Hepatic arterial therapy with yttrium-90 microspheres exploits the avenue provided by the neoplastic microvasculature to deliver high-energy, low-penetrating therapeutic doses of radiation. Variant hepatic arterial anatomy, collateral vessels, and changes in flow dynamics during treatment can affect particle dispersion and lead to nontarget particle distribution and subsequent gastrointestinal morbidity. Awareness of these variances and techniques to prevent gastrointestinal tract microsphere delivery is essential in mitigating this serious complication. Our aim is to increase the understanding of the role of various imaging and preventative techniques in minimizing this undesired effect.