TITLE:
Contrast Optimization for an Animal Model of Prostate Cancer MRI at 3T
AUTHORS:
Christopher Brian Abraham, Boguslaw Tomanek, Laura Curiel
KEYWORDS:
MRI, Tissue Contrast, Prostate Cancer, Spin Echo
JOURNAL NAME:
Journal of Modern Physics,
Vol.7 No.8,
April
29,
2016
ABSTRACT:
Purpose: To
optimize contrast to noise ratio (CNR) in magnetic resonance imaging (MRI) of
prostate cancer using at 3T. Methods: CNR was expressed as a difference in MR
signals of two samples. Amulti-echo spin-echo (MESE) pulse sequence was used.
The theoretical value of the maximum CNR was obtained using the derivative of
CNR with echo time (TE) as a variable. The T1 relaxation time was
ignored as repetition time (TR) was assumed to be very long (TR >> T1).
The theoretical calculations were confirmed with in vitro and in vivo experiments. For in vitro experiments
we used samples with different T2 values using various
concentrations of super paramagnetic iron oxide (SPIO) and for in vivo experiments we used an animal model
of prostate cancer. Results: CNR was maximized by selecting the optimum TE for
a multi-echo spin-echo (MESE) pulse sequence based on theoretical predictions.
MR images of prostate cancer at 3T were obtained and showed maximum CNR at the
predicted TE. Conclusions: It was possible to maximize CNR of prostate tumour
by selecting the optimal TE based on simple theoretical calculations. The
proposed method can be applied to other pulse sequences and tissues. It can be
applied to any MRI system at any magnetic field. However the method requires
knowledge of T2 relaxation times.