Which of the following is not a common indication for imaging with N13 ammonia?

The correct answer indicates that monitoring tumor progression is not a common indication for imaging with N13 ammonia. N13 ammonia is primarily used in cardiac imaging, particularly for assessing myocardial perfusion, evaluating cardiac output, and identifying coronary artery disease. These applications are essential in understanding issues related to heart function and blood flow.

In contrast, while imaging with radiopharmaceuticals plays a critical role in oncology, N13 ammonia specifically is not typically used for monitoring tumor progression. Instead, other agents and imaging modalities are better suited for evaluating the status of tumors, as they provide more relevant information regarding tumor metabolism, size, and response to treatment. Thus, the use of N13 ammonia is limited to more cardiovascular-centric assessments rather than oncological monitoring.