动态对比增强磁共振成像定量参数在直肠癌分化程度与血管侵犯评估中的价值

目的：探讨动态对比增强磁共振成像(DCE-MRI)的定量参数在直肠癌分化程度及血管侵犯评估中的价值。方法：前瞻性分析经术前内镜下病理证实为直肠腺癌并行DCE-MRI扫描的43例患者,其中高分化腺癌12例,中分化20例,低分化11例;有血管侵犯13例,无血管侵犯30例。使用Tofts模型测定各定量参数,即血管外细胞外间隙容积分数(V_e)、血管内至血管外间隙转运系数(K^trans)、血管外间隙返回至血管内速率常数(K_ep)。比较高、中、低分化组及有无血管侵犯组的V_e、K^trans、K_ep。结果：K^trans及V_e在高、中、低分化组中差异均有统计学意义(均P<0.05),K_ep差异无统计学意义(P>0.05)。血管侵犯组与无血管侵犯组的K_ep差异有统计学意义(P<0.05),K^trans及V_e差异均无统计学意义(均...     

动态增强磁共振成像在直肠癌术前分化程度评估中的应用价值

目的 探讨动态增强磁共振成像(DCE-MRI)在直肠癌术前评估分化程度中的临床价值.方法 搜集40例经病理证实的直肠癌患者及非直肠癌的15例受试者(对照组)的DCE-MRI检查资料.由2名医师采用盲法阅片,应用Toffs模型后处理得到感兴趣区(ROI)的微循环参数容积转移常数(Ktrans)、速率常数(Kep)、体积百分数(Ve)及增强的曲线下面积(iAUC)值.绘制时间-信号强度曲线.根据病理诊断结果制作受试者工作特征曲线(ROC),计算分析DCE-MRI各参数的ROC曲线下面积,分析2名医师测量结果的一致性.将患者组的DCE-MRI参数结果与术后病理分化程度进行相关性分析.结果 患者组的Ktrans值、Kep值、Ve值、iAUC值均较对照组升高(均P＜0.05).直肠癌病灶的时间-信号强度曲线表现为流出型.参数Ktrans、iAUC的ROC曲线下面积较大,分别为医师1:0.987、0.975;医师2:0.990、0.978.2名医师测量各参数的组内相关系数(ICC)分别为0.991、0.988、0.972、0.984,观测结果有良好一致性.40例直肠癌中,病灶Ktrans值、iAUC值与病理分化程度具有一定程度的相关性,r值分别为医师1:0.393、0.594;医师2:0.443、0.659(均P＜0.05).结论 DCE-MRI能反映直肠癌的微循环差异,其参数指标与直肠癌分化程度存在一定程度的相关性,对直肠癌的术前评估有一定作用.     

磁共振扩散加权成像对直肠癌术前分期的价值

目的:探讨MR扩散加权成像在直肠癌诊断中的临床应用价值。方法:回顾性分析43例直肠癌患者的MRI资料,所有患者均行常规序列T1WI、T2WI及DWI检查,将MRI诊断结果与手术病理结果进行对照分析。结果:常规序列T1分期的诊断符合率为60.0%(3/5),T2、T3、T4分期分别为80.0%(12/15)、66.7%(12/18)和80.0%(4/5);常规序列联合DWI的T1分期诊断符合率为100%(5/5),T2、T3、T4分期分别为100.0%(15/15)、83.3%(15/18)和100.0%(5/5)。常规序列及常规序列联合DWI的直肠癌T分期总诊断符合率分别为72.1%和93.0%。结论:MR扩散加权成像结合常规序列能够对直肠癌T分期做出较准确的诊断。     

动态增强磁共振成像对肌肉骨骼系统肿瘤性质鉴别的定量研究

目的 评价动态增强ＭＲＩ鉴别良恶性肌肉骨骼（简称肌骨）肿瘤的价值。方法 前瞻性量化分析３２例肌骨肿瘤患者的动态增强磁共振图像,采用差别分析法确定良恶性患者的动态增强ＭＲＩ检查指标有无差别,并通过绘制接受者操作特征（ＲＯＣ）曲线得出最佳评价指标。采用相关分析法确定定量指标与肿瘤组织血管化程度及ＤＮＡ指数（ＤＩ）的关系。     

动态增强磁共振成像术前评估直肠癌肿瘤出芽等级的价值

目的：探讨动态增强磁共振成像（DCE-MRI）各灌注参数术前评估直肠癌肿瘤出芽（TB）等级的价值。方法：回顾性分析我院72例经病理证实的局部进展期直肠癌（LARC）患者的临床、DCE-MRI及术后病理资料。2名医师分别在术前DCE-MRI伪彩图上勾画靶区,得到半定量灌注参数：平均强化时间（MTE）、达峰时间（TTP）、最大上升斜率（MSI）及正性增强积分（PEI）,计算各参数的组内相关系数（ICC）,分析各参数与术后病理TB等级的相关性。将出芽1级及2级纳为低-中级别TB组,3级纳为高级别TB组,绘制各灌注参数ROC曲线,计算曲线下面积（AUC）。结果：最终LARC患者纳入高级别TB组7例,中-低级别TB组65例。2名医师测量得到的MSI、MTE、PEI、TTP各参数ICC值分别为0.724、0.980、0.803、0.743。参数PEI和MSI与TB等级呈正相关（P<0.05）。参数PEI与MSI的ROC分析均表现出比较好的诊断效能,AUC分别为0.910及0.784,准确度分别为87.5%与63.9%。结论：DCE-MRI的参数指标PEI和MSI与LARC肿瘤出芽等级之间具有...     

3.0T磁共振扩散加权成像诊断直肠癌最适b值的选取

目的对直肠癌患者行3.0T磁共振不同b值的扩散加权成像,选取显示直肠癌的最适b值。方法对75例术后确诊的直肠癌患者分别行b=800、1 000、1 200、1 500 s/mm2与1 800 s/mm2五组扩散加权成像,分别将不同b值的各组间肿瘤本身SNR、肿瘤与肌肉的对比噪声比CNR和肿瘤与脂肪的CNR作比较。结果 SNR、CNR值均呈正态分布,b值为1 200 s/mm2与1 500 s/mm2时SNR、CNR差异无显著性意义(P>0.05),但低于b值1 200 s/mm2及高于1 500 s/mm2的差异均有显著性意义(P<0.05)。结论超高场3.0T磁共振扩散加权成像诊断直肠癌的b值选取1 200 s/mm2和1 500 s/mm2较合适。     

直肠癌MUSE-DWI与常规DWI成像对比研究

目的:对比分析基于复合灵敏度编码的高分辨率磁共振扩散成像(MUSE-DWI)与常规扩散加权成像(DWI)在直肠癌的成像质量。方法:回顾性纳入分析桂林医学院附属医院2021年11月-2022年6月经病理确诊为直肠癌的48例患者资料,采用3.0T磁共振进行常规序列扫描,以及进行MUSE-DWI和单次激发自旋回波平面成像(SS-EPI)图像对比研究。由2名放射科医师分别对2组DWI图像进行主观和客观评价。主观评价：采用5分法对病变可见性、病灶变形、轮廓清晰度、伪影水平以及图像噪声进行评分。客观评价：对信噪比(SNR)、对比度(CR)、表观扩散系数(ADC)以及病灶最大横纵径测量计算。主观评分一致性采取Kappa检验,以及采取配对t检验、Wilcoxon秩和检验比较图像质量客观评分之间的差异。结果:MUSE-DWI在病变可见性、几何变形、轮廓清晰度、磁敏感伪影以及图像整体质量的评分均高于SS-EPI DWI,差异具有统计学意义(P<0.001)。客观评价得出MUSE-DWI的SNR、CNR均优于常规DWI(P<0.001),2组DWI间的ADC值差异无统计学意义(P=0.55),并...     

恶性血液病骨髓动态增强磁共振成像特征的初步研究

目的探讨利用动态增强MR成像技术检测恶性血液病患者骨髓构成的变化，判定其骨髓浸润程度，以减少血液病患者治疗随访过程中穿刺活检的次数。方法25例恶性血液病患者经动态增强MPJ（DCE-MR）及髂嵴穿刺活检，测定骨髓灌注的最大强化率（PER），最大强化斜率值（Slopemax），峰值时间（TTP），平均时间（MT），以及骨髓活检分析细胞构成、肿瘤分数（TF）。结果25例恶性血液病患者骨髓的PER、Slopemax、TTP、MT的中位值分别为0．27、0．21s^-1。、79．08s、84．43s。不同细胞构成（低、正常、高）骨髓的灌注特征性变量的中位数值分别为PER（0．29、0．24、1．15）、Slopemax（0．20s^-1、0．21s^-1、1．28s^-1）、TTP（96．67s、83．49s、25．52s）、MT（77．52s，86．25s，84．34s）。肿瘤浸润组首次灌注值（PER0．32，Slopemax0．28s。）高于肿瘤缓解组，（PER0．20，Slopemax0．20s^-1），而对比剂到达峰值时间（TTP68．66s）低于缓解组（TTP85．85s）。肿瘤浸润组与缓解组骨髓的PER差异有统计学意义（P=0．02），而Slopewmax、TTP、MT差异无统计学意义（P值均＞0．05）。PER（r=0．564，P=0．003）、Slopemax（r=0．478，P=0．016）、MT（r=0．186，P＞0．05）与骨髓细胞构成状态（低、正常、高）呈正相关，而TTP（r=-0．222）与骨髓细胞构成状态呈负相关。PER（r=0．561，P=0．004）、Slopemax（r=0．318，P=0．121）、MT（r=0．207，P＞0．05）与TF呈正相关，而TTP（r=-0．305，P＞O．05）与TF呈负相关。结论动态增强MR成像能够监测恶性血液病骨髓肿瘤细胞浸润和细胞构成的变化。     

水脂分离增强序列在3.0T磁共振直肠癌术前分期中的应用

目的:将水脂分离增强扫描序列应用于直肠癌磁共振术前分期检查,探讨其在直肠癌术前分期中的应用价值。方法:选择经肠镜活检证实为直肠癌患者46例,随机盲法均分为两组,一组序列采用常规序列及T1脂肪抑制增强扫描序列;另一组序列采用常规序列及水脂分离增强扫描序列,结果与病理分期对照,比较两组序列图像信噪比及T、N分期。结果:组一T分期总敏感度为74%,特异度为78%。N分期总敏感度为74%,特异度为74%;N0分期敏感度78.6%,特异度66.7%,准确率为78%;N1分期敏感度57%,特异度81%,准确率为71%;N2分期敏感度100%,特异度100%,准确率为100%。组二T分期总敏感度为83%、特异度为83%;N分期总敏感度91%,特异度为91%;N0分期敏感度94%,特异度83%,准确率为94%;N1分期敏感度75%,特异度95%,准确率为75%;N2分期敏感度100%,特异度94.5%,准确率为100%。结论:水脂分离序列可提高图像信噪比,脂相有助于提高N分期,此序列在直肠癌术前分期中具有一定的临床应用价值。     

Prognostic aspects of dynamic contrast-enhanced magnetic resonance imaging in synchronous distant metastatic rectal cancer

Objectives

To explore the correlations between DCE-MRI quantitative parameters and synchronous distant metastasis and the clinicopathological factors in rectal cancers.

Methods

Sixty-three patients with rectal cancer (synchronous distant metastasis, n?=?31; non-metastasis, n?=?32) were enrolled in this study. Student’s t test and ANOVA were used to compare DCE-MRI parameters (K ^trans , K _ep and V _e ). The receiver operating characteristic (ROC) analysis was used to find the reasonable threshold of DCE-MRI parameters to differentiate lesions with synchronous distant metastasis from those without metastasis.

Results

The K ^trans , K _ep , and V _e value were significantly higher in the lesions with distant metastasis than in the lesions without distant metastasis (0.536?±?0.242 vs. 0.299?±?0.118 min^-1, p?<?0.001; 1.598?±?0.477 vs. 1.341?±?0.390 min^-1, p?=?0.022; and 0.324?±?0.173 vs. 0.249?±?0.091, p?=?0.034; respectively). The K ^trans showed the highest AUCs of 0.788 (p?<?0.001), with sensitivity of 61.29 % and specificity of 87.5 %, respectively.

Conclusions

DCE-MRI parameters may represent a prognostic indicator for synchronous distant metastases in patients with rectal cancer.

Key Points

? The K ^trans , K _ep and V _e values correlated with synchronous distant metastasis. ? Higher K ^trans , K _ep and V _e values were noted among patients with metastasis. ? DCE-MRI parameters might represent a prognostic indicator for synchronous distant metastases.

     

Functional tumor imaging with dynamic contrast-enhanced magnetic resonance imaging

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is the acquisition of serial MRI images before, during, and after the administration of an MR contrast agent. Unlike conventional enhanced MRI, which simply provides a snapshot of enhancement at one point in time, DCE-MRI permits a fuller depiction of the wash-in and wash-out contrast kinetics within tumors, and thus provides insight into the nature of the bulk tissue properties. Such data is readily amenable to two-compartment pharmacokinetic modeling from which parameters based on the rates of exchange between the compartments can be generated. These parameters can be used to generate color-encoded images that aid in the visual assessment of tumors. DCE-MRI is used currently to characterize masses, stage tumors, and noninvasively monitor therapy. While DCE-MRI is in clinical use, there are also a number of limitations, including overlap between malignant and benign inflammatory tissue, failure to resolve microscopic disease, and the inconsistent predictive value of enhancement pattern with regard to clinical outcome. Current research focuses on improving understanding of the meaning of DCE-MRI at a molecular level, evaluating macromolecular and targeted contrast agents, and combining DCE-MRI with other physiologic imaging techniques such as positron emission tomography. Efforts to standardize DCE-MRI acquisition, analysis, and reporting methods will allow wider dissemination of this useful functional imaging technique.     

ADC 值和 DCE-MRI 定量参数值与直肠癌临床病理的相关性研究

目的：探讨3.0T MR 表观扩散系数(ADC)值和动态对比增强定量参数容量转移常数(Ktrans )、血管外细胞外间隙容积比(Ve )、速率常数(Kep )值与直肠癌临床病理学特征的相关性。方法通过对82例经病理证实的直肠癌患者扩散加权成像(DWI)及动态对比增强磁共振成像(DCE-MRI)图像进行回顾性分析,获得 ADC 值及定量参数 Ktrans 、Kep 、Ve 值,进一步将这些参数与肿瘤的分化程度、Dukes 分期及有无淋巴结转移进行相关性分析。结果直肠癌的 ADC 值随肿瘤分化程度的降低和 Dukes 分期的增加而减低(P 值均<0.01)。定量参数 Ktrans 、Ve 值随肿瘤分化程度的减低而升高(P 值均<0.01);Ktrans 、Kep 值则随 Dukes 分期的增加而升高(P 值均<0.01)。ADC 值及 Ktrans 值与淋巴结转移均具有统计学相关性(P <0.01)。结论DWI 的 ADC 值及 DCE-MRI的定量参数 Ktrans 、Ve 、Kep 值与直肠癌的临床病理学特征存在一定的相关性,这些参数不仅可以作为直肠癌影像学生物标记物,而且能够为预测肿瘤的恶性程度提供一定的参考价值。     

Computerized analysis of enhancement kinetics for preoperative lymph node staging in rectal cancer using dynamic contrast-enhanced magnetic resonance imaging

For this feasibility study, dynamic contrast-enhanced magnetic resonance imaging (dceMRI) was performed preoperatively in 9 patients with histologically proven rectal carcinoma. A total of 41 lymph nodes detected were matched to histopathology. Their contrast enhancement patterns were evaluated using computer-aided analysis and categorized in persistent, plateau, and washout curve type. Highest diagnostic accuracy for detecting malignancy was observed, when less than 31.8% of the voxels within a lymph node demonstrated a washout curve (sensitivity/specificity of 81.8%/89.7%; area under the curve, AUC=0.87). In comparison, conventional size measurements revealed lower AUC of 0.81 (sensitivity/specificity of 75%/72.4%). We conclude that dceMRI might be of diagnostic value for preoperative lymph node staging.     

动态增强MR成像在胰腺疾病中的应用

胰腺微循环变化及血流动力学改变在胰腺的多种疾病发生发展过程中起着至关重要的作用,而动态增强MR成像（DCE-MRI）具有评估组织器官微循环及血流灌注状态的能力,因此有关DCE-MRI灌注参数在胰腺疾病的诊断、鉴别诊断及疗效评估中的作用是当前研究的热点。就DCE-MRI成像原理及其在正常胰腺及胰腺疾病中的应用现状予以综述。     

Gadolinium-enhanced dynamic magnetic resonance imaging with endorectal coil for local staging of rectal cancer

Purpose  

The aim of this study was to evaluate the accuracy of dynamic gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) with endorectal coil for assessing tumor invasion based on simple classification criteria.     

乳腺癌新辅助化疗的动态增强磁共振成像评价

目的:探讨乳腺癌患者新辅助化疗(NAC)后通过动态增强MRI评估肿瘤边界的准确性;观察NAC前、后时间-信号强度曲线(TIC)变化。方法:搜集57例行NAC乳腺癌患者,化疗前后均行病理及MRI检查,以病理结果作为金标准,将NAC后MRI所测肿瘤最大径与其进行比较;观察记录NAC前、后TIC类型。结果:化疗后MRI测量的肿瘤最大径与病理量出的最大径有很高的相关性(r=0.926,P<0.005);NAC后TIC类型变化多样。结论:动态增强MRI可以对乳腺癌NAC后进行有效评价。化疗前、后的TIC变化可以为临床评价NAC疗效提供丰富的信息。     

Assessment of dynamic contrast-enhanced magnetic resonance imaging in the differentiation of malignant from benign orbital masses

Objective

Dynamic contrast enhanced MR imaging (DCE-MRI) allows imaging of the physiology of the microcirculation. The purpose of this study was to determine the diagnostic efficacy of time intensity curve (TIC) and DCE parameters for characterization of orbital masses.

Methods

Fifty-nine patients with untreated orbital lesions underwent DCE-MRI before surgery. For each lesion, peak height (PH), maximum enhancement ratio (ER_max), time of peak enhancement (T_peak) and maximum rise slope (Slope_max) were plotted and calculated. Receiver operator characteristics (ROC) analysis was conducted to assess the appropriate cut-off value.

Results

All 26 lesions that demonstrated persistent pattern (type-I) TICs were benign. Most of the masses with the washout pattern (type-III) TIC were malignant (10/14), including lymphoma (n = 6) and melanoma (n = 4). The Slope_max of benign lesions was statistically lower than malignant ones, while the ER_max and T_peak values of benign lesions were significantly higher. No statistical difference was found in PH (P = 0.121). The AUC for ER_max, T_peak and Slope_max in differentiating benign orbital lesions from malignant ones were 0.683, 0.837 and 0.738, respectively. In the three DCE parameters, Slope_max cut-off value of 1.10 provided the highest sensitivity of 93.8%; however, the corresponding specificity was low (58.1%). The ER_max cut-off value of 1.37 and T_peak cut-off value of 35.14 respectively offered the best diagnostic performances.

Conclusion

DCE-MRI, especially the qualitative TIC pattern and quantitative value of Slope_max, ER_max and T_peak, could be a complementary investigation in distinguishing malignant orbital tumor from benign ones.