Applying quantitative CMR parameters for detecting myocardial lesion in immune checkpoint inhibitors-associated myocarditis.

PURPOSE: Sparse researches evaluated the quantitative cardiovascular magnetic resonance (CMR) parameters for immune checkpoint inhibitors (ICI)-associated myocarditis. We aimed to apply quantitative CMR mappings and late gadolinium enhancement (LGE) extent for detecting ICI-associated myocarditis. METHOD: The retrospective study included patients with ICI-associated myocarditis and CMR examination from August 2018 to August 2021 in our hospital. ICI-associated myocarditis was clinically diagnosed based on the clinical criteria by European Society of Cardiology guidelines. The multiparametric CMR images including T2 mapping and black blood T2-weighted images were used to evaluate myocardial edema. The myocardial edema ratio (ER) ≥ 2.0 was applied for determining myocardial edema on T2-weighted images. RESULTS: 56 patients with ICI-associated myocarditis were included. The global T2 value and native T1 value of patients with ICI-associated myocarditis were significantly higher than the reference ranges in our hospital (p < 0.05). The rate of elevated global T2 value (92%) was significantly higher than those of abnormal native T1 value (73%), ER (52%) and LGE presence (68%) in patients with ICI-associated myocarditis (p < 0.05). The LGE extent and left ventricular ejection fraction of patients with ICI-associated myocarditis were 10.38 ± 9.64% and 56.42 ± 8.54%, respectively. LGE extent inversely correlated with left ventricular ejection fraction (r = -0.38, p = 0.004) but positively correlated with native T1 value (r = 0.28, p < 0.04) and extracellular volume (r = 0.50, p = 0.001). CONCLUSIONS: T2 mapping could detect higher rate of patients with ICI-associated myocarditis than native T1 mapping, ER and LGE presence. LGE extent inversely correlated with left ventricular ejection fraction but positively correlated with native T1 value and extracellular volume in patients with ICI-associated myocarditis.

The prognostic value of global myocardium strain by CMR-feature tracking in immune checkpoint inhibitor-associated myocarditis.

OBJECTIVES: Immune checkpoint inhibitor (ICI)-associated myocarditis is a potentially fatal complication. Sparse published researches evaluated the prognostic value of cardiovascular magnetic resonance feature tracking (CMR-FT) for ICI-associated myocarditis. METHODS: In the single-center retrospective study, 52 patients with ICI-associated myocarditis and CMR were included from August 2018 to July 2021. The ICI-associated myocarditis was diagnosed by using the clinical criteria of the European Society of Cardiology guidelines. Major adverse cardiovascular events (MACE) were comprised of cardiovascular death, cardiogenic shock, cardiac arrest, and complete heart block. RESULTS: During a median follow-up of 171 days, 14 (27%) patients developed MACE. For patients with MACE, the global circumferential strain (GCS), global radial strain (GRS), global longitudinal strain (GLS), and left ventricular ejection fraction (LVEF) were significantly worse and native T1 values and late gadolinium enhancement (LGE) extent were significantly increased, compared with patients without MACE (p < 0.05). The GLS remained the independent factor associated with a higher risk of MACE (hazard ratio (HR): 2.115; 95% confidence interval (CI): 1.379-3.246; p = 0.001) when adjusting for LVEF, LGE extent, age, sex, body mass index, steroid treatment, and prior cardiotoxic chemotherapy or radiation. After adjustment for LVEF, the GLS remained the independent risk factor associated with a higher rate of MACE among patients with a preserved LVEF (HR: 1.358; 95% CI: 1.007-1.830; p = 0.045). CONCLUSIONS: GLS could provide independent prognostic value over GCS, GRS, traditional CMR features, and clinical features in patients with ICI-associated myocarditis. KEY POINTS: • The global circumferential strain (GCS), global radial strain (GRS), and global longitudinal strain (GLS) by cardiovascular magnetic resonance feature tracking were significantly impaired in patients with an immune checkpoint inhibitor (ICI)-associated myocarditis. • GLS was still significantly impaired in patients with preserved left ventricular ejection fraction. • The worse GLS was an independent risk factor over GCS, GRS, traditional CMR features, and clinical features for predicting major adverse cardiovascular events in patients with ICI-associated myocarditis.

Feasibility of compressed sensing technique for isotropic dynamic contrast-enhanced liver magnetic resonance imaging.

PURPOSE: To investigate whether an isotropic T1-weighted gradient echo (T1-GRE) sequence using a compressed sensing (CS) technique during liver magnetic resonance imaging (MRI) can improve the image quality compared to that using a standard parallel imaging (PI) technique in patients with hepatocellular carcinoma (HCC). METHODS: Forty-nine patients with single pathologically confirmed HCC were included in the prospective study, who underwent a 3.0 T MRI including the two T1-GRE sequences (CS and PI). Qualitative analysis including the relative contrast (RC) of liver-to-lesion, liver-to-portal vein and liver-to-hepatic vein on pre-contrast and postcontrast (delayed phase) images were calculated. Respiratory motion artifact, gastrointestinal motion artifact and overall image quality were scored by using a 4-point scale. RESULTS: RC of liver-to-lesion, liver-to-portal vein and liver-to-hepatic vein measured on both pre-contrast and postcontrast phase images were significantly higher for CS than for PI. The scores of overall image quality was comparable between PI and CS (3.98 ±â€¯0.10vs 3.96 ±â€¯0.13, P = 0.083 for pre-contrast; 3.96 ±â€¯0.16 vs 3.93 ±â€¯0.17, P = 0.132 for postcontrast, respectively). The scores of gastrointestinal motion artifact was significantly higher for PI than for CS (3.92 ±â€¯0.21 vs 3.69 ±â€¯0.33 for pre-contrast; 3.86 ±â€¯0.21 vs 3.59 ±â€¯0.30 for postcontrast, P < 0.001 for both). The scores of respiratory motion artifact was significantly higher for PI only in pre-contrast sequence (3.97±0.11 vs 3.89 ±â€¯0.22, P = 0.002 for pre-contrast; 3.95 ±â€¯0.18 vs 3.90 ±â€¯0.22, P = 0.083 for postcontrast, respectively). CONCLUSIONS: Compared to the standard PI sequence, the CS technique can provide greater contrast in displaying HCCs and hepatic vessels in MRI without compromise of overall image quality.

Gd-EOB-DTPA-enhanced MR findings in chemotherapy-induced sinusoidal obstruction syndrome in colorectal liver metastases.

BACKGROUND: We assessed the clinical presentations, biomarkers, and Gd-EOB-DTPA-enhanced MRI features that were associated with oxaliplatin-induced sinusoidal obstruction syndrome (SOS) to detect chemotherapy-associated SOS in a timely manner. METHODS: Fifty-seven patients who underwent oxaliplatin-based chemotherapy and Gd-EOB-DTPA-enhanced MRI were included. Post-oxaliplatin heterogeneity in liver parenchyma was scored on a grading scale of 0 to 3. Abnormal clinical findings, including splenomegaly, hepatomegaly, gall bladder wall thickening, and hepatic vein narrowing, were also assessed. Additionally, alanine transaminase (ALT) levels, aspartate aminotransferase (AST) levels, and platelet counts were measured. RESULTS: For SOS, 21 patients were scored grade 0, 24 were grade 1, seven were grade 2, and five were grade 3. Hepatomegaly, splenomegaly, gall bladder wall thickening, and hepatic vein narrowing were significantly correlated with the grade for non-tumorous hepatic parenchymal heterogeneity. For laboratory findings, ALT and AST levels, the AST-to-platelet ratio index score, and platelet counts were significantly associated with a high grade (≥2) of non-tumorous hepatic parenchymal heterogeneity. CONCLUSIONS: We assessed the clinical presentations, biomarkers, and Gd-EOB-DTPA-enhanced MRI features that were associated with oxaliplatin-induced sinusoidal obstruction syndrome (SOS) to detect chemotherapy-associated SOS in a timely manner. Additionally, specific laboratory findings were significantly associated with a high grade (≥2).

Assessing liver fibrosis in chronic hepatitis B using MR extracellular volume measurements: Comparison with serum fibrosis indices.

OBJECTIVES: To evaluate the diagnostic value of liver extracellular volume (ECVliver) measurement by equilibrium MR in staging liver fibrosis in chronic hepatitis B (CHB) patients, and to compare its performance with serum fibrosis indices. MATERIALS AND METHODS: 91 CHB patients were included and underwent gadopentetate dimeglumine-enhanced MRI with T1 mapping sequence before and 15-min after contrast. ECVliver, aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis index based on the four factors (FIB-4) were calculated and compared between fibrosis subgroups, and the correlations between the three indices and fibrosis stage or inflammatory activity were measured by Spearman correlation analysis and stepwise multiple regression analysis. Diagnostic performance in evaluating liver fibrosis stage was assessed and compared using receiver operating characteristic analysis. RESULTS: Interobserver agreement showed an excellent interclass correlation coefficient of 0.895 for ECVliver. ECVliver, APRI and FIB-4 were different between fibrosis stages as a whole (F/H = 18.44-24.36, P ≤ 0.001). ECVliver had the strongest correlation with fibrosis stage (r = 0.727, P < 0.001), while APRI and FIB-4 had weak correlations (r = 0.466 and 0.440, P < 0.001). Multivariate analysis showed that only ECVliver was independently correlated with fibrosis stage (P < 0.001). The fibrosis stage was the only independent factor correlated with ECVliver comparing to inflammatory activity (P < 0.001). AUCs of ECVliver were larger than both APRI and FIB-4 in fibrosis staging, with significant differences in the diagnosis of advanced fibrosis (≥F3) and cirrhosis (F4) (P = 0.0024 to 0.0049). CONCLUSION: MR ECVliver provides a promising noninvasive tool in staging liver fibrosis for CHB patients, superior to the fibrosis indices of APRI and FIB-4.

Pre-TACE kurtosis of ADCtotal derived from histogram analysis for diffusion-weighted imaging is the best independent predictor of prognosis in hepatocellular carcinoma.

PURPOSE: To determine the feasibility of pre-TACE IVIM imaging based on histogram analysis for predicting prognosis in the treatment of unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Fifty-five patients prospectively underwent 1.5T MRI 1 week before TACE. Histogram metrics for IVIM parameters and ADCs maps between responders and non-responders with mRECIST assessment were compared. Kaplan-Meier, log-rank tests and Cox proportional hazard regression model were used to correlate variables with time to progression (TTP). RESULTS: Mean (p = 0.022), median (p = 0.043), and 25th percentile (p < 0.001) of perfusion fraction (PF), mean (p < 0.001), median (p < 0.001), 25th percentile (p < 0.001) and 75th percentile (p = 0.001) of ADC(0,500), mean (p = 0.005), median (p = 0.008) and 25th percentile (p = 0.039) of ADCtotal were higher, while skewness and kurtosis of PF (p = 0.001, p = 0.005, respectively), kurtosis of ADC(0,500) and ADCtotal (p = 0.005, p = 0.001, respectively) were lower in responders compared to non-responders. Multivariable analysis demonstrated that mRECIST was associated with TTP independently, and kurtosis of ADCtotal had the best predictive performance for disease progression. CONCLUSION: Pre-TACE kurtosis of ADCtotal is the best independent predictor for TTP. KEY POINTS: • mRECIST was associated with TTP independently. • Lower kurtosis and higher mean for ADCs tend to have good response. • Pre-TACE kurtosis of ADC total is the best independent predictor for TTP.

Comparison of gadoxetic acid versus gadopentetate dimeglumine for the detection of hepatocellular carcinoma at 1.5 T using the liver imaging reporting and data system (LI-RADS v.2017).

PURPOSE: The goal of this study was to investigate the Liver Imaging Reporting and Data System (LI-RADS) v.2017 for the categorization of hepatocellular carcinomas (HCCs) with gadoxetic acid compared with gadopentetate dimeglumine-enhanced 1.5-T magnetic resonance imaging (MRI). MATERIAL AND METHODS: We included 141 high-risk patients with 145 pathologically-confirmed HCCs who first underwent gadopentetate dimeglumine-enhanced 1.5-T followed by gadoxetic acid-enhanced 1.5-T MRI. Two independent radiologists evaluated the presence or absence of major HCC features and assigned LI-RADS categories after considering ancillary features on both MRIs. Finally, the sensitivity of LI-RADS category 5 (LR-5) and the frequencies of major HCC features were compared between gadoxetic acid- and gadopentetate dimeglumine-enhanced 1.5-T MRI using the Wilcoxon test. RESULTS: The sensitivity of LR-5 for diagnosing HCCs was significantly different between gadoxetic acid- and gadopentetate dimeglumine-enhanced MRI (73.8% [107/145] vs 26.2% [38/145], P < 0.001; 71% [103/145] vs 29% [42/145], P < 0.001 for reviewers 1 and 2, respectively). Among the major HCC LI-RADS features, capsule appearance was less frequently demonstrated on gadoxetic acid-enhanced MRI than on gadopentetate dimeglumine-enhanced MRI (3.4% [5/145] vs 5.5% [8/145], P = 0.793; 4.1% [6/145] vs 5.5% [8/145], P = 0.87 for reviewers 1 and 2, respectively), and the frequency of arterial hyperenhancement was not significantly different between gadoxetic acid and gadopentetate dimeglumine (89% [129/145] vs 89% [129/145], P = 1.000). In addition, the frequency of a washout appearance was less in the transitional phase (TP) than in the portal venous phase (PVP) on gadoxetic acid-enhanced MRI (43% [46/107] vs 57% [61/107], P = 0.367). CONCLUSION: Gadoxetic acid-enhanced MRI showed a comparable sensitivity to gadopentetate dimeglumine-enhanced MRI for the diagnosis of HCCs, and LI-RADS category 4 (LR-4) hepatic nodules were upgraded to LR-5 when taking into account the major features according to LI-RADS v.2017.

T1 mapping on gadoxetic acid-enhanced MR imaging predicts recurrence of hepatocellular carcinoma after hepatectomy.

PURPOSE: Our purpose was to demonstrate the prognostic significance of T1 mapping on gadoxetic acid-enhanced MR imaging in prediction of recurrence of single HCC after hepatectomy. MATERIALS AND METHODS: One hundred and seven patients with single nodular HCC (≤3 cm) who underwent preoperative gadoxetic acid-enhanced MRI were included in the study. T1 mapping with syngo MapIt was obtained on a 1.5 T scanner. Radiological features and reduction rate of T1 relaxation time (Δ%) of tumors were assessed by two radiologists. Cumulative recurrence rates were compared between groups of low and high reduction rate of T1 relaxation time. A further classified cumulative recurrence rate of the overall cohort was based on the numbers of independent predictive factors. RESULTS: Reduction rate of T1 relaxation time (P = 0.001) and non-hypervascular hypointense nodules (P = 0.042) in preoperative gadoxetic acid-enhanced MRI were independently related to recurrence of HCC after hepatectomy. Patients of lower reduction rates group had higher cumulative recurrence rates (P < 0.0001) than patients of higher reduction rates group. A combination of the two risk factors in patients with single HCC had significantly higher recurrence rates compared to those with either or none of the two risk factors. CONCLUSIONS: Reduction rate of T1 relaxation time combined with non-hypervascular hypointense nodules can be reliable biomarkers in the preoperative prediction of recurrence of HCC after hepatectomy.

Diffusion kurtosis imaging and diffusion-weighted imaging in assessment of liver fibrosis stage and necroinflammatory activity.

PURPOSE: To investigate and compare the diagnostic value of diffusion kurtosis imaging (DKI) with diffusion-weighted imaging (DWI) in assessing and quantifying hepatic fibrosis. METHODS: Thirty rats were divided into the control group (n = 6) and the fibrosis experimental groups (n = 6 per group) with CCl4 administration for 2, 4, 6, and 8 weeks. Liver fibrosis stage (S) and necroinflammatory activity grade (G) were histopathologically determined. DKI and DWI were performed; mean apparent diffusion (MD), mean kurtosis (MK), and apparent diffusion coefficient (ADC) values were calculated. DKI parameters were compared with ADC values according to G/S scores. RESULTS: Strong inverse correlations were found between the degree of fibrosis and both MD and ADC (r = -0.840 and r = -0.760), while only weak correlation existed in MK (r = 0.405). ROC analyses demonstrated the AUC in MD, MK, and ADC of 0.862, 0.684, 0.817 for identifying mild and severe fibrosis, and 0.757, 0.675, 0.733 for non-cirrhosis and cirrhosis, respectively. The degree of fibrosis was significantly correlated with α-smooth muscle actin (α-SMA) (P < 0.0001); α-SMA had strong inverse correlation with MD (r = -0.723), moderate inverse correlation with ADC (r = -0.613), and very weak correlation with MK (r = 0.175). Additionally, MD was strongly correlated with the necroinflammatory activity (r = -0.758), ADC was moderately correlated (r = -0.492), and MK was weakly correlated (r = 0.254). CONCLUSION: DKI may provide added information and serve as a valuable tool for the characterization and surveillance of liver fibrosis in a non-invasive manner.

Role of MR in the differentiation of IgG4-related from non-IgG4-related hepatic inflammatory pseudotumor.

BACKGROUND: Hepatic inflammatory pseudotumor (IPT) is classified into 2 types based on IgG4 stain: IgG4-related and non-IgG4-related; the two types differ not only in their pathological characteristics, but also in the clinical features. This study aimed to investigate the MR character of hepatic IPT, and differentiate the IgG4-related IPT from the non-IgG4-related IPT. METHODS: Twenty-five patients with 27 histologically proven hepatic IPTs were retrospectively analyzed. Ten lesions were diagnosed as IgG4-related IPT, and the other 17 as non-IgG4-related IPT. The MR signal features on T1, T2-weighted, dynamic-enhanced, and diffusion-weighted imaging were evaluated and compared. RESULTS: The dominant lesions were subcapsularly distributed (n=17, 63.0%) with clear boundary (n=20, 74.1%), and showed progressive enhancement pattern (n=21, 77.8%) with diffuse homogeneous (n=12, 44.4%) or heterogeneous (n=8, 29.6%) hyperintensity, accompanied by delayed capsule-like enhancement (n=17, 63.0%) and central nonenhanced areas (n=18, 66.7%). Morphological features (P>0.05) were not sufficient to differentiate IgG4-related IPT from non-IgG4-related IPT; the wash-out pattern was only found in 2 IgG4-related IPT, while the progressive enhancement pattern was more common in the non-IgG4-related lesions (n=16) (P=0.022). During portal and delayed phases, iso-/hypoenhanced lesions were only seen in 3 IgG4-related IPT, and circular-enhanced lesions (n=5) existed exceptionally in the non-IgG4-related group with significant differences (P=0.029 and 0.027). Most IgG4-related IPTs had lower apparent diffusion coefficient compared with the liver parenchyma (n=6), while most non-IgG4-related IPTs had higher apparent diffusion coefficient value (n=13) (P=0.046). CONCLUSIONS: Although MR images of hepatic IPT have certain characteristics, they are not enough to differentiate IgG4-related IPT from non-IgG4-related IPT. The enhancement pattern, signal features on portal and delayed phases, and the apparent diffusion coefficient value of the lesion may be helpful for the diagnosis.

MR comparative study of combined hepatocellular-cholangiocarcinoma in normal, fibrotic, and cirrhotic livers.

PURPOSE: To compare MR imaging features of combined hepatocellular-cholangiocarcinoma (cHCC-CC) in normal, fibrotic, and cirrhotic livers. METHODS: A total of 64 patients with 67 pathologically proven cHCC-CCs were retrospectively analyzed. Patients were classified into three groups according to the patients' liver condition: patients with normal liver (F0, group 1), fibrosis without cirrhosis (F1-3, group 2), and cirrhosis (F4, group 3). The morphological and MR signal features on T1- and T2-weighted, dynamic contrast-enhanced, diffusion-weighted imaging, as well as the accompanying imaging findings, were evaluated and compared. RESULTS: There were 12, 19, and 33 patients in groups 1, 2, and 3, respectively. Tumors in the fibrotic and cirrhotic livers were smaller than those in the normal liver, and tumors with cirrhosis had the smallest size (P = 0.0326). No statistical difference was found when comparing the signal intensity on T2-weighted imaging (P = 0.496), but iso- or hypointense lesions were only found in the fibrosis (n = 2) or cirrhosis group (n = 2). Enhancement pattern was different between groups, the washout pattern was more often seen in the cirrhosis group (P = 0.049), and the accompanying mosaic architecture was also more commonly seen in the cirrhosis group (P = 0.048). The ADC values of the lesions were not different among the three groups (P = 0.899). CONCLUSION: MRI may provide valuable information for the diagnosis and differential diagnosis of cHCC-CC in normal, fibrotic, and cirrhotic livers. The nodule size, enhancement pattern, and the presence of mosaic architecture in cHCC-CC differ between different degrees of background liver disease.

Intrahepatic distant recurrence following complete radiofrequency ablation of small hepatocellular carcinoma: risk factors and early MRI evaluation.

BACKGROUND: Radiofrequency ablation (RFA) is related to a high intrahepatic distant recurrence (IDR) rate, and the associations between IDR and relevant imaging features have not yet been fully investigated. This study aimed to determine both clinical and imaging risk factors of IDR after complete RFA for HBV-related small hepatocellular carcinoma (HCC) (≤ 3 cm). METHODS: Thirty-five patients (29 men and 6 women; mean age 60.7 years) with 40 HBV-related small HCCs who underwent complete RFA were included in our study. The incidence and potential clinical and MR imaging risk factors for IDR after RFA were assessed using the Kaplan-Meier method, the log-rank test and a stepwise Cox hazard model. RESULTS: The median follow-up period was 25 (4-45) months, and IDR was observed in 20 (57.1%) patients. The 12- and 24-month cumulative IDR-free survival rates were 76.7% and 61.3%, respectively. Univariate analysis revealed that pretreatment albumin < 3.5 g/dL (P = 0.026), multinodular tumor (P = 0.032), ablative margin < 3 mm (P = 0.007), no or disrupted periablational enhancement within 24 hours (P = 0.001) and at 1 month (P = 0.043) after RFA, and hyperintensity of the central ablative zone on T1-weighted images (T1WI) at 1 month after RFA (P = 0.004) were related to IDR. Multivariate analysis showed that pretreatment albumin < 3.5 g/dL (P = 0.032), multinodular tumor (P = 0.012), no or disrupted periablational enhancement within 24 hours after RFA (P = 0.001), and hyperintensity of the central ablative zone on T1WI at 1 month after RFA (P = 0.003) were independent risk factors for IDR. During the 1-month follow-up, the apparent diffusion coefficient exhibited an up-and-down evolution without significant value in the prediction of IDR following RFA. CONCLUSIONS: Patients with HBV-related small HCC had a high IDR rate after RFA. The risk factors included low serum albumin, multiple nodules, lesions with no or disrupted periablational enhancement and persistent hyperintensity in the central ablative zone on T1WI within 1 month after RFA.

MR features of small hepatocellular carcinoma in normal, fibrotic, and cirrhotic livers: a comparative study.

PURPOSE: The objective of this study is to compare MR imaging features of small hepatocellular carcinoma (HCC) (≤ 2 cm) in normal, fibrotic, and cirrhotic liver. METHODS: A total of 215 patients with 235 pathologically proven sHCC were retrospectively analyzed. Patients were classified into three groups according to the patients' liver condition: patients with normal liver (F0, group 1), fibrosis without cirrhosis (F1-3, group 2), and cirrhosis (F4, group 3). The morphological and MR signal features on T1, T2-weighted, dynamic enhanced, and diffusion-weighted imaging were evaluated and compared. RESULTS: There were 10, 38, and 167 patients in group 1, 2, and 3, respectively. Patients with normal liver were older than those with fibrosis or cirrhosis (P = 0.0086), and tumors in the normal liver were larger than those in the fibrotic or cirrhotic liver (P = 0.0407). No statistical differences were found among groups in signals on T2-weighted images (P = 0.163), signals on each phase after contrast (P = 0.269, 0.893, and 0.259, respectively), enhancement patterns (P = 0.753), ADC values (P = 0.760), as well as the presence of capsule-like enhancement (P = 0.953), mosaic pattern (P = 0.572), fat content (P = 0.222), iron sparing (P = 1.000), hemorrhage (P = 0.181), and venous invasion (P = 0.175). Both signal-to-noise ratios (SNR) (χ (2) = 2.045, P = 0.132) and lesion-to-liver contrast-to-noise ratios (CNR) (χ (2) = 0.438, P = 0.646) were not different as well. But confusing features of iso/hypointensity on T2-weighted imaging (n = 11, 6.0%) and progressive enhancement pattern (n = 2, 1.1%) were exclusively found in the cirrhosis background, and hypovascular tumors with iso/hypointensity on arterial phase were only seen in the fibrosis (n = 5, 11.9%) and cirrhosis groups (n = 10, 5.5%). CONCLUSION: MR features of sHCC were similar among patients with normal, fibrotic, and cirrhotic livers.

Usefulness of two-point Dixon fat-water separation technique in gadoxetic acid-enhanced liver magnetic resonance imaging.

AIM: To compare differences between volumetric interpolated breath-hold examination (VIBE) using two-point Dixon fat-water separation (Dixon-VIBE) and chemically selective fat saturation (FS-VIBE) with magnetic resonance imaging examination. METHODS: Forty-nine patients were included, who were scanned with two VIBE sequences (Dixon-VIBE and FS-VIBE) in hepatobiliary phase after gadoxetic acid administration. Subjective evaluations including sharpness of tumor, sharpness of vessels, strength and homogeneity of fat suppression, and artifacts that were scored using a 4-point scale. The liver-to-lesion contrast was also calculated and compared. RESULTS: Dixon-VIBE with water reconstruction had significantly higher subjective scores than FS-VIBE in strength and homogeneity of fat suppression (< 0.0001) but lower scores in sharpness of tumor (P < 0.0001), sharpness of vessels (P = 0.0001), and artifacts (P = 0.034). The liver-to-lesion contrast on Dixon-VIBE images was significantly lower than that on FS-VIBE (16.6% ± 9.4% vs 23.9% ± 12.1%, P = 0.0001). CONCLUSION: Dixon-VIBE provides stronger and more homogenous fat suppression than FS-VIBE, while has lower clarity of focal liver lesions in hepatobiliary phase after gadoxetic acid administration.

Intravoxel incoherent motion diffusion-weighted MR imaging in differentiation of lung cancer from obstructive lung consolidation: comparison and correlation with pharmacokinetic analysis from dynamic contrast-enhanced MR imaging.

OBJECTIVES: To test whether parameters derived from intravoxel incoherent motion (IVIM) can be used to distinguish lung cancer from obstructive pulmonary consolidation by comparing them with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)-derived parameters and to evaluate the correlation between these quantitative parameters. METHODS: A total of 31 lung cancer patients, confirmed by pathology and obstructive consolidations confirmed by positron emission tomography/computed tomography (PET-CT), were recruited. All of them were assessed with structural MRI and IVIM and 17 of them underwent additional DCE-MRI examinations. Parameters derived from IVIM and DCE-MRI in the tumour and consolidation were analysed, and the optimal cut-off values in differential diagnosis were obtained. RESULTS: ADC(total), D and f values were lower (P < 0.05), while IAUC60 was higher in lung cancers (P = 0.013) compared with obstructive pulmonary consolidations. According to the ROC curve, ADC(total) outperformed other perfusion and diffusion parameters with the optimal cut-off value of 1.409 × 10(-3) mm(2)/s (AUC = 0.95). Poor correlations were found between parameters derived from IVIM and DCE-MRI. CONCLUSIONS: IVIM-MRI is potentially useful in the differentiation of lung cancer and obstructive pulmonary consolidation. ADC(total), D and f may be reliable independent discriminating markers, but D* is variable with low diagnostic accuracy. KEY POINTS: • Lung cancer and consolidation differentiation is essential for treatment decision-making. • Perfusion and diffusion characteristics of lesions could help differential diagnosis. • IVIM can separate reflection of tissue diffusivity and microcapillary perfusion. • The relationship between perfusion quantified by IVIM and DCE-MRI is controversial.

Hepatocellular carcinoma 20 mm or smaller in cirrhosis patients: early magnetic resonance enhancement by gadoxetic acid compared with gadopentetate dimeglumine.

PURPOSE: To evaluate the differences in enhancement pattern of hepatocellular carcinoma (HCC) 20 mm or smaller and enhancement effects of hepatic vessels on early dynamic contrast-enhanced magnetic resonance imaging (MRI) obtained with gadoxetic acid and gadopentetate dimeglumine in the same patients with cirrhosis. METHODS: We reviewed MR images using gadoxetic acid and gadopentetate dimeglumine in the same 34 patients with 42 histologically confirmed HCCs (median diameter, 14.5 mm). The percentage enhancements (PEs) of HCC, the hepatic artery and portal vein and relative contrasts (RCs) between HCC and the liver were calculated and analyzed statistically. RESULTS: The PEs of HCC, the hepatic artery and portal vein were significantly lower for gadoxetic acid in comparison with gadopentetate dimeglumine in the arterial phase (p = 0.0256 for HCC, p < 0.0001 for hepatic artery) and portal phase (p < 0.0001 for HCC, portal vein). The RC between HCC and the liver was significantly lower for gadoxetic acid in comparison with gadopentetate dimeglumine in the arterial phase (p = 0.0422), but was not significantly different in the portal phase (p = 0.1133). Forty-one of the 42 (97.62 %) nodules showed arterial hypervascularization. Of these, 31 (75.61 %) nodules were hypointense in the portal phase for gadoxetic acid, and 22 (53.66 %) were hypointense for gadopentetate dimeglumine (p = 0.038). CONCLUSIONS: Compared with gadopentetate dimeglumine, gadoxetic acid-enhanced MRI demonstrated a different enhancement pattern of inferior arterial enhancement and was more rapidly hypointense in the portal phase for HCC. It showed markedly lower enhancement for hepatic artery and portal vein in the patients with cirrhosis.

Primary hepatic neuroendocrine carcinoma: MR imaging findings including preliminary observation on diffusion-weighted imaging.

PURPOSE: To investigate MR imaging findings of primary hepatic neuroendocrine carcinoma (PHNEC) including preliminary observations on diffusion-weighted imaging (DWI). MATERIALS AND METHODS: MR images of eight patients with pathologically confirmed PHNEC were retrospectively analyzed. The morphological characteristics and dynamic enhancement patterns were evaluated. RESULTS: One case showed a well-defined solitary nodule with homogenous hypointensity on T1-weighted imaging (T1WI) and hyperintensity on T2-weighted imaging (T2WI) and DWI. The remaining seven cases appeared as well-defined dominant masses with multiple satellite nodules. The dominant masses demonstrated heterogeneous hypointensity on T1WI and hyperintensity on T2WI, which all appeared as a marked enhancement at arterial phase and rapid washout at portal venous phase. Six cases demonstrated rim-like enhancement at equilibrium phase. The satellite lesions showed heterogeneous hypointensity on T1WI and marked hyperintensity on T2WI with variable enhancements, such as homogeneous, rim-like enhancement. All the dominant masses and satellite nodules appeared as markedly hyperintensity and reduced apparent coefficient (ADCs) values on DWI. The mean ADC value of the tumors was significantly lower than that of surrounding liver parenchyma (1.02 ± 0.57 vs. 2.24 × 10(-3) mm(2)/s, p = 0.000). CONCLUSION: PHNECs typically appear as a large dominant hypervascular mass accompanied by satellite nodules, with rapid washout and capsular enhancement on dynamic MR imaging and restricted diffusion on DWI.

Increased ratio of glutamate/glutamine to creatine in the right hippocampus contributes to depressive symptoms in patients with epilepsy.

PURPOSE: Our study aimed to investigate whether the glutamatergic system in the hippocampus is correlated with depressive symptoms in patients with epilepsy. METHODS: Fifty patients with epilepsy were recruited and divided into three groups on the basis of their Hamilton Depression Rating Scale (HAMD) scores. Single-voxel proton magnetic resonance spectroscopy ((1)H-MRS) was carried out. Pearson correlation analysis and multiple linear regression analysis were performed to investigate any correlation between the variables of hippocampal metabolites and HAMD scores. RESULTS: Proton magnetic resonance spectroscopy analysis showed that the ratio of glutamate/glutamine to creatine (Glx/Cr) in the right hippocampus was significantly increased in patients with moderate depression and correlated positively with HAMD scores. Multiple linear regression analysis showed that the ratio of Glx/Cr in the right hippocampus was an independent risk factor relating to depressive symptoms in patients with epilepsy. CONCLUSION: A disturbance of the hippocampal glutamatergic system may be involved in the pathogenesis of depression in epilepsy.

Decreased serum hepcidin concentration correlates with brain iron deposition in patients with HBV-related cirrhosis.

PURPOSE: Excessive brain iron accumulation contributes to cognitive impairments in hepatitis B virus (HBV)-related cirrhotic patients. The underlying mechanism remains unclear. Hepcidin, a liver-produced, 25-aminoacid peptide, is the major regulator of systemic iron metabolism. Abnormal hepcidin level is a key factor in some body iron accumulation or deficiency disorders, especially in those associated with liver diseases. Our study was aimed to explore the relationship between brain iron content in patients with HBV-related cirrhosis and serum hepcidin level. METHODS: Seventy HBV-related cirrhotic patients and forty age- sex-matched healthy controls were enrolled. Brain iron content was quantified by susceptibility weighted phase imaging technique. Serum hepcidin as well as serum iron, serum transferrin, ferritin, soluble transferrin receptor, total iron binding capacity, and transferrin saturation were tested in thirty cirrhotic patients and nineteen healthy controls. Pearson correlation analysis was performed to investigate correlation between brain iron concentrations and serum hepcidin, or other iron parameters. RESULTS: Cirrhotic patients had increased brain iron accumulation compared to controls in the left red nuclear, the bilateral substantia nigra, the bilateral thalamus, the right caudate, and the right putamen. Cirrhotic patients had significantly decreased serum hepcidin concentration, as well as lower serum transferring level, lower total iron binding capacity and higher transferrin saturation, compared to controls. Serum hepcidin level negatively correlated with the iron content in the right caudate, while serum ferritin level positively correlated with the iron content in the bilateral putamen in cirrhotic patients. CONCLUSIONS: Decreased serum hepcidin level correlated with excessive iron accumulation in the basal ganglia in HBV-related cirrhotic patients. Our results indicated that systemic iron overload underlined regional brain iron repletion. Serum hepcidin may be a clinical biomarker for brain iron deposition in cirrhotic patients, which may have therapeutic potential.

Three-dimensional whole-liver perfusion magnetic resonance imaging in patients with hepatocellular carcinomas and colorectal hepatic metastases.

BACKGROUND: Three-dimensional (3D) whole-liver perfusion magnetic resonance (MR) imaging with parallel imaging, a novel imaging method to characterize tumor vascularization in vivo, has recently been applied to comprehensively image perfusion changes in large tumors. Coupled with new perfusion software, this technique enables motion correction, registration, and evaluation of perfusion MR parameters. The purpose of this study was to assess the feasibility of 3D whole-liver perfusion MR, for imaging hepatocellular carcinoma (HCC) and colorectal hepatic metastases (CRHM). METHODS: 26 patients with hepatic tumors (10 HCC; 16 CRHM) were subjected to 3D whole-liver perfusion MR with a temporal resolution of 3.7 seconds. The following estimated perfusion parameters were measured: the volume transfer constant K(trans) (min(-1)); the volume (V(e)) of extravascular extracellular space (EES) per volume unit of tissue; and the flux rate constant between EES and plasma K(ep) (min(-1)). Statistical analysis was conducted to investigate inter-observer characteristics and significance of the measured parameters. RESULTS: Inter-observer agreement analysis (95% limits of agreement) yielded a mean difference of -0.0048 min(-1) (-0.0598 ~ 0.0502) for K(trans), -0.0630 ml (-0.5405 ~ 0.4145) for V(e), and -0.0031 min(-1) (-0.0771 ~ 0.0709) for K(ep) respectively. When comparing images from patients with HCC vs. CRHM, significant differences were seen for the mean K(trans) (p = 0.017), but not for V(e) (p = 0.117) or K(ep) (p = 0.595). CONCLUSION: Herein we show that 3D whole-liver MR perfusion imaging with semi-automatic data analysis is feasible and enables the reliable quantitative evaluation of the perfusion parameters for HCCs and CRHMs.