title: MRI internal segmentation of optic pathway gliomas: clinical implementation of a novel algorithm.
abstract: OBJECTIVE
  Optic pathway gliomas (OPGs) are diagnosed based on typical MR features and require careful monitoring with serial MRI. Reliable, serial radiological comparison of OPGs is a difficult task, where accuracy becomes very important for clinical decisions on treatment initiation and results. Current radiological methodology usually includes linear measurements that are limited in terms of precision and reproducibility.
  
  
  METHODS
  We present a method that enables semiautomated segmentation and internal classification of OPGs using a novel algorithm. Our method begins with co-registration of the different sequences of an MR study so that T1 and T2 slices are realigned. The follow-up studies are then re-sliced according to the baseline study. The baseline tumor is segmented, with internal components classified into solid non-enhancing, solid-enhancing, and cystic components, and the volume is calculated. Tumor demarcation is then transferred onto the next study and the process repeated. Numerical values are correlated with clinical data such as treatment and visual ability.
  
  
  RESULTS
  We have retrospectively implemented our method on 24 MR studies of three OPG patients. Clinical case reviews are presented here. The volumetric results have been correlated with clinical data and their implications are also discussed.
  
  
  CONCLUSIONS
  The heterogeneity of OPGs, the long course, and the young age of the patients are all driving the demand for more efficient and accurate means of tumor follow-up. This method may allow better understanding of the natural history of the tumor and provide a more advanced means of treatment evaluation.
authors: Department of Pediatric Neurosurgery, Dana Children's Hospital, Tel Aviv Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 64239, Israel.
authors: Ben
authors: B
authors: Shofty
authors: Lior
authors: L
authors: Weizman
authors: Leo
authors: L
authors: Joskowicz
authors: Shlomi
authors: S
authors: Constantini
authors: Anat
authors: A
authors: Kesler
authors: Dafna
authors: D
authors: Ben-Bashat
authors: Michal
authors: M
authors: Yalon
authors: Rina
authors: R
authors: Dvir
authors: Sigal
authors: S
authors: Freedman
authors: Jonathan
authors: J
authors: Roth
authors: Liat
authors: L
authors: Ben-Sira
mesh_terms: D000465:Algorithms; D002675:Child, Preschool; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging; D008297:Male; D020339:Optic Nerve Glioma / Q000175:diagnosis* / Q000628:therapy