3D phase contrast MRI: Partial volume correction for robust blood flow quantification in small intracranial vessels

Bouillot, Pierre; Delattre, Bénédicte; Brina, Olivier; Ouared, Rafik; Farhat, Mohamed; Chnafa, Christophe; Steinman, David A.; Lövblad, Karl-Olof; Pereira, Vítor Mendes; Vargas, Maria Isabel

doi:10.1002/mrm.26637

Cited by 35 publications

(48 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, the spatial resolution used here was limited compared with the intracranial vessel sizes. The mixture of different spins (such as stationary and flowing spins) within a given voxel will lead to velocity and flow measurement errors . As a result, it is easy to suffer from partial volume effects for intracranial vessels compared with the case of aorta.…”

Section: Discussionsupporting

confidence: 87%

Test–retest multisite reproducibility of neurovascular 4D flow MRI

Wen

Tian

Cheng

et al. 2018

Magnetic Resonance Imaging

View full text Add to dashboard Cite

Background 4D flow MRI shows great potential in neurovascular disorders such as stenosis, atherosclerotic disease, aneurysms, and vascular malformations. Its widespread application in the neurovascular system requires evidence of good test–retest multicenter reproducibility. Purpose To assess the multicenter reproducibility, test–retest reliability and interobserver dependence of 4D flow MRI in measurements of cerebral blood flow/velocity in main intracranial vessels. Study Type Prospective study. Subjects Ten healthy subjects underwent 4D flow scans at three different centers. All subjects were scanned twice at 2 different days at each center. Field Strength/Sequence 3.0 T; 4D flow sequence. Assessment Multicenter reproducibility, test–retest reliability and interobserver agreement for measurements of the blood flow and peak velocity from five regions of interest were assessed (bilateral internal carotid arteries, bilateral medial cerebral arteries, and sagittal sinus). Statistical Test A Shapiro–Wilks test was conducted to assess normality of measurements in each scan. Coefficient of variances (CVs) was computed to evaluate intra‐ and intersite variances of all measurements. The multicenter reproducibility was assessed by two‐way mixed intraclass correlation coefficient (ICC). A Bland–Altman plot and Pearson correlation were used to evaluate test–retest reliability. ICC was calculated to assess interobserver agreements. Results All P‐values for Shapiro–Wilks tests were greater than 0.05, which indicated the normality of all measurements. Both intra‐ and intersite CVs were lower than 12%. There was good test–retest reliability for both blood flow and peak velocity of all ROIs (r = 0.75–0.94). In addition, high multicenter reproducibility was detected (ICC = 0.77–0.96, all P < 0.001). The results of these measurements also showed great interobserver agreement (all ICC > 0.9 and all P < 0.001). Data Conclusion High multicenter reproducibility and test–retest reliability was shown for 4D flow in the measurements of blood flow and peak velocity of intracranial vessels. In addition, these measurements showed great interobserver agreement. Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:1543–1552.

show abstract

Section: Discussionsupporting

confidence: 87%

Test–retest multisite reproducibility of neurovascular 4D flow MRI

Wen

Tian

Cheng

et al. 2018

Magnetic Resonance Imaging

View full text Add to dashboard Cite

show abstract

“…Generally, our data suggest the robustness of 4D flow MRI in estimating blood flow rates in cerebral arteries. This result adds to a growing body of literature that have begun exploring the agreement between 4D flow MRI and conventional 2D phase contrast techniques . Importantly, such measurements have also been shown consistent across sites …”

Section: Discussionsupporting

confidence: 60%

Accuracy of blood flow assessment in cerebral arteries with 4D flow MRI: Evaluation with three segmentation methods

Dunås

Holmgren

Wåhlin

et al. 2019

Magnetic Resonance Imaging

View full text Add to dashboard Cite

Background Accelerated 4D flow MRI allows for high‐resolution velocity measurements with whole‐brain coverage. Such scans are increasingly used to calculate flow rates of individual arteries in the vascular tree, but detailed information about the accuracy and precision in relation to different postprocessing options is lacking. Purpose To evaluate and optimize three proposed segmentation methods and determine the accuracy of in vivo 4D flow MRI blood flow rate assessments in major cerebral arteries, with high‐resolution 2D PCMRI as a reference. Study Type Prospective. Subjects Thirty‐five subjects (20 women, 79 ± 5 years, range 70–91 years). Field Strength/Sequence 4D flow MRI with PC‐VIPR and 2D PCMRI acquired with a 3 T scanner. Assessment We compared blood flow rates measured with 4D flow MRI, to the reference, in nine main cerebral arteries. Lumen segmentation in the 4D flow MRI was performed with k‐means clustering using four different input datasets, and with two types of thresholding methods. The threshold was defined as a percentage of the maximum intensity value in the complex difference image. Local and global thresholding approaches were used, with evaluated thresholds from 6–26%. Statistical Tests Paired t‐test, F‐test, linear correlation (P < 0.05 was considered significant) along with intraclass correlation (ICC). Results With the thresholding methods, the lowest average flow difference was obtained for 20% local (0.02 ± 15.0 ml/min, ICC = 0.97, n = 310) or 10% global (0.08 ± 17.3 ml/min, ICC = 0.97, n = 310) thresholding with a significant lower standard deviation for local (F‐test, P = 0.01). For all clustering methods, we found a large systematic underestimation of flow compared with 2D PCMRI (16.1–22.3 ml/min). Data Conclusion A locally adapted threshold value gives a more stable result compared with a globally fixed threshold. 4D flow with the proposed segmentation method has the potential to become a useful reliable clinical tool for assessment of blood flow in the major cerebral arteries. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:511–518.

show abstract

“…On average, flow rates of 3.2 ± 0.7 ml/s and 1.3 ± 0.8 ml/s were measured in ICAs and VAs, respectively. These values are consistent with previously published phase‐contrast magnetic resonance imaging (PCMRI) data, for example, ICAs: 4.0 ± 0.8 ml/s, VAs: 1.4 ± 0.8 ml/s in Cebral et al., ICAs: 4.3 ± 0.8 ml/s, VAs: 1.7 ± 0.4 ml/s in Zarrinkoob et al., or ICAs: 3.4 ± 0.7 ml/s after partial volume correction in Bouillot et al . (see discussion below).…”

Section: Resultssupporting

confidence: 92%

“…On one hand, the flow rates derived from in vitro 4D‐CTA acquisitions in a patient‐specific model showed good agreement with the flow meter values in both steady‐ and pulsatile flow conditions. On the other hand, the in vivo 4D‐CTA flow rates were globally consistent with previously published data based on PCMRI with a flow ratio ICA:VA = 71:29, even though an underestimation of ≈ 20% was observed compared to Refs. .…”

Section: Discussionsupporting

confidence: 90%

Robust cerebrovascular blood velocity and flow rate estimation from 4D‐CTA

et al. 2019

Self Cite

View full text Add to dashboard Cite

Purpose Blood velocity and flow rate information may be helpful for a wide variety of applications, but it often requires separate acquisitions. The dynamic information combined with the high spatial resolution of four‐dimensional computed tomography angiography (4D‐CTA) offers the possibility to quantify blood flow simultaneous to vascular anatomy. Methods A 4D‐CTA clinical protocol with a novel dedicated postprocessing were validated in vitro in a patient‐specific model, and tested in a pilot study of six patients. Blood flow was assessed in both internal carotid (ICAs) and vertebral (VAs) arteries by analyzing spatial displacement of contrast agent in the form of time‐intensity curves (TICs). Unlike previous approaches, it does not require any a priori assumptions about TIC shape, but rather computes mean velocity and flow rates from the spatial displacement of the TICs along the automatically segmented vessels. Results In vitro experiments showed good agreement between 4D‐CTA and flowmeter measurements under steady and pulsatile flow conditions. In vivo measurements exhibited large interpatient variability of the TIC shapes, from which blood flow rates could nevertheless be successfully measured in all patients and investigated vessels. On average, measured flow rates were 3.2 ± 0.7 ml/s (in ICAs) and 1.3 ± 0.8 ml/s (in VAs) consistent with previous reference standards. Contrary to our novel approach, which considered the full TIC shape, application of previous time‐to‐peak analyses based on idealized TIC shapes showed limited reliability. Conclusions We demonstrate the high potential of 4D‐CTA for assessing blood velocity and flow rate in addition to anatomical evaluation. The wide variety of TIC shapes encountered in vivo highlights the importance of an adaptive TIC analysis as proposed in the present work.

show abstract

3D phase contrast MRI: Partial volume correction for robust blood flow quantification in small intracranial vessels

Cited by 35 publications

References 49 publications

Test–retest multisite reproducibility of neurovascular 4D flow MRI

Test–retest multisite reproducibility of neurovascular 4D flow MRI

Accuracy of blood flow assessment in cerebral arteries with 4D flow MRI: Evaluation with three segmentation methods

Robust cerebrovascular blood velocity and flow rate estimation from 4D‐CTA

Contact Info

Product

Resources

About