Optimized Schlieren imaging for real-time visualization of high-intensity focused ultrasound waves.

Objectives: This article presents an low-cost experimental setup for visualizing refraction anomalies caused by high-intensity focused ultrasound (HIFU). The technique is based on Schlieren imaging, commonly used to visualize temperature and pressure differences in a medium. With this setup, double images of the Schlieren or their shadows to be investigated occur, so that the experimental setup is modified to avoid these double image artifacts.

Monitoring of tumor burden in vivo by optical imaging in a xenograft SCID mouse model: evaluation of two fluorescent proteins of the GFP-superfamily.

Background: Mouse models of human-malignant-melanoma (MM) are important tools to study tumor dynamics. The enhanced green fluorescent protein (EGFP) is widely used in molecular imaging approaches, together with optical scanners, and fluorescence imaging.

Purpose: Currently, there are no data available as to whether other fluorescent proteins are more suitable.

[Radiological knowledge management with the help of departmental wikis].

In times of RIS (radiology information system) and KIS (hospital information system) systems, patient-related data are at the radiologist's disposal at the push of a button. However, this is not the case for other important data. The increasing complexity of modern medicine demands that up-to-date information like protocols, SOPs (Standards of Practice), news and modifications are constantly accessible to all employees.

[Imaging in intensive care].

The application of imaging methods in patients that are highly dependent on medical support is limited. Ultrasound has a prominent impact due to its flexibility, bedside availability, rapid results, and cost-effectiveness - especially in the assessment of cardiovascular and abdominal diseases. Ultrasound artifacts at the pleura-air interface play an emerging role in the diagnosis of thoracic disease.

Hypersensitivity reactions and contrast medium injection: are they always related?

Background: Hypersensitivity (allergic or non-allergic) reactions that occur after contrast medium (CM) injection are usually related to the CM. Recent studies, and case reports lack the analysis of alternate causes that could be also responsible in individual cases.

Patients And Methods: We investigated the individual relevant factor/causative agent of adult patients with hypersensitivity reactions that occurred in radiological units during CM-enhanced procedures (CT, angiography, urography, or MR-examinations).

[Long-term results after balloon angioplasty of the crural artery].

Purpose: To evaluate the technical success rate, procedure-related complications, and clinical long-term results for patients who underwent infrapopliteal angioplasty.

Materials And Methods: We retrospectively evaluated all patients who underwent infrapopliteal angioplasty to treat critical chronic limb ischemia or severe claudication from 1/1997 to 12/1999. We excluded patients with acute (< 2 weeks) limb ischemia.

[Combination of radiological and nuclear medical imaging in animals: an overview about today's possibilities].

Molecular imaging of small animals has made considerable progress in the last years. Various research fields are interested in imaging small animals due to the lower numbers of animals per experiment. This has advantages with respect to financial, ethical and research aspects.

Efficacy of 99mTc pertechnetate and 131I radioisotope therapy in sodium/iodide symporter (NIS)-expressing neuroendocrine tumors in vivo.

Purpose: There is growing interest in the human sodium/iodide symporter (NIS) gene both as a molecular imaging reporter gene and as a therapeutic gene. Here, we show the feasibility of radioisotope therapy of neuroendocrine tumors. As a separate application of NIS gene transfer, we image NIS-expressing tumors with pinhole SPECT in living subjects.

Manifestations of hereditary hemorrhagic telangiectasia in children and adolescents.

The medical literature provides little information on manifestations of hereditary hemorrhagic telangiectasia (HHT) in children. The presented investigation was initiated to analyze early presenting symptoms in HHT, which should help to make the diagnosis at a young age and thus prevent potential complications from occult visceral arteriovenous malformations (AVM), which have commonly been described in HHT. A series of 15 children and adolescents with a suspicious diagnosis of HHT were examined clinically for typical signs and symptoms of the disorder.

Local administration of NF-kappa B decoy oligonucleotides to prevent restenosis after balloon angioplasty: an experimental study in New Zealand white rabbits.

Purpose: To evaluate the efficacy of NF-kappa B oligonucleotides (ODN) administered by local administration with the channeled balloon catheter to prevent restenosis after balloon angioplasty in restenotic iliac arteries of New Zealand white rabbits.

Materials And Methods: In vitro, 8000 rabbit vascular smooth muscle cells (rVSMC) where transfected with a liposomal carrier (TfX50) with 100 ng of decoy and scrambled ODN. Inhibition of proliferation was measured using a MTT assay after 24 hours in comparison to control.

Aortic stentgraft movement detection using digital roentgen stereophotogrammetric analysis on plane film radiographs -- initial results of a phantom study.

Purpose: To evaluate the feasibility of aortic stentgraft micromovement detection using digital roentgen stereophotogrammetric analysis on plane film radiographs.

Material And Methods: An aortic stentgraft used for demonstration purposes was marked with 10 tantalum markers of 0.8 mm in diameter.

Primary and transplanted ENU induced rat tumors in neurooncology.

In neurooncology transplanting, tumors can be used for many purposes e.g. to solve questions concerning the etiology and pathogenesis of such tumors or their management.

Volumetric analysis of mice lungs in a clinical magnetic resonance imaging scanner.

Small animal models are widely used to study various pathologies. Magnetic resonance imaging (MRI) allows investigation of these animals in a non-invasive way. Therefore, the aim of our study was to develop and evaluate a low-cost approach to measure lung volumes in small animal MRI using a clinical scanner and a specially designed RF coil.

[Embolization of pulmonary arteriovenous malformations with electrolytically detachable coils in patients with hereditary hemorrhagic telangiectasia].

Background: Pulmonary arteriovenous malformations (PAVM) can be found in approximately 20 % to 35 % of patients with hereditary hemorrhagic telangiectasia (HHT). PAVM should be treated since they are a source of paradoxical embolization, potentially resulting in severe neurologic complications. The treatment of choice is the endovascular embolization with coils.

Analysis of mice tumor models using dynamic MRI data and a dedicated software platform*.

Purpose: To implement a software platform (DynaVision) dedicated to analyze data from functional imaging of tumors with different mathematical approaches, and to test the software platform in pancreatic carcinoma xenografts in mice with severe combined immunodeficiency disease (SCID).

Materials And Methods: A software program was developed for extraction and visualization of tissue perfusion parameters from dynamic contrast-enhanced images. This includes regional parameter calculation from enhancement curves, parametric images (e.

Treatment of benign tracheal stenosis utilizing self-expanding nitinol stents.

We assessed the results of self-expanding metallic stent insertion into benign proximal tracheal stenosis in patients not appropriate or unfit for surgical repair. Proximal benign tracheal stenoses had occurred in 11 patients (7 men, 4 women, mean age 68.8 years) after long-time intubation (n = 6), tracheostomy (n = 4), or chondropathia (n = 1).

Effects of different application parameters on penetration characteristics and arterial vessel wall integrity after local nanoparticle delivery using a porous balloon catheter.

Catheter-based local delivery of drug loaded nanoparticles agents offers a potential therapeutic approach to reducing restenosis. However, high delivery pressures and large volumes of infusates may cause severe vascular damage and increase intimal thickening. Therefore, we investigated the penetration pattern and vessel wall integrity of fluorescence-labelled nanoparticles (217 nm in diameter) into the non-atherosclerotic aorta abdominalis of New Zealand white rabbits in dependence of the volume (2.

Encapsulation of gadobutrol in AVE-based liposomal carriers for MR detectability.

Artificial virus-like envelopes (AVEs) are liposomal carriers that may be useful for target-site-specific delivery of contrast agents. We speculated that T(1) relaxation times of a suspension of Gadolinium-filled AVEs might be shortened after internalization and lysosomal breakdown. To test this hypothesis we evaluated the T(1) relaxation times of Gadobutrol-containing AVEs before and after degradation in vitro and after receptor-mediated cellular uptake.

[Interventional therapy of peripheral arterial disease-potentials and limitations].

The technical success rate of endovascular interventions in order to improve perfusion in peripheral arterial disease in the lower extremities has been markedly improved in the last decade due to clinical application of new recanalization techniques like application of hydrophil-coated guide wires, implantation of stents or stent grafts. If the-even long-segment-obstruction can be recanalized, the interventional radiologist is able to open the arterial vessel sufficiently. The excellent immediate results are limited in the long term by recurrent stenoses, which appear in different rates according to the vascular region.

[MR-Imaging of lower leg muscle perfusion].

Purpose: This article describes the potential of dynamic contrast- enhanced magnetic resonance tomography (DCE-MRT) for the visualization and quantification of blood flow of lower leg muscles at rest and after individually adjusted muscular exercise.

Patients And Methods: Five cases were chosen to exemplify the qualitative and semi-quantitative blood flow evaluation in the lower leg muscles. The crural muscle state was determined with an isometric maximal strength measurement from a female patient with peripheral arterial occlusive disease (pAVK), a male patient with coronary heart disease (KHK) without clinical signs of a pAVK, a volunteer with sufficient physical activity in accordance with the Freiburg Questionnaire of Physical Activity and two professional athletes.

Effects of altering infusion parameters on intimal hyperplasia following local catheter-based delivery into the rabbit iliac artery.

Background: Efficient local gene or drug therapy requires optimized application modalities to avoid vessel damage, which might lead to increased neointimal hyperplasia. Aim of the study was to evaluate different application parameters for local delivery using the channeled balloon catheter in order to minimize vessel trauma induced by local application.

Methods And Results: Sixty cholesterol fed rabbits were randomly enrolled into twelve groups of different local application parameters: group I, application pressure 2atm/application volume 1ml physiologic saline; group II, 2atm/2ml; group III, 2atm/5ml; group IV, 4atm/1ml; group V, 4atm/2ml; group VI, 4atm/5ml.

The value of screening for multiple arterio-venous malformations in hereditary hemorrhagic telangiectasia: a diagnostic study.

Occult visceral arterio-venous malformations (AVMs) may be a constant threat to patients suffering from hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome (M. ROW). HHT patients predominantly become symptomatic through chronic, recurrent epistaxis, a symptom that can alert physicians at an early stage of the disease.

[Radiological diagnosis and treatment of acute limb ischemia].

Acute limb ischemia is associated with significant morbidity and mortality, despite diagnostic and therapeutic advances. Threatened limbs require immediate imaging in order to determine the subsequent therapeutic procedures. Conventional angiography in the DSA technique still has advantages over CT and MR angiography.