title: Cold pressor gel test: A safe alternative to the cold pressor test in fMRI.
abstract: This study describes a new methodology-the cold pressor gel test (CPGT)-for delivering an accessible experimental pain stimulus, which is reproducible and safe for functional MRI (fMRI).
  
  
  
  The cold pressor test was modified to put safety precautions into the CPGT. The material used is cool gelled water with a thickening product, which provides a stable temperature at 0.2 °C. Thirteen women with chronic pelvic pain were scanned using a 3 Tesla (T) MR scanner equipped with a 12-channel head coil. Changes in BOLD activation during cold-induced pain were estimated.
  
  
  
  The results have demonstrated that gel substances maintain a stable temperature during the experiment, resulting in an insignificant variation. Before the experiment, the mean temperature was 0.2 ± 0.11 °C, and at the end it was 0.7 ± 0.15 °C. The time taken by participants to reach the maximum level of pain during the CPGT was 56.92 ± 11.09 s. The pain intensity during the experiments was 6.92 ± 1.66 on the visual analog scale (VAS). The fMRI analysis showed significant BOLD activation in the main brain regions involved in chronic pain processing.
  
  
  
  The CPGT is an experimental tool to deliver pain that is easily reproducible, particularly in brain functional imaging studies. Moreover, it is cost-effective, safe, and compatible with fMRI. Magn Reson Med 78:1464-1468, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors: Doctorate program in Clinical Medicine and Public Health, University of Granada, Spain.
authors: Maryna
authors: M
authors: Lapotka
authors: Department of Experimental Psychology, University of Granada, Spain.|Brain, Mind and Behavior Research Center, University of Granada, Spain.
authors: María
authors: M
authors: Ruz
authors: Department of Obstetrics and Gynecology, University of Granada, Spain.|Obstetrics and Gynecology, Virgen de las Nieves Hospital, Granada, Spain.
authors: Alberto
authors: A
authors: Salamanca Ballesteros
authors: Department of Obstetrics and Gynecology, University of Granada, Spain.
authors: Olga
authors: O
authors: Ocón Hernández
mesh_terms: D000328:Adult; D035843:Biomedical Research / Q000379:methods* / Q000592:standards; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology; D003080:Cold Temperature / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology*; D015203:Reproducibility of Results
keywords: cold pressor test; fMRI; pain stimuli