钆塞酸二钠增强MRI在结直肠癌肝转移系统治疗疗效评价中的价值

目的 探讨肝细胞特异性对比剂钆塞酸二钠(Gd-EOB-DTPA)在评价结直肠癌肝转移系统治疗疗效中的价值.方法 回顾性分析系统治疗后经手术切除的48例结直肠癌患者的83个肝转移瘤,所有患者术前行Gd-EOB-DTPA增强MRI检查.判断动脉期强化特征(环形强化/非环形强化)、肝胆期强化特征(靶样强化/非靶样强化),测量...     

MRI肝胆特异性对比剂Gd-EOB-DTPA对小肝细胞癌的诊断研究进展

肝细胞癌(HCC)是常见的原发性肝脏恶性肿瘤,全球的发病率逐年增长。HCC的早期发现与及时治疗是提高病人预后及生存率的关键。钆塞酸二钠(Gd-EOB-DTPA)是一种新型的MRI肝胆特异性对比剂,不仅具有普通细胞外间隙对比剂的功能,还可被肝细胞特异性摄取,进而提供肝胆期信息。Gd-EOB-DTPA增强MRI对HCC的诊断价值优于常规细胞外间隙对比剂增强MRI。就Gd-EOB-DTPA增强MRI在小HCC诊断及鉴别诊断中的应用现状进行综述。     

Confident Diagnosis of Bronchobiliary Fistula Using Contrast-Enhanced Magnetic Resonance Cholangiography

We report the utility of contrast-enhanced magnetic resonance cholangiography (MRC) using gadoxetic acid (Gd-EOB-DTPA) in the diagnosis of bronchobiliary fistula associated with liver hydatid cyst. Contrast-enhanced MRC clearly delineated the leakage of contrast agent from the biliary duct and its communication with the bronchial tree. Providing functional information about physiologic or pathologic biliary flow in addition to the display of biliary anatomy, contrast-enhanced MRC stands as a robust technique in confidently detecting bronchobiliary fistula and bile leaks.     

Imaging features of intrahepatic cholangiocarcinoma in Gd-EOB-DTPA-enhanced MRI

Objective

The aim of this study is to describe the imaging features of intrahepatic cholangiocarcinoma in Gd-EOB-DTPA-enhanced MRI and to determine whether it results in improved tumour conspicuity of cholangiocarcinoma.

Materials and methods

Fifty-four patients with histologically proven intrahepatic cholangiocarcinoma underwent MRI of the liver using a 1.5 T MR-scanner with Gadoxetic acid disodium (Gd-EOB-DTPA; Eovist/Primovist, Bayer Healthcare, Berlin, Germany). The standard imaging protocol included a T2w multi-shot TSE sequence with fat saturation (fs), a T2w single shot sequence without fs and a T1w 3D GRE sequences with fs (unenhanced and arterial, portovenous, late venous and hepatobiliary phase). Two board certified radiologists experienced in liver MRI (5 and 10 years experience) evaluated retrospectively all MRI scans qualitatively and quantitatively. Signal was measured with region-of-interests (ROI) and signal-to-noise (SNR) as well as contrast-to-noise (CNR) was calculated. Statistical significance was tested with an ANOVA and a pairwise Wilcoxon rank test.

Results

All intrahepatic cholangiocarcinomas presented as hypointense lesions in the late venous and hepatobiliary phase. Images in the hepatobiliary phase showed the highest lesion conspicuity, i.e. n = 9 blurred (16.6%), n = 31 moderate (57.4%) and n = 14 sharp (26%). This was significantly higher than the lesion conspicuity of all other sequences or phases. Furthermore, the CNR was the highest in this sequence with 76.8 ± 51.3, with significantly higher values than the CNR of the unenhanced T1w sequence (CNR: 35.6 ± 21.0; p < 0.0001) and the arterial phase images (CNR: 53.6 ± 36.8; p < 0.001). The hepatobiliary phase images showed a SNR of 97.3 ± 59.7 (p < 0.001) and thus was significantly different from the unenhanced T1w sequence (SNR: 60.4 ± 35.3; p < 0.001), whereas the increase in SNR from the late venous to hepatobiliary phase was neglectable, indicating that no liver-specific contrast uptake is present in cholangiocarcinoma.

Conclusion

Intrahepatic cholangiocarcinoma presents as a hypointense lesion in Gd-EOB-DTPA-enhanced MRI in late venous phase images. The lesion conspicuity as well as CNR was highest in the hepatobiliary phase. Consequently, hepatobiliary phase images in Gd-EOB-DTPA-enhanced MRI images might be helpful for therapy planning due to the exact depiction of the tumour borders.     

Transarterial Chemoembolization of Hepatocellular Carcinoma Using Radiopaque Drug-Eluting Embolics: How to Pursue Periprocedural Cross-Sectional Imaging?

Purpose

To compare different imaging techniques (volume perfusion CT, cone-beam CT, and dynamic gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid–enhanced dynamic contrast–enhanced MR imaging with golden-angle radial sparse parallel MR imaging) in evaluation of transarterial chemoembolization of hepatocellular carcinoma (HCC) using radiopaque drug-eluting embolics (DEE).

钆塞酸二钠动态增强MRI在肝脏结节定性诊断中的价值分析

目的分析钆塞酸二钠(Gd-EOB-DTPA)动态增强MRI在肝脏结节定性诊断中的价值。方法回顾性分析100例肝脏结节患者的临床资料,均行常规MRI以及Gd-EOB-DTPA动态增强扫描,以穿刺活检结果为标准,分析常规MRI以及Gd-EOB-DTPA动态增强MRI在肝脏结节定性诊断中的价值。结果穿刺活检结果显示,100例肝脏结节患者中30例为恶性,70例为良性。Gd-EOB-DTPA动态增强MRI诊断良、恶性肝脏结节的准确率均较常规MRI高,差异有统计学意义(P <0.05)。结论与常规MRI相比,Gd-EOB-DTPA动态增强MRI在肝脏结节定性诊断中的准确率更高,更具诊断价值。     

Imaging features of small hepatocellular carcinomas with microvascular invasion on gadoxetic acid-enhanced MR imaging

Objectives

Detection of hepatocellular carcinomas (HCCs) before microvascular invasion (MVI) occurs is important due to the poor outcomes associated with MVI. We retrospectively investigated the imaging features of small HCCs with MVI on gadoxetic acid-enhanced MR imaging.

Methods

Fifty patients (40 men and 10 women; mean age, 54 years) with 58 surgically proven small (2 cm or less) HCCs were evaluated by gadoxetic acid-enhanced MRI. Signal intensities on imaging sequences and the presence of the typical dynamic enhancement pattern (arterial enhancement and washout) were assessed. Fisher's exact tests were performed to evaluate the relationships between the presence of MVI, tumor size, and imaging findings.

Results

None of the 12 small HCCs with diameters of 1 cm or less had MVI, while 15 (33%) of the 46 small HCCs with diameters of 1.1–2.0 cm had MVI (p = 0.025, Fisher's exact test). Among the small HCCs with diameters of 1.1–2.0 cm, all HCCs with MVI showed the typical dynamic pattern and hyperintensity on T2- and diffusion-weighted images. Most HCCs (54 lesions, 93%) were hypointense on hepatobiliary phase images regardless of the presence of MVI.

Conclusions

All small HCCs with MVI showed typical dynamic pattern and hyperintensity on T2-weighted and diffusion-weighted images, while atypical dynamic pattern and size of less than 1 cm in diameter may suggest absence of MVI.     

Image quality of Gd-EOB-DTPA-enhanced magnetic resonance imaging of the liver using dual-source parallel radiofrequency transmission technology: Comparison with the post-processing correction method for B1 inhomogeneity-induced signal loss

Purpose

To evaluate the efficacy of the dual-source parallel radiofrequency system (DS system) for gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI).

Materials and methods

Twenty-six subjects with liver diseases underwent hepatobiliary phase imaging of Gd-EOB-MRI using either the DS system or a single-source radiofrequency system with or without body-tuned CLEAR, which is a post-processing correction method of B1 inhomogeneity-induced signal loss (SSBTC+ and SSBTC−, respectively). The left and right lobes of the liver were separately assessed. Qualitatively, the homogeneity of signal intensity distribution was scored using a 3-point scale. Quantitatively, lesion-to-liver and spleen-to-liver contrast ratios (CRs) were calculated. The scores and CRs were compared among the three techniques by two-way analysis of variance and Tukey's Honestly Significant Difference post hoc test. Values of p < 0.05 were considered statistically significant for each analysis.

Results

The DS system showed a significantly better score in the left lobe of the liver, and higher lesion-to-liver and spleen-to-liver CRs in the left and right lobes of the liver, compared with SSBTC+ or SSBTC− (p < 0.05). The DS system and SSBTC− showed no significant differences in scores in the right lobe of the liver but they showed significantly better scores than SSBTC+ (p < 0.05).

Conclusion

The DS system is more advantageous to improve the homogeneity of signal intensity distribution and tissue contrast of Gd-EOB-MRI than the post-processing correction method independently of the site.     

Gadoxetic acid-enhanced 3.0 T MRI for the evaluation of hepatic metastasis from colorectal cancer: Metastasis is not always seen as a “defect” on the hepatobiliary phase

Purpose

To determine specific imaging features of hepatic metastasis from colorectal cancer, focusing on the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI.

Materials and methods

Over a 2-year period, 79 hepatic metastatic lesions were identified from 32 patients (22 men and 10 women) who proven colorectal cancer and underwent gadoxetic acid-enhanced 3.0 T MRI. Hepatic metastases were proven pathologically in 16 patients: by surgical liver resection (n = 14) and by US-guided biopsy (n = 2). The remaining 16 patients were considered to have hepatic metastasis based on imaging studies and clinical information. Two radiologists evaluated the imaging features of each MRI sequence, including high resolution T2WI, dynamic contrast enhancement study with hepatobiliary phase, and diffusion weighted image. We also compared SI of the lesions on T2WI and HBP.

Results

T2WI showed homogeneous high SI (n = 25; 31.7%), target appearance (n = 3; 3.8%), reversed target appearance (n = 2; 2.6%), and heterogeneously high SI (n = 49; 62%). On HBP, homogeneous defect were seen in 22 lesions (27.9%), target appearance in five lesions (6.4%), reversed target appearance in two lesions (2.5%), and heterogeneous defect in 50 lesions (63.3%); including reticular (70%), partially globular (26%), and diffuse GGO-like (4%) patterns. According to the imaging features on HBP, the homogeneous defect and heterogeneous defect groups had a mean ADC value of 0.99 × 10⁻³ and 1.07 × 10⁻³ mm²/s, respectively, without statistically significant difference.

Conclusion

Hepatic metastasis from colorectal cancer usually showed as a heterogeneous defect on HBP and a heterogeneous high SI on T2WI. The generally accepted “true defect” was not a common finding in hepatic metastasis from colorectal cancer.