Gynaecological Ultrasound Felipe Moretti, MD Griff Jones, MD, FRCS Assistant Professor – UOttawa Maternal Fetal Medicine Division

Basic physics Gynaecology

Ultrasound used for medical purposes is from one MHz (one million cycles per second) to 20 MHz.

Higher frequency wave assesses the object more often in any given time period. This results in more information and allows sharper images

If each wave represents a path, the walker uses the same energy to reach point X. Low frequency waves penetrate deeper into the tissues than high frequency waves

Summary Low frequency sound waves can penetrate more deeply but have less definition than high frequency waves The farther something is away from the probe, the worse the resolution

In OB GYN Ultrasound – – We use low frequency probes for abdominal scanning – We use high frequency probes for transvaginal scanning

Gyne Ultrasound Assess: Uterine pathologies (ex. Fibroids); Endometrial pathologies (ex.polyps); Ovarian pathologies (cysts)

Uterus

Uterine Position

Uterus Transvaginal

Uterine Fibroid

Uterine Enlargement

Difficult Fibroids

Endometrium changes Throughout the cycle

Anteverted uterus with follicular endometrium Retroverted uterus with secretory endometrium

Abnormal Endometrium

Cavity Enlargement

Ovaries

Trans-abdominal Ovarian Scan

Transvaginal Ovarian Scan

Depth of penetration was not an issue here. But the improved resolution due to the higher frequency of the TV probe shows ovarian substance and allows a diagnosis of polycystic ovaries Transabdominal Transvaginal

Normal Ovary

Ovarian appearance changes throughout the menstrual cycle

Cystic Follicle

Cyst Complications

resolved 2 weeks later

Ovarian Masses

Thank You