ObjectiveTo investigate the feasibility of proton magnetic resonance spectroscopy (1H-MRS) imaging, by which to quantitatively analyze liver fat content for therapeutic evaluation of fatty liver at 3.0 T MRI. MethodsTwenty-six patients who diagnosed with fatty liver were examined with proton MRS at Siemens Trio Tim 3.0 T MRI before treatment and 3, 6 months after treatment, respectively. The water peak, fat peak, water peak area, and fat peak area were detected, and the relative lipid content 1 (RLC1) and relative lipid content 2 (RLC2)were calculated. Fatty liver index (FLI) was referred to the standard which was calculated from triglycerides (TG), gammaglutamyl-transferase (GGT), waist circumference, and body mass index. ResultsThere were significantly different differences of RLC1 and RLC2 among before treatment and 3, 6 months after treatment (Plt;0.05). Compared with before treatment, the RLC1 and RLC2 values significantly decreased on month 3 or 6 after treatment (Plt;0.05). There were positive correlation between RLC1 or RLC2 and FLI (r=0.476, Plt;0.00; r=0.475, Plt;0.001). The intraclass correlation coefficient was more than 0.75 before treatment, the repeatability was better. ConclusionsProton MRS can quantitatively measure liver fat content. It can be reliably used for dynamic monitoring the therapeutic effects for fatty liver. Proton MRS is accurate, and has a good clinical application in dynamically monitoring the progression of fatty liver and evaluating the therapeutic effects of various treatments.
Objective To investigate the diagnostic value of proton magnetic resonance spectroscopy （1 H-MRS） on the quantification of hepatic steatosis at 3.0 T MR united.Methods Twenty-two patients who were candidated for liver surgery (living liver transplantation donor candidates, lobectomy or segmental resection for focal liver diseases, etc.) were enrolled in this study. 1 H-MRS was conducted with point resolved selective spectroscopy （PRESS） sequence, using SAGE software packages. The values of water peak (PW), lipid peak (PL) were measured, the area under water peak (AW) and lipid peak (AL), and then the relative lipid content of liver cells (RLC1, RLC2) was calculated. All subjects underwent surgical resection of liver shortly after MR scanning, fresh frozen specimens were obtained for Sudan Ⅲ staining, and staging was conducted.Results In all 22 patients, 7 patients without fatty liver, 11 patients with mild fatty liver, 4 patients with moderate or severe fatty liver. Intercomparison between different histopathological grades showed following findings: the values of PL, AL, RLC1 and RLC2 had statistical significance (Plt;0.05). The values of PL， AL， RLC1 and RLC2 were positively correlated with the proportion of fatty degenerative cells (PFDC), Plt;0.05, and the highest correlation factor was 0.771 (RLC1 to the PFDC).Conclusion 1 H-MRS can accurately quantify liver fat content and reflect the severity of hepatic steatosis. It has the potential to replace invasive liver biopsy.
Objective To summarize the principle and application of functional MR imaging of pancreatic carcinoma and chronic mass-forming type pancreatitis. Methods Articles about diffusion-weighted imaging (DWI), magnetic resonance spectrum imaging (MRSI) and dynamic contrast-enhanced MR imaging of pancreatic carcinoma and chronic pancreatitis were reviewed and analyzed. Results Functional MR imaging could reflected the differences in molecules diffusion, metabolism and tissue perfusion between pancreatic carcinoma and chronic pancreatitis. Conclusion As a non-invasive protocol, functional MR imaging can provide useful information in differential diagnosis between chronic mass-forming type pancreatitis and pancreatic carcinoma.
Objective To observe the characteristics of magnetic resonance diffusion tensor imaging（MR-DTI）for optic nerves and optic radiation in blind patients.Methods The optic nerves and optic radiation of 20 blind patients（blind group）and 20 controls（control group） were scanned by MR-DTI. Fractional anisotropy (FA) and directional encoded color (DEC) maps were acquired through postprocessing with the aid of volumeone 1.72 software. The signal intensity of optic nerves and optic radiation were then observed. The FA, mean diffusivity (MD), lambda;∥ and lambda;perp; value of bilateral optic nerves and optic radiation in two groups were measured in the DEC maps.Results While the high signal intensity was found in bilateral optic nerves in FA and DEC maps in control group，the signal decreased markedly in the blind group. The FA and lambda;∥ value of optic nerves in the blind group were declined obviously compared to that in the control group. The difference was statistically significant (t=16.294, 14.660;P=0.000). The MD and lambda;perp; value of optic nerves in the blind group were increased obviously compared to that in the control group, the difference was also statistically significant (t=8.096, 8.538; P=0.000). The high signal intensity was found in bilateral optic radiation in FA and DEC maps in both the blind and control groups. There were no statistic differences in FA and MD value in bilateral optic radiation between the blind and control groups (Left：t=1.456，1.811；P=0.152，0.076. Right：t=0.779，0.073；P=0.440，0.942). Conclusion A low signal intensity of bilateral optic nerves and a high signal intensity of bilateral optic radiation were found in blind patients.
Objective To investigate the MRI characteristics of the tumor of optic pathway and damage degree of visual function. Methods Analysis of 119 cases surgically and pathologically proved tumor suffering from optic pathway was carried out retrospectively. The patients included:36 ones with tumors in anterior segment of optic pathway,70 ones in middle segment of optic pathway,and 13 ones in posterior segment of optic pathway. The MRI examination series were transverse T-1WI SE,transverse and coronal T-2WI TSE,coronal T-2WI SPIR,and transverse,sagittal,coronal T-1WI SE after Gd-DTPA enhancement. Results The tumors of optic pathway included:the primary tumors of the optic pathway and the tumors of any other part of the body which invaded the optic pathway. There was a special MRI feature on the each tumor suffering from optic pathway,but the pituitary adenoma which affects visual function was the most common tumor. Conclusion MRI is an effective method in the diagnosis of optic-pathway tumor. (Chin J Ocul Fundus Dis, 2002, 18: 101-103)
OBJECTIVE:To investigate the diagnostic meaning of MRI in intraocular tumors. METHODS:Forty-six cases of confirmed intraocular tumors,including choroidal melanoma(20 cases),retinoblastoma(18 cases),Coats disease(6 cases)and choroidal hemangioma(2 cases),were studied with MRI and compared with ultrasonography and CT. RESULTS:In making discoveries about intraocular tumors,there were no sighificant difference between MRI and B-ultrasonography or CT （P＞0.03，chi;2=1.0716）while there were highly statistic sighificance in dediding characters and position （P＜0.01，deceding character chi;2=29.8314，positionchi;2=13.659）of them. CONCLUSION:Among the examinations to find out about the position,character and secondary pathological insults of in traocular tumors MRI might be more available than CT and ultrasonography. （Chin J Ocul Fundus Dis,1997,13:93-95 ）
摘要:目的: 探讨磁共振波谱(MRS)对鉴别桥小脑角神经鞘瘤与脑膜瘤的价值。 方法 :对8例神经鞘瘤和8例脑膜瘤病例进行MRI平扫和增强扫描,并采用点分辨波谱序列(PRESS,TR/TE=2000/136ms)进行单体素波谱分析。从事磁共振诊断专业的医师根据肿瘤的MRI及MRS表现特征进行鉴别诊断。 结果 :尽管多数神经鞘瘤(5/8)和脑膜瘤(6/8)具有典型的MRI表现特征并仅经MRI即可得到正确鉴别,但部分病例(5/16)为不典型表现者,如脑膜瘤呈长T1长T2信号并伴有囊变,以及神经鞘瘤呈等信号、均匀强化且不伴有囊变或内听道扩大者,鉴别诊断困难。MRS显示脑膜瘤的胆碱/肌酸比值(Cho/Cr)(2.74±1.47)略高于神经鞘瘤(2.70±1.21),但差异无统计学意义。丙氨酸(Ala)在脑膜瘤中的出现率(4/8)显著高于神经鞘瘤(0/8)(Plt;0.05),谷氨酸盐/谷氨酰胺(Glx)在脑膜瘤中的出现率(5/8)也高于神经鞘瘤(2/8);而肌醇(Ins)在神经鞘瘤中的出现率(4/8)高于脑膜瘤(2/8)。结合MRS表现,在MRI上尚难鉴别的病例可被明确诊断,并与最终病理结果相符。 结论 : MRI有助于多数桥小脑角神经鞘瘤与脑膜瘤的鉴别诊断,但对不典型病例有一定局限性;MRS对不典型病例的鉴别具有重要的参考价值。Abstract: Objective: To explore the value of magnetic resonance spectroscopy (MRS) in the differentiation of neurinoma and meningioma in the cerebellopontine angle. Methods : 16 cases, including 8 cases of meningiomas and 8 cases of neurinomas, underwent MRI (plan and gadoliniumenhanced scan) and singlevoxel proton MRS (PRESS series, TR/TE=2000/136ms). MRI and MRS results were reviewed and differential diagnoses were made by professional radiologists. Results : Although most cases (11/16) were typical and clearly classified on MRI, atypical cases were also observed, such as meningioma of long T1/T2 signal intensity with small cystic foci, and neurinoma of isointensity and homogenous enhancement without cystic change or enlargement of internal acoustic meatus. The choline to creatine ratio (Cho/Cr) of meningioma (2.74±1.47) was higher than that of neurinoma (2.70±1.21), however the difference was not significant (Pgt;0.05). Alanine was observed in 4/8 meningiomas but none of neurinomas (Plt;0.05), and glutamine/glutamate was more frequently visualized in meningiomas (5/8) than in neurinomas (2/8), whilemyoinositol was more frequently observed in neurinomas (4/8) than in meningiomas (2/8). With MRS, cases difficult to differentiate were clearly and correctly classified. Conclusion : Although most CPA neurinomas and meningiomas can be diagnosed by MRI, MRS is useful for the differential diagnosis of atypical cases.
摘要:目的: 探讨臂丛神经磁共振成像的技术方法及其可行性。 方法 :对15例正常志愿者行双侧臂丛神经成像:包括常规快速自旋回波序列T1加权(T1W/TSE)、快速自旋回波序列T2加权(T2W/TSE)、快速自旋回波序列T2加权加SPIR脂肪抑制(T2W/SPIR)冠状位扫描以及弥散加权背景抑制成像序列(DWIBS)轴位扫描。 结果 :T1W/TSE、T2W/TSE、及T2W/SPIR对臂丛节后神经同层显示率分别为533%、567%和833%;DWIBS MIP重建图像对臂丛神经的全貌显示较为完整、清晰、直观;T1W/TSE、T2W/TSE、T2W/SPIR及DWIBS MIP重建图像的对比噪声比分别为109±09、107±13、185±68和299±133,T2W/SPIR序列和DWIBS MIP重建图像的对比噪声比明显高于T1W/TSE和T2W/TSE序列。 结论 :T2W/SPIR序列对臂丛神经的同层显示率及图像的对比噪声比明显高于常规T1W/TSE、T2W/TSE序列, DWIBS MIP重建图像能够显示臂丛神经的全貌,两者为臂丛神经成像较为有效的技术方法,对于臂丛神经病变的诊断即具有十分重要的意义。Abstract: Objective: To determine the optimal sequences of brachial plexus with MRI. Methods : Fifteen volunteers were underwent MRI on 15T scanner, the Sequences of T1W/TSE/COR, T2W/TSE/COR, T2W/SPIR/COR and Diffusionweighted imaging with background body signal suppression were performed. Results : The display rates of brachial plexus postganglionic segment nerve showing at the same slice were 533%, 567% and 833% on T1W/TSE/COR, T2W/TSE/COR, T2W/SPIR/COR. Brachial plexus on DWIBS MIP were clear and complete. Contrastnoise ratio of four sequences was 109±09, 107±13, 185±68 and 299±133,respectively. Contrastnoise ratio of T2W/SPIR/COR and DWIBS MIP was significantly higher than that of the other two sequences. Conclusion : Display rate of brachial plexus and contrastnoise ratio of images on T2W/SPIR/COR were higher than those of routine sequences. Image of DWIBS MIP can show the outline of brachial plexus clearly. The two sequences were reliable and effetive techoniquic in diagnosis of brachial plexus lesion.
摘要:目的: 分析肝脏局灶性结节增生(FNH)的MRI表现和病理特点,探讨两者的相关性,提高FNH诊断的准确率。 方法 :回顾性分析23例(共28个病灶)经手术切除病理证实为FNH的MRI平扫及增强表现,与其病理特点进行对照。 结果 :25个病灶在平扫T1WI上呈等或稍低信号,T2WI上呈等或稍高信号,3个病灶在平扫T1WI及T2WI上均呈稍高信号,增强后所有28病灶动脉期可见明显强化,门脉期及延迟期呈稍高、等或稍低信号,其中12个病灶可见中心纤维瘢痕延迟强化。FNH组织病理上表现为富血供的实质性肿块,肿物内部组织较均匀,没有异型细胞,中心可见纤维瘢痕。 结论 :肝脏MRI平扫及增强检查能很好的反映FNH的组织病理及血供特点,能为FNH的诊断及鉴别诊断提供可靠证据。Abstract: Objective: To analyze the MRI manifestations and pathology characteristic of hepatic focal nodular hyperplasia(FNH),and to investigate their correlation. Methods : A retrospective analysis was made on the unenhanced and dynamic enhanced MR images of 23 patients (totally 28 lesions) with surgical and pathological proved FNH. Results :25 FNH lesions demonstrated isointensity or slightly hypointense on unenhanced T1WI,and isointensity or slightly hyperintense on unenhanced T2WI,3 FNH demonstrated hyperintense on both unenhanced T1WI and T2WI. 28 FNHs were markediyhyperintense in the arterial phase of dynamic contrast enhanced MRI, and isointense or slightly hyperintense in the portal and delayed phase．The seals were shown in 12 lesions, and enhanced in delayed phase．FNH is solid mass with vast blood supply,its inside structure is homogemeous. Typical seal can be found by microscopic examination．〖WTHZ〗Conclusion : MRI could disclose the pathologic features of FNH and its blood supply and improve the accuracy 0f its diagnosis．
摘要:目的:探讨平山病的MRI影像特点及其临床应用价值。方法:5例临床确诊平山病病例组和10例正常对照组进行颈椎自然位及屈颈位MRI检查,矢状位T1WI、T2WI及轴位T2WI,观察颈髓、蛛网膜下腔及硬膜外腔变化情况。结果:病例组的5例平山病均系16~20岁男性。自然位:5例下位颈髓均萎缩变扁,硬膜外间隙未显示增宽。屈颈位:5例C5~7颈髓前移变扁中,将变扁颈髓又分为上中下三段,以中段最窄,上下段渐移行至正常;C5~7蛛网膜下腔亦变窄,硬脊膜伴随前移;而C4~7硬脊膜后间隙则增宽,呈新月形影,增宽程度分为轻、中、重三度,最重者位于C6椎体平面,T2加权像及T1WI增强呈高信号,其中1例内见血管流空信号影。对照组为10例志愿者,自然位: 4例C3~7颈髓形态、大小基本一致,6例颈髓自颈3逐渐移行与胸1脊髓其大小一致;屈颈位:颈髓和蛛网膜下腔大小与自然位比较无明显变化,硬膜后间隙自C3平面向下延至T1平面,T2WI上呈均匀线样高信号影。结论:下位颈髓萎缩变扁,屈颈位颈髓及硬脊膜前移、硬脊膜后间隙增宽呈新月形影等,是临床诊断平山病较特征性的MRI表现。Abstract: Objective: To evaluate clinical value and MRI features of Hirayama disease. Methods: Five cases of hirayama disease, which had been clinically confirmed using siemens sonata 1.5T MRI scan, physiological condition and flexional condition, Sagittal view T1WI, T2WI and Axial View T2WI, and GdDTPA enhanced examination, for MRI changes of spinal cord, subarachnoid cavity, duramater of spinal membrae and extra dural space, etc were studied. Results: In case group of 5 cases of hirayama disease, age was mainly in 16–20 years old, All of 5 cases were men. Which were pressed and become thinner of spinal cord, strictic changes of subarachnoid cavity, new moony shape and enlargement changes and pushed forward of extra duramater space, and higher intensity signal of GdDTPA enhancement, and vascular flow effect (one case ) in C5–C7. but also, for contrast group 10 cases of normal volunteer, physiological condition:4 cases in cervical spinal cord with shape and structure were uniformity, and duramater, subarachnoid cavity, extra duramater space etc in C3–C7 were abnormal. Six cases in cervical spinal cord with shape and structure gradully changed from C3 to T1; flexional condition: 10 cases of MRI changes of spinal cord, subarachnoid cavity were as same as it in physiological condition,all of T2 WI, higher intensity signal were homogeneous of extraduramater space in C3–T1. Conclusion: The feature findings of cervical spinal cord became thinner, and cervical cord, durameter pussed forward, new moony shape and enlargment of extradurameter space, vascular flow effusion, etc in MRI were useful value for clinical diagnosis.