Related Experiment Video
Updated: Apr 13, 2026
Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images
Published on: November 20, 2015
Distinct perforator hemodynamic phenotypes differentiate mechanisms of single subcortical infarction: In vivo
Ning Wei1, Yu-Yuan Xu1, Yue Suo1
1Tiantan Neuroimaging Center of Excellence, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
Objective:
Single subcortical infarction (SSI) arises from heterogeneous mechanisms, most commonly parent artery disease (PAD) or intrinsic small vessel pathology. However, whether these mechanisms produce distinct in vivo hemodynamic signatures within perforating arteries remains unknown. We aimed to determine whether lenticulostriate artery (LSA) hemodynamics differ between SSI subtypes and whether such differences provide mechanistic insight into SSI pathophysiology.
Methods:
Patients with recent SSI confined to the LSA territory were prospectively enrolled and underwent 7T magnetic resonance imaging. Based on intracranial vessel wall imaging, patients were classified as SSI + PAD (ipsilateral middle cerebral artery (MCA) plaque on T1-weighted vessel wall imaging defined by eccentric wall thickening) or SSI - PAD (no ipsilateral MCA plaque). LSA flow velocity was quantified at the arterial ostium and distal segment using phase-contrast magnetic resonance angiography (PC-MRA), and along-vessel velocity decline was calculated. LSA morphology was assessed with time-of-flight MRA. Linear mixed-effects models adjusted for age and sex were used for group comparisons.
Results:
Forty-two patients (21 SSI + PAD and 21 SSI - PAD) were included. In SSI + PAD, ostial velocity in the symptomatic hemisphere was significantly lower than in the contralateral hemisphere (7.25 vs. 9.61 cm/s; p < 0.001) and the symptomatic side of SSI - PAD (8.95 cm/s, p = 0.001), indicating proximal inflow restriction. In contrast, SSI - PAD preserved ostial inflow (8.95 vs. 9.15 cm/s, p = 0.70) but exhibited a greater along-vessel velocity decline on both hemispheres compared with SSI + PAD, suggesting distal microvascular dysfunction. Morphologically, the symptomatic hemisphere showed fewer visible LSA branches and shorter LSA length than the contralateral hemisphere in both groups. In addition, LSA diameter tended to be smaller in SSI - PAD than in SSI + PAD.
Conclusion:
7T PC-MRA revealed distinct hemodynamic patterns in SSI. SSI + PAD was characterized by proximal inflow limitation, whereas SSI - PAD reflected diffuse distal hypoperfusion characteristic of small vessel pathology. Quantitative perforator flow assessment may refine etiologic classification and guide secondary prevention in SSI.
Insights
Single subcortical infarction (SSI) in the lenticulostriate artery (LSA) territory shows distinct hemodynamic patterns. Parent artery disease (PAD) causes inflow restriction, while small vessel disease indicates distal hypoperfusion, aiding etiological classification.
Area of Science:
- Neurology
- Cardiovascular Medicine
- Medical Imaging
Background:
- Single subcortical infarction (SSI) results from diverse causes, primarily parent artery disease (PAD) or small vessel pathology.
- Distinct in vivo hemodynamic signatures within perforating arteries for these SSI mechanisms are not well understood.
Purpose of the Study:
- To investigate if lenticulostriate artery (LSA) hemodynamics differ between SSI subtypes (SSI+PAD vs. SSI-PAD).
- To determine if these hemodynamic differences offer mechanistic insights into SSI pathophysiology.
Main Methods:
- Prospective enrollment of patients with recent LSA territory SSI.
- Classification into SSI+PAD (MCA plaque) or SSI-PAD (no MCA plaque) using 7T MRI vessel wall imaging.
- Quantification of LSA flow velocity and along-vessel velocity decline using phase-contrast MRA (PC-MRA).
Main Results:
- SSI+PAD patients exhibited significantly lower ostial LSA velocity, indicating proximal inflow restriction.
- SSI-PAD patients showed preserved ostial inflow but greater along-vessel velocity decline, suggesting distal microvascular dysfunction.
- Morphological analysis revealed fewer LSA branches and shorter LSA length in the symptomatic hemisphere for both groups, with smaller LSA diameter in SSI-PAD.
Conclusions:
- 7T PC-MRA identified unique hemodynamic patterns differentiating SSI subtypes.
- SSI+PAD is linked to proximal inflow limitation, while SSI-PAD is associated with distal hypoperfusion.
- Quantitative perforator flow assessment can refine SSI etiological classification and guide secondary prevention strategies.
