Multiparametric MRI Examination and Image Analysis
Multiparametric prostate MRI was performed using a 3.0-T MR unit (Verio;
Siemens Medical Solutions, Erlagen, Germany) with a 16-channel pelvic
phased array coil. Imaging sequences comprised thin-section turbo spin
echo T2-weighted (TSE) images (number of slices, 20; slice thickness, 3
mm with no intersection gap; TR/TE, 5800/100 ms; number of signals
acquired, 2; and resolution, 0.8x0.8 mm) in the transverse, sagittal and
coronal planes. Diffusion-weighted images were obtained using multiple b
values (b-factor, 50/500/1000/1500 s/mm2; number of
slices, 20; slice thickness, 3 mm; TR/TE, 3900/75; and resolution, 1.4
mmx1.4 mm) in the transverse plane and apparent diffusion coefficient
(ADC) maps were constructed from the b50, b100, b1000 and b1500 images
by utilizing SyngoVia WorkStation software. Dynamic contrast-enhanced
(DCE)-MRI sequences (T1 high-resolution isotropic volume with fat
suppression) obtained after the administration of a gadolinium injection
(slice thickness, 3 mm; intersection gap, none; TR/TE, 5.08/1.77;
resolution, 1.4 mmx1.4 mm, contrast agent injection started 24 seconds
after first acquisition; temporal resolution, 8 seconds; total DCE time,
200 seconds; and number of dynamic time points, 25). We stratified the
study cohort into two groups using a tumor diameter of 1 cm. Group A
consisted of patients with normal MRI findings or a suspicious tumor
lesion of <1 cm in diameter, and Group B comprised those with
a tumor diameter of > 1 cm (Figure 1).