Imaging of anorectal disease

BACKGROUND: Over the past two decades developments in imaging have changed the assessment of patients with anorectal disease. METHODS: The literature on imaging techniques for anorectal diseases was reviewed over the period 1980-1999. RESULTS: For the staging of primary rectal tumours, phased array magnetic resonance imaging (MRI) may be regarded as the most appropriate single technique. The combination of endosonography or endoluminal MRI with ultrasonography or spiral computed tomography yields similar results. All techniques have limitations both for local staging and in the assessment of distant metastases. MRI or positron emission tomography is preferable for tumour recurrence. For perianal fistula, high-resolution MRI (phased array or endoluminal) is the technique of choice. For constipation, defaecography is the preferred technique, nowadays with emphasis on functional information. The role of magnetic resonance defaecography is currently being evaluated. For faecal incontinence, endosonography and endoluminal MRI give similar results in detecting sphincter defects; endoluminal MRI has the advantage of detecting external sphincter atrophy. CONCLUSION: High-resolution MRI, endosonography and defaecography are currently the optimal imaging techniques for anorectal disease.