Dark Lumen MR colonography vs. Colonoscopy for the detection of colorectal lesions

Colorectal carcinoma (CRC) is one of the most common causes of cancer related
death in the Netherlands. MR colonography is considered as potential screening
tool for CRC and recent studies on MR colonography show promising diagnostic
accuracy with low patient burden regarding bowel preparation. Rapid
developments in hardware and software now permit the use of gas (CO2) as a
negative contrast medium for colonic distension without important geometric
distortion and artefacts. This most likely further reduces patient burden. To
date, no study has evaluated accuracy and burden of MR colonography with CO2,
except for initial data in a few patients.

To investigate the diagnostic accuracy and burden of MR colonography at 3.0
Tesla, using limited bowel preparation and CO2 for colonic distension.

Prospective cohort study. The study population consists of 110 symptomatic
patients for CRC, who will undergo MR colonography with limited bowel
preparation and a low-fiber diet prior to scheduled colonoscopy. MR
colonography results will be prospectively compared to colonoscopy findings
(segmental unblinding), the latter is being regarded as the reference standard.
Exclusion criteria for this study are an age of less than 18 years, suspicion
of bowel perforation or pathologic obstruction and the inability to hold breath
for 25 seconds and contraindications to undergo MRI; pacemakers, claustrophobia
and pregnancy. Further exclusion criteria exist regarding the use of
intravenous injection of buscopan, include glaucoma or severe cardiac
arrhythmia and contraindications for the usage of iodine-based contrast agent
(Telebrix) including: iodine contrast allergy, hyperthyroidism.

Risks for the subjects undergoing the MRC examination are minimal. MRC is a
diagnostic procedure so there are no direct therapeutic effects. With the use
of a small flexible rectal catheter and an automatic CO2 insufflator, there is
a very minimal risk of rectal perforation (< 1 in 50,000). A group-related
benefit of this diagnostic study is the introduction of a minimally invasive
diagnostic tool in the detection of colorectal pathology. A possible health
gain for participating patients is obtained as significant polyps might be
detected with MR Colonography, which are missed during colonoscopy.