眼球孤立性脉络膜血管瘤的HR-MRI表现

目的　探讨眼球孤立性脉络膜血管瘤的高分辨率磁共振 (HR MRI)影像学特征 ,进一步提高诊断水平。资料与方法　回顾性分析诊断明确的孤立性脉络膜血管瘤 16例共计 17个病灶的位置、数目、形态、大小、MRI信号、强化情况、有无合并视网膜脱离及有无视神经和眼外侵犯等。所有病例均行HR MRI及增强扫描 ,部分病例行脂肪抑制。结果　 17个病灶中的 16个呈扁丘状位于眼球内壁的后极。 15个病灶厚度 <5mm ,平均厚度为2 .9mm。病灶边缘清晰 ,T1WI上呈轻度高信号者 16个 ,T2 WI上呈等信号者 15个 ,增强扫描显著强化者有 12个。 3例合并视网膜脱离 ,在T2 WI上多呈等信号 ,T1WI上呈轻度高信号者 ,均无强化。无视神经及眼外侵犯病例。结论　 94 %孤立性脉络膜血管瘤的HR MRI表现具有特征性 ,表现为位于眼球内壁后极的较小、基底较宽、边缘清晰的扁丘状病灶。其T1WI信号高于玻璃体 ,T2 WI信号等于玻璃体 ,增强扫描瘤体显著强化。明确其HR MRI影像学特征有助于临床与恶性葡萄膜黑色素瘤相鉴别 ,避免不必要的眼球摘除     

多层动态增强MRI技术对肝血管瘤诊断的评价

目的:研究射频毁坏傅立叶采集稳态技术(RFFAST)的动态增强及延迟增强扫描MRI对肝血管瘤的诊断价值。方法:34例肝血管瘤患者行常规MRT1WI和T2WI横断面扫描。经肘静脉团注GdDTPA0.1mmol/kg,后推入10ml生理盐水冲洗(推入时间5～6s),再行射频毁坏傅立叶采集稳态技术T1WI动态增强扫描及延迟增强扫描,分析病灶及邻近肝实质增强。结果:共发现肝血管瘤病灶67个,T1WI上呈低信号,T2WI上呈高信号;动态增强显示46个病灶呈边缘不连续的结节样强化,21个病灶呈周边不规则强化或迅速强化充填;5个病灶动态增强早期见引流静脉较早强化,14个瘤周肝实质强化。结论:磁共振成像检查中,射频毁坏傅立叶采集稳态技术T1WI动态增强扫描能够显示肝血管瘤及邻近实质强化方式,与其他成像序列结合更有利于肝血管瘤的诊断。     

MRI平扫及动态增强扫描对肾透明细胞癌的诊断价值

目的:探讨MRI平扫及动态增强扫描在肾透明细胞癌(RCCC)诊断及鉴别诊断中的价值。方法 :回顾性分析31例经手术或穿刺病理证实为RCCC患者的临床及MRI资料。结果:31例共33个病灶,其中单侧发病29例,双侧发病2例。病灶位于左肾15个,右肾18个。MRI平扫5个病灶信号较均匀,28个呈高低混杂信号。12个病灶内见出血信号,6个发生囊变,6个含脂肪信号。26个在T1WI、T2WI上于肿瘤边缘可见假包膜。DWI 2个病灶呈低信号,31个呈均匀或不均匀高信号。动态增强扫描33个病灶在皮质早期均明显强化;21个在皮质晚期持续强化达到峰值,肾实质期强化信号降低,排泄期信号更低;10个病灶在皮质晚期、实质期、排泄期信号呈渐进性降低;2个在皮质晚期呈持续性强化,肾实质期信号达到峰值,排泄期信号降低。结论:MRI平扫结合动态增强扫描对RCCC的诊断、鉴别诊断有着重要的临床价值。     

眼球肿瘤的CT和MRI表现及其临床价值

目的：探讨眼球肿瘤的CT和MRI表现及其在诊断和鉴别诊断中的价值。资料与方法：73例眼球肿瘤行CT扫描，45例行MRI扫描，回顾性分析眼球肿瘤的CT和MRI表现。结果：28例视网膜母细胞瘤CT表现为有钙化的肿块；26例色素膜黑色素瘤MRI显示为短T1短T2信号，增强后轻至中度强化；9例脉络膜骨瘤CT表现为眼球壁高密度扁平性肿块；6例转移瘤MRI表现为扁平性肿块，呈略长T1长T2信号；4例脉络膜血管瘤呈长T1明显长T2信号，增强后明显均匀强化。结论：CT和MRI可显示眼球肿瘤的形态、大小及内部特征，有助于诊断和鉴别诊断。     

软组织海绵状血管瘤的MRI诊断

目的探讨软组织海绵状血管瘤的MRI表现及其诊断价值。方法回顾性分析35例软组织海绵状血管瘤患者的影像资料,全部患者均有MRI平扫和增强扫描,12例有X线平片检查,10例有CT检查。结果单发病灶31例,2~4个多发病灶者4例,共检出43个病灶。SE序列T1WI上33个病灶呈中等略高信号,T2WI上全部病灶呈高信号,信号不均匀。33个病灶内及周边可见高信号的病变,Flash2d序列21个病灶T1WI上高信号被抑制,12个病灶内T1WI上高信号未被抑制。Gd-DTPA增强扫描39个病灶呈明显强化,但强化不甚均匀,其内可见点条状不强化影。结论软组织海绵状血管瘤在MRI表现上有一定特征性,MRI对诊断软组织海绵状血管瘤有重要价值。     

肝脏局灶性结节增生的MR表现及病理对照研究

目的:探讨肝脏局灶性结节增生(FNH)的MRI表现及其病理基础.方法:回顾性分析26例手术病理证实的FNH患者MRI平扫(T1WI、T2WI及DWI)和动态增强扫描的资料,对病灶信号及强化特点进行评价.结果:26例共33个病灶,单发型23例,多发型3例.实质部分于T1 WI显示31例,其中低信号3例、略低信号28例;T2WI显示32例,其中略高信号25例,高信号7例;DWI显示29例,其中略高信号21例,高信号8例.共21例病灶显示中央瘢痕,其中T1WI显示19例,均为低信号;T2WI均可显示,且均呈高信号;DWI显示15例,均为高信号.增强后,实质部分均于动脉期明显、均匀强化,延迟扫描呈略高信号28例,等信号4例,略低信号l例.中央瘢痕于动脉期明显强化1例,延迟期仍持续强化,余32例均表现为延迟强化.8例病灶周围可见增粗、扭曲的供血动脉,4例病灶周围见不完整的环形包膜样延迟强化影.结论:MRI能全面展示FNH病理改变及血流动力学特征,DWI可以提供辅助诊断信息.     

海绵窦海绵状血管瘤的MRI诊断

目的 探讨海绵窦海绵状血管瘤的MRI表现,以提高诊断正确率.方法 收集经手术病理证实的海绵窦海绵状血管瘤9例,全部病例均行头颅MRI平扫及增强扫描.结果 MRI扫描病灶形态呈哑铃状或类圆形,边界清楚,T1WI 6例呈脑灰质信号,3例稍低于脑灰质信号,T2WI 9例均呈类似于脑脊液的均匀极高信号,T1WI增强扫描均匀显著强化8例,不均匀强化1例.结论 MRI对海绵窦海绵状血管瘤的诊断有重要价值.     

Littoral cell angioma of the spleen: correlation between magnetic resonance imaging and pathology features

目的:探讨脾脏窦岸细胞血管瘤的MRI表现和病理学特点.方法:经手术病理证实的脾脏窦岸细胞血管瘤患者5例,回顾性分析其MRI表现及病理学表现.结果:5例中2例为单发,3例为多发,T1WI上病灶呈等、低信号,边界欠清,4例T2 WI上病灶呈高信号为主,其内有斑点状低信号,动态增强扫描动脉期病灶呈不均匀中度强化,门脉期呈较均匀的等或稍高信号,病灶内低信号区无强化;1例T2 WI上病灶呈低信号,动态增强扫描示病灶无明显强化.病理检查5例,镜下显示脾窦细胞增生,病灶由相互吻合的血管性腔隙组成,腔隙表面覆以呈短柱状或扁平形的内皮细胞,胞质内有含铁血黄素颗粒.免疫组化示内皮细胞和组织细胞标记物阳性.结论:脾脏窦岸细胞血管瘤一般为多发病灶,呈血管瘤样强化及T2 WI上病灶内有点状低信号区且其增强后无强化的特点,对本病的诊断具有一定的特异性.     

MRI Value in the Differentiation of Choroidal Hemangioma and Choroidal Melanoma

目的 分析眼球脉络膜血管瘤与黑色素瘤的常规及动态增强MRI特征,以提高对这两种疾病的诊断和鉴别诊断水平.资料与方法 脉络膜血管瘤9例,脉络膜黑色素瘤12例,均经术后病理或临床证实,所有病例均行常规和动态增强MRI检查,观察各个序列MRI表现,并通过动态增强时间-信号强度曲线(TIC),计算最大强化时间(Tmax)、最大强化率(ER)、上升斜率( Slope)及流出率(WR),最后进行统计学分析.结果 脉络膜血管瘤与黑色素瘤无论在发病部位、病灶大小、信号特征、强化方式,还是在ER、Slope及WR上均有显著性差异(P＜0.05),而且后者可以提供定量信息.结论 MRI常规序列结合动态增强检查在脉络膜血管瘤和黑色素瘤的鉴别诊断上具有重要价值,同时为鉴别眼球内其他病变提供有力的依据.     

MRI对微波固化治疗肝癌疗效的评价

目的评价1.5TMRI平扫和动态增强对肝癌微波固化治疗后表现和疗效随访的价值。方法回顾性分析26例32个病灶肝癌微波固化治疗后MRI表现,并与AFP和DSA结果进行对照。结果微波固化治疗3天后的MRI平扫表现,T1WI呈相对高信号,T2WI呈相对低信号,病灶周围可见长T1,长T2水肿带。微波固化治疗1月后的MRI表现①单独行微波固化治疗的19个病灶以凝固性坏死为主,平扫T1WI呈相对等高信号,T2WI呈相对低信号或等信号,动态增强扫描无强化;②多种介入方法联合应用的5个病灶,特别是与TACE联合治疗的病灶,以凝固性坏死、液化性坏死合并存在,表现为局部T1WI呈相对低信号,T2WI呈相对高信号,但动态增强扫描无强化;③8个病灶不完全坏死:在T1WI上呈相对高信号的病灶周边有低信号结节或同时伴新月形低信号带,在T2WI上则表现为等低信号病灶周边出现相对高信号结节或新月形高信号带,在动态增强扫描时呈快进快出强化表现。结论 MRI平扫和动态增强评价微波固化的疗效可靠、准确,微波固化术后定期MRI随访具有重要意义。     

Intraocular tumors: evaluation with MR imaging

Sixty-seven ocular tumors were studied with magnetic resonance (MR) imaging and computed tomography (CT). These tumors included primary uveal melanoma (n = 55), circumscribed choroidal hemangioma (n = 3), diffuse choroidal hemangioma (n = 1), retinal capillary hemangioma (n = 1), medulloepithelioma (n = 1), choroidal nevus (n = 1), retinoblastoma (n = 1), and choroidal metastases (n = 4). MR imaging demonstrated all these lesions, while CT demonstrated 88%. Associated retinal detachment was more easily distinguished from the neoplasms with MR imaging. Extrascleral extension of melanoma and hemorrhagic cystic necrosis within the melanoma were clearly demonstrated with MR imaging, but not with CT. Ninety-three percent of melanomas were markedly hyperintense, compared with the intensity of the vitreous body, on T1-weighted images and hypointense on T2-weighted images. All metastatic lesions were isointense on T1-weighted images and hypointense on T2-weighted images. The circumscribed choroidal hemangiomas were hyperintense on T1-weighted images and isointense on T2-weighted images. MR imaging is superior to CT in detection of intraocular tumors and may be more specific in diagnosis.     

Choroidal hemangioma: MR findings and differentiation from uveal melanoma.

BACKGROUND AND PURPOSEThe aim of this study was to establish the MR imaging characteristics of choroidal hemangioma and to compare them with those of uveal melanoma.METHODSAmong 41 patients examined at 1.5 T (4-cm surface coil, T1-weighted and fast spin-echo T2-weighted sequences), 25 had uveal melanoma and 16 had circumscribed choroidal hemangioma. After i.v. bolus injection of gadopentetate dimeglumine, dynamic and T1-weighted sequences were acquired.RESULTSIn patients with choroidal hemangioma, uniform signal characteristics were detected on fast T2-weighted images. In 15 of 16 patients with choroidal hemangioma, lesions were isointense with vitreous on fast spin-echo T2-weighted images, whereas lesions in 24 of 25 patients with uveal melanoma were hypointense. Signal characteristics of uveal melanoma and hemangioma did not differ significantly on plain T1-weighted images. Enhancement was earlier and much stronger for circumscribed choroidal hemangioma than for uveal melanoma. After i.v. bolus application of gadopentetate dimeglumine, the increase of signal intensity was higher for circumscribed choroidal hemangioma (signal intensity ratio, 5.8) than for uveal melanoma (signal intensity ratio, 2.2).CONCLUSIONCircumscribed choroidal hemangioma may be difficult to differentiate from melanoma by ophthalmologic examination. Differentiation may not be possible if direct viewing of uveal space-occupying lesions is hampered by opaque vitreous media. The characteristic findings on fast spin-echo T2-weighted MR images and early enhanced images aid in differentiating choroidal hemangioma from uveal melanoma.     

葡萄膜转移瘤的MRI表现

目的探讨葡萄膜转移瘤的MRI表现特点。方法回顾性分析20例经病理或临床随访证实的葡萄膜转移瘤的MRI表现。1例仅行平扫，19例同时行平扫和增强扫描，其中4例行动态增强扫描。结果20例葡萄膜转移瘤中，位于虹膜和睫状体2例，18例位于脉络膜；2例表现为略长T1、等T2信号，9例表现为等T1、等T2信号，3例表现为等T1、略长T2信号，3例表现为等T1、略短T2信号，2例表现为略短T1、略短T2信号，1例表现为略短T1、略长T2信号；8例表现为眼球壁轻度增厚，3例呈新月形，7例呈梭形，2例呈结节状。19例呈中度至明显强化；行动态增强扫描的4例时间-信号强度曲线均呈速升、缓降型。伴有视网膜脱离11例和玻璃体信号异常2例。结论MRI能显示葡萄膜转移瘤的部位、形态、信号及强化特点，有助于葡萄膜转移瘤的诊断与鉴别诊断。     

MR findings in eosinophilic infiltration of the liver

OBJECTIVE: This study describes the findings of magnetic resonance imaging (MRI) of focal eosinophilic infiltration of the liver. METHODS: Contrast-enhanced MR images of 8 patients with focal hepatic eosinophilic infiltration were reviewed retrospectively. We evaluated the signal intensity of focal lesions in T1-weighted and T2-weighted images and the pattern of enhancement in a dynamic contrast study. RESULTS: A total 22 focal hepatic lesions were observed; the lesions were isointense (55%) or hypointense (45%) on T1-weighted images and isointense (14%) or hyperintense (86%) on T2-weighted images. The arterial phase of the contrast study revealed 11 hyperintense lesions (50%). During the portal and delayed phases, 18 (82%) and 17 lesions (77%) were hyperintense, respectively. CONCLUSION: The focal eosinophilic infiltrations showed homogeneous enhancement in the portal and delayed phases in the dynamic contrast MR study. These findings should help to distinguish focal eosinophilic infiltration, especially from metastasis in patients with malignancy.     

Dynamic MR imaging of liver lesions with superparamagnetic iron oxide (SH-U-555A)

Dynamic MRI with SH-U-555 (SPIO) was evaluated. Dynamic MRI was performed for 17 patients with 22 lesions. Dynamic study with T2*-weighted imaging (T2* dynamic) and T1-weighted imaging (T1 dynamic) were performed in 8 cases (10 lesions) and 9 cases (12 lesions), respectively. T2* dynamic MR images were obtained before and 30, 90, 180, 270, 360, and 450 seconds and 31 minutes after the intravenous injection of SPIO, and T1 dynamic MR images were obtained before and 0, 40, 80, 120, 180, 240, 300, 360, 420, and 480 seconds and 28 minutes after the injection of SPIO. The signal intensity of each lesion was measured before and after the injection of SPIO. The enhancement ratio of the lesions was calculated and evaluated. The enhancement ratio of hypervascular lesions decreased rapidly in the first phase of T2* dynamic MRI, while that of hypovascular lesions decreased gradually. The enhancement ratio of hypervascular lesions increased in the first phase of T1 dynamic MRI and decreased gradually, while that of hypovascular lesions lacked the increase in the first phase, in contrast to hypervascular lesions. However, the changing of signal intensity could not be recognized on images with T2* dynamic and T1 dynamic study. In conclusion, quantitative analysis using the enhancement ratio made it possible to anticipate lesion vascularity.     

Patterns of lesion development in multiple sclerosis: longitudinal observations with T1-weighted spin-echo and magnetization transfer MR.

PURPOSEWe evaluated the appearance of enhancing multiple sclerosis (MS) lesions on unenhanced T1-weighted MR images and the natural course of enhancing MS lesions on serial unenhanced T1-weighted and magnetization transfer (MT) MR images.METHODSOne hundred twenty-six enhancing lesions were followed up monthly for 6 to 12 months to determine their signal intensity on unenhanced T1-weighted and MT MR images. At the time of initial enhancement, the size of the lesion and the contrast ratio of enhancement were calculated for each enhancing lesion. During follow-up, the contrast ratio on the corresponding unenhanced T1-weighted image was measured, and an MT ratio (MTR) was calculated.RESULTSTwenty-five enhancing lesions (20%) appeared isointense and 101 lesions (80%) appeared hypointense relative to normal-appearing white matter on unenhanced T1-weighted images. During 6 months of follow-up, four MR patterns of active lesions were detected: initially isointense lesions remained isointense (15%); initially isointense lesions became hypointense (5%, most of which reenhanced); initially hypointense lesions became isointense (44%); and initially hypointense lesions remained hypointense (36%). MTR was significantly lower for hypointense lesions as compared with isointense lesions at the time of initial enhancement. For lesions that changed from hypointense to isointense, MTR increased significantly during 6 months of follow-up. Multiple regression analysis showed that strongly decreased MTR at the time of initial enhancement and enhancement duration of more than one scan were predictive of a hypointense appearance on unenhanced T1-weighted images at 6 months'' follow-up. Ring enhancement was found to be the only (weak) predictor of persistently hypointense signal intensity.CONCLUSIONMost enhancing lesions appear slightly to significantly hypointense on unenhanced T1-weighted images. Although most hypointensities are reversible, only those lesions that fail to recover on unenhanced T1-weighted and MT images may have considerable irreversible structural changes.     

乳腺磁共振成像:组织学与病灶定性、定量特征的相关性

目的　通过分析定性、定量MR特征鉴别良、恶性乳腺病灶。方法　对 46例患者的病灶定性、定量MR特征及BI -RADS分类积分与组织学的相关性进行比较。结果　定性特征中的形状、边缘类型、T2 WI相对信号强度、早期周边环形强化、晚期不均匀强化、时间 -信号强度曲线类型与恶性具有统计学显著相关性 (Ρ <0 .0 5 ) ;定量特征中的强化峰值时间、增强曲线最大斜率和流出率与恶性具有统计学显著相关性 (Ρ <0 .0 0 1) ;BI -RADS分类积分系统与恶性具有统计学显著相关性 (Ρ <0 .0 0 1)。结论　定性、定量特征相结合能够提高乳腺病灶诊断的准确性。     

肝海绵状血管瘤MRI动态增强表现

目的研究肝脏海绵状血管瘤MRI动态增强表现。材料与方法107例患者行MRI平扫及FL2D或SE序列动态增强扫描,分析其中的119个血管瘤的动态增强表现。结果41个血管瘤在增强早期(团注造影剂后1min内)表现为均一高信号增强,78个血管瘤表现为边缘结节状增强并逐渐向中间充填增强。SE序列扫描1.2％(1/84)的病灶延迟期呈等信号充填增强,FL2D扫描11.5％(4/35)的病灶延迟期呈等信号充填增强,余病灶均表现为高信号充填增强。结论肝血管瘤可归纳为两种增强类型快速充填型和边缘结节增强充填型。少部分血管瘤FL2D序列扫描时病灶可呈等信号充填增强。     

脑实质内海绵状血管瘤MRI表现

目的分析脑实质内海绵状血管瘤的MRI表现，提高本病的诊断水平。方法回顾分析18例经临床及手术病理证实脑实质内海绵状血管瘤的MRI影像表现。结果18例共26个病灶，表现为T1WI等信号、高信号、混杂信号或环状高信号，T2WI低信号、均匀高信号或环状高信号，周围可见低信号环；大部分病灶无占位效应及周围水肿，所有病灶在梯度回波（GRE）序列上均可见到病灶边缘低信号环；Gd—DTPA增强扫描部分病灶强化。结论海绵状血管瘤MRI表现较为特异，MRI检查是诊断脑实质内海绵状血管瘤最为敏感的方法。     

动态及延时增强磁共振成像对肝血管瘤诊断的评价

目的:研究动态增强及延迟增强扫描磁共振成像对肝血管瘤的诊断价值。材料和方法:34例肝血管瘤病人行常规MRT1WI、T2WI横断面扫描。经肘静脉手推团注0.1mmol/kg体重Gd-DTPA后,再推入10ml生理盐水冲洗后(推入时间5~6s)行射频毁坏傅立叶采集稳态技术T1WI动态增强扫描及延迟增强扫描,分析病灶及邻近肝实质增强。结果:共发现肝血管瘤病灶67个。动态增强见46个病灶呈边缘不连续样的结节样强化,21个病灶呈周边不规则强化或迅速强化充填;5个病灶动态增强早期见引流静脉强化,14个瘤周肝实质强化。延迟增强扫描见53个病灶完全充填强化,14个病灶显示斑片状或裂隙状的低信号未充填区。结论:在磁共振成像检查中,动态增强扫描能够显示肝血管瘤及邻近实质强化方式,延迟增强显示病灶的充填程度,两者结合更有利于肝血管瘤的诊断。