3D多体素1H-MRS对星形细胞瘤分级的诊断价值

目的探讨3D多体素质子波谱成像(1H-MRS)对脑低、高级星形细胞瘤鉴别诊断的价值和限度。资料与方法前瞻分析60例星形细胞瘤患者的传统平扫加增强及3D多体素1H-MRS资料,病理分为高级别组(WHOⅢ、Ⅳ级)和低级别组(WHOⅠ、Ⅱ级)。结果(1)传统MR平扫加增强诊断高级别星形细胞瘤的敏感性为70.5%、特异性为68.8%。(2)瘤体实质区胆碱(Cho)/N-乙酰天门冬氨酸(NAA)的敏感性82.0%,特异性81.0%;瘤周区Cho/NAA的敏感性77.0%,特异性81.0%;瘤体实质区乳酸(Lac)/肌酸(Cr)的敏感性82.0%,特异性88.0%;瘤周区乳酸盐(Lac)/肌酸(Cr)的敏感性91.0%,特异性69.1%。结论同传统MR相比,1H-MRS 3D多体素检查能增加星形细胞瘤分级诊断的敏感性,是传统MR检查的一种重要补充。     

3．0T磁共振多体素^1H-MRS和DWI对常见脑肿瘤特征分析的价值

目的：探讨3．0T磁共振多体素^1H-MRS及DWI在常见颅内肿瘤特征分析的价值。方法：脑肿瘤患者30例,多体素^1H-MRS感兴趣区包括肿瘤实质区、瘤周水肿区及正常参照区。计算上述各区域的NAA、Cho、Cr等多种代谢物的值;DWI测量肿瘤不同部位信号值,计算ADC值。结果：胶质瘤、转移瘤、脑膜瘤三者之间肿瘤实质区的NAA／Cho、NAA／Cr和Cho／Cr平均值与参照区比较有显著性差异（P〈0．05）;高、低级别胶质瘤间瘤周水肿区的NAA／Cho和Cho／Cr具有统计学差异（P〈0．05）,高级别胶质瘤与转移瘤间瘤周水肿区的NAA／Cho、NAA／Cr和Cho／Cr均有统计学差异（P〈0．05）。DWI示高、低级别胶质瘤间肿瘤实质区及瘤周水肿区的ADC值均有显著性差异（P〈0．05）;高级别胶质瘤与转移瘤间瘤周水肿区的ADC值有统计学差异（P〈0．05）。结论：多体素^1H-MRS与DWI相结合有助于脑肿瘤的特征分析、胶质瘤恶性程度分级、确定病灶浸润范围等。     

3.0 T ~1H-MRS在正常肝脏的定量研究

目的采用3.0 T多射频MR仪对正常志愿者行氢质子磁共振波谱(1H-MRS)检查,提出肝脏MRS代谢物正常值范围,并进一步探讨其临床诊断价值。方法 38名正常志愿者,年龄25～75岁,平均(41.22±14.67)岁,男19例,女19例。分别按年龄分为两组:≥45岁组及<45岁组,按性别分为男、女两组。采用3.0 T MR仪对所有正常志愿者及脂肪肝患者行肝脏1H-MRS扫描,统计其水峰峰值、水峰峰下面积、脂峰峰值、脂峰峰下面积及脂肪分数,并进行统计学比较分析。结果 (1)16名正常志愿者首先进行两次1H-MRS扫描,取同一位置、相同大小感兴趣区(ROI),两次测量代谢物数值差异无统计学意义(P>0.05);38名正常志愿者肝脏水峰下面积95%可信区间为163.05±27.45,脂肪峰值95%可信区间为4.00±2.10,脂肪峰下面积的95%可信区间为4.22±4.98,脂肪分数的95%可信区间为(2.51±2.61)%。(2)按照年龄分组,≥45岁组及<45岁组,两组正常志愿者水峰峰值、水峰下面积、脂峰峰值、脂峰下面积及脂肪分数差异均无统计学意义(P>0.05);(3)不同性别正常志愿者比较,除水峰峰值外,余代谢物数值男女两组差异无统计学意义(P>0.05)。结论 3.0 T1H-MRS可应用于正常人肝内代谢的定量研究;肝脏水及脂肪含量的正常值范围可对肝脏代谢性疾病的诊断提供重要参考依据。     

Human cervical lymphadenopathy: evaluation with in vivo 1H-MRS at 1.5 T

AIM: To evaluate the feasibility of performing in vivo proton magnetic resonance spectroscopy ((1)H-MRS) of cervical lymph nodes, and the clinical usefulness of the technique in the characterization of cervical lymphadenopathy. MATERIALS AND METHODS: Cervical lymphadenopathy was examined in 20 individuals with malignant disease, i.e. 10 with squamous cell carcinoma (SCC), 6 with undifferentiated carcinoma (UDC) and 4 with non-Hodgkin's lymphoma (NHL). Cervical lymphadenopathy was also examined in 4 individuals with benign disease, i.e. 3 with tuberculosis (TB) and 1 with Castleman's disease. A point-resolved spectroscopic sequence with echo times (TE) of 136 and 272 ms and a time-domain spectral fitting procedure were used to estimate peak amplitude of choline (Cho), creatine (Cr) and unsuppressed water. Cho/Cr and Cho/water ratios were measured for each lesion. The mean ratio for each lesion group was obtained and results were compared statistically. RESULTS: At TE of 136 ms, spectra were interpretable in all 24 cases and a Cr peak was identified with post-processing in 15 cases. The Cho/Cr and Cho/water ratios for NHL were 9.1 +/- 5.2 and 1.7 +/- 0.2 x 10(-3), for UDC were 4.4 +/- 0.9 and 1.2 +/- 0.4 x 10(-3), and for SCC were 2.1 +/- 0.6 and 0.5 +/- 0.3 x 10(-3), respectively. Both Cho/Cr and Cho/water ratios for UDC were significantly higher than SCC (p = 0.002 and 0.026, respectively). At TE of 272 ms, spectra were interpretable in 22 of 24 cases and a Cr peak was identified with post-processing in 11 cases. Cho/Cr and Cho/water ratios for NHL were 5.4 and 4.6 +/- 1.4 x 10(-3), for UDC were 4.2 +/- 1.5 and 2.6 +/- 1.0 x 10(-3) and for SCC were 2.5 +/- 1.1 and 1.3 +/- 0.6 x 10(-3), respectively. The Cho/water ratio for UDC was significantly higher than for SCC (p = 0.04). The Cho/Cr ratio for UDC was also higher than for SCC, but this difference was not statistically significant (p = 0.07). Neither Cho nor Cr was detected in the 3 cases of TB. CONCLUSION: In vivo (1)H-MRS is a feasible technique for the evaluation of cervical lymph nodes and it offers potential as a clinical tool in the investigation of cervical lymphadenopathy. However, further studies with larger patient cohorts are needed to validate the findings of this initial report.     

前列腺MRI检查:直肠内表面线圈与体线圈的对比研究

目的　研究直肠线圈对前列腺病变的诊断价值。方法　对前列腺癌 9例 ,前列腺增生 4例 ,正常 2例 ,共 15例前列腺检查作了体线圈与直肠线圈自旋回波 (SET1WI、FSET2 WI)序列扫描的对照研究。评分比较体线圈与直肠线圈横轴位的图像质量 ,并进行诊断分析。结果　T2 WI图像的平均评分 :体线圈 ( 2 .97± 0 .61)分 ,表面线圈 ( 3.4± 0 .60 )分 ,Ρ <0 .0 5。T1WI图像的平均评分 :体线圈 ( 2 .70± 0 .46)分 ,直肠表面线圈 ( 3.2 7± 0 .68)分 ,Ρ <0 .0 5。图像诊断分析显示 :前列腺癌 9例中 ,直肠线圈图像观察病灶范围 7例较体线圈清楚 ,包膜外侵犯 2例较体线圈清楚 ,精囊侵犯 1例常规图像未能显示。前列腺增生及正常病例中直肠线圈图像观察增生结节及合并的小囊肿更为清楚。结论　直肠表面线圈提高前列腺病变的分辨率 ,有助于前列腺癌的诊断和分期     

小儿正常小脑半球组织~1H-MRS研究

目的:测定和计算0～7岁小儿正常小脑半球组织代谢物比值,并观察各比值随年龄变化规律。方法:应用多体素2D1H-MRS点分辨波谱(PRESS)序列测定70例0～7岁小儿正常小脑半球组织的双侧灰质及白质区代谢物浓度,按年龄分为0-1岁,1-2岁,2-3岁,3-5岁,5-7岁五组,计算和分析NAA/Cr、Cho/Cr、NAA/Cho的比值。结果:正常小脑灰质区在各年龄组间NAA/Cho(P=0.0143)和NAA/Cr(P=0.0050);白质区的NAA/Cho和NAA/Cr均P<0.001;灰质和白质区的Cho/Cr(P=0.1195,P>0.05);灰质和白质区NAA/Cho值与年龄呈正相关(P<0.001,P<0.0001);NAA/Cr值与年龄呈正相关(P=0.0004,P<0.0001);灰质区Cho/Cr与年龄呈负相关(P=0.038),白质区与年龄呈负相关(P=0.568>0.05)。结论:0～7岁小儿正常小脑半球灰、白质的代谢物比值在不同年龄组会不同,灰质和白质区NAA/Cho、NAA/Cr值随年龄增长逐渐升高,而灰质区Cho/Cr值逐渐减小,白质区无明显变化,临床上应用MRS要考虑其年龄和部位的因素。     

Frame-by-frame PRESS 1H-MRS of the brain at 3 T: the effects of physiological motion.

1H-MRS at high field has been increasingly utilized to study brain metabolism in healthy and pathological states. The aim of this work was to determine the effects of physiological motion on the results of this exam in the presence of the increased susceptibility differences at high field. Single voxel spectra of various regions in the human brain were acquired using frame-by-frame PRESS 1H-MRS at a 0.5 Hz sampling rate. The frame-by-frame variations of the FID phase and the frequency and fractional amplitude variations of the residual water-signal were analyzed. In the human brain the standard deviations of these variations were 3.9 +/- 0.5 degrees, 0.83 +/- 0.32 Hz, and 0.028 +/- 0.013 of the mean amplitude (n=15). In a motionless phantom, smaller phase and frequency variations were detected in water-suppressed acquisitions. However, the end effects of physiological motion on PRESS 1H-MRS of the brain at 3 T were negligible.     

3.0T~1H-MRS在正常肝脏与脂肪肝的对照研究

目的采用3.0 T多射频核磁共振仪对正常志愿者及脂肪肝患者行氢质子磁共振波谱(1H-MRS)检查,探讨其对脂肪肝的诊断价值。方法招募38名正常志愿者,男19名,女19名,年龄25～75岁,平均(41.22±14.67)岁。27例脂肪肝患者,男17例,女10例,年龄25～62岁,平均(45.86±9.49)岁。采用3.0 T磁共振仪对所有正常志愿者及脂肪肝患者行肝脏1H-MRS扫描。统计所有肝脏1H-MRS谱线其水峰峰值、水峰峰下面积、脂峰峰值、脂峰峰下面积及脂肪分数,分别按年龄和性别分组,并采用SPSS 11.5统计分析软件进行统计学比较分析。结果同年龄组正常志愿者与脂肪肝患者间比较,除水峰峰值差别不明显外,其水峰下面积、脂峰峰值、脂峰下面积及脂肪分数差异均存在统计学意义(P水峰下面积(正常VS脂肪肝)=0.004,P脂峰峰值(正常VS脂肪肝)=0.00395,P脂峰峰下面积(正常VS脂肪肝)=0.001,P脂肪分数(正常VS脂肪肝)=0.000000033,P均<0.05);男性组正常志愿者与脂肪肝患者水峰峰值差别不明显,余代谢物数值差异均存在统计学意义;女性组正常志愿者与脂肪肝患者代谢物数值差异均有统计学意义(P水峰峰值(正常VS脂肪肝)=0.04,P水峰下面积(正常VS脂肪肝)=0.03,P脂峰峰值(正常VS脂肪肝)=0.000687,P脂峰峰下面积(正常VS脂肪肝)=0.000514,P脂肪分数(正常VS脂肪肝)=0.000406,P均<0.05);正常肝脏与脂肪肝MRS代谢物阈值:脂肪峰值为9.55(敏感性0.909,1-特异性0),脂肪峰下面积为8.65(敏感性0.955,1-特异性0.029),脂肪分数4.97%(敏感性0.955,1-特异性0.029)。结论 3.0 T1H-MRS可应用于正常肝脏及脂肪肝的定量研究;正常肝脏与脂肪肝MRS代谢物阈值提出对肝脏脂肪变性诊断提供客观、科学的参考价值。     

常规MRI阴性HIV感染者无神经症状期脑1H-MRS分析

目的探讨常规MRI阴性人类获得性免疫缺陷病毒(HIV)感染者无神经症状期脑氢质子磁共振波谱(1H-MRS)特点。资料与方法搜集无神经症状期HIV感染者28例,HIV阴性健康自愿者30名,行MRI平扫、点分辨波谱(PRESS)1H-MRS扫描。测定脑皮质、深部核团及白质区N-乙酰天门冬氨酸(NAA)、胆碱化合物(Cho)、肌酸(Cr)峰下面积;计算NAA/Cr、Cho/Cr、NAA/Cho、(NAA+Cho)/Cr及(Cho+Cr)/NAA值。结果无神经症状期HIV感染者脑皮质、深部核团及白质NAA/Cr值均降低,(Cho+Cr)/NAA值升高,Cho/Cr值无明显变化。额上回皮质NAA/Cr、NAA/Cho、(Cho+Cr)/NAA值,额上回白质NAA/Cr、(NAA+Cho)/Cr、(Cho+Cr)/NAA值,顶叶白质NAA/Cho、(Cho+Cr)/NAA值差异有统计学意义(P<0.05)。结论在HIV感染无神经症状期,常规MRS阴性时,1H-MRS可以检测到脑早期代谢异常。额上回皮质、尾状核头部、额上回、顶叶白质NAA/Cr、NAA/Cho、(Cho+Cr)/NAA值有明显变化。     

成人线粒体脑肌病的MRI和1H-MRS诊断价值

目的 分析MRI和1H-MRS对线粒体脑肌病的诊断价值.方法 经病理活检确诊的 6例成人 (男3例,女3例)线粒体脑肌病患者采用1.5T磁共振仪扫描,其中3例行1H-MRS检查,并分析MRI和1H-MRS的表现. 结果6例线粒体脑肌病患者MRI显示病变累及多个脑叶,多位于皮层及皮层下白质,并可同时累及大脑深部灰质和大脑皮层.脑梗死样病灶呈斑片状或楔形,非对称性.T1WI为低信号或等低信号,T2WI为高信号.急性期病变区域脑组织轻度肿胀,慢性期全脑萎缩,并可见皮质层状坏死.4例行MR增强扫描未见强化.3例1H-MRS检查均显示病灶内Lac峰明显升高和NAA峰不同程度的降低.结论 线粒体脑肌病MRI表现具有一定的特征,1H-MRS可提供更多脑组织代谢信息,对本病诊断具有重要的价值.