Which procedure is least likely to require patient catheterization?

Radionuclide liver imaging is least likely to require patient catheterization because this procedure typically involves the injection of a radiopharmaceutical agent intravenously to visualize the liver and assess its function. The process does not necessitate direct access to the urinary tract or a vascular system beyond the intravenous route.

In contrast, other procedures listed often involve catheterization for access or assessment purposes. Radionuclide cystography, for example, involves the assessment of bladder function and usually requires catheterization to instill the radiopharmaceutical into the bladder. LeVeen shunt patency assessment may involve catheterization to evaluate the patency of the shunt within the body. A stress test with Sestamibi focuses on heart function and typically might involve catheterization if further cardiac assessments or direct measurements are needed.

Thus, the requirements and purposes of catheterization in these procedures make the need for it in radionuclide liver imaging significantly lower.