A method for visualizing high-density porous polyethylene (medpor, porex) with computed tomographic scanning

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Plastic Surgery

Background:

• Medpor (porous polyethylene) is widely used in craniofacial reconstruction.
• Conventional radiologic studies have limited diagnostic capabilities for Medpor due to its radiolucence.
• Distinguishing Medpor implants from surrounding tissues can be difficult, complicating complication diagnosis.

Purpose of the Study:

• To establish a practical method for visualizing Medpor implants using standard computed tomographic (CT) scanning.
• To improve diagnostic accuracy for Medpor-related complications.

Main Methods:

• Retrospective review of CT scans from 11 patients (12 implants) post-craniofacial reconstruction.
• Evaluation of three distinct CT window settings: "bone" (W1100/L450), "soft tissue" (W500/L50), and "implant" (W800/L200).
• Quantitative and qualitative assessment of Medpor visualization and density (Hounsfield units).

Main Results:

• The "implant" window setting (W800/L200) was most effective for visualizing Medpor in all cases.
• Medpor implants were distinguishable from surrounding tissues in "implant" and "soft tissue" windows.
• Mean Hounsfield unit density of Medpor was -38.7 (7.4), falling between fat and fluid densities.

Conclusions:

• Optimal visualization of Medpor on conventional CT scans is achieved using "implant" window settings (W800/L200).
• This imaging technique can assist in diagnosing Medpor-related complications.
• The findings provide a clinically useful method for evaluating Medpor implants.