Combined diffusion imaging and MR spectroscopy in the diagnosis of human prion diseases.

Damien Galanaud (1, 2) , Stéphane Haïk (3) , Marius George Linguraru (4) , Jean-Philippe Ranjeva (1) , Baptiste Faucheux (2) , Elsa Kaphan (2) , Nicholas Ayache (4) , Jacques Chiras (2) , Patrick J Cozzone (1) , Didier Dormont (2, 5, 6, 7) , Jean-Philippe Brandel (8)

1 CRMBM - Centre de résonance magnétique biologique et médicale
2 CHU Pitié-Salpêtrière [AP-HP]
3 Laboratoire de Neuropathologie Raymond Escourolle [CHU Pitié-Salpétriêre]
4 ASCLEPIOS - Analysis and Simulation of Biomedical Images
5 NCIC - Neurosciences cognitives et imagerie cérébrale
6 LIF - Laboratoire d'Imagerie Fonctionnelle
7 CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière
8 Neuroépidémiologie

BACKGROUND AND PURPOSE: The physiopathologic bases underlying the signal intensity changes and reduced diffusibility observed in prion diseases (TSEs) are still poorly understood. We evaluated the interest of MRS combined with DWI both as a diagnostic tool and a way to understand the mechanism underlying signal intensity and ADC changes in this setting. MATERIALS AND METHODS: We designed a prospective study of multimodal MR imaging in patients with suspected TSEs. Forty-five patients with a suspicion of TSE and 11 age-matched healthy volunteers were included. The MR imaging protocol included T1, FLAIR, and DWI sequences. MRS was performed on the cerebellum, pulvinar, right lenticular nucleus, and frontal cortex. MR images were assessed visually, and ADC values were calculated. RESULTS: Among the 45 suspected cases, 31 fulfilled the criteria for probable or definite TSEs (19 sCJDs, 3 iCJDs, 2 vCJDs, and 7 genetic TSEs); and 14 were classified as AltDs. High signals in the cortex and/or basal ganglia were observed in 26/31 patients with TSEs on FLAIR and 29/31 patients on DWI. In the basal ganglia, high DWI signals corresponded to a decreased ADC. Metabolic alterations, increased mIns, and decreased NAA were observed in all patients with TSEs. ADC values and metabolic changes were not correlated; this finding suggests that neuronal stress (vacuolization), neuronal loss, and astrogliosis do not alone explain the decrease of ADC. CONCLUSIONS: MRS combined with other MR imaging is of interest in the diagnosis of TSE and provides useful information for understanding physiopathologic processes underlying prion diseases.

Mots clés: Adolescent, Adult, Aged, 80 and over, Brain Diseases/metabolism/pathology/physiopathology, Cerebellum/metabolism/pathology, Corpus Striatum/metabolism/pathology, Diffusion Magnetic Resonance Imaging/*methods, Frontal Lobe/metabolism/pathology, Humans, Magnetic Resonance Spectroscopy/*methods, Middle Aged, Prion Diseases/*metabolism/*pathology/physiopathology, Prospective Studies, Pulvinar/metabolism/pathology, Sensitivity and Specificity; Adolescent, Adult, Aged, 80 and over, Brain Diseases/metabolism/pathology/physiopathology, Cerebellum/metabolism/pathology, Corpus Striatum/metabolism/pathology, Diffusion Magnetic Resonance Imaging/*methods, Frontal Lobe/metabolism/pathology, Humans, Magnetic Resonance Spectroscopy/*methods, Middle Aged, Prion Diseases/*metabolism/*pathology/physiopathology, Prospective Studies, Pulvinar/metabolism/pathology, Sensitivity and Specificity

Domaines: Imagerie médicale; Modélisation et simulation; Imagerie; Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]

Damien Galanaud, Stéphane Haïk, Marius George Linguraru, Jean-Philippe Ranjeva, Baptiste Faucheux, et al.. Combined diffusion imaging and MR spectroscopy in the diagnosis of human prion diseases.. American Journal of Neuroradiology, 2010, 31 (7), pp.1311-8. ⟨10.3174/ajnr.A2069⟩. ⟨inria-00616097⟩