In this study there will be 2 different patient groups 1 and 2 that will consist of 40 and 64 patients, respectively with hepatocellular carcinoma who are eligible for resection and to receive Y90 radioembolization who have inadequate future liver remnant.

Y90 radioembolization uses radioactive beads (microspheres), which are tiny glass particles that are loaded with radiation. The beads are injected into an artery of the liver that supplies blood to the tumor(s). The beads flow to the tumor(s) and become trapped inside. The beads release the Y90 radiation inside the tumor(s).

Liver resection is used to remove the part of the liver that has the HCC tumor(s). It has been shown that Y90 radioembolization can also increase the untreated liver's size and volume. Patients with HCC may be liver resection candidates if they have a large enough liver.

The purpose of this research is to determine if there is an ideal Y90 dose to increase liver volume of the future liver remnant. This research may help determine the best Y90 dose for future patients who need a larger liver to have a liver resection.

Participants in Group 1 will have standard-of-care Y90 radioembolization as well as study-specific optional liver biopsy.

Participants who already have a planned Y90 radioembolization treatment with the dose range established in Group 1 will be enrolled into Group 2. Patient Group 2 will have blood drawn and a quantitative MRI performed at specific timepoints.

The study will last up to 3 months. Participants' health status will be followed up to 5 years.