Which statement about the modified in vivo method of labeling red blood cells with 99mTc pertechnetate is true?

The modified in vivo method of labeling red blood cells with 99mTc pertechnetate involves mixing the radiotracer with a reduced volume of the patient's blood. This approach is designed to simplify the labeling process and minimize the amount of blood drawn from the patient. By using a small volume of blood, the method not only reduces patient discomfort but also allows for efficient and effective radiolabeling, contributing to a higher quality imaging result. In this technique, the interaction between 99mTc pertechnetate and the red blood cells occurs after the blood has been collected, leading to successful labeling while ensuring that only a limited amount of blood is required for the procedure.

Other methods may involve larger volumes of blood, or the use of more complex labeling protocols, which are not characteristic of this modified in vivo method. Thus, the statement about mixing 99mTc pertechnetate with only a small volume of the patient’s blood accurately reflects a key feature of this approach.