ELECTRONIC POSTER - ismrm

elaxation provided the intracellular T1 and intracellular fraction, measures of β cell labeling. Increased intracellular T1 and lower
intracellular fraction in nifedipine-treated mice confirmed Mn2+ enters β cells through Ca2+ channels. The timecourse of intracellular
T1 and fraction in normal mice revealed 3 phases of Mn2+ kinetics: 1) labeling β cells, 2). washout from β cells, 3). nonspecific
labeling of other cells.
Lung MRI
Hall B Wednesday 13:30-15:30 Computer 95
13:30 4622. Dynamic Contrast Enhanced Pulmonary Perfusion with Undersampled Stack-Of-
Stars and Iterative Highly Constrained Back-Projection
Nathan S. Artz 1 , Rafael L. O'Halloran 2 , Mark Schiebler 3 , James H. Holmes 4 , Sean B.
Fain 1,3
1 Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2 Radiology, Stanford
University, Stanford, CA, United States; 3 Radiology, University of Wisconsin-Madison, Madison, WI, United
States; 4 Applied Science Laboratory, GE Healthcare, Madison, WI, United States
Pulmonary perfusion was assessed in two healthy volunteers using a contrast-enhanced 3D stack-of-stars GRE sequence. Consecutive
groups of 32 projection angles were reconstructed with IHYPR for a temporal resolution of ~1s. The signal vs. time curves
demonstrate an expected trend with the pulmonary artery peaking first, followed next by the parenchyma and later the left atrium.
Mean transit time, relative pulmonary blood volume and relative pulmonary blood flow maps demonstrate expected results with mean
transit times from 3-5 s after the main pulmonary artery trunk and shorter MTT’s in the posterior region due to gravity related effects.
14:00 4623. Comparison of Three Quantification Algorithms (RFM, TSVD, LCC) for Absolute
Quantification of Pulmonary Perfusion in Patients with COPD and Pulmonary Embolism by
MRI
Mona Salehi Ravesh 1 , Michael Puderbach 2 , Sebastian Ley 3 , Julia Ley-Zaporzhan 3 , Frank
Risse 1 , Wilfried Schranz 4 , Wolfhard Semmler 1 , Frederik Bernd Laun 1
1 Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany;
2 Department of Radiology, German Cancer Research Center, Heidelberg, Germany; 3 Diagnostic and
Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany; 4 Nonlinear Physics Group,
Faculty of Physics, University of Vienna, Vienna, Austria
Lung perfusion is a crucial prerequisite for effective gas exchange. An accurate quantification of pulmonary perfusion is therefore
important for diagnostic considerations and treatment planning in various diseases of the lungs.The assessment of pulmonary
perfusion by Dynamic Contrast-Enhanced Magnetic Resonance Imaging requires deconvolution of the arterial input function. In the
presence of noise this is an ill-posed problem which leads to strongly oscillating, unphysical solutions when it is solved without
regularization. In this study a novel method to quantify the pulmonary perfusion is used and compared to the singular value
decomposition and L-curve criterion based on simulated and patient data.
14:30 4624. Bronchial Perfusion in the Lungs Observed by Dynamic Contrast-Enhanced MRI
Nabil Saouti 1 , Anton Vonk Noordegraaf 1 , Michael Ingrisch 2 , J. Tim Marcus 1
1 VU University Medical Center, Amsterdam, Netherlands; 2 Ludwig-Maximilian University, Munich, Germany
The aim is to visualise the perfusion of the lungs by the pulmonary and bronchial system separately, based on the fact that a contrast
bolus injected intravenously will arrive later in the bronchial than in the pulmonary system. Included were 7 patients with whole left or
right pulmonary artery atresia, and 6 chronic thromboembolic pulmonary hypertension patients. Using 3D dynamic contrast-enhanced
MRI with 1 s temporal resolution, a 5 s signal-intensity onset delay was measured between open lung or lung region, and obstructed
lung (region), providing evidence for bronchial arterial supply after a pulmonary artery obstruction.
15:00 4625. Ventilation/Perfusion MR Imaging of the Lung Using T1-Weighted Ultra-Short
Echo Time (UTE) Imaging: Animal Experiment in a 3 T Clinical MRI System
Osamu Togao 1 , Marc van Cauteren 2 , Yoshiharu Ohno 3 , Ivan Dimitrov 1,2 , Masaya
Takahashi 1
1 Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United
States; 2 MR Clinical Science, Philips Healthcare, Best, Netherlands; 3 Radiology, Kobe University Graduate
School of Medicine, Kobe , Hyogo, Japan
We have demonstrated that an UTE sequence could bring inherent MR signal of the lung parenchyma that closely related to the
parenchymal tissue anatomy. We hypothesize that the capability of the method to acquire inherent MR signal of the lung parenchyma
should allow us to assess changes in SI due to inhalation of molecular oxygen or intravenous injection of gadolinium. In the present
study, we tested the feasibility of a T1-weighted UTE sequence for assessment of regional pulmonary ventilation/perfusion which is
essential for the evaluation of a variety of lung diseases in a 3T clinical MRI system.