Variation of heart-to-mediastinal ratio in (123)I-mIBG cardiac sympathetic imaging: its affecting factors and potential corrections.

Studies have repeatedly shown the utility of (123)I-mIBG cardiac sympathetic imaging for identifying symptomatic heart failure patients most likely to experience adverse cardiac events. Delayed heart-to-mediastinal ratio (H/M) and washout rate derived from meta-iodobenzylguanidine (mIBG) scintigraphy have been used to monitor response to medical treatment. However, there is great variation of H/M ratio among publications from various institutions. The current article systemically reviews factors that can potentially affect H/M ratio, particularly the acquisition parameters, and proposes new approaches and/or procedures to standardize the imaging procedure and minimize the variation of H/M among institutions.