Functional MRI of human pancreas using BOLD contrast: Responses following glucose ingestion.

PURPOSE: To evaluate the response of the pancreas to glucose ingestion in healthy volunteers by blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI).

MATERIALS AND METHODS: This study was approved by the local Ethics Committee, and informed consent was obtained from all subjects. A multiple gradient recalled echo (mGRE) sequence was performed on a 3.0T MR scanner in 12 healthy volunteers before and after glucose or water ingestion. Pancreatic T2* values were calculated from it at each timepoint, and changes following stimulation were analyzed using summary measures. The valley values and times were compared between the glucose and water ingestion by paired samples t-test. The repeatability of the pancreatic T2* measurements was assessed by calculating the intraclass correlation coefficient (ICC) and coefficient of variation (CV).

RESULTS: Pancreatic T2* measurements showed good repeatability (all ICC >0.75). CV for the six baseline acquisitions was 2.74 ± 0.97%, indicating a 5.37% measurement error. A transient but significant decrease (-6.88 ± 1.01%, P value, 0.0005-0.0467) in the pancreatic T2* values was observed within 5 minutes after glucose ingestion, rather than water consumption. Compared to water, glucose ingestion induced earlier (valley times: 3.46 ± 3.22 vs. 7.75 ± 4.09 min, P = 0.0006) and remarkable pancreatic T2* decrease (valley values: -15.33 ± 5.90% vs. -6.88 ± 3.11%, P = 0.0006).

CONCLUSION: BOLD MRI enabled noninvasive quantification of pancreatic T2* changes during glucose stimulation. Glucose ingestion resulted in a rapid and significant pancreatic T2* decrease in healthy young volunteers.

LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:831-836.