Ingestion and effects of polystyrene nanoparticles in the silkworm Bombyx mori.

Information on the occurrence and effects of nanoplastics in ecosystems worldwide currently represent one of the main challenges from the ecotoxicological point of view. This is particularly true for terrestrial environments, in which nanoplastics are released directly by human activities or derive from the fragmentation of larger plastic items incorrectly disposed. Since insects can represent a target for these emerging contaminants in land-based community, the aim of this study was the evaluation of ingestion of 0.5 µm polystyrene nanoplastics and their effects in silkworm (Bombyx mori) larvae, a useful and well-studied insect model. The ingestion of nanoplastics, the possible infiltration in the tissues and organ accumulation were checked by confocal microscopy, while we evaluated the effects due to the administered nanoplastics through a multi-tier approach based on insect development and behaviour assessment, as endpoints at organism level, and the measurements of some biochemical responses associated with the imbalance of the redox status (superoxide dismutase, catalase, glutathione s-transferase, reactive oxygen species evaluation, lipid peroxidation) to investigate the cellular and molecular effects. We observed the presence of microplastics in the intestinal lumen, but also inside the larvae, specifically into the midgut epithelium, the Malpighian tubules and in the haemocytes. The behavioural observations revealed a significant (p < 0.05) increase of erratic movements and chemotaxis defects, potentially reflecting negative indirect effects on B. mori survival and fitness, while neither effect on insect development nor redox status imbalance were measured, with the exception of the significant (p < 0.05) inhibition of superoxide dismutase activity.

Source apportionment to support air quality planning: Strengths and weaknesses of existing approaches.

Information on the origin of pollution constitutes an essential step of air quality management as it helps identifying measures to control air pollution. In this work, we review the most widely used source-apportionment methods for air quality management. Using theoretical and real-case datasets we study the differences among these methods and explain why they result in very different conclusions to support air quality planning. These differences are a consequence of the intrinsic assumptions that underpin the different methodologies and determine/limit their range of applicability. We show that ignoring their underlying assumptions is a risk for efficient/successful air quality management as these methods are sometimes used beyond their scope and range of applicability. The simplest approach based on increments (incremental approach) is often not suitable to support air quality planning. Contributions obtained through mass-transfer methods (receptor models or tagging approaches built in air quality models) are appropriate to support planning but only for specific pollutants. Impacts obtained via "brute-force" methods are the best suited but it is important to assess carefully their application range to make sure they reproduce correctly the prevailing chemical regimes.

The Benefits of High Relaxivity for Brain Tumor Imaging: Results of a Multicenter Intraindividual Crossover Comparison of Gadobenate Dimeglumine with Gadoterate Meglumine (The BENEFIT Study).

BACKGROUND AND PURPOSE: Gadobenate dimeglumine (MultiHance) has higher r1 relaxivity than gadoterate meglumine (Dotarem) which may permit the use of lower doses for MR imaging applications. Our aim was to compare 0.1- and 0.05-mmol/kg body weight gadobenate with 0.1-mmol/kg body weight gadoterate for MR imaging assessment of brain tumors. MATERIALS AND METHODS: We performed crossover, intraindividual comparison of 0.1-mmol/kg gadobenate with 0.1-mmol/kg gadoterate (Arm 1) and 0.05-mmol/kg gadobenate with 0.1-mmol/kg gadoterate (Arm 2). Adult patients with suspected or known brain tumors were randomized to Arm 1 (70 patients) or Arm 2 (107 patients) and underwent 2 identical examinations at 1.5 T. The agents were injected in randomized-sequence order, and the 2 examinations were separated by 2-14 days. MR imaging scanners, imaging sequences (T1-weighted spin-echo and T1-weighted high-resolution gradient-echo), and acquisition timing were identical for the 2 examinations. Three blinded readers evaluated images for diagnostic information (degree of definition of lesion extent, lesion border delineation, visualization of lesion internal morphology, contrast enhancement) and quantitatively for percentage lesion enhancement and lesion-to-background ratio. Safety assessments were performed. RESULTS: In Arm 1, a highly significant superiority (P < .002) of 0.1-mmol/kg gadobenate was demonstrated by all readers for all end points. In Arm 2, no significant differences (P > .1) were observed for any reader and any end point, with the exception of percentage enhancement for reader 2 (P < .05) in favor of 0.05-mmol/kg gadobenate. Study agent-related adverse events were reported by 2/169 (1.2%) patients after gadobenate and by 5/175 (2.9%) patients after gadoterate. CONCLUSIONS: Significantly superior morphologic information and contrast enhancement are demonstrated on brain MR imaging with 0.1-mmol/kg gadobenate compared with 0.1-mmol/kg gadoterate. No meaningful differences were recorded between 0.05-mmol/kg gadobenate and 0.1-mmol/kg gadoterate.

Compensatory biliary and urinary excretion of gadobenate ion after administration of gadobenate dimeglumine (MultiHance(®)) in cases of impaired hepatic or renal function: a mechanism that may aid in the prevention of nephrogenic systemic fibrosis?

OBJECTIVE: To determine whether increased elimination of gadobenate ion via the hepatobiliary pathway might compensate for reduced/absent elimination via the urinary pathway in the event of compromised renal function, as a possible protective mechanism against nephrogenic systemic fibrosis (NSF). METHODS: 15 male Crl:CD(®) R(SD)Br rats (Charles River Italia, Como, Italy) randomized to three treatment groups: (1) animals with occluded bile ducts, (2) animals with occluded renal vessels and (3) control animals, each received 0.25 mmol kg(-1) of bodyweight of gadobenate dimeglumine (MultiHance(®); Bracco Imaging SpA, Milan, Italy). Urine and bile were collected from 0-30, 30-60, 60-120, 120-240 and 240-480 min after gadobenate dimeglumine administration prior to exsanguination. Determinations of gadobenate ion in blood, bile and urine were performed by high-performance liquid chromatography. Gadolinium (Gd(3+)) levels in excised liver and kidneys were determined by X-ray fluorescence. RESULTS: The recovery of gadobenate ion in the urine of rats with bile duct occlusion was significantly higher than that in the urine of normal rats (89.1 ± 4.2% vs 60.6 ± 2.8%; p < 0.0001). Conversely, mean recovery in the bile of rats with renal vessel occlusion was significantly higher than that in the bile of normal rats (96.16 ± 0.55% vs 33.5 ± 4.7%; p < 0.0001). Gadobenate ion was not quantifiable in any group 8 h post-injection. CONCLUSION: Compensatory elimination may be an effective means to overcome compromised renal or hepatobiliary elimination. ADVANCES IN KNOWLEDGE: The absence of NSF in at-risk patients administered with gadobenate dimeglumine may in part reflect greater Gd(3+) elimination via the hepatobiliary route.

Are there differences between macrocyclic gadolinium contrast agents for brain tumor imaging? Results of a multicenter intraindividual crossover comparison of gadobutrol with gadoteridol (the TRUTH study).

BACKGROUND AND PURPOSE: Gadobutrol (Gadavist) and gadoteridol (ProHance) have similar macrocyclic molecular structures, but gadobutrol is formulated at a 2-fold higher (1 mol/L versus 0.5 mol/L) concentration. We sought to determine whether this difference impacts morphologic contrast-enhanced MR imaging. MATERIALS AND METHODS: Two hundred twenty-nine adult patients with suspected or known brain tumors underwent two 1.5T MR imaging examinations with gadoteridol or gadobutrol administered in randomized order at a dose of 0.1 mmol/kg of body weight. Imaging sequences and T1 postinjection timing were identical for both examinations. Three blinded readers evaluated images qualitatively and quantitatively for lesion detection and for accuracy in characterization of histologically confirmed brain tumors. Data were analyzed by using the Wilcoxon signed rank test, the McNemar test, and a mixed model. RESULTS: Two hundred nine patients successfully completed both examinations. No reader noted a significant qualitative or quantitative difference in lesion enhancement, extent, delineation, or internal morphology (P values = .69-1.00). One hundred thirty-nine patients had at least 1 histologically confirmed brain lesion. Two readers found no difference in the detection of patients with lesions (133/139 versus 135/139, P = .317; 137/139 versus 136/139, P = .564), while 1 reader found minimal differences in favor of gadoteridol (136/139 versus 132/139, P = .046). Similar findings were noted for the number of lesions detected and characterization of tumors (malignant/benign). Three-reader agreement for characterization was similar for gadobutrol (66.4% [κ = 0.43]) versus gadoteridol (70.3% [κ = 0.45]). There were no significant differences in the incidence of adverse events (P = .199). CONCLUSIONS: Gadoteridol and gadobutrol at 0.1 mmol/kg of body weight provide similar information for visualization and diagnosis of brain lesions. The 2-fold higher gadolinium concentration of gadobutrol provides no benefit for routine morphologic imaging.

Serological survey of leptospiral infection in kennelled dogs in Italy.

Two hundred and forty-five dogs were examined serologically for the presence of antibodies against different serovars of Leptospira interrogans. The dogs belonged to five different groups: group 1 was composed of clinically healthy pet dogs referred for a regular veterinary check-up visit or for vaccination; group 2 was composed of stray dogs; and groups 3, 4 and 5 were composed of dogs maintained in three different kennels which had varying standards of hygiene. Seventy-two out of the 245 dogs examined were seropositive for leptospirosis. In group 1, there were 3-4 per cent seropositive dogs; in group 2, 30.3 per cent; in group 3, 13.8 per cent; in group 4, 38.6 per cent; and in group 5, 49.2 per cent. This study demonstrates that leptospiral infection is common in dogs housed in kennels, despite most of them being vaccinated, and that crowding of animals into unsanitary quarters is associated with a high prevalence of infection. The most common infecting serovars found were bratislava and grippotyphosa, confirming recent observations that demonstrate a significant change in the epidemiology of canine leptospirosis.

Magnetic resonance imaging of metastatic disease to the brain with gadobenate dimeglumine.

Seventy-four patients with one to eight proven intraaxial brain metastases received a total cumulative dose of 0.2 mmol/kg bodyweight gadobenate dimeglumine, administered as sequential injections of 0.05, 0.05 and 0.1 m mol/kg over a 20-min period. MR imaging was performed before the first administration (T2- and T1-weighted sequences) and after each injection of contrast agent (T1-weighted sequences only). Quantitative assessment of images revealed significant (P <0.01) dose-related increases in lesion-to-brain (L/B) ratio and percent enhancement of lesion signal intensity. Qualitative assessment by two independent, blinded assessors revealed additional lesions in 22%, 25% and 38% (assessor 1) and 29%, 32% and 34% (assessor 2) of patients after each cumulative dose when compared with combined T1- and T2-weighted pre-contrast images. Significantly more lesions (P < 0.01) were noted by both assessors after the first injection and by one assessor after each subsequent injection. For patients with just one lesion observed on unenhanced T1- and T2-weighted images, additional lesions were noted in 12%, 16% and 28% of patients by assessor 1 following each dose and in 24%, 27% and 30% of patients by assessor 2. Contemporaneously, diagnostic confidence was increased and lesion conspicuity improved over unenhanced MRI. For patients with one lesion observed after an initial dose of 0.05 mmol/kg, additional lesions were noted by assessors 1 and 2 in 9.1% and 11.8% of patients, respectively, after a cumulative dose of 0.1 mmol/kg and in a further 9.1% and 5.9% of patients, respectively, after a cumulative dose of 0.2 mmol/kg. No safety concerns were apparent.

Gadobenate dimeglumine-enhanced magnetic resonance imaging of intracranial metastases: effect of dose on lesion detection and delineation.

Seventy-four patients with one to eight proven intraaxial metastatic lesions to the brain received a total gadobenate dimeglumine dose of 0.3 mmol/kg of body weight, administered as three sequential bolus injections of 0.1 mmol/kg, at 10-minute intervals over a 20-minute period. Quantitative and qualitative assessments of efficacy were performed after each injection and a full evaluation of safety was conducted. Cumulative dosing produced significant (P < 0.01) dose-related increases in lesion-to-brain (L/B) ratio and lesion signal intensity (SI) enhancement. Two independent, blinded assessors noted additional lesions, compared to unenhanced images in 31% and 33%, 49% and 42%, and 50% and 48% of patients after each cumulative dose, respectively. Significantly more lesions were noted after the first injection, compared to unenhanced images (P = 0.002 and P < 0.001; assessors 1 and 2, respectively), and after a second injection, compared to the first (P < 0.001 and P = 0.039; assessors 1 and 2, respectively). Neither assessor noted significantly more lesions after the third injection. For patients with just one lesion observed on unenhanced T1- and T2-weighted images, additional lesions were noted by assessors 1 and 2 for 27% and 26%, 48% and 35%, and 42% and 41% of patients, respectively, following each injection. Contemporaneously, diagnostic confidence was increased and lesion conspicuity improved over unenhanced magnetic resonance imaging (MRI). For patients with one lesion observed after 0.1 mmol/kg of gadobenate dimeglumine, additional lesions were noted for 24% and 17% of patients (assessors 1 and 2, respectively) following a second 0.1 mmol/kg injection. Only assessor 2 noted additional lesions following the third 0.1 mmol/kg injection. The findings of on-site investigators concurred with those of the two off-site assessors. No safety concerns were apparent.

Safety assessment of gadobenate dimeglumine (MultiHance): extended clinical experience from phase I studies to post-marketing surveillance.

Clinical trials completed by September 2000 on gadobenate dimeglumine (Gd-BOPTA; MultiHance) included 2540 adult and pediatric subjects that were administered this agent. For adult patient volunteers, the overall incidence of adverse events (AEs) was 19.8%, although marked study- and indication-related differences were apparent. Events potentially related to Gd-BOPTA administration were reported for 15.1% of adult patients. The vast majority of AEs were non-serious, mild, transient, and self-resolving. Headache, injection site reaction, nausea, taste perversion, and vasodilation were the most common AEs, reported with a frequency of between 1.0% and 2.6%. Serious AEs potentially related to Gd-BOPTA were reported for five (0.2%) patients overall. Controlled studies revealed no differences between Gd-BOPTA and other gadolinium chelates or placebo in the incidence and type of AEs. Similarly, no differences with respect to adult patients and/or comparator were noted in studies on pediatric subjects and subjects with renal or liver insufficiency. Post-marketing surveillance of approximately 100000 doses revealed an overall AE incidence of < 0.03% with serious AEs reported for < 0.005% of patients.

Detection of malignant primary hepatic neoplasms with gadobenate dimeglumine (Gd-BOPTA) enhanced T1-weighted hepatocyte phase MR imaging: results of off-site blinded review in a phase-II multicenter trial.

OBJECTIVE: To investigate the efficacy of gadobenate dimeglumine (Gd-BOPTA) enhanced MR imaging for the detection of liver lesions in patients with primary malignant hepatic neoplasms. MATERIALS AND METHODS: Thirty-one patients with histologically proven primary malignancy of the liver were evaluated before and after administration of Gd-BOPTA at dose 0.05 or 0.10 mmol/kg. T1-weighted spin echo (T1W-SE) and gradient echo (T1W-GRE) images were evaluated for lesion number, location, size and confidence by three off-site independent reviewers and the findings were compared to reference standard imaging (intraoperative ultrasound, computed tomography during arterial portography or lipiodol computed tomography). Results were analyzed for significance using a two-sided McNemar's test. RESULTS: More lesions were identified on Gd-BOPTA enhanced images than on unenhanced images and there was no significant difference in lesion detection between either concentration. The largest benefit was in detection of lesions under 1 cm in size (7 to 21, 9 to 15, 16 to 18 for reviewers A, B, C respectively). In 68% of the patients with more than one lesion, Gd-BOPTA increased the number of lesions detected. CONCLUSION: Liver MR imaging after Gd-BOPTA increases the detection of liver lesions in patients with primary malignant hepatic neoplasm.

Evaluation of the accuracy of gadobenate dimeglumine-enhanced MR imaging in the detection and characterization of focal liver lesions.

OBJECTIVE: We evaluated the extent to which hepatic lesion characterization and detection is improved by using gadobenate dimeglumine for enhancement of MR images. MATERIALS AND METHODS: Eighty-six patients were imaged before gadobenate dimeglumine administration, immediately after the 2 mL/sec bolus administration of a 0.05 mmol/kg dose (dynamic imaging), and at 60-120 min after the IV infusion at 10 mL/min of a further 0.05 nmol/kg dose (delayed imaging). The accuracy for lesion characterization was assessed for a total of 107 lesions. Sensitivity for lesion detection was assessed for a total of 149 lesions detected on either intra-operative sonography, iodized oil CT, CT during arterial portography, or follow-up contrast-enhanced CT as the gold standard. RESULTS: The accuracy in differentiating benign from malignant liver lesions increased from 75% and 82% (the findings of two observers) on unenhanced images alone, to 89% and 80% on dynamic images alone (p<0.001, p = 0.8), and to 90.7% when combining the unenhanced and dynamic image sets (p<0.001, p = 0.023). Delayed images did not further improve accuracy (90% and 91%; p = 0.002, p< 0.05). A similar trend was apparent in terms of accuracy for specific diagnosis: values ranged from 49% and 62% on unenhanced images alone, to 76% and 70% on combined unenhanced and dynamic images (p<0.001, p = 0.06), and to 75% and 70% on inclusion of delayed images (p<0.001, p = 0.12). The sensitivity for lesion detection increased from 77% and 81% on unenhanced images alone, to 87% and 85% on combined unenhanced and dynamic images (p = 0.001, p = 0.267), and to 92% and 89% when all images were considered (p<0.001, p = 0.01). CONCLUSION: Contrast-enhanced dynamic MR imaging with gadobenate dimeglumine significantly increases sensitivity and accuracy over unenhanced imaging for the characterization of focal hepatic lesions, and delayed MR imaging contributes to the improved detection of lesions.

Focal liver lesions: evaluation of the efficacy of gadobenate dimeglumine in MR imaging--a multicenter phase III clinical study.

PURPOSE: To evaluate gadobenate dimeglumine (Gd-BOPTA) for dynamic and delayed magnetic resonance (MR) imaging of focal liver lesions. MATERIALS AND METHODS: In 126 of 214 patients, MR imaging was performed before Gd-BOPTA administration, immediately after bolus administration of a 0.05- mmol/kg dose of Gd-BOPTA, and 60-120 minutes after an additional intravenously infused 0.05-mmol/kg dose. In 88 patients, imaging was performed before and 60-120 minutes after a single, intravenously infused 0.1-mmol/kg dose. T1- and T2-weighted spin-echo and T1-weighted gradient-echo images were acquired. On-site and blinded off-site reviewers prospectively evaluated all images. Intraoperative ultrasonography, computed tomography (CT) during arterial portography, and/or CT with iodized oil served as the reference methods in 110 patients. RESULTS: Significantly more lesions were detected on combined pre- and postcontrast images compared with on precontrast images alone (P <. 01). All reviewers reported a decreased mean size of the smallest detected lesion and improved lesion conspicuity on postcontrast images. All on-site reviewers and two off-site reviewers reported increased overall diagnostic confidence (P <.01). Additional lesion characterization information was provided on up to 109 (59%) of 184 delayed images and for up to 50 (42%) of 118 patients in whom dynamic images were assessed. Gd-BOPTA would have helped change the diagnosis in 99 (47%) of 209 cases and affected patient treatment in 408 (23%) of 209 cases. CONCLUSION: Gd-BOPTA increases liver lesion conspicuity and detectability and aids in the characterization of lesions.

Hepatocellular carcinoma: correlation between gadobenate dimeglumine-enhanced MRI and pathologic findings.

RATIONALE AND OBJECTIVES: To correlate the appearance of hepatocellular carcinoma on delayed (60 minutes) postcontrast T1-weighted gradient echo images with the mode of action of gadobenate dimeglumine (Gd-BOPTA) and the anatomic and pathologic characteristics of the lesions. METHODS: A total of 34 patients with hepatocellular carcinoma and varying degrees of diffuse liver disease were studied. T2-weighted spin echo and T1-weighted spin echo and gradient echo images were acquired before and 60 minutes after the intravenous administration of 0.1 mmol/kg Gd-BOPTA. Qualitative and quantitative evaluations of the images were performed and correlated with histologic findings. The quantitative evaluation, performed on T1-weighted gradient echo images, looked at the percentage increase of liver enhancement after Gd-BOPTA administration, the lesion-to-liver contrast/noise (C/N) ratio before and after Gd-BOPTA administration, and the C/N variation after Gd-BOPTA administration. Qualitative assessment considered the morphologic features of the lesions as well as the visual variation of contrast before and after Gd-BOPTA administration. Finally, a histologic evaluation was made of the degree of differentiation of the lesions and of the presence of fatty metaplasia, necrosis, bile, or intratumoral peliosis. RESULTS: Among the parameters affecting lesion identification were the extent of liver function, degree of vascularization, residual functionality of the tumor cells, and characteristics of the neoplastic tissue. Positive correlations (Spearman coefficients = 0.359 and 0.393, respectively) were observed precontrast between the degree of liver failure and the amount of contrast noise, and postcontrast between the amount of intralesional fatty metaplasia and the extent to which lesion conspicuity worsened after Gd-BOPTA administration. An inverse correlation (Spearman coefficient = -0.330) was observed between the degree of lesion differentiation and the visible appearance after Gd-BOPTA administration, with well-differentiated lesions tending toward worsened conspicuity postcontrast. A statistically significant difference (P = 0.001) was observed in the mean precontrast C/N ratio for lesions later showing unchanged conspicuity and worse conspicuity on postcontrast images, respectively. Marked variation (P = 0.019) was also observed between Child A and B cirrhotic patients for the degree of hepatic enhancement on postcontrast images. CONCLUSIONS: The results suggest that liver parenchyma signal intensity is influenced by the extent to which liver function is compromised, that residual hepatocytic functionality permits Gd-BOPTA uptake by certain lesions and that this uptake might subsequently impair the observed C/N ratio on delayed images, and that the worsening of lesion conspicuity on postcontrast images is influenced also by high quantities of intralesional fatty metaplasia.

MultiHance in the assessment of intracranial tumors: results of phase II clinical studies.

PURPOSE: To assess preliminarily the efficacy of 0.1 and 0.2 mmol/kg doses of MultiHance for contrast-enhanced magnetic resonance imaging of brain tumors. METHODS: Patients were imaged pre-dose using proton density (PD), T2-weighted and T1-weighted spin-echo sequences, and post-dose by repetition of the T1-weighted sequences at 0-15, 15-30, 30-45 and 45-60 min after the completion of MultiHance administration. Qualitative efficacy assessments of the image sets were performed by two blinded neuroradiologists in terms of the level of diagnostic information, the type of additional information provided by post-contrast images, the best post-contrast image set in terms of diagnostic information, the radiological utility of MultiHance, and the detectability of brain metastases. Extensive safety and tolerability controls were performed at 3 and 24 h post-contrast. RESULTS: Additional diagnostic information was available on MultiHance-enhanced images as compared to pre-contrast images for 58.678.9% of patients administered 0.1 mmol/kg MultiHance and 66.1-74.6% of patients administered 0.2 mmol/kg MultiHance. Generally, the early (0 to 30 min) post-contrast image sets were preferred, with a clear superiority at the 15-30 min post-dose time point. In a subgroup of 21 patients with brain metastases, a higher number of lesions was detected in 55.6-66.7% of the cases with 0.1 mmol/kg MultiHance and in 58.3% of the cases with 0.2 mmol/kg MultiHance. Overall, the usefulness of MultiHance was judged as good to excellent in 91.4% of the patients at both dose levels. A total of 12 of 120 patients (10%) reported 15 transient, self-resolving adverse events of mild-to-moderate intensity. No difference between doses was observed in the incidence of adverse events and no laboratory, ECG or vital signs abnormalities were reported. CONCLUSION: MultiHance is a safe and effective contrast agent for magnetic resonance assessment of brain tumors when administered intravenously at doses up to 0.2 mmol/kg.

Clinical utility and safety of MultiHance in magnetic resonance imaging of liver cancer: results of multicenter studies in Europe and the USA.

MultiHance (gadobenate dimeglumine; Gd-BOPTA, Bracco SpA, Milano, Italy) is a novel gadolinium-based contrast agent which has recently been made commercially available in Europe for magnetic resonance imaging of the liver. It combines the properties of a conventional extracellular fluid contrast agent with those of a liver-specific agent and has been shown in numerous clinical trials to improve the impact of magnetic resonance imaging for both the detection and characterization of focal liver masses. The present article briefly summarizes the safety and efficacy results of Phase I, II and III clinical studies carried out in almost 800 patient and non-patient volunteers in both Europe and the USA.

MultiHance in the dynamic phase of contrast enhancement: a pictorial assessment.

The present article demonstrates pictorially the use of MultiHance (gadobenate dimeglumine, Gd-BOPTA) in dynamic magnetic resonance imaging and is aimed at ensuring that the product is not misconceived as solely a hepatobiliary agent for use in delayed, static magnetic resonance imaging for the improved detection of focal liver lesions. The enhancement patterns of three malignant (hepatocellular carcinoma, cholangiocarcinoma and metastasis) and three benign (hemangioma, focal nodular hyperplasia and adenoma) lesion types are demonstrated. Each was imaged during the dynamic phase of contrast enhancement immediately following the intravenous bolus administration of 0.05 mmol/kg MultiHance. The article demonstrates that the enhancement patterns observed for these relatively common lesions are similar to those reported in the literature after the intravenous bolus administration of conventional, non-specific 'extracellular fluid' contrast agents, and concludes by inferring that MultiHance behaves in the liver as a conventional gadolinium-based agent in the first minutes after administration.

Delayed MR imaging of hepatocellular carcinoma enhanced by gadobenate dimeglumine (Gd-BOPTA).

The purpose of this study was to determine the efficacy of gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance (MR) imaging for evaluation of hepatocellular carcinoma HCC. MR images were obtained in 14 patients with 31 HCC nodules as a part of a phase III clinical trial. T1- and T2-weighted images were obtained before and after iv administration of 0.1 mmol/kg of Gd-BOPTA. Two blinded readers evaluated pre- and delayed postcontrast images separately for detection of tumor nodules. Quantitative measurements of signal-to-noise (SNR) and tumor/liver contrast-to-noise (CNR) ratios were also performed. A signal/intensity ratio was calculated. Tumor enhancement was correlated with histologic findings. Consensus agreement of precontrast T1- and T2-weighted images revealed 23/31 HCC nodules in 14 patients; postcontrast T1-weighted images demonstrated 24/31 HCC nodules in the same number of patients. Combining both pre- and postcontrast images, 27/31 lesions were detected. Four patients had four well-differentiated HCC nodules detected only on postcontrast images, while three well-differentiated lesions in two patients were only seen on precontrast images. Quantitative evaluation showed an SNR ratio increase in both liver parenchyma and HCC nodules, as well as a significant increase in the absolute CNR ratio on postcontrast T1-weighted gradient-recalled images (P < 0.05). Well-differentiated HCC lesions showed a greater enhancement than poorly differentiated HCC lesions.

Safety, tolerance, biodistribution, and MR imaging enhancement of the liver with gadobenate dimeglumine: results of clinical pharmacologic and pilot imaging studies in nonpatient and patient volunteers.

PURPOSE: The purpose of this study was to assess safety, tolerance, biodistribution, and magnetic resonance (MR) imaging enhancement of the liver with gadobenate dimeglumine. MATERIALS AND METHODS: Phase I single-blind studies were performed in 53 healthy volunteers, of whom 39 received gadobenate dimeglumine and 14 placebo. Another 106 patients with focal liver disease received gadobenate dimeglumine in parallel-group, open-label, phase II studies. The imaging potential of gadobenate dimeglumine was assessed in all 106 patients plus 11 healthy volunteers, whereas pharmacokinetics were determined for 42 healthy volunteers. Safety was assessed for all subjects enrolled in the study. Imaging protocols for healthy volunteers were similar to those for patients and comprised predose T2-weighted sequences and pre- and postinjection T1-weighted spin-echo and gradient-echo sequences. RESULTS: Gadobenate dimeglumine was safe and well tolerated in healthy volunteers and patients, with pharmacokinetics described adequately as a distribution phase and an elimination phase. Most of the injected dose of gadobenate was excreted unchanged in urine within 24 hours, although a fraction corresponding to 0.6%-4.0% of the injected dose was eliminated with the bile and recovered in the feces. The gadobenate dimeglumine-enhanced signal intensity of liver parenchyma was dose-related and constant for 120 minutes. Gadobenate dimeglumine-enhanced MR imaging was superior to nonenhanced MR imaging in more than 50% of patient studies, with more lesions seen in 26%-38% of patients and smaller lesions in 21%-33% of patients. In general, image sets acquired 40-180 minutes after administration of a dose were preferred, whereas images acquired during the dynamic phase after administration were typical of those obtained with extracellular fluid contrast agents. CONCLUSION: Gadobenate dimeglumine is a safe and efficacious MR imaging contrast agent suitable for both delayed and dynamic imaging of the liver.