confirming the normal range for mebrofenin liver function indices

Objective(s): to establish normal ranges for [99mtc] tc-mebrofenin hepatobiliary scintigraphy (hbs) indices of liver function and the associated uncertainty in clinical measures due to region placement.methods: 47 patients referred for gallbladder assessment with no history of liver disease were included in the study. patients underwent dynamic hbs following injection of 200 mbq of [99mtc] tc-mebrofenin at 10 seconds/frame for 36 frames. analysis was performed by 5 experienced technologists using in-house software (mim software, cleveland, ohio) to establish blood pool (bp) clearance rate (%/min), blood clearance half-time (min), mebrofenin liver uptake rate (mur) (%/min) and mur normalised to body-surface-area (murbsa) (%/min/m2). limits of normal ranges (95%) were established and correlation of functional indices with age was investigated. analysis was repeated after a minimum of 4 weeks to establish intra-user variability and uncertainty associated with measures.results: data were collected for 27 women and 20 men, with an age range of 20 – 81 years. twenty-seven patients were aged over 50 and 20 patients were aged below 50. the data were found to have a normal distribution. the mean values derived for the entire cohort for bp clearance rate, blood clearance half time, mur, and murbsa were 16.8±2.6 %/min, 4.3±0.7 min, 14.4±2.0 %/min and 8.0±1.5 %/min/m2, respectively. no significant difference in values was found between age groups and no correlation between liver function and age was found. the lower range of normal for murbsa was established as 5.1%/min/m2, with clinical measures expected to have an uncertainty of ±0. 6 %/min/m2.conclusion: the murbsa value for a patient with normal liver function can be expected to be approximately 8.0±1.5 %/min/m2, with a lower limit of normal function at 5.1 %/min/m2. patients receiving liver surgery or treatment that express murbsa values below this may be at higher risk and should potentially be treated with caution.