Comparative study of USPIO-enhanced and Gd-enhanced MRI in the diagnosis of atherosclerotic plaques in rabbits / 实用医学杂志

Objective To investigate the imaging characteristics of USPIO-enhanced and Gd-enhanced MRI in atherosclerosis and to compare the detection rate of atherosclerotic plaque between them. Methods Thirty-five healthy male rabbits were assigned to experimental group (n=30) to establish a model of atherosclerosis by damaging aortic tunica intima with Foley′s tube in combination with a high fat diet and 5 to control group without any intervention. At week 12, USPIO-enhanced and Gd-enhanced MRI scanning were conducted to compare the signal changes of atherosclerotic plaque before and after enhancement with the 2 contrast media. Ninety seven pictures were randomly selected respectively from the pictures enhanced by the 2 contrast media to compare the detection rate plaque between them. Pthology examination was used for detection standard. For the control group , pictures were randomly selected. Results In the experimental group, 7 rabbits died of Foley′s tube damaging, 2 died of raising and 1 died of anesthesia. All 5 rabbits in control group survived. A total of 172 pathological sections were made with 134 plaques and 72 vulnerable plaques pathologically confirmed. In pictures enhanced by USPIO , 84 plaques were confirmed by HE staining with a detection rate of 86.6%. In pictures enhanced by Gd, 72 plaques were confirmed by HE staining with a detection rate of 74.2%. Detection rate of USPIO-enhanced MRI in atherosclerosis plaque was significantly higher than that of Gd-enhanced MRI (X2=3.96, P=0.046). Conclusion USPIO shows its superiority as a new contrast medium in detection of atherosclerosis plaque.

Realce por contraste de lesões hepáticas em pacientes com cirrose: estudo cruzado comparativo de dois agentes de contraste para RM realizado em uma única instituição. Resultados preliminares / Contrast enhancement of liver lesions in cirrhotic patients: a single institution crossover comparative study of two MR contrast agents. Preliminary results

OBJETIVO: Comparar, prospectivamente, gadopentato de dimeglumina (Gd-DTPA) e gadobenato de dimeglumina (Gd-BOPTA), ambos em dose plena, na detecção de lesões hepáticas focais, por meio de RM em pacientes com doença hepática crônica. MATERIAIS E MÉTODOS: Oito pacientes com cirrose hepática e forte suspeita de um pequeno carcinoma hepatocelular, baseada em RM anterior, foram submetidos a exames de RM contrastada, um com dose plena de Gd-DTPA e outro com dose plena de Gd-BOPTA. Os exames foram realizados com um intervalo de 72 a 108 horas. Dois radiologistas independentes realizaram avaliação às cegas das imagens, considerando número, caracterização e realce das lesões, além de preferências subjetivas. RESULTADOS: Não houve diferença estatisticamente significante entre os dois exames quanto à detecção e caracterização das lesões. Observou-se um incremento de 18 por cento no realce da lesão dominante pelo Gd-BOPTA, em comparação com o Gd-DTPA. Na maioria dos casos, ambos os observadores cegos subjetivamente preferiram as imagens utilizando Gd-BOPTA àquelas com Gd-DTPA, com base no maior realce e melhor definição das margens das lesões. CONCLUSÃO: Em doses plenas equivalentes, Gd-BOPTA e Gd-DTPA são similares na detecção e caracterização de lesões hepáticas focais em pacientes com doença hepática crônica. Entretanto, o Gd-BOPTA foi superior em relação ao realce da lesão, assim como na preferência subjetiva dos observadores.

OBJECTIVE: To prospectively compare full dose gadopentetate dimeglumine (Gd-DTPA) with full dose gadobenate dimeglumine (Gd-BOPTA) in the detection of focal hepatic lesions in patients with chronic liver disease on MRI. MATERIALS AND METHODS: Eight patients with hepatic cirrhosis and a strong suspicion for small hepatocellular carcinoma based on prior MRI underwent contrast-enhanced MR examinations, one with full dose Gd-DTPA and one with full dose Gd-BOPTA. The exams were performed from 72-108 hours apart. Two blinded and independent radiologists evaluated images for lesion number, characterization, enhancement, and subjective preference. RESULTS: There was no statistically significant difference between the two studies for lesion detection or characterization. There was 18 percent increased lesion enhancement for Gd-BOPTA, compared to Gd-DTPA, of the dominant lesion. Both blinded readers subjectively preferred the images using Gd-BOPTA over Gd-DTPA in the majority of cases, based on greater lesion enhancement and better edge definition. CONCLUSION: At equivalent full doses, Gd-BOPTA compared similarly with Gd-DTPA in the detection and characterization of focal hepatic lesions in patients with chronic liver disease. However, Gd-BOPTA was superior for increased lesion enhancement and subjective preference of the reader.

Preparation and characterization of pulmonary targeting DepoFoam loaded MR contrast media: Gadopentetate dimeglumine / 第二军医大学学报

Objective: To prepare a pulmonary targeting DepoFoam loaded MR contrast media: gadopentetate dimeglumine (Gd-DTPA), and to observe its physi-chemical and biologic characteristics. Methods: The routine magnetic resonance contrast media Gd-DTPA was encapsulated with multivesicular liposome (DepoFoam, Depo) labelled with red fluorescence to obtain a new particle Depo-Gd. The morphology, diameter, and the encapsulation rate of the new particle were examined. The targeting efficiency of the particle was assessed by animal test with mice. Ten mice were evenly divided into 2 groups: one group received caudal vein-injection of Depo-Gd and the other group received vena mesenterica-injection of Depo-Gd. Twenty minutes after the injection the slices of the mouse liver, lung, and kidney were obtained from both group and the fluorescence labeling were observed. Results: Under microscope, the produced Depo-Gd particles were round in shape and stable in status, with good mobility and well-distributed diameter (18 μm in average). The encapsulation rate of the particles was 50% and the concentration of Gd was 0.0417 mmol/ml. The animal fluorescence test showed that mice in the 2 groups were all active and with normal respiratory and conscious status after the injection. In the Depo-Gd caudal vein-injection group, large amount of red dyeing was found in the lung while little red dyeing was found in the liver and kidney; in vena mesenterica-injection group, satisfactory dyeing was found in the liver but not in the lung. Conclusion: The produced Depo-Gd particles have a stable physic-chemical property and with satisfactory encapsulation rate. There is no obvious biological toxicity and allergic reaction. Besides, the particles have, a good pulmonary targeting ability when injected into peripheral veins, making them promising in future clinical application.

Visualization of endolymphatic hydrops using Magnetic Resonance Imaging after intratympanic Gd-DTPA administration in patients with Meniere's disease

BACKGROUND AND OBJECTIVES: Endolymphatic hydrops are known as major causes of Meniere's disease. MRI (Magnetic resonance imaging) with contrast tried recently makes it possible to visualize perilymphatic and endolymphatic space without invasive procedures. There are no tryouts in the interior of our country. We attempted MRI after injection of gadolinium-diethylen-triamine pentaacetic acid (Gd-DTPA) in normal adults and patients with Meniere's disease to make sure 3D-FLAIR (fluid-attenuated inversion recovery) MRI parameters and to visualize endolymphatic spaces. MATERIALS AND METHODS: Five normal adults and Five patients with Meniere's disease were included in this study. Twenty-four hours after Gd-DTPA intratympanic injection, we performed 3D-FLAIR and 3D-IR imaging at 3T. MRI region of interest signal intensity was used to determine the diffusion of Gd-DTPA into the perilymphatic fluid spaces over time. RESULTS: Five of five in normal group, using 3D-IR MRI after Gd injection, had enhanced imagings (perilymphatic spaces) of inner ears. Five of five in patients group, using 3D-IR after Gd injection, had enhanced perilymphatic spaces and non-enhanced endolymphatic hydrops. CONCLUSIONS: Delayed contrast imaging of the inner ear with 3D-IR MRI after Gd-DTPA intratympanic injection revealed in vivo visualization of endolymphatic hydrops.

Gastrointestinal contrast agents for improving imaging quality of MRCP:comparison between Gd-DTPA and BaSO_4 suspension / 上海第二医科大学学报

Objective To assess and compare the effectiveness of gadolinium diethylenetriamine pentacetic acid(Gd-DTPA) solution and barium sulfate(BaSO4) suspension with different concentrations in improving the imaging quality of magnetic resonance cholangiopancreatography(MRCP). Methods The phantom study was carried out to determine the optimal concentration of Gd-DTPA and BaSO4 suspension used as an oral negative contrast agent in MRCP.The patients were grouped randomly and performed MRCP before and after using oral contrast agents in combination with intravenous injection of contrast agents.A comparison of the influence of BaSO4 suspension and Gd-DTPA with different concentrations on the signal intensity of the fluid in gastrointestinal tract on MRCP images was made.Results The phantom study showed that the dilution ratio 1∶10 of Gd-DTPA solution and 100%(W/V)BaSO4 suspension were the optimal concentrations in decreasing the signal intensity.In all patients the high signal intensity of the gastrointestinal fluid was completely suppressed after oral administration of Gd-DTPA diluted solution(P

The Diagnostic Value of Paramagnetic Contrast Media in MagneticResonance Imaging(MRI)of low Field(A Report of 406 Cases) / 实用放射学杂志

Objective To research paramagnetic contrast media(PCM)dose,injection speed and imaging time etc in low field MRI.Methods 406 patients with lesions spreading all over the body received Gadolinium-DTPA-enhanced scan by bolus injection with the dose of 0.1～0.15 mmol/kg within 60 seconds,and the effects of contrast-enhanced were observed.Results Among 406 patients lesions,337 cases(83%)were enhanced,9 undiscovered lesions displayed enhancement on the precontrast views,5 cases were discovered new lesions in delaying enhancement scan.Conclusion It is safe to apply the above mentioned dose and injection speed in clinic.The side-effects is small,and the development effect is good.It is especially important for lesions involving the structure of the blood brain barrier(BBB).

3 Cases of Adverse Reactions to Gd-DTPA and A Review of the Literatures / 实用放射学杂志

Objective Adverse reactions to Gd-DTPA contrast media should be noticed enough.Methods Three cases of adverse reactions to Gd-DTPA contrast media were studied, and literatures were reviewed.Results The rate of adverse reactions to Gd-DTPA contrast media in our hospital was 0.206%.Conclusion Although the rate of adverse reactions to Gd-DTPA contrast media is very low, this problem must be noticed enough with the medical quality’s developement.