Jakob Assländer1,2,3, Steffen J Glaser4, Jürgen Hennig1. 1. Faculty of Medicine, Department of Radiology, Medical Physics, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany. 2. Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA. 3. Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, New York, USA. 4. Department of Chemistry, Technische Universität München, Munich, Germany.
Abstract
PURPOSE: This work presents an approach to mapping the entire lung's proton density and T1 within a single breath-hold and analyzes the apparent T1 when exciting with a spin echo generating pulse in comparison to a standard gradient echo acquisition. METHODS: An inversion-recovery SNAPSHOT-FLASH sequence with a stack-of-stars k-space readout with a golden angle increment was modified to use a spin echo generating radiofrequency-pulse for excitation. Data of five volunteers were acquired on a 3T scanner and image reconstruction was performed by an iterative algorithm adopted from MR-Fingerprinting. RESULTS: The feasibility of acquiring quantitative maps of the entire lung with a resolution of 5 × 5 × 10 mm within 7.5 s is demonstrated. It is shown that the proposed spin echo forming radiofrequency-pulse increases the apparent proton density compared to a rectangular pulse. Further, the apparent T1 is reduced in the spin echo case compared to the gradient echo sequence. CONCLUSION: The proposed spin echo based method results in T1 maps that are comparable to the ones that were acquired with ultra-short echo time sequences elsewhere. The T1 shortening is believed to originate from increased signal contributions of the extra vascular compartment, which has a short T2∗ and T1 . Magn Reson Med 79:960-967, 2018.
PURPOSE: This work presents an approach to mapping the entire lung's proton density and T1 within a single breath-hold and analyzes the apparent T1 when exciting with a spin echo generating pulse in comparison to a standard gradient echo acquisition. METHODS: An inversion-recovery SNAPSHOT-FLASH sequence with a stack-of-stars k-space readout with a golden angle increment was modified to use a spin echo generating radiofrequency-pulse for excitation. Data of five volunteers were acquired on a 3T scanner and image reconstruction was performed by an iterative algorithm adopted from MR-Fingerprinting. RESULTS: The feasibility of acquiring quantitative maps of the entire lung with a resolution of 5 × 5 × 10 mm within 7.5 s is demonstrated. It is shown that the proposed spin echo forming radiofrequency-pulse increases the apparent proton density compared to a rectangular pulse. Further, the apparent T1 is reduced in the spin echo case compared to the gradient echo sequence. CONCLUSION: The proposed spin echo based method results in T1 maps that are comparable to the ones that were acquired with ultra-short echo time sequences elsewhere. The T1 shortening is believed to originate from increased signal contributions of the extra vascular compartment, which has a short T2∗ and T1 . Magn Reson Med 79:960-967, 2018.
Authors: Jakob Assländer; Martijn A Cloos; Florian Knoll; Daniel K Sodickson; Jürgen Hennig; Riccardo Lattanzi Journal: Magn Reson Med Date: 2017-03-05 Impact factor: 4.668
Authors: Philipp Ehses; Nicole Seiberlich; Dan Ma; Felix A Breuer; Peter M Jakob; Mark A Griswold; Vikas Gulani Journal: Magn Reson Med Date: 2012-02-29 Impact factor: 4.668
Authors: Simon M F Triphan; Bertram J Jobst; Felix A Breuer; Mark O Wielpütz; Hans-Ulrich Kauczor; Jürgen Biederer; Peter M Jakob Journal: J Magn Reson Imaging Date: 2015-01-21 Impact factor: 4.813
Authors: Martin Uecker; Peng Lai; Mark J Murphy; Patrick Virtue; Michael Elad; John M Pauly; Shreyas S Vasanawala; Michael Lustig Journal: Magn Reson Med Date: 2014-03 Impact factor: 4.668
Authors: Dan Ma; Vikas Gulani; Nicole Seiberlich; Kecheng Liu; Jeffrey L Sunshine; Jeffrey L Duerk; Mark A Griswold Journal: Nature Date: 2013-03-14 Impact factor: 49.962