Purpose: We compared the regional cerebral blood flow (rCBF) obtained by pulsed continuous arterial spin labeling (pCASL) and iodine-123-N-isopropyl-p-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) using 3-dimensional stereotactic region-of-interest (ROI) software for automated definition of ROIs in anatomic regions of the brain.Methods: Thirteen patients with cerebrovascular occlusive disease and three with transient ischemic attacks underwent pCASL and IMP SPECT imaging. We compared rCBF values of each anatomic region and calculated the correlation coefficients between pCASL and IMP SPECT. We also calculated the asymmetry index (AI) using ROIs in contralateral regions of the hemispheres.Results: The rCBF values calculated from pCASL and IMP SPECT were comparable in most segments, but rCBF in the thalamus (P < 0.0001) and hippocampus (P = 0.0006) was significantly higher measured by pCASL than IMP SPECT. The correlation of rCBF between pCASL and IMP SPECT in the affected hemisphere (r = 0.50) tended to be lower than that in the normal hemisphere (r = 0.59), but not significantly different (P = 0.25). Moreover, there was a fixed bias for underestimation of rCBF by pCASL (P = 0.0047) in the affected hemisphere. The calculated AI showed a significant relationship between methods (r = 0.79, P < 0.0001).Conclusion: The rCBF obtained by pCASL had positive relationships with IMP SPECT. However, it should be considered that pCASL tends to have a weak relationship with IMP SPECT in some normal regions and regions affected by cerebrovascular occlusive disease.

Our results demonstrated the feasibility of intravoxel incoherent motion assessment of the normal anterior pituitary lobe by using TSE-DWI. High D and f values in the anterior pituitary lobe were thought to reflect its microstructural and perfusion characteristics.

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Background and Purpose: Differentiation between hemangioblastoma and brain metastasis remains a challenge in neuroradiology using conventional MRI. Amide proton transfer (APT) imaging can provide unique molecular information. This study aimed to evaluate the usefulness of APT imaging in differentiating hemangioblastomas from brain metastases and compare APT imaging with diffusion-weighted imaging and dynamic susceptibility contrast perfusion-weighted imaging.Methods: This retrospective study included 11 patients with hemangioblastoma and 20 patients with brain metastases. Region-of-interest analyses were employed to obtain the mean, minimum, and maximum values of APT signal intensity, apparent diffusion coefficient (ADC), and relative cerebral blood volume (rCBV), and these indices were compared between hemangioblastomas and brain metastases using the unpaired t-test and Mann-Whitney U test. Their diagnostic performances were evaluated using receiver operating characteristic (ROC) analysis and area under the ROC curve (AUC). AUCs were compared using DeLong's method.Results: All MRI-derived indices were significantly higher in hemangioblastoma than in brain metastasis. ROC analysis revealed the best performance with APT-related indices (AUC = 1.000), although pairwise comparisons showed no significant difference between the mean ADC and mean rCBV.Conclusions: APT imaging is a useful and robust imaging tool for differentiating hemangioblastoma from metastasis.

Prediction of tumor consistency is valuable for planning transsphenoidal surgery for pituitary adenoma. A prospective study was conducted involving 49 participants with pituitary adenoma to determine whether quantitative pharmacokinetic analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is useful for predicting consistency of adenomas. Pharmacokinetic parameters in the adenomas including volume of extravascular extracellular space (EES) per unit volume of tissue (ve), blood plasma volume per unit volume of tissue (vp), volume transfer constant between blood plasma and EES (Ktrans), and rate constant between EES and blood plasma (kep) were obtained. The pharmacokinetic parameters and the histologic percentage of collagen content (PCC) were compared between soft and hard adenomas using Mann–Whitney U test. Pearson’s correlation coefficient was used to correlate pharmacokinetic parameters with PCC. Hard adenomas showed significantly higher PCC (44.08 ± 15.14% vs. 6.62 ± 3.47%, p < 0.01), ve (0.332 ± 0.124% vs. 0.221 ± 0.104%, p < 0.01), and Ktrans (0.775 ± 0.401/min vs. 0.601 ± 0.612/min, p = 0.02) than soft adenomas. Moreover, a significant positive correlation was found between ve and PCC (r = 0.601, p < 0.01). The ve derived using DCE-MRI may have predictive value for consistency of pituitary adenoma.