Arterial Spin Labeling (ASL) is a valuable non-contrast perfusion MRI technique with numerous clinical applications. Many previous ASL MRI studies have utilized either Echo-Planar Imaging (EPI) or True Fast Imaging with Steady-State Free Precession (True FISP) readouts that are prone to off-resonance artifacts on high field MRI scanners. We have developed a rapid ASL-FISP MRI acquisition for high field preclinical MRI scanners providing perfusion-weighted images with little or no artifacts in less than 2 seconds. In this initial implementation, a FAIR (Flow-Sensitive Alternating Inversion Recovery) ASL preparation was combined with a rapid, centrically-encoded FISP readout. Validation studies on healthy C57/BL6 mice provided consistent estimation of in vivo mouse brain perfusion at 7 T and 9.4 T (249±38 ml/min/100g and 241±17 ml/min/100g, respectively). The utility of this method was further demonstrated in detecting significant perfusion deficits in a C57/BL6 mouse model of ischemic stroke. Reasonable kidney perfusion estimates were also obtained for a healthy C57/BL6 mouse exhibiting differential perfusion in the renal cortex and medulla. Overall, the ASL-FISP technique provides a rapid and quantitative in vivo assessment of tissue perfusion for high field MRI scanners with minimal image artifacts.

Dystrophin, the main component of the dystrophin–glycoprotein complex, plays an important role in maintaining the structural integrity of cells. It is also involved in the formation of the blood–brain barrier (BBB). To elucidate the impact of dystrophin disruption in vivo, we characterized changes in cerebral perfusion and diffusion in dystrophin-deficient mice (mdx) by magnetic resonance imaging (MRI). Arterial spin labeling (ASL) and diffusion-weighted MRI (DWI) studies were performed on 2-month-old and 10-month-old mdx mice and their age-matched wild-type controls (WT). The imaging results were correlated with Evan's blue extravasation and vascular density studies. The results show that dystrophin disruption significantly decreased the mean cerebral diffusivity in both 2-month-old (7.38± 0.30 × 10−4mm2/s) and 10-month-old (6.93 ± 0.53 × 10−4 mm2/s) mdx mice as compared to WT (8.49±0.24×10−4, 8.24±0.25× 10−4mm2/s, respectively). There was also an 18% decrease in cerebral perfusion in 10-month-old mdx mice as compared to WT, which was associated with enhanced arteriogenesis. The reduction in water diffusivity in mdx mice is likely due to an increase in cerebral edema or the existence of large molecules in the extracellular space from a leaky BBB. The observation of decreased perfusion in the setting of enhanced arteriogenesis may be caused by an increase of intracranial pressure from cerebral edema. This study demonstrates the defects in water handling at the BBB and consequently, abnormal perfusion associated with the absence of dystrophin.

Epidermolysis bullosa (EB) is a group of rare, inherited diseases characterized by skin fragility and multiorgan system involvement that presents many anesthetic challenges. Although the literature regarding anesthetic management focuses primarily on the pediatric population, as life expectancy improves, adult patients with EB are more frequently undergoing anesthesia in nonpediatric hospital settings. Safe anesthetic management of adult patients with EB requires familiarity with the complex and heterogeneous nature of this disease, especially with regard to complications that may worsen during adulthood. General, neuraxial, and regional anesthetics have all been used safely in patients with EB. A thorough preoperative evaluation is essential. Preoperative testing should be guided by EB subtype, clinical manifestations, and extracutaneous complications. Advanced planning and multidisciplinary coordination are necessary with regard to timing and operative plan. Meticulous preparation of the operating room and education of all perioperative staff members is critical. Intraoperatively, utmost care must be taken to avoid all adhesives, shear forces, and friction to the skin and mucosa. Special precautions must be taken with patient positioning, and standard anesthesia monitors must be modified. Airway management is often difficult, and progressive airway deterioration can occur in adults with EB over time. A smooth induction, emergence, and postoperative course are necessary to minimize blister formation from excess patient movement. With careful planning, preparation, and precautions, adult patients with EB can safely undergo anesthesia.