Adenoma Discrimination by 3-Slices Washout Calculation on CT Scans

Adrenal lesions are common incidental findings in clinical practice, which are mostly benign and harmless; adenomas are the most common benign adrenal tumors, representing more than 75% adrenal lesions. Medical information provided by CT scans such as lesions' dimension, attenuation values, etc., are crucial for the diagnosis of adenoma. Measurements of percentage washout of injected contrast material from contrast-enhanced CT provide reproducible means to distinguish adenomas from malignant masses. Despite of the 3D volume CT data, only selected 2D slices are used in this diagnosis process, which introduces uncertainty of clinical decision and requires high expertise of medical professionals. To alleviate this problem and to facilitate the diagnosis, we proposed an region-growing based 3-Slices washout calculation method, as a preliminary study of our further work of automatic 3D adrenal lesion characterisation. Comparing with the expert's diagnosis, our method showed a significant (more than 10%) improvement on the accuracy, revealing that computer-based 3D lesion characterisation could become a promising and reliable tool for the diagnosis of adrenal lesions.