Marc Miquel

Marc Miquel
Queen Mary, University of London | QMUL · Barts and the London School of Medicine and Dentistry

PhD

About

87
Publications
9,675
Reads
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1,945
Citations
Citations since 2016
37 Research Items
1039 Citations
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
Introduction
Marc Miquel currently works at Barts Health NHS Trust and Queen Mary, University of London. Marc is an MRI physicist with current project in DWI, MS imaging and real time MRI of speech.

Publications

Publications (87)
Article
Full-text available
The human voice carries socially relevant information such as how authoritative, dominant, and attractive the speaker sounds. However, some speakers may be able to manipulate listeners by modulating the shape and size of their vocal tract to exaggerate certain characteristics of their voice. We analysed the veridical size of speakers’ vocal tracts...
Article
Full-text available
Purpose Validation of quantitative MR measures for myelin imaging in the postmortem multiple sclerosis spinal cord. Methods Four fixed spinal cord samples were imaged first with a 3T clinical MR scanner to identify areas of interest for scanning, and then with a 7T small bore scanner using a multicomponent-driven equilibrium single-pulse observati...
Article
Humans have a remarkable capacity to finely control the muscles of the larynx, via distinct patterns of cortical topography and innervation that may underpin our sophisticated vocal capabilities compared with non-human primates. Here, we investigated the behavioural and neural correlates of laryngeal control, and their relationship to vocal experti...
Article
Full-text available
Purpose: Pre-operative nodal staging is important for planning treatment in cervical cancer (CC) and endometrial cancer (EC) but remains challenging. We compare nodal staging accuracy of 18F-ethyl-choline-(FEC)-PET/CT, 18F-Fluoro-deoxy-glucose-(FDG)-PET/CT and diffusion-weighted-MRI (DW-MRI) with conventional morphological MRI. Experimental desig...
Article
Aim: The study aims to assess minimal apparent diffusion coefficient (ADCmin) and SUVmax as predictors of histological differentiation in patients with anal squamous cell carcinoma (ASCC) and to determine cutoff values for each histopathological tumor grade. Patients and methods: A retrospective study of 41 ASCC patients (14 males, 27 females; m...
Preprint
Humans have a remarkable capacity to finely control the muscles of the larynx, via distinct patterns of cortical topography and innervation that may underpin our sophisticated vocal capabilities compared with non-human primates. Here, we investigated the behavioural and neural correlates of laryngeal control, and their relationship to vocal experti...
Article
Full-text available
Background and Objective Magnetic resonance (MR) imaging is increasingly used in studies of speech as it enables non-invasive visualisation of the vocal tract and articulators, thus providing information about their shape, size, motion and position. Extraction of this information for quantitative analysis is achieved using segmentation. Methods hav...
Article
Full-text available
Dynamic and real-time MRI (rtMRI) of human speech is an active field of research, with interest from both the linguistics and clinical communities. At present, different research groups are investigating a range of rtMRI acquisition and reconstruction approaches to visualise the speech organs. Similar to other moving organs, it is difficult to crea...
Article
No PDF available ABSTRACT Humans are unrivalled amongst the great apes in our capacity for vocal learning, which forms a key component our facility for articulate speech. Here, we used a speech imitation task to investigate the neural representation of the human larynx, which has a distinct cortical topography and innervation in humans that may und...
Article
Aim: To compare retrospectively fused FDG PET/CT and MRI (PET/MRI) to FDG PET/CT and MRI for characterisation of indeterminate focal liver lesions as malignant or benign in patients with a known primary malignancy. Materials and method: A retrospective review of 70 patients (30 females, 40 males; mean age 56 ± 14 years) with 150 indeterminate le...
Article
Purpose To investigate: (1) the feasibility of using through‐time radial GeneRalized Autocalibrating Partially Parallel Acquisitions (rGRAPPA) and hybrid radial GRAPPA (h‐rGRAPPA) in single‐ and multislice dynamic speech MRI; (2) whether single‐slice dynamic speech MRI at a rate of 15 frames per second (fps) or higher and with adequate image qualit...
Conference Paper
Introduction The traditional teaching, that basic airway manoeuvres align the three airway axes of mouth, pharynx and larynx, has been disproved in adults using MRI. An alternative model of airway management has been proposed, considering the airway not as axes but as two curves; a primary (oropharyngeal) and a secondary (pharyngo-glotto-tracheal)...
Chapter
The appearance of blood on magnetic resonance (MR) images is directly linked to its flowing nature. The contrast mechanism relies on the time-of-flight mechanism. In spin echo sequences, the excited blood flows out before the echo is created, resulting in black blood images, whereas in gradient echo images, the rapid succession of radiofrequency pu...
Chapter
Good and reproducible image quality is essential for clinical diagnosis. Although image quality can be defined in numerous ways, signal-to-noise and contrast-to-noise ratios are often used as indicators. Despite our best efforts, image artefacts are part and parcel of CMR imaging and are sometimes unavoidable. Image artefacts can be caused by patie...
Chapter
This chapter introduces the different methods used to synchronize pulse sequences with both cardiac and respiratory motions, to suppress motion-related blurring and image artefacts. A single frame or a series of images (cine imaging) can be acquired at different time points (cardiac phases) throughout the cardiac cycle by detecting the patient’s he...
Chapter
Pulse sequences control the timing of radiofrequency pulses and time-varying gradients that are necessary to create an image. Sequences are divided into different types: gradient echo, spin echo, and hybrid echo sequences. In cardiac imaging, ‘black blood’ spin echo images are used for anatomical imaging, while ‘bright blood’ imaging is used to stu...
Chapter
In magnetic resonance, the properties of protons in tissue giving rise to so-called magnetic moments are exploited. The sum of many magnetic moments yields what is referred to as net magnetization, which can be seen as similar to the magnetization a bar magnet produces. The relation and interaction between magnetic moments, net magnetization, the s...
Chapter
In cardiovascular magnetic resonance imaging, scan time is of critical importance, as many applications require breath-holding to suppress respiratory-related image artefacts. In this chapter, approaches to reduce scan time, while maintaining resolution, are described. Besides partial sampling of k-space, non-Cartesian k-space trajectories are intr...
Chapter
In order to form images with the required resolution and anatomical coverage, gradient magnetic fields are used to excite magnetization in a predefined slice or slab, with subsequent spatial encoding to obtain spatial resolution in the slice or slab. It is demonstrated how the spatial encoding principle is implemented and how it can be conceptualiz...
Chapter
In the magnetic resonance (MR) scanner, a well-controlled interplay of a static main magnetic field, time-varying gradient magnetic fields, and radiofrequency fields is used to generate images. Here these three different types of magnetic or electromagnetic fields are summarized in relation to hardware components of the MR system. The sequential ac...
Chapter
Assessment of cardiac morphology, function, and pathology requires the use of different pulse sequences (spin echo, gradient echo, hybrid echo), preparation pulses to manipulate image contrast, and data acquisition strategies such as parallel imaging, single-shot versus segmented acquisition, or contrast versus non-contrast imaging techniques. This...
Preprint
Purpose: This study aims to improve clinical reliability of real-time Magnetic Resonance Imaging (rt-MRI) in the visualisation of velopharyngeal motion during speech. Methods: Seven subjects were imaged at 3T during natural phonation. Speech rt-MRI methodologies were investigated with (i) a comparison of commercial Cartesian and non-Cartesian (r...
Article
Full-text available
Multiple sclerosis (MS) is a common inflammatory, demyelinating and degenerative disease of the central nervous system. The majority of people with MS present with symptoms due to spinal cord damage, and in more advanced MS a clinical syndrome resembling that of progressive myelopathy is not uncommon. Significant efforts have been undertaken to pre...
Article
Full-text available
OBJECTIVE: Application of whole body diffusion-weighted MRI (WB-DWI) for oncology are rapidly increasing within both research and routine clinical domains. However, WB-DWI as a quantitative imaging biomarker (QIB) has significantly slower adoption. To date, challenges relating to accuracy and reproducibility, essential criteria for a good QIB, have...
Article
Full-text available
Introduction: Application of whole body diffusion weighted MRI (WB-DWI) for oncology are rapidly increasing within both research and routine clinical domains. However, WB-DWI as a quantitative imaging biomarker (QIB) has significantly slower adoption. To date challenges relating to accuracy and reproducibility, essential criteria for a good QIB, h...
Article
Background: Cardiovascular Magnetic Resonance (CMR) imaging is an important modality that allows the assessment of regional myocardial function by measuring myocardial deformation parameters such as strain and strain rate throughout the cardiac cycle. Feature tracking is a promising quantitative post-processing technique that is increasingly used....
Article
Full-text available
A cost-effective regularly structured three-dimensional (3D) printed grid phantom was developed to enable the quantification of machine-related magnetic resonance (MR) distortion. This phantom contains reference features, “point-like” objects, or vertices, which resulted from the intersection of mesh edges in 3D space. 3D distortions maps were comp...
Article
Full-text available
Sensorimotor transformation (ST) may be a critical process in mapping perceived speech input onto non-native (L2) phonemes, in support of subsequent speech production. Yet, little is known concerning the role of ST with respect to L2 speech, particularly where learned L2 phones (e.g., vowels) must be produced in more complex lexical contexts (e.g.,...
Article
Full-text available
Imitating speech necessitates the transformation from sensory targets to vocal tract motor output, yet little is known about the representational basis of this process in the human brain. Here, we address this question by using real-time MR imaging (rtMRI) of the vocal tract and functional MRI (fMRI) of the brain in a speech imitation paradigm. Par...
Article
Full-text available
Objective To explore the potential of a post-processing technique combining FLAIR and T2* (FLAIR*) to distinguish between lesions caused by multiple sclerosis (MS) from cerebral small vessel disease (SVD) in a clinical setting. MethodsFLAIR and T2* head datasets acquired at 3T of 25 people with relapsing MS (pwRMS) and ten with pwSVD were used. Aft...
Article
Full-text available
Dynamic imaging of the vocal tract using real-time MRI has been an active and growing area of research, having demonstrated great potential to become routinely performed in the clinical evaluation of speech and swallowing disorders. Although many technical advances have been made in regards to acquisition and reconstruction methodologies, there is...
Article
Full-text available
Objectives: The purpose of this work was to assess heating and radiofrequency (RF) deposition and image quality effects of a prototype three-section carbon fibre flatbed insert for use in MRI. Methods: RF deposition was assessed using two different thermometry techniques, infrared thermometry and Bragg-grating thermometry. Image quality effects...
Article
Full-text available
Real-time magnetic resonance imaging (RT-MRI) is being increasingly used for speech and vocal production research studies. Several imaging protocols have emerged based on advances in RT-MRI acquisition, reconstruction, and audio-processing methods. This review summarizes the state-of-the-art, discusses technical considerations, and provides specifi...
Conference Paper
Objectives: To explore whether FLAIR* is superior to current MRI criteria for a diagnosis of MS using MRI datasets acquired at a single time point and a standard field strength (3T). Background: Current MRI criteria to support the diagnosis of MS are based on dissemination in time (DIT) and space (DIS) of CNS white matter lesions (WML). Application...
Article
Full-text available
Methods: Common orthodontic appliances were studied on 1.5 T scanner using standard spin and gradient echo sequences (based on the American Society for Testing and Materials standard test method) and sequences previously applied for high-resolution anatomical and dynamic real-time imaging during speech. Images were evaluated for the presence and s...
Article
Full-text available
Background Although myocardial function is clinically assessed with global measurements (ventricular volumes, ejection fraction), recent research has shown that regional measurements, such as wall-thickening, strain, and torsion, could provide earlier sub-clinical markers to examine left ventricular (LV) dysfunction and myocardial diseases. Cardiov...
Article
153 hepatic lesions (39 metastasis, 27 haemangiomas, 26 hepatocellular carcinomas, 25 cysts, 15 adenomas, 8 FNH, 5 abscesses, 4 hamartomas and 4 cholangiocarcinomas) in 150 patients were evaluated during a 24 months period. ADC values of benign lesions (1.994 × 10-3 mm2.s-1) were significantly higher than ADC values of malignant lesions (1.070 × 10...
Article
Full-text available
Objective: Semi-quantitative dynamic contrast-enhanced MRI (DCE MRI) has proven useful in discriminating benign from borderline/malignant adnexal lesions. Our aim was to assess if the use of a lesion-to-internal-reference ratio improved the performance in characterizing adnexal masses and which internal reference was suitable. Methods: Semi-quan...
Article
PurposeTo compare DW-MRI between 1.5 and 3 Tesla (T) in terms of image quality, apparent diffusion coefficient (ADC), reproducibility, lesion-to-background contrast and signal-to-noise ratio (SNR), using a test object. Materials and MethodsA spherical diffusion phantom was used for qualitatively assessing image quality and performing quantitative m...
Article
Magnetic Resonance Imaging (MRI) plays an increasing role in the study of speech. This article reviews the MRI literature of anatomical imaging, imaging for acoustic modelling and dynamic imaging. It describes existing imaging techniques attempting to meet the challenges of imaging the upper airway during speech and examines the remaining hurdles a...
Article
In 2012, two articles were published describing new species of the genus Chelotrupes Jekel, 1866 (Coleoptera: Geotrupidae); the first one included fi ve new species and the second a single species. However, the species described in the second article, Chelotrupes annamariae Byk 2012, is identical to Chelotrupes algarvicus Hillert, Král and Schneide...
Article
Full-text available
Background: Current imaging criteria for categorising disease response in metastatic renal cell carcinoma (mRCC) correlate poorly with overall survival (OS) in patients on anti-angiogenic therapies. We prospectively assess diffusion-weighted and multiphase contrast-enhanced (MCE) MR imaging (MRI) as markers of outcome. Methods: Treatment-naive mRC...
Article
Achieving sufficient temporal and spatial resolution with adequate signal-to-noise ratio (SNR) in dynamic soft palate imaging is challenging. Triggered acquisitions require repeated reproducible speech samples, and while real-time imaging is more reliable, it may lack SNR. Adaptive averaging was implemented to improve SNR in nongated imaging during...
Article
Objective: The objective of this study was to demonstrate soft palate MRI at 1.5 and 3 T with high temporal resolution on clinical scanners. Methods: Six volunteers were imaged while speaking, using both four real-time steady-state free-precession (SSFP) sequences at 3 T and four balanced SSFP (bSSFP) at 1.5 T. Temporal resolution was 9-20 frame...
Article
Objective: To study the in vitro and in vivo (abdomen) variability of apparent diffusion coefficient (ADC) measurements at 1.5 T using a free-breathing multislice diffusion-weighted (DW) MRI sequence. Methods: DW MRI images were obtained using a multislice spin-echo echo-planar imaging sequence with b-values=0, 100, 200, 500, 750 and 1000 s mm(-...
Article
Organ and tumour motion has a significant impact on the planning and delivery of radiotherapy treatment. At present imaging modality such as four-dimensional computer tomography (4DCT) cannot be used to measure the variability of motion between different respiratory cycles. To create reliable motion models, one needs to acquire volumetric data sets...
Article
To determine whether threshold criteria using semi-quantitative multiphase-dynamic contrast-enhanced magnetic resonance imaging (DCE- MRI) can improve prediction of malignancy in complex adnexal masses. MRI features of 70 complex adnexal masses with enhancing components in 63 patients were reviewed and correlated with histopathology (n = 67) or rad...
Article
Full-text available
Endometrial cancer is the most common gynaecological malignancy in developed countries. Histological grade and subtype are important prognostic factors obtained by pipelle biopsy. However, pipelle biopsy "samples" tissue and a high-grade component that requires more aggressive treatment may be missed. The purpose of the study was to assess the use...
Article
Objective: To use finite element analysis animated simulations to investigate factors affecting velopharyngeal closure. Design: A coronal section multicomponent finite element analysis model of a human soft palate was created in Simulia Abaqus 6.5-1 from high resolution MRI images of a single adult female subject, interpreted by reference to pub...
Article
Full-text available
This paper shows how concept mapping can be used to measure the quality of e-learning. Six volunteers (all of them 3rd-year medical students) took part in a programme of e-learning designed to teach the principles of magnetic resonance imaging (MRI). Their understanding of MRI was measured before and after the course by the use of concept mapping....
Article
To present a method for the dosimetric analysis of permanent prostate brachytherapy implants using a combination of stereoscopic X-ray radiography and magnetic resonance (MR) imaging (XMR) in an XMR facility, and to compare the clinical results between XMR- and computed tomography (CT)-based dosimetry. Patients who had received nonstranded iodine-1...
Article
Complex radiotherapy techniques call for three-dimensional dosimetric methods with high spatial resolution. Radiation-sensitive polymer gel systems (e.g. commercially available BANG(TM) gel), read using MRI T2 mapping, offer a promising solution. A series of calibration test tubes is traditionally used to calculate the dose delivered to a larger, d...
Article
Respiratory organ motion has a significant impact on the planning and delivery of radiotherapy (RT) treatment for lung cancer. Currently widespread techniques, such as 4D-computed tomography (4DCT), cannot be used to measure variability of this motion from one cycle to the next. In this paper, we describe the use of fast magnetic resonance imaging...
Article
The lack of magnetic resonance (MR) safe catheters and guide wires remains an important obstacle to widespread clinical use of MR-guided endovascular procedures. The authors looked at the feasibility of using multiple tuned fiducial markers (TFM) and novel imaging sequences to track catheters reliably under MR and to evaluate the safety of such mar...
Article
Full-text available
Post-implantation dosimetry is an important element of permanent prostate brachytherapy. This process relies on accurate localization of implanted seeds relative to the surrounding organs. Localization is commonly achieved using CT images, which provide suboptimal prostate delineation. On MR images, conversely, prostate visualization is excellent b...
Article
Pulmonary hypertensive disease is assessed by quantification of pulmonary vascular resistance. Pulmonary total arterial compliance is also an indicator of pulmonary hypertensive disease. However, because of difficulties in measuring compliance, it is rarely used. We describe a method of measuring pulmonary arterial compliance utilizing magnetic res...
Article
New radiotherapy techniques call for three-dimensional dosimetric methods with high spatial resolution. Radiation sensitive gels read out using MRI T(2) mapping provide an extremely promising option, and commercially available BANG polymer gels provide a convenient route into gel dosimetry. Gel dosimetry is dependent on the ability to calibrate gel...
Article
Pulmonary vascular resistance (PVR) quantification is important in the treatment of children with pulmonary hypertension. The Fick principle, used to quantify pulmonary artery flow, may be a flawed technique. We describe a novel method of PVR quantification by the use of magnetic resonance (MR) flow data and invasive pressure measurements. In 24 pa...
Article
Passive catheter tracking involves direct interaction between the device and its surroundings, creating a local signal loss or enhancement of the image. Using only standard balloon catheters filled with CO(2) and imaged with a steady-state free precession sequence, it was possible to visualize and passively track catheters in a flow phantom and in...
Article
Full-text available
Two patients, aged 3 days (weight 2 kg) and 40 years (weight 80 kg) underwent gadolinium-enhanced magnetic resonance angiography (MRA) because of diagnostic uncertainty. The newborn infant was antenatally diagnosed with truncus arteriosis. Postnatal echocardiography confirmed the diagnosis. It was thought that the branch pulmonary arteries were con...
Article
Fluoroscopically guided cardiac catheterisation is an essential tool for diagnosis and treatment of congenital heart disease. Drawbacks include poor soft tissue visualisation and exposure to radiation. We describe the first 16 cases of a novel method of cardiac catheterisation guided by MRI with radiographic support. In our cardiac catheterisation...
Article
We describe a new method of three-dimensional magnetic resonance imaging of the heart that has been used to produce high quality diagnostic images in 274 patients with congenital cardiac disease, ranging in age from 1 day to 66 years. Using a steady state free precession gradient echo technique and parallel imaging, rapid acquisition of the entire...
Article
The present study was designed to evaluate the feasibility and clinical usefulness of three-dimensional (3D) reconstruction of intra-cardiac anatomy from a series of two-dimensional (2D) MR images using commercially available software. Sixteen patients (eight with structurally normal hearts but due to have catheter radio-frequency ablation of atria...
Article
This paper describes experimental results relating to solid chocolate that has been ‘cold’- extruded and provides insight into the mechanism of the process and the temporary flexibility that occurs in the extrudate. Experimental data of temperature changes after extrusion are presented together with NMR data that follow the change in liquid fat pha...
Article
Storage of chocolate confectionery products was monitored non-invasively by Magnetic Resonance Imaging. Using a Carr–Purcell–Meiboom–Gill–(CPMG) sequence, 20 echo images (first echo 5 ms, subsequent echo every 5 ms) were acquired with a 2 s repetition time in a total 8-min scan time. Images were processed to give spatial maps of the proton density...
Article
Migration of hazelnut oil into chocolate was followed non-invasively by magnetic resonance imaging, using a spin echo pulse sequence to acquire images with a 5 ms echo time and a 2000 ms repetition time. A calibration curve was used to correlate the image intensity with the concentration of hazelnut oil. Two different degrees of chocolate temper, a...
Article
A selection of chocolate confectionery products have been studied non-invasively by three-dimensional magnetic resonance imaging (MRI). Using a spin echo pulse sequence, 128 × 64 × 64 data sets were acquired with either a 5- or 20-ms echo time, 500-ms repetition time and four signal averages, in a total 2-h scan time. Such images localize and disti...
Article
Magnetic resonance imaging (MRI) has been used to survey the structure of a range of chocolate products, including tablet, straightline and countline products: typically two dimensional MRI at 2 Tesla gives 50 × 50 mm spatial resolution for a 3 mm thick slice in 8 mins. High signal intensity and excellent image contrast is obtained for nuts or othe...