Liver parenchymal enhancement of hepatocyte‐phase images in Gd‐EOB‐DTPA‐enhanced MR imaging: Which biological markers of the liver function affect the enhancement?

Purpose:

To clarify the factors that predict enhancement of the liver parenchyma in hepatocyte‐phase of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd‐EOB‐DTPA)‐enhanced MR imaging.

Materials and Methods:

Gd‐EOB‐DTPA–enhanced hepatocyte‐phase MR images of 198 patients with chronic liver diseases (Child‐Pugh class A in 112 patients, class B in 74 patients, and class C in 12 patients) were retrospectively analyzed. The hepatocyte‐phase images were obtained using fat‐suppressed T1‐weighted gradient‐echo images with a 3D acquisition sequence 10 min and 20 min after IV administration of Gd‐EOB‐DTPA (0.025 mmol/kg body weight). The quantitative liver–spleen contrast ratio (Q‐LSC) was calculated using the signal intensities of the liver and spleen. Serum albumin levels, total bilirubin levels, prothrombin activity, and the results of indocyanine green clearance tests (ICGs) were recorded and correlated with the Q‐LSC. Logistic regression analysis was performed to analyze which factors predict sufficient liver enhancement using a Q‐LSC of 1.5 as a cutoff value.

Results:

Only ICGs and Child‐Pugh classifications showed a statistically significant correlation with the Q‐LSC. Logistic regression analysis showed that ICGs were the only factors that accurately predicted liver enhancement on hepatocyte‐phase images.

Conclusion:

ICGs were found to be predictors of sufficient liver enhancement on hepatocyte‐phase images. J. Magn. Reson. Imaging 2009;30:1042–1046. © 2009 Wiley‐Liss, Inc.     

Differentiating combined hepatocellular and cholangiocarcinoma from mass-forming intrahepatic cholangiocarcinoma using gadoxetic acid-enhanced MRI

Purpose:

To examine the differential features of combined hepatocellular and cholangiocarcinoma (HCC‐CC) from mass‐forming intrahepatic cholangiocarcinoma (ICC) on gadoxetic acid‐enhanced MRI.

Materials and Methods:

Forty patients with pathologically proven combined HCC‐CC (n = 20) and ICCs (n = 20) who had undergone gadoxetic acid‐enhanced MRI were enrolled in this study. MR images were analyzed for the shape of lesions, hypo‐ or hyperintense areas on the T2‐weighted image (T2WI), rim enhancement during early dynamic phases, and central enhancement with hypointense rim (target appearance) on the 10‐min and 20‐min hepatobiliary phase (HBP). The significance of these findings was determined by the χ² test.

Results:

Irregular shape and strong rim enhancement during early dynamic phases, and absence of target appearance on HBP favored combined HCC‐CCs (P < 0.05). Lobulated shape, weak peripheral rim enhancement, and the presence of complete target appearance on the 10‐min and 20‐min HBP favored ICCs (P < 0.05). However, 10 CC‐predominant type of combined HCC‐CC showed complete or partial target appearance on 10‐min HBP.

Conclusion:

The shape of tumors, degree of rim enhancement during early dynamic phases, and target appearance on HBP were valuable for differentiating between combined HCC‐CC and mass‐forming ICC on gadoxetic acid‐enhanced MRI. J. Magn. Reson. Imaging 2012;36:881–889. © 2012 Wiley Periodicals, Inc.     

High‐risk nodules detected in the hepatobiliary phase of Gd‐EOB‐DTPA‐enhanced mr imaging in cirrhosis or chronic hepatitis: Incidence and predictive factors for hypervascular transformation,preliminary results

Purpose:

To evaluate the incidence and predictive factors of hypervascular transformation during follow‐up of “high‐risk nodules” detected in the hepatobiliary phase of initial Gd‐EOB‐DTPA‐enhanced MRI in chronic liver disease patients.

Materials and Methods:

A total of 109 patients with chronic liver disease who underwent Gd‐EOB‐DTPA‐enhanced MRI several times were investigated. Of these, 43 patients had 76 high‐risk nodules with both hypointensity in the hepatobiliary phase and hypovascularity in the arterial phase of initial MRI. These nodules were observed until hypervascularity was detected. MRI and clinical findings were compared to assess the incidence and potential predictive factors for hypervascular transformation between the group showing hypervascular transformation and the group not showing hypervascularization.

Results:

The median observation period was 242.5 ± 203.2 days (range, 47–802 days). Overall, 24 of 76 high‐risk nodules (31.6%) showed hypervascular transformation during follow‐up (median observation period, 186.0 ± 190.3 days). The growth rate of the nodules (P < 0.001), the presence of fat within nodules (P = 0.037), and hyperintensity on T1‐weighted images (P = 0.018) were significantly correlated with hypervascularization.

Conclusion:

Subsets of high‐risk nodules tended to show hypervascular transformation during follow‐up, with an increased growth rate, the presence of fat, and hyperintensity on T1‐weighted images as predictive factors. J. Magn. Reson. Imaging 2013;37:1377–1383. © 2013 Wiley Periodicals, Inc.     

Different signal intensity at Gd-EOB-DTPA compared with Gd-DTPA-enhanced MRI in hepatocellular carcinoma transgenic mouse model in delayed phase hepatobiliary imaging

Purpose:

To evaluate hyperintense Gd‐DTPA‐ compared with hyper‐ and hypointense Gd‐EOB‐DTPA‐enhanced magnet resonance imaging (MRI) in c‐myc/TGFα transgenic mice for detecting hepatocellular carcinoma (HCC).

Materials And Methods:

Twenty HCC‐bearing transgenic mice with overexpression of the protooncogene c‐myc and transforming growth factor‐alpha (TGF‐α) were analyzed. MRI was performed using a 3‐T MRI scanner and an MRI coil. The imaging protocol included Gd‐DTPA‐ and Gd‐EOB‐DTPA‐enhanced T1‐weighted images. The statistically evaluated parameters are signal intensity (SI), signal intensity ratio (SIR), contrast‐to‐noise ratio (CNR), percentage enhancement (PE), and signal‐to‐noise ratio (SNR).

Results:

On Gd‐DTPA‐enhanced MRI compared with Gd‐EOB‐DTPA‐enhanced MRI, the SI of liver was 265.02 to 573.02 and of HCC 350.84 to either hyperintense with 757.1 or hypointense with 372.55 enhancement. Evaluated parameters were SNR of HCC 50.1 to 56.5/111.5 and SNR of liver parenchyma 37.8 to 85.8, SIR 1.32 to 1.31/0.64, CNR 12.2 to 26.1/?30.08 and PE 42.08% to 80.5/?98.2%, (P < 0.05).

Conclusion:

Gd‐EOB‐DTPA is superior to Gd‐DTPA for detecting HCC in contrast agent‐enhanced MRI in the c‐myc/TGFα transgenic mouse model and there was no difference between the hyperintense or hypointense appearance of HCC. Either way, HCCs can easily be distinguished from liver parenchyma in mice. J. Magn. Reson. Imaging 2012;35:1397–1402. © 2012 Wiley Periodicals, Inc.

     

Peripheral low intensity sign in hepatic hemangioma: diagnostic pitfall in hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI of the liver

Purpose:

To describe the presence of “peripheral low intensity sign” in hepatic hemangioma in the hepatobiliary phase (HP) of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd‐EOB‐DTPA)‐enhanced magnetic resonance imaging (MRI) and to compare the frequency of this sign between hepatic hemangiomas and hepatic metastases.

Materials and Methods:

The Institutional Review Board approved this study and waived the requirement for informed consent. Sixty‐four patients with 51 hepatic hemangiomas (n = 31 patients) and with 58 hepatic metastases (n = 33 patients) underwent Gd‐EOB‐DTPA‐enhanced MRI. In all hepatic hemangiomas, 41 lesions were the typical type and 10 were the high flow type. HP images were qualitatively evaluated for the frequency of peripheral low intensity sign in hepatic hemangiomas and hepatic metastases using a four‐point scale. Statistical evaluations were performed with a Mann–Whitney U‐test.

Results:

Peripheral low intensity signs were demonstrated in 24 (47%) of 51 hepatic hemangiomas, while they were seen in 27 (47%) of 58 hepatic metastases. There was no significant difference in the mean visual score of peripheral low intensity sign between all hepatic hemangiomas (0.84 ± 1.03) and hepatic metastases (0.76 ± 0.92). The mean visual score of peripheral low intensity sign in typical hemangiomas (1.02 ± 1.06) was significantly higher than that in high flow hemangiomas (0.10 ± 0.32) (P = 0.008).

Conclusion:

Peripheral low intensity sign is not specific for malignant tumors, and can be seen even in hepatic hemangiomas on HP of Gd‐EOB‐DTPA‐enhanced MRI. J. Magn. Reson. Imaging 2012;35:852–858. © 2011 Wiley Periodicals, Inc.     

Effect of isoflurane anesthesia and hypothermia on the hepatic kinetics of Gd-EOB-DTPA: evaluation using MRI of conscious mice

Purpose:

To develop a method for body magnetic resonance imaging (MRI) of conscious mice and investigate the effect of isoflurane anesthesia and hypothermia on the hepatic kinetics of gadoxetate disodium (Gd‐EOB‐DTPA).

Materials and Methods:

Conscious or anesthetized mice were restrained on a holder and the rectal temperature was measured serially. Serial MRI of the liver was performed after intravenous injection of Gd‐EOB‐DTPA with or without temperature control. Three mice were studied for each condition.

Results:

The temperature dropped rapidly in anesthetized mice beside the MR unit. The decline was less prominent in conscious mice. The temperature decreased less in anesthetized mice and remained constant in conscious mice in the radiofrequency (RF) coil. The washout of Gd‐EOB‐DTPA was slower in anesthetized hypothermic mice than in conscious normothermic mice. Warmed anesthetized mice showed faster washout, and cooled conscious mice showed delayed washout. Severer hypothermia in anesthetized mice resulted in weaker initial enhancement and slower washout.

Conclusion:

By separately manipulating the presence or absence of anesthesia and hypothermia, we demonstrated that washout of Gd‐EOB‐DTPA was delayed under hypothermia, regardless of anesthesia. Serial body MRI of conscious mice was feasible and allowed the evaluation of kinetics of a contrast agent, while excluding the possible effects of anesthesia. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.     

Gd‐EOB‐DTPA‐enhanced MR imaging: Prediction of hepatic fibrosis stages using liver contrast enhancement index and liver‐to‐spleen volumetric ratio

Purpose:

To develop and evaluate a quantitative parameter for staging hepatic fibrosis by contrast enhancement signal intensity and morphological measurements from gadoxetic acid (Gd‐EOB‐DTPA)‐enhanced MR imaging.

Materials and Methods:

MR images were obtained in 93 patients; 75 patients had histopathologically proven hepatic fibrosis and 18 patients who had healthy livers were evaluated. The liver‐to‐muscle signal intensity ratio (SI_post = SIliver/SImuscle), contrast enhancement index (CEI = SIpost/SIpre), and liver‐to‐spleen volumetric ratio (VR = Vliver/Vspleen) were evaluated for staging hepatic fibrosis.

Results:

VR was most strongly correlated with fibrosis stage (7.21; r = ?0.83; P < 0.001). Sensitivity, specificity, and area under the ROC curve demonstrated by linear regression formula generated by VR and CEI in predicting fibrous scores were 100%, 73%, and 0.91, respectively, for the detection of hepatic fibrosis F1 or greater (≥ F1),100%, 87%, and 0.96 for ≥ F2, 74%, 98%, and 0.93 for ≥ F3 and 91%, 100%, and 0.97 for F4.

Conclusion:

The liver‐to‐spleen volumetric ratio and contrast enhancement index were reliable biomarkers for the staging of hepatic fibrosis on Gd‐EOB‐DTPA‐enhanced MR imaging. J. Magn. Reson. Imaging 2012;36:1148–1153. © 2012 Wiley Periodicals, Inc.

     

Dynamic contrast‐enhanced magnetic resonance imaging of abdominal solid organ and major vessel: Comparison of enhancement effect between Gd‐EOB‐DTPA and Gd‐DTPA

Purpose

To evaluate the differences in enhancement of the abdominal solid organ and the major vessel on dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) obtained with gadolinium ethoxybenzyldiethylenetriamine pentaacetic acid (Gd‐EOB‐DTPA: EOB) and gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) in the same patients.

Materials and Methods

A total of 13 healthy volunteers underwent repeat assessments of abdominal MR examinations with DCE‐MRI using either Gd‐DTPA at a dose of 0.1 mmol/kg body weight or EOB at a dose of 0.025 mmol/kg body weight. DCE images were obtained at precontrast injection and in the arterial phase (AP: 25 seconds), portal phase (PP: 70 seconds), and equilibrium phase (EP: 3 minutes). The signal intensities (SIs) of liver at AP, PP, and EP; the SIs of spleen, renal cortex, renal medulla, pancreas, adrenal gland, aorta at AP; and the SIs of portal vein and inferior vena cava (IVC) at PP were defined using region‐of‐interest measurements, and were used for calculation of signal intensity ratio (SIR).

Results

The mean SIRs of liver (0.195 ± 0.140), spleen (1.35 ± 0.353), renal cortex (1.58 ± 0.517), renal medulla (0.548 ± 0.259), pancreas (0.540 ± 0.183), adrenal gland (1.04 ± 0.405), and aorta (2.44 ± 0.648) at AP as well as the mean SIRs of portal vein (1.85 ± 0.477) and IVC (1.16 ± 0.187) at PP in the EOB images were significantly lower than those (0.337 ± 0.200, 1.99 ± 0.443, 2.01 ± 0.474, 0.742 ± 0.336, 0.771 ± 0.227, 1.26 ± 0.442, 3.22 ± 1.20, 2.73 ± 0.429, and 1.68 ± 0.366, respectively) in the Gd‐DTPA images (P < 0.05 each). There was no significant difference in mean SIR of liver at PP between EOB (0.529 ± 0.124) and Gd‐DTPA (0.564 ± 0.139). Conversely, the mean SIR of liver at EP was significantly higher with EOB (0.576 ± 0.167) than with Gd‐DTPA (0.396 ± 0.093) (P < 0.001).

Conclusion

Lower arterial vascular and parenchymal enhancement with Gd‐EOB, as compared with Gd‐DTPA, may require reassessment of its dose, despite the higher late venous phase liver parenchymal enhancement. J. Magn. Reson. Imaging 2009;29:636–640. © 2009 Wiley‐Liss, Inc.     

Optimal scanning protocol of arterial dominant phase for hypervascular hepatocellular carcinoma with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MR

Purpose:

To investigate optimal delay time of hepatic arterial phase in Gadoxetate‐enhanced MR for detecting hypervascular hepatocellular carcinoma (HCC).

Materials and Methods:

Forty‐five patients with 85 hypervascular HCCs and 9 patients with 16 hypervascular HCCs underwent Gadoxetate‐ and Gd‐DTPA‐enhanced MR at 1.5 Tesla (T) system, respectively. All HCCs were analyzed 10–38 s after injection using a time‐resolved dynamic MR sequence with keyhole data sampling. Seven sequential phase images (1 phase = 4 s) were obtained during a single breath hold of 28 s. Time–intensity curves of the abdominal aorta, liver parenchyma, and HCC were obtained, then aortic contrast arrival time, time of peak HCC enhancement, duration time of HCC and aortic enhancement, and time delay from aortic contrast arrival to peak enhancement of HCC were measured.

Results:

Aortic contrast arrival time was 15.1 ± 2.9 s, time of peak HCC enhancement 29.9 ± 4.6 s, duration time of HCC enhancement 17.4 ± 6.4 s postinjection of Gadoxetate. Duration of aortic enhancement (23.6 ± 3.5 s) of Gadoxetate‐enhanced MR was significantly less than that of Gd‐DTPA‐enhanced MR (26.3 ± 2.8 s) (P < 0.0059).

Conclusion:

Peak enhancement time of HCC on Gadoxetate‐enhanced MR imaging occurred at 14.6 ± 4.6 s after aortic contrast arrival. J. Magn. Reson. Imaging 2011;33:864–872. © 2011 Wiley‐Liss, Inc.     

Can MR fluoroscopic triggering technique and slow rate injection provide appropriate arterial phase images with reducing artifacts on gadoxetic acid‐DTPA (Gd‐EOB‐DTPA)‐enhanced hepatic MR imaging?

Purpose:

To evaluate whether using MR fluoroscopic triggering technique and slow rate injection improves the quality of arterial phase images in gadoxetic acid‐DTPA‐enhanced (Gd‐EOB‐DTPA) MR imaging because of proper acquisition timing and reduction of artifacts.

Materials and Methods:

Two hundred sixteen patients undergoing examination for liver diseases were retrospectively reviewed. All MR images were obtained with two Gd‐EOB‐DTPA injection protocols: (i) a combination protocol, in which the MR fluoroscopic triggering technique and slow rate injection (1 mL/s) were used; and for comparison, (ii) a conventional protocol, in which adjusted fixed scan delay and ordinary rate injection (2 mL/s) were adopted. Signal‐to‐noise ratio (SNR) of aorta, portal vein, and liver parenchyma on arterial phase images were calculated. Two blinded readers independently evaluated the obtained arterial phase images in terms of acquisition timing and degree of artifacts.

Results:

The SNRs of aorta and portal vein on arterial phase images were significantly higher in the combination protocol group (aorta/portal: 221.9 ± 91.9/197.1 ± 89.8) than that in the conventional protocol group (aorta/portal: 169.8 ± 97.4/92.7 ± 48.5) (P < 0.05). The acquisition timing for arterial phase images with the combination protocol was significantly better than that with the conventional protocol (P < 0.01). The image quality of the combination protocol was significantly higher than that of the conventional protocol (P < 0.01). The occurrence rate of moderate or severe degree of artifacts in the conventional protocol (38.0%) was more prominent than that in the combination protocol (18.5%).

Conclusion:

The combination of the MR fluoroscopic triggering technique and slow rate injection provides proper arterial phase images and reduces the artifacts in Gd‐EOB‐DTPA MR imaging. J. Magn. Reson. Imaging 2010;32:334–340. © 2010 Wiley‐Liss, Inc.     

Dilution method of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd‐EOB‐DTPA)‐enhanced magnetic resonance imaging (MRI)

Purpose

To elucidate whether a contrast agent dilution method (dilution method), in which gadoxetate disodium (Gd‐EOB‐DTPA) is diluted with saline, is useful for good‐quality arterial‐phase images.

Materials and Methods

In this study we observed 494 hypervascular hepatocellular carcinomas (HCCs) in 327 patients with chronic liver disease. Three Gd‐EOB‐DTPA injection methods were adopted for comparison: 1) test injection method (undiluted Gd‐EOB‐DTPA and modified scan delay), in which a test dose of 0.5 mL of Gd‐EOB‐DTPA was injected to determine scan delay; 2) conventional method (undiluted Gd‐EOB‐DTPA and fixed scan delay); and ( 3 ) dilution method (diluted Gd‐EOB‐DTPA and fixed scan delay), in which Gd‐EOB‐DTPA was diluted to 20 mL with saline. Lesion‐liver contrast was calculated. Image quality and lesion detectability were evaluated by two radiologists blinded to the injection methods.

Results

The lesion‐liver contrast of the dilution method was significantly higher than that of the other two methods. Lesion detectability of the conventional method (64%) was significantly lower than that of the other two methods (contrast agent dilution method, 95%; test injection method, 93%). The image quality of the contrast agent dilution method was significantly better than that of the other two methods.

Conclusion

The dilution method contributed to improved image quality, high lesion‐liver contrast, and high lesion detectability in the arterial‐phase images of GD‐EOB‐DTPA‐enhanced MRI. J. Magn. Reson. Imaging 2009;30:849–854. © 2009 Wiley‐Liss, Inc.     

Simple Method for evaluating the degree of liver parenchymal enhancement in the hepatobiliary phase of gadoxetic acid‐enhanced magnetic resonance imaging

Purpose:

To establish a simple method to evaluate the degree of liver parenchymal enhancement in the hepatobiliary phase (HP) of gadoxetic acid‐enhanced magnetic resonance imaging (MRI).

Materials and Methods:

Subjects comprised 75 patients with or without chronic liver disease who underwent gadoxetic acid‐enhanced MRI and indocyanine green retention at 15 minutes (ICG‐R15). HP images were used for data analysis. In the quantitative evaluation, liver‐to‐phantom signal intensity (SI) ratio (LPR), liver‐to‐portal vein SI ratio (LPVR), and liver‐to‐kidney SI ratio (LKR) were calculated. In qualitative visual assessment, liver‐to‐portal vein contrast (LPVC) and liver‐to‐kidney contrast (LKC) were assessed using a 5‐point scale (1, hyperintense; 2, slightly hyperintense; 3, isointense; 4, slightly hypointense; 5, hypointense). Statistical evaluations included the Spearman's rank correlation test.

Results:

LPVC and LKC correlated significantly with LPR (ρ = ?0.445, P < 0.001; ρ = ?0.576, P < 0.001, respectively). LPVC and LKC showed significant correlations with LPVR and LKR (ρ = ?0.659, P < 0.001; ρ = ?0.674, P < 0.001, respectively). In addition, LPVC and LKC correlated significantly with ICG‐R15 (ρ = 0.696, P < 0.001; ρ = 0.795, P < 0.001, respectively).

Conclusion:

LPVC and LKC can be used as simple visual indicators to objectively assess the degree of liver parenchymal enhancement on HP of gadoxetic acid‐enhanced MRI. J. Magn. Reson. Imaging 2013;37:1115–1121. © 2012 Wiley Periodicals, Inc.