椎管内髓外肿瘤的MRI定位定性诊断

目的:提高MRI对椎管内髓外肿瘤的诊断水平。方法:回顾性分析44例经手术病理或临床资料证实的椎管内髓外肿瘤患者的MRI表现。结果:(1)神经源性肿瘤T1WI多为低信号,T2WI多为高信号,信号多数均匀,部分囊变者信号不均,肿瘤多位于硬膜下,部分骑跨硬膜内外,呈哑铃形;(2)脊膜瘤T1WI和T2WI趋向等信号,大部信号均匀,强化明显,但强化程度不如神经源性肿瘤,可见脊膜尾征;(3)脂肪瘤的MRI信号具有特征性,多位于腰段硬膜下,部分伴脊髓拴系;(4)畸胎瘤信号混杂,增强扫描多不强化;(5)转移瘤多位于硬膜外,伴有椎体及附件的骨质破坏。结论:MRI对椎管内髓外肿瘤有较高的定位定性诊断价值。     

膝关节髌下脂肪垫区肿瘤的MRI诊断

目的:研究发生于膝关节髌下脂肪垫区肿瘤或肿瘤样病变及其MRI表现。方法:回顾性研究14例经手术病理证实的膝关节髌下脂肪垫区的肿瘤或肿瘤样病变的MRI表现。分析病变的MRI形态、平扫与增强的信号特点。结果:14例15个病灶,滑膜腱鞘巨细胞瘤7例,肿块T1WI呈等信号或稍高信号,T2WI呈等信号5例,高信号肿块内有含铁血黄素低信号灶2例,轻度或不强化。髌下脂肪垫内海绵状血管瘤2例,T1WI呈等信号,T2WI呈显著高信号,明显强化。囊肿4例,T1WI低信号,T2WI呈高信号,无强化。滑膜纤维脂肪瘤2例,T1WI呈等或高信号,T2WI呈高信号。结论:膝关节髌下脂肪垫区可发生多种肿瘤或肿瘤样病变,以滑膜腱鞘巨细胞瘤、海绵状血管瘤及滑膜囊肿多见。MRI表现具有一定的特征性,不失为术前定性诊断的有效方法。     

自发性脊髓硬膜外血肿的MRI诊断及鉴别诊断

目的探讨自发性脊髓硬膜外血肿的MRI表现及鉴别诊断。方法11例自发性脊髓硬膜外血肿，男7例，女4例，年龄27～74岁，均无明确外伤史。常规行SET1WI、T2WI矢状位及T2WI轴位，部分病例行脂肪抑制扫描，6例注射Gd-DTPA后行增强扫描。结果11例自发性脊髓硬膜外血肿中，9例位于椎管内背侧脊髓后方，2例位于椎管内背外侧。病变范围覆盖4～5个锥体节段，颈段8例，胸段3例。血肿呈长条状及长梭形，5例血肿呈T1WI、T2WI高信号，4例血肿呈T1WI、T2WI等、低、高混杂信号，2例呈T1WI及T2WI等信号。增强扫描2例血肿壁强化，4例未见强化。结论MRI是脊髓硬膜外血肿最佳检查方法，能清楚显示血肿部位，范围，区分急慢性血肿，判定脊髓受压受损情况     

膝关节髌下脂肪垫区肿瘤的MRI诊断

目的:研究发生于膝关节髌下脂肪垫区肿瘤或肿瘤样病变及其MRI表现。方法:回顾性研究14例经手术病理证实的膝关节髌下脂肪垫区的肿瘤或肿瘤样病变的MRI表现。分析病变的MRI形态、平扫与增强的信号特点。结果:14例15个病灶,滑膜腱鞘巨细胞瘤7例,肿块T1WI呈等信号或稍高信号,T2WI呈等信号5例,高信号肿块内有含铁血黄素低信号灶2例,轻度或不强化。髌下脂肪垫内海绵状血管瘤2例,T1WI呈等信号,T2WI呈显著高信号,明显强化。囊肿4例,T1WI低信号,T2WI呈高信号,无强化。滑膜纤维脂肪瘤2例,T1WI呈等或高信号,T2WI呈高信号。结论:膝关节髌下脂肪垫区可发生多种肿瘤或肿瘤样病变,以滑膜腱鞘巨细胞瘤、海绵状血管瘤及滑膜囊肿多见。MRI表现具有一定的特征性,不失为术前定性诊断的有效方法。     

椎管内硬膜外血管脂肪瘤影像学表现及鉴别诊断

[目的]探讨椎管内血管脂肪瘤特征性影像学表现,并回顾国内外文献,以提高该病的诊断准确率。[方法]收集本院7例经病理确诊的椎管内硬膜外血管脂肪瘤患者的临床表现和影像学资料,结合病理结果,观察并分析病灶易发部位、形态、分型、影像学特点和强化方式以及鉴别诊断。[结果] 7例患者中发生于胸椎5例,腰椎1例,腰骶椎1例。1例位于硬脊膜前方,6例位于硬脊膜后方。3例局限于椎管内生长(Ⅰ型,42.86%),4例沿椎间孔向椎管外生长,患侧椎间孔扩大(Ⅱ型,57.14%)。肿瘤是由脂肪和血管组成,7例患者MRI表现存在流空血管2例,内部可见脂肪信号5例。增强扫描呈不均匀明显强化5例,呈均匀明显强化2例。7例患者中4例做了CT,其中稍高密度2例,等密度2例;内密度较均匀3例,内密度不均匀1例;4例均未见坏死及钙化。[结论] MRI是诊断椎管内血管脂肪瘤的较可靠的影像学方法,能够更好的观察到肿瘤部位、形态及其分型,有助于及时做出定位、定性诊断及选择手术方案。     

MRI影像特征与肿瘤距离测量在直肠癌术前评估中的应用

目的总结MRI检查在直肠癌术前评估中的应用。方法结合文献,阐述直肠癌的MRI影像分期,壁外血管侵犯和环周切缘累及的MRI影像特征,以及肿瘤远端边缘距肛管直肠环/肛缘距离的测量。结果在T2WI序列图像中,T1期表现为等信号肿瘤组织取代正常黏膜下层,未侵及固有肌层;T2期表现为固有肌层内见肿瘤信号,但肿瘤没有侵及高信号的直肠系膜脂肪;T3期表现为肿瘤突破固有肌层,侵犯高信号的直肠系膜脂肪;T4期表现为肿瘤侵犯邻近结构或器官。转移淋巴结表现为边界不规则,在T2WI序列图像中呈混杂信号。在T1WI序列图像上,直肠壁外血管内可见肿瘤信号,并伴有血管不规则迂曲和扩张。在T2WI序列图像上,存在转移淋巴结、壁外血管侵犯及残留肿瘤距低信号直肠系膜筋膜在1 mm以内者,预示环周切缘阳性。在T2WI序列图像上,高信号的黏膜下层与等信号肿瘤连接处为肿瘤远端边缘,等信号耻骨直肠肌顶端为肛管直肠环的顶点,等信号外括约肌皮下部的最低点为肛缘。结论 MRI检查可为直肠癌的术前分期、肿瘤高度的测量及判断预后提供可靠的影像学信息,有助于直肠癌的早期诊治。     

腹膜孤立性纤维瘤CT和MRI表现与病理对照分析

目的探讨腹膜孤立性纤维瘤的cT和MRI影像学特征及其与病理学的关系。方法回顾分析经手术病理证实的腹膜孤立性纤维瘤的3例CT和2例MRI影像学表现。并与手术病理组织学结果作对照分析。结果本病的CT表现为肿块境界清楚．轮廓光滑,由两种不同密度的实质成分组成,增强扫描显著强化,动脉期瘤内见多条肿瘤血管影,平衡期肿瘤持续显著强化。MRI表现为T1WI与骨骼肌等信号,T2WI高于肌肉信号,增强扫描显著强化。病理学检查：肿瘤由散在分布密集区和稀疏区的梭形细胞组成,瘤细胞间含有粗细不均的胶原纤维。免疫组化：CD34和Vimentin阳性。结论腹膜孤立性纤维瘤的CT、MRI表现具有一定的特征性,CT和MRI对孤立性纤维瘤的诊断具有重要价值。     

肝血管平滑肌脂肪瘤的诊断与治疗

目的：报告8例肝血管平滑肌脂肪瘤的影像学特征及病理学特点，探讨其诊断与治疗方法。方法：对8例经手术及病理证实的肝血管平滑肌脂肪瘤的术前影像学表现（B超、CT、MRI、^99mTc-PMT）、手术情况及病理特点进行分析。结果：B超：肿瘤呈强回声光团6例，低回声光团2例；边界清楚7例，血供丰富、内部回声不均匀4例，其中1例内部呈分隔网状结构。彩色Doppler超声示肿瘤血供丰富，均测及动脉频谱，阻力指数为0.4-0.5。静脉造影示肿瘤内血流信号明显增加。CT：平扫示肿瘤呈低密度影7例，不均匀5例，边界清楚7例，肿瘤内见软组织影2例，脂肪成分2例。增强扫描示动脉期明显强化，门脉期及延迟期逐渐呈低密度。MRI：肿瘤呈短T1、长T2信号，增强后强化明显，脂肪抑制后短T1变成长T1。^99mTc-PMT示肿瘤呈放射性增强，5min相肿块区呈放射性缺损，2h、5h延迟相肿块区未见放射性填充，肝血池相肿块呈放射性填充。病理及免疫组化：肿瘤由成熟的脂肪、血管及平滑肌组成，HMB-45阳性。术前确诊3例。结论:B超示强回声光团，CT呈低密度影中出现软组织影、脂肪成分，增强明显，MRI出现脂肪信号，脂肪抑制后短T1变成长T1，增强明显。^99mTc-PMT示肿瘤呈放射性增强，5min相呈放射性缺损，延迟相未见放射性填充，肝血池相呈放射性填充。这些是肝血管平滑肌脂肪瘤的影像学特点，结合病史可作出诊断。此病应尽早手术治疗，行肝部分切除。最后确诊依靠病理检查及免疫组化分析。     

MRI不同序列在骨挫伤诊断中的应用价值

[目的]探讨MRI不同序列在骨挫伤诊断中的应用价值。[方法]对2006年8月～2006年12月间的45例骨挫伤患者行MRI检查，MRI扫描前均经CR、DR或CT扫描证实没有发生骨皮质的断裂与移位。临床主要表现为局部肿胀、疼痛及活动受限。使用SiemensNovus1．5T超导MRI机器，脊柱扫描使用肢体线圈，膝关节扫描使用膝关节线圈，行矢状位、冠状位及横断扫描。扫描序列包括自旋回波序列（SE）T1WI、快速自旋回波序列（TSE）T2WI、梯度回波序列（FL2D）T2WI、脂肪抑制序列T2WI。[结果]自旋回波序列（sE）T1WI检出44例，检出率为97．7％，快速自旋回波序列（TSE）T2WI检出37例，检出率82．2％，梯度回波序列（FL2D）T2WI检出24例，检出率75％，脂肪抑制序列T2WI检出45例，检出率100％。骨挫伤检出率脂肪抑制序列T2WI高于TSET2WI（P〈0．05），TSET2WI高于FL2DT2WI（P〈0．05）。骨挫伤高场MRI信号改变主要表现为T1WI呈低信号，rISET2WI呈等高信号，FL2DT2WI呈混杂稍高信号，脂肪抑制序列T2WI呈明显高信号。边界不清，信号不均匀。[结论]对于骨挫伤脂肪抑制序列T2WI检查好于TSET2WI及FL2DT2WI，与SE T1WI相结合能够更敏感的发现骨挫伤改变。     

肾上腺髓样脂肪瘤的CT和MRI表现

目的 分析肾上腺髓样脂肪瘤的CT、MRI表现,提高其影像诊断的准确性。 方法 回顾性分析手术病理证实的12例肾上腺髓样脂肪瘤的CT、MRI表现。 结果 12例肾上腺髓样脂肪瘤,右侧7例,左侧4例,双侧1例,共13个病灶。肿瘤最大径为2～9cm,边界清楚,呈圆形、分叶状或不规则形。肿瘤的CT和MRI表现与瘤内脂肪组织和类骨髓组织所占的比例相关;脂肪组织在CT表现为低密度,CT值为-120Hu~-30Hu,MRI T1WI和T2WI上都呈高信号,脂肪抑制序列上信号下降;类骨髓组织CT值为20Hu~45Hu,在M RI与肝脏的信号强度相似;增强扫描,瘤内脂肪组织不强化,类骨髓组织可呈轻度至中度强化。1例肿块见出血灶,3例肿块见钙化灶,4例肿块见坏死灶。1例肿块伴发于左侧肾上腺腺瘤上。 结论 肾上腺髓样脂肪瘤的CT、MRI表现具有一定的特征性,有助于诊断。     

MRI对椎体骨折与愈合过程的评价

目的总结与评价MRI对外伤性椎体骨折的诊断和愈合过程的诊断价值。方法回顾性分析62例椎体外伤骨折．共83个椎体．分为压缩性骨折、爆裂性骨折、隐匿性骨折。结果新鲜压缩性骨折T1WI信号，T2WI呈高信号，STIR序列呈高信号：陈旧压缩性骨折T1WI呈高信号，T2WI呈低信号，STIR序列呈低信号；爆裂性骨折T1WI呈高低混杂信号，T2WI呈高信号，STIR序列呈高信号。椎体呈分裂状：隐匿性骨折为T1wI及T2WI对应位置条状低信号，且于T1WI低信号周同见片状高信号，STIR序列呈高信号．结论MRI可以从椎体信号的变化来评价椎体外伤性骨折的程度与康复过程，且能够弥补传统X线与CT诊断椎体骨折的诸多不足之处。     

化脓性肌炎的MRI表现

目的分析化脓性肌炎的MRI表现特点。方法回顾分析我院经临床手术及病理证实的8例化脓性肌炎患者的MRI表现。检查序列包括SET1W、TSET2W、STIR,其中4例同时接受增强SET1w扫描。结果8例中1例发生于腰大肌,余7例均发生于下肢肌肉。MRI显示所有8例受累肌肉弥漫性肿大,T2WI表现为较明显不均匀高信号,STIR为明显高信号;T1WI呈与邻近肌肉等、稍低或稍高信号改变,邻近肌间隙水肿。4例病灶中见单个或多个T1WI低信号、T2WI高信号脓肿形成,周围脓肿壁在T1WI上为相对高信号。增强扫描中2例受累肌肉呈明显弥漫性强化,2例脓肿形成呈环状强化,脓腔及小的炎性坏死区无强化。结论MRI可清晰显示化脓性肌炎病变部位、特点及范围,具有重要诊断价值。     

Spinal epidural cavernous hemangioma in an HIV-positive patient

BackgroundSpinal epidural cavernous hemangioma is rare.PurposeHere, we report a case of spinal epidural cavernous hemangioma in an HIV-positive patient.Study designSingle case report.MethodA 40-year-old known HIV-positive woman presented with a 6-month history of slowly progressive bilateral leg weakness and pain. Neuroimaging showed an epidural mass lesion, which was isointense on T1–WI, hyperintense on T2–WI, and homogenously enhanced with gadolinium diethylenetriamine pentaacetate (Gd-DTPA), from T8 to T10.ResultsThe patient underwent T8–T10 laminectomy and removal of this lesion. Pathological diagnosis was cavernous hemangioma.ConclusionAlthough soft-tissue tumors such as Kaposi's sarcoma and lymphomas have been well documented in association with HIV infection, this is the first reported case of spinal epidural cavernous hemangioma. This may be an incidental finding or perhaps a causal relationship exists, suggesting that cavernous hemangioma could be a differential diagnosis of a spine lesion in HIV-positive patients.     

MRI对肝不典型增生结节癌变的诊断价值

目的:探寻肝不典型增生结节癌变的早期MRI表现,并评价其诊断价值。方法:对29例32个肝不典型增生结节癌变灶常规MRI及动态增强图像进行分析,并经手术及病理证实。结果:MRI检出32个癌变灶中的25个,检出率78%;25个病灶中,在T1WI上呈略高信号13个,等信号7个,略低信号5个;T2WI上呈略高信号的病灶6个,8个呈等信号,11个表现为"结节中结节";增强扫描动脉期21个病灶明显强化;7个病灶内可见脂肪变性。结论:肝不典型增生结节癌变的早期MRI表现具有典型特征,对帮助诊断具有一定价值。     

MSCT和MRI诊断巨大子宫肌瘤

目的分析巨大子宫肌瘤的临床表现与MSCT、MRI特征。方法收集28例经手术、病理证实的最大直径>7cm的巨大子宫肌瘤患者,分析其临床及MSCT、MRI表现并与手术病理对照。结果 28例共37个瘤体,其中浆膜下肌瘤15例,肌壁间肌瘤9例,黏膜下肌瘤4例。MSCT平扫肌瘤密度均混杂不均,增强扫描呈不均匀强化,其中4例主要表现为囊性变性。病变MR平扫T1WI为等或略低信号,T2WI为混杂信号,增强扫描呈不均匀强化。结论巨大子宫肌瘤的MSCT、MRI表现有一定特征性,对诊断巨大子宫肌瘤有较高临床价值。     

MRI在腰骶神经根畸形诊断中的价值

目的确定MRI对腰骶神经根畸形（lumbosacralnerverootanomalies,LNRA）潜在的诊断价值。方法复习376例腰腿痛患者的腰椎MRI片。矢状面及水平面采用T1加权或T2加权成像,冠状面采用短TI反转回复序列成像。结果发现65例存在LNRA,其中分叉神经57例,尾侧起源7例,近邻根1例。手术患者术前诊断的畸形根,在术中显露到的均得到证实。结论MRI特别是短TI反转回复序列冠状面成像能够直观清晰地显示LNRA的起源、路径及大小等信息。     

MRI对胆囊癌的诊断价值

目的 探讨胆囊癌的MRI表现,提高胆囊癌的影像诊断水平。方法 回顾性分析47例临床诊断为胆囊癌的MRI影像学资料,其中43例经病理证实。分析胆囊癌的形态、信号、强化特点、周围结构侵犯及转移情况,并与手术及病理对照。结果 厚壁型12例,腔内型19例,肿块型16例。MRI信号T1WI为等、稍低信号,T2WI稍高、高信号,增强模式为持续或渐进性强化。20例肝内外胆管扩张,梗阻点多位于肝总管占80%。25例肝脏受侵,6例十二指肠受侵,4例网膜侵犯,3例胰腺侵犯。24例淋巴结转移,N1：9例,N2：15例,与病理符合率达83.3%。肝脏转移10例,与病理符合率为100%。根据MR的临床分期与手术分期符合率90.7%。结论 MRI能够清楚显示胆囊癌病灶,并能够准确地评价胆囊癌的周围结构侵犯及转移情况,能够准确进行临床分期,有助于制定治疗策略。     

Solitary spinal epidural cavernous angioma: report of nine surgically treated cases and review of the literature

Purpose

We intend to report the largest series of spinal epidural cavernomas (SEC), discuss their clinical features, imaging characteristics, surgical findings, outcome analysis and compare them with similar reports in the literature.

Methods

Among the cases of spinal tumors treated surgically by the authors, there have been nine cases of SEC’s. All the data were collected prospectively and the cases have been followed after surgery up to the time of this analysis.

Results

There were six female and three male patients with the ages ranging between 13 and 74 years. The lesions were located in the thoracic spine (4 cases), lumbar spine (4 cases) and one at the sacral level. Clinical presentations included acute spinal pain and paraparesis in two, low back pain and radiculopathy in five, and slowly progressive myelopathy in the other two cases. The lesion was iso-intense with the spinal cord in T1W images and hyperintense in T2W images and showed strong homogeneous enhancement after contrast medium injection in most of our cases. In the presence of hemorrhage inside the lesion, it was hyperintense in both T1W and T2W MR sequences as in our case 6. In the single case presenting with acute hemorrhage, epidural hematoma was the only finding, our case 1. Complete surgical removal was achieved in all our cases, and confirmed by postoperative MRI.

Conclusion

SEC is hard to be differentiated from other epidural spinal lesions before intervention but should be considered in the list of differential diagnosis regarding its favorable outcome.     

Magnetic resonance imaging findings and histopathological observations after percutaneous renal cryoablation in the rabbit model

PURPOSE: We investigated sequential changes in MRI and relevant histopathological findings after PRC. MATERIALS AND METHODS: A total of 15 rabbits were examined with MRI and sacrificed immediately (3), and 7 (4), 45 (4) and 90 (4) days after PRC. MRI studies were reviewed for the signal intensity of cryolesions and correlated with pathological findings. MRI and pathological measurements of cryolesion sizes were compared using the paired t test. RESULTS: CCN was produced in central areas of cryolesions and associated with hemorrhage, hemolysis, fibrous granulation and fibrosis that was orderly through days 1 to 90. Signal intensity was slightly hyperintense on T1-weighted spin-echo images immediately after PRC, and hyperintense on T1 and T2-weighted fast spin-echo images at 7 days. On T2-weighted fast spin-echo images there was a hypointense zone in peripheral areas between the central area and renal parenchyma at the prior 2 stages, which was consistent with PCN histologically. It was enhanced at 7 days. At 45 and 90 days the signal intensity of cryolesions was isointense or hypointense on the 2 sequences. Parenchymal injury adjacent to cryolesions was histologically recognized and visible as a hyperintense zone in 2 lesions at 45 days. This zone was enhanced in 2 lesions at 45 and 90 days. No statistical significance was apparent between the 2 measurements of cryolesions and CCN sizes (p <0.05). CONCLUSIONS: The MRI appearance of cryolesions reflects orderly histopathological findings. MRI distinguishes CCN from PCN, reveals injury to the renal parenchyma outside of cryolesions and accurately estimates the size of cryolesions and CCN.