Alterations of the Whole Cerebral Blood Flow in Patients With Different Total Cerebral Small Vessel Disease Burden

Abstract

Background: Cerebral small vessel disease (CSVD) is a common age-related vascular disease of the brain associated with slowly accumulating tissue damage. At present, total CSVD burden score is a commonly used method to evaluate the severity of the disease.

Purpose: To observe whether global and regional cerebral perfusion is related to total CSVD score and to explore global and regional cerebral blood flow (CBF) changes in patients with different degrees of CSVD.

Methods: We collected 130 subjects with different total burden score of CSVD (0 point: 33 subjects, 1 point: 39 subjects, 2 points: 24 subjects, 3 points: 24 subjects, 4 points: 10 subjects). Total CSVD burden score was evaluated by clinically routine sequences (T2WI, T2-FLAIR, T1WI, DWI, and SWAN sequence). Global and regional CBF were calculated and correlation analysis was used to investigate the relationship between total CSVD score and CBF of the whole brain and several brain regions.

Results: The analysis results showed that there was a negative correlation between total CSVD burden score and global CBF (r = -0.33, p = 0.001). Total CSVD burden score also had moderately negative correlations with CBF of almost all the brain regions.

Conclusion: CSVD is a disease that affects the whole brain. With the increase of total CSVD burden score, the global and regional CBF decreased. The CSVD total burden score could be used to evaluate the overall condition of brain perfusion.

Keywords: MRI; arterial spin labeling; cerebral blood flow; cerebral small vessel disease; total CSVD burden score.

FIGURE 1

MRI images of subjects with different CSVD total burden score. The subject with score of zero point was a 57-year-old man with no abnormal lesions in MRI images. The patient with score of one point was a 61-year-old female, the bilateral basal ganglia represented punctate and linear lesions with diameter less than 3 mm, hypointensity on T1WI, hyperintensity on T2WI and low signal intensity on T2-FLAIR. The DWI and SWAN sequences showed no abnormality. The bilateral basal ganglia region coincided with EPVS (grade 2–3). For the patient with score of two points, bilateral basal ganglia showed dotted, linear cerebrospinal fluid signal shadow (diameter < 3mm), T2WI showed high signal intensity, T1WI showed low signal intensity, T2-FLAIR showed low signal intensity, which was consistent with the characteristics of EPVS. SWAN sequence of the right parietal lobe showed low signal intensity with diameter ≤ 10 mm, which conformed to the characteristics of CMBs. This CSVD patient was consistent with two points according to the criteria of total CSVD burden score. The patient with score of three points was a 60-year-old female. MRI showed EPVS (grade 2–3) in the bilateral basal ganglia, large confluent areas WMH (Fazekas 3 for DWMH) and lacunar infarction in the center of bilateral semioval center. SWAN sequences showed no abnormality. The patient with CSVD score of four points was a 62-year-old male. There were EPVS (grade 2–3) in the bilateral basal ganglia, large fused WMH (Fazekas 3 for DWMH) in the center of the bilateral semiovale center, acute lacunar infarction with high signal intensity in the right basal ganglia region in DWI image, and CMBs in the right temporal lobe. All the four kinds of imaging markers appeared in this patient.

FIGURE 2

Flow chart of imaging preprocessing, segmentation and CBF extraction.

FIGURE 3

(A–K) Demonstrates relationship between CSVD total burden score and CBF in the whole brain and several brain regions and CBF maps of subjects with different CSVD total burden scores. The horizontal axis on the picture represents CSVD total burden score and the vertical axis represents the CBF values (unit: ml/100 g/min) of the corresponding brain region. In (B), (D), (F), (H), and (J), red line represents CBF of the cortex and blue represents CBF of the white matter. Error bar represents mean and standard deviation. (L) shows CBF maps of five subjects with CSVD total burden from 0 to 4.