Preliminary study on quantification of rabbit central nervous system by DTI sequence / 实用放射学杂志

Objective To explore the feasibility and application in quantifying the rabbit central nervous system by using magnetic resonance diffusion tensor imaging(DTI)sequences.Methods 12 normal New Zealand rabbits were used to scan the brain and spinal cord of rabbits by DTI sequence of 1.5T MR machine,and the normal apparent diffusion coefficient(ADC)and fractional anisotropy (FA)values were obtained in the different regions of the brain and every spinal segment of rabbits,to analyse the characteristics and regularity of numerical changes.Results The average ADC value in the brain of rabbits was (0.87±0.08)×10-3mm2/s,the average FA value was 0.23±0.09;the average ADC value in cervical spinal cord was (1.05±0.14)×10-3mm2/s,the average FA value was 0.55±0.08.The average ADC value in thoracic spinal cord was (1.14±0.12)×10-3mm2/s,and the average FA value was 0.57±0.06;the average ADC value in lumber spinal cord was (1.20±0.12)×10-3mm2/s,and the average FA value was 0.61±0.06.Conclusion FA average value in the brain is lower than that in spinal cord (P<0.001),the difference is related to the distribution of nerve fibers and physiological curvature of spine.ADC average value in the brain is lower than that in spinal cord(P<0.001),this is related to the volume of spinal canal and the peripheral structure of spinal cord.The difference of FA value in the brain and spinal cord is higher than ADC value.

MRI Diagnosis of Ligament Trauma of Knee / 实用放射学杂志

Objective To evaluate the value of magnetic resonance imaging(MRI) in diagnosing ligament injury of the knee.Methods MRI manifestations of ligament injury of the knee confirmed by operation or joint-screen examination in 32 cases were retrospectively analyzed. All cases underwent routine MR scanning. The cases with suspicious anterior cruciate ligament injury undenwent oblique saqittal section fast spin echo-T_2 weight (FSE-T_2WI )and the cases with suspicious medical accessory ligament injury underwent coronal section fat suppressed-fast spin echo-T_2 weight(FS-FSE-T_2W).Results 36 ligaments were found having injury in all cases, including 16 anterior cruciare ligaments, 14 posterior cruciate ligaments, 5 medical accessory ligaments and 1 lateral accessory ligament. The ligaments injuries included tear completely and part.Conclusion MRI is the ideal non-invasive method for studying ligament injury of the knee.