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1.
Br J Radiol ; 94(1120): 20201215, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33710907

RESUMO

MRI has been an essential diagnostic tool in healthcare for several decades. It offers unique insights into most tissues without the need for ionising radiation. Historically, MRI has been predominantly used qualitatively, images are formed to allow visual discrimination of tissues types and pathologies, rather than providing quantitative measurements. Increasingly, quantitative MRI (qMRI) is also finding clinical application, where images provide the basis for physical measurements of, e.g. tissue volume measures and represent aspects of tissue composition and microstructure. This article reviews some common current research and clinical applications of qMRI from the perspective of measurement science. qMRI not only offers additional information for radiologists, but also the opportunity for improved harmonisation and calibration between scanners and as such it is well-suited to large-scale investigations such as clinical trials and longitudinal studies. Realising these benefits, however, presents a new kind of technical challenge to MRI practioners. When measuring a parameter quantitatively, it is crucial that the reliability and reproducibility of the technique are well understood. Strictly speaking, a numerical result of a measurement is meaningless unless it is accompanied by a description of the associated measurement uncertainty. It is therefore necessary to produce not just estimates of physical properties in a quantitative image, but also their associated uncertainties. As the process of determining a physical property from the raw MR signal is complicated and multistep, estimation of uncertainty is challenging and there are many aspects of the MRI process that require validation. With the clinical implementation of qMRI techniques and its continued expansion, there is a clear and urgent need for metrology in this field.


Assuntos
Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/normas , Estudos de Avaliação como Assunto , Humanos , Reprodutibilidade dos Testes
2.
Radiol Med ; 126(3): 365-379, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33629237

RESUMO

Cardiac magnetic resonance (CMR) has emerged as new mainstream technique for the evaluation of patients with cardiac diseases, providing unique information to support clinical decision-making. This document has been developed by a joined group of experts of the Italian Society of Cardiology and Italian society of Radiology and aims to produce an updated consensus statement about the current state of technology and clinical applications of CMR. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac radiology. Part 1 of the document will cover ischemic heart disease, congenital heart disease, cardio-oncology, cardiac masses and heart transplant.


Assuntos
Técnicas de Imagem Cardíaca/normas , Consenso , Cardiopatias Congênitas/diagnóstico por imagem , Neoplasias Cardíacas/diagnóstico por imagem , Transplante de Coração , Imagem por Ressonância Magnética/normas , Isquemia Miocárdica/diagnóstico por imagem , Cardiologia , Cardiotoxicidade/diagnóstico por imagem , Tomada de Decisão Clínica , Neoplasias Cardíacas/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio sem Supradesnível do Segmento ST/diagnóstico por imagem , Cuidados Pós-Operatórios , Prognóstico , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Sociedades Médicas
3.
AJR Am J Roentgenol ; 216(3): 718-733, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33534618

RESUMO

OBJECTIVE. The purpose of this article is to provide a practice-focused review of the clinical application of advanced acceleration techniques for rapid musculoskeletal MRI examinations. CONCLUSION. Parallel imaging, simultaneous multislice acquisition, compressed sensing-based sampling, and synthetic MRI techniques provide unprecedented opportunities for rapid musculoskeletal MRI examinations. For 2D and 3D fast spin-echo and turbo spin-echo pulse sequences, acceleration factors between 3 and 8 can be realized in clinical practice, amounting to a time savings of 66-85% when compared with unaccelerated acquisitions.


Assuntos
Imagem por Ressonância Magnética/métodos , Sistema Musculoesquelético/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética/normas , Fatores de Tempo
4.
AJR Am J Roentgenol ; 216(3): 704-717, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33534619

RESUMO

OBJECTIVE. The purpose of this article is to provide a practice-focused review of accelerating musculoskeletal MRI with the use of widely accessible techniques and to assess the effects of such acceleration on the value of musculoskeletal MRI. CONCLUSION. Echo-train compaction with fast radiofrequency pulses, high gradient performance modes, and high receiver bandwidth, as well as basic phase undersampling techniques, affords at least twofold acceleration of musculoskeletal MRI examinations while retaining image quality, comprehensiveness, and diagnostic performance. Optimized efficiency is a cornerstone for adding value to musculoskeletal MRI.


Assuntos
Lista de Checagem , Imagem por Ressonância Magnética/métodos , Sistema Musculoesquelético/diagnóstico por imagem , Adulto , Análise de Fourier , Humanos , Imagem por Ressonância Magnética/normas , Masculino , Fatores de Tempo
5.
Magn Reson Med ; 85(6): 3343-3352, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33507591

RESUMO

PURPOSE: To assess the reproducibility of percentage ventilated lung volume (%VV) measurements in healthy volunteers acquired by fluorine (19 F)-MRI of inhaled perfluoropropane, implemented at two research sites. METHODS: In this prospective, ethically approved study, 40 healthy participants were recruited (May 2018-June 2019) to one of two research sites. Participants underwent a single MRI scan session on a 3T scanner, involving periodic inhalation of a 79% perfluoropropane/21% oxygen gas mixture. Each gas inhalation session lasted about 30 seconds, consisting of three deep breaths of gas followed by a breath-hold. Four 19 F-MR ventilation images were acquired per participant, each separated by approximately 6 minutes. The value of %VV was determined by registering separately acquired 1 H images to ventilation images before semi-automated image segmentation, performed independently by two observers. Reproducibility of %VV measurements was assessed by components of variance, intraclass correlation coefficients, coefficients of variation (CoV), and the Dice similarity coefficient. RESULTS: The MRI scans were well tolerated throughout, with no adverse events. There was a high degree of consistency in %VV measurements for each participant (CoVobserver1 = 0.43%; CoVobserver2 = 0.63%), with overall precision of %VV measurements determined to be within ± 1.7% (95% confidence interval). Interobserver agreement in %VV measurements revealed a high mean Dice similarity coefficient (SD) of 0.97 (0.02), with only minor discrepancies between observers. CONCLUSION: We demonstrate good reproducibility of %VV measurements in a group of healthy participants using 19 F-MRI of inhaled perfluoropropane. Our methods have been successfully implemented across two different study sites, supporting the feasibility of performing larger multicenter clinical studies.


Assuntos
Flúor , Pulmão/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Adulto , Idoso , Meios de Contraste/administração & dosagem , Meios de Contraste/farmacocinética , Feminino , Flúor/administração & dosagem , Flúor/farmacocinética , Fluorcarbonetos/administração & dosagem , Fluorcarbonetos/farmacocinética , Humanos , Pulmão/metabolismo , Medidas de Volume Pulmonar/métodos , Imagem por Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
6.
Am Fam Physician ; 103(1): 42-50, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33382559

RESUMO

The use of diagnostic radiography has doubled in the past two decades. Image Gently (children) and Image Wisely (adults) are multidisciplinary initiatives that seek to reduce radiation exposure by eliminating unnecessary procedures and offering best practices. Patients with an estimated glomerular filtration rate less than 30 mL per minute per 1.73 m2 may have increased risk of nephropathy when exposed to iodinated contrast media and increased risk of nephrogenic systemic fibrosis when exposed to gadolinium-based contrast agents. American College of Radiology Appropriateness Criteria can help guide specific diagnostic imaging choices. Noncontrast head computed tomography is the first-line modality when a stroke is suspected. Magnetic resonance imaging stroke protocols and computed tomography perfusion scans can augment evaluation and potentially expand pharmacologic and endovascular therapy timeframes. Imaging should be avoided in patients with uncomplicated headache syndromes unless the history or physical examination reveals red flag features. Cardiac computed tomography angiography, stress echocardiography, and myocardial perfusion scintigraphy (nuclear stress test) are appropriate for patients with chest pain and low to intermediate cardiovascular risk and have comparable sensitivity and specificity. Computed tomography pulmonary angiography is the preferred test for high-risk patients or those with a positive d-dimer test result, and ventilation-perfusion scintigraphy is reserved for patients with an estimated glomerular filtration rate less than 30 mL per minute per 1.73 m2 or a known contrast allergy. Computed tomography with intravenous contrast is preferred for evaluating adults with suspected appendicitis; however, ultrasonography should precede computed tomography in children, and definitive treatment should be initiated if positive. Ultrasonography is the first-line modality for assessing right upper quadrant pain suggestive of biliary disease. Mass size and patient age dictate surveillance recommendations for adnexal masses. Imaging should not be performed for acute (less than six weeks) low back pain unless red flag features are found on patient history. Ultrasonography should be used for the evaluation of suspicious thyroid nodules identified incidentally on computed tomography.


Assuntos
Imagem por Ressonância Magnética/normas , Neoplasias Induzidas por Radiação/prevenção & controle , Segurança do Paciente/normas , Radiografia/normas , Cintilografia/normas , Humanos , Guias de Prática Clínica como Assunto , Saúde Radiológica , Tomografia Computadorizada por Raios X/normas , Procedimentos Desnecessários/efeitos adversos
7.
PLoS One ; 15(12): e0244003, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33373375

RESUMO

PURPOSE: Radiological assessment of primary brain neoplasms, both high (HGG) and low grade tumors (LGG), based on contrast-enhancement alone can be inaccurate. We evaluated the radiological value of amide proton transfer weighted (APTw) MRI as an imaging complement for pre-surgical radiological diagnosis of brain tumors. METHODS: Twenty-six patients were evaluated prospectively; (22 males, 4 females, mean age 55 years, range 26-76 years) underwent MRI at 3T using T1-MPRAGE pre- and post-contrast administration, conventional T2w, FLAIR, and APTw imaging pre-surgically for suspected primary/secondary brain tumor. Assessment of the additional value of APTw imaging compared to conventional MRI for correct pre-surgical brain tumor diagnosis. The initial radiological pre-operative diagnosis was based on the conventional contrast-enhanced MR images. The range, minimum, maximum, and mean APTw signals were evaluated. Conventional normality testing was performed; with boxplots/outliers/skewness/kurtosis and a Shapiro-Wilk's test. Mann-Whitney U for analysis of significance for mean/max/min and range APTw signal. A logistic regression model was constructed for mean, max, range and Receiver Operating Characteristic (ROC) curves calculated for individual and combined APTw signals. RESULTS: Conventional radiological diagnosis prior to surgery/biopsy was HGG (8 patients), LGG (12 patients), and metastasis (6 patients). Using the mean and maximum: APTw signal would have changed the pre-operative evaluation the diagnosis in 8 of 22 patients (two LGGs excluded, two METs excluded). Using a cut off value of >2.0% for mean APTw signal integral, 4 of the 12 radiologically suspected LGG would have been diagnosed as high grade glioma, which was confirmed by histopathological diagnosis. APTw mean of >2.0% and max >2.48% outperformed four separate clinical radiological assessments of tumor type, P-values = .004 and = .002, respectively. CONCLUSIONS: Using APTw-images as part of the daily clinical pre-operative radiological evaluation may improve diagnostic precision in differentiating LGGs from HGGs, with potential improvement of patient management and treatment.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Adulto , Idoso , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Feminino , Glioma/patologia , Glioma/cirurgia , Humanos , Imagem por Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Valor Preditivo dos Testes
8.
PLoS One ; 15(12): e0244184, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33347471

RESUMO

OBJECTIVES: To analyse the predictive values of inflammatory back pain (IBP), positive HLA B27 antigen, increased C-reactive protein (CRP), Spondyloarthritis (SpA) features, familial history (FH), magnetic resonance sacroiliac joints (MRI-SIJ) imaging and its weight in early SpA diagnosis. METHODS: 133 patients with back pain, aged <50, duration of the pain <2 years were included. Data such as IBP, HLA B27, increased CRP, SpA features, FH, SIJ´s radiography and MRI were collected for each patient. STIR sequences were classified as strongly positive bone morrow oedema (SPBME ≥2), clearly present and easily recognisable as positive according to the ASAS criterion, weakly positive (WPBME ≥2), suggestive, but not easily recognisable and, clearly negative none of those features. T1-weighted sequences were assessed as positive/negative for erosion, fat metaplasia, backfill and sclerosis, if ≥1, for each lesion was present. MRI images were read by three blinded readers. RESULTS: The average age was 38.9 years. 47 (35.3%) patients received SpA diagnosis according to the clinical opinion. IBP was highly specific, 0.81 and sensitive, 0.83. HLA B27 was positive in a half of the SpA patients. SPBME ≥2 provided a great specificity, 0.94 and an acceptable sensitivity, 0.79. Erosion was significantly more frequent in SpA patients (72% vs 7%), specificity 0.93. The addition of erosion ≥1 to the WPBME ≥2 noticeably improved specificity, 0.98, although slightly decreased sensitivity, 0.64. Fat metaplasia and backfill were highly specific, but poorly sensitive. Factors forecasting positive diagnosis were IBP, followed by SpA features and increased CRP. CONCLUSIONS: At the onset, IBP might be a good marker for selecting patients with suspicion of SpA. The addition of erosion to the ASAS criterion might be helpful for early diagnosis, especially in patients with doubtful STIR imaging where BME is present but it is hard to determinate whether the ASAS "highly suggestive" criterion is met.


Assuntos
Dor nas Costas/patologia , Proteína C-Reativa/análise , Antígeno HLA-B27/sangue , Imagem por Ressonância Magnética/normas , Espondilite Anquilosante/diagnóstico , Adulto , Biomarcadores/sangue , Proteína C-Reativa/normas , Diagnóstico Precoce , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
9.
J Cardiovasc Magn Reson ; 22(1): 87, 2020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33308262

RESUMO

Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included.


Assuntos
Coração/diagnóstico por imagem , Imagem por Ressonância Magnética/normas , Função Ventricular Esquerda , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Coração/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Valores de Referência , Adulto Jovem
10.
Cancer Imaging ; 20(1): 64, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32912319

RESUMO

BACKGROUND: Patients with esophageal cancer (EC) undergo endoscopic ultrasound and CT based cancer staging. Recent technical developments allow improved MRI quality with diminished motion artifact that may allow MRI to compare favorable to CT for noninvasive staging. Hence the purpose of the study was to assess image quality and diagnostic accuracy of 3 T MRI versus CT and EUS for preoperative T-staging of potentially resectable esophageal cancer. METHODS: Between October-2014 and December-2017, esophageal cancer patients with T-staging by EUS were enrolled in this prospective study. Post-operative histopathologic T-staging was the reference standard. All participants underwent MRI [T2- multi-shot turbo spin echo sequence (msTSE), diffusion-weighted imaging (DWI), and 3D gradient-echo based sequence (3D-GRE)] and CT [non-contrast and multiphase contrast-enhanced CT scanning] 5.6 + 3.6 days after endoscopy. Surgery was performed within 3.6 + 3.5 days after imaging. Two blinded endoscopists (reader 1 and 2) and radiologists (reader 3 and 4) independently evaluated EUS and CT/MRI, respectively. Considering the clinical relevance, patients were dichotomized into early (T1 and T2) vs late (T3 and T4) stage cancer before assessment. For statistical purpose, the binary decision was defined as the ability of the imaging technique to diagnose early stage/not early stage esophageal cancer. Diagnostic performance of EUS, MRI and CT was compared using McNemar's test with Bonferroni correction; kappa values were assessed for reader performance. RESULTS: 74 study participants (60 ± 8 yrs.; 56 men) with esophageal cancer were evaluated, of whom 85%(63/74) had squamous cell carcinoma, 61%(45/74) were at early stage and 39%(29/74) were at late stage cancer, as determined by histopathology. Intra- and Inter-reader agreement for pre-operative vs post-operative T-staging was excellent for all imaging modalities. Compared to CT, MRI showed significantly higher accuracy for both the readers (reader3: 96% vs 82%, p = 0.0038, reader4: 95% vs 80%, p = 0.0076, for MRI vs CT, respectively). Further, MRI outperformed EUS with higher specificity (reader 1 vs 3: 59% vs 93%, p = 0.0015, reader 2 vs 4: 66% vs 93%, p = 0.0081, for EUS vs MRI respectively), and accuracy (reader 1 vs 3: 81% vs 96%, p = 0.0022, reader 2 vs 4: 85% vs 95%, p = 0.057, for EUS vs MRI, respectively). CONCLUSION: For resectable esophageal cancer, MRI had better diagnostic performance for tumor staging compared to CT and EUS. TRIAL REGISTRATION: ChiCTR, ChiCTR-DOD, Registered 2nd October 2014, http://www.chictr.org.cn/showproj.aspx?proj=9620.


Assuntos
Carcinoma de Células Escamosas/diagnóstico por imagem , Endossonografia/normas , Neoplasias Esofágicas/diagnóstico por imagem , Imagem por Ressonância Magnética/normas , Tomografia Computadorizada por Raios X/normas , Adulto , Idoso , Carcinoma de Células Escamosas/patologia , Endossonografia/métodos , Neoplasias Esofágicas/patologia , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório , Tomografia Computadorizada por Raios X/métodos
11.
Cancer Imaging ; 20(1): 65, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32933585

RESUMO

BACKGROUND: To establish pharmacokinetic parameters and a radiomics model based on dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for predicting sentinel lymph node (SLN) metastasis in patients with breast cancer. METHODS: A total of 164 breast cancer patients confirmed by pathology were prospectively enrolled from December 2017 to May 2018, and underwent DCE-MRI before surgery. Pharmacokinetic parameters and radiomics features were derived from DCE-MRI data. Least absolute shrinkage and selection operator (LASSO) regression method was used to select features, which were then utilized to construct three classification models, namely, the pharmacokinetic parameters model, the radiomics model, and the combined model. These models were built through the logistic regression method by using 10-fold cross validation strategy and were evaluated on the basis of the receiver operating characteristics (ROC) curve. An independent validation dataset was used to confirm the discriminatory power of the models. RESULTS: Seven radiomics features were selected by LASSO logistic regression. The radiomics model, the pharmacokinetic parameters model, and the combined model yielded area under the curve (AUC) values of 0.81 (95% confidence interval [CI]: 0.72 to 0.89), 0.77 (95% CI: 0.68 to 0.86), and 0.80 (95% CI: 0.72 to 0.89), respectively, for the training cohort and 0.74 (95% CI: 0.59 to 0.89), 0.74 (95% CI: 0.59 to 0.90), and 0.76 (95% CI: 0.61 to 0.91), respectively, for the validation cohort. The combined model showed the best performance for the preoperative evaluation of SLN metastasis in breast cancer. CONCLUSIONS: The model incorporating radiomics features and pharmacokinetic parameters can be conveniently used for the individualized preoperative prediction of SLN metastasis in patients with breast cancer.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Metástase Linfática/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Linfonodo Sentinela/diagnóstico por imagem , Neoplasias da Mama/patologia , Feminino , Humanos , Modelos Logísticos , Metástase Linfática/patologia , Imagem por Ressonância Magnética/normas , Curva ROC , Linfonodo Sentinela/patologia
12.
Cancer Imaging ; 20(1): 61, 2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32811559

RESUMO

BACKGROUND: To evaluate the inter- and intrareader agreement and reproducibility of the NI-RADS scoring system and lexicon with contrast-enhanced computed tomography (CECT) and contrast-enhanced magnetic resonance imaging (CEMRI). METHODS: This retrospective study included 97 CECT and CEMRI scans from 58 treated cases of head and neck squamous cell carcinoma (HNSCC) after the exclusion of head and neck cancers (HNCs) other than SCC and noncontrast and poor quality CT and MRI scans, with a total of 111 primary targets and 124 lymph node (LN) targets. Two experienced readers independently scored the likelihood of residual/recurrence for these targets based on the NI-RADS criteria and filled in report templates for NI-RADS lexicon diagnostic features. Inter- and intraobserver reproducibility was assessed with Cohen's kappa, and the percent agreement was calculated. RESULTS: Almost perfect interreader agreement was found for the final NI-RADS category of the primary lesions and LNs, with K = 0.808 and 0.806, respectively. Better agreement was found for CT than for MRI (K = 0.843 and 0.77, respectively, P value 0.001). There was almost perfect agreement for excluding tissue enhancement (K = 0.826, 95% CI = 0.658-0.993, P value 0.001), with a percent agreement of 96.4%, and substantial agreement for discrete nodular and diffuse mucosal enhancement (K = 0.826, 95% CI = 0.658-0.993, P value 0.001), with a percent agreement of 96.4%. There was fair agreement for focal mucosal nonmass and deep ill-defined enhancement. The intrareader agreement was almost perfect for most of the rated features (K ranging from 0.802 to 1), with the exception of enlarging discrete nodule/mass and focal mucosal nonmass-like enhancement, which had substantial intraobserver agreement (K ranging from 0.768 to 0.786). CONCLUSION: The individual features of NI-RADS show variable degrees of confidence; however, the overall NI-RADS category was not significantly affected.


Assuntos
Sistemas de Dados , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Imagem por Ressonância Magnética/normas , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico por imagem , Tomografia Computadorizada por Raios X/normas , Idoso , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos
13.
Neurocirugía (Soc. Luso-Esp. Neurocir.) ; 31(4): 184-194, jul.-ago. 2020. ilus
Artigo em Espanhol | IBECS | ID: ibc-193899

RESUMO

INTRODUCCIÓN: La cirugía de los tumores cerebrales se ha implementado en los últimos años con nuevas técnicas de imagen intraoperatoria, que tratan de mejorar la resección tumoral, aunque conllevan un aumento de recursos. Con el fin de hacer una actualización de este tema, se ha elaborado este manuscrito desde el grupo de tumores de la Sociedad Española de Neurocirugía. MATERIAL Y MÉTODOS: Se ha propuesto a expertos en el uso de cada una de las técnicas intraoperatorias más empleadas en la cirugía de los tumores cerebrales, la descripción de la técnica y una breve revisión de la literatura. Se describirán indicaciones de uso, sus ventajas e inconvenientes basados en la experiencia clínica y en lo publicado en la literatura. RESULTADOS: La técnica de imagen intraoperatoria más consistente sería la resonancia de bajo y alto campo, pero a su vez es la que supone un mayor gasto de recursos. La ecografía intraoperatoria navegada es portátil y tiene un menor coste, aunque discrimina peor los tumores de alto grado y es observador-dependiente. Las técnicas de fluorescencia más empleadas son el 5-aminolevulínico para gliomas de alto grado y la fluoresceína, de utilidad en lesiones que rompen la barrera hematoencefálica. Por último, la TAC intraoperatoria es la más versátil en el quirófano de neurocirugía, pero tiene menos indicaciones en la cirugía neurooncológica. CONCLUSIONES: Las técnicas de imagen intraoperatoria se emplean cada vez con más frecuencia en la cirugía de los tumores cerebrales, y el neurocirujano debe valorar su posible uso en función de sus recursos y las necesidades de cada paciente


INTRODUCTION: New intraoperative imaging techniques, which aim to improve tumour resection, have been implemented in recent years in brain tumour surgery, although they lead to an increase in resources. In order to carry out an update on this topic, this manuscript has been drafted by a group from the Sociedad Española de Neurocirugía (Spanish Society of Neurosurgery). MATERIAL AND METHODS: Experts in the use of each one of the most-used intraoperative techniques in brain tumour surgery were presented with a description of the technique and a brief review of the literature. Indications for use, their advantages and disadvantages based on clinical experience and on what is published in the literature will be described. RESULTS: The most robust intraoperative imaging technique appears to be low- and high-field magnetic resonance imaging, but this is the technique which results in the greatest expenditure. Intraoperative ultrasound navigation is portable and less expensive, but it provides poorer differentiation of high-grade tumours and is observer-dependent. The most-used fluorescence techniques are 5-aminolevulinic acid for high-grade gliomas and fluorescein, useful in lesions which rupture the blood-brain barrier. Last of all, intraoperative CT is more versatile in the neurosurgery operating theatre, but it has fewer indications in neuro-oncology surgery. CONCLUSIONS: Intraoperative imaging techniques are used with increasingly greater frequency in brain tumour surgery, and the neurosurgeon should assess their possible use depending on their resources and the needs of each patient


Assuntos
Humanos , Neoplasias Encefálicas/cirurgia , Procedimentos Neurocirúrgicos , Processamento de Imagem Assistida por Computador , Monitorização Intraoperatória/instrumentação , Imagem por Ressonância Magnética/instrumentação , Monitorização Intraoperatória/normas , Imagem por Ressonância Magnética/normas
14.
Cancer Imaging ; 20(1): 48, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32665028

RESUMO

BACKGROUND: Whole body magnetic resonance imaging (MRI) is now incorporated into international guidance for imaging patients with multiple myeloma. The aim of this study was to investigate inter-observer agreement of triple reported baseline whole-body MRI in myeloma and highlight potential pitfalls. METHODS: Fifty-seven patients with symptomatic myeloma at first presentation or relapse and planned for autologous stem cell transplant were included. All patients completed baseline whole body MRI within 2 weeks prior to starting treatment. Each scan was reported independently by 3 radiologists using a defined scoring system. Differences in observer scores were compared using analysis of variance (ANOVA) and inter-observer agreement assessed using intra class correlation coefficient (ICC). RESULTS: There was no significant difference in mean observer scores for whole skeleton and ICC demonstrated excellent inter-observer agreement at 0.91. ICC varied between skeletal regions with spine, pelvis and ribs showing good inter-observer agreement, whereas skull and long bones were moderate. Scans with variation in observer scores were re-examined and cause of discrepancies identified. This information was used to describe potential anatomical pitfalls in reporting . CONCLUSION: Whole-body MRI has excellent inter-observer agreement in reporting symptomatic myeloma at baseline. Inter-observer agreement varied between skeletal regions highlighting specific areas of difficulty.


Assuntos
Imagem por Ressonância Magnética/normas , Mieloma Múltiplo/diagnóstico por imagem , Imagem Corporal Total/normas , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Imagem Corporal Total/métodos
15.
Br J Radiol ; 93(1113): 20200082, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32584595

RESUMO

OBJECTIVE: To understand the status of pre-procedural safety practices in radiological examinations at radiology residency training institutions in various Asian regions. METHODS: A questionnaire based on the Joint Commission International Accreditation Standards was electronically sent to 3 institutions each in 10 geographical regions across 9 Asian countries. Questions addressing 45 practices were divided into 3 categories. A five-tier scale with numerical scores was used to evaluate safety practices in each institution. Responses obtained from three institutions in the United States were used to validate the execution rate of each surveyed safety practice. RESULTS: The institutional response rate was 70.0% (7 Asian regions, 21 institutions). 44 practices (all those surveyed except for the application of wrist tags for identifying patients with fall risks) were validated using the US participants. Overall, the Asian participants reached a consensus on 89% of the safety practices. Comparatively, most Asian participants did not routinely perform three pre-procedural practices in the examination appropriateness topic. CONCLUSION: Based on the responses from 21 participating Asian institutions, most routinely perform standard practices during radiological examinations except when it comes to examination appropriateness. This study can provide direction for safety policymakers scrutinizing and improving regional standards of care. ADVANCES IN KNOWLEDGE: This is the first multicenter survey study to elucidate pre-procedural safety practices in radiological examinations in seven Asian regions.


Assuntos
Consenso , Pesquisas sobre Serviços de Saúde , Segurança do Paciente/normas , Qualidade da Assistência à Saúde/normas , Radiografia/normas , Ásia , China , Pesquisas sobre Serviços de Saúde/estatística & dados numéricos , Humanos , Internato e Residência , Japão , Imagem por Ressonância Magnética/normas , Malásia , Tomografia por Emissão de Pósitrons , Radiologia/educação , República da Coreia , Gestão da Segurança/normas , Singapura , Taiwan , Tomografia Computadorizada por Raios X/normas
16.
PLoS One ; 15(6): e0234520, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520950

RESUMO

PURPOSE: To investigate the validity of contrast kinetic parameter estimates from Active Contrast Encoding (ACE)-MRI against those from conventional Dynamic Contrast-Enhanced (DCE)-MRI for evaluation of tumor treatment response in mouse tumor models. METHODS: The ACE-MRI method that incorporates measurement of T1 and B1 into the enhancement curve washout region, was implemented on a 7T MRI scanner to measure tracer kinetic model parameters of 4T1 and GL261 tumors with treatment using bevacizumab and 5FU. A portion of the same ACE-MRI data was used for conventional DCE-MRI data analysis with a separately measured pre-contrast T1 map. Tracer kinetic model parameters, such as Ktrans (permeability area surface product) and ve (extracellular space volume fraction), estimated from ACE-MRI were compared with those from DCE-MRI, in terms of correlation and Bland-Altman analyses. RESULTS: A three-fold increase of the median Ktrans by treatment was observed in the flank 4T1 tumors by both ACE-MRI and DCE-MRI. In contrast, the brain tumors did not show a significant change by the treatment in either ACE-MRI or DCE-MRI. Ktrans and ve values of the tumors from ACE-MRI were strongly correlated with those from DCE-MRI methods with correlation coefficients of 0.92 and 0.78, respectively, for the median values of 17 tumors. The Bland-Altman plot analysis showed a mean difference of -0.01 min-1 for Ktrans with the 95% limits of agreement of -0.12 min-1 to 0.09 min-1, and -0.05 with -0.37 to 0.26 for ve. CONCLUSION: The tracer kinetic model parameters estimated from ACE-MRI and their changes by treatment closely matched those of DCE-MRI, which suggests that ACE-MRI can be used in place of conventional DCE-MRI for tumor progression monitoring and treatment response evaluation with a reduced scan time.


Assuntos
Meios de Contraste/farmacocinética , Gadolínio DTPA/farmacocinética , Imagem por Ressonância Magnética/métodos , Neoplasias Experimentais/diagnóstico por imagem , Animais , Antineoplásicos/uso terapêutico , Bevacizumab/uso terapêutico , Linhagem Celular Tumoral , Fluoruracila/uso terapêutico , Imagem por Ressonância Magnética/efeitos adversos , Imagem por Ressonância Magnética/normas , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neoplasias Experimentais/terapia , Sensibilidade e Especificidade
17.
Adv Exp Med Biol ; 1235: 35-52, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32488635

RESUMO

Functional connectivity magnetic resonance imaging (fcMRI), performed during resting wakefulness without tasks or stimulation, is a non-invasive technique to assess and visualise functional brain networks in vivo. Acquisition of resting-state imaging data has become increasingly common in longitudinal studies to investigate brain health and disease. However, the scanning protocols vary considerably across different institutions creating challenges for comparability especially for the interpretation of findings in patient cohorts and establishment of diagnostic or prognostic imaging biomarkers. The aim of this chapter is to discuss the effect of two experimental conditions (i.e. a low cognitive demand paradigm and a pure resting-state fcMRI) on the reproducibility of brain networks between a baseline and a follow-up session, 30 (±5) days later, acquired from 12 right-handed volunteers (29 ± 5 yrs). A novel method was developed and used for a direct statistical comparison of the test-retest reliability using 28 well-established functional brain networks. Overall, both scanning conditions produced good levels of test-retest reliability. While the pure resting-state condition showed higher test-retest reliability for 18 of the 28 analysed networks, the low cognitive demand paradigm produced higher test-retest reliability for 8 of the 28 brain networks (i.e. visual, sensorimotor and frontal areas); in 2 of the 28 brain networks no significant changes could be detected. These results are relevant to planning of longitudinal studies, as higher test-retest reliability generally increases statistical power. This work also makes an important contribution to neuroimaging where optimising fcMRI experimental scanning conditions, and hence data visualisation of brain function, remains an on-going topic of interest. In this chapter, we provide a full methodological explanation of the two paradigms and our analysis so that readers can apply them to their own scanning protocols.


Assuntos
Mapeamento Encefálico/normas , Encéfalo/fisiologia , Imagem por Ressonância Magnética/normas , Descanso/fisiologia , Humanos , Reprodutibilidade dos Testes
18.
Top Magn Reson Imaging ; 29(3): 131-134, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32568975

RESUMO

Patients undergoing MRI may experience fear, claustrophobia, or other anxiety manifestations due to the typically lengthy, spatially constrictive, and noisy MRI acquisition process and in some cases are not able to tolerate completion of the study. This article discusses several patient-centered aspects of radiology practice that emphasize interpersonal interactions. Patient education and prescan communication represent 1 way to increase patients' awareness of what to expect during MRI and therefore mitigate anticipatory anxiety. Some patient interaction strategies to promote relaxation or calming effects are also discussed. Staff teamwork and staff training in communication and interpersonal skills are also described, along with literature evidence of effectiveness with respect to patient satisfaction and productivity endpoints. Attention to how radiologists, nurses, technologists, and other members of the radiology team interact with patients before or during the MRI scan could improve patients' motivation and ability to cooperate with the MRI scanning process as well as their subjective perceptions of the quality of their care. The topics discussed in this article are relevant not only to MRI operations but also to other clinical settings in which patient anxiety or motion represent impediments to optimal workflow.


Assuntos
Comunicação , Imagem por Ressonância Magnética/métodos , Satisfação do Paciente , Assistência Centrada no Paciente/métodos , Humanos , Imagem por Ressonância Magnética/normas , Equipe de Assistência ao Paciente , Educação de Pacientes como Assunto , Assistência Centrada no Paciente/normas , Relações Profissional-Paciente , Qualidade da Assistência à Saúde , Radiologia/educação , Radiologia/métodos
19.
Cancer Imaging ; 20(1): 39, 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32546207

RESUMO

PURPOSE: Evaluate the feasibility of fluorine-18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) and magnetic resonance (MR) imaging in patients with gastric cancer by optimizing the scan protocol and to compare the image quality to 18F FDG PET and computed tomography (CT). METHODS: The PET/CT and PET/MR imaging were sequentially performed in 30 patients with gastric cancer diagnosed by gastroscope using a single-injection-with-dual-imaging protocol. After intravenous injection of 18F-FDG (mean, 249 MBq), PET/CT imaging including low-dose CT was performed (mean uptake time, 47 ± 6 min), and PET/MR imaging including a T1-weighted Dixon sequence for attenuation correction and two different T2-weighted sequences was subsequently acquired (88 ± 15 min after 18F-FDG injection). Four series of images (CT from PET/CT, T1W, T2W Half-Fourier acquisition single-shot turbo spin-echo [T2W-HASTE] and T2W-BLADE from PET/MR) were visually evaluated using a 3-4 points scale for: (1) image artifacts, (2) lesion conspicuity and (3) image fusion quality. The characteristics of the primary lesions were assessed and compared between the PET/CT and PET/MR acquisitions. RESULTS: The image quality and lesion conspicuity of the T2W-HASTE images were significantly improved compared to that of the T2W-BLADE images. A significantly higher number of artifacts were seen in the T2W-HASTE images compared with the T1W and CT images (p < 0. 05). No differences in the accuracy of image fusion between PET/MR and PET/CT (p > 0. 05); however, significant difference was seen in the lesion conspicuity measurements (p < 0.05) with T2W-HASTE being superior. For information about the primary lesion characteristics, the T2W-HASTE images provided the most successful identifications compared with those of the T1W and PET/CT (13vs7vs5) images. CONCLUSIONS: PET/MR with the T2W-HASTE was better at revealing the details of local stomach lesions compared with PET/CT imaging. Combining the PET/MR with the T2W-HASTE technique is a promising imaging method for diagnosing and staging gastric cancer.


Assuntos
Imagem por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Tomografia por Emissão de Pósitrons/métodos , Neoplasias Gástricas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Feminino , Fluordesoxiglucose F18 , Humanos , Imagem por Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/normas , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons/normas , Compostos Radiofarmacêuticos , Neoplasias Gástricas/patologia , Tomografia Computadorizada por Raios X/normas
20.
Phys Med Biol ; 65(19): 195008, 2020 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-32531763

RESUMO

Magnetic resonance imaging (MRI) offers outstanding soft tissue contrast that may reduce uncertainties in target and organ-at-risk delineation and enable online adaptive image-guided treatment. Spatial distortions resulting from non-linearities in the gradient fields and non-uniformity in the main magnetic field must be accounted for across the imaging field-of-view to prevent systematic errors during treatment delivery. This work presents a modular phantom and software application to characterize geometric distortion (GD) within the large field-of-view MRI images required for radiation therapy simulation. The modular phantom is assembled from a series of rectangular foam blocks containing high-contrast fiducial markers in a known configuration. The modular phantom design facilitates transportation of the phantom between different MR scanners and MR-guided linear accelerators and allows the phantom to be adapted to fit different sized bores or coils. The phantom was evaluated using a 1.5 T MR-guided linear accelerator (MR-Linac) and 1.5 T and 3.0 T diagnostic scanners. Performance was assessed by varying acquisition parameters to induce image distortions in a known manner. Imaging was performed using T1 and T2 weighted pulse sequences with 2D and 3D distortion correction algorithms and the receiver bandwidth (BW) varied as 250-815 Hz pixel-1. Phantom set-up reproducibility was evaluated across independent set-ups. The software was validated by comparison with a non-modular phantom. Average geometric distortion was 0.94 ± 0.58 mm for the MR-Linac, 0.90 ± 0.53 mm for the 1.5 T scanner, and 1.15 ± 0.62 mm for the 3.0 T scanner, for a 400 mm diameter volume-of-interest. GD increased, as expected, with decreasing BW, and with the 2D versus 3D correction algorithm. Differences in GD attributed to phantom set-up were 0.13 mm or less. Differences in GD for the two software applications were less than 0.07 mm. A novel modular phantom was developed to evaluate distortions in MR images for radiation therapy applications.


Assuntos
Algoritmos , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/normas , Aceleradores de Partículas/instrumentação , Imagens de Fantasmas , Software , Humanos , Reprodutibilidade dos Testes
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