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B Ertl-Wagner

Publications and source records attributed to B Ertl-Wagner.

16 recordsLinked to original sources
PubMed2005

[MR imaging in congenital disorders of the brain].

MR imaging is an excellent tool for use in diagnosing congenital malformations of the brain. Such malformations cannot be reliably recognized or classified without an insight in to the basic processes of the fetal development of the brain. Cortical malformations are classically divided into (1) malformations of neuronal proliferation, i.e. of stem cell proliferation in the periventricular germinal matrix zone, (2) disorders of neuronal migration, i.e. of the radial migration of the neurons from the periventricular germinal matrix zone to the cortical surface, and (3) disorders of cortical organisation. Other cerebral malformations are agenesis or dysgenesis of the corpus callosum, encephaloceles and various kinds of holoprosencephaly. Chiari malformations and disorders on the Dandy-Walker spectrum are relatively common, primarily infratentorial disorders. Rarer infratentorial disorders are Joubert syndrome, rhombencephalosynapsis and Lhermitte Duclos syndrome.

Adolescent↗
PubMed2005

The Application of Photofrin II as a sensitizing agent for ionizing radiation--a new approach in tumor therapy?

Radiosensitizers represent an enticing concept in tumor therapy. As ionizing radiation affects both neoplastic and normal tissues, its effects are generally non-specific. The aim of applying a radiosensitizing agent is to achieve a maximum effect on tumor tissue, while minimizing the damage to normal tissues. A variety of parameters such as the oxygen supply and the state in the cell cycle, need to be taken into account when evaluating a potential radiosensitizer. Most of the previously known radiosensitizers are neither selective nor tumor specific. In this article, we review the properties and radiosensitizing potential of Photofrin II. Photofrin II is well-known as a photosensitizing agent in photodynamic therapy. In recent years, a radiosensitizing potential of the substance has been demonstrated, specifically increasing the sensitivity of solid tumor tissues, especially of radio-resistant, hypoxic tumor cells, to radiation. This radiosensitizing effect has been demonstrated both by in vitro studies and by animal experiments. Several studies with tissue cultures have demonstrated a radiosensitizing effect of Photofrin II in glioblastoma (U-373MG) and bladder cancer cell lines (RT-4). No effect was noted in colon carcinoma cell lines (HT-29). Unpublished data of additional cell lines will be mentioned in the review. Animal experiments with Lewis sarcoma and with bladder cancer have moreover demonstrated an in vivo effect of Photofrin II as a radiosensitizer. The mechanism of this radiosensitizing effect is not completely understood. In vitro data, however, support the hypothesis that the radiosensitizing action involves OH-radicals in addition to a potential impairment of repair mechanisms after sublethal damage of ionizing radiation. Moreover, early results of a phase I trial are available and document the potential feasibility of the application of Phototofrin II as a radiosensitizing agent in clinical practice.

Animals↗
PubMed2004

[Diagnostic evaluation of carotid artery stenoses with multislice CT angiography. Review of the literature and results of a pilot study].

BACKGROUND: The accurate evaluation of carotid artery stenoses is important for therapeutic decision making. Catheter digital subtraction angiography (DSA) still represents the gold standard, while the advent of multislice CT (MSCT) has led to improved temporal and spatial resolutions of CTA. MATERIAL AND METHODS: In a pilot study, we investigated 14 diseased vessels in 9 symptomatic patients (7m, 2f; mean age 60.7+/-10,9 years) comparing biplanar DSA with standardized 16-slice MS-CTA. The degree of stenosis was evaluated in a consensus reading following modified NASCET criteria. RESULTS: DSA demonstrated 4 occlusions, 5 high-grade stenoses (>70%) and 5 lower-grade stenoses (<70%). One dissecting, infrapetrous stenosis was not adequately quantified by CTA due to a close topographic relation to the skull base. In the carotid bifurcation (n=13), an excellent correlation was demonstrated between DSA and CTA with a correlation coefficient of 0.99. CONCLUSION: MS-CTA has a good diagnostic potential in the evaluation of carotid artery stenoses. Larger studies will need to demonstrate the relative diagnostic value for different subtypes of stenosis and for different reader experience levels.

Aged↗
PubMed2003

[Congenital malformations of the cerebral brain. 1: Malformations of the cerebral cortex].

Disorders of supratentorial cortical development are usually divided into disorders of neuronal proliferation, neuronal migration and cortical organization. Based upon molecular biologic discoveries, a modified classification has recently been proposed. The category of malformations of abnormal neuronal and glial proliferation and apoptosis now includes microlissencephalies, megalencephalies, hemimegalencephalies and cortical dysplasias with balloon cells. Malformations due to abnormal neuronal migration now subsume the lissencephaly spectrum including the subcortical band heterotopias, the cobblestone complex and the group of heterotopias. Malformations due to abnormal cortical organization include the spectrum of polymicrogyria and schizencephaly as well as cortical dysplasias without balloon cells. High-resolution magnetic resonance imaging (MRI) has led to an increasing awareness of these malformations. This article aims to illustrate the classification, MRI presentation and relevant clinical features of the most commonly encountered disorders of cortical development.

Brain↗
PubMed2003

[Congenital malformations of the brain. 2: Malformations of the corpus callosum and holoprocencephalies].

The corpus callosum is formed between the 7th and the 20th gestational week. If this process is disrupted, partial or complete callosal agenesis may ensue. As large parts of the supra- and infratentorial brain are created during this critical period, associated anomalies need always to be searched for when callosal agenesis is present. Associations with neuro-genetic syndromes also exist. The corpus callosum is generally formed from front to back ("front-to-back rule"). Therefore, a partial callosal agenesis usually involves the posterior portion of the corpus callosum, while a secondary lesion of the corpus callosum does not follow this rule. Holoprosencephalies are a notable exception to this rule, as the frontal part of the corpus callosum is absent in spite of their classification as congenital malformations. They represent a disturbance of the differentiation and cleavage of the prosencephalon with a disruption of the separation of the cerebral hemispheres. Holoprosencephalies can be due to genetic causes, but also to intrauterine infections or other teratogenic causes. The holoprosencephalies are subdivided into alobar, semilobar and lobar holoprosencephalies. This article aims to describe the most important features of callosal agenesis and holoprosencephalies highlighting the respective imaging characteristics.

Abnormalities, Multiple↗
PubMed2003

Feasibility and morbidity of combined hyperthermia and radiochemotherapy in recurrent rectal cancer--preliminary results.

BACKGROUND: The local recurrence rate of colorectal cancer has been significantly reduced due to the use of combined radiochemotherapy. Despite this improvement regarding locally advanced tumour recurrences, the treatment strategy for pre-treated patients remains difficult and unresolved. PATIENTS AND METHODS: We analysed treatment and follow-up data of 14 patients with local recurrence of rectal cancer who were treated with radiation therapy (RT), chemotherapy (CT) and regional hyperthermia (RHT) from November 1997 to December 2001. Nine of these patients had received irradiation and CT (= pre-treated patients) in the past. For this group, 30.6-39.6 Gy RT, 5-fluorouracil (5-FU) as a continuous infusion over 5 days per week (350 mg/m(2)/24 h) combined with RHT twice a week was given. The 5 remaining patients (= not pre-treated) received conformal irradiation of 45 Gy with a boost between 9 and 14.4 Gy, combined with continuous infusion of 5-FU on days 1-4, and 29-33 (500 mg/m(2)/ 24 h), and RHT twice a week. Response to therapy was evaluated by means of computed tomography (CT) or magnetic resonance imaging (MRI) and by clinical follow-up. RESULTS: Among 13 evaluated cases, the overall objective response rate was 54% (5 complete responses, 2 partial responses). At mean follow-up of 13.9 months (range 5-32 months) 7 patients were alive. CONCLUSION: The therapeutic regimen appears to be active in the treatment of local recurrences of rectal cancer. Larger-scaled studies are needed to evaluate the potency of hyperthermia in this therapeutic strategy.

Antimetabolites, Antineoplastic↗
PubMed2003

Porphyrins as radiosensitizing agents for solid neoplasms.

The biological effects of radiation affect both neoplastic and normal tissues. The nature and extent of such effects, however, depend on selected biological parameters (e.g., oxygen supply, cell cycle) and can be modified by chemical agents such as radiosensitizers, radioprotectors and chemotherapeutic agents. A precise control of the mode of action of the radiation is important in order to achieve the maximum effect on tumor tissue, while minimizing the effect on normal tissues. Most of the known and routinely used radiosensitizers are neither selective nor tumor specific. This article reviews a new selective and specific modality that increases the sensitivity of solid tumor tissue, especially of radio resistant, hypoxic tumor cells, to radiation. This modality is currently under early clinical evaluation and encompasses the application of Photofrin II, which is already used as a photosensitizer in photodynamic therapy (PDT) at predetermined times prior to irradiation.

Humans↗
PubMed2002

[Diagnostic evaluation of the craniocervical vascular system with a 16-slice multi-detector row spiral CT. Protocols and first experiences].

PURPOSE: The newly developed 16-slice multi detector row computed tomography (MDCT) allows for isotropic imaging at rotation times under 500 ms. We aim to describe our first experiences with this novel technology in the diagnostic imaging of the craniocervical vascular system. METHODS: The craniocervical vascular system of 8 consecutive patients was examined with a standardized protocol with the new 16-slice MDCT. The volume covered included the carotid arteries from their origin at the aortic arch and the intracranial arterial and venous vessels in their entirety. Homogeneity of contrast, contrast-to-parenchyma ratios, image quality and radiation doses were assessed. RESULTS: A homogeneous vessel-to-parenchyma ratio was reached in the carotids as well as in the intracranial arterial and venous vessels. Image quality was rated as excellent in all patients. The estimated mean effective radiation dose amounted to 2.31 mSv +/-0.57, the mean dose length product to 608 mGy*cm +/-151. CONCLUSION: The newly developed 16-slice MDCT technology appears to be a promising tool in the diagnostic assessment of the cervicocranial vessels.

Aged↗
PubMed2002

[CT-angiographic evaluation of intracranial aneurysms - a review of the literature and first experiences with 4- and 16-slice multi detector CT scanners].

Intracranial aneurysms are a common pathology faced by the diagnostic radiologist in daily practice. They can present as symptomatic aneurysms with a subarachnoid hemorrhage or as an incidental finding in another radiological study. Moreover, clipped or coiled aneurysms sometimes require a postinterventional work-up to exclude residual perfusion. Previous studies assessing the value of CT angiography in the diagnosis of intracranial aneurysms have been conducted using single slice spiral CT-scanners. They have shown a limited sensitivity in the diagnosis of small aneuryms with a diameter of equal to or smaller than 3 mm.Presently, there is only limited experience regarding the use of multi-detector row CT (MDCT) in the diagnosis of intracranial aneurysms. We have examined eight patients with a total of eleven aneurysms with MDCT technology, five patients with a 4-slice MDCT and three with a 16-slice MDCT. Of these, five were untreated aneurysms and six posttherapeutic with a status post surgical clipping. The mean diameter of the aneurysms was 5 mm (range 2 to 13 mm, median 3 mm). Of the treated aneuryms, two showed residual perfusion of the aneurysmal neck with a diameter of 2 and 6 mm respectively. In all cases, MDCT-angiography was in full agreement with the DSA diagnosis. Studies on larger patient populations will need to demonstrate the value of CTA in the diagnosis of intracranial aneurysms compared to the reference standard DSA.

Adult↗
PubMed2002

Application of Photofrin II as a specific radiosensitising agent in patients with bladder cancer--a report of two cases.

BACKGROUND: The effect of ionizing radiation on tumour tissues can be optimised by adding radiosensitising agents to enhance tumour inactivation. Photofrin II has been approved as a photosensitising agent for the photodynamic therapy (PDT) of selected solid tumours. At present, no chemical modifier has been found to act as a selective radiosensitiser. We report here the first use of Photofrin II as a radiosensitising agent to enhance radiation therapy. PATIENTS: Two patients, one female with unresectable bladder cancer and one male with recurrent inoperable bladder cancer, were treated with radiation therapy (44.8 Gy + 14 Gy boost) of the pelvic region. 24 hours before initiation of therapy the patients were intravenously injected with 1 mg kg(-1) Photofrin II (Axcan, Canada). RESULTS: Magnetic resonance imaging of the pelvis with a standardized protocol demonstrated a reduction in tumour volume of approximately 40% in the female patient and 35% in the male patient. The female patient was operated upon after conclusion of radiotherapy, the male patient refused the operation. No severe side effects were observed. CONCLUSION: Photofrin II is a promising radiosensitising agent in the treatment of patients with advanced solid tumours.

Aged↗
PubMed2001

[Evaluation of an electromagnetic virtual target system (CT-guide) for CT-guided interventions].

PURPOSE: Evaluation of the accuracy of a new electromagnetic target system for interventional CT-guided procedures with virtual navigation in a previously acquired helical CT. MATERIAL AND METHODS: The new target system CT-Guide 1010 (Ultraguide, Tirat Hacarmel, Israel) for CT-guided interventions was adapted to the video signal of the Somatom Plus 4 and Volume Zoom (Siemens, Erlangen, Germany). A helical CT-dataset including skin-based sensor cubes was transferred to the integrated navigation system inside the scanner room. 50 image-guided interventions and biopsies were performed outside the gantry using virtual navigation to reach the lesion. The accuracy of the procedures was evaluated using documentation of the needle tip with CT-fluoroscopy, results of histology, and follow-up. RESULTS: The deviation between planned and documented needle tip was 2.2 +/- 2.1 mm in 50 procedures. Time between the end of planning-CT and needle positioning using the system was 13 minutes. There were no complications due to the use of the system. CONCLUSION: The CT-Guide allows for virtual real-time navigation with high accuracy. Advantages are the free needle angulation without gantry tilt, use of optimal CT perfusion phase for virtual navigation, and reduction of radiation exposure to the patient and interventionalist.

Adult↗
PubMed2001

Diagnostic value of increased diffusion weighting of a steady-state free precession sequence for differentiating acute benign osteoporotic fractures from pathologic vertebral compression fractures.

BACKGROUND AND PURPOSE: Differentiating acute benign from neoplastic vertebral compression fractures can pose a problem in differential diagnosis on routine MR sequences, as signal changes can be quite similar. Our purpose was to assess the value of increasing the diffusion weighting of a diffusion-weighted steady-state free precession (SSFP) sequence for differentiating these two types of vertebral compression fractures. METHODS: Twenty-nine patients with 32 acute vertebral compression fractures caused by osteoporosis (n = 15) or malignancy (n = 17) were examined with a diffusion-weighted SSFP sequence, a T1-weighted spin-echo sequence, and a short-inversion-time inversion recovery sequence. The SSFP sequence was performed with increased diffusion weighting (delta = 0.6, 3.0, 6.0, and 9.0 ms). The signal intensities of the fractured vertebral bodies were rated on a five-point scale from markedly hypointense to markedly hyperintense relative to normal adjacent vertebral bodies. Quantitative analysis was performed by region-of-interest measurements and by calculating the bone marrow contrast ratio. Statistical analysis was performed with the Mann Whitney U test and Student's t test. RESULTS: At delta = 3 ms, the osteoporotic fractures yielded hypointense signal in seven cases, isointense signal in six, and hyperintense signal in two. The fractures showed a progressive signal loss with increased diffusion weighting, so that hypointensity was reached in all but one case. All metastatic fractures had hyperintense signal with delta = 3 and 6.0 ms. With delta = 9.0 ms, four fractures became isointense. CONCLUSION: Increasing diffusion weighting can reduce false-positive hyperintense osteoporotic fractures or make hypointensity more obvious in cases of osteoporotic fractures.

Acute Disease↗
PubMed1999

[Comparison of computer tomography and magnetic resonance tomography in the diagnosis of acute intracerebral hemorrhage].

BACKGROUND AND PURPOSE: Stroke symptoms are caused in 10 to 15% by intracerebral hemorrhage. From the clinical examination it is often impossible to differentiate intracerebral hemorrhage from cerebral ischemia. To exclude intracerebral hemorrhage as the cause of clinical symptoms a CT is usually performed. The aim of our study was a direct comparison of the sensitivity of Computed Tomography and MRI using different MR sequences for the detection of acute intracerebral hemorrhage. METHODS: In 8 male Wistar rats intracerebral hemorrhage was induced by infusion of collagenase into the caudate nucleus. After 1hour the brains were subsequently imaged with CT and MRI using T2- and T1-weighted Spin Echo sequences, diffusion-weighted sequences, T2*-weighted gradient echo sequences and FLAIR-sequences. Visibility of the intracerebral hemorrhage was examined using a scoring system from 1 = not visible to 5 = excellent visible. Finally, the intracerebral hemorrhage was verified by histological staining. RESULTS: In all animals, intracerebral hemorrhage was visible in T2*-weighted gradient echo and diffusion weighted MR images 1 h after infusion of collagenase. T2- and PD-weighted SE images were positive in 7/8 rats. T1-weighted images revealed signal changes in 5/8 rats, and FLAIR sequence was positive in 8/8 rats. In CT intracerebral hemorrhage was only visible in 3/8 rats. When measuring the increase of Hounsfield units within the suspected hemisphere we saw a mean increase of 7% compared to the normal hemisphere in 3/8 rats. CONCLUSIONS: In this animal model, T2*-weighted magnetic resonance imaging proved to be the most sensitive imaging modality in the detection of acute intracerebral hemorrhage and is by far more sensitive than CT.

Animals↗
PubMed1999

Relative value of MR imaging as compared with CT in the diagnosis of inflammatory paranasal sinus disease.

PURPOSE: To evaluate the relative value of magnetic resonance (MR) imaging versus computed tomography (CT) in the diagnosis of inflammatory paranasal sinus disease. MATERIALS AND METHODS: In 30 patients suspected of having or known to have inflammation of the paranasal sinuses, both coronal CT and coronal T1-weighted, three-dimensional, gradient-echo MR imaging of the paranasal sinuses were performed. Visualization of anatomic details, kind and extent of inflammatory disease, and artifacts from dental work were scored. The scores were compared by using the Wilcoxon matched pairs signed rank test. Interexamination agreement between the two methods was calculated by using a kappa analysis. RESULTS: Most bone structures of the infundibular complex were significantly better visualized at CT than at MR imaging. Orbital and brain anatomy were visualized better at MR imaging than at CT. No artifacts from dental work occurred in diagnostically relevant regions at MR imaging. There was a substantial to almost perfect agreement between CT and MR imaging for every kind and extent of the disease except for mucosal thickening in the maxillary and frontal sinuses, in the nasal cavity, and in the infundibulum. CONCLUSION: CT is superior to MR imaging in the depiction of fine bony details and anatomic variants and thus is superior to MR imaging in helping plan functional endoscopic sinus surgery. However, there are patient groups in which MR imaging can be used as a primary tool in screening for sinusitis.

Adult↗
PubMed1999

Diagnostic and therapeutic consequences of repeat brain imaging and follow-up vascular imaging in stroke patients.

BACKGROUND AND PURPOSE: Recently, the diagnostic and therapeutic importance of repeat radiologic imaging in stroke patients has been questioned. The aim of this study was to show the therapeutic and diagnostic consequences of both repeat brain imaging and follow-up vascular imaging in this group of patients. METHODS: Neuroradiologic images and reports as well as clinical records of 317 patients (209 men and 108 women; mean age, 63 years) were reviewed retrospectively to determine the number of modifications made to the diagnosis and therapeutic regimen and to the classification of neuroradiologic findings. RESULTS: Two hundred thirty-eight repeat imaging procedures were performed in 171 patients. Of these, 76 were vascular imaging examinations (11 CT angiograms, 13 MR angiograms, 52 digital subtraction angiograms) and 162 were cross-sectional brain imaging studies (54 MR images, 108 CT scans). Forty of the 76 vascular imaging procedures and 77 of the 162 repeat cross-sectional brain imaging studies led to important diagnostic modifications with consequences for the patients' therapy and prognosis. CONCLUSION: Our study establishes that vascular imaging methods as well as cross-sectional brain imaging used as repeat imaging procedures in stroke patients can have important diagnostic and therapeutic consequences. We believe that repeat imaging in selected subgroups will be cost-effective.

Angiography, Digital Subtraction↗