动态增强MRI在肺部结块病变中的诊断价值

【摘要】目的：探讨动态增强MRI在肺部结块样病变中的诊断价值。方法：66例经病理证实的肺结块样病变患者（恶性病变50例,良性病变16例）行常规MRI平扫及动态增强（DCE-MRI）检查,绘制时间-信号强度增强比曲线（TIC）,并测量DCE-MRI参数：最大增强比（MER）、达峰时间（Tmax）、平均强化斜率（SLE）、最大强化斜率（SS）和廓清率。结果：本组病变的TIC分为4种类型：速升-下降型（A型）仅见于恶性肿瘤;速升-平台型和持续缓升型在良恶性结节中均可见,无明显强化型仅见于良性病变。肺鳞癌和小细胞癌的主要强化方式为环状强化,而腺癌为不均匀强化。DCE-MRI参数中,良性组Tmax明显较恶性组长（P<0.001）,SLE明显小于恶性组（P=0.002）。Tmax对良恶性病变的鉴别最具价值,临界值取280s时其诊断敏感度、特异度和符合率分别为88.0%、63.5%和76.5%。结论：DCE-MRI能提供肺结节血流动力学方面的信息,对肺部良恶性肿瘤的鉴别诊断具有较高价值。     

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。     

ROC曲线分析在肾上腺肿瘤的动态增强CT、MRI检查中的应用

目的 探讨应用受试者操作特性(ROC)曲线评价以肿瘤廓清率为标准利用动态增强CT、MRI检查鉴别肾上腺肿瘤的价值及其这两种检查方法的相关性.资料与方法 25例共28个肾上腺肿瘤均先行平扫及动态增强CT检查,之后再行平扫及动态增强MRI检查,以肿瘤的廓清率为鉴别标准,利用ROC曲线对所选取的诊断标准进行评价,通过ROC曲线下面积(AZ值)来确定所选择诊断标准的价值,并对这两种检查方法行相关性分析.结果 在延迟5～35 min时间点,以肿瘤的廓清率为标准对肾上腺肿瘤的鉴别诊断价值较大(AZ值均在0.7以上),两者之间差异无统计学意义(P＞0.05),再通过对两组变量,即两种检查方法中的廓清率进行分析,认为在延迟5～50 min时,两组变量对肾上腺肿瘤的鉴别诊断均具有高度相关性.结论 以肿瘤的廓清率为诊断标准,无论是利用动态增强CT还是动态增强MRI检查,均可提高肾上腺肿瘤的鉴别诊断水平,两种检查方法对于肾上腺肿瘤的鉴别诊断价值差异无统计学意义,且检查结果具有一致性.     

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CT检查对肾上腺腺瘤与非腺瘤的鉴别诊断价值

目的探讨动态增强CT检查技术对肾上腺腺瘤与非腺瘤的鉴别诊断价值并优选出有意义的参数，以进一步明确两者的鉴别诊断标准。资料与方法对44例共49个肾上腺肿瘤先平扫再行动态增强CT检查，观察以肿瘤的CT绝对值、绝对开始廓清率及相对开始廓清率作为标准鉴别肾上腺腺瘤与非腺瘤的诊断价值。结果延时3min，以36％的绝对开始廓清率或35％的相对开始廓清率分别与CT绝对值58HU相结合作为标准，对腺瘤有较高的诊断价值，对于腺瘤中的乏脂质性腺瘤与非腺瘤的鉴别诊断也具有同样的价值。结论以肿瘤的廓清率与延时增强后的CT绝对值作为联合标准，能明显提高腺瘤的诊断价值。     

动态增强MRI时间信号强度曲线在卵巢良恶性肿瘤鉴别中的价值

目的探讨动态增强MRI时间信号强度曲线(TIC)鉴别卵巢肿瘤良恶性的价值。方法收集2016年1月—2017年8月间于我院超声检查发现盆腔附件肿块的71例女性病人,年龄14～78岁,中位年龄52岁。所有病人行MRI常规及动态增强检查后经手术获得病理结果。利用工作站在肿块实性区和正常子宫外肌层设置兴趣区获取TIC,以子宫外肌层强化曲线为基准,对卵巢肿块实性区的TIC类型进行校正,分析曲线类型与良恶性卵巢肿瘤的关系。采用χ~2检验比较良恶性肿瘤间3种TIC类型差异。结果 71例病人中包括卵巢恶性肿瘤40例,良性肿瘤26例,交界性肿瘤5例。上述3种肿瘤的TIC类型的差异有统计学意义(P0.05)。良性肿瘤以Ⅰ型TIC为主(73.1%),恶性肿瘤以Ⅲ型TIC为主(77.5%)。MRI+TIC鉴别肿瘤良恶性的敏感度、特异度、阳性预测值和阴性预测值较单独常规MRI检查各指标均有不同程度提高。结论动态增强MRI及其TIC对卵巢良恶性肿瘤具有重要的鉴别诊断价值。     

动态增强MRI对软组织肿块良、恶性的鉴别诊断价值

目的 评价动态增强MRI对软组织肿块和肿瘤样病变的良、恶性的鉴别价值。方法 对30例经病理证实的软组织肿块进行动态增强扫描，其中恶性肿瘤11例，良性肿块19例。将感兴趣区(ROI)的信号强度绘制成时间-信号强度曲线(TIC)，并分别计算其0．5min斜率值。结果 30例软组织肿块的TIC分为3型，12例表现为I型曲线，其中10例为恶性肿瘤，2例为良性肿瘤；12例表现为Ⅱ型曲线，其中11例为良性肿块，1例为恶性肿瘤；6例表现为Ⅲ型曲线，均为良性肿块。11例恶性肿瘤中，10例病变的0．5min斜率值大于0．0057；19例良性肿块中，17例0．5min斜率小于0．0057；良、恶性肿瘤的TIC斜率值之间存在显著性差异，Logistic回归分析病变良、恶性和斜率值有相关性。以0．5min斜率值0．0057作为鉴别肿块良恶性的阈值，判断肿块良、恶性的敏感性为90．9%，特异性为89．4％，阳性预测值为83．3％，阴性预测值为94．4％。结论 动态增强MRI可以较准确地预测肿瘤病变的良、恶性。     

MR动态增强及减影成像对乳腺良恶性疾病的诊断价值

目的探讨MR动态增强成像技术所获得的参数及减影成像在乳腺良、恶性疾病诊断及鉴别诊断中的价值。资料与方法经病理证实乳腺病变50例,共计58个病灶。采用快速小角度激发扰相梯度回波序列（FLASH）行动态增强扫描。观察：时间一信号强度曲线类型,早期增强率,增强后病灶形态学特征及间接征象,于3D减影最大强度投影（MIP）图计数肿瘤血管数目。结果50例58个病灶经病理证实,其中恶性32个,良性26个。良性病变中时间一信号强度曲线57．7％为单向型,38．5％为平台型。恶性病变中71．9％为流出型。良、恶性病变的时间一信号强度曲线类型比较,差异有统计学意义（X^2=32．365,P＜0．05）。良性肿瘤中95％边缘光滑,55％均匀强化;恶性肿瘤中93．8％的形态不规则,78．1％有毛刺和分叶,81．3％不均匀强化。良、恶性肿瘤的形态特点差异有统计学意义（X^2=44．25,P＜0．05）。良性病变中73．1％无肿瘤血管：恶性病变中68．8％有多支肿瘤血管,良、恶性病变肿瘤血管计数差异有统计学意义（X^2=32．288,P＜0．05）。结论乳腺增强MRI及减影成像能够提供清晰、丰富的形态学信息,时间一信号强度曲线反映了病变的血流动力学信息,两者的结合对乳腺良、恶性疾病的正确诊断和鉴别诊断具有重要价值。     

肾上腺肿瘤影像学检查的临床应用价值(附102例分析)

目的：评价各种影像学检查方法诊断肾上腺肿瘤的临床价值,为临床医师合理选择和设计检查程序提供参考。材料与方法：以手术病理为依据,用比较影像学的方法,对各种影像学检查方法的定位、定性诊断正确率对比分析。结果：102例肾上腺肿瘤中良性肿瘤84例（内含囊性占位10例）,恶性肿瘤18例。IVP、BUS、CT、CDFI、MRI的术前定位诊断正确率分别为46．3％、91．6％、96.9％、94．1％、92.9％,定性诊断正确率分别为13.4％、83.2％（鉴别囊、实性）、69.4％、64.7％、78.6％;综合影像组则高达100％及84．3％。结论：IVP定位、定性诊断正确率低;BUS对囊、实性的识别力高;IVP＋BUS可作为肾上腺肿瘤的筛选手段;CT、CDFI、MRI对肾上腺肿瘤的定位诊断正确率高,定性诊断正确率相近,对鉴别良恶性有一定价值。综合影像检查可发挥多种检查的互补作用,明显提高肾上腺肿瘤的诊断正确率。     

双能CT成像鉴别肾上腺良恶性病变的初步研究

目的:通过对肾上腺病变的CT能谱特征分析,初步探讨双能CT成像在鉴别肾上腺良恶性病变中的价值。方法:在本院行肾上腺CT扫描的患者23例(共24个肾上腺结节),对全部结节的平扫双能CT成像的能谱曲线、单能量的密度测量、水-钙和水-碘基物质定量测量和有效原子序数进行分析。结果:经病理及临床诊断,24例结节中共有良性病变17例、交界性肿瘤4例、恶性病变3例。良性病变的能谱曲线有上升型(3例)、勺子型(4例)和下降型三种;而交界性肿瘤和恶性病变均只有下降型一种(7例)。在不同单能量(40～140keV)图像上,良性结节的密度值最小[(35.5±37.3)～(11.9±13.3)HU],交界性肿瘤最高[(111.4±118.9)～(29.1±11.4)HU],且差异具有统计学意义(P<0.05)。水-钙和水碘基物质测量显示恶性病变的含水量最高分别为(1024.7±8.9)和(1029.9±7.3)mg.ml-1,良性病变量低[分别为(1008.8±10.7)和(1010.3±12.0)mg.ml-1]。而有效原子序数三者之间差异无显著性意义(P>0.05)。结论:肾上腺良恶性病变在双能CT成像上具有不同的特征。应用双能CT成像的多种参数对鉴别良性结节与交界性肿瘤和恶性病变具有很大的潜能。     

Characterization of breast masses by dynamic enhanced MR imaging. A logistic regression analysis

PURPOSE: To identify features useful for differentiation between malignant and benign breast neoplasms using multivariate analysis of findings by MR imaging. MATERIAL AND METHODS: In a retrospective analysis, 61 patients with 64 breast masses underwent MR imaging and the time-signal intensity curves for precontrast dynamic postcontrast images were quantitatively analyzed. Statistical analysis was performed using a logistic regression model, which was prospectively tested in another 34 patients with suspected breast masses. RESULTS: Univariate analysis revealed that the reliable indicators for malignancy were first the appearance of the tumor border, followed by the washout ratio, internal architecture after contrast enhancement, and peak time. The factors significantly associated with malignancy were irregular tumor border, followed by washout ratio, internal architecture, and peak time. For differentiation between benignity and malignancy, the maximum cut-off point was to be found between 0.47 and 0.51. In a prospective application of this model, 91% of the lesions were accurately discriminated as benign or malignant lesions. CONCLUSION: Combination of contrast-enhanced dynamic and postcontrast-enhanced MR imaging provided accurate data for the diagnosis of malignant neoplasms of the breast. The model had an accuracy of 91% (sensitivity 90%, specificity 93%).     

Delayed enhanced CT of lipid-poor adrenal adenomas

OBJECTIVE. Although representing a minority of adrenal adenomas, the lipid-poor variety cannot be accurately identified on unenhanced CT or chemical shift MR imaging. We compared the delayed contrast-enhanced CT features of lipid-poor adenomas with those of lipid-rich adenomas and of adrenal nonadenomas to determine whether there were differences in the washout features between these groups of lesions. SUBJECTS AND METHODS. Eighteen proven lipid-poor adenomas, 56 lipid-rich adenomas, and 40 adrenal nonadenomas underwent CT before, immediately after, and 15 min delay after IV contrast injection. Region-of-interest measurements were made of all adrenal lesions at the three time points. The degree of enhancement, enhancement washout, percentage enhancement washout, and relative percentage enhancement washout were calculated for each adrenal mass. Pooled data were analyzed statistically. Optimal threshold values for diagnosing adrenal adenomas were also determined. RESULTS. The mean CT attenuation of lipid-poor adenomas was significantly higher than that of lipid-rich adenomas at all three phases but not significantly different from that of nonadenomas. The mean percentage enhancement washout on images obtained 15 min after administration of contrast material was similar for lipid-rich and lipid-poor adenomas but was significantly higher than that of nonadenomas. The mean relative percentage enhancement washout was significantly different among all three groups. CONCLUSION. Lipid-poor adenomas cannot be differentiated from adrenal nonadenomas on the basis of a single mean attenuation value. However, lipid-poor adrenal adenomas show enhancement and enhancement washout features nearly identical to lipid-rich adenomas and can be distinguished from nonadenomas on the basis of a percentage washout threshold value of 60% and a relative percentage washout of 40%.     

Magnetic resonance tomography of adrenal gland tumors. Detection and differentiation using fast gradient echo sequences and dynamic contrast media studies

The use of fast gradient echo sequences enable reduction of the acquisition times in MR imaging, allowing examinations during suspended respiration. Furthermore, repeated single slices in the same position after administration of a paramagnetic contrast agent provide dynamic evaluation of tissue perfusion. These new diagnostic modalities were applied for imaging normal adrenal glands in 128 cases and for differentiation of 83 adrenal tumors in 74 patients. CT remains the imaging method of choice for the detection of adrenal masses, due to the higher spatial resolution. Fast gradient echo MRI offers the possibility of differentiation between benign and malignant adrenal lesions. The 70% accuracy reached with precontrast scans can be augmented to 90% using dynamic contrast-enhanced studies.     

MRI成像对肾上腺高密度肿瘤的应用价值

目的 探讨3T MRI化学位移成像(CSI)和扩散加权成像(DWI)对肾上腺高密度病变的应用价值.方法 回顾性分析48例患者61个CT值大于10HU的肾上腺高密度病变CSI及DWI成像,对肾上腺肿块同反相位的信号衰减值(SII)、肾上腺肿块-脾脏信号比(ASR)、表观扩散系数(ADC)值行散点图分析.采用SPSS 11.5进行统计学分析,并通过ROC曲线确定最佳诊断阈值、敏感性、特异性.结果 23个良性嗜铬细胞瘤,CSI信号衰减SII平均为3.73％;ASR平均为0.97,病变实性部分ADC值平均为(1.17×103)mm2/s.20个高密度腺瘤CSI示信号衰减SII平均为34.48％;ASR平均0.70,ADC值平均(1.08×103)mm2/s.13例恶性肿瘤CSI信号衰减SII为16.58％;ASR为0.96,ADC值为(0.88×10-3)mm2/s.良恶性病变间ADC值有明显统计学差异(P=0.002＜0.05),以ADC值小于0.99为标准,诊断高密度腺瘤的敏感性为70.8％,特异性为84.6％.高密度腺瘤的SII及ASR与其它高密度肿瘤有明显统计学差异,嗜铬细胞瘤的SII及ASR与其它高密度肿瘤有明显统计学差异.结论 CSI可有助于鉴别高密度腺瘤、嗜铬细胞瘤和恶性肿瘤;但无法鉴别嗜铬细胞瘤和恶性肿瘤.ADC值可有助于鉴别病变的良恶性.     

PET／MR与PET／CT显像中FDG阳性病变SUVmax的比较

目的通过PET／CT与PET／MRSUVmax的配对比较,评价PET／MR定量分析的能力。方法150例在同天先后接受PET／CT及PET／MR检查的具有肿瘤相关主诉患者纳入该研究。其中男86例[平均年龄（53．63±13．05）岁],女64例[平均年龄（50．28±11．23）岁]。PET／MR检查：躯干部MRI扫描采用横轴位三维容量呼吸保持T,加权,T2抑脂加权快速自旋回波以及弥散加权成像序列;同时行PET数据采集,累计45min／5个床位。V01分别置于基于MRI的AC图（MRAC—PET）和基于CT的AC图（CTAC—PET）中FDG阳性病变的最大层面,获得SUVmax-CT,和SUVmax-MR。将Person相关分析及Bland．Ahman图用于2组SUV…的比较,配对符号秩和检验用于比较良、恶性病变之间SUVmax的差异。结果150例患者中经病理证实有152个恶性及12个良性病灶。SUVmax-CT与SUVmax-MR在良性（r=0．909）及恶性（r=0．934）病灶中均存在较好的相关性。良性病灶中,2组SUV。。均值差为0．1（95％CI：-3．1∽3．3）;恶性病变均值差为0．6（95％CI：-4．2∽3．0）。恶性病灶的SUVmax-MR高于对应SUVmaxⅡ（8．42±5．12和7．83±4．73;u=-3．47,P〈0．01）;良性病变SUV—MR略低于对应的SUVmax-CT,但差异无统计学意义（6．17±3．82和6．28±3．87;u=-1．68,P〉0．05）。结论在良性及恶性病变中,PET／MR均能提供可靠的、与PET／CT相似的定量诊断信息。     

Soft-tissue tumors: value of static and dynamic gadopentetate dimeglumine-enhanced MR imaging in prediction of malignancy

PURPOSE: To prospectively evaluate static and dynamic gadopentetate dimeglumine-enhanced magnetic resonance (MR) imaging relative to nonenhanced MR imaging in differentiation of benign from malignant soft-tissue lesions and to evaluate which MR imaging parameters are most predictive of malignancy, with associated interobserver variability. MATERIALS AND METHODS: One hundred forty consecutive patients (78 male patients [median age, 51 years], 62 female patients [median age, 53 years]) with a soft-tissue mass underwent nonenhanced static and dynamic contrast material-enhanced MR imaging. Diagnosis was based on histologic findings in surgical specimens (86 of 140), findings at core-needle biopsy (43 of 140), or results of all imaging procedures with clinical follow-up (11 of 140). Multivariate logistic regression analysis was used to identify the best combination of MR imaging parameters that might be predictive of malignancy. Subjective overall performance of two observers was evaluated with receiver operating characteristic analysis. RESULTS: For subjective overall diagnosis, area under the receiver operating characteristic curve, a measure for diagnostic accuracy, was significantly larger for combined nonenhanced and contrast-enhanced MR imaging than it was for nonenhanced MR imaging alone, with no significant difference between observers. Multivariate analysis of all lesions revealed that combined nonenhanced static and dynamic contrast-enhanced MR imaging parameters were significantly superior to nonenhanced MR imaging parameters alone and to nonenhanced MR imaging parameters combined with static contrast-enhanced MR imaging parameters in prediction of malignancy. The most discriminating parameters were presence of liquefaction, start of dynamic enhancement (time interval between start of arterial and tumor enhancement), and lesion size (diameter). Results for extremity lesions were the same, with one exception: With dynamic contrast-enhanced MR imaging parameters, diagnostic performance of one observer did not improve. CONCLUSION: Static and dynamic contrast-enhanced MR imaging, when added to nonenhanced MR imaging, improved differentiation between benign and malignant soft-tissue lesions.     

CT动态增强鉴别肾上腺乏脂肪腺瘤与肾上腺结节样增生的价值

目的探讨CT动态增强对鉴别肾上腺乏脂肪腺瘤与肾上腺结节样增生的价值。方法回顾性分析经手术病理证实的12例肾上腺乏脂肪腺瘤和27例肾上腺结节样增生患者的病例资料,统计两组病例各期增强CT值,利用公式灌注值P=CT静脉期-CT平扫期、廓清值C=CT静脉期-CT延迟期、绝对廓清灌注指数APC=(C/P)×100%及相对廓清灌注指数RAPC=(C/CT静脉期)×100%得到相关参数,并通过绘制受试者工作特征曲线,鉴别两者的最佳价值。结果肾上腺乏脂肪腺瘤直径较结节样增生更大;肾上腺乏脂肪腺瘤病灶各期CT值均明显高于结节样增生,且两者灌注值P、廓清值C、APC及RAPC有明显的统计学差异。年龄、性别、高血压、病灶位置、对侧肾上腺萎缩及动脉期CT值对鉴别两者无显著意义。结论CT动态增强扫描有助于鉴别肾上腺乏脂肪腺瘤和肾上腺结节样增生。     

非特异性肉芽肿性前列腺炎的MRI表现

目的：探讨非特异性肉芽肿性前列腺炎的MRI表现特点。方法：8例经病理证实的非特异性肉芽肿性前列腺炎患者行T1WI、T2WI、扩散加权成像（DWI）及增强检查,回顾性分析其临床及影像学表现特点。结果：8例患者病灶均为结节灶,以右侧前列腺中部外周带多见（5／8）。病灶在T。wI上呈低、稍低及等信号,T2WI上主要为低及稍低信号,DWI上表现为高及稍高信号,表观扩散系数（ADC）图上呈局灶性低信号。4例患者行动态增强MRI检查,病灶明显强化,时间一信号强度曲线呈Ⅰ型（1例）或Ⅱ型强化（3例）。结论：非特异性肉芽肿性前列腺炎的常规MRI检查缺乏特异性,而动态增强扫描可能有助于该病的诊断及鉴别诊断。