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Posts Tagged ‘Colonoscopy’

Have an overview, how computed tomography is viable for bowel/colorectal cancer!

CT scan_metastatic colon cancer

In Computed tomography, as we know, X-rays are used to scan body organs/tissues, where a computer unit is employed for cross-sectional image (slice) construction. The technology is feasible for a variety of medical conditions; in case of patients with cancer/colorectal polyps, CT colonography (virtual colonoscopy) is a practicable approach over traditional colonoscopy procedure, for the diagnosis.

Colonoscopy (endoscopic procedure) is commonly used to visualize interior of the colon/large intestine for irregular growths, tissue inflammation, bleeding and ulcers. The large bowel cancer includes cancerous growth on colon, rectum/alimentary canal, appendix; in the U.S., death rate due to colon/colorectal cancer is high, in contrast to other medical conditions.

For patients suspected of cancer/polyps in the large intestine, computed tomography colonography is a feasible approach for early-stage detection of such, so that the tumor could be taken out, prior it develops further.

People that have a family history, or at increased risk of colorectal cancer (malignant disorder) are proposed for an early scan; men and women, 50+ years are even suggested to go for colon cancer/polyps screening, taking expert consultation.

Various medical groups/associations suggest individuals for – CT colonography once in every 5 years, and colonoscopy in every 10 years.

Stay tuned with MedicExchange, for various health related blogs and stories, from the radiology community, and related!

CT Colonography or Virtual Colonoscopy can detect colonic as well as extra-colonic abdomino-pelvic lesions, an added advantage over colonoscopy.  Virtual colonoscopy uses computerized tomography (CT) to produce hundreds of cross-sectional images of the abdominal organs which are analysed tp produce a veirtual image of the inside of the colon and rectum while colonoscopy is the endoscopic examination of the colon using a colonoscope allowing direct vizualisation of the colon and rectum.

The new findings were reported in the September issue of the American Journal of Roentgenology.

Even though CT colonography (CTC) cannot be compared to CT pelvis and abdomen, the extracolonic findings detected during the procedure can be significant and provides a clear advantage over conventional optical colonoscopy Dr. Ganesh R. Veerappan, MD, of Walter Reed Army Medical Center in Washington and colleagues conducted a retrospective study to analyse the significance of these lesions.

The researchers found that out of the 2277 patients who underwent CTC, about 45 percent cases had extracolonic findings and a quarter of these findings were significant. Further radiology procedures, surgery and follow-up revealed 7 high-risk lesions among the significant lesions and the radiology studies added approximately $50 extra per patient. The virtual colonoscopy examination found six intracolonic malignancies and three adenomas with high-grade dysplasia.

“CT colonography [CTC] not only identifies colorectal cancer [CRC] but also doubles the yield of identifying significant early extracolonic lesions, resulting in lives saved,” Ganesh Veerappan reported in the journal.

The team concluded that the odds of identifying high-risk lesions were raised by 78% with CTC and thus the examination should be considered as an alternative to conventional colonoscopy in colo-ractal cancer screening or as a one-time screening procedure for intracolonic and extra-colonic lesions.

A study suggests that Virtual colonoscopy or CT colonography can detect malignant cancer outside the colon. According to the study, one out of every 200 people having no symptom of disease possess unsuspected malignant cancer, that too outside the colon.

Colonoscopy is usually done to detect Colorectal cancer, which is supposed to be one of the leading causes of cancer death in U.S. It is recommended to start colorectal cancer screening for people with average risk at the age of 50, but the uneasiness caused by the conventional optical colonoscopy resist people from undergoing screening.

Compared to optical colonoscopy, Virtual colonoscopy has many advantages.

• Less invasive
• Produce detailed image of the interior portion of colon without inserting the scope into it
• The risk of bleeding in the colon, which usually occur with the optical colonoscopy is almost null
• It can be done without sedating the patient
• The structures outside the colon, like pelvis, abdomen and portions of the lungs can be assessed to a limit with this technique. In some cases, virtual colonoscopy is used to diagnose extracolonic parts and most of them appear to be clinically relevant.
• Cost effective
• Saves on time, taking just 10 minutes or less.

The study was conducted by Pickhardt, M.D., professor of radiology and chief of GI Imaging, at the University of Wisconsin School of Medicine & Public Health, and colleagues. For the study, the researchers selected 10,286 adults (5,388 men and 4,898 women) with a mean age of 59.8 years who showed no symptom of the disease. The selected population underwent colorectal cancer screening with virtual colonoscopy either at the University of Wisconsin or at National Naval Medical Center and their medical records were reviewed. It took a mean time 30.2 months for follow-up.

The results showed that 58 patients had unsuspected colorectal cancers, 22 patients had invasive colorectal cancer, extracolonic cancer was found in 36 patients and 31 patients with localized cancers.

Dr. Pickhardt commented,

Although extracolonic evaluation at screening CT colonography does carry some disadvantages, such as patient anxiety, inconvenience, or the potential for benign biopsy, our results suggest that early detection of asymptomatic extracolonic cancer represents an additional benefit of screening CT colonography that is not available with optical colonoscopy. Virtual colonoscopy is an accurate, safe and convenient screening test that could potentially be a life-saving examination.