The primary objective is to demonstrate that the accuracy of SC and SC+MP for determining whether a VP shunt is patent or obstructed is statistically no different than the accuracy of the accepted standard test, radionuclide shunt patency study, when performed simultaneously.
A secondary objective is to determine SC and SC+MP results in the presence of possible partial obstruction, which defined as subjects with radionuclide clearance measured by T1/2 of 8 to 10 minutes.
A secondary objective is to compare ShuntCheck flow rate results to simultaneous radionuclide clearance as measured by T1/2. A secondary objective is to demonstrate that ShuntCheck flow rate results are statistically equivalent to simultaneous radionuclide clearance measured by T1/2