Objective To observe the bone marrow signals of acetabulum and proximal femur of asymptomatic non?professional marathoners by 3.0 T magnetic resonance imaging (MRI) T1WI, and evaluate the bone marrow transformation, so as to obtain the effect of Marathon exercise on bone marrow composition and function. Methods The study group was randomly selected to participate in and complete the whole marathon at least once a year in the past two years. The training mileage of long?distance running was not less than 1 600 kilometers per year. There were no symptoms such as hip pain. There were no abnormalities in hip joint physical examination. The age of 22?53 years old. A total of 31 and 62 hips were evaluated. The control group was randomly selected 29 healthy persons (58 hip joints), aged 23?53 years, without hip pain and regular exercise. All subjects underwent hip joint MRI scan, and the hip joint MRI showed normal. At least 12 hours before MR scan, he did not engage in long?distance running or other sports. The bone marrow signal intensity of acetabulum and proximal femur in T1WI was compared with that of surrounding muscles and fat. The signal intensity was graded from low to high and evaluated by grade. The research group was divided into two groups according to the training years of marathon (running age). The running age of group A was more than 4 years and group B was less than 4 years. The distribution of bone marrow signal in proximal femur was also evaluated by a more intuitive 3?4 classification method. Mann?Whitney U test was used for statistical analysis. Results Bone marrow signal grading evaluation showed that there were significant differences in bone marrow signal grade distribution between the two groups (Z=-6.828, -4.779, -3.046,-5.266,-3.490,-5.053, P<0.05). In the study group, there were 14, 28 hips and 168 parts in group A, 17, 34 hips and 204 parts in group B, bone marrow signals were graded. There were significant differences in acetabulum, femoral neck and upper femoral shaft bone (Z=-2.202, -2.214, -2.730, P<0.05), but no significant differences in femoral head, trochanter and trochanter bone (Z=-0.886,-1.642,-0.711, P>0.05). To evaluate the classification of bone marrow signals in proximal femur, 62 cases of bone marrow signals in the study group were classified as follows: 10 cases with type 1a, 24 cases with type 1b, 17 cases with type 2 and 11 cases with type 3. In the control group, 58 cases of bone marrow signals in proximal femur were classified as follows: 2 cases with type 1a, 13 cases with type 1b, 26 cases with type 2 and 17 cases with type 3. There were significant differences between the two groups (Z=-4.003, P<0.05). Conclusion The T1WI signal intensity of asymptomatic non?professional marathoners′acetabulum and proximal femur bone marrow is lower than that of non?marathoners; the T1WI signal intensity of acetabulum, femoral neck and upper femoral shaft bone marrow of the elderly runners is lower; that is, marathon exercise has certain influence on the bone marrow signal of acetabulum and proximal femur, that is, the change of bone marrow signal in weight?bearing area has a certain phase with the amount of exercise.

目的 通过动态增强磁共振(dynamic contrast enhanced magnetic resonance imaging,DCE-MRI)评价股骨头坏死高危人群股骨头微循环灌注的变化及正常人群股骨头内血流灌注的异质性,为超早期股骨头坏死提供影像学依据.材料与方法 共选取50人60例股骨头,实验组为30例高危股骨头,对照组为30例正常股骨头,两组均行髋部DCE-MRI扫描,在股骨头负重区(前上方)、非负重区(下方)及股骨头中心区分别选取感兴趣区(region of interest,ROI),绘制百分比时间信号曲线(time-intensity curve,TIC),读取TIC上首次峰值(fEmax)、最高信号强度(Emax)、达峰时间(time to peak,TTP)参数,通过独立样本t检验比较股骨头坏死高危人群股骨头不同ROI与正常股骨头相应区域ROI灌注参数的差异;股骨头负重区与非负重区及股骨头中心ROI灌注参数差异的比较采用方差分析.结果 实验组与对照组负重区fEmax、Emax差异有统计学意义(P<0.05),实验组与对照组非负重区TTP差异有统计学意义(P<0.05),实验组与对照组股骨头中心区fEmax、Emax、TTP差异有统计学意义(P<0.05).对照组内负重区、中心区fEmax、Emax大于非负重区fEmax、Emax,且差异有统计学意义(P<0.01),对照组内不同ROI间TTP差异无统计学意义(P>0.05).结论 股骨头坏死高危患者比正常人股骨头血流灌注低;正常人群中股骨头负重区与非负重区血流灌注具有异质性,负重区血流灌注较多.此外,高危人群股骨头血流灌注量小于健康人,灌注时间较正常股骨头长,存在血流瘀滞现象.因此,DCE-MRI可应用于指导临床进行早期预防股骨头坏死发生.

BACKGROUND:Research on the changes to knee structures in asymptomatic amateur ice hockey players (AAIHPs) has been limited. We aimed to assess the performance of the knees in AAIHPs using 3.0-T magnetic resonance imaging (MRI).METHODS:A total of 71 asymptomatic knees (32 AAIHPs and 39 age- and sex-matched controls) were imaged using a 3.0-T MRI scanner at the Affiliated Zhongshan Hospital of Dalian University in April 2017. Two experienced musculoskeletal radiologists were blinded to assess all MRI findings, including bursae around the knee, bone marrow edema (BME), meniscal signal changes, and articular cartilage and ligament damage. Any disagreements were resolved by a third professor of musculoskeletal radiology. Categorical variables were compared using the Chi-square test and continuous variables using the Student's t-test or Mann-Whitney U-test.RESULTS:The most common finding was fluid-filled bursae surrounding the knee. In the AAIHP group, which totaled 32 knees and 416 bursae, 155 (37%) fluid-filled bursae were present. In the control group, there were a total of 39 knees and 507 bursae, and 91 (18%) fluid-filled bursae were present. There was a significant difference in the number of fluid-filled bursae between the two groups (P < 0.05). However, in AAIHPs, the prevalence of meniscal signal changes (16 knees, 50%) was higher than in the control group (2 knees, 5%; P < 0.001). Importantly, 15 of the 19 were grade II signals. Other changes were only found in AAIHPs. Articular cartilage lesions were detected in 47% of their knees, predominantly at the patellofemoral joint, and BME was found in 34% of their knees.CONCLUSION:The MRI findings of knees in AAIHPs mainly manifested as self-protection reaction, and proper ice hockey exercise could be advocated.

目的 利用MRI测量退变性中央型腰椎管狭窄(LSS)硬膜囊横截面积(CSA),研究其与神经根沉降征(NRS)相关性,探讨NRS对LSS的诊断价值.方法 选择2017年4月至12月于大连大学附属中山医院就诊经MRI诊断中央型LSS患者500例,其中男性189例,女性311例;年龄45～80岁,平均年龄62.83岁;临床主要表现为腰腿痛、下肢无力、下肢麻木及间歇性跛行等症状.根据最小CSA分组,并获取每组内所有狭窄节段NRS的阳性病例,计算其阳性率.运用SPSS 20.0统计学软件行统计学分析,获得NRS阳性发生率与CSA间的相关性及退变性ISS在不同腰椎节段中的分布特点.结果 500例患者中1 038个狭窄节段共43.0％病变节段位于L4～5节段,39.1％位于L3～4节段,17.9％位于L2～3节段;其中NRS阳性组550个狭窄节段,NRS阴性组488个狭窄节段.阳性NRS在L2～3、I3～4、L4～5节段的分布差异有统计学意义(x2=8.688,P＜0.05);经两两比较得NRS阳性率在L3～4,L～5节段的分布差异有统计学意义(P＜0.05),I4～5节段的NRS阳性率高于L3～4节段.LSS轻度狭窄中NRS阳性103例,NRS阴性332例;LSS中度狭窄中NRS阳性147例,NRS阴性122例ASS重度狭窄中NRS阳性300例,NRS阴性34例;NRS阳性率与最小CSA的变化呈显著的负相关(r=-0.940,P＜0.05),CSA越小,阳性NRS的发生率越高.LSS组中NRS阳性率,单节段＜双节段＜多节段,差异有统计学意义(X2=65.612,P＜0.05).结论 退变性中央型LSS中NRS阳性与CSA具有显著相关性,NRS阳性可提示椎管狭窄,并可以作为临床评估和量化LSS的一种辅助方法.