An fMRI study on brain activation patterns of males and females during video sexual stimulation / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the difference in the brain activation patterns of males and females during video sexual stimulation by functional magnetic resonance imaging (fMRI).</p><p><b>METHODS</b>The participants were 20 adult males and 20 adult females, all healthy, right-handed, and with no history of sexual function disorder and physical, psychiatric or neurological diseases. Blood-oxygen-level-dependent fMRI was performed using a 1.5 T MR scanner. Three-dimensional anatomical image of the entire brain were obtained by using a T1-weighted three-dimensional anatomical image spoiled gradient echo pulse sequence. Each person was shown neutral and erotic video sequences for 60 s each in a block-study fashion, i.e. neutral scenes--erotic scenes--neutral scenes, and so on. The total scanning time was approximately 7 minutes, with a 12 s interval between two subsequent video sequences in order to avoid any overlapping between erotic and neutral information.</p><p><b>RESULTS</b>The video sexual stimulation produced different results in the men and women. The females showed activation both in the left and the right amygdala, greater in the former than in the latter ([220.52 +/- 17.09] mm3 vs. [155.45 +/- 18.34] mm3, P < 0.05), but in the males only the left amygdala was activated. The males showed greater brain activation than the females in the left anterior cingulate gyrus ([420.75 +/- 19.37] mm3 vs. [310.67 +/- 10.53] mm3, P < 0.05), but less than the females in the splenium of the corpus callosum ([363.32 +/- 13.30] mm3 vs. [473.45 +/- 14.92] mm3, P < 0.01).</p><p><b>CONCLUSION</b>Brain activation patterns of males and females during video sexual stimulation are different, underlying which is presumably the difference in both the structure and function of the brain between men and women.</p>

Correlation between magnetic resonance diffusion weighted imaging and cell density in astrocytoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the apparent diffusion coefficients (ADC) in magnetic resonance diffusion weighted imaging with echo-planar technique in depicting the tumor cellularity and grading of astrocytoma.</p><p><b>METHODS</b>Thirty-four astrocytoma patients including 18 male and 16 female with age from 10 to 73 years (mean 38.4 years) were examined by MRI and eventually proved by surgical resection and pathological examination. Of them, 26 had low-grade (grade I, II) astrocytoma and 8 high-grade (grade III, IV) astrocytoma. ADC value of astrocytoma was determined on magnetic resonance diffusion weighted images. Cellularity of the astrocytoma was analyzed using Adobe Photoshop 7.0.1 software.</p><p><b>RESULTS</b>The mean ADC value (in units of 10(-4) mm(2)/s) of the high-grade astrocytomas (7.34 +/- 2.95) was significantly lower than that of the low-grade astrocytomas (13.76 +/- 3.31) (t = 4.91, P < 0.001). The mean cellularity of the high-grade astrocytomas (19.81 +/- 9.73)% was significantly higher than that of the low-grade astrocytomas (4.74 +/- 2.96)% (t = 4.32, P = 0.003). ADC value of the astrocytoma was significantly and negatively correlated with its cellularity (r = -0.535, P = 0.001).</p><p><b>CONCLUSION</b>ADC value of astrocytoma is significantly and negatively correlated with its cellularity. Magnetic resonance diffusion weighted imaging may well be highly potential in predicting the degree of astrocytoma.</p>

1H-MRS of the hippocampus of psychogenic erectile dysfunction / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the changes of the hippocampus metabolites with MRS to provide some clues for exploring the possible underlying unrecognised factors and pathophysiological mechanisms of psychogenic erectile dysfunction (ED).</p><p><b>METHODS</b>Fifteen cases of psychogenic erectile dysfunction and 15 normal volunteers (the control) were studied by a clinical 1. 5T MRI/MRS system. Proton multi-voxel spectroscopy imaging (1H-MRSI) was obtained from both sides of the hippocampus region. N-acetylaspartate (NAA), creatine and phosphocreatine (Cr) and choline-containing compounds (Cho) were determined and the ratios of NAA/Cr and Cho/Cr were calculated respectively.</p><p><b>RESULTS</b>The NAA/Cr ratio was significantly lower in the ED patients than in the control (P < 0.05). There was no significant difference in the Cho/Cr ratio between the two groups (P > 0.05).</p><p><b>CONCLUSION</b>Psychogenic erectile dysfunction may not be simply a functional disease. The hippocampus may be involved in the pathophysiology of psychogenic ED. The disease may have some previously unrecognised underlying aetiological factors and pathophysiological mechanisms.</p>

Correlation study between MR spectroscopic findings and cell proliferation in astrocytoma / 中华放射学杂志

Objective To investigate the relationship between findings of proton magnetic resonance spectroscopy(~1H-MRS)and tumor proliferative potential in patents with astrocytoma.Methods Thirty four patients of astrocytomas proved by surgery and pathology were examined by MRI and ~1H-MRS,among them 26 were of grade Ⅰ or Ⅱ(low grade)and 8 of grade Ⅲ or Ⅳ(high grade).Twenty one eases of astrocytomas(17 low-grade and 4 high grade respectively)were homogeneous type.Expression of proliferating cell nuclear antigen(PCNA)was detected by immunohistochemical method of streptavidin- biotin-peroxidase(SP).Results The Cho/NAA and Cho/Cr ratios of high-grade astrocytomas(M=4.895, 4.845 respectively)were significantly higher than those of low-grade astrocytomas(M=2.920, 2.000 respectively)in the 21 homogeneous astrocytomas(Z=-2.597,P=0.009;Z=-2.687,P= 0.007 respectively),and the ratios were found to be significantly correlated to the expression of PCNA(A= 7.880)(r=0.607,P=0.003;r=0.457,P=0.038 respectively).However,the differences of Cho/NAA、 Cho/Cr ratios between the high-grade and low-grade astrocytomas were not significant when 34 cases were included,and no relationship was found between Cho/NAA(M=3.965,2.890 respectively)、Cho/Cr(M= 3.080、1.960 respectively)ratios and the expression of PCNA(A=8.100)(r=0.060,P=0.738;r= 0.125,P=0.480 respectively).Conclusion By measuring the Cho/NAA and Cho/Cr ratios,~1 H-MRS may be a valuable method for presurgical in invo prediction of the malignant degree,tumor proliferative potential and prognosis of homogeneous-type astrocytomas.