Using a numerical method to precisely evaluate the alpha angle in a hip image.
Med Biol Eng Comput
; 57(7): 1525-1535, 2019 Jul.
Article
en En
| MEDLINE
| ID: mdl-30963390
The alpha angle is a parameter extensively used to assess for cam-type femoroacetabular impingement (FAI) in a 2D image of the hip. As this angle requires estimation of the axis of the femoral neck, the drawing of this axis often results in measurement errors due to subjective judgment, influencing inter-rater and intra-rater agreements. In the present study, sampling points were captured from the edges of a femoral neck and head in the 2D image, and the best curves of the two were fitted respectively by using the curve fitting method. The morphology of the femoral neck was outlined by two polynomials, and the femoral head was represented by an equation of a circle. By means of the proposed method, the results reveal that the inter-rater ICCs in X-ray and MRI were respectively 0.905 and 0.969, and the intra-rater ICCs in X-ray and MRI were respectively 0.892 and 0.840. The Bland-Altman plot shows that the values obtained by the proposed method and the conventional method were not consistent; nevertheless, the linear regression analysis indicated the two measurement results had a significant association (p < 0.001). This study provides a repeatable and agreed α angle measuring method, which contributes to identifying normal and abnormal femoral head-neck morphologies. The proposed numerical method would contribute to diagnose early FAI.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Procesamiento de Imagen Asistido por Computador
/
Cuello Femoral
/
Pinzamiento Femoroacetabular
/
Cadera
Tipo de estudio:
Diagnostic_studies
Límite:
Humans
Idioma:
En
Revista:
Med Biol Eng Comput
Año:
2019
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
Estados Unidos