F.  Usman, R.  Zainon, H.  Mohammed, K.J.  Nizam, B.W.  Gbolahan, 
    CAD SPECT/CT in Managing Liver Tumours and Other Related Abnormalities,
    Surgery Journal,
    Volume 15,Issue 1,
    2020,
    Pages 1-9,
    ISSN 1816-3211,
    sjour.2020.1.9,
    (https://makhillpublications.co/view-article.php?doi=sjour.2020.1.9)
    Abstract: This research is aimed at evaluating the effect
of incorporating OSEM and FBP reconstructed liver
SPECT/CT with a modeled CAD system in the
management of liver tumors and other radiation induced
liver diseases. An Anthropomorphic torso phantom with
lung and liver inserts was injected with <sup>99m</sup>Tc. The liver
and the background were given 0.2 and 0.07 Mbq mL<sup>&#150;1</sup>,
respectively. The lungs inserts were filled with
polystyrene beads for humanisation. A mimicked
30 mL tumour (27 mm) in the liver insert was given
2 Mbq mL<sup>&#150;1</sup>. Sequential SPECT (step and shot, 10 min
over 1800 per head) and CT (120 kVp, 80 mAs)
projections were acquired using dual head SPECT/16
slice CT system. The projections were reconstructed using
OSEM (10 subsets for 2-10 numbers of iterations,
Butterworth post filtering, 10 orders and 0.48 frequencies)
and FBP (using Butterworth post filtering at 10 order and
cut-off frequencies of 0.38-0.58, 0.05 gaps). Segmented
and non-segmented SPECT/CT data were obtained. The
image j Software made the analysis. Statistical t-test
tested the mean grey values of the tumour and its
background. The OSEM and FBP reconstructed images
were evaluated from their Contrast to Noise Ratio (CNR).
The detection ability was evaluated based on 3-5 CNR
detection range set by the rose criterion. The t-test showed
the background and the tumour&#146;s mean values to be
statistically significant (p[<]0.05). The CNR values for
both modeled and non-modeled CAD FBP images were
all under the detection range. Nevertheless, the maximum
CNR value was noted at the cutoff frequency 0.48 (1.69).
In OSEM reconstructed images, the peak was observed at
around 3-4 numbers of iterations. In accession, its
modeled CAD based evaluation gave CNR values within
the detection range from 2-8 numbers of iteration with
maximum value (4.89) at 4 numbers of iteration. While
the detection range was unattainable for the non-modeled
CAD OSEM reconstructed liver SPECT/CT. CAD
improves liver tumour detection in SPECT/CT imaging.
OSEM is the best for tumour detection. In addition,
administered activity can be brought down at 4 OSEM&#146;s
of iterations (40 MLEM iterations) for patient safety.
Ultimately, well developed CAD systems are
recommended for proper management of liver and its
other related abnormalities.
    Keywords: Anthropomorphic torso phantom;99mTc;SPECT/CT;iterative reconstruction (OSEM);Filtered Back Projection (FBP);CNR;p-value;CAD