目的探讨负重位磁共振成像(weight bearing magnetic resonance imaging,MRI)与平卧位MRI对前交叉韧带损伤患者的胫骨前移的对比研究。方法对16例前交叉韧带损伤的患者术前分别进行平卧位和负重位膝关节MRI检查,根据矢状位下外侧胫骨平...目的探讨负重位磁共振成像(weight bearing magnetic resonance imaging,MRI)与平卧位MRI对前交叉韧带损伤患者的胫骨前移的对比研究。方法对16例前交叉韧带损伤的患者术前分别进行平卧位和负重位膝关节MRI检查,根据矢状位下外侧胫骨平台后缘与股骨外侧髁后缘的相对位置测量胫骨前移程度,比较平卧位和负重位磁共振检查中胫骨前移阳性率的差异。结果本组16例中,负重位MRI胫骨前移为(6.56±3.81)mm,平卧位MRI测量胫骨前移为(3.87±3.14)mm,差异有统计学意义(P=0.04)。胫骨前移征阳性率负重位MRI为68.8%(11/16),平卧位MRI为31.2%(5/16),差异有统计学意义(P=0.014)。结论与平卧位MRI相比,负重位MRI能够更容易发现前交叉韧带损伤后胫骨前移征,具有更高的阳性率,为前交叉韧带损伤患者膝关节功能评估提供一种新的方案。展开更多
Background Dysembryoplastic neuroepithelial tumor （DNT） is a rare benign neoplasm of the central nervous system affecting young people. A correct preoperative diagnosis is helpful for planning surgical strategies an...Background Dysembryoplastic neuroepithelial tumor （DNT） is a rare benign neoplasm of the central nervous system affecting young people. A correct preoperative diagnosis is helpful for planning surgical strategies and improving prognosis. The purpose of this study was to characterize DNTs using magnetic resonance imaging （MRI） and magnetic resonance spectroscopy （MRS） and to analyze the value of these two techniques in the diagnosis of DNTs. Methods MR images of 13 patients with DNTs were reviewed retrospectively; and five of the patients also underwent MRS. Tumors were confirmed by surgery. The distribution, extension and signal features of the lesions were assessed, and the MRS results were analyzed. Results All tumors were supratentorial. The cortex was the main area involved, with nine tumors located in the temporal lobe, three in the frontal lobe, and one on the boundary between the temporal and occipital lobes. All cases had decreased signal intensity on Tl-weighted MR images and increased signal intensity on T2-weighted images. On fluid attenuated inversion recovery weighted images, the hyperintense ＂ring sign＂ and internal septation of the lesion were seen in 9 cases. Eight tumors had well-demarcated borders. Peritumoral edema or mass effect was absent in all cases. A contrast enhancement examination was performed in 9 cases. Contrast enhancement was absent in five cases, and four cases showed significant enhancement. The MRS showed a low N-acetylaspartate peak and a lack of elevated choline-containing component （Cho） or Cho-Cr ratio （Cho/Cr） in five patients. Conclusions The MRI findings of DNTs were stereotypical. The combination of MRI and MRS techniques were helpful in making a correct presurgical diagnosis.展开更多
Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocamp...Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocampal formation （HF） in patients with medial temporal lobe epilepsy （MTLE）. Methods Fourteen patients with MTLE and 14 healthy subjects were evaluated. Mean diffusivity （MD） and fractional anisotropy （FA） from the symmetrical-voxel sampling regions of the anterior HF were calculated in all subjects. The MD and FA values were compared across the groups. Results No significant differences of MD and FA values were noted between right and left HF in the controls. In the patient group, MD significantly increased in the HF ipsilateral to the lesioned side [（9.27±1.09）×10^-4 mm^2/s], compared with the values in the contralateral HF [（8.20±0.59）×10^-4 min^2]s] （t = 4.479, P = 0.001） and healthy subjects [（7.58±0.51）×10^-4 mm^2/s] （P 〈 0.001）, but no significant differences were found in FA. When compared with the controls, patients had a significantly higher MD in the contralateral HF （P 〈 0.05）, but the difference in FA was not statistically significant. Conclusions DTI could detect hippocampal abnormality in patients with MTLE. This technique may be helpful for preoperative evaluation of such patients.展开更多
文摘目的探讨负重位磁共振成像(weight bearing magnetic resonance imaging,MRI)与平卧位MRI对前交叉韧带损伤患者的胫骨前移的对比研究。方法对16例前交叉韧带损伤的患者术前分别进行平卧位和负重位膝关节MRI检查,根据矢状位下外侧胫骨平台后缘与股骨外侧髁后缘的相对位置测量胫骨前移程度,比较平卧位和负重位磁共振检查中胫骨前移阳性率的差异。结果本组16例中,负重位MRI胫骨前移为(6.56±3.81)mm,平卧位MRI测量胫骨前移为(3.87±3.14)mm,差异有统计学意义(P=0.04)。胫骨前移征阳性率负重位MRI为68.8%(11/16),平卧位MRI为31.2%(5/16),差异有统计学意义(P=0.014)。结论与平卧位MRI相比,负重位MRI能够更容易发现前交叉韧带损伤后胫骨前移征,具有更高的阳性率,为前交叉韧带损伤患者膝关节功能评估提供一种新的方案。
文摘Background Dysembryoplastic neuroepithelial tumor （DNT） is a rare benign neoplasm of the central nervous system affecting young people. A correct preoperative diagnosis is helpful for planning surgical strategies and improving prognosis. The purpose of this study was to characterize DNTs using magnetic resonance imaging （MRI） and magnetic resonance spectroscopy （MRS） and to analyze the value of these two techniques in the diagnosis of DNTs. Methods MR images of 13 patients with DNTs were reviewed retrospectively; and five of the patients also underwent MRS. Tumors were confirmed by surgery. The distribution, extension and signal features of the lesions were assessed, and the MRS results were analyzed. Results All tumors were supratentorial. The cortex was the main area involved, with nine tumors located in the temporal lobe, three in the frontal lobe, and one on the boundary between the temporal and occipital lobes. All cases had decreased signal intensity on Tl-weighted MR images and increased signal intensity on T2-weighted images. On fluid attenuated inversion recovery weighted images, the hyperintense ＂ring sign＂ and internal septation of the lesion were seen in 9 cases. Eight tumors had well-demarcated borders. Peritumoral edema or mass effect was absent in all cases. A contrast enhancement examination was performed in 9 cases. Contrast enhancement was absent in five cases, and four cases showed significant enhancement. The MRS showed a low N-acetylaspartate peak and a lack of elevated choline-containing component （Cho） or Cho-Cr ratio （Cho/Cr） in five patients. Conclusions The MRI findings of DNTs were stereotypical. The combination of MRI and MRS techniques were helpful in making a correct presurgical diagnosis.
文摘Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocampal formation （HF） in patients with medial temporal lobe epilepsy （MTLE）. Methods Fourteen patients with MTLE and 14 healthy subjects were evaluated. Mean diffusivity （MD） and fractional anisotropy （FA） from the symmetrical-voxel sampling regions of the anterior HF were calculated in all subjects. The MD and FA values were compared across the groups. Results No significant differences of MD and FA values were noted between right and left HF in the controls. In the patient group, MD significantly increased in the HF ipsilateral to the lesioned side [（9.27±1.09）×10^-4 mm^2/s], compared with the values in the contralateral HF [（8.20±0.59）×10^-4 min^2]s] （t = 4.479, P = 0.001） and healthy subjects [（7.58±0.51）×10^-4 mm^2/s] （P 〈 0.001）, but no significant differences were found in FA. When compared with the controls, patients had a significantly higher MD in the contralateral HF （P 〈 0.05）, but the difference in FA was not statistically significant. Conclusions DTI could detect hippocampal abnormality in patients with MTLE. This technique may be helpful for preoperative evaluation of such patients.
