Colorectal cancer: the case for barium enema

MR colonography: development of optimized method with ex vivo and in vivo systems

An ex vivo magnetic resonance (MR) colonographic system with a bovine colon with polyps of predetermined dimensions was developed for evaluation and optimization of different combinations of imaging sequences and intraluminal contrast agents. Findings were then applied during in vivo testing in human subjects. The results show that optimized contrast and lesion conspicuity and minimized motion artifacts can be obtained with true fast imaging with steady-state precession combined with water as an intraluminal contrast agent.

Colorectal carcinoma: radiological diagnosis and staging

Colorectal carcinomas are the most common gastrointestinal tract tumors. 50-60% of the colorectal carcinomas originate in rectum and sigmoid colon. The new developments in imaging modalities have brought improvements in therapeutic aspects. The survival rates in these patients depend on the tumor penetration and the presence of regional lymph node or distant metastasis. The recurrence rates have decreased with the new operation techniques and preoperative radiotherapy, thus increasing the importance of accurate tumor staging. Double contrast barium enema studies enable the diagnosis while staging and follow-up is best done by topographic imaging techniques.

The double contrast barium enema: a retrospective single centre audit of the detection of colorectal carcinomas

AIM

To determine retrospectively the sensitivity and specificity of the double contrast barium enema (DCBE) as performed in one institution for the detection of colorectal carcinoma.

SUBJECTS AND METHODS

Eight hundred and eighty barium enema reports were reviewed of consecutive adult patients who underwent DCBE and also had hospital case notes with a minimum follow up of two years, a later diagnostic colonoscopy, or operative and histological findings.

RESULTS

Seventy-four true positive cases of colorectal carcinoma diagnosed at DCBE were confirmed at surgery and histological examination. There were four false positive diagnoses of carcinoma at DCBE. Eight false negative cases at DCBE were demonstrated within a two-year follow-up period. The sensitivity of the DCBE for detecting colorectal carcinoma was therefore 90.2% and the specificity was 99.5%.

CONCLUSION

DCBE is a sensitive and highly specific investigation for the detection of colorectal carcinoma.

A prospective single centre study comparing computed tomography pneumocolon against colonoscopy in the detection of colorectal neoplasms

BACKGROUND AND AIMS

To determine the sensitivity and specificity of computed tomography (CT) pneumocolon in the detection of colorectal neoplasms.

METHODS

A total of 201 consecutive patients with colorectal symptoms or requiring surveillance for colorectal neoplasms underwent both conventional colonoscopy and CT pneumocolon.

RESULTS

On conventional colonoscopy 13 invasive colorectal carcinomas were detected in 13 patients, and 118 polyps in 63 patients (14 polyps were > or =1 cm in diameter, 25 were 6-9 mm, and 79 were < or =5 mm). CT pneumocolon detected all 13 cancers, two false positive cancers, but only 20 polyps (seven were > or =1 cm). This resulted in a sensitivity of 100% (95% confidence interval (CI) 87-100%) and specificity of 99% (95% CI 97-100%) for detection of invasive carcinoma, and a sensitivity of 73% (95% CI 56-90%) and specificity of 94% (95% CI 91-98%) for detection of invasive carcinoma and/or > or =1 cm polyps. CT pneumocolon also identified invasive carcinoma not seen at colonoscopy because of incomplete examination in three patients, and detected metastases in six colorectal carcinoma patients and extracolonic carcinoma in a further seven patients.

CONCLUSIONS

CT pneumocolon had a high sensitivity and specificity for detection of invasive colorectal carcinoma but not colorectal polyps. CT pneumocolon may be suitable for initial investigation of patients with symptoms of colorectal malignancy.

Diagnosis of colorectal neoplasms at double-contrast barium enema examination

The double-contrast barium enema examination has been recognized as an option for colorectal cancer screening in Americans with average risk who are greater than 50 years of age. The purpose of this article is to review the principles for diagnosing colorectal neoplasms on double-contrast images and the spectrum of findings associated with these lesions. Colonic polyps can be sessile or pedunculated; their appearance depends on whether they are located on the dependent or nondependent wall of the bowel. Villous tumors may be flat, lobulated lesions, also known as "carpet" lesions, that are characterized by a finely nodular or reticular surface pattern, without a discrete mass. Colonic carcinomas may manifest as plaquelike, polypoid, semiannular ("saddle") or annular lesions. Colonic neoplasms sometimes are more difficult to detect in the region of the ileocecal valve or the distal rectum or in patients with severe diverticulosis. Careful double-contrast technique and meticulous scrutiny of the images therefore are required to optimize detection of these lesions.

Colon cancer at barium enema examination and colonoscopy: a study from the county of Hordaland, Norway

PURPOSE

To evaluate the efficacy of barium enema examination as routinely performed in the detection of colon cancer in the inhabitants of a well-defined and circumscribed geographic region.

MATERIALS AND METHODS

The study comprised 571 patients with histopathologically verified colon cancer during 1990-1993 from the county of Hordaland. The barium enema examination results were reviewed retrospectively.

RESULTS

The correct diagnosis was reached in 351 cases (sensitivity, 90.9%) in 386 tumor locations on the basis of the results of 381 barium enema examinations. Cancer or an important precancerous lesion was overlooked in 26 cases (6.7%), and the examination was not feasible in nine cases (2.3%). The correct diagnosis was reached in 172 cases (sensitivity, 80.0%) in patients with 215 tumor locations on the basis of the results of 213 colonoscopies. Cancer or an important precancerous lesion was overlooked in 13 cases (6.0%). The examination was technically not successful (i.e., the affected area was not reached with the scope) in 30 cases (13.9%).

CONCLUSION

Barium enema examination is valuable in the diagnosis of colon cancer and compares favorably with colonoscopy. The main reason for missed radiologic diagnosis is failure to observe important lesions visible on the radiographs.

Comparison of two oral evacuants (Citromag and Golytely) for bowel preparation before barium enema

Oral regimens for bowel preparation before barium enema examination are routinely used because of their convenience and simplicity, rather than the traditional method of colonic wash-out. We performed a prospective study comparing the side-effects and efficacy of two commonly used oral bowel evacuants (Citromag and Golytely) for bowel preparation before barium enema examination in 102 patients. The side-effects associated with the agents were assessed by analysing a questionnaire completed by the patients. There was no significant difference in the side-effects between the two agents although more patients taking Golytely (45.5%) deemed its taste unacceptable than those taking Citromag (25.9%). The results of the bowel preparation were assessed by two independent radiologists giving scores on the amount of faecal residue and the quality of mucosal coating. The amount of faecal residue was less in the Golytely group (p < 0.05). The quality of mucosal coating by barium was also better in the Golytely group than the Citromag group (p < 0.05).

The frequency of total colonoscopy and terminal ileal intubation in the 1990s

We examined the frequency of total colonoscopy and terminal ileal intubation in a training setting using modern videoendoscopic equipment and techniques with examinations supervised or done by the two authors. The cecum was considered reached if the endoscopic report included a description of the cecal landmarks visualized and if electronic images documenting these landmarks were obtained. One of us also routinely attempted terminal ileal intubation for documentation purposes, allotting a minute or two for the purpose. In cases of chronic diarrhea and possible inflammatory bowel disease, a more prolonged attempt was made to visualize the terminal ileum. Among 418 consecutive colonoscopies, the cecum was reached in 96% of cases. If cases of malignant obstruction were excluded, the success rate improved to 97%. When routinely attempted, the terminal ileum was intubated and inspected in 74% of cases (excluding cases of malignant obstruction). In cases in which terminal ileal intubation and inspection was deemed necessary, the success rate was 91%. We conclude that total colonoscopy can be accomplished in the 1990s in excess of 90% of cases and can be documented by high-quality photographs that can be attached to the procedure report. High rates of successful total colonoscopy should be attainable even in training programs. Routine intubation of the terminal ileum can be performed to provide further objective proof of the extent of colonoscopy and to allow the endoscopist to develop and maintain the skill. A skilled, practiced endoscopist can inspect the terminal ileum in about 90% of cases in which such examination is needed.

Significance of a low serum ferritin level in elderly in-patients

Iron deficiency, defined as a serum ferritin level less than or equal to 50 micrograms/l was found in 28 (11%) of 252 consecutive elderly in-patients (mean age 81 years). Sixteen among them were anaemic and only five had a microcytic anaemia. In a separate study, 15 anaemic and 13 non-anaemic iron-deficient elderly in-patients were investigated in order to evaluate the prevalence of gastrointestinal symptoms and lesions in both groups. In nine of the anaemic and seven of the non-anaemic patients a potential cause for the iron deficiency was established. Most anaemic and non-anaemic patients lacked the symptoms described as suggestive of underlying gastrointestinal pathology. Thus, a ferritin level less than or equal to 50 micrograms/l justifies a gastrointestinal investigation if the general condition allows for it as well in anaemic as in non-anaemic elderly hospitalized patients. Therefore, serum ferritin should be part of the routine biochemical investigation of elderly in-patients.