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Purpose To evaluate the feasibility of magnetic resonance T2 values in diagnosing hepatic fibrosis (HF).Materials and M1etdheds The models of HF were induced in rats by repetitive dosing of carbon tetrachloride.The stage of hepatic fibrosis (S),grade of inflammation (G) and degree of fatty liver (F) for the HF model animals and their normal controls were evaluated by pathology.The relationship between T2 values and liver fibrosis was analyzed by using multiple echo gradient spin echo sequences.Results According to the stage of hepatic fibrosis,the HF model rats were staged into S1-S4.The grade of inflammation of the HF model rats was G0 or G1,and the degree of fatty liver was F3 or F4,both of which had no statistical differences among the HF model rats at different fibrosis stages (P＞0.05).The T2 values for all rats including normal control rats in the stage of liver fibrosis from S0 to S4 were (38.27±1.45) ms,(42.08±2.63) ms,(45.93±3.61) ms,(50.23 ± 2.23) ms and (57.79± 5.40) ms,respectively,with a significant difference (F=31.903,P＜0.01).Except the T2 values had no significant difference between the S0 and S 1 stages (P＞0.05),the pairwise comparisons of the T2 values between the rest stages were statistically significant (P＜0.01).The T2 values were positively correlated with the stages of hepatic fibrosis (rs=0.921,P＜0.01).Conclusion The T2 value can quantitatively reflect the degree of hepatic fibrosis.
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Objective To evaluate the changes of cerebrospinal fluid dynamics of Chiari malformation type I associated syringomyelia patients with phase-contrast MRI (PC-MRI).Methods Thirty cases diagnosed with Chiari malformation type Ⅰ associated with syringomyelia clinically underwent cisterna plasty treatment.Cerebrospinal fluid dynamics changes were measured before 24 h and 6 months after operation with PC-MRI.The stroke volume (SV),mean flow (MF),regurgitation fractions (RF) and the maximum peak flow velocity (Vmax) were analyzed.Results After operation,PC-MRI showed SV and MF increased,the bidirectional Vmax decreased,which had statistical difference compared with those of preoperation (all P＜0.05),and the C2-3 level was the most obvious.Conclusion PC-MRI can quantitative analysis of preoperative and postoperative changes of cerebrospinal fluid flow and peak velocity.
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Objective To observe the imaging features of partiallythreaded screw fixation using in various kinds of C2 pedicel fracture.Methods CT image materials of 160 Chinese Han patients who suffered from atlantoaxial injury without vertebral body and pedicle fracture of C2 was included in this study,including 120 males and 40 females.Pedical trajectory selected according to Ebraheim method in threedimensional CT reconstruction was analyzed in ADW 4.4 workstation.The posterior wall fracture of C2 vertebral body,isthmus fracture and fractures under C2 laminar were simulated according to clinical observation.The trajectory length (partiallythreaded screw length) from entry point to anterior cortical bone of C2,bolt shank length from entry point to fracture line and fillet of screw length from fracture line to anterior cortical bone of C2 were measured.Relations between height,gender and partiallythreaded screw length bolt shank and fillet of screw length was evaluated.Results Male height was 167±7.9 cm on average,and female was 156±6.6 cm.The length of partiallythreaded screw was 29 mm in male and 25 mm in female on average.Height and gender was positively correlated with partiallythreaded screw length.In posterior wall fracture of C2 vertebral body,length of bolt shank was an average of 17 mm in male and 15mm in female,while fillet of screw length was 12 mm in male and 10 mm in female.The mean length of bolt shank was 14mm in male and 13 mm in female,while mean fillet of screw length was 15 mm in male and 12 mm in female in isthmus fracture.In fractures under C2 laminar,length of bolt shank was 10 mm in male and 9 mm in female on average,while mean fillet of screw length was 18 mm in male and 15mm in female.Conclusion The length of partiallythreaded screw used in posterior axial pedicle fracture may have a close correlation to length and height.The length of bolt shank and fillet of screw was different according to the position of the fracture.