脑内结核瘤Gd-DTPA增强MRI表现特点

目的总结和分析脑内结核瘤在Gd-DTPA增强MRI上的表现特点. 资料与方法对24例脑内结核瘤患者进行平扫和Gd-DTPA增强扫描,比较和分析平扫及增强扫描MRI上的表现特点,包括病灶检出数目、分布情况、病灶的形态、信号特点等.结果结核瘤在Gd-DTPA增强扫描自旋回波T1WI上强化明显,呈结节样或环形强化,有多个病灶聚合成团的特点;病变与周边组织分界清楚.结论脑内结核瘤在增强MRI上有一定的特征性表现,Gd-DTPA增强MR检查较平扫更敏感,能早期发现脑内结核瘤.     

中枢型神经纤维瘤病的临床表现与MR影像特征(附4例报告及文献复习)

目的 研究中枢型神经纤维瘤病（神经纤维瘤病2型，NF2）的临床表现与MR影像特征。方法 4例可疑NF2患于临床症状出现或加重后3周至2年内行头颅Gd-DTPA增强前后MRI检查，NF2的MRI诊断得到手术与病理证实。同时，记录了每例患的临床表现。结果 MRI平扫显示，NF2病灶的特征性表现为T1WI上呈低，等信号，而在T2WI上呈高信号，Gd-DTPA增强后，病灶呈明显强化，MRI还证实了4例NF2患均合并脑膜瘤，这些患最常见的症状是进行性耳聋，耳鸣，眩晕，步态不稳。结论 NF2具有恒常的能通过对比增强MR像证实的强化特征，因此，头颅Gd-DTPA增强前后MRI检查应成为诊断MF2的主要手段。     

鼻咽癌复发的增强前后MRI诊断

评价Gd-DTPA增强前后MR I在鼻咽癌放疗后复发(RNPC)与放射性纤维化(RF)鉴别诊断中的作用.材料和方法:对MR平扫显示鼻咽部或邻近区域有软组织肿块的28例鼻咽癌放疗后患者行Gd-DTPA增强MR I检查.RNPC22例,RF6例,炎性肿块2例,2例颅底RNPC分别合并鼻咽侧壁RF与炎性病灶.分析病灶形态及信号强度.结果:大多数RNPC病灶表现为TIWI上低信号TZWI高信号,RF在TIWI和T2WI上均显示低或中等信号,平扫两者信号强度区别在于T2WI上,但有一定重叠.增强扫描TIWI示绝大多数RNPC病灶(90.9%)有中度以上明显强化,而RF无或轻度强化,两者信号强度有显著性差异(P<0.01),且增强后肿瘤边界显示更清楚.病灶无强化,可除外RNPC,有强化则不一定是RNPC,明显强化可见于炎性病变.结论:肿块在MR平扫T2WI和增强后TIWI上的信号强度是鉴别RNPC与RF的主要依据,Gd-DTPA增强扫描有助于确定病变性质及其侵犯范围.     

骨肿瘤的MR灌注和扩散加权成像研究

目的对临床常见的骨肿瘤进行MR灌注成像(PWI)和扩散加权成像(DWI)研究,探讨其在骨肿瘤定性诊断中的价值。方法收集恶性骨肿瘤18例,良性骨肿瘤21例,行MR PWI和MR DWI,应用Functool2软件分析,于灌注像上得到病灶时间-信号曲线(TIC)、首过期(FP)信号递减幅度、TIC最大线性斜率、两次稳态信号差值;于DWI上获得病灶表观扩散系数(ADC)值;采用SPSS13.0统计分析软件,将从良、恶性骨肿瘤两组样本中获得的各种参数用成组设计的两样本均数进行t检验,采用受试者操作特征(ROC)曲线选择良恶性肿瘤鉴别诊断的阈值,计算MR PWI和MR DWI诊断恶性骨肿瘤的敏感度、特异度、和准确度。结果MR PWI显示,17/21的良性骨肿瘤TIC表现为I型(平稳型)及II型(缓降缓升型),恶性骨肿瘤TIC表现为III型和IV型(速降型);良、恶性骨肿瘤之间的FP信号递减幅度、TIC最大线性斜率及两次稳态信号差值在良、恶性骨肿瘤之间的差异均具有显著性统计学意义,其据此诊断恶性骨肿瘤的准确度分别为82.1%、79.5%和87.2%;有4例良性骨肿瘤可根据其MR-PWI作定性判断,结果误诊为恶性肿瘤。MR DWI显示:b=300s/mm2时,良、恶性骨肿瘤的ADC值的差异具有统计学意义;若以ADC1.63×10-3mm2/s为恶性阈值,其诊断恶性骨肿瘤的准确度为79.5%。MR PWI和MR DWI诊断恶性骨肿瘤的准确度分别为89.7%和79.5%。结论MR PWI比MR DWI更有助于鉴别良、恶性骨肿瘤及肿瘤样病变,但恶性骨肿瘤与富血供良性骨肿瘤及肿瘤样病变的灌注参数存在重叠,此时结合MR DWI可以提高诊断准确度。     

肝脏占位性病变的磁共振成像研究：超顺磁性氧化铁与钆喷替酸葡甲胺的比较

通过与常用造影剂钆喷替酸葡甲胺（Gd-DTPA）的配对实验来评价新型造影剂超磁性氧化铁（SPIO）对有肝占位的检出率和定性诊断能力。材料和方法：53个病例132个肝占位首日行平扫及Gd-DTPA的动态增强扫描,次日行SPIO增强扫描,对照病理及临床随访证实结果,探讨各种占位SPIO增强扫描的强化特点,比较平扫联合Gd-DTPA动态增强扫描与平扫联合SPIO增强扫描的病灶检出率和定性诊断率。结果：SPIO增强扫描良性肝占位的信号随肝实质降低,而恶性肝占位的信号保持不变。平扫联合SPIO增强扫描的病灶检出率和定性诊断率较平扫联合Gd-DTPA增强扫描的略高,但统计学上相差不显著。结论：SPIO强化的原理、强化方式直至临床应用方法、特点与Gd-DTPA均完全不同,两者可相互补充和印证,当Gd-DTPA动态增强扫描定性诊断困难时应积极行SPIO增强扫描。     

骨肿瘤的MR灌注和扩散加权成像研究

目的 对临床常见的骨肿瘤进行MR灌注成像(PWI)和扩散加权成像(DWI)研究,探讨其在骨肿瘤定性诊断中的价值.方法 收集恶性骨肿瘤18例,良性骨肿瘤21例,行MR PWI和MR DWI,应用Functool 2软件分析,于灌注像上得到病灶时间一信号曲线(TIC)、首过期(FP)信号递减幅度、TIC最大线性斜率、两次稳态信号差值;于DWI上获得病灶表观扩散系数(ADC)值;采用SPSS 13.0统计分析软件,将从良、恶性骨肿瘤两组样本中获得的各种参数用成组设计的两样本均数进行t检验,采用受试者操作特征(ROC)曲线选择良恶性肿瘤鉴别诊断的阈值,计算MR PWI和MR DWI诊断恶性骨肿瘤的敏感度、特异度、和准确度.结果 MRP PWI显示,17/21的良性骨肿瘤TIC表现为Ⅰ型(平稳型)及Ⅱ型(缓降缓升型),恶性骨肿瘤TIC表现为Ⅲ型和Ⅳ型(速降型);良、恶性骨肿瘤之间的FP信号递减幅度、TIC最大线性斜率及两次稳态信号差值在良、恶性骨肿瘤之间的差异均具有显著性统计学意义,其据此诊断恶性骨肿瘤的准确度分别为82.1%、79.5%和87.2%;有4例良性骨肿瘤可根据其MR-PWI作定性判断,结果误诊为恶性肿瘤.MR DWI显示:b=300 s/mm2时,良、恶性骨肿瘤的ADC值的差异具有统计学意义;若以ADCI.63x103mm3/s为恶性阈值,其诊断恶性骨肿瘤的准确度为79.5%.MR PWI和MR DWI诊断恶性骨肿瘤的准确度分别为89.7%和79.5%.结论 MR PWI比MR DWI更有助于鉴别良、恶性骨肿瘤及肿瘤样病变,但恶性骨肿瘤与富血供良性骨肿瘤及肿瘤样病变的灌注参数存在重叠,此时结合MR DWI可以提高诊断准确度.     

Gd-DTPA标记单克隆抗体对荷人肝癌裸鼠的MR成像研究

目的评价特异性MR对比剂Gd-DTPA-单克隆抗体HAb18对肿瘤的强化效果.材料与方法制备Gd-DTPA标记的单克隆抗体,并测定每分子抗体所结合的Gd 3数目及其免疫活性.12只荷人肝癌裸鼠分为两组,分别给予Gd-DTPA-McAb和Gd-DTPA后进行MR扫描,测量SE T1WI平扫及增强后10 min、30 min、1 h、3 h、6 h、12 h、24 h、48 h图像内肿瘤的信号强度,绘制信号强度-时间曲线,并计算肿瘤强化率及对比度噪声比.结果 Gd-DTPA-单克隆抗体组在注射MR对比剂后的早期,肿瘤表现为缓慢轻度的强化,在注射对比剂24 h后,肿瘤强化达25%,与其他各时间点有统计学差异.Gd-DTPA对照组内,肿瘤表现为快进快出的强化特点.结论使用Gd-DTPA-单克隆抗体进行靶向显像具有特异性作用,有助于肿瘤的定性诊断.     

髓内肿瘤的磁共振诊断与鉴别诊断

本文通过对30例髓内肿瘤和20例非肿瘤病变MR表现的回顾性对比分析,总结了髓内肿瘤MR诊断和鉴别诊断经验。指出髓内肿瘤的MR主要征象为脊髓局部增宽、膨大,病灶Gd-DTPA明显强化,以及伴有囊变。而非肿瘤病变脊髓轮廓改变较轻,Gd-DTPA为轻至中度强化。增强特点为偏心性、点片状或环状,较具特异性。     

肝细胞癌在MR扩散加权成像与动态增强成像中的影像表现

信号;2个T1WI平扫等信号的病变,各期增强仍然呈等信号,DWI表现为高信号,其中1个病理证实为再生结节.1个肝硬化再生结节T1WI平扫及DWI均为高信号,动脉期明显强化,门静脉及平衡期为等信号.结论 多数HCC在MR动态增强图像上表现为动脉期明显强化,部分小HCC可表现为等信号.Gd-DTPA动态增强与DWI结合可能有助提高HCC的诊断准确性.     

增强MRI对周围性肺结节的诊断价值

目的:探讨Gd-DTPA增强MRI对孤立性肺结节的诊断价值.材料和方法:对29例孤立性肺结节行平扫和Gd-DTPA增强MR检查,Gd-DTPA按0.1mml/kg体重静脉内注射,观察不同性质结节的强化模式差异,测量增强前后信号强度变化.结果:恶性肿瘤明显强化,而良性肿瘤不强化或轻度强化,两者有显著差异(P<0.01).部分结核瘤表现为特征性的“周边薄层环状”强化.结论:良恶性结节间强化程度和模式有差异,增强MR对CT不能确诊的肺结节有重要鉴别诊断价值.     

软组织肿瘤的MRI征象

目的:分析下肢软组织良、恶性肿瘤的MRI特点,探讨MRI对软组织良、恶性肿瘤的诊断及鉴别诊断价值。方法:回顾性分析经手术病理证实的48例下肢软组织良、恶性肿瘤的MRI表现,总结其不同影像学征象并进行统计学分析。结果:囊壁特征及侵袭性特点在软组织良、恶性肿瘤中的差异具有统计学意义(P均<0.05),肿瘤大小、瘤周水肿、瘤内出血、T2信号均匀性及对周围结构的侵犯在两组肿瘤中的差异无统计学意义(P均>0.05)。MRI对软组织肿瘤潜在恶性评估的敏感度、特异度分别是82.61%和80.77%。结论:囊壁特征及侵袭性特点在软组织肿瘤的定性诊断中具有重要意义。MRI对软组织肿瘤的诊断和鉴别诊断具有重要意义。     

Differentiating Benign from Malignant Bone Tumors Using Fluid-Fluid Level Features on Magnetic Resonance Imaging

Objective

To analyze different fluid-fluid level features between benign and malignant bone tumors on magnetic resonance imaging (MRI).

Materials and Methods

This study was approved by the hospital ethics committee. We retrospectively analyzed 47 patients diagnosed with benign (n = 29) or malignant (n = 18) bone tumors demonstrated by biopsy/surgical resection and who showed the intratumoral fluid-fluid level on pre-surgical MRI. The maximum length of the largest fluid-fluid level and the ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane were investigated for use in distinguishing benign from malignant tumors using the Mann-Whitney U-test and a receiver operating characteristic (ROC) analysis. Fluid-fluid level was categorized by quantity (multiple vs. single fluid-fluid level) and by T1-weighted image signal pattern (high/low, low/high, and undifferentiated), and the findings were compared between the benign and malignant groups using the χ² test.

Results

The ratio of the maximum length of the largest fluid-fluid level to the maximum length of bone tumors in the sagittal plane that allowed statistically significant differentiation between benign and malignant bone tumors had an area under the ROC curve of 0.758 (95% confidence interval, 0.616-0.899). A cutoff value of 41.5% (higher value suggests a benign tumor) had sensitivity of 73% and specificity of 83%.

Conclusion

The ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane may be useful to differentiate benign from malignant bone tumors.     

跟骨病变的影像学诊断

目的评价跟骨病变的影像学表现。资料与方法回顾性分析经穿刺和手术病理证实的25例跟骨病变影像学表现,其中7例感染性病变(松毛虫感染1例,慢性骨髓炎3例,Reiter’s病1例,结核2例),14例良性肿瘤和肿瘤样病变(骨囊肿4例,动脉瘤样骨囊肿3例,成软骨细胞瘤、血管瘤、内生软骨瘤、软骨黏液样纤维瘤、巨细胞瘤、巨细胞瘤伴动脉瘤样骨囊肿和脂肪瘤各1例),4例恶性骨肿瘤(骨肉瘤和软骨肉瘤各2例)。25例均行X线平片检查,16例行CT检查,8例行MRI检查。结果14例良性肿瘤和肿瘤样病变中11例发生于跟距关节下方,部位较具特征性。感染性病变和良、恶性骨肿瘤影像表现各异,具有各自的相对特征性。结论结合病变部位和平片、CT及MRI综合表现可对跟骨病变进行比较准确的定性。     

Benigne und maligne Veränderungen der Innenohr- und Kleinhirnbrückenwinkelregion

Tumorous lesions in the region of the inner ear and cerebellopontine angle are very rare and can be classified into benign and malignant disease forms. This contribution presents and explains the CT and MRI characteristics of these tumors.High-resolution computed tomography (HRCT) in the axial projection is applied for evaluation in the high-resolution bone window. The coronary slices can be reconstructed from the axial datasets or in individual cases examined in the coronary plane.HRCT excellently demonstrates osseous lesions and in individual cases - e.g., exostoses - it can simply suffice to perform HRCT of the temporal bone, while HRCT is also excellent for detecting osseous lesions to determine whether the tumor is benign or malignant.MRI, on the other hand, excellently shows the extent of tumor spread because of its superb soft tissue contrast. Consequently, HRCT and MRI images of the inner ear and cerebellopontine angle provide meaningful information for visualization and classification of tumorous lesions. The two methods should not be considered as competing but rather as complementary and among other aspects exert considerable influence on the therapeutic approach.     

肾上腺外腹膜后副节瘤的CT、MRI表现

目的:研究肾上腺外腹膜后副节瘤CT、MRI表现。方法:本组经手术病理证实14例,其中男7例,女7例,平均年龄39.2岁。其中功能性副节瘤8例,非功能性副节瘤6例;良性9例,恶性5例。CT平扫检查9例,其中5例作了强化扫描;MRI检查6例。结果:病变<10cm者9/11例良性,>10cm3/3恶性;<5cm者5/6例功能性,>5cm者6/8例为非功能性。CT密度和MRI信号强度对鉴别良恶性作用不大,但出现明确囊变恶性多见(4/5例),有明确侵犯者4/4例恶性。结论:腹膜后副节瘤的CT、MRI表现多样,其大小、囊变及侵犯对鉴别良恶性有帮助。     

胰腺实性假乳头状瘤的CT及MRI诊断

目的:探讨胰腺实性假乳头状瘤(SPTP)的CT及MRI表现.方法:9例经外科手术后病理组织学证实的SPTP,术前5例进行CT及MRI平扫和增强扫描,4例只进行CT平扫和增强扫描.结果:肿瘤3例发生在胰头颈部,6例发生在胰尾部.直径2～11cm,均含有囊壁的囊实性肿块,囊性、实性成分比例各有不同,肿瘤内伴有不同程度的出血,囊壁与周围组织分界清楚,9例均未见钙化灶.增强扫描肿瘤实性部分及囊壁有强化,动脉期呈轻度强化,静脉期及延迟期呈轻中度强化,延迟期肿瘤实性部分强化体积及程度更大,囊性和实性结构变得清晰,但均低于正常胰腺.结论:SPTPCT及MRI表现具有一定的特征性.     

面颊部软组织异常影像分析

目的提高对面颊部软组织异常影像的认识。方法回顾分析47例面颊部软组织异常患者的影像表现。结果(1)原发于面颊部软组织病变15例,良性8例,恶性7例。邻近颌面部病变侵犯面颊软组织6例,良性1例,恶性5例。颌骨病变累及面颊部软组织26例,良性颌骨肿瘤9例,恶性颌骨肿瘤14例,颌骨慢性骨髓炎3例,均有骨质破坏。(2)根据起源部位,21例非颌骨源性面颊软组织异常,5例有骨质破坏(占23.8%)。(3)颌骨源性面颊部软组织异常26例,其中9例良性肿瘤的软组织肿块均主要局限于颌骨内,而14例恶性肿瘤的软组织肿块位于颌骨内、外,两者差别有显著意义(P=0.000)。9例良性肿瘤均呈膨胀性骨破坏,14例恶性肿瘤中,12例为溶骨性骨质破坏,2例为成骨性骨质破坏,两者差别有显著意义(P=0.000)。结论CT和MRI对判断面颊部软组织异常病变的起源部位、范围、鉴别其良恶性具有重要意义。     

Benign breast lesions that simulate malignancy: magnetic resonance imaging with radiologic-pathologic correlation

The typical appearance of benign breast conditions on magnetic resonance imaging (MRI) is well established and diagnosis is usually easy. However, cases of benign breast lesions that are extremely difficult to differentiate from malignant breast tumors are occasionally encountered in MRI of the breast because overlap between benign and malignant lesions characteristics is found. This article describes the MRI features of a variety of suspicious breast conditions that were confirmed to be benign in the histopathologic study. We evaluated both enhancement kinetics and lesion morphological information to differentiate malignant from benign lesions. We also correlated the MRI findings with clinical data, and mammographic, ultrasound, and pathologic findings. Lesions evaluated included benign proliferative breast disease, fibroadenoma, intraductal papilloma, granular cell tumor, pseudoangiomatous stromal hyperplasia, fat necrosis, mastitis, inflammatory granuloma, epidermal inclusion cyst, and benign intramammary lymph node.     

Roles of magnetic resonance imaging in management of bone tumors

The roles of magnetic resonance imaging (MRI) in the diagnosis and treatment of bone tumors are reviewed. Most bone tumors can be detected on plain radiography or bone scintigraphy. MRI is helpful in detecting tumors that do not destroy bone matrix or suppress reactive bone formation. Detailed analysis by plain radiography is still the most reliable method for differentiating between benign and malignant bone tumors. The T1 and T2 values, internal texture, and peritumoral edema depicted on MRI are not helpful for this differentiation. In characterizing the histologic types of bone tumors, MRI is of some advantage. For example, MRI can demonstrate cartilage matrix, hemoglobin metabolites, vascular components, and fat contents more clearly than conventional radiological techniques. MRI is now indispensable for the preoperative delineation of malignant bone tumors, because of its excellent soft tissue contrast and multiplanar imaging capability. In this article, the guidelines for evaluation of the surgical margin advocated by the JOA Musculo-skeletal Tumor Committee are introduced for radiologists. MRI monitoring of malignant bone tumors after chemotherapy or surgery can reveal change in the size of enhanced areas that may reflect viable tumors. Dynamic MRI is helpful to differentiate recurrent tumors from granulation tissue.     

Kernspintomographische Diagnostik benigner und prämaligner abdomineller Tumoren im Kindesalter

PURPOSE: To evaluate the potential of MRI in determining benign and premalignant abdominal tumors in childhood. METHODS: MR images of 93 children with 69 malignant and 24 benign abdominal tumors were analyzed retrospectively without and with knowledge of clinical findings. Based on the final diagnosis, MR findings were surveyed with regard to the correct differential diagnosis and to the differentiation between benign and malignant masses. RESULTS: Analysis of MRI alone revealed relatively low sensitivity of 67% for diagnosis of a benign tumor. The main reason was unspecific morphologic criteria leading to the false-negative diagnosis of a malignant tumor. Together with clinical and laboratory findings, sensitivity could be increased to 92%. The main criterion for differentiation of malignant tumors turned to be out the origin of tumor. Benign tumors could be best differentiated by their internal structure. CONCLUSION: When considering clinical findings in pediatric abdominal tumors, MRI represents a valuable modality for differential diagnosis.