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1.
Chest ; 103(4): 1293-5, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8131494

RESUMO

Transcatheter embolization therapy of vascular abnormalities is a well-accepted technique. It is particularly useful in the preoperative management of cerebral arteriovenous malformations, in which the risk of significant hemorrhage at surgery would otherwise be unacceptably high. A patient developed symptomatic pulmonary emboli and infarction following an uneventful embolization using polyvinyl alcohol particles. The authors believe this to be the first reported case of this complication of embolic therapy using polyvinyl alcohol.


Assuntos
Embolização Terapêutica/efeitos adversos , Malformações Arteriovenosas Intracranianas/terapia , Álcool de Polivinil/efeitos adversos , Embolia Pulmonar/etiologia , Adulto , Feminino , Humanos , Embolia Pulmonar/diagnóstico por imagem , Radiografia
2.
AJNR Am J Neuroradiol ; 13(1): 145-54, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1595432

RESUMO

PURPOSE: To study the usefulness of MR in the evaluation of spinal cord infarctions and associated findings. MATERIALS AND METHODS: MR examinations of 12 patients (10 men and two women) were reviewed retrospectively. Onset of symptoms of spinal cord ischemia was abrupt in all patients; MR was performed 8 hr to 4 months after onset. Contrast-enhanced MR was performed in four of the patients. RESULTS: Abnormal MR findings of the spinal cord included abnormal cord signal (11 of 12), best demonstrated on T2-weighted images, and morphologic changes (cord enlargement during the acute phase in nine patients and cord atrophy during the chronic phase in two), best demonstrated on T1-weighted images. Vascular abnormalities (aortic) were detected by MR in four of the 12 patients. Three of these four patients also had abnormal bone marrow signal, predominantly in the anterior half (one) or in multiple areas near the endplate and/or deep medullary portion of the vertebral body involving several vertebrae (two). T1-weighted images were not sensitive in detecting signal changes in either the bone marrow (two of three) or spinal cord (nine of 12). Enhanced MR imaging was performed in four patients (two in the acute phase and two in the chronic phase) and showed diffuse enhancement of the spinal cord proximal to a relatively unenhancing distal conus in one of the two patients imaged during the acute phase. No abnormal enhancement was noted in the other three patients. CONCLUSION: MR is a useful means of detecting spinal cord infarction and associated vascular and bony changes. The patterns of bone marrow abnormalities reflect the underlying pathophysiology of the blood supply to the spinal cord and bone. The associated vascular and bone marrow abnormalities serve as additional information for the diagnosis of spinal cord infarction.


Assuntos
Infarto/diagnóstico , Imageamento por Ressonância Magnética , Medula Espinal/irrigação sanguínea , Coluna Vertebral/irrigação sanguínea , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Infarto/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
3.
AJNR Am J Neuroradiol ; 12(4): 631-9, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1882735

RESUMO

Eighty patients with a total of 82 ischemic lesions were examined with contrast-enhanced MR imaging 1 hr to 1 month after onset of symptoms. The studies were reviewed retrospectively to determine the presence of arterial enhancement and the patterns of parenchymal enhancement. Arterial enhancement was often detected on the initial MR examination (45%), was frequently demonstrated in cortical infarction (86%), in some cases preceded the development of signal changes on T2-weighted images, and resolved by 11 days. The presence of arterial enhancement appeared to be a better indicator of clinical severity than was the presence of proximal vessel occlusion on MR or angiographic studies. Two patterns of parenchymal enhancement were seen: progressive enhancement and early and/or intense enhancement. In patients with the progressive pattern, parenchymal enhancement on postcontrast T1-weighted images was rarely seen before 7 days, while signal abnormalities on T2-weighted images were intense during the first few days. The early and/or intense enhancement pattern was usually present within the first 3 days, approximated or exceeded the area and intensity of signal changes on T2-weighted images, and was usually associated with minimal or reversible neurologic sequelae (except when located in or near a watershed zone), suggesting a lesser degree of ischemic insult than was associated with the progressive pattern.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Isquemia Encefálica/diagnóstico , Aumento da Imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Artérias/patologia , Encéfalo/patologia , Circulação Cerebrovascular , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
4.
AJNR Am J Neuroradiol ; 12(4): 621-9, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1688348

RESUMO

MR changes of cerebral ischemia have been shown to occur as early as 1-2 hr after vessel occlusion in experimental models of stroke. However, the MR findings in the early stages of ischemic stroke in the clinical population have not been well established. We studied 41 lesions in 39 patients in whom MR was performed within the first 24 hr after onset of ischemic symptoms. Twenty-five lesions were studied with gadopentetate dimeglumine. Vascular flow-related abnormalities, including absence of normal flow void and presence of arterial enhancement, were the earliest MR findings, detected within minutes of onset. Morphologic changes (brain swelling) on T1-weighted images without signal changes on T2-weighted images could be detected within the first few hours. Signal changes were not usually found before 8 hr on T2-weighted images or before 16 hr on T1-weighted images. In contrast to the absence of parenchymal enhancement typically found in cortical infarctions in the first 24 hr, a few lesions (including transient occlusions, partial occlusions, and isolated watershed infarctions) exhibited early, exaggerated parenchymal enhancement. We conclude that signal changes may not be reliable in detecting ischemic stroke within the first 8 hr after onset. Vascular abnormalities, when present, are the most reliable and earliest findings. Other MR findings of early ischemic stroke, including morphologic changes and early, exaggerated parenchymal enhancement, may also precede signal changes. Paramagnetic contrast administration often provides valuable information in the detection and evaluation of acute ischemia.


Assuntos
Isquemia Encefálica/diagnóstico , Imageamento por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Vasos Sanguíneos/patologia , Encéfalo/patologia , Circulação Cerebrovascular , Feminino , Humanos , Aumento da Imagem , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
5.
Ann Otol Rhinol Laryngol ; 100(1): 54-62, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1985527

RESUMO

Fifty-three magnetic resonance imaging (MRI) and 25 computed tomography (CT) studies of 53 head and neck masses in pediatric patients were reviewed retrospectively. All lesions had pathologic proof except for 2 metastatic and 2 recurrent lesions, which only had prior pathologic confirmation at their primary sites. These included 12 malignant tumors, 23 benign tumors, 6 inflammatory masses, and 12 congenital lesions. The MRI performance ranged predominantly from good to excellent in detection of the lesion and the extent of involvement and in contrast to the surrounding tissue; when CT comparison was available, MRI proved to be equal to or better than it in detection of these factors and in preoperative diagnosis. Our results suggest that MRI should be the method of choice for the initial evaluation of the pediatric head and neck region, especially in those patients requiring multiple examinations. However, CT and MRI should be used conjunctively in complicated cases, especially those possibly involving lesions with calcifications or bony involvement.


Assuntos
Cistos/diagnóstico , Neoplasias de Cabeça e Pescoço/diagnóstico , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Adolescente , Criança , Pré-Escolar , Cistos/congênito , Estudos de Avaliação como Assunto , Humanos , Lactente , Recém-Nascido , Estudos Retrospectivos
9.
J Comput Assist Tomogr ; 14(4): 536-41, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2370352

RESUMO

We studied 40 consecutive patients clinically suspected of having meningeal disease, in whom both Gd-diethylenetriamine pentaacetic acid (DTPA)-enhanced magnetic resonance (MR) examinations and CSF or surgical pathologic samples were obtained. The MR examinations were retrospectively reviewed for the presence of abnormal meningeal enhancement, as well as pattern and site of enhancement. The MR findings correctly correlated with pathology results in 15 of 19 patients with suspected tumor involvement (including one true negative) and in 18 of 21 patients with suspected inflammatory meningeal conditions (including 2 true negatives). Pial enhancement was demonstrated in 62% (10 of 16) of patients with meningitis and in 29% (4 of 14) of patients with meningeal neoplastic involvement. A diffuse meningeal distribution was commonly present with inflammatory conditions (69%, 11 of 16). A nodular appearance was seen in two patients with tumor involvement of the meninges as well as in a single case of sarcoidosis but was not seen with infectious meningitis. Our data suggest that Gd-DTPA-enhanced MR imaging is sensitive to the presence of meningeal pathology but is nonspecific as to disease entity. Recognition of certain MR patterns in conjunction with clinical presentation may improve diagnosis and management of patients with suspected meningeal disease.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias Meníngeas/diagnóstico , Meningite/diagnóstico , Compostos Organometálicos , Ácido Pentético , Meios de Contraste , Reações Falso-Negativas , Reações Falso-Positivas , Gadolínio , Gadolínio DTPA , Humanos , Neoplasias Meníngeas/secundário , Meninges/patologia
10.
Radiology ; 174(3 Pt 2): 951-5, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2305099

RESUMO

Three separate variables--volume of contrast material, site of contrast material injection, and arterial inflow occlusion--were tested in a prospective, randomized fashion in 52 patients to determine the best technique for lower-limb angiography. Twelve patients received 30 and 60 mL of contrast material injected at the level of the external iliac artery (EIA), 20 patients received 60 mL injected at the level of the EIA with and without inflow occlusion, and 20 patients received 120 mL injected at the level of the aortic bifurcation and 60 mL injected at the level of the EIA. A total of 104 angiograms were obtained, two in each patient. Two examiners reviewed all angiograms in a blinded fashion, initially as 104 separate studies for diagnostic adequacy (ie, the need for additional angiography) and then as 52 paired studies for direct comparison of the quality of arterial filling (ie, the best-appearing angiogram). The 60-mL studies were significantly better (P less than .001) in both categories when compared with both the 30- and the 120-mL studies. There was, however, no significant difference between the 60-mL studies with and without inflow occlusion. The authors conclude that the best screen-film lower-limb angiograms are obtained with large volumes (60 mL) of contrast material injected below the pelvic vessels (EIA).


Assuntos
Angiografia/métodos , Perna (Membro)/irrigação sanguínea , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste/administração & dosagem , Feminino , Pé/irrigação sanguínea , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Distribuição Aleatória
11.
J Comput Assist Tomogr ; 14(2): 272-5, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2179305

RESUMO

Cerebral ventriculitis is an uncommon site and manifestation of infection of the central nervous system. We report the magnetic resonance findings in two patients with cytologic and CSF culture proof of ventriculitis. The findings included abnormal signal intensity of the ependyma and CSF on T2-weighted images. In addition, ependymal, meningeal, and dural enhancement was seen in one case, on T1-weighted images, after administration of Gd-diethylenetriamine pentaacetic acid.


Assuntos
Ventrículos Cerebrais/patologia , Encefalite/diagnóstico , Imageamento por Ressonância Magnética , Adulto , Infecções Bacterianas/diagnóstico , Encefalite/microbiologia , Infecções por Escherichia coli/diagnóstico , Humanos , Masculino , Peptostreptococcus
12.
AJR Am J Roentgenol ; 159(5): 1063-8, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1414776

RESUMO

OBJECTIVE: Permanent occlusion of the internal carotid artery may be required for en bloc resection of a neck tumor or to treat certain aneurysms. The risk of ischemic infarct is usually assessed with carotid balloon test occlusion and concurrent distal arterial pressure measurement. However, up to 20% of patients who tolerate the test occlusion have delayed neurologic sequelae. We propose enhanced MR imaging and hexamethylpropyleneamine oxime (HMPAO) scintigraphy to detect subclinical signs of ischemia and hypoperfusion as adjuncts to the balloon test occlusion to identify patients at risk for delayed sequelae. SUBJECTS AND METHODS: We prospectively examined 12 patients referred for balloon test occlusion of the carotid artery. Serial measurements of distal occluded internal carotid pressure were recorded. 99mTc-HMPAO was injected IV after 2 min of asymptomatic test occlusion, and single-photon emission computed tomographic (SPECT) data acquisition was done 1-6 hr later. Contrast-enhanced MR imaging was performed 1-8 hr after completion of the 30-min test occlusion. Signs of decreased perfusion or ischemia on these tests were compared with the mean distal arterial pressure and neurologic status of the patient during test occlusion. RESULTS: Seven (58%) of 12 patients had abnormal findings on HMPAO scintigraphy or contrast-enhanced MR imaging. Only one patient had neurologic deficits that corresponded to abnormal MR enhancement. The other 11 patients (92%) remained asymptomatic during the 30-min test occlusion. Of these 11 asymptomatic patients, five (45%) had areas of decreased perfusion on scintigraphy and three (27%) had abnormal MR contrast enhancement suggesting residual focal ischemia as a result of the test occlusion. Mean arterial pressures in the distal occluded artery did not correlate well with the imaging results. CONCLUSION: HMPAO scintigraphy can show clinically silent areas of decreased perfusion, while enhanced MR shows signs of acute ischemia (i.e., significant hypoperfusion) associated with asymptomatic balloon test occlusion. Theoretically, such patients would be at increased risk for permanent sequelae after permanent carotid occlusion.


Assuntos
Isquemia Encefálica/epidemiologia , Artéria Carótida Interna , Cateterismo , Circulação Cerebrovascular/fisiologia , Adulto , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Isquemia Encefálica/diagnóstico , Circulação Colateral/fisiologia , Feminino , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Compostos de Organotecnécio , Oximas , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Fatores de Risco , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único
13.
J Magn Reson Imaging ; 1(4): 469-76, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1790370

RESUMO

Hippel-Lindau disease is an autosomal dominant disorder characterized by tumors of the central nervous system and abdominal viscera. Frequent multisystem radiologic evaluation of persons at risk is desirable. Twenty-seven patients with Hippel-Lindau disease or a family history of the disease were examined with both unenhanced and gadopentetate dimeglumine-enhanced magnetic resonance (MR) imaging to study the usefulness of the contrast medium in the evaluation of these patients. The MR studies were correlated with computed tomographic (CT) scans in seven patients and cerebral angiograms in five. Twelve patients had hemangioblastomas in the brain, and eight of these patients also had spinal cord lesions (most were multiple), well demonstrated with gadopentetate dimeglumine. Contrast-enhanced MR imaging enabled detection of more central nervous system lesions and provided better delineation than unenhanced MR imaging, CT, or angiography. In addition, four patients with multiple renal cysts seen on CT scans and unenhanced MR images had enhancing lesions that were later proved to be renal cell carcinoma at angiography and/or surgery. Four patients had cystic lesions in the pancreas that did not enhance and were later proved to be pancreatic cysts. The authors conclude that gadopentetate dimeglumine-enhanced MR imaging appears to be a useful method for evaluating and following up patients with Hippel-Lindau disease.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética , Meglumina , Compostos Organometálicos , Ácido Pentético , Doença de von Hippel-Lindau/diagnóstico , Adolescente , Adulto , Combinação de Medicamentos , Feminino , Gadolínio DTPA , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Doença de von Hippel-Lindau/epidemiologia
14.
Radiology ; 180(2): 485-91, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2068317

RESUMO

In phase II and III trials of gadoteridol (Gd-HP-D03A), a new nonionic, low-osmolar contrast agent, 40 patients with intracranial neoplasms underwent magnetic resonance (MR) imaging with experimental doses of 0.05-0.3 mmol/kg. Fifteen patients also underwent contrast studies with the standard dose (0.1 mmol/kg) of gadopentetate dimeglumine. Both gadopentetate dimeglumine and gadoteridol appear to have a similar effect when given in equal doses (0.1 mmol/kg, n = 5). Lesion enhancement and delineation were better at higher experimental doses (0.2 or 0.3 mmol/kg, n = 7) and worse at a lower experimental dose (0.05 mmol/kg, n = 3). Quantitative analysis of 10 lesions examined with identical imaging protocols revealed a directly proportional relationship (r = .975) between lesion contrast ratio and dose over a range of 0.05-0.3 mmol/kg. Phantom experiments support the clinical results. Improved enhancement, detection, and delineation of central nervous system (CNS) neoplasms resulting from increased injected doses of gadoteridol have the potential to be clinically significant and may justify the possibly higher cost of increased contrast material dosage. Lower doses may not be adequate for the evaluation of most CNS tumors.


Assuntos
Neoplasias Encefálicas/diagnóstico , Meios de Contraste , Gadolínio , Compostos Heterocíclicos , Imageamento por Ressonância Magnética , Meglumina , Compostos Organometálicos , Ácido Pentético , Adulto , Ágar , Idoso , Meios de Contraste/administração & dosagem , Combinação de Medicamentos , Avaliação de Medicamentos , Feminino , Gadolínio/administração & dosagem , Gadolínio DTPA , Compostos Heterocíclicos/administração & dosagem , Humanos , Aumento da Imagem , Imageamento por Ressonância Magnética/métodos , Masculino , Meglumina/administração & dosagem , Pessoa de Meia-Idade , Modelos Estruturais , Compostos Organometálicos/administração & dosagem , Ácido Pentético/administração & dosagem , Método Simples-Cego
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