ABSTRACT
Endometrial imaging has taken on a new dimension with the advent of transvaginal ultrasonography. With recent advances in the field of ultrasonography, the amount and quality of information available to the clinician and patient, on the screen, in an office setting, is becoming increasingly spectacular. Perhaps, the current limitations of this technology reflect the limitations of our imagination. Ultrasounds are high frequency sound waves exceeding 20,000 cycles per second. Most of the equipment in use today in diagnostic ultrasonography operates at frequencies of 2-10 megahertz (MHz). The vast majority of vaginal transducers operate at 5-7.5MHz while the abdominal transducers operate at 3.5-5MHz. The higher the frequency of the sound waves, the better the resolution of the images produced but the more limited the field (depth) of view. In other words, the highest frequency possible that penetrates to the desired structure under examination is recommended. Transvaginal ultrasonography, compared with abdominal ultrasonography, has emerged as a valuable tool for assessing the endometrium because it is well tolerated, it does not require a full bladder, and the vaginal probe is closer to the target thereby allowing higher frequency probes offering more detailed images. Threedimensional ultrasonography and magnetic resonance imaging are two other diagnostic modalities with encouraging results. The role of magnetic resonance imaging for assessment of the endometrium is purely investigational at the moment. The equipment is complex, expensive and restricted to major radiologic diagnostic centers. Threedimensional ultrasonography, as a new measurement technique still requires careful validation before being incorporated into research and clinical practice. Consequently, this imaging modality is beyond the scope of this chapter.
