Basem AL Al Zahrany How effective is CT Colonography in detecting colon cancer? Introduction The second cause leading to death in the United States is colorectal cancer in the same way colorectal cancer is the third common cancer in women and men. In the United States 135,260 people diagnosed with colorectal cancer in 2011. Colorectal cancer caused for 51,783 people from them the death. The number of colorectal cancer patients is predictable to rise in the future. Built on the present data, cost scenario and survival for colorectal cancer Yabroff et al expected the cost effect in 2020 for the primary $4.05 billion, making a significant cost load on the healthcare system. Colorectal cancer mortality was decreased by 18% to13 % with apply CT Colonography to detect colonic polyps before they developed to colorectal cancer (Trilisky et al, 2015). CT Colonography has been shown to have polyp discovery rates similar to the patient how use colonoscopy. CT Colonography is an exam for colorectal cancer screening which became generally effected for detecting polyps similar to those of colonoscopy. It has the prospective to improve colorectal cancer screening rates because of colorectal is come to be insignificant noninvasive ,faster patient in quantity ,no sedation requirement and potential for reduced cathartic examination . Appropriate program of a CT Colonography screening must implement and needs important announce to several aspects, counting proper patient preparation before the investigation, image acquisition, and post-processing of the developed images. A CT Colonography need workstation with special software and high quality monitors. Special software called Computer-Aided Detection CAD which is manipulate to reduce mistakes of spotting and showing polyps to the radiologist for images interpretation. These essay will discuss technique, advantages , disadvantages of CT Colonography and how CT Colonography can be affect for colorectal cancer . Exam technique Currently, patients go through intestine preparation procedure which has the purpose of avoid misdiagnosed of polyps by cleaning the colon. So far there is no agreement on a best program of food adjustment and releasing preparation of flexible period and amount. There is continuing studies aimed to rise patient relaxation and acceptance. To distinguish polyps from other residual the use usually fecal and fluid tagging with bowel laxative. Some time they do it with small quantity of both iodine-based contrast material and barium or one of them to improve the image and to eliminate the artifact of image which could be accrue ,which may rise the sensitivity of polyp detection, Digital subtraction is a post-acquisition processing technique use to improve the image quality(Trilisky,2015). Advantages of CT Colonography CT Colonography shows high sensitivit ...

1. Basem AL Al Zahrany
How effective is CT Colonography in detecting colon cancer?
Introduction
The second cause leading to death in the United States is
colorectal cancer in the same way colorectal cancer is the third
common cancer in women and men. In the United States
135,260 people diagnosed with colorectal cancer in 2011.
Colorectal cancer caused for 51,783 people from them the
death. The number of colorectal cancer patients is predictable to
rise in the future. Built on the present data, cost scenario and
survival for colorectal cancer Yabroff et al expected the cost
effect in 2020 for the primary $4.05 billion, making a
significant cost load on the healthcare system. Colorectal cancer
mortality was decreased by 18% to13 % with apply CT
Colonography to detect colonic polyps before they developed to
colorectal cancer (Trilisky et al, 2015). CT Colonography has
been shown to have polyp discovery rates similar to the patient
how use colonoscopy. CT Colonography is an exam for
colorectal cancer screening which became generally effected for
detecting polyps similar to those of colonoscopy. It has the
prospective to improve colorectal cancer screening rates
because of colorectal is come to be insignificant noninvasive
,faster patient in quantity ,no sedation requirement and potential
for reduced cathartic examination . Appropriate program of a
CT Colonography screening must implement and needs
important announce to several aspects, counting proper patient
preparation before the investigation, image acquisition, and
post-processing of the developed images. A CT Colonography
need workstation with special software and high quality
monitors. Special software called Computer-Aided Detection
CAD which is manipulate to reduce mistakes of spotting and
showing polyps to the radiologist for images interpretation.

2. These essay will discuss technique, advantages , disadvantages
of CT Colonography and how CT Colonography can be affect
for colorectal cancer .
Exam technique
Currently, patients go through intestine preparation procedure
which has the purpose of avoid misdiagnosed of polyps by
cleaning the colon. So far there is no agreement on a best
program of food adjustment and releasing preparation of
flexible period and amount. There is continuing studies aimed
to rise patient relaxation and acceptance. To distinguish polyps
from other residual the use usually fecal and fluid tagging with
bowel laxative. Some time they do it with small quantity of both
iodine-based contrast material and barium or one of them to
improve the image and to eliminate the artifact of image which
could be accrue ,which may rise the sensitivity of polyp
detection, Digital subtraction is a post-acquisition processing
technique use to improve the image quality(Trilisky,2015).
Advantages of CT Colonography
CT Colonography shows high sensitivity and specificity of
detecting cancer lesions than colonoscopy. According to Perry
Pickhardt(2015) the sensitivity of CT Colonography to detect
lesion showed after a meta-analysis and systematic revision an
overall 96% and it is coming higher if oral contrast is applied.
This ratio give CT Colonography opportunity to use it for
preventive and screening more than colonoscopy. In addition,
colonoscopy y is invasive exam which might harmful the
patients. However, this high percentage of detecting legion is
my decay with lesions less than 6mm. Andrik, Aschoff
(2007),fond after reviewing many studies don from 2000 until
2005 the specificity and sensitivity of catching of colon cancer
is high with 10mm or more in size of polyps .He estimate that

3. CT Colonography could increase sensitivity in this coming
years and this is what happened now it is increase up to 6 mm
for detection of polyps.
Bleeding, colonic perforation, cardiovascular events and even
death are complication with low percent of colonoscopy exams
while almost zero percent in CT Colonography when automated
low – pressure CO2 is used. Igor Trilisky, is radiologist in
University of Chicago Medical Center, recommended to
establish CT Colonography screening program for colon cancer
on condition of implementing a quality assurance in the center.
Proper patient preparation and image acquisition help the
radiologist to read the image correctly. High quality training of
radiologist and technologist is potential to good image
interpretation. In particular, time of CTC exam is short in
procedure but it take time to processing the image and read it
mort ah Colonoscopy. In addition, using updated CAD help to
improve sensitivity in image interpretation CT Colonography
exams and decrease the specificity.
All of the aforementioned reasons to prefer CT Colonography
form most patients especially how had colonoscopy before or
both and if we look to Self-appreciation we found it is one of
the most reason push the patents to choose CT Colonography as
first option. Based on Pickhardt(2015) multicenter surveying
1400 adult how had CTC before founded high satisfaction
percentage almost higher than 90% and same percent preferred
to choose CT Colonography again for second screening.
Researcher found highly ratio of chosen CT Colonography than
colonoscopy for patent how had CT Colonography and
colonoscopy before with nearly 6:1 ratio. Pickhardt(2015) found
same thing happened with Moawad et al. They found that 95%
of patients how had both experience of exams preferred CT
Colonography screening.

4. Disadvantages of CT Colonography
Radiation exposure is the most concern issue in CT exams in
general because there is no threshold of ionization radiation. In
the same time too high exposure have same value of very low
exposure dose for radiologist it means no data can be collected
from image. J. Stoker, H. W. Venema, and R. E. van Gelder
fond in tow studies ,don in 2004, low dose technique 120Kv and
10mAs (in supine position only )with series patient preparation
held on 137 patient sensitivity and specify 70% and 80.8%
respectively for polyps more than 4 mm. The other study were
done in same year for 203 patients with 140Kv and 10mAs ( tow
position) result in 95% in sensitivity and 92.2% in specify for
polyps more than 7mm and 100% for both for polyps more
than9mm. The average effective doses in first study was 0.7ms
for men and 1.2 ms for women and 1.8 ms for men and average
effective dose 2.4ms for women in second study (Tack,
Gevenois,2007). Nowadays, we have inflation of the technology
of post processing data which will may increase the sensitivity
and specificity of detecting polyps and as the technology
progressed as the ability of diagnose the polyps in early stage.
So radiation can cause cancer itself which incumbent us to
adequate using of exam.
CTC has the ability to detected most of polyps which might be
developed to colorectal cancer. On the other hand, it may
missed detection happened with small polyps less than 5mm.
Generally 90 % of polyps are detected by CTC. 3.36. Based on
Pickhardt(2015) experience, radiologist in University of
Wisconsin School of Medicine and Public Health, 50% from
small polyps are stable, 30 % regress and 20% remaining
developed under observation. Instead of this, CT Colonography
is extra colonic exam as well, it can evaluate the entire organ

5. (abdomen and pelvis) also it has opportunity to evaluate
osteoporosis without need to extra radiation dose. In fact, CT
Colonography has high chance to be the first screening exam
for colorectal cancer.
Experience of CTC observers
CT Colonography is observer dependent make image reading
defer from center to other. A cumulative experience of reading
CT Colonography is helpful to increase sensitivity and
specificity as the English Bowel Cancer Screening Program find
high positive rate in centers with experience of interpretation of
1000 case or more and centers which have at least 175 study for
radiologist yearly. This outcome of Dutch study held on six
radiologist and three CT technologist. They had training
program of CT Colonography image interpretation. It shows
significant increasing of average sensitivity of detecting polyps
6mm or more for 50 case from 76% in first set to 91% in fourth
set. They recommend 164 case for training for each radiologist
to increase his ability of interpretation (Haan, 2014).
In conclusion, CT Colonography has prospect to be good option
of colorectal cancer screening considering a proper patent
preparation, high quality training for both radiologist and CT
technologist, highly cooperation from patients and updated CAD
soft were. CT scan device has an inflation of soft were and hard
were in this recent year make the sensitivity of detecting polyps
increase rabidly with almost zero percent of complication. In
terms of this advantages medical practitioners have to trust the
exam and generalize it to help patients to survive from
colorectal disease.

6. Index:
· CAD : Computer-Aided Detection special software called
CAD which is manipulate to reduce mistakes of spotting and
showing polyps to the radiologist for images interpretation.
· CRC : colorectal colon cancer colorectal adenoma is a benign
glandular tumor of the colon and the rectum.
· CT computer-processed combinations of many X-ray images
taken from different angles to produce cross-sectional images.
· Contrast media: is a substance used to enhance the contrast of
structures or fluids within the body in medical imaging.
· CTC : computer tomography for colon.
· Ionization radiation: is radiation that carries enough energy to
free electrons from atoms or molecules.
· Kv: The strong of power penetration
· ms : The amount of electromagnetic radiation.
· Polyps : small clump of cells that forms on the lining of the
colon. Most colon polyps are harmless. But over time, some
colon polyps can develop into colon cancer, which is often fatal
when found in its later stages.
Bibliography:
· Aschoff, A.J., Ernst, A.S., Brambs, H. & Juchems, M.S. 2008,
"CT colonography: an update", European Radiology,vol. 18, no.

7. 3, pp. 429-437. Available from: http://www.gcu.ac.uk/library/
· De Haan, M.C., Pickhardt, P.J. & Stoker, J. 2015, "CT
colonography: accuracy, acceptance, safety and position in
organised population screening", Gut, vol. 64, no. 2, pp. 342-
350. Available from: http://www.gcu.ac.uk/library/
· Pickhardt, P.J. 2015, "CT colonography for population
screening: ready for prime time?", Digestive diseases and
sciences, vol. 60, no. 3, pp. 647-659. Available
from:http://www.gcu.ac.uk/library/
· Tack, D., Gevenois, P.A., Abada, H.T. & Springer EBook
Complete Collection. Owned. 2005-2014 2007, Radiation dose
from adult and pediatric multidetector computed
tomography, Springer, New York;Berlin;. Available from:
http://www.gcu.ac.uk/library/
· Trilisky, I., Ward, E. & Dachman, A.H. 2015, "Errors in CT
colonography", Abdominal Imaging, vol. 40, no. 7, pp. 2099-
2111. Available from: http://www.gcu.ac.uk/library/
· Venema, H.W., Laméris, J.S., Jensch, S., Stoker, J., Bossuyt,
P.M.M., Reitsma, J.B. & Gelder, v., R.E 2006, "Effective
radiation doses in CT colonography: results of an inventory
among research institutions", European Radiology, vol. 16, no.
5, pp. 981-987. Available from: http://www.gcu.ac.uk/library/
Appendix:
1- Introduction
page 1
2- Exam technique page

8. 2
3- Advantages of CT Colonography page2
4- Disadvantages of CT Colonography page4
5- Experience of CTC observers page5
6- Conclusion
page5
How effective is CT Colonography in detecting colon cancer?
Name : Basem AL Zahrany
Class: Claudia team
Date : 15/02/2016
Word count : 1385 words