[CT diagnosis of a diffuse episcleritis].
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Adult↗
Biomedical subjects
T Helmberger
Publications and source records attributed to T Helmberger.
MRI in focal liver disease: a comparison of small and ultra-small superparamagnetic iron oxide as hepatic contrast agents.
The purpose of this study was to compare small and ultrasmall superparamagnetic iron oxide particles (SPIO and USPIO, respectively) as MR contrast agents for the evaluation of focal hepatic disease. In two different patient groups (SPIO [n = 53], USPIO [n = 27]), with focal liver disease (metastases, hepatocellular carcinoma [HCC], hepatocellular adenoma [HCA], and focal nodular hyperplasia [FNH]), spin-echo T1- and T2-weighted images (T1WI, T2WI) were obtained at 1.0T, before and after intravenous contrast administration. The percentage signal-to-noise ratio (SNR) change and lesion-to-liver contrast (LLC) were measured and statistically compared. The liver decreased in signal intensity (SI) after SPIO administration (-28%) and increased after USPIO administration (+16%) on T1WI. On T2WI, the liver decreased in SI on postcontrast images with both agents (-78% SPIO, -73% USPIO). This difference was not statistically significantly different (P < or = .07). Both SPIO and USPIO provided >500% improvement in LLC on T2WI. On T1WI, LLC was increased in metastases (120%) and HCC (325%) with SPIO. Post-USPIO, LLC was increased on T1WI only in metastases (>500%). Both SPIO and USPIO show excellent hepatic uptake, presumed secondary to reticuloendothelial activity, based on the degree of %SI change seen in the liver after administration of contrast on T2WI. However, USPIO preparations exhibit blood pool activity that may aid in further characterization of focal liver lesions, as is evidenced by their greater T1 effect in the liver and in some focal liver lesions.
Adenoma, Liver Cell↗
Rectal perflubron: new application in MRI of perirectal fistulae.
PURPOSE: Our goal was to determine the efficacy of MRI with rectal administration of perflubron in the evaluation of perirectal and pelvic fistulae, with an emphasis on development of an improved method for fistula visualization. METHOD: Fourteen pelvic and/or perirectal fistulae were evaluated in nine patients with MRI after the rectal administration of 200 ml of perflubron. Images were reviewed by two independent readers and evaluated for the presence or absence of fistulae. Qualitative assessment was also performed, rating the examinations for the ability to visualize the fistulae. Comparison was made with the clinical examination and/or operative findings, as well as available preperflubron imaging studies (CT = 10; fluoroscopy = 1; preperflubron MRI = 4). RESULTS: MRI with rectal perflubron demonstrated all 14 fistulae (100%), while preperflubron imaging demonstrated only 7 of 14 (50%) fistulae (p < or = 0.008, Wilcoxon signed rank test). In addition, MRI with perflubron resulted in significantly improved qualitative visualization of fistulae (overall very good rating versus poor rating for preperflubron imaging, p < or = 0.006, Wilcoxon signed rank test). CONCLUSION: MRI with rectal perflubron is a superior modality for imaging of fistulae, compared with conventional methods, since it allows a noninvasive means of demonstrating the presence of a fistula as well as offers improved qualitative assessment of fistulous disease.
Administration, Rectal↗
Improved technique for pancreatic MRI: value of oblique fat suppression imaging with oral barium administration.
PURPOSE: Our goal was to determine the efficacy of a dedicated protocol for pancreatic MRI using fat suppression, oblique plane orientation, and barium as an oral contrast agent. METHOD: Fifty-two patients were enrolled in our study. In each patient, the stomach and duodenum were opacified with 300 ml oral barium. In all patients conventional SE T1- and T2-weighted images and fat-suppressed axial and oblique T1-weighted images of the upper abdomen and the pancreas, respectively, were obtained. The different T1-weighted sequences were compared for visualization of the pancreas and for lesion conspicuity. Oblique images were obtained in a plane parallel to the overall axis of the pancreas. All sequences were qualitatively assessed by two independent blinded readers and statistically compared. RESULTS: The combination of fat suppression and oblique imaging significantly improved the visualization of the different anatomic portions of the normal pancreas as well as pathologic findings in the pancreas in 70-92% of the cases compared with conventional axial T1-weighted imaging (p < 0.001) and in 52-75% of the cases compared with axial fat-suppressed T1-weighted imaging (p < 0.001), respectively. Increased image noise and blurring artifacts resulted in slight image degradation after Gd-DTPA administration. Barium as a duodenal contrast agent was beneficial for delineation of the pancreatic head from the adjacent bowel structures. CONCLUSION: In pancreatic imaging, fat-suppressed T1-weighted imaging is superior to conventional T1-weighted imaging, and oblique imaging is superior to axial imaging. Intravenous Gd-DTPA administration was useful only in selected cases.
Adipose Tissue↗