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Papers by Julien Savatovsky
RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-680-C-10
RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-680-C-10
RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-680-C-10
RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-680-C-10
Journal of Neuroradiology, 2021
Diagnostic and Interventional Imaging, 2021
PURPOSE The purpose of this study was to assess the inter-slice radiomic feature repeatability in... more PURPOSE The purpose of this study was to assess the inter-slice radiomic feature repeatability in ultrasound imaging and the impact of preprocessing using intensity standardization and grey-level discretization to help improve radiomics reproducibility. MATERIALS AND METHODS This single-center study enrolled consecutive patients with an orbital lesion who underwent ultrasound examination of the orbit from December 2015 to July 2019. Two images per lesion were randomly assigned to two subsets. Radiomic features were extracted and inter-slice repeatability was assessed using the intraclass correlation coefficient (ICC) between the subsets. The impact of preprocessing on feature repeatability was assessed using image intensity standardization with or without outliers removal on whole images, bounding boxes or regions of interest (ROI), and fixed bin size or fixed bin number grey-level discretization. Number of inter-slice repeatable features (ICC ≥0.7) between methods was compared. RESULTS Eighty-eight patients (37 men, 51 women) with a mean age of 51.5 ± 17 (SD) years (range: 20-88 years) were enrolled. Without preprocessing, 29/101 features (28.7%) were repeatable between slices. The greatest number of repeatable features (41/101) was obtained using intensity standardization with outliers removal on the ROI and fixed bin size discretization. Standardization performed better with outliers removal than without (P < 0.001), and on ROIs than on native images (P < 0.001). Fixed bin size discretization performed better than fixed bin number (P = 0.008). CONCLUSION Radiomic features extracted from ultrasound images are impacted by the slice and preprocessing. The use of intensity standardization with outliers removal applied to the ROI and a fixed bin size grey-level discretization may improve feature repeatability.
Diagnostic and Interventional Imaging, 2021
PURPOSE The purpose of this study was to describe the MRI characteristics of intralabyrinthine sc... more PURPOSE The purpose of this study was to describe the MRI characteristics of intralabyrinthine schwannoma (ILS) on post contrast three-dimensional (3D) fluid-attenuation-inversion-recovery (FLAIR) images obtained four hours after intravenous administration of a gadolinium-based contrast agent (4h-3D-FLAIR). MATERIALS AND METHODS This IRB-approved retrospective multi-center study included patients presenting with typical ILS from January 2016 to October 2020. All medical charts were systematically collected. All MRI examinations, including 4h-3D-FLAIR images, were reviewed by two board-certified neuroradiologists. Main outcome measures were location, signal intensity and associated anomalies of ILS. RESULTS Twenty-seven out of 8730 patients (0.31%) referred for the investigation of a cochleovestibular disorder had a final diagnosis of ILS. There were 13 men and 14 women with a mean age of 52 ± 17 (SD) years (age range: 20-86 years). The most common clinical presentation was unilateral progressive sensorineural hearing loss (16/27; 59%). All ILS were unilateral and 15 (15/27; 55%) were intracochlear. All ILS presented as a hypointense filling defect within the labyrinth on T2-weighted images that enhanced on post-contrast T1-weighted images. On 4h-3D-FLAIR images, all ILS presented as a hypointense filling defect, associated with diffuse perilymphatic hyperintensity. Two patients (2/27; 7%) presented with ipsilateral endolymphatic hydrops. CONCLUSION ILS displays consistent features on post-contrast 4h-3D-FLAIR images. ILS should not be confused with endolymphatic hydrops and requires a systematic analysis of the corresponding T2-weighted images.
European Radiology, 2020
Objectives To determine the diagnostic accuracy of MRI intravoxel incoherent motion (IVIM) when c... more Objectives To determine the diagnostic accuracy of MRI intravoxel incoherent motion (IVIM) when characterizing orbital lesions, which is challenging due to a wide range of locations and histologic types. Methods This IRB-approved prospective single-center study enrolled participants presenting with an orbital lesion undergoing a 3-T MRI prior to surgery from December 2015 to July 2019. An IVIM sequence with 15 b values ranging from 0 to 2000 s/mm 2 was performed. Two neuroradiologists, blinded to clinical data, individually analyzed morphological MRIs. They drew one region of interest inside each orbital lesion, providing apparent diffusion coefficient (ADC), true diffusion coefficient ( D ), perfusion fraction ( f ), and pseudodiffusion coefficient ( D *) values. T test, Mann-Whitney U test, and receiver operating characteristic curve analyses were performed to discriminate between orbital lesions and to determine the diagnostic accuracy of the IVIM parameters. Results One hundred fifty-six participants (84 women and 72 men, mean age 54.4 ± 17.5 years) with 167 orbital lesions (98/167 [59%] benign lesions including 54 orbital inflammations and 69/167 [41%] malignant lesions including 32 lymphomas) were included in the study. ADC and D were significantly lower in malignant than in benign lesions: 0.8 × 10 −3 mm 2 /s [0.45] versus 1.04 × 10 −3 mm 2 /s [0.33], p < 0.001, and 0.75 × 10 −3 mm 2 /s [0.40] versus 0.98 × 10 −3 mm 2 /s [0.42], p < 0.001, respectively. D * was significantly higher in malignant lesions than in benign ones: 12.8 × 10 −3 mm 2 /s [20.17] versus 7.52 × 10 −3 mm 2 /s [7.57], p = 0.005. Area under curve was of 0.73, 0.74, 0.72, and 0.81 for ADC, D , D *, and a combination of D , f , and D *, respectively. Conclusions Our study showed that IVIM might help better characterize orbital lesions. Key Points • Intravoxel incoherent motion (IVIM) helps clinicians to assess patients with orbital lesions. • Intravoxel incoherent motion (IVIM) helps clinicians to characterize orbital lymphoma versus orbital inflammation. • Management of patients becomes more appropriate.
European Radiology, 2021
To determine the diagnostic performances of a single Dixon-T2-weighted imaging (WI) sequence comp... more To determine the diagnostic performances of a single Dixon-T2-weighted imaging (WI) sequence compared to a conventional protocol including T1-, T2-, and fat-suppressed T2-weighted MRI at 3 T when assessing thyroid eye disease (TED). This IRB-approved prospective single-center study enrolled participants presenting with confirmed TED from April 2015 to October 2019. They underwent an MRI, including a conventional protocol and a Dixon-T2WI sequence. Two neuroradiologists, blinded to all data, read both datasets independently and randomly. They assessed the presence of extraocular muscle (EOM) inflammation, enlargement, fatty degeneration, or fibrosis as well as the presence of artifacts. The Wilcoxon signed-rank test was used. Two hundred six participants were enrolled (135/206 [66%] women, 71/206 [34%] men, age 52.3 ± 13.2 years). Dixon-T2WI was significantly more likely to detect at least one inflamed EOM as compared to the conventional set (248/412 [60%] versus 228/412 [55%] eyes; (p = 0.02). Dixon-T2WI was more sensitive and specific than the conventional set for assessing muscular inflammation (100% versus 94.7% and 71.2% versus 68.5%, respectively). Dixon-T2WI was significantly less likely to show major or minor artifacts as compared to fat-suppressed T2WI (20/412 [5%] versus 109/412 [27%] eyes, p < 0.001, and 175/412 [42%] versus 257/412 [62%] eyes, p < 0.001). Confidence was significantly higher with Dixon-T2WI than with the conventional set (2.35 versus 2.24, p = 0.003). Dixon-T2WI showed higher sensitivity and specificity and showed fewer artifacts than a conventional protocol when assessing thyroid eye disease, in addition to higher self-reported confidence. • Dixon-T2WI has better sensitivity and specificity than a conventional protocol for assessing inflamed extraocular muscles in patients with thyroid eye disease. • Dixon-T2WI shows significantly fewer artifacts than fat-suppressed T2WI. • Dixon-T2WI is faster and is associated with significantly higher self-reported reader confidence as compared to a conventional protocol when assessing inflammatory extraocular muscles.
European Journal of Neurology, 2020
BACKGROUND Malignant MCA infarction (MMI) is a severe complication of acute ischemic stroke (AIS)... more BACKGROUND Malignant MCA infarction (MMI) is a severe complication of acute ischemic stroke (AIS). The aim of our study was to assess whether successful reperfusion after endovascular therapy (EVT) in AIS with clinical and imaging predictors of MMI decreased its occurrence. METHODS Data were collected between January 2014 and July 2018 in a monocentric prospective AIS registry of patients treated with EVT. Patients selected were under 65 years old, with severe anterior circulation AIS with a National Institutes of Health Stroke Scale (NIHSS) score higher than 15, a baseline Diffusion-Weighted Imaging- Alberta Stroke Program Early CT (DWI-ASPECT) score ≤6 and a baseline DWI lesion volume larger than 82ml within 6 hours of symptom onset. Successful reperfusion was defined as a Thrombolysis in Cerebral Ischemia (TICI) score ≥2b. Occurrence of MMI was the primary endpoint. RESULTS Sixty-six EVT-treated patients were included in our study. MMI occurred in 27 patients (42%). In unadjusted analysis, successful reperfusion was associated with fewer MMI (31.8% vs 65.0%; p=0.015) and with more 3-month favorable outcome (50% vs 20%, p=0.023). In multivariate analysis, successful reperfusion was associated with an adjusted OR (95%CI) of 0.35 (0.10 to 1.12) for MMI and 2.77 (0.84 to 10.43) for 3-month favorable outcome occurrence. CONCLUSIONS Early successful reperfusion performed in AIS patients with clinical and imaging predictors of MMI was associated with decreased MMI occurrence. Reperfusion status might be considered in evaluating the need for craniectomy in patients with early predictors of MMI.
Journal of Neuroradiology, 2020
Objectif Illustrer des modèles de mismatch clinicoradiologique concluant, éligibles à une revascu... more Objectif Illustrer des modèles de mismatch clinicoradiologique concluant, éligibles à une revascularisation urgente. Matériel et méthodes Étude de cas de patients présentant des accidents vasculaires cérébraux ischémiques (AVCI) traités par rtPA 0,9 mg au CHU Mohammed VI d'Oujda, dont la décision thérapeu
PLOS ONE, 2020
To compare peripapillary retinal nerve-fiber-layer (pRNFL) thickness, total retina macular volume... more To compare peripapillary retinal nerve-fiber-layer (pRNFL) thickness, total retina macular volume, and ganglion-cell-layer (GCL) macular volume and thickness between persons living with HIV (PLHIVs) with well-controlled infections and good immune recovery, and sexand age-matched HIV-uninfected controls (HUCs). Methods This prospective cross-sectional study (www.clinicaltrials.gov identifier: NCT02003989) included 56 PLHIVs, infected for �10 [median 20.2] years and with sustained plasma HIVload suppression on combined antiretroviral therapy (cART) for �5 years, and 56 matched HUCs. Participants underwent spectral-domain optical coherence tomography (SD-OCT) with thorough ophthalmological examinations and brain magnetic resonance imaging (MRI). Their overall and quadrant pRNFL thicknesses, total macular volumes, and GCL macular volumes and thicknesses were compared. Cerebral small-vessel diseases (CSVD) complied with STRIVE criteria. Results Median [interquartile range, IQR] ages of PLHIVs and HUCs, respectively, were 52 [46-60] and 52 [44-60] years. Median [IQR] PLHIVs' nadir CD4+ T-cell count and current CD4/CD8 T-cell ratio were 249/μL [158-350] and 0.
Journal of Neuroradiology, 2020
Francois Cotton, for the Imaging Working Group of the "Observatoire Français de la Sclérose en Pl... more Francois Cotton, for the Imaging Working Group of the "Observatoire Français de la Sclérose en Plaques" (OFSEP) and the OFSEP imaging group PII: S0150-9861(20)30095-X
Journal of Clinical Oncology, 2018
2005Background: to characterize clinical, molecular and radiological features of diffuse gliomas ... more 2005Background: to characterize clinical, molecular and radiological features of diffuse gliomas with FGFR3-TACC3 fusions or FGFR1 mutations, which are both actionable with new oral anti-FGFR inhibitors. Methods: We screened for FGFR3-TACC3 fusions 1112 gliomas (861 grade IV, 140 grade III and 111 grade II) by RT-PCR. We performed sequencing for hotspot FGFR1 mutations (N546 and K656) in 73 midline gliomas (8 grade II, 10 grade III, 54 grade IV, affecting cerebellum, spinal cord, brainstem, thalamus and diencephalon) and 479 hemispheric gliomas (170 grade IV, 151 grade III, 157 grade II). Results: We identified 50 gliomas (all IDH wild-type) with FGFR3-TACC3 fusion (45 grade IV, 2 grade III and 3 grade II). FGFR3-TACC3 fusion was mutually exclusive with EGFR amplification (p = 0.000) and co-occured with CDK4 and MDM2 amplifications (p = 0.011 and p = 0.005). FGFR3-TACC3 positive glioblastoma patients had a longer median overall survival (OS) (40.1 months versus 19.0; p = 0.006). Multivariate analysis show...
Investigative Radiology, 2019
Background: Anterior ischemic optic neuropathy (AION) is the most common cause of acute optic neu... more Background: Anterior ischemic optic neuropathy (AION) is the most common cause of acute optic neuropathy in older patients. Distinguishing between arteritic AION (A-AION) and nonarteritic (NA-AION) is paramount for improved patient management. Purpose: The aim of this study was to evaluate 3-dimensional high-resolution vessel wall (HR-VW) magnetic resonance imaging (MRI) at 3 T to discriminate A-AION from NA-AION. Materials and Methods: This prospective single-center study was approved by a national research ethics board and included 27 patients (17 A-AION and 10 NA-AION) with 36 AIONs from December 2014 to August 2017 who underwent 3 T HR-VW MRI. Two radiologists blinded to clinical data individually analyzed the imaging separately and in random order. Discrepancies were resolved by consensus with a third neuroradiologist. The primary diagnostic criterion was the presence of inflammatory changes of the ophthalmic artery. Secondary diagnostic criteria included the presence of an enhancement of the optic nerve or its sheath, the optic disc, or inflammatory changes of posterior ciliary or extracranial arteries. A Fisher exact test was used to compare A-AION from NA-AION patients. Results: Inflammatory changes of the ophthalmic artery were present in all patients with A-AION but in none of NA-AION (P < 0.0001). Its sensitivity, specificity, positive predictive value, and negative predictive value were 100%. Inflammatory changes of posterior ciliary arteries were significantly more likely in A-AOIN (82% vs 0%, P < 0.0001). Interreader and intrareader agreements were almost perfect (κ = 0.82-1). Conclusions: High-resolution vessel wall MRI seems highly accurate when distinguishing A-AION from NA-AION and might be useful to improve patient management.
American Journal of Neuroradiology, 2019
BACKGROUND AND PURPOSE: Leptomeningeal enhancement can be found in a variety of neurologic diseas... more BACKGROUND AND PURPOSE: Leptomeningeal enhancement can be found in a variety of neurologic diseases such as Susac Syndrome. Our aim was to assess its prevalence and significance of leptomeningeal enhancement in Susac syndrome using 3T postcontrast fluidattenuated inversion recovery MR imaging. MATERIALS AND METHODS: From January 2011 to December 2017, nine consecutive patients with Susac syndrome and a control group of 73 patients with multiple sclerosis or clinically isolated syndrome were included. Two neuroradiologists blinded to the clinical and ophthalmologic data independently reviewed MRIs and assessed leptomeningeal enhancement and parenchymal abnormalities. Follow-up MRIs (5.9 MRIs is the mean number per patient over a median period of 46 months) of patients with Susac syndrome were reviewed and compared with clinical and retinal fluorescein angiographic data evaluated by an independent ophthalmologist. Fisher tests were used to compare the 2 groups, and mixed-effects logistic models were used for analysis of clinical and imaging follow-up of patients with Susac syndrome. RESULTS: Patients with Susac syndrome were significantly more likely to present with leptomeningeal enhancement: 5/9 (56%) versus 6/73 (8%) in the control group (P ϭ .002). They had a significantly higher leptomeningeal enhancement burden with Ն3 lesions in 5/9 patients versus 0/73 (P Ͻ .001). Regions of leptomeningeal enhancement were significantly more likely to be located in the posterior fossa: 5/9 versus 0/73 (P Ͻ .001). Interobserver agreement for leptomeningeal enhancement was good (ϭ 0.79). There was a significant association between clinical relapses and increase of both leptomeningeal enhancement and parenchymal lesion load: OR ϭ 6.15 (P ϭ .01) and OR ϭ 5 (P ϭ .02), respectively. CONCLUSIONS: Leptomeningeal enhancement occurs frequently in Susac syndrome and could be helpful for diagnosis and in predicting clinical relapse. ABBREVIATIONS: CIS ϭ clinically isolated syndrome; CC ϭ corpus callosum; FA ϭ fluorescein angiography; LME ϭ leptomeningeal enhancement; pcFLAIR ϭ postcontrast FLAIR; SuS ϭ Susac syndrome S usac Syndrome (SuS) is a vasculopathy characterized by a triad of neurologic, hearing, and ophthalmologic disorders. 1-3 Fluorescein angiography (FA) typically shows branch retinal ar
Journal of Neuroradiology, 2019
Journal of Neuroradiology, 2019
Background and purpose.-To compare the accuracy and utility of contrast enhanced magnetic resonan... more Background and purpose.-To compare the accuracy and utility of contrast enhanced magnetic resonance angiography (MRA) (CEMRA) to Time of Flight MRA (TOF MRA) during detection and evaluation of occlusions on patients diagnosed with acute ischemic stroke (AIS). Methods.-This single-center study was approved by our local institutional research ethics board. From August 2014 to July 2016, 131 consecutive adult patients with confirmed AIS were included. Detection of an arterial occlusion and its characterization were evaluated independently with CEMRA or TOF MRA by two blinded neuroradiologists, then by consensus using all available MR sequences. A Cohen's Kappa coefficient () and intra-class correlation coefficients (ICC) were used to compare the two techniques. Results.-There was substantial concordance in the detection of arterial occlusion between CEMRA and TOF MRA (= 0.75). TOF MRA was more likely to show an arterial occlusion than CEMRA (63 versus 52 patients respectively). There were 13 and 1 false positive arterial occlusion with TOF MRA and CEMRA respectively, and 1 false negative with TOF MRA. There was excellent concordance between the location of arterial occlusions and CEMRA and TOF MRA [ = 0.89 (0.72-0.97)]. CEMRA was significantly more likely to allow measurement of the thrombus than was TOF MRA [38 (75%) versus 14 (22%)] (P < 0.0001). Conclusions.-Our study showed that CEMRA imaging detected arterial occlusions better than TOF MRA in AIS patients and more precisely such that thrombus length and location could be known, which improves the patient's management and care.
RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-680-C-10
RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-680-C-10
RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-680-C-10
RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-680-C-10
Journal of Neuroradiology, 2021
Diagnostic and Interventional Imaging, 2021
PURPOSE The purpose of this study was to assess the inter-slice radiomic feature repeatability in... more PURPOSE The purpose of this study was to assess the inter-slice radiomic feature repeatability in ultrasound imaging and the impact of preprocessing using intensity standardization and grey-level discretization to help improve radiomics reproducibility. MATERIALS AND METHODS This single-center study enrolled consecutive patients with an orbital lesion who underwent ultrasound examination of the orbit from December 2015 to July 2019. Two images per lesion were randomly assigned to two subsets. Radiomic features were extracted and inter-slice repeatability was assessed using the intraclass correlation coefficient (ICC) between the subsets. The impact of preprocessing on feature repeatability was assessed using image intensity standardization with or without outliers removal on whole images, bounding boxes or regions of interest (ROI), and fixed bin size or fixed bin number grey-level discretization. Number of inter-slice repeatable features (ICC ≥0.7) between methods was compared. RESULTS Eighty-eight patients (37 men, 51 women) with a mean age of 51.5 ± 17 (SD) years (range: 20-88 years) were enrolled. Without preprocessing, 29/101 features (28.7%) were repeatable between slices. The greatest number of repeatable features (41/101) was obtained using intensity standardization with outliers removal on the ROI and fixed bin size discretization. Standardization performed better with outliers removal than without (P < 0.001), and on ROIs than on native images (P < 0.001). Fixed bin size discretization performed better than fixed bin number (P = 0.008). CONCLUSION Radiomic features extracted from ultrasound images are impacted by the slice and preprocessing. The use of intensity standardization with outliers removal applied to the ROI and a fixed bin size grey-level discretization may improve feature repeatability.
Diagnostic and Interventional Imaging, 2021
PURPOSE The purpose of this study was to describe the MRI characteristics of intralabyrinthine sc... more PURPOSE The purpose of this study was to describe the MRI characteristics of intralabyrinthine schwannoma (ILS) on post contrast three-dimensional (3D) fluid-attenuation-inversion-recovery (FLAIR) images obtained four hours after intravenous administration of a gadolinium-based contrast agent (4h-3D-FLAIR). MATERIALS AND METHODS This IRB-approved retrospective multi-center study included patients presenting with typical ILS from January 2016 to October 2020. All medical charts were systematically collected. All MRI examinations, including 4h-3D-FLAIR images, were reviewed by two board-certified neuroradiologists. Main outcome measures were location, signal intensity and associated anomalies of ILS. RESULTS Twenty-seven out of 8730 patients (0.31%) referred for the investigation of a cochleovestibular disorder had a final diagnosis of ILS. There were 13 men and 14 women with a mean age of 52 ± 17 (SD) years (age range: 20-86 years). The most common clinical presentation was unilateral progressive sensorineural hearing loss (16/27; 59%). All ILS were unilateral and 15 (15/27; 55%) were intracochlear. All ILS presented as a hypointense filling defect within the labyrinth on T2-weighted images that enhanced on post-contrast T1-weighted images. On 4h-3D-FLAIR images, all ILS presented as a hypointense filling defect, associated with diffuse perilymphatic hyperintensity. Two patients (2/27; 7%) presented with ipsilateral endolymphatic hydrops. CONCLUSION ILS displays consistent features on post-contrast 4h-3D-FLAIR images. ILS should not be confused with endolymphatic hydrops and requires a systematic analysis of the corresponding T2-weighted images.
European Radiology, 2020
Objectives To determine the diagnostic accuracy of MRI intravoxel incoherent motion (IVIM) when c... more Objectives To determine the diagnostic accuracy of MRI intravoxel incoherent motion (IVIM) when characterizing orbital lesions, which is challenging due to a wide range of locations and histologic types. Methods This IRB-approved prospective single-center study enrolled participants presenting with an orbital lesion undergoing a 3-T MRI prior to surgery from December 2015 to July 2019. An IVIM sequence with 15 b values ranging from 0 to 2000 s/mm 2 was performed. Two neuroradiologists, blinded to clinical data, individually analyzed morphological MRIs. They drew one region of interest inside each orbital lesion, providing apparent diffusion coefficient (ADC), true diffusion coefficient ( D ), perfusion fraction ( f ), and pseudodiffusion coefficient ( D *) values. T test, Mann-Whitney U test, and receiver operating characteristic curve analyses were performed to discriminate between orbital lesions and to determine the diagnostic accuracy of the IVIM parameters. Results One hundred fifty-six participants (84 women and 72 men, mean age 54.4 ± 17.5 years) with 167 orbital lesions (98/167 [59%] benign lesions including 54 orbital inflammations and 69/167 [41%] malignant lesions including 32 lymphomas) were included in the study. ADC and D were significantly lower in malignant than in benign lesions: 0.8 × 10 −3 mm 2 /s [0.45] versus 1.04 × 10 −3 mm 2 /s [0.33], p < 0.001, and 0.75 × 10 −3 mm 2 /s [0.40] versus 0.98 × 10 −3 mm 2 /s [0.42], p < 0.001, respectively. D * was significantly higher in malignant lesions than in benign ones: 12.8 × 10 −3 mm 2 /s [20.17] versus 7.52 × 10 −3 mm 2 /s [7.57], p = 0.005. Area under curve was of 0.73, 0.74, 0.72, and 0.81 for ADC, D , D *, and a combination of D , f , and D *, respectively. Conclusions Our study showed that IVIM might help better characterize orbital lesions. Key Points • Intravoxel incoherent motion (IVIM) helps clinicians to assess patients with orbital lesions. • Intravoxel incoherent motion (IVIM) helps clinicians to characterize orbital lymphoma versus orbital inflammation. • Management of patients becomes more appropriate.
European Radiology, 2021
To determine the diagnostic performances of a single Dixon-T2-weighted imaging (WI) sequence comp... more To determine the diagnostic performances of a single Dixon-T2-weighted imaging (WI) sequence compared to a conventional protocol including T1-, T2-, and fat-suppressed T2-weighted MRI at 3 T when assessing thyroid eye disease (TED). This IRB-approved prospective single-center study enrolled participants presenting with confirmed TED from April 2015 to October 2019. They underwent an MRI, including a conventional protocol and a Dixon-T2WI sequence. Two neuroradiologists, blinded to all data, read both datasets independently and randomly. They assessed the presence of extraocular muscle (EOM) inflammation, enlargement, fatty degeneration, or fibrosis as well as the presence of artifacts. The Wilcoxon signed-rank test was used. Two hundred six participants were enrolled (135/206 [66%] women, 71/206 [34%] men, age 52.3 ± 13.2 years). Dixon-T2WI was significantly more likely to detect at least one inflamed EOM as compared to the conventional set (248/412 [60%] versus 228/412 [55%] eyes; (p = 0.02). Dixon-T2WI was more sensitive and specific than the conventional set for assessing muscular inflammation (100% versus 94.7% and 71.2% versus 68.5%, respectively). Dixon-T2WI was significantly less likely to show major or minor artifacts as compared to fat-suppressed T2WI (20/412 [5%] versus 109/412 [27%] eyes, p < 0.001, and 175/412 [42%] versus 257/412 [62%] eyes, p < 0.001). Confidence was significantly higher with Dixon-T2WI than with the conventional set (2.35 versus 2.24, p = 0.003). Dixon-T2WI showed higher sensitivity and specificity and showed fewer artifacts than a conventional protocol when assessing thyroid eye disease, in addition to higher self-reported confidence. • Dixon-T2WI has better sensitivity and specificity than a conventional protocol for assessing inflamed extraocular muscles in patients with thyroid eye disease. • Dixon-T2WI shows significantly fewer artifacts than fat-suppressed T2WI. • Dixon-T2WI is faster and is associated with significantly higher self-reported reader confidence as compared to a conventional protocol when assessing inflammatory extraocular muscles.
European Journal of Neurology, 2020
BACKGROUND Malignant MCA infarction (MMI) is a severe complication of acute ischemic stroke (AIS)... more BACKGROUND Malignant MCA infarction (MMI) is a severe complication of acute ischemic stroke (AIS). The aim of our study was to assess whether successful reperfusion after endovascular therapy (EVT) in AIS with clinical and imaging predictors of MMI decreased its occurrence. METHODS Data were collected between January 2014 and July 2018 in a monocentric prospective AIS registry of patients treated with EVT. Patients selected were under 65 years old, with severe anterior circulation AIS with a National Institutes of Health Stroke Scale (NIHSS) score higher than 15, a baseline Diffusion-Weighted Imaging- Alberta Stroke Program Early CT (DWI-ASPECT) score ≤6 and a baseline DWI lesion volume larger than 82ml within 6 hours of symptom onset. Successful reperfusion was defined as a Thrombolysis in Cerebral Ischemia (TICI) score ≥2b. Occurrence of MMI was the primary endpoint. RESULTS Sixty-six EVT-treated patients were included in our study. MMI occurred in 27 patients (42%). In unadjusted analysis, successful reperfusion was associated with fewer MMI (31.8% vs 65.0%; p=0.015) and with more 3-month favorable outcome (50% vs 20%, p=0.023). In multivariate analysis, successful reperfusion was associated with an adjusted OR (95%CI) of 0.35 (0.10 to 1.12) for MMI and 2.77 (0.84 to 10.43) for 3-month favorable outcome occurrence. CONCLUSIONS Early successful reperfusion performed in AIS patients with clinical and imaging predictors of MMI was associated with decreased MMI occurrence. Reperfusion status might be considered in evaluating the need for craniectomy in patients with early predictors of MMI.
Journal of Neuroradiology, 2020
Objectif Illustrer des modèles de mismatch clinicoradiologique concluant, éligibles à une revascu... more Objectif Illustrer des modèles de mismatch clinicoradiologique concluant, éligibles à une revascularisation urgente. Matériel et méthodes Étude de cas de patients présentant des accidents vasculaires cérébraux ischémiques (AVCI) traités par rtPA 0,9 mg au CHU Mohammed VI d'Oujda, dont la décision thérapeu
PLOS ONE, 2020
To compare peripapillary retinal nerve-fiber-layer (pRNFL) thickness, total retina macular volume... more To compare peripapillary retinal nerve-fiber-layer (pRNFL) thickness, total retina macular volume, and ganglion-cell-layer (GCL) macular volume and thickness between persons living with HIV (PLHIVs) with well-controlled infections and good immune recovery, and sexand age-matched HIV-uninfected controls (HUCs). Methods This prospective cross-sectional study (www.clinicaltrials.gov identifier: NCT02003989) included 56 PLHIVs, infected for �10 [median 20.2] years and with sustained plasma HIVload suppression on combined antiretroviral therapy (cART) for �5 years, and 56 matched HUCs. Participants underwent spectral-domain optical coherence tomography (SD-OCT) with thorough ophthalmological examinations and brain magnetic resonance imaging (MRI). Their overall and quadrant pRNFL thicknesses, total macular volumes, and GCL macular volumes and thicknesses were compared. Cerebral small-vessel diseases (CSVD) complied with STRIVE criteria. Results Median [interquartile range, IQR] ages of PLHIVs and HUCs, respectively, were 52 [46-60] and 52 [44-60] years. Median [IQR] PLHIVs' nadir CD4+ T-cell count and current CD4/CD8 T-cell ratio were 249/μL [158-350] and 0.
Journal of Neuroradiology, 2020
Francois Cotton, for the Imaging Working Group of the "Observatoire Français de la Sclérose en Pl... more Francois Cotton, for the Imaging Working Group of the "Observatoire Français de la Sclérose en Plaques" (OFSEP) and the OFSEP imaging group PII: S0150-9861(20)30095-X
Journal of Clinical Oncology, 2018
2005Background: to characterize clinical, molecular and radiological features of diffuse gliomas ... more 2005Background: to characterize clinical, molecular and radiological features of diffuse gliomas with FGFR3-TACC3 fusions or FGFR1 mutations, which are both actionable with new oral anti-FGFR inhibitors. Methods: We screened for FGFR3-TACC3 fusions 1112 gliomas (861 grade IV, 140 grade III and 111 grade II) by RT-PCR. We performed sequencing for hotspot FGFR1 mutations (N546 and K656) in 73 midline gliomas (8 grade II, 10 grade III, 54 grade IV, affecting cerebellum, spinal cord, brainstem, thalamus and diencephalon) and 479 hemispheric gliomas (170 grade IV, 151 grade III, 157 grade II). Results: We identified 50 gliomas (all IDH wild-type) with FGFR3-TACC3 fusion (45 grade IV, 2 grade III and 3 grade II). FGFR3-TACC3 fusion was mutually exclusive with EGFR amplification (p = 0.000) and co-occured with CDK4 and MDM2 amplifications (p = 0.011 and p = 0.005). FGFR3-TACC3 positive glioblastoma patients had a longer median overall survival (OS) (40.1 months versus 19.0; p = 0.006). Multivariate analysis show...
Investigative Radiology, 2019
Background: Anterior ischemic optic neuropathy (AION) is the most common cause of acute optic neu... more Background: Anterior ischemic optic neuropathy (AION) is the most common cause of acute optic neuropathy in older patients. Distinguishing between arteritic AION (A-AION) and nonarteritic (NA-AION) is paramount for improved patient management. Purpose: The aim of this study was to evaluate 3-dimensional high-resolution vessel wall (HR-VW) magnetic resonance imaging (MRI) at 3 T to discriminate A-AION from NA-AION. Materials and Methods: This prospective single-center study was approved by a national research ethics board and included 27 patients (17 A-AION and 10 NA-AION) with 36 AIONs from December 2014 to August 2017 who underwent 3 T HR-VW MRI. Two radiologists blinded to clinical data individually analyzed the imaging separately and in random order. Discrepancies were resolved by consensus with a third neuroradiologist. The primary diagnostic criterion was the presence of inflammatory changes of the ophthalmic artery. Secondary diagnostic criteria included the presence of an enhancement of the optic nerve or its sheath, the optic disc, or inflammatory changes of posterior ciliary or extracranial arteries. A Fisher exact test was used to compare A-AION from NA-AION patients. Results: Inflammatory changes of the ophthalmic artery were present in all patients with A-AION but in none of NA-AION (P < 0.0001). Its sensitivity, specificity, positive predictive value, and negative predictive value were 100%. Inflammatory changes of posterior ciliary arteries were significantly more likely in A-AOIN (82% vs 0%, P < 0.0001). Interreader and intrareader agreements were almost perfect (κ = 0.82-1). Conclusions: High-resolution vessel wall MRI seems highly accurate when distinguishing A-AION from NA-AION and might be useful to improve patient management.
American Journal of Neuroradiology, 2019
BACKGROUND AND PURPOSE: Leptomeningeal enhancement can be found in a variety of neurologic diseas... more BACKGROUND AND PURPOSE: Leptomeningeal enhancement can be found in a variety of neurologic diseases such as Susac Syndrome. Our aim was to assess its prevalence and significance of leptomeningeal enhancement in Susac syndrome using 3T postcontrast fluidattenuated inversion recovery MR imaging. MATERIALS AND METHODS: From January 2011 to December 2017, nine consecutive patients with Susac syndrome and a control group of 73 patients with multiple sclerosis or clinically isolated syndrome were included. Two neuroradiologists blinded to the clinical and ophthalmologic data independently reviewed MRIs and assessed leptomeningeal enhancement and parenchymal abnormalities. Follow-up MRIs (5.9 MRIs is the mean number per patient over a median period of 46 months) of patients with Susac syndrome were reviewed and compared with clinical and retinal fluorescein angiographic data evaluated by an independent ophthalmologist. Fisher tests were used to compare the 2 groups, and mixed-effects logistic models were used for analysis of clinical and imaging follow-up of patients with Susac syndrome. RESULTS: Patients with Susac syndrome were significantly more likely to present with leptomeningeal enhancement: 5/9 (56%) versus 6/73 (8%) in the control group (P ϭ .002). They had a significantly higher leptomeningeal enhancement burden with Ն3 lesions in 5/9 patients versus 0/73 (P Ͻ .001). Regions of leptomeningeal enhancement were significantly more likely to be located in the posterior fossa: 5/9 versus 0/73 (P Ͻ .001). Interobserver agreement for leptomeningeal enhancement was good (ϭ 0.79). There was a significant association between clinical relapses and increase of both leptomeningeal enhancement and parenchymal lesion load: OR ϭ 6.15 (P ϭ .01) and OR ϭ 5 (P ϭ .02), respectively. CONCLUSIONS: Leptomeningeal enhancement occurs frequently in Susac syndrome and could be helpful for diagnosis and in predicting clinical relapse. ABBREVIATIONS: CIS ϭ clinically isolated syndrome; CC ϭ corpus callosum; FA ϭ fluorescein angiography; LME ϭ leptomeningeal enhancement; pcFLAIR ϭ postcontrast FLAIR; SuS ϭ Susac syndrome S usac Syndrome (SuS) is a vasculopathy characterized by a triad of neurologic, hearing, and ophthalmologic disorders. 1-3 Fluorescein angiography (FA) typically shows branch retinal ar
Journal of Neuroradiology, 2019
Journal of Neuroradiology, 2019
Background and purpose.-To compare the accuracy and utility of contrast enhanced magnetic resonan... more Background and purpose.-To compare the accuracy and utility of contrast enhanced magnetic resonance angiography (MRA) (CEMRA) to Time of Flight MRA (TOF MRA) during detection and evaluation of occlusions on patients diagnosed with acute ischemic stroke (AIS). Methods.-This single-center study was approved by our local institutional research ethics board. From August 2014 to July 2016, 131 consecutive adult patients with confirmed AIS were included. Detection of an arterial occlusion and its characterization were evaluated independently with CEMRA or TOF MRA by two blinded neuroradiologists, then by consensus using all available MR sequences. A Cohen's Kappa coefficient () and intra-class correlation coefficients (ICC) were used to compare the two techniques. Results.-There was substantial concordance in the detection of arterial occlusion between CEMRA and TOF MRA (= 0.75). TOF MRA was more likely to show an arterial occlusion than CEMRA (63 versus 52 patients respectively). There were 13 and 1 false positive arterial occlusion with TOF MRA and CEMRA respectively, and 1 false negative with TOF MRA. There was excellent concordance between the location of arterial occlusions and CEMRA and TOF MRA [ = 0.89 (0.72-0.97)]. CEMRA was significantly more likely to allow measurement of the thrombus than was TOF MRA [38 (75%) versus 14 (22%)] (P < 0.0001). Conclusions.-Our study showed that CEMRA imaging detected arterial occlusions better than TOF MRA in AIS patients and more precisely such that thrombus length and location could be known, which improves the patient's management and care.