A Semi-Automatic Algorithm for Determining the Demyelination Load in Metachromatic Leukodystrophy

作者：Clas Philipp; Groeschel Samuel^*; Wilke Marko

来源：Academic Radiology, 2012, 19(1): 26-34.

DOI：10.1016/j.acra.2011.09.008

• Metachromatic leukodystrophy
• demyelination load
• semiautomatic segmentation
• magnetic resonance imaging
• lesion load

Rationale and Objectives: Metachromatic leukodystrophy is a lysosomal storage disorder leading to progressive demyelination of brain white matter. This is sensitively detected using magnetic resonance imaging. The volume of demyelination, the %26quot;demyelination load,%26quot; could serve as a useful parameter for assessing both the natural course of the disease and treatment effects. The aim of this study was to develop and validate a semiautomated approach for determining the demyelination load to achieve reliable and time-efficient segmentation results. %26lt;br%26gt;Materials and Methods: The demyelination load was determined in 77 magnetic resonance imaging data sets from 35 patients both manually and semiautomatically. For manual segmentation, regarded as the gold standard, the software ITK-Snap was used. For semiautomatic segmentation, a new algorithm called Clusterize was developed and implemented in MATLAB, consisting of automatic iterative region growing followed by the interactive selection of clusters. %26lt;br%26gt;Results were compared in terms of the obtained volumes, spatial overlap, and time taken to conduct the segmentation. Results: Performance of the semiautomatic algorithm was excellent, with the volumes generated by the new algorithm showing good agreement with the ones generated by the gold standard (93.4 +/- 45.5 vs 96.1 +/- 49.0 mL, P = NS) with high spatial overlap (Dice%26apos;s similarity coefficient = 0.7861 +/- 0.0697). The semiautomatic algorithm was significantly faster than the gold standard (8.2 vs 27.0 min, P %26lt; .001). Intrarater and interrater reliability determined high reproducibility of the method. %26lt;br%26gt;Conclusion: The demyelination load in metachromatic leukodystrophy can be determined in a time-efficient manner using a semiautomatic algorithm, showing high agreement with the current gold standard.

• 出版日期2012-1