0000000000444127
AUTHOR
François Brunotte
Application of the optically stimulated luminescence (OSL) technique for mouse dosimetry in micro-CT imaging
International audience; Purpose: Micro-CT is considered to be a powerful tool to investigate various models of disease on anesthetized animals. In longitudinal studies, the radiation dose delivered by the micro-CT to the same animal is a major concern as it could potentially induce spurious effects in experimental results. Optically stimulated luminescence dosimeters (OSLDs) are a relatively new kind of detector used in radiation dosimetry for medical applications. The aim of this work was to assess the dose delivered by the CT component of a micro-SPECT (single-photon emission computed tomography)/CT camera during a typical whole-body mouse study, using commercially available OSLDs based o…
DOTAGA-Trastuzumab. A New Antibody Conjugate Targeting HER2/Neu Antigen for Diagnostic Purposes.
International audience; Improved bifunctional chelating agents (BFC) are required for indium-111 radiolabeling of monoclonal antibodies (mAbs) under mild conditions to yield stable, target-specific agents. 2,2',2″-(10-(2,6-Dioxotetrahydro-2H-pyran-3-yl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid (DOTAGA-anhydride) was evaluated for mAb conjugation and labeling with indium-111. The DOTA analogue was synthesized and conjugated to trastuzumab-which targets the HER2/neu receptor-in mild conditions (PBS pH 7.4, 25 °C, 30 min) and gave a mean degree of conjugation of 2.6 macrocycle per antibody. Labeling of this immunoconjugate with indium-111 was performed in 75% yield after 1 h a…
N-ACETYL-ASPARTATE ABNORMALITIES IN INTERNAL-TEMPORAL EPILEPTICUS FOCUS USING PROTON MAGNETIC-RESONANCE SPECTROSCOPY
International audience; Abstract: The aim of this study was to characterize the neurochemical abnormalities related to N-acetyl-aspartate which is a neuronal marker, within an epilepticus focus located in the internal-temporal area, using proton magnetic resonance spectroscopy, Eleven patients,with a mono-hippocampal epilepticus focus on clinical and per-critical electroencephalographical criteria, were matched with II controls by age, sex and laterality. Proton spectroscopy of a volume of 8 cm(3) was performed within the ipsilateral and the contralateral internal-temporal area and within the 2 hippocampus of controls. Volumetry of the ipsilateral and the contralateral hippocampus and of th…
SKELETAL-MUSCLE METABOLISM IN THE LEG DURING EXERCISE IN PATIENTS WITH CONGESTIVE HEART-FAILURE
International audience
PRELIMINARY-OBSERVATIONS OF METABOLIC CHARACTERIZATION OF BILATERAL TEMPORAL EPILEPTIC FOCUS, USING PROTON MAGNETIC-RESONANCE SPECTROSCOPY - 3 CASES
International audience; Abstract: The authors report the case of 3 patients with bilateral temporal lobe epilepsy demonstrated by EEG and sphenoidal electrodes. Two out of the 3 patients presented with childhood febrile convulsions. Their neurological and mental examination was normal. EEG showed spikes within the anterior part of the 2 temporal lobes. CT scan and MRI showed no atrophic lesion within the 2 temporal lobes. Proton magnetic resonance spectroscopy, performed within a cube of 8 cube-centimetres localized in the anterior part of the 2 temporal lobes showed a significant decrease of N-acetyl-aspartate in the 2 temporal lobes of the 3 cases, compared with controls matched with age,…
Initial performance evaluation of a preclinical PETscanner available as a clippable assembly in a sequential PET/MRI system
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Cardiac motion tracking using a deformable 2D-mesh modeling
International audience; Abstract: The work reported here deals with movement tracking in sequences of medical images in order to quantify the general movements and deformations of the heart For this purpose, we partition the first image into triangular patches in order that each object of the image corresponds to a set of triangles. Then, the nodes of the mesh are tracked across the image sequence giving a mesh which warps with the images. The method is applied to cardiac image sequences where the study of the deformation of the triangles is applied to the determination of the movement of the ventricles
Automatic classification of tissues on pelvic MRI based on relaxation times and support vector machine
International audience; Tissue segmentation and classification in MRI is a challenging task due to a lack of signal intensity standardization. MRI signal is dependent on the acquisition protocol, the coil profile, the scanner type, etc. While we can compute quantitative physical tissue properties independent of the hardware and the sequence parameters, it is still difficult to leverage these physical properties to segment and classify pelvic tissues. The proposed method integrates quantitative MRI values (T1 and T2 relaxation times and pure synthetic weighted images) and machine learning (Support Vector Machine (SVM)) to segment and classify tissues in the pelvic region, i.e.: fat, muscle, …
Tumour-derived and host-derived nitric oxide differentially regulate breast carcinoma metastasis to the lungs.
To study the role of nitric oxide (NO) in lung metastasis of breast carcinoma, we isolated two cell clones (H and J) from the parental EMT-6 murine breast carcinoma cell line, based on their differential NO production. In vitro, EMT-6 J cells, but not EMT-6H cells, constitutively expressed inducible NO synthase (NOS II) and secreted high levels of NO. IL-1beta increased NO production in both clones, and TNF-alpha had a synergistic effect on IL-1beta-induced NO production, but NO production by EMT-6 J cells was always higher than by EMT-6H cells. Proliferation, survival and adhesion to lung-derived endothelial cells of both clones were similar and were not affected by NO. In vivo, both clone…
Prostate Metabolism After the Completion of Exclusive Radiation Is More Depleted After Seeds Brachytherapy Compared to External Beam Radiation Therapy for Prostate Cancer Patients
International audience; Biochemical outcome after radiation therapy requires a protracted time. PSA decreases slowly over time so that it is difficult to differentiate immediately after the completion of radiation the impact of radiation in the prostate using brachytherapy or external radiotherapy. At 3 months, the mean PSA values were similar between the 2 groups: 2.54 ng/mL (±1.59) in the EBRT group and 1.88 ng/mL (±1.14) in the PPI group (p=0.23). For Choline levels, 3-months Choline / Baseline Choline ratios were 1.13 (±0.60) after EBRT vs. 0.45 (±0.23) in the PPI group (p=0.003). Similar results were observed for Citrate levels: 3-months Citrate level / Baseline Citrate level ratios we…
Dual Labeling of Lipopolysaccharides for SPECT-CT Imaging and Fluorescence Microscopy.
International audience; : Lipopolysaccharides (LPS) or endotoxins are amphipathic, pro-inflammatory components of the outer membrane of Gram-negative bacteria. In the host, LPS can trigger a systemic inflammatory response syndrome. To bring insight into in vivo tissue distribution and cellular uptake of LPS, dual labeling was performed with a bimodal molecular probe designed for fluorescence and nuclear imaging. LPS were labeled with DOTA-Bodipy-NCS, and pro-inflammatory properties were controlled after each labeling step. LPS were then radiolabeled with (111)In and subsequently injected intravenously into wild-type, C57B16 mice, and their in vivo behavior was followed by single photon emis…
Place de l’imagerie dans l’évaluation de l’efficacité des traitements dans le cancer du sein
Resume Cette revue decrit le role de differentes methodes d’imagerie pour evaluer la reponse au traitement dans le cancer du sein. Deux situations sont envisageables : celle de la chimiotherapie neoadjuvante du cancer du sein et celle des metastases. Beaucoup de donnees cliniques sont disponibles pour trois criteres : le volume de la tumeur, la captation du fluorodeoxyglucose mesuree en TEP et la perfusion de la tumeur evaluee soit par IRM dynamique, soit en TEP. La TEP au 2-18F fluoro-2-desoxy-D-glucose (FDG) permet la prediction de la reponse apres une ou deux cures de chimiotherapie. De nouvelles approches pourraient prochainement affiner le role de l’imagerie. Ainsi, la TEP a la thymidi…
Object tracking in medical imaging using a 2D active mesh system
International audience; Abstract: This article proposes a technique for tracking moving organs in medical imaging. It can be split into two stages. We first initialize a 2D-triangular mesh on the first image of the sequence. We distinguish different objects of interest by grouping together the triangles that make them up. Afterwards, we deform this mesh on the successive images in order to track each identified object. The tracking stage uses optical flow by adding a node relaxation step to avoid mesh deteriorations. The mesh deformations analysis provides access to motion information along the sequence. This technique is applied to a cine-MRI sequences of the heart and allows the analysis …
An adapted optical flow algorithm for robust quantification of cardiac wall motion from standard cine-MR examinations
International audience; This paper presents a method for local myocardial motion estimation from a conventional steady-state free precession cine-MRI sequence using a modified phase-based optical flow (OF) technique. Initially, the technique was tested on synthetic images to evaluate its robustness with regards to Rician noise and to brightness variations. The method was then applied to cardiac images acquired on 11 healthy subjects. Myocardial velocity is measured in centimeter per second in each studied pixel and visualized as colored vectors superimposed on MRI images. The estimated phase-based OF results were compared with a reference OF method and gave similar results on synthetic imag…
Automatic determination of aortic compliance with cine-magnetic resonance imaging - An application of fuzzy logic theory
International audience; Abstract: RATIONALE AND OBJECTIVES. Aortic compliance is defined as the relative change in aortic cross-sectional area divided by the change in arterial pressure. Magnetic resonance imaging (MRI) is a useful imaging modality for the noninvasive evaluation of aortic compliance. However, manual tracing of the aortic contour is subject to important interobserver variations. To estimate the aortic compliance from cine-MRI, a method based on fuzzy logic theory was elaborated. MATERIALS AND METHODS. Seven healthy volunteers and eight patients with Marfan syndrome were examined using an ECG gated cine-MRI sequence. The aorta was imaged in the transverse plane at the level o…
Implementation of routine sequential PET/MR of the rat heart in an in-line preclinical scanner
International audience
Major impact of admission glycemia on myocardial perfusion assessed by magnetic resonance imaging, in patients with acute myocardial infarction
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Quantifying stenosis in renal arteriograms: a fuzzy syntactic analysis.
AbstractThe introduction of fuzzy logic improves a system for the automatic quantification of renal artery lesions seen in digital subtraction angiograms. A two-step approach has been followed. An earlier system based on non-fuzzy syntactic analysis provided a clear symbolic description of the stenotic lesions. Although this system worked correctly, it did not take into account the variability and uncertainty inherent to image processing and to knowledge on the reference diameter. This system has been improved by the introduction of fuzzy logic in the representation of the reference diameter. It provides a description of the stenosis in terms of fuzzy quantities. To illustrate the benefits …
18F-FDG PET-Derived Tumor Blood Flow Changes After 1 Cycle of Neoadjuvant Chemotherapy Predicts Outcome in Triple-Negative Breast Cancer
International audience; Previous studies have suggested that early changes in blood flow (BF) in response to neoadjuvant chemotherapy and evaluated with 150-water are a surrogate biomarker of outcome in women with breast cancer. This study investigates, in the triple-negative breast cancer subtype, the prognostic relevance of tumor BF changes (Delta BF) in response to chemotherapy, assessed using a short dynamic F-18-FDG PET acquisition. Methods: Forty-six consecutive women with triple-negative breast cancer and an indication for neoadjuvant chemotherapy were prospectively included. Women benefited from a baseline F-18-FDG PET examination with a 2-min chest-centered dynamic acquisition, sta…
Validation of SiPM-based PET imaging for left ventricular volumes measurements in preclinical imaging: comparison with simultaneously-acquired cardiac magnetic resonance at 7T.
International audience
Automatic evaluation of the peri-infarct area of myocardial infarction from delayed enhancement MRI
International audience; Delay Enhancement - Magnetic Resonance Imaging (DE-MRI) can be considered as the gold standard for the assessment of myocardial viability after myocardial infarction (MI). Around the infarcted areas that appear with hyper-enhanced signal, there is a peri-infarct border zone that may be an important arrhythmogenic substrate. The extent of this area is an independent predictor of post-MI mortality (1). However, it is difficult to separate peri-infarct border zones from infarct core or normal areas, because of their intermediate signal intensity. We propose a new automatic approach to detect this area, based on a modified Gaussian Mixture Model (GMM) and spatial-weighte…
Minor changes in the macrocyclic ligands but major consequences on the efficiency of gold nanoparticles designed for radiosensitization
International audience; Many studies have been devoted to adapting the design of gold nanoparticles to efficiently exploit their promising capability to enhance the effects of radiotherapy. In particular, the addition of magnetic resonance imaging modality constitutes an attractive strategy for enhancing the selectivity of radiotherapy since it allows the determination of the most suited delay between the injection of nanoparticles and irradiation. This requires the functionalization of the gold core by an organic shell composed of thiolated gadolinium chelates. The risk of nephrogenic systemic fibrosis induced by the release of gadolinium ions should encourage the use of macrocyclic chelat…
N-Acetylaspartate/Creatine and Choline/Creatine Ratios in the Thalami, Insular Cortex and White Matter as Markers of Hypertension and Cognitive Impairment in the Elderly
International audience; Abstract: Our objective was to investigate the influence of hypertension on N-acetylaspartate (NAA) and choline (Cho) ratios in brain tissues in a community-dwelling elderly population. Brain flexibility was also evaluated with regard to the same metabolite ratios. Proton magnetic resonance spectroscopy (MRS) and the Trail Making Test (TMT) were performed in 80 subjects (75.7 +/- 4 years old) from the Three-City Study. Fifty-eight participants had hypertension. The NAA/creatine (Cr) and Cho/Cr ratios were obtained in the insular cortex, the thalami and the deep periventricular white matter. In addition, the B-A score of the TMT was evaluated. Uniand multi-variate ana…
Asymmetric metabolic profile in mesial temporal lobes: Localized H-1 MR spectroscopy in healthy right-handed and non-right-handed subjects
International audience; Abstract: PURPOSE: To determine a possible asymmetric metabolic profile in right-handed and non-right-handed healthy subjects by comparing proton spectra from temporal lobes. MATERIALS AND METHODS: Twenty-eight healthy adults (17 right-handers, 11 non-right-handers) underwent magnetic resonance (MR) imaging and single-voxel MR spectroscopy. N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) peak areas were measured. RESULTS: Volume of hippocampal formations was larger on the right in right-handers (right volume: 4.04 cm(3) +/- 0.67 vs left volume: 3.84 cm(3) +/- 0.62; P = .00004) and in non-right-handers (right volume: 4.22 cm(3) +/- 0.78 vs left volume: 4.05 …
Multi-modal image fusion for small animal studies in in-line PET /3T MRI
Congrès sous l’égide de la Société Française de Génie Biologique et Médical (SFGBM).; National audience; In the framework of small animal multi-modal imaging, the current progression of the IMAPPI project is illustrated by the design of an in-line PET/MRI prototype, coupled to a dedicated multi-resolution registration method allowing the robust fusion of data coming from both modalities. The first results show a good alignment of the data from tumor imaging at the level of the abdomen.
Relationship between fragmented QRS and no-reflow, infarct size, and peri-infarct zone assessed using cardiac magnetic resonance in patients with myocardial infarction.
International audience; BACKGROUND: The relation between fragmented QRS complex (fQRS) and cardiac magnetic resonance parameters is poorly documented in ischemic cardiopathy. METHODS: Among 209 consecutive patients, those with fQRS were compared with those without fQRS. Cardiac magnetic resonance studies with late gadolinium-enhanced sequences were done during the week after acute myocardial infarction. RESULTS: fQRS was present in 113 (54%) patients, and associated with a significantly lower left ventricular ejection fraction, increased left ventricular volumes, a larger infarct size (IS), and a larger peri-infarct zone. Microvascular obstruction was more frequent in patients with fQRS (62…
MANOTA: a promising bifunctional chelating agent for copper-64 immunoPET
International audience; Improved bifunctional chelating agents (BFC) are required for copper-64 radiolabelling of monoclonal antibodies (mAbs) under mild conditions to yield stable, target-specific imaging agents. Four different bifunctional chelating agents (BFC) were evaluated for Fab (Fragment antigen binding) conjugation and radiolabelling with copper-64. Two DOTA- (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and two NOTA- (1,4,7-triazacyclononane-1,4,7-triacetic acid) derivatives bearing a p-benzyl-isothiocyanate group were conjugated to Fab-trastuzumab - which targets the HER2/neu receptor - and the average number of chelators attached ranged from 2.4 to 4.3 macrocycles …
[18F]FDG-PET predicts complete pathological response of breast cancer to neoadjuvant chemotherapy
To evaluate, in breast cancer patients treated by neoadjuvant chemotherapy, the predictive value of reduction in FDG uptake with regard to complete pathological response (pCR).Forty-seven women with non-metastatic, non-inflammatory, large or locally advanced breast cancer were included. Tumour uptake of FDG was evaluated before and after the first course of neoadjuvant chemotherapy. Four indices were used: maximal and average SUV without or with correction by body surface area and glycaemia (SUV(max), SUV(avg), SUV(max-BSA-G) and SUV(avg-BSA-G), respectively). The predictive value of reduction in FDG uptake with respect to pCR was studied by logistic regression analysis. Relationships betwe…
Changes in 18F-FDG tumor metabolism after a first course of neoadjuvant chemotherapy in breast cancer: influence of tumor subtypes
BACKGROUND The aim of this study is to evaluate the impact of the different breast cancer subtypes on the tumor (18)F-FDG uptake at baseline and on its changes after the first course of neoadjuvant chemotherapy (NAC). PATIENTS AND METHODS One hundred and fifteen women with newly diagnosed, large or locally advanced breast cancer undergoing NAC were included. Estrogen receptor (ER), progesterone receptor (PR) and HER2 status were used to define three major tumor subtypes: triple negative (TN) (ER-/PR-/HER2-), luminal (ER+ and/or PR+; HER2-) and HER2 positive (HER2+). Using Fluorine-18 fluorodeoxyglucose positron emission tomography, the tumoral standard uptake value (SUV) maximal index was m…
Utility of Cardiac Magnetic Resonance to assess association between admission hyperglycemia and myocardial damage in patients with reperfused ST-segment elevation myocardial infarction
Abstract Aims to investigate the association between admission hyperglycemia and myocardial damage in patients with ST-segment elevation myocardial infarction (STEMI) using Cardiac Magnetic Resonance (CMR). Methods We analyzed 113 patients with STEMI treated with successful primary percutaneous coronary intervention. Admission hyperglycemia was defined as a glucose level ≥ 7.8 mmol/l. Contrast-enhanced CMR was performed between 3 and 7 days after reperfusion to evaluate left ventricular function and perfusion data after injection of gadolinium-DTPA. First-pass images (FP), providing assessment of microvascular obstruction and Late Gadolinium Enhanced images (DE), reflecting the extent of in…
18F-Choline PET/CT and multiparametric MRI for the detection of local recurrence of prostate cancer initially treated by radiotherapy: comparison with systematic transperineal mapping biopsy
International audience
Dynamic 4D Blood Flow Representation in the Aorta and Analysis from Cine-MRI in Patients
International audience; Abstract: Natural evolution of aortic disease is characterized by a diameter increase that can result in aortic dissection or rupture. Currently the evaluation of risk of rupture or dissection is based on the size of the aorta. However, this parameter is not always relevant and it appears necessary to define new parameters. In this perspective, 3D velocity imaging acquired with ECG gated velocity-encoded cine-MRI allows the aortic blood flow study. As the acquired images are not directly usable, the present study proposes a 4D-representation Of aortic blood flow in order to optimize the visualization of the particularities of non-laminar flow within the aorta. Image …
Compliance and Pulse Wave Velocity Assessed by MRI Detect Early Aortic Impairment in Young Patients With Mutation of the Smooth Muscle Myosin Heavy Chain
Purpose To evaluate aortic elasticity with MRI on young asymptomatic individuals with mutation of the smooth muscle myosin heavy chain in whom aortic enlargement is not present. Materials and Methods Aortic compliance, aortic distensibility, and pulse wave velocity (PWV) were semiautomatically measured from MRI in 8 asymptomatic subjects having a mutation of the MYH11 gene (M+) and 21 nonmutated relatives (M−) of similar age, sex, and blood pressure characteristics. Results Despite a similar aortic diameter in both groups, the aortic compliance and distensibility were significantly lower in M+ subjects compared with M− (0.84 ± 0.33 versus 2.03 ± 0.54 mm2/mmHg, 1.18 ± 0.62 10−3 versus 5.11 ±…
Role of Positron Emission Tomography for the Monitoring of Response to Therapy in Breast Cancer
Abstract This review considers the potential utility of positron emission tomography (PET) tracers in the setting of response monitoring in breast cancer, with a special emphasis on glucose metabolic changes assessed with 18F-fluorodeoxyglucose (FDG). In the neoadjuvant setting of breast cancer, the metabolic response can predict the final complete pathologic response after the first cycles of chemotherapy. Because tumor metabolic behavior highly depends on cancer subtype, studies are ongoing to define the optimal metabolic criteria of tumor response in each subtype. The recent multicentric randomized AVATAXHER trial has suggested, in the human epidermal growth factor 2-positive subtype, a …
Bone metastasis of a breast cancer detected by 3'-deoxy-3'-18F-fluorothymidine PET/CT
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Influence of age and sex on aortic distensibility assessed by MRI in healthy subjects
International audience; Abstract: Magnetic resonance imaging (MRI) is particularly well adapted to the evaluation of aortic distensibility. The calculation of this parameter, based on the change in vessel cross-sectional area per unit change in blood pressure, requires precise delineation of the aortic wall on a series of cine-MR images. Firstly, the study consisted in validating a new automatic method to assess aortic elasticity. Secondly, aortic distensibility was studied for the ascending and descending thoracic aortas in 26 healthy subjects. Two homogeneous groups were available to evaluate the influence of sex and age (with an age limit value of 35 years). The automatic postprocessing …
Realignment of myocardial first-pass MR perfusion images using an automatic detection of the heart-lung interface
International audience; Abstract: Magnetic resonance first-pass imaging of a bolus of contrast agent is well adapted to distinguish normal and hypoperfused areas of the myocardium. In most cases, the signal intensity-time curves in user defined regions of interest (ROI) are studied. As image acquisition is ECG-gated, the images are acquired at the same moment in the cardiac cycle, and the basic shape of the heart is similar from one view to the next. However, superficial respiratory motion can displace the heart in the short-axis plane. The aim of this study is to correct for the respiratory motion of the heart by performing an automatic realignment of the myocardial ROI based on a method t…
Pattern of occult nodal relapse diagnosed with 18F-fluoro-choline PET/CT in prostate cancer patients with biochemical failure after prostate-only radiotherapy
Abstract Introduction The purpose of this study was to describe the pattern of nodal relapse with 18 F-fluoro-choline (FCH) Positron Emission Tomography/Computerized Tomography (PET/CT) in prostate cancer patients after radiotherapy. Materials and methods Eighty-three patients had a FCH PET/CT at time of biochemical failure. Of 65 patients with positive findings, 33 had positive nodes. This analysis included 31 patients who had undergone prior prostate-only radiotherapy with or without a prior radical prostatectomy. Each FCH positive node was assigned to a lymph node station with respect to the CTV defined by the RTOG guidelines (CTV RTOG ). 3D mapping was performed after each node was manu…
Integrated PET/MRI in preclinical studies State of the art
International audience; The exquisite tissue contrast of magnetic resonance imaging (MRI), the absence of ionising radiation and the opportunity to obtain new molecular and functional data have strengthened the enthusiasm for coupling MRI rather than computed tomography (CT) to positron emission tomography (PET). When reviewing the current literature one might be surprised by the almost unlimited diversity of what is placed under the name of PET/MRI in the articles. The magnetic field is varying from 0.3 Tesla (T) to 9.4 T, the size of the bore varies also from the wide bore of clinical scanners to volumes limited to a few tens of mL. Many preclinical studies are performed using separate PE…
Should aortic stiffness be evaluated in thoracic aortic aneurysm/dissection relatives to prevent risks?
International audience
Correlation between clinical prognostic factors and MR spectroscopy-based biomarkers determined at 3.0 T without endorectal coils for patients with localised prostate cancer
International audience
MR imaging of the heart in patients after myocardial infarction: effect of increasing intersection gap on measurements of left ventricular volume, ejection fraction, and wall thickness.
International audience; Abstract: PURPOSE: To determine the extent to which the number of planes imaged at magnetic resonance (MR) imaging could be reduced without modifying the volume and thickness of the left ventricle. MATERIALS AND METHODS: Sixty-one patients were examined after a myocardial infarction. The whole left ventricle was imaged by using 5-mm contiguous breath-hold cine MR short-axis sections with no gap (SA(ng)) (two-dimensional fast low-angle shot sequence, 9/4.8 [repetition time msec/echo time msec]). The effect of omitting in two (short-axis sections with 5-mm gap [SA(5mm)]) or two sections in three(short-axis sections with 10-mm gap [SA(10mm)]) was studied. RESULTS: In th…
Evaluation automatique du remodelage ventriculaire gauche à partir d'imagerie multimodale en pré-clinique et clinique.
Automatic evaluation of the left ventricular remodelling from MRI in pre-clinical and clinical practice.
Left ventricular ejection fraction calculation from automatically selected and processed diastolic and systolic frames in short-axis cine-MRI
International audience; Abstract: The calculation of the left ventricular ejection fraction (LVEF) is dependent upon the accurate measurement of diastolic and systolic left ventricular volumes. Although breath-hold cine magnetic resonance imaging (MRI) allows coverage of the whole cardiac cycle with an excellent time resolution, many authors rely on the visual selection of diastolic and the systolic short-axis slices in order to reduce the postprocessing time. An automatic method was developed to detect the endocardial contour on each image, allowing an automatic selection of the systolic frame. The calculated ejection fraction was compared with radionuclide ventriculography (RNV). Sixty-fi…
Automatic fuzzy classification of the washout curves from magnetic resonance first-pass perfusion imaging after myocardial infarction.
International audience; Abstract: Objectives: We sought to investigate the diagnostic ability of cardiac magnetic resonance imaging (MRI) perfusion in acute reper-fused myocardial infarction. The study used fuzzy logic to automatically classify signal intensity-time curves from myocardial segments into 3 categories: normal, hypointense, and Hyperintense. Materials and Methods: Thirty-eight patients with myocardial infarction underwent short-axis cine-MRI and contrast-enhanced MRI to provide data on wall thickening and the transmural extent of infarction. Of these, 17 had a second cardiac MRI to ascertain the functional recovery in each segment. Results: The fuzzy logic based classification …
Automatic fuzzy contouring and parameter extraction of the left ventricle from multi-slice MR Images.
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Multi-variate analysis predicts clinical outcome 30 days after middle cerebral artery infarction
BACKGROUND AND PURPOSE: To evaluate the functional prognostic value of proton magnetic resonance spectroscopy performed within the 5 days of an infarction of the middle cerebral artery territory, compared with previously demonstrated prognostic factors. METHODS: Proton magnetic resonance spectroscopy was performed on 77 consecutive non-comatosed patients during the acute stage of middle cerebral artery infarction. The functional status was determined for each patient via the Orgogozo score. Proton magnetic resonance spectroscopic data were acquired in the infarction and in contra-lateral normal tissue and the results were expressed as metabolite ratios. Correlations were evaluated between t…
IMPAIRMENT OF DIASTOLIC FUNCTION DURING SHORT-TERM ANTHRACYCLINE CHEMOTHERAPY
International audience; Abstract: Objective-To assess the early changes in left ventricular diastolic and systolic function due to anthracycline treatment. Design-A prospective study of cardiac function by radionuclide angiography in adults before and one month after the end of anthracycline treatment. Patients-60 patients without cardiac disease treated with chemotherapy containing anthracycline. Methods-Cardiac function was assessed by radionuclide measurement throughout treatment. Ejection fraction, peak ejection rate, time to peak ejection rate, filling rate, and time to peak filling rate were measured before and after treatment, To normalise radionuclide measurements of the left ventri…
Evaluation of breast tumor blood flow with dynamic first-pass 18F-FDG PET/CT: comparison with angiogenesis markers and prognostic factors
The purpose of this study was to prospectively evaluate the relationship between tumor blood flow and glucose metabolism as evaluated by dynamic first-pass (18)F-FDG PET and by proliferation and endothelial pathologic markers in the setting of newly diagnosed breast cancer.Forty patients were prospectively included. Biopsy samples of each tumor were used to assess the Ki67 index of proliferation and immunostaining for CD34 (a panendothelial cell marker) and CD105 (a proliferation-related endothelial cell marker). All patients underwent (18)F-FDG PET/CT at least 1 wk after sample biopsy and before any treatment. A dynamic 2-min acquisition was performed immediately after intravenous injectio…
Indications de l'IRM cardiaque.
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Mutations in myosin heavy chain 11 cause a syndrome associating thoracic aortic aneurysm/aortic dissection and patent ductus arteriosus
We have recently described two kindreds presenting thoracic aortic aneurysm and/or aortic dissection ( TAAD) and patent ductus arteriosus (PDA)(1,2) and mapped the disease locus to 16p12.2-p13.13 (ref. 3). We now demonstrate that the disease is caused by mutations in the MYH11 gene affecting the C-terminal coiled-coil region of the smooth muscle myosin heavy chain, a specific contractile protein of smooth muscle cells (SMC). All individuals bearing the heterozygous mutations, even if asymptomatic, showed marked aortic stiffness. Examination of pathological aortas showed large areas of medial degeneration with very low SMC content. Abnormal immunological recognition of SM-MHC and the colocal…
ProstateAnalyzer: web-based medical application for the management of prostate cancer using multiparametric MR imaging
Objectives: In this paper, we present ProstateAnalyzer, a new web-based medical tool for prostate cancer diagnosis. ProstateAnalyzer allows the visualization and analysis of magnetic resonance images (MRI) in a single framework. Methods: ProstateAnalyzer recovers the data from a PACS server and displays all the associated MRI images in the same framework, usually consisting of 3D T2-weighted imaging for anatomy, dynamic contrast-enhanced MRI for perfusion, diffusion-weighted imaging in the form of an apparent diffusion coefficient (ADC) map and MR Spectroscopy. ProstateAnalyzer allows annotating regions of interest in a sequence and propagates them to the others. Results: From a representat…
Familial thoracic aortic aneurysm/dissection with patent ductus arteriosus: genetic arguments for a particular pathophysiological entity.
International audience; Thoracic aortic aneurysm and aortic dissection (TAA and AD) are an important cause of sudden death. Familial cases could account for 20% of all cases. A genetic heterogeneity with two identified genes (FBN1 and COL3A1) and three loci (3p24-25 or MFS2/TAAD2, 5q13-q14 and 11q23.2-24) has been shown previously. Study of a single family composed of 179 members with an abnormally high occurrence of TAA/AD disease. A total of 40 subjects from three generations were investigated. In addition to five cases of stroke and three cases of sudden death, there were four cases of AD and four cases of TAA in adults. In all, 11 cases of patent ductus arteriosus (PDA) were observed, t…
EARLY CHOLINE LEVELS FROM 3-TESLA MR SPECTROSCOPY AFTER EXCLUSIVE RADIATION THERAPY IN PATIENTS WITH CLINICALLY LOCALIZED PROSTATE CANCER ARE PREDICTIVE OF PLASMATIC LEVELS OF PSA AT 1 YEAR
International audience; Abstract: Purpose: To investigate the time course response of prostate metabolism to irradiation using magnetic resonance spectroscopy (MRS) at 3-month intervals and its impact on biochemical control. Methods and Materials: Between January 2008 and April 2010, 24 patients with localized prostate cancer were prospectively enrolled in the Evaluation of the Response to Irradiation with MR Spectroscopy (ERIS) trial. All the patients had been treated with intensity-modulated radiation therapy with or without long-term adjuvant hormonal therapy (LTHT) and underwent 3-T MRS and prostate-specific antigen (PSA) assays at baseline and every 3 months thereafter up to 12 months.…
Influence of Software Tool and Methodological Aspects of Total Metabolic Tumor Volume Calculation on Baseline [18F]FDG PET to Predict Survival in Hodgkin Lymphoma
Aim To investigate the respective influence of software tool and total metabolic tumor volume (TMTV0) calculation method on prognostic stratification of baseline 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography ([18F]FDG-PET) in newly diagnosed Hodgkin lymphoma (HL). Methods 59 patients with newly diagnosed HL were retrospectively included. [18F]FDG-PET was performed before any treatment. Four sets of TMTV0 were calculated with Beth Israel (BI) software: based on an absolute threshold selecting voxel with standardized uptake value (SUV) >2.5 (TMTV02.5), applying a per-lesion threshold of 41% of the SUVmax (TMTV041) and using a per-patient adapted threshold based on SUVmax of the…
DOTAGA-anhydride: a valuable building block for the preparation of DOTA-like chelating agents.
International audience; A DOTA derivative that contains an anhydride group was readily synthesized by reacting DOTAGA with acetic anhydride and its reactivity was investigated. Opening the anhydride with propylamine led to the selective formation of one of two possible regioisomers. The structure of the obtained isomer was unambiguously determined by 1D and 2D NMR experiments, including COSY, HMBC, and NOESY techniques. This bifunctional chelating agent offers a convenient and attractive approach for labeling biomolecules and, more generally, for the synthesis of a large range of DOTA derivatives. The scope of the reaction was extended to prepare DOTA-like compounds that contained various f…
Identification of Biomarkers Including 18FDG-PET/CT for Early Prediction of Response to Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer.
Abstract Purpose: To investigate the value of the metabolic tumor response assessed with 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), compared with clinicobiologic markers to predict pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) in women with triple-negative breast cancer (TNBC). Experimental Design: Fifty consecutive women with TNBC and an indication for NAC were prospectively included. Different pretreatment clinical, biologic, and pathologic biomarkers, including SBR grade, the Ki-67 proliferation index, androgen receptor expression, EGF receptor (EGFR), and cytokeratin 5/6 staining, were assessed. Tumor glucose metabolism at baseline and its chan…
Magnetic resonance image segmentation and heart motion tracking with an active mesh based system
International audience; Abstract: The work presented here relates to a method fir motion tracking in sequences of medical images. The purpose is to. quantify the general motions and the local deformations of a beating heart during a cardiac cycle. In order to achieve this goal, we first tessellate the,first image of the sequence into triangular patches. A Delaunay triangulation is applied to find the optimal set of triangles describing this image, giving a mesh covering the organs. One imposes the contours of the organs to correspond to edges of triangles so that each part of the heart (left ventricle, right ventricle, myocardium) can he described as a different set of triai izles, each set…
Cerebral metabolism after transient ischemic attack. A 1H MR spectroscopy study
International audience; Abstract: Metabolic changes induced by cerebral infarction or by stenosis and occlusion of the internal carotid artery have been previously described in 1H Magnetic Resonance Spectroscopy (1H MRS). These changes are essentially characterized by decreased N-acetyl-aspartate (NAA) and increased lactate concentration. Little is known about the metabolic changes observed in the three days following a transient ischemic attack (TIA) in the absence of stenosis or occlusion of the internal carotid artery, and without visible infarction on Magnetic Resonance imaging (MRI). We studied five patients with a TIA lasting between 30 min and 3 h, affecting the sensory and motor fun…
LEFT-VENTRICULAR CONTRACILITY AFTER HYPOTHERMIC PRESERVATION - PREDICTIVE VALUE OF P-31 - NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY
International audience; Abstract: Early graft failure accounts for a substantial portion of the mortality after heart transplantation. This factor underscores the need for the development of reliable methods for predicting graft performance and thus ensuring optimal clinical outcome. The aim of this study was to describe the link between myocardial metabolism evaluated throughout preservation with the use of phosphorus 31-nuclear magnetic resonance spectroscopy and ventricular contractility after reperfusion. Thirteen pig hearts were excised and preserved from 3 to 12 hours with clinical techniques. During preservation the hearts underwent, phosphorus 31-nuclear magnetic resonance spectrosc…
Automatic Detection of Left Ventricular Contours from Cardiac Cine Magnetic Resonance Imaging Using Fuzzy Logic
Gated cardiac cine magnetic resonance imaging provides accurate dynamic data of the left ventricular function. However, the manual extraction of important physiologic parameters such as myocardium wall thickness and left ventricular volumes is invariably time consuming and subjective. To reduce the variability and time constraints inherent in observer contour tracing, the authors developed an automatic left ventricle contour-detection method.The purpose was to apply fuzzy logic-based automatic contour detection to identification of endocardial and epicardial borders in short-axis magnetic resonance images. The automatic contouring was compared with manual tracing using the calculated ejecti…
MR-based biomarkers in the diagnosis and the evaluation of the therapeutic response to radiotherapy (ETRR) in prostatic carcinoma (PCa): Implementation of clinical and experimental approaches
e16136 Background: ETRR in PCa remains a challenging task. New biomarkers in the form of metabolites, detected with Proton Magnetic Resonance Spectroscopy (1H-MRS), and quantitative Apparent Diffusion Coefficient (ADC), determined with Diffusion-Weighted Magnetic Resonance Imaging, could be of value in the ETRR for PCa. Methods: Twenty-one men with biopsy proven localized PCa were examined before external radiotherapy. 3D-1H-MRS was performed at 3.0T without endorectal coils. The delivered radiotherapy dose was 78 Gy in 39 fractions with 6 MV photons. MR follow-up examinations up to 36 months post-radiotherapy were performed. For the pre-clinical study, healthy rat prostate was studied in …