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Biomedical subjects

B Fritz-Zieroth

Publications and source records attributed to B Fritz-Zieroth.

23 records · Page 2Linked to original sources

[MR imaging of cerebral lesions accompanying stroke in stroke-prone spontaneously hypertensive rats].

Cerebral lesions accompanying stroke in male stroke-prone spontaneously hypertensive rats (SHRSP, n = 10) were examined by both magnetic resonance imaging (MRI) and histological evaluation. T2-weighted MR images (T2-WI), taken 1-2 days after animals showed behavioral hyperactivity, indicated hyperintense regions in the occipital cortex, caudate putamen and/or thalamus. The areas of hyperintensity on T2-WI corresponded to neurodegenerative regions including edema, gliosis, and softening of the tissue. T1-weighted images (T1-WI) did not show any hyperintense regions. However T1-weighted images enhanced by the contrast media Gd-DTPA (Gd-T 1-WI) showed hyperintense spots within some of the hyperintense areas on T2-WI, which exhibited neurodegenerative regions such as thrombus, angionecrosis and hemorrhage in addition to the edematous formation. The hyperintense areas on Gd-T1-WI were smaller than those on T2-WI. In some animals, hypointense spots on T2-, T1- and Gd-T1-WI were found within the hyperintense areas, which corresponded to clots. Extensive histological examination did not reveal any additional cerebral degeneration which had not been detected on the MR images. These findings indicate that MRI is useful for detecting and differentiating various types of cerebrovascular disease in this model.

Aging↗

Cerebral oxygen utilization analyzed by the use of oxygen-17 and its nuclear magnetic resonance.

In order to assess the usefulness of oxygen-17, a stable isotope of oxygen, oxygen-17, was administered to rats for studying cerebral oxygen utilization, and the produced metabolic water was detected by 17O-NMR spectroscopy in vitro and an 1H-NMR imaging system in vivo. In the vitro study, the increment in signal amplitude of oxygen-17 was observed in the brain extracted from rats that inhaled oxygen-17 gas. The in vivo study demonstrated that there were changes in the 1H-NMR image intensity of brain of rats that inhaled oxygen-17 gas. These facts indicate that oxygen-17 can serve as a tracer in the study of cerebral oxygen utilization.

Animals↗

Contrast enhancement with Gd-EOB-DTPA in MR imaging of hepatocellular carcinoma in mice: a comparison with superparamagnetic iron oxide.

The purpose of this study was to evaluate the ability of the new liver-specific magnetic resonance contrast agent gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA) to detect hepatocellular carcinoma (HCC). Seventeen mice with 66 chemically induced HCCs underwent magnetic resonance imaging with both Gd-EOB-DTPA (30 mumol/kg) and superparamagnetic iron oxide (SPIO; 10 mumol/kg). After enhancement, lesion-to-liver contrast-to-noise ratios (CNRs) of 47 detected HCCs increased negatively from 3.7 +/- 10.7 (mean +/- SD) to -55.1 +/- 25.8 with Gd-EOB-DTPA (P < .001) and increased positively from 10.4 +/- 10.4 to 26.1 +/- 16.3 with SPIO (P < .001). The improvement of CNR after administration of SPIO was less in smaller lesions (< 4 mm), whereas that after administration of Gd-EOB-DTPA was independent of lesion size. However, Gd-EOB-DTPA positively enhanced four HCCs (8.5%), both highly differentiated (grade 1) and moderately differentiated (grade 2). Gd-EOB-DTPA allows the conspicuous detection of small HCCs; however, moderately differentiated HCCs occasionally may be positively enhanced.

Animals↗

Paradoxic uptake of Gd-EOB-DTPA by hepatocellular carcinoma in mice: quantitative image analysis.

To determine whether paradoxic uptake of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) occurs only with highly differentiated hepatocellular carcinomas, quantitative image analysis was performed in 37 mice with 133 hepatocellular carcinomas. The results of lesion/ liver signal intensity measurement and relative enhancement calculation indicate that paradoxic positive enhancement occurs independently of cellular differentiation.

Animals↗