An ever-increasing number of 3.0 Tesla(T) magnets are installed worldwide. Moving from the standard of 1.5 T to higher field strength implies a number of potential advantage and drawbacks, requiring careful optimizati...An ever-increasing number of 3.0 Tesla(T) magnets are installed worldwide. Moving from the standard of 1.5 T to higher field strength implies a number of potential advantage and drawbacks, requiring careful optimization of imaging protocols or implementation of novel hardware components. Clinical practice and literature review suggest that state-of-the-art 3.0 T is equivalent to 1.5 T in the assessment of focal liver lesions and diffuse liver disease. Therefore, further technical improvements are needed in order to fully exploit the potential of higher field strength.展开更多
Objective To investigate effect of MR field strength on texture features of cerebral T2 fluid attenuated inversion recovery(T2-FLAIR)images.Methods We acquired cerebral 3 D T2-FLAIR images of thirty patients who were ...Objective To investigate effect of MR field strength on texture features of cerebral T2 fluid attenuated inversion recovery(T2-FLAIR)images.Methods We acquired cerebral 3 D T2-FLAIR images of thirty patients who were diagnosed with ischemic white matter lesion(WML)with MR-1.5 T and MR-3.0 T scanners.Histogram texture features which included mean signal intensity(Mean),Skewness and Kurtosis,and gray level co-occurrence matrix(GLCM)texture features which included angular second moment(ASM),Contrast,Correlation,Inverse difference moment(IDM)and Entropy,of regions of interest located in the area of WML and normal white matter(NWM)were measured by ImageJ software.The texture parameters acquired with MR-1.5 T scanning were compared with MR-3.0 T scanning.Results The Mean of both WML and NWM obtained with MR-1.5 T scanning was significantly lower than that acquired with MR-3.0 T(P<0.001),while Skewness and Kurtosis between MR-1.5 T and MR-3.0 T scanning showed no significant difference(P>0.05).ASM,Correlation and IDM of both WML and NWM acquired with MR-1.5 T revealed significantly lower values than those with MR-3.0 T(P<0.001),while Contrast and Entropy acquired with MR-1.5 T showed significantly higher values than those with MR-3.0 T(P<0.001).Conclusion MR field strength showed no significant effect on histogram textures,while had significant effect on GLCM texture features of cerebral T2-FLAIR images,which indicated that it should be cautious to explain the texture results acquired based on the different MR field strength.展开更多
Objective: A comparison of the difference between the two types of field MR scan in diagnosis of shoulder joint injury. Method: Randomly selected 153 patients with arthroscopic or open arthroplasty who had shoulder pa...Objective: A comparison of the difference between the two types of field MR scan in diagnosis of shoulder joint injury. Method: Randomly selected 153 patients with arthroscopic or open arthroplasty who had shoulder pain or dysfunction treated in our hospital from 2014 to 2017 were divided into 1.5 T group and 3.0 according to the field strength of MRI examination. Postoperative pathology was a gold standard. The sensitivity, specificity, consistency, and predictive value of two field-strength MRI examinations in the diagnosis of rotator cuff tears were calculated and compared. Results: The sensitivity, specificity, crude consistency, positive predictive value, and negative predictive value of the 1.5 T group were 68.75%, 82.35%, 73.47%, 88.00%, and 58.33%, respectively. The 3.0 T group was 72.22%, 89.47%, 78.18%, 92.86% and 62.96%, the differences between the above indicators were not statistically significant (P > 0.05). Conclusion: There was no difference in the authenticity and benefit index of rotator cuff injury diagnosed by 1.5 T and 3.0 T MRI.展开更多
7 T MRI可以显著提高膝关节成像的信噪比及空间分辨率,能够进行超高分辨率成像和功能代谢成像。其通过测定骨、关节软骨、半月板及韧带内的不同成分,可以很好地评估骨质疏松的程度,更早地发现关节软骨和半月板的损伤以及评估损伤修复后...7 T MRI可以显著提高膝关节成像的信噪比及空间分辨率,能够进行超高分辨率成像和功能代谢成像。其通过测定骨、关节软骨、半月板及韧带内的不同成分,可以很好地评估骨质疏松的程度,更早地发现关节软骨和半月板的损伤以及评估损伤修复后的表现,为骨质疏松、骨性关节炎以及半月板损伤的早期诊断与治疗提供有力的依据。就7 T MRI在膝关节病变中的研究进展进行综述。展开更多
目的分析高场强磁共振成像(high field strength magnetic resonance imaging,MRI)对前列腺良恶性病变的鉴别诊断价值。方法选取2016年1月—2021年12月盐城市第三人民医院影像科收治的疑似前列腺病变患者60例,均以高场强MRI检查,以手术...目的分析高场强磁共振成像(high field strength magnetic resonance imaging,MRI)对前列腺良恶性病变的鉴别诊断价值。方法选取2016年1月—2021年12月盐城市第三人民医院影像科收治的疑似前列腺病变患者60例,均以高场强MRI检查,以手术穿刺活检病理诊断结果为金标准,分析高场强MRI诊断效能及影像学特征。结果手术病理确诊30例为良性前列腺增生(阴性)、30例为前列腺癌(阳性)。高场强MRI诊断准确度为95.00%,敏感度为93.33%,特异度为96.67%,阳性预测值为96.55%,阴性预测值为93.55%。经一致性系数分析,高场强与MRI诊断一致性为0.900,一致性良好。前列腺增生:前列腺体积弥漫性增大,T_(2)WI显示前列腺中央叶明显增大,信号不均匀,呈类圆形高信号/低信号,外周带受压变窄。前列腺癌:癌组织呈弥漫性浸润性生长,T_(2)WI移行带呈低信号,边界模糊,病变位于包膜内或突破包膜、侵犯精囊腺或血管神经束,或合并淋巴结肿大、骨盆骨转移。结论高场强MRI在前列腺良恶性病变鉴别诊断中的准确性和可靠性较高,具有推广应用价值。展开更多
目的比较不同场强不同序列伪影的差异。方法制作钛合金水模,分别在1.5 T和3.0 T MRI扫描仪上采用矢状位快速自旋回波(TSE)-T1、TSE-T2、TSE的短反转时间的反转恢复(STIR)的脂肪抑制、TSE的频率选择饱和法(FS)抑制、梯度回波序列(GRE)/...目的比较不同场强不同序列伪影的差异。方法制作钛合金水模,分别在1.5 T和3.0 T MRI扫描仪上采用矢状位快速自旋回波(TSE)-T1、TSE-T2、TSE的短反转时间的反转恢复(STIR)的脂肪抑制、TSE的频率选择饱和法(FS)抑制、梯度回波序列(GRE)/快速小角度激发(FLASH)、扩散加权成像(DWI)等常用序列扫描。分析扫描得到图像伪影特点及进行伪影大小测量。结果GRE/FLASH序列图像和DWI图像伪影最大,FS抑制序列得到图像伪影比STIR序列图像伪影大,各序列伪影形状也有差别。在不同场强下相同类型序列扫描伪影也不同,高场强伪影明显大于低场强伪影。同一场强不同序列伪影大小不同,同一类型序列3.0 T MRI图像伪影比1.5 T MRI图像伪影要大,差异有统计学意义(P<0.05)。结论可以通过场强选择、序列的选择来减少金属植入物磁共振扫描带来的伪影。展开更多
文摘An ever-increasing number of 3.0 Tesla(T) magnets are installed worldwide. Moving from the standard of 1.5 T to higher field strength implies a number of potential advantage and drawbacks, requiring careful optimization of imaging protocols or implementation of novel hardware components. Clinical practice and literature review suggest that state-of-the-art 3.0 T is equivalent to 1.5 T in the assessment of focal liver lesions and diffuse liver disease. Therefore, further technical improvements are needed in order to fully exploit the potential of higher field strength.
文摘Objective To investigate effect of MR field strength on texture features of cerebral T2 fluid attenuated inversion recovery(T2-FLAIR)images.Methods We acquired cerebral 3 D T2-FLAIR images of thirty patients who were diagnosed with ischemic white matter lesion(WML)with MR-1.5 T and MR-3.0 T scanners.Histogram texture features which included mean signal intensity(Mean),Skewness and Kurtosis,and gray level co-occurrence matrix(GLCM)texture features which included angular second moment(ASM),Contrast,Correlation,Inverse difference moment(IDM)and Entropy,of regions of interest located in the area of WML and normal white matter(NWM)were measured by ImageJ software.The texture parameters acquired with MR-1.5 T scanning were compared with MR-3.0 T scanning.Results The Mean of both WML and NWM obtained with MR-1.5 T scanning was significantly lower than that acquired with MR-3.0 T(P<0.001),while Skewness and Kurtosis between MR-1.5 T and MR-3.0 T scanning showed no significant difference(P>0.05).ASM,Correlation and IDM of both WML and NWM acquired with MR-1.5 T revealed significantly lower values than those with MR-3.0 T(P<0.001),while Contrast and Entropy acquired with MR-1.5 T showed significantly higher values than those with MR-3.0 T(P<0.001).Conclusion MR field strength showed no significant effect on histogram textures,while had significant effect on GLCM texture features of cerebral T2-FLAIR images,which indicated that it should be cautious to explain the texture results acquired based on the different MR field strength.
文摘Objective: A comparison of the difference between the two types of field MR scan in diagnosis of shoulder joint injury. Method: Randomly selected 153 patients with arthroscopic or open arthroplasty who had shoulder pain or dysfunction treated in our hospital from 2014 to 2017 were divided into 1.5 T group and 3.0 according to the field strength of MRI examination. Postoperative pathology was a gold standard. The sensitivity, specificity, consistency, and predictive value of two field-strength MRI examinations in the diagnosis of rotator cuff tears were calculated and compared. Results: The sensitivity, specificity, crude consistency, positive predictive value, and negative predictive value of the 1.5 T group were 68.75%, 82.35%, 73.47%, 88.00%, and 58.33%, respectively. The 3.0 T group was 72.22%, 89.47%, 78.18%, 92.86% and 62.96%, the differences between the above indicators were not statistically significant (P > 0.05). Conclusion: There was no difference in the authenticity and benefit index of rotator cuff injury diagnosed by 1.5 T and 3.0 T MRI.
文摘7 T MRI可以显著提高膝关节成像的信噪比及空间分辨率,能够进行超高分辨率成像和功能代谢成像。其通过测定骨、关节软骨、半月板及韧带内的不同成分,可以很好地评估骨质疏松的程度,更早地发现关节软骨和半月板的损伤以及评估损伤修复后的表现,为骨质疏松、骨性关节炎以及半月板损伤的早期诊断与治疗提供有力的依据。就7 T MRI在膝关节病变中的研究进展进行综述。
文摘目的分析高场强磁共振成像(high field strength magnetic resonance imaging,MRI)对前列腺良恶性病变的鉴别诊断价值。方法选取2016年1月—2021年12月盐城市第三人民医院影像科收治的疑似前列腺病变患者60例,均以高场强MRI检查,以手术穿刺活检病理诊断结果为金标准,分析高场强MRI诊断效能及影像学特征。结果手术病理确诊30例为良性前列腺增生(阴性)、30例为前列腺癌(阳性)。高场强MRI诊断准确度为95.00%,敏感度为93.33%,特异度为96.67%,阳性预测值为96.55%,阴性预测值为93.55%。经一致性系数分析,高场强与MRI诊断一致性为0.900,一致性良好。前列腺增生:前列腺体积弥漫性增大,T_(2)WI显示前列腺中央叶明显增大,信号不均匀,呈类圆形高信号/低信号,外周带受压变窄。前列腺癌:癌组织呈弥漫性浸润性生长,T_(2)WI移行带呈低信号,边界模糊,病变位于包膜内或突破包膜、侵犯精囊腺或血管神经束,或合并淋巴结肿大、骨盆骨转移。结论高场强MRI在前列腺良恶性病变鉴别诊断中的准确性和可靠性较高,具有推广应用价值。
文摘目的比较不同场强不同序列伪影的差异。方法制作钛合金水模,分别在1.5 T和3.0 T MRI扫描仪上采用矢状位快速自旋回波(TSE)-T1、TSE-T2、TSE的短反转时间的反转恢复(STIR)的脂肪抑制、TSE的频率选择饱和法(FS)抑制、梯度回波序列(GRE)/快速小角度激发(FLASH)、扩散加权成像(DWI)等常用序列扫描。分析扫描得到图像伪影特点及进行伪影大小测量。结果GRE/FLASH序列图像和DWI图像伪影最大,FS抑制序列得到图像伪影比STIR序列图像伪影大,各序列伪影形状也有差别。在不同场强下相同类型序列扫描伪影也不同,高场强伪影明显大于低场强伪影。同一场强不同序列伪影大小不同,同一类型序列3.0 T MRI图像伪影比1.5 T MRI图像伪影要大,差异有统计学意义(P<0.05)。结论可以通过场强选择、序列的选择来减少金属植入物磁共振扫描带来的伪影。
