Potential use of Doppler perfusion index in detection of occult liver metastases from colorectal cancer

Many clinical and preclinical studies demonstrated that measurements of liver hemodynamic[Doppler perfusion index (DPI)] may be used to accurately diagnose and predict liver metastases fromprimary colorectal cancer in a research setting. However, Doppler measurements have some seriouslimitations when applied to general population. Ultrasound is very operator-dependent, and requires skilledexaminers. Also, many conditions may limit the use of Doppler ultrasound and ultrasound in general, such asthe presence of air in digestive tract, cardiac arrhythmias, vascular anomalies, obesity and other conditions.Therefore, in spite of the results from clinical studies, its value may be limited in everyday practice. Onthe contrary, scientific research of the DPI in detection of liver metastases is of great importance, sincecurrent research speaks strongly for the presence of systemic vasoactive substance responsible for observedhemodynamic changes. Identification of such a systemic vasoactive substance may lead to the developmentof a simple and reproducible laboratory test that may reliably identify the presence of occult liver metastasesand therefore increase the success of adjuvant chemotherapy through better selection of patients. Furtherresearch in this subject is therefore of great importance.