Evaluation of diffusivity in pituitary adenoma: 3D turbo field echo with diffusion-sensitized drivenequilibrium preparation

Objective: Diffusivity of pituitary adenoma has not been investigated fully. The purpose of this study was to evaluate the feasibility of turbo field echo with diffusion-sensitized driven-equilibrium (DSDE-TFE) preparation for pituitary adenoma in the sella turcica and unaffected anterior lobe of the pituitary gland. Methods: This retrospective study included 23 adult patients with pituitary adenomas. Among them, 6 each were prolactin-producing adenomas and growth hormoneproducing adenomas (GH) and the remaining 11 were non-functioning adenomas (NON). The apparent diffusion coefficients (ADCs) were measured in the pituitary adenoma and in the unaffected pituitary gland using coronal reformatted plane. Results: All pituitary adenomas were clearly visualized on DSDE-TFE and ADC maps without obvious geometrical distortion. There were no statistically significant differences in ADC of the all pituitary adenoma (1.506 0.61×10^-3mm² s^-1) and the unaffected anterior lobe of the pituitary gland (1.49±0.37×10^-3mm² s^-1, p=0.99). The ADC in prolactin-producing adenomas (2.04± 0.7×10^-3mm² s^-1) was significantly higher than that in GH (1.26±0.47×10^-3mm² s^-1; p<0.05) and NON (1.33±0.42×10^-3mm² s^-1; p=0.04). There was no statistically significant difference between GH and NON (p=0.97). The intraclass correlation coefficient for ADC was 0.985 in adenomas and 0.635 in unaffected glands. Conclusion: With its insensitivity to field inhomogeneity and high spatial resolution, DSDE-TFE proved a feasible method for evaluating the diffusivity in the pituitary gland and adenoma. Advances in knowledge: DSDE-TFE could enable us to assess ADC of pituitary adenoma in the sella turcica with high resolution and few susceptibility artefacts.