Biomedical subjects

Xiu-yi Zhao

Publications and source records attributed to Xiu-yi Zhao.

2 recordsLinked to original sources

PubMed2004

[Correlation between age and average apparent diffusion coefficient in normal-appearing cerebral white matter].

OBJECTIVE: To quantitatively study the effect of ages on the average apparent diffusion coefficient (ADCav) of normal-appearing white matter. METHODS: Fifty patients with normal-appearing white matter were divided into four age groups, namely 16-30 years, (n=13), 31-45 years (n=12), 46-60 years (n=14) and >60 years (n=11). All the subjects were examined with conventional and trace-weighted diffusion imaging in three orthogonal directions. The ADCav of the white matter was measured and compared between various age groups. RESULTS: In the white matter, the ADCav of all the patients was (0.71+/-0.08) x 10(-3) mm2/s; the ADCav of the white matter in the first to fourth age groups were (0.69+/-0.06) x 10(-3) mm2/s, (0.71+/-0.07) x 10(-3) mm2/s, (0.71+/-0.09) x 10(-3) mm2/s, and (0.73+/-0.10) x 10(-3) mm2/s respectively. ADCav of patients between 16-30 years was significantly different from that of patients over 60 years of age (P=0.014). Patients older than 60 years had an ADCav of the white matter significantly higher than the value of (0.70+/-0.07) x 10(-3) mm2)/s in the total patients younger than 60 years (P=0.026). CONCLUSION: Water diffusibility shows a slight increase in human white matter with aging, possibly due to mild ultrastructural changes associated with aging.

Adolescent↗

PubMed2002

[Diagnosis of lesions in the major abdominal blood vessels by three-dimensional dynamic contrast-enhanced magnetic resonance angiography].

OBJECTIVE: To elucidate the working principles of three-dimensional dynamic contrast-enhanced magnetic resonance angiography(3D DCE-MRA)and assess its value in the diagnosis of lesions in the major abdominal blood vessels. METHODS: The imaging data of 3D DCE-MRA and conventional MR examination in 32 cases of suspected major abdominal blood vessel diseases were obtained and analyzed retrospectively. RESULTS: The peak flow of contrast agents through the abdominal aorta at the level of renal artery occurred 17 to 23 s after the injections. Normal presentation was found in 3 cases, with clear images of the abdominal aorta and its branches. Abdominal aortic aneurysm was identified in 7 cases, where the involved segment of the aorta was irregularly broadened and the actual lumen of the abdominal aorta was displayed. Aortic dissection was found in 18 cases, and the intima, the double-lumen, and the position where the abdominal aortic branches originated could be seen with 12 entry sites and 16 re-entry sites. Atherosclerosis was found in 3 cases, with tortuous abdominal aorta whose lumen was morphologically irregular. One case was found with thrombosis in the left iliac vein which was not visualized. CONCLUSIONS: 3D DCE-MRA is a non-invasive alternative for conventional angiography and has significant importance in the diagnosis of lesions in major abdominal blood vessels.

Adult↗