Functool 4

A pelvic MRI examination (1.5-T system, Signa Excite HD, GE Healthcare, Milwaukee, WI, USA) with an eight-channel phased-array coil was obtained in all patients at baseline and 30 ± 15 days after the end of C-RT. The imaging protocol consisted of high resolution fast spin echo (FSE) T2-weighted sequences in almost 3 planes oriented perpendicularly and parallel to the axial extension of the lesion in the rectal lumen [20 (link)]. DWI based on echo-planar spin-echo (SE-EPI) sequence, with 90° and 180° radiofrequency pulse series application, was also acquired.
A fat-saturated pulse was always applied to avoid chemical shift artifacts. This sequence was acquired in the same axial oblique plane of the T2-weighted images by application of a b-factor 0 and 800 s/mm² (DW images) on three orthogonal directions. Finally, ADC maps were extrapolated from DWI data set by a commercial software (Functool 4.4, GE Healthcare, USA).

Magnetic resonance imaging (MRI) was performed within the first 48 h from the onset of stroke symptoms by a 1.5 tesla Optima 450 w scanner (G.E. Healthcare, Chicago, IL, USA). The investigation was conducted in the Department of Radiology at the University Hospital No. 1 in Bydgoszcz. The quantitative analysis of diffusion-weighted imaging (DWI) was assessed by standard diagnostic software package (Functool 4.4, Advantage Workstation 4.4, G.E.Healthcare, Chicago, IL, USA). We set proper threshold values of signal intensities in the series of DWI images to remain only voxels overlapping with the ischemic focus. Then, we manually removed other voxels located outside the area of interest (e.g., noise) within the selected intensity range. Finally, we used a special dedicated function for automatic calculation of the volume of displayed voxels. We provided a final result of the size of acute ischemic infarct in cm³. On the basis of obtained volumes, we subdivided the participants into strokes with large and small acute ischemic size, setting the limit value at a volume of 2 cm³.