肝海绵状血管瘤的MRI诊断

目的分析肝海绵状血管瘤的ＭＲＩ表现并探讨最佳扫描方案。方法收集２８例经ＭＲＩ诊断的肝海绵状血管瘤,分析其ＭＲＩ表现。男１６例,女１２例,年龄３６～６８岁。均无明显临床症状。ＭＲＩ用０５Ｔ超导型机,常规Ｔ１加权及Ｔ２加权扫描后,再行重Ｔ２加权成像,ＴＲ＝４０００～６０００ｍｓ,ＴＥ＝１４０～１８０ｍｓ。１８例行ＧｄＤＴＰＡ增强扫描,９例为动态增强扫描。结果多发病灶１２例,单发１６例。瘤体在ＳＥＴ１加权像上呈低信号,在Ｔ２加权像上呈明显高信号,在重Ｔ２加权像上亦呈明显高信号,边缘均清楚锐利。增强扫描病灶呈明显持久强化,较大病灶呈向心性强化。结论重Ｔ２加权像及ＧｄＤＴＰＡ增强扫描对肝海绵状血管瘤具有确诊价值     

顺磁造影对脑转移瘤的诊断价值

目的：总结顺磁造影在脑转移瘤诊断中的重要价值。材料和方法：脑转移瘤３０例,均经病理和临床证实,全部病例均做了ＧＤ－ＤＴＰＡ顺磁造影。使用０．３Ｔ水磁ＭＲ仪,估常规平扫及造影扫描。结果：脑转移灶单发１４例,多发１６例,其中发生在幕上２４例,幕下６例,兼有２例灶最大径０．２～７ｃｍ,平均２．８ｃｍ。发现病灶数：Ｔ１ＷＩ４４个,Ｔ２ＷＩ５４个,顺磁造影为１２４个,结论：顺磁造影发现的脑转移瘤病灶明显多于     

磁共振成像诊断脑灰质异位症108例报告

磁共振成像诊断脑灰质异位症１０８例报告朱富生孙晓民河南省许昌市中心医院儿科磁共振室（４６１０００）我院使用的磁共振成像（ＭＲＩ）诊断仪为：ＡＳＭＯ１５Ｐ永磁型，选用自旋回波（ＳＥ）序列，Ｔ１加权像ＴＲ＝５００ｍｓ，ＴＥ＝３００ｍｓ，Ｔ２加权像ＴＲ＝...     

磁显葡胺在低场强MR的应用价值

磁显葡胺 (Ｇｄ ＤＴＰＡ)在ＭＲ成像上的应用 ,不仅能提高人体病变的检出率 ,而且在定性上有长足的进步。故ＧＤ ＤＴＰＡ常应用在ＭＲ成像上。本文总结Ｇｄ ＤＴＰＡ在低场强ＭＲ的应用 ,以期引起同道的重视。1　材料与方法收集 1993年 6月至 1998年 8月5 0 0余病例的ＭＲ增强资料。并以椎管内神经鞘瘤 60例 ,脊膜瘤 2 0例 ;脑梗塞10 0例 ,脑脓肿 2 5例 ,脑胶质瘤 5 0例 ;多发性硬化 (ＭＳ) 6例作为本文研究的重点。应用ＡＳＰ 0 15永磁型低场强 ( 0 .15Ｔ)ＭＲ装置。ＳＥ序列 :平扫Ｔ1ＷＩ:3 5 0～ 5 0 0 /3 0ｍｓ,Ｔ2ＷＩ :180 0～ 3 0 …     

磁共振在五官肿瘤诊断的应用（五）

磁共振在五官肿瘤诊断的应用（五）邓开鸿供稿华西医科大学附一院放射科病例１．女，３６岁，ＭＲＩ号３７２６双侧听神经瘤。横断位，Ｔ１加权显示双侧桥小脑角池及内听道内肿块影，右大于左侧，呈稍低信号影，桥脑和小脑受压，右侧明显（图１）。Ｇｄ－ＤＴＰＡ增强Ｔ１...     

脑血肿的低场MR成像

１材料与方法本文９７例，男５２例，女４５例，年龄３３～８９岁。全部病例经临床确诊或ＣＴ扫描证实为脑实质出血。ＭＲ检查用ＡＳＰ－０１５Ｔ扫描仪，场强０．１５Ｔ。常规作轴位成像，成像矩阵２５５×２５６。扫描参数：ＳＥＴ１加权：ＴＲ／ＴＥ＝５００ｍｓ／３０...     

星形胶质细胞瘤的MRI与病理对照研究

目的：探讨星形胶质细胞瘤ＭＲＩ表现与病理分级之间的关系。材料方法：对４２例经病理证实幕上星形胶质细胞瘤的ＳＥＴ１ＷＩ、Ｔ２ＷＩ及Ｇｄ－ＤＴＰＡ增强图像与手术病理对照研究。结果：星形胶质细胞瘤的ＭＲＩ信号强度与病理分级有关。用ＭＲＩ评分标准，低级别星形细胞瘤均值为０４９±０２０，分化不良性星形细胞瘤为１２±０１７，多形性胶质母细胞瘤为１４７±０３４。经统计分析ＭＲＩ评分增加，病理级别亦增加（Ｐ＜００１－０００１）。结论：依靠ＭＲＩ信号差异可以达到病理分级诊断目的。星形胶质细胞瘤与瘤细胞多少、排列、变性及瘤血管多少相关     

椎间盘炎的MRI诊断(附10例报告)

目的：总结椎间盘炎的ＭＲＩ表现。方法：复习１０例经病理和临床证实的ＭＲＩ表现，其中５例是血源性感染，５例是手术后或椎间盘穿刺术后椎间盘炎。９例的病变部位在腰椎，１例在颈椎。所有病人都进行了Ｇｄ－ＤＴＰＡ前后的Ｔ１ＷＩ和Ｔ２ＷＩ扫描。结果：ＭＲＩ表现包括：①椎间隙变窄，Ｔ２像呈高或低信号，Ｔ１像呈低或等信号。髓核内裂隙消失。②两个椎体的邻近部分由于充血和水肿而呈长Ｔ１长Ｔ２弛豫时间，终板侵蚀和终板下松质骨有小的脓肿。③椎旁软组织肿胀。④注射Ｇｄ－ＤＴＰＡ后椎间隙和邻近的椎体信号强度明显增强。结论：ＭＲＩ对椎间盘炎的诊断非常有用，并且还能显示象蛛网膜炎这样严重的并发症     

颅内脊索瘤的MRI诊断价值

目的：探讨磁共振成像（ＭＲＩ）技术诊断颅内脊索瘤的价值。材料与方法：回顾性分析了１８例经手术和病理证实的颅内脊索瘤的ＭＲＩ表现。结果：颅内脊索瘤大部分（本组１６例,占８８．９％）发生于颅底中线处的斜坡和／或鞍区,并广泛侵儿颅底的神经和大血管等重要结构;在Ｔ１加权像上肿瘤主要表现为低信号,Ｔ２加权像上表现为不均匀高信号,Ｇｄ－ＤＴ－ＰＡ静脉注射增强后（８例）均出现较明显的不均匀织经。此外,有１５例（     

国产Gd-DTPA大剂量(0.3mmol/kg)静脉注射的初步研究

目的研究国产ＧｄＤＴＰＡ大剂量（０３ｍｍｏｌ／ｋｇ）静脉注射的安全性、耐受性和效果。方法共研究了４１例患者。分两次注射,第一次注射０１ｍｍｏｌ／ｋｇ,３０分钟后再注射０２ｍｍｏｌ／ｋｇ,从而达到累积０３ｍｍｏｌ／ｋｇ。每次注射后即刻和延时２０分钟时分别行Ｔ１ＷＩ扫描。观察患者检查前后的生命体征,询问患者的主观感觉,２４小时后随访。对于３１例颅内病变患者的６７个病灶还进行了增强效果的分析,计算病灶的相对信噪比：Ｃ／Ｎ＝（病灶信号强度－正常脑白质信号强度）／背景信号强度。结果检查前后患者的生命体征未见明显差异。４例患者报告有副作用,均未经治疗而自行缓解。副作用发生的概率是９７６％。三倍量国产ＧｄＤＴＰＡ的使用可以普遍地提高颅内病灶的相对信噪比。结论使用大剂量（０３ｍｍｏｌ／ｋｇ）国产ＧｄＤＴＰＡ可认为是安全的。对于颅内病变,三倍量增强ＭＲ可提高相对信噪比和病灶的检出率,对于颅内小病变和脑转移瘤尤其有意义。     

三维超高场7T高分辨磁敏感加权像静脉造影

目的 超高场磁共振具有高信噪比和独特的磁敏感对比,使其在无创性脑血管造影尤其是对小静脉的检测有明显优势。本文探讨如何在超高场磁共振7T优化和获取高质量的磁敏感加权像（SWI）静脉造影。方法选择10例正常志愿者作为研究对象,采集一系列7TSWI静脉造影数据并与3T结果作对比。选择参数TR=30-45ms,TE=13～26ms,带宽（Bw）=80～140Hz／pixel,翻转角（FA）=10～25°;所有的数据用同样的图像后处理方式得到最小信号叠加投影（mIP）的SWI静脉造影像,并进行定量化分析。结果图像优化后,我们得到高分辨率的7T静脉造影图像。根据静脉血的T2°选择优化TE：16ms（7T）,28ms（337）;FA：15°（3T和7T）。相对于3T,7TSWI图像有较高的信噪比和静脉与周围组织的对比度,并显示出更多的微小静脉。结论超高场SWI静脉造影对于显示微小静脉具有明显的优势。     

MRI of Budd-Chiari syndrome

A retrospective study was undertaken to reassess the various magnetic resonance imaging (MRI) features of Budd-Chiari syndrome (BCS). MRI examinations of 22 patients with pathologically confirmed BCS were studied. Spin-echo (SE) T1- (TR = 300–450 ms/TE = 12–15 ms), and SE T2-weighted (TR = 1600–2000 ms/TE = 30–60/90–120 ms) MRI images were obtained in all patients. Gradient-recalled-echo (GRE) images (TR = 7–60 ms/TE = 3–19 ms, flip angle = 10–40°) were obtained in 14 patients. MRI showed thrombosis of three or two hepatic veins in 19 (86%) and 3 (14%) patients, respectively. Spontaneous intrahepatic anastomoses was depicted in five (23%) patients. Ascites appeared in 15 patients (68%). Thrombosis or external compression of the inferior vena cava (IVC) by an enlarged caudate lobe was depicted in six (27%) and five (23%) patients, respectively. Prominent azygos and hemiazygos veins were demonstrated in seven (32%) patients (six of whom had thrombosis of the IVC). MRI showed hepatomegaly in all patients and enlarged caudate lobe in 18 (82%) patients. SE T1- and SE T2-weighted MRI images revealed inhomogeneous signal intensity of hepatic parenchyma in 14 (64%) patients. SE T1- and SE T2-weighted MRI images showed homogeneous signal intensity of hepatic parenchyma in eight (36%) patients. Our results demonstrate that BCS displays various features on MRI images, and such information is important for diagnosis.     

鼠肝MR成像技术参数探讨

探寻大白鼠肝脏MR成像序列及参数。材料和方法:采用GE0.5T Veetra MR成像仪匹配的SE序列,选择不同大小的像素及TR、TE进行MR成像,然后根据图像的解剖结构图像的均一性,伪影信噪比(SNR),对比噪声比(CNR),和对癌灶的显示,判断图像的优劣,分析不同的成像参数对图像的影响。结果:像素为0.491mm(成像孔径11cm,成像矩阵224×128)时,T_1加权图像的SNR,CNR及优质率分别为17.851±1.774,14.333±3.152,及77.78％(7/9),T_2加权图像的SNR,CNR及优质率分别为8.851±2.518,7.435±1.096及77.78％(7/9);像素为0.351mm(成像孔径9cm,成像矩阵256×160)时,T_1加权图像的SNR,CNR及优质率分别为9.207±1.644,8.203±0.657,及20％(1/5),T_2加权图像SNR,CNR及优质率分别为5.961±1.326,4.463±0.590及20％(1/5)。前者明显后者(P<0.05)。TR 2000ms图像的清晰度和对癌灶显示能力较TR 1500,2500ms为好;TE 30ms,80ms较60ms,120ms好。结论:T_1加权像(TR 480ms,TE 21ms),T_2加权像(TR 2000ms,TE 30/80ms)像素0.491mm是GE0.5T Vectra鼠肝MR成像较为理想的成像参数。     

锥体束Wallerian变性的MRI诊断

目的探讨MRI在诊断脑损害后锥体束Wallerian变性中的应用。方法对22例脑损害后锥体束Walle-rian变性患者均行MRI检查。常规行快自旋回波序列(FSE)横断位T1WI(TR 2 286ms,TE 19.6ms)、T2WI(TR4 300ms,TE 113ms)和T2Flair序列(TR 8 502ms,TE 133ms)。视野(FOV)24cm,矩阵320×256,激发次数(NEX)1～2,层厚6mm,层间距1mm,层数21层。22例患者均加扫横轴位DWI(b值为1 000s.mm-2),其中10例另加扫3D-TOF-MRA(TR 26ms,TE 6.8ms)检查。结果 22例患者中,12例患者在脑损害≥4周～≤12个月后行常规MRI检查,主要表现为病变同侧的锥体束呈长T1、长T2信号并同侧大脑脚及桥脑体积稍萎缩;2例患者在脑损害<4周行常规MRI检查,主要表现为病变侧锥体束稍长T1、长T2信号;8例患者在脑损害>1年行常规MRI检查,主要表现为原发病灶、大脑脚及桥脑萎缩并T2Flair像呈现散在斑片稍高信号影。结论 MRI可明确显示脑损害后锥体束Wallerian变性,有助于临床医师对患者运动功能康复的治疗。     

Leiomyoma of the adrenal gland in a patient with AIDS

Leiomyoma of the adrenal gland is an exceptional localization. We report a case occurring in a young patient with AIDS. Diagnosis was a surprise on pathologic examination. On enhanced computed tomographic (CT) scan, the adrenal mass had a low central attenuation area and a thin enhancing peripheral ring. On magnetic resonance (MR) imaging the left adrenal mass was isointense with the liver on T1-(TR/TE = 500/ 300 ms) and T2-(TR/TE = 2030/60, 120 ms) weighted spin-echo images, except a central area with a lower signal on T1-weighted images and a higher signal on T2-weighted images. The mass was slightly enhanced after Gd-DOTA injection, but the central area remained unchanged.     

不同TR TE组合的GRASE序列3D MRCP成像质量比较

目的探讨不同TR、TE值对3D GRASE-MRCP图像质量的影响,优选出最佳TR、TE组合。方法选择2019年3月至2019年5月行3D MRCP检查的患者12例,设计五组不同TR、TE组合GRASE序列,采用PHILIPS 1.5T磁共振进行3D MRCP扫描,观察评估五组不同TR、TE组合的GRASE序列成像质量,并进行比较。结果采用GRASE序列进行MRCP检查,不同TR、TE值将产生不同的图像质量,A、B两组图像质量比较,差异无统计学意义(P>0.05),A/C、A/D、A/E三组图像质量比较,差异均有统计学意义(P<0.05)。结论PHILIPS 1.5T磁共振采用TR值300~500、TE值100左右的GRASE序列,3D MRCP图像质量最佳。     

MR findings of hepatic cavernous hemangioma after intraarterial infusion of iodized oil

Magnetic resonance (MR) imaging was performed on five tumors of three patients who had hepatic hemangiomas. Four tumors were given an intraarterial infusion of 3–8 ml of iodized oil, while one tumor was not. MR images were obtained at 2.0 or 0.5 T. A single spin echo sequence with TE of 30 ms and TR of 500 ms and a double echo sequence with TEs of 60 and 150 ms and TR of 2000 ms, were used to produce relatively T1-, T2-weighted, and heavily T2-weighted images, respectively. Follow-up MR imaging was done 1–5 months after infusion of iodized oil. On relatively T1 weighted images, hemangiomas showed iso or hypointensity. On T2-weighted images, all tumors showed hyperintensity. However, on heavily T2-weighted images, tumors with iodized oil showed heterogeneous, slight hyperintensity, while tumors without iodized oil showed characteristic appearance of marked hyperintensity in hemangiomas. In hepatic cavernous hemangiomas with intraarterial infusion of iodized oil, familiarity with this unusual MR intensity of tumors on heavily T2-weighted images is useful to avoid the incorrect diagnosis and to reduce the frequency of inappropriate hepatic resection.     

低场强MR动态增强扫描对肝脏肿瘤的诊断与鉴别诊断

目的:运用Gd-DTPA增强研究肝肿瘤低场强MR动态扫描及其价值。材料与方法:32例肝肿瘤39个病灶SE序列(TR/TE200～250/30ms)于1′、2′、5′、10′、20′分别作增强扫描,Gd-DTPA剂量0.1mmol/kg。结果:病例经手术病理和/或临床综合检查随访证实,包括原发性肝癌(HCC)22个病灶,血管瘤8个、囊肿5个,转移癌3个,局灶结节增生(FNH)1个。增强表现分为均匀增强(HCC 16/22、血管瘤2/8 FNH 1/1),延迟增强(血管瘤6/8,FNH1/1),不均匀增强(HCC 6/22、转移癌3/3)不增强(囊肿5/5)。结论:低场强MR短TR/TE SE序列可获得满意诊断图像;Gd-DTPA动态增强扫描对肝脏肿瘤诊断与鉴别诊断有重要价值。但目前此技术尚不能完全替代CT动态扫描。     

In vivo 3D MRI of insect brain: cerebral development during metamorphosis of Manduca sexta

High-resolution 3D MRI of male pupae of Manduca sexta was performed at 2.35 T in order to evaluate its potential for an in vivo characterization of insect brain during metamorphosis. T1-weighted 3D FLASH (TR/TE = 20/7.8 ms, 25 degrees flip angle) and T2-weighted 3D fast SE MRI data sets (TR/TEeff = 3000/100 ms) were acquired at different developmental stages with an isotropic resolution of 100 microm. Both T1- and T2-weighted 3D MRI allowed for the identification of cerebral structures such as the antennal nerve, antennal and optical lobe, and central brain. Pronounced developmental alterations of the morphology were observed during metamorphosis. The results demonstrate the feasibility of 3D MRI at nanoliter resolution to identify major brain systems of M. sexta and respective changes during pupal development from caterpillar to sphinx moth. Together with the use of suitable contrast agents, this approach may provide new ways for studying the axonal connectivity and neural function of the developing insect brain.     

Hepatic MR imaging: comparison of RARE derived sequences with conventional sequences for detection and characterization of focal liver lesions

Background: We compared two T2-weighted turbo spin echo (TSE) sequences with a T2-weighted conventional SE (CSE) sequence to determine whether sequences derived from rapid acquisition with relaxation enhancement such as TSE could replace CSE for the detection and subsequent characterization of focal liver lesions. Methods: A total of 55 consecutive patients with 107 liver lesions underwent magnetic resonance imaging examinations at 1.5 Tesla, with a constant imaging protocol. TSE pulse sequences were acquired with eight echo trains (repetition time [TR], 4718 ms; echo time [TE], 90 ms; acquisition time [TA], 4.03 min; and a symmetric k-space ordering scheme) and 11 echo trains (TR, 4200 ms; TE, 140 ms; TA, 4.40 min; and an asymmetric k-space ordering scheme) and compared with CSE (TR, 2300 ms; TE, 45/90 ms; TA, 9.53 min). Images were analyzed qualitatively by scoring image quality and artifacts and counting focal liver lesions by independent reading with consensus obtained for discrepancies. Quantitative analysis was performed by measuring signal-to-noise (S/N), contrast-to-noise (C/N), and tumor–liver signal intensity (T/L) ratios. Results: T2-weighted TSE sequences provided better subjective image quality and reduced artifacts as compared with the T2-weighted CSE sequence. CSE and TSE sequences exhibited no statistically significant differences in liver S/N, lesion–liver C/N (CSE TE, 90 ms: 18.6 ± 14.0; TSE TE, 90 ms: 16.5 ± 12.9) and the detectability of focal liver lesions. Heavily T2-weighted TSE with a TE of 140 ms allowed correct characterization of focal liver lesions based on a T/L ratio of 3.0 in 84% of patients. Conclusions: T2-weighted TSE sequences are as suited as CSE for the detection (TE, 90 ms), and appear to be superior for the characterization (TE, 140 ms), of focal hepatic lesions. Whether a single sequence, such as a double-echo TSE or a single-echo TSE sequence with a TE between 110 and 120 ms, might perform both functions as well or better than CSE is unknown. However, because of time savings, TSE eventually may be preferred over CSE. Received: 13 December 1994/Accepted after revision: 31 March 1995