M.J. Fartaria

M.J. Fartaria
Varian Medical Systems · Treatment Planning and Management Ecosystem

Doctor of Engineering

About

61
Publications
7,013
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333
Citations
Additional affiliations
September 2013 - September 2014
École Polytechnique Fédérale de Lausanne
Position
  • Researcher
January 2012 - July 2013
Technical University of Lisbon
Position
  • Researcher

Publications

Publications (61)
Article
Full-text available
Background: Early infratentorial and focal spinal cord lesions on magnetic resonance imaging (MRI) are associated with a higher risk of long-term disability in patients with multiple sclerosis (MS). The role of diffuse spinal cord lesions remains less understood. The purpose of this study was to evaluate focal and especially diffuse spinal cord le...
Article
Full-text available
Objective Pathology in multiple sclerosis is not homogenously distributed. Recently, it has been shown that structures adjacent to CSF are more severely affected. A gradient of brain tissue involvement was shown with more severe pathology in periventricular areas and in proximity to brain surfaces such as the subarachnoid spaces and ependyma, and h...
Article
Full-text available
The translational potential of MR-based connectivity modelling is limited by the need for advanced diffusion imaging, which is not part of clinical protocols for many diseases. In addition, where diffusion data is available, brain connectivity analyses rely on tractography algorithms which imply two major limitations. First, tracking algorithms are...
Article
Background Age-related white matter lesions (WML) are common, impact neuronal connectivity, and affect motor function and cognition. In addition to pathological nigrostriatal losses, WML are also common co-morbidities in Parkinson's disease (PD) that affect postural stability and gait. Automated brain volume measures are increasingly incorporated i...
Preprint
Full-text available
The translational potential of MR-based connectivity modelling is limited by the need for advanced diffusion imaging, which is not part of clinical protocols for many diseases. In addition, where diffusion data is available, brain connectivity analyses rely on tractography algorithms which imply two major limitations. First, tracking algorithms are...
Article
Full-text available
Background To date, little is known about the presence and extent of cerebellar cortical pathology in early stages of MS. Objective The aims of this study were to (i) investigate microstructural changes in the normal-appearing cerebellar cortex of early MS patients by using 7 T MRI and (ii) evaluate the influence of those changes on clinical perfo...
Article
Full-text available
Introduction: Changes in cortical and white matter lesion (CL, WML) load are pivotal metrics to diagnose and monitor multiple sclerosis patients. Yet, the relationship between (i) changes in CL/WML load and disease progression and between (ii) changes in CL/WML load and neurodegeneration at early MS stages is not yet established. In this work, we h...
Article
Full-text available
The structural complexity of the thalamus, due to its mixed composition of gray and white matter, make it challenging to disjoint and quantify each tissue contribution to the thalamic anatomy. This work promotes the use of partial‐volume‐based over probabilistic‐based tissue segmentation approaches to better capture thalamic gray matter differences...
Article
Full-text available
Neurofilament light chain (NfL) has been demonstrated to correlate with multiple sclerosis disease severity as well as treatment response. Nevertheless, additional serum biomarkers are still needed to better differentiate disease activity from disease progression. The aim of our study was to assess serum glial fibrillary acid protein (s-GFAP) and n...
Article
Full-text available
The presence of cortical lesions in multiple sclerosis patients has emerged as an important biomarker of the disease. They appear in the earliest stages of the illness and have been shown to correlate with the severity of clinical symptoms. However, cortical lesions are hardly visible in conventional magnetic resonance imaging (MRI) at 3T, and thus...
Article
The central vein sign (CVS) is an efficient imaging biomarker for multiple sclerosis (MS) diagnosis, but its application in clinical routine is limited by inter‐rater variability and the expenditure of time associated with manual assessment. We describe a deep learning‐based prototype for automated assessment of the CVS in white matter MS lesions u...
Article
Full-text available
Purpose The goals of this study were to assess the performance of a novel lesion segmentation tool for longitudinal analyses, as well as to validate the generated lesion progression map between two time points using conventional and non-conventional MR sequences. Material and methods The lesion segmentation approach was evaluated with (LeMan-PV) a...
Article
Full-text available
The relation of white matter hyperintense lesions to episodic memory impairment in patients with Parkinson’s disease (PD) is still controversial. We aimed at evaluating the relation between white matter hyperintense lesions and episodic memory decline in patients with PD. In this multicentric prospective study, twenty-one normal controls, 15 PD pat...
Poster
Automated brain segmentation approaches are increasingly being used for decision support in routine clinical settings. While segmentation may be considered a “solved problem” in research, it is still challenging to assure reliable performance of automated tools in clinical settings, which is a crucial requirement for diagnostic tools. To ensure cor...
Poster
Highly precise measurements from fully automated techniques are required to quantify brain atrophy in individual multiple sclerosis (MS) patients. We developed a novel approach to reliably estimate brain atrophy in MS that combines two techniques applied to different image contrasts and incorporates inter-scanner calibrations. We validated this app...
Article
Objectives: The aim of this study was to develop a new automated segmentation method of white matter (WM) and cortical multiple sclerosis (MS) lesions visible on magnetization-prepared 2 inversion-contrast rapid gradient echo (MP2RAGE) images acquired at 7 T MRI. Materials and methods: The proposed prototype (MSLAST [Multiple Sclerosis Lesion An...
Preprint
Full-text available
In this work, we present a comparison of a shallow and a deep learning architecture for the automated segmentation of white matter lesions in MR images of multiple sclerosis patients. In particular, we train and test both methods on early stage disease patients, to verify their performance in challenging conditions, more similar to a clinical setti...
Conference Paper
The presence of a vein inside white matter lesions was recently proposed as an imaging biomarker that can help in the differential diagnosis of Multiple Sclerosis (MS), potentially reducing the challenging clinical-radiological gap. Here, we propose a prototype based on ensembling small 3D convolutional networks to classify perivenular (P+) and non...
Conference Paper
Longitudinal analyses in Multiple Sclerosis are often performed to assess disease progression and evaluate treatment response. The number of new and enlarged lesions as well as total lesion volume variations over time are imaging biomarkers used in MS follow-up assessment. Here, we evaluate the performance of an in-house prototype algorithm for les...
Conference Paper
A reliable and accurate quantification of brain tissue loss is important to distinguish changes due to biological aging from pathological atrophy caused by diseases such as dementia or multiple sclerosis. However, accuracy and reproducibility of current methods are often limited by partial volume effects, especially at tissue interfaces. We present...
Conference Paper
We assessed the effect of age on the longitudinal evolution of intralesional neurite density and orientation dispersion indices (NDI, ODI), magnetization transfer ratio and T1 relaxometry in a cohort of set of relapsing-remitting MS (RRMS) patients.
Conference Paper
White matter lesions (WMLs) have an impact on neuronal connectivity and consequently balance, mobility and cognition are affected in both healthy elderly and other disease states. In this work, automatic volumetric quantification of WMLs was assessed in order to predict the severity of symptoms in a cohort of Parkinson’s disease (PD) patients and h...
Conference Paper
Variability in image quality induced by external factors commonly induces experimental errors in brain segmentation methods. This is relevant to discriminate between volume changes due to experimental errors, age-related brain atrophy or progression of neurodegenerative diseases. We study the relationship between brain volume (BV) changes and varia...
Conference Paper
The thalamus has a central role in the pathophysiology of schizophrenia. Formed by several nuclei, it is mainly constituted by partial volume (PV) of grey and white matter. We hypothesize that a PV segmentation will be better in measuring subtle changes in schizophrenia than total thalamus volume or local measurements that do not consider PV. We co...
Conference Paper
One goal of the Multiple Sclerosis Partners Advancing Technology and Health Solutions (MS PATHS) initiative is to develop high-quality MRI metrics integrated into routine clinical practice. The first steps towards this goal are to assess existing techniques for brain volume measurement and to gain a better understanding of fluctuations in brain vol...
Article
Full-text available
This article aims to present the protocol on Quality Controls in Digital Mammography published online in 2015 by the European Federation of Organisations for Medical Physics (EFOMP) which was developed by a Task Force under the Mammo Working Group. The main objective of this protocol was to define a minimum set of easily implemented quality control...
Article
Full-text available
White-matter lesion count and volume estimation are key to the diagnosis and monitoring of multiple sclerosis (MS). Automated MS lesion segmentation methods that have been proposed in the past 20 years reach their limits when applied to patients in early disease stages characterized by low lesion load and small lesions. We propose an algorithm to a...
Article
Although having a relatively homogeneous cytoarchitectonic organization, the cerebellar cortex is a heterogeneous region characterized by different amounts of myelin, iron and protein expression profiles. In this study, we used quantitative T1 and T2* mapping at ultra-high field (7T) MRI to investigate the tissue characteristics of the cerebellar g...
Article
To characterise the mean glandular dose (MGD) in a sample of healthcare providers for digital mammography in Portugal. To compare the achieved values with European references. The MGD was measured on a poly-methyl-methacrylate phantom (45 mm) for each system using dosimeters. In addition, MGD was estimated using exposure settings collected from mam...
Conference Paper
7T MRI provides additional insights in Multiple Sclerosis (MS) due to improved signal-to-noise and contrast-to-noise ratios as well as improved spatial resolution, resulting in reduced partial volume effects. In this context, we have developed an in-house automated tool to perform automatic detection of MS lesions at 7T.
Conference Paper
We propose a novel method to automatically detect and segment multiple sclerosis lesions, located both in white matter and in the cortex. The algorithm consists of two main steps: (i) a supervised approach that outputs an initial bitmap locating candidates of lesional tissue and (ii) a Bayesian partial volume estimation framework that estimates the...
Article
Full-text available
Objective Quantitative and semi-quantitative MRI (qMRI) metrics provide complementary specificity and differential sensitivity to pathological brain changes compatible with brain inflammation, degeneration, and repair. Moreover, advanced magnetic resonance imaging (MRI) metrics with overlapping elements amplify the true tissue-related information a...
Conference Paper
In multiple sclerosis (MS) patients, lesion load and activity, as identified by conventional magnetic resonance imaging (MRI), moderately correlate with patients clinical status and evolution. Cortical lesion number and volume as measured with advanced MRI acquisitions at 3T and 7T, provide more powerful correlates to cognitive dysfunction and disa...
Conference Paper
Partial volume (PV) is the effect of having a mixture of different tissues present within a voxel. This effect most often occurs in tissue borders and affects small structures, notably those of size close to the image spatial resolution, such as multiple sclerosis (MS) lesions. Ignoring these PV effects in volumetry of small brain structures may le...
Conference Paper
Ultra-high-field Magnetic Resonance Imaging (7T MRI) has been shown to be a valuable tool to assess focal and diffuse pathology in multiple sclerosis (MS) patients, both in grey and in white matter. In this work, we developed and evaluated a method to automatically assess MS lesion load using magnetization-prepared two inversion-contrast rapid grad...
Conference Paper
MR imaging of the cortical structure in vivo is challenging, due to its complex microstructure and its heterogeneity across the brain. Hardware and software advances in MRI have enabled unprecedented spatial resolution in in vivo, thereby providing a precious window into cortical grey matter microstructure. Magnetization prepared 2 rapid gradient e...
Article
Full-text available
PurposeTo assess current practices in digital mammography (DM) in Portuguese healthcare providers using digital systems. To investigate compliance with European standards regarding mean glandular dose and quality control practice and to identify optimisation needs. Methods Two questionnaires, targeted at breast radiographers and chief radiographers...
Conference Paper
Full-text available
Breast Tomosynthesis is a novel technique that has been increasingly used for breast imaging. In this work the dose distribution pattern in 2D digital mammography and 3D tomosynthesis were measured and compared. A semicircular PMMA slab phantom with dimensions 24 cm length and 45 mm thick was prepared. Some slabs contained inserts for the placement...
Article
Objectives: The aim of this study was to study focal cerebellar pathology in early stages of multiple sclerosis (MS) using ultra-high-field magnetization-prepared 2 inversion-contrast rapid gradient-echo (7T MP2RAGE). Materials and methods: Twenty early-stage relapsing-remitting MS patients underwent an MP2RAGE acquisition at 7 T magnetic resona...
Article
The aim of this paper is the characterization of four thermoluminescence detectors (TLD), namely, LiF:Mg,Ti, LiF:Mg,Cu,P, Li2B4O7:Mn and Li2B4O7:Cu for the measurement of the entrance surface air kerma (ESAK) and estimation of the mean glandular dose (MGD) in digital mammography examinations at hospitals and clinics. Low-energy x-ray beams in the t...
Conference Paper
Full-text available
Magnetic Resonance Imaging(MRI) is extensively used in the diagnosis of Multiple Sclerosis(MS). Follow-up brain MRI is required in order to identify new lesions and perform early diagnosis, quantify disease activity and monitor treatment response. To date, there are essentially two types of automated methods for time-series analyses: I)methods wher...
Conference Paper
Full-text available
In this work, we assessed the sensitivity of MP2RAGE at 7T MRI to detect focal cerebellar pathology, both in grey and white matter. To do this, we compared cerebellar lesion count in 7T and 3T MP2RAGE images in a cohort of MS patients. Lesion detection rate at 7T MRI was higher than the one at 3T, yet the total lesion volume was comparable at diffe...
Conference Paper
Full-text available
Magnetic Resonance Imaging (MRI) plays an important role for lesion assessment in early stages of Multiple Sclerosis (MS). This work aims at evaluating the performance of an automated tool for MS lesion detection, segmentation and tracking in longitudinal data, only for use in this research study. The method was tested with images acquired using bo...
Conference Paper
The quantitative properties of the cerebellum were assessed by acquiring T1 and T2*contrasts at 7T and mapping these onto the cerebellar cortex. T1 maps showed medial-lateral alternating stripes of different intensities while T2* values were homogeneously distributed across the lobes. This study showed the heterogeneity of the cerebellar cortex in...
Conference Paper
We compared ultra-high field, high resolution quantitative T1 and T2* measurements in the cerebellum of MS patients to that of healthy controls. A correlation between the multiple sclerosis functional scale scores and local T2* values was found for several motor and cognitive related lobules. No significant differences between groups were found.
Article
Purpose: To develop a method to automatically detect multiple sclerosis (MS) lesions, located both in white matter (WM) and in the cortex, in patients with low disability and early disease stage. Materials and methods: We developed a lesion detection method, based on the k-nearest neighbor (k-NN) technique, to detect lesions as small as 0.0036 m...
Presentation
Full-text available
Early detection of Multiple Sclerosis (MS) lesions is critical for patients diagnosis, follow-up and optimal treatment. Today, advanced Magnetic Resonance Imaging (MRI) sequences provide improved spatial resolution and intensity contrast for MS lesions visualization, both in the cortex and subcortical white matter (WM). In the last years, several g...
Conference Paper
Full-text available
The aim of this study was to investigate the contribution of advanced MRI sequences on the performance of an automated lesion detection tool in early-stage MS patients. In addition, more than existing state-of-the-art methods, we targeted both WM and cortical lesions, starting from a small lesion volume of 3.6 μL.
Thesis
Full-text available
The population’s exposure to ionizing radiation, due to medical radiological examinations, is the biggest contribution for the dose in the group of radiation exposure sources produced by man-kind. The frequency of radiological examinations and the radiation dose received by patients, in each exam, has brought attention to health professionals and e...

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