Comparison of Blood Flow Velocity Quantification by 4D Flow MR Imaging with Ultrasound at the Carotid Bifurcation

Harloff, Andreas; Zech, Tobias; Wegent, Felix; Strecker, Christoph; Weiller, Cornelius; Markl, Michael

doi:10.3174/ajnr.a3419

Cited by 65 publications

(58 citation statements)

References 20 publications

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“…8). On the in-vivo scan, the proposed method showed consistent vector velocity estimates and the velocities matches with data from the literature for healthy individuals [27], and it also presented a complex vortex observed in previous studies [28], [29]. However, has not in previous studies the vortex in the carotid bulb been captured with such a high frame rate and in such a detail.…”

Section: Discussionsupporting

confidence: 83%

Accurate Angle Estimator for High-Frame-Rate 2-D Vector Flow Imaging

Hoyos

Stuart

Hansen

et al. 2016

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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This paper presents a novel approach for estimating 2-D flow angles using a high-frame-rate ultrasound method. The angle estimator features high accuracy and low standard deviation (SD) over the full 360° range. The method is validated on Field II simulations and phantom measurements using the experimental ultrasound scanner SARUS and a flow rig before being tested in vivo. An 8-MHz linear array transducer is used with defocused beam emissions. In the simulations of a spinning disk phantom, a 360° uniform behavior on the angle estimation is observed with a median angle bias of 1.01° and a median angle SD of 1.8°. Similar results are obtained on a straight vessel for both simulations and measurements, where the obtained angle biases are below 1.5° with SDs around 1°. Estimated velocity magnitudes are also kept under 10% bias and 5% relative SD in both simulations and measurements. An in vivo measurement is performed on a carotid bifurcation of a healthy individual. A 3-s acquisition during three heart cycles is captured. A consistent and repetitive vortex is observed in the carotid bulb during systoles.

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Section: Discussionsupporting

confidence: 83%

Accurate Angle Estimator for High-Frame-Rate 2-D Vector Flow Imaging

Hoyos

Stuart

Hansen

et al. 2016

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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“…Shakur et al specified that the velocity of feeders is related to the overall cross-sectional area of vessels instead of the number of vessels or the mean diameter 26. Our findings showed a good correlation between the volumetric size of the AVM and the velocity of feeders estimated from t-RA.…”

Section: Discussionsupporting

confidence: 69%

In-room assessment of intravascular velocity from time-resolved rotational angiography in patients with arteriovenous malformation: a pilot study

Lin

Yang

Chien

et al. 2017

J NeuroIntervent Surg

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BackgroundTime-resolved rotational angiography (t-RA) enables interventionists to better comprehend complex arteriovenous malformations (AVMs), thereby facilitating endovascular treatment. However, its use in evaluating hemodynamic changes has rarely been explored.ObjectiveThis study uses t-RA to estimate intravascular flow in patients with AVM to compare this with flow in the normal population.MethodsPatients with available t-RA scans were prospectively categorized into one of three groups: hemorrhagic AVM, non-hemorrhagic AVM and control. Pulsatile time–density curves (TDCs) for C1, C6 and VOIMCA were used for amplitude and velocity estimation. C1 was at the cervical internal carotid artery (ICA), 2–3 cm below the carotid canal, C6 was at the paraclinoid segment of the ICA, and VOIMCA was at the junction of the first and second segment of the middle cerebral artery (MCA). A waveform amplitude ratio was defined as (peak − trough)/trough contrast intensity. VICA was defined as the distance between C6 and C1 divided by the time required for the wave to pass, and correspondingly, the average velocity of MCA (VMCA) was defined as the distance between C6 and VOIMCA divided by the duration for the same peak to travel from C6 and VOIMCA, AVM volume was estimated by MR angiography.ResultsAmplitude ratios AC1 and AC6, and average flow velocities VICA and VMCA were significantly larger in the non-hemorrhagic group than in the control group, while the hemorrhagic AVM group was not significantly different from the controls. VICA and VMCA showed moderate to good correlations with AVM volume (r=0.51 and 0.73, respectively). VMCA (33.0±9.1) was significantly lower than VICA (41.3±13.2) in the control group, but not in the two AVM groups.ConclusionTDC waveform propagation derived from t-RA can quantify hemodynamic differences between AVM and the control group. t-RA provides both real-time anatomic and hemodynamic evaluation, and can thus potentially improve the interventional workflow.

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“…The latter technique (phase contrast with vastly undersampled isotropic projection reconstruction [PC-VIPR]) allows a time-resolved measurement of blood flow in vivo and 3D visualization and quantification of blood flow patterns, velocities, and flow. It is similar to another flow-sensitive MR angiography (4D flow MR imaging) that has been successfully applied to study blood flow within intracranial arteries, 15 carotid arteries, 16 and liver veins, 17 but not yet within the veins of the neck and head. The current study of Schrauben et al 14 convincingly shows the feasibility of this MR imaging technique for the assessment of these vessels.…”

mentioning

confidence: 98%