DiscussionMDCT may be used to evalu

DiscussionMDCT may be used to evaluate patients with known colonic carcinoma for staging purposes or detect tumors in patients with non-specific abdominal complaints. CT isa sensitive tool for determining the extent of pelvic and abdominal neoplasms, and is used in assessment of metastases to lymph nodes, liver, peritoneal cavity, and retroperitoneum (15, 16). PET/CT or MRI/diffusion-weighted MRI may also be used for such purposes (17, 18). The CT features of colonic carcinoma are well known (19, 20), however, the usefulness of routine CT as a screening technique, its rateof detection, and its role during preoperative staging remain controversial (21, 22). Several authors have investigated the potential role of CT in the diagnosis and staging of colorectal cancer, however, reported accuracy rates have been disappointing, ranging between 64% and 81% (20, 23, 24). However, several recent studies have reported higher accuracies for tumor staging when CT is used incombination with multiplanar reformatting (25– 27).Barton et al. (28) reported that in terms of defining theextent of surgery, explaining operative plans to patients,preparing for the procedure, and evaluation of intraperitoneal seeding or metastases, CT was helpful in 37% of 70 patients who underwent preoperative CT. About 30 years ago, roentgenologic investigation of the growth rate of CRC was conducted using double contrast barium examinations. In a study using radiography for evaluation of 27 carcinomas, Bolin et al. (29), who assumed a three-dimensional growth pattern, reported a median linear growth rate of 0.083 mm/day (0.0080.262 mm/day) over a median observation time of 11 months (4–91months), and a median time of tumor volume doubling of 130 days (53–1570 days). In addition, a significant positive correlation was observed between poor differentiation and linear growth rate (0.1 mm/day). It was suggested that the high growth rate observed was probably due to the large sizes of the tumors included, and, thus, to a high probabilityof malignancy at first examination. In the current study, the median longitudinal tumor growth rate was 0.071 mm/day (0–0.29), which also suggests rapid growth.