MR信号强度在良、恶性胸膜疾病鉴别诊断中的作用

目的 探讨MR信号强度在良、恶性胸膜疾病鉴别诊断中的作用。方法 利用1.5T磁共振诊断仪对88例经病理证实的胸膜病变进行了检查,分别获取T1加权、T2加权及增强T2加权自旋回波像,对胸膜病变的MR信号强度进行了主观评估。结果 良、恶性胸膜病变在T1加权像MR信号强度无显著性差异;在T2加权像上41／48例恶性及11／35例良性胸膜病变表现为高信号（敏感度85％,特异度69％）;在增强T1加楷像上,48／53例恶性及19／35例良性胸膜病变表现为高信号（敏感度91％,特异度46％）。结论 MR信号强度对良、恶性胸膜病变的鉴别诊断有重要的价值,但不宜将MR信号强度作为一项独立的评估指标。     

MRI of abdominal hydatid disease

Seventy hydatid cysts in 30 patients were studied with magnetic resonance imaging (MRI) and computed tomography (CT); all cases were confirmed surgically. MRI detected all cysts when confined to solid organs, whereas small-sized cysts (2 cm) may be missed when located in the peritoneal cavity. Hydatid cysts of less than 3 cm (noncomplicated) present no specific findings of hydatid disease. MRI findings suggesting hydatid disease demonstrate a relatively thick hydatid cyst wall, daughter cysts, and germinal membrane detachment. T2-weighted images proved to be superior to T1 or PD-weighted images in demonstrating hydatid cyst wall thickness, germinal membrane detachment, and daughter cysts. In all spin-echo sequences, the maternal cystic content presented much higher signal intensities than that of daughter cysts. This difference in signal intensity is more obvious in T2 weighted images, except in complicated, infected cases. CT proved to be superior to MRI in demonstrating wall calcifications.     

Multidetector CT and MR imaging cardiac hydatidosis: case report and review of the literature

Cardiac hydatid cysts are uncommon but potentially fatal. We present a case of isolated unilocular and multivesicular hydatid cysts in the heart, and provide a literature review of this rare condition. A 35-year-old man presented to our cardiology unit with acute chest pain. Computed tomography showed two cystic lesions in the heart. One unilocular cyst was located close to the left atrium and compressed the pulmonary artery. The other multivesicular cyst adhered to the left ventricle and displaced the left coronary arteries. T2-weighted magnetic resonance images revealed lesions in the pericardial cavity with bright signal intensity. Dot immunogold filtration assay was performed, and positive results for anti-EgCF antibody, anti-EgP antibody and anti-EgB antibody for cystic hydatidosis were found. Cardiac hydatidosis was diagnosed because of typical imaging findings and positive serology. The patient underwent surgical excision of the cysts. Postoperatively, symptoms of the patient resolved.     

磁共振T_1加权像在急性闭塞性脑血管病诊断中的价值

目的　评价磁共振T1加权像在急性闭塞性脑血管病诊断中的价值。方法　急性闭塞性脑血管病 15例 ,其中急性脑皮层动脉闭塞 9例 ,急性脑静脉窦闭塞 6例。结果　 9例急性脑皮层动脉闭塞 ,T1加权像上MR信号强度正常 ,但可见梗死区脑肿胀征象 ;T2 加权像时 ,病变区信号强度无异常发现。 6例急性脑静脉窦闭塞中 ,横窦和乙状窦闭塞 4例 ,上矢状窦后 1/ 3处闭塞 2例。T1加权像见闭塞的静脉窦血管流空影消失 ,静脉窦呈稍高信号强度影。此外 ,相应静脉回流区可见脑肿胀征象。T2 加权像也可见闭塞的静脉窦血管流空影消失 ,但脑组织内无异常信号改变。结论　急性闭塞性脑血管病 (皮层动脉或大静脉窦闭塞 )的MR检查中 ,T1加权像形态学变化要早于T2加权像信号的变化。     

Myxoid liposarcoma of the spermatic cord: US and MR imaging findings

We report a patient with myxoid liposarcoma of the spermatic cord in whom combined use of both ultrasound (US) and MRI helped to suggest the diagnosis. The lesion was solid at US and vascularized at color Doppler. T1‐weighted MRI did not show fat within it; on T2‐weighted images it had high signal intensity, with a cyst‐like appearance. It is known that fat‐poor myxoid liposarcomas with high water content may mimic a cystic lesion on non‐contrast‐enhanced MR; then, a combination of MRI findings, suggesting a cyst, and of US findings, showing the mass was actually solid and vascularized, allowed preoperatively the diagnosis of fat‐poor myxoid liposarcoma. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 42 :96–99, 2014     

卵巢肿瘤的MR 影像学诊断

目的 评价ＭＲ对卵巢肿瘤的诊断价值。方法 回顾性分析了１５例经手术、病理证实的卵巢肿瘤的ＭＲ影像资料,包括卵巢囊肿６例、卵巢囊腺瘤４例、卵巢癌２例、卵巢畸胎瘤２例和卵巢恶性畸胎瘤１例。其中１例卵巢囊肿和１例卵巢囊腺瘤同时伴有子宫肌瘤。结果１５例卵巢肿瘤中,囊性８例,囊实性７例;肿瘤边缘光滑１３例,模糊２例;３例恶性肿瘤均为囊实性,２例边缘模糊,１例边缘光滑;８例囊性肿瘤中,６例表现为长Ｔ１、长Ｔ     

神经节细胞瘤的MRI与组织病理学对照研究

目的 评价神经节细胞瘤的MR征象及其组织病理学基础。方法 10名经组织病理学证实为神经节细胞瘤患者，行常规及动态增强MR检查，分别分析了形态学特征，信号强度以及肿瘤的动态增强形式，并与组织病理学特征相对照。结果 神经节细胞瘤的MR征象表现为长T1长T2信号。所有肿瘤的组织学检查均有被膜存在，其中5例肿瘤被膜在MR增强后的T1WI上也可被显示。这5例肿瘤T1和T2WI上涡漩状征象与组织学标本上成束的雪旺细胞及胶原蛋白相互交织的现象相对应。在T2WI上呈高信号的肿瘤在组织学上含有大量黏液样基质而细胞和纤维成分相对较少。中到高信号的瘤体含有大量的细胞和纤维成分而黏液样基质较少。在动态增强MR上除一例肿瘤呈早期增强外，其余均呈现逐渐增强影像。结论 神经节细胞瘤的MR特征与组织学特点密切相关。     

前列腺癌和良性前列腺增生的MR影像表现——与组织病理对比研究

目的：了解磁共振成像在前列腺癌和良性前列腺增生诊断与鉴别诊断的价值。方法：本文对２１例有手术病理证实的前列腺癌和良性前列腺增生的病人进行ＭＲ检查，并与组织病理作对比研究。其中６例前列腺癌，２例前列腺肉瘤，１３例良性前列腺增生。采用自旋回波（ＳＥ）Ｔ１和Ｔ２加权像对所有病例进行分析。结果：ＭＲＴ２加权像５２％（１１／２１）的病人显示位于前列腺两侧及后部的边缘带腺体呈高信号，而中央带的腺体呈低信号。７６％（１０／１３）的良性前列腺增生显示为中央带腺体增大呈较低信号强度而两侧高信号的边缘带腺体呈压缩变薄的改变。在前列腺癌和肉瘤中７例表现为ＭＲＴ２加权像一侧或两侧的边缘带高信号消失，且周边不见低信号的纤维包膜。２１例前列腺增生与癌的诊断准确率为８０．９％。此外本文还对肿瘤外侵的估计作了初步探讨。结论：我们认为ＭＲ在前列腺增生和癌的诊断和鉴别诊断上有应用价值。     

脊髓型多发性硬化的MRI诊断

目的探讨脊髓型多发性硬化MR表现及其诊断价值.方法对20例脊髓型多发性硬化行脊髓和/或头颅MR检查,对其征象进行分析.结果病灶分布上以颈髓受累最多,占40%,颈胸髓同时受累占30%,胸髓受累占25%,全部脊髓受累最少,为5%.病灶形态,以条带状最多见,为40%,斑片状或云雾状为25%.矢状面T2WI均表现高或稍高信号,T1WI 90%为等信号,T2WI轴位病变,以类圆形高信号和点片状高信号为主,增强后病灶强化或不强化.结论 MRI有助于发现病灶,明确病灶位置,是目前诊断脊髓多发性硬化最敏感的影像学方法.     

髋关节周围滑囊炎MRI诊断及鉴别诊断

目的 研究髋关节周围滑囊炎的MR表现,探讨其临床及影像学表现的关系.方法 回顾性分析15例经穿刺或手术病理证实的髋关节周围滑囊炎MR资料,患者包括男性8例和女性7例,年龄为43～70岁,平均58岁,所有病例都进行了MR平扫和增强扫描.MRI资料由2名放射科医师阅片并取得一致性意见,对病变的部位、大小及内在特征作出评价.结果 15例病灶均表现为圆形或椭圆形囊性占位.囊内信号特点：在T1加权像,与邻近肌肉相比,表现为低信号;所有15例在T2加权像上都呈极高信号,10例信号均匀.5例信号不均匀：囊壁信号特点：在T1加权及T2加极像上囊壁均显示不清;其中4例有分隔,11例无分隔.DWI图信号很低,ADC图明显高信号,ADC值极高,平均ADC值为2.98×10-3mm2/s;增强扫描示囊内无强化,囊壁及分隔轻度强化且厚薄不均.结论 髋关节周围滑囊炎MR表现有特征性,包括特定部位、在T2WI呈明显高信号等,依据典型MR表现可以作出正确诊断.     

Sonographic appearance of focal fatty infiltration of the pancreas

We report the sonographic, CT, and MRI findings in a case of focal fatty infiltration of the pancreas. Sonography revealed an echogenic mass in pancreas head. On CT, the mass was hypodense. The mass showed same signal intensity to the surrounding normal pancreas on in‐phase T1‐weighted MR images and a loss of signal intensity on opposed‐phase MR images. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2010     

Paraovarian cyst: MR imaging features

BACKGROUND: Paraovarian cysts are common intrapelvic neoplasms, but the magnetic resonance (MR) findings of paraovarian cyst have never been reported. We investigated the spectrum of MR imaging features of paraovarian cyst. METHODS: MR images of 18 paraovarian cysts in 16 patients were reviewed retrospectively. MR images were evaluated for the size and location of paraovarian cysts, single or multicystic, signal intensity on T1- and T2-weighted images, and visualization of the normal ovary on the affected side. RESULTS: The normal ovary of the affected side was recognized in 13 lesions. Four of these 13 cysts were separated from the ipsilateral ovary. In seven cysts, the normal ovary was abutted by cysts but maintained its shape. In two cysts, the beak sign was recognized at the interface between the cyst and the ovary. Most other MR features were nonspecific. CONCLUSION: Most paraovarian cysts were homogeneous cystic masses near the ipsilateral round ligament and the uterus. Demonstration of a normal ipsilateral ovary close to, but separated from, the adnexal cyst may be an important MR finding for the diagnosis of paraovarian cysts.     

Magnetic resonance imaging of the kidneys and adrenal glands

A simple renal cyst will have low signal intensity on T1-weighted SE images with short TE and short TR because of the long T1 values of the cyst fluid. With increasing TE and TR, cysts demonstrate increased signal intensity due to the long T2 values of the cyst fluid. On T1-weighted images a complicated cyst will have higher signal intensity than a simple cyst; it may not be possible to differentiate these complicated cysts from solid masses. MRI seems to be useful in identifying simple cyst fluid and, therefore, has potential in characterization of cystic lesions considered complex by CT or ultrasound. Unfortunately, imaging techniques have not yet been optimized, diagnostic criteria are somewhat vague, and accuracy has not been established in a representative patient population. Solid masses often can be identified and differentiated from simple, uncomplicated cysts on MR images. The inability to differentiate among various types of solid tumors or to separate these from complicated cysts or inflammatory masses remains a limitation. Most lesions are more readily seen on contrast-enhanced CT than on MR images and therefore the role of MRI in the detection and diagnosis of renal cell carcinoma remains limited. Although the high detection rate of renal cell carcinoma is encouraging, CT is still more sensitive than MR in demonstrating solid lesions less than 3 cm in diameter. MRI cannot be used as a screening modality for renal tumors. MRI seems quite helpful in the staging of renal cell carcinoma. Macroscopic extension into the perinephric fat, tumor extension into the renal vein and the inferior vena cava, and macroscopic metastases to other organs are readily seen. Furthermore, differentiation between enlarged nodes and vessels is possible with MRI. Some authors recommended the use of MRI to stage renal cell carcinoma in patients with known contraindication to contrast, prior suboptimal bolus contrast enhanced CT scan, and equivocal CT findings. MRI can replace the inferior vena cavagram in the staging work-up and MR may be superior to CT for planning the surgical approach in Stage IIIA lesions by determining the upper extent of tumor thrombus within the inferior vena cava or the right atrium.(ABSTRACT TRUNCATED AT 400 WORDS)     

实验性肝细胞癌MR成像与铜含量的关系研究

目的 初步阐明在MRI的常规SE序列,铜含量对肝细胞癌T1W1信号的影响。方法 用0.2?N（Sigma产品）灌喂Wistar大鼠（n=80),诱癌成功行常规SE序列T1WI、T2WI,对照组（n=20)不灌喂DEN,余同实验组。扫描后处死动物取肝组织与肝癌组织作HE染色,并测定组织内水、铜含量。结果 肝癌组织与癌周肝组织含水量无显著差异。肝癌组织内铜含量高于癌周肝组织,在呈高信号的肝组织内铜含量明显高于呈其它信号强度类型的肝组织。结论 水的含量不是影响肝癌MR表现的主要因素。肝癌内铜的蓄积对在SET1WI呈高信号起作用。     

腱鞘巨细胞瘤的影像学诊断

目的分析腱鞘巨细胞瘤的影像学表现,以提高对该病的认识及影像诊断的准确率。方法回顾性分析14例经手术病理证实的腱鞘巨细胞瘤患者的X线平片及MRI表现,其中6例行X线平片检查,13例行MRI平扫及增强扫描。结果X线平片显示局部稍高密度软组织肿块影,邻近骨质未见明显异常或局部侵蚀破坏;MRI表现为相应部位软组织信号肿块影,在T1WI多呈较低信号,内可见条片状更低信号影,T2WI呈高低混杂信号影,增强扫描强化明显,病灶与邻近肌腱或关节关系密切,局部骨皮质可受侵。结论腱鞘巨细胞瘤的影像学表现具有一定的特征性。      

Tornwaldt囊肿的低场MRI表现

目的探讨低场磁共振成像（MRI）Tornwaldt囊肿的影像表现。方法观察15例Tomwaldt囊肿的MRI信号强度、形状、大小和位置。结果15例病变在T2WI上均与脑脊液等信号,T1WI上7例病变与肌肉信号相同,8例病变信号低于肌肉。13例病变呈圆形,2例呈椭圆形,病变最大径自2～14mm不等。结论Tornwaldt囊肿较少见,在常规头部MRI中占0．83％,在低场T1WI上低于或等于肌肉信号,T2WI上等同于脑脊液信号。     

甲状腺专用表面线圈在甲状腺MRI中的图像质量研究

目的 探讨8通道特制甲状腺专用表面线圈对甲状腺磁共振检查图像质量的影响.材料与方法 对49名健康志愿者使用8通道甲状腺专用表面线圈行甲状腺磁共振检查,扫描序列包括T1WI、T2WI、T2WI-FS(fat-suturation)、扩散加权成像(diffusion weighted imaging,DWI)-STIR和D...     

肝包虫病的CT和MR诊断

目的 探讨肝包虫病的CT和MRI表现.方法 临床手术、病理证实的肝包虫病42例,就其CT和MRI表现回顾性分析并就相关文献进行复习.结果 本组肝细粒棘球蚴病占85.71%,蛋壳样或条带状钙化、"囊内囊"、"飘带征"等为其主要表现;肝泡球蚴病占14.29%,钙化、"小泡征"、"半岛征"及囊腔或液化、坏死等为其主要表现;MR T2WI显示囊壁及纤维间隔、飘带征等优于CT,但钙化显示逊于CT.结论 CT和MR均可诊断肝包虫病,CT在综合诊断方面优于MR.     

Magnetic resonance imaging of bladder hemangioma

An 18-year-old woman with a bladder hemangioma is described. The tumor had a low signal intensity with multilocular pattern on T1-weighted magnetic resonance (MR) images and high signal intensity on T2-weighted MR images. MR images were useful in evaluating tumor character and its extent.     

碘油在磁共振上信号特点的探讨

目的探讨碘油在磁共振上信号特点。方法收集2例肝癌插管化疗栓塞（TACE）患者，于0．5T的MR仪行常规腹部磁共振检查，包括SE序列T1WI、T2WI。制备样品：碘油样品取作肝栓塞剂的碘化油，并各取12ml的蒸馏水、泛影葡胺、碘海醇、碘（分析纯）、大豆色拉油、菜子油、血清置试管内作为对照。将试管顺序排列，于0．5T的MR仪进行多参数扫描；同时，将各制备品试管置于随机选取的常规扫描者体侧，获得试管与身体组织共同扫描图象，计算SNR值进行对比。结果在不同的磁场强度中碘油产生的信号强度不同，但可以通过调整扫描参数使信号强度趋于一致。碘油在体外SE序列T1WI上呈高信号，T2WI上低信号。体内成像的表现与周围环境的信号对比有关，在与正常肝脏对比中均为低信号。碘在MRI各个序列上均不成像，并且影响其他物质的碘油的信号强度低于油脂的信号强度。自旋回波长TR多回波的图像上信号强度SNR，TE30=6．3、TE60=2．8，TE90=1．6。结论可以用在自旋回波长TR多回波的图像来区分碘油，判断碘油的沉积情况，同时显示残存肿瘤的信号。