What is the initial imaging modality of choice for evaluating an abdominal mass?

Ultrasound is considered the initial imaging modality of choice for evaluating an abdominal mass, particularly in specific patient populations such as children and during pregnancy. It is non-invasive, does not involve ionizing radiation, and is generally well-tolerated. Ultrasound is highly effective for assessing the characteristics of a mass, such as distinguishing between solid and cystic lesions, and can help guide further management and diagnostic steps.

In many scenarios, ultrasound can also provide valuable information regarding the size, location, and potential involvement of surrounding structures without the risks associated with other modalities. It is often used as the first-line approach because it can be quickly performed at the bedside and provides immediate results, making it an ideal choice for initial evaluations.

While other imaging methodologies, such as CT scans and MRIs, offer more detailed views and are used in subsequent evaluations, they are generally reserved for cases where ultrasound provides inconclusive findings or further characterization is necessary. Therefore, the choice of ultrasound for the initial evaluation of an abdominal mass aligns with clinical guidelines and practice standards.