====== Peak systolic velocity ======


Peak systolic velocity (PSV) is an index measured in spectral [[Doppler ultrasound]]. On a Doppler waveform, the peak systolic velocity corresponds to each tall “peak” in the spectrum window
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[[Internal carotid artery]] [[hemodynamics]] ([[maximum systolic velocity]] and average velocity [Vmax , Vavg ], average blood flow [Flowavg ], and wall shear stress) were analyzed based on [[4D flow MRI]] data. [[Cerebral infarction]], defined as the occurrence of events, in 124 brain hemispheres was determined according to clinical symptoms and conventional [[Brain magnetic resonance imaging]].

Statistical tests: The independent-sample [[T-test]] was used to evaluate differences in [[Internal carotid artery]] [[hemodynamics]] between infarcted and non-infarcted [[hemisphere]]s. [[Binary logistic regression]] was performed to investigate the relationship between ICA hemodynamics and events. A P value < 0.05 was considered statistically significant.

Results: Sixty-one infarcted hemispheres (eight hemispheres with acute ischemic damage, 30 with chronic ischemic damage, and 23 with chronic hemorrhagic damage) had [[cerebrovascular event]]s and 63 non-infarcted hemispheres did not. The hemodynamic parameters in the infarcted hemispheres (Vmax : P < 0.001; Vavg : P = 0.003; and Flowavg : P = 0.004) were significantly lower than those in the non-infarcted hemispheres. However, Vmax (P = 0.052), Vavg (P = 0.107), and Flowavg (P = 0.074) were not significantly different among hemispheres with acute ischemic lesions, chronic ischemic lesions and chronic hemorrhagic lesions. Vmax (odds ratio 3.033, 95% CI: 1.075-8.562) was independently associated with cerebrovascular events.

Data conclusion: Vmax may be a higher risk factor for cerebrovascular events in MMA patients.

[[Evidence level]]: 2 TECHNICAL EFFICACY STAGE: 3
((Wang M, Yang Y, Zhang W, Zhou F, Zhang X, Zhang J, Zhang B. [[Risk Factor]]s for [[Cerebrovascular]] [[Event]]s in [[Moyamoya]] [[Angiopathy]] Using [[4D Flow MRI]]: A Pilot Study. J Magn Reson Imaging. 2022 Nov 9. doi: 10.1002/jmri.28522. Epub ahead of print. PMID: 36349829.))
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[[Logistic regression]] analysis showed that the internal diameter of the [[internal carotid artery]], [[peak systolic velocity]] of the internal carotid artery and peak systolic velocity of the [[posterior cerebral artery]] were independently correlated factors for [[stroke]] in patients with [[Moyamoya disease]] MMD. The fourth quartile group of the above three ultrasound parameters was taken as the reference group, and the [[odds]] ratio of the first quartile group were 11.679 (95% CI 2.918-46.749, P = 0.001), 19.594 (95% CI 4.973-77.193, P < 0.001), and 11.657 (95% CI 3.221-42.186, P < 0.001), respectively.

Ultrasound parameters are independently correlated with ipsilateral [[cerebral]] [[stroke]] in patients with [[Moyamoya disease]] (MMD). [[Ultrasound]] provides a new way to identify stroke in MMD patients. Future [[prospective]] [[cohort]] studies are needed to verify the clinical value of ultrasound in identifying patients with MMD at high risk of stroke
((Zheng S, Wang F, Cheng L, Li R, Zhang D, He W, Zhang W. [[Ultrasound]] parameters associated with [[stroke]] in patients with [[moyamoya disease]]: a [[logistic regression]] analysis. Chin Neurosurg J. 2022 Oct 11;8(1):32. doi: 10.1186/s41016-022-00300-5. PMID: 36221122.)).