Objective To discuss the value of detection of small liver tumor with Galactose-Bovine-serum-albumin containing superparamagetic(Gal-BSA-SPIO) in rabbits primarily.Methods Gal-BSA-SPIO was obtained by stabilizing small superparamagnetic iron with galactose-bovine-serum-albumin,and its size was measured.Models of liver tumor(diameter＜1.5 cm) in rabbits were founded.The animals were randomly divided into groups of SPIO (n=10) and group of Gal-BSA-SPIO (n=10).Each group was further subdivided as 5 μmol Fe/kg group (n=5) and 10 μmol Fe/kg group (n=5),respectively.All animals were performed magnetic resonance imaging before and after administration of agents according to groups.SE T2WI,FSE T2WI and GRE T2WI sequences were used.Then signal of noise(SNR) of liver and contrast-noise ratio(CNR) of tumor-liver were measured and compared statistically.The histopathology study was performed for liver and tumor specimens after MR imaging.Results The mean value for the volume size was 34.4 nm,and the core particle size was 14.8 nm.The differences of liver SNR between before and after enhancement for 5 μmol Fe/kg SPIO,5 μmol Fe/kg Gal-BSA-SPIO,10 μmol Fe/kg SPIO and 10 μmol Fe/kg Gal-BSA-SPIO group were (1.92±0.42),(3.75±0.51),(3.25±0.72) and (4.73±0.34) on SE sequence,respectively;(1.56±0.18),(3.56±0.64),(3.33±0.16) and (4.83±0.16) on FSE sequence,respectively;(5.55±0.91),(9.58±0.66),(9.20±0.29) and (10.63±0.32) on GRE sequence,respectively.There were significant differences between all groups for difierent doses and agents and within all different sequences (P＜0.01).The differences of tumor-liver CNR between before and after enhancement of these 4 groups were(2.22±0.68),(5.27±0.22),(4.25±0.51) and (6.97±0.63) on SE sequence,respectively;(1.73±0.41),(4.46±0.54),(3.73±0.49)and (5.39±0.39) on FSE sequence,respectively;(5.98±0.71),(11.79±0.57),(9.57±0.54)and(14.64±1.35)on GRE sequence,respectively.The differences between all groups of different doses and agents and within all sequences showed significant (P＜0.01). Histopathological study revealed that Gal-BSA-SPIO was mainly distributed in hepatocytes while SPIO mainly in Kupffer cells.Conclusion Gal-BSA-SPIO is a agent with good negative enhancement effect in liver.It may be helpful for detecting small tumor of liver.

Objective Comparison of the levator ani muscles in three-dimensional (3D) MRI-based models in women with and without pelvic organ prolapse at rest to analyze the morphological characteristics of levator ani muscles in women with POP. Methods Twenty-five women with POP and 22 women with normal pelvic support were selected from Nanfang Hospital of Southern Medical University. Axial, sagittal, and coronal T2-weighted pelvic magnetic resonance scans were obtained with the women in the supine position.The 3D models were reconstructed from the source images. Morphological changes was compared within the two groups of levator ani muscles, and the 3D models were measured to determine the levator ani muscle volume (LVOL), levator plate angle (LPA), levator hiatus width (LH-W) and length (LH-L), distance between symphysis and levator sling muscle (LSG). Results There were no puborectalis avulsions in control, in POP, 3 cases of avulsions just in left, 3 cases of avulsions just in right, 7 cases in bilateral. The shape of iliococcygeus were all dome-shaped in control, 11 cases were U-shaped and 14 cases were dome-shaped in POP. The shape of levator hiatus were 7 cases of U-shape, 12 cases of V-shape, 3 cases of irregular in control; 5 cases of U-shape, 4 cases of V-shape, 16 cases of irregular in POP. POP versus control: LH-L: (68.0 ± 8.9) versus (61.6 ± 7.2) mm (P<0.05); LH-W: (41.4 ± 3.9) versus (38.0 ± 3.2) mm (P<0.05); LSG-L: (29.6 ± 7.4) versus (24.6 ± 3.7) mm (P<0.05); LSG-R: (28.4 ± 6.8) versus (23.9 ± 3.2) mm (P<0.05); LPA: (51.0 ± 11.3)° versus (40.6 ± 6.3)° (P<0.05); LVOL: (23.7 ± 5.8) versus (24.6 ± 5.0) cm3 (P>0.05). Conclusions It is possible to assess the morphologic changes of levator ani by using 3D MRI models objectively, our 3D data demonstrate larger in LVOL, LPA, LH-W, LH-L, LSG, and the changes in shape. It is helpful to diagnose and assess the specific situation of patients POP in clinic.