Feasibility of 5-minute delayed transition phase imaging with 30° flip angle in gadoxetic acid-enhanced 3D gradient-echo MRI of liver, compared with 20-minute delayed hepatocyte phase MRI with standard 10° flip angle.

OBJECTIVE: The purpose of this study was to compare 5-minute delayed transitional phase imaging using a 30° flip angle (hereafter, 5 min-FA30) and 20-minute hepatocyte phase imaging using a 10° flip angle (hereafter, 20 min-FA10) in gadoxetic acid-enhanced MRI for focal hepatic lesion detection and lesion-to-liver contrast-to-noise ratio (CNR), and to determine whether 5 min-FA30 could replace 20 min-FA10 with a 15-minute time saving. MATERIALS AND METHODS: One hundred sixteen patients with 282 focal hepatic lesions (size range, 0.2-12.5 cm; malignant, n = 146; benign, n = 136) underwent gadoxetic acid-enhanced MRI with 5 min-FA30 and 20 min-FA10 with a 3D T1-weighted gradient-echo sequence. Three radiologists independently assessed the presence of focal hepatic lesions using a 4-point scale, and detection sensitivity of focal hepatic lesions was calculated. Lesion-to-liver CNRs were calculated and compared in two image groups. RESULTS: There was no significant difference in detection sensitivity of focal hepatic lesions for all three readers between 5 min-FA30 (mean, 95.4%) and 20 min-FA10 (mean, 95.6%), irrespective of lesion size or malignancy. The mean CNR on 5 min-FA30 (167.9 ± 84.1) was significantly higher than that on 20 min-FA10 (160.2 ± 79.5). However, the mean CNR difference between the two image groups was relatively small (7.8 ± 41.9). CONCLUSION: Compared with 20 min-FA10, 5 min-FA30 provided higher CNR and similar sensitivity. These findings indicate that 5 min-FA30 could replace 20-min delayed hepatocyte phase imaging using a 10° flip angle with similar diagnostic performance and 15 minutes of time saving.

Presence of a hypovascular hepatic nodule showing hypointensity on hepatocyte-phase image is a risk factor for hypervascular hepatocellular carcinoma.

PURPOSE: To determine whether the presence of a hypovascular nodule in the liver showing hypointensity on hepatocyte-phase of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) is a risk factor for hypervascular hepatocellular carcinoma (HCC) in patients with chronic liver disease. MATERIALS AND METHODS: Forty-one patients with pathologically confirmed hypervascular HCC and 41 age- and gender-matched controls were retrospectively selected. These patients had undergone EOB-MRI at least twice: the latest EOB-MRI and EOB-MRI performed more than 6 months earlier. History of hypervascular HCC, presence of a hypointense hypovascular nodule in previous hepatocyte-phase MR images, percent prothrombin time, platelet count, serum levels of albumin, total bilirubin, aspartate aminotransferase, alanine aminotransferase, α-fetoprotein, and protein induced by vitamin K absence-II (PIVKA-II) were variables evaluated by multivariate logistic regression analysis. RESULTS: Multivariate analysis revealed that serum albumin level (odds ratio [95% confidence interval], 0.19 [0.06-0.57]; P = 0.0024), history of hypervascular HCC (8.62 [2.71-32.8]; P = 0.0001), and presence of a hypointense hypovascular nodule (4.18 [1.18-17.2]; P = 0.0256) were significant risk factors for hypervascular HCC. CONCLUSION: Patients with chronic liver disease showing a hypointense hypovascular nodule in the liver on hepatocyte-phase EOB-MRI have a high risk of HCC development.

Hepatocellular carcinoma risk assessment using gadoxetic acid-enhanced hepatocyte phase magnetic resonance imaging.

AIM: To investigate whether the patients with hypovascular liver nodules determined on the arterial phase and hypointensity on the hepatocyte phase gadoxetic acid-enhanced magnetic resonance imaging (hypovascular hypointense nodules) are at increased risk of hepatocarcinogenesis, we assessed subsequent typical hepatocellular carcinoma (HCC) development at any sites of the liver with and without such nodules. METHODS: One hundred and twenty-seven patients with chronic hepatitis B or C and without a history of HCC, including 68 with liver cirrhosis, were divided into those with (non-clean liver group, n = 18) and without (clean liver group, n = 109) hypovascular hypointense nodules. All the patients were followed up for 3 years, and HCC development rates and risk factors were analyzed with the Kaplan-Meier method and the Cox proportional hazard model, respectively. RESULTS: A total of 17 patients (10 in the non-clean liver group and seven in the clean liver group) developed typical HCC. Cumulative 3-year rates of HCC development were 55.5% in the non-clean liver group and 6.4% in the clean liver group (P < 0.001), and those at the different sites from the initial nodules was also higher in the non-clean liver group (22.2%) than the clean liver group (6.4%) (P = 0.003). Multivariate analysis identified older age (P = 0.024), low platelet counts (P = 0.017) and a non-clean liver (P < 0.001) as independent risk factors for subsequent HCC development. CONCLUSION: Patients with hypovascular hypointense liver nodules are at a higher risk for HCC development at any sites of the liver than those without such nodules.

A convenient and reproducible protocol for acquisition of the hepatocyte phase for liver function-impaired patients in gadoxetic acid disodium-enhanced magnetic resonance imaging.

Background: The hepatocyte phase (HCP) in gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) plays an important role in the detection and characterization of liver lesions, treatment planning, and liver function evaluation. However, the imaging protocol is complicated and time-consuming. This cross-sectional study aimed to develop a convenient and reproducible protocol for the HCP acquisition in Gd-EOB-DTPA-enhanced MRI. Methods: A total of 107 patients were prospectively included and assigned to three groups based on Child-Pugh (CP) classification, with 37, 40, and 30 in the non-cirrhosis, CP A, and CP B groups, respectively. Dynamic HCPs were acquired every 5 min after the Gd-EOB-DTPA administration and ended in 25 min in non-cirrhosis patients and 40 min in cirrhotic patients. The HCP acquired 5 min after the initial visualization of the intrahepatic bile duct (IBD) was selected from the dynamic HCPs as the adequate HCP (HCPproposed) and the corresponding acquisition time was recorded as Timeproposed. In addition, according to the 2016 Expert Consensus (EC) on the definition of the adequate HCP from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), the adequate HCPEC and the corresponding TimeEC were also determined from the dynamic HCPs. The hepatic relative enhancement ratio (RER), the contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of hepatic focal lesions in the HCPEC and HCPproposed images, as well as the TimeEC and Timeproposed were compared by the paired t-test for the three groups, respectively. Inter-observer agreement of the determination of the HCPEC and HCPproposed was compared by the χ2 test. Results: The RER, CNR, and SNR showed no significant difference between the HCPEC and HCPproposed in all three groups (all P>0.05). The paired differences between TimeEC and Timeproposed were 1.08±3.56 min (P=0.07), 2.88±4.22 min (P<0.001), and 5.83±5.27 min (P<0.001) in the three groups, respectively. Inter-observer agreement of the determination of the HCPEC and HCPproposed were 0.804 (86/107) and 0.962 (103/107), respectively (χ²=13.09, P=0.001). Conclusions: The adequate HCP could be acquired 5 min after the initial visualization of the IBD, which could serve as a convenient and reproducible protocol for the HCP imaging.

Diagnostic value of gadobenate dimeglumine-enhanced hepatocyte-phase magnetic resonance imaging in evaluating hepatic fibrosis and hepatitis.

AIM: To evaluate the diagnostic value of gadobenate dimeglumine (Gd-BOPTA)-enhanced hepatocyte-phase magnetic resonance imaging (MRI) in evaluating hepatic fibrosis and hepatitis. METHODS: Hepatocyte-phase images of Gd-BOPTA-enhanced MRI were retrospectively evaluated in 76 patients with chronic liver disease. These patients were classified into five groups according to either the histopathological fibrosis stage (S0-S4) or the histopathological hepatitis grade (G0-G4). The relative enhancement ratio (RE) of the liver parenchyma in the T1-vibe sequence was calculated by measuring the signal intensity before (SI pre) and 90 min after (SI post) intravenous injection of Gd-BOPTA using the following formula: RE = (SI post - SI pre)/SI pre. One-way analysis of variance was used to compare the difference between the relative RE in the hepatocyte phase (REh) and the stage of hepatic fibrosis and the grade of hepatitis. Pearson's product-moment correlation analysis was used to evaluate the relationship between the REh and the levels of serologic liver functional parameters. RESULTS: According to histopathological hepatic fibrosis stage, the 76 patients were classified into five groups: 16 in S0, 15 in S1, 21 in S2, 9 in S3, and 15 in S4 group. According to histopathological hepatitis grade, the 76 patients were also classified into five groups: 0 in G0, 44 in G1, 22 in G2, 8 in G3, and 2 in G3 group. With regard to the stage of hepatic fibrosis, REh showed significant differences between the S2 and S3 groups and between the S2 and S4 groups (P < 0.05), but no significant difference was observed between the other groups. With regard to the grade of hepatitis, REh showed significant differences between the G1 and G2 groups and between the G1 and G4 groups (P < 0.05), but no significant difference was observed between the other groups. Increased REh showed correlations with decreased serum levels of TB, ALT and AST (P < 0.05). CONCLUSION: To some extent, measuring the REh using Gd-BOPTA-enhanced MRI might be a noninvasive technique for assessing the stage of hepatic fibrosis. This method is able to differentiate no/mild hepatitis from advanced hepatitis. TB, ALT and AST levels can predict the degree of liver enhancement in the hepatocyte phase of Gd-BOPTA-enhanced MRI.

Quantitative evaluation of gadoxetate hepatocyte phase homogeneity: potential imaging markers for detection of early cirrhosis.

OBJECTIVE: Does quantitative analysis of the gadoxetate hepatocyte phase homogeneity, measuring percent standard deviation of hepatocyte phase (SDHP) and liver-to-kidney enhancement ratio (LiKER) detect early hepatic fibrosis? MATERIALS AND METHODS: Retrospective review of gadoxetate liver MRI plus biopsy-proven fibrosis within 6 months included 31 reversible hepatic fibrosis, 33 irreversible hepatic fibrosis, and 15 donors. Parenchymal and vascular SDHP and LiKER were measured on the 20-min hepatocyte phase using region of interest. RESULTS: Parenchymal SDHP, vascular SDHP and LiKER measurements differentiate early hepatic fibrosis from controls (P<.01). CONCLUSION: Quantitative analysis of gadoxetate hepatocyte phase homogeneity using SDHP and LiKER is a promising imaging biomarker for diagnosis of early liver fibrosis.

Optimal timing and diagnostic adequacy of hepatocyte phase imaging with gadoxetate-enhanced liver MRI.

RATIONALE AND OBJECTIVES: To evaluate clinical and imaging features associated with adequacy of the hepatocyte phase (HP) in gadoxetate disodium-enhanced liver magnetic resonance imaging (MRI) in patients without chronic liver disease (CLD). MATERIALS AND METHODS: This was a retrospective institutional review board-approved study of 97 patients who underwent liver MRI examinations with gadoxetate disodium and had no history of CLD. Available late dynamic and HP sequences (3-20 minutes postinjection) were independently analyzed by four radiologists for perceived image adequacy and level of biliary enhancement. Signal intensity ratios (SIRs) of liver/inferior vena cava (IVC), liver/spleen, and liver/muscle were measured. The Spearman ρ and receiver operating characteristic analyses were performed correlating various factors with HP adequacy. A rule for predicting HP adequacy was also derived and tested to determine whether overall examination time could be shortened. RESULTS: A visually adequate HP was observed in 12% of subjects by 10 minutes, 80% by 15 minutes, and 93% by 20 minutes. An SIRliver/IVC > 1.8 was the imaging feature that had the strongest correlation with an adequate HP (ρ = 0.813, P < .001), and was more predictive of adequacy of the HP than the time postinjection (ρ = 0.5, P < .001). The time at which an adequate HP was first observed did not correlate with any tested demographic or laboratory values. Stopping imaging when an SIRliver/IVC > 1.8 would have successfully reduced mean postcontrast time to 15:39 ± 4:02 from 20:00 (P < .001), although maintaining HP adequacy. CONCLUSIONS: Most patients without CLD undergoing gadoxetate-enhanced liver MRI achieve adequate HP at 20 minutes. However, a shorter postcontrast stopping time can be used in most patients.