Segmentation of avascular necrosis of the femoral head using 3-D MR images

Avascular necrosis of the femoral head (ANFH) is a common clinical disorder in the orthopedic field. Traditional approaches to study the extent of ANF H rely primarily on manual segmentation of clinical magnetic resonance imag es (MRI). However, manual segmentation is insufficient for quantitative eva luation and staging of ANFH. This paper presents a new computerized approac h for segmentation of necrotic lesions of the femoral head. The segmentatio n method consists of several steps including histogram based thresholding, 3-D morphological operations, oblique data reconstruction, and 2-D ellipse fitting. The proposed technique is rapid and efficient. In addition, it is available as a Microsoft Windows free software package on the Internet. Fea sibility of the method is demonstrated on the data sets of 30 patients (150 0 MR images). (C) 2001 Elsevier Science Ltd. All rights reserved.