Phantom calibrations: Measurements: area/volume at 1% low-contrast,
accurate to 1/10th of a pixel.
Field-examples:
(1) 30 radial MRA MIP images at 6 degree intervals of an aneurysm of the anterior communicating artery of a 72 year-old male patient were analyzed.
For demonstration purposes,
Slice #14 (at 840) [IMG00013#14] was used.
Figure 1 shows the original image with region of interest (ROI) placed on the aneurysm.
Figure 2 shows images of 'before' and 'after' enhancement at 9x magnification.
Figure 3 shows the measurement of the Indirect Mean Width,
d of the aneurysm.
Table 1 and Figure 4 shows the distribution of the Indirect Mean Width over the whole range of angles.
Table 1
Indirect Measurement,
d,
of 1st Year data – Aneurysm- MRA MIP
IMG00000#1 5xROI Indirect: d=7.84mm
IMG00001#2 5xROI Indirect: d=8.34mm
IMG00002#3 5xROI Indirect: d=8.60mm
IMG00003#4 5xROI Indirect: d=8.59mm
IMG00004#5 5xROI Indirect: d=8.49mm
IMG00005#6 5xROI Indirect: d=8.56mm
IMG00006#7 5xROI Indirect: d=8.47mm
IMG00007#8 5xROI Indirect: d=8.34mm
IMG00008#9 5xROI Indirect: d=8.02mm
IMG00009#10 5xROI Indirect: d=8.06mm
IMG00010#11 5xROI Indirect: d=8.24mm
IMG00011#12 5xROI Indirect: d=7.24mm
IMG00012#13 5xROI Indirect: d=7.85mm
IMG00013#14 5xROI Indirect: d=8.08mm
IMG00014#15 5xROI Indirect: d=7.79mm
IMG00015#16 5xROI Indirect: d=8.22mm
IMG00016#17 5xROI Indirect: d=8.16mm
IMG00017#18 5xROI Indirect: d=8.01mm
IMG00018#19 5xROI Indirect: d=7.85mm
IMG00019#20 5xROI Indirect: d=7.73mm
IMG00020#21 5xROI Indirect: no measurement (due to obscured view)
IMG00021#22 5xROI Indirect: d=8.38mm
IMG00022#23 5xROI Indirect: d=8.71mm
IMG00023#24 5xROI Indirect: d=8.60mm
IMG00024#25 5xROI Indirect: d=7.73mm
IMG00025#26 5xROI Indirect: d=8.24mm
IMG00026#27 5xROI Indirect: d=8.55mm
IMG00027#28 5xROI Indirect: d=8.31mm
IMG00028#20 5xROI Indirect: d=8.52mm
IMG00029#30 5xROI Indirect: d=8.36mm
.............................................................................................................
Indirect Method:- d = 2x SQR(A/pi),
Mirror images of the 30 slices of image were generated to cover the subtending arc from 1800 to 3600.
An animated view of enhanced at magnification 5x for the whole rotation range was generated using the software ImageMagicK.
It may be viewed at the web-link:
(http://iet.org.uk/img/animation-5x256-360.gif) .
(2) 63 CT slices of a humerus fracture of a 28 year-old male patient were analyzed.
Slice 8 was used for the CAD demonstration of image enhancement.
Figure 5 shows the original image with ROI on the fractured bone.
Figure 6 shows images of 'before' and 'after' enhancement of 7x ROI.
Figure 7 shows the measurement of the fractured gap.
Again,
the 63 images of 'before' and 'after' enhancement were compiled to generate the animated view,
which may be viewed at the web-link:
(http://iet.org.uk/img/ct-bone2-animation.gif) .