MRI诊断Maisonneuve骨折骨间膜断裂范围的研究

目的 探讨Ｍａｉｓｏｎｎｅｕｖｅ骨折（ＭＦＦ）骨间膜损伤及损伤范围的ＭＲＩ表现。方法 １２例急诊收治的ＭＦＦ患者术前进行ＭＲＩ检查。采用膝关节线圈对小腱全长分２段进行检查以获得骨间膜全长的图像。采用轴面Ｔ１ＷＩ（ＴＲ５００ｍｓ,ＴＥ４０ｍｓ）、Ｔ１脂肪抑制（ＳＴＩＲ）像、Ｔ２ＷＩ（ＴＲ３０００～４０００ｍｓ,ＴＥ１８０～２００ｍｓ）,３例行双侧对比,５例术中探查骨间膜。结果 １２例患者均存在骨间膜     

MRI定位诊断甲状旁腺腺瘤二例

ＭＲＩ定位诊断甲状旁腺腺瘤二例田伟我院１９９４年曾遇２例甲状旁腺腺瘤，均用ＭＲＩ定位诊断，使用０．５Ｔ超导型ＭＲ成像系统。ＳＥ序列Ｔ１ＷＩ：ＴＲ４５０毫秒，ＴＥ２０～２５毫秒，Ｔ２ＷＩ：ＴＲ１８００毫秒，ＴＥ１００毫秒，层厚５ｍｍ，间隔２ｍｍ，视野１...     

原发性肝细胞癌磁共振成像与血管造影检查的对照研究

目的：探讨原发性肝细胞癌（ＨＣＣ）的ＭＲ与肝血管造影表现的相关性。材料与方法：研究对象：于ＭＲＩ检查后１０日内行肝血管造影检查的ＨＣＣ患者６６例。ＭＲＩ采用ＳＥ序列,矩阵１２８×２５６,层厚５～１０ｎｍ,层间隔１ｍｍ。Ｔ１加权像：ＴＲ＝５３０ｍｓ,ＴＥ＝１５ｍｓ,Ｔ２加权像：ＴＲ＝２０００ｍｓ,ＴＥ＝８０ｍｓ。肝血管造影采用Ｓｅｌｄｉｎｇｅｒ经皮穿刺股动脉插管技术,行肝动脉和间接门静脉造影。结果：     

快速自旋回波颈脊髓MR造影技术-2D,3D比较

目的：分析评价２Ｄ，３ＤＴＳＥ颈脊髓造影。方法：１６例健康志愿者分别选２Ｄ，３ＤＴＳＥ行ＭＲ颈脊髓造影，３３例颈椎病患者选３ＤＭＲ颈脊髓造影，比较２Ｄ，３Ｄ图像及参数选择注意事项。结果：１．ＭＲ颈脊髓造影能良好地显示Ｃ１—Ｃ８神经根，对２Ｄ，３Ｄ各１９２幅ＭＩＰ分析３Ｄ在各方位对神经根显示清晰度明显优于２Ｄ（Ｐ＜０．０５）；２．ＴＳＥ序列中ＥＴＬ及ＥＳ的选择直接影响图像质量及成像时间，我们选择ＴＲ／ＴＥ为６０００ｍｓ／５００ｍｓ回波间隔（ＥＳ）选择在２１～２４ｍｓ图像质量较满意；３．ＭＲ颈脊髓造影像有两个解剖标志可记数Ｃ１，Ｃ２神经根：①双侧椎动脉进入硬膜处下缘为记数Ｃ１神经根标记，②环椎侧块对硬膜压迹形成的双侧凹陷，紧邻其下方为记数Ｃ２神经根标记；４．ＭＲ颈脊髓造影可直接显示神经根受压移位，骤拢，上翘的细节及根袖囊肿。结论：ＭＲ颈脊髓造影是一种无创，有效的脊髓造影方法，３Ｄ成像更为满意，可为常规颈椎ＭＲＩ成像提供重要的影像补充资料。     

中线颅内脂肪瘤的磁共振影像诊断

颅内脂肪瘤ＭＲＩ特征性的信号表现及位置的中线性说明ＭＲＩ对诊断具有重要意义。材料与方法：对１６例ＭＲＩ诊断的颅内脂肪瘤进行回顾性分析总结。全部 病例临床表现无特异性，均用Ｐｈｉｌｉｐｓ０．５Ｔ－Ⅲ型超导磁共振机采用自旋回波序列（ＳＥ）进行扫描，Ｔ：加权像ＴＲ＝５００－５２０／ＴＥ＝２５，Ｔ２加权像ＴＲ＝２２７３／ＴＥ＝９０，距阵２５６×２５６，行同、矢状及冠状位扫描，就其信号表现及颅内益进行分析总     

脑肿瘤磁化传递成像和钆剂增强协同作用的研究

目的：研究钆剂（磁显葡胺）和磁化传递（ＭＴ）成像对脑肿瘤增强效果的协同作用。材料和方法：对６０例脑肿瘤行ＳＥＴ１Ｗ和ＰＤＷ，Ｔ２ＷＭＲＩ检查后，继以行钆剂增强后ＳＥＴ１Ｗ和ＭＴＩＳＥＴ１ＷＭＲＩ。然后测定各种脑肿瘤钆剂和ＭＴＩ合用的增强效价。结果：ＭＴＩ能降低脑实质（背景）信号强度，而对肿瘤病灶的信号强度无甚影响，所以钆剂和ＭＴＩ合用的增强效果为不用ＭＴＩ者的２．２４～８倍。能使脑肿瘤病灶增强范围和突出程度有所增加，并显示更多的病灶。ＭＴＩ和半量（０．０５ｍｍｏｌ／ｋｇ）钆剂合用其增强效果相当于双倍剂量钆剂者。结论：ＭＴＩ和钆剂增强对脑肿瘤具有协同增强效果，故可用作脑肿瘤增强ＭＲＩ检查的常规方法。     

卵巢子宫内膜异位囊肿的MRI和CT表现（附13例分析）

目的：探讨卵巢子宫内膜异位囊肿的ＭＲＩ及ＣＴ表现的特点。材料和方法：回顾性研究１９９４年１月至１９９５年１０月经ＭＲＩ、ＣＴ扫描表现异常的１３例共２２个卵巢子宫内膜异位囊肿，１３例中１２例作ＭＲＩ，２例同时作ＭＲＩ和ＣＴ，１例仅作ＣＴ扫描。全部病例均经手术病理证实。结果：在２１个囊肿中，ＭＲＩＴ１、Ｔ２加权像显示囊肿的不同信号强度，在Ｔ１加权像中，３个显示低信号，３个显示中等信号，６个显示混杂信号，９个显示高信号；在Ｔ２加权像中，２个显示低信号，９个显示混杂信号，１０个显示高信号。另外，２例ＣＴ平扫＋增强扫描为高密度，１例为低密度。囊肿直径约２～９ｃｍ，最大９ｃｍ×７ｃｍ。囊肿反复出血，是ＭＲＩ信号和ＣＴ密度不同的主要原因。结论：认识卵巢子宫内膜异位囊肿ＭＲＩ以高信号和混杂信号为主要表现的特点，将有助于作出正确的诊断。而卵巢子宫内膜异位囊肿在ＣＴ平扫和增强扫描表现为高密度，可能有定性诊断意义     

CT及MRI诊断嗅神经母细胞瘤的价值

目的：探讨ＣＴ和ＭＲＩ在嗅神经母细胞瘤的诊断、分期及疗后随诊中的价值。材料和方法：回顾性复习１０例嗅神经母细胞瘤的ＣＴ扫描和１例ＭＲＩ的表现。男６例，女５例。年龄１３～６５岁，中位年龄３２岁。临床表现为鼻堵、鼻衄各６例，眼外突４例，偏头痛、视力下降、鼻翼肿物各２例。ＣＴ平扫５例，增强扫描６例；横断面８例，冠状面７例。ＭＲＩ为ＳＥ序列，Ｔ１和Ｔ２加权像，并用Ｇｄ－ＤＴＰＡ作增强扫描。６例有随诊ＣＴ，１例有随诊ＭＲＩ。结果：按Ｋａｄｉｓｈ分期标准：Ａ期１例，Ｂ期２例，Ｃ期８例。侵犯范围为鼻腔１１例，同侧筛窦、眼眶各６例，蝶窦、上颌窦、前颅凹内各４例，鼻翼软组织２例。ＣＴ增强扫描６例中５例为中度不均质强化，１例为高度强化。ＭＲＩＴ１加权像呈中、低信号，Ｔ２加权像呈中、高信号。结论：嗅神经母细胞瘤的影像学表现无特异性。影像学检查目的为界定肿瘤侵犯范围。冠状面扫描有助于显示颅内、眶内病变，必不可少。ＭＲＩ的Ｔ２加权像有助于鉴别肿瘤和鼻窦内积液，在界定肿瘤范围方面优于ＣＴ。疗后的基线所见和定期随诊影像学检查有助于检出复发，及时行补救治疗     

胆管细胞型肝癌的CT,MRI及血管造影表现（附八例报告）

报告８例经手术及病理证实的胆管细胞型肝癌，主要观察其ＣＴ、ＭＲＩ及血管造影表现。８例中男６例，妇２例，年龄４２－６４岁，影像学检查包括、ＭＲＩ及血管造影，主要表现：（１）ＣＴ平扫为单发分叶状低密度块影，巨块型者密度不均；注射造影剂后４例呈边缘性增强（４／６）；１例伴有肝硬化、脾大。（２）ＭＲＩＴ１加权像上病变呈低信号，Ｔ２加权像上信号较高，５例可见瘢痕结构（５／７）；注射造影剂后早期，５例呈中等度     

老年人皮质下动脉硬化性脑病的病理学基础和CT,MRI对照研究

本文就２６例皮质下动脉硬化性脑病患者的ＣＴ、ＭＲＩ检查结合病理学基础进行了分析。ＭＲＩ检查，当ＴＲ＝２０００ｍｓｅｅ，ＴＥ＝３０、６０ｍｓｅｃ时，皮质动脉硬化性脑病损害均为明显的高信号，Ｔ１加权像为低信号。ＣＴ像为低密度改变。Ｔ２加权像上半卵圆中心的白质表现为不均匀弥漫的高信号区，可累及基底节、丘脑、脑干及小脑的白质，并有不同程度的侧脑室扩大、脑室边缘呈斑片状改变可有脑萎缩。病理学特征是弥漫不完全     

鼻咽癌放疗后放射性脑病MRI评价

本文分析12例鼻咽癌放疗所致放射性脑病的CT和MRI表现。MRI检查采用SE序列(TR=1800ms,TE=99、132ms)和RARE序列,T_2加权成像。结果表明:MRI显示病变较CT敏感,以表现侧脑室旁白质内爪样高强度信号病灶为特征,颞叶病变最重,向上逐渐减轻,严重者累及颞叶灰质。作者认为MRI是放射性脑病的有效诊断手段。     

MR imaging of peripheral cholangiocarcinoma.

A prospective study was performed to compare MR spin-echo (SE) sequences [repetition time/echo time (TR/TE) 2,000/80, 500/44 ms], unenhanced CT, and rapid intravenous contrast enhanced CT in eight consecutive patients with peripheral cholangiocarcinoma. All the tumors (ranging from 5 to 9.6 cm in size) were detected with all four techniques. Tumor contrast, however, was qualitatively greatest on long TR/TE SE images. With long TR/TE SE images, tumors were demonstrated as well-demarcated homogeneous regions of high signal intensity, and the anatomic relations between tumors and intrahepatic blood vessels were easily perceived. Detection of small intrahepatic metastatic foci was best on long TR/TE images. Tumor invasion of the portal vein's branches was also best seen on long TR/TE SE images. These results indicate that long TR/TE SE sequence is the most effective initial screening method in demonstrating the presence and determining resectability of peripheral cholangiocarcinoma.     

Magnetic resonance imaging of multiple sclerosis: a study of pulse-technique efficacy

Forty-two patients with the clinical diagnosis of multiple sclerosis were examined by proton magnetic resonance imaging (MRI) at 0.5 T. An extensive protocol was used to facilitate a comparison of the efficacy of different pulse techniques. Results were also compared in 39 cases with high-resolution x-ray computed tomography (CT). MRI revealed characteristic abnormalities in each case, whereas CT was positive in only 15 of 33 patients. Milder grades 1 and 2 disease were usually undetected by CT, and in all cases, the abnormalities noted on MRI were much more extensive than on CT. Cerebral abnormalities were best shown with the T2-weighted spin-echo sequence (TE/TR = 120/1000); brainstem lesions were best defined on the inversion-recovery sequence (TE/TI/TR = 30/400/1250). Increasing TE to 120 msec and TR to 2000 msec heightened the contrast between normal and abnormal white matter. However, the signal intensity of cerebrospinal fluid with this pulse technique obscured some abnormalities.     

Fast T1- and T2-weighted pulmonary MR-imaging in patients with bronchial carcinoma

PURPOSE: A prospective study to evaluate the diagnostic potential and limitations of three fast MRI sequences in patients with bronchial carcinoma based on the comparison with spiral CT. MATERIAL AND METHODS: Three fast chest MRI sequences from 20 patients with central or peripheral bronchial carcinoma were evaluated by two observers for relation of tumour to adjacent structures, lymph node enlargement, additional pulmonary lesions and artefacts. The information from MR-imaging was compared with the results from spiral CT. MRI comprised a T1-3D-GRE breath-hold examination ("VIBE", TR/TE 4.5/1.9 ms, flip-angle 12 degrees , matrix 502 x 512, 2.5 mm coronal slices), a breath-hold, T2-HASTE sequence (TR/TE 2000/43 ms, matrix 192 x 256, 10 mm coronal slices) and a respiration-triggered T2-TSE sequence (TR/TE 3000-6000/120 ms, matrix 270 x 512, 6 mm transverse slices). The FOV was adapted individually (380-480 mm). RESULTS: The presence of the primary bronchial carcinoma and infiltration of thoracic structures by tumour tissue could be demonstrated by all sequences. VIBE sequence was more suitable for detecting small pulmonary nodules than the other MRI examinations, but compared to CT still 20% of these lesions were missed. Contrary to VIBE and T2-weighted TSE scans, HASTE sequence was limited in imaging mediastinal lymph nodes due to missing relevant findings in 2/20 patients. HASTE images significantly provided the lowest rate of artefacts in imaging lung parenchyma (P < 0.001 in peripheral parenchyma), but spatial resolution was limited in this sequence. Concerning the differentiation between tumour and adjacent atelectasis (n = 8), T2-weighted TSE imaging was superior to CT and VIBE in all cases and to HASTE sequence in 4/8 patients. CONCLUSION: The combination of VIBE and HASTE sequence allows for an adaequate imaging of thoracic processes in patients with bronchial carcinoma, limited only in visualizing small pulmonary nodules. To obtain more detail resolution and to differentiate tumour tissue from adjacent atelectasis, T2-TSE examination may be added in selected cases.     

ESWAN序列参数对出血性剪切灶及脑静脉显示的影响和分析

目的研究多回波采集的增强T2*加权血管成像(ESWAN)序列的TR和TE参数对磁敏感效应的影响;调整更适合出血性剪切灶检出的ESWAN序列参数。资料与方法 10例弥漫性轴索损伤(DAI)患者经两种不同参数设置的ESWAN序列(两种序列的参数区别在于:短TE的ESWAN序列的首个回波TE 10 ms,TR 77 ms;长TE的ESWAN序列的首个回波TE 48 ms,TR 104 ms)扫描获得两组ESWAN图像,经后处理得到两组幅度图,将幅度图行最小强度投影(MinIP)后在两组图像上分别计数出血灶的数目、测量出血灶的容积,在三脑室上部及室间孔层面对显影的脑深部静脉计数。用配对t检验的方法检验两组数据的差异性。结果两组图像显示的微出血灶的数量及分布完全一致;长TE的ESWAN序列测量的微出血灶容积显著大于短TE的ESWAN序列;长TE的ESWAN序列显示的脑深部静脉数量明显多于短TE的ESWAN序列。结论 ESWAN序列的多回波采集优势,即使明显缩短首个回波的TE,后续的回波仍能保障对微出血灶检出的磁敏感效应;随着TE的延长,显影的静脉数量明显增多,但模糊效应也逐步放大,出血灶容积的放大比例也增加。对于脑外伤...     

MRI evaluation of the patellar articular cartilage in patients with subluxation of the patella

In patients with subluxation of the patella, injury of the patellar articular cartilage is frequently observed and correct evaluation is important to manage these patients. We examined 11 patients with subluxation of the patella and five normal volunteers. In 12 patellofemoral joints of seven patients with subluxation of the patella, the abnormalities observed on MRI were compared with those on arthroscopy and/or at operation. MRI was performed with a Magnetom 1.5 T (Siemens) using the round surface coil. Pulse sequences were SE (TR 400 ms/TE 19 ms), FLASH (TR 320 ms/TE 15 ms FA 90 degrees and 40 degrees), and SE (TR 2000 ms/TE 26, 70 ms). We analysed MR findings of the 12 abnormal joints and 10 normal joints according to the following classification of abnormalities observed on arthroscopy. (1) normal appearance (n = 3 joints), (2) softening and fibrillation (n = 6), (3) fragmentation (n = 3), and (4) erosion to bone (n = 0). In only one of the six cases with softening and fibrillation observed on arthroscopy, MRI could visualize the thickening of patellar articular cartilage, but in all three cases with fragmentation observed on arthroscopy, MRI could visualize the thin inhomogenous cartilage with irregular surface. The combination of SE (TR 400 ms/TE 19 ms) and FLASH (TR 320 ms/TE 15 ms FA 90 degrees) are extremely effective pulse sequence to detect the abnormalities of patellar articular cartilage. We conclude that MRI is a useful noninvasive method of detecting advanced changes in patellar articular cartilage.     

Sodium-23 imaging of supratentorial lesions at 4.0 T.

In 27 patients with low and high grade gliomas (n = 17), meningiomas (n = 4), and other supratentorial tumors and lesions (n = 6), the results of sodium-23 MR imaging with high spatial resolution were compared to CT and proton MRI. The Na MR studies were performed with a 4.0-T whole-body MR system and an isotropic 3D-Flash sequence (TR 70 ms, TE 11 ms), which depicts the long T2 component of sodium. All patients tolerated the sodium study at 4.0 T well. The sodium images revealed almost all lesions, but the resolution was inferior to that of the reference methods. Two small meningiomas did not show up at all in the sodium study. Furthermore in one case small hemorrhages and calcifications within one of the tumors could not be found. Sodium imaging of the long T2 component did not provide any additional information regarding the histology, grading, size, and differentiation of the tumor from the surrounding edema which had not already been provided by CT or H MRI.     

Diagnostic value of MR imaging in comparison to CT in the detection and differential diagnosis of renal masses: ROC analysis

The aim of this work was to compare MR imaging and CT in the detection of renal masses and in the differential diagnosis between benign and malignant lesions. In 33 patients with 54 renal lesions CT and MR images were evaluated by four readers with regard to tumor detection and characterization using a receiver-operating-characteristics (ROC) analysis. The MRI protocol consisted of a T1-weighted spin-echo (SE) sequence (TR/TE: 300/10 ms) before and after contrast administration and a heavily T2-weighted turbo-SE (TSE) sequence (TR/TE: 5500/150 ms). A_z values for the area under the ROC curves for lesion detection were 0.92 ± 0.04 for CT and 0.91 ± 0.05 for MRI, respectively, which was not statistically different. The MRI technique was slightly, but not significantly, better than CT in the overall characterization (accuracy in differentiation between benign and malignant) of renal lesions with an A_z value of 0.90 ± 0.05 compared with 0.88 ± 0.06 for CT. The MRI technique proved to be statistically superior to CT (p < 0.01) in the correct characterization of benign renal lesions. MRI equals CT in the overall detection and differential diagnosis of renal masses. MRI is very helpful for further differential diagnosis of lesions which are equivocal on CT especially in the differentiation between complicated cysts and cystic or hypovascular renal cell carcinoma. Received 29 April 1996; Revision received 14 August 1996; Accepted 2 September 1996     

Gadolinium-DOTA enhanced fast imaging of liver tumors at 1.5 T

Twenty patients [15 men, 5 women, 19-71 years old (mean 52 years)] highly suspected of having tumoral liver pathology were prospectively studied with motion compensated T2-weighted spin echo (SE) [repetition time (TR) 2,200 ms, echo time (TE) 90 ms] and Gd-DOTA enhanced gradient echo fast low angle shot [TR 60 ms, TE 10 ms, angle 30 degrees) sequences. The final diagnoses were hemangioma (five), hepatocellular carcinoma (four), focal nodular hyperplasia (one), adenoma (one), metastasis (two), abscess (two), echinococcal cyst (one), tumor of unknown origin (three), cirrhosis (one). Contrast enhanced images were obtained during the early vascular phases after intravenous bolus injection of Gd-DOTA at a dose of 0.1 mmol/kg (0.2 ml/kg). After Gd-DOTA, positive contrast enhancement was seen in 11 cases, negative enhancement in 4, and nonenhancement in 6. Contrast patterns were similar to contrast enhanced CT. In terms of visibility of lesions, the unenhanced motion-compensated T2 SE sequences were superior to the nonenhanced gradient echo sequences in 12 patients and equal in 8. After gadolinium enhancement, T2-weighted SE images were superior to the postcontrast gradient echo images in eight cases, equal in eight and inferior in four cases.     

Discrimination of benign from malignant hepatic lesions based on their T2-relaxation times calculated from moderately T2-weighted turbo SE sequence

The differentiation of hemangioma from other hepatic neoplasms using MRI usually relies on the evaluation of heavily T2-weighted images. The aim of this study was to assess the value of T2-relaxation times calculated from moderately T2-weighted turbo spin-echo (TSE) sequence in characterization of focal hepatic lesions, including hepatic malignancies, focal nodular hyperplasia (FNH), hemangioma, and cyst. Fifty-two patients with 114 proven lesions (61 malignant masses, 6 focal nodular hyperplasias, 28 hemangiomas, 19 cystic lesions) were examined on 1.5-T system using a double-echo TSE sequence (TR=1800 ms; TE(eff) 1=40 ms; TE(eff) 2=120 ms). Signal intensities (SI) of the liver as well as SI of all lesions were measured, and then the T2-relaxation times were calculated. The mean T2 time for the liver was 54 ms (+/-8 ms), for FNH 66 ms (+/-7 ms), for malignant hepatic lesions 85 ms (+/-17 ms), for hemangiomas 155 ms (+/-35 ms), and for cystic lesions 583 ms (+/-369) ms. Most malignant hepatic lesions were best differentiated between the thresholds of 67 and 116 ms, generating a sensitivity of 90% and a specificity of 94%. There were six false-negative diagnoses of malignant tumor and three false-positive cases (two hemangiomas and one FNH). Calculation of the T2-relaxation times obtained from the double-echo TSE sequence with moderate T2-weighting allowed differentiation between malignant and benign hepatic lesions with high sensitivity and specificity.