American Board of Internal Medicine (ABIM) Certification Practice Exam

For pregnant patients with suspected nephrolithiasis, ultrasonography is preferred because it does not expose them to what?

1. Magnetic fields

2. Radiation

3. High pressure

4. Extreme temperatures

The correct answer is: Radiation

Ultrasonography is the preferred imaging technique for evaluating pregnant patients with suspected nephrolithiasis primarily because it does not expose them to radiation. During pregnancy, particularly in the first and second trimesters, minimizing exposure to radiation is crucial due to the potential risks it poses to the developing fetus. Ionizing radiation, such as that used in X-rays or CT scans, can have harmful effects, including an increased risk of developmental abnormalities and other adverse outcomes. Ultrasonography, on the other hand, uses sound waves to create images of the body's organs and structures, making it a safe option for both the mother and the baby. This imaging modality is effective in identifying kidney stones and evaluating the urinary tract without carrying the risks associated with radiation exposure. The other options—magnetic fields, high pressure, and extreme temperatures—are not relevant concerns associated with ultrasound in the context of pregnancy. Magnetic resonance imaging (MRI), for instance, does raise concerns about magnetic fields, but is typically considered safe during pregnancy, particularly when necessary. Overall, the absence of radiation exposure is the key factor that makes ultrasonography the imaging technique of choice in this scenario.