Velocity and Diameter Measurements of Penetrating Arteries by Model Based Analysis of Complex Difference Images in Phase Contrast MRI

Mapping Intimacies ◽

10.1101/293308 ◽

2018 ◽

Author(s):

Xiaopeng Zong ◽

Weili Lin

Keyword(s):

Measurement Errors ◽

Phase Contrast ◽

Small Vessel Disease ◽

Quantitative Mri ◽

In Vivo Studies ◽

Phase Contrast Mri ◽

Model Based ◽

Complex Difference ◽

Difference Images ◽

Model Based Analysis

AbstractPathological changes of penetrating arteries (PAs) within deep white matter (WM) may be an important contributing factor of cerebral small vessel disease (SVD). Quantitative characterization of the PAs is important for further illuminating their roles in SVD but remains challenging due to their sub-voxel sizes. We propose a quantitative MRI approach for measuring the diameters and flow velocities of PAs based on model based analysis of complex difference images in phase contrast MRI. The complex difference image of each PA is fitted by a model image calculated by taking into account the partial volume effect and signal enhancement due to in flow effects to obtain velocity , diameter (D), and volume flow rate (VFR) of the PAs. Simulation, phantom, and in vivo studies were carried out to evaluate the accuracy and measurement errors of the proposed method. Our results suggest that PAs with velocities ≥ 0.8 cm/s can be accurately measured with , D, and VFR errors of 0.28 cm/s, 20 μm, and 0.024 mm3/s, respectively, although the mean lumen area occupies only 18% of the acquired pixel area. The PAs have a distribution peak at ~1.2 cm/s and diameters distribution mostly in the range of 88 – 200 μm Quantitative measurements of PAs with the MBAC method may serve as an invaluable tool for illuminating the role of PAs in the aetiopathogenesis of cerebral SVD.

Download Full-text

Associations between blood and cerebrospinal fluid flow impairments assessed with phase-contrast MRI and brain damage in patients with age-related cerebral small vessel disease

Bulletin of Russian State Medical University ◽

10.24075/brsmu.2019.054 ◽

2019 ◽

pp. 16-23

Author(s):

E.I. Kremneva ◽

B.M. Akhmetzyanov ◽

L.A. Dobrynina ◽

M.V. Krotenkova

Keyword(s):

Cerebrospinal Fluid ◽

Brain Damage ◽

Phase Contrast ◽

Small Vessel Disease ◽

Cerebral Small Vessel Disease ◽

Small Vessel ◽

Csf Flow ◽

Phase Contrast Mri ◽

Vessel Disease ◽

Age Related

Hemodynamic parameters of blood and cerebrospinal fluid (CSF) flow can be measured in vivo using phase-contrast MRI (PC-MRI). This opens new horizons for studying the mechanisms implicated in the development and progression of age-related cerebral small vessel disease (SVD). In this paper, we analyze associations between cerebral arterial, venous and CSF flow impairments and SVD features visible on MRI. The study was carried out in 96 patients with SVD (aged 60.91 ± 6.57 years) and 23 healthy volunteers (59.13 ± 6.56 years). The protocol of the MRI examination included routine MRI sequences (T2, FLAIR, T1, SWI, and DWI) applied to assess the severity of brain damage according to STRIVE advisory standards and PC-MRI used to quantify blood flow in the major arteries and veins of the neck, the straight and upper sagittal sinuses, and CSF flow at the aqueduct level. We analyzed the associations between linear and volumetric parameters of blood/CSF flow and the degree of brain matter damage using the Fazekas scale. We observed a reduction in tABF, stVBF, sssVBF, aqLF, Saq, and ICC values and a rise in Pi associated with WMH progression, as well as a gradual decline in tABF and an increase in Pi, Saq and ICC associated with a growing number of lacunes (р < 0.05). Patients with early (< 5) MB had lower sssVBF and stVBF rates in comparison with patients without MB; aqLF, Saq, and ICC values were elevated in patients with 5 to 10 MB, as compared to patients without MB or early (< 5) MB. The established associations between MRI findings in patients with SVD and blood/CSF flow impairments suggest the important role of mechanisms implicated in the disruption of Monro–Kellie intracranial homeostasis in promoting SVD.

Download Full-text