title: A PET/CT approach to spinal cord metabolism in amyotrophic lateral sclerosis.
abstract: OBJECTIVE
  In amyotrophic lateral sclerosis, functional alterations within the brain have been intensively assessed, while progression of lower motor neuron damage has scarcely been defined. The aim of the present study was to develop a computational method to systematically evaluate spinal cord metabolism as a tool to monitor disease mechanisms.
  
  
  METHODS
  A new computational three-dimensional method to extract the spinal cord from (18)F-FDG PET/CT images was evaluated in 30 patients with spinal onset amyotrophic lateral sclerosis and 30 controls. The algorithm identified the skeleton on the CT images by using an extension of the Hough transform and then extracted the spinal canal and the spinal cord. In these regions, (18)F-FDG standardized uptake values were measured to estimate the metabolic activity of the spinal canal and cord. Measurements were performed in the cervical and dorsal spine and normalized to the corresponding value in the liver.
  
  
  RESULTS
  Uptake of (18)F-FDG in the spinal cord was significantly higher in patients than in controls (p < 0.05). By contrast, no significant differences were observed in spinal cord and spinal canal volumes between the two groups. (18)F-FDG uptake was completely independent of age, gender, degree of functional impairment, disease duration and riluzole treatment. Kaplan-Meier analysis showed a higher mortality rate in patients with standardized uptake values above the fifth decile at the 3-year follow-up evaluation (log-rank test, p < 0.01). The independence of this value was confirmed by multivariate Cox analysis.
  
  
  CONCLUSIONS
  Our computational three-dimensional method enabled the evaluation of spinal cord metabolism and volume and might represent a potential new window onto the pathophysiology of amyotrophic lateral sclerosis.
authors.affiliation: CNR Institute of Bioimages and Molecular Physiology, Milan, Section of Genoa, Italy. Cecilia.Marini@unige.it.|Nuclear Medicine, IRCCS San Martino IST, and Depth of Health Science, University of Genoa, Genoa, Italy. Cecilia.Marini@unige.it.|CNR Institute of Bioimages and Molecular Physiology, Section of Genoa, C/o Nuclear Medicine, IRCCS AOU San Martino-IST, 16132, Genoa, Italy. Cecilia.Marini@unige.it.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Marini
authors.affiliation: Positron Emission Tomography Centre IRMET, Affidea, Turin, Italy.
authors.forename: Angelina
authors.initials: A
authors.lastname: Cistaro
authors.affiliation: SPIN Institute, CNR, Genoa, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Campi
authors.affiliation: ALS Center, "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy.|AUO Città della Salute e della Scienza, Turin, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Calvo
authors.affiliation: Department of Neuroscience, IRCCS San Martino IST, Genoa, Italy.|DINOGMI University of Genoa, Genoa, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Caponnetto
authors.affiliation: Department of Neuroscience, IRCCS San Martino IST, Genoa, Italy.|DINOGMI University of Genoa, Genoa, Italy.
authors.forename: Flavio Mariano
authors.initials: FM
authors.lastname: Nobili
authors.affiliation: Positron Emission Tomography Centre IRMET, Affidea, Turin, Italy.
authors.forename: Piercarlo
authors.initials: P
authors.lastname: Fania
authors.affiliation: Department of Mathematics (DIMA), University of Genoa, Genoa, Italy.
authors.forename: Mauro C
authors.initials: MC
authors.lastname: Beltrametti
authors.affiliation: ALS Center, "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy.|AUO Città della Salute e della Scienza, Turin, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Moglia
authors.affiliation: Department of Neuroscience, IRCCS San Martino IST, Genoa, Italy.|DINOGMI University of Genoa, Genoa, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Novi
authors.affiliation: Nuclear Medicine, IRCCS San Martino IST, and Depth of Health Science, University of Genoa, Genoa, Italy.
authors.forename: Ambra
authors.initials: A
authors.lastname: Buschiazzo
authors.affiliation: SPIN Institute, CNR, Genoa, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Perasso
authors.affiliation: ALS Center, "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy.|AUO Città della Salute e della Scienza, Turin, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Canosa
authors.affiliation: Department of Neuroscience, IRCCS San Martino IST, Genoa, Italy.|DINOGMI University of Genoa, Genoa, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Scialò
authors.affiliation: Nuclear Medicine, IRCCS San Martino IST, and Depth of Health Science, University of Genoa, Genoa, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Pomposelli
authors.affiliation: SPIN Institute, CNR, Genoa, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Massone
authors.affiliation: Medical Physics unit, IRCCS AOU San Martino-IST, Genoa, Italy.
authors.forename: Maria Caludia
authors.initials: MC
authors.lastname: Bagnara
authors.affiliation: ALS Center, "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy.|AUO Città della Salute e della Scienza, Turin, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Cammarosano
authors.affiliation: Statistics and Epidemiology Unit, IRCCS AOU San Martino-IST, Genoa, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Bruzzi
authors.affiliation: Nuclear Medicine, IRCCS San Martino IST, and Depth of Health Science, University of Genoa, Genoa, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Morbelli
authors.affiliation: Nuclear Medicine, IRCCS San Martino IST, and Depth of Health Science, University of Genoa, Genoa, Italy.
authors.forename: Gianmario
authors.initials: G
authors.lastname: Sambuceti
authors.affiliation: Department of Neuroscience, IRCCS San Martino IST, Genoa, Italy.|DINOGMI University of Genoa, Genoa, Italy.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Mancardi
authors.affiliation: SPIN Institute, CNR, Genoa, Italy.|Department of Mathematics (DIMA), University of Genoa, Genoa, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Piana
authors.affiliation: ALS Center, "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy.|AUO Città della Salute e della Scienza, Turin, Italy.
authors.forename: Adriano
authors.initials: A
authors.lastname: Chiò
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D059906:Neuroimaging / Q000379:methods; D009928:Organ Specificity; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013116:Spinal Cord / Q000000981:diagnostic imaging* / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Amyotrophic lateral sclerosis; Neuroimaging; PET/CT; Spinal cord