Yin Wu1,2, Iris Y Zhou1, Takahiro Igarashi1, Dario L Longo3, Silvio Aime4, Phillip Zhe Sun1. 1. Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA. 2. Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Key Laboratory for MRI, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China. 3. Institute of Biostructure and Bioimaging (CNR) c/o Molecular Biotechnology Center, University of Torino, Torino, Italy. 4. Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Torino, Italy.
Abstract
PURPOSE: To extend the pH detection range of iopamidol-based ratiometric chemical exchange saturation transfer (CEST) MRI at sub-high magnetic field and establish quantitative renal pH MRI. METHODS: Chemical exchange saturation transfer imaging was performed on iopamidol phantoms with pH of 5.5 to 8.0 and in vivo on rat kidneys (n = 5) during iopamidol administration at a 4.7 T. Iopamidol CEST effects were described using a multipool Lorentzian model. A generalized ratiometric analysis was conducted by ratioing resolved iopamidol CEST effects at 4.3 and 5.5 ppm obtained under 1.0 and 2.0 µT, respectively. The pH detection range was established for both the standard ratiometric analysis and the proposed resolved approach. Renal pH was mapped in vivo with regional pH assessed by one-way analysis of variance. RESULTS: Good-fitting performance was observed in multipool Lorentzian resolving of CEST effects (R2 s > 0.99). The proposed approach extends the in vitro pH detection range to 5.5 to 7.5 at 4.7 T. In vivo renal pH was measured to be 7.0 ± 0.1, 6.8 ± 0.1, and 6.5 ± 0.2 for cortex, medulla and calyx, respectively (P < 0.05). CONCLUSIONS: The proposed ratiometric approach extended the iopamidol pH detection range, enabling the renal pH mapping in vivo, which is promising for pH imaging studies at sub-high or low fields with potential clinical applicability. Magn Reson Med 79:1553-1558, 2018.
PURPOSE: To extend the pH detection range of iopamidol-based ratiometric chemical exchange saturation transfer (CEST) MRI at sub-high magnetic field and establish quantitative renal pH MRI. METHODS: Chemical exchange saturation transfer imaging was performed on iopamidol phantoms with pH of 5.5 to 8.0 and in vivo on rat kidneys (n = 5) during iopamidol administration at a 4.7 T. Iopamidol CEST effects were described using a multipool Lorentzian model. A generalized ratiometric analysis was conducted by ratioing resolved iopamidol CEST effects at 4.3 and 5.5 ppm obtained under 1.0 and 2.0 µT, respectively. The pH detection range was established for both the standard ratiometric analysis and the proposed resolved approach. Renal pH was mapped in vivo with regional pH assessed by one-way analysis of variance. RESULTS: Good-fitting performance was observed in multipool Lorentzian resolving of CEST effects (R2 s > 0.99). The proposed approach extends the in vitro pH detection range to 5.5 to 7.5 at 4.7 T. In vivo renal pH was measured to be 7.0 ± 0.1, 6.8 ± 0.1, and 6.5 ± 0.2 for cortex, medulla and calyx, respectively (P < 0.05). CONCLUSIONS: The proposed ratiometric approach extended the iopamidol pH detection range, enabling the renal pH mapping in vivo, which is promising for pH imaging studies at sub-high or low fields with potential clinical applicability. Magn Reson Med 79:1553-1558, 2018.
Authors: Maria L Garcia-Martin; Gary V Martinez; Natarajan Raghunand; A Dean Sherry; Shanrong Zhang; Robert J Gillies Journal: Magn Reson Med Date: 2006-02 Impact factor: 4.668
Authors: Ferdia A Gallagher; Mikko I Kettunen; Sam E Day; De-En Hu; Jan Henrik Ardenkjaer-Larsen; René in 't Zandt; Pernille R Jensen; Magnus Karlsson; Klaes Golman; Mathilde H Lerche; Kevin M Brindle Journal: Nature Date: 2008-05-28 Impact factor: 49.962
Authors: Feng Wang; David Kopylov; Zhongliang Zu; Keiko Takahashi; Suwan Wang; C Chad Quarles; John C Gore; Raymond C Harris; Takamune Takahashi Journal: Magn Reson Med Date: 2015-11-26 Impact factor: 4.668
Authors: Daniel Coman; Dana C Peters; John J Walsh; Lynn J Savic; Steffen Huber; Albert J Sinusas; MingDe Lin; Julius Chapiro; R Todd Constable; Douglas L Rothman; James S Duncan; Fahmeed Hyder Journal: Magn Reson Med Date: 2019-11-05 Impact factor: 4.668
Authors: Soo Hyun Shin; Michael F Wendland; Brandon Zhang; An Tran; Albert Tang; Moriel H Vandsburger Journal: Magn Reson Med Date: 2019-09-04 Impact factor: 3.737
Authors: Shaowei Bo; Farzad Sedaghat; KowsalyaDevi Pavuluri; Steven P Rowe; Andrew Cohen; Max Kates; Michael T McMahon Journal: Tomography Date: 2021-03-02