Publications by authors named "Melhem E"

Background: Glioblastoma is the most aggressive adult primary brain cancer, characterized by significant heterogeneity, posing challenges for patient management, treatment planning, and clinical trial stratification.

Methods: We developed a highly reproducible, personalized prognostication and clinical subgrouping system using machine learning (ML) on routine clinical data, MRI, and molecular measures from 2,838 demographically diverse patients across 22 institutions and 3 continents. Patients were stratified into favorable, intermediate, and poor prognostic subgroups (I, II, III) using Kaplan-Meier analysis (Cox proportional model and hazard ratios [HR]).

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  • The modified Stoppa approach is becoming a leading technique in surgery for pelvic ring and acetabulum but can pose risks, such as vascular injury.
  • This study analyzed patients' CT angiography data to measure the division levels of common iliac vessels and their variability related to certain anatomical landmarks.
  • Results showed significant differences in the right and left arterial division levels, highlighting the need for careful assessment of iliac vessel morphology to reduce bleeding risks during surgery.
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Background And Objectives: Magnetic resonance-guided focused ultrasound (MRgFUS) central lateral thalamotomy (CLT) has not yet been validated for treating refractory neuropathic pain (NP). Our aim was to assess the safety and potential efficacy of MRgFUS CLT for refractory NP.

Methods: In this prospective, nonrandomized, single-arm, investigator-initiated phase I trial, patients with NP for more than 6 months related to phantom limb pain, spinal cord injury, or radiculopathy/radicular injury and who had undergone at least one previous failed intervention were eligible.

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Purpose: Acetabular fractures are associated to an increased risk of subsequent hip osteoarthritis. The only available score for post-operative reduction assessment in acetabular fractures (Matta's score) is x-ray based. CT-scan was shown superior to X-rays in post-operative reduction assessment.

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  • Glioblastoma is a common and aggressive brain tumor, but many existing public datasets are limited by factors like small sample sizes and inconsistent data quality.
  • The UPenn-GBM dataset addresses these issues by providing a comprehensive collection of data from 630 patients, including advanced MRI scans and detailed clinical information.
  • This dataset aims to facilitate better research in glioblastoma by enabling more accurate predictive and diagnostic studies through its high-quality imaging and annotations.
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Objective: MR-guided focused ultrasound (MRgFUS) is increasingly being used to treat patients with essential tremor (ET) and Parkinson's disease (PD) with thalamotomy and pallidotomy, respectively. Pallidotomy is performed off-center within the cranium compared to thalamotomy and may present challenges to therapeutic lesioning due to this location. However, the impact of target location on treatment efficiency and ability to create therapeutic lesions has not been studied.

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Background: Arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) denoising through deep learning (DL) often faces insufficient training data from patients. One solution is to train DL models using healthy subjects' data which are more widely available and transfer them to patients' data.

Purpose: To evaluate the transferability of a DL-based ASL MRI denoising method (DLASL).

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Stem cell and immune cell therapies are being investigated as a potential therapeutic modality for CNS disorders, performing functions such as targeted drug or growth factor delivery, tumor cell destruction, or inflammatory regulation. Despite promising preclinical studies, delivery routes for maximizing cell engraftment, such as stereotactic or intrathecal injection, are invasive and carry risks of hemorrhage and infection. Recent developments in MRI-guided focused ultrasound (MRgFUS) technology have significant implications for treating focal CNS pathologies including neurodegenerative, vascular and malignant processes.

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Hyperpolarized magnetic resonance spectroscopic imaging (MRSI) of [1-C]pyruvate metabolism has previously been used to assess the effects of traumatic brain injury (TBI) in rats. Here, we show that MRSI can be used in conjunction with dichloroacetate to measure the phosphorylation state of pyruvate dehydrogenase (PDH) following mild-to-moderate TBI, and that measurements can be repeated in a longitudinal study to monitor the course of injury progression and recovery. We found that the level of C-bicarbonate and the bicarbonate-to-lactate ratio decreased on the injured side of the brain four hours after injury and continued to decrease through day 7.

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Introduction: The use of per-operative cone beam tomography imaging for displaced acetabular fractures yields increased post-operative articular reduction accuracy. This study evaluates the need for total hip replacement (THR) and hip-related functional outcomes in patients with displaced acetabular fractures treated with O-ARM guidance compared to those treated under C-ARM guidance.

Materials And Methods: This is a prospective matched cohort study.

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Purpose: Acetabular fractures are frequently associated with other skeletal injuries, particularly knee injuries. This study aims to evaluate the relationship between posterior acetabular fractures and knee injury, analyzing its patterns and association with other injuries.

Methods: This is a retrospective monocentric study in a tertiary referral centre.

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Background And Purpose: Transcranial MR imaging-guided focused ultrasound is a promising novel technique to treat multiple disorders and diseases. Planning for transcranial MR imaging-guided focused ultrasound requires both a CT scan for skull density estimation and treatment-planning simulation and an MR imaging for target identification. It is desirable to simplify the clinical workflow of transcranial MR imaging-guided focused ultrasound treatment planning.

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Objective: Magnetic resonance-guided focused ultrasound (MRgFUS) ablation of the globus pallidus interna (GPi) is being investigated for the treatment of advanced Parkinson's disease symptoms. However, GPi lesioning presents unique challenges due to the off-midline location of the target. Furthermore, it remains uncertain whether intraprocedural MR thermometry data can predict final lesion characteristics.

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Introduction: Acetabular and pelvic fracture accounts for 1.5% of fractures in adults and 2-5% of fractures requiring hospital admission. Several national-level epidemiological studies have been conducted outside France, but French national data are not known.

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Background: Magnetic resonance-guided focused ultrasound ablation of the thalamic ventral intermediate nucleus is a safe and effective treatment for medically refractory essential tremor. However, indirect targeting of the ventral intermediate nucleus using stereotactic coordinates from normal neuroanatomy can be inefficient. We therefore evaluated the feasibility of supplementing this method with direct targeting of the dentato-rubro-thalamic tract.

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Elevated levels of choline are generally emphasized as marker of increased cellularity and cell membrane turnover in gliomas. In this study, we investigated the incidence rate of lack of choline/creatine and choline/water elevation in a population of grade I-III gliomas. A cohort of 41 patients with histopathologically confirmed gliomas underwent multi-voxel proton magnetic resonance spectroscopy on a 3 T magnetic resonance system prior to treatment.

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Transcranial MRI-guided focused ultrasound (tcMRgFUS) is increasingly used to non-invasively treat a wide variety of neurological disorders including essential tremors, Parkinson's disease, and neuropathic pain. Although this treatment is an MRI-guided procedure, the current pre-treatment screening and planning involve a CT of the head to obtain 3D skull images. These images are necessary for estimating the proportion of absorbed energy and the acoustic phase shift associated with the skull and determining the transmit energy of ultrasonic waves to create thermal lesions at a desired focal spot.

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Traumatic brain injury (TBI) is known to cause perturbations in the energy metabolism of the brain, but current tests of metabolic activity are only indirect markers of energy use or are highly invasive. Here we show that hyperpolarized C magnetic resonance spectroscopic imaging (MRSI) can be used as a direct, non-invasive method for studying the effects of TBI on energy metabolism. Measurements were performed on rats with moderate TBI induced by controlled cortical impact on one cerebral hemisphere.

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Background And Purpose: Synthetic MR imaging enables reconstruction of various image contrasts from 1 scan, reducing scan times and potentially providing novel information. This study is the first large, prospective comparison of synthetic-versus-conventional MR imaging for routine neuroimaging.

Materials And Methods: A prospective multireader, multicase noninferiority trial of 1526 images read by 7 blinded neuroradiologists was performed with prospectively acquired synthetic and conventional brain MR imaging case-control pairs from 109 subjects (mean, 53.

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Background: Extensive wound dehiscence and wide plate and screw exposure in the early weeks following orthopaedic surgery in children is usually managed either by extensive debridement, lavage and secondary closure or hardware removal and external fixation.

Patients: Three children with LCP plate and screws exposure were managed by simple repetitive debridement and local wound care without any IV antibiotics, nor secondary closure or hardware removal. All three cases occurred in the tibia, one following tibial osteotomy in lateral hemimelia with a long history of previous surgeries, one following wide excision of a tibial Ewing sarcoma with chemo- and radiotherapy, and the third following wide excision of a 12cm necrotic tibial segment due to chronic osteomyelitis.

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Purpose: For children with sickle cell disease (SCD) and at low risk category of stroke, we aim to build a predictive model to differentiate those with decline of intelligence-quotient (IQ) from counterparts without decline, based on structural magnetic-resonance (MR) imaging volumetric analysis.

Materials And Methods: This preliminary prospective cohort study included 25 children with SCD, homozygous for hemoglobin S, with no history of stroke and transcranial Doppler mean velocities below 170cm/s at baseline. We administered the Kaufman Brief Intelligence Test (K-BIT) to each child at yearly intervals for 2-4 years.

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