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1.
Radiol Clin North Am ; 58(2): 305-327, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32044009

RESUMO

Reporting MR imaging of pelvic floor dysfunction can be made easy if radiologists understand the aim of each MR sequence and what to report in each set of MR images. For an MR imaging report that is critical in decision making for patient management, it is of paramount importance to the radiologist to know what to look for and where to look for it. This article presents a new term, integrated MR analytical approach. A reporting template is included in which all MR findings are presented in a schematic form that can be easily interpreted by clinicians from different subspecialties.


Assuntos
Imageamento Tridimensional/métodos , Imagem por Ressonância Magnética/métodos , Distúrbios do Assoalho Pélvico/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética/tendências , Diafragma da Pelve/diagnóstico por imagem , Diafragma da Pelve/fisiopatologia , Distúrbios do Assoalho Pélvico/fisiopatologia
2.
World Neurosurg ; 131: 328-338, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31658576

RESUMO

Glioblastomas are the most common malignant brain tumor and despite extensive research have a dismal prognosis. This review focuses on the current treatment paradigms of glioblastoma and highlights current advances in surgical approaches, imaging techniques, molecular diagnostics, and translational efforts. Several promising clinical trials in immunotherapy and personalized medicine are discussed and the importance of quality of life in the patients and their caregivers both during active treatment and survivorship is also commented on.


Assuntos
Neoplasias Encefálicas/terapia , Glioblastoma/terapia , Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/diagnóstico , Ensaios Clínicos como Assunto , Fracionamento da Dose de Radiação , Feminino , Previsões , Glioblastoma/diagnóstico , Humanos , Imunoterapia/métodos , Imunoterapia/tendências , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/tendências , Masculino , Terapia de Alvo Molecular/tendências , Procedimentos Neurocirúrgicos/métodos , Procedimentos Neurocirúrgicos/tendências , Tomografia por Emissão de Pósitrons/métodos , Tomografia por Emissão de Pósitrons/tendências , Medicina de Precisão/métodos , Medicina de Precisão/tendências , Qualidade de Vida , Fatores de Risco
3.
Neurology ; 93(14): e1348-e1359, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31484713

RESUMO

OBJECTIVE: To determine which pathologic process could be responsible for the acceleration of cognitive decline during the course of multiple sclerosis (MS), using longitudinal structural MRI, which was related to cognitive decline in relapsing-remitting MS (RRMS) and progressive MS (PMS). METHODS: A prospective cohort of 230 patients with MS (179 RRMS and 51 PMS) and 59 healthy controls was evaluated twice with 5-year (mean 4.9, SD 0.94) interval during which 22 patients with RRMS converted to PMS. Annual rates of cortical and deep gray matter atrophy as well as lesion volume increase were computed on longitudinal (3T) MRI data and correlated to the annual rate of cognitive decline as measured using an extensive cognitive evaluation at both time points. RESULTS: The deep gray matter atrophy rate did not differ between PMS and RRMS (-0.82%/year vs -0.71%/year, p = 0.11), while faster cortical atrophy was observed in PMS (-0.87%/year vs -0.48%/year, p < 0.01). Similarly, faster cognitive decline was observed in PMS compared to RRMS (p < 0.01). Annual cognitive decline was related to the rate of annual lesion volume increase in stable RRMS (r = -0.17, p = 0.03) to the rate of annual deep gray matter atrophy in converting RRMS (r = 0.50, p = 0.02) and annual cortical atrophy in PMS (r = 0.35, p = 0.01). CONCLUSIONS: These results indicate that cortical atrophy and cognitive decline accelerate together during the course of MS. Substrates of cognitive decline shifted from worsening lesional pathology in stable RRMS to deep gray matter atrophy in converting RRMS and to accelerated cortical atrophy in PMS only.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/psicologia , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/psicologia , Adulto , Idoso , Atrofia/diagnóstico por imagem , Atrofia/epidemiologia , Atrofia/psicologia , Disfunção Cognitiva/epidemiologia , Estudos de Coortes , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Imagem por Ressonância Magnética/tendências , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/epidemiologia , Estudos Prospectivos
4.
J Orthop Surg Res ; 14(1): 298, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488187

RESUMO

BACKGROUND: There are few studies to investigate changes in imaging parameters of Modic changes (MCs). The imaging studies examining the distinctions in the lumbar sagittal parameters between MCs and lumbar disc degeneration (LDD) are still lacking. The purpose of this study was to identify the differences in the lumbar sagittal parameters among patients for LDD with/without Modic type 2 change (MII). METHODS: A total of 208 patients with lumbar degenerative disease from January 2017 to August 2018 volunteered for this study. Sixty-two patients with MII were used as the MC group. The other 146 patients served as the disc degeneration (DD) group. The DD scores and sagittal parameters were measured on magnetic resonance imaging (MRI) and X-ray by using Surgimap software. RESULTS: The prevalence of MII for patients with degenerative lumbar diseases in this study was 29.81%, primarily located at L5/S1. There were significant differences in lumbar lordosis (LL) and sacral slope (SS) between these two groups (P < 0.05). Similarly, the significant decrease in intervertebral height index (IHI) was found at L3-S1 in the MC group, compared with the DD group (P < 0.05). However, a significant difference in intervertebral angle (IVA) was observed only at L5/S1 (P < 0.05). The MC group had the smaller endplate concave angle (ECA) than the DD group from L3 caudal endplate to S1 cranial endplate (P < 0.05). CONCLUSIONS: MII has a severe radiographic representation in the process of lumbar degeneration than patients without MII, and the overconcentration of load caused by the smaller LL, SS, and IVA may be a reasonable explanation to answer why MCs are more common at the L5/S1.


Assuntos
Degeneração do Disco Intervertebral/diagnóstico por imagem , Disco Intervertebral/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Imagem por Ressonância Magnética/tendências , Índice de Gravidade de Doença , Adulto , Feminino , Humanos , Degeneração do Disco Intervertebral/epidemiologia , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
5.
Urologiia ; (4 ()): 25-27, 2019 Sep.
Artigo em Russo | MEDLINE | ID: mdl-31535794

RESUMO

Imaging studies play a crucial role in the diagnosis of urologic diseases. X-ray and ultrasound studies are used as first-line diagnostic methods. Computed tomography and magnetic resonance imaging (MD-CT and MRI), radionuclide and hybrid methods allow to clarify diagnosis. Currently, the trend "from simple to complex" contributes to obtaining maximum information in the shortest possible time with a minimum cost.


Assuntos
Técnicas de Diagnóstico Urológico/tendências , Imagem por Ressonância Magnética , Tomografia Computadorizada por Raios X , Doenças Urológicas/diagnóstico por imagem , Urologia/tendências , Alemanha , Humanos , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/tendências , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/tendências , Ultrassonografia/métodos , Ultrassonografia/tendências , Urografia
6.
World J Gastroenterol ; 25(32): 4682-4695, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31528094

RESUMO

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality worldwide. Various imaging modalities provide important information about HCC for its clinical management. Since positron-emission tomography (PET) or PET-computed tomography was introduced to the oncologic setting, it has played crucial roles in detecting, distinguishing, accurately staging, and evaluating local, residual, and recurrent HCC. PET imaging visualizes tissue metabolic information that is closely associated with treatment. Dynamic PET imaging and dual-tracer have emerged as complementary techniques that aid in various aspects of HCC diagnosis. The advent of new radiotracers and the development of immuno-PET and PET-magnetic resonance imaging have improved the ability to detect lesions and have made great progress in treatment surveillance. The current PET diagnostic capabilities for HCC and the supplementary techniques are reviewed herein.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Imunoconjugados/administração & dosagem , Neoplasias Hepáticas/diagnóstico por imagem , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/administração & dosagem , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Diagnóstico Diferencial , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/tendências , Estadiamento de Neoplasias , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/tendências , Prognóstico
7.
Br J Radiol ; 92(1104): 20190513, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31529977

RESUMO

MRI is an invaluable diagnostic tool in the investigation and management of patients with pathology of the head and neck. However, numerous technical challenges exist, owing to a combination of fine anatomical detail, complex geometry (that is subject to frequent motion) and susceptibility effects from both endogenous structures and exogenous implants. Over recent years, there have been rapid developments in several aspects of head and neck imaging including higher resolution, isotropic 3D sequences, diffusion-weighted and diffusion-tensor imaging as well as permeability and perfusion imaging. These have led to improvements in anatomic, dynamic and functional imaging. Further developments using contrast-enhanced 3D FLAIR for the delineation of endolymphatic structures and black bone imaging for osseous structures are opening new diagnostic avenues. Furthermore, technical advances in compressed sensing and metal artefact reduction have the capacity to improve imaging speed and quality, respectively. This review explores novel and evolving MRI sequences that can be employed to evaluate diseases of the head and neck, including the skull base.


Assuntos
Neoplasias dos Nervos Cranianos/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Neoplasias da Base do Crânio/diagnóstico por imagem , Artefatos , Osso e Ossos/diagnóstico por imagem , Tecido Conjuntivo/diagnóstico por imagem , Meios de Contraste , Imagem de Difusão por Ressonância Magnética , Hidropisia Endolinfática/diagnóstico por imagem , Gadolínio , Perda Auditiva Neurossensorial/diagnóstico por imagem , Perda Auditiva Súbita/diagnóstico por imagem , Humanos , Angiografia por Ressonância Magnética , Imagem por Ressonância Magnética/tendências
8.
JAMA ; 322(9): 843-856, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31479136

RESUMO

Importance: Medical imaging increased rapidly from 2000 to 2006, but trends in recent years have not been analyzed. Objective: To evaluate recent trends in medical imaging. Design, Setting, and Participants: Retrospective cohort study of patterns of medical imaging between 2000 and 2016 among 16 million to 21 million patients enrolled annually in 7 US integrated and mixed-model insurance health care systems and for individuals receiving care in Ontario, Canada. Exposures: Calendar year and country (United States vs Canada). Main Outcomes and Measures: Use of computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and nuclear medicine imaging. Annual and relative imaging rates by imaging modality, country, and age (children [<18 years], adults [18-64 years], and older adults [≥65 years]). Results: Overall, 135 774 532 imaging examinations were included; 5 439 874 (4%) in children, 89 635 312 (66%) in adults, and 40 699 346 (30%) in older adults. Among adults and older adults, imaging rates were significantly higher in 2016 vs 2000 for all imaging modalities other than nuclear medicine. For example, among older adults, CT imaging rates were 428 per 1000 person-years in 2016 vs 204 per 1000 in 2000 in US health care systems and 409 per 1000 vs 161 per 1000 in Ontario; for MRI, 139 per 1000 vs 62 per 1000 in the United States and 89 per 1000 vs 13 per 1000 in Ontario; and for ultrasound, 495 per 1000 vs 324 per 1000 in the United States and 580 per 1000 vs 332 per 1000 in Ontario. Annual growth in imaging rates among US adults and older adults slowed over time for CT (from an 11.6% annual percentage increase among adults and 9.5% among older adults in 2000-2006 to 3.7% among adults in 2013-2016 and 5.2% among older adults in 2014-2016) and for MRI (from 11.4% in 2000-2004 in adults and 11.3% in 2000-2005 in older adults to 1.3% in 2007-2016 in adults and 2.2% in 2005-2016 in older adults). Patterns in Ontario were similar. Among children, annual growth for CT stabilized or declined (United States: from 10.1% in 2000-2005 to 0.8% in 2013-2016; Ontario: from 3.3% in 2000-2006 to -5.3% in 2006-2016), but patterns for MRI were similar to adults. Changes in annual growth in ultrasound were smaller among adults and children in the United States and Ontario compared with CT and MRI. Nuclear medicine imaging declined in adults and children after 2006. Conclusions and Relevance: From 2000 to 2016 in 7 US integrated and mixed-model health care systems and in Ontario, rates of CT and MRI use continued to increase among adults, but at a slower pace in more recent years. In children, imaging rates continued to increase except for CT, which stabilized or declined in more recent periods. Whether the observed imaging utilization was appropriate or was associated with improved patient outcomes is unknown.


Assuntos
Diagnóstico por Imagem/tendências , Abdome/diagnóstico por imagem , Adolescente , Adulto , Idoso , Criança , Diagnóstico por Imagem/estatística & dados numéricos , Cabeça/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética/estatística & dados numéricos , Imagem por Ressonância Magnética/tendências , Pessoa de Meia-Idade , Ontário , Cintilografia/estatística & dados numéricos , Cintilografia/tendências , Coluna Vertebral/diagnóstico por imagem , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Tomografia Computadorizada por Raios X/tendências , Ultrassonografia/estatística & dados numéricos , Ultrassonografia/tendências , Estados Unidos , Adulto Jovem
9.
Dev Cogn Neurosci ; 39: 100700, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31426010

RESUMO

Major depressive disorder (MDD) often emerges during adolescence with detrimental effects on development as well as lifetime consequences. Identifying neurobiological markers that are associated with the onset or course of this disorder in childhood and adolescence is important for early recognition and intervention and, potentially, for the prevention of illness onset. In this systematic review, 68 longitudinal neuroimaging studies, from 34 unique samples, that examined the association of neuroimaging markers with onset or changes in paediatric depression published up to 1 February 2019 were examined. These studies employed different imaging modalities at baseline; structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), functional MRI (fMRI) or electroencephalography (EEG). Most consistent evidence across studies was found for blunted reward-related (striatal) activity (fMRI and EEG) as a potential biological marker for both MDD onset and course. With regard to structural brain measures, the results were highly inconsistent, likely caused by insufficient power to detect complex mediating effects of genetic and environmental factors in small sample sizes. Overall, there were a limited number of samples, and confounding factors such as sex and pubertal development were often not considered, whereas these factors are likely to be relevant especially in this age range.


Assuntos
Encéfalo/diagnóstico por imagem , Depressão/diagnóstico por imagem , Transtornos do Neurodesenvolvimento/diagnóstico por imagem , Neuroimagem/métodos , Adolescente , Encéfalo/fisiopatologia , Criança , Depressão/fisiopatologia , Depressão/psicologia , Imagem de Tensor de Difusão/métodos , Imagem de Tensor de Difusão/tendências , Eletroencefalografia/métodos , Eletroencefalografia/tendências , Feminino , Humanos , Estudos Longitudinais , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/tendências , Masculino , Transtornos do Neurodesenvolvimento/fisiopatologia , Transtornos do Neurodesenvolvimento/psicologia , Neuroimagem/tendências , Recompensa
10.
Brain Stimul ; 12(6): 1526-1536, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31296402

RESUMO

BACKGROUND: Evidence suggests that repetitive transcranial magnetic stimulation (rTMS), a non-invasive neuromodulation technique, alters resting brain activity. Despite anecdotal evidence that rTMS effects wear off, there are no reports of longitudinal studies, even in humans, mapping the therapeutic duration of rTMS effects. OBJECTIVE: Here, we investigated the longitudinal effects of repeated low-intensity rTMS (LI-rTMS) on healthy rodent resting-state networks (RSNs) using resting-state functional MRI (rs-fMRI) and on sensorimotor cortical neurometabolite levels using proton magnetic resonance spectroscopy (MRS). METHODS: Sprague-Dawley rats received 10 min LI-rTMS daily for 15 days (10 Hz or 1 Hz stimulation, n = 9 per group). MRI data were acquired at baseline, after seven days and after 14 days of daily stimulation and at two more timepoints up to three weeks post-cessation of daily stimulation. RESULTS: 10 Hz stimulation increased RSN connectivity and GABA, glutamine, and glutamate levels. 1 Hz stimulation had opposite but subtler effects, resulting in decreased RSN connectivity and glutamine levels. The induced changes decreased to baseline levels within seven days following stimulation cessation in the 10 Hz group but were sustained for at least 14 days in the 1 Hz group. CONCLUSION: Overall, our study provides evidence of long-term frequency-specific effects of LI-rTMS. Additionally, the transient connectivity changes following 10 Hz stimulation suggest that current treatment protocols involving this frequency may require ongoing "top-up" stimulation sessions to maintain therapeutic effects.


Assuntos
Imagem por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Córtex Sensório-Motor/diagnóstico por imagem , Córtex Sensório-Motor/metabolismo , Estimulação Magnética Transcraniana/métodos , Animais , Imagem por Ressonância Magnética/tendências , Masculino , Ratos , Ratos Sprague-Dawley , Descanso/fisiologia , Fatores de Tempo , Estimulação Magnética Transcraniana/tendências
11.
Int J Radiat Oncol Biol Phys ; 105(3): 581-590, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31319091

RESUMO

PURPOSE: Previous studies demonstrated that the radiation therapy, image technology, and the application of chemotherapy have developed in the last 2 decades. This study explored the survival trends and treatment failure patterns of patients with nonmetastatic nasopharyngeal carcinoma (NPC) treated with radiation therapy. Furthermore, we evaluated the survival benefit brought by the development of radiation therapy, image technology, and chemotherapy based on a large cohort from 1990 to 2012. METHODS AND MATERIALS: Data from 20,305 patients with nonmetastatic NPC treated between 1990 and 2012 were analyzed. Patients were divided into 4 calendar periods (1990-1996, 1997-2002, 2003-2007, and 2008-2012). Overall survival (OS) was the primary endpoint. RESULTS: Magnetic resonance imaging has replaced computed tomography as the most important imaging technique since 2003. Conventional 2-dimensional radiation therapy, which was the main radiation therapy technique in our institution before 2008, was replaced by intensity modulated radiation therapy later. An increasing number of patients have undergone chemotherapy since 2003. The 5-year OS across the 4 calendar periods increased at each TNM stage with progression-free survival (PFS) and locoregional relapse-free survival (LRFS) showing a similar trend, whereas distant metastasis-free survival showed small differences. Multivariate analyses showed that the application of intensity modulated radiation therapy and magnetic resonance imaging were independent protective factors in OS, PFS, LRFS, and distant metastasis-free survival. Chemotherapy benefited patients in OS, PFS, and LRFS. The main pattern of treatment failure shifted from recurrence to distant metastasis. CONCLUSIONS: The development of radiation therapy, image technology, and chemotherapy increased survival rates among patients with NPC because of excellent locoregional control. Distant failure has become the greatest challenge for NPC treatment.


Assuntos
Carcinoma Nasofaríngeo/mortalidade , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/radioterapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança , Estudos de Coortes , DNA Viral/sangue , Feminino , Humanos , Imagem por Ressonância Magnética/mortalidade , Imagem por Ressonância Magnética/tendências , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Carcinoma Nasofaríngeo/diagnóstico por imagem , Carcinoma Nasofaríngeo/tratamento farmacológico , Neoplasias Nasofaríngeas/diagnóstico por imagem , Neoplasias Nasofaríngeas/tratamento farmacológico , Recidiva Local de Neoplasia/mortalidade , Papillomaviridae/genética , Prognóstico , Intervalo Livre de Progressão , Radioterapia/métodos , Radioterapia/mortalidade , Radioterapia/tendências , Radioterapia de Intensidade Modulada/mortalidade , Radioterapia de Intensidade Modulada/tendências , Taxa de Sobrevida , Fatores de Tempo , Tomografia Computadorizada por Raios X/tendências , Falha de Tratamento , Adulto Jovem
12.
Dev Cogn Neurosci ; 38: 100675, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31279245

RESUMO

In the United States over one-third of the population, including children and adolescents, are overweight or obese. Despite the prevalence of obesity, few studies have examined how food cravings and the ability to regulate them change throughout development. Here, we addressed this gap in knowledge by examining structural brain and behavioral changes associated with regulation of craving across development. In a longitudinal design, individuals ages 6-26 completed two structural scans as well as a behavioral task where they used a cognitive regulatory strategy to decrease the appetitive value of foods. Behaviorally, we found that the ability to regulate craving improved with age. Neurally, improvements in regulatory ability were associated with cortical thinning in medial and lateral prefrontal cortex. We also found that models with cortical thickness measurements and age chosen by a lasso-based variable selection method could predict an individual's regulation behavior better than age and other behavioral factors alone. Additionally, when controlling for age, smaller ventral striatal volumes were associated with higher body mass index and predicted greater increases in weight two years later. Taken together, these results demonstrate a role for structural brain changes in supporting the ability to resist cravings for appetitive foods across development.


Assuntos
Desenvolvimento do Adolescente/fisiologia , Encéfalo/crescimento & desenvolvimento , Desenvolvimento Infantil/fisiologia , Fissura/fisiologia , Estimulação Luminosa/métodos , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Criança , Feminino , Humanos , Estudos Longitudinais , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/tendências , Masculino , Adulto Jovem
13.
Magn Reson Imaging Clin N Am ; 27(3): 465-473, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31279450

RESUMO

The potential role of cardiac MR imaging in the diagnosis, risk-stratification, and treatment of patients with cardiac arrhythmias is rapidly evolving. Beyond substrate identification and characterization, it is now feasible to perform MR imaging-based noninvasive virtual programmed stimulation to identify potential ablation targets. The next phase of MR imaging-guided electrophysiology may involve intraprocedural guidance of electrophysiologic interventions using real-time MR imaging. This review discusses the spectrum of MR imaging applications in electrophysiology ranging from those that are established in clinical practice to those that are in the experimental phase of development.


Assuntos
Eletrofisiologia/métodos , Cardiopatias/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Coração/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética/tendências
14.
Int J Radiat Oncol Biol Phys ; 105(3): 479-492, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31271829

RESUMO

The use of magnetic resonance (MR) imaging scans alone for radiation therapy treatment planning (MR-only planning) has been highlighted as one method of improving patient outcomes. Recent technologic advances have meant that introducing MR-only planning to the clinic is becoming a reality, with several specialist radiation therapy clinics using this technique for treatment. As such, substantial efforts are being made to introduce this technique into wide-spread clinical implementation. A systematic review of publications investigating the clinical implementation of pelvic MR-only radiation therapy treatment planning was undertaken following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Medline, Embase, Scopus, Science Direct, Cumulative Index to Nursing and Allied Health Literature, and Web of Science databases were searched (timespan: all years to January 2, 2019). Twenty-six articles met the inclusion criteria. The studies were grouped into the following categories: (1) MR acquisition and synthetic computed tomography generation verification, (2) MR distortion quantification and phantom development, (3) clinical validation of patient treatment positioning in an MR-only workflow, and (4) MR-only commissioning processes. Key conclusions from this review are (1) MR-only planning has been implemented clinically for prostate cancer treatments; (2) a substantial amount of work remains to translate MR-only planning into widespread clinical implementation for all pelvic sites; (3) MR scanner distortions are no longer a barrier to MR-only planning, but they must be managed appropriately; (4) MR-only-based patient positioning verification shows promise, but limited evidence is reported in the literature and further investigation is required; and (5) a number of MR-only commissioning processes have been reported, which can aid centers as they undertake local commissioning; however, this needs to be formalized in guidance from national bodies.


Assuntos
Imagem por Ressonância Magnética/métodos , Posicionamento do Paciente , Neoplasias Pélvicas/diagnóstico por imagem , Neoplasias Pélvicas/radioterapia , Imagens de Fantasmas , Planejamento da Radioterapia Assistida por Computador/métodos , Bases de Dados Factuais/estatística & dados numéricos , Feminino , Humanos , Imagem por Ressonância Magnética/tendências , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/tendências , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos , Fluxo de Trabalho
15.
Nat Rev Neurol ; 15(10): 594-606, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31341275

RESUMO

Candidates for epilepsy surgery must undergo presurgical evaluation to establish whether and how surgical treatment can stop seizures without causing neurological deficits. Various techniques, including MRI, PET, single-photon emission CT, video-EEG, magnetoencephalography and invasive EEG, aim to identify the diseased brain tissue and the involved network. Recent technical and methodological developments, encompassing both advances in existing techniques and new combinations of technologies, are enhancing the ability to define the optimal resection strategy. Multimodal interpretation and predictive computer models are expected to aid surgical planning and patient counselling, and multimodal intraoperative guidance is likely to increase surgical precision. In this Review, we discuss how the knowledge derived from these new approaches is challenging our way of thinking about surgery to stop focal seizures. In particular, we highlight the importance of looking beyond the EEG seizure onset zone and considering focal epilepsy as a brain network disease in which long-range connections need to be taken into account. We also explore how new diagnostic techniques are revealing essential information in the brain that was previously hidden from view.


Assuntos
Epilepsia/diagnóstico por imagem , Epilepsia/cirurgia , Cuidados Pré-Operatórios/tendências , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Encéfalo/cirurgia , Eletroencefalografia/métodos , Eletroencefalografia/tendências , Epilepsia/fisiopatologia , Humanos , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/tendências , Cuidados Pré-Operatórios/métodos
16.
Spine (Phila Pa 1976) ; 44(13): 937-942, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31205171

RESUMO

STUDY DESIGN: Retrospective, observational study. OBJECTIVE: To examine the costs associated with nonoperative management (diagnosis and treatment) of cervical radiculopathy in the year prior to anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: While the costs of operative treatment have been previously described, less is known about nonoperative management costs of cervical radiculopathy leading up to surgery. METHODS: The Humana claims dataset (2007-2015) was queried to identify adult patients with cervical radiculopathy that underwent ACDF. Outcome endpoint was assessment of cumulative and per-capita costs for nonoperative diagnostic (x-rays, computed tomographic [CT], magnetic resonance imaging [MRI], electromyogram/nerve conduction studies [EMG/NCS]) and treatment modalities (injections, physical therapy [PT], braces, medications, chiropractic services) in the year preceding surgical intervention. RESULTS: Overall 12,514 patients (52% female) with cervical radiculopathy underwent ACDF. Cumulative costs and per-capita costs for nonoperative management, during the year prior to ACDF was $14.3 million and $1143, respectively. All patients underwent at least one diagnostic test (MRI: 86.7%; x-ray: 57.5%; CT: 35.2%) while 73.3% patients received a nonoperative treatment. Diagnostic testing comprised of over 62% of total nonoperative costs ($8.9 million) with MRI constituting the highest total relative spend ($5.3 million; per-capita: $489) followed by CT ($2.6 million; per-capita: $606), x-rays ($0.54 million; per-capita: $76), and EMG/NCS ($0.39 million; per-capita: $467). Conservative treatments comprised of 37.7% of the total nonoperative costs ($5.4 million) with injections costs constituting the highest relative spend ($3.01 million; per-capita: $988) followed by PT ($1.13 million; per-capita: $510) and medications (narcotics: $0.51 million, per-capita $101; gabapentin: $0.21 million, per-capita $93; NSAIDs: 0.107 million, per-capita $47), bracing ($0.25 million; per-capita: $193), and chiropractic services ($0.137 million; per-capita: $193). CONCLUSION: The study quantifies the cumulative and per-capital costs incurred 1-year prior to ACDF in patients with cervical radiculopathy for nonoperative diagnostic and treatment modalities. Approximately two-thirds of the costs associated with cervical radiculopathy are from diagnostic modalities. As institutions begin entering into bundled payments for cervical spine disease, understanding condition specific costs is a critical first step. LEVEL OF EVIDENCE: 3.


Assuntos
Vértebras Cervicais , Custos de Cuidados de Saúde , Formulário de Reclamação de Seguro/economia , Procedimentos Neurocirúrgicos/economia , Radiculopatia/economia , Radiculopatia/terapia , Adulto , Idoso , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Estudos de Coortes , Bases de Dados Factuais/economia , Bases de Dados Factuais/tendências , Discotomia/economia , Discotomia/tendências , Feminino , Custos de Cuidados de Saúde/tendências , Humanos , Formulário de Reclamação de Seguro/tendências , Imagem por Ressonância Magnética/economia , Imagem por Ressonância Magnética/tendências , Masculino , Manipulação Quiroprática/economia , Manipulação Quiroprática/tendências , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos/tendências , Modalidades de Fisioterapia/economia , Modalidades de Fisioterapia/tendências , Radiculopatia/diagnóstico por imagem , Estudos Retrospectivos , Fusão Vertebral/economia , Fusão Vertebral/tendências , Tomografia Computadorizada por Raios X/economia , Tomografia Computadorizada por Raios X/tendências , Resultado do Tratamento
17.
Top Magn Reson Imaging ; 28(3): 101-124, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31188271

RESUMO

The potential value of ultrahigh field (UHF) magnetic resonance imaging (MRI) and spectroscopy to biomedical research and in clinical applications drives the development of technologies to overcome its many challenges. The increased difficulties of imaging the human torso compared with the head include its overall size, the dimensions and location of its anatomic targets, the increased prevalence and magnitude of physiologic effects, the limited availability of tailored RF coils, and the necessary transmit chain hardware. Tackling these issues involves addressing notoriously inhomogeneous transmit B1 (B1) fields, limitations in peak B1, larger spatial variations of the static magnetic field B0, and patient safety issues related to implants and local RF power deposition. However, as research institutions and vendors continue to innovate, the potential gains are beginning to be realized. Solutions overcoming the unique challenges associated with imaging the human torso are reviewed as are current studies capitalizing on the benefits of UHF in several anatomies and applications. As the field progresses, strategies associated with the RF system architecture, calibration methods, RF pulse optimization, and power monitoring need to be further integrated into the MRI systems making what are currently complex processes more streamlined. Meanwhile, the UHF MRI community must seize the opportunity to build upon what have been so far proof of principle and feasibility studies and begin to further explore the true impact in both research and the clinic.


Assuntos
Imagem por Ressonância Magnética/métodos , Tronco/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética/efeitos adversos , Imagem por Ressonância Magnética/instrumentação , Imagem por Ressonância Magnética/tendências , Ondas de Rádio
18.
Top Magn Reson Imaging ; 28(3): 145-158, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31188273

RESUMO

Radiofrequency (RF) coils are an essential part of the magnetic resonance (MR) system. To exploit the inherently higher signal-to-noise ratio at ultrahigh magnetic fields (UHF), research sites were forced to build up expertise in RF coil development, as the number of commercially available RF coils were limited. In addition, an integrated transmit body RF coil, which is well-established at MR systems of lower field strength, is still missing at UHF due to technical and physical constraints. This review article provides a brief recapitulation of RF characteristics and RF coils in general to introduce terminology and RF-related parameters, and will then provide an extensive overview of current state-of-the-art RF coils used for MRI from head to toe at 7 Tesla. Finally, a section on RF safety will briefly discuss challenges in performing a safety assessment for custom-designed RF coils, and issues arising from the interaction of the RF field and potentially implanted medical devices.


Assuntos
Encéfalo/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/instrumentação , Imagem de Difusão por Ressonância Magnética/métodos , Desenho de Equipamento , Humanos , Imagem por Ressonância Magnética/instrumentação , Imagem por Ressonância Magnética/tendências , Ondas de Rádio
19.
J Clin Neurosci ; 66: 51-55, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31155343

RESUMO

The data for oligoclonal IgG bands (OCB) in cerebrospinal fluid and the association with clinical profiles of Chinese patients with multiple sclerosis (MS) is lacking. We aimed to investigate the positive OCB incidence, as well as the clinical and magnetic resonance imaging (MRI) features associated with positive OCB in MS patients in South China. Consecutive MS patients were recruited from two centers, located in Guangzhou city and Hong Kong in South China. MS was re-diagnosed by McDonald criteria 2017. OCB was tested using isoelectric focusing method. The difference in the clinical and MRI features between OCB-positive and OCB-negative MS patients was evaluated. Among 184 MS patients analyzed (102 from Guangzhou and 82 from Hong Kong), 110 (59.8%) patients were OCB-positive. Except for onset age (P = 0.019), there was no significant difference between MS patients with or without OCB in relation to the course of disease, symptoms of first attack, lesion distribution on MRI, relapse rates, or disability progression. Our results demonstrate no significant clinical differences between the OCB positive and negative MS patients in this MS cohort. Larger cohort in Chinese patients with MS is warranted.


Assuntos
Esclerose Múltipla/epidemiologia , Esclerose Múltipla/metabolismo , Bandas Oligoclonais/metabolismo , Adulto , Idade de Início , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , China/epidemiologia , Estudos de Coortes , Progressão da Doença , Feminino , Seguimentos , Hong Kong/epidemiologia , Humanos , Imagem por Ressonância Magnética/tendências , Masculino , Esclerose Múltipla/diagnóstico por imagem , Recidiva , Adulto Jovem
20.
J Neurol ; 266(9): 2294-2303, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31175433

RESUMO

BACKGROUND: In patients with MS, the effect of structural damage to the corticospinal tract (CST) has been separately evaluated in the brain and spinal cord (SC), even though a cumulative impact is suspected. OBJECTIVE: To evaluate CST damages on both the cortex and cervical SC, and examine their relative associations with motor function, measured both clinically and by electrophysiology. METHODS: We included 43 patients with early relapsing-remitting MS. Lesions were manually segmented on SC (axial T2*) and brain (3D FLAIR) scans. The CST was automatically segmented using an atlas (SC) or tractography (brain). Lesion volume fractions and diffusion parameters were calculated for SC, brain and CST. Central motor conduction time (CMCT) and triple stimulation technique amplitude ratio were measured for 42 upper limbs, from 22 patients. RESULTS: Mean lesion volume fractions were 5.2% in the SC portion of the CST and 0.9% in the brain portion. We did not find a significant correlation between brain and SC lesion volume fraction (r = 0.06, p = 0.68). The pyramidal EDSS score and CMCT were both significantly correlated with the lesion fraction in the SC CST (r = 0.39, p = 0.01 and r = 0.33, p = 0.03), but not in the brain CST. CONCLUSION: Our results highlight the major contribution of SC lesions to CST damage and motor function abnormalities.


Assuntos
Encéfalo/diagnóstico por imagem , Medula Cervical/diagnóstico por imagem , Potencial Evocado Motor/fisiologia , Destreza Motora/fisiologia , Esclerose Múltipla Recidivante-Remitente/diagnóstico por imagem , Tratos Piramidais/diagnóstico por imagem , Adulto , Encéfalo/fisiologia , Medula Cervical/fisiologia , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Imagem por Ressonância Magnética/tendências , Masculino , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Tratos Piramidais/fisiologia , Substância Branca/diagnóstico por imagem , Substância Branca/fisiologia
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