PMID- 17877822 OWN - NLM STAT- MEDLINE DCOM- 20071119 LR - 20220129 IS - 1472-6947 (Electronic) IS - 1472-6947 (Linking) VI - 7 DP - 2007 Sep 18 TI - Generating prior probabilities for classifiers of brain tumours using belief networks. PG - 27 AB - BACKGROUND: Numerous methods for classifying brain tumours based on magnetic resonance spectra and imaging have been presented in the last 15 years. Generally, these methods use supervised machine learning to develop a classifier from a database of cases for which the diagnosis is already known. However, little has been published on developing classifiers based on mixed modalities, e.g. combining imaging information with spectroscopy. In this work a method of generating probabilities of tumour class from anatomical location is presented. METHODS: The method of "belief networks" is introduced as a means of generating probabilities that a tumour is any given type. The belief networks are constructed using a database of paediatric tumour cases consisting of data collected over five decades; the problems associated with using this data are discussed. To verify the usefulness of the networks, an application of the method is presented in which prior probabilities were generated and combined with a classification of tumours based solely on MRS data. RESULTS: Belief networks were constructed from a database of over 1300 cases. These can be used to generate a probability that a tumour is any given type. Networks are presented for astrocytoma grades I and II, astrocytoma grades III and IV, ependymoma, pineoblastoma, primitive neuroectodermal tumour (PNET), germinoma, medulloblastoma, craniopharyngioma and a group representing rare tumours, "other". Using the network to generate prior probabilities for classification improves the accuracy when compared with generating prior probabilities based on class prevalence. CONCLUSION: Bayesian belief networks are a simple way of using discrete clinical information to generate probabilities usable in classification. The belief network method can be robust to incomplete datasets. Inclusion of a priori knowledge is an effective way of improving classification of brain tumours by non-invasive methods. FAU - Reynolds, Greg M AU - Reynolds GM AD - Department of Electrical, Electronic and Computer Engineering, University of Birmingham, Birmingham, UK. gmr001@bham.ac.uk FAU - Peet, Andrew C AU - Peet AC FAU - Arvanitis, Theodoros N AU - Arvanitis TN LA - eng GR - G0601327/MRC_/Medical Research Council/United Kingdom PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20070918 PL - England TA - BMC Med Inform Decis Mak JT - BMC medical informatics and decision making JID - 101088682 SB - IM MH - *Bayes Theorem MH - Brain Neoplasms/*classification/diagnosis MH - Child MH - Databases, Factual MH - *Decision Support Techniques MH - *Diagnosis, Computer-Assisted MH - Diagnosis, Differential MH - Germinoma/*classification/diagnosis MH - Humans MH - Magnetic Resonance Spectroscopy MH - Neoplasm Staging MH - Neuroectodermal Tumors/*classification/diagnosis MH - Probability PMC - PMC2040142 EDAT- 2007/09/20 09:00 MHDA- 2007/12/06 09:00 PMCR- 2007/09/18 CRDT- 2007/09/20 09:00 PHST- 2007/05/12 00:00 [received] PHST- 2007/09/18 00:00 [accepted] PHST- 2007/09/20 09:00 [pubmed] PHST- 2007/12/06 09:00 [medline] PHST- 2007/09/20 09:00 [entrez] PHST- 2007/09/18 00:00 [pmc-release] AID - 1472-6947-7-27 [pii] AID - 10.1186/1472-6947-7-27 [doi] PST - epublish SO - BMC Med Inform Decis Mak. 2007 Sep 18;7:27. doi: 10.1186/1472-6947-7-27.