months but was evident as early as 2 to 3 months. CONCLUSION: In this small cohort, a reciprocal relationship between direct STA bypass flow and indirect EDAS collaterals frequently occurred. This substantiates the notion that combined direct/indirect bypass can provide temporally complementary revascularization.

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