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Karl G. Helmer, Ph.D.


Publications listed below are automatically derived from MEDLINE/PubMed and other sources, which might result in incorrect or missing publications. Faculty can login to make corrections and additions.
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PMC Citations indicate the number of times the publication was cited by articles in PubMed Central, and the Altmetric score represents citations in news articles and social media. (Note that publications are often cited in additional ways that are not shown here.) Fields are based on how the National Library of Medicine (NLM) classifies the publication's journal and might not represent the specific topic of the publication. Translation tags are based on the publication type and the MeSH terms NLM assigns to the publication. Some publications (especially newer ones and publications not in PubMed) might not yet be assigned Field or Translation tags.) Click a Field or Translation tag to filter the publications.
  1. Maillard P, Lu H, Arfanakis K, Gold BT, Bauer CE, Zachariou V, Stables L, Wang DJJ, Jann K, Seshadri S, Duering M, Hillmer LJ, Rosenberg GA, Snoussi H, Sepehrband F, Habes M, Singh B, Kramer JH, Corriveau RA, Singh H, Schwab K, Helmer KG, Greenberg SM, Caprihan A, DeCarli C, Satizabal CL. Instrumental validation of free water, peak-width of skeletonized mean diffusivity, and white matter hyperintensities: MarkVCID neuroimaging kits. Alzheimers Dement (Amst). 2022; 14(1):e12261. PMID: 35382232; PMCID: PMC8959640.
  2. Liu P, Jiang D, Albert M, Bauer CE, Caprihan A, Gold BT, Greenberg SM, Helmer KG, Jann K, Jicha G, Rodriguez P, Satizabal CL, Seshadri S, Singh H, Thompson JF, Wang DJJ, Lu H. Multi-vendor and multisite evaluation of cerebrovascular reactivity mapping using hypercapnia challenge. Neuroimage. 2021 12 15; 245:118754. PMID: 34826595; PMCID: PMC8783393.
    Citations:    Fields:    Translation:Humans
  3. Rost NS, Meschia JF, Gottesman R, Wruck L, Helmer K, Greenberg SM. Cognitive Impairment and Dementia After Stroke: Design and Rationale for the DISCOVERY Study. Stroke. 2021 08; 52(8):e499-e516. PMID: 34039035; PMCID: PMC8316324.
    Citations: 2     Fields:    Translation:Humans
  4. Wilcock D, Jicha G, Blacker D, Albert MS, D'Orazio LM, Elahi FM, Fornage M, Hinman JD, Knoefel J, Kramer J, Kryscio RJ, Lamar M, Moghekar A, Prestopnik J, Ringman JM, Rosenberg G, Sagare A, Satizabal CL, Schneider J, Seshadri S, Sur S, Tracy RP, Yasar S, Williams V, Singh H, Mazina L, Helmer KG, Corriveau RA, Schwab K, Kivisäkk P, Greenberg SM. MarkVCID cerebral small vessel consortium: I. Enrollment, clinical, fluid protocols. Alzheimers Dement. 2021 04; 17(4):704-715. PMID: 33480172; PMCID: PMC8122220.
    Citations: 8     Fields:    Translation:Humans
  5. Lu H, Kashani AH, Arfanakis K, Caprihan A, DeCarli C, Gold BT, Li Y, Maillard P, Satizabal CL, Stables L, Wang DJJ, Corriveau RA, Singh H, Smith EE, Fischl B, van der Kouwe A, Schwab K, Helmer KG, Greenberg SM. MarkVCID cerebral small vessel consortium: II. Neuroimaging protocols. Alzheimers Dement. 2021 04; 17(4):716-725. PMID: 33480157; PMCID: PMC8627001.
    Citations: 7     Fields:    Translation:Humans
  6. Kinzel P, Marx CE, Sollmann N, Hartl E, Guenette JP, Kaufmann D, Bouix S, Pasternak O, Rathi Y, Coleman MJ, van der Kouwe A, Helmer K, Kilts JD, Naylor JC, Morey RA, Shutter L, Andaluz N, Coimbra R, Lang AJ, George MS, McAllister TW, Zafonte R, Stein MB, Shenton ME, Koerte IK. Serum Neurosteroid Levels Are Associated With Cortical Thickness in Individuals Diagnosed With Posttraumatic Stress Disorder and History of Mild Traumatic Brain Injury. Clin EEG Neurosci. 2020 Jul; 51(4):285-299. PMID: 32186207.
    Citations: 1     Fields:    Translation:Humans
  7. Warner GC, Helmer KG. Characterization of Diffusion Metric Map Similarity in Data From a Clinical Data Repository Using Histogram Distances. Front Neurosci. 2018; 12:133. PMID: 29568257; PMCID: PMC5852401.
  8. Maumet C, Auer T, Bowring A, Chen G, Das S, Flandin G, Ghosh S, Glatard T, Gorgolewski KJ, Helmer KG, Jenkinson M, Keator DB, Nichols BN, Poline JB, Reynolds R, Sochat V, Turner J, Nichols TE. Sharing brain mapping statistical results with the neuroimaging data model. Sci Data. 2016 12 06; 3:160102. PMID: 27922621.
    Citations: 17     Fields:    Translation:Humans
  9. Malyarenko DI, Wilmes LJ, Arlinghaus LR, Jacobs MA, Huang W, Helmer KG, Taouli B, Yankeelov TE, Newitt D, Chenevert TL. QIN DAWG Validation of Gradient Nonlinearity Bias Correction Workflow for Quantitative Diffusion-Weighted Imaging in Multicenter Trials. Tomography. 2016 Dec; 2(4):396-405. PMID: 28105469; PMCID: PMC5241082.
    Citations: 9     Fields:    
  10. Helmer KG, Chou MC, Preciado RI, Gimi B, Rollins NK, Song A, Turner J, Mori S. Multi-site study of diffusion metric variability: effects of site, vendor, field strength, and echo time on regions-of-interest and histogram-bin analyses. Proc SPIE Int Soc Opt Eng. 2016 Feb 27; 9788. PMID: 27330240; PMCID: PMC4909120.
    Citations: 10     
  11. Helmer KG, Chou MC, Preciado RI, Gimi B, Rollins NK, Song A, Turner J, Mori S. Multi-site Study of Diffusion Metric Variability: Characterizing the Effects of Site, Vendor, Field Strength, and Echo Time using the Histogram Distance. Proc SPIE Int Soc Opt Eng. 2016 Feb 27; 9788. PMID: 27350723; PMCID: PMC4919981.
    Citations: 9     
  12. Malyarenko DI, Newitt D, J Wilmes L, Tudorica A, Helmer KG, Arlinghaus LR, Jacobs MA, Jajamovich G, Taouli B, Yankeelov TE, Huang W, Chenevert TL. Demonstration of nonlinearity bias in the measurement of the apparent diffusion coefficient in multicenter trials. Magn Reson Med. 2016 Mar; 75(3):1312-23. PMID: 25940607.
    Citations: 34     Fields:    
  13. Echlin PS, Johnson AM, Holmes JD, Tichenoff A, Gray S, Gatavackas H, Walsh J, Middlebro T, Blignaut A, MacIntyre M, Anderson C, Fredman E, Mayinger M, Skopelja EN, Sasaki T, Bouix S, Pasternak O, Helmer KG, Koerte IK, Shenton ME, Forwell LA. The Sport Concussion Education Project. A brief report on an educational initiative: from concept to curriculum. J Neurosurg. 2014 Dec; 121(6):1331-6. PMID: 25280091; PMCID: PMC4386878.
    Citations: 7     Fields:    Translation:Humans
  14. Helmer KG, Pasternak O, Fredman E, Preciado RI, Koerte IK, Sasaki T, Mayinger M, Johnson AM, Holmes JD, Forwell LA, Skopelja EN, Shenton ME, Echlin PS. Hockey Concussion Education Project, Part 1. Susceptibility-weighted imaging study in male and female ice hockey players over a single season. J Neurosurg. 2014 Apr; 120(4):864-72. PMID: 24490839; PMCID: PMC4450742.
    Citations: 16     Fields:    Translation:Humans
  15. Pasternak O, Koerte IK, Bouix S, Fredman E, Sasaki T, Mayinger M, Helmer KG, Johnson AM, Holmes JD, Forwell LA, Skopelja EN, Shenton ME, Echlin PS. Hockey Concussion Education Project, Part 2. Microstructural white matter alterations in acutely concussed ice hockey players: a longitudinal free-water MRI study. J Neurosurg. 2014 Apr; 120(4):873-81. PMID: 24490785; PMCID: PMC4386884.
    Citations: 44     Fields:    Translation:HumansCells
  16. Sasaki T, Pasternak O, Mayinger M, Muehlmann M, Savadjiev P, Bouix S, Kubicki M, Fredman E, Dahlben B, Helmer KG, Johnson AM, Holmes JD, Forwell LA, Skopelja EN, Shenton ME, Echlin PS, Koerte IK. Hockey Concussion Education Project, Part 3. White matter microstructure in ice hockey players with a history of concussion: a diffusion tensor imaging study. J Neurosurg. 2014 Apr; 120(4):882-90. PMID: 24471841; PMCID: PMC4863636.
    Citations: 30     Fields:    Translation:HumansCells
  17. Keator DB, Helmer K, Steffener J, Turner JA, Van Erp TG, Gadde S, Ashish N, Burns GA, Nichols BN. Towards structured sharing of raw and derived neuroimaging data across existing resources. Neuroimage. 2013 Nov 15; 82:647-61. PMID: 23727024.
    Citations: 32     Fields:    Translation:Humans
  18. Shenton ME, Hamoda HM, Schneiderman JS, Bouix S, Pasternak O, Rathi Y, Vu MA, Purohit MP, Helmer K, Koerte I, Lin AP, Westin CF, Kikinis R, Kubicki M, Stern RA, Zafonte R. A review of magnetic resonance imaging and diffusion tensor imaging findings in mild traumatic brain injury. Brain Imaging Behav. 2012 Jun; 6(2):137-92. PMID: 22438191.
    Citations: 309     Fields:    Translation:Humans
  19. Poline JB, Breeze JL, Ghosh S, Gorgolewski K, Halchenko YO, Hanke M, Haselgrove C, Helmer KG, Keator DB, Marcus DS, Poldrack RA, Schwartz Y, Ashburner J, Kennedy DN. Data sharing in neuroimaging research. Front Neuroinform. 2012; 6:9. PMID: 22493576.
    Citations: 110     
  20. Cohen-Adad J, Polimeni JR, Helmer KG, Benner T, McNab JA, Wald LL, Rosen BR, Mainero C. T2* mapping and B0 orientation-dependence at 7 T reveal cyto- and myeloarchitecture organization of the human cortex. Neuroimage. 2012 Apr 02; 60(2):1006-14. PMID: 22270354.
    Citations: 50     Fields:    Translation:Humans
  21. Magnotta VA, Matsui JT, Liu D, Johnson HJ, Long JD, Bolster BD, Mueller BA, Lim K, Mori S, Helmer KG, Turner JA, Reading S, Lowe MJ, Aylward E, Flashman LA, Bonett G, Paulsen JS. Multicenter reliability of diffusion tensor imaging. Brain Connect. 2012; 2(6):345-55. PMID: 23075313.
    Citations: 39     Fields:    Translation:Humans
  22. Helmer KG, Ambite JL, Ames J, Ananthakrishnan R, Burns G, Chervenak AL, Foster I, Liming L, Keator D, Macciardi F, Madduri R, Navarro JP, Potkin S, Rosen B, Ruffins S, Schuler R, Turner JA, Toga A, Williams C, Kesselman C. Enabling collaborative research using the Biomedical Informatics Research Network (BIRN). J Am Med Inform Assoc. 2011 Jul-Aug; 18(4):416-22. PMID: 21515543.
    Citations: 28     Fields:    Translation:Humans
  23. Augustinack JC, Helmer K, Huber KE, Kakunoori S, Zöllei L, Fischl B. Direct visualization of the perforant pathway in the human brain with ex vivo diffusion tensor imaging. Front Hum Neurosci. 2010; 4:42. PMID: 20577631.
    Citations: 43     
  24. Paskavitz JF, Sweet LH, Wellen J, Helmer KG, Rao SM, Cohen RA. Recruitment and stabilization of brain activation within a working memory task; an FMRI study. Brain Imaging Behav. 2010 Mar; 4(1):5-21. PMID: 20503110.
    Citations: 3     Fields:    Translation:Humans
  25. Schaechter JD, Fricker ZP, Perdue KL, Helmer KG, Vangel MG, Greve DN, Makris N. Microstructural status of ipsilesional and contralesional corticospinal tract correlates with motor skill in chronic stroke patients. Hum Brain Mapp. 2009 Nov; 30(11):3461-74. PMID: 19370766.
    Citations: 136     Fields:    Translation:Humans
  26. Salat DH, Greve DN, Pacheco JL, Quinn BT, Helmer KG, Buckner RL, Fischl B. Regional white matter volume differences in nondemented aging and Alzheimer's disease. Neuroimage. 2009 Feb 15; 44(4):1247-58. PMID: 19027860; PMCID: PMC2810540.
    Citations: 149     Fields:    Translation:HumansCells
  27. Henning EC, Azuma C, Sotak CH, Helmer KG. Multispectral quantification of tissue types in a RIF-1 tumor model with histological validation. Part I. Magn Reson Med. 2007 Mar; 57(3):501-12. PMID: 17326181.
    Citations: 13     Fields:    Translation:Animals
  28. Henning EC, Azuma C, Sotak CH, Helmer KG. Multispectral tissue characterization in a RIF-1 tumor model: monitoring the ADC and T2 responses to single-dose radiotherapy. Part II. Magn Reson Med. 2007 Mar; 57(3):513-9. PMID: 17326182.
    Citations: 12     Fields:    Translation:Animals
  29. Helmer KG, Nair G, Cannella M, Grigg P. Water movement in tendon in response to a repeated static tensile load using one-dimensional magnetic resonance imaging. J Biomech Eng. 2006 Oct; 128(5):733-41. PMID: 16995760.
    Citations: 11     Fields:    Translation:Animals
  30. Wellen J, Helmer KG, Grigg P, Sotak CH. Spatial characterization of T1 and T2 relaxation times and the water apparent diffusion coefficient in rabbit Achilles tendon subjected to tensile loading. Magn Reson Med. 2005 Mar; 53(3):535-44. PMID: 15723394.
    Citations: 7     Fields:    Translation:Animals
  31. Helmer KG, Wellen J, Grigg P, Sotak CH. Measurement of the spatial redistribution of water in rabbit Achilles tendon in response to static tensile loading. J Biomech Eng. 2004 Oct; 126(5):651-6. PMID: 15648818.
    Citations: 7     Fields:    Translation:AnimalsCells
  32. Wellen J, Helmer KG, Grigg P, Sotak CH. Application of porous-media theory to the investigation of water ADC changes in rabbit Achilles tendon caused by tensile loading. J Magn Reson. 2004 Sep; 170(1):49-55. PMID: 15324757.
    Citations: 9     Fields:    Translation:AnimalsCells
  33. Helmer KG, Meiler MR, Sotak CH, Petruccelli JD. Comparison of the return-to-the-origin probability and the apparent diffusion coefficient of water as indicators of necrosis in RIF-1 tumors. Magn Reson Med. 2003 Mar; 49(3):468-78. PMID: 12594749.
    Citations: 3     Fields:    Translation:Animals
  34. Silva MD, Omae T, Helmer KG, Li F, Fisher M, Sotak CH. Separating changes in the intra- and extracellular water apparent diffusion coefficient following focal cerebral ischemia in the rat brain. Magn Reson Med. 2002 Nov; 48(5):826-37. PMID: 12417997.
    Citations: 34     Fields:    Translation:AnimalsCells
  35. Silva MD, Helmer KG, Lee JH, Han SS, Springer CS, Sotak CH. Deconvolution of compartmental water diffusion coefficients in yeast-cell suspensions using combined T(1) and diffusion measurements. J Magn Reson. 2002 May; 156(1):52-63. PMID: 12081442.
    Citations: 8     Fields:    Translation:AnimalsCells
  36. Li F, Liu KF, Silva MD, Meng X, Gerriets T, Helmer KG, Fenstermacher JD, Sotak CH, Fisher M. Acute postischemic renormalization of the apparent diffusion coefficient of water is not associated with reversal of astrocytic swelling and neuronal shrinkage in rats. AJNR Am J Neuroradiol. 2002 Feb; 23(2):180-8. PMID: 11847039.
    Citations: 19     Fields:    Translation:AnimalsCells
  37. Carano RA, Li F, Irie K, Helmer KG, Silva MD, Fisher M, Sotak CH. Multispectral analysis of the temporal evolution of cerebral ischemia in the rat brain. J Magn Reson Imaging. 2000 Dec; 12(6):842-58. PMID: 11105022.
    Citations: 28     Fields:    Translation:Animals
  38. Li F, Silva MD, Liu KF, Helmer KG, Omae T, Fenstermacher JD, Sotak CH, Fisher M. Secondary decline in apparent diffusion coefficient and neurological outcomes after a short period of focal brain ischemia in rats. Ann Neurol. 2000 Aug; 48(2):236-44. PMID: 10939575.
    Citations: 25     Fields:    Translation:Animals
  39. Han S, Gemmell SJ, Helmer KG, Grigg P, Wellen JW, Hoffman AH, Sotak CH. Changes in ADC caused by tensile loading of rabbit achilles tendon: evidence for water transport. J Magn Reson. 2000 Jun; 144(2):217-27. PMID: 10828190.
    Citations: 14     Fields:    Translation:AnimalsCells
  40. Carano RA, Takano K, Helmer KG, Tatlisumak T, Irie K, Petruccelli JD, Fisher M, Sotak CH. Determination of focal ischemic lesion volume in the rat brain using multispectral analysis. J Magn Reson Imaging. 1998 Nov-Dec; 8(6):1266-78. PMID: 9848739.
    Citations: 9     Fields:    Translation:Animals
  41. Hürlimann MD, Helmer KG, Sotak CH. Dephasing of Hahn echo in rocks by diffusion in susceptibility-induced field inhomogeneities. Magn Reson Imaging. 1998 Jun-Jul; 16(5-6):535-9. PMID: 9803904.
    Citations:    Fields:    Translation:Cells
  42. Helmer KG, Han S, Sotak CH. On the correlation between the water diffusion coefficient and oxygen tension in RIF-1 tumors. NMR Biomed. 1998 May; 11(3):120-30. PMID: 9699495.
    Citations: 8     Fields:    Translation:AnimalsCells
  43. Takano K, Latour LL, Formato JE, Carano RA, Helmer KG, Hasegawa Y, Sotak CH, Fisher M. The role of spreading depression in focal ischemia evaluated by diffusion mapping. Ann Neurol. 1996 Mar; 39(3):308-18. PMID: 8602749.
    Citations: 39     Fields:    Translation:Animals
  44. Helmer KG, Dardzinski BJ, Sotak CH. The application of porous-media theory to the investigation of time-dependent diffusion in in vivo systems. NMR Biomed. 1995 Nov-Dec; 8(7-8):297-306. PMID: 8739268.
    Citations: 10     Fields:    Translation:AnimalsCells
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Funded by the NIH National Center for Advancing Translational Sciences through its Clinical and Translational Science Awards Program, grant number UL1TR002541.