Biomedical subjects

Ren-min Chang

Publications and source records attributed to Ren-min Chang.

3 recordsLinked to original sources

PubMed2004

Perfusion homogeneity of hepatic parenchyma in magnetic resonance imaging during splenoportography.

OBJECTIVE: To evaluate the homogeneity of hepatic parenchyma enhancement in magnetic resonance imaging during splenoportography (MRSP) in the portal phase. METHODS: MRSP was performed in 16 patients suspected of space-occupying lesions in the livers. The signal intensity of non-lesion abnormal perfusion areas and that of peripheral parenchyma were measured in all the scanning phases including unenhanced phase, portographic phase, equilibrium phase, and delayed phase. RESULTS: Perfusion abnormalities were observed in 8 non-lesion foci in the portal phase in 4 cases of hepatic cirrhosis, most frequently appearing in triangle or fan-like shapes (7/8) with unpredictable locations. Hepatic cirrhosis patients had more non-lesion perfusion abnormalities than non-cirrhosis patients. CONCLUSIONS: The presence of non-lesion perfusion abnormalities in MRSP does not affect the diagnosis of the disease, and more homogeneous enhancement of the hepatic parenchyma in the portal phase can be achieved in MRSP than in CT during arterial portography and magnetic resonance imaging during arterial portography.

Adult↗

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↗

PubMed2003

[Comparative study of four GRE sequences in MnDPDP-enhanced magnetic resonance imaging for primary hepatocellular carcinoma].

OBJECTIVE: To assess the value of four T(1)-weighted (T(1)W) gradient-recalled-echo (GRE) sequences in MnDPDP-enhanced magnetic resonance imaging (MRI) for diagnosing primary hepatocellular carcinoma (HCC). METHODS: T(1)W images of fast low-angle shot (FLASH), fat-suppressed (FS) FLASH, in-phase and opposed-phase (IP/OP) FLASH were obtained from 13 HCC patients before and 30 min after the patients were given 5 micromol/kg.b.w. MnDPDP. The delayed (24 h) images were also obtained with the same sequences in addition to the T(2)W turbo spin-echo (TSE) sequence performed before MnDPDP administration. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the liver parenchyma and the tumor foci were calculated for each sequence. RESULTS: No statistical differences were found in SNR and CNR between the images obtained with the four T(1)W sequences (P > 0.05). The fatty degeneration of HCC could be detected by OP imaging, but not by T(1)W FLASH or IP T(1)W imaging. CONCLUSION: IP and OP FLASH produces better and easier performance in characterizing the fatty degeneration of HCC, and are recommended for MnDPDP-enhanced MRI of HCC.

Adult↗