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Twenty patients with MR imaging negative for temporal lobe epilepsy who underwent preoperative evaluation and 10 healthy controls were scanned using PET/MR imaging with simultaneous acquisition of PET and arterial spin-labeling. On the basis of the standard uptake value and CBF, receiver operating characteristic analysis and a logistic regression model were used to evaluate the predictive value for the localization. Complete concordance was noted in lateralization and localization among the PET, arterial spin-labeling, and histopathologic findings in 12/20 patients based on visual assessment. PET/MR imaging–based multiparametric imaging involving arterial spin-labeling may increase the clinical value of localizing the epileptogenic zone by providing concordant and complementary information.

Fifteen male freedivers underwent repetitive 3T pseudocontinuous ASL and ³¹P-/¹H-MR spectroscopy before, during, and after a 5-minute breath-hold (split into early and late phases) and gave temporally matching venous blood gas samples. The spatial coefficient of variation of CBF (by arterial spin-labeling) decreased during the early breath-hold phase whereas CBF remained almost stable during this phase and increased in the late phase. Cerebrovascular reactivity differed between the anterior and the posterior circulation during all phases. The cerebral energy metabolism of trained freedivers withstands severe hypoxic hypercarbia in prolonged breath-hold due to a complex cerebrovascular hemodynamic response.