Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 248
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Clin Radiol ; 74(8): 649.e1-649.e10, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31072592

RESUMO

Primary repair of the anterior cruciate ligament (ACL) is being performed increasingly in the treatment of acute proximal ACL ruptures. Advantages of ACL repair over surgical reconstruction with a tendon graft include preservation of the anatomy and proprioceptive function of the native ACL, and therefore, faster rehabilitation. The addition of an internal brace protects the repair during ACL healing and can increase the success rate of the procedure. Given this evolution of ACL surgical treatment, radiologists should be familiar with the new repair techniques and their appearances on postoperative imaging. In this article, we describe two different surgical techniques for primary ACL repair, dynamic intraligamentary stabilisation and internal brace ligament augmentation, and provide an overview of the normal and abnormal appearances after this type of repair at magnetic resonance imaging (MRI) follow-up.


Assuntos
Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem , Lesões do Ligamento Cruzado Anterior/cirurgia , Imageamento por Ressonância Magnética/métodos , Ligamento Cruzado Anterior/diagnóstico por imagem , Ligamento Cruzado Anterior/cirurgia , Humanos , Resultado do Tratamento
2.
Neuroradiology ; 55(3): 307-11, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23129016

RESUMO

INTRODUCTION: Skull base meningiomas are often missed on non-contrast CT or MR examinations due to their close proximity to bone and low lesion to brain contrast. The purpose of this study is to illustrate that pneumosinus dilatans can be an indicator of anterior skull base meningiomas. METHODS: A retrospective search of the radiology information system and picture archiving and computing system database was performed. Search terms were "meningioma" in association with "pneumosinus dilatans." Medical records and imaging studies were reviewed independently by two experienced neuroradiologists and were read in consensus. We recorded the patient age at the time of discovery of the meningioma, main presenting symptom(s), location of the tumor, and imaging characteristics. We also performed a comparative literature search for pneumosinus dilatans and its association with meningiomas. RESULTS: Ten patients (six women; four men) were identified in whom a meningioma of the anterior skull base was associated with a pneumosinus dilatans. Three patients had multiple meningiomas, so a total of 14 intracranial tumors were identified. Mean age at discovery was 59 years with an age range of ± 20years. All meningiomas were diagnosed by MRI and/or CT. CONCLUSION: Pneumosinus dilatans can be a helpful sign to indicate the presence of a meningioma of the anterior skull base.


Assuntos
Neoplasias Meníngeas/diagnóstico , Meningioma/diagnóstico , Doenças dos Seios Paranasais/diagnóstico , Neoplasias da Base do Crânio/diagnóstico , Idoso , Dilatação Patológica/patologia , Feminino , Humanos , Masculino , Neoplasias Meníngeas/complicações , Meningioma/complicações , Pessoa de Meia-Idade , Doenças dos Seios Paranasais/complicações , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Neoplasias da Base do Crânio/complicações
3.
AJNR Am J Neuroradiol ; 44(4): 460-466, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36997286

RESUMO

BACKGROUND AND PURPOSE: Approaches to management of intracranial aneurysms are inconsistent, in part due to apprehension relating to potential malpractice claims. The purpose of this article was to review the causes of action underlying medical malpractice lawsuits related to the diagnosis and management of intracranial aneurysms and to identify the factors associated and their outcomes. MATERIALS AND METHODS: We consulted 2 large legal databases in the United States to search for cases in which there were jury awards and settlements related to the diagnosis and management of patients with intracranial aneurysms in the United States. Files were screened to include only those cases in which the cause of action involved negligence in the diagnosis and management of a patient with an intracranial aneurysm. RESULTS: Between 2000 and 2020, two hundred eighty-seven published case summaries were identified, of which 133 were eligible for inclusion in the analysis. Radiologists constituted 16% of 159 physicians sued in these lawsuits. Failure to diagnose was the most common medical malpractice claim referenced (100/133 cases), with the most common subgroups being "failure to include cerebral aneurysm as a differential and thus perform adequate work-up" (30 cases), and "failure to correctly interpret aneurysm evidence on CT or MR imaging" (16 cases). Only 6 of these 16 cases were adjudicated at trial, with 2 decided in favor of the plaintiff (awarded $4,000,000 and $43,000,000, respectively). CONCLUSIONS: Incorrect interpretation of imaging is relatively infrequent as a cause of malpractice litigation compared with failure to diagnose aneurysms in the clinical setting by neurosurgeons, emergency physicians, and primary care providers.


Assuntos
Aneurisma Intracraniano , Imperícia , Humanos , Estados Unidos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Radiologistas , Neurocirurgiões , Bases de Dados Factuais
4.
Eur Spine J ; 20(10): 1650-7, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21744284

RESUMO

INTRODUCTION: The results of platelet-rich plasma (PRP) in spinal fusion applications are limited and controversial. Both beneficial and inhibitory effects have been shown. In this prospective randomised controlled trial, our objective was to assess both the clinical and radiological effect of PRP when added to autograft iliac crest bone in posterior lumbar interbody fusion. METHODS AND MATERIALS: Forty patients were recruited for the study fulfilling strict entry requirements and were randomised with a 1:1 ratio. In each group, one patient was lost to follow-up. Thirtyeight patients completed the Visual Analogue Scale (VAS), the Oswestry Disability Index (ODI), and the Short-Form 36 (SF-36) preoperatively and postoperatively at 3, 6, 12, and 24 months, respectively. CT-scans of the lumbar spine were taken at 3, 6, and 12 months. Posterior stabilisation was achieved with pedicle screws and interbody fusion was aimed at with carbon cages filled with autologous bone. RESULTS: Baseline demographic data (age, sex, smoking history, preoperative outcome measures) showed no relevant difference between groups. For patients who received autograft only, the mean VAS improved by 4.0 points (p < 0.01), mean ODI improved by 32.1 points (p < 0.001), and mean SF-36 showed statistically significant improvement in each of the eight domains and in the physical (p < 0.001) and mental (p < 0.001) component summary measures. For patients who received autograft with PRP, the mean VAS improved by 4.92 points (p < 0.01), mean ODI improved by 30 points (p < 0.001), and mean SF-36 showed statistically significant improvement in six of the eight domains (p < 0.02) and in the physical (p = 0.016) and mental (p < 0.001) component summary measures. The improvement of the VAS score and the physical component summary score was more pronounced in patients who received autograft with PRP. These differences were, however, not statistically significant. CT-scans showed uneventful osseous healing in all but one patient with no difference between groups. CONCLUSION: In this prospective randomised controlled clinical and radiological trial, adding PRP in posterior lumbar interbody fusion did not lead to a substantial improvement or deterioration when compared with autologous bone only. No inhibitory effect of PRP was observed on CT-scans. From a clinical and radiological point of view, the use of PRP seems to be justified in posterior lumbar interbody fusion surgery. From an economical point of view, the expense of using PRP cannot be justified until statistical significance can be reached in a larger study.


Assuntos
Transplante Ósseo/métodos , Vértebras Lombares/cirurgia , Plasma Rico em Plaquetas/fisiologia , Fusão Vertebral/métodos , Adulto , Feminino , Seguimentos , Humanos , Ílio/transplante , Disco Intervertebral/diagnóstico por imagem , Disco Intervertebral/metabolismo , Disco Intervertebral/cirurgia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/metabolismo , Masculino , Estudos Prospectivos , Radiografia , Fusão Vertebral/instrumentação , Resultado do Tratamento
5.
Minim Invasive Neurosurg ; 54(5-6): 257-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22278791

RESUMO

BACKGROUND: Oxidized regenerated cellulose is commonly used in many surgical fields as a hemostatic agent. Complications related to swelling or compression after application of small portions of Surgicel® Fibrillar™ have not yet been described. PATIENTS: We report on a 65-year-old woman who was operated for a high-grade spinal stenosis at the L2-L3 level. Small portions of Surgicel® Fibrillar™ were used to control bleeding from the epidural venous plexus. The immediate postoperative course was uneventful. However, one day after surgery, the patient complained about progressive worsening pain at the operated level. A non-contrast lumbar CT scan showed no evidence of a postoperative hematoma or other complication. MR imaging showed a horseshoe-shaped mass compressing the dural sac at the operated level from posterior and both sides. Because we suspected a postoperative hematoma, the patient was re-operated. No hemorrhage was seen but instead we found large, swollen firm pieces of Surgicel® Fibrillar™ compressing the dural sac. These pieces were removed. RESULT: Postoperatively no neurological deficit or pain was present. Histological examination of the removed mass of Surgicel® Fibrillar™ revealed only the presence of blood, fibrin and an amorphous eosinophilic content. There was no sign of any inflammation. CONCLUSION: On the basis of this experience, we advise caution with the use of hemostatic agents during spinal surgery and - if used - strongly advise the removal of Surgicel® Fibrillar™ after the hemostasis has been achieved to avoid the development of complications due to a mass effect.


Assuntos
Celulose Oxidada/efeitos adversos , Hemostáticos/efeitos adversos , Laminectomia/métodos , Vértebras Lombares/cirurgia , Compressão da Medula Espinal/etiologia , Estenose Espinal/cirurgia , Idoso , Remoção de Dispositivo , Feminino , Hemostasia Cirúrgica/efeitos adversos , Hemostasia Cirúrgica/métodos , Humanos , Compressão da Medula Espinal/cirurgia , Resultado do Tratamento
6.
J Neurol Neurosurg Psychiatry ; 81(1): 90-3, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20019223

RESUMO

BACKGROUND: m.14487T>C, a missense mutation (p.M63V) affecting the ND6 subunit of complex I of the mitochondrial respiratory chain, has been reported in isolated childhood cases with Leigh syndrome (LS) and progressive dystonia. Adult-onset phenotypes have not been reported. OBJECTIVES: To determine the clinical-neurological spectrum and associated mutation loads in an extended m.14487T>C family. METHODS: A genotype-phenotype correlation study of a Belgian five-generation family with 12 affected family members segregating m.14487T>C was carried out. Clinical and mutation load data were available for nine family members. Biochemical analysis of the respiratory chain was performed in three muscle biopsies. RESULTS: Heteroplasmic m.14487T>C levels (36-52% in leucocytes, 97-99% in muscle) were found in patients with progressive myoclonic epilepsy (PME) and dystonia or progressive hypokinetic-rigid syndrome. Patients with infantile LS were homoplasmic (99-100% in leucocytes, 100% in muscle). We found lower mutation loads (between 8 and 35% in blood) in adult patients with clinical features including migraine with aura, Leber hereditary optic neuropathy, sensorineural hearing loss and diabetes mellitus type 2. Despite homoplasmic mutation loads, complex I catalytic activity was only moderately decreased in muscle tissue. INTERPRETATION: m.14487T>C resulted in a broad spectrum of phenotypes in our family. Depending on the mutation load, it caused severe encephalopathies ranging from infantile LS to adult-onset PME with dystonia. This is the first report of PME as an important neurological manifestation of an isolated mitochondrial complex I defect.


Assuntos
Doença de Leigh/genética , Epilepsias Mioclônicas Progressivas/genética , NADH Desidrogenase/genética , Adulto , Idade de Início , Bélgica , Criança , DNA Mitocondrial/genética , Distúrbios Distônicos/genética , Família , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Mutação de Sentido Incorreto/genética , Linhagem , Fenótipo , Adulto Jovem
7.
Eur Spine J ; 19 Suppl 1: S8-17, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19727855

RESUMO

Traumatic injuries of the spine and spinal cord are common and potentially devastating lesions. We present a comprehensive overview of the classification of vertebral fractures, based on morphology (e.g., wedge, (bi)concave, or crush fractures) or on the mechanism of injury (flexion-compression, axial compression, flexion-distraction, or rotational fracture-dislocation lesions). The merits and limitations of different imaging techniques are discussed, including plain X-ray films, multi-detector computed tomography (MDCT), and magnetic resonance imaging (MRI) for the detection. There is growing evidence that state-of-the-art imaging techniques provide answers to some of the key questions in the management of patients with spine and spinal cord trauma: is the fracture stable or unstable? Is the fracture recent or old? Is the fracture benign or malignant? In summary, we show that high-quality radiological investigations are essential in the diagnosis and management of patients with spinal trauma.


Assuntos
Diagnóstico por Imagem/métodos , Traumatismos da Medula Espinal/diagnóstico , Fraturas da Coluna Vertebral/diagnóstico , Traumatismos da Coluna Vertebral/diagnóstico , Diagnóstico por Imagem/tendências , Humanos , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/normas , Prognóstico , Radiografia/métodos , Radiografia/normas , Traumatismos da Medula Espinal/classificação , Traumatismos da Medula Espinal/fisiopatologia , Fraturas da Coluna Vertebral/classificação , Fraturas da Coluna Vertebral/fisiopatologia , Traumatismos da Coluna Vertebral/classificação , Traumatismos da Coluna Vertebral/fisiopatologia , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/normas , Índices de Gravidade do Trauma , Ferimentos e Lesões/classificação , Ferimentos e Lesões/diagnóstico , Ferimentos e Lesões/fisiopatologia
8.
B-ENT ; 6(2): 147-51, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20681371

RESUMO

It is rare for neuroendocrine tumours to originate in the sphenoid sinus and the nasopharynx. Neuroendocrine tumours can be classified into typical carcinoids, atypical carcinoids and small cell neuroendocrine carcinomas. Here we report the case of a 48-year-old man with a typical carcinoid tumour of the nasopharynx and sphenoid sinus. This is a very rare diagnosis, and only a few cases of a typical carcinoid in this region have been described in the literature.


Assuntos
Carcinoma Neuroendócrino/diagnóstico , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias dos Seios Paranasais/diagnóstico , Seio Esfenoidal , Carcinoma Neuroendócrino/sangue , Carcinoma Neuroendócrino/tratamento farmacológico , Carcinoma Neuroendócrino/radioterapia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/sangue , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/radioterapia , Neoplasias dos Seios Paranasais/sangue , Neoplasias dos Seios Paranasais/tratamento farmacológico , Neoplasias dos Seios Paranasais/radioterapia , Tomografia por Emissão de Pósitrons , Radioterapia Adjuvante
9.
Diagn Interv Imaging ; 101(1): 25-33, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31402334

RESUMO

PURPOSE: The purpose of this study was to investigate if lesion detection using a single "All-in-One" (AIO) window was non-inferior to lesion detection on conventional window settings in thoracic oncology chest computed tomography (CT) examinations. MATERIALS AND METHODS: In a retrospective study, 50 consecutive chest CT examinations of 50 patients (31 men, 19 women; mean age 64±10 [SD] years, range: 35-82 years) containing 417 lesions, were reviewed by 6 radiologists, subdivided into 2 groups of 3 radiologists each, with similar levels of expertise in each group (senior staff member, junior staff member and radiology resident). All examinations were reviewed in conventional or AIO window settings by one of the groups. A 'lesion' was defined as any abnormality seen on the chest CT examination, including both benign and malignant lesions, findings in chest and upper abdomen, and measurable and non-measurable disease. Lesions were listed as 'missed' when they were not seen by at least two out of three observers. F-tests were used to evaluate the significance of the variables of interest within a mixed model framework and kappa statistics to report interobserver agreement. RESULTS: On a reader level, 54/417 lesions (12.9%) were not detected by the senior staff member reading the studies in conventional window settings and 45/417 (10.8%) by the senior staff member reading the AIO images. For the junior staff member and radiology resident this was respectively 55/417 (13.2%) and 67/417 (16.1%) for the conventional window settings and 43/417 (10.3%) and 61/417 (14.6%) for the AIO window. On a lesion level, 68/417 (16.3%) were defined as 'missed' lesions (lesions not detected by at least 2 readers): 21/68 (30.9%) on the AIO-window, 30/68 (44.1%) on conventional views and 17/68 (25.0%) on both views. The use of the AIO window did not result in an increase of missed lesions (P>0.99). Interobserver agreement in both groups was similar (P=0.46). Regarding lesions that were categorized as 'missed' on the AIO window or on conventional window settings, there was no effect of location (chest or upper abdomen) (P=0.35), window (P=0.97) and organ (P=0.98). CONCLUSIONS: A single AIO-window is non-inferior to multiple conventional window settings for lesion detection on chest CT examinations in thoracic oncology patients.


Assuntos
Neoplasias Torácicas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
10.
Eur Respir J ; 34(2): 452-74, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19648522

RESUMO

Nonthrombotic pulmonary embolism (NTPE) is defined as embolisation to the pulmonary circulation of different cell types (adipocytes, haematopoietic, amniotic, trophoblastic or tumour), bacteria, fungi, foreign material or gas. The purpose of this article is to describe the clinical signs, pathogenesis, diagnosis and treatment of the different NTPE subtypes. The complex and diverse pathogenesis of different subtypes of emboli is subject to continuing speculation and is certainly far more complex than "simple" mechanical obstruction after embolisation of vascular thrombi. Nonthrombotic emboli may also lead to a severe inflammatory reaction both in the systemic and pulmonary circulation, as well as in the lung. NTPE presents a formidable diagnostic challenge, as the condition often presents with very unusual and peculiar clinical signs that are frequently overlooked. They range from very dramatic acute presentations such as acute respiratory distress syndrome to signs observed late in the disease course. Pathological observations play a key role in the exact diagnosis, and sometimes carefully aspirated blood from the pulmonary artery or specific staining of cells recovered from bronchoalveolar lavage fluid may be helpful. Frequently, lung biopsies revealing severe granulomatous reaction or unfortunate post-mortem pathological investigations of pulmonary tissue are necessary to confirm the diagnosis. Here, we also aim to familiarise the reader with the atypical radiological features of NTPE. Thin-section computed tomography of the lungs showing peculiar radiographic findings, such as a feeding vessel, the so-called tree-in-bud pattern or the appearance of micronodules distributed at the termination of bronchovascular bundles, may be observed in certain forms of NTPE. Increased awareness of NTPE as an underestimated cause of acute and chronic embolism, which may result in acute and chronic pulmonary hypertension, is needed. Despite the fact that detailed descriptions of several forms of NTPE have existed for nearly 100 years, well-designed trials have never been performed to evaluate therapy in the different subsets of these patients.


Assuntos
Hipertensão Pulmonar/fisiopatologia , Embolia Pulmonar/fisiopatologia , Líquido Amniótico/metabolismo , Biópsia , Líquido da Lavagem Broncoalveolar , Equinococose/complicações , Gorduras/metabolismo , Feminino , Gases , Doença Trofoblástica Gestacional/metabolismo , Humanos , Hipertensão Pulmonar/terapia , Neoplasias Pulmonares/complicações , Masculino , Gravidez , Embolia Pulmonar/terapia , Sepse/complicações , Tomografia Computadorizada por Raios X/métodos
11.
Acta Radiol ; 50(9): 1057-63, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19863417

RESUMO

BACKGROUND: Magnetic resonance (MR) arthrography is generally regarded as the gold standard for shoulder imaging. As an alternative to direct MR arthrography, the less invasive indirect MR arthrography technique was proposed, offering logistic advantages because fluoroscopic or ultrasonographic guidance for joint injection is not required. PURPOSE: To assess the diagnostic performance of indirect MR arthrography in the diagnosis of full- and partial-thickness supraspinatus tears in a symptomatic population. MATERIAL AND METHODS: Two radiologists with different levels of experience independently and retrospectively interpreted indirect MR (1.5T) arthrograms of the shoulder obtained in 67 symptomatic patients who underwent subsequent arthroscopy. On MR, the supraspinatus tendon was evaluated for full- or partial-thickness tear. With arthroscopy as the standard of reference, sensitivity, specificity, and diagnostic accuracy of indirect MR arthrography in the detection of full- and partial-thickness tears of the supraspinatus tendon was calculated. Kappa (kappa) statistics were used for the assessment of the agreement between arthroscopic and imaging findings and for the assessment of interobserver agreement. RESULTS: For full-thickness tears of the supraspinatus tendon, sensitivities, specificities, and accuracies exceeded 90% for both observers, with excellent interobserver agreement (kappa = 0.910). For partial-thickness tears, sensitivities (38-50%) and accuracies (76-78%) were poor for both reviewers, and interobserver agreement was moderate (kappa = 0.491). Discrepancies between MR diagnosis and arthroscopy were predominantly observed with small partial-thickness tears. CONCLUSION: Indirect MR arthrography is highly accurate in the diagnosis of full-thickness rotator cuff tears. However, the diagnosis of partial-thickness tears with indirect MR arthrography remains faulty, because exact demarcation of degenerative change and partial rupture is difficult. On the basis of the above findings, we do not recommend indirect MR arthrography on patients for whom rotator cuff disease is suspected clinically.


Assuntos
Imageamento por Ressonância Magnética/métodos , Lesões do Manguito Rotador , Sensibilidade e Especificidade , Lesões do Ombro , Traumatismos dos Tendões/diagnóstico , Adolescente , Adulto , Idoso , Artroscopia , Meios de Contraste/administração & dosagem , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Injeções Intravenosas , Masculino , Meglumina/administração & dosagem , Pessoa de Meia-Idade , Compostos Organometálicos/administração & dosagem , Estudos Retrospectivos , Manguito Rotador/patologia , Articulação do Ombro/patologia
12.
J Biomech ; 41(1): 106-13, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17698073

RESUMO

The effect of a bronchodilator in asthmatics is only partially described by changes in spirometric values since no information on regional differences can be obtained. Imaging techniques like high-resolution computed tomography (HRCT) provide further information but lack detailed information on specific airway responses. The aim of the present study was to improve the actual imaging techniques by subsequent analysis of the imaging data using computational fluid dynamics (CFD). We studied 14 mild to moderately severe asthmatics. Ten patients underwent HRCT before and 4h after inhalation of a novel long acting beta(2) agonist (LABA) that acts shortly after inhalation. Four patients were studied for chronic effects and underwent CT scans twice after adequate wash-out of bronchodilators. In the active group, a significant bronchodilator response was seen with a forced expiratory volume in 1s (FEV1) increase of 8.78 +/- -6.27% pred vs -3.38 +/- 6.87% pred in the control group. The changes in FEV1 correlated significantly with the changes in distal airway volume (r = 0.69, p = 0.007), total airway resistance (r = -0.73, p = 0.003) and distal airway resistance (r = -0.76, p = 0.002) as calculated with the CFD method. The changes in distal R(aw) were not fully homogeneous. In some patients with normal FEV1 at baseline, CFD-based changes in R(aw) were still detectable. We conclude that CFD calculations, based on airway geometries of asthmatic patients, provide additional information about changes in regional R(aw). All changes in the CFD-based calculated R(aw) significantly correlate with the observed changes in spirometric values therefore validating the CFD method for the studied application.


Assuntos
Resistência das Vias Respiratórias/efeitos dos fármacos , Asma/fisiopatologia , Broncodilatadores/farmacologia , Biologia Computacional/métodos , Tomografia Computadorizada por Raios X/métodos , Agonistas Adrenérgicos beta/farmacologia , Agonistas Adrenérgicos beta/uso terapêutico , Adulto , Resistência das Vias Respiratórias/fisiologia , Anfetaminas/farmacologia , Anfetaminas/uso terapêutico , Asma/tratamento farmacológico , Brônquios/efeitos dos fármacos , Brônquios/patologia , Brônquios/fisiopatologia , Broncodilatadores/uso terapêutico , Simulação por Computador , Feminino , Volume Expiratório Forçado/efeitos dos fármacos , Humanos , Hidroxiquinolinas/farmacologia , Hidroxiquinolinas/uso terapêutico , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Quinolonas/farmacologia , Quinolonas/uso terapêutico , Testes de Função Respiratória/métodos , Reologia , Espirometria , Capacidade Pulmonar Total/efeitos dos fármacos , Capacidade Vital/efeitos dos fármacos
13.
Med Eng Phys ; 30(7): 872-9, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18096425

RESUMO

Computational fluid dynamics (CFD) is increasingly applied in the respiratory domain. The ability to simulate the flow through a bifurcating tubular system has increased the insight into the internal flow dynamics and the particular characteristics of respiratory flows such as secondary motions and inertial effects. The next step in the evolution is to apply the technique to patient-specific cases, in order to provide more information about pathological airways. This study presents a patient-specific approach where both the geometry and the boundary conditions (BC) are based on individual imaging methods using computed tomography (CT). The internal flow distribution of a 73-year-old female suffering from chronic obstructive pulmonary disease (COPD) is assessed. The validation is performed through the comparison of lung ventilation with gamma scintigraphy. The results show that in order to obtain agreement within the accuracy limits of the gamma scintigraphy scan, both the patient-specific geometry and the BC (driving pressure) play a crucial role. A minimal invasive test (CT scan) supplied enough information to perform an accurate CFD analysis. In the end it was possible to capture the pathological features of the respiratory system using the imaging and computational fluid dynamics techniques. This brings the introduction of this new technique in the clinical practice one step closer.


Assuntos
Pulmão/patologia , Ventilação Pulmonar/fisiologia , Idoso , Biologia Computacional/métodos , Simulação por Computador , Diagnóstico por Computador , Feminino , Volume Expiratório Forçado , Humanos , Pulmão/anatomia & histologia , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Pressão , Cintilografia/métodos , Software , Tomografia Computadorizada por Raios X/métodos
14.
Int J Pediatr Otorhinolaryngol ; 72(6): 905-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18355927

RESUMO

We present a 6-week-old girl, referred because of failed newborn hearing screening in the right ear. Click-evoked oto-acoustic emissions were present in both ears, auditory brainstem responses (ABR) were present in the left but totally absent in the right ear. A magnetic resonance imaging (MRI) study revealed a large arachnoid cyst in the right cerebellopontine angle (CPA) and a diagnosis of "auditory neuropathy/auditory dyssynchrony" was established. A microsurgical resection of the cyst wall and fenestration was performed by a retro sigmoid approach. This is the first case in the literature of auditory neuropathy (AN) in an infant caused by a cerebellopontine angle arachnoid cyst.


Assuntos
Cistos Aracnóideos/diagnóstico , Ângulo Cerebelopontino/cirurgia , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Doenças do Nervo Vestibulococlear/fisiopatologia , Cistos Aracnóideos/fisiopatologia , Cistos Aracnóideos/cirurgia , Limiar Auditivo/fisiologia , Ângulo Cerebelopontino/patologia , Feminino , Perda Auditiva Bilateral/fisiopatologia , Perda Auditiva Bilateral/cirurgia , Humanos , Lactente , Imageamento por Ressonância Magnética , Doenças do Nervo Vestibulococlear/cirurgia
15.
J Biomech ; 40(10): 2207-13, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17178125

RESUMO

Determination of the apnea hypopnea index (AHI) as a measure of the severity of obstructive sleep apnea/hypopnea syndrome (OSAHS) is a widely accepted methodology. However, the outcome of such a determination depends on the method used, is time consuming and insufficient for prediction of the effect of all treatment modalities. For these reasons more methods for evaluating the severity of OSAHS, based on different imaging modalities, have been looked into and recent studies have shown that anatomical properties determined from three-dimensional (3D) computed tomography (CT) images are good markers for the severity of the OSAHS. Therefore, we correlated anatomical measurements of a 3D reconstruction of the upper airway together with flow simulation results with the severity of OSAHS in order to find a combination of variables to indicate the severity of OSAHS in patients. The AHI of 20 non-selected, consecutive patients has been determined during a polysomnography. All patients also underwent a CT scan from which a 3D model of the upper airway geometry was reconstructed. This 3D model was used to evaluate the anatomical properties of the upper airway in OSAHS patients as well as to perform computational fluid dynamics (CFD) computations to evaluate the airflow and resistance of this upper airway. It has been shown that a combination of the smallest cross-sectional area and the resistance together with the body mass index (BMI) form a set of markers that predict very well the severity of OSAHS in patients within this study. We believe that these markers can be used to evaluate the outcome of an OSAHS treatment.


Assuntos
Imageamento Tridimensional , Laringe/patologia , Laringe/fisiopatologia , Faringe/patologia , Faringe/fisiopatologia , Apneia Obstrutiva do Sono/patologia , Apneia Obstrutiva do Sono/fisiopatologia , Simulação por Computador , Feminino , Humanos , Laringe/diagnóstico por imagem , Masculino , Faringe/diagnóstico por imagem , Valor Preditivo dos Testes , Índice de Gravidade de Doença , Apneia Obstrutiva do Sono/diagnóstico por imagem , Apneia Obstrutiva do Sono/terapia , Tomografia Computadorizada por Raios X
16.
J Biomech ; 40(16): 3708-14, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17663990

RESUMO

Mandibular advancement devices (MADs) have emerged as a popular alternative for the treatment of sleep-disordered breathing. These devices bring the mandibula forward in order to increase upper airway (UA) volume and prevent total UA collapse during sleep. However, the precise mechanism of action appears to be quite complex and is not yet completely understood; this might explain interindividual variation in treatment success. We examined whether an UA model, that combines imaging techniques and computational fluid dynamics (CFD), allows for a prediction of the treatment outcome with MADs. Ten patients that were treated with a custom-made mandibular advancement device (MAD), underwent split-night polysomnography. The morning after the sleep study, a low radiation dose CT scan was scheduled with and without the MAD. The CT examinations allowed for a comparison between the change in UA volume and the anatomical characteristics through the conversion to three-dimensional computer models. Furthermore, the change in UA resistance could be calculated through flow simulations with CFD. Boundary conditions for the model such as mass flow rate and pressure distributions were obtained during the split-night polysomnography. Therefore, the flow modeling was based on a patient specific geometry and patient specific boundary conditions. The results indicated that a decrease in UA resistance and an increase in UA volume correlate with both a clinical and an objective improvement. The results of this pilot study suggest that the outcome of MAD treatment can be predicted using the described UA model.


Assuntos
Avanço Mandibular/instrumentação , Modelos Biológicos , Mecânica Respiratória , Reologia/métodos , Apneia Obstrutiva do Sono/fisiopatologia , Apneia Obstrutiva do Sono/reabilitação , Terapia Assistida por Computador/métodos , Simulação por Computador , Humanos , Avanço Mandibular/métodos , Prognóstico , Radiografia , Apneia Obstrutiva do Sono/diagnóstico por imagem , Resultado do Tratamento
17.
Eur J Radiol ; 62(2): 273-82, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17223002

RESUMO

PURPOSE: To determine the role of magnetic resonance (MR) mammography in detection and assessment of extent of tumors with extensive intraductal component (EIC+). MATERIAL AND METHODS: In a prospective study, 233 consecutive women with a suspicious lesion underwent preoperative MR mammography and 209 invasive ductal carcinomas were detected. We studied the prediction of intraductal spread on mammography (MX), ultrasound (US) and MR. We compared the size of the total lesion on MX, US and MR and correlated it with histopathology. Enhancement patterns on MR were described. RESULTS: Of 209 invasive ductal carcinomas, 50 were EIC+ (24%). MX predicted intraductal spread in EIC+ carcinomas in 48.5%, US in 34.2% and MR in 68%. Compared to MX and US, MR was best in assessment of total tumor size. On MR, ductal spread in EIC+ tumors presented as ductal or linear enhancement, long spicules, a regional enhancing area or nodules adjacent to a mass. CONCLUSION: MR had the highest sensitivity to predict intraductal spread and was superior in assessing total tumor size.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Ductal de Mama/secundário , Carcinoma Intraductal não Infiltrante/diagnóstico , Carcinoma Intraductal não Infiltrante/secundário , Imageamento por Ressonância Magnética , Mamografia , Mastectomia Segmentar , Adulto , Idoso , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/diagnóstico por imagem , Carcinoma Ductal de Mama/cirurgia , Carcinoma Intraductal não Infiltrante/diagnóstico por imagem , Carcinoma Intraductal não Infiltrante/cirurgia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Mamografia/métodos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Sensibilidade e Especificidade , Ultrassonografia Mamária
18.
Semin Ultrasound CT MR ; 28(1): 35-51, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17366707

RESUMO

A wide range of vascular disorders can affect the spleen. Although clinical presentation is often nonspecific, early diagnosis and treatment are mandatory in most conditions. Noninvasive imaging techniques are well suited to meet these objectives. Familiarity with normal macroscopic and microscopic vascular anatomy is a prerequisite to understand the pathophysiology of vascular disorders of the spleen. This article deals with diseases of the splenic vasculature (aneurysms, arteriovenous fistula, splenic vein thrombosis, collateral circulation in portal hypertension) as well as vascular disorders affecting the splenic parenchyma (splenic infarct, Gamna-Gandy bodies). Primary vascular tumors and tumor-like conditions of the spleen will be discussed very briefly.


Assuntos
Baço/irrigação sanguínea , Esplenopatias/diagnóstico , Doenças Vasculares/diagnóstico , Diagnóstico Diferencial , Humanos
19.
B-ENT ; 3 Suppl 7: 27-35, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18225606

RESUMO

OBJECTIVES: The place of MRI in the diagnostic work-up of patients with bilateral perceptive hearing loss, tinnitus and vertigo is under discussion. The purpose of this study is to investigate the role of MRI in patients with otovestibular and cranial nerve complaints of unknown aetiology. METHODOLOGY: After thorough otologic examination, 430 patients were consecutively referred for an MR examination of the cerebellopontine angle. RESULTS: The detection rate for essential lesions was 4.9%. Two groups of retrocochlear lesions were frequently observed: central WMLs/atrophy and neurovascular conflict affecting a cranial nerve. CONCLUSIONS: MR imaging of the cerebellopontine angle, fossa posterior and petrous bones makes it possible to observe abnormalities of the vestibulocochlear nerve and inner ear. Additional T2-weighted FSE images of the whole brain make it possible to evaluate the occurrence of early central lesions. This imaging protocol can diagnose essential lesions relating directly to the complaint in 4.9% of the patients with hearing loss, subjective tinnitus or vertigo. We frequently observed two groups of lesions of uncertain significance in our study population. WMLs are present in 50% of patients with a mean age of 59 years. In the younger subpopulation aged under 51 years the prevalence of WMLs is 24%. It remains unclear whether these lesions can be accounted for by the diversity of symptoms with which the patients presented. In addition, we found a high number of neurovascular conflicts involving different cranial nerves.


Assuntos
Perda Auditiva/diagnóstico , Imageamento por Ressonância Magnética/métodos , Zumbido/diagnóstico , Vertigem/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ângulo Cerebelopontino/patologia , Criança , Pré-Escolar , Fossa Craniana Posterior/patologia , Diagnóstico Diferencial , Feminino , Perda Auditiva/etiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Osso Petroso/patologia , Estudos Retrospectivos , Zumbido/etiologia , Vertigem/etiologia
20.
Eur J Surg Oncol ; 32(9): 901-10, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16920327

RESUMO

AIM: Due to its high sensitivity, magnetic resonance (MR) mammography is increasingly used as adjunct to mammography and ultrasound. The technique, however, has a relatively limited specificity. Therefore, it may only be used for specific indications. One of the indications is preoperative staging of breast carcinoma. This review serves to give an overview of the studies published on the role of MR in preoperative local staging. METHODS: We reviewed studies of the role of MR mammography in the detection of breast carcinomas and in the assessment of the diameter and extent of carcinomas. We also reviewed published studies on detection of multifocal and multicentric carcinomas that were occult on mammography and ultrasound. Advantages and drawbacks of preoperative MR mammography and the effect on treatment, as reported in different published studies, are described. The review is based on a search of PubMed, using specific terms for the different topics. RESULTS: MR has the highest sensitivity to detect invasive carcinomas and is best in assessment of tumor extent, including detection of multifocal, multicentric and bilateral disease. CONCLUSION: MR mammography is a valuable adjunct to conventional imaging in the preoperative local staging of breast cancer.


Assuntos
Neoplasias da Mama/patologia , Imageamento por Ressonância Magnética/métodos , Estadiamento de Neoplasias/métodos , Feminino , Humanos , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA