Color Doppler Ultrasounds (CDU) and Thyroid Scanning (TS) have much improved in recent years and offer a likely diagnosis of the disorder and its main subtypes. This especially applies when diagnosing permanent or transient causes of congenital hypothyroidism (CH), where dual imaging has proven to be more informative than single scanning. Though both isotopes have acceptable performances, the use of ¹²³I appears more advisable, since it more accurately identifies the various aetiologies of CH and probably has better dosimetric characteristics than ^99mTc. Detailed dual imaging patterns are presented in connection with most of the underlying mechanisms explaining CH, thyroid dysgenesis (75%) and dyshormonogenesis (20%). Imaging of thyroid autoimmunity, of immunogenic thyrotoxicosis and of thyroid autonomy, is helped by CDU but most often requires a quantified ¹²³I-TS (molecular imaging). We finally show the interest of CDU to sort suspicious nodule and present the new TIRADS scoring system.