The article entitled, "Mn-porphyrins as novel molecular MRI contrast agents" by Mouraviev et al., published online ahead of print on November 3, 2011 (DOI: 10.1089/end.2011.0133), in its unedited, uncorrected format, is being officially withdrawn from Journal of Endourology. This early version of the manuscript was not in its final form. A further revision has since submitted for re-review and has been accepted for publication. It is currently published in its Instant Online format (the raw, unedited manuscript) and carries a DOI of 10.1089/end.2012.0171. It will be included in the November 2012 issue of Journal of Endourology.