title: Optimal Contrast Agent Staining of Ligaments and Tendons for X-Ray Computed Tomography.
abstract: X-ray computed tomography has become an important tool for studying the microstructures of biological soft tissues, such as ligaments and tendons. Due to the low X-ray attenuation of such tissues, chemical contrast agents are often necessary to enhance contrast during scanning. In this article, the effects of using three different contrast agents--iodine potassium iodide solution, phosphotungstic acid and phosphomolybdic acid--are evaluated and compared. Porcine anterior cruciate ligaments, patellar tendons, medial collateral ligaments and lateral collateral ligaments were used as the basis of the study. Three samples of each of the four ligament/tendon types were each assigned a different contrast agent (giving a total of twelve samples), and the progression of that agent through the tissue was monitored by performing a scan every day for a total period of five days (giving a total of sixty scans). Since the samples were unstained on day one, they had been stained for a total of four days by the time of the final scans. The relative contrast enhancement and tissue deformation were measured. It was observed that the iodine potassium iodide solution penetrated the samples fastest and caused the least sample shrinkage on average (although significant deformation was observed by the time of the final scans), whereas the phosphomolybdic acid caused the greatest sample shrinkage. Equations describing the observed behaviour of the contrast agents, which can be used to predict optimal staining times for ligament and tendon X-ray computed tomography, are presented.
authors.affiliation: School of Materials, University of Manchester, Manchester, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Balint
authors.affiliation: Henry Moseley X-ray Imaging Facility, School of Materials, University of Manchester, Manchester, United Kingdom.
authors.forename: Tristan
authors.initials: T
authors.lastname: Lowe
authors.affiliation: School of Materials, University of Manchester, Manchester, United Kingdom.|School of Mathematics, University of Manchester, Manchester, United Kingdom.
authors.forename: Tom
authors.identifier: http://orcid.org/0000-0001-7536-5547
authors.initials: T
authors.lastname: Shearer
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging*; D017885:Collateral Ligaments / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000493:pharmacokinetics*; D017613:Iodine Compounds / Q000493:pharmacokinetics*; D008982:Molybdenum / Q000493:pharmacokinetics*; D017847:Patellar Ligament / Q000000981:diagnostic imaging; D010756:Phosphoric Acids / Q000493:pharmacokinetics*; D013552:Swine; D013710:Tendons / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D017613:Iodine Compounds; D010756:Phosphoric Acids; C439385:iodine potassium iodide; D008982:Molybdenum; C003125:phosphomolybdic acid