钆塞酸二钠增强MRI肝胆期高信号病变影像表现与特征分析

目的 探讨钆塞酸二钠（Gd-EOB-DTPA）增强MRI肝胆期高信号病变的影像学特征并进行分型。 方法 回顾性纳入经手术病理或典型影像表现及临床随访证实为肝脏局灶性病变的病人124例,平均年龄（55.1±15.8）岁。分析肝脏局灶性病变124个,包括肝细胞癌（HCC）52个、胆管细胞癌（ICC）7个、混合型肝细胞癌-胆管癌（cHCC-CC）4个、转移瘤（HM）6个、局灶性结节增生（FNH）及FNH样变42个、肝腺瘤（HCA）2个、异型增生结节（DN）5个、肝海绵状血管瘤（CHL）6个。所有病人均行肝脏Gd-EOB-DTPA增强MRI检查,观察分析肝胆期高信号病变特征并对其进行分型。同一病变中不同分型间占比的比较采用Fisher确切概率检验。计算肝胆期病灶-肝脏信号强度比（LLR）,不同病变间LLR的比较采用Kruskal-Wallis检验。 结果 HCC、ICC、HM、FNH/FNH样变和DN病变中不同分型间占比的差异均有统计学意义（均P<0.05）。HCC病灶中28个可见包膜（53.85%）,各分型中Ⅱb型最多（23/52,44.23%）;ICC病灶中Ⅱa型和Ⅲ型最多（均为3/7,42.86%）;HM病灶中Ⅱa型最多（4/6,66.66%）,且均为胃肠道转移瘤;FNH/FNH样变中Ⅳa型最多（32/42,76.19%）;DN病灶中Ⅰa型最多（4/5,80.00%）。肝胆期不同高信号的病变间LLR的差异有统计学意义（P<0.05）,HCC的LLR低于FNH/FNH样变（P<0.05）。 结论 Gd-EOB-DTPA增强MRI肝胆期高信号病变的影像特征分型对肝脏局灶性病变的诊断具有一定价值。     

肝功能正常患者Gd-EOB-DTPA增强MRI肝胆期延迟时间的研究

目的：评估钆塞酸二钠(gadolinium ethoxybenzyl diethylenetriamine-pentaacetic acid,Gd-EOB-DTPA)增强磁共振成像(magnetic resonance imaging, MRI)延迟10 min的肝胆期是否能够满足肝功能正常患者肝脏局灶性病变的检出和诊断。材料与方法38位存在肝脏局灶性病变的肝功能正常患者,经静脉注射Gd-EOB-DTPA后分别于25 s、60 s、180 s行MRI动态增强扫描,延迟10 min和20 min行肝胆期扫描。测量肝脏和竖脊肌的信号强度(signal intensity,SI),分别计算增强后肝脏和竖脊肌SI相对增加率、肝脏与竖脊肌SI比值、肝脏信号噪声比(signal to noise ratio,SNR)、肝胆期高信号和低信号病灶SNR及对比噪声比(contrast to noise ratio,CNR),记录Gd-EOB-DTPA经胆道排泄的时间,比较10 min与20 min肝胆期肝脏的信号强度和病灶的显示情况。结果注射Gd-EOB-DTPA后,相对于动态增强,肝实质信号在10 min肝胆期明显增加,随后趋于稳定。10 min与20 min肝胆期之间,肝脏SI相对增加率、竖脊肌SI相对增加率及肝脏与竖脊肌SI比值差异均有统计学意义(P＜0.05),肝脏SNR差异无统计学意义(P＞0.05),低信号病灶SNR差异无统计学意义(P＞0.05),高信号病灶SNR差异有统计学意义(P＜0.05),低信号及高信号病灶CNR差异均无统计学意义(P＞0.05)。26例注射Gd-EOB-DTPA后10 min胆道可见对比剂排泄,占68.42%。结论 Gd-EOB-DTPA增强MRI延迟10 min的肝胆期能够满足肝功能正常患者肝脏局灶性病变的检出和诊断。     

慢性肝病背景下钆塞酸二钠肝胆期成像对肝癌的检出与定性

目的探讨钆塞酸二钠(Gd-EOB-DTPA)肝胆期成像在慢性肝病背景下对肝癌检出和定性的价值。方法回顾性分析99例慢性肝病患者的Gd-EOB-DTPA增强MRI表现,89例患者经临床诊断或病理诊断有肝癌病灶,10例患者临床诊断未见明确异常,作为阴性对照。所有MR图像数据,由2名高年资医师共同阅片,分析肝胆期图像与DWI对肝癌的检出率;另由3名中低年资医师将其分为有肝胆期组和无肝胆期组,并对两组图像独立盲法阅片,比较两组图像肝癌病灶的检出率、诊断信心分值及ROC曲线。组间结果的比较采用Wilcoxon或McNemar非参数检验。结果 89例肝癌患者共检出130个病灶,其中肝癌病灶111个,良性结节19个,111个肝癌病灶中100个经病理证实,11个临床诊断。肝胆期成像对肝癌的检出率高于DWI[99.10%(110/111)vs 90.99%(101/111),P=0.012];有肝胆期组阅片者平均信心分值明显高于无肝胆期组(P=0.001);对于长径≤1cm的小肝癌,有肝胆期组平均检出率高于无肝胆期组[93.00%(17.67/19)vs 70.16%(13.33/19),P=0.016];有肝胆期组ROC曲线下面积亦高于无肝胆期组[0.949(95%CI:0.815~0.995)vs 0.744(95%CI:0.566~0.877),P=0.0023]。结论慢性肝病背景下应用Gd-EOB-DTPA的肝胆期图像的肝癌检出率优于DWI,尤其对于长径≤1cm的小肝癌,同时能够提高诊断信心。     

Gd-EOB-DTPA增强MRI T1 mapping技术在肝脏疾病的应用进展

T_1 mapping成像是定量分析组织T_1值的方法,主要包括Look-Locker(LL)序列、改良的Look-Locker反转恢复序列(MOLLI)及可变多翻转角成像技术。近年来,基于Gd-EOB-DTPA的T_1 mapping成像广泛应用于肝脏。根据注射对比剂前后肝实质的T_1变化,不仅能用于对肝脏损伤程度、肝纤维化分期、肝硬化病人肝储备功能的评估,而且对肝脏局灶性病变的鉴别、肝细胞肝癌分化程度的预测也有一定的价值。就Gd-EOB-DTPA增强MRI T_1 mapping技术在肝脏疾病中的应用现状及研究进展予以综述。     

钆塞酸二钠肝脏MRI多期增强扫描各期相图像质量的对比研究

目的 比较钆塞酸二钠(Gd-EOB-DTPA)肝脏MRI增强扫描各期相图像的质量,寻找Gd-EOB-DTPA增强扫描呼吸伪影出现的相关因素.方法 回顾性分析近期行Gd-EOB-DTPA MRI增强扫描的患者共250例,由2位放射专业医师采用双盲法对各个期相的图像质量进行评分.结果 动脉早期出现严重呼吸伪影的比例明显高于动脉晚期、门脉期、延迟期及肝胆特异期(比例分别为21.6％、8.8％、5.6％、2.4％和1.2％).动脉早期与动脉晚期(x2=15.89,P=0.000)、门脉期(x2=27.23,P=0.000)、延迟期(x2 =43.64,P=0.000)及肝胆特异期(x2=51.50,P=0.000)呼吸伪影的差异有统计学意义.动脉晚期与延迟期(x2=9.685,P=0.02)及肝胆特异期(x2=15.20,P=0.000)呼吸伪影的差异也有统计学意义.动脉早期、动脉晚期、门脉期、延迟期及肝胆特异期图像质量的分值分别为3.28±1.09、3.65±0.91、3.86±0.85、4.06±0.79和4.19±0.77.在图像质量分值的比较中,动脉早期明显低于其余各期,动脉晚期明显低于延迟期及肝胆特异期,门脉期明显低于肝胆特异期(P均=0.000).结论 MRI Gd-EOB-DTPA增强扫描动脉早期最易出现呼吸伪影,且伪影的程度最为严重.     

钆塞酸二钠增强MRI影像组学对肝血管瘤腹腔镜肝切除术后疗效的预测价值

目的 探讨钆塞酸二钠（Gd-EOB-DTPA）增强MRI影像组学对肝血管瘤腹腔镜肝切除术疗效的预测价值。方法 选取2018年2月至2020年10月行腹腔镜肝切除术治疗的肝血管瘤患者131例作为研究对象。采用计算机产生随机数法将131例肝血管瘤患者以7:3的比例分为训练集（92例）和验证集（39例）,分别用于构建和验证预测模型效能。根据术后是否出现并发症将训练集患者分为预后不良组和预后良好组,比较两组患者的临床特征资料。使用最小绝对收缩和选择算子（the least absolute shrinkage and selection operator,LASSO）回归5折交叉验证方法筛选训练集临床和影像组学特征,得到最优特征子集。使用机器学习算法构建预测模型,并使用受试者工作特征（receiver operating characteristics,ROC）曲线评价各模型对肝血管瘤术后疗效的预测价值。结果 训练集中预后良好64例,预后不良28例,两组在慢性疾病、肝血管瘤最大径、血管瘤数、血管瘤供血动脉支数、肝切除大小、术中出血量方面差异均有统计学意义（P<0.05）。依据LASSO回归中的最佳λ取值筛选出14个非零系数特征构成的最优特征子集,其中包括12个组学特征和2个临床特征。利用训练集筛选出的最优特征子集构建Logistic回归、CatBoost、XGBoost和LightGBM模型的AUC分别为0.820、0.722、0.784、0.693。验证集构建的Logistic回归、CatBoost、XGBoost和LightGBM模型的ROC曲线下面积（AUC）分别为0.814、0.706、0.785、0.684。4种机器学习模型的预测效果良好,其中Logistic回归的预测效果优于其他3种。结论 血管瘤最大径和血管瘤数目,结合Gd-EOB-DTPA增强MRI影像组学,以此构建的机器学习模型可用于预测肝血管瘤腹腔镜肝切除术后疗效,其中Logistic回归算法构建的模型更加精准。     

Hypovascular hepatic nodule showing hypointensity in the hepatobiliary phase of gadoxetic acid-enhanced MRI in patients with chronic liver disease: prediction of malignant transformation

Purpose

To investigate the predictive factors of malignant transformation of hypovascular hepatic nodule showing hypointensity in the hepatobiliary phase images of gadoxetic acid-enhanced MRI (HHN).

Materials and Methods

The clinical data and imaging findings of dynamic contrast-enhanced computed tomography (DCE-CT) and gadoxetic acid-enhanced MRI for a total of 103 HHNs in 24 patients with chronic liver disease were retrospectively investigated. After the results of follow-up examinations were investigated, HHNs were categorized into the three groups for each comparison: (1) nodules with enlargement and/or vascularization and others, (2) nodules with only enlargement and others, (3) nodules with only vascularization and others. Enlargement and/or vascularization during the follow-up period were defined as malignant transformation of HHN. The frequency of each clinical datum and imaging finding in each group was compared to identify the predictive factors for malignant transformation in HHN.

Results

Multivariate analysis showed that a nodule size of 9 mm or more on the initial gadoxetic acid-enhanced MRI was a significant predictive factor for the enlargement and/or vascularization of HHN (P < 0.05). On the other hand, the hypoattenuation on the delayed phase imaging of the initial DCE-CT was a significant predictive factor for the enlargement or vascularization of HHN (P < 0.05).

Conclusion

A nodule size of 9 mm or more on the initial gadoxetic acid-enhanced MRI and hypoattenuation on the delayed phase imaging of initial DCE-CT would be helpful for predicting the outcome of HHN in patients with a risk of hepatocellular carcinoma.     

Hyperintense HCC on hepatobiliary phase images of gadoxetic acid-enhanced MRI: Correlation with clinical and pathological features

Purpose

To retrospectively determine whether the hyperintense hepatocellular carcinomas (HCCs) seen on the hepatobiliary phase of gadoxetic acid-enhanced MR imaging (EOB-MRI) might have different histologic characteristics from usual hypointense HCCs.

Materials and methods

Two hundred three surgically proven HCCs from 192 patients who underwent preoperative EOB-MRI were analyzed. The demographic and histologic characteristics of hyperintense HCCs were compared with usual hypointense HCCs by using the t-test or Fisher's exact test.

Results

By visual assessment, 18 (8.8%) tumors were classified as hyperintense HCCs. Patients with hyperintense HCC were significantly (p < 0.05) older (60.1 vs. 55.2 years) than those with hypointense HCCs. Hyperintense HCCs showed significantly lower rate of microvascular invasion (27.8% vs. 53.5%) and significantly higher rate of peliosis (61.1% vs. 30.8%). Hyperintense HCCs were more frequently expanding type, and none showed infiltrative type or scirrhous histologic pattern.

Conclusions

Hyperintense HCCs seem to have clinical and histologic features that might be related with more favorable outcomes.     

Diffusion weighted imaging of liver lesions suspect for metastases: Apparent diffusion coefficient (ADC) values and lesion contrast are independent from Gd-EOB-DTPA administration

Purpose

Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced liver MRI is widely used for detection and differentiation of focal liver lesions. Diffusion weighted imaging (DWI) including apparent diffusion coefficient (ADC) measurements is increasingly utilised as a fast and, with limitations, quantitative method for liver lesion detection and characterisation. Herein we investigate whether the administration of Gd-EOB-DTPA affects DWI.

Materials and methods

31 consecutive patients referred to standardised liver MRI (1.5 T, Gd-EOB-DTPA, 0.025 mmol/kg) were retrospectively reviewed. All underwent a breathhold DWI sequence before and after contrast agent administration (EPI-DWI, TR/TE (effective): 2100/62 ms, b-values: 0 and 800 s/mm²). Patients with previously treated liver lesions were excluded. Signal intensity of lesion, parenchyma and noise on DWI images as well as the ADC value were measured after identification by two observers in consensus using manually placed regions of interest. The reference standard was imaging follow-up determined separately by two radiologists. Data analysis included signal-to-noise (SNR) ratio and contrast-to-noise ratio (CNR) calculations, comparisons were drawn by employing multiple Bonferroni corrected Wilcoxon signed-rank tests.

Results

50 malignant and 39 benign lesions were identified. Neither SNR, CNR nor ADC values showed significant differences between pre- and postcontrast DWI. Both pre- and postcontrast ADC values differed significantly between benign and malignant lesions (P < 0.001).

Conclusion

We did not identify a significant influence of Gd-EOB-DTPA on DWI of liver lesions. This allows for individual tailoring of imaging protocols according to clinical needs.     

Diagnostic efficacy of gadoxetic acid-enhanced MRI for hepatocellular carcinoma and dysplastic nodule

AIM:To evaluate the relationship between the signal intensity of hepatobiliary phase images on gadoxetic acid-enhanced magnetic resonance imaging(MRI)and histological grade.METHODS:Fifty-nine patients with 82 hepatocellular lesions were evaluated retrospectively.Hepatobiliary phase images on gadoxetic acid-enhanced MRI were classified into 3 groups:low,iso or high.Angiographyassisted computed tomography(CT)findings were also classified into 3 groups:CT during arterial portography,and CT hepatic arteriograph...