原发性肾上腺肿瘤的MRI评价

目的:探讨MRI对原发性肾上腺肿瘤的诊断及鉴别诊断价值。方法:对96例经手术病理及临床证实的原发性肾上腺肿瘤的MRI表现进行回顾性分析,46例患者平扫后作了Gd-DTPA增强扫描,15例患者(腺瘤12例和非腺瘤3例)作了化学位移成像(CSI)序列扫描。结果:MRI对原发性肾上腺肿瘤的定位、定性(区分良、恶性肿瘤)及判断肿瘤组织学类型的准确度分别为98%、95%和91%。与同相位(IP)相比较,反相位(OP)图像上12例腺瘤的信号强度(SI)都有明显下降,SI指数平均为(52±18)%;3例非腺瘤OP图像上肿瘤的信号强度无明显下降。结论:结合临床表现和生化检查,MRI能诊断大部分原发性肾上腺肿瘤,对较大肿瘤的定位、定性及肿瘤组织学类型的判断有优越性。     

动态增强MRI检查对于肾上腺腺瘤与非腺瘤的鉴别诊断价值

MRI检查能清晰地显示肿瘤的大小、形态、与周围组织的关系及有无淋巴结转移,也能反映出肿瘤的某些组织学特征,而且由于MRI检查的多方位、多参数、多序列成像的特点,为研究应用各种不同的检查方法鉴别肾上腺腺瘤与非腺瘤提供了可能.就动态增强MRI检查技术在鉴别诊断肾上腺腺瘤与非腺瘤时的应用方法及价值进行综述.     

肾上腺间质组织肿瘤的CT和MRI表现

目的 分析５例罕见的肾上腺质组织肿瘤的ＣＴ和ＭＲＩ表现。方法 对５例经手术和病理证实的肾上腺间质组织肿瘤的ＣＴ和ＭＲＩ表现进行回顾性分析。其中右肾上腺神经纤维瘤２例,右肾上腺神经鞘瘤１例,左肾上腺纤维脂肪瘤１例,双侧肾上腺脂肪瘤１例。结果１例神经纤维瘤和１例神经鞘瘤有大的囊空区,１例神经纤维瘤显示多发性钙化和片状的增强。１例纤维脂肪瘤为Ｔ１ＷＩ低信号,Ｔ２ＷＩ稍高信号,注射钆剂后明显增强。１例双     

肾上腺肿瘤的MRI诊断

目的　探讨肾上腺肿瘤的MRI诊断价值。方法　回顾性分析 2 6例经手术病理证实的肾上腺肿瘤的MRI表现 ,并与手术病理对照。所有病例均行MRI平扫及增强扫描 ,观察分析病变的形态大小、边界、信号及强化特征。结果　本组 2 6例肾上腺肿瘤中 ,嗜铬细胞瘤 8例 ,表现为有完整包膜的长T1 混杂T2 信号 ,增强后呈不均匀强化 ,MRI特异性表现为T2 WI呈明显高信号 ,出血、坏死、囊腔形成表现为信号不均匀。转移瘤 5例 ,均为肺癌双侧肾上腺转移 ,形态信号规则或不规则。皮质腺瘤 6例 ,表现为边界清晰的类圆形结节 ,信号均匀 ,无坏死囊变。皮脂腺癌 4例 ,表现为较大不规则长T1 混杂T2 信号 ,不均匀强化 ,伴周围组织血管受侵。髓样脂肪瘤 3例 ,短T1 短T2 (抑脂 )信号为其特征。结论　MRI对肾上腺肿瘤的诊断及鉴别诊断具有重要价值 ,对评价肿瘤与周围结构的关系和制定手术方案具有重要意义。     

肾上腺肿瘤的MRI初步研究

本文通过26例31个肾上腺病变的MR 影像分析,提示MR 具有鉴别良恶性肾上腺肿瘤的能力。在SE 长TR/TE 序列中,皮质腺瘤信号与肝实质相似或稍高。而腺癌及大多数转移瘤信号明显比肝实质高,但较脂肪信号稍低。嗜铬细胞瘤信号则与脂肪相似或更高。     

定量动态增强MRI鉴别乳腺良恶性病变的研究

目的 探讨定量动态增强MRI鉴别乳腺良恶性病变的价值.方法 118例乳腺疾病患者行3.0 T定量动态增强MR检查,测量定量参数:容量转移常数(Ktrans)、速率常数(Kep)和血管外细胞外间隙容积比(Ve),对恶性病变、良性病变及正常腺体组间定量参数行单因素方差分析及LSD法两两比较;对浸润性癌与导管原位癌组间行独立样本t检验;最后绘制ROC曲线.结果 恶性病变组Ktrans、Ken、Ve均值分别为(1.010±0.580)min-1、(1.634±1.481)min-1、(0.735±0.273);良性病变组三者均值分别为(0.331±0.192)min-1、(0.417±0.324)min-1、(0.847±0.291);正常腺体组间三者均值分别为(0.051±0.028)min-1、(0.133±0.125)min-1、(0.597±0.354).正常腺体与良性病变、正常腺体与恶性病变及良性病变与恶性病变间Ktrans差异均有统计学意义(t值分别为9.681、11.189、5.590,P值均＜0.01);正常腺体与恶性病变、良性病变与恶性病变间Kep差异有统计学意义(t值分别为5.287、3.874,P值均＜0.05);正常腺体与良性病变、正常腺体与恶性病变间Ve差异有统计学意义(t值分别为2.932、2.562,P值均＜0.05);正常腺体与良性病变间Kep、良性病变与恶性病变间Ve差异无统计学意义(t值分别为0.760、0.832,P值均＞0.05).浸润性癌与导管原位癌组间Ktrans、Kep、Ve差异均无统计学意义(t值分别为0.834、0.075、0.454,P值均＞0.05).Ktrans、Kep、Ve三者ROC曲线下面积分别为0.934、0.941、0.659,以最大约登指数为最佳诊断切点值,则三者判断乳腺良恶性病变的敏感性分别为77.01%、91.95%、56.32%;特异性分别为95.65%、86.96%、78.26%.结论 定量动态增强参数Ktrans、Kep值可以对乳腺良恶性病变做出鉴别诊断,并表现出相对高的诊断效能,但对浸润性癌与导管原位癌鉴别效能较低.

Abstract：

Objective To evaluate the value of quantitative 3T dynamic contrast enhanced MRI in the diagnosis of breast lesions. Methods One-hundred and eighteen patients suspected of breast lesions underwent MRI examination. A 3.0 T MR scanner was used to obtain the quantitative MR pharmacokinetic parameters: Ktrans( volume transfer constant), Kep (exchange rate constant) and Ve (extravascular extracellular volume fraction). The mean Ktrans, Kep and Ve of malignant, benign and normal glandular tissues were calculated and compared each other using LSD method. Independent sample t test was used between invasive ductal carcinoma and ductal carcinoma in situ (microinvasion included). Finally, the areas under the ROC curve (AUC) of Ktrans, Kep and Ve between malignant and benign lesions were compared. Results The mean Ktrans, Kep and Ve of malignant lesions (n=87) were (1.010±0.580) min-1, (1.634 ± 1.481) min-1 and (0.735 ±0.273); the mean Ktrans, Kep and Ve of benign lesions (n=23) were (0.331±0.192) min - 1, (0.417±0.324) min - 1 and (0.847±0.291); and the mean Ktrans, Kep and Ve of normal glandular tissues (n =83) were (0.051 ±0.028) min-1, (0.133±0.125) min-1 and (0.597±0.354), respectively. There were significant differences between normal glandular tissues and benign lesions, normal glandular tissues and malignant lesions, benign and malignant lesions in Ktrans (t=9.681, 11.189, 5. 590, respectively, P ＜ 0. 01 ), normal glandular tissues and malignant lesions, benign and malignant lesions in Kep(t =5. 287, 3. 874, P＜0. 05). There were a statistic differences between normal glandular tissues and benign lesions, normal glandular tissues and malignant lesions in Ve(t =2. 932, 2. 562 ,P ＜0. 05). There were no significant differences between normal glandular tissues and benign lesions in Kep, benign and malignant lesions in Ve ( t = 0. 760, 0. 832, P ＞ 0.05 ),invasive ductal carcinoma and ductal carcinoma in situ (microinvasion included) in Ktrans, Kep and Ve(t =0.834,0.075,0.454,P＞0.05). The areas under the ROC curve (AUC) of Ktrans, Kep and Ve between malignant and benign lesions were 0. 934, 0. 941 and 0. 659. The sensitivity of Ktrans, Kep and Ve were 77.01% ,91.95% ,56. 32% and the specificity of Ktrans, Kep and Ve were 95. 65%, 86. 96%, 78.26% for the differential diagnosis of breast lesions if taken the maximum Youden's index as cut-off. Conclusion The differential diagnosis of benign and malignant breast lesions by Ktrans, Kep is applicable.     

MRI在良、恶性胸膜肿瘤鉴别诊断中的价值

目的：探讨磁共振成像在良、恶性胸膜肿瘤鉴别诊断中的作用。方法：对45例胸膜肿瘤患者（良性8例,恶性37例）进行了CT和MRI检查。评估分析良、恶性胸膜肿瘤的CT和MRI形态学特点及其分别在T1WI、T2WI和增强T1WI上的信号特点。结果：在CT图像上,共出现弥漫性胸膜增厚30例（恶性29例,良性1例）,纵隔胸膜受累28例（恶性27例,良性1例）、环绕或不规则胸膜增厚23例（恶性22例,良性1例）,胸壁或膈肌浸润9例（全部为恶性）;在MRI上,共出现弥漫性胸膜增厚32例（恶性31例,良性1例）,纵隔胸膜受累29例（恶性27例,良性2例）、环绕或不规则胸膜增厚24例（恶性23例,良性1例）,胸壁或膈肌浸润1例（全部为恶性）。根据前述形态学特点,CT与MRI对诊断胸膜恶性肿瘤总的敏感性分别为83．8％和86．5％,总特异性均为62．5％。结论形态学及信号特点,MRI对诊断良、恶性肿瘤病变的敏感性为97．3％,特异性为100％。结论：单纯依据其形态学特点,MRI对胸膜肿瘤的发现与诊断价值与CT相仿。但当MR信号与形态学特点结合时,其对良、恶性胸膜肿瘤的鉴别诊断价值则明显优于CT。     

乳腺MRI动态增强对良恶性病变的鉴别价值

目的：探讨磁共振动态增强技术（DCE-MRI）对乳腺良恶性病变的鉴别诊断价值。方法：18例乳腺良性病变、16例恶性肿瘤及2例交界性病变患者行DCEMRI检查（平均年龄51．7岁）。对病变的边缘、形态、有无播散征、时间信号曲线、最大增强斜率（MSI）、信号增强率（SER）和信号增强幅度（SEE）等7项指标进行了良恶性组比较。结果：除了MSI以外,其余6项指标在良恶性组之间差异均有显著性意义。用病变形态、时间信号曲线及SEE等五项指标对36例乳腺病变综合评分结果显示：综合评分对诊断乳腺恶性肿瘤的灵敏度、特异度和准确性分别为93．8％、83．3％及88．2％。结论：结合DCE～MRI的病变形态学改变及动态增强表现对乳腺良恶性病变的鉴别有很好的诊断价值。     

动态增强MRI鉴别乳腺良恶性病变的前瞻性研究

目的　前瞻性评估乳腺良恶性病灶的增强形态、时间-信号强度曲线形态、早期增强率以及鉴别病变的价值。方法　40例乳腺病变行三维动态增强MRI检查,在工作站上绘制时间-信号强度曲线并计算早期增强率,分别根据病灶增强形态、时间-信号强度曲线分型和早期增强率大小诊断病变的良恶性。结果　40例41个病灶经病理证实,恶性病灶23个,良性病灶18个。良性病变边缘77.8%（14/18）为光滑或分叶,16.7%(3/18)为不规则或毛刺,早期增强率为(55.5±28.3)%,时间-信号强度曲线72%(13/18)为单相型;恶性病变边缘82.6%(19/23)为不规则或毛刺,13%（3/23）为光滑或分叶,早期增强率为(90.5±38.6)%,时间-信号强度曲线78.3%(18/23)为流出型。良恶性病变的形态分布、时间-信号强度曲线类型和早期增强率差异有显著性意义(χ2值分别为18.42、20.68、10.38,P值均<0.01)。病灶增强形态诊断的敏感性82.6%（19/23）,特异性77.8%（14/18）。时间-信号强度曲线诊断的敏感性95.7%（22/23）,特异性72.2%（13/18）。早期增强率诊断的敏感性87%（20/23）,特异性61.1%（11/18）。结论　典型毛刺状形态和流出型时间-信号强度曲线均强烈提示恶性;单相型时间-信号强度曲线强烈提示良性;早期增强率诊断的特异性差。     

肾上腺放射学：肾上腺良,恶性肿块的鉴别

本复习上肾上腺良、恶性肿瘤的影像特点，讨论鉴别二的方法。     

定量动态增强MRI在乳腺癌中的研究进展

MRI具有良好的软组织分辨力,在乳腺良恶性肿瘤的鉴别以及早期评价乳腺癌治疗效果及预后中具有独特的优势,而动态增强MRI定量分析作为一种MR技术的新方法,可以准确地监测乳腺癌病灶内微血管灌注及渗透情况,并从细胞分子水平上反映出肿瘤的生物学行为。现就定量动态增强MRI的基本原理、数据采集方法、临床应用现状及技术上的局限性进行综述。     

肾上腺腺瘤和非腺瘤的动态增强CT检查

目的采用规范化的动态增强CT检查技术,对大样本病例进行深人地多角度评价．使肾上腺肿瘤动态增强CT检查能够在临床上广泛应用。资料与月法经手术和临床证实的70例共79个肾上腺肿块（腺瘤44个．非腺瘤35个）分别以相同的扫描条件行CT平扫和动态增强检查（静脉注人对比剂后30s开始扫描）,然后延时1、2、3、5．7min扫描。剂量1．2ml／kg体重,注射流率2．5ml／s。分析评价肾上腺肿块的T—D曲线和廓清率Wash（相对廓清率Washr和绝对廓清率Washa）。结果T—D曲线分为5种类型,即A、B、C、D和E各型。腺瘤的特征曲线为A、C型,非腺瘤为B、D、E型（P=0．000）。Washr和Washa于腺瘤和非腺瘤间存在显著性差异（P=0．000）,腺瘸的Washr和Washa均高于非腺瘤,并且Washr诊断效果优于Washa。7min延时点诊断价值较大．Washr≥34HU提示为腺瘤．反之提示为非腺瘤。结论肾上腺CT动态增强检查能够对腺瘤和非腺瘤尤其对乏脂性腺瘤与非腺瘤的鉴别诊断具有较大价值。     

动态增强MRI在评价前列腺肿瘤微血管生成的临床应用

血管生成是前列腺癌(PCa)发生、发展及转移的关键因素.动态增强磁共振成像(DCE-MRI)是静脉注射小分子质量的钆螯合物通过T1WI 及T2*WI 技术来无创地反映肿瘤组织复杂的血流动力学情况(如灌注异常,微血管的高通透性等),从而了解前列腺肿瘤血管的生成及微血管密度情况.就DCE-MRI 与前列腺肿瘤组织中微血管生成的相关性进行综述.     

Evaluation of T2-weighted and dynamic contrast-enhanced MRI in localizing prostate cancer before repeat biopsy

We assessed the accuracy of T2-weighted (T2w) and dynamic contrast-enhanced (DCE) 1.5-T magnetic resonance imaging (MRI) in localizing prostate cancer before transrectal ultrasound-guided repeat biopsy. Ninety-three patients with abnormal PSA level and negative prostate biopsy underwent T2w and DCE prostate MRI using pelvic coil before repeat biopsy. T2w and DCE images were interpreted using visual criteria only. MR results were correlated with repeat biopsy findings in ten prostate sectors. Repeat biopsy found prostate cancer in 23 patients (24.7%) and 44 sectors (6.6%). At per patient analysis, the sensitivity, specificity, positive and negative predictive values were 47.8%, 44.3%, 20.4% and 79.5% for T2w imaging and 82.6%, 20%, 24.4% and 93.3% for DCE imaging. When all suspicious areas (on T2w or DCE imaging) were taken into account, a sensitivity of 82.6% and a negative predictive value of 100% could be achieved. At per sector analysis, DCE imaging was significantly less specific (83.5% vs. 89.7%, p < 0.002) than T2w imaging; it was more sensitive (52.4% vs. 32.1%), but the difference was hardly significant (p = 0.09). T2w and DCE MRI using pelvic coil and visual diagnostic criteria can guide prostate repeat biopsy, with a good sensitivity and NPV.     

Differences in perfusion parameters between upper and lower lumbar vertebral segments with dynamic contrast-enhanced MRI (DCE MRI)

To investigate the influence of age, sex and spinal level on perfusion parameters of normal lumbar bone marrow with dynamic contrast-enhanced MRI (DCE MRI). Sixty-seven subjects referred for evaluation of low back pain or sciatica underwent DCE MRI of the lumbar spine. After subtraction of dynamic images, a region of interest (ROI) was placed on each lumbar vertebral body of all subjects, and time intensity curves were generated. Consequently, perfusion parameters were calculated. Statistical analysis was performed to search for perfusion differences among lumbar vertebrae and in relation to age and sex. Upper (L1, L2) and lower (L3, L4, L5) vertebrae showed significant differences in perfusion parameters (p<0.05). Vertebrae of subjects younger than 50 years showed significantly higher perfusion compared to vertebrae of older ones (p<0.05). Vertebrae of females demonstrated significantly increased perfusion compared to those of males of corresponding age (p<0.05). All perfusion parameters, except for washout (WOUT), showed a mild linear correlation with age. Time to maximum slope (TMSP) and time to peak (TTPK) showed the same correlation with sex (0.22<r<0.32, p<0.05). Our results indicate increased perfusion of the upper compared to the lower lumbar spine, of younger compared to older subjects and of females compared to males.     

Quantitative analysis of dynamic contrast-enhanced MRI datasets of the metacarpophalangeal joints

RATIONALE AND OBJECTIVES: In this article, we propose an alternative approach to voxel-by-voxel analysis, which overcomes problems associated with heuristic methods currently used for dynamic contrast-enhanced MRI (DCE-MRI) data assessment. We aim to allow fully automated extraction of various heuristic parameters via robust preprocessing methods and a new technique for classification of temporal patterns of contrast agent uptake, making full use of all available dynamic frames of the datasets. We also demonstrate that application of efficient preprocessing methods permits more accurate analysis of the dynamic data. MATERIAL AND METHODS: Ten DCE-MRI datasets enhanced by gadolinium diethylene triamine pentacetic acid were acquired from patients with rheumatoid arthritis using a 1.5-T MRI scanner. Fully automated voxel-by-voxel analysis of DCE-MRI signal intensity curves from 60 temporal slices was performed using a new method. Qualitative evaluation of the degree of inflammation was done via constructing parametric maps and quantitative by computing various heuristics such as maximum rate of enhancement, initial rate of enhancement, and time of onset of enhancement. RESULTS: Quantitative and qualitative evaluation obtained for 10 DCE-MRI datasets is presented. We demonstrate that preprocessing techniques compensate for patient movement, contribute to data fidelity and therefore permit more robust estimation of various heuristics such as maximum rate of enhancement, initial rate of enhancement, and time of onset of enhancement. Automatically generated parametric maps of these heuristics show favorable characteristics, permitting easier differentiation of structures of interest. These results are free from the subjective input and therefore easily reproducible. Furthermore, the proposed classification scheme provides information on the pattern of contrast uptake previously unavailable. CONCLUSION: Our preliminary results demonstrate the potential of the proposed method for providing objective quantitative and qualitative assessment of DCE-MRI in the metacarpophalangeal joints. Further evaluation within a clinical setting is needed to examine the method's diagnostic utility.     

Evaluation of semi-quantitative dynamic contrast-enhanced MRI parameters for prostate cancer in correlation to whole-mount histopathology

Purpose

To evaluate the use of semi-quantitative dynamic contrast-enhanced MRI (DCE-MRI) parameters for the detection of prostatic carcinoma in correlation to whole-mount histopathology.

Materials and methods

Fifty-three patients with biopsy-proven prostate cancer were examined by DCE-MRI at 1.5-T. Cancerous and benign prostatic tissue regions of interest were delineated based on the histopathology of whole-mount sections and several semi-quantitative parameters were calculated: time to peak (TTP), maximal contrast enhancement (Cpeak), speed of contrast uptake (Wash-in) and clearance rate of the contrast agent (Wash-out). The area under the ROC curve was determined for each parameter.

Results

Within individual patients, a consistently higher Cpeak and faster Wash-in were present in cancerous compared to benign prostatic tissue. Both the TTP and the Wash-out occurred more rapidly in tumour tissue than in normal prostatic tissue. Despite a considerable inter-patient overlap of parameter values between tumour and normal prostatic tissue, area under the ROC curve analysis demonstrated that the Wash-in was a good discriminator for cancer and benign tissue (AUC 0.82). Combination of the Wash-in and the Wash-out proved to be even more accurate (AUC 0.87) to discriminate between cancerous and benign prostatic regions.

Conclusion

The Wash-in is a useful parameter for prostate cancer detection by DCE-MRI.     

动态增强MRI检查分级评估良恶性乳腺团块型病灶的价值

目的 探讨鉴别乳腺良恶性病灶的客观评分方法,为乳腺团块型病灶的良恶性判断提供客观评价依据.方法 将第4版乳腺影像和报告系统(BI-RADS)的MR部分对团块型病灶的描述作为病灶评价指标对188个高血供团块型病灶评分,根据评分结果与病理结果进行ROC曲线分析,计算曲线下面积并计算最佳良恶性诊断阈值;根据最佳诊断阈值及病灶良恶性倾向将病灶归入Ⅰ～Ⅴ级(Ⅰ级阴性、Ⅱ级良性、Ⅲ级可能良性、Ⅳ级可疑恶性、Ⅴ级高度提示恶性),最后检测评分方法诊断恶性团块型病灶的敏感度和特异度.结果 病理证实188个高血供病灶中有91个恶性,97个良性.ROC曲线下面积为0.938±0.016,评分法鉴别病灶良恶性的最佳阈值为5分.病灶分级结果为Ⅱ级24例、Ⅲ级72例、Ⅳ级54例、Ⅴ级38例.评分法诊断恶性乳腺团块型病灶的敏感度为87.91％,特异度为87.62％.除去Ⅲ级中3例假阴性的导管原位癌,特异度提高到90.90％.结论 建立在多参数标准化分析基础上的评分方法有助于客观判读乳腺动态增强MR影像.     

Limitations of the keyhole technique for quantitative dynamic contrast-enhanced breast MRI

The effect of keyhole data acquisition on quantitative analysis of dynamic MRI was examined. Experiments were performed retrospectively on raw data obtained from clinical dynamic contrast-enhanced breast imaging procedures. The effects of keyhole phase-encoding acquisition and type of reconstruction algorithm on the accuracy of derived quantitative parameters was assessed. Results indicate that the minimum keyhole size used should be restricted by the approximate minimum size of the expected lesions. Furthermore, reconstruction algorithms that offer improved image resolution do not circumvent this restriction.     

Optimal breathing protocol for dynamic contrast-enhanced MRI of solitary pulmonary nodules at 3T

The purpose of this study was to evaluate optimal breathing maneuvers that minimize lung parenchymal movement for dynamic contrast-enhanced MRI (DCE-MRI), which requires longer scan times, beyond the limit of a single breath hold. A healthy volunteer was scanned on a 3T MR scanner using two different breathing maneuvers. In the first, the healthy volunteer was instructed to hold his breath as much as possible and breathe in between breath holds while an image was obtained. In the second, the volunteer was instructed to breathe shallowly and freely throughout the scan. On the obtained images, the excursion of the highest point of the right diaphragm and the pulmonary vessel branches located in the four different anatomic regions of the lung were measured in two orthogonal planes. A patient with a solitary pulmonary nodule (SPN) underwent DCE-MRI utilizing a 2D spoiled gradient-echo (SPGR) sequence while the patient breathed shallowly and freely during the scan. The standard deviations of the excursion of the highest point and selected pulmonary vessels were much smaller during shallow, free breathing maneuver scans than those during breath hold maneuver scans. A dynamic perfusion-fitting curve of the SPN was obtained during the DCE-MRI using shallow free breathing. Shallow, free breathing allows smaller diaphragmatic cranial caudal and lung parenchymal displacements. Therefore, it can be useful during exams where targeting of the lesion is necessary, in studies with long scan times, such as dynamic MRI. This breathing maneuver makes it possible to analyze SPN with DCE-MRI while making use of the advantages of a higher magnetic field in conjunction.