颅内表皮样囊肿的CT、MRI及DWI诊断

目的:通过分析55例颅内表皮样囊肿CT、MRI和DWI表现,探讨表皮样囊肿的影像学诊断和鉴别诊断。方法:对55例经手术病理证实的颅内表皮样囊肿的CT、MRI及DWI表现进行回顾性分析。男33例,女22例。全部病例均行MR平扫检查,其中26例行MR增强扫描,18例行扩散加权成像,26例行CT平扫检查,5例行CT增强扫描。结果:表皮样囊肿位于脑外29例,脑实质23例,脑室3例。CT平扫24例呈低密度,2例密度稍高于脑实质。51例类似脑脊液信号,1例呈短T1短T2信号,2例呈短T1长T2信号,1例T1WI大部分呈等信号,少部分为低信号,T2WI呈低信号。2例囊壁似有轻微强化。DWI上囊肿均表现为高信号,且ADC值高于脑实质。结论:形态不规则、类似脑脊液信号、DWI呈高信号、不强化是表皮样囊肿的影像学表现特点,不典型表皮样囊肿可呈其它密度和信号变化,可根据不强化和DWI呈高信号与其它类似病变鉴别。     

颅内表皮样囊肿的MRI诊断

目的 分析颅内表皮样囊肿的MR影像特征。资料与方法经手术病理证实的颅内表皮祥囊肿30例，男13例，女17例，除9例仅作MR平扫外，其余均作MR平扫 增强扫描。12例选用FLAIR序列。结果 典型表现者27例，占90％，T1WI上表现为低信号，有时不均匀；非典型表现者3例，占10％，T1WI上肿瘤实质内为高信号。21例增强扫描中，16例无强化，1例分隔状强化，4例边缘强化。T2WI上大多表现为均匀高信号，少数信号不均匀。结论 典型常见的表皮样囊肿T1WI为低信号，信号欠均匀；非典型的表皮样囊肿T1WI呈高信号，信号形成原因是高浓度蛋白质所致，并非脂类物质。     

颅内表皮样囊肿的非典型CT和MRI表现

目的 探讨颅内表皮样囊肿的非典型CT和MRI表现,提高对本病的认识.方法 收集经手术病理证实的8例表皮样囊肿,术前均行MRI平扫,其中2例行扩散加权成像(difussion weighted imaging,DWI)检查,CT检查5例.MRI增强扫描4例.结果 8例表皮样囊肿发生于桥小脑角2例,大脑纵裂2例,脑实质2例,颅骨2例.CT显示囊肿表现为均匀高密度2例;混杂密度1例;囊壁及囊内钙化2例.MRI平扫2例T1WI呈均匀高信号,T2WI呈稍高、高信号;3例T1WI和T2WI呈混杂信号;3例T1WI呈不均匀低信号,T2WI呈高信号;其中1例DWI表现为高信号.4例MRI增强扫描显示囊壁显著环形强化和囊内不均匀强化2例,囊壁轻度强化2例.结论 颅内表皮样囊肿的CT和MRI非典型表现主要包括CT呈高密度、混杂密度、囊壁和囊内钙化,MRI T1 WI、T2WI呈高信号、混杂信号,增强扫描显著环形强化,在诊断时应充分结合DWI检查,以提高术前诊断准确性.     

椎管内表皮样囊肿的MRI表现

目的:探讨椎管内表皮样囊肿的MR表现。方法:回顾性分析16例经手术病理证实的椎管内表皮样囊肿的 MRI表现。常规行SE T1WI、TSE T2WI和STIR扫描,14例行Gd-DTPA增强扫描。结果:16例中12例病灶位于髓外硬膜下,4例位于脊髓内,合并其它先天畸形6例。MR表现为T1WI上呈低信号8例,等、低混杂信号6例,等、低、高混杂信号2例;T2WI上呈高信号10例,等、高混杂信号5例、等、低混杂信号1例;3例肿瘤内有脂肪信号。11例患者行增强扫描,肿瘤内部均无强化,肿瘤边缘轻度强化2例。结论:椎管内表皮样囊肿的MRI表现有一定特征性,除与皮样囊肿鉴别困难外,与其它椎管内肿瘤容易鉴别。     

弥散MRI诊断颅内表皮样囊肿的价值

目的:探讨磁共振弥散加权成像(DWI)及表观弥散系数(ADC)图诊断颅内表皮样囊肿的价值.材料和方法:分析19例表皮样囊肿常规MRI和DWI的信号特征,定量测定表皮样囊肿、正常脑实质和脑脊液的ADC值.结果:17例表皮样囊肿T1WI、T2WI呈等或稍高于脑脊液信号,2例T1WI呈高低混杂信号.肿瘤边缘弧线形增强或不增强.19例肿瘤DWI呈明显高于脑实质和脑脊液信号,肿瘤较脑脊液的平均ADC值显著减低,较脑实质的平均ADC值显著增高.结论:DWI优于常规MRI发现颅内表皮样囊肿,DWI上表皮样囊肿的高信号可能是肿瘤组织的T2余辉效应所致.     

磁共振扩散加权成像在颅内表皮样囊肿中的诊断价值

目的：探讨磁共振扩散加权成像（DWI）在颅内表皮样囊肿中的诊断价值。方法：收集颅内表皮样囊肿病例16例，均行常规MRI和DWI检查，分析表皮样囊肿在T2WI、T1WI、增强扫描和DWI上的影像表现。结果：16例均呈长T2长T1信号，其中2例伴短T2间隔信号，增强扫描14例无强化，2例呈包膜和间隔强化。16例DWI上均呈明显高信号。结论：磁共振DWI在颅内表皮样囊肿中具有重要的诊断价值，可作为常规MRI的重要补充检查方法。     

双流率扫描技术在活体肾移植术前供肾血管评估中的应用价值

目的:探讨颅内表皮样囊肿破裂的MRI表现特征。方法:回顾性分析4例经手术病理证实的颅内表皮样囊肿破裂的MRI表现。结果:4例颅内表皮样囊肿均呈混杂T1、混杂T2信号,FLAIR呈混杂信号,DWI呈高信号,增强扫描未见强化。破裂的脂滴均位于蛛网膜下腔内,3例位于脑室内,脂滴均呈短T1、长T2信号,FLAIR呈低信号,DWI上呈低信号,增强扫描均未见强化。其中2例脑室内可见脂肪-脑脊液平面。结论:颅内表皮样囊肿破裂具有特征性MRI表现,MRI对本病的诊断及鉴别诊断具有重要意义。     

颅内表皮样囊肿的MRI表现

目的　分析颅内表皮样囊肿的MRI影像学表现。方法　证实的 18例患者中 ,男 7例 ,女 11例 ,全部行MRI检查。结果　典型表现者 16例 ,占 88.9% ,T1WI表现为低信号 ,T2 WI表现为高信号 ;不典型表现者 2例 ,占 11.1% ,T1WI表现为欠均匀高信号 ,T2 WI表现为高信号。增强扫描 ,16例肿瘤不强化 ,2例边缘强化。结论　典型表皮样囊肿是T1WI呈低信号 ,且欠均质 ;非典型表皮样囊肿T1WI呈高信号 ,应注意此类肿瘤的鉴别诊断。     

颅骨表皮样囊肿的影像学表现及文献回顾

目的 探讨颅骨表皮样囊肿CT及MRI表现特点.方法 回顾性分析7例经手术证实的颅骨表皮样囊肿的CT及MRI表现,3例行CT及MRI平扫,其中2例行MRI增强扫描,4例只行CT扫描.结果 病变发生于枕骨4例,顶骨2例,颞骨1例.7例CT表现为颅骨膨胀性骨质破坏,类圆形或分叶状,边缘锐利,周围见断续钙化边或硬化带,病变中心呈混杂密度,3例病灶内可见死骨样高密度影.MRI表现为T1WI混杂低信号,T2WI混杂高信号,脂肪抑制序列呈高信号,增强扫描病变较小者无明显强化,病变较大者周围见淡薄线样强化,囊内容物无强化.当囊内容物中以蛋白、胆固醇结晶为主、轻微钙化时,CT表现为混杂密度,其内可出现高密度影,对应的MR T1WI呈等或高信号,T2WI为低或等信号.手术显示病变相邻脑实质均未受累.结论 CT与MRI结合对术前诊断颅骨表皮样囊肿很有价值.     

颅内表皮样囊肿MRI诊断的序列选择及应用价值

目的探讨MR各种扫描序列对颅内表皮样囊肿的诊断价值。资料与方法49例经手术及病理证实的颅内表皮样囊肿,均行T1WI、T2WI、液体衰减反转恢复序列(FLAIR)、扩散加权成像(DWI)及增强扫描。9例T1WI呈高信号者加扫脂肪抑制像。结果49例肿瘤中不规则形36例,圆形或类椭圆形13例。在T2WI上,38例呈高信号,另11例为高信号中夹杂斑片状等信号;肿瘤在T1WI上信号多变,其中40例为低信号,余9例为高低混杂信号(6例)或高信号(3例),经脂肪抑制后,其中3例部分高信号衰减;FLAIR为中等及低混杂信号;所有患者DWI均为高信号;增强后34例无强化,15例边缘弧线形强化。结论颅内表皮样囊肿在MR各序列上均有特征性表现。DWI扫描有助于鉴别诊断。MRI多方位、多序列扫描的综合应用,能术前准确诊断,使选择最佳手术方式和入路成为可能。     

Epidermal inclusion cyst of phalanx: a case report and review of the literature

Epidermal cyst within a toe phalanx is an extremely rare condition. It is important to differentiate this benign lesion, which can be easily treated by curettage, from other benign and malignant lesions of the bone with a similar clinical presentation, and which may require amputation of the toe. This report describes one such lesion in the mid-phalanx of the fourth toe in a 48-year-old woman, and which was successfully identified by intra-operative frozen diagnosis and treated by curettage.     

超声引导下卵巢囊肿穿刺术与腹腔镜卵巢囊肿剥除术治疗卵巢囊肿的疗效比较

目的比较超声引导下卵巢囊肿穿刺术与腹腔镜卵巢囊肿剥除术治疗卵巢囊肿的疗效。方法选取2016年1月至2018年10月我院卵巢囊肿患者50例,随机数字表法分为观察组和对照组,各25例。对照组行腹腔镜卵巢囊肿剥除术治疗,观察组行超声引导下卵巢囊肿穿刺术治疗。比较2组手术相关指标及卵泡数、卵巢体积。结果观察组手术用时、住院用时、术中出血量、术后排气用时均低于对照组,差异具有统计学意义(P<0.05);手术后,2组卵泡数以及卵巢体积低于手术前,而观察组高于对照组,差异有统计学意义(P<0.05)。结论超声引导下卵巢囊肿穿刺术治疗卵巢囊肿的效果优于腹腔镜卵巢囊肿剥除术治疗,且对卵巢的影响较小,利于改善患者预后。     

Assessment of Hounsfield unit in the differential diagnosis of odontogenic cysts

Objectives:The purpose of this study was to evaluate the usefulness of Hounsfield unit (HU) assessment with multislice-CT in the differentiation of radicular cysts (RCs), dentigerous cysts (DCs) and odontogenic keratocysts (OKCs).Methods:In total, 307 odontogenic cysts (RCs, DCs and OKCs) were included in this study. Cysts with lesion diameter <10 mm, cysts with artefacts affecting measurement of HU values, cysts involving infection and recurrent cysts were regarded as exclusion criteria. Images were acquired in three different types of CT scanners: Aquilion ONE, Discovery CT750 HD and SOMATOM Definition Flash. Differences in HU values among scanners and among types of odontogenic cysts were assessed using one-way analysis of variance; multiple comparisons were performed post hoc, using the Tukey–Kramer honestly significant difference test.Results:In total, 164 cysts were analysed in this study (64 RCs, 57 DCs and 43 OKCs). Regardless of the type of lesion, the Aquilion ONE scanner demonstrated a significant difference in HU value, compared with the Discovery CT750 HD scanner. Regardless of CT scanner model, HU values significantly differed between DCs and OKCs (p < 0.0001), as well as between OKCs and RCs (p < 0.0001).Conclusions:HU values were found to vary among CT scanners and should always be associated with other lesion imaging features while interpreting and elaboration diagnostic hypothesis. Notably, the results suggested that OKCs might be able to be differentiated from DCs and RCs by using HU values.     

Midline cystic malformations of the brain: imaging diagnosis and classification based on embryologic analysis

This article describes a classification and imaging diagnosis of intracranial midline cystic malformations based on neuroembryologic analysis. Midline cystic malformations are classified into two categories from an embryologic point of view. In one category, the cyst represents expansion of the roof plate of the brain vesicle, and in the other the cyst consists of extraaxial structures such as an arachnoid membrane or migrating ependymal cells. Infratentorial cysts, such as the Dandy-Walker cyst or Blake's pouch cyst, and supratentorial cysts, such as a communicating interhemispheric cyst with callosal agenesis or a dorsal cyst with holoprosencephaly, are included in the first category. Infratentorial arachnoid cavities, such as the arachnoid cyst, arachnoid pouch, and mega cisterna magna, are in the second category. Noncommunicating interhemispheric cysts, such as interhemispheric arachnoid cyst or ependymal cyst, with callosal agenesis are also in the second category. A careful review of embryologic development is essential for understanding these midline cysts and for making a more accurate radiologic diagnosis. This work was presented as an educational lecture at the 64^th Japan Radiological Society meeting (April 2005) in Yokohama.     

Lymphoepithelial cyst of the pancreas: radiological and pathological findings

We report a case of a rare lymphoepithelial cyst of the body of the pancreas that developed in a woman complaining of constipation for 15 years. Ultrasonography revealed a homogeneous isoechoic lesion, while CT demonstrated a polycystic homogeneous mass with central scar and calcification. Cytological investigation of a CT-guided biopsy permitted diagnosis of lymphoepithelial cyst. The patient was operated on and had an uneventful recovery. The histological finding was of a cyst wall lined with keratinised squamous epithelium surrounded by lymphoid tissue with reactive follicular hyperplasia. The radiological findings and differential diagnosis are discussed. Correspondence to: D. Regge     

Myelographic and MRI appearances of a thoracic spinal extradural arachnoid cyst of the spine with extra-and intraspinal extension

Summary An unusual arachnoid, cyst of the thoracic spine is reported. The clinical and neuroradiological features are described.     

关节旁骨内腱鞘囊肿的影像学诊断

目的 探讨关节旁骨内腱鞘囊肿的发病机制、临床表现及X线特征、诊断及鉴别诊断。资料与方法 回顾性分析经病理证实的11例关节旁骨内腱鞘囊肿的临床及影像学资料，其中5例位于膝关节附近，5例位于踝关节附近，1例位于肘关节，且均为单发。结果 11例X线表现：7例为单房性圆形或椭圆形密度减低区，其中2例与关节腔有一宽约1mm的通道；2例呈多房性囊状扩张，其内有粗细不等的间隔；另2例呈半圆形骨质缺损，开口朝向关节腔。11例均显示边界清楚，周围有宽约1mm的硬化边。结论 关节旁骨内腱鞘囊肿在临床和X线片上可早期诊断，但应与相关疾病鉴别，防止误诊。     

眶额区先天性皮样囊肿和表皮样囊肿的CT表现(附4例报道及文献复习)

目的 报道眶额区皮样囊肿和表皮样囊肿的CT征象. 资料与方法 回顾性分析经手术病理证实的眶额区皮样囊肿和表皮样囊肿各2例的CT表现. 结果 4例囊肿边界清晰,囊内密度不均,3例以脂性密度为主,其中2例表皮样囊肿局限性压迫额骨颧突,1例皮样囊肿以水样密度为主伴小斑片低密度影,沿颧额缝向外生长. 结论 眶额区皮样囊肿和表皮样囊肿具有特征性CT表现.     

影像学诊断骶神经根囊肿的价值

目的：探讨骶神经根囊肿的影像学特点，提高临床诊断水平。材料和方法：对68例骶神经根囊肿的MRI（35例）、CT（16例）、X线脊髓造影（29例）和X线平片（68例）等影像学特征进行回顾性分析。结果：X线平片一般不能检出骶神经根囊肿。脊髓造影一般能清楚显示神经根囊肿。CT扫描能显示骶管扩大、骶骨椎板变簿、椎体后缘凹陷性侵蚀性改变。MRI能清楚显示骶骶神经囊肿的位置、大小和形态，可做出定性诊断。结论：脊髓造影、MR和CT对本病诊断和鉴别诊断具有重要的临床价值；由于CT受扫描范围的限制和囊肿大小的影响，有时易发生漏诊。