CerviHFENet: hybrid feature extraction-based deep learning for multi-label classification of upper cervical spine abnormalities in X-ray imaging

Accurate diagnosis of upper cervical spine abnormalities is crucial for effective treatment and prognosis. However, the diversity of anatomical structures and pathological abnormalities poses significant challenges to the diagnostic process. These challenges highlight the need for deep learning models, which are capable of identifying multiple abnormalities to assist in diagnosis. Traditional deep learning approaches have exhibited limitations in extracting sequential features from multi-positional X-ray images and in performing joint diagnosis of multiple coexisting abnormalities. Therefore, a CerviHFENet-based framework is proposed to perform multi-label classification of six upper cervical spine abnormalities using three-view radiographs (extension, neutral, and flexion) obtained from individual patients. The system first incorporates an adaptive region of interest (ROI) detection module to minimize irrelevant information by precisely localizing the upper cervical spine. Following this, the CerviHFENet model integrates a hybrid feature extraction (HFE) mechanism that extracts both the anatomical features of the upper cervical vertebrae and the dynamic variations in bone structure across different neck positions, thereby fully representing the comprehensive characteristics of the upper cervical spine. Furthermore, a modified focal loss function is employed to enable the model to learn the mutual exclusivity or conditionally dependent relationships among the six abnormalities. A total of 249 patients participated in the study, contributing 747 X-ray images. The model achieved a mean AUC of 96.22% and a mean mAP of 94.6% on the test set, indicating promising diagnostic performance and validating the feasibility and effectiveness of the proposed model.