Relationship Between Pituitary Adenoma Consistency and Extent of Resection Based on Tumor/Cerebellar Peduncle T2-Weighted Imaging Intensity (TCTI) Ratio of the Point on Preoperative Magnetic Resonance Imaging (MRI) Corresponding to the Residual Point on Postoperative MRI.

BACKGROUND Controversies exist in imaging modalities for predicting adenoma consistency. In this study, we proposed a method of predicting consistency by magnetic resonance T2-sequence imaging based on adenoma to cerebellar peduncle signal (TCTI) ratio. MATERIAL AND METHODS Between January 2013 and May 2017, 191 consecutive patients with pituitary adenoma diagnosed at our institution were retrospectively studied. The consistency grade for each lesion was assigned. And the TCTI ratio based on preoperative and postoperative T2-weighted imaging was calculated. RESULTS The median TCTI ratio was 1.55, 1.28, and 1.25 for soft, fibrous, and hard adenomas, respectively. The differences were significant for all groups (p<0.001). A cutoff value of 1.38 for soft adenomas was found to be 80.2% sensitive and 88.7% specific. The median ratio of the outermost layer of residual tumor was 1.25 (SD±0.408, 95% CI 1.27-1.42). It was less than that ratio of the upper, lower quarter, and middle region of adenoma, respectively, and the inter-group differences were all statistically significant with p≤0.001. The extent of resection for the soft group was significantly greater than that of the hard group (85.3% vs. 70.6%, p=0.011). Analysis of Variance (ANOVA) revealed that the consistency grade was the influencing factor of degree of resection. p=0.003. CONCLUSIONS The TCTI ratio showed a good correlation with pituitary adenoma consistency. We also determined the optimal ratio of the residual adenoma.

The difference of apparent diffusion coefficient in the middle cerebellar peduncle among parkinsonian syndromes: Evidence from a meta-analysis.

The measurement of middle cerebellar peduncle (MCP) width allows for differential diagnosis between Parkinson's disease (PD) and multiple system atrophy with predominant parkinsonian features (MSA-P). However, it remains controversial whether apparent diffusion coefficient (ADC) value in the MCP of MSA-P is elevated or not. In the present study, we aimed to assess the usefulness of ADC value in the MCP for differential diagnosis between PD and MSA-P. An on-line literature search yielded 5 eligible studies. We expressed between-group difference of ADC value as the standardized mean difference (SMD). The proportion of variation due to heterogeneity was computed and expressed as I(2). ADC in the MCP of MSA-P was significantly increased compared with PD with heterogeneous studies (P=0.0007, I(2)=81%). A meta-regression analysis of MSA-P was conducted for "UPDRS III", and revealed a significant correlation between UPDRS III and SMD (P=0.01). Our meta-regression analysis has clarified the contribution of severity of MSA-P to heterogeneity of the included studies for ADC in the MCP. This finding raised the possibility that ADC in the MCP depended on severity of MSA-P, and less severe patients with MSA-P should be mainly enrolled in future study to assess the ability for differential diagnostic tool.

Guanidinoacetic acid versus creatine for improved brain and muscle creatine levels: a superiority pilot trial in healthy men.

In this randomized, double-blind, crossover trial, we evaluated whether 4-week supplementation with guanidinoacetic acid (GAA) is superior to creatine in facilitating creatine levels in healthy men (n = 5). GAA (3.0 g/day) resulted in a more powerful rise (up to 16.2%) in tissue creatine levels in vastus medialis muscle, middle-cerebellar peduncle, and paracentral grey matter, as compared with creatine (P < 0.05). These results indicate that GAA as a preferred alternative to creatine for improved bioenergetics in energy-demanding tissues.