Objective To study MRI manifestation of the non-diver bone infarction. Methods Six cases of non-diver bone infarction involved 18 bones totally, in which 15 bones were confirmed by surgical operation and pathology. All cases were examined by MRI through T 1WI, T 2WI, PDWI, FLASH T 2WI, and by X-ray plain film. Result (1) Major MRI manifestation was moderate signal intensity on T 1WI and inhomogenous high signal intensity on T 2WI in the centers of the foci whose margin were rugged and rough bands which were low signal intensity on T 1WI and two layers on T 2WI. (2) MRI manifestation was atypical when focus was small (

Objective To investigate the X-ray and MRI manifestations of osteochondritis dissecans (OCD) and to compare the sensitivity of detection among different sequences. Methods Thirty-six OCD cases (thirty-eight knees) with complete data were selected and analyzed. The sagittal and coronal images were acquired on T 1WI, T 2WI, PDWI, and FLASH T * 2WI. MRI manifestations were analyzed retrospectively with double blind contrast method. The radiographies were obtained on the same day. The sensitivity of detection among different sequences was also compared. Results (1) The medial femoral condyle was the most commonly affected location in the knee (63.2%). The proportion of classical type, expanded type, and inferocentral type was 55.3%, 15.8%, and 28.9%, respectively. (2) On radiographs, the lesions typically appeared as a well circumscribed area of sclerotic subchondral bone separated from the remainder of the epiphysis by a radiolucent line. (3) Subchondral bone lesion was displayed as small and crescent-shaped ( n =38) on the sagittal image and as wedge (14) or short bar (24) shape on coronal image. The signal of the lesion was hypointense or isointense on T 1WI,surrounded by a hypointense or hyperintense (FLASH T * 2WI, T 2WI) line. The subchondral plate disappeared or became thinner. Interruption or disappearance of the hyaline cartilage could be seen sometimes. (4) The detection rate on T 1WI was higher than that of PDWI, T 2WI, and FLASH T * 2WI. Conclusion (1) Osteochondritis dissecans has specific X-ray and MRI manifestations. The abnormality of the hyaline cartilage and the subchondral bone can be displayed by MRI. Thus a proper diagnosis can be made. (2) The detection rate on T 1WI is higher than that of PDWI, T 2WI, and FLASH T  2WI.

Objective To investigates the feasibility of diffusion tensor imaging (DTI) and diffusion tensor tracking (DTT) for evaluation of the effect of childbearing history on female pelvic floor muscles. Methods Forty-six healthy females were divided into two groups: nulliparous and primiparous. MR conventional sequences and DTI were acquired. The optimized FA threshold value was obtained by regulating the FA to fiber tracking. The two groups were compared in terms of ADC, FA, VRA and T2-WT. Results (1)The DTT of FA 0.18 got the highest score in fiber tracking . ( 2 ) The ADC of nulliparous subjects and the subjects who had given birth were (1.24 ± 0.11) ×10-3 mm2/s, (1.33 ± 0.11) ×10-3 mm2/s (P = 0.017). There were no statistical differences in FA, VRA and T2-WT between the two groups (P > 0.05). Conclusions The optimized FA threshold of fiber tracking in pelvic floor muscles is 0.18. DTI and DTT may be used to evaluate the effect of childbearing history on female pelvic floor muscles.

Objective To explore the value of enhanced T2 star weighted angiography(ESWAN)in the treatment of uterine fibroids with high intensity focus ultrasound(HIFU) by analyzing the changes of ESWAN. Methods Uterine fibroids were detected through pelvic conventional MRI and ESWAN 1 day before and after HIFU operation. Different indexes of ESWAN were measured ,and differences were compared with the paired t-test. Results The preoperative and postoperative values of magnitude were 1624.59 ± 53.07 and 1750.13 ± 39.81, phase values were 0.0012 ± 0.0081 Hz and 0.0025 ± 0.1063 Hz,R2*value were 27.69 ± 1.27 Hz and 24.19 ± 1.20 Hz,and T2*values were 34.66 ± 2.07 ms and 36.46 ± 2.14 ms. After HIFU operation,magnitude value,phase value and T2*value were higher(P=0.04,P=0.91 and P=0.45),and R2*value was lower(P=0.019). Conclusions ESWAN can provide more information about histopathologic changes of uterine fibroids after HIFU.

Objective To observe the urodynamic change after spinal cord injury at different levels and the relationship with neurogenic dysfunction of bladder and urethra. Methods Eighty female rats were divided into a control group (20 rats) , a suprasacral spinal cord injury group (30 rats) and a sacral spinal cord injury (30 rats). The urodynamic exam was performed with all the rats before and 20 days after the spinal cord injury model was established by surgical operation. Results The maximum bladder volume and compliance in the su- prasacral injury group were significantly less than the sacral spinal cord injury group and the control, the maxi- mum volume and compliance in sacral spinal cord injury group were significantly less than the control. The DLPP in suprasacral injury group was significantly higher than that in the sacral spinal cord injury group and the con- trol, the DLPP in sacral spinal cord injury group was significantly less than that in the control group. Conclu- sion Urodynamic study is very useful for the early diagnosis and individualized treatment of the neurogenic bladder after spinal cord injury.