Fig. 2From: Echogenicity and size of substantia nigra on transcranial sonography (TCS) in patients with attention-deficit/hyperactivity disorder and healthy children aged 6–12 years: a comparative studyAbnormal echogenicity of the SN. A–C show normal echogenicity, increasing echogenicity, and area decreasing echogenicity, respectively (Figure C shows only red nuclei in the medial)Back to article page