Life Enhancement Research Articles

Self-organized Mn2+-Block Copolymer Complexes and Their Use for In Vivo MR Imaging of Biological Processes.

Manganese-block copolymer complexes (MnBCs) that contain paramagnetic Mn ions complexed with ionic-nonionic poly(ethylene oxide-b-poly(methacrylate) have been developed for use as a T1-weighted MRI contrast agent. By encasing Mn ion within ionized polymer matrices, r1 values could be increased by 250-350 % in comparison with free Mn ion at relative high fields of 4.7 to 11.7 T. MnBCs were further manipulated by treatment with NaOH to achieve more stable complexes (iMnBCs). iMnBCs delayed release of Mn2+ which could be accelerated by low pH, indeed by cellular uptake via endocytosis into acidic compartments. Both complexes exhibited good T1 contrast signal enhancement in liver following intravenous infusion. The contrast was observed in gallbladder due to the clearance of Mn ion from liver to biliary process. iMnBCs, notably, showed a delayed contrast enhancement profile in gallbladder, which was interpreted to be due to degradation and excretion of Mn2+ ions into the gallbladder. Intracortical injection of iMnBCs into the rat brain also led to delayed neuronal transport to thalamus. The delayed enhancement feature may have benefits for targeting MRI contrast to specific cells and surface receptors that are known to be internalized by endocytosis.

Quantitative evaluation of liver function by liver enhancement in hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRI

Objective To investigate the utilization of liver enhancement in hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI for liver function evaluation.Methods Fifty-five patients who received enhanced MRI with Gd-EOB-DTPA were retrospectively analyzed.Images were obtained before injection and in hepatobiliary phase (5,10,and 20 minutes after Gd-EOB-DTPA injection).The patients were assigned into two subgroups according to individual liver function (n =35 in Group 1:normal liver and Child-Pugh class A; n =20 in Group 2:Child-Pugh class B and C).The relative liver enhancement (RE) was calculated at different time point.The general data (age,sex) and relevant laboratory results were recorded.Independent sample t-test was conducted to compare the RE between two groups at different time point.ROC curve was used to determine the best time point and RE threshold that can reflect the differences between two groups.Univariate analyses was performed to analyze the relationship between RE at the best time point and laboratory results.Multivariate analyses was performed to screen the independent influencing factor for RE at the best time point.Results The differences of RE between two groups were statistically significant at all time points (P ＜ 0.0001).10 minutes was the best time point for detecting the differences of liver function between two groups.When an RE cutoff value (＞ 1.52) was applied,normal or Child-Pugh class A could be predicted with sensitivity of 74.3％ and specificity of 90％.RE at the best time point was significantly related with total serum bilirubin level (TBil),serum albumin level (Alb) and prothrombin time (PT).And TBil was an independent influencing factor.Conclusion RE can be used to evaluate the liver function,and 10 minutes is the best time point that can be used to differentiate patients with normal or mild liver damage from those with moderate or severe liver damage. Key words: Liver function; Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) ; Magnetic resonance imaging (MRI)

Relationship between liver enhancement in hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRI and liver function

Objective To evaluate the effect of liver function on liver enhancement in hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid(Gd-EOB-DTPA)-enhanced MRI.Methods Sixty-seven patients who suffered from cirrhosis and received enhanced MRI with Gd-EOB-DTPA were retrospectively analyzed,and divided into three subgroups according to ChildPugh score(45 patients in group A,20 in group B,5 in group C).All the individuals of both groups had MRI before injection,and hepatobiliary phase images were obtained at 5,10,and 20 minutes after bolus administration of Gd-EOB-DTPA.The relative enhancement(RE) was calculated by dividing the signal intensity of liver(SI) at t min after injection(SIt) by precontrast SI(SI0).The total serum bilirubin level(TB),serum albumin level(Alb) and prothrombin time(PT) were recorded.The one-way ANOVA was used to compare the RE among three groups at 5,10 and 20 minutes.SNK was used for further pairwise comparison.The effect of liver function on RE was assessed with the generalized linear model.Pearson correlation coefficients were measured between each biochemical test result(TB,Alb,PT) and RE at different time points.Results The RE at 5,10 and 20 minutes were 1.59±0.20,1.65±0.22,1.69±0.25 of group A; 1.47± 0.14,1.48±0.18,1.50±0.22 of group B,1.35±0.07,1.27±0.06,1.26±0.06 of group C.There were statistically significant differences of RE among groups at 5,10 and 20 minutes(F=5.854,11.207,9.666,P＜0.01).Statistically pairwise comparison differences of RE were found between group A and C at 5,10 and 20 minutes(P＜0.01),between B and C at 10 and 20 minutes(P＜0.05),between A and B at 10 minutes(P＜ 0.05).There were statistically significant differences of TB,Alb and PT among groups(P＜0.01).RE at 10 and 20 minutes had moderate negative correlation with TB(r=-0.483,-0.500; P＜0.01),low negative correlation with PT(r=-0.326,-0.351;P＜0.01) and weak positive correlation with Alb(r=0.290,0.292;P＜0.05).Conclusions There are differences of RE among patients with different liver function,and the RE is associated with TB,Alb and PT.Thus,it may allow us to estimate the liver function. Key words: Liver function; Contrast media; Magnetic resonance imaging

Hepatobiliary magnetic resonance imaging in patients with liver disease: correlation of liver enhancement with biochemical liver function tests

To evaluate hepatobiliary magnetic resonance imaging (MRI) using Gd-EOB-DTPA in relation to various liver function tests in patients with liver disorders. Fifty-one patients with liver disease underwent Gd-EOB-DTPA-enhanced liver MRI. Based on region-of-interest (ROI) analysis, liver signal intensity was calculated using the spleen as reference tissue. Liver-spleen contrast ratio (LSCR) and relative liver enhancement (RLE) were calculated. Serum levels of total bilirubin, gamma glutamyl transpeptidase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH), serum albumin level (AL), prothrombin time (PT), creatinine (CR) as well as international normalised ratio (INR) and model for end-stage liver disease (MELD) score were tested for correlation with LSCR and RLE. Pre-contrast LSCR values correlated with total bilirubin (r = -0.39; p = 0.005), GGT (r = -0.37; p = 0.009), AST (r = -0.38; p = 0.013), ALT (r = -0.29; p = 0.046), PT (r = 0.52; p < 0.001), GLDH (r = -0.55; p = 0.044), INR (r = -0.42; p = 0.003), and MELD Score (r = -0.53; p < 0.001). After administration of Gd-EOB-DTPA bilirubin (r = -0.45; p = 0.001), GGT (r = -0.40; p = 0.004), PT (r = 0.54; p < 0.001), AST (r = -0.46; p = 0.002), ALT (r = -0.31; p = 0.030), INR (r = -0.45; p = 0.001) and MELD Score (r = -0.56; p < 0.001) significantly correlated with LSCR. RLE correlated with bilirubin (r = -0.40; p = 0.004), AST (r = -0.38; p = 0.013), PT (r = 0.42; p = 0.003), GGT (r = -0.33; p = 0.020), INR (r = -0.36; p = 0.011) and MELD Score (r = -0.43; p = 0.003). Liver-spleen contrast ratio and relative liver enhancement using Gd-EOB-DTPA correlate with a number of routinely used biochemical liver function tests, suggesting that hepatobiliary MRI may serve as a valuable biomarker for liver function. The strongest correlation with liver enhancement was found for the MELD Score. • Relative enhancement (RLE) of Gd-EOB-DTPA is related to biochemical liver function tests. • Correlation of RLE with bilirubin, ALT, AST, GGT, INR and MELD Score is reverse. • The correlation of relative liver enhancement with prothrombin time is positive. • AST, ALT, GLDH, prothrombin time, INR and MELD Score correlate with pre-contrast liver-spleen contrast ratio. • Such biomarkers may help to evaluate liver function.

Influence of Repetitive Contrast Agent Injections on Functional and Molecular Ultrasound Measurements

Quantitative contrast-enhanced ultrasound plays an important role in tumor characterization and treatment assessment. Besides established functional ultrasound techniques, ultrasound molecular imaging using microbubbles targeted to disease-associated markers is increasingly being applied in pre-clinical studies. Often, repeated injections of non-targeted or targeted microbubbles during the same imaging session are administered. However, the influence of repeated injections on the accuracy of the quantitative data is unclear. Therefore, in tumor-bearing mice, we investigated the influence of multiple injections of non-targeted microbubbles (SonoVue) on time to peak and peak enhancement in liver and tumor tissue and of vascular endothelial growth factor receptor 2 (VEGFR2)-targeted contrast agents (MicroMarker) on specific tumor accumulation. We found significantly decreasing values for time to peak and a tendency for increased values for peak enhancement after multiple injections. Repeated injections of VEGFR2-targeted microbubbles led to significantly increased tumor accumulation, which may result from the exposure of additional binding sites at endothelial surfaces caused by mechanical forces from destroyed microbubbles.

Gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid conjugate of arabinogalactan as a potential liver-targeting magnetic resonance imaging contrast agent

A novel biocompatible macromolecule (AG-CM-EDA-DOTA-Gd) was synthesized as a liver magnetic resonance imaging (MRI) contrast agent. AG-CM-EDA-DOTA-Gd consisted of a carboxymethyl-arabinogalactan unit conjugated with gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (Gd-DOTA) via ethylenediamine, and was specifically designed to bind to hepatocyte asialoglycoprotein in vivo, in an effort to develop a potential new tool for the diagnosis of liver diseases. The T1-relaxivity (8.87mmol−1Ls−1) of AG-CM-EDA-DOTA-Gd was 1.86 times than that of Gd-DOTA (4.76mmol−1Ls−1) in D2O at 9.4 T and 25°C. MRI experiments showed significant enhancement in rat liver following the intravenous administration of AG-CM-EDA-DOTA-Gd (0.094mmol Gd3+/kg body weight), which persisted for longer than Gd-DOTA (0.098mmol Gd3+/kg body weight). The mean percentage enhancements in the liver parenchyma were 85.2±6.5% and 19.3±3.3% for AG-CM-EDA-DOTA-Gd and Gd-DOTA, respectively. The results of this study therefore indicate that AG-CM-EDA-DOTA-Gd could be used as a potential liver-targeting contrast agent for MRI.

CT and MRI of primary and metastatic fibrolamellar carcinoma: a case series of 37 patients.

Fibrolamellar carcinoma (FLC) is a rare disease, with limited radiographic reported information. We assessed the imaging patterns of primary and metastatic FLC. CT and MR examinations of patients with FLC were retrospectively reviewed. Imaging features were assessed for primary and recurrent liver tumours, including dimension, enhancement characteristics, and presence or absence of central scars. Locations of nodal and extranodal metastases were also recorded. Of 37 patients (18 males and 19 females; average age, 23.5 years) with FLC, 24 had imaging of their primary tumour; 13 had metastases at presentation and 7 developed metastases on follow-up. The remaining 13 patients had follow-up imaging of metastatic disease. Primary FLC had a mean diameter >11 cm, with central scars in ten (46%) patients. Most tumours enhanced heterogeneously (96%) and showed arterial enhancement (81%). On MRI, 62% of FLCs were hypointense on T1 weighted imaging and 54% were hyperintense on T2 weighted imaging. 13 patients (54%) had nodal metastases at presentation, mostly in the upper abdomen (92%) and commonly in the chest (38%). Extrahepatic metastases were most frequently pulmonary or peritoneal. Predominantly small and homogeneous intrahepatic recurrences were detected on follow-up in 15 patients. FLC often presents as a large hepatic tumour with nodal and distant metastases. Thoracic adenopathy and lung metastases were frequently found in our series, suggesting the need for pre-operative and follow-up chest imaging. Thoracic nodal and lung metastases are common in FLC; therefore, dedicated chest imaging should be part of the evaluation of a patient with FLC.

Gadoxetic acid enhanced MRI for differentiation of FNH and HCA: a single centre experience

Evaluation of enhancement characteristics of histopathologically confirmed focal nodular hyperplasias (FNHs) and hepatocellular adenomas (HCAs) with gadoxetic acid-enhanced MRI. Sixty-eight patients with 115 histopathologically proven lesions (FNHs, n=44; HCAs, n=71) examined with gadoxetic acid-enhanced MRI were retrospectively enrolled (standard of reference: surgical resection, n=53 patients (lesions: FNHs, n=37; HCAs, n=53); biopsy, n=15 (lesions: FNHs, n=7; HCAs, n=18)). Two radiologists evaluated all MR images regarding morphological features as well as the vascular and hepatocyte-specific enhancement in consensus. For the hepatobiliary phase, relative enhancement of the lesions and lesion to liver enhancement were significantly lower for HCAs (mean, 48.7 (±48.4)%and 49.4 (±33.9) %) compared to FNHs (159.3 (±92.5) %; and 151.7 (±79) %; accuracy of 89%and 90 %, respectively; P<0.001). Visual strong uptake of FNHs vs. hypointensity of HCAs in the hepatobiliary phase resulted in an accuracy of 92 %. This parameter was superior to all other morphological and dynamic vascular criteria alone and in combination (accuracy, 54–85 %). For differentiation of FNHs and HCAs by means of MRI, gadoxetic acid uptake in the hepatobiliary phase was found to be superior to all other criteria alone and in combination. EOB-MRI is well suited to differentiate FNHs and hepatocellular adenomas. For this purpose hepatobiliary phase is superior to unenhanced and dynamic imaging. Hepatobiliary phase (peripheral) hyper- or isointensity is typical for FNH. Hepatobiliary phase hypointensity is typical for hepatocellular adenomas. EOB-MRI helps to avoid misinterpretations of benign hepatocellular lesions.

DYNAMIC CONTRAST-ENHANCED MAGNETIC RESONANCE ANGIOGRAPHY OF Gd-TTDA-BOM COMPARED WITH Gd-DTPA IN NORMAL RAT AT 3T

Dynamic contrast-enhanced magnetic resonance angiography (DCE-MRA) is a good modality for the diagnosis of vascular diseases. Contrast agents that produce higher and longer enhancement in vessels are highly valued. The complex of gadolinium with (R,S)-4-carboxy-5,9,12-tris(carboxymethyl)-l-phenyl-2-oxa-5,9,12-triazatridecan-14-oic acid (Gd-TTDA-BOM) possesses a benzyloxymethyl group in the ligand TTDA-BOM with the capability of raising lipophilicity. The Gd-TTDA-BOM complex expresses higher and longer enhancement in mouse liver than that of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) because of its faster water exchange rate, higher reorientation time, and higher lipophilicity. Phantom studies have shown that Gd-TTDA-BOM has expressed with higher affinity to human serum albumin (HSA) than Gd-DTPA. In general, these characteristics might provide an advantage for vascular imaging. To verify this in vivo, a 3T MR scanner was used to investigate the signal enhancement in the aorta of normal rats by DCE-MRA after the bolus injection of Gd-TTDA-BOM and compared this with the injection of Gd-DTPA. Gd-TTDA-BOM expressed higher and longer signal enhancement in the aorta than Gd-DTPA. These results suggest that Gd-TTDA-BOM could provide better image quality than Gd-DTPA as an enhancement agent in DCE-MRA.

Noninvasive Differentiation of Simple Steatosis and Steatohepatitis by Using Gadoxetic Acid–enhanced MR Imaging in Patients with Nonalcoholic Fatty Liver Disease: A Proof-of-Concept Study

To determine whether gadoxetic acid-enhanced magnetic resonance (MR) imaging can be used to distinguish between simple steatosis and nonalcoholic steatohepatitis (NASH) in patients with nonalcoholic fatty liver disease (NAFLD), defined according to the steatosis activity and fibrosis (SAF) scoring system, which is based on the semiquantitative scoring of steatosis activity and liver fibrosis. The local institutional review committee approved this study and waived written informed consent. This was a retrospective study of gadoxetic acid-enhanced 3-T MR imaging performed in 81 patients with NAFLD (45 men [56%]; mean age, 56 years; range, 25-78 years). The MR images were analyzed by using the relative enhancement (the ratio of signal intensities of the liver parenchyma before and 20 minutes after intravenous administration of gadoxetic acid). Univariate and multiple regression analyses were applied to identify variables associated with relative enhancement measurements. The ability of relative enhancement to allow differentiation between simple steatosis and NASH was assessed by using area under the receiver operating characteristic (ROC) curve analysis. Relative enhancement negatively correlated with the degree of lobular inflammation (r = -0.59, P < .0001), ballooning (r = -0.44, P < .0001), and fibrosis (r = -0.59, P ≤ .0001), but not with steatosis (r = -0.16, P = .15). Patients with NASH had a significantly lower relative liver enhancement (0.82 ± 0.22) than those with simple steatosis (1.39 ± 0.52) (P < .001). Relative enhancement measurements performed well in the differentiation between simple steatosis and NASH, with an area under the ROC curve of 0.85 (95% confidence interval: 0.75, 0.91) (cutoff = 1.24, sensitivity = 97%, specificity = 63%). Gadoxetic acid relative enhancement was significantly lower in patients with NASH than in patients with simple steatosis, but further prospective studies are warranted.

Assessing liver function by liver enhancement during the hepatobiliary phase with Gd-EOB-DTPA-enhanced MRI at 3 Tesla

The purpose of this study was to evaluate the usefulness of Gd-EOB-DTPA-enhanced 3-T MRI to determine the hepatic functional reserve expressed by the model for end-stage liver disease (MELD) score. A total of 121 patients with normal liver function (NLF; MELD score ≤ 10) and 29 patients with impaired liver function (ILF; MELD score > 10) underwent contrast-enhanced MRI with a hepatocyte-specific contrast agent at 3T. T1-weighted volume interpolated breath-hold examination (VIBE) sequences with fat suppression were acquired before and 20 min after contrast injection. Relative enhancement (RE) between plain signal intensity and contrast-enhanced signal intensity was calculated and was used to determine Gd-EOB-DTPA uptake into the liver parenchyma for patients with different MELD scores. RE differed significantly (p ≤ 0.001) between patients with NLF (87.2 ± 29.5 %) and patients with ILF (45.4 ± 26.5 %). The optimal cut-off value for RE to differentiate NLF from ILF was 47.7 % (AUC 0.87). This cut-off value showed a sensitivity of 82.8 % and a specificity of 92.7 % for the differentiation of the analysed groups. Gd-EOB-DTPA uptake in hepatocytes is strongly affected by liver function. Gd-EOB-DTPA-enhanced MRI and assessment of RE during the hepatobiliary phase (HBP) may serve as a useful image-based test in liver imaging for determining regional and global liver function. Hepatic uptake of Gd-EOB-DTPA is strongly affected by liver function. Relative enhancement during HBP in GD-EOB-DTPA MRI correlates with the MELD score. Assessment of relative enhancement may help improve treatment in routine clinical practice.

Patient-Tailored Scan Delay for Multiphase Liver CT: Improved Scan Quality and Lesion Conspicuity With a Novel Timing Bolus Method

The purpose of this study was to compare scan quality and lesion conspicuity for late arterial and portal venous phase liver CT scans using fixed versus patient-tailored scan delay derived with an evidence-based timing bolus method. We retrospectively identified the cases of 73 patients who underwent both multiphase liver CT with fixed late arterial and portal venous phase scan delay times of 45 and 80 seconds and subsequent multiphase liver CT with patient-tailored scan delay determined with a timing bolus and a previously reported relation between the time to peak aortic and liver enhancement. Both late arterial and portal venous phase scans were graded in terms of scan quality. Hepatic lesion conspicuity (difference in attenuation between lesion and liver parenchyma) for hypervascular lesions (late arterial phase) and hypovascular lesions (portal venous phase) was recorded. Patient-tailored scan delay reflected a wide range of times to peak aortic enhancement (mean, 24 seconds; range, 18-32 seconds) and yielded a greater proportion of optimal scans compared with fixed scan delay for both late arterial phase (92% versus 74%, p < 0.01) and portal venous phase (86% versus 70%, p < 0.05) scans. Mean hypervascular lesion conspicuity was greater for lesions imaged with patient-tailored scan delay rather than fixed scan delay (84.0 versus 57.0 HU, p < 0.01). Compared with examinations with fixed scan delay, multiphase liver CT that incorporates patient-tailored scan delay produces more optimally timed late arterial and portal venous phase CT scans with greater lesion conspicuity.

Characterization of the Intestinal and Hepatic Uptake/Efflux Transport of the Magnetic Resonance Imaging Contrast Agent Gadolinium-Ethoxylbenzyl-Diethylenetriamine-Pentaacetic Acid

The objectives of the study were to measure the pharmacokinetics and liver enhancement of gadoxetate (gadolinium-ethoxylbenzyl-diethylenetriamine-pentaacetic acid [Gd-EOB-DTPA], Eovist, Primovist) after oral and intravenous administration in wild-type and (multidrug resistance-associated protein 2) Mrp2-deficient rats and to evaluate the in vitro transport of the contrast agent via intestinal and hepatic transporter proteins. Gadolinium-ethoxylbenzyl-diethylenetriamine-pentaacetic acid-enhanced magnetic resonance imaging and pharmacokinetics of Gd-EOB-DTPA after intravenous and oral administration were evaluated in wild-type and Mrp2-deficient rats using T1-weighted magnetic resonance imaging and a validated liquid chromatography-mass spectrometry method, respectively. Cellular uptake of Gd-EOB-DTPA was measured in stably transfected human embrionic kidney 293-cells expressing oragnic anion-transporting polypeptide 1A2 or organic cation transporter 3 and Madin Darby canine kidney 2-cells expressing apical sodium dependent bile acid transporter. The affinity to MRP2 and multidrug resistance-associated protein 3 was measured using inside-out vesicles. In vitro, Gd-EOB-DTPA was demonstrated to be a substrate for OATP1A2 (mean [SD] of the Michaelis-Menten constant [K(m)], 1.0 [0.4] mmol/L; mean [SD] of the maximal uptake rate [V(max)], 101.3 [21.1] pmol/mg per minute), MRP2 (K(m), 1.0 [0.5] mmol/L; V(max), 86.8 [31.1] pmol/mg per minute), and multidrug resistance-associated protein 3 (K(m), 1.8 [0.3] mmol/L; V(max), 116 [15.9] pmol/mg per minute) but not for the apical sodium-dependent bile acid transporter and organic cation transporter 3. After the oral administration to the wild-type animals, Gd-EOB-DTPA was considerably absorbed from the small intestine (bioavailability, approximately 17%) and predominately eliminated via feces after intravenous dosing (approximately 96%). In the Mrp2-deficient rats, oral bioavailability increased to approximately 21% and Gd-EOB-DTPA was exclusively excreted into urine. Magnetic resonance enhancement of the liver was significantly prolonged in the Mrp2-deficient rats compared with the wild-type rats (mean [SD] area under the curve0-90, 36.4 [8.5] vs 14.8 [10.3] arbitary units per minute; P = 0.003; time to maximum plasma concentration, 48.6 [23.8] vs 6.0 [3.1] minutes; P = 0.001). The nonmetabolized Gd-EOB-DTPA may have some potentials to be used as a probe-contrast agent to evaluate transporter-mediated mechanisms along the enterohepatic absorption route for drugs by functional visualization in vivo.

Automatic Bolus Tracking Versus Fixed Time-Delay Technique in Biphasic Multidetector Computed Tomography of the Abdomen

BackgroundBolus tracking can individualize time delay for the start of scans in spiral computed tomography (CT).ObjectivesWe compared automatic bolus tracking method with fixed time-delay technique in biphasic contrast enhancement during multidetector CT of abdomen.Patients and MethodsAdult patients referred for spiral CT of the abdomen were randomized into two groups; in group 1, the arterial and portal phases of spiral scans were started 25 s and 55 s after the start of contrast material administration; in group 2, using the automatic bolus tracking software, repetitive monitoring scans were performed within the lumen of the descending aorta as the region of interest with the threshold of starting the diagnostic scans as 60 HU. The contrast enhancement of the aorta, liver, and spleen were compared between the groups.ResultsForty-eight patients (23 males, 25 females, mean age=56.4±13.5 years) were included. The contrast enhancement of the aorta, liver, and spleen at the arterial phase was similar between the two groups (P>0.05). Regarding the portal phase, the aorta and spleen were more enhanced in the bolus-tracking group (P<0.001). The bolus tracking provided more homogeneous contrast enhancement among different patients than the fixed time-delay technique in the liver at portal phase, but not at the arterial phase.ConclusionsThe automatic bolus-tracking method, results in higher contrast enhancement of the aorta and spleen at the portal phase, but has no effect on liver enhancement. However, bolus tracking is associated with reduced variability for liver enhancement among different patients.

Budd-Chiari Syndrome Caused by TIPS Malposition: A Case Report.

Budd-Chiari syndrome refers to hepatic pathology secondary to diminished venous outflow, most commonly associated with venothrombotic disease. Clinically, patients with Budd-Chiari present with hepatomegaly, ascites, abdominal distension, and pain. On imaging, Budd-Chiari syndrome is hallmarked by occluded IVC and or hepatic veins, caudate lobe enlargement, heterogeneous liver enhancement, intrahepatic collaterals, and hypervascular nodules. Etiopathological factors for Budd-Chiari syndrome include several systemic thrombotic and nonthrombotic conditions that can cause venous outflow obstruction at hepatic veins and/or IVC. While the transjugular intrahepatic portosystemic shunt (TIPS) is used as a treatment option for Budd-Chiari syndrome, Budd-Chiari syndrome is not a well-known complication of TIPS procedure. We report a case of Budd-Chiari syndrome that occurred in a transplanted cirrhotic liver from malpositioned proximal portion of the TIPS in IVC causing occlusion of the ostia of hepatic veins which was subsequently diagnosed on contrast-enhanced CT.

Hepatic Sinusoidal Obstruction Syndrome Caused by Herbal Medicine: CT and MRI Features

ObjectiveTo describe the CT and MRI features of hepatic sinusoidal obstruction syndrome (HSOS) caused by herbal medicine Gynura segetum.Materials and MethodsThe CT and MRI features of 16 consecutive Gynura segetum induced HSOS cases (12 men, 4 women) were analyzed. Eight patients had CT; three patients had MRI, and the remaining five patients had both CT and MRI examinations. Based on their clinical presentations and outcomes, the patients were classified into three categories: mild, moderate, and severe. The severity of the disease was also evaluated radiologically based on the abnormal hepatic patchy enhancement in post-contrast CT or MRI images.ResultsAscites, patchy liver enhancement, and main right hepatic vein narrowing or occlusion were present in all 16 cases. Hepatomegaly and gallbladder wall thickening were present in 14 cases (87.5%, 14/16). Periportal high intensity on T2-weighted images was present in 6 cases (75%, 6/8). Normal liver parenchymal enhancement surrounding the main hepatic vein forming a clover-like sign was observed in 4 cases (25%, 4/16). The extent of patchy liver enhancement was statistically associated with clinical severity classification (kappa = 0.565).ConclusionAscites, patchy liver enhancement, and the main hepatic veins narrowing were the most frequent signs of herbal medicine induced HSOS. The grade of abnormal patchy liver enhancement was associated with the clinical severity.

Efficacy of liver parenchymal enhancement and liver volume to standard liver volume ratio on Gd-EOB-DTPA-enhanced MRI for estimation of liver function

We aimed to develop and assess the efficacy of a liver function index that combines liver enhancement and liver volume to standard liver volume (LV/SLV) ratio on gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MRI. In all, 111 patients underwent a Gd-EOB-DTPA-enhanced MRI, including T1 mapping, before and 20min after Gd-EOB-DTPA administration. We calculated the following Gd-EOB-DTPA-enhanced MRI-based liver function indices: relative enhancement of the liver, corrected enhancement of the liver-to-spleen ratio, LSC_N20, increase rate of the liver-to-muscle ratio, reduction rate of T1 relaxation time of the liver, ΔR1 of the liver and K Hep; the indices were multiplied by the LV/SLV ratio. We calculated the correlations between an indocyanine green (ICG) clearance and the Gd-EOB-DTPA-enhanced MRI-based liver function indices multiplied by the LV/SLV ratio, by using Pearson correlation analysis. There were significant correlations between all Gd-EOB-DTPA-enhanced MRI-based liver function indices and ICG clearance (r = -0.354 to -0.574, P < 0.001). All Gd-EOB-DTPA-enhanced MRI-based liver function indices multiplied by the LV/SLV ratio (r = -0.394 to -0.700, P < 0.001) were more strongly correlated with the ICG clearance than those without multiplication by the LV/SLV ratio. Gd-EOB-DTPA-enhanced MRI-based liver function indices that combine liver enhancement and the LV/SLV ratio may more reliably estimate liver function. • Gd-EOB-DTPA-enhanced MRI is useful for assessing liver function. • Liver enhancement on Gd-EOB-DTPA-enhanced MRI correlates with indocyanine green (ICG) clearance. • Liver volume to standard liver volume (LV/SLV) ratio correlates with ICG clearance. • Liver enhancement and LV/SLV ratio help to estimate liver function.

Free Radical Scavenging and Antioxidant Activities of Silymarin Components

Silymarin is an over the counter food supplement that is sold as a liver enhancement and liver protection preparation. It is a major constituent of the seeds of Silybum marianum which is composed of a mixture of seven major components and several minor compounds. The seven major components: taxifolin, silychristin, silydianin, silybin A, silybin B, iso-silybin A and iso-silybin B were isolated and purified from the crude mixture of silymarin using preparative high performance liquid chromatography to determine which were the most effective for liver protection. Free radical scavenging, hydroxyl radical antioxidant capacity, oxygen radical antioxidant capacity, trolox-equivalent antioxidant capacity and total antioxidant capacity antioxidant activities were determined for each of the individual purified components as well as the crude silymarin mixture. Taxifolin was the most effective component for scavenging free radicals in the DPPH assay with an EC50 of 32 µM far more effective than all other components which showed EC50 ranging from 115 to 855 µM. Taxifolin was also found to be the most effective antioxidant in the oxygen radical antioxidant capacity (ORAC) assay with a trolox equivalent of 2.43 and the second most effective in the hydroxyl radical antioxidant capacity (HORAC) assay with a gallic acid equivalent of 0.57. Other antioxidants assays did not show significant differences between samples.

Liver Failure after Major Liver Resection: Risk Assessment by Using Preoperative Gadoxetic Acid–enhanced 3-T MR Imaging

To determine if gadoxetic acid-enhanced magnetic resonance (MR) imaging with measurement of relative liver enhancement (RLE) on hepatobiliary phase images can allow preoperative assessment of the risk of liver failure after major liver resection. The local institutional review committee approved this retrospective analysis and waived written informed consent. The study included 73 patients (39 men; median age, 64.4 years) who underwent gadoxetic acid-enhanced 3-T MR imaging before resection of three or more liver segments. RLE was calculated as the ratio of signal intensity measurements of the liver parenchyma before and 20 minutes after intravenous administration of gadoxetic acid. RLE was assessed in each liver segment and the mean value of all segments was used for analysis. Posthepatectomy liver failure was defined according to the "50-50 criteria" (ie, prothrombin time <50% and serum bilirubin >50 µmol/L on postoperative day 5) and the International Study Group of Liver Surgery (ISGLS) classification. The association of RLE and liver failure was tested with univariate and multivariate logistic regression analysis. In addition to RLE, the latter also included demographic, clinical, operative, and histologic variables. Patients with liver failure according to the 50-50 criteria (n = 3) had significantly lower RLE (54.5%) than those without (125.6%) (P = .009). According to ISGLS criteria, RLE was 112.5% in patients with grade A liver failure (n = 20), 88.4% in patients with grade B (n = 7), 41.7% (n = 2) in patients with grade C, and 136.5% (P < .001) in those without liver failure. In a logistic regression analysis, RLE was inversely related to the probability of liver failure according to the 50-50 (P = .02) and ISGLS (P < .001) criteria. In a multivariate analysis, RLE was independently associated with a higher probability of liver failure according to ISGLS classification (P = .003). Gadoxetic acid-enhanced MR imaging can help with the assessment of the risk for liver failure after major liver resection.

Long (heterogeneous) liver enhancement on contrast enhanced ultrasound

Purpose: Long (heterogeneous) liver enhancement (LLE) is a rare phenomenon that is similar with the ultrasound findings of portal venous gas. The purpose of this report is to describe the phenomenon of LLE after injection of the ultrasound contrast agent SonoVue®.