To cite oro.dicom in publications use:

Brandon Whitcher, Volker J. Schmid, Andrew Thornton (2011). Working with the DICOM and NIfTI Data Standards in R. Journal of Statistical Software, 44(6), 1-28. URL http://www.jstatsoft.org/v44/i06/.

Corresponding BibTeX entry:

  @Article{,
    title = {Working with the {DICOM} and {NIfTI} Data Standards in
      {R}},
    author = {Brandon Whitcher and Volker J. Schmid and Andrew
      Thornton},
    journal = {Journal of Statistical Software},
    year = {2011},
    volume = {44},
    number = {6},
    pages = {1--28},
    url = {http://www.jstatsoft.org/v44/i06/},
  }