TRADITIONAL POSTER - ismrm

Poster Sessions
2977. Single Point Sequences with Shortest Possible TE – GOSPEL
David Manuel Grodzki 1,2 , Michael Deimling 1 , Björn Heismann 1 , Hans-Peter Fautz 1 , Peter Jakob 2
1 Magnetic Resonance, Siemens Healthcare, Erlangen, Bavaria, Germany; 2 Department of Experimental Physics 5, University of
Würzburg, Würzburg, Bavaria, Germany
We present a novel single point sequence, GOSPEL (Gradient Optimised Single Point Imaging with Echo-time Leveraging). Based on a RASP / SPRITE
sequence, it uses the shortest possible echo-time for each acquired k-space point. Especially for clinical scanners with limited gradient strength, the reduction
of the echo-time enables an improved measurement of tissues with short T2 times. We present an image of a human hand, depicting both the bone structure
and tendons. The results indicate that GOSPEL can be used for bone and tendon imaging or MR-PET attenuation correction.
2978. Imaging of Renal Stones in Vitro with UTE MRI
Aya Yassin 1 , Ivan Pedrosa 1 , Michael Kearney 2 , Elizabeth Genega 3 , Neil M. Rofsky 1 , Robert E. Lenkinski 1
1 Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 2 Urology, Beth Israel
Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 3 Pathology, Beth Israel Deaconess Medical Center,
Harvard Medical School, Boston, MA, United States
Renal stones have short T2 values and are therefore difficult to demonstrate when using conventional MR sequences. We utilized the UTE MR sequence to
characterize renal stones in vitro. Thirty-six stones from patients were scanned, and T1 and T2 values were calculated for every stone. The results were
correlated with the composition. The 21/36 visualized stones showed high signal on UTE images. Having demonstrated the feasibility of the UTE sequence
for imaging renal stones we anticipate employing this technique on a wider scale to patients suspected of having renal stones, especially to those in whom it
is desirable to avoid ionizing radiation exposure such as children, women of child bearing age and pregnant females.
2979. MRI Signal Delay: A Potential Probing Mechanism for Cellular Imaging in the Brain
Yongxain Qian 1 , Fernando E. Boada 1
1 MR Research Center, Radiology, University of Pittsburgh, Pittsburgh, PA, United States
This work presents new observations of the delay of MRI signal in human brain on 3T MRI scanner with ultrashort echo time (UTE) acquisitions. The MRI
signal delay was related, by our hypotheses, to those parameters such as ion concentration and T2* relaxation time, that characterize cellular micro
environment inside/outside a cell as well as cell membrane. An electromagnetic (EM) interaction between RF pulse and mobile ions in tissue was employed
to illuminate the delay of MRI signals.
2980. Detection of Short T2 Component in Brain by SWIFT
Lauri Juhani Lehto 1 , Djaudat Idiyatullin 2 , Curtis Andrew Corum 2 , Michael Garwood 2 , Olli Heikki Gröhn 1
1 A. I. Virtanen Institute for Molecular Medicine, University of Kuopio, Kuopio, Eastern Finland, Finland; 2 Center for Magnetic
Resonance Research, University of Minnesota, Minneapolis, MN, United States
The aim of this work was to directly detect signal from the short T2 component in the brain using the SWIFT sequence that allows almost simultaneous
excitation and detection. To detect the short T2 component, the overwhelming long T2 component signal was suppressed either by using long adiabatic
inversion pulses or by suppressing the short T2 component and subtracting that from a normal SWIFT image. Results show relative enhancement of white
matter structures in the brain. The contrast in the latter approach is interpreted to have a contribution also from MTC and thus represents combined direct and
indirect detection of the short T2 pool.
Magnetization Transfer & CEST
Hall B Wednesday 13:30-15:30
2981. Pulsed CEST for the Quantification of PH
Kimberly Lara Desmond 1 , Greg J. Stanisz 1,2
1 Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 2 Imaging Research, Sunnybrook Health Sciences Centre,
Toronto, Ontario, Canada
We present a method for the quantification of pH using a pulsed chemical exchange saturation transfer (CEST) method. Experimental data is from a
phantom model consisting of 1M ammonium chloride in 10mM citric acid buffer for the modification of pH. This data is fit using a two-compartment Bloch
equation model of exchange in the presence of off-resonance excitation. A linear relationship is observed between the log of the fitted exchange rate and the
true pH of the phantom.
2982. Ytterbium (Yb)-Based PARACEST Agent: Feasibility of CEST Imaging on a Clinical 3.0 T Scanner
Yukihisa Takayama 1 , Akihiro Nishie 1 , Takashi Yoshiura 1 , Tomohiro Nakayama 1 , Eiki Nagao 1 , Naoki Kato 2 ,
Satoshi Yoshise 2 , Shutaro Saiki 2 , Dirk Burdinski 3 , Holger Grull 3 , Jochen Keupp 3 , Hiroshi Honda 1
1 Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; 2 Philips Electronics
Japan, Tokyo, Japan; 3 Philips Research Europe, Hamburg, Germany
Chemical Exchange-dependent Saturation Transfer (CEST) is a novel contrast mechanism for magnetic resonance (MR) imaging, but it is not yet common in
clinical practice. We investigated the feasibility of CEST imaging on a clinical MR scanner by in vitro study using a ytterbium complex of paramagnetic
CEST agents. The CEST effect could be observed at specific offset frequencies. In addition, it increased and decreased depending on the degrees of
concentration, pH or solution. We showed the clinical potential of CEST imaging using these agents, but further modifications, such as optimized
presaturation RF pulse, imaging protocols or other techniques, remain necessary.