肝脏囊性转移瘤的CT和MR征象的比较

目的:分析肝脏囊性转移瘤在CT和MR上的表现,比较CT和MR检查对囊性转移瘤的临床诊断价值.材料和方法:18例(共52个病灶)肝脏囊性转移瘤中10例行CT平扫和增强门脉期扫描.8例行MR T1WI和FMP-SPGR多期动态增强扫描.观察肿瘤的大小、形态、数目、囊壁和壁结节的强化情况.结果:2例为单发病灶外,其余均为多发病灶.病灶呈类圆形或椭圆形.CT上8例见到囊壁不规则增厚,其中6例可见向囊腔内突起的壁结节,1例内有分隔.2例薄壁且均匀的病灶误诊为肝囊肿.T1WI上,7例为低信号,1例为混杂信号.T2WI上,病灶均为明显高信号,2例信号均匀,6例信号不均匀,可见到壁结节为略低信号.增强动脉期所有病灶均无强化表现,门脉期和延迟期,可见到边缘环形强化和壁结节的强化.也有1例见到分隔.结论:CT和MR均可显示肝脏囊性转移瘤的特征,MR在显示病灶的出血、囊变、分隔和囊壁的情况等比CT更为敏感、可靠,在鉴别诊断方面价值更大.     

胚胎发育不良性神经上皮瘤的CT和MRI表现

目的:探讨胚胎发育不良性神经上皮瘤(DNET)的CT和MRI表现。方法:回顾性分析6例经手术病理证实的DNET的MRI和CT资料。6例均行常规MRI检查,其中4例行液体衰减翻转恢复(FLAIR)序列和扩散加权成像(DWI),3例行MR波谱检查。6例中5例行CT平扫。结果:6例中5例为单发,1例为弥漫性。病灶均位于或主要位于皮层区,单发者呈倒三角型表现。肿瘤以囊性成分为主,于CT平扫上均为低密度影,1例可见钙化;其MRI表现为T1WI低信号,T2WI高信号,FLAIR序列上病灶边缘和分隔呈高信号改变,增强扫描示病灶实质结节或分隔有轻度强化,病灶周围均未见水肿。结论:瘤周无水肿、倒三角征和瘤内分隔为PNET的特异性影像学表现,其影像学表现有助于临床诊断和治疗。     

11例囊性脑转移瘤的低场MRI分析

目的:探讨囊性脑转移瘤的低场MRI表现特点。方法:回顾性分析11例(共20个病灶)经临床或病理证实的囊性脑转移瘤的低场MRI表现。结果:11例中,单发4例,多发7例。共检出20个囊性转移病灶,位于幕上皮髓质交界区15个,幕下小脑病灶5个。病灶呈圆形或类圆形。病灶周围伴轻度水肿9个(45%);中度水肿4个(20%);重度水肿2个(10%);无水肿5个(25%)。根据囊壁形态,分为:规整型、结节型、不规整型。囊壁MRI T1WI和T2WI呈等或稍低信号,囊内容物呈稍高于脑脊液长T1长T2信号,增强扫描病灶呈环状强化,部分病灶可见强化壁结节。结论:囊性脑转移瘤低场MRI表现具有一定特征性。低场MRI在囊性脑转移瘤诊断方面作用等同于高场MRI,具有重要临床价值。     

成人单发肝脏胆管性错构瘤的影像学表现(附3例报告)

目的 探讨成人单发肝脏胆管性错构瘤的影像学表现,以提高对本病的认识.方法 回顾性分析3例经手术、病理证实的单发肝脏胆管性错构瘤的影像学表现.男1例,女2例,年龄分别为28、43、76岁.3例均行B超和CT检查,1例还做MRI检查.结果 病灶长径为2～4 cm.本组肝脏胆管错构瘤的B超表现为:稍低或稍强回声,内部回声不均匀;CT表现为:平扫呈较均匀或不均匀的较低密度,增强扫描呈较均匀或不均匀轻中度强化,有延迟强化;1例MRI表现为:T1WI呈较低信号,T2WI呈较高信号,增强扫描呈环状强化.结论 成人单发肝脏胆管性错构瘤在影像学上无特征性表现,可类似于肝转移瘤、肝脓肿、肝海绵状血管瘤等常见的肝占位病变.     

颅内孤立性纤维瘤的CT和MRI表现

目的分析颅内孤立性纤维瘤的CT和MRI表现,提高对其认识。资料与方法回顾性分析5例经手术病理证实的颅内孤立性纤维瘤的CT和MRI表现。1例行CT增强扫描,3例行MRI平扫和增强扫描,1例同时行CT和MRI扫描。结果 5例颅内孤立性纤维瘤均为单发,肿块形态不规则,边界清楚,直径1.2～6.5 cm。发生于颞叶1例,鞍内1例,桥小脑角区1例,中后颅窝三叉神经走行区1例,顶叶1例。CT平扫病灶均为高密度,增强扫描均匀强化。MR T1WI上3例病灶为等信号;1例为多发分隔囊状低信号。T2WI上3例病灶表现为等、低混杂信号,病灶内见少量斑片状高信号;1例为多发分隔囊状高信号。MRI增强所有病灶实质部分显著强化,T2WI低信号区明显强化,坏死囊变区未见强化。结论颅内孤立性纤维瘤MRI表现有一定的特点,MR T2WI上低信号、增强扫描呈显著强化较具特征。     

小脑单发转移瘤的MR诊断价值

目的探讨小脑单发转移瘤的MRI表现,提高对小脑单发脑转移瘤的MRI诊断和鉴别诊断的准确性。方法回顾性分析经手术和病理证实的20例小脑单发脑转移瘤的MRI平扫及增强表现,分析小脑单发转移瘤的部位、大小、形态、瘤周水肿程度及瘤体的强化特征。结果本组20例单发小脑转移瘤,发生于右侧小脑半球11例(55%),左侧小脑半球9例(45%)。肿瘤最大径线2cm 5例,2~3cm 8例,3cm 7例,瘤周水肿以轻中度水肿为主16例(80%)。实性病灶13例(65%),囊性病灶4例(20%),囊实性病灶3例(15%),实性病灶中有5例可见边界征,增强扫描实性病灶强化呈结节状、花环状,囊性病灶囊壁呈均匀或不均匀强化、部份可见壁结节,3例直肠癌转移灶T2WI均呈低信号。结论小脑单发转移瘤的MRI表现多样但具有一定的特征性,结合临床病史,注意观察肿瘤的部位、形态、信号、周围水肿及增强等对其诊断和鉴别诊断具有重要价值。     

囊性脑转移瘤的CT和MRI表现

目的：探讨CT和MRI诊断囊性脑转移瘤的价值。材料和方法：回顾性分析17例（共28个病灶）经手术病理证实或临床综合诊断确诊为囊性脑转移瘤的CT和MRI表现。结果：多发2例，单发15例。病灶呈圆形或椭圆形。位于大脑半球14例，其中位于脑皮质及皮质下区13例。单囊型10例，大囊小结节型4例。位于小脑呈大囊小结节型3例。CT平扫表现为囊性低密度，边缘有环状略高密度包膜15例和包膜毛糙2例。囊内液体呈长T1低信号，长他高信号。增强扫描病灶明显增强呈环状增强15例，结节状增强4例。病灶周围无明确水肿2例、中度水肿10例和重度水肿5例。结论：囊性脑转移瘤多位于脑皮质及皮质下区，CT、MRI具有一定的特征性表现，结合临床有助于正确诊断。     

肝脏上皮样血管内皮瘤的CT和MRI表现

目的 总结肝脏上皮样血管内皮瘤(HEHE)的CT和MRI表现.方法 搜集经手术或穿刺活检后病理证实的HEHE 11例,所有的病例均行CT检查,其中5例行CT平扫及双期增强扫描(动脉期+门静脉期),其他6例行CT平扫及三期增强扫描(动脉期+门静脉期+延迟期).11例中有5例加做MRI平扫及动态增强扫描.回顾性分析病变的生长方式、分布特点、密度(信号)特点、强化方式及邻近组织情况.结果 11例均表现为肝内多发病灶,大部分病灶位于肝包膜下,根据生长方式分为三型:结节型(5例),匍匐生长型(1例)和混合型(5例).CT平扫,病灶均呈低密度,直径＞2 cm的病灶内见类圆形更低密度.MRI平扫:病灶呈T1WI低信号、T2WI高信号,直径＞2 cm的病灶信号不均匀(T1WI内见更低信号,T2WI内见更高信号).其他影像学征象包括“棒棒糖征”(6例)、包膜退缩征(6例).增强扫描:病灶直径＜1 cm的表现为轻度较均匀强化;病灶直径为1～2 cm主要表现为轻度较均匀强化;病灶直径＞2 cm的多为不均匀渐进性强化.结论 HEHE的CT和MRI表现具有一定的特征性,其强化方式与病灶的大小相关.     

肝血管周上皮细胞瘤的多种影像表现

目的探讨肝血管周上皮细胞瘤(PEComa)的多种影像表现,以提高对该病的诊断水平。方法回顾分析经手术病理证实的11例肝血管周上皮细胞瘤的多种影像表现。结果11例患者均为肝脏单发病灶,10例病灶位于肝右叶,1例位于肝左叶,病灶为圆形或类圆形,最大者直径约13.5cm,最小者直径约1.8cm,平均5.7cm。CT平扫示肝内圆形或类圆形稍低密度影,增强扫描动脉期病灶周边明显强化,门脉期病灶呈向心性不均匀强化,较大病灶内可见分隔,延迟期病灶强化明显减退呈等或稍低密度影。MRI平扫示病灶T1WI呈中等信号或稍低信号,较大病灶信号不均匀,病灶T2WI呈稍高信号,DWI病灶呈高信号,增强特征与CT类似。PET/CT检查所见,直径大于3.0cm病灶均可见放射性摄取异常浓聚或不均匀浓聚,SUV值最大为12.2,最小为3.6,平均值为5.7;直径小于3.0cm病灶表现为放射性摄取轻度浓聚,SUV值最高为4.7,平均为2.9;仅1例直径约1.8cm的病灶表现为无明显放射性浓聚,与正常肝组织放射性摄取相同;延迟1h PET/CT显像示,所有病灶的SUV值均不同程度降低。结论肝血管周上皮细胞瘤PET/CT显像检查具有特征性,与常规影像检查相结合,可以明显提高诊断水平。     

肝脏孤立性坏死结节的CT、MRI表现与病理对照研究

目的:探讨肝脏孤立性坏死结节(SNN)的CT、MRI表现及其分型诊断价值和病理基础.方法:分析经临床和病理证实的肝孤立性坏死结节29例(所有病例均行MR检查,其中15例行CT检查),探讨SNN的CT、MRI表现及其分型诊断价值和病理基础.结果:①单纯凝固性坏死型(14例),T1WI、T2WI上均呈低或低-等信号,增强扫描病灶内凝固性坏死无强化,周围包膜呈延迟强化.其中8例行CT检查,CT平扫呈低或等密度,增强扫描无强化,5例可见包膜呈延迟期环形强化.②伴液化性坏死型(5例),T1WI上呈低信号,较大病灶内可见更低信号;T2WI上病灶呈低-等信号,其内液化性坏死呈点片状更高信号;增强后病灶无强化,周围包膜呈轻-中度强化.CT检查3例,CT平扫呈低或等密度,增强扫描无强化,2例周围包膜呈延迟期环形强化.CT不能反映病灶内液化性坏死.③多结节融合型(10例),T1WI呈低信号,其内可见低-等信号分隔;T2WI病灶以等-稍高信号为主,其内可见等或略高信号分隔,其中6例合并液化性坏死还可见裂隙状高信号.增强扫描病灶无强化,其内分隔及周围包膜呈轻-中度强化.CT检查4例,其中3例为低或等密度融合结节,增强扫描内部分隔及周围包膜呈延迟期强化.CT不能显示内部液化性坏死和病灶全部分隔.结论:CT、MRI能较好反映肝脏孤立性坏死结节的分型及各型的病理特征,MRI在多结节融合型和伴液化坏死型的诊断价值明显优于CT.     

囊性脑转移瘤的CT和MRI诊断

目的探讨囊性脑转移瘤的CT、MR I表现特点。方法经临床或病理证实的囊性脑转移瘤26例,男13例,女13例,平均年龄52.7岁。15例行CT平扫,13例行MR平扫,11例行增强CT和/或增强MR I扫描。结果26例共48个囊性脑转移灶,囊壁CT平扫呈等或稍高密度,MR T1W I和T2W I呈等或稍低信号,根据囊壁的形态将其分为3种类型:不均型、结节型、均匀型。MR T1W I囊液信号强度略高于、T2W I高于脑脊液信号强度,而CT密度与之相似或略高。增强扫描肿瘤呈环形强化,部分病灶可见强化壁结节。结论囊性脑转移瘤形态多样,需与脑脓肿及其他肿瘤性囊性病变相鉴别,MR I多方位增强扫描对诊断很有帮助。     

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。     

Evaluation of cystic renal masses: comparison of CT and MR imaging by using the Bosniak classification system

PURPOSE: To compare computed tomography (CT) and magnetic resonance (MR) imaging in the evaluation of cystic renal masses by using the Bosniak classification system. MATERIALS AND METHODS: Images of 69 renal masses in 59 patients (38 men, 21 women; mean age, 60.4 years; range, 30-86 years), who had undergone both CT and MR imaging examinations within 1 year (average, 60.5 days; range, 0-356 days), were retrospectively analyzed by two radiologists in consensus. For each lesion, images were compared for thickness of wall and septa, number of septa, and presence of enhancement. Each mass was categorized (Bosniak classification) first on CT images and then on MR images, and results were compared. Pathologic correlation was available in 25 lesions. RESULTS: On CT images, there were 15 category I, 16 category II, 10 category IIF, 19 category III, and nine category IV lesions. Findings on CT and MR images were similar in 56 (81%) lesions; in 13 (19%) lesions, there were differences. In eight (12%) lesions, MR imaging depicted more septa than did CT, which resulted in an upgrade of the classification at MR imaging in two cases. In seven (10%) lesions, MR imaging depicted increased wall and/or septa thickness compared with CT, resulting in a classification upgrade in six cases. Three lesions had both increased numbers of septa and thickening of the wall and/or septa. In two (3%) lesions, enhancement characteristics at CT and MR imaging were different. One of these lesions also had an increased number of septa. Overall, MR imaging results led to a cyst classification upgrade of seven lesions, from category II to IIF (n = 2), IIF to III (n = 3), or III to IV (n = 2). Pathologic correlation in 25 lesions revealed 20 malignant and five benign lesions. CONCLUSION: CT and MR imaging findings were similar in the majority of cystic renal masses. In some cases, however, MR images may depict additional septa, thickening of the wall and/or septa, or enhancement, which may lead to an upgraded Bosniak cyst classification and can affect case management.     

儿童脑神经母细胞瘤的CT、MRI和病理分析

目的 :探讨儿童脑神经母细胞瘤的CT、MRI表现及和病理的关系。方法 :对 9例经组织病理学证实的脑神经母细胞瘤进行回顾性分析 ,研究肿瘤的CT及MRI影像学特征。结果 :9例神经母细胞瘤中 ,4例肿瘤位于右侧额叶 ,1例位于左侧额叶 ,3例位于右侧颞叶并累及同侧额叶 ,1例位于左侧顶叶。 9例肿瘤均呈囊实性肿块 ,边界清楚 ,5例有钙化。肿瘤实质性部分CT平扫呈略高密度 ,MRT1WI呈等或稍低信号 ,T2 WI呈等或稍高信号 ,增强后肿瘤实性部分和囊性部分的壁明显强化。结论 :神经母细胞瘤是儿童期少见的恶性肿瘤 ,常发生钙化、囊变、坏死。肿瘤实性部分CT平扫密度通常高于脑灰质 ,MRT1WI呈等或稍低信号 ,T2 WI呈等或稍高信号。     

颅底及面部骨纤维病变的影像学分析

目的 探讨颅底及面部骨纤维病变的CT和MRI诊断及鉴别诊断价值,提出术后影像学随访的重要性. 资料与方法回顾性分析经临床病理和组织学活检证实的颅底及面部20例骨化性纤维瘤和23例骨纤维发育不良患者的CT和MR影像学资料,并对两类病变共计27例进行术后影像随访.结果 20例骨化性纤维瘤中,18例为单骨发病,2例为多骨病变.CT表现为椭圆形或分叶状稍高密度肿块,边界清晰,瘤周有一层较完整或不完整的骨性包壳.内部呈不均匀密度13例,均匀磨玻璃样密度7例,其中11例有明显囊变坏死区;11例MR T_1WI以等、低信号为主,T_2WI以等、高信号为主,11例增强后间隔和实性部分强化.23例骨纤维发育不良中,多骨型20例,单骨型3例,无明确边界,密度均匀或不均匀,骨皮质变薄、模糊,骨质周围无软组织肿块和骨膜反应.5例MRT_1WI、T_2WI均以等、低信号为主,信号不均匀.结论 颅底及面部骨化性纤维瘤和骨纤维发育不良有相似的临床、病理特点,影像学有一定特征,有助于诊断和鉴别,部分病例两者鉴别困难.术后影像学随访以CT为主,MRI对需要再次手术者为重要补充.     

肾嫌色细胞癌:动态增强CT及MR表现

目的:分析肾嫌色细胞癌的影像学表现及其血液动力学特征与病理的关系,提高诊断准确性.方法:经手术病理证实的肾嫌色细胞癌16例,术前经螺旋CT或多层螺旋CT平扫、皮髄交界期和实质期扫描,注射流率3 ml/s;3例经MRI SE T1WI、T2WI和扰相梯度回波动态增强成像.仔细复习CT和MRI扫描结果并与手术病理作回顾性对照分析.结果:16例嫌色细胞癌中肿瘤呈球形14例,椭圆形2例,边缘光整.所有肿瘤平扫软组织密度均匀,3例可见钙化,1例瘢痕伴钙化.肿瘤直径3.5～13.0cm,平均7.6cm.实质性肿瘤15例,1例实质期增强可见小囊变.肿瘤平扫CT值22.7～34.2 HU,平均27.1 HU;动态增强皮髓交界期CT值30.4～71.8 HU,平均43.3 HU;实质期CT值32.9～82.4 HU,平均51.7 HU.4例可见轮辐状强化.3例行MRI检查,MR T1WI为略低信号,T2WI为略高信号,1例可见中心轮辐状瘢痕,皮髄交界期轻中度强化,实质期强化相仿.结论:肾嫌色细胞癌多位于髓质,瘤体呈球形,坏死囊变很少见,瘤肾分界截然;皮髄交界期强化低于、等于或高于肾髓质,但明显低于肾皮质,实质期强化多低于或等于皮髄交界期,少数高于皮髄交界期;轮辐状强化或轮辐状中心瘢痕超过1/3.     

多房囊性肾瘤的影像学表现

目的 探讨多房囊性肾瘤的影像学特征及相关的多房囊性病变的鉴别诊断。方法 回顾性分析8例经手术病理证实的多房囊性肾瘤的CT和MRI资料。结果 8例多房囊性肾瘤均为单侧，直径从2．5～7．5cm不等。CT或MR扫描显示有完整囊壁，内由多个小囊腔和分隔构成，其中2例囊内分隔显示清晰，4例显示尚清晰，另2例显示不清，边缘模糊。所有囊腔问无交通，囊壁和囊内分隔有不同程度的强化，但均未见实质性结节。4例MR扫描在T1WI上呈低信号，T2WI为高信号，延迟增强扫描囊壁和囊内分隔显示较同步的CT扫描清晰。组织病理学显示所有病例的包膜和分隔内衬扁平或立方上皮。结论 多房囊性肾瘤是肾脏的少见病变，CT和MRI能准确地显示病灶的形态学特征，并提供相应的诊断依据，但在和多房囊性肾癌等病变鉴别时仍有一定的难度。     

Computed tomography and magnetic resonance imaging findings in cerebral hydatid disease

Purpose: The purpose of this study was to describe the discriminative computed tomography (CT) and magnetic resonance imaging (MRI) features of cerebral hydatid disease.Methods: The CT and MRI findings of four cases of surgically proven cerebral hydatid cysts were retrospectively reviewed. Results: CT demonstrated well-defined cystic lesions with no perilesional oedema and no contrast enhancement in all cases except one recurrent disease that showed both peripheral oedema and rim enhancement. MR images revealed well-defined cystic lesions with a quite clear rim that showed relative hypointensity limited to some aspects of the cyst walls on T2-weighted images. The cysts were spherical and obvious mass effect was observed on both CT and MR examinations. Conclusions: Although the cystic nature of intracranial hydatid disease could be equally well demonstrated on CT and MR examinations, CT is superior in detecting calcification of the cyst wall or septa, when present, and MR is better in demonstrating cyst capsule, detecting multiplicity and defining the anatomic relationship of the lesion with the adjacent structures and helps in surgical planning.     

Colloid Cysts of the Third Ventricle: Are MR Imaging Patterns Predictive of Difficulty with Percutaneous Treatment?

BACKGROUND AND PURPOSE: Colloid cysts of the third ventricle are rare benign brain tumors. The purpose of this study was to correlate their patterns on MR images with the probability of success of percutaneous treatment. METHODS: Nineteen patients underwent endoscopic treatment for colloid cysts of the third ventricle. The cases were divided into two groups based on difficulty of the aspiration procedure. We reviewed CT scans and MR images and divided cysts into groups based on their signal intensity on the MR images and their density on CT scans. Intensity and density were correlated with difficulty of aspiration during the endoscopic procedure. RESULTS: The aspiration procedure was difficult in 63% of the cases. Eighty-nine percent of hyperdense cysts on unenhanced axial CT scans were categorized as difficult, and 75% of hypodense cysts were categorized as easy. On T2-weighted MR sequences, 100% of low-signal cyst contents were difficult and nearly 63% of high-signal lesions were easy. There was a significant correlation between the T2-weighted sequences and the CT scans regarding the difficulty of the aspiration procedure. CONCLUSION: T2-weighted MR sequences are useful for predicting difficulty of aspiration during stereotactic or endoscopic procedures. A T2-weighted low-signal cyst is correlated with high-viscosity intracystic contents.     

胰腺少见囊性病变的CT及MRI诊断

目的 探讨胰腺少见囊性肿瘤的影像学特征,提高诊断水平. 方法 回顾分析经手术病理证实的11例少见胰腺囊性肿瘤的临床特征及术前平扫和增强的CT、MRI表现,其中表皮样囊肿4例, 淋巴上皮囊肿4例,淋巴管瘤3例. 结果 (1)表皮样囊肿病变位于胰尾部,囊壁光滑完整,CT平扫囊性病变内的实质成分和脾的密度相同.CT和MRI增强后实质成分表现出和脾完全相同的强化方式.(2)淋巴上皮囊肿老年男性多见,病变呈现多房状境界清楚的肿块.CT平扫呈等密度,MRI T_1WI和T_2WI上混杂的等高信号,增强后囊壁分隔强化.(3)淋巴瘤表现为体尾部的分叶状多囊性病变,CT平扫密度略低于胰腺实质,MRI平扫呈长T_1长T_2信号.增强后分隔和囊壁轻度强化,肿瘤不与胰管交通,胰管轻度受压移位.结论胰腺少见的囊性病变具有一定的特征性的临床和影像学特征.