Ultrasound is an invaluable diagnostic tool in gynecology, as it allows visualization of the reproductive organs without x-ray radiation exposure. This test used to be done by placing an external transducer (which emits sound waves) over the abdomen. Recently, ultrasound examination using a vaginal transducer has become popular for evaluation of many gynecological conditions, as it allows closer visualization of the structures of interest. The transducer is about the size of a large tampon. It is inserted into the vagina only, and thus causes no opening of the uterus. It is generally well lubricated and thus unlikely to cause bleeding. Performance of this exam should not render a woman niddah. If blood is noted on the transducer she should ask the doctor to explain the source of the bleeding and then consult a rabbi.
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