Ultrasound colonography in visualization of large intestine cancer pathology

Abstract

Introduction: colon oncopathology takes the 2-nd place among different kinds of cancer and tends to grow constantly. Thus, the incidence of colorectal cancer (CRC) in Ukraine is 20.6 cases per 100 thousands of population. 70-75% of patients are diagnosed only at the 3-4 stage of the disease, due to its long asymptomatic initial period.

The gold standard of diagnostic of CRC is endoscopy, which enables not only to visualize altered intestinal mucosa, but also to perform a biopsy for morphological study. Modern imaging diagnostic methods (virtual CT colonography, MRI, PET / CT), which are used in developed countries, are not been widely spreded in Ukraine, unfortunately. Complex ultrasound examination reveals new diagnostic capabilities in the solution of this problem. Ultrasound colonography allows morphology assessing of all parts of the large intestine. This method is primarily justified for those patients who can’t be examined with conventional irrigoscopy and endoscopic colonoscopy because of some objective reasons.

Objectives of the research: to objectify the diagnostic capabilities of ultrasound colonography as an alternative method of imaging of colorectal cancer.

Matherials and methods: The colonography was performed with the ultrasound scanner HD11 (Philips) in 26 patients with clinically suspected large intestine pathology. There were 10 male and 16 female patients with the average age 55,3±9,2. All patients were performed X-ray multislice computed tomography (MSCT) as the reference method. 9 patients were operated on with the followed morphological analysis of affected parts of the intestine.

Results and discussion: the colon pathology in our research was found in 10 patients (38.5% of the patients). Among them stenotic form of colorectal cancer was diagnosed in 6 patients (22.8%). In 4 patients (15.2%) the polypoid form of colorectal cancer was found. In both cases, the affected area was located in the region of rectosigmoid junction. In number of patients (3 patients, 11.5%), few single color loci were detected in the affected parts using color Doppler mode. This acoustic phenomenon was regarded as the objectification of hypervascularisation of the tumor.

Examining patients with cancer pathology, a radiologist faces to a number of problems, one of which is the evaluation of the pathological process in accordance to the TNM classification. It is due to the need of making the right decisions concerning the amount and type of forthcoming treatment. Integrated Ultrasound examination enables preoperative tumour invasion assessing. It concerns to intestinal wall, paracolic fatty tissue and surrounding organs. Method also reveals metastases to regional and distant lymph nodes and evaluates the state of the liver.

In our study, multiple metastatic lesions of the liver were revealed in one (3.8%) of the patients during a complex ultrasound examination of the abdomen in the preoperative stage. This fact made us to reject the tactics of radical surgical treatment. In 6 patients (23.1%) the volume colon pathology was diagnosed, the neoplastic regional lymphadenopathy was found. Later it was also confirmed operatively and histologically.

Conclusion: US-colonography is a highly informative, noninvasive imaging method of all parts of the colon. The technique allows to identify oncological process at different stages of it’s development, including early ones, causing minimal discomfort for the patient. First of all, it is recommended for patients whom performing traditional diagnostic imaging techniques (endoscopic colonoscopy and barium enema) is technically impossible.