Myocardium microcirculation study in a healthy Chinese population using 3.0-T cardiac magnetic resonance intravoxel incoherent motion imaging

Background Intravoxel incoherent motion imaging (IVIM) can non-invasively evaluate diffusion and microvascular perfusion. Purpose To explore the myocardium microcirculation of a healthy Chinese population by using cardiac magnetic resonance (CMR) IVIM. Material and Methods A total of 80 healthy volunteers (44 men, 36 women) who underwent 3.0-T CMR examination were enrolled. All participants had cardiac cine imaging and short-axis CMR-IVIM of the left ventricle (LV) using multiple b-values. The consistency of the IVIM parameters was assessed by intraclass correlation coefficient (ICC) and the Bland–Altman test. Spearman correlation analysis was performed between IVIM parameters and age, and body mass index (BMI). The differences of IVIM parameters were analyzed between gender and different ages. Results LV end-diastolic volume (EDV), end-systolic volume (ESV), LVmass, cardiac output (CO), and BMI in the male group were higher than those in the female group ( P<0.05). IVIM parameters had good intra-observer and inter-observer consistency (≥0.75). Bland–Altman analysis also showed good intra-observer and inter-observer consistency. ADCfast decreased with increasing female age (rs = –0.37; P = 0.01), while IVIM parameters had no correlation with BMI regardless of sex. ADCfast in the female group had a statistical difference between different age groups. The ADCslow and f in the male group were lower than those in the female group ( P<0.05); however, there was no statistical difference in ADCfast between genders. Conclusion IVIM parameters in healthy Chinese volunteers provided good consistency. There was a negative correlation between ADCfast and age in the female group.

Baseline Blood-Brain Barrier Leakage and Longitudinal Microstructural Tissue Damage in the Periphery of White Matter Hyperintensities

ObjectiveTo investigate the 2-year change in parenchymal diffusivity, a quantitative marker of microstructural tissue condition, and the relationship with baseline blood-brain barrier (BBB) permeability, in tissue at risk, i.e., the perilesional zone surrounding white matter hyperintensities (WMH) in patients with cerebral small vessel disease (cSVD).MethodsPatients with sporadic cSVD (lacunar stroke or mild vascular cognitive impairment) underwent 3T MRI at baseline, including dynamic contrast-enhanced MRI to quantify BBB permeability (i.e., leakage volume and rate) and intravoxel incoherent motion imaging (IVIM), a diffusion technique that provides parenchymal diffusivity D. After 2 years, IVIM was repeated. We assessed the relation between BBB leakage measures at baseline and change in parenchymal diffusivity (∆D) over 2 years in the perilesional zones (divided in 2-mm contours) surrounding WMH.ResultsWe analyzed 43 patients (age 68 ± 12 years, 58% male). In the perilesional zones, ∆D increased 0.10% (confidence interval [CI] 0.07–0.013%) (p < 0.01) per 2 mm closer to the WMH. Furthermore, ∆D over 2 years showed a positive correlation with both baseline BBB leakage volume (r = 0.29 [CI 0.06–0.52], p = 0.013) and leakage rate (r = 0.24 [CI 0.02–0.47], p = 0.034).ConclusionBBB leakage at baseline is related to the 2-year change in parenchymal diffusivity in the perilesional zone of WMH. These results support the hypothesis that BBB impairment might play an early role in subsequent microstructural white matter degeneration as part of the pathophysiology of cSVD.