Development of 3D Multi-Parametric Ultrasound (MPUS) as a Decision Support Tool for Patients With Abdominal and Pelvic Tumors Undergoing Therapy

Inclusion Criteria: 1. Participant has untreated liver metastases from colorectal low-grade adenocarcinoma (biopsy-proven and/or characteristic findings on CT, MRI, or FDG-PET) and has planned to undergo a new course of cancer therapy\*. 2. Participant is age \>/=18 years. 3. Participant has at least one target lesion that measures ≥1cm in diameter (minimum size according to RECIST 1.1) with a maximum diameter of 14cm amenable to imaging with ultrasound 4. Participant is willing to comply with protocol requirements. 5. Participant has given written informed consent to participate in this study. * Any line of cancer therapy is allowed, including systemic and localized treatments, after any prior treatment. For systemic combination treatments, prior treatment with either drug is allowed at the discretion of the investigators, including rechallenges with the same drug combination, for example upon progression on imaging after a treatment break. For combination treatments where patients start treatment with different drugs at different times, the start date of treatment is determined at the discretion of the investigators and can be the start date of the first drug or of the combination treatment. Repeat participation in the study is allowed, if patients are eligible again per their treatment plan. Exclusion Criteria: 1. Participant has documented anaphylactic or other severe reaction to any ultrasound contrast media or polyethylene glycol (PEG). 2. Participant has any comorbid condition\*\* that, in the opinion of the treating provider or the Protocol Director, compromises the participant's ability to participate in the study. 3. Participant is pregnant (positive urine or serum beta-hCG) or lactating. 4. Presence of cardiac shunt or presence of pulmonary hypertension (contradiction for ultrasound contrast agent) 5. Renal insufficiency with a creatinine level \>1.5mg/dl, per our institutional guidelines (contradiction for CT imaging). * Examples: any mental condition that compromises the ability to follow a consent discussion, or to make informed decisions (except if represented by a Legally Authorized Representative \[LAR\]); any condition that makes the participant not a good candidate to have ultrasound exams with contrast agent.