Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
1.
J Vasc Surg ; 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38710420

RESUMO

OBJECTIVE: Our group has previously demonstrated that patients with asymptomatic carotid artery stenosis (ACAS) demonstrate cognitive impairment. One proposed mechanism for cognitive impairment in patients with ACAS is cerebral hypoperfusion due to flow-restriction. We tested whether the combination of a high-grade carotid stenosis and inadequate cross-collateralization in the Circle of Willis (CoW) resulted in worsened cognitive impairment. METHODS: Twenty-four patients with high-grade (≥70% diameter-reducing) ACAS underwent carotid duplex ultrasound, cognitive assessment, and 3D time-of-flight magnetic resonance angiography (MRA). The cognitive battery consisted of nine neuropsychological tests assessing four cognitive domains: learning and recall, attention and working memory, motor and processing speed, and executive function. Raw cognitive scores were converted into standardized T-scores. A structured interpretation of the MRA images was performed with each segment of the CoW categorized as being either normal or abnormal. Abnormal segments of the CoW were defined as segments characterized as narrowed or occluded due to congenital aplasia or hypoplasia, or acquired atherosclerotic stenosis or occlusion. Linear regression was used to estimate the association between the number of abnormal segments in the CoW, and individual cognitive domain scores. Significance was set to p<0.05. RESULTS: The mean age of the patients was 66.1 + 9.6 (mean + SD) years and 79.2% (n=19) were male. A significant negative association was found between the number of abnormal segments in the CoW and cognitive scores in the learning and recall (ß = -6.5, p = 0.01), and attention and working memory (ß = -7.0, p = 0.02) domains. There was a trend suggesting a negative association in the motor and processing speed (ß = -2.4, p = 0.35) and executive function (ß = -4.5, p = 0.06) domains that did not reach significance. CONCLUSION: In patients with high-grade ACAS, the concomitant presence of increasing occlusive disease in the CoW correlates with worse cognitive function. This association was significant in the learning and recall and attention and working memory domains. While motor and processing speed and executive function also declined numerically with increasing abnormal segments in the CoW, the relationship was not significant. Since flow restriction at a carotid stenosis compounded by inadequate collateral compensation across a diseased CoW worsens cerebral perfusion, our findings support the hypothesis that cerebral hypoperfusion underlies the observed cognitive impairment in patients with ACAS.

2.
Neuroscience ; 311: 243-52, 2015 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-26520849

RESUMO

The distribution of spinal primary afferent terminals labeled transganglionically with the choleratoxin B subunit (CTB) or its conjugates changes profoundly after perineural treatment with capsaicin. Injection of CTB conjugated with horseradish peroxidase (HRP) into an intact nerve labels somatotopically related areas in the ipsilateral dorsal horn with the exceptions of the marginal zone and the substantia gelatinosa, whereas injection of this tracer into a capsaicin-pretreated nerve also results in massive labeling of these most superficial layers of the dorsal horn. The present study was initiated to clarify the role of C-fiber primary afferent neurons in this phenomenon. In L5 dorsal root ganglia, analysis of the size frequency distribution of neurons labeled after injection of CTB-HRP into the ipsilateral sciatic nerve treated previously with capsaicin or resiniferatoxin revealed a significant increase in the proportion of small neurons. In the spinal dorsal horn, capsaicin or resiniferatoxin pretreatment resulted in intense CTB-HRP labeling of the marginal zone and the substantia gelatinosa. Electron microscopic histochemistry disclosed a dramatic, ∼10-fold increase in the proportion of CTB-HRP-labeled unmyelinated dorsal root axons following perineural capsaicin or resiniferatoxin. The present results indicate that CTB-HRP labeling of C-fiber dorsal root ganglion neurons and their central terminals after perineural treatment with vanilloid compounds may be explained by their phenotypic switch rather than a sprouting response of thick myelinated spinal afferents which, in an intact nerve, can be labeled selectively with CTB-HRP. The findings also suggest a role for GM1 ganglioside in the modulation of nociceptor function and pain.


Assuntos
Transporte Axonal , Capsaicina/farmacologia , Toxina da Cólera/metabolismo , Peroxidase do Rábano Silvestre/metabolismo , Fibras Nervosas Amielínicas/metabolismo , Nociceptores/metabolismo , Vias Aferentes/metabolismo , Vias Aferentes/ultraestrutura , Animais , Axônios/metabolismo , Axônios/ultraestrutura , Gânglios Espinais/metabolismo , Gânglios Espinais/ultraestrutura , Vértebras Lombares , Masculino , Microscopia Eletrônica , Fibras Nervosas Amielínicas/ultraestrutura , Nociceptores/ultraestrutura , Ratos Wistar , Nervo Isquiático/metabolismo , Medula Espinal/metabolismo , Medula Espinal/ultraestrutura
3.
Radiologe ; 55(6): 487-96, 2015 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-26066755

RESUMO

Tumor pain occurs in 70-80% of all cancer patients who have reached an advanced tumor stage. In the case of failure or poor response to chemotherapy and in cases of recurrence following radiotherapy, tumors will often become enlarged with infiltration of organs, nerve roots or bone which causes severe pain to the patient. Interventional radiological minimally invasive local tumor therapy is often the last resort for tumor patients suffering from severe pain. Interventional radiologists have several options to treat tumor pain but firstly the cause of the pain must be identified. This article presents a classification of patients suffering from tumor pain which can help therapists to decide on the correct form of treatment. Treatment options are discussed using typical case histories and it is shown that patients suffering from severe tumor pain must be treated sequentially, which means that treatment is carried out in multiple steps and each cycle of therapy has to be adapted to the stage of the disease. Local pain treatment is fundamentally based on individual case decisions which should be discussed within an interdisciplinary tumor board and the panel should arrive at a consensus decision. In addition, the radiologist performing the procedure should have many years of experience in interventional oncological radiology. By fulfilling these conditions the interventional radiologist can help the patient in a variety of ways because the available treatment options are effective and do not result in much distress for the patient.


Assuntos
Dor Crônica/diagnóstico , Dor Crônica/terapia , Hipertermia Induzida/métodos , Neoplasias/complicações , Bloqueio Nervoso/métodos , Radiografia Intervencionista/métodos , Dor Crônica/etiologia , Terapia Combinada/métodos , Etanol/uso terapêutico , Humanos , Neoplasias/diagnóstico , Neoplasias/terapia , Medição da Dor/métodos , Cuidados Paliativos/métodos , Soluções Esclerosantes/uso terapêutico
4.
Z Gastroenterol ; 51(11): 1269-326, 2013 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-24243572

RESUMO

The interdisciplinary guidelines at the S3 level on the diagnosis of and therapy for hepatocellular carcinoma (HCC) constitute an evidence- and consensus-based instrument that is aimed at improving the diagnosis of and therapy for HCC since these are very challenging tasks. The purpose of the guidelines is to offer the patient (with suspected or confirmed HCC) adequate, scientifically based and up-to-date procedures in diagnosis, therapy and rehabilitation. This holds not only for locally limited or focally advanced disease but also for the existence of recurrences or distant metastases. Besides making a contribution to an appropriate health-care service, the guidelines should also provide the foundation for an individually adapted, high-quality therapy. The explanatory background texts should also enable non-specialist but responsible colleagues to give sound advice to their patients concerning specialist procedures, side effects and results. In the medium and long-term this should reduce the morbidity and mortality of patients with HCC and improve their quality of life.


Assuntos
Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/terapia , Oncologia/normas , Guias de Prática Clínica como Assunto , Alemanha , Humanos
5.
Neuroscience ; 201: 320-30, 2012 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-22108615

RESUMO

In situ hybridization, quantitative reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blot analysis were applied to study the changes in expression of the major nociceptive ion channel transient receptor potential vanilloid type 1 receptor (TRPV1) after the perineural application of capsaicin or nerve transection. In control rats, quantitative morphometric and statistical analyses of TRPV1 protein and mRNA expression in L5 dorsal root ganglion cells revealed distinct populations of small (type C) and small-to-medium (type B) neurons, which showed very high and moderate levels of TRPV1, whereas larger (type A) neurons mostly did not express this receptor. After either transection or capsaicin treatment of the sciatic nerve, immunohistochemistry and Western blotting demonstrated a massive (up to 80%) decrease in the proportion of TRPV1-immunoreactive neurons and TRPV1 protein at all postoperative survival times. In situ hybridization indicated marked decreases (up to 85%) in the proportion of neurons that expressed TRPV1 mRNA after sciatic nerve transection. In contrast, although perineural treatment with capsaicin resulted in similar substantial decreases in the proportions of type B and C neurons of the L5 dorsal root ganglia 3 days postoperatively, a clear-cut tendency to recovery was observed thereafter. Hence, the proportions of both type B and C neurons expressing TRPV1 mRNA reached up to 70% of the control levels at 30 days postoperatively. In accord with these findings, quantitative RT-PCR revealed a marked and significant recovery in TRPV1 mRNA after perineural capsaicin but not after nerve transection. These observations suggest the involvement of distinct cellular mechanisms in the regulation of the TRPV1 mRNA expression of damaged neurons, specifically triggered by the nature of the injury. The present findings imply that the antinociceptive and anti-inflammatory effects of perineurally applied capsaicin involve distinct changes in neuronal TRPV1 mRNA expression and long-lasting alterations in (post)translational regulation.


Assuntos
Gânglios Espinais/patologia , Neurônios/metabolismo , RNA Mensageiro/metabolismo , Neuropatia Ciática/patologia , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/metabolismo , Análise de Variância , Animais , Capsaicina/efeitos adversos , Contagem de Células , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Neurônios/efeitos dos fármacos , Ratos , Ratos Wistar , Neuropatia Ciática/induzido quimicamente , Neuropatia Ciática/etiologia , Fármacos do Sistema Sensorial/efeitos adversos , Fatores de Tempo
6.
Rofo ; 181(11): 1073-80, 2009 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-19408212

RESUMO

PURPOSE: High-resolution MR imaging of the layers of the gastrointestinal wall to provide a foundation for tumor staging based on morphological criteria. MATERIALS AND METHODS: Over a period of 12 months, miscellaneous parts of the gastrointestinal tract of 15 human specimens and 30 porcine specimens were scanned using a 1.5 Tesla clinical MRI scanner combined with an endoluminal receiver coil. The sequences used were T 1-weighted opposed-phase, T 2-weighted turbo spin echo with fat saturation and fast T 2-weighted inversion recovery. The number of differentiable layers, their width and the signal intensity were documented. Then, the results were compared with histological specimens in order to link the imaged wall layers to the anatomical layers. Spearman's Rank Correlation was used to determine the soundness of the link between the images and their related histology. RESULTS: For both human and animal specimens, the MRI scanning produced 3 to 5, maximum 6 (pig), differentiable layers. The mucosa, submucosa and muscularis could be differentiated with a hyperintense, hypointense and intermediary signal, respectively. The subserosal layer displayed a hypointense signal. CONCLUSION: High-resolution MRI is able to produce differentiable images of the anatomical layers of the gastrointestinal wall in both humans and pigs. Accordingly, it is possible to use MR imaging to diagnose the extent of local tumor infiltration of the gastrointestinal wall.


Assuntos
Endoscópios Gastrointestinais , Neoplasias Gastrointestinais/patologia , Trato Gastrointestinal/patologia , Aumento da Imagem/instrumentação , Processamento de Imagem Assistida por Computador/instrumentação , Imageamento por Ressonância Magnética/instrumentação , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Desenho de Equipamento , Feminino , Humanos , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade , Músculo Liso/patologia , Estadiamento de Neoplasias , Sensibilidade e Especificidade , Software
7.
Neuroscience ; 161(3): 887-94, 2009 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-19362118

RESUMO

Neurogenic inflammation of the dura mater encephali has been suggested to contribute to the mechanisms of meningeal nociception and blood flow regulation. Recent findings demonstrated that the rat dura mater is innervated by trigeminal capsaicin-sensitive peptidergic nociceptive afferent nerves which mediate meningeal vascular responses through activation of the transient receptor potential vanilloid type 1 (TRPV1) receptor. The present work explored the functional significance of the capsaicin-sensitive subpopulation of dural afferent nerves via their contribution to the meningeal vascular responses evoked through activation of the proteinase-activated receptor 2 (PAR-2). The vascular responses of the dura mater were studied by laser Doppler flowmetry in a rat open cranial window preparation. Topical applications of trypsin, a PAR-2-activator, or Ser-Leu-Ile-Gly-Arg-Leu-amide (SLIGRL-NH(2)), a selective PAR-2 agonist peptide, resulted in dose-dependent increases in meningeal blood flow. The SLIGRL-NH(2)-induced vasodilatation was significantly reduced following capsaicin-sensitive afferent nerve defunctionalization by prior systemic capsaicin treatment and by pretreatment of the dura mater with the calcitonin gene-related peptide (CGRP) receptor antagonist CGRP(8-37). Nomega-nitro-L-arginine methyl ester hydrochloride (L-NAME) an unspecific inhibitor of nitric oxide (NO) production, but not 1-(2-trifluoromethylphenyl) imidazole (TRIM), a neuronal NO synthase inhibitor, also inhibited the vasodilator response to SLIGRL-NH(2). The vasodilator responses elicited by very low concentrations of capsaicin (10 nM) were significantly enhanced by prior application of SLIGRL-NH(2). The present findings demonstrate that activation of the PAR-2 localized on capsaicin-sensitive trigeminal nociceptive afferent nerves induces vasodilatation in the dural vascular bed by mechanisms involving NO and CGRP release. The results indicate that the PAR-2-mediated activation and sensitization of meningeal capsaicin-sensitive C-fiber nociceptors may be significantly implicated in the pathophysiology of headaches.


Assuntos
Dura-Máter/irrigação sanguínea , Neurônios Aferentes/fisiologia , Receptor PAR-2/metabolismo , Vasodilatação/fisiologia , Animais , Peptídeo Relacionado com Gene de Calcitonina/administração & dosagem , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina , Capsaicina/administração & dosagem , Relação Dose-Resposta a Droga , Dura-Máter/efeitos dos fármacos , Inibidores Enzimáticos/administração & dosagem , Imidazóis/administração & dosagem , Fluxometria por Laser-Doppler , Masculino , NG-Nitroarginina Metil Éster/administração & dosagem , Neurônios Aferentes/efeitos dos fármacos , Óxido Nítrico Sintase/antagonistas & inibidores , Oligopeptídeos/administração & dosagem , Fragmentos de Peptídeos/administração & dosagem , Ratos , Ratos Wistar , Receptor PAR-2/agonistas , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fluxo Sanguíneo Regional/fisiologia , Fármacos do Sistema Sensorial/administração & dosagem , Tripsina/administração & dosagem , Vasodilatação/efeitos dos fármacos
8.
Br J Pharmacol ; 155(8): 1139-41, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18997813

RESUMO

Pharmacological modulation of the transient receptor potential vanilloid-1 (TRPV1) receptor function offers a promising means of producing pain relief at the level of the primary sensory neuron. In this issue of the BJP, the pharmacological approaches and the available experimental data that focus on the TRPV1 receptor to achieve therapeutically useful alleviation of pain and inflammation are reviewed. The potentials to inactivate TRPV1 receptor function by site- and modality-specific TRPV1 antagonists, uncompetitive TRPV1 blockers and drugs interfering with TRPV1 sensitization, are evaluated. A crucial issue of producing pain relief at the level of the nocisensor remains whether it can be achieved solely through inactivation of the TRPV1 receptor or TRPV1 agonist-induced defunctionalization of the whole primary afferent neuron is required. The accumulated evidence indicates that both pharmacological modulation of the intracellular trafficking of the TRPV1 receptor and defunctionalization of the nocisensors by TRPV1 agonists are promising novel approaches to tame the TRPV1 receptor.


Assuntos
Analgésicos/farmacologia , Dor/tratamento farmacológico , Canais de Cátion TRPV/agonistas , Analgésicos/uso terapêutico , Animais , Humanos
10.
Neuroscience ; 150(1): 194-201, 2007 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-17920775

RESUMO

Neuropathic alterations of sensory nerves involved in the mediation of neurogenic inflammation of the meninges may contribute to the increased incidence of headaches in diabetics. In the rat, activation of capsaicin-sensitive nociceptors, which express the transient receptor potential vanilloid type 1 (TRPV1) receptor, induces meningeal vasodilatation, a significant component of neurogenic inflammation, through the release of calcitonin gene-related peptide (CGRP). This study examines the effects of streptozotocin-induced diabetes on TRPV1 receptor-mediated neurogenic sensory vasodilatation, CGRP release and nerve fiber density in the rat dura mater. In a cranial window preparation, epidural application of capsaicin (10(-7) M) produced distinct vasodilatory responses in control animals as measured by laser Doppler flowmetry. In diabetic rats, capsaicin-induced vasodilatation was reduced or even abolished 6, but not 2 or 4 weeks after diabetes induction. In contrast, vasoconstriction, a non-neurogenic response to capsaicin at a higher concentration (10(-5) M), was not altered in diabetic rats. The vasodilatory effects of histamine (10(-5) M), acetylcholine (10(-4) M) and CGRP (10(-5) M) were similar in control, diabetic and insulin-treated diabetic animals. In diabetic rats, a significant decrease in the capsaicin-evoked release of CGRP and reduction in the density of TRPV1-immunoreactive (IR) nerves were demonstrated. Treatment of the diabetic rats with insulin restored both the vasodilatory response and the capsaicin-induced CGRP release toward control values. In conclusion, this study revealed a marked impairment of meningeal TRPV1-IR nerves in streptozotocin diabetic rats by showing reduced neurogenic sensory vasodilatation, decreased capsaicin-evoked CGRP release and reduction in the number of TRPV1-IR nerve fibers of the dura mater. The findings suggest that capsaicin-sensitive afferents may play an important role in meningeal nociceptor function and their dysfunction, e.g. due to a limited removal of inflammatory mediators and/or tissue metabolites from the meningeal tissue, may contribute to the enhanced incidence of headaches in diabetics.


Assuntos
Capsaicina/farmacologia , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/fisiopatologia , Dura-Máter/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , Acetilcolina/farmacologia , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Dura-Máter/irrigação sanguínea , Histamina/farmacologia , Técnicas In Vitro , Insulina/farmacologia , Fluxometria por Laser-Doppler/métodos , Masculino , Fibras Nervosas/efeitos dos fármacos , Ratos , Ratos Wistar , Fluxo Sanguíneo Regional/efeitos dos fármacos , Canais de Cátion TRPV/metabolismo , Fatores de Tempo
11.
Cephalalgia ; 27(6): 481-91, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17441973

RESUMO

Calcitonin gene-related peptide (CGRP), nitric oxide (NO) and histamine are implicated in primary headaches but their role in vascular and nociceptive events in the dura mater is not well described. In an in vitro preparation of the hemisected rat skull, CGRP and histamine release from the cranial dura was measured using enzyme-linked immunoassays. While the NO donator NONO(ate) (10(-4) M) was without effect, CGRP (10(-5) M) induced considerable histamine release from the rat cranial dura, which was blocked by the CGRP receptor antagonist CGRP(8-37) (10(-5) M). Conversely, histamine (10(-4) M) did not stimulate CGRP release. In vitro recordings from single rat meningeal afferents showed that only one of 12 mechanically identified units but several mechanically insensitive units responded to histamine (up to 10(-5) M). Increases in meningeal blood flow after histamine application (10(-4) M) to the rat cranial dura remained unchanged during CGRP receptor blockade with CGRP(8-37), inhibition of NO synthesis with L-NAME (20 mg/kg i.v.) and H(3) receptor blockade with thioperamide (10(-4) M). We conclude that histamine produces direct vasodilatation and activates a subset of largely non-mechanically sensitive, non-CGRP containing afferents in the rat meninges. Histamine is released from meningeal mast cells which are stimulated by CGRP. Similar mechanisms may be involved in the pathogenesis of headaches.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Circulação Cerebrovascular/fisiologia , Dura-Máter/metabolismo , Histamina/metabolismo , Neurônios Aferentes/fisiologia , Óxido Nítrico/metabolismo , Potenciais de Ação/efeitos dos fármacos , Animais , Dura-Máter/irrigação sanguínea , Ensaio de Imunoadsorção Enzimática , Feminino , Cefaleia/etiologia , Cefaleia/fisiopatologia , Liberação de Histamina/fisiologia , Masculino , Mastócitos/metabolismo , Microeletrodos , Técnicas de Cultura de Órgãos , Ratos , Ratos Wistar , Receptores Histamínicos H3/metabolismo , Vasodilatação
12.
Rofo ; 177(9): 1250-4, 2005 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-16123871

RESUMO

PURPOSE: To evaluate the prevalence of latent and manifest hyperthyroidism in a non-selected group of patients admitted for contrast enhanced CT studies blood samples were tested for the levels of thyroid-stimulating hormone (TSH). MATERIAL AND METHODS: TSH blood levels were obtained in 548 consecutive patients who were scheduled for contrast-enhanced (Iopromide; 300 mg iodine/ml) CT scanning. In case of TSH levels < 0.4 mU/l, blood samples were also tested for triiodothyronine (T3) and tetraiodothyronine (T4) blood levels, and treatment with Irenat (sodium perchlorate) was commenced before scanning. In case of TSH levels < 0.1 mU/l, CT scanning was not performed but further evaluation of the thyroid function was initiated. RESULTS: TSH blood levels ranged from 0.4 to 7.5 mU/l in 512 patients, and 36 patients (6.6%) had TSH blood levels < 0.4 mU/l and 9 patients blood levels < 0.1 mU/l, with 32 of those patients (5.8%) having regular T3 and T4 blood levels consistent with latent hyperthyroidism. In 4 patients (0.8%), T3 or T4 blood levels were increased consistent with manifest hyperthyroidism. CONCLUSION: In South Germany, the prevalence of latent or manifest hyperthyroidism in a non-selected patient group is high. Therefore TSH blood levels should be obtained prior to contrast-enhanced CT studies.


Assuntos
Meios de Contraste , Hipertireoidismo/epidemiologia , Iohexol/análogos & derivados , Tireotropina/sangue , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Alemanha/epidemiologia , Humanos , Hipertireoidismo/sangue , Pessoa de Meia-Idade , Percloratos/administração & dosagem , Prevalência , Compostos de Sódio/administração & dosagem , Tiroxina/sangue , Tri-Iodotironina/sangue
13.
Rofo ; 177(7): 986-91, 2005 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-15973601

RESUMO

PURPOSE: Experimental feasibility study of a new MR-Coil concept for enhanced visualization of the gastric wall. MATERIAL AND METHODS: The newly developed single-loop receiver coil for endoluminal imaging (Fraunhofer Institute, St. Ingbert, Germany) was evaluated in 4 explanted pig stomachs in a 1.5T MR unit (Siemens Symphony, Erlangen, Germany) with T1 w and T2 w MR sequences in three planes. The new coil consists of a foldable and self-expanding single loop coil (receiver coil) of a shape memory metal (nitinol). It was covered with a biocompatible material (silicone) to prevent direct contact of the wire with stomach tissue. The coil assumes a circular configuration with a diameter of 8 cm because of its memory metal properties. The flexible characteristics of the material used allow the passage through the instrument channel (13 mm diameter) of a specially designed MR-compatible endoscope. The purpose of our study was to assess feasibility of the coil design as a first step in developing a new endoluminal MRI-concept. Additionally the number and signal intensity of visible gastric wall layers were evaluated and findings were correlated with histopathological results of a pig stomach. RESULTS: The new coil concept was a feasible system in all 4 cases and showed good image quality for analysis. On T1 w images, 3 layers were visible in all cases, and on T2 w images 4 different gastric wall layers were seen in 2 cases. Due to histopathological correlation, the different gastric wall layers were identified as follows: mucosa, submucosa and muscularis propria if three layers were depicted; in cases of 4 visible wall layers, serosa and subserosa could be detected additionally. For each gastric wall layer, a distinct signal intensity was found. CONCLUSION: The new MR coil concept for endoluminal imaging proved to be a feasible technique. Good differentiation of gastric wall layers in the pig stomach could be demonstrated. We have shown that endoscopic MR-imaging with our new coil concept is a valuable technique for the visualization of gastric wall layers. Due to this fact, follow-up studies including assessing safety aspects are necessary to finally conduct an experimental-clinical study on in-vivo human gastric specimens to detect tumor growth and morphology within the gastric wall. Endoscopic MRI may have the potential in the future to overcome today's limitations of diagnostic imaging in gastric cancer.


Assuntos
Endoscopia Gastrointestinal/métodos , Análise de Falha de Equipamento , Gastroscópios , Imageamento por Ressonância Magnética/instrumentação , Estômago/citologia , Animais , Desenho de Equipamento , Estudos de Viabilidade , Imageamento por Ressonância Magnética/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suínos
14.
Rofo ; 176(12): 1794-802, 2004 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-15573291

RESUMO

PURPOSE: A retrospective analysis of long-term efficacy of combined transcatheter arterial chemoembolization (TACE) and percutaneous ethanol injection (PEI) and TACE monotherapy was conducted in patients with large, non-resectable hepatocellular carcinoma (HCC). METHODS AND MATERIALS: Fifty patients with large, unresectable HCC lesions underwent selective TACE. Liver cirrhosis was present in 42 patients, due to alcohol abuse (n = 22) and viral infection (n = 17). In three patients, the underlying cause for liver cirrhosis remained unclear. Child A cirrhosis was found in 22 and Child B cirrhosis in 20 patients. Repeated and combined TACE and PEI were performed in 22 patients and repeated TACE monotherapy was performed in 28 patients. Survival and complication rates were determined and compared. RESULTS: The 6-,12-, 24- and 36-month survival rates were 61 %, 21 %, 4 %, and 4 % for TACE monotherapy and 77 %, 55 %, 39 % and 22 % for combined TACE and PEI (Kaplan-Meier method). The kind of treatment significantly affected the survival rate (p = 0.002 log-rank test). Severe side effects were present in two patients of the monotherapy group and in three patients of the combination therapy group. CONCLUSION: The combination of TACE and PEI is an effective and safe method in the palliative treatment of large HCC that has the potential of improving long term survival compared to TACE monotherapy.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica , Etanol/administração & dosagem , Neoplasias Hepáticas/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/administração & dosagem , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/mortalidade , Interpretação Estatística de Dados , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Injeções Subcutâneas , Cirrose Hepática/complicações , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Cuidados Paliativos , Estudos Retrospectivos , Análise de Sobrevida , Fatores de Tempo
15.
Rofo ; 176(11): 1624-33, 2004 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-15497081

RESUMO

PURPOSE: To evaluate multislice-CT versus MRI in the diagnosis and staging of pancreatic carcinoma in a prospective multi-reader analysis. MATERIALS AND METHODS: Fifty patients with suspected pancreatic carcinoma underwent both multislice-CT (4-Row, "hydro-technique") and state-of-the-art MRI (two 1.5 T units). In correlation with histopathologic findings or in case of a non-lesion diagnosis by follow-up (6-month interval), we evaluated MRI versus CT in a multi-reader analysis (2 reader pairs) for: 1. diagnostic quality; 2. examination time; 3. accuracy of potential resectability; 4. kappa analysis of observer variations; and 5. overall diagnostic reliability. RESULTS: A total of 28 lesions (n = 22 malignant, n = 6 benign) were present in the cohort group versus 22 patients without a focal lesion (n = 10 pancreatitis, n = 12 no tumor). For lesion detection, CT had a sensitivity of 100/89 % (reader pair 1/2) and specificity of 77 %, and MRI had a sensitivity of 75/89 % and specificity of 77/73 %. For the subgroup of adenocarcinomas of the pancreas (n = 17), we found a sensitivity of 100 % and a specificity of 61 % for CT versus a sensitivity of 82/94 % and a specificity of 67/61 % for MRI. The accuracy for determining the resectability was 91/82 % for CT and 90/82 % for MRI. The kappa analysis showed a good correlation for CT (0.71) and a moderate correlation of both groups for MRI (0.49). CONCLUSION: CT and MRI showed comparable results in the detection of pancreatic carcinomas as well as in the determination of resectability. Chronic pancreatitis as a "tumor-like-lesion" was the major factor of a missed diagnosis. The results of multi-reader analysis for both reading groups were almost identical with a moderate to good kappa correlation. There is no reason to prefer MRI (more expensive) over CT for patients with the presumptive diagnosis of pancreatic cancer.


Assuntos
Adenocarcinoma/diagnóstico , Cistadenoma/diagnóstico , Imageamento por Ressonância Magnética/métodos , Tumores Neuroendócrinos/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Tomografia Computadorizada Espiral/métodos , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Cistadenoma/diagnóstico por imagem , Cistadenoma/patologia , Diagnóstico Diferencial , Seguimentos , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/patologia , Pâncreas/patologia , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/secundário , Neoplasias Pancreáticas/cirurgia , Pancreatite/diagnóstico , Pancreatite/diagnóstico por imagem , Estudos Prospectivos , Sensibilidade e Especificidade , Fatores de Tempo
16.
Rofo ; 176(5): 679-87, 2004 May.
Artigo em Alemão | MEDLINE | ID: mdl-15122466

RESUMO

Imaging studies, ultrasonography, play a central role for the diagnosis and follow-up of cystic echinococcosis (hydatid disease) due to the non-specific clinical symptoms and still inadequate sensitivity and specificity of currently available serological tests. Due to the increasing number of people immigrating to central Europe from countries with a high incidence of cystic echinococcosis, cystic echinococcosis has become an important differential diagnosis of cystic lesions. The imaging modality to localize and stage the disease depends on the organs affected. Ultrasonography is the most important imaging technique to screen for abdominal lesions (more than 75 % of the cases). Therefore, an expert committee of the WHO Working Group on echinococcosis has recently suggested a standardized ultrasonographic classification of hepatic cystic echinococcosis. This classification proofs to be very useful for staging echinococcal cysts with respect to parasite activity. Ultrasonography is not only an excellent tool for the primary diagnosis and therapeutic decision but also for follow-up of patients treated for cystic echinococcosis. Indications for computed tomography or magnetic resonance tomography are restricted to extra abdominal disease, patients not suited for ultrasonography because of obesity or meteorism, complicated cysts and planning of surgery or interventional therapy. Apart from surgery three other treatment options are well established: (1) chemotherapy with albendazole or mebendazole, (2) percutaneous drainage and sterilization (PAIR) and (3) observation of inactive echinococcal stages ("watch and wait" approach).


Assuntos
Equinococose/diagnóstico , Equinococose/terapia , Albendazol/uso terapêutico , Anticestoides/uso terapêutico , Diagnóstico Diferencial , Drenagem , Equinococose/diagnóstico por imagem , Equinococose/tratamento farmacológico , Equinococose/cirurgia , Equinococose Hepática/classificação , Equinococose Hepática/diagnóstico , Equinococose Hepática/diagnóstico por imagem , Equinococose Hepática/terapia , Equinococose Pulmonar/diagnóstico , Equinococose Pulmonar/diagnóstico por imagem , Equinococose Pulmonar/terapia , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Mebendazol/uso terapêutico , Radiografia Torácica , Sensibilidade e Especificidade , Esterilização , Fatores de Tempo , Tomografia Computadorizada por Raios X , Ultrassonografia , Organização Mundial da Saúde
17.
Radiologe ; 43(8): 656-60, 2003 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-14504766

RESUMO

Percutaneous angioplasty of a renal artery stenosis may lead to dissection and acute thrombosis that may put the organ at risk. In this case, it should be discussed individually how to treat the patient and the decision on interventional therapy should be based on interdisciplinary consensus. Local fibrinolysis usually allows to recognize the cause of obstruction which then is the basis for further treatments. The case report presented in this article describes how a dissection involving two thirds of the renal artery and leading to significant obstruction may successfully be treated by means of interventional radiology.


Assuntos
Angioplastia com Balão , Obstrução da Artéria Renal/terapia , Artéria Renal/lesões , Angiografia , Angioplastia com Balão/efeitos adversos , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Radiologia Intervencionista , Recidiva , Artéria Renal/diagnóstico por imagem , Stents , Fatores de Tempo
18.
Z Orthop Ihre Grenzgeb ; 141(2): 177-81, 2003.
Artigo em Alemão | MEDLINE | ID: mdl-12695954

RESUMO

AIM: It was the aim of this study to investigate the success of biceps tenoplasty in massive interval rotator cuff tears. METHOD: Fifteen patients, who had a massive rotator cuff tear in the area of the interval and a pathology of the long head of the biceps tendon, were examined clinically and by MRI. A primary reconstruction of the rotator cuff tear was possible in none of the patients. All patients had a secondary reconstruction with a biceps tenoplasty. The Constant Score was determined postoperatively and the satisfaction of the patients was explored. RESULTS: The mean age at the time of the operation was 55 years. The examination was 23 months postoperatively. A simultaneous rupture of the supraspinatus- and subscapularis tendon was seen in 12 patients, an additional rupture of the infraspinatus tendon in 3 patients intraoperatively. The long head of the biceps was dislocated in 10 patients and subluxated in 5 patients. The postoperative determined Constant Score was 82.7 points. The personal satisfaction was investigated by asking for the German schoolmarks, which extend from 1 (excellent) to 6 (not satisfactory). The preoperative schoolmark was 5.2 and the postoperative schoolmark 1.4. In the MRI examination one rerupture could be seen, an atrophy of the supraspinatus tendon was evaluated in four patients. Knowing the postoperative result, all patients would have repeated the operation. CONCLUSION: The biceps tenoplasty is a suitable operative method to achieve a better function and relief of pain in massive interval rotator cuff tears with simultaneous pathology of the long head of the biceps tendon. A high degree of personal satisfaction for the patient can be achieved.


Assuntos
Complicações Pós-Operatórias/diagnóstico , Lesões do Manguito Rotador , Luxação do Ombro/cirurgia , Traumatismos dos Tendões , Traumatismos dos Tendões/cirurgia , Adulto , Idoso , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Amplitude de Movimento Articular/fisiologia , Estudos Retrospectivos , Manguito Rotador/patologia , Manguito Rotador/cirurgia , Luxação do Ombro/diagnóstico , Técnicas de Sutura , Traumatismos dos Tendões/diagnóstico , Tendões/patologia , Tendões/cirurgia , Resultado do Tratamento
19.
Eur Radiol ; 13(4): 794-801, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12664119

RESUMO

The aim of this study was to assess the value of contrast-enhanced three-dimensional MR angiography (CE 3D MRA) in the preoperative assessment of potential living renal donors, and to compare the accuracy for the depiction of the vascular anatomy using three different rendering algorithms. Twenty-three potential living renal donors were examined with CE 3D MRA (TE/TR=1.3 ms/3.7 ms, field of view 260-320x350 mm, 384-448x512 matrix, slab thickness 9.4 cm, 72 partitions, section thickness 1.3 mm, scan time 24 s, 0.1 mmol/kg body weight gadobenate dimeglumine). Magnetic resonance angiography data sets were processed with maximum intensity projection (MIP), volume rendering (VR), and shaded-surface display (SSD) algorithms. The image analysis was performed independently by three MR-experienced radiologists recording the number of renal arteries, the presence of early branching or vascular pathology. The combination of digital subtraction angiography (DSA) and intraoperative findings served as the gold standard for the image analysis. In total, 52 renal arteries were correspondingly observed in 23 patients at DSA and surgery. Other findings were 3 cases of early branching of the renal arteries, 4 cases of arterial stenosis and 1 case of bilateral fibromuscular dysplasia. With MRA source data all 52 renal arteries were correctly identified by all readers, compared with 51 (98.1%), 51-52 (98.1-100%) and 49-50 renal arteries (94.2-96.2%) with the MIP, VR and SSD projections, respectively. Similarly, the sensitivity, specificity and accuracy was highest with the MRA source data followed by MIP, VR and SSD. Time requirements were lowest for the MIP reconstructions and highest for the VR reconstructions. Contrast-enhanced 3D MRA is a reliable, non-invasive tool for the preoperative evaluation of potential living renal donors. Maximum intensity projection is favourable for the processing of 3D MRA data, as it has minimal time and computational requirements, while having similar or superior accuracy for the depiction of vessel anomalies or pathology compared with VR and SSD, respectively.


Assuntos
Algoritmos , Transplante de Rim , Doadores Vivos , Angiografia por Ressonância Magnética , Meglumina/análogos & derivados , Angiografia Digital , Meios de Contraste , Feminino , Gadolínio , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos , Artéria Renal/anatomia & histologia , Sensibilidade e Especificidade
20.
Radiologe ; 43(1): 51-8, 2003 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-12552375

RESUMO

PURPOSE: In acute diverticulitis accurate diagnosis and staging are mandatory to decide on the treatment of the patient. The impact of computed tomography (CT) on the treatment of acute diverticulitis will be discussed. MATERIAL AND METHOD: CT is performed after distension of the distal colon by means of positive,water-soluble contrast media to depict intestinal perforation or penetration. Then intravenous contrast material is administered and spiral scanning is repeated to judge enhancement patterns of the abdominal structures/organs especially of the intestinal wall and to diagnose abscess formation. CT-morphologies of different stages of acute diverticulitis will be described. RESULTS: CT imaging is the only diagnostic method that in case of an acute diverticulitis combines safety with accuracy. On the one hand, it is fast and therefore safe with respect to patient control and on the other hand, it allows accurate staging of the inflammatory process reaching a sensitivity and specificity of up to 100%, each. CT is an appropriate tool to diagnose acute diverticulitis complicated by abscess formation, intestinal penetration or perforation and therefore has direct impact on the treatment of the patient. DISCUSSION: If acute diverticulitis is suspected CT is the method of choice for imaging because of its high impact on the choice of therapy and on the management of complications.


Assuntos
Diverticulite/diagnóstico por imagem , Tomografia Computadorizada Espiral/métodos , Doença Aguda , Neoplasias do Colo/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Diagnóstico Diferencial , Doença Diverticular do Colo/diagnóstico por imagem , Divertículo/diagnóstico por imagem , Divertículo do Colo/diagnóstico por imagem , Emergências , Humanos , Doenças do Colo Sigmoide/diagnóstico por imagem , Neoplasias do Colo Sigmoide/diagnóstico por imagem , Ultrassonografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...