Perfusion computed tomography in colorectal cancer: protocols, clinical applications and emerging trends.

Perfusion computed tomography (CT) has emerged as a novel functional imaging technique with gradually increasing importance in the management of colorectal cancer (CRC). By providing the functional tumor microvasculature, it also helps the assessment of therapeutic response of anti-angiogenic drugs as it may reflect tumor angiogenesis. Perfusion CT has been applied in clinical practice to delineate inflammatory or neoplastic lymph nodes irrespective of their size, identify micro-metastases and to predict metastases in advance of their development. It is of increasing significance for preoperative adjuvant therapies and avoidance of unnecessary interventions. Despite controversies regarding the techniques employed, its validity and reproducibility, it can be advantageous in the management of CRCs in which the prognosis is dependent on preoperative staging. With recent advances in the perfusion CT techniques, and incorporation to other modalities like positron emission tomography, perfusion CT will be a novel tool in the overall management of CRCs. This article aims at reviewing the existing clinical applications and recent advances of perfusion CT with a reference to future development in the management of CRCs.