1: Park S, Plishker W, Quon H, Wong J, Shekhar R, Lee J. Deformable registration 
of CT and cone-beam CT with local intensity matching. Phys Med Biol. 2017 Feb
7;62(3):927-947. doi: 10.1088/1361-6560/aa4f6d. Epub 2017 Jan 11. PubMed PMID:
28074785; PubMed Central PMCID: PMC5283299.

2: Park S, McNutt T, Plishker W, Quon H, Wong J, Shekhar R, Lee J. Technical
Note: scuda: A software platform for cumulative dose assessment. Med Phys. 2016
Oct;43(10):5339. PubMed PMID: 27782691; PubMed Central PMCID: PMC5018004.

3: Robertson MS, Liu X, Plishker W, Zaki GF, Vyas PK, Safdar NM, Shekhar R.
Software-based PET-MR image coregistration: combined PET-MRI for the rest of us! 
Pediatr Radiol. 2016 Oct;46(11):1552-61. doi: 10.1007/s00247-016-3641-8. Epub
2016 Jul 5. PubMed PMID: 27380195; PubMed Central PMCID: PMC5039099.

4: Tokuda J, Plishker W, Torabi M, Olubiyi OI, Zaki G, Tatli S, Silverman SG,
Shekher R, Hata N. Graphics Processing Unit-Accelerated Nonrigid Registration of 
MR Images to CT Images During CT-Guided Percutaneous Liver Tumor Ablations. Acad 
Radiol. 2015 Jun;22(6):722-33. doi: 10.1016/j.acra.2015.01.007. Epub 2015 Mar 14.
PubMed PMID: 25784325; PubMed Central PMCID: PMC4428967.

5: Tian J, Jeudy J, Smith MF, Jimenez A, Yin X, Bruce PA, Lei P, Turgeman A, Abbo
A, Shekhar R, Saba M, Shorofsky S, Dickfeld T. Three-dimensional
contrast-enhanced multidetector CT for anatomic, dynamic, and perfusion
characterization of abnormal myocardium to guide ventricular tachycardia
ablations. Circ Arrhythm Electrophysiol. 2010 Oct;3(5):496-504. doi:
10.1161/CIRCEP.109.889311. Epub 2010 Jul 24. PubMed PMID: 20657032.

6: Brock KK; Deformable Registration Accuracy Consortium. Results of a
multi-institution deformable registration accuracy study (MIDRAS). Int J Radiat
Oncol Biol Phys. 2010 Feb 1;76(2):583-96. doi: 10.1016/j.ijrobp.2009.06.031. Epub
2009 Nov 10. PubMed PMID: 19910137.

7: Wu J, Lei P, Shekhar R, Li H, Suntharalingam M, D'Souza WD. Do tumors in the
lung deform during normal respiration? An image registration investigation. Int J
Radiat Oncol Biol Phys. 2009 Sep 1;75(1):268-75. doi:
10.1016/j.ijrobp.2009.03.008. Epub 2009 Jun 8. PubMed PMID: 19515506.

8: Lei P, Dandekar O, Widlus D, Shekhar R. Incorporation of preprocedural PET
into CT-guided radiofrequency ablation of hepatic metastases: a nonrigid image
registration validation study. J Digit Imaging. 2010 Dec;23(6):780-92. doi:
10.1007/s10278-009-9204-x. Epub 2009 May 27. PubMed PMID: 19472008; PubMed
Central PMCID: PMC3046698.

9: Wu J, Li H, Shekhar R, Suntharalingam M, D'Souza W. An evaluation of planning 
techniques for stereotactic body radiation therapy in lung tumors. Radiother
Oncol. 2008 Apr;87(1):35-43. doi: 10.1016/j.radonc.2008.02.010. Epub 2008 Mar 24.
PubMed PMID: 18359529; PubMed Central PMCID: PMC2706126.

10: Dickfeld T, Lei P, Dilsizian V, Jeudy J, Dong J, Voudouris A, Peters R, Saba
M, Shekhar R, Shorofsky S. Integration of three-dimensional scar maps for
ventricular tachycardia ablation with positron emission tomography-computed
tomography. JACC Cardiovasc Imaging. 2008 Jan;1(1):73-82. doi:
10.1016/j.jcmg.2007.10.001. PubMed PMID: 19356409.

11: Walimbe V, Dandekar O, Mahmoud F, Shekhar R. Automated 3D elastic
registration for improving tumor localization in whole-body PET-CT from combined 
scanner. Conf Proc IEEE Eng Med Biol Soc. 2006;1:2799-802. PubMed PMID: 17946137.

12: Dandekar O, Walimbe V, Shekhar R. Hardware implementation of hierarchical
volume subdivision-based elastic registration. Conf Proc IEEE Eng Med Biol Soc.
2006;1:1425-8. PubMed PMID: 17946046.

13: Shekhar R, Lei P, Castro-Pareja CR, Plishker WL, D'Souza WD. Automatic
segmentation of phase-correlated CT scans through nonrigid image registration
using geometrically regularized free-form deformation. Med Phys. 2007
Jul;34(7):3054-66. PubMed PMID: 17822013.

14: Dandekar O, Shekhar R. FPGA-Accelerated Deformable Image Registration for
Improved Target-Delineation During CT-Guided Interventions. IEEE Trans Biomed
Circuits Syst. 2007 Jun;1(2):116-27. doi: 10.1109/TBCAS.2007.909023. PubMed PMID:

15: Feng Y, Castro-Pareja C, Shekhar R, Yu C. Direct aperture deformation: an
interfraction image guidance strategy. Med Phys. 2006 Dec;33(12):4490-8. PubMed
PMID: 17278800.

16: Castro-Pareja C, Shekhar R. Physically correct mesh manipulation in
multi-level free-form deformation-based nonrigid registration. Conf Proc IEEE Eng
Med Biol Soc. 2004;3:1687-90. PubMed PMID: 17272028.

17: Walimbe V, Garcia M, Lalude O, Thomas J, Shekhar R. Quantitative real-time
3-dimensional stress echocardiography: a preliminary investigation of feasibility
and effectiveness. J Am Soc Echocardiogr. 2007 Jan;20(1):13-22. PubMed PMID:

18: Walimbe V, Shekhar R. Automatic elastic image registration by interpolation
of 3D rotations and translations from discrete rigid-body transformations. Med
Image Anal. 2006 Dec;10(6):899-914. Epub 2006 Oct 31. PubMed PMID: 17079184.

19: Shekhar R, Walimbe V, Raja S, Zagrodsky V, Kanvinde M, Wu G, Bybel B.
Automated 3-dimensional elastic registration of whole-body PET and CT from
separate or combined scanners. J Nucl Med. 2005 Sep;46(9):1488-96. PubMed PMID:

20: Zagrodsky V, Walimbe V, Castro-Pareja CR, Qin JX, Song JM, Shekhar R.
Registration-assisted segmentation of real-time 3-D echocardiographic data using 
deformable models. IEEE Trans Med Imaging. 2005 Sep;24(9):1089-99. PubMed PMID:

21: Shekhar R, Zagrodsky V, Garcia MJ, Thomas JD. Registration of real-time 3-D
ultrasound images of the heart for novel 3-D stress echocardiography. IEEE Trans 
Med Imaging. 2004 Sep;23(9):1141-9. PubMed PMID: 15377123.

22: Castro-Pareja CR, Jagadeesh JM, Shekhar R. FAIR: a hardware architecture for 
real-time 3-D image registration. IEEE Trans Inf Technol Biomed. 2003
Dec;7(4):426-34. PubMed PMID: 15000369.

23: Walimbe V, Zagrodsky V, Raja S, Jaber WA, DiFilippo FP, Garcia MJ, Brunken
RC, Thomas JD, Shekhar R. Mutual information-based multimodality registration of 
cardiac ultrasound and SPECT images: a preliminary investigation. Int J
Cardiovasc Imaging. 2003 Dec;19(6):483-94. PubMed PMID: 14690187.

24: Shekhar R, Zagrodsky V, Castro-Pareja CR, Walimbe V, Jagadeesh JM. High-speed
registration of three- and four-dimensional medical images by using voxel
similarity. Radiographics. 2003 Nov-Dec;23(6):1673-81. PubMed PMID: 14615572.

25: Shekhar R, Zagrodsky V. Mutual information-based rigid and nonrigid
registration of ultrasound volumes. IEEE Trans Med Imaging. 2002 Jan;21(1):9-22. 
PubMed PMID: 11838664.