Keywords:
Neoplasia, Diverticula, Cancer, Computer Applications-Virtual imaging, Computer Applications-3D, Colonography CT, CT-High Resolution, CT, Computer applications, Colon, Abdomen
Authors:
I. Kiss, I. Kiss, T. Novák, A. Tóth, I. Horváth, A. Palko; Szeged/HU
DOI:
10.1594/ecr2013/C-0746
Methods and Materials
PATIENTS AND METHODS: 1125 patients with abdominal pain and a history of colorectal cancer were studied during a 7 years period (769 women,
358 men,
age 55±44 years) before conventional colonoscopy.
During the evaluation the colon was divided into 6 segments (sigmoid colon,
descending colon,
splenic flexure,
transverse colon,
hepatic flexure,
ascending colon with the cecum).
Segments seen by both method were compared.
CT colonoscopy was performed with a 64 slice multislice instrument (General Electric,
USA) with low dose values.
For the optimal distension of the colon supine and prone positions were both applied.
The radiologist was blinded to the colonoscopic results.
Preparing of the patient (total bowel cleaning,
patient has clinical symptoms),
marker medium (local clinical experience)
Distension (carbon-dioxide,
air - acceptable alternatives,
automatic or manual pumping)
I.v.
contrast medium – It is necessary in patients with clinical symptoms (in screening)
Technical parameters: effective slide thickness -1,25 mm (less than 3 mm)
Administering iv.
contrast medium when the patient lies prone or back( the value of total tube-flow is more than around 50 mAs)
Reading protocol: 2D axial,
2D MPR and 3D,
previous overview (2D) then 3D TOTAL overview (4 hours/ 10 examination)
Advantages of virtual colonoscopy:
The whole colon can be examined.
In 10-10% of cases the proximal part cannot be examined by colonoscopy.
-Both sides of bowel wall can be examined.
-Correct size of polyp,
localisation
-less invasive
-short time of examination
-It can be performed in elder patients
-The possibility of perforation is low
Disadvantages of virtual colonoscopy:
-Histological sample cannot be taken
-Polyp cannot be removed
-Not the real mucosa can be seen.