This trial studies how well a Millar Mikro-tip catheter and shear wave elastography measure pressure and stiffness inside tumors among patients with solid tumors undergoing an ultrasound-guided biopsy. A Millar Mikro-tip catheter measures the pressure inside the tumor. Shear wave elastography is similar to an ultrasound and uses sound waves to vibrate the tissue in order to study tissue stiffness. These measurements may help doctors learn if pressure and stiffness are related to intratumoral fibrosis (the thickening and scarring of connective tissue).

PRIMARY OBJECTIVES:

I. To determine the feasibility of measuring tumor intratumoral pressures in vivo using a commercially available, sterile, single use, cardiovascular catheter device.

II. To determine the feasibility of measuring tumor intratumoral stiffness in vivo using a commercially available shear wave elastography with ultrasound.

SECONDARY OBJECTIVES:

I. To assess the relationship of tumor pressure, stiffness, and fibrosis.

OUTLINE:

Patients scheduled for an ultrasound-guided tumor biopsy undergo stiffness assessment of the tumor with shear wave elastography over 2 minutes and pressure measurements of the tumor using a Millar Mikro-tip catheter before and after the biopsy is collected.

After completion of the study, patients are followed up at 24-48 hours and at 30 days.

Inclusion Criteria:

• Patients who are scheduled for at least one biopsy (diagnostic or research) for solid organ tumors (excluding bone) at MD Anderson.
• Patients who are able to understand and give consent to participation in the study.

Exclusion Criteria:

• Tumor size < 1.5 cm or > 5 cm in size on pre-procedural imaging for 1st assessment and < 1 cm for 2nd assessment
• Pregnant women (these patients will be tested for pregnancy before they are scheduled for a diagnostic or research biopsy per inclusion criteria #1).
• Tumors involving bone.