1. T1-Based Synthetic Magnetic Resonance Contrasts Improve Multiple Sclerosis and Focal Epilepsy Imaging at 7 T
- Author
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Jean-Philippe Ranjeva, Thomas Troalen, Tobias Kober, Axel Bartoli, Aurélien Massire, Virginie Callot, Charlotte Seiler, Gilles Brun, Olivier M. Girard, Pierre Lehmann, Maxime Guye, Fabrice Bartolomei, Jean Pelletier, Bertrand Audoin, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Institut de Neurosciences des Systèmes (INS), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Aix Marseille Université (AMU), and Assistance Publique - Hôpitaux de Marseille (APHM)
- Subjects
medicine.medical_specialty ,Magnetic Resonance Spectroscopy ,genetic structures ,Lesion Identification ,Wilcoxon signed-rank test ,Image quality ,[SDV]Life Sciences [q-bio] ,7 t ,ultra-high field mri ,multiple sclerosis ,030218 nuclear medicine & medical imaging ,Lesion ,[SPI]Engineering Sciences [physics] ,03 medical and health sciences ,Epilepsy ,0302 clinical medicine ,medicine ,Humans ,neuroradiology ,Radiology, Nuclear Medicine and imaging ,ComputingMilieux_MISCELLANEOUS ,Retrospective Studies ,medicine.diagnostic_test ,synthetic mri ,business.industry ,Multiple sclerosis ,Brain ,Magnetic resonance imaging ,General Medicine ,medicine.disease ,Magnetic Resonance Imaging ,3. Good health ,Multiple comparisons problem ,epilepsy ,Epilepsies, Partial ,Radiology ,medicine.symptom ,business ,mp2rage ,030217 neurology & neurosurgery - Abstract
Objectives, Ultra-high field magnetic resonance imaging (MRI) (>= 7 T) is a unique opportunity to improve the clinical diagnosis of brain pathologies, such as multiple sclerosis or focal epilepsy. However, several shortcomings of 7 T MRI, such as radiofrequency field inhomogeneities, could degrade image quality and hinder radiological interpretation. To address these challenges, an original synthetic MRI method based on T-1 mapping achieved with the magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) sequence was developed. The radiological quality of on-demand T-1-based contrasts generated by this technique was evaluated in multiple sclerosis and focal epilepsy imaging at 7 T. Materials and Methods, This retrospective study was carried out from October 2017 to September 2019 and included 21 patients with different phenotypes of multiple sclerosis and 35 patients with focal epilepsy who underwent MRI brain examinations using a whole-body investigative 7 T magnetic resonance system. The quality of 2 proposed synthetic contrast images were assessed and compared with conventional images acquired at 7 T using the MP2RAGE sequence by 4 radiologists, evaluating 3 qualitative criteria: signal homogeneity, contrast intensity, and lesion visualization. Statistical analyses were performed on reported quality scores using Wilcoxon rank tests and further multiple comparisons tests. Intraobserver and interobserver reliabilities were calculated as well. Results, Radiological quality scores were reported higher for synthetic images when compared with original images, regardless of contrast, pathologies, or raters considered, with significant differences found for all 3 criteria (P < 0.0001, Wilcoxon rank test). None of the 4 radiologists ever rated a synthetic image "markedly worse" than an original image. Synthetic images were rated slightly less satisfying for only 3 epileptic patients, without precluding lesion identification. Conclusion, T-1-based synthetic MRI with the MP2RAGE sequence provided on-demand contrasts and high-quality images to the radiologist, facilitating lesion visualization in multiple sclerosis and focal epilepsy, while reducing the magnetic resonance examination total duration by removing an additional sequence.
- Published
- 2020