葡萄膜转移瘤的MRI表现

目的探讨葡萄膜转移瘤的MRI表现特点。方法回顾性分析20例经病理或临床随访证实的葡萄膜转移瘤的MRI表现。1例仅行平扫，19例同时行平扫和增强扫描，其中4例行动态增强扫描。结果20例葡萄膜转移瘤中，位于虹膜和睫状体2例，18例位于脉络膜；2例表现为略长T1、等T2信号，9例表现为等T1、等T2信号，3例表现为等T1、略长T2信号，3例表现为等T1、略短T2信号，2例表现为略短T1、略短T2信号，1例表现为略短T1、略长T2信号；8例表现为眼球壁轻度增厚，3例呈新月形，7例呈梭形，2例呈结节状。19例呈中度至明显强化；行动态增强扫描的4例时间-信号强度曲线均呈速升、缓降型。伴有视网膜脱离11例和玻璃体信号异常2例。结论MRI能显示葡萄膜转移瘤的部位、形态、信号及强化特点，有助于葡萄膜转移瘤的诊断与鉴别诊断。     

Carcinosarcoma of the uterus: MR findings

PURPOSE: To clarify the imaging characteristics of carcinosarcomas, which are the most common malignant mixed epithelial and mesenchymal tumors (MEMTs) of the uterus. MATERIALS AND METHODS: We retrospectively reviewed MR findings of 17 histopathologically confirmed cases with carcinosarcomas, including the size, growth pattern, signal intensity, contrast enhancement, and extrauterine spread in each case. RESULTS: The maximum tumor diameter was 11-165 mm (mean 88 mm). Nine cases (53%) showed exophytic with a stalk and eight cases (47%) showed broad-based exophytic growth. None of them showed invasive growth. Fourteen cases (82%) were isointense and three cases (18%) were hyperintense to myometrium on T1-weighted images (T1WI). An extremely high intensity area suggesting intratumoral hemorrhage was seen in only two cases. In 15 cases (88%), more than half of the tumor showed higher signal intensity than the outer myometrium on T2WI. Eight of the 16 cases (50%) had an unenhanced area, whereas 13 cases (81%) had a strongly enhanced area. Extrauterine extension was observed in only two cases (12%) at initial presentation. CONCLUSION: Uterine carcinosarcomas reveal a spectrum of imaging findings with a high signal on T2WI, with a prolonged intense enhancement being the most common imaging feature.     

侵蚀性葡萄胎的MRI诊断

目的 探讨侵蚀性葡萄胎的MRI表现及其诊断价值.资料与方法 回顾性分析8例经临床手术和病理证实的侵蚀性葡萄胎患者的MRI表现.结果 所有8例患者MRI表现为宫腔增大,肌层不均匀增厚,宫腔和肌层内可见长T1、长T2信号的囊性影和等信号结节影,外肌层和盆腔内可见大量的血管流空信号.5例宫腔和肌层内见斑点状、条片状高信号出血灶.6例双侧附件出现实性或囊性肿块.增强扫描表现为宫腔、肌层及附件病灶呈环形和结节状强化.结论 侵蚀性葡萄胎MRI表现具有特征性,有助于诊断.     

Uncommon presentation of a giant biliary cystadenoma: correlation between MRI and pathologic findings.

An uncommon case of a giant mucinous biliary cystadenoma (BCA) of the liver is described. On T2-weighted and STIR images, a large hyperintense cystic mass revealed some septations and multiple intracystic masses of similar size and shape and uniform signal intensity, which was isointense to liver parenchyma. On T1-weighted images, intracystic bodies were obscured and the cyst was hyperintense. The magnetic resonance (MR) appearance of intracystic fluid and structures was not due to mucinous or proteinous or hyperproteinous material, but corresponded to clots floating within hemorrhagic fluid.     

胼胝体非出血性挫伤的MRI诊断(附四例报告)

目的报告4例胼胝体非出血性挫伤的MRI表现。材料与方法回顾性分析4例胼胝体非出血性挫伤的MRI资料;3例为车祸伤,1例为坠落伤,都进行了CT和MR非增强检查。结果4例胼胝体挫伤灶2例位于压部、1例位于干部、1例累及胼胝体大部。CT扫描胼胝体区未见异常密度。MR图像上均表现为等或略低T1WI信号与明显高T2WI信号,未见出血信号。SE或FSET2WI(轴位或矢状位)对病变显示清楚,而FLAIR序列则能抑制脑脊液的高信号、使病变显示更加突出。1例4个月后MR检查显示挫伤灶演变为类似脑脊液信号的软化灶。4例中3例还合并颅内多处脑挫伤和血肿。结论胼胝体非出血性挫伤较少见,CT检查难以发现病灶MR是其最佳的影像学检查手段,轴位与矢状位SE或FSET2WI是显示挫伤灶的主要序列,FLAIR序列对病灶的显示更佳。本病典型的MRI表现是胼胝体区T1WI等或略低信号、T2WI高信号,无出血信号;胼胝体非出血性挫伤可合并颅内多发性外伤性改变。     

MR findings in eosinophilic infiltration of the liver

OBJECTIVE: This study describes the findings of magnetic resonance imaging (MRI) of focal eosinophilic infiltration of the liver. METHODS: Contrast-enhanced MR images of 8 patients with focal hepatic eosinophilic infiltration were reviewed retrospectively. We evaluated the signal intensity of focal lesions in T1-weighted and T2-weighted images and the pattern of enhancement in a dynamic contrast study. RESULTS: A total 22 focal hepatic lesions were observed; the lesions were isointense (55%) or hypointense (45%) on T1-weighted images and isointense (14%) or hyperintense (86%) on T2-weighted images. The arterial phase of the contrast study revealed 11 hyperintense lesions (50%). During the portal and delayed phases, 18 (82%) and 17 lesions (77%) were hyperintense, respectively. CONCLUSION: The focal eosinophilic infiltrations showed homogeneous enhancement in the portal and delayed phases in the dynamic contrast MR study. These findings should help to distinguish focal eosinophilic infiltration, especially from metastasis in patients with malignancy.     

Early hepatocellular carcinoma: MR imaging.

All areas in hepatic lesions designated as adenomatous hyperplasia (AH) with malignant foci have recently been recognized as cancer. AH with malignant foci can be classified into two types, depending on the presence of overt cancerous nodules. Lesions without macroscopic nodules are defined as early hepatocellular carcinoma (HCC), while those with a macroscopic component are defined as HCC with early components. A comparative study of early HCC and HCC with early components was performed with magnetic resonance imaging. Early HCC lesions (n = 20) were isointense (n = 11) and hyperintense (n = 9) on T1-weighted spin-echo images and isointense (n = 17), partially hyperintense (n = 2), or hypointense (n = 1) on T2-weighted spin-echo images relative to the surrounding liver. Lesions classified as HCC with early components (n = 8) were hyperintense (n = 5), isointense (n = 2), and of mixed signal intensity (n = 1) on T2-weighted images. T1-weighted imaging was superior to T2-weighted imaging in depicting early HCC, but the latter could be useful in evaluating the progression of HCC in the histopathologically early stages.     

Magnetic resonance imaging appearance of well-differentiated hepatocellular carcinoma

OBJECTIVE: To investigate the magnetic resonance imaging (MRI) features of well-differentiated hepatocellular carcinoma (HCC). METHODS: We reviewed the MRI of 32 patients with 33 pathologically confirmed well-differentiated HCC. The MRI protocol included T2-weighted imaging with and without fat saturation, dual-phase T1-weighted imaging, and gadolinium-enhanced dynamic study. The signal intensity of each lesion was categorized as hyperintense, isointense, and hypointense with reference to the surrounding liver parenchyma. RESULTS: Thirty-one (93.9%) of 33 well-differentiated HCC were demonstrated on the MRI. The remaining 2 were isointense in all magnetic resonance sequences and, therefore, could not be identified. Most of them were hyperintense (n = 15 [45.4%]) or isointense (n = 16 [48.5%]) on T1-weighted imaging, and hyperintense (n = 12 [36.4%]) or isointense (n = 17 [51.5%]) on T2-weighted imaging. On the dynamic study, 17 lesions (51.5%) were enhanced. CONCLUSIONS: MRI may identify most well-differentiated HCC; however, the imaging appearance is diverse. Biopsy should be performed if magnetic resonance study is inconclusive.     

Rhabdomyolysis: magnetic resonance imaging and computed tomography findings

OBJECTIVE: Our purpose was to describe the magnetic resonance (MR) imaging and computed tomography (CT) findings in patients with rhabdomyolysis. METHODS: The medical records and imaging studies of 10 patients (5 males, 5 females; age range, 14-60 years; mean age, 28.3 years) with rhabdomyolysis were retrospectively reviewed. Magnetic resonance imaging was available in 9 patients and CT in 2 patients. RESULTS: Two distinct imaging types of rhabdomyolysis were observed. For type 1 rhabdomyolysis (n = 2), the affected muscles revealed homogeneously isointense to hyperintense on T1-weighted, homogeneously hyperintense on T2-weighted and short-tau inversion recovery (STIR) images, and homogeneously enhanced on contrast-enhanced MR images. For type 2 rhabdomyolysis (n = 8), the affected muscles revealed homogeneously or heterogeneously isointense to hyperintense on T1-weighted images, heterogeneously hyperintense on T2-weighted and STIR images, heterogeneously hypodense on CT images, and rim enhanced on contrast-enhanced MR and CT images with the presence of a specific presentation, named as the "stipple sign." CONCLUSIONS: Rhabdomyolysis is a clinical and biochemical syndrome comprising 2 distinct imaging types. Homogeneous signal changes and enhancement in the affected muscles advocate type 1 rhabdomyolysis. The stipple sign is helpful in demonstrating the areas of myonecrosis in type 2 rhabdomyolysis and, together with clinical and laboratory presentations, in reaching the correct diagnosis.     

垂体腺瘤MRI与病理对照研究

目的分析垂体腺瘤的MRI表现与手术、病理关系.材料与方法对242例垂体腺瘤的MRI特征性表现进行分析,并与手术病理对照.结果大腺瘤(高度＞10 mm)161例,MRI平扫T1WI等信号101例,略低信号21例,混合信号39例,T2WI等信号112例,高信号11例,混合信号38例,增强后肿瘤实质部分均有强化,出血、囊变、坏死和钙化区无强化,微腺瘤(高度＜10mm)81例,MRI平扫表现为T1WI略低信号53例,等信号28例,T2WI等信号42例,高信号39例,注射Gd-DTPA后立即成像,77例呈相对低信号,4例呈等信号.手术和病理发现,T1WI等或略低信号区为肿瘤实质,T1WI低信号、T2WI高信号区为坏死或囊变区,T1WI、T2WI均呈高信号区为出血,手术和病理发现钙化6例,术前MRI未发现.结论MRI能清晰显示垂体瘤的大小、形态、轮廓和与周围结构的关系,可为制定手术方案提供重要依据.     

MRI诊断非出血性脑弥漫性轴索损伤的临床价值

目的探讨MRI对非出血性脑弥漫性轴索损伤的临床应用价值.材料和方法回顾性分析36例非出血性脑弥漫性轴索损伤的MRI资料.结果全部病例行CT和MRI检查.36例非出血性挫伤灶中,位于胼胝体16例,脑干8例,小脑蚓部2例,放射冠8例,内囊4例,额、颞叶20例.CT扫描仅2例(5.6%)显示出低密度灶.MRIT1WI均呈等或略低信号,T2WI呈高信号.结论MRI是诊断非出血性脑弥漫性轴索损伤最佳的影像学手段,对临床正确诊断本病具有重要的应用价值.     

视神经肿瘤的MRI诊断

目的:探讨视神经肿瘤的MRI表现。方法:回顾了18例经MRI检查并经临床病理确诊的视神经肿瘤的病例。结果:视神经脑膜瘤8例,表现为视神经增粗1例,梭形肿块5例,软组织肿块2例。MR T1WI呈等或稍低信号,T2WI呈高信号。视神经胶质瘤6例,表现为视神经梭形增粗2例,椭圆形肿块4例,MR T1WI呈等信号,T2WI呈高信号。视神经转移瘤4例,3例为视网膜母细胞瘤累及视神经,MRI表现为眼球内病变侵犯视神经和视交叉,T1WI呈稍低信号,T2WI呈稍高信号;1例为乳腺癌转移至视神经,MRI表现为视神经椭圆形增粗,T1WI呈等信号,T2WI呈高低混杂信号。结论:MRI是检查和诊断视神经肿瘤的重要检查手段,对大多数病变可做出明确诊断。     

MR imaging of uterine adenosarcoma: case report and literature review

We report a case of uterine adenosarcoma demonstrated on magnetic resonance (MR) imaging. A 74-year-old woman with a large uterine mass underwent MR examination before total abdominal hysterectomy. Imaging revealed a markedly enlarged uterus with thin myometrium occupied by a large polypoid mass. The mass contained solid components with low intensity on T(1)-weighted images and high intensity on T(2)-weighted images compared to the myometrium and areas of small cysts.     

颅内淋巴瘤的影像学诊断

目的:探讨原发性颅内淋巴瘤的影像学表现,以提高诊断水平。方法:回顾性分析9例经手术病理证实的原发性颅内淋巴瘤的影像学表现。结果:单发病灶8例,1例为两个病灶,肿瘤常位于额叶或中线附近的脑白质,位于幕上8例,幕下1例。CT平扫呈等或稍高密度,边界较清,增强扫描呈均匀强化。MRI平扫T1WI呈稍低或等信号,T2WI呈等或高信号。肿瘤占位效应轻,轻中度水肿。结论:原发性颅内淋巴瘤的影像学表现有一定的特征性,对诊断和鉴别诊断具有重要价值。     

蝶窦内异位垂体腺瘤的CT和MRI诊断

目的 探讨蝶窦内异位垂体腺瘤的CT和MRI表现,并评价2种影像检查方法的临床应用价值.方法 回顾性分析8例经组织学证实蝶窦内异位垂体腺瘤的影像学资料.8例患者均经CT和MR检查.结果 8例垂体瘤均位于蝶窦,与鞍内垂体不相连;3例呈卵圆形,不规则形5例,病灶最大径20～46 mm,边界均较清楚.CT表现:与脑灰质比较,平扫呈等密度7例,稍低密度1例,其中2例增强呈较均匀中度强化;病变周围的骨质不同程度受压、变形、硬化,其中5例并可见局部侵蚀状破坏;鞍底骨质完整3例,骨质破坏5例.MRI表现:与邻近脑厌质比较,在T1WI呈稍低信号2例,等信号6例,T2WI呈稍高信号2例,等信号6例,病变信号不均匀,内散在小泡状、细条状长T1、长T2信号,对应组织学上扩大的腺泡;增强后病变不均匀低中度强化,外观近似筛网状.2例行MR动态增强扫描,时间-信号强度曲线均为速升缓降璎.5例伴有空蝶鞍,5例包绕邻近海绵窦,与邻近颈内动脉分界不清,4例侵及斜坡.结论 T2WI小泡状、细条状高信号和增强后T1WI筛网状外观是该病的特征性表现.CT和MRI联合使用能够对该病的诊断、治疗提供更全面的信息.     

Subcutaneous granuloma annulare: MR imaging features in six children and literature review

PURPOSE: To describe the magnetic resonance (MR) imaging findings of subcutaneous granuloma annulare (SGA), a rare mass of early childhood. MATERIALS AND METHODS: MR imaging studies and clinical records in six children aged 2 1/2-4 years in whom SGA was diagnosed between 1993 and 1997 were retrospectively reviewed. All MR imaging examinations included T1-weighted and fast spin-echo T2-weighted sequences. Three children received intravenous contrast material. The diagnosis was established by using excisional biopsy results, with confirmation by means of characteristic features in mucin-stained specimens. RESULTS: All children presented with a nontender, nonmobile mass. The lesion in all six children was confined to the pretibial (n = 5) or prepatellar (n = 1) soft tissues. MR imaging characteristics were uniform. Masses were subcutaneous in location and had ill-defined margins. On T1-weighted images, the lesion was isointense or slightly hyperintense to muscle. On T2-weighted images, the signal intensity was more heterogeneous, but the lesion was predominantly hyperintense. In three children who received contrast material, the lesion enhanced nearly homogeneously. CONCLUSION: Although SGA can often be diagnosed on the basis of clinical characteristics, MR imaging may be requested by practitioners unfamiliar with the lesion. In these cases, with recognition of typical MR imaging features, a limited biopsy and specific histologic preparation that includes mucin staining can be recommended.     

Epidural fibrosis and recurrent disk herniation in the lumbar spine: MR imaging assessment

Twenty patients were enrolled in a prospective study to evaluate MR imaging in the differentiation of epidural scar and herniated disk material. Fourteen patients had surgical verification of imaging findings. In 12 (86%) of these patients, the MR interpretations fully agreed with the observations at surgery. Careful integration of the findings on sagittal and axial T1-weighted images with more T2-weighted axial images was important for analysis. Anterior and lateral recess scars were hypo- or isointense on T1-weighted sequences and hyperintense on more T2-weighted sequences relative to the "parent" anulus intensity. Free fragments demonstrated a slightly hyperintense signal intensity on T1-weighted images relative to epidural fibrosis but had a similar hyperintense signal intensity on T2-weighted sequences. Prolapsed or extruded disk fragments were hypo- or isointense relative to the parent anulus on all sequences. Morphology, epidural location, mass effect, and often signal intensity were the important parameters by which scar and herniated disk could be differentiated with MR.     

颞下窝原发肿瘤的CT及MR表现

目的：探讨颞下窝原发肿瘤CT及MRI表现。方法回顾性分析20例经病理证实的颞下窝原发肿瘤的CT及MR资料。结果颞下窝肿瘤形态多不规则。神经鞘瘤多边界清楚（5/6）,MR T1WI为等信号,T2WI为高信号肿物伴线状分隔样低信号,2例通过卵圆孔伸入中颅窝呈哑铃状生长。恶性外周神经鞘膜肿瘤边界多不清楚（4/5）,MR T1WI为等信号,T2WI为不均匀高信号,病变可侵犯邻近肌肉及骨质。横纹肌肉瘤MR T1WI为等信号,T2WI为高信号。孤立性纤维性肿瘤边界清楚,MR T1 WI等信号,T2 WI为混杂略高信号,增强后较明显强化。腺样囊性癌边界不清,沿神经浸润生长。侵袭性多形性腺瘤MR T1 WI为等、低信号,T2 WI为高信号,侵犯邻近肌肉。淋巴瘤形态不规则,边界清楚,MR T1WI为低信号,T2WI为中高信号,轻度强化,内有线样血管影穿行。结论熟悉颞下窝原发肿瘤CT及MRI表现,有助于提高该部位病变诊断及鉴别诊断水平。     

肝硬化结节与小肝癌的MRI研究

目的:回顾性分析肝硬化合并小肝癌、再生结节(RN)及肝不典型增生结节(DN)的MR表现,探讨其MR诊断与鉴别诊断。方法:收集50例结节性肝硬化病例MR检查资料,患者行正反相位T1WI、脂肪抑制T2WI、动态增强扫描和弥散加权(DWI)扫描,总结肝内结节的信号特点。结果:RN在T1WI脂肪抑制上多为等信号或稍高信号,T2WI多为低信号,增强后与周围正常肝组织强化相似或信号稍低;DN在T1WI多为较高信号,T2WI多为稍低或等信号,增强后强化不明显;癌结节T1WI多为稍低或等信号,偶有稍高信号,T2WI多为较高信号,DWI为高信号,强化多为动脉中晚期强化,门静脉期以后强化减退。结论:磁共振平扫加动态增强能对大多数RN、DN和小肝癌结节做出明确诊断和鉴别。     

脑膜瘤的MRI表现与组织病理对照研究

目的　研究脑膜瘤的磁共振表现与其病理分类之间的关系。方法　回顾分析 12 8例经手术病理证实为脑膜瘤患者的MRI表现。结果　T1WI图像 ,上皮型脑膜瘤 2 9例 ( 4 9% )呈低信号 ,11例 ( 19% )呈稍低信号 ,17例 ( 2 9% )呈等信号。而纤维型脑膜瘤T1WI信号类型分别为 2 3例 ( 5 9% ) ,5例 ( 13 % )和 9例 ( 2 3 % )。在T2 WI图像上 ,3 4例 ( 5 8% )上皮型脑膜瘤呈高信号 ,15例 ( 2 5 % )呈稍高信号 ,10例 ( 17% )呈等信号 ,而纤维型分别为 2例 ( 5 % ) ,8例 ( 2 0 .5 % )和 11例 ( 2 8% )。上皮型、纤维型、移行型在T1WI上均呈现等、低信号 ,而在T2 WI图像上 ,上皮型、血管瘤型及移行型呈现为高信号或稍高信号 ;纤维型脑膜瘤T1WI以低或稍低信号为主。结论　在MRIT1WI图像上 ,各组织学类型之间信号强度的分布无显著性差别 ,而在T2 WI上 ,信号强度与病理类型具有统计学的相关性