Monitoring Cerebral Perfusion Changes Using Arterial Spin-Labeling Perfusion MRI after Indirect Revascularization in Children with Moyamoya Disease

Pseudo-continuous and territorial arterial spin labeling MRI for assessment of cerebral perfusion in moyamoya disease after revascularization: A comparative study with digital subtraction angiography

Purpose

To evaluate if pseudo-continuous arterial spin labeling (pcASL) and territorial ASL (tASL) can assess cerebral perfusion post-revascularization in Moyamoya disease and compare with digital subtraction angiography (DSA) outcomes.

Materials and methods

Patients diagnosed with Moyamoya disease who underwent pcASL using two post-labeling delays (short ASL, 1,525 ms; delayed ASL, 2,525 ms), tASL, and DSA 3 months after surgery at a single institution were retrospectively evaluated. Manual delineation on pcASL cerebral blood flow (CBF) maps covered middle cerebral artery (MCA) territory on both sides, and cerebellum. Normalized CBF (nCBF) was calculated. Revascularization in the MCA territory was evaluated with external carotid angiography and tASL, graded on a three-point scale. Intermodality agreement was analyzed with weighted κ statistics. Correlation between pcASL-derived nCBF and tASL-measured revascularization, and revascularization grade from direct angiography, was determined. Diagnostic performance of pcASL and tASL was evaluated using DSA as a reference via receiver operating characteristic (ROC) curve analysis.

Results

A total of 32 hemispheres from 31 patients were assessed. On the operated side, sASL and dASL had nCBF values of 1.00 ± 0.30 and 1.31 ± 0.31, respectively. Revascularization area grading showed substantial intermodality agreement (weighted κ = 0.68; 95 % CI: 0.49, 0.87). DSA revascularization moderately correlated with sASL and dASL nCBF values (r = 0.56 and 0.47) and strongly correlated with tASL revascularization area (r = 0.73). ROC analysis revealed that sASL and dASL nCBF values reflected revascularization (area under the curve (AUC) = 0.86 and 0.77) and tASL revascularization area (AUC = 0.91). Combined pcASL and tASL had an AUC of 0.93, comparable to tASL alone, improving diagnostic performance. The diagnostic accuracy of nCBF for sASL was 87.5 %, superior to 75 % for dASL. The diagnostic accuracy of tASL external carotid artery revascularization area was 87.5 %, with sensitivity and specificity of 88 % and 85.7 %, respectively.

Conclusion

The combination of pcASL and tASL outperformed pcASL alone in assessing cerebral perfusion post-Moyamoya disease revascularization.

Predictive Factors for Seizures after Revascularization in Patients with Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is a rare and complex cerebrovascular disorder that is diagnosed through imaging studies, such as computed tomography or magnetic resonance imagin, which show progressive narrowing of the terminal portion of the internal carotid arteries and the development of compensatory capillary collaterals. The objective of our study was to identify and clarify the predictive factors for seizures in patients with MMD.

METHODS

From January 2019 to March 2023, a total of 102 patients with MMD were enrolled in this study. Ten patients with seizures after surgery as the main presentation were included. Patients with epilepsy were compared to those without epilepsy in terms of their clinical characteristics. Multivariable analysis was applied to determine factors linked with postoperative seizures.

RESULTS

Ten patients developed seizures after revascularization for MMD. Logistic regression analysis revealed that early seizure (odds ratio [OR], 0.068; 95% CI, 0.014-0.342; P = 0.001), cortical involvement (OR, 9.593; 95% CI, 2.256-40.783; P = 0.002), and postoperative hyperperfusion (OR, 7.417; 95% CI, 1.077-51.093; P = 0.042) were significantly associated with seizures. In a multivariate analysis, it was found that early seizures were significantly associated with a higher likelihood of experiencing seizures (OR, 5.88; 95% CI, 1.01-33.96; P = 0.048), while patients who had seizures were more likely to have cortical involvement (OR, 8.90; 95% CI, 1.55-50.96; P = 0.014) or postoperative hyperperfusion (OR, 12.44; 95% CI, 1.21-127.74; P = 0.034).

CONCLUSIONS

Epilepsy in patients with MMD link with several clinical factors. In patients with MMD who undergo bypass surgery, early seizures, cortical involvement, and postoperative hyperperfusion are significant independent predictive factors for the development of epilepsy.

Predictive value of CT perfusion-derived parameters in Moyamoya disease

OBJECTIVE

To explore the applicability of CT perfusion-derived parameters and collateral index in prediction of functional and clinical outcomes in patients with Moyamoya disease (MMD) who have not been treated surgically.

METHODS

All hemispheres were categorized into four groups: those with ischemic (IS) lesions, hemorrhagic (HE) lesions, subarachnoid hemorrhage (SAH) and normal hemisphere (NH). The clinical review included primary outcomes (whether a patient survived the cerebrovascular event) and secondary outcomes (the modified Rankin scale [mRS] and Katz-activity of daily living [ADL] scale). CTP-derived parameters of the frontal, temporal lobe and basal ganglia were calculated. Collateral index of the hypointensity ratio (HIR) was defined as a volume of Tmax >10 s/ Tmax >4 s.

RESULTS

Between December 2020 and December 2021, 21 MMD patients (15 bilateral cases and 6 unilateral cases, for a total of 36 hemispheres) were retrospectively included. Compared with the NH group, the IS group showed obviously abnormal hemodynamics. As for the primary outcomes, HIR showed an excellent area under the curve of 0.955 (95 % CI: 0.886-1.000, p < 0.001). Significant correlations were found between CTP-derived parameters and secondary outcomes. Furthermore, HIR was significantly correlated with mRS (r = 0.576, p = 0.001) and ADL scores (r = 0.644, p < 0.001).

CONCLUSION

Among different imaging types, IS hemispheres were characterized by distinct changes of hemodynamic parameters. Collateral index of HIR could be considered a clinically accessible and promising indictor of functional and clinical outcomes in MMD.

Monitoring Posterior Cerebral Perfusion Changes With Dynamic Susceptibility Contrast-Enhanced Perfusion MRI After Anterior Revascularization Surgery in Pediatric Moyamoya Disease

OBJECTIVE

To determine whether dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) can be used to evaluate posterior cerebral circulation in pediatric patients with moyamoya disease (MMD) who underwent anterior revascularization.

MATERIALS AND METHODS

This study retrospectively included 73 patients with MMD who underwent DSC perfusion MRI (age, 12.2 ± 6.1 years) between January 2016 and December 2020, owing to recent-onset clinical symptoms during the follow-up period after completion of anterior revascularization. DSC perfusion images were analyzed using a dedicated software package (NordicICE; Nordic NeuroLab) for the middle cerebral artery (MCA), posterior cerebral artery (PCA), and posterior border zone between the two regions (PCA-MCA). Patients were divided into two groups; the PCA stenosis group included 30 patients with newly confirmed PCA involvement, while the no PCA stenosis group included 43 patients without PCA involvement. The relationship between DSC perfusion parameters and PCA stenosis, as well as the performance of the parameters in discriminating between groups, were analyzed.

RESULTS

In the PCA stenosis group, the mean follow-up duration was 5.3 years after anterior revascularization, and visual disturbances were a common symptom. Normalized cerebral blood volume was increased, and both the normalized time-to-peak (nTTP) and mean transit time values were significantly delayed in the PCA stenosis group compared with those in the no PCA stenosis group in the PCA and PCA-MCA border zones. TTP_PCA (odds ratio [OR] = 6.745; 95% confidence interval [CI] = 2.665-17.074; P < 0.001) and CBV_PCA-MCA (OR = 1.567; 95% CI = 1.021-2.406; P = 0.040) were independently associated with PCA stenosis. TTP_PCA showed the highest receiver operating characteristic curve area in discriminating for PCA stenosis (0.895; 95% CI = 0.803-0.986).

CONCLUSION

nTTP can be used to effectively diagnose PCA stenosis. Therefore, DSC perfusion MRI may be a valuable tool for monitoring PCA stenosis in patients with MMD.

Association of Cerebral Hemodynamics and Cognitive Function in Adult Patients with Moyamoya Disease: A Three-Dimensional Pseudo-Continuous Arterial Spin Labeling Study

OBJECTIVE

Cognitive dysfunction is a serious complication of moyamoya disease (MMD) in adults, and reduced cerebral blood flow (CBF) might be the potential cause. We aimed to explore the correlation between cerebral hemodynamics and cognitive function in adults with MMD by using three-dimensional pseudo-continuous arterial spin labeling (3D-pCASL).

METHODS

A total of 24 MMD patients with a history of cerebral infarction, 25 asymptomatic MMD patients, and 25 healthy controls were prospectively enrolled in this study. All participants were performed 3D-pCASL, and cognitive function was evaluated with the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment Scale (MoCA), and the Trail Making Test Part A (TMTA). The correlation between cerebral hemodynamics and cognitive function was explored in the region of interest-based analysis.

RESULTS

Compared with healthy controls, both CBF and cognition decreased in adult MMD. In the infarction group, the MMSE and MoCA scores correlated with CBF of the right anterior cerebral artery (P = 0.037 and 0.010, respectively) and the left middle cerebral artery (MCA) cortical territories (P = 0.002 and 0.001, respectively), and the TMTA time-consuming has a negative correlation with CBF of the right and left MCA cortical territories (P = 0.044 and 0.010, respectively); in the asymptomatic group, the MMSE and MoCA scores correlated with CBF of the left MCA cortical territory (P = 0.032 and 0.029, respectively).

CONCLUSIONS

The 3D-pCASL can find the hypoperfusion area of CBF in adults with MMD, and hypoperfusion in specific brain regions may cause cognitive dysfunction even in asymptomatic patients.