动态对比增强MRI在肺部良恶性病变鉴别诊断中的初步应用

目的 探讨动态对比增强(DCE)-磁共振成像(MRI)在肺部良恶性病变鉴别诊断中的应用价值.方法 收集经病理证实的肺占位性病变患者32例,其中恶性19例,良性13例,均行DCE-MRI检查.测量MRI定量参数,包括:容积转运常数(Ktrans)、回流速率常数(Kep)、血管外细胞外容积分数(Ve)和血管内血浆容积(Vp).采用独立样本t检验比较良恶性病变各测量参数值间的差异.绘制ROC曲线评估定量DCE-MRI鉴别肺部良恶性病变的诊断效能.结果 恶性病变参数Ktrans、Kep、Ve和Vp值分别为(0.632±0.418) min-1、(1.324±0.514) min1、0.431±0.207和0.193±0.103,良性病变Ktrans、Kep、Ve和Vp值分别为(0.107±0.091) min-1、(0.667±0.259) min-1、0.357±0.125和0.096±0.042,恶性病变与良性病变间Ktrans、Kep差异有统计学意义(t值分别为4.112、3.625,P值均＜0.05),恶性病变与良性病变间Ve、Vp差异无统计学意义(t值分别为1.284、2.248,P值均＞0.05).Ktrans、Kep这2个参数ROC曲线下面积分别为0.882、0.846,判断肺良恶性病变的敏感度分别为92.3％、91.7％,特异度分别为87.5％、75.0％.结论 DCE-MRI可定量评估肺部病变毛细血管的通透性,参数Ktrans、Kep值在肺良恶性病变的鉴别诊断中具有重要临床价值.     

MR扩散加权和动态增强成像在老年乳腺肿瘤中的应用

目的探讨磁共振扩散加权成像和动态增强成像在乳腺良恶性病变鉴别诊断方面的新进展及临床应用价值。方法收集自2009年3月至2010年3月期间,共31例患者,33个病灶。所有病灶进行扩散加权成像(DWI)和MRI动态增强成像(DCE-MRI)扫描。结果 MRI动态增强中形态学改变、早期增强率及时间-信号强度曲线对鉴别乳腺病变良恶性均有一定意义;在扩散加权成像中,通过ADC值鉴别良恶性病变敏感性、特异性和准确性均较高。结论MRI动态增强成像和扩散加权成像相结合对老年乳腺病变良恶性的鉴别诊断具有重要价值。     

MRI动态增强定量分析早期预测乳腺癌患者NAC疗效的可行性

目的探讨动态对比增强MRI(DCE-MRI)定量分析早期预测乳腺癌患者NAC疗效的可行性。方法收集经穿刺证实的女性浸润性导管癌患者55例,均予4～6个周期的新辅助化疗。化疗前后分别行DCE-MRI检查。根据化疗后同一病灶穿刺病理结果有无癌灶浸润将所有患者分为缓解组和非缓解组。比较化疗前后两组患者细胞外血管外间隙容积比(Ve)、容量转移常数(Ktrans)、速率常数(Kep)的差异。分析DCE-MRI对乳腺癌患者化疗后疗效判定的敏感度、特异度、阳性预测值、阴性预测值。结果化疗前两组患者的DCE-MRI参数无统计学差异(P>0.05)。化疗4个周期后DCE-MRI缓解组的Ktrans及Kep变化值大于非缓解组〔(1.60±0.25)vs(1.80±0.20)/min;(3.01±0.96)vs(2.87±0.88)/min〕,而Ve变化值小于非缓解组〔(0.62±0.14)vs(0.67±0.10)/min〕(P<0.05)。DCE-MRI对乳腺癌患者化疗后疗效判定的敏感度、特异度、阳性预测值、阴性预测值分别为60.0%、85.7%、70.6%、78.9%。结论 DCE-MRI定量分析对早期预测乳腺癌患者NAC疗效有一定的可行性。     

老年乳腺病变的MRI检查

目的 探讨老年乳腺病变的MR影像改变及评估MR的诊断价值。方法 对60例患者进行1．5T超导高场MR乳腺检查，年龄：60-85岁，平均：72．6岁。女：45例，男：15例。全部病例行平扫检查，其中50例行增强动态扫描。后处理图像进行增强动态曲线分析、减影重建。18例手术，其中15例有B超、钼靶检查。未手术病例均进行2年以上的临床随访。结果 MR诊断女性乳腺癌8例、纤维腺瘤3例，乳腺病5例。男性乳腺增生15例，乳腺未见异常29例。手术18例，术前诊断16例，手术符合率89％。未手术者2年以上临床随访无异常。结论 MR软组织分辨率高，能准确反应病灶的形态学信息，在确定乳房肿块性质、排除触诊的假阳性及追踪随访方面十分优越。MR无X线辐射、简便易行、诊断准确，是老年乳腺病变检查的有效方法。扫描技术处理以平扫结合动态增强为佳。     

MRA在脑血管疾病诊断中的应用

目的 探讨磁共振血管成像(MRA)在脑血管疾病诊断中的应用价值.方法 采用西门子0.35T磁共振对33例颅脑常见脑血管患者进行MRA检查.结果 MRA能清楚显示颅内主要血管形态,发现血管疾病的异常改变.结论 颅脑MRA作为一种无创性的检查方法,在常见脑血管疾病诊断中发挥着重要作用.     

3.0T MRI LAVA动态增强序列在乳腺良恶性病变诊断中的价值

目的探讨3.0T核磁共振成像(MRI)LAVA动态增强序列在乳腺良恶性病变鉴别诊断中的价值。方法回顾性分析经手术或穿刺病理证实的47例乳腺病变患者的MRI资料,分析病变信号、形态、时间—信号强度增强曲线,计算LAVA动态增强序列诊断良恶性病变的灵敏度、特异度、准确度。结果 3.0T MRI平扫示乳腺良恶性病变T1WI多呈等、低信号影,T2WI多呈等、高信号影,二者信号差异无统计学意义;LAVA动态增强序列示恶性病变形态不规则、边缘模糊、不均匀强化,与良性病变差异均有统计学意义,分别以形态不规则、边缘不清作为诊断乳腺恶性病变的标准,LAVA动态增强扫描的灵敏度、特异度及准确度均>76.1%。良性病变多表现为Ⅰ型曲线,恶性病变多表现为Ⅲ型曲线;Ⅱ型曲线在良恶性病变中均可见到。以Ⅰ型曲线作为诊断良性病变的标准,LAVA动态增强扫描的特异度可达96.1%;以Ⅲ型曲线作为诊断乳腺恶性病变的标准,LAVA动态增强扫描的准确度可达87.2%。结论 3.0T MRI LAVA动态增强扫描有助于乳腺良恶性病变的鉴别诊断,且特异性、敏感性、准确性较高。     

乳腺数字三维断层摄影技术与MRI在良恶性乳腺结构扭曲性病变诊断中的应用

目的 探讨乳腺数字三维断层摄影技术（DBT）和乳腺MRI在良恶性乳腺结构扭曲性病变诊断中的应用。方法 收集116例经数字化乳腺X线摄影诊断为结构扭曲性病变乳腺疾病患者,经病理检查确诊为恶性58例、良性58例。入院后均行DBT和MRI检查,采用受试者工作特征曲线（ROC）比较DBT、MRI单独及二者联合对良恶性病变的诊断效能。结果 116例患者中,单独DBT检查诊断为恶性59例、良性57例,单独MRI诊断为恶性72例、良性44例,DBT+MRI诊断为恶性64例、良性52例。MRI、DBT+MRI诊断良恶性乳腺结构扭曲性病变的敏感度最高,均为100%;DBT、DBT+MRI的特异度均高于MRI;DBT+MRI的阳性预测值和准确度均高于DBT、MRI。ROC曲线显示,DBT、MRI、DBT+MRI诊断良恶性病变的曲线下面积分别为0.854、0.903、0.953,DBT+MRI高于DBT(P<0.05),与MRI无统计学差异（P>0.05）。结论 乳腺DBT联合MRI检查对良恶性病变的诊断效能优于单独DBT检查,与单独乳腺MRI检查的诊断效能相近,但特异度有所提高。     

三维动态增强磁共振血管成像与彩色多普勒超声检查在下肢血管病变中应用的价值

目的探讨三维动态增强磁共振血管成像(3DCE-MRA)及彩色多普勒超声(CDFI)检查在下肢血管病变中的应用价值。方法对20例CDFI诊断为下肢血管病变的患者进行下肢血管3DCE-MRA扫描,范围包括肾平面以下腹主动脉、双侧髂内动脉、髂外动脉及股总动脉、股深动脉、股浅动脉、腘动脉、胫前动脉、胫后动脉、腓动脉。其中19例诊断为下肢动脉硬化、斑块形成,1例诊断为外伤后下肢血管损伤。结果20例患者均成功行3DCE-MRA扫描,图像显示清晰,诊断明确。CDFI检出155段病变血管,3DCE-MRA扫描显示病变血管共205段。3DCE-MRA检出病变的阳性率高于CDFI(χ2=14.88,P0.05)。结论3DCE-MRA以其诊断病变阳性率高,无创性,无辐射,对比剂过敏反应少、肝肾毒性小,可以整体显示感兴趣区血管等优点,在下肢血管病变诊断中应用越来越广泛。     

三维动态增强磁共振血管成像表面重建在主动脉弓畸形诊断中的价值初探

目的 探讨三维动态增强磁共振血管成像（3－dimensional dynamic contrast enhanced MRA,3D DCE MRA)表面重建（surface shade display,SSD）对主动脉弓畸形的诊断价值。方法 磁共振血管成像确诊的9例主动脉弓畸形中，2例行时间飞跃法磁共振血管成像（2－dimensional time-of-flight MRA,2D TOF MRA）检查，6例行3D DCE MRA检查，1例同时行2D TOF MRA及3D DCE MRA检查。结果 5例迷走锁骨下动脉及3例颈位主动脉弓的显示，3D DCE MRA优于2D TOF MRA，SSD优于最大强度投影（MIP）；1例右位主动脉弓的显示，MIP同SSD；2例主动脉弓褶曲及1例主动脉弓离断的显示，SSD优于MIP。结论 对于主动脉弓畸形的显示，SSD是3D DCE MRA最好的方法。     

磁共振胆胰管造影联用动态增强对胆管癌的诊断价值

目的：评价屏气磁共振胆胰管造影(MRCP)及联合应用动态增强MRI对胆管癌的临床诊断价值。方法：回顾性分析88例经手术、病理证实的胆管癌的MRCP及动态增强MRI表现。结果：88例检查均一次成功，全部病例胆胰管显示满意。MRCP对肝门型胆管癌和肝外胆管型胆管癌的定位诊断准确率均为l00％，定性诊断准确率为100％和52．2％，结合动态增强MRI扫描，对肝外胆管型胆管癌定性诊断准确率提高到91．3％。结论：MRCP检查成功率高，对肝门型胆管癌和肝外胆管型胆管癌定位准确，结合动态增强MRI扫描，定性诊断也有较高准确性。     

Contrast enhanced body magnetic resonance angiography

The use of gadolinium contrast for body MRA is reviewed. Considerations for timing of the bolus of contrast are discussed. The utility of this technique is illustrated through clinical examples. Contrast enhanced MRA is rapidly replacing conventional angiography for many applications.     

Effect of dopamine agonists on prolactinomas and normal pituitary assessed by dynamic contrast enhanced magnetic resonance imaging (DCE-MRI)

Context Dopamine agonists (DA) may act on prolactinoma size and secretion through additional effects on adenoma vascularity that can be visualized using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). Objective We hypothesized that DAs may exert their effect through a change in tumour functional vascularity leading to a reduction of prolactin (PRL) levels and tumour size. Subjects and methods To investigate this, 23 subjects were studied comprising five with macroprolactinomas, 11 with microprolactinomas, seven with non-lesion hyperprolactinemia and 15 normal volunteers (including five females on oral contraceptive pills). Patients with macroprolactinomas were treated with cabergoline 4 mg weekly and microprolactinomas were treated with quinagolide 75 μg daily for the duration of study. DCE-MRI was performed immediately pre-treatment and at 3–4 days, 1 and 3–4 months after treatment. Normal volunteers took three 75 μg quinagolide doses and were scanned pre-treatment and at 3 days. Data were analysed using the Brix model, producing a measure of vascular permeability and leakage space. Results PRL levels were significantly reduced in all patients and volunteers. Vascular parameters decreased significantly for four of five macroprolactinomas and all microprolactinomas which were maintained during the treatment period (p < 0.01). No changes were seen in normal volunteers or non-lesion hyperprolactinemia. One of five macroprolactinomas showed no change in either permeability or tumour size. Conclusion Functional prolactinoma vascularity differs from non-lesion hyperprolactinemic pituitary and normal pituitary, and is responsive to DA therapy. The reduction in vascular parameters precedes shrinkage in macroprolactinomas, and if not seen within days of treatment may indicate DA resistance requiring early surgery.     

老年血管疾病患者3D DCE MRA检查的临床应用

目的探讨应用Tim外周血管线圈、自动移床及无缝连接技术行动态增强磁共振三维血管成像（3DDCE MRA）的特点,并研究其在老年血管疾病中的临床应用价值.方法共78例疑血管疾病的老年患者行3DDCE MRA,包括颈动脉19例,胸、腹主动脉14例,肺动脉8例,肾动脉11例,双下肢动脉21例,全身动脉5例.采用1.5T磁共振机,Tim外周血管线圈,自动移床及无缝连接技术,行3D DCE MRA检查（3D-FLASH自减影序列）;通过双筒高压注射器经肘正中静脉注射对比剂Gd-DTPA,浓度0.5mmol/ml,总量30ml,流量2.5～3.0ml/s;扫描延迟时间70例采用Test-bolus法,8例采用Care-bolus法;对靶血管作最大信号强度投影（MIP）后处理重建.其中21例经数字减影动脉血管造影（IADSA）或（和）手术证实;图像质量采用优、良、差三级评价.结果78例3D DCEMRA图像质量优良者74例,占94.9%.21例经手术、IADSA证实的3D DCE MRA的敏感性、特异性和准确性分别为93.3%、83.3%和90.5%;假阳性及假阴性各1例,病变程度低估2例.3D DCE MRA结果与IADSA或（和）手术符合率为83.7%,其中主动脉及其主要分支病变符合率为100.0%,但较细分支病变符合率为81.8%.结论Tim线圈、自动移床及无缝连接技术3D DCE MRA是适合老年血管疾病诊断的一种无创或微创性血管显像技术,正确掌握延迟时间是3D DCE MRA成功的关键,对主动脉及其主要分支病变的诊断有较高的可靠性,但对动脉较细分支的分辨率尚待进一步提高.     

超声、MRI检查在乳腺癌诊断中的应用效果比较

目的比较超声(US)与磁共振成像(MRI)在乳腺癌诊断中的应用效果。方法在100例疑似乳腺癌患者术前行US和MRI检查,并将结果与术后的病理结果相对比。结果病理检查诊断乳腺癌67例,余33例为乳腺良性肿块。US、MRI检查分别确诊乳腺癌58例(86.5%)、60例(89.6%),其敏感度分别为86.5%、89.6%。特异度分别为78.8%、75.8%,阳性预测值分别为89.2%、88.2%,阴性预测值分别为74.3%、78.1%。US、MRI诊断乳腺癌的敏感性相比P<0.05,特异性、阳性预测值、阴性预测值相比P均>0.05。结论与US相比,MRI诊断乳腺癌有较高的敏感性。     

心脏疾病的磁共振成像观察

目的 :了解磁共振成像 （MRI）诊断心脏疾病的价值。方法 :分析 3 1例心脏疾病的 MRI解剖结构和血流动力学改变 ,其中心包积液 （PCE） 11例 ,心包血肿 （PCH） 1例 ,主动脉瓣关闭不全 （AI） 12例 ,二尖瓣狭窄并发关闭不全（MS+MI） 1例 ,肥厚型心肌病 （HCM） 3例 ,房间隔缺损 （ASD） 2例 ,ASD并发室间隔缺损 （VSD） 1例。结果 :在 SE序列 ,PCE在 T1 WI呈低信号 （9例 ）和高信号 （2例 ） ,T2 WI呈高信号 ;PCH分别呈略高信号和略低信号 ;AI和 MS+MI分别有左心室和左心室、左心房扩大 ;HCM左心室心肌明显增厚 ,ASD缺损清楚 ,VSD显示不清。在 cine-MRI上 ,AI和 MS+MI分别在左心室和左心室、左心房内出现低信号区 ;HCM的心肌收缩率下降 ,ASD和 VSD分别在右侧房室出现低信号区。结论 :MRI可以较好地显示心脏疾病的解剖异常和血流动力学状态的改变 ,多数疾病可明确诊断     

Ischemic heart disease: value of MR techniques

Background. The cardiovascular applications of magnetic resonance (MR) techniques in coronary artery disease have increased considerably in recent years. Technical advantages of MR imaging are the excellent spatial resolution, the characterization of myocardial tissue, and the potential for three-dimensional imaging. These characteristics allow the accurate assessment of left ventricular mass and volume, the differentiation of infarcted from normal tissue, and the determination of systolic wall thickening and regional wall motion abnormalities. Methods. In addition to the conventionally used spin-echo and cine-echo techniques, newer techniques such as myocardial tagging, ultrafast MR imaging and MR coronary angiography have been developed. These newer techniques allow a more accurate assessment of ventricular function (tagging), myocardial perfusion (ultrafast imaging), and evaluation of stenosis severity (MR coronary angiography). Particularly early detection and flow assessment of stenosed coronary arteries and bypasses by MR angiography would constitute a major breakthrough in cardiovascular MR imaging. Apart from the MR imaging techniques, cardiac metabolism may be well assessed using MR spectroscopy. This provides unique information on the metabolic behaviour of the myocardium under conditions stress-induced ischemia. However, the definite niche of cardiac MR spectroscopy has still to be settled. Conclusion. Currently, MR techniques allow the evaluation of anatomy and function (accepted use), perfusion and viability (development phase), and coronary angiography (experimental phase). A particular strength of MR imaging is that one single MR test may encompass cardiac anatomy, perfusion, function, metabolism and coronary angiography. The replacement of multiple diagnostic tests with one MR test may have major effects on cardiovascular healthcare economics and would outweigh the cost inherent to the MR angiography procedure.     

A preliminary study of the combination of ultrafast and abbreviated dynamic contrast: Enhanced breast magnetic resonance imaging

We combined the abbreviated and ultrafast magnetic resonance imaging (MRI) technique with the standard MRI protocol and compared lesion characterization quantitatively and qualitatively to the standard MRI protocol.Fifty-six patients with breast cancer who underwent MRI from June 2017 to May 2018 and fulfilled our inclusion criteria were included. Three radiologists measured the lesion sizes, described the MRI findings using BI-RADS lexicon, and demarcated the regions of interest to extract the volumetric quantitative and semi-quantitative parameters. We used Pearson''s correlation analysis comparing the quantitative and semi-quantitative parameters. To evaluate the inter-observer variability, we calculated the intra-correlation coefficient (ICC). We also analysed the correlation in BI-RADS lexicon.There were 45 (80.4%) luminal and 11 (19.6%) non-luminal breast cancers, and the most common tumour subtype was invasive carcinoma (n = 48, 85.7%), followed by ductal carcinoma in situ (n = 8, 14.3%). Regarding correlation between the quantitative and semi-quantitative parameters, K^trans significantly correlated with the wash-in factor (r, 0.862; P < .001) and AUC value (r, 0.951; P < .001). The lesion size measured by standard and combined abbreviated-ultrafast phases and that from the surgical pathological specimens showed moderate agreement (ICC range, 0.516−0.578). The ICCs among the 3 readers were excellent for lesion size measurement, BI-RADS lexicon regarding lesion type, mass shape, margin, internal enhancement, non-mass enhancement distribution, and internal enhancement by the standard and combined abbreviated-ultrafast protocols.The use of the modified and combined abbreviated-ultrafast MRI protocol provides a reliable measurement of the quantitative parameters and may aid in the screening of breast cancer.     

3.0T磁共振弥散加权成像在肝脏局灶性病变中的诊断价值初探

目的初步探讨3.0T磁共振弥散加权成像（DWI）对肝脏局灶性病变的鉴别诊断价值。方法采用GE 3.0T Signal EXCITE超导型磁共振扫描系统对65例共68个病灶患者行DWI,并分析病灶信号特征。肝囊肿13个病灶,肝血管瘤12个病灶,炎性假瘤4个病灶,局灶性结节性增生（FNH）5个病灶;肝细胞癌13个病灶,转移瘤21个病灶。应用弥散敏感系数b值0、500、1000 s/mm2的图像拟合出ADC图并测量ADC值。结果肝囊肿、血管瘤、炎性假瘤、FNH、肝细胞癌、转移瘤平均ADC值（×10-3mm2/s）分别为3.34±0.45、2.07±0.35、1.59±0.16、1.50±0.18、1.25±0.31、1.04±0.20;肝囊肿、血管瘤与其它病灶平均ADC之间差异均有统计学意义（P〈0.05）。随着b值的增加,肝囊肿信号衰减最明显,肝细胞癌、转移瘤信号衰减不明显。结论 3.0T磁共振弥散加权成像及其定量ADC值对肝脏占位病变的鉴别诊断具有重要的临床价值。     

磁共振弥散加权成像对胰腺癌与慢性肿块型胰腺炎的鉴别诊断价值

目的 比较磁共振弥散加权成像(diffusion-weighted imaging,DWI)对胰腺癌与慢性肿块型胰腺炎的鉴别能力.方法 对38例胰腺癌、9例肿块型CP、15例正常胰腺行DWI.在x、Y、Z轴3个方向上选择3个不同弥散系数(b=0、500、1 000 s/mm2)进行扫描,共行2次DWI.根据表观弥散系数(apparent diffusion coefficient,ADC)图像测量ADC值.结果 38例胰腺癌平均ADC值为(1.411±0.101)×10m-3mm2/s,9例肿块型CP的平均ADC值为(1.053±0.113)×10-3mm2/s,15例正常胰腺平均ADC值为(1.245±0.112)×10-3mm2/s,两两比较均有统计学意义(P＜0.05).结论 DWI可对胰腺癌与肿块型CP进行鉴别诊断,具有较大的临床意义.