ENHANCING XRAY / CT INSPECTIONS WITH CONTRAST AGENTS
Industrial CT scanning is used to identify and evaluate internal flow paths, leak locations, and material entrapment zones. One visualization enhancement method we use is barium sulfate or tungsten contrast solutions which provide high-density, radiopaque visualization within microchannels and fluid paths. Their inert nature and compatibility with many polymers and metals make them ideal tracers for inspecting critical assemblies without altering their structural integrity.
We’ve prepared three demonstrations to show how contrast agents are used.
Colonoscope
In the case of reusable colonoscopes, barium sulfate contrast dye was introduced into the internal channels to evaluate areas where organic material might accumulate and become trapped during use. Digital radiographs and CT scans are used to evaluate specific bends and junctions within the scope’s internal tubing where the dye accumulated, indicating potential zones for residue buildup.
These findings were critical for both design and maintenance considerations, and engineers used the data to modify channel geometry for better fluid flush-out, while reprocessing teams revised their cleaning protocols to target the identified risk areas. The ability to visualize internal flow and entrapment points in a non-destructive, real-time manner provided actionable insights that directly improved device hygiene, patient safety, and regulatory compliance.
Dialysis Cassette
For a multilayer dialysis cassette, barium sulfate contrast dye was pressurized to detect potential leak paths between bonded membrane layers. During industrial CT scanning, the dense contrast agent clearly outlined unintended fluid migration between layers, revealing microchannels and delamination zones that were otherwise invisible through conventional inspection methods. This analysis enabled the engineering team to pinpoint weaknesses in the sealing process, leading to improvements in both adhesive selection and bonding temperature.
LIFESTRAW FILTER
For the LifeStraw personal water filter, barium sulfate contrast dye was used to trace the internal flow of liquid through the device’s complex filter matrix. By introducing the dye into the inlet and scanning the unit with industrial CT, engineers are able to visualize the actual paths taken by fluid, identify areas of stagnation, and assess the effectiveness of the filtration layout. The scan revealed uneven distribution in certain regions, where the flow bypassed parts of the membrane, clogged, or failed to reach the full filtering surface.
