Radiological imaging of rectal cancer

Abstract

This article discusses the possibilities of diagnosing abdominal imaging in patients with rectal cancer, detecting lesions and assessing the stage of the lesions, in order to select the appropriate therapy. Before the introduction of imaging technologies, the diagnosis of colorectal pathology was based on conventional methods of inspecting intestines with a barium enema, with either a single or double contrast barium enema. Following the development of endoscopic methods and the wide use of colonoscopy, colonoscopy became the method of choice for diagnosing colorectal diseases. The improvement of Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI), gave us new possibilities for diagnosing colorectal cancer. For rectal cancer, trans-rectal US (TRUS) or endo-anal US (EAUS) have a significant role. For staging rectal cancer, the Multi Slice Computed Tomography (MSCT) is not the method of choice, but Magnetic Resonance Imaging (MRI) is preferred when it comes to monitoring the rectum. Therole of the MRI in the T staging of rectal cancer is crucial in preoperative assessment of: thickness – the width of the tumor, the extramural invasion, the circumference of resection margin (CRM), andthe assessment of the inclusion of mesorectal fascia. For successful execution of surgical techniques, good diagnostic imaging of the cancer is necessary in order to have a low level of recurrence. According to medical studies, the sensitivity of FDG-PET in diagnosing metastatic nodals is low, but for now it is not recommended in routine diagnosis of metastatic colorectal carcinoma.

Keywords

• Colorectal cancer
• TRUS
• MSCT
• MRI
• Staging