Purpose To evaluate the accuracy and feasibility of a free‐breathing 4D flow technique using compressed sensing (CS), where imaging thoracic aorta is performed in 2 min with inline image reconstruction on MRI scanner less than 5 min. Methods The 10 vitro scans were different acceleration rates pulsatile phantom (9 CS factors [R = 5.4–14.1], 1 generalized autocalibrating partially parallel acquisition [GRAPPA] R 2). Based results, CS‐accelerated was acquired 20 healthy volunteers (38.3 ± 15.2...

Purpose To implement, validate, and apply a self-gated free-running whole-heart five-dimensional (5D) flow MRI framework to evaluate respiration-driven effects on three-dimensional (3D) hemodynamics in clinical setting. Materials Methods In this prospective study, sequence was implemented with 3D radial sampling, self-gating, compressed-sensing reconstruction. The 5D evaluated pulsatile phantom adult participants aortic and/or valvular disease who were enrolled between May August 2019....

Background: Balanced steady-state free precession (bSSFP) sequences offer high SNR and excellent tissue contrast for whole-heart MRI. However, inadequate fat suppression can introduce artifacts, particularly with non-Cartesian readouts. This study aimed to compare novel rapid water-excitation (WE) pulses 3D radial free-running MRI at 1.5T, specifically Binomial Off-Resonant Rectangular (BORR), Lipid Insensitive RF Excitation (LIBRE), (LIBOR) pulses, alongside a Fast Interrupted Steady-State...

Purpose To systematically assess the feasibility and performance of a highly accelerated compressed sensing (CS) 4D flow MRI framework at three different acceleration factors (R) for quantification aortic dynamics wall shear stress (WSS) in patients with disease. Methods Twenty disease (58 ± 15 y old; 19 M) underwent four scans: one conventional (GRAPPA, R = 2) CS flows 5.7, 7.7, 10.2. All scans were acquired otherwise equivalent imaging parameters on 1.5T scanner. Peak‐systolic velocity (V...

Purpose In this work, we integrated the pilot tone (PT) navigation system into a reconstruction framework for respiratory and cardiac motion‐resolved 5D flow. We tested hypotheses that PT would provide equivalent curves, triggers, corresponding flow measurements to previously established self‐gating (SG) technique while being independent from changes acquisition parameters. Methods Fifteen volunteers 9 patients were scanned with free‐running sequence, integrated. Respiratory curves triggers...

Purpose This study used a 5D flow framework to explore the influence of arrhythmia on thrombogenic hemodynamic parameters in patients with atrial fibrillation (AF). Methods A fully self‐gated, 3D radial, highly accelerated free‐running sequence interleaved four‐point velocity‐encoding was acquired using an vitro arrhythmic phantom and 25 history AF (68 ± 8 y, 6 female). Self‐gating signals were calculate burden, bin data, tag each k‐space line its RR Length . Data binned as RR‐resolved...

Purpose To evaluate the utility of an efficient triple velocity‐encoding (VENC) 4D flow MRI implementation to improve velocity unwrapping data with same scan time as interleaved dual‐VENC acquisition. Methods A balanced 7‐point acquisition was used derive 3 sets images corresponding different VENCs. These datasets were then unwrap aliased lowest VENC into a minimally aliased, triple‐VENC dataset. Triple‐VENC evaluated and compared over ranges (50‐150, 60‐150, 60‐180 cm/s) in vitro steadily...

Purpose To validate a respiratory motion correction method called focused navigation (fNAV) for free‐running radial whole‐heart 4D flow MRI. Methods Using fNAV, signals derived from readouts are converted into three orthogonal displacements, which then used to correct in datasets. Hundred acquisitions were simulated with non‐rigid and validation. The difference between generated fNAV displacement coefficients was calculated. Vessel area measurements reconstructions without (uncorrected)...

Retrospective electrocardiogram-gated, 2D phase-contrast (PC) flow MRI is routinely used in clinical evaluation of valvular/vascular disease pediatric patients with congenital heart (CHD). In not requiring general anesthesia, standard PC conducted free breathing for several minutes per slice averaging. younger under breath-holding. One approach to overcome this limitation using either navigator gating or self-navigation respiratory motion, at the expense lengthening scan times. An...

This study aimed to validate respiratory-resolved five-dimensional (5D) flow cardiovascular magnetic resonance (CMR) against real-time two-dimensional (2D) phase-contrast MRI, assess the impact of number respiratory states, and measure respiration on hemodynamics in congenital heart disease (CHD) patients.

Dual-velocity encoded (dual-venc or DV) 4D flow MRI achieves wide velocity dynamic range and velocity-to-noise ratio (VNR), enabling accurate neurovascular characterization. To reduce scan time, we present interleaved dual-venc Flow with independently prescribed, prospectively undersampled spatial resolution of the high-venc (HV) acquisition: Variable Spatial Resolution Dual Venc (VSRDV).

To develop a reliable, consistent, and reproducible reference phantom for error quantification of phase-contrast MRI so it can be used validation quality control.An air-driven rotation consisting steadily rotating cylinder surrounded by static ring both filled with agarose gel was developed. Rotational speed measured controlled in real time using an optical counter closed-loop controller. Consistency the assessed recording variations rotational speed. The imaged 2D MRI, velocity at each...

Purpose The purpose of this study was to evaluate the accuracy four‐dimensional (4D) flow MRI for direct assessment peak velocity, volume, and momentum a mitral regurgitation (MR) jets using an in vitro pulsatile jet phantom. We systematically investigated impact spatial resolution quantification location along on quantities with Doppler ultrasound as reference velocity. Methods Four‐dimensional data through circular, elliptical, 3D‐printed patient‐specific MR orifice model acquired varying...

Background In phase‐contrast (PC) MRI, several dual velocity encoding methods have been proposed to robustly increase velocity‐to‐noise ratio (VNR), including a standard dual‐VENC (SDV), an optimal (ODV), and bi‐ triconditional methods. Purpose To develop correction method for the ODV approach perform comparison between Study Type Case–control study. Population Twenty‐six volunteers. Field Strength/Sequence 1.5 T MRI with VENCs of 50, 75, 150 cm/second. Assessment Since we acquired...

We illustrate a pilot study of the first implementation dual-venc 5D flow MRI. found excellent voxel-wise agreement with single-venc in pulsatile phantom. In two healthy controls, we find good agreement, but identify unexpected aliasing dual venc which requires further investigation.

We adapted our novel respiratory gating method to evaluate the impact of state (RS) resolution on driven flow measured by 5D MRI. found that was both anatomy and vessel dependent. Caval veins measurements in single ventricle disease patients were most impacted reduction states. Shunt pulmonary artery more robust reduced RS may be able take advantage decreased acceleration associated with fewer RS. MRI is well suited for this variable need as retrospective.

Motivation: Single-venc 5D flow is useful for measuring the impact of respiration on hemodynamics, however, its single velocity encoding sensitivity (venc) limit utility in congenital heart disease patients where both venous and arterial measurements are clinically necessary. Goal(s): We aimed to validate respiratory-resolved dual-venc vivo. Approach: Nine healthy volunteers underwent CMR studies including flow, single-venc 4D flow. Net peak were compared. Results: found good agreement net...

RR-resolved 5D flow is a novel MRI technique that can acquire time-resolved 3D hemodynamics for varying RR-interval durations during atrial fibrillation (AF) (5D = 3D+cardiac time+RR-interval duration). The purpose of this study was to apply in cohort AF patients with and without prior history stroke. We saw significantly lowered left peak velocities trends toward higher blood stasis previous stroke vs no who underwent arrhythmia acquisition. may be promising approach cardiovascular imaging...

This paper introduces an early prototype of a decision support tool (DST) for evaluating the effectiveness and logistical considerations biodosimetry methods. Biodosimetry methods allow estimation individual's radiation exposure facilitate process screening population into treatment categories following potential large-scale nuclear or radiological event. The DST was implemented using STELLA <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...