A feasibility study on model-based evaluation of kidney perfusion measured by means of FAIR prepared true-FISP arterial spin labeling (ASL) on a 3-T MR scanner

RATIONALE AND OBJECTIVES: A feasibility study on measuring kidney perfusion by a contrast-free magnetic resonance (MR) imaging technique is presented. MATERIALS AND METHODS: A flow-sensitive alternating inversion recovery (FAIR) prepared true fast imaging with steady-state precession (TrueFISP) arterial spin labeling sequence was used on a 3.0-T MR-scanner. The basis for quantification is a two-compartment exchange model proposed by Parkes that corrects for diverse assumptions in single-compartment standard models. RESULTS: Eleven healthy volunteers (mean age, 42.3 years; range 24-55) were examined. The calculated mean renal blood flow values for the exchange model (109 +/- 5 [medulla] and 245 +/- 11 [cortex] ml/min - 100 g) are in good agreement with the literature. Most important, the two-compartment exchange model exhibits a stabilizing effect on the evaluation of perfusion values if the finite permeability of the vessel wall and the venous outflow (fast solution) are considered: the values for the one-compartment standard model were 93 +/- 18 (medulla) and 208 +/- 37 (cortex) ml/min - 100 g. CONCLUSION: This improvement will increase the accuracy of contrast-free imaging of kidney perfusion in treatment renovascular disease.

Implementation of Evidence-Based Practices for Treatment of Alcohol and Drug Disorders: The Role of the State Authority

The current climate of increasing performance expectations and diminishing resources, along with innovations in evidence-based practices (EBPs), creates new dilemmas for substance abuse treatment providers, policymakers, funders, and the service delivery system. This paper describes findings from baseline interviews with representatives from 49 state substance abuse authorities (SSAs). Interviews assessed efforts aimed at facilitating EBP adoption in each state and the District of Columbia. Results suggested that SSAs are concentrating more effort on EBP implementation strategies such as education, training, and infrastructure development, and less effort on financial mechanisms, regulations, and accreditation. The majority of SSAs use EBPs as a criterion in their contracts with providers, and just over half reported that EBP use is tied to state funding. To date, Oregon remains the only state with legislation that mandates treatment expenditures for EBPs; North Carolina follows suit with legislation that requires EBP promotion within current resources.