The present invention features peptides of a PorB polypeptide, which PorB peptides are useful in production of antibodies that bind the full-length PorB polypeptide and as a therapeutic agent. The lactone-containing copolymer is represented by a copolymer of the following compounds, , and. At least one of an attenuation, confidence or density map accounting for the metal element is generated and the location of the local receive coil within the imaging volume is determined.