Eckart Grönewäller

In Vitro Evaluation of Teratogenic Effects by Time‐Varying MR Gradient Fields on Fetal Human Fibroblasts

The purpose of this study was to evaluate the influence on fetal cell growth in vitro of rapidly changing magnetic gradient fields such as those produced by the gradient coils of a typical magnetic resonance (MR) imager. The static magnetic field and the radiofrequency pulses were disabled during all measurements. Human fetal fibroblasts were placed within a specially designed MR‐compatible incubation system inside the magnet. Trapezoid‐shaped waveforms of 500 and 75 Hz base frequency and an amplitude of 2 mT were applied for 2–24 hours. Proliferation of the cells was monitored for 3 weeks after exposure. Cell cycle analysis was performed until 24 hours after exposure to detect alterations in cell division. Tests were performed under two different conditions of growth to detect increased as well as decreased proliferation effects. None of these tests showed differences in proliferation and cell cycle distribution between exposed and nonexposed cells. J. Magn. Reson. Imaging 2000;12:150–156.

The value of hyoscine butylbromide in abdominal MR imaging with and without oral magnetic particles

Abstract.Purpose: The purpose of this article was to assess the impact of intravenous (IV) anticholinergic hyoscine butylbromide in abdominal magnetic resonance (MR) imaging with oral magnetic particles (OMP) [ABDOSCAN, Ferristene (USAN), Nycomed Imaging AS, Oslo, Norway]. Materials and methods: In 31 patients with abdominal tumors, T1-weighted spin-echo (SE) images (SE 600/15; 1.5 T) were obtained without and with IV hyoscine butylbromide (20 mg) before and after administration of 800 ml of OMP. Two blinded readers assessed motion artifacts, bowel-wall visualization, and lesion delineation on the four sets of T1-weighted images. The two-tailed Wilcoxon paired sample test was used for statistical analysis (p < .05). Results: Hyoscine butylbromide reduced motion artifacts and improved bowel-wall visualization on precontrast and OMP-enhanced images at a statistically significant level (p= 0.0006–0.037). The lowest degree of artifacts was recorded on OMP images with hyoscine butylbromide. OMP with hyoscine butylbromide significantly improved lesion delineation compared to studies without antiperistaltic drug before (p= 0.019) and after OMP administration (p= 0.01). Conclusions: The authors conclude that the use of IV hyoscine butylbromide is recommended for OMP-enhanced abdominal MR imaging with T1-weighted SE pulse sequences at 1.5 T.

Pneumatosis cystoides intestinalis with pneumoperitoneum and pneumoretroperitoneum following chemotherapy

Abstract. Pneumatosis cystoides intestinalis (PCI) is a relatively rare, mostly benign, condition. We report a case of chemotherapy-induced PCI with free retro- and intraperitoneal gas in a 17-year-old man with acute lymphoblastic leukemia. Chest radiography and upright abdominal radiography showed free intra- and retroperitoneal gas; computed tomography demonstrated subserosal gas collections. Conservative treatment with oxygen, metronidazol, and parenteral alimentation was performed, and PCI resolved within 2 weeks.

MRI‐compatible incubation chamber for cell culture experiments

To develop an incubation chamber that is compatible with MRI, while avoiding sources of error due to the experimental setup.

Progressive multifokale Leukenzephalopathie: Diagnose und Differentialdiagnose

ZusammenfassungHintergrund: Die progressive multifokale Leukenzephalopathie ist eine opportunistische Virusinfektion des Gehirns, die bei Patienten mit Immunschwäche auftritt. Die Prognose der Erkrankung ist schlecht. Das charakteristische Zeichen in der MRT sind Läsionen in den subkortikalen U-Fasern des Gehirns ohne Schrankenstörung. Eigener Patient: Wir berichten den seltenen Fall einer progressiven multifokalen Leukenzephalopathie als initialen Befund bei einem Patienten mit einer später erkannten chronisch lymphatischen Leukämie und diskutieren die Differentialdiagnosen.AbstractBackground: Progressive multifocal leukencephalopathy is an infectious demyelinating disorder of the central nervous system, occurring due to internal reactivation of JC-virus. Patients always have an immunological deficit, mostly due to AIDS, immunosuppressive treatment or an immunoproliferative disorder. Progressive multifocal leukencephalopathy has a desperate prognosis. Imaging signs are subcortical lesions involving the U-fibers without demonstration of contrast enhancement. Own Patient: We report imaging and clinical signs in a rare patient, who presented with progressive multifocal leukencephalopathy as the initial sign of a immunological disease and discuss differential diagnoses.

Unilaterale Thrombose der inneren Hirnvenen: seltenes Initialsymptom einer lebensbedrohlichen Erkrankung

ZusammenfassungHintergrund: Die innere Hirnvenenthrombose ist eine Variante der zerebralen venösen Thrombose mit besonders ernster Prognose. Bildgebende Diagnostik: Das charakteristische Zeichen in der bildgebenden Diagnostik sind die bilateralen thalamischen Stauungsödeme, da beide Thalami in die unpaare Vena magna Galeni und den Sinus rectus drainieren. In seltenen Fällen kann jedoch eine innere Hirnvenenthrombose als unilaterales thalamisches Stauungsödem auffallen. Diese Einseitigkeit geht möglicherweise auf unterschiedliche venöse Kollateralen zurück. Die meisten bisher beschriebenen Fälle eines einseitigen Ödems wurden auf der linken Seite festgestellt, obwohl die Drainage der Thalami seitengleich ist. Eine mögliche Ursache liegt in der unterschiedlichen klinischen Initialsymptomatik, die nur bei linksseitigen Läsionen eine bildgebende Diagnostik initiiert. Eigene Patienten: Wir berichten über drei Fälle mit unilateralen thalamischen Stauungsödemen, zweimal links, einmal rechts, von denen nur die linksseitigen eindeutige klinische Symptome verursachten. Die Läsion auf der rechten Seite wurde zufällig entdeckt.AbstractBackground: Thrombosis of the internal cerebral veins is a dangerous form of cerebral venous thrombosis (CVT). Diagnosis: Bilateral thalamic involvement is frequently encountered in internal cerebral venous thrombosis, because both thalami drain into the vein of Galen and straight sinus. However, unilateral thalamic edema has also been observed in cases of occlusion of the vein of Galen, possibly due to collateral venous drainage. Patients with unilateral congestion of the thalamus in cerebral venous thrombosis had mostly left-sided involvement, indicating that right-sided unilateral thalamic involvement in cerebral venous thrombosis may be clinically silent. Own Patients: We report on three patients with unilateral internal venous thrombosis, two on the left, one on the right. The right-sided thrombosis was clinically silent and a purely incidental finding.