Caizhong Chen

Contribution of diffusion-weighted magnetic resonance imaging in the characterization of hepatocellular carcinomas and dysplastic nodules in cirrhotic liver.

Objectives: To evaluate the diagnostic value of diffusion-weighted magnetic resonance imaging (DWI) for the characterization of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) in cirrhotic liver, compared with contrast material-enhanced magnetic resonance imaging (CE-MRI). Methods: A total of 54 patients with 40 HCC and 19 DN lesions were included in our study, and all lesions were histopathologically confirmed. All lesions were evaluated with CE-MRI, and breath-hold DWI was performed with b = 500 s/mm2. The signal intensity (SI) of the lesions were classified as low, iso-, slightly high, and strongly high SI compared with that of the surrounding liver parenchyma on DWI for qualitative assessment. Apparent diffusion coefficients (ADCs) and lesion-to-liver ADC ratio of HCCs and DNs were measured and compared by using the Mann-Whitney U test. The lesions were characterized with the use of CE-MRI criteria and DWI, respectively. Receiver operating characteristic analysis was performed to assess the diagnostic value of DWI, CE-MRI, and these techniques combined in the differentiation of HCCs from DNs. Results: In the qualitative analysis, among 40 HCCs, 39 (97.5%) had slightly high or strongly high SI on DWI, and 1 (2.5%) had low SI; only 4 (21.5%) of 19 DNs had slightly high SI, and 15 (78.95%) had iso-SI or low SI. The mean (SD) ADC and ADC ratio for HCCs (1.28 × 10−3 [0.25] mm2/s and 0.88 [0.15], respectively) were significantly lower (P < 0.01 and P < 0.001, respectively) than those for DNs (1.53 × 10−3 [0.33] mm2/s and 1.00 [0.08], respectively). The area, Az, under the receiver operating characteristic curve for the SI feature, the ADC ratio, and the ADCs based on the diagnosis of HCC versus DN were 0.88, 0.81, and 0.68, respectively. When the slightly high SI of lesion with a cutoff ADC ratio less than 0.92 was applied as a criterion, the Az, the sensitivity, the specificity, and the accuracy of DWI for the diagnosis of HCC versus DN were 0.81, 67.50%, 94.74%, and 76.27%, respectively. The corresponding Az, sensitivity, specificity, and accuracy of CE-MRI were 0.70, 82.50%, 57.89%, and 74.58%, respectively. Combined DWI plus CE-MRI had 0.91 Az, 97.50% sensitivity, and 93.22% accuracy, which increased significantly compared with those of CE-MRI alone. Conclusions: Diffusion-weighted MRI can provide additional information to differentiate HCC from DN. Combined with CE-MRI, DWI allows improved characterization of HCC versus DN in cirrhotic liver.

Improving detection of siderotic nodules in cirrhotic liver with a multi-breath-hold susceptibility-weighted imaging technique.

To evaluate the role of abdominal susceptibility‐weighted imaging (SWI) in the detection of siderotic nodules in cirrhotic liver.

Assessing liver function in patients with HBV-related HCC: a comparison of T 1 mapping on Gd-EOB-DTPA-enhanced MR imaging with DWI

AbstractObjectivesTo compare the potential of T1 mapping on gadoxetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) for assessing liver function in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).MethodsOne hundred consecutive patients with known HBV-related HCCs were included. T1 relaxation time and apparent diffusion coefficient (ADC) of the liver were measured, and the reduction rate of T1 relaxation time (∆%) was calculated. T1 relaxation time measurements were compared with ADC values according to the Model for End-Stage Liver Disease (MELD) score.ResultsHepatobiliary phase (HBP) and ∆% of T1 relaxation time measurements showed significant correlations with MELD score (rhou2009=u20090.571, pu2009<u20090.0001; rhou2009=u2009−0.573, pu2009<u20090.0001, respectively). HBP and ∆% of T1 relaxation time were significantly different between good (MELD ≤8) and poor liver function (MELD ≥9) (pu2009<u20090.0001 for both). Areas under the receiver operating characteristic curves (AUCs) of T1 relaxation time for HBP (AUC 0.84) and ∆% (AUC 0.82) were significantly better than for ADC (AUC 0.53; pu2009<u20090.0001).ConclusionsT1 mapping on Gd-EOB-DTPA-enhanced MRI showed promise for evaluating liver function in patients with HBV-related HCC, while DWI was not reliable. HBP T1 relaxation time measurement was equally accurate as ∆% measurement.Key Points• T1mapping on Gd-EOB-DTPA MRI was accurate for assessing liver function.• HBP T1relaxation time measurement was as accurate as ∆%xa0T1n • T1mapping on Gd-EOB-DTPA MRI was more accurate than DWI-ADC measurement.

Liver fibrosis staging using T1 mapping on gadoxetic acid-enhanced MRI compared with DW imaging.

AIMnTo evaluate the utility of T1 mapping on gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) for staging liver fibrosis.nnnMATERIALS AND METHODSnThis retrospective study was approved by the institutional review board and included 145 patients (mean age: 54 years old; 115 men and 30 women). Necro-inflammatory activity grade (G) and liver fibrosis stage (S) were histopathologically determined. T1 relaxation time and apparent diffusion coefficient (ADC) of the liver were measured and the reduction rate of the T1 relaxation time (Δ%) was calculated. T1 relaxation time measurements were compared with ADC values according to S/G scores.nnnRESULTSnUnenhanced hepatobiliary phase (HBP) and Δ% of T1 relaxation times showed significant correlations with S/G scores (rho: 0.28, 0.51, -0.35 for the S score, 0.26, 0.39, -0.26 for the G score, respectively, p<0.05). ADC values showed significant correlation with the S score (rho: -0.17, p = 0.04) and did not correlate significantly with the G score (rho: -0.07, p = 0.39). The areas under receiver operator characteristics (AUC) curve of unenhanced HBP, Δ% T1 relaxation time, and the ADC value were 0.68, 0.82, 0.71, 0.61 for the identification of S ≥ 3, and 0.63, 0.68, 0.62, 0.52 for the identification of G ≥ 3, respectively. The HBP T1 relaxation time was better than that of ADC for identification of S ≥ 3 (p = 0.0005) and G ≥ 3 (p = 0.014).nnnCONCLUSIONSnThe HBP T1 relaxation time measurement on gadoxetic acid-enhanced MRI images might be a potential biomarker in the staging of hepatic fibrosis, and was more accurate than the ADC measurement.

Usefulness of T1 mapping on Gd-EOB-DTPA-enhanced MR imaging in assessment of non-alcoholic fatty liver disease

AbstractObjectivesThis study evaluates the value of Gd-EOB-DTPA-enhanced MRI for diagnosis and staging of non-alcoholic fatty liver disease (NAFLD) in an animal model by T1 relaxation time measurement.MethodsThirty-four rabbits were divided into the control group (nu2009=u200910) and NAFLD group, which was split into four groups (nu2009=u20096) with a high-fat diet for an interval of 3 weeks. A dual flip angle was performed before and at the hepatobiliary phase (HBP). T1 relaxation times of the liver parenchyma and the decrease rate (∆%) were calculated. Histological findings according to semi-quantitative scoring of steatosis, activity and fibrosis were the standard of reference.ResultsHBP and ∆%xa0T1 relaxation time measurement showed significant differences between normal and NAFLD groups, between non-alcoholic steatohepatitis (NASH) and NAFLD without NASH (pu2009=u20090.000–0.049), between fibrosis groups (pu2009=u20090.000–0.019), but no difference between F1 and F2 (pu2009=u20090.834). The areas under the receiver operating characteristic curves (AUCs) of T1 relaxation time for HBP and ∆% were 0.86–0.93 for the selection of NASH and activity score ≥2, and 0.86–0.95 for the selection of F ≥ 1, 2, 3. No significant difference was found for diagnostic performance between HBP and ∆%xa0T1 relaxation time.ConclusionsHBP T1 relaxation time measurement of Gd-EOB-DTPA-enhanced MRI was useful to evaluate NAFLD according to the SAF score. HBP T1 relaxation time measurement was as accurate as ∆%xa0T1 relaxation time.Key Points• Gd-EOB-DTPA-enhanced MRI could give useful information on NAFLD.•HBP T1relaxation time measurement was useful for the evaluation of NAFLD.n • HBP T1relaxation time measurement was as accurate as ∆%.

Using a 2D multibreath‐hold susceptibility‐weighted imaging to visualize intratumoral hemorrhage of hepatocellular carcinoma at 3T MRI: Correlation with pathology

To assess the value of 2D multibreath‐hold susceptibility‐weighted imaging (SWI) for visualizing intratumoral hemorrhage of hepatocellular carcinoma (HCC) and correlate with pathological results.

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

PurposeTo investigate MR imaging findings of primary hepatic neuroendocrine carcinoma (PHNEC) including preliminary observations on diffusion-weighted imaging (DWI).Materials and methodsMR images of eight patients with pathologically confirmed PHNEC were retrospectively analyzed. The morphological characteristics and dynamic enhancement patterns were evaluated.ResultsOne 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 (1.02xa0±xa00.57 vs. 2.24xa0×xa010−3xa0mm2/s, pxa0=xa00.000).ConclusionPHNECs 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.

T2* MRI of minimal hepatic encephalopathy and cognitive correlates in vivo.

To evaluate regional brain iron deposition in minimal hepatic encephalopathy (MHE) patients using T2*‐weighted gradient‐echo imaging and to explore the relationship between T2* MR changes and cognitive performance.

Influence of Applying Nitroglycerin in Whole-Heart Free-Breathing 3D Coronary MR Angiography

OBJECTIVEnThe purpose of our study was to assess the impact of sublingual nitroglycerin (NTG) spray on free-breathing 3D whole-heart coronary MR angiography (MRA).nnnSUBJECTS AND METHODSnWe compared the timing parameters; measured the lumen diameter of the major coronary arteries; calculated coronary vasodilation, apparent signal-to-noise ratio (SNR), and apparent contrast-to-noise ratio (CNR); and evaluated the image quality on pre- and post-NTG coronary MRA in 15 volunteers. Statistical analysis was performed with p value less than 0.05 considered significant.nnnRESULTSnThe mean trigger delay and optimal acquisition window were shortened significantly and the mean scanning time was prolonged statistically after NTG administration. There was no significant alteration in terms of apparent SNR and apparent CNR. The lumen diameters were significantly larger in coronary MRA post-NTG than in that of pre-NTG, with an average 25.35% +/- 6.51% (SD) increase, and the left circumflex coronary artery (LCX) had slightly lower vasodilation in comparison with the right coronary artery. Image quality scores of 53 (39.3%, 53/135) segments were increased and 15 segments (11.1%, 15/135) decreased after NTG administration, and the remaining 67 segments (49.6%, 67/135) were unchanged.nnnCONCLUSIONnIn general, sublingual NTG is useful for improving visualization of the coronary artery lumen and alleviating the impact of artifact. However, several alterations and disadvantages should be taken into consideration in view of the disturbed assessment of vasodilatory response in the LCX and the impaired quality in a minority of segments after NTG administration. Further studies are needed to evaluate the effect of beta-blockade on eliminating the disadvantages of sublingual NTG.

A study of in vitro and in vivo MR of free-breathing whole-heart 3D coronary angiography using parallel imaging

To evaluate parallel-imaging methods in free-breathing whole-heart 3D coronary magnetic resonance angiography and assess the navigator techniques and visualization rates of the major coronary arteries. We compared key parameters of the generalized autocalibrating partially parallel acquisition and modified sensitive encoding images in vitro phantom MRI; performed the MRA with GRAPPA parallel imaging in healthy volunteers; compared 1D- and 2D-prospective acquisition correction and analyzed the differences; and evaluated the visualization of major coronary arterial branches. GRAPPA images had higher signal-to-noise ratio and contrast-to-noise ratio and fewer aliasing artifacts. The coronary arteries were adequately visualized in 38 volunteers. 2D-PACE had a higher navigator efficiency, shorter scan time, and gave clearer reconstructed images in comparison with 1D-PACE. GRAPPA images were superior to mSENSE images. Whole-heart 3D coronary MRA along with parallel-imaging technique is a potential clinical method, and 2D-PACE is a better navigation technique than 1D-PACE.