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Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Impaired glymphatic system in patent foramen ovale based on diffusion tensor imaging analysis along the perivascular
Liqiang Sun1,2, Kaige Cui1, Jing Hu1
1Department of Medical Imaging, The Second Hospital of Hebei Medical University, Shijiazhuang, China.
Background:
Patent foramen ovale (PFO) is often complicated by cerebral diseases. Notably, PFO is disproportionately prevalent in cryptogenic stroke patients, but the mechanism of PFO is not clear yet. This study aimed to investigate whether there was a decline in the diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) index that partially indicates interstitial fluid (ISF) dynamics and glymphatic system function in PFO patients, which had not been reported before, and to discuss the glymphatic metabolism mechanism by which PFO causes cryptogenic stroke.
Methods:
In total, 52 PFO patients and 50 age- and gender-matched healthy controls (HCs) who underwent diffusion tensor imaging (DTI) with magnetic resonance imaging (MRI) scanning were included in the study. Diffusivity maps in the x-axis (Dxx), y-axis (Dyy), z-axis (Dzz), and the DTI-ALPS index from the projection and association fibers were extracted, and differences between PFO and HC groups were analyzed.
Results:
The PFO patients had significantly higher Dxx and Dyy from the projection fibers, Dzz from the association fibers, lower DTI-ALPS indexes in both hemispheres, and higher Dxx from the association fibers in the left hemisphere than the HCs (P<0.01). The PFO patients had a lower DTI-ALPS index than the HCs in the left (1.358±0.116 vs. 1.624±0.281, P<0.001) and right (1.360±0.135 vs. 1.531±0.208, P<0.001) hemispheres. The areas under the receiver operating characteristic (ROC) curve were 0.83 with an ALPS index cut-off value of 1.434 in the left hemisphere, and 0.76 with an ALPS index cut-off value of 1.420 in the right hemisphere. Further, the paired samples t-tests revealed slight lateral differences in the DTI-ALPS index between the left and right hemispheres in the HCs (P=0.012). The reduced DTI-ALPS index of the left hemisphere (0.267±0.042) was greater than that of the right hemisphere (0.171±0.035).
Conclusions:
The PFO patients showed a decrease in the DTI-ALPS index, which partly indicates ISF dynamic disorder and glymphatic system dysfunction, especially in dominant hemispheres. The DTI-ALPS index could serve as a neuroimaging biomarker for PFO. Further, the state of the impaired glymphatic system in PFO may increase the risk of stroke.
Insights
Patent foramen ovale (PFO) is linked to impaired glymphatic function, as shown by a lower DTI-ALPS index in patients. This finding suggests PFO may increase stroke risk due to glymphatic system dysfunction.
Area of Science:
- Neuroimaging
- Cerebrovascular Diseases
- Glymphatic System
Background:
- Patent foramen ovale (PFO) is frequently associated with cerebral diseases.
- PFO is disproportionately common in cryptogenic stroke patients, but the underlying mechanisms remain unclear.
Purpose of the Study:
- To investigate potential declines in the diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) index in PFO patients.
- To explore the relationship between PFO, interstitial fluid (ISF) dynamics, glymphatic system function, and cryptogenic stroke risk.
Main Methods:
- Diffusion tensor imaging (DTI) was performed on 52 PFO patients and 50 healthy controls (HCs).
- DTI-ALPS index and diffusivity maps were extracted from projection and association fibers.
- Statistical analyses compared DTI-ALPS index values between PFO patients and HCs.
Main Results:
- PFO patients exhibited significantly lower DTI-ALPS indexes in both hemispheres compared to HCs.
- Specific diffusivity metrics (Dxx, Dyy, Dzz) showed significant differences between groups.
- The DTI-ALPS index demonstrated potential as a neuroimaging biomarker for PFO, with ROC analysis yielding AUCs of 0.83 and 0.76.
Conclusions:
- PFO patients demonstrate reduced DTI-ALPS index, indicating impaired interstitial fluid dynamics and glymphatic system function.
- The DTI-ALPS index may serve as a valuable neuroimaging biomarker for identifying PFO.
- Impaired glymphatic function in PFO may contribute to an increased risk of stroke.
