Gadoxetate disodium is a widely used magnetic resonance (MR) contrast agent for liver MR imaging, and it provides both dynamic and hepatobiliary phase images. However, acquiring optimal arterial phase images at liver MR using gadoxetate disodium is more challenging than using conventional extracellular MR contrast agent because of the small volume administered, the gadolinium content of the agent, and the common occurrence of transient severe motion. In this article, we identify the challenges in obtaining high-quality arterial-phase images of gadoxetate disodium-enhanced liver MR imaging and present strategies for optimizing arterial-phase imaging based on the thorough review of recent research in this field.
Angiography ; Arteries/anatomy & histology ; Contrast Media/*chemistry ; Gadolinium DTPA/*chemistry ; Humans ; Liver/*radiography ; *Magnetic Resonance Imaging

Objective To investigate the value of gadolinium ethoxybenzyl diethylene-triamine-pentaacetic-acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) in detecting different stages of liver fibrosis in rats.Methods Rat models of liver fibrosis were induced by carbon tetrachloride intraperitoneal injection for 4 - 12 weeks (n=45). The control group was applied with 0.9% saline (n=15). The MRI protocol contained both dynamic contrast-enhanced sequence (60 continuous scans within 3 minutes,including three pre-contrast measurements) and multiple hepatobiliary-phase acquisitions (every 5 minutes after contrast injection,60 minutes in total). METAVIR score was used to grade liver fibrosis:normal (F0),mild fibrosis (F1 - F2),and advanced fibrosis (F3 - F4). Liver perfusion parameters [transfer constant (K ),extravascular extracellular volume fraction (V),initial area under curve (iAUC),maximum relative enhancement (RE),and time of maximum RE (T)] as well as hepatobiliary-phase parameters [RE at different time point,the decrease of RE (RE=RE - RE),and elimination half-life of RE (T)] were measured and compared with ANOVA analysis and Spearman rank correlation.Results Thirty-one rats completed MRI exams and were then divided into normal (n=10),mild fibrosis (n=10),and advanced fibrosis (n=11) groups. K ,V and iAUC decreased as liver fibrosis progressed (r=-0.631,P=0.002;r=-0.503,P=0.017;r=-0.446,P=0.037). K and V showed significant differences among three groups(F=7.011,P=0.005;F=4.656,P=0.023). K and V were significantly lower in advanced fibrosis group than in normal group (P=0.001,P=0.009). There were statistical significant differences of T,T and RE among groups(F=6.633,P=0.005;F=5.493,P=0.010;F=5.343,P=0.014). Compared to normal and mild fibrosis groups,advanced fibrosis group had significantly longer T and T (P=0.005,P=0.004;P=0.008,P=0.008)and significantly lower RE(P=0.007,P=0.012).Conclusion Perfusion and multi-hepatobiliary-phase parameters such as K ,V,T, T and RE obtained from Gd-EOB-DTPA-enhanced MRI,may be valuable for detecting and staging liver fibrosis.
Animals ; Contrast Media ; chemistry ; Gadolinium DTPA ; chemistry ; Liver ; diagnostic imaging ; pathology ; Liver Cirrhosis ; diagnostic imaging ; Magnetic Resonance Imaging ; Rats

OBJECTIVETo prepare a novel MRI targeted contrast agent Gd-DTPA-Granzyme B monoclonal antibody (mAb) and to test its reaction conditions.

METHODSThe Granzyme B mAb was coupled with DTPA,and then conjugated with Gd. The Gd-DTPA antibody was characterized using MALDI-TOF-MS. Cytotoxicity test was performed with MTT assay, and immune activation was examined with immunohistochemistry.

RESULTMALDI-TOF-MS demonstrated that the molecular weight shifted from granzyme B mAb (133986) to Gd-DTPA-GB mAb (139736), which indicated the conjugation of the antibody with Gd-DTPA. The molar ratio of Gd per IgG molecule was about 20. MTT assay showed that Gd, DTPA, Gd-DTPA and Gd-DTPA-GB mAb groups did not make an impact on cell viability, and there were no significant differences among 4 groups (P>0.05). Immunohistochemistry results showed that compared with the positive control group the targeted contrast agent had a high immune activity.

CONCLUSIONThe novel contrast agent Gd-DTPA-Granzyme B mAb prepared in this study keeps a good immune activity and has no significant cytotoxicity.

Antibodies, Monoclonal ; chemistry ; Cells, Cultured ; Contrast Media ; chemistry ; toxicity ; Gadolinium DTPA ; chemistry ; Granzymes ; immunology ; Magnetic Resonance Imaging ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

No abstract available.
Adult ; Female ; Focal Nodular Hyperplasia/*diagnosis/pathology ; Gadolinium DTPA/chemistry ; Hepatitis B, Chronic/diagnosis ; Humans ; Image-Guided Biopsy ; Liver/pathology ; Magnetic Resonance Imaging ; Tomography, X-Ray Computed

No abstract available.
Antigens, CD34/metabolism ; Carcinoma, Hepatocellular/pathology/*radiography ; Contrast Media/chemistry/diagnostic use ; Gadolinium DTPA/chemistry/*diagnostic use ; Humans ; Immunohistochemistry ; Liver Neoplasms/pathology/*radiography ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Tomography, X-Ray Computed

OBJECTIVE: To visualize tumor angiogenesis using the MRI contrast agent, Gd-DTPA-anti-VEGF receptor 2 antibody conjugate, with a 4.7-Tesla MRI instrument in a mouse model. MATERIALS AND METHODS: We designed a tumor angiogenesis-targeting T1 contrast agent that was prepared by the bioconjugation of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and an anti-vascular endothelial growth factor receptor-2 (VEGFR2) antibody. The specific binding of the agent complex to cells that express VEGFR2 was examined in cultured murine endothelial cells (MS-1 cells) with a 4.7-Tesla magnetic resonance imaging scanner. Angiogenesis-specific T1 enhancement was imaged with the Gd-DTPA-anti-VEGFR2 antibody conjugate using a CT-26 adenocarcinoma tumor model in eight mice. As a control, the use of the Gd-DTPA-anti-rat immunoglobulin G (Gd-DTPA-anti-rat IgG) was imaged with a tumor model in eight mice. Statistical significance was assessed using the Mann-Whitney test. Tumor tissue was examined by immunohistochemical analysis. RESULTS: The Gd-DTPA-anti-VEGFR2 antibody conjugate showed predominant binding to cultured endothelial cells that expressed a high level of VEGFR2. Signal enhancement was approximately three-fold for in vivo T1-weighted MR imaging with the use of the Gd-DTPA-anti-VEGFR2 antibody conjugate as compared with the Gd-DTPA-rat IgG in the mouse tumor model (p < 0.05). VEGFR2 expression in CT-26 tumor vessels was demonstrated using immunohistochemical staining. CONCLUSION: MR imaging using the Gd-DTPA-anti-VEGFR2 antibody conjugate as a contrast agent is useful in visualizing noninvasively tumor angiogenesis in a murine tumor model.
Adenocarcinoma/*pathology ; Animals ; Colonic Neoplasms/*pathology ; Contrast Media/chemistry/*diagnostic use ; Gadolinium DTPA/chemistry/*diagnostic use ; Immunoenzyme Techniques ; Magnetic Resonance Imaging/*methods ; Mice ; Mice, Nude ; Neovascularization, Pathologic/*diagnosis ; Rats ; Statistics, Nonparametric ; Tumor Cells, Cultured ; Vascular Endothelial Growth Factor Receptor-2/*antagonists & inhibitors/chemistry

BACKGROUND/AIMS: The therapeutic effect of transarterial chemoembolization (TACE) against hepatocellular carcinoma (HCC) is usually assessed using multidetector computed tomography (MDCT). However, dense lipiodol depositions can mask the enhancement of viable HCC tissue in MDCT. Contrast-enhanced ultrasonography (CEUS) could be effective in detecting small areas of viability and patency in vessels. We investigated whether arterial enhancement in CEUS after treatment with TACE can be used to detect HCC viability earlier than when using MDCT. METHODS: Twelve patients received CEUS, MDCT, and gadoxetic-acid-enhanced dynamic magnetic resonance imaging (MRI) at baseline and 4 and 12 weeks after TACE. The definition of viable HCC was defined as MRI positivity after 4 or 12 weeks. RESULTS: Eight of the 12 patients showed MRI positivity at 4 or 12 weeks. All patients with positive CEUS findings at 4 weeks (n=8) showed MRI positivity and residual viable HCC at 4 or 12 weeks. Five of the eight patients with positive CEUS findings at 4 weeks had negative results on the 4-week MDCT scan. Four (50%) of these eight patients did not have MRI positivity at 4 weeks and were ultimately confirmed as having residual HCC tissue at the 12-week MRI. Kappa statistics revealed near-perfect agreement between CEUS and MRI (kappa=1.00) and substantial agreement between MDCT and MRI (kappa=0.67). CONCLUSIONS: In the assessment of the response to TACE, CEUS at 4 weeks showed excellent results for detecting residual viable HCC, which suggests that CEUS can be used as an early additive diagnosis tool when deciding early additional treatment with TACE.
Aged ; Aged, 80 and over ; Antineoplastic Agents/administration & dosage ; Carcinoma, Hepatocellular/pathology/therapy/*ultrasonography ; Chemoembolization, Therapeutic ; Contrast Media/*chemistry ; Female ; Gadolinium DTPA/chemistry ; Humans ; Liver Neoplasms/pathology/therapy/*ultrasonography ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Pilot Projects ; Tomography, X-Ray Computed ; Treatment Outcome

No abstract available.
Adenoma, Bile Duct/pathology/*radiography ; Adult ; Aged ; Angiomyolipoma/pathology/*radiography ; Bile Duct Neoplasms/pathology/*radiography ; Bile Ducts, Intrahepatic ; Carcinoma, Hepatocellular/radiography ; Diagnosis, Differential ; Female ; Gadolinium DTPA/*chemistry ; Humans ; Liver Diseases/pathology/*radiography ; Liver Neoplasms/pathology/*radiography ; *Magnetic Resonance Imaging ; Male ; Middle Aged ; Pseudolymphoma/pathology/*radiography ; Tomography, X-Ray Computed