129 research outputs found
Magnetic Resonance Spectroscopy of the Breast at 3T: Pre- and Post-Contrast Evaluation for Breast Lesion Characterization
Purpose. To determine whether in vivo proton magnetic resonance spectroscopy at 3T can provide accurate breast lesion characterization, and to determine the effect of gadolinium on the resonance of tCho. Methods. Twenty-four positive-mammogram patients were examined on a 3T MR scanner. 1H-MRS was performed before and after gadolinium administration. tCho peak was qualitatively evaluated before and after contrast injection. Results. Fourteen out of 27 lesions proved to be malignant after histopathological diagnosis. Using 1H-MRS, before contrast injection, 6/14 confirmed malignancies and 11/13 benign lesions were correctly classified; while, after contrast injection, 11/14 confirmed malignancies and 12/13 benign processes were correctly classified. Post gadolinium 1H-MRS proved useful in picking up tCho signal, improving the overall accuracy, sensitivity, and specificity by 35%, 83%, and 9%, respectively. Conclusion. 1H-MRS overall accuracy, sensitivity, and specificity in detecting breast lesion's malignancy were increased after gadolinium administration. It is prudent to perform 1H-MRS before contrast injection in large breast lesions to avoid choline underestimation. In cases of small or non-mass lesions, it is recommended to perform 1H-MRS after contrast injection for better voxel prescription to enable a reliable preoperative diagnosis
Cytolytic T-cell response against Epstein-Barr virus in lung cancer patients and healthy subjects
<p>Abstract</p> <p>Background</p> <p>This study aimed to examine whether EBV seropositive patients with lung cancer have an altered virus-specific CTL response, as compared to age-matched healthy controls and whether any variation in this response could be attributed to senescence.</p> <p>Methods</p> <p>Peripheral blood mononuclear cells from lung cancer patients, age-matched and younger healthy individuals were used to measure EBV-specific CTLs after in vitro amplification with the GLCTLVAML and RYSIFFDYM peptides followed by HLA-multimer staining.</p> <p>Results</p> <p>Lung cancer patients and aged-matched controls had significantly lesser EBV-specific CTL than younger healthy individuals. Multimer positive populations from either group did not differ with respect to the percentage of multimer positive CTLs and the intensity of multimer binding.</p> <p>Conclusions</p> <p>This study provides evidence that patients with lung cancer exhibit an EBV-specific CTL response equivalent to that of age-matched healthy counterparts. These data warrant the examination of whether young individuals have a more robust anti-tumor response, as is the case with the anti-EBV response.</p
A comparison of NTCP models and parameters predicting radiation induced pneumonitis in breast and lung cancer radiotherapy
Advanced MR neuroimaging: From theory to clinical practice
Over the last decade, some of the greatest achievements in the field of neuroimaging have been related to remarkable advances in magnetic resonance techniques, including diffusion, perfusion, magnetic resonance spectroscopy, and functional MRI. Such techniques have provided valuable insights into tissue microstructure, microvasculature, metabolism and brain connectivity. Previously available mostly in research environments, these techniques are now becoming part of everyday clinical practice in a plethora of clinical MR systems. Nevertheless, despite growing interest and wider acceptance, there remains a lack of a comprehensive body of knowledge on the subject, exploring the intrinsic complexity and physical difficulty of the techniques. This book focuses on the basic principles and theories of diffusion, perfusion, magnetic resonance spectroscopy, and functional MRI. It also explores their clinical applications and places emphasis on the associated artifacts and pitfalls with a comprehensive and didactic approach. This book aims to bridge the gap between research applications and clinical practice. It will serve as an educational manual for neuroimaging researchers and radiologists, neurologists, neurosurgeons, and physicists with an interest in advanced MR techniques. It will also be a useful reference text for experienced clinical scientists who wish to optimize their multi-parametric imaging approach. © 2018 by Taylor & Francis Group, LLC. All rights reserved
Reply to: The usefulness of diffusion-tensor imaging for the differential diagnosis of breast lesions
[No abstract available
Incorporating diffusion-weighted imaging in a diagnostic algorithm for multiparametric MR mammography
Background: Apparent diffusion coefficient (ADC) measurements are not incorporated in BI-RADS classification. Purpose: To assess the probability of malignancy of breast lesions at magnetic resonance mammography (MRM) at 3 T, by combining ADC measurements with the BI-RADS score, in order to improve the specificity of MRM. Material and Methods: A total of 296 biopsy-proven breast lesions were included in this prospective study. MRM was performed at 3 T, using a standard protocol with dynamic sequence (DCE-MRI) and an extra echo-planar diffusion-weighted sequence. A freehand region of interest was drawn inside the lesion, and ADC values were calculated. Each lesion was categorized according to the BI-RADS classification. Logistic regression analysis was employed to predict the probability of malignancy of a lesion. The model combined the BI-RADS classification and the ADC value. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were calculated. Results: In total, 153 malignant and 143 benign lesions were analyzed; 257 lesions were masses and 39 lesions were non-mass-like enhancements. The sensitivity and specificity of the combined method were 96% and 86%, respectively, in contrast to 95% and 81% with BI-RADS classification alone. Conclusion: We propose a method of assessing the probability of malignancy in breast lesions by combining BI-RADS score and ADC values into a single formula, increasing sensitivity and specificity compared to BI-RADS classification alone. © The Foundation Acta Radiologica 2021
Reproducibility of apparent diffusion coefficient measurements evaluated with different workstations
Aim To evaluate apparent diffusion coefficient (ADC) measurements of breast lesions on different computer platforms to address post-processing influences on ADC measurement reproducibility. Materials and methods One hundred biopsy-proven breast lesions were included in this prospective study. MRI examination was performed at 3 T using standard sequences and an echo planar diffusion-weighted imaging sequence with b-values of 0 and 850 s/mm2. The images were reviewed by two radiologists in consensus. Regions of interest were placed manually within the lesion, following its contour. Care was taken to exclude adjacent normal tissue or necrotic tissue and cystic components within the lesion. The mean ADC value was measured for each lesion on two different platforms: On the MRI workstation that came with the scanner and on a commercially available DICOM (digital imaging and communication in medicine) viewer. Agreement between workstation measurements was evaluated using intraclass correlation coefficient and Bland–Altman plots. Results Fifty-nine malignant and 41 benign lesions were analysed. Of the benign lesions, 28 were mass lesions and 13 were non-mass-like enhancements. In addition, 46 of the malignant lesions were masses and 13 were non-mass-like enhancements. Agreement between the two workstation measurements was high (intraclass correlation coefficients=0.981). Using Bland–Altman plots, no systematic differences were identified between workstations. Limits of agreement ranged between a minimum of –0.071×10−3 mm2/s and a maximum of 0.102×10−3 mm2/s. Conclusion ADC measurements are reproducible among the workstations considered in this study. © 2017 The Royal College of Radiologist
A free software for the evaluation and comparison of dose response models in clinical radiotherapy (DORES)
Purpose: The aim of this work was to develop a user-friendly and simple tool for fast and accurate estimation of Normal Tissue Complication Probabilities (NTCP) for several radiobiological models, which can be used as a valuable complement to the clinical experience. Materials and methods: The software which has been named DORES (Dose Response Evaluation Software) has been developed in Visual Basic, and includes three NTCP models (Lyman-Kuther-Burman (LKB), Relative Seriality and Parallel). Required input information includes the Dose-Volume Histogram (DVH) for the Organs at Risk (OAR) of each treatment, the number of fractions and the total dose of therapy. Results: NTCP values are computed, and subsequently placed in a spreadsheet file for further analysis. A Dose Response curve for every model is automatically generated. Every patient of the study population can be found on the curve since by definition their corresponding dose-response points fall exactly on the theoretical dose-response curve, when plotted on the same diagram. Conclusion: Distributions of absorbed dose alone do not provide information on the biological response of tissues to irradiation, so the use of this software may aid in the comparison of outcomes for different treatment plans or types of treatment, and also aid the evaluation of the sensitivity of different model predictions to uncertainties in parameter values. This was illustrated in a clinical case of breast cancer radiotherapy
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