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1.
AJNR Am J Neuroradiol ; 44(10): 1116-1125, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37591773

RESUMO

Sinonasal and skull base tumors are a heterogeneous group of neoplasms with considerable histologic variation and overlapping imaging features. In 2022, the World Health Organization updated the head and neck tumor classification, further emphasizing the importance of molecular data and genetic alterations in sinonasal neoplasms. The changes include the addition of new entities and discussion of emerging entities, as well as changes to the taxonomy and characterization of tumors. The new classification focuses on entities that develop in these sites either exclusively (eg, olfactory neuroblastoma) or most frequently. Another change includes reduction in the number of categories by creating separate category-specific chapters for soft-tissue, hematolymphoid, and neuroectodermal lesions. In this review, we briefly discuss the various categories in the new classification with a more detailed description of the 2 new entities (SWItch/Sucrose Non-Fermentable complex-deficient sinonasal carcinomas and human papillomavirus-related multiphenotypic sinonasal carcinoma). We also highlight the emerging entities including IDH-mutant sinonasal malignancies and DEK-AFF2 carcinoma, presently classified as sinonasal undifferentiated carcinoma and nonkeratinizing squamous cell carcinoma, respectively.

2.
AJNR Am J Neuroradiol ; 44(9): 1002-1008, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37500288

RESUMO

Epstein-Barr virus is a ubiquitous herpesvirus that may cause both infective (encephalitis, meningitis, and so forth) and postinfection inflammatory (such as Guillain-Barré syndrome, acute disseminated encephalomyelitis) manifestations in the CNS. Diagnosis of Epstein-Barr virus-related CNS pathologies is often complicated due to a nonspecific clinical presentation and overlap with other infectious and noninfectious causes, both clinically and on imaging. The Epstein-Barr virus is also implicated in several lymphoproliferative disorders in both immunocompromised and immunocompetent hosts. MR imaging is preferred for evaluating the extent of involvement and monitoring therapy response, given its high sensitivity and specificity, though imaging findings may be nonspecific. Herein, we review the imaging spectrum of Epstein-Barr virus-associated CNS disorders.


Assuntos
Encefalite , Infecções por Vírus Epstein-Barr , Transtornos Linfoproliferativos , Humanos , Herpesvirus Humano 4/fisiologia , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/diagnóstico por imagem , Imageamento por Ressonância Magnética , Transtornos Linfoproliferativos/complicações , Transtornos Linfoproliferativos/diagnóstico , Transtornos Linfoproliferativos/terapia
3.
AJNR Am J Neuroradiol ; 44(3): 236-246, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36657945

RESUMO

PET with amino acid tracers provides additional insight beyond MR imaging into the biology of gliomas that can be used for initial diagnosis, delineation of tumor margins, planning of surgical and radiation therapy, assessment of residual tumor, and evaluation of posttreatment response. Hybrid PET MR imaging allows the simultaneous acquisition of various PET and MR imaging parameters in a single investigation with reduced scanning time and improved anatomic localization. This review aimed to provide neuroradiologists with a concise overview of the various amino acid tracers and a practical understanding of the clinical applications of amino acid PET MR imaging in glioma management. Future perspectives in newer advances, novel radiotracers, radiomics, and cost-effectiveness are also outlined.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/terapia , Neoplasias Encefálicas/patologia , Aminoácidos , Glioma/diagnóstico por imagem , Glioma/terapia , Glioma/patologia , Tomografia por Emissão de Pósitrons/métodos , Imageamento por Ressonância Magnética/métodos
4.
AJNR Am J Neuroradiol ; 41(9): 1550-1557, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32855194

RESUMO

Tumor resection followed by chemoradiation remains the current criterion standard treatment for high-grade gliomas. Regardless of aggressive treatment, tumor recurrence and radiation necrosis are 2 different outcomes. Differentiation of tumor recurrence from radiation necrosis remains a critical problem in these patients because of considerable overlap in clinical and imaging presentations. Contrast-enhanced MR imaging is the universal imaging technique for diagnosis, treatment evaluation, and detection of recurrence of high-grade gliomas. PWI and PET with novel radiotracers have an evolving role for monitoring treatment response in high-grade gliomas. In the literature, there is no clear consensus on the superiority of either technique or their complementary information. This review aims to elucidate the diagnostic performance of individual and combined use of functional (PWI) and metabolic (PET) imaging modalities to distinguish recurrence from posttreatment changes in gliomas.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Neuroimagem/métodos , Imagem de Perfusão/métodos , Tomografia por Emissão de Pósitrons/métodos , Lesões por Radiação/diagnóstico por imagem , Adulto , Neoplasias Encefálicas/patologia , Diagnóstico Diferencial , Progressão da Doença , Feminino , Glioma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Lesões por Radiação/patologia
5.
Clin Radiol ; 75(10): 796.e1-796.e9, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32703543

RESUMO

AIM: To assess the prevalence of various imaging manifestations in neurosarcoidosis (NS) patients at presentation and to explore if specific imaging findings may cluster in different sub-groups. MATERIALS AND METHODS: A retrospective, dual-institution, systematic imaging review was undertaken of the magnetic resonance imaging (MRI) findings in 100 consecutive NS patients who presented over a 15-year period. Clustering analysis (k-mode) was performed to evaluate co-occurrence of imaging findings. RESULTS: Non-enhancing white matter (NEWM) lesions were the most common imaging abnormality (56%), followed by leptomeningeal (47%) and pachymeningeal (32%) involvement. Other common manifestations included cranial nerve involvement (30%), parenchymal granulomas (27%), hypothalamic-pituitary-adrenal axis involvement (26%), and hydrocephalus (14%). Additionally, a higher prevalence of perivascular enhancement (23%), cerebrovascular events (including ischaemic and haemorrhagic events; 17%), and ependymal involvement (20%) were noted than recognised previously. Additional k-mode analysis was performed to explore underlying disease sub-clusters. This was evaluated for clusters varying between two though five (k=2-5). For k=4, the analysis revealed that the imaging findings may possibly be divided into disease sub-sets of four groups, each with varying distribution of imaging manifestations and clinical manifestations. CONCLUSION: Overall, NEWM lesions and meningeal involvement are the most common imaging manifestations of NS. The prevalence of perivascular enhancement, cerebrovascular events, and ependymal involvement is likely higher than reported previously. Additionally, different imaging findings in NS may cluster together and imaging subtypes in NS possibly exist.


Assuntos
Doenças do Sistema Nervoso Central/diagnóstico por imagem , Doenças do Sistema Nervoso Central/epidemiologia , Imageamento por Ressonância Magnética , Neuroimagem/métodos , Sarcoidose/diagnóstico por imagem , Sarcoidose/epidemiologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Estados Unidos/epidemiologia
6.
Domest Anim Endocrinol ; 72: 106371, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31421986

RESUMO

High ambient temperature exhibits a retrograde effect on buffalo reproduction because of heat stress. Moreover, melatonin is known to regulate reproductive changes in seasonally reproductive animals by binding to high affinity, G protein-coupled receptors. The MTNR1A gene is a prime receptor, mediating the effect of melatonin at the neuroendocrine level to control seasonal reproduction. In sheep, the role of melatonin is well known; however, studies have not been conducted in buffalo to determine its effect during favorable and unfavorable breeding seasons. Therefore, the present study aimed to (1) determine the expression of MTNR1A, ERα, ERß, and PR gene transcripts in the ovarian follicles of buffalo during the summer and winter seasons and (2) analyze melatonin, 17ß-estradiol, and progesterone concentrations in the follicular fluid of buffalo during both seasons. Murrah buffalo ovaries were collected during both the summer (May-June) and winter (December-January) seasons. All visible ovarian follicles were allocated into one of three groups: (1) small (8-9.9 mm); (2) medium (10-11.9 mm); and (3) large (12-14 mm). Follicular fluid was aspirated from each group of follicles for hormone analyses. The granulosa cells were processed for RNA extraction. Furthermore, they were subjected to real-time quantitative PCR to analyze the expression (relative quantification) of MTNR1A, ERα, ERß, and PR in each follicular group. The expression of MTNR1A gene transcript decreased with the increasing size of the follicle and intrafollicular melatonin concentration. Expression of ERα and PR remained unaffected by the season and was similar (P > 0.05) in all groups. Expression of ERß was higher (P < 0.05) in summer than winter; nevertheless, small-sized follicles from the summer exhibited higher (P < 0.05) expressions than medium- and large-sized follicles. The overall intrafollicular melatonin concentration was positively correlated (P < 0.05) with 17ß-estradiol and progesterone concentrations. In conclusion, the decreased expression of MTNR1A and increased concentration of intrafollicular melatonin with the increasing size of the follicle indicates a probable role in folliculogenesis and ovulation in buffalo.


Assuntos
Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Melatonina/metabolismo , Receptor MT1 de Melatonina/metabolismo , Receptores de Progesterona/metabolismo , Esteroides/metabolismo , Animais , Búfalos/fisiologia , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Feminino , Regulação da Expressão Gênica , Folículo Ovariano/metabolismo , Receptor MT1 de Melatonina/genética , Receptores de Progesterona/genética , Estações do Ano , Transcriptoma
7.
AJNR Am J Neuroradiol ; 40(6): 928-934, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31122918

RESUMO

Texture analysis is a continuously evolving, noninvasive radiomics technique to quantify macroscopic tissue heterogeneity indirectly linked to microscopic tissue heterogeneity beyond human visual perception. In recent years, systemic oncologic applications of texture analysis have been increasingly explored. Here we discuss the basic concepts and methodologies of texture analysis, along with a review of various MR imaging texture analysis applications in glioma imaging. We also discuss MR imaging texture analysis limitations and the technical challenges that impede its widespread clinical implementation. With continued advancement in computational processing, MR imaging texture analysis could potentially develop into a valuable clinical tool in routine oncologic imaging.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Humanos
8.
Musculoskelet Surg ; 103(1): 99-105, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29855782

RESUMO

PURPOSE: No study in literature clearly gives advantage of one method of surgical fixation of fracture over the other in metacarpal and phalangeal bones of hand comparing wider outcome measures. MATERIALS AND METHODS: A randomized controlled trial between closed reduction and percutaneous Kirschner wire fixation or open reduction and internal fixation with mini fragment plates was conducted. A total of 32 patients with 16 in each group were taken in tertiary-level teaching hospital from 2014 to 2016. Four patients lost to follow-up apart from 32 studied. Inclusion criteria were age group 16-60 years, fresh (3 days) closed shaft fractures of metacarpal and phalanges. Outcome evaluated were time to union of fracture, degree of strength achieved measured with dynamometer, DASH scoring, range of motion of hand and each digit. RESULTS: Both groups were comparable in terms of return to full hand function, union and total range of motion. K wire fixation results were slightly better than plating group in terms of early DASH score and grip strength after fixation. CONCLUSION: No modality was found to be superior for fixation of small bone fractures of hand. But K wire being cheaper and without inherent complication of plating like scar and tendon irritation, K wire fixation is preferred over plating in shaft fractures of metacarpal and phalanges. LEVEL OF EVIDENCE: Level I Therapeutic study.


Assuntos
Placas Ósseas , Fios Ortopédicos , Falanges dos Dedos da Mão/lesões , Fixação de Fratura/métodos , Fraturas Fechadas/cirurgia , Ossos Metacarpais/lesões , Adolescente , Adulto , Falanges dos Dedos da Mão/diagnóstico por imagem , Fixação de Fratura/instrumentação , Consolidação da Fratura , Fraturas Fechadas/diagnóstico por imagem , Força da Mão , Humanos , Ossos Metacarpais/diagnóstico por imagem , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Resultado do Tratamento , Adulto Jovem
9.
J Assoc Physicians India ; 65(12): 66-72, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29327524

RESUMO

Tobacco use is one of the main preventable causes of mortality and morbidity worldwide. The global disease burden due to tobacco use is huge with projected mortality of eight million lives per year by 2030. Metabolic syndrome (MS) is defined as a constellation of cardiovascular and endocrine risk factors such as insulin resistance, obesity, raised blood pressure, and abnormal lipid profile. The relationship between tobacco use and MS has been well established. Also, the causal association between tobacco use and development of individual components of MS is well established. The Uttar Pradesh Association of Physicians of India (UP API) has drafted this position statement on managing tobacco use among persons with or at risk of developing Metabolic Syndrome (MS). This position statement presents evidence-based recommendations as described below. Scope and purpose The objective of this position statement is to offer clinical recommendations for screening, diagnosis and management of tobacco use among persons with or at risk of developing Metabolic Syndrome (MS). The purpose of this document is to aid in identification and treatment of maladaptive patterns of tobacco use i.e. tobacco use disorder (tobacco dependence, harmful use, abuse) in person with or at risk of developing MS. Intended Audience The position statement is targeted at the clinicians engaged in care and management of person with or at risk of developing Metabolic Syndrome (MS). This might also be of relevance to the policy makers considering the public health burden of both MS and tobacco use disorders.


Assuntos
Síndrome Metabólica , Obesidade , Abandono do Hábito de Fumar , Uso de Tabaco , Humanos , Índia , Síndrome Metabólica/complicações , Obesidade/complicações , Fatores de Risco
10.
J Hand Surg Asian Pac Vol ; 21(3): 410-3, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27595963

RESUMO

Incidence of multiple flexor tendon rupture following distal radius fractures is rare with very few cases being reported in literature. We present an unusual case of a patient who had come to us with complaints of weakness and paresthesia of the right hand of one month prior and with a past history of dorsal plating for distal radius fracture nine years ago. Radiographs showed a distal radius fracture malunion with intact dorsal plate and protrusion of screws through the volar cortex. On exploration, attritional ruptures of all digital flexors were found with sparing of the Flexor Pollicis Longus tendon. The fibrous mass was excised and flexors reconstructed with a fascia lata graft. Attempt was made to correct the malunion with radial and ulnar osteotomies. At one year the patient had excellent restoration of digital flexion.


Assuntos
Fascia Lata/transplante , Fixação Interna de Fraturas/efeitos adversos , Fraturas Mal-Unidas/complicações , Procedimentos de Cirurgia Plástica/métodos , Fraturas do Rádio/complicações , Traumatismos dos Tendões/cirurgia , Adulto , Placas Ósseas/efeitos adversos , Fraturas Mal-Unidas/cirurgia , Humanos , Masculino , Radiografia , Fraturas do Rádio/cirurgia , Ruptura/etiologia , Traumatismos dos Tendões/etiologia
11.
J Ophthalmic Vis Res ; 11(3): 313-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27621791

RESUMO

Loss of light perception (LP) after open globe injury (OGI) does not necessarily mean the patient will have permanent complete visual loss. Findings that seem to be associated reliably with permanent profound vision loss after OGI include optic nerve avulsion, optic nerve transection, and profound loss of intraocular contents, which can be identified with CT/MRI imaging albeit with varying degrees of confidence. Eyes with NLP after OGI that undergo successful primary repair with intact optic nerves may be considered for additional surgery, particularly if there is: (1) recovery of LP on the first day after primary repair; (2) treatable pathology underlying NLP status (e.g., extensive choroidal hemorrhage, dense vitreous and subretinal hemorrhage); (3) NLP in the fellow eye. We counsel patients that the chance of recovering ambulatory vision under these circumstances is very low (~5%).

12.
Clin Exp Immunol ; 186(3): 313-320, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27568583

RESUMO

An increased expansion of T helper type 17 (Th17) cells in the synovium has been shown to play a key role in cartilage and bone destruction in rheumatoid arthritis (RA). Because the correlation of the peripheral blood helper T cell subsets and various inflammatory cytokines with the magnetic resonance imaging (MRI)-based parameters have not been studied adequately to date, we sought to look for the same in this study. RA patients with disease duration less than 36 months, disease-modifying anti-rheumatic drugs (DMARDs) and steroid-naive, were recruited. MRI of the dominant hand and wrist was performed using a 0·2 Tesla MRI machine. Peripheral blood Th1 and Th17 were enumerated by flow cytometry and serum interleukin (IL)-6 and IL-17 by enzyme-linked immunosorbent assay (ELISA). Forty consecutive seropositive RA patients [33 females, mean disease duration 12·2 months, mean disease activity score (DAS)28 = 4·4] were included. MRI revealed erosions in 80% of these subjects. On subgroup analysis, prevalence of erosions (94 versus 68%) as well as mean erosion score (11·5 ± 18·9 versus 3·5 ± 6·0) were significantly higher in established RA (13-36 months' duration) compared to early RA (0-12 months). The median peripheral blood Th17 frequencies were significantly higher in patients (1·4%) compared to healthy controls (0·7%) and had a strong negative correlation with MRI parameters of erosion and osteitis as well as with DAS28 in the established RA subgroup. The frequency of peripheral blood Th17 subset was significantly expanded in established RA which correlated inversely with disease activity as well as MRI based erosions and osteitis.


Assuntos
Artrite Reumatoide/sangue , Artrite Reumatoide/diagnóstico , Contagem de Linfócitos , Imageamento por Ressonância Magnética , Osteíte/patologia , Células Th17/imunologia , Adulto , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Biomarcadores , Estudos de Casos e Controles , Citocinas/sangue , Citocinas/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Células Th17/metabolismo
13.
Dis Esophagus ; 29(7): 837-841, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26227908

RESUMO

Post-cricoid web is an uncommon cause for dysphagia and is most frequently reported in middle-aged women. Triad of web, iron deficiency anemia (IDA), and dysphagia is known as Plummer-Vinson syndrome (PVS). Literature on PVS is very limited. Here we report the first prospective study of PVS with predefined diagnostic criteria and management plan. Adults with dysphagia or those incidentally found to have esophageal web were prospectively enrolled between July 2011 and June 2013. Participants were evaluated with hemogram, barium swallow, and esophagogastroduodenoscopy. PVS was diagnosed if a person had IDA and a post-cricoid web in barium swallow and/or endoscopy. Patients were managed with dilation using through-the-scope controlled radial expansion balloon followed by oral iron and folic acid supplementation. Thirty-seven patients (age, median [range] 40 [19-65] years; 32 [86%] women) were enrolled. Thirty-one symptomatic patients had dysphagia grade 1 (n = 12, 39%), 2 (n = 13, 42%), and 3 (n = 6, 19%) for a median (range) duration of 24 (4-324) months. Barium swallow, done in 29, showed web in 25 which were either circumferential or anterior in position. Twenty-nine (29/31, 94%) patients had complete and two had partial response after the first session of endoscopic dilatation without any complication. Dysphagia recurred in three (10%) of the 30 patients who were followed for a median (range) of 10 (1-24) months. Esophageal-web related dysphagia in patients with PVS responds favorably after single session of endoscopic dilation.


Assuntos
Transtornos de Deglutição/cirurgia , Dilatação/métodos , Esofagoscopia/métodos , Síndrome de Plummer-Vinson/cirurgia , Adulto , Idoso , Anemia Ferropriva/etiologia , Sulfato de Bário , Meios de Contraste , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/patologia , Endoscopia do Sistema Digestório , Esôfago/anormalidades , Esôfago/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndrome de Plummer-Vinson/diagnóstico , Síndrome de Plummer-Vinson/patologia , Estudos Prospectivos , Recidiva , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
14.
Health Technol Assess ; 17(3): 1-156, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23369845

RESUMO

BACKGROUND: There is increasing evidence that invasive fungal disease (IFD) is more likely to occur in non-neutropenic patients in critical care units. A number of randomised controlled trials (RCTs) have evaluated antifungal prophylaxis in non-neutropenic, critically ill patients, demonstrating a reduction in the risk of proven IFD and suggesting a reduction in mortality. It is necessary to establish a method to identify and target antifungal prophylaxis at those patients at highest risk of IFD, who stand to benefit most from any antifungal prophylaxis strategy. OBJECTIVES: To develop and validate risk models to identify non-neutropenic, critically ill adult patients at high risk of invasive Candida infection, who would benefit from antifungal prophylaxis, and to assess the cost-effectiveness of targeting antifungal prophylaxis to high-risk patients based on these models. DESIGN: Systematic review, prospective data collection, statistical modelling, economic decision modelling and value of information analysis. SETTING: Ninety-six UK adult general critical care units. PARTICIPANTS: Consecutive admissions to participating critical care units. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Invasive fungal disease, defined as a blood culture or sample from a normally sterile site showing yeast/mould cells in a microbiological or histopathological report. For statistical and economic modelling, the primary outcome was invasive Candida infection, defined as IFD-positive for Candida species. RESULTS: Systematic review: Thirteen articles exploring risk factors, risk models or clinical decision rules for IFD in critically ill adult patients were identified. Risk factors reported to be significantly associated with IFD were included in the final data set for the prospective data collection. DATA COLLECTION: Data were collected on 60,778 admissions between July 2009 and March 2011. Overall, 383 patients (0.6%) were admitted with or developed IFD. The majority of IFD patients (94%) were positive for Candida species. The most common site of infection was blood (55%). The incidence of IFD identified in unit was 4.7 cases per 1000 admissions, and for unit-acquired IFD was 3.2 cases per 1000 admissions. Statistical modelling: Risk models were developed at admission to the critical care unit, 24 hours and the end of calendar day 3. The risk model at admission had fair discrimination (c-index 0.705). Discrimination improved at 24 hours (c-index 0.823) and this was maintained at the end of calendar day 3 (c-index 0.835). There was a drop in model performance in the validation sample. Economic decision model: Irrespective of risk threshold, incremental quality-adjusted life-years of prophylaxis strategies compared with current practice were positive but small compared with the incremental costs. Incremental net benefits of each prophylaxis strategy compared with current practice were all negative. Cost-effectiveness acceptability curves showed that current practice was the strategy most likely to be cost-effective. Across all parameters in the decision model, results indicated that the value of further research for the whole population of interest might be high relative to the research costs. CONCLUSIONS: The results of the Fungal Infection Risk Evaluation (FIRE) Study, derived from a highly representative sample of adult general critical care units across the UK, indicated a low incidence of IFD among non-neutropenic, critically ill adult patients. IFD was associated with substantially higher mortality, more intensive organ support and longer length of stay. Risk modelling produced simple risk models that provided acceptable discrimination for identifying patients at 'high risk' of invasive Candida infection. Results of the economic model suggested that the current most cost-effective treatment strategy for prophylactic use of systemic antifungal agents among non-neutropenic, critically ill adult patients admitted to NHS adult general critical care units is a strategy of no risk assessment and no antifungal prophylaxis. FUNDING: Funding for this study was provided by the Health Technology Assessment programme of the National Institute for Health Research.


Assuntos
Antifúngicos/administração & dosagem , Antifúngicos/economia , Candidíase Invasiva/epidemiologia , Candidíase Invasiva/prevenção & controle , Cuidados Críticos/estatística & dados numéricos , Modelos Estatísticos , Quimioprevenção , Análise Custo-Benefício , Sistemas de Apoio a Decisões Clínicas , Humanos , Micoses/epidemiologia , Micoses/prevenção & controle , Medição de Risco , Fatores de Risco , Medicina Estatal , Reino Unido
15.
Eur Radiol ; 22(12): 2654-61, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22752461

RESUMO

OBJECTIVES: To evaluate a new iterative reconstruction (IR) algorithm for radiation dose, image quality (IQ), signal-to-noise-ratio (SNR), and contrast-to-noise-ratio (CNR) in multidetector computed tomography (MDCT) dynamic myocardial perfusion imaging (MPI). METHODS: ECG-gated 256-slice MDCT dynamic MPI was performed in six pigs after subtotal balloon occlusion of one artery. Two 100 kVp protocols were compared: high dose (HD): 150 mAs; low dose (LD): 100 mAs. HD images were reconstructed with filtered back projection (FBP), LD images with FBP and different strengths of IR (L1, L4, and L7). IQ (5-point scale), SNR, and CNR (ischemic vs. normal myocardium) values derived from the HD (FBP) images and the different LD images were compared. RESULTS: Mean SNR values for myocardium were 16.3, 11.3, 13.1, 17.1, and 28.9 for the HD, LD (FBP), LD (L1), LD (L4), and LD (L7) reconstructions, respectively. Mean CNR values were 8.9, 6.3, 7.8, 9.3, and 12.8. IQ was scored as 4.6, 3.3, 4.4, 4.7, and 3.4, respectively. A significant loss of IQ was observed for the LD (L7) images compared to the HD (FBP) images (P < 0.05). CONCLUSION: Appropriate levels of iterative reconstruction can improve SNR and CNR, facilitating radiation dose savings in CT-MPI without influencing diagnostic quality. KEY POINTS: Iterative reconstruction (IR) can reduce radiation dose in myocardial perfusion CT. Our study also demonstrated improvements in image quality (noise, SNR, and CNR). Dynamic CT-MPI could help determine the hemodynamic significance of coronary artery disease. With dynamic CT MPI, myocardial blood flow can be determined quantitatively.


Assuntos
Técnicas de Imagem de Sincronização Cardíaca/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada por Raios X/métodos , Adenosina/farmacologia , Algoritmos , Animais , Oclusão com Balão , Meios de Contraste/administração & dosagem , Modelos Animais de Doenças , Iopamidol/administração & dosagem , Iopamidol/análogos & derivados , Estudos Prospectivos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Razão Sinal-Ruído , Estatísticas não Paramétricas , Suínos
17.
Med Phys ; 39(6Part14): 3774, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28517254

RESUMO

PURPOSE: To quantify the effect of 192Ir source attenuation due to titanium material used in manufacturing the new CT-compatible FSD device during treatment delivery. METHODS: A typical cervical cancer treatment includes primary external beam followed by a course of HDR Intra-Cavitary brachytherapy using FSD applicator. A detailed geometry of the applicator obtained from the manufacturer is implemented using Monte Carlo (MC) simulation package MCNP5. The bending angles of tandem and colpostats are 150 and 1200 respectively. The source geometry is of the VariSource wire model VS2000. We assigned 8 dwell positions in the tandem and 4 dwell positions in each colpostat to calculate dose rate at reference points with and without titanium wall present in the simulation. RESULTS: Based on the MC computation, the titanium tube reduced the overall dose to point A by ∼1.5%, with contributions varying for each dwell position. We also compare MC results with BrachyVision treatment planning system calculations. The clinically used algorithm is based on AAPM report TG-43, which calculates the dose without inhomogeneity correction. The latest Varian release of the planning software BrachyVision-Acuros has the updated algorithm capable of inhomogeneity corrected dose calculation. For this study a treatment plan is created based on the exact coordinates of the MC model and used to calculate dose at reference points. The dose to reference point A with BrachyVision traditional algorithm is in excellent agreement with the homogeneous MC model result. CONCLUSION: The attenuation due to Ti wall is ∼1.5% at point A compared to ∼5% using a non-CT compatible system. Comparative accuracy of the two treatment planning systems with MC, especially in their abilities to account for the source attenuation due to the applicator titanium walls will also be presented.

19.
Phytomedicine ; 16(1): 47-55, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17574826

RESUMO

The current study has concentrated on assessment of the radioprotective potential of REC-2001, a semi-purified fraction of rhizomes of Podophyllum hexandrum, in Swiss albino Strain 'A' mice exposed to 10 Gy whole-body gamma radiation. Animals were treated with 10 and 15 mg/kg b wt (i.p.) of REC-2001 1h prior to exposure to a lethal dose of gamma-radiation (10 Gy) and observed upto 30 days. For analysis of maximum tolerable dose (MTD), LD(50) and acute toxic dose, different concentrations of the extract were administered to animals and their mortality and morbidity status was observed upto 72 h and one week, respectively. Dose reduction factor (DRF) was determined by exposing REC-2001 pre-treated mice to supra-lethal doses of gamma-radiation. Endogenous spleen colony forming units (CFU), DNA strand breaks in thymocytes (alkaline halo assay) and lipid degradation was studied to understand the mechanism of radioprotection. A single dose of REC-2001 (10 and 15 mg/kg b wt i.p.) exhibited >90% survival in the pre-treated irradiated group versus no survival in radiation control group. Single doses of upto 75 mg/kg b wt (i.p.) did not cause any mortality (MTD) in mice. REC-2001, a dose of 90 mg/kg b wt, resulted in 50% mortality (LD(50)), while the LD(100) was 115 mg/kg b wt REC-2001 exhibited a DRF of 1.62. CFU counts in the REC-2001 treated group were found significantly high (5.33/spleen) as compared to controls. Exposure of thymocytes to 10 Gy radiation resulted in increased halo diameter (45+/-3 microm) in comparison to untreated controls (8+/-1 microm). REC-2001 administration (500 microg/ml) decreased the halo diameter to 15+/-2 microm. Radiation-induced lipid degradation was also inhibited by REC-2001. The present study has revealed that REC-2001 is a promising radioprotective fraction that can be effectively used against lethal doses of gamma-radiation after further investigations in higher animal models.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Raios gama , Fitoterapia , Lesões Experimentais por Radiação/tratamento farmacológico , Protetores contra Radiação/uso terapêutico , Irradiação Corporal Total , Animais , Berberidaceae , Peso Corporal , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/toxicidade , Estimativa de Kaplan-Meier , Ácido Linoleico/metabolismo , Dose Máxima Tolerável , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Baço/efeitos da radiação , Irradiação Corporal Total/mortalidade
20.
Phys Rev Lett ; 103(23): 231801, 2009 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-20366141

RESUMO

A precise measurement of the cross section of the process e(+)e(-) --> pi(+)pi(-)(gamma) from threshold to an energy of 3 GeV is obtained with the initial state radiation (ISR) method using 232 fb(-1) of data collected with the BABAR detector at e(+)e(-) center-of-mass energies near 10.6 GeV. The ISR luminosity is determined from a study of the leptonic process e(+)e(-) --> mu(+)mu(-)gamma(gamma). The leading-order hadronic contribution to the muon magnetic anomaly calculated using the pipi cross section measured from threshold to 1.8 GeV is (514.1 +/- 2.2(stat) +/- 3.1(syst)) x 10(-10).

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