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

Publication Type Academic Article
Authors Vendemia N, Chao J, Ivanidze J, Sanelli P, Spinelli H
Journal J Craniofac Surg
Volume 22
Issue 1
Pagination 73-6
Date Published 01/01/2011
ISSN 1536-3732
Keywords Biocompatible Materials, Oral Surgical Procedures, Polyethylenes, Tomography, X-Ray Computed
Abstract BACKGROUND: Medpor (Porex Surgical, Inc, Newnan, GA) is composed of porous polyethylene and is commonly used in craniofacial reconstruction. When complications such as seroma or abscess formation arise, diagnostic modalities are limited because Medpor is radiolucent on conventional radiologic studies. This poses a problem in situations where imaging is necessary to distinguish the implant from surrounding tissues. OBJECTIVE: To present a clinically useful method for imaging Medpor with conventional computed tomographic (CT) scanning. MATERIALS AND METHODS: Eleven patients (12 total implants) who have undergone reconstructive surgery with Medpor were included in the study. A retrospective review of CT scans done between 1 and 16 months postoperatively was performed using 3 distinct CT window settings. Measurements of implant dimensions and Hounsfield units were recorded and qualitatively assessed. RESULTS: Of the 3 distinct window settings studied, namely, "bone" (W1100/L450), "soft tissue"; (W500/L50), and "implant" (W800/L200), the implant window proved the most ideal, allowing the investigators to visualize and evaluate Medpor in all cases. Qualitative analysis revealed that Medpor implants were able to be distinguished from surrounding tissue in both the implant and soft tissue windows, with a density falling between that of fat and fluid. In 1 case, Medpor could not be visualized in the soft tissue window, although it could be visualized in the implant window. Quantitative analysis demonstrated a mean (SD) density of -38.7 (7.4) Hounsfield units. CONCLUSIONS: Medpor may be optimally visualized on conventional CT scans using the implant window settings W800/L200, which can aid in imaging Medpor and diagnosing implant-related complications.
DOI 10.1097/SCS.0b013e3181f6f5fc
PubMed ID 21187769
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