Assessment of pleomorphic adenomas using MRI and dynamic contrast enhanced MRI

We evaluated magnetic resonance images (MRI) and the value of dynamic contrast enhanced MRI (DCE-MRI) of pleomorphic adenomas retrospectively. MRI was performed for 18 pleomorphic adenomas, including 11 cases with DCE-MRI. We obtained the following results on the MRI and DCE-MRI. (a). Pleomorphic adenomas showed a predilection for homogeneous intermediate signal intensity on T1-weighted images (T1WI), heterogeneous high signal intensity on T2-weighted images, and heterogeneous enhancement on Gd-T1WI. (b). Of 11 contrast index (CI) curves of pleomorphic adenomas, nine CI curves (81.8%) increased gradually to 600 s or increased gradually, reached a plateau, and sustained the plateau to 600 s. The remaining two (18.2%) increased gradually and decreased gradually thereafter. (c). CI curves reached the maximum CI index at 135-300 s.     

MRI征象在腮腺肿瘤定性诊断中的价值及其病理基础

背景与目的：腮腺肿瘤的病理类型非常复杂,MRI在其诊断中具有明显的优越性,但在诸多方面诊断标准仍不统一,需要大样本的病例分析以探讨MRI征象在其诊断中的价值及其病理基础。本文总结常见腮腺良、恶性肿瘤的MRI表现,以探讨各征象在腮腺肿瘤定性诊断中的作用。方法：收集132例腮腺肿瘤及其它病变患者(共140个病灶)的MRI资料,其中良性者89例,恶性者43例。112例经手术病理证实,17例经活检证实,3例经临床观察证实。对其中58例手术切除病灶完整者的标本行病理逐层切片检查,并将结果与MRI影像进行对照分析。MRI平扫采用TlWI、T2WI,其中108例共115个病灶同时行平扫和增强扫描。统计学分析采用X^2检验。结果：(1)常见腮腺良性肿瘤的MRI特征表现：所有行增强扫描的40个腺淋巴瘤均呈轻度增强,其中25例T2WI表现为低、等信号;22例混合瘤T2WI表现为高而不均匀信号;5例血管瘤可见异常增粗的血管结构;3例囊性淋巴管瘤的形状特别不规则并包绕邻近结构;4例脂肪瘤的信号类似于其它部位的脂肪瘤。(2)常见腮腺恶性肿瘤的MRI特征表现：8例混合瘤恶变的T2WI信号高而不均匀,且形状不规则,边界不清楚;7例腺样囊性癌以侵犯范围广泛为特征;8例粘液表皮样癌中,3例低度恶性者边界清楚,与良性肿瘤难区别,5例中、高度恶性者边界不清,易发生坏死及淋巴结转移;9例淋巴瘤均为继发,范围较广,可分辨出由多个结节组成;3例腺泡细胞癌内有TlWI和T2WI均为高信号的囊变区,形状规则或不规则。结论：常见腮腺良、恶性肿瘤在MRI表现上各有特点,对大多数病例用MN进行定性诊断是可能的。     

腮腺多形性腺瘤与沃辛瘤MRI影像学特点的对比分析

多形性腺瘤和沃辛瘤是腮腺最常见的两种良性肿瘤。发生于腮腺的多形性腺瘤MRI平扫T1WI表现为等或稍低信号,T2WI表现为高信号,因含黏液其信号高于脑脊液;如发生坏死、囊变,T2WI表现为高低混杂信号;肿瘤有纤维包膜,T1WI和T2WI均表现为低信号,与正常组织分界清楚。沃辛瘤（腺淋巴瘤）内上皮成分嗜酸性并具有淋巴组织及密集排列的细胞核,故T2WI多以低信号为主,且信号均匀居多,可作为与混合瘤的鉴别点。本文研究发现腮腺多形性腺瘤与沃辛瘤在MRI成像上有不同的影像学特点,期望对临床工作有所帮助。     

Value of dynamic enhanced MR imaging for the differential diagnosis between ovarian fibroma and subserosal leiomyoma

Objective To study the value of dynamic enhanced MR imaging in the differential diagnosis between ovarian fibroma and subserosai leiomyoma, both of which produce a intermediate to tow signal intensity on T2WI. Methods Plain and dynamic enhanced MRI results of 45 patients were analyzed, 35 cases of which were subserosal leiomyoma and 10 were ovarian fibroma. All of the tumors were verified by histologic analysis. Results The 10 ovarian fibroma cases showed low signai intensities on T1WI, but 2 produced intermediate signal intensities and 8 showed low signal intensities on T2WI. There was little enhancement of the early phase and the delayed phase was long, so the enhancement index of the early phase (SHOO) was low and the time to peak (TTP200) was long. Of the 35 subserosal leiomyoma cases, all showed low signal intensity on T1WI, 7 were intermediate in signal intensity and 28 generated a low signal intensity on T2WI. The enhancement of the early phase was moderate to highly evident and the index was high. The time to peak was short (TTP200). The enhancement -time curve was different in the two groups, and the difference had statistical significance (P<0.001). Conclusion Dynamic enhanced MR imaging was helpful in the differential diagnosis between ovarian fibroma and subserosal leiomyoma by the difference of the early phase enhancement.     

Value of Dynamic Enhanced MR Imaging for the Differential Diagnosis between Ovarian Fibroma and Subserosal Leiomyoma

Objective  To study the value of dynamic enhanced MR imaging in the differential diagnosis between ovarian fibroma and subserosai leiomyoma, both of which produce a intermediate to tow signal intensity on T2WI. Methods  Plain and dynamic enhanced MRI results of 45 patients were analyzed, 35 cases of which were subserosal leiomyoma and 10 were ovarian fibroma. All of the tumors were verified by histologic analysis. Results  The 10 ovarian fibroma cases showed low signai intensities on T1WI, but 2 produced intermediate signal intensities and 8 showed low signal intensities on T2WI. There was little enhancement of the early phase and the delayed phase was long, so the enhancement index of the early phase (SHOO) was low and the time to peak (TTP200) was long. Of the 35 subserosal leiomyoma cases, all showed low signal intensity on T1WI, 7 were intermediate in signal intensity and 28 generated a low signal intensity on T2WI. The enhancement of the early phase was moderate to highly evident and the index was high. The time to peak was short (TTP200). The enhancement -time curve was different in the two groups, and the difference had statistical significance (P<0.001). Conclusion  Dynamic enhanced MR imaging was helpful in the differential diagnosis between ovarian fibroma and subserosal leiomyoma by the difference of the early phase enhancement.     

低磁场核磁共振对小鼠原发性和移植性肿瘤的成像效果

目的 利用小鼠原发性和移植性肿瘤模型检测0.5T低磁场小动物核磁共振（MRI）的成像效果。方法 采用0.5T低磁场MRI仪对小鼠皮下移植瘤（HepG2、S180、H-ras12V转基因小鼠肝肿瘤组织）和原发性肝肿瘤（H-ras12V转基因肝癌小鼠）进行检测,观察其影像学表现并对H-ras12V转基因小鼠原发性肝肿瘤进行病理学确认。结果 皮下移植瘤小鼠（S180、HepG2、H-ras12V转基因小鼠肝肿瘤组织）的肿瘤生长状态良好,肉眼及X光检测均可观察到显著的肿瘤团块。MRI成像结果表明,皮下肿瘤部位的T1WI上表现为低信号、T2WI上表现为高信号、成像清晰、效果良好,且三种小鼠皮下移植瘤的MRI成像效果相似。对于H-ras12V转基因小鼠原发性肝肿瘤的MRI成像结果表明,在转基因小鼠的肝区出现了T1WI上表现为低信号的多个区域,这些相应区域在T2WI上表现为高信号。病理解剖及病理切片证实,这些区域为多发性肝肿瘤。结论 利用低磁场MRI可以对小鼠原发性肝肿瘤和移植性肿瘤进行有效的检测,可作为小鼠肿瘤无创检测的有效方法。     

四肢横纹肌肉瘤的MRI和CT影像学特征——附9例报告

背景与目的:四肢横纹肌肉瘤的影像学研究少见报道,本研究探讨四肢横纹肌肉瘤的MRI和CT影像学特征.方法:对9例四肢横纹肌肉瘤的MRI和CT资料进行回顾性分析.结果:8例进行了MRI检查的病变与肌肉相比,在T1WI都表现为等、低信号相混杂,以前者为主;在T2WI则均呈高信号与等和/或低信号相混杂的表现;注射造影剂后,病变都表现为显著强化,且明显不均.其中5例边界不清,周围可见水肿,3例边界清楚,周围未见水肿.3例进行了CT检查的病变与肌肉相比在平扫可见等、低密度成分,以前者为主,均未见钙化.其中1例边界清楚,2例边界不清;1例进行了增强扫描,表现为显著强化,且明显不均.全部9例患者的病变中8例可见坏死或囊变,均未见出血以及邻近骨骼破坏,但3例包绕邻近血管,1例形成静脉瘤栓.结论:MRI和CT检查若显示发生在四肢的软组织肿瘤,有坏死,强化明显且不均匀时,要在鉴别诊断中考虑横纹肌肉瘤,在没有出血、钙化及邻近骨破坏时更要考虑其可能性.     

磁共振弥散加权成像对良恶性腮腺肿瘤鉴别诊断的效果分析

目的 分析磁共振弥散加权成像(DWI)对良恶性腮腺肿瘤鉴别诊断的效果.方法 回顾性分析55例疑似腮腺肿瘤患者的磁共振成像(MRI)和DWI资料,比较良恶性腮腺肿瘤影像学表现和表观扩散系数(ADC),分析MRI动态增强扫描中时间-强度曲线(TIC)分型在良恶性腮腺肿瘤中的差异,以病理检查结果 为准,分析常规MRI诊断、DWI诊断和两者联合诊断恶性肿瘤的效果.结果良性肿块边界多清晰,以腺瘤和腺淋巴瘤最常见,T2WI呈等信号或低信号,增强扫描显著强化;恶性肿瘤形态不规则,边界模糊,信号不均匀,增强扫描均匀或不规则强化,伴周围结构侵犯和颈部淋巴结肿大.良性腮腺肿瘤中腺淋巴瘤和良性淋巴上皮病变的ADC值均较低,其他良性肿瘤的ADC值较高,恶性肿瘤的ADC值多数介于两者之间;良性腮腺肿瘤中多形性腺瘤和其他良性肿瘤及恶性腮腺肿瘤的ADC值分别为(1.185±0.113)×10-3、(1.430±0.524)×10-3、(0.996±0.254)×10-3 mm2/s,均高于良性肿瘤中腺淋巴瘤(0.768±0.133)×10-3 mm2/s,差异均有统计学意义(P﹤0.05).良性肿瘤的TIC曲线分型中缓升型34.29％、平台型25.71％、速升速降型40.00％与恶性肿瘤10.00％、75.00％、15.00％比较,差异均有统计学意义(P﹤0.05).MRI联合DWI诊断恶性腮腺肿瘤的灵敏度85.00％和准确度87.27％高于单纯MRI诊断或DWI诊断(P﹤0.05),特异度比较差异无统计学意义(P﹥0.05).结论 DWI应用于鉴别良恶性腮腺肿瘤的效果较好,值得临床推广应用.     

子宫内膜间质肉瘤的MRI表现

目的:探讨子宫内膜间质肉瘤的MRI表现特点。方法:回顾性分析7例经手术及病理证实的子宫内膜间质肉瘤患者的临床和MRI资料。所有病例均行MRI平扫。结果:本组7例患者子宫体积均增大。6例病变位于宫腔内,呈息肉状突向宫腔或弥漫性填充宫腔;1例位于子宫肌壁间,类似囊性变性子宫肌瘤。2例囊实混合性占位,5例实性占位。7例ESS病变直径范围为2.5cm-15cm,平均8.8cm。肿瘤在MRI平扫上5例T1WI 呈等信号或低信号,T2WI呈稍高信号;2例T1WI呈等及低信号,T2WI呈稍高为主的混杂信号,伴有出血或坏死囊变,其中1例位于子宫肌壁间。6例可见向子宫肌层侵润性生长,子宫T2WI结合带低信号中断或消失,其中1例可见宫颈、双侧输卵管壁、卵巢及膀胱受侵,1例子宫肌层及宫旁可见扭曲条点状流空信号影。4例合并少量盆腔积液,2例合并子宫肌瘤,1例合并卵巢滤泡囊肿,3例合并增殖期子宫内膜。病理示低度恶性ESS 6例,未分化ESS 1例。结论:子宫内膜间质肉瘤好发于宫腔内,也可见于子宫肌壁间,多向子宫肌层浸润性生长,于T1WI呈等或低信号,T2WI呈稍高信号,伴出血或坏死囊变时呈T2WI稍高信号为主的混杂信号,其在MRI上具有一定的信号特点,能为该病的诊断提供帮助。     

滑膜肉瘤MRI影像特征与组织病理学的相关性研究

背景与目的：磁共振成像(magnetic resonance imaging,MRI)是检查软组织肿瘤最好的影像学方法。滑膜肉瘤是常见的恶性软组织肿瘤之一,本研究探讨滑膜肉瘤的MRI影像特征与病理组织学的相关性．以期提高MRI对该肿瘤的诊断水平。材料和方法：12例滑膜肉瘤均经手术病理证实,位于上肢2例,位于下肢lO例;患者年龄35～50岁,中位年龄45岁;男女比例为3：1。MRI扫描采用PHILIPS GYROSCAN 0．5T超导型磁共振成像系统．扫描序列采用SE、FSE、FFE和Stir等序列,所有病例均作T,WI、T2WI和T1W Gd-DTPA静脉内注射增强扫描检查。取手术标本进行病理学检查,比较滑膜肉瘤MRI影像学表现与病理组织学的关系。结果：MRI可见12例肿块均位于关节旁,其中2例向关节内侵犯,3例侵犯邻近的骨质。在T1W12例肿块均呈以等信号为主的肿块．但其中3例肿块可见部分斑片状和囊状高信号区。在T2W6例肿块信号表现为三重信号;6例肿块表现为多结节状,3例呈不规则状,3例为圆形或椭圆形肿块。5例肿瘤内可见分隔征象,液-液平面征l例,肿块最大直径3～13cm。T1WGd-DTPA增强肿块均呈明显不均匀性强化。12例滑膜肉瘤病理分型：低分化单相梭形细胞为主型7例,高分化3例;双相分化2例。肿块内有大范围出血和囊性变6例,大量瘤组织坏死5例,钙化2例。结论：滑膜肉瘤的MRI具有一些特征性,并和肿瘤的组织学类型具有一定相关性。     

磁共振成像对原发性肝癌立体定向放射治疗疗效的评价

目的探讨MRI对原发性肝癌三维立体定向放射治疗（3DCRT）疗效的临床价值。方法106例原发性肝癌患者3DCRT后行MRIT1WI、T2WI及动态增强检查,并进行临床分析。结果放疗后肝癌缩小缓慢,病灶在T1WI和T2WI上信号多变。存活肿瘤动态增强早期强化,静脉期和延迟期呈低信号;肿瘤坏死组织无强化。放射性肝损伤T1WI主要呈低信号,T2WI主要呈高信号,动态增强动脉期无强化或强化,静脉期及延迟期明显强化,强化持续时间长。结论MRI可判断放射治疗后原发性肝癌存活或坏死情况,能客观评价放疗的效果。     

膀胱非上皮性肿瘤的影像学表现

目的 探讨膀胱非上皮性肿瘤的影像学表现特点,提高术前诊断的准确率.方法 回顾性分析加例经手术病理证实为膀胱非上皮性肿瘤患者的临床病理和影像学检查资料,其中平滑肌瘤9例,嗜铬细胞瘤6例,平滑肌肉瘤2例,横纹肌肉瘤、癌肉瘤及炎性肌纤维母细胞瘤各1例.结果 平滑肌瘤呈圆形,边缘清晰、锐利,密度均匀;MRI的TIWI及T2WI序列均呈低信号;7例患者行cT增强扫描,有6例表现为轻度强化;4例患者行彩色多普勒超声检查,有3例显示为血流不丰富或有少许血流.嗜铬细胞瘤呈圆形或卵圆形,有时略有分叶,边缘清楚,密度均匀,1例伴有钙化;MRI的T1WI序列呈低信号、T2WI序列呈明显高信号;6例患者行CT增强扫描,有4例呈高度强化;5例患者行彩色多普勒超声检查,有3例显示为血流丰富.炎性肌纤维母细胞瘤的影像学表现同嗜铬细胞瘤.其他恶性肿瘤旱不规则实性肿块,边缘模糊,密度不均匀;CT增强扫描呈不均匀中等强化.结论 膀胱平滑肌瘤及嗜铬细胞瘤的影像学表现有一定特点,再结合临床症状,术前能够作出正确诊断;其他恶性肿瘤的影像学表现无特征,仅能作出定性诊断.影像学检查是膀胱非上皮性肿瘤有价值的检查方法 ,术前可提供肿瘤部位及部分肿瘤性质的信息,有助于临床制定治疗计划.     

在体和离体胰头癌的磁共振成像表现与病理对照

目的 分析在体和离体胰头癌磁共振成像(MRI)的信号特征,研究其与大体标本及组织病理特征的相关性.方法 16例胰头癌患者行MRI检查(包括2D FLASH T1WI平扫、动态增强和抑脂TSE T2WI序列扫描),行Whipple手术切除肿瘤.新鲜手术标本再行MRI检查,扫描结束后,即将肿瘤标本按MRI检查方向完整切开,制成连续切片,分析MRI表现与大体切片和组织病理的对应关系.结果 肿瘤大小1.5 cm×2.0 cm～4.8 cm×4.2 cm,平均3.6 cm×3.1 cm.在体MRI检查:T1WI序列上,14例肿瘤呈低信号,2例呈等信号;抑脂TSE T2WI序列上,3例肿瘤呈等信号,13例肿瘤呈混杂信号;胰腺实质期增强扫描,15例强化不明显呈低信号,其中11例肿瘤周围呈环形强化;肝脏期增强扫描,9例呈不规则中等强化;增强延迟期,4例延迟强化呈等或略高信号.离体MRI检查: T1WI序列上,16例肿瘤均为低信号;在抑脂TSE T2WI序列中,均为混杂信号.MRI表现和病理的相关性:各类肿瘤成分在T1WI序列上均可为低信号,等信号区以肿瘤组织及炎性细胞为主;T2WI序列上,等低信号以纤维成分为主,略高信号以肿瘤组织和慢性炎症为主,高信号为黏液变性和受压扩张的胰腺导管.增强胰腺期环形强化是多种病理成分共同作用的结果,无明显强化区为肿瘤组织及纤维组织.肝脏期和延迟期强化以纤维成分为主.结论 胰头癌肿瘤内由多种病理成分按不同比例混合而成,MRI可揭示胰头癌的病理特征.在可切除的胰头癌肿瘤内,未见明显出血坏死的病理改变.     

原发性脑淋巴瘤的MRI与CT表现特点分析

目的探讨原发性脑淋巴瘤的MRI与CT检查特点及应用。方法对收治的13例经病理证实的原发性脑淋巴瘤患者的MRI和CT资料进行回顾性分析。结果 13例原发性脑淋巴瘤患者中,9例单发,4例多发,共有病灶21个。CT平扫多表现为等或稍高密度,而MRI平扫时T1WI表现为等或稍低信号,T2WI呈高信号。结论原发性脑淋巴瘤的CT和MRI表现具有一定的特征,对CT和MRI影像资料进行综合分析,有利于原发性脑淋巴瘤的早期诊断。     

Ⅰ、Ⅱ期子宫内膜癌MRI表现与病理对照研究

Objective： To analyze MRI features of FIGO stage Ⅰ and Ⅱ endometrial carcinoma and to study the value of MRI in assessing myometrial and cervical invasion of endometrial carcinoma. Methods： Thirty patients with surgicopathologically proven endometrial carcinoma were included in this retrospective study. All patients underwent Tl-weighted spin-echo, T2-weighted fast spin-echo and dynamic contrastenhanced fast multiplanar spoiled gradient echo sequences before surgery. The type, signal intensity and enhancement features of the tumors and the appearance of junctional zone or subendometrial enhancement were analyzed. The MRI diagnosis of myometrial and cervical invasion was correlated with pathologic findings.Results： Endometrial carcinoma demonstrated diffuse widening of endometrial stripe （n=14） or polypoid or large mass in the endometrial cavity （n=16）. The tumors were usually isointense relative to the myometrium on TlWI and hyperintensity on T2WI. In the first phase of dynamic contrast-enhanced sequences, diffuse endometrial carcinoma usually showed mild （n=8） or moderate （n=5） enhancement, while focal endometrial carcinoma tended to enhance markedly （n=6） or moderately （n=9）. On T2WI junctional zone was seen in 18 cases. On dynamic contrast-enhanced images subendometrial enhancement was seen in 17 cases. The sensitivity, specificity and diagnostic accuracy of dynamic contrast-enhanced images in combination with T2WI were 87.5%, 95.5% and 93.3% for assessing deep myometrial invasion, and 75%, 95.5% and 90% for assessing cervical invasion. Conclusion： MRI is accurate and reliable in the evaluation of myometrial and cervical invasion of endometrial carcinoma, and should be performed as preoperative routine examination.     

术前MRI评价垂体瘤质地与病理学对照研究

背景与目的：垂体瘤的质地影响手术切除的难易,术前预测垂体瘤的质地对手术入路选择有指导意义。本探讨术前MRI预测实质性垂体瘤质地的可能性及其病学基础。方法：连续搜集20例经蝶手术切除的垂体瘤标本,术前行MRI检查,术中根据肿瘤硬度分为质地软,中等,韧。标本行HE染色和1型胶原免疫组化染色－自动图像分析。结果：10例质软,T2WI瘤体／白质信号强度比均值2．34,I型胶原阳怀面积比均值17．38％,6例质地中等,T2WI瘤体／白质信号强度比均值2．01,I型胶原阳性面积比均值27．30％,4例质地坚韧,T2TI瘤体／白质信号强度比均值1．56,I型胶原阳性面积比均值40．31％,三组之间I型胶原阳性面积比有显著差异（P＜0．01）,T2WI瘤体／白质信号强度比有显著差异（P＜0．01）,I型胶原阳性面积比和T2WI上瘤体／白质信号强度比有显著负相关（P＜0．01）。结论：I型胶原含量影响垂体瘤的质地,MRI可以预测垂体瘤的质地,在T2WI上显示较低信号强度的垂体瘤质地较韧。     

Peripheral primitive neuroectodermal tumor: Dynamic CT,MRI and clinicopathological characteristics - analysis of 36 cases and review of the literature

Background

The peripheral primitive neuroectodermal tumor (pPNET) is a rare malignant tumor originating from neuroectoderm. The accurate diagnosis is essential for the treatment of pPNET.

Methods

we performed the largest cases of retrospective analysis thus far to review the unique computed tomography (CT), magnetic resonance imaging (MRI), and clinicopathological features of pPNET. The tumor location, morphological features, signal intensity, contrast enhancement characteristics, and involvement of local soft tissues of 36 pPNETs were assessed.

Results

Our results showed that there were more men (25/36) than women pPNETs patients. Unenhanced MRI (16 cases) showed that 14 cases were isointense and 2 cases were hypointense on T1WI. Nine cases were isointense and 7 were hyperintense on T2WI. Most pPNETs had heterogeneous signal intensity with small necrosis (CT: 31/36; MRI: 14/16) as well as heterogeneous enhancement (CT: 34/30; MRI: 15/16). The tumors usually had ill-defined borders and irregular shapes (CT: 30/36; MRI: 15/16). Pathologic exam showed small areas of necrosis in all tumors.

Conclusions

The diagnosis of pPNET should be suggested in young men when the imaging depicts a single large ill-defined solid mass with small area of necrosis, especially for those whose images show iso-intense on T1WI and T2WI and have heterogeneous enhancement.     

无脂肪的腹膜后脂肪肉瘤的 CT 和 MRI 表现

目的：探讨并分析影像学评价无脂肪的腹膜后脂肪肉瘤（lipid poor retroperitoneal liposarcomas, LPRL）的 CT 和 MRI 表现及其临床诊断、鉴别价值。方法回顾性分析21例经病理证实的无脂肪的腹膜后脂肪肉瘤患者的临床及 CT、MRI 影像学资料,并与病理和组织学表现对照分析。结果21例患者病变表现为腹膜后软组织肿物,大小为（12.5±8.0）cm,范围为1.9～21.0 cm。肿瘤边界清晰者12例,边界不清者9例。病变呈分叶状或形态不规则。肿瘤位于肾周间隙者12例,位于肾旁前间隙者6例,位于肾旁后间隙者3例。9例患者的肿瘤伴粗大血管影,11例伴分隔,7例伴坏死,4例伴钙化（粗大、散在、多发钙化）。该病有特征性的CT、MRI 表现,多表现为软组织实性肿物;平扫密度或信号不均匀,增强后实性部分不均匀强化,病变多伴坏死或分隔、血管影。结论 CT 及 MRI 对无脂肪的腹膜后脂肪肉瘤患者的临床诊断和鉴别有重要的参考价值。     

颅内皮样囊肿的MRI和CT诊断

目的探讨颅内皮样囊肿的MRI和CT表现及其诊断价值。方法回顾性分析23例经手术病理证实的颅内皮样囊肿病例,对其MRI和CT表现、病理和临床特征进行分析。23例均行MRI检查,20例同时行CT检查。结果22例MRI表现T1WI和T2WI均为不均匀高信号,1例T1WI为等高信号,T2WI为低信号。8例DWI表现斑片状不均匀高信号。19例CT标准窗宽、窗位,表现为均匀低密度影,宽窗宽、低窗位,表现为不均匀低密度影。另1例CT标准窗宽、窗位,表现为高密度影。其中8例CT和MRI可见蛛网膜下腔和双侧脑室内散布的脂肪滴和间质性脑水肿。结论颅内皮样囊肿有较典型的MRI和CT表现,特别是皮样囊肿破裂有影像学和临床特征性表现,可实现术前正确诊断,MRI优于CT诊断。