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1.
Rev Neurol (Paris) ; 177(9): 1176-1182, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33648780

RESUMO

We report serial magnetic resonance imaging (MRI) findings and follow-up in a case of human African trypanosomiasis (HAT) presenting with limited lesions followed by early and complete resolution. We searched the literature for documented cases and reviewed MRI findings before treatment. A 30-year-old Lebanese man, who had lived in Gabon for six years, presented with a two-year history of rash, anorexia, weight loss, arthralgia, paresthesia, and hypersomnia. Previously, the patient had received corticosteroid therapy for unconfirmed ANCA-associated vasculitis. Physical examination revealed a painless chancre on the left arm located at the site of an old insect bite, enlarged cervical, axillar and inguinal lymph nodes, hepatosplenomegaly and impaired concentration. Blood analysis showed an elevated protein level (90g/L) with hypoalbuminemia (24.2g/L) and elevated IgM (26.4g/L). Bone marrow aspirate and biopsy failed to detect any parasite. Polymerase chain reaction tests on blood and cerebrospinal fluid were positive for Trypanosoma. Serology tests confirmed the diagnosis of HAT due to Trypanosoma brucei gambiense infection. 3T MRI showed lesions in the hypothalamus and basal ganglia, the internal capsule, and the mesencephalon bilaterally. Follow-up MRI showed interval progression of the abnormalities. Treatment with melarsoprol was followed by clinical improvement with regression of the lesions on the three-month MRI, then total resolution at the 10-month follow-up. This case highlights a pattern of mild MRI lesions in T. brucei gambiense HAT with a total and rapid resolution under treatment. The literature review (16 HAT cases with sufficient radiological data, included ours) revealed an MRI pattern of brain lesion distribution that could be helpful for diagnosis and orienting biological tests.


Assuntos
Trypanosoma brucei gambiense , Tripanossomíase Africana , Adulto , Animais , Humanos , Imageamento por Ressonância Magnética , Masculino , Reação em Cadeia da Polimerase , Testes Sorológicos , Tripanossomíase Africana/diagnóstico por imagem , Tripanossomíase Africana/tratamento farmacológico
2.
Rev Neurol (Paris) ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38744570
4.
Cerebrovasc Dis ; 35(4): 327-36, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23615478

RESUMO

BACKGROUND: Cerebral complications are well-identified causes of morbidity and mortality in patients with infective endocarditis (IE). Few studies have analysed the impact of brain magnetic resonance imaging (MRI) in IE patients with neurological manifestations. OBJECTIVES: The aims of this study were to assess the MRI contribution to the management of patients with IE neurological manifestations and to compare cerebral CT and MRI findings. MATERIAL AND METHODS: Patients with definite or probable IE and neurological manifestations were prospectively enrolled from 2005 to 2008, in a university hospital (Bichat Claude Bernard Hospital, Paris). Clinical and radiological characteristics and echocardiographic findings were systematically recorded. Brain MRI with angiography was performed and compared to available CT scans. The contribution of MRI results to cerebral involvement staging and to therapeutic plans was evaluated. RESULTS: Thirty patients, 37-89 years old, were included. Nineteen suffered from pre-existing heart disease. Blood cultures were positive in 29 cases and the main micro-organisms were streptococci (n = 14) and staphylococci (n = 13). The IE was mainly located on mitral (n = 15) and aortic valves (n = 13). Neurological events were strokes (n = 12), meningitis (n = 5), seizures (n = 1), impaired consciousness (n = 11) and severe headache (n = 1). MRI findings included ischaemic lesions (n = 25), haemorrhagic lesions (n = 2), subarachnoid haemorrhage (n = 5), brain abscess (n = 6), mycotic aneurysm (n = 7), vascular occlusion (n = 3) and cerebral microbleeds (n = 17). In 19/30 cases, neurological manifestations were observed before the diagnosis of IE. MRI was more sensitive than CT scan in detecting both clinically symptomatic cerebral lesions (100 and 81%, respectively) and additional asymptomatic lesions (50 and 23%, respectively). Therapeutic plans were modified according to MRI results in 27% of patients: antibiotherapy regimen modifications in 7% (switch for molecules with high cerebral diffusion) and surgical plan modifications in 20% (indication of valvular replacement due to the embolic nature of the vegetations revealed by MRI or postponement of surgery due to haemorrhagic lesions). None of the 16/30 (51%) operated-on patients experienced postoperative neurological worsening. In-hospital death occurred in 4 patients. CONCLUSION: In patients with IE neurological manifestations, MRI revealed a broader involvement of the brain (type and number of lesions) than indicated by clinical signs and/or CT scan. With a better disease staging of neurological manifestations, MRI brain imaging may help in patient management and the decision-making process especially for cardiac surgery indication and timing of valve replacement.


Assuntos
Encefalopatias/diagnóstico , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Angiografia Cerebral/métodos , Artérias Cerebrais/patologia , Imagem de Difusão por Ressonância Magnética , Endocardite Bacteriana/complicações , Angiografia por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Encefalopatias/etiologia , Encefalopatias/mortalidade , Encefalopatias/patologia , Encefalopatias/terapia , Artérias Cerebrais/diagnóstico por imagem , Transtornos Cerebrovasculares/diagnóstico , Transtornos Cerebrovasculares/etiologia , Ecocardiografia , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/microbiologia , Endocardite Bacteriana/mortalidade , Endocardite Bacteriana/terapia , Feminino , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Paris , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Tomografia Computadorizada por Raios X
5.
Ann Cardiol Angeiol (Paris) ; 72(6): 101690, 2023 Dec.
Artigo em Francês | MEDLINE | ID: mdl-37944222

RESUMO

Anomalous aortic origin of the coronary arteries are congenital anomalies with many anatomical forms. Due to the varying risk of sudden death, these abnormalities must be classified accurately. There are still questions about the mechanism and individual risk of sudden death, the natural history of these abnormalities and the benefits of a surgical correction. Large-scale observational registries may provide more evidence-based data to practitioners caring for the patients concerned. The ANOCOR registry, the largest in size published to date, enrolled 472 patients (mean age 63 years) with 496 coronary abnormalities. The angiographic representation (with invasive coronary angiography or coronary CT angiography) according to the coronary artery and initial ectopic course could be specified with the identification of two main phenotypes: the circumflex artery (n = 235) with a retroaortic course in 97% of cases and the right coronary artery (n = 165) with an interarterial course in 89.7% of cases. Two left coronary anatomical forms have been confused by non-expert cardiologists: those with a retropulmonary or interarterial course. Sudden death related to coronary anomaly was a very rare mode of presentation (3 patients or 0.6% of the cohort) in this population with very few young patients < 35 years (11 cases or 2.3% of the cohort).


Assuntos
Anomalias dos Vasos Coronários , Humanos , Pessoa de Meia-Idade , Angiografia por Tomografia Computadorizada , Angiografia Coronária , Anomalias dos Vasos Coronários/diagnóstico por imagem , Anomalias dos Vasos Coronários/cirurgia , Morte Súbita , Sistema de Registros , Tomografia Computadorizada por Raios X
6.
Lupus ; 20(7): 745-8, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21427136

RESUMO

Fatigue is a prominent feature of systemic lupus erythematosus (SLE), usually ascribed to various factors, such as muscle or joint involvement, anaemia or depression. The Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoantibody-mediated disorder of neuro-muscular transmission. We report on a well-defined LEMS associated with thymus hyperplasia in a SLE patient. An African 41 years-old SLE patient presented with persisting fatigue, myalgia and dyspnea, abolished reflexes and a bilateral ptosis. Neuromuscular electrodiagnostic study showed a clear-cut potentiation that was typical of a pre-synaptic neuromuscular junction disease. Anti-calcium gated channels antibodies were disclosed in serum and a diagnosis of LEMS was made. A total body CT-scan revealed an antero-superior mediastinal mass, compatible with thymoma. The tumour was surgically removed with a final diagnosis of follicular thymic hyperplasia. In conclusion, our observation provides a new example of entangled organ-specific and systemic autoimmunity in the context of thymus pathology. Potentiation study during electromyography should be performed systematically to rule out LEMS in patients with SLE and muscle weakness.


Assuntos
Síndrome Miastênica de Lambert-Eaton/complicações , Lúpus Eritematoso Sistêmico/complicações , Hiperplasia do Timo/complicações , Adulto , Fadiga/diagnóstico , Fadiga/etiologia , Humanos , Síndrome Miastênica de Lambert-Eaton/diagnóstico , Masculino , Mauritânia , Timoma/diagnóstico , Timoma/cirurgia , Hiperplasia do Timo/diagnóstico , Neoplasias do Timo/diagnóstico , Neoplasias do Timo/cirurgia , Tomografia Computadorizada por Raios X , Imagem Corporal Total
7.
J Radiol ; 91(5 Pt 2): 602-8, 2010 May.
Artigo em Francês | MEDLINE | ID: mdl-20657365

RESUMO

Cardiac MRI in patients with acute coronary syndrome with elevated troponin levels but normal coronarography can now routinely be performed on most MR units. MRI plays an important role in this clinical setting by its ability to detect myocardial infarction in patients with normal coronarography or suggest a different, potentially severe, alternate diagnosis such as myocarditis or takotsubo cardiomyopathy.


Assuntos
Síndrome Coronariana Aguda/diagnóstico , Aumento da Imagem , Imageamento por Ressonância Magnética , Síndrome Coronariana Aguda/diagnóstico por imagem , Adulto , Angiografia Coronária , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Fatores de Tempo
8.
J Radiol ; 90(4): 481-4, 2009 Apr.
Artigo em Francês | MEDLINE | ID: mdl-19503029

RESUMO

PURPOSE: To use diffusion weighted MR imaging (DWI), a technique routinely used in patients with stroke, for diagnosis of myocardial infarction (MI). MATERIALS AND METHODS: A breath hold ECG gated DWI sequence (b = 300 sec/mm2) was developped and applied to 7 patients with recent MI (3-15 days), 3 patients with chronic MI (> 6 months) and 4 patients with valvular heart disease without MI (control cases). DWI data were correlated to T2W, first pass perfusion and delayed enhancement data. RESULTS: In all patients with recent MI, DWI showed an area of increased signal with reduction of ADC relative to normal myocardium. Hyperintense lesion on DWI corresponded to areas of delayed enhancement. The diffusion images were normal in patients with chronic MI or no MI. CONCLUSION: Even though no animal model or other reference method is available, these preliminary results indicate that DWI could assist clinicians in detecting recent MI.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Infarto do Miocárdio/diagnóstico , Miocárdio/patologia , Adulto , Idoso , Doença Crônica , Meios de Contraste , Diagnóstico Diferencial , Eletrocardiografia , Estudos de Viabilidade , Feminino , Frequência Cardíaca/fisiologia , Doenças das Valvas Cardíacas/diagnóstico , Humanos , Masculino , Meglumina , Pessoa de Meia-Idade , Variações Dependentes do Observador , Compostos Organometálicos , Fatores de Tempo
10.
Neurochirurgie ; 65(1): 32-35, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30711258

RESUMO

We report an unusual case of a frontal partially calcified pilocytic astrocytoma (PA) (WHO grade 1) in an 18-year-old woman who presented with acute, spontaneous intracerebral hemorrhage. Histopathology revealed the PA was mixed with psammoma bodies and areas of vascular proliferation responsible for a hypervascular pattern. The patient underwent a total gross resection. MRI showed no residual tumor at the 18-month follow-up and her neurological deficits improved after rehabilitation. Only 20 cases, including ours, of hemorrhagic presentation of PA in adults have been reported to date with enough radiological data. Furthermore, hemorrhagic presentation of a calcified PA is extremely rare. To date only two other cases of calcified PA with hemorrhagic presentation have been reported, one in an adult and one in an infant as described by Shibao et al. (2012) and Kapoor et al. (2015) respectively. Endothelial proliferation may be the main cause of bleeding in these lesions. In our case, a hypervascular pattern was exhibited by histopathological findings. A diagnosis of PA should be considered, especially when calcifications are present within a hemorrhagic tumor lesion.


Assuntos
Astrocitoma/cirurgia , Neoplasias Encefálicas/cirurgia , Hemorragia Cerebral/terapia , Neoplasia Residual/cirurgia , Adolescente , Astrocitoma/diagnóstico , Neoplasias Encefálicas/diagnóstico , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/etiologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Resultado do Tratamento
11.
Ann Dermatol Venereol ; 135(6-7): 499-502, 2008.
Artigo em Francês | MEDLINE | ID: mdl-18598802

RESUMO

BACKGROUND: Extraskeletal osteosarcoma is a rare mesenchymatous tumour occurring in adults aged over 50 years and is located mainly in the limbs or retroperitoneum. We report a case of metastatic extraskeletal osteosarcoma revealed by a cutaneous occipital tumour site. CASE-REPORT: A 53-year-old woman was admitted for dyspnea and weight loss. An occipital tumour, noticed for one year by the patient, was discovered. It was freely movable on the bone, of hard consistency and responsible for alopecia. In addition to left-sided pleural effusion, a chest CAT revealed a large mass in the left lung, including areas of necrosis and calcifications with intracardiac extension. Histological examination of biopsies of the skin and of pulmonary and intracardiac lumps showed an osteosarcomatous proliferation. No primary osteosarcoma was found in the bones. A diagnosis was made of metastatic extraskeletal osteosarcoma. Intravenous chemotherapy was given followed by radiotherapy. After a six-month stabilization period, the disease progressed. DISCUSSION: Extraskeletal cutaneous locations of osteosarcoma are extremely rare. They may comprise either the primary tumour or a metastatic lesion. In this patient, the immediately metastatic nature of the disease was a poor prognostic factor for this high-grade sarcoma.


Assuntos
Neoplasias de Cabeça e Pescoço/secundário , Osteossarcoma/secundário , Couro Cabeludo , Neoplasias Cutâneas/secundário , Alopecia/etiologia , Biópsia , Progressão da Doença , Feminino , Neoplasias de Cabeça e Pescoço/complicações , Humanos , Imuno-Histoquímica , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/secundário , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Osteossarcoma/complicações , Osteossarcoma/diagnóstico , Osteossarcoma/patologia , Prognóstico , Radiografia Torácica , Pele/patologia , Neoplasias Cutâneas/complicações , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologia , Tomografia Computadorizada por Raios X
12.
Med Mal Infect ; 48(8): 533-539, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30017477

RESUMO

BACKGROUND: Miliary tuberculosis (miliary TB) is characterized by a hematogenous spread of Mycobacterium tuberculosis. Cerebral lesions associated with miliary TB have been reported with diverse frequencies. METHODS: We retrospectively analyzed brain imaging in 34 patients presenting with proven miliary TB hospitalized in our teaching hospital between 2008 and 2014. RESULTS: Neurological symptoms were present at admission in 15 patients, emerged during treatment in six, and were never reported in 13. Twenty-one of 34 patients had cerebral involvement, of which five patients did not present with any neurological symptoms. The most common brain lesions on MRI were tuberculomas. Cerebrospinal fluid (CSF) analysis showed elevated cell count in eight patients who all had abnormal MRI results. Nine patients with normal CSF had abnormal MRI results. CSF cultures were positive in only eight patients. Paradoxical clinical worsening during TB and corticosteroid treatment was observed in six patients. CONCLUSION: Among patients presenting with miliary TB who underwent brain imaging, more than 60% demonstrated cerebral involvement. Abnormal imaging could occur without any clinical nor CSF impairment. Systematically performing brain imaging in miliary TB patients could therefore be informative.


Assuntos
Imageamento por Ressonância Magnética , Neuroimagem , Tomografia Computadorizada por Raios X , Tuberculoma Intracraniano/diagnóstico por imagem , Tuberculoma Intracraniano/microbiologia , Tuberculose Miliar/complicações , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
13.
Rev Med Interne ; 27(3): 248-52, 2006 Mar.
Artigo em Francês | MEDLINE | ID: mdl-16406161

RESUMO

INTRODUCTION: Sirolimus is a new immunosuppressive drug used in organ transplantation, particularly in renal transplantation. In the future, it could replace calcineurin inhibitors such as cyclosporine. It is currently associated with side effects, such as thrombocytopenia and hyperlipidemia. Several interstitial pneumonitis associated with sirolimus has been previously described in renal transplant recipients associated with marked general symptoms. EXEGESIS: We report on a 65-year-old renal recipient presenting with a non typical case of sirolimus interstitial pneumonitis. He presented with fever and marked general symptoms for several months. CT scan showed a unilateral interstitial pneumonitis. After infectious, inflammatory and tumoral diseases were ruled out, sirolimus associated interstitial pneumonitis was evoked. The patient improved quickly after discontinuation of sirolimus. CONCLUSION: It is important to evoke, after eliminating other aetiologies, sirolimus induced pneumonitis in face of an organ transplant recipient presenting with marked general symptoms even if the pulmonary symptoms are not predominant.


Assuntos
Imunossupressores/efeitos adversos , Transplante de Rim , Doenças Pulmonares Intersticiais/induzido quimicamente , Sirolimo/efeitos adversos , Idoso , Líquido da Lavagem Broncoalveolar/citologia , Broncoscopia , Humanos , Doenças Pulmonares Intersticiais/diagnóstico , Masculino , Tomografia Computadorizada por Raios X
14.
J Radiol ; 87(5): 533-40, 2006 May.
Artigo em Francês | MEDLINE | ID: mdl-16733409

RESUMO

Pluridisciplinary management of women with postpartum hemorrhage is mandatory in order to precisely assess initial seriousness, to maintain hemodynamic parameters and to confirm the cause of bleeding. Embolization should be offered only after exploration of the uterine cavity, inspection of the vagina, cervix and perineum and failure of uterotonic drugs. Embolization should be carried out in an angiography suite under constant monitoring of the patient by the anesthesiologist. Indications to perform arterial embolization include uterine atony particularly following a vaginal delivery, cervico-uterine hemorrhage, cervicovaginal lacerations (previously repaired or if surgical repair has failed) and vaginal thrombus, particularly in case of associated coagulopathy. Arterial embolization is effective in about 85% of cases. Placenta acccreta can also be successfully managed with arterial embolization as an alternative to hysterectomy. Unilateral femoral approach allows selective study of both internal iliac arteries and branches. Selective embolization of both uterine arteries should be ideally performed. In case of spasm or difficult catheterization, embolization of the anterior division of both internal iliac arteries should be considered. In case of bleeding from the cervico-vaginal region, selective evaluation and embolization of cervicovaginal branches should be performed. In case of failure or recurrence of bleeding, ovarian and round ligament arteries should be evaluated. In most cases, resorbable gelatin sponge pledgets should be used to perform embolization. The use of microcatheters and non resorbable embolization agents should be considered by trained interventional radiologists in case of placenta accreta or vascular lesions. After embolization, the patient should be transferred to the intensive care unit for further observation in order to offer emergent surgical procedure or another session of embolization in case of recurrence of bleeding.

15.
Diagn Interv Imaging ; 97(10): 991-1002, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27693089

RESUMO

Lung cancer is the leading cause of cancer death worldwide. Prognosis and treatment outcomes are known to be related to the disease stage at the time of diagnosis. Therefore, an accurate assessment of the extent of disease is critical to determine the most appropriate therapy. Currently available imaging modalities for diagnosis and follow-up consist of morphological and functional imaging. Morphological investigations are mainly performed with CT-scan and in some cases with MRI. In this review, we describe the contribution of MRI in lung cancer staging focusing on solid pulmonary nodule characterization and TNM staging assessment using chest and whole-body MRI examinations, detailing in each chapter current recommendations and future developments.


Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Imageamento por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Seguimentos , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Neoplasias Pulmonares/terapia , Estadiamento de Neoplasias/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Prognóstico , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos
17.
JBR-BTR ; 98(2): 68-71, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30394427

RESUMO

PURPOSE: To assess the normal values of fractional anisotropy (FA) and mean diffusivity (MD) of L4, L5 and S1 nerve roots using diffusion tensor imaging (DTI) in healthy volunteers. MATERIALS AND METHODS: 37 subjects without previous history of lumbalgia or radiculalgia were prospectively examined: 27 at 1.5T and 10 at 3T MRI. The protocol included standard anatomical sequences and a DTI acquisition. Nerve root fibers were semi automatically extracted from DTI tractography. FA and MD values were measured at 4 key portions along each L4, L5 and S1 nerve roots. RESULTS: At 1.5T MRI, FA and MD were 0.221 ± 0.011 and 460.9 ± 35.5 mm2.s-1 respectively; at 3T MRI, FA and MD were 0.216 ± 0.01 and 480.1 ± 36.1 mm2.s-1 respectively, which may be considered as normal values for mobile lumbar spine nerve roots, independently of intersomatic space level (p = 0.06) and nerve root portion (p = 0.08) or magnetic field (p = 0.06). CONCLUSION: Normal FA and MD values can be measured along lumbar mobile spine nerve roots in healthy subjects. These values were not dependent on intersomatic space level, side or anatomical portion of the nerve root or magnetic field.

18.
Chest ; 110(5): 1243-7, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8915228

RESUMO

OBJECTIVE: To evaluate right ventricle (RV) anatomy and performance and its relationships with pulmonary circulation in AIDS patients. DESIGN: We conducted a prospective blinded study by using cine-MRI, a well-accepted method to assess RV and pulmonary circulation. SETTING: A university hospital. PARTICIPANTS: Ten healthy volunteers and 13 asymptomatic AIDS patients. MEASUREMENTS: RV end-diastolic and end-systolic volumes, RV ejection fraction (RVEF), pulmonary artery (PA) diameter, main pulmonary artery distensibility (MPAD), RV free wall diastolic thickness (RVWT), and RV mass were measured. The RVWT/left ventricular wall thickness index was calculated. RESULTS: AIDS patients had significantly increased RV end-diastolic and end-systolic volumes and decreased RVEF (50 +/- 10 vs 59 +/- 6; p < 0.03). Four AIDS patients had RV wall motion abnormalities; 5 (38%) had an RVEF under 45%. RVWT, the RVWT/left ventricular wall thickness index, and PA diameter were significantly increased in AIDS patients. RV mass was increased in 54% of AIDS patients. MPAD was significantly lower in AIDS patients (18.8 +/- 15 vs 26 +/- 4; p < 0.01). A significant relationship was found between RV mass and MPAD (r = 0.76; p = 0.02). CONCLUSIONS: RV function is frequently impaired in AIDS patients. Anatomic and functional abnormalities found in RV and PA parameters suggest a systolic overload on RV. Pulmonary circulation abnormalities may influence RV structure and function in AIDS patients.


Assuntos
Síndrome da Imunodeficiência Adquirida/fisiopatologia , Imagem Cinética por Ressonância Magnética , Artéria Pulmonar/fisiopatologia , Função Ventricular Direita , Síndrome da Imunodeficiência Adquirida/patologia , Adulto , Volume Cardíaco , Diástole , Elasticidade , Feminino , Ventrículos do Coração/patologia , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Estudos Prospectivos , Artéria Pulmonar/patologia , Circulação Pulmonar , Método Simples-Cego , Volume Sistólico , Sístole , Disfunção Ventricular Direita/diagnóstico , Disfunção Ventricular Direita/fisiopatologia
19.
Invest Radiol ; 35(11): 647-52, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11110300

RESUMO

RATIONALE AND OBJECTIVES: To assess the abilities of dynamic diffusion-weighted MRI to demonstrate the effects in vivo of a high-viscosity iodinated contrast agent on medullary and cortical blood flow in the rat kidney. METHODS: Dynamic diffusion-weighted, echoplanar MR images obtained from five b-value single-shot acquisitions and their isotropic apparent diffusion coefficient maps were obtained from nine rats anesthetized by pentobarbital sedation, before and after intravenous injection of a high-viscosity, dimeric iso-osmolar iodinated contrast medium (iodixanol), and compared with those obtained from four control rats that received saline. RESULTS: The mean baseline apparent diffusion coefficient values were 1.64 +/- 0.05 x 10(-3) mm2/s for the cortex and 1.75 +/- 0.06 x 10(-3) mm2/s for the medulla. In the iodixanol group, a significant decrease in renal diffusion was observed at 12 minutes and lasted at least until 24 minutes. The decrease in diffusion occurred earlier for the cortex and lasted less than for the medulla. There was no significant modification in diffusion over time in the control group. CONCLUSIONS: This preliminary experience in rats shows that dynamic diffusion-weighted MRI can be used to study noninvasively the in vivo renal hemodynamic response after injection of iodinated contrast.


Assuntos
Meios de Contraste/farmacologia , Imagem Ecoplanar , Circulação Renal/efeitos dos fármacos , Ácidos Tri-Iodobenzoicos/farmacologia , Animais , Estudos de Viabilidade , Córtex Renal/irrigação sanguínea , Medula Renal/irrigação sanguínea , Masculino , Ratos , Ratos Wistar
20.
Invest Radiol ; 34(3): 218-24, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10084667

RESUMO

RATIONALE AND OBJECTIVES: The authors sought to evaluate prospectively magnetic resonance angiography (MRA) versus fistulography in the detection and characterization of complications associated with malfunctioning hemodialysis access fistulas (arteriovenous fistulas [AVF]). METHODS: Nineteen patients with clinical AVF dysfunction were studied by MRA and fistulography. Data from each study were collected prospectively and analyzed in a blinded manner. RESULTS: The main diagnosis was stenosis in eight patients, thrombosis in five patients (mural thrombosis with preserved flow in one), aneurysm without stenosis in two patients, and normal AVF in four patients. A hazy flow void, assumed to be related to turbulence, was observed in normal arterial anastomoses. When flow void was considered as a criterion of stenosis or thrombosis, one false-positive and one false-negative MRA study were determined, yielding a sensitivity and specificity of 92% and 86%, respectively. CONCLUSIONS: Magnetic resonance angiography is a feasible and sensitive technique with which to portray suspected malfunctioning hemodialysis access fistulas.


Assuntos
Derivação Arteriovenosa Cirúrgica , Angiografia por Ressonância Magnética , Diálise Renal/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Flebografia , Estudos Prospectivos , Sensibilidade e Especificidade
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