Which of the following is NOT a main type of sonography?

The correct answer is C, Psychological sonography, as it is not recognized as a main type of sonography. Sonography primarily focuses on the use of high-frequency sound waves to produce images of structures within the body for diagnostic and therapeutic purposes. Diagnostic sonography encompasses a wide range of applications including obstetric, abdominal, and cardiac imaging, primarily aimed at identifying and diagnosing medical conditions.

Therapeutic sonography involves the use of ultrasound waves for treatment purposes, such as in physiotherapy or to target tissues in certain medical procedures. Vascular sonography specifically deals with imaging the blood vessels and assessing blood flow, playing a critical role in diagnosing vascular diseases.

In contrast, psychological sonography does not exist as a recognized category within medical sonography, making it distinct from the other established fields. This term may unintentionally suggest a connection between ultrasound technology and psychological assessment, which is not applicable in clinical practice. Such distinctions help clarify the primary roles and applications of sonography in the medical field.