INTRODUCTION: Ultrasmall superparamagnetic iron oxide (USPIO)-enhanced MRI has been shown to be a useful modality to image activated macrophages in vivo, which are principally responsible for plaque inflammation. This study determined the optimum imaging time-window to detect maximal signal change post-USPIO infusion using T1-weighted (T1w), T2*-weighted (T2*w) and quantitative T2* (qT2*) imaging. METHODS: Six patients with an asymptomatic carotid stenosis underwent high resolution T1w, T2*w and qT2* MR imaging of their carotid arteries at 1.5 T. Imaging was performed before and at 24, 36, 48, 72 and 96 h after USPIO (Sinerem, Guerbet, France) infusion. Each slice showing atherosclerotic plaque was manually segmented into quadrants and signal changes in each quadrant were fitted to an exponential power function to model the optimum time for post-infusion imaging. RESULTS: The power function determining the mean time to convergence for all patients was 46, 41 and 39 h for the T1w, T2*w and qT2* sequences, respectively. When modelling each patient individually, 90% of the maximum signal intensity change was observed at 36 h for three, four and six patients on T1w, T2*w and qT2*, respectively. The rates of signal change decrease after this period but signal change was still evident up to 96 h. CONCLUSION: This study showed that a suitable imaging window for T1w, T2*w and qT2* signal changes post-USPIO infusion was between 36 and 48 h. Logistically, this would be convenient in bringing patients back for one post-contrast MRI, but validation is required in a larger cohort of patients.
INTRODUCTION: Ultrasmall superparamagnetic iron oxide (USPIO)-enhanced MRI has been shown to be a useful modality to image activated macrophages in vivo, which are principally responsible for plaque inflammation. This study determined the optimum imaging time-window to detect maximal signal change post-USPIO infusion using T1-weighted (T1w), T2*-weighted (T2*w) and quantitative T2* (qT2*) imaging. METHODS: Six patients with an asymptomatic carotid stenosis underwent high resolution T1w, T2*w and qT2* MR imaging of their carotid arteries at 1.5 T. Imaging was performed before and at 24, 36, 48, 72 and 96 h after USPIO (Sinerem, Guerbet, France) infusion. Each slice showing atherosclerotic plaque was manually segmented into quadrants and signal changes in each quadrant were fitted to an exponential power function to model the optimum time for post-infusion imaging. RESULTS: The power function determining the mean time to convergence for all patients was 46, 41 and 39 h for the T1w, T2*w and qT2* sequences, respectively. When modelling each patient individually, 90% of the maximum signal intensity change was observed at 36 h for three, four and six patients on T1w, T2*w and qT2*, respectively. The rates of signal change decrease after this period but signal change was still evident up to 96 h. CONCLUSION: This study showed that a suitable imaging window for T1w, T2*w and qT2* signal changes post-USPIO infusion was between 36 and 48 h. Logistically, this would be convenient in bringing patients back for one post-contrast MRI, but validation is required in a larger cohort of patients.
Authors: Rikin A Trivedi; Chinthake Mallawarachi; Jean-Marie U-King-Im; Martin J Graves; Jo Horsley; Martin J Goddard; Andrew Brown; Liqun Wang; Peter J Kirkpatrick; John Brown; Jonathan H Gillard Journal: Arterioscler Thromb Vasc Biol Date: 2006-04-20 Impact factor: 8.311
Authors: S P S Howarth; T Y Tang; R Trivedi; R Weerakkody; J U-King-Im; M E Gaunt; J R Boyle; Z Y Li; S R Miller; M J Graves; J H Gillard Journal: Eur J Radiol Date: 2008-03-19 Impact factor: 3.528
Authors: S J McLachlan; M R Morris; M A Lucas; R A Fisco; M N Eakins; D R Fowler; R B Scheetz; A Y Olukotun Journal: J Magn Reson Imaging Date: 1994 May-Jun Impact factor: 4.813
Authors: T Y Tang; S P S Howarth; S R Miller; M J Graves; J M U-King-Im; Z Y Li; S R Walsh; P D Hayes; K Varty; J H Gillard Journal: Eur J Vasc Endovasc Surg Date: 2008-01-02 Impact factor: 7.069
Authors: Rikin A Trivedi; Jean-Marie U-King-Im; Martin J Graves; Justin J Cross; Jo Horsley; Martin J Goddard; Jeremy N Skepper; George Quartey; Elizabeth Warburton; Ilse Joubert; Liqun Wang; Peter J Kirkpatrick; John Brown; Jonathan H Gillard Journal: Stroke Date: 2004-05-27 Impact factor: 7.914
Authors: Stephan Metz; Ambros J Beer; Marcus Settles; Jaroslav Pelisek; René M Botnar; Ernst J Rummeny; Peter Heider Journal: Int J Cardiovasc Imaging Date: 2010-10-24 Impact factor: 2.357
Authors: Aiguo Wu; Tatjana Paunesku; Zhuoli Zhang; Stefan Vogt; Barry Lai; Jörg Maser; Vahid Yaghmai; Debiao Li; Reed A Omary; Gayle E Woloschak Journal: AIP Conf Proc Date: 2011-09-09
Authors: Samuel Maritim; Daniel Coman; Yuegao Huang; Jyotsna U Rao; John J Walsh; Fahmeed Hyder Journal: Contrast Media Mol Imaging Date: 2017-11-22 Impact factor: 3.161
Authors: Patrícia M Carvalho; Mário R Felício; Nuno C Santos; Sónia Gonçalves; Marco M Domingues Journal: Front Chem Date: 2018-06-25 Impact factor: 5.221
Authors: Li Dong; William S Kerwin; Marina S Ferguson; Rui Li; Jinnan Wang; Huijun Chen; Gador Canton; Thomas S Hatsukami; Chun Yuan Journal: J Cardiovasc Magn Reson Date: 2009-12-15 Impact factor: 5.364