Purpose: To investigate the different sound spectrum of carotid arteries and to analyze its relationship to the vessel disease, and to build a new biomarker about vascular disorder.

Methods: To record the carotid phonoangiography with digital stereoscopy and analysis the spectrum with different algorithm such as FFT, wavelet, entropy, complexity, and HHT. The results will be correlated and comparison to the finding in clinical, carotid Doppler and duplex, CTA, MR, and catheter angiography.

Statistics:

The significance of difference between parameters was computed using t-tests or paired t-test etc. A p value <0.05 is defined as significant.

The investigators plan to recruit data from patients that come to their department for angiography study and intervention (n=300) with different disease entity such as atherosclerosis, tumor, aneurysm, arteriovenous malformation or fistula, and other vascular disorders. A period of about 20 seconds of the carotid phonoangiography was recorded.

Standard for comparison: catheter angiography, CTA, MRI/MRA. The degree of stenosis, the wall thickness, SI and density change was clustered and compared. The clinical and laboratory data will be reviewed and the vascular risk factors will be calculated.

Spectrum analysis: The sound spectrum will be analysis with the FFT, wavelet, entropy, complexity, and HHT algorithms.

The correlation between change of spectrums and also the correlated clinical, images, and laboratory change will be further analysis by statistic method.

Inclusion Criteria:

1. Age: 20 years old to 99 years old
2. Gender: Unlimited
3. Because different types of brain diseases, those who received conventional catheter vascular examination.

Exclusion Criteria:

1. Neck inflammation locally who can not admit the sound.
2. Due to inability to cooperate to accept those recordings.

the patients who is going to have carotid angiography study and with informed consent signed.