毛细胞星形细胞瘤的CT、MRI诊断分析

目的探讨毛细胞型星形细胞瘤的CT、MRI特征。方法回顾性分析8例经手术病理证实的毛细胞型星形细胞瘤的CT及MRI表现。结果（1）病变好发于小脑,8例毛细胞星形细胞瘤中,起源于幕下者5例。幕上者3例。（2）肿瘤呈类圆形,伴不同程度囊变,根据囊变程度可分为囊肿型、囊肿结节型和肿块型,以囊肿结节型最多见;（3）肿瘤囊性部分CT平扫呈低密度,MR平扫T1WI呈明显低信号,T2W1呈明显高信号;肿瘤实性部分、囊壁及壁结节CT呈等或稍低密度,MRT1W1呈等或稍低信号,T2WI呈稍高信号。增强后肿瘤囊壁不强化或轻度强化,壁结节及实性部分明显强化,囊性部分不强化;（4）肿瘤边界清楚,瘤周无水肿;（5）肿瘤出血与钙化少见。结论毛细胞型星形细胞瘤在CT、MRI表现具有一定特征性,可为临床术前提供信息。     

中枢神经细胞瘤的影像学诊断

目的:探讨中枢神经细胞瘤(central neurocytoma,CNC)的CT和MRI表现特点,提高该病的影像诊断准确率。方法:回顾性分析9例经病理确诊的CNC的CT和MRI资料,研究本病影像学特点。结果:9例肿块均位于侧脑室内,呈类圆形或不规则分叶状,8例位于侧脑室前部透明隔区域,另1例位于侧脑室体部。CT平扫9例肿瘤实体部分2例为等密度,7例呈稍高密度,内部密度不均,3例同一病灶内见点、片状钙化及低密度囊变,1例单纯见钙化,不伴有囊变;2例单纯见低密度囊变,不伴有钙化。注射对比剂后,病灶呈轻、中度不均匀强化;MRI平扫,病灶多呈囊实性,信号不均,实性部分T1WI信号强度同脑实质,T2WI与脑实质相比呈等或稍高信号,增强扫描肿瘤实性部分明显强化,囊性部分呈"丝瓜瓤样"或"蜂窝状"改变。结论:CNC的CT和MRI表现有一定的特征,综合分析其临床和影像表现,能够提高诊断正确率。     

室管膜母细胞瘤的CT和MRI表现

目的 探讨室管膜母细胞瘤的CT和MRI表现特点及其鉴别诊断.方法 回顾性分析5例经手术病理证实的室管膜母细胞瘤患者的临床及影像学资料,5例均接受MRI平扫及增强扫描,其中2例同时接受CT平扫.结果 5例室管膜母细胞瘤中4例为单发病灶,其中1例发生于右侧额叶,3例发生于脑室内(右侧侧脑室、左侧侧脑室及四脑室各1例).1例为多发病灶,主体位于双侧额叶侵犯胼胝体膝部并脑室及鞍上池多发播散转移.肿瘤体积2.6 cm ×2.4 cm×3.4 cm～5.7 cm×5.6 cm×5.4 cm.CT平扫1例发生于左侧侧脑室内病灶表现为大片状钙化,边界清晰,瘤周无水肿,另1例发生于双侧额叶病灶表现为不均匀稍高密度,边界不清,可见大片水肿.MRI平扫T1WI多表现为等稍低信号,T2 WI呈不均匀高信号,增强扫描呈均匀或不均匀强化,3例见肿瘤内囊变.结论 CT和MR检查能准确显示室管膜母细胞瘤部位、范围及周围受累情况,但是影像学表现无特异性,定性诊断有赖于病理检查.     

脑室外神经细胞瘤的MRI诊断

目的探讨脑室外神经细胞瘤(extraventricular neurocytoma,EVN)MRI特征,提高对该肿瘤的认识。资料与方法回顾性分析6例EVN的MRI表现,并结合文献研究其MRI特征。结果6例均经手术及病理证实。肿瘤位于额叶3例,其余3例分别位于顶叶、颞叶及鞍区;肿瘤呈类圆形者边界清楚,形态不规则者境界不清;肿瘤实性或囊实性,实性多见,T1WI呈等或稍低信号,T2WI呈稍高信号,其间夹杂等、低或高信号,可提示钙化、流空血管、出血或囊变坏死,液态衰减反转恢复序列(FLAIR)呈高信号为主的混杂信号;囊实性者,实性部分信号同实性肿瘤,囊性部分呈长T1、长T2信号,信号较均匀;瘤周水肿无或轻;增强后呈轻-中度不均匀强化;占位效应轻。结论EVN的MRI表现具有一定特征性,MRI平扫及增强扫描有助于其诊断。     

中枢神经细胞瘤的MR影像特征分析

目的:探讨中枢神经细胞瘤的MRI征象。方法:回顾性分析9例经手术和病理证实的中枢神经细胞瘤的MRI征象。结果:9例肿瘤中6例位于侧脑室前部Monro孔附近,1例位于右侧侧脑室体后部,1例位于三脑室,1例位于右侧额叶。9例病变均为囊实性,T1WI病变实性部分呈等或略低信号,囊性部分呈低信号;T2WI实性部分呈等或高信号,囊性部分呈高信号。囊性部分表现为肿瘤边缘或内部多发的蜂窝状改变,5例实性部分DWI呈高信号;增强扫描病变实性部分呈明显或中度强化。结论:结合MR影像学及病理表现,有助于明确中枢神经细胞瘤的诊断。     

儿童纵隔神经母细胞瘤的CT与MRI诊断

目的 探讨儿童纵隔神经母细胞瘤的CT与MRI表现及其诊断价值.方法 回顾性分析21例经病理证实的儿童纵隔神经母细胞瘤的CT和MRI表现.19例行CT检查,8例行MRI检查.结果 20例肿瘤位于后纵隔,呈椭圆形或不规则形软组织肿块,突向肺野,边界较清楚.CT平扫示肿瘤密度较均匀12例,密度不均匀7例,15例肿瘤内伴有钙化.13例行增强检查,7例均匀强化,6例不均匀强化.8例MRI检查T1WI示肿瘤呈等或稍低信号,与胸壁肌肉相近,T2 WI呈不均匀稍高信号,3例肿瘤内伴出血、囊变呈混杂信号.结论 儿童患者,CT或MRI检查发现后纵隔肿物,特别是其内伴钙化者,诊断时应首先考虑神经母细胞瘤.     

小脑血管母细胞瘤的MRI表现及其病理探讨

目的 分析小脑血管母细胞瘤的MRI表现与病理特点,探讨二者之间的关系.方法 回顾性分析经手术病理证实的32例小脑血管母细胞瘤,探讨其MRI表现和病理特点.结果 MRI表现大囊小结节型21例,实质型9例,囊性型2例.T1 WI上肿瘤囊性部分呈均一低信号,实性部分或瘤结节呈稍低或等信号;T2WI及FLAIR上肿瘤囊性部分呈均一高信号,实性部分或瘤结节呈稍高信号;增强后实性部分或瘤结节明显强化.病理表现实性部分或瘤结节主要由基质细胞构成,囊性部分主要由毛细血管网构成.结论 小脑血管母细胞瘤具有典型的MRI表现,且与其病理基础密切相关.MRI是诊断小脑血管母细胞瘤的有效检查方法.     

儿童眼眶横纹肌肉瘤临床及影像：5例分析

目的探讨儿童眼眶横纹肌肉瘤(RMS)的临床及CT、MRI影像特征。方法收集5例经手术病理证实的儿童眼眶RMS的临床、病理及CT、MRI影像资料,并结合文献进行分析。结果5例儿童眼眶RMS均位于眼眶内,左侧3例,右侧2例。5例中3例为实性病灶,与眼直肌相比,CT平扫呈稍高密度,增强后明显均匀强化;MRI平扫T_1WI呈稍低信号、T_2WI呈稍高信号,DWI呈高信号,增强后明显均匀强化,动态增强MRI时间-信号强度曲线呈"流入"型。另2例为囊实性病灶,以实性成分为主,中心小片状囊变,实性部分密度/信号及强化方式与实性病灶一致,中心囊性部分CT平扫呈低密度,MRI平扫T_1WI呈低信号、T_2WI呈高信号,DWI呈等信号,增强扫描无强化。病理诊断为胚胎性RMS。结论儿童眼眶RMS的临床及影像表现具有一定特征性,但临床上少见、术前诊断困难,充分认识其影像特征并结合临床表现有助于临床诊断和术前评估。     

小脑髓母细胞瘤的MRI表现

目的：探讨小脑半球髓母细胞瘤的MRI表现,提高对髓母细胞瘤的认识。方法：8例经手术病理证实的小脑半球髓母细胞瘤患者,男5例,女3例,年龄1～33岁,所有病例均行MRI平扫及增强扫描,其中2例行CT平扫,回顾性分析其临床及影像学表现。结果：肿瘤位于小脑半球深部4例,小脑半球表面且突向桥小脑角区2例,双侧小脑半球及小脑蚓部多发病灶2例。肿瘤内发生囊变5例,囊变区大小不一,3例位于肿瘤周边,2例位于中央,其内壁光滑。MRI平扫肿瘤实性部分T1W1呈稍低信号,T2WI呈等信号或稍高信号,且信号不均匀,5例肿瘤周围有轻度水肿。增强扫描3例肿瘤有轻度强化,5例中度强化,其中1例有脑回状强化。2例CT平扫示肿瘤呈稍高密度。结论小脑半球髓母细胞瘤的MRI表现具有一定特征性,MRI检查对诊断本病有重要价值。     

后纵隔神经节细胞瘤和神经节神经母细胞瘤的CT和MRI诊断

目的分析后纵隔神经节细胞瘤和神经节神经母细胞瘤的CT和MRI表现及其诊断.材料和方法分析经手术、病理证实的神经节细胞瘤7例,神经节神经母细胞瘤2例的CT和MRI表现.结果肿瘤常呈半圆形或椭圆形,纵径比横径或前后径长,边缘锐利,1例神经节细胞瘤呈哑铃形.CT示肿瘤实性部分呈等或稍低于胸壁肌密度,囊变部分的密度比脑脊液稍高.T1WI示肿瘤等或稍低于胸壁肌信号,囊变部分稍高于脑脊液的低信号;T2WI呈高信号.结论肿瘤纵径长于其它径是重要征象,CT和MRI能显示肿瘤形态特征,提示诊断.     

脑原发淋巴瘤的MRI分析

目的：分析脑原发淋巴瘤的MRI影像学表现特征,以加强对该肿瘤影像学表现的认识。方法：对经病理证实的11例脑原发淋巴瘤的临床和MRI资料进行回顾性研究,分析肿瘤的部位分布、形态和肿瘤的信号特征。结果：11例肿瘤中,顶叶4例,额叶3例．胼胝体及透明隔区3例,眼球及海绵窦区1例。全部肿瘤呈实质性肿块,7例T1WI呈稍低信号．T1WI呈稍高信号;4例T1WI和T2WI呈等信号;增强后11例肿瘤均呈明显均匀性强化。结论：脑原发淋巴瘤多起源于脑实质和胼胝体区．肿瘤通常没有囊变和坏死,增强后呈明显强化是其特征。     

卵巢甲状腺肿的CT和MRI表现与病理对照分析

目的：探讨卵巢甲状腺肿(SO)的 CT、MR 影像学表现特点。方法回顾性分析经手术病理证实的10例 SO 患者的影像学及组织学资料,其中6例行 CT 平扫及增强扫描,4例行 MR 平扫及增强扫描。结果10例 SO 均为单发,呈分叶状或椭圆形,边缘清楚,直径<10 cm,4例伴有腹腔积液。6例囊实性,4例囊性,囊性部分密度及信号多变,CT 表现为低密度或高密度,4例出现高密度囊腔。MRI 表现为以 T1 WI 低信号、T2 WI 高信号或 T2 WI 低信号为主,1例表现为 T1 WI 低信号、T2 WI 极低信号的“真空征”,增强后实性部分及囊壁明显强化。结论SO 的 CT、MR 表现反映了其病理学特征,对其诊断及鉴别诊断有重要价值。     

MRI of brain abscesses

Four cases of brain abscess were examined on 1.5T MR and their findings were evaluated retrospectively. Preoperative cases had relatively characteristic findings, such as 1) peripheral edema producing hypointensity on T1-weighted images (T1WI) and hyperintensity on T2-weighted images (T2WI); 2) central necrosis with abscess fluid hypointense relative to white matter on T1WI and hyperintense on T2WI; 3) abscess rim iso- to hypointense on T2WI. Gd-DTPA enhanced T1WI carried further information; comparison of iso- to hypointense rim on T2WI (abscess rim) and enhanced area by Gd-DTPA on T1WI suggested that the former represented zone of macrophage infiltration.     

Metastatic liver tumor from cystic ovarian carcinomas: CT and MRI appearance.

OBJECTIVE: The initial and follow-up CT and MRI images of ten patients with hepatic metastases from ovarian tumors were retrospectively analyzed to establish their features and sequential changes in appearance. MATERIALS AND METHODS: Ten patients with hepatic metastasis from ovarian tumors received initial and follow-up CT and MRI examinations. Six patients were followed up every two to three weeks before surgical tumor resection. Both CT and MR images were analyzed by two radiologists. RESULTS: A total of fourteen lesions were detected by CT and MRI in 10 patients. All 14 lesions were demonstrated as areas of marked hyperintensity on T2-weighted MRI. Eleven cyst-like tumors were demonstrated as round or oval low density lesions on CT and as areas of hypointensity on T1-weighted imaging. Three lesions were shown as solid masses with slightly low attenuation at the initial CT examination and slightly low or iso-intensity areas on T1-weighted imaging, and these lesions showed early peripheral globular enhancement and delayed enhancement on contrast-enhanced CT and MR imaging. Cystic formation was observed two to three weeks later after initial study in all the 3 solid lesions. Rapid subcapsular effusion, which showed obvious enhancement on delayed Gd-DTPA enhanced MR imaging, was observed in two patients. CONCLUSION: The hepatic metastatic tumor from cystic ovarian carcinoma may manifest as a well-defined cystic lesion or as a solid mass, and the solid mass shows delayed enhancement on contrast-enhanced CT and MR imaging. Furthermore, rapid cystic formation and rapid subcapsular extension is frequently seen.     

颅内神经元肿瘤的影像诊断

目的 探讨颅内神经元肿瘤的影像学表现,评价CT和MRI对该类肿瘤的诊断价值。方法 经手术不病理证实的神经元肿瘤10例,回顾分析其CT及MRI表现,结果 节细胞胶质瘤3例;中枢神经细胞瘤3例;胚胎发育不良性神经上上皮肿瘤（DNT）3例（7个病灶）,肿瘤外形呈脑回状或结节脑回状,2个局灶性者呈中度强化,其余无明显强化。多纤维组织性婴儿节细胞胶质瘤（DIG）1例,病灶囊变明显,可见钙化,肿瘤实体明显均匀强化,结论 部分神经元肿瘤CT及MRI表现具有一定的特征性,但仅造影像学表现作出诊断是困难的,须结合临床资料,可进一步提高该类肿瘤的诊断正确率。     

软骨肉瘤的影像诊断与鉴别诊断

目的:探讨软骨肉瘤的影像学表现,提高对本病诊断的准确性。方法:回顾性分析25例经手术病理证实的软骨肉瘤的X线、CT和MRI资料。结果:25例软骨肉瘤中原发23例,其中普通型20例,去分化型、黏液型及透明细胞型各1例;继发2例。X线及CT表现:原发的23例中溶骨性骨破坏5例,混合性骨破坏18例,形成软组织肿块20例,其中表现为低密度19例,等密度1例。20例普通型及1例黏液型见散在钙化。MRI表现:普通型软骨肉瘤T1WI呈等或稍低信号,T2WI呈等或稍高信号;黏液型T1WI呈等、低混杂信号,T2WI呈稍高、低的混杂信号,钙化T2WI呈低信号;透明细胞型病例T1WI及T2WI呈近乎等信号;去分化型T1WI呈等低混杂信号,T2WI呈不均匀高信号。6例普通型及1例继发型出现环形、间隔样中等-明显强化,黏液型及去分化型呈不均匀中等-明显强化。结论:普通X线及CT是软骨肉瘤影像诊断及鉴别诊断的主要手段,MRI显示软骨信号为重要提示。MRI显示病变范围更为清楚、准确,为临床治疗提供可靠依据。     

Microwave coagulation therapy on hepatomas: CT and MR appearance after therapy

Laparoscopic microwave coagulation (LMC) for hepatocellular carcinomas (HCCs) was performed on 26 HCCs in 17 patients. Contrast-enhanced CT (CECT) and MR images (T1-weighted imaging [T1WI], T2WI, gadolinium-diethylenetriamine pentaacetic acid [Gd-DTPA] T1WI) were obtained to determine changes over time. The irradiated center exhibited low to moderate intensity with surrounded high intensity (HI) on T2WI and Gd-DTPA T1WI. On T1WI, lesions showed four patterns of intensity: uniform HI (30.8%), arcuate HI (26.9%), mainly low with spot HI (30.8%), and isointensity to hypointensity (11.5%). Follow-up imaging at more than 170 days revealed isointensity to hypointensity on T1WI (96.2%) and reduced HI on T2-weighted imaging (T2WI) and Gd-DTPA T1WI. All lesions became less conspicuous and were reduced in volume. HCC shows time-related changes in signals and size after LMC. Identifying the irradiated lesion is necessary to estimate the adequacy of treatment by comparison with the pretherapeutic image.     

腮腺基底细胞腺瘤的CT和MRI特点

目的 探讨腮腺基底细胞腺瘤的CT和MRI表现特点.方法 回顾性分析经手术病理证实的9例腮腺基底细胞腺瘤的CT和MRI的影像特点(6例CT检查,3例MR检查).9例中男4例,女5例,中位年龄58岁(40～79岁).对肿瘤的部位、大小、形态、边缘、CT密度或MRI信号及强化形式进行分析.结果 9例患者均为单发肿瘤,8例位于腮腺浅叶,1例位于腮腺深叶.9个肿瘤中7个为类圆形,无分叶;2个为长椭圆形,有浅分叶.9个肿瘤边缘均光滑清楚;MR检查3例,2个肿瘤周边见T2wI低信号的包膜,1个肿瘤周边见一较薄的T2WI高信号环.3个肿瘤MRI均表现为长T1、短T2信号,增强后呈不均匀轻、中度强化,内见裂隙样、小片状低信号,并出现延迟强化,1例见壁结节;CT检查6例,平扫肿瘤均表现为低密度,其中4个肿瘤CT强化共同特点均为薄壁环形强化,且有大小不等的壁结节,肇结节呈中～重度强化(平均CT值增加为65.5 HU),另外2个呈均匀中度强化.结论 老年女性患者腮腺浅叶内单发边界清楚病灶,CT增强表现为薄壁环形强化且有壁结节,MRI表现为长T1、短T2信号,强化内见裂隙样、小片状低信号且出现延迟强化,要考虑基底细胞腺瘤的可能.     

幕上原始神经外胚层肿瘤的CT、MRI和病理分析

目的探讨幕上原始神经外胚层肿瘤（PNET）的CT及MRI特点,以提高影像学诊断的准确性。资料与方法分析经手术病理证实的8例PNET的CT及MRI表现。结果8例PNET分别位于幕上大脑半球的额顶、额颞、枕叶、胼胝体区,病灶普遍较大,多为偏实性肿瘤,边界清晰,瘤周水肿较轻,其中病灶内囊变4例,合并出血3例,肿瘤T1WI呈稍低信号,T2WI呈稍高信号4例,T1WI、T2WI呈混杂信号3例,2例DWI显示呈高信号。增强检查肿瘤可表现为不均一强化、不规则“印戒”样强化,2例显示沿室管膜播散。结论PNET影像学表现有一定特征,影像学表现结合临床症状有助于与其他肿瘤区分。     

CT and MR imaging of benign primary cardiac neoplasms with echocardiographic correlation.

Benign primary cardiac neoplasms are rare but may cause significant morbidity and mortality. However, they are usually treatable and can often be diagnosed with echocardiography, computed tomography (CT), or magnetic resonance (MR) imaging. Myxomas typically arise from the interatrial septum from a narrow base of attachment. Fibroelastomas are easily detected at echocardiography as small, mobile masses attached to valves by a short pedicle. Cardiac fibromas manifest as a large, noncontractile, solid mass in a ventricular wall at echocardiography and as a homogeneous mass with soft-tissue attenuation at CT. They are usually homogeneous and hypointense on T2-weighted MR images and isointense relative to muscle on T1-weighted images. Paragangliomas usually appear as large, echogenic left atrial masses at echocardiography and as circumscribed, heterogeneous masses with low attenuation at CT. These tumors are usually markedly hyperintense on T2-weighted MR images and iso- or hypointense relative to myocardium on T1-weighted images. Cardiac lipomas manifest at CT as homogeneous, low-attenuation masses in a cardiac chamber or in the pericardial space and demonstrate homogeneous increased signal intensity that decreases with fat-saturated sequences at T1-weighted MR imaging. Cardiac lymphangiomas manifest as cystic masses at echocardiography and typically demonstrate increased signal intensity at T1- and T2-weighted MR imaging. Familiarity with these imaging features and with the relative effectiveness of these modalities is essential for prompt diagnosis and effective treatment.