title: Second harmonic generation imaging distinguishes both high-grade dysplasia and cancer from normal colonic mucosa.
abstract: OBJECTIVE
  Second harmonic generation (SHG) is a novel imaging technology that could provide optical biopsy during endoscopy with advantages over current technology. SHG has the unique ability to evaluate the amount of extracellular matrix collagen protein and its alignment.
  
  
  METHODS
  Hematoxylin- and eosin-stained slides from colon biopsies (normal, low-grade dysplasia (LGD), high-grade dysplasia (HGD), and cancer) were examined with SHG imaging. Both signal intensity and collagen fiber alignment were measured. Average intensity per pixel (AIPP) was obtained, and an analyzing polarizer was used to calculate β, an alignment parameter.
  
  
  RESULTS
  The mean AIPP for normal mucosa was 48, LGD was 38, HGD was 42, and malignancy was 123 (p < 0.01). The AIPP ROC curve between malignant versus non-malignant tissue was 0.96 (0.93-0.99). An AIPP value of 60 can differentiate malignancy with 87 % sensitivity and 90 % specificity. The mean β for normal tissue was 0.490, LGD was 0.379, HGD was 0.345, and cancer was 0.453 (p = 0.013), with a normal tissue mean rank of 6.5 compared to 2.5 for HGD (p = 0.029).
  
  
  CONCLUSIONS
  SHG signal intensity can differentiate malignant from non-malignant colonic polyp tissue with high sensitivity and specificity. Anisotropic polarization can discern HGD from normal colonic polyp tissue. SHG can thus distinguish both HGD and malignant lesions in an objective numeric fashion, without contrast agents or interpretation skills. SHG could be incorporated into endoscopy equipment to enhance white light endoscopy.
authors.affiliation: Division of Gastroenterology and Hepatology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT, 06030-1845, USA, birk@uchc.edu.
authors.forename: John W
authors.initials: JW
authors.lastname: Birk
authors.forename: Micheal
authors.initials: M
authors.lastname: Tadros
authors.forename: Koorosh
authors.initials: K
authors.lastname: Moezardalan
authors.forename: Oleg
authors.initials: O
authors.lastname: Nadyarnykh
authors.forename: Faripour
authors.initials: F
authors.lastname: Forouhar
authors.forename: Joseph
authors.initials: J
authors.lastname: Anderson
authors.forename: Paul
authors.initials: P
authors.lastname: Campagnola
mesh_terms: D016880:Anisotropy; D003106:Colon / Q000473:pathology*; D003110:Colonic Neoplasms / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology; D003113:Colonoscopy / Q000379:methods*; D003937:Diagnosis, Differential; D005240:Feasibility Studies; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology*; D061848:Optical Imaging / Q000295:instrumentation / Q000379:methods*; D012372:ROC Curve; D012680:Sensitivity and Specificity
references.citation: Biophys J. 2002 Jan;82(1 Pt 1):493-508
references.pmid: 11751336
references.citation: Opt Express. 2007 Apr 2;15(7):4054-65
references.pmid: 19532649
references.citation: PLoS One. 2012;7(6):e38655
references.pmid: 22715404
references.citation: Anal Chem. 2011 May 1;83(9):3224-31
references.pmid: 21446646
references.citation: J Struct Biol. 2003 Jan;141(1):53-62
references.pmid: 12576020
references.citation: J Biomed Opt. 2008 Nov-Dec;13(6):064010
references.pmid: 19123657
references.citation: Opt Commun. 2008 Apr 1;281(7):1823-1832
references.pmid: 19343083
references.citation: Gastrointest Endosc. 2009 Aug;70(2):197-200
references.pmid: 19559426
references.citation: Opt Lett. 2006 Sep 15;31(18):2756-8
references.pmid: 16936882
references.citation: Invest Ophthalmol Vis Sci. 2006 Dec;47(12):5251-9
references.pmid: 17122110
references.citation: Nat Methods. 2006 Jan;3(1):47-53
references.pmid: 16369553
references.citation: Opt Express. 2009 Mar 16;17(6):4868-78
references.pmid: 19293918
references.citation: Nat Med. 2003 Jun;9(6):796-800
references.pmid: 12754503
references.citation: J Invest Dermatol. 2003 Dec;121(6):1332-5
references.pmid: 14675178
references.citation: Biophys J. 2006 Jan 1;90(1):328-39
references.pmid: 16214853
references.citation: Best Pract Res Clin Gastroenterol. 2012 Jun;26(3):221-33
references.pmid: 22704566
references.citation: Gastrointest Endosc. 2008 Sep;68(3):528-30
references.pmid: 18760179
references.citation: Biophys J. 2006 Dec 15;91(12):4665-77
references.pmid: 17130233
references.citation: Biophys J. 2005 Feb;88(2):1377-86
references.pmid: 15533922
references.citation: J Biomed Opt. 2004 Jul-Aug;9(4):760-6
references.pmid: 15250763
references.citation: J Biomed Opt. 2007 Sep-Oct;12(5):051805
references.pmid: 17994883
references.citation: Biophys J. 1986 Oct;50(4):693-712
references.pmid: 3779007
references.citation: BMC Cancer. 2010 Mar 11;10:94
references.pmid: 20222963
references.citation: Nat Biotechnol. 2003 Nov;21(11):1356-60
references.pmid: 14595363
references.citation: Hepatology. 2001 Jul;34(1):82-8
references.pmid: 11431737
references.citation: BMC Med. 2006 Dec 26;4(1):38
references.pmid: 17190588
references.citation: Biomed Opt Express. 2011 Aug 1;2(8):2307-16
references.pmid: 21833367
references.citation: Biophys J. 2008 Jun;94(11):4504-14
references.pmid: 18281387
references.citation: Opt Express. 2007 Aug 6;15(16):10135-48
references.pmid: 19547362
references.citation: J Cell Physiol. 2002 Sep;192(3):259-67
references.pmid: 12124771
references.citation: J Cell Physiol. 2007 Nov;213(2):374-83
references.pmid: 17680632
references.citation: Opt Express. 2005 Jul 25;13(15):5791-7
references.pmid: 19498583
references.citation: J Microsc. 2008 Jan;229(Pt 1):32-8
references.pmid: 18173642
references.citation: Biophys J. 2006 Jan 15;90(2):693-703
references.pmid: 16258040
references.citation: Opt Express. 2005 Oct 3;13(20):8231-42
references.pmid: 19498853
references.citation: J Natl Cancer Inst. 2002 Aug 7;94(15):1134-42
references.pmid: 12165638
references.citation: BMC Med. 2008 Apr 28;6:11
references.pmid: 18442412
references.citation: Lijec Vjesn. 2009 Mar-Apr;131(3-4):69-73
references.pmid: 19514252
references.citation: J Biomed Opt. 2011 Dec;16(12):120501
references.pmid: 22191906
references.citation: J Phys Chem B. 2009 Oct 8;113(40):13437-45
references.pmid: 19754079
references.citation: J Opt Soc Am A Opt Image Sci Vis. 2007 Nov;24(11):3573-86
references.pmid: 17975584
references.citation: Semin Reprod Med. 2006 Sep;24(4):270-82
references.pmid: 16944424
references.citation: J Biophotonics. 2010 Jan;3(1-2):34-43
references.pmid: 19771581
references.citation: J Gastrointestin Liver Dis. 2006 Jun;15(2):161-5
references.pmid: 16802011