Final answer:
To obtain cells from a hepatic tumor, physicians can use ultrasound-guided, CT-guided, or MRI-guided biopsies, which allow for precise needle placement while avoiding major blood vessels.
Step-by-step explanation:
The radiologic method that would allow a physician to obtain cells via needle biopsy from a hepatic tumor while avoiding major blood vessels is called ultrasound-guided biopsy or CT-guided biopsy. These imaging techniques offer real-time visualization, allowing the interventional radiologist to accurately guide the needle to the tumor while avoiding important structures such as blood vessels. Another advanced option is MRI-guided biopsy, which is particularly useful due to its high-contrast imaging capabilities that help in identifying the tumor and surrounding blood vessels without exposure to ionizing radiation.
In radioembolization, an interventional radiologist utilizes a fine needle to access the liver's blood vessels and delivers tiny radioactive seeds to disrupt the blood supply to liver tumors. This minimally invasive procedure uses the guidance of imaging techniques to accurately place the seeds, illustrating how modern radiology can aid in both diagnosis and treatment.