title: Quantification of Diaphragm Mechanics in Pompe Disease Using Dynamic 3D MRI.
abstract: BACKGROUND
  Diaphragm weakness is the main reason for respiratory dysfunction in patients with Pompe disease, a progressive metabolic myopathy affecting respiratory and limb-girdle muscles. Since respiratory failure is the major cause of death among adult patients, early identification of respiratory muscle involvement is necessary to initiate treatment in time and possibly prevent irreversible damage. In this paper we investigate the suitability of dynamic MR imaging in combination with state-of-the-art image analysis methods to assess respiratory muscle weakness.
  
  
  METHODS
  The proposed methodology relies on image registration and lung surface extraction to quantify lung kinematics during breathing. This allows for the extraction of geometry and motion features of the lung that characterize the independent contribution of the diaphragm and the thoracic muscles to the respiratory cycle.
  
  
  RESULTS
  Results in 16 3D+t MRI scans (10 Pompe patients and 6 controls) of a slow expiratory maneuver show that kinematic analysis from dynamic 3D images reveals important additional information about diaphragm mechanics and respiratory muscle involvement when compared to conventional pulmonary function tests. Pompe patients with severely reduced pulmonary function showed severe diaphragm weakness presented by minimal motion of the diaphragm. In patients with moderately reduced pulmonary function, cranial displacement of posterior diaphragm parts was reduced and the diaphragm dome was oriented more horizontally at full inspiration compared to healthy controls.
  
  
  CONCLUSIONS
  Dynamic 3D MRI provides data for analyzing the contribution of both diaphragm and thoracic muscles independently. The proposed image analysis method has the potential to detect less severe diaphragm weakness and could thus be used to determine the optimal start of treatment in adult patients with Pompe disease in prospect of increased treatment response.
authors.affiliation: Biomedical Imaging Group Rotterdam, Departments of Medical Informatics & Radiology, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Katja
authors.initials: K
authors.lastname: Mogalle
authors.affiliation: Biomedical Imaging Group Rotterdam, Departments of Medical Informatics & Radiology, Erasmus MC, Rotterdam, the Netherlands.|Department of Pediatric Pulmonology, Erasmus MC-Sophia Children's Hospital, Rotterdam, the Netherlands.
authors.forename: Adria
authors.initials: A
authors.lastname: Perez-Rovira
authors.affiliation: Department of Radiology, Erasmus MC, Rotterdam, the Netherlands.|Department of Pediatrics, Respiratory Medicine and Allergology, Erasmus MC-Sophia, Rotterdam, the Netherlands.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Ciet
authors.affiliation: Department of Neurology, Erasmus MC, Rotterdam, the Netherlands.|Centre for Lysosomal and Metabolic Diseases, Erasmus MC-Sophia, Rotterdam, the Netherlands.
authors.forename: Stephan C A
authors.initials: SC
authors.lastname: Wens
authors.affiliation: Department of Neurology, Erasmus MC, Rotterdam, the Netherlands.|Centre for Lysosomal and Metabolic Diseases, Erasmus MC-Sophia, Rotterdam, the Netherlands.
authors.forename: Pieter A
authors.initials: PA
authors.lastname: van Doorn
authors.affiliation: Department of Radiology, Erasmus MC, Rotterdam, the Netherlands.|Department of Pediatrics, Respiratory Medicine and Allergology, Erasmus MC-Sophia, Rotterdam, the Netherlands.
authors.forename: Harm A W M
authors.initials: HA
authors.lastname: Tiddens
authors.affiliation: Centre for Lysosomal and Metabolic Diseases, Erasmus MC-Sophia, Rotterdam, the Netherlands.|Department of Pediatrics, Division of Metabolic Diseases and Genetics, Erasmus MC-Sophia, Rotterdam, the Netherlands.
authors.forename: Ans T
authors.initials: AT
authors.lastname: van der Ploeg
authors.affiliation: Biomedical Imaging Group Rotterdam, Departments of Medical Informatics & Radiology, Erasmus MC, Rotterdam, the Netherlands.|Department of Computer Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Marleen
authors.initials: M
authors.lastname: de Bruijne
mesh_terms: D000328:Adult; D000368:Aged; D003964:Diaphragm / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006009:Glycogen Storage Disease Type II / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009068:Movement; D015656:Respiratory Mechanics