Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros












Base de dados
Intervalo de ano de publicação
1.
Sci Data ; 11(1): 496, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38750041

RESUMO

Meningiomas are the most common primary intracranial tumors and can be associated with significant morbidity and mortality. Radiologists, neurosurgeons, neuro-oncologists, and radiation oncologists rely on brain MRI for diagnosis, treatment planning, and longitudinal treatment monitoring. However, automated, objective, and quantitative tools for non-invasive assessment of meningiomas on multi-sequence MR images are not available. Here we present the BraTS Pre-operative Meningioma Dataset, as the largest multi-institutional expert annotated multilabel meningioma multi-sequence MR image dataset to date. This dataset includes 1,141 multi-sequence MR images from six sites, each with four structural MRI sequences (T2-, T2/FLAIR-, pre-contrast T1-, and post-contrast T1-weighted) accompanied by expert manually refined segmentations of three distinct meningioma sub-compartments: enhancing tumor, non-enhancing tumor, and surrounding non-enhancing T2/FLAIR hyperintensity. Basic demographic data are provided including age at time of initial imaging, sex, and CNS WHO grade. The goal of releasing this dataset is to facilitate the development of automated computational methods for meningioma segmentation and expedite their incorporation into clinical practice, ultimately targeting improvement in the care of meningioma patients.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias Meníngeas , Meningioma , Meningioma/diagnóstico por imagem , Humanos , Neoplasias Meníngeas/diagnóstico por imagem , Masculino , Feminino , Processamento de Imagem Assistida por Computador/métodos , Pessoa de Meia-Idade , Idoso
2.
J Stroke Cerebrovasc Dis ; 30(4): 105603, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33484980

RESUMO

OBJECTIVE: To describe the clinical, laboratory, temporal, radiographic, and outcome features of acute Intracranial Hemorrhage (ICH) in COVID-19 patients. METHODS: Retrospective, observational, consecutive case series of patients admitted with ICH to Maimonides Medical Center from March 1 through July 31, 2020, who had confirmed or highly suspected COVID-19. Demographic, clinical, laboratory, imaging, and outcome data were analyzed. ICH rates among all strokes were compared to the same time period in 2019 in two-week time intervals. Correlation of systolic blood pressure variability (SBPV) and neutrophil-to-lymphocyte ratio (NLR) to clinical outcomes were performed. RESULTS: Of 324 patients who presented with stroke, 65 (20%) were diagnosed with non-traumatic ICH: 8 had confirmed and 3 had highly suspected COVID-19. Nine (82%) had at least one associated risk factor for ICH. Three ICHs occurred during inpatient anticoagulation. More than half (6) suffered either deep or cerebellar hemorrhages; only 2 were lobar hemorrhages. Two of 8 patients with severe pneumonia survived. During the NYC COVID-19 peak period in April, ICH comprised the highest percentage of all strokes (40%), and then steadily decreased week-after-week (p = 0.02). SBPV and NLR were moderately and weakly positively correlated to discharge modified Rankin Scale, respectively. CONCLUSIONS: COVID-19 associated ICH is often associated with at least one known ICH risk factor and severe pneumonia. There was a suggestive relative surge in ICH among all stroke types during the first peak of the NYC pandemic. It is important to be vigilant of ICH as a possible and important manifestation of COVID-19.


Assuntos
COVID-19/epidemiologia , Hemorragias Intracranianas/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/diagnóstico , COVID-19/terapia , Feminino , Humanos , Hemorragias Intracranianas/diagnóstico por imagem , Hemorragias Intracranianas/terapia , Masculino , New York/epidemiologia , Prevalência , Prognóstico , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo
3.
AJR Am J Roentgenol ; 217(4): 959-974, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33236647

RESUMO

Neurologic involvement is well-recognized in COVID-19. This article reviews the neuroimaging manifestations of COVID-19 on CT and MRI, presenting cases from the New York City metropolitan region encountered by the authors during the first surge of the pandemic. The most common neuroimaging manifestations are acute infarcts with large clot burden and intracranial hemorrhage, including microhemorrhages. However, a wide range of additional imaging patterns occur, including leukoencephalopathy, global hypoxic injury, acute disseminated encephalomyelitis, cytotoxic lesions of the corpus callosum, olfactory bulb involvement, cranial nerve enhancement, and Guillain-Barré syndrome. The described CNS abnormalities largely represent secondary involvement from immune activation that leads to a prothrombotic state and cytokine storm; evidence for direct neuroinvasion is scant. Comorbidities such as hypertension, complications of prolonged illness and hospitalization, and associated supportive treatments also contribute to the CNS involvement in COVID-19. Routine long-term neurologic follow-up may be warranted, given emerging evidence of long-term microstructural and functional changes on brain imaging after COVID-19 recovery.


Assuntos
Encefalopatias/complicações , Encefalopatias/diagnóstico por imagem , COVID-19/complicações , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Encéfalo/diagnóstico por imagem , Humanos , Pandemias , SARS-CoV-2
4.
Emerg Radiol ; 27(3): 229-232, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32285222

RESUMO

PURPOSE: Coronavirus disease 2019 (COVID-19) is caused by a novel strain of coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has quickly spread around the globe. Health care facilities in the USA currently do not have an adequate supply of COVID-19 tests to meet the growing demand. Imaging findings for COVID-19 are non-specific but include pulmonary parenchymal ground-glass opacities in a predominantly basal and peripheral distribution. METHODS: Three patients were imaged for non-respiratory-related symptoms with a portion of the lungs in the imaged field. RESULTS: Each patient had suspicious imaging findings for COVID-19, prompting the interpreting radiologist to suggest testing for COVID-19. All 3 patients turned out to be infected with COVID-19, and one patient is the first reported case of the coincident presentation of COVID-19 and an intraparenchymal hemorrhage. CONCLUSION: Using imaging characteristics of COVID-19 on abdominal or neck CT when a portion of the lungs is included, patients not initially suspected of COVID-19 infection can be quarantined earlier to limit exposure to others.


Assuntos
Infecções por Coronavirus/diagnóstico por imagem , Pneumonia Viral/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Betacoronavirus , COVID-19 , Hemorragia Cerebral/complicações , Humanos , Pulmão/diagnóstico por imagem , Masculino , Pandemias , SARS-CoV-2
5.
World Neurosurg ; 124: 366-369, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30684702

RESUMO

BACKGROUND: Although rare, spinal meningiomas may cause motor and sensory deficits or difficulty with bladder or bowel function due to spinal cord compression. Although hemorrhage of intracranial meningiomas is well documented, there are very few cases of hemorrhage or hematoma associated with spinal meningiomas in the literature. Spinal meningiomas have been reported to be associated with subdural, epidural, intratumoral, and subarachnoid hemorrhage, and usually in the setting of an inciting event such as lumbar puncture or anticoagulation therapy. CASE DESCRIPTION: A 68-year-old women presented to the emergency room with acute onset of paraparesis in the lower extremities. Magnetic resonance imaging findings were inconclusive for cause but showed spinal cord compression. Intraoperative findings demonstrated an intratumoral hemorrhage and pathology was consistent with meningioma. CONCLUSIONS: To the best of our knowledge, this is the first report in English literature of a patient who first develops symptoms from a spinal meningioma with spontaneous intratumoral hemorrhage presenting with acute paraparesis. Magnetic resonance imaging findings in retrospect match surgical intraoperative findings. Prompt surgical intervention can result in complete resolution of neurologic deficits.

6.
Radiol Case Rep ; 12(2): 371-375, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28491191

RESUMO

Craniocervical artery dissection is a potentially disabling condition caused by an intimal tear allowing blood to enter and dissect the media in the cranial direction which can occur spontaneously or as a result of trauma. When the dissection extends toward the adventitia, it can form a protrusion from the weakened vessel wall called a pseudoaneurysm, which may become a nidus for distal thromboembolism or cause mass effect on adjacent structures. Accurate and prompt diagnosis is critical as timely treatment can significantly reduce the risk of complications such as stroke. Here, we present a case of cervical ICA dissection and pseudoaneurysm formation causing mass effect with resultant compressive ipsilateral hypoglossal nerve palsy.

7.
J Clin Hypertens (Greenwich) ; 18(6): 522-7, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26293622

RESUMO

The authors aimed to determine whether clinical findings of preeclampsia predict magnetic resonance imaging (MRI) diagnosis of posterior reversible encephalopathy syndrome (PRES). The course among preeclamptics/eclamptics with clinically suspected PRES with vs without MRI diagnosis of PRES was compared. Of 46 patients who underwent MRI (eight eclamptics, 38 preeclamptics), five eclamptics (62.5%) and four preeclamptics (10.5%) had confirmed PRES (P=.004). Patients with PRES were younger (26 years vs 31 years, P=.008) and had a higher prevalence of thrombocytopenia (33% vs 8%, P=.04), a greater prevalence of proteinuria (100% vs 61%, P=.04), and higher peak systolic and diastolic blood pressures (P<.05). As opposed to findings from previous reports, PRES was not seen uniformly among eclamptic women and was found in 10.5% of preeclamptics with clinical suspicion of PRES in this study. Given that no single or set of findings were reliable predictors of PRES, consideration for rigorous management of hypertension should be applied to all patients with preeclampsia and eclampsia.


Assuntos
Síndrome da Leucoencefalopatia Posterior/diagnóstico por imagem , Pré-Eclâmpsia/diagnóstico por imagem , Adulto , Feminino , Humanos , Hipertensão/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Síndrome da Leucoencefalopatia Posterior/sangue , Pré-Eclâmpsia/sangue , Gravidez , Proteinúria/diagnóstico por imagem , Estudos Retrospectivos , Fatores de Risco , Trombocitopenia/diagnóstico por imagem , Adulto Jovem
8.
J Emerg Med ; 49(6): e187-91, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26409671

RESUMO

BACKGROUND: Late postpartum eclampsia is defined as occurrence of eclampsia >48 h after delivery and is a rare clinical entity. The delayed onset and nonspecific symptoms at presentation make this entity a challenge to diagnose in patients presenting to the emergency department (ED); however, early recognition and timely interventions are the keys to reducing morbidity and mortality in patients with late postpartum eclampsia. CASE REPORT: A 28-year-old woman presented to our ED with a chief complaint of headache of 4 days duration, 8 days after an uncomplicated, normal vaginal delivery. Her past medical history was unremarkable and her entire pregnancy was without medical incident. The patient's examination was within normal limits other than a blood pressure of 152/111 mm Hg and pulse of 54 beats/min. Given her undifferentiated headache and the possibility of preeclampsia, the patient was treated with magnesium sulfate, which was subsequently stopped due to worsening bradycardia. Hydralazine was administered for blood pressure control. Three hours after the magnesium was stopped, the patient reported blurry vision, which was immediately followed by a generalized tonic-clonic seizure. After the seizure, lorazepam was given for control of seizures, and the patient was admitted to the medical intensive care unit. The patient was transferred to the postpartum floor 6 days later in stable condition and without any further seizure activity. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Patients with late postpartum eclampsia are infrequently encountered in the ED due to the rarity of this condition. Increased awareness of this entity among emergency physicians will lead to early interventions, which are crucial in decreasing morbidity and mortality in these patients.


Assuntos
Eclampsia/diagnóstico , Transtornos Puerperais/diagnóstico , Doenças Vasculares/diagnóstico , Adulto , Anticonvulsivantes/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Quimioterapia Combinada , Eclampsia/tratamento farmacológico , Serviço Hospitalar de Emergência , Feminino , Humanos , Hidralazina/uso terapêutico , Lorazepam/uso terapêutico , Sulfato de Magnésio/uso terapêutico , Gravidez , Transtornos Puerperais/tratamento farmacológico , Doenças Vasculares/tratamento farmacológico
9.
Clin Nucl Med ; 39(2): 198-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24368530

RESUMO

There are many causes of cerebrospinal (CSF) leaks. Most cases are secondary to blunt trauma and iatrogenic trauma caused by postoperative sequelae. Occasionally, CSF leakage may occur from nontraumatic or "spontaneous" causes, such as benign intracranial hypertension and "empty sella syndrome." Mass effect due to an encephalocele or meningocele may also be seen. Radionuclide cisternography is a sensitive method of determining CSF leak when combined with intranasal cotton pledget placement and analysis. We present a spontaneous CSF fluid leak that was detected when scintigraphic activity appeared first in the gastrointestinal tract.


Assuntos
Rinorreia de Líquido Cefalorraquidiano/diagnóstico por imagem , Trato Gastrointestinal/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Vazamento de Líquido Cefalorraquidiano , Feminino , Humanos , Pessoa de Meia-Idade , Cintilografia
10.
Oncologist ; 18(10): 1108-17, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24037978

RESUMO

OBJECTIVE: The objective of this study was to compare the efficacy of surveillance high-resolution computed tomography (HRCT) and physical examination/endoscopy (PE/E) with the efficacy of fluorodeoxyglucose (FDG)-positron emission tomography (PET)/HRCT for the detection of relapse in head and neck squamous cell carcinoma (HNSCC) after primary treatment. METHODS: This is a retrospective analysis of contemporaneously performed FDG-PET/HRCT, neck HRCT, and PE/E in 99 curatively treated patients with HNSCC during post-therapy surveillance to compare performance test characteristics in the detection of early recurrence or second primary cancer. RESULTS: Relapse occurred in 19 of 99 patients (20%) during a median follow-up of 21 months (range: 9-52 months). Median time to first PET/HRCT was 3.5 months. The median time to radiological recurrence was 6 months (range: 2.3-32 months). FDG-PET/HRCT detected more disease recurrences or second primary cancers and did so earlier than HRCT or PE/E. The sensitivity, specificity, and positive and negative predictive values for detecting locoregional and distant recurrence or second primary cancer were 100%, 87.3%, 56.5%, and 100%, respectively, for PET/HRCT versus 61.5%, 94.9%, 66.7%, and 93.8%, respectively, for HRCT versus 23.1%, 98.7%, 75%, and 88.6%, respectively, for PE/E. In 19 patients with true positive PET/HRCT findings, a significant change in the management of disease occurred, prompting either salvage or systemic therapy. Of the 14 curatively treated patients, 11 were alive with without disease at a median follow-up of 31.5 months. CONCLUSION: FDG-PET/HRCT has a high sensitivity in the early detection of relapse or second primary cancer in patients with HNSCC, with significant management implications. Given improvements in therapy and changes in HNSCC biology, appropriate modifications in current post-therapy surveillance may be required to determine effective salvage or definitive therapies.


Assuntos
Diagnóstico Precoce , Neoplasias de Cabeça e Pescoço/diagnóstico , Recidiva Local de Neoplasia/diagnóstico , Neoplasias de Células Escamosas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Endoscopia , Feminino , Fluordesoxiglucose F18 , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Neoplasias de Células Escamosas/diagnóstico por imagem , Neoplasias de Células Escamosas/patologia , Tomografia por Emissão de Pósitrons/métodos , Radiografia , Análise de Sobrevida
11.
J Am Coll Radiol ; 7(5): 351-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20439078

RESUMO

PURPOSE: Advances in medical imaging have been associated with increased utilization and increased radiation exposure, especially for patients with chronic and recurrent conditions. The authors estimated the cumulative radiation doses from medical imaging for specific cohorts with chronic and recurrent conditions. METHODS: All patients diagnosed with hydrocephalus (n = 1,711), pulmonary thromboembolic disease (n = 3,220), renal colic (n = 5,855), and cardiac disease (n = 11,072) from January 1, 2000, to December 31, 2005, were retrospectively identified. Each imaging examination that used ionizing radiation from 2000 to 2008 was incorporated into an estimate of total effective dose and organ-specific doses. Patients with high levels of radiation exposure after 3 years (total effective dose > 50 mSv; dose to the ocular lens > 150 mSv) were identified. RESULTS: The mean estimated effective doses for the surviving diagnostic cohorts after 3 years were 12.3 mSv for patients with hydrocephalus, 21.7 mSv for those with pulmonary thromboembolic disease, 18.7 mSv for those with renal colic, and 14.0 mSv for those with cardiac disease. Among patients with hydrocephalus, 26.3% (339 of 1,291) had radiation doses > 150 mSv to the ocular lens within 3 years. In all cohorts, the proportion of patients with total effective doses > 50 mSv within 3 years was significantly higher for those diagnosed in 2004 and 2005 than for those diagnosed in 2000 and 2001. CONCLUSION: Patients with hydrocephalus, pulmonary thromboembolic disease, renal colic, and cardiac disease received radiation exposures that may put them at increased risk for cancer. Moreover, the proportion who received estimated total effective doses > 50 mSv within 3 years was significantly higher for those diagnosed most recently. It is the responsibility of institutions and physicians to critically evaluate their infrastructures, diagnostic strategies, and imaging techniques for each individual patient, with an eye toward minimizing cumulative medical radiation exposure.


Assuntos
Diagnóstico por Imagem/efeitos adversos , Neoplasias Induzidas por Radiação , Neoplasias/etiologia , Doses de Radiação , Humanos , Hidrocefalia/diagnóstico por imagem , Radiografia , Fatores de Risco , Tromboembolia/diagnóstico por imagem , Fatores de Tempo
12.
Emerg Radiol ; 17(5): 353-60, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20306104

RESUMO

We sought to determine whether laboratory parameters could be found, predictive of a negative abdominal CT scan in young adults with nontraumatic abdominal pain. Following institutional review board approval, we evaluated CT reports of 522 patients, aged 21-35 years old, who presented to the Emergency Department with nontraumatic abdominal pain. Bivariate analyses relating ten laboratory parameters to whether the CT detected a cause for abdominal pain were conducted. A multivariate logistic regression model was then derived, with all variables in the final model significant at p < 0.05. Variables were dichotomized to yield odds ratios and 95% confidence intervals. Of the 522 patients meeting inclusion criteria, 45% had a cause for pain demonstrated by CT. Predictors of a negative CT in men were normal hematocrit and negative urine blood (p = 0.045, p = 0.016, respectively), and in women normal hematocrit, granulocyte percent, and alkaline phosphatase (p = 0.023, p = 0.039, p < 0.0001, respectively). When standard normal values were used to calculate descriptive statistics, only granulocyte percent in women had a significant confidence interval (odds ratio 2.5, confidence interval 1.6-4.0). Among the 208 women with normal granulocyte percent, the final clinical diagnosis was appendicitis, cholecystitis, and diverticulitis, in three, three, and two cases, respectively (4% combined). In summary, no laboratory test was sufficient to offer reassurance that a CT is not necessary in a young adult patient with nontraumatic abdominal pain. Alternative strategies should be considered to decrease the use of CT, and its associated radiation exposure, in young adults with nontraumatic abdominal pain.


Assuntos
Dor Abdominal , Enteropatias/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Análise Química do Sangue , Bases de Dados como Assunto , Serviço Hospitalar de Emergência , Feminino , Humanos , Enteropatias/diagnóstico , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Tomografia Computadorizada por Raios X/estatística & dados numéricos
13.
AJR Am J Roentgenol ; 194(2): 392-7, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20093601

RESUMO

OBJECTIVE: The purpose of our study was to determine whether the radiation exposure to patients with suspected pulmonary embolism (PE) could be decreased by safely increasing the use of ventilation-perfusion (V/Q) scanning and decreasing the use of CT pulmonary angiography (CTPA) through an educational intervention. MATERIALS AND METHODS: Collaborative educational seminars were held among the radiology, nuclear medicine, and emergency medicine departments in December 2006 and January 2007 regarding the radiation dose and accuracies of V/Q scanning and CTPA for diagnosing PE. To reduce radiation exposure, an imaging algorithm was introduced in which emergency department patients with a clinical suspicion of PE underwent chest radiography. If the chest radiograph was normal, V/Q scanning was recommended, otherwise CTPA was recommended. We retrospectively tallied the number and results of CTPA and V/Q scanning and calculated mean radiation effective dose before and after the intervention. False-negative findings were defined as subsequent thromboembolism within 90 days. RESULTS: The number of CTPA examinations performed decreased from 1,234 in 2006 to 920 in 2007, and the number of V/Q scans increased from 745 in 2006 to 1,216 in 2007. The mean effective dose was reduced by 20%, from 8.0 mSv in 2006 to 6.4 mSv in 2007 (p < 0.0001). The patients who underwent CTPA and V/Q scanning in 2006 were of similar age. In 2007, the patients who underwent V/Q scanning were significantly younger. There was no significant difference in the false-negative rate (range, 0.8-1.2%) between CTPA and V/Q scanning in 2006 and 2007. CONCLUSION: The practice patterns of physicians changed in response to an educational intervention, resulting in a reduction in radiation exposure to emergency department patients with suspected PE without compromising patient safety.


Assuntos
Algoritmos , Angiografia , Embolia Pulmonar/diagnóstico por imagem , Pneumologia/educação , Lesões por Radiação/prevenção & controle , Radiologia/educação , Tomografia Computadorizada por Raios X , Distribuição de Qui-Quadrado , Meios de Contraste , Reações Falso-Negativas , Feminino , Gadolínio DTPA , Humanos , Capacitação em Serviço , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Estudos Retrospectivos , Resultado do Tratamento
14.
J Comput Assist Tomogr ; 33(4): 523-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19638843

RESUMO

OBJECTIVE: To determine the prevalence and clinical significance of normal, variant, and anomalous branching patterns of the aortic arch and the central veins on computed tomographic (CT) angiography in adults. METHODS: We retrospectively reviewed 1000 consecutive CT angiograms of the chest in 658 women and 342 men with a median age of 53 years. RESULTS: A total of 65.9% of patients had both normal aortic arch branching patterns and normal venous anatomy. Variants in the aortic arch branching pattern were present in 32.4% and anomalies in 1.5%. Venous anomalies were present in 0.7%. Review of CT reports showed that cardiothoracic radiologists correctly reported the anomaly more frequently than other radiologists (94% vs 20%, P = 0.003). CONCLUSIONS: Whereas anomalies of the central thoracic vasculature are uncommon, variants in the aortic arch branching pattern are common. An appreciation of the appearance of these entities on CT angiography allows for precise reporting and is useful in preprocedure planning.


Assuntos
Aorta Torácica/anormalidades , Aorta Torácica/diagnóstico por imagem , Vasos Sanguíneos/anormalidades , Tomografia Computadorizada por Raios X/métodos , Malformações Vasculares/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia/métodos , Aorta Torácica/anatomia & histologia , Vasos Sanguíneos/anatomia & histologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
15.
Semin Nucl Med ; 38(6): 432-40, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19331837

RESUMO

After the publication of the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study in 1990, there was considerable controversy concerning the ventilation-perfusion (V/Q) study in regard to its low sensitivity and high number of nondiagnostic examinations when used in patients with suspected pulmonary embolism (PE). Many lessons have been learned from the PIOPED database that have greatly improved our interpretive skills in the 2 decades since the study was performed. One of the key problems negatively impacting interpretation was the predominantly inpatient population that was studied. Inpatients generally are sicker patients with abnormal chest x-rays. This factor significantly degrades V/Q interpretation. A normal chest x-ray greatly facilitates accurate interpretation of the lung scan. The emergence of computed tomography angiography (CTA) in the early to mid-1990s provided a superb new means of imaging patients with suspected PE. As this technology became more sophisticated with multidetector units, it became the procedure of choice in the great majority of medical centers. CT scanners located in or proximal to many emergency departments as well as its 24/7 availability supported this preference. Within the past 2 to 3 years, the publication of the PIOPED II study as well as some other prospective and retrospective studies have confirmed similar diagnostic accuracy for CTA and V/Q studies. Additionally, there have been several recent publications cautioning physicians about the large radiation dose associated with CTA, particularly to the female breast. Considering the great benefits of both techniques as well as their limitations, it is prudent for both clinicians and imaging physicians to develop an appropriate approach to studying patients with suspected PE. Considerations such as objective clinical assessment, D-dimer assay and the chest x-ray appearance all play significant roles in this decision-making process.


Assuntos
Imagem de Perfusão/métodos , Embolia Pulmonar/diagnóstico por imagem , Angiografia/efeitos adversos , Angiografia/métodos , Feminino , Humanos , Masculino , Imagem de Perfusão/efeitos adversos , Valor Preditivo dos Testes , Gravidez , Embolia Pulmonar/fisiopatologia , Doses de Radiação , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X/efeitos adversos , Tomografia Computadorizada por Raios X/métodos , Relação Ventilação-Perfusão
16.
J Vasc Interv Radiol ; 18(7): 914-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17609454

RESUMO

A new technique for percutaneous gastrostomy of a decompressed excluded gastric segment after Roux-en-Y gastric bypass (RYGBP) surgery is described and the results in a single institution are reviewed. Computed tomography guidance was used to place a 21- or 22-gauge needle into the lumen of the stomach and distend it to allow placement of a feeding catheter. Ten women underwent the procedure, and despite only three patients having clear access windows, gastrostomy placement was ultimately successful in all 10 patients. Percutaneous gastrostomy of the decompressed excluded gastric segment after RYGBP surgery can be challenging, but a high rate of success can be achieved.


Assuntos
Derivação Gástrica , Gastrostomia/métodos , Obesidade Mórbida/cirurgia , Adulto , Anastomose em-Y de Roux , Feminino , Humanos , Pessoa de Meia-Idade , Radiografia Intervencionista , Tomografia Computadorizada por Raios X , Resultado do Tratamento
17.
J Vasc Interv Radiol ; 17(6): 1043-9, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16778240

RESUMO

Failure to treat deep vein thrombosis (DVT) is associated with significant morbidity and mortality. Anticoagulation, although effective at preventing clot progression, is not able to prevent postthrombotic syndrome. Catheter-directed thrombolysis is a more aggressive alternative, with some small studies suggesting a better long-term outcome, but the associated risks are significant, and the treatment can require 2-3 days in a monitored setting. This report describes the power pulse technique, in which mechanical thrombectomy is combined with thrombolytic agents to maximize the effectiveness of the treatment and reduce the need for prolonged infusion and its associated risks. A 24-patient retrospective study showed complete thrombus removal (>90%) in 12 patients, substantial thrombus removal (50%-90%) in seven patients, and partial thrombus removal (<50%) in five patients. All 24 patients had resolution of presenting symptoms. Only two patients required blood transfusion, and one patient experienced temporary nephropathy.


Assuntos
Trombectomia/métodos , Terapia Trombolítica/métodos , Trombose Venosa/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Veia Poplítea , Síndrome Pós-Flebítica/prevenção & controle , Punções , Retratamento , Estudos Retrospectivos , Resultado do Tratamento , Ultrassonografia de Intervenção
18.
J Biol Chem ; 278(28): 26007-14, 2003 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-12707268

RESUMO

Tyrosine 984 in the juxtamembrane region of the insulin receptor, between the transmembrane helix and the cytoplasmic tyrosine kinase domain, is conserved among all insulin receptor-like proteins from hydra to humans. Crystallographic studies of the tyrosine kinase domain and proximal juxtamembrane region reveal that Tyr-984 interacts with several other conserved residues in the N-terminal lobe of the kinase domain, stabilizing a catalytically nonproductive position of alpha-helix C. Steady-state kinetics measurements on the soluble kinase domain demonstrate that replacement of Tyr-984 with phenylalanine results in a 4-fold increase in kcat in the unphosphorylated (basal state) enzyme. Moreover, mutation of Tyr-984 in the full-length insulin receptor results in significantly elevated receptor phosphorylation levels in cells, both in the absence of insulin and following insulin stimulation. These data demonstrate that Tyr-984 plays an important structural role in maintaining the quiescent, basal state of the insulin receptor. In addition, the structural studies suggest a possible target site for small molecule activators of the insulin receptor, with potential use in the treatment of noninsulin-dependent diabetes mellitus.


Assuntos
Membrana Celular/metabolismo , Receptor de Insulina/química , Receptor de Insulina/fisiologia , Tirosina/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Cristalografia por Raios X , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Cinética , Modelos Moleculares , Dados de Sequência Molecular , Fosforilação , Ligação Proteica , Estrutura Terciária de Proteína , Receptor de Insulina/metabolismo , Transfecção
19.
J Biol Chem ; 278(15): 13257-64, 2003 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-12551896

RESUMO

Grb7, Grb10, and Grb14 are members of a distinct family of adapter proteins that interact with various receptor tyrosine kinases upon receptor activation. Proteins in this family contain several modular signaling domains including a pleckstrin homology (PH) domain, a BPS (between PH and SH2) domain, and a C-terminal Src homology 2 (SH2) domain. Although SH2 domains are typically monomeric, we show that the Grb10 SH2 domain and also full-length Grb10 gamma are dimeric in solution under physiologic conditions. The crystal structure of the Grb10 SH2 domain at 1.65-A resolution reveals a non-covalent dimer whose interface comprises residues within and flanking the C-terminal alpha helix, which are conserved in the Grb7/Grb10/Grb14 family but not in other SH2 domains. Val-522 in the BG loop (BG3) and Asp-500 in the EF loop (EF1) are positioned to interfere with the binding of the P+3 residue of a phosphopeptide ligand. These structural features of the Grb10 SH2 domain will favor binding of dimeric, turn-containing phosphotyrosine sequences, such as the phosphorylated activation loops in the two beta subunits of the insulin and insulin-like growth factor-1 receptors. Moreover, the structure suggests the mechanism by which the Grb7 SH2 domain binds selectively to pTyr-1139 (pYVNQ) in Her2, which along with Grb7 is co-amplified in human breast cancers.


Assuntos
Proteínas/química , Domínios de Homologia de src , Proteínas Adaptadoras de Transdução de Sinal , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Dimerização , Receptores ErbB/química , Receptores ErbB/metabolismo , Proteína Adaptadora GRB10 , Proteína Adaptadora GRB7 , Humanos , Ligantes , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Conformação Proteica , Estrutura Secundária de Proteína , Proteínas/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Soluções , Especificidade por Substrato
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...