An Investigational Device (Millar Mikro-Tip Catheter) and Imaging Scan (Shear Wave Elastography) in Measuring Tumor Pressure and Stiffness in Patients With Solid Tumors Undergoing Ultrasound-Guided Biopsy

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.