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BACKGROUND Suspected cerebral edema diabetic ketoacidosis (SCEDKA) is more common than perceived with symptoms including altered mentation, headache with vomiting, depressed Glasgow coma scale (GCS), abnormal motor or verbal responses, combativeness, and neurological depression. Suspected cerebral edema diabetic ketoacidosis has been associated with initial diabetic ketoacidosis (DKA) presentation and at start of DKA therapy.Cerebral oximetry (bihemispheric regional cerebral oxygen saturation [rcSO2] and cerebral blood volume index [CBVI]) can detect increased intracranial pressure (ICP)-induced altered bihemispheric cerebral physiology (rcSO2) (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700). In pediatrics, rcSO2 of less than 60% or rcSO2 of greater than 85% reflects increased ICP and cerebral edema (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700). Cerebral oximetry can detect increased ICP-induced altered bihemispheric cerebral physiology (rcSO2, CBVI) and cerebral physiological changes (rcSO2, CBVI changes) during therapeutic mechanical cerebral spinal fluid removal to decrease increased ICP (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700).In the pediatric intensive care units, SCEDKA patients with nonbihemispheric cerebral oximetry showed an initial rcSO2 of greater than 90%. Bihemispheric rcSO2 with CBVI in SCEDKA patients has the potential to detect the abnormal cerebral physiology and disruptive autoregulation while detecting 3% hypertonic saline solution (HTS) effects on the SCEDKA altered cerebral physiology (rcSO2). PURPOSE The purposes of this study were to analyze and compare 3% HTS effect on bihemispheric rcSO2 readings, neurological and biochemical parameters in SCEDKA with 3% HTS infusion to non-SCEDKA patients in pediatric emergency department (PED). METHODS An observational retrospective comparative analysis study of bihemispheric rcSO2 readings, neurological and biochemical parameters in 2 groups of PED DKA patients were performed: PED DKA patients with SCEDKA +3% HTS infusions versus non-SCEDKA without 3% HTS infusions. RESULTS From 2008 to 2013, of the 1899 PED DKA patients, 60 SCEDKA patients received 3% HTS (5 mL/kg via peripheral intravenous) infusion (median age of 5 years [range, 3.7-7 years]), with 42 new DKA insulin dependent diabetes mellitus onset. Suspected cerebral edema diabetic ketoacidosis patients had GCS of 11 (range, 11-12), with consistent SCEDKA signs and symptoms (severe headaches with vomiting, confusion, blurred vision, altered speech, lethargy, and combativeness). Suspected cerebral edema diabetic ketoacidosis patients' initial (0-5 minutes) left rcSO2 readings were 91.4% (range, 88.4%-94.1%) and right was 90.3% (range, 88.6%-94.1%) compared with non-SCEDKA patients' left rcSO2 readings of 73.2% (range, 69.7%-77.8%) and right of 73.2% (range, 67.6%-77%) (P < 0.0001). The rcSO2 monitoring time before 3% HTS infusion was 54.9 minutes (range, 48.3-66.8 minutes) with 3% HTS time effect change: pre-3% HTS (54.9 minutes [range, 48.3-66.8 minutes]). Before 3% HTS infusion, the left rcSO2 readings were 90.0% (range, 89%-95%) and right was 91% (range, 86%-95%). The 30 to 45 minutes post-3% HTS showed that left was 64% (range, 62%-69%) and right was 65.4% (range, 63%-70%) (P < 0.0001). rcSO2 Δ change for post-3% HTS (0-20 minutes) to pre-3% HTS was as follows: left, -26.58 (-29.5 to -23.7) (P < 0.0001); right, -25.2 (-27.7 to -22.6) (P < 0.0001). Post-3% HTS GCS (14,15) and biochemistry compared with pre-3% HTS infusions all improved (P < 0.001). CONCLUSIONS In PED SCEDKA patients, the pre-3% HTS bihemispheric rcSO2 readings were greater than 90% and had lower GCS than non-SCEDKA patients. The post-3% HTS infusion rcSO2 readings showed within minutes a substantial reduction compared with non-SCEDKA patients, with no complications. Changes in rcSO2 readings after 3% HTS correlated with improved SCEDKA indicators (improved mental status, headache, and GCS) without any complications. We showed that cerebral oximetry in PED SCEDKA patients has shown an initial bihemispheric of greater than 90% readings signifying abnormal bihemispheric cerebral physiology. We also showed the cerebral oximetry's functionality in detecting 3% HTS therapeutic effects on SCEDKA's abnormal cerebral physiology and the beneficial therapeutic effects of 3% HTS infusion in SCEDKA patients. Using cerebral oximetry in pediatric DKA patients' initial cerebral assessment could have a significant impact in detecting SCEDKA patients. Further SCEDKA research using cerebral oximetry should be considered.

Accurate, near-real-time temperature measurements are essential for effective monitoring of all types of thermal therapies. Current methods are too slow, subject to substantial errors from motion and fail in fat. We propose: 1) To develop a modification of the PRF technique to allow simultaneous measurement of proton longitudinal relaxation rate, T1. 2) To continue the implementation of model-based linear predictive techniques to utilize the best estimate of tissue thermal properties and linear predictive filtering (e.g., Kalman filter) to obtain the current estimate of the temperature distribution from the prior temperature distribution. Tissue thermal properties will be estimated based upon segmentation from multiple MRI contrasts.

The aim of this proposal is to implement MR temperature measurement techniques that accelerate data acquisition speed and are robust to motion-related errors. Collaboration between the research groups at the University of Utah and the University of Geneva will facilitate the transmission, implementation, and further development of these site-specific MR temperature measurement techniques and will accelerate the two goups' respective goals of using MRgHIFU to treat tumors in breast and liver.

Accelerated data acquisition with simultaneous multi-slice (SMS) imaging for functional MRI studies leads to interacting and opposing effects that influence the sensitivity to blood oxygen level-dependent (BOLD) signal changes. Image signal to noise ratio (SNR) is decreased with higher SMS acceleration factors and shorter repetition times (TR) due to g-factor noise penalties and saturation of longitudinal magnetization. However, the lower image SNR is counteracted by greater statistical power from more samples per unit time and a higher temporal Nyquist frequency that allows for better removal of spurious non-BOLD high frequency signal content. This study investigated the dependence of the BOLD sensitivity on these main driving factors and their interaction, and provides a framework for evaluating optimal acceleration of SMS-EPI sequences. functional magnetic resonance imaging (fMRI) data from a scenes/objects visualization task was acquired in 10 healthy volunteers at a standard neuroscience resolution of 3 mm on a 3T MRI scanner. SMS factors 1, 2, 4, and 8 were used, spanning TRs of 2800 ms to 350 ms. Two data processing methods were used to equalize the number of samples over the SMS factors. BOLD sensitivity was assessed using g-factors maps, temporal SNR (tSNR), and t-score metrics. tSNR results show a dependence on SMS factor that is highly non-uniform over the brain, with outcomes driven by g-factor noise amplification and the presence of high frequency noise. The t-score metrics also show a high degree of spatial dependence: the lower g-factor noise area of V1 shows significant improvements at higher SMS factors; the moderate-level g-factor noise area of the parahippocampal place area shows only a trend of improvement; and the high g-factor noise area of the ventral-medial pre-frontal cortex shows a trend of declining t-scores at higher SMS factors. This spatial variability suggests that the optimal SMS factor for fMRI studies is region dependent. For task fMRI studies done with similar parameters as were used here (3T scanner, 32-channel RF head coil, whole brain coverage at 3 mm isotropic resolution), we recommend SMS accelerations of 4x (conservative) to 8x (aggressive) for most studies and a more conservative acceleration of 2x for studies interested in anterior midline regions.

The aim of this proposal is to implement MR temperature measurement techniques that accelerate data acquisition speed and are robust to motion-related errors. Collaboration between the research groups at the University of Utah and the University of Geneva will facilitate the transmission, implementation, and further development of these site-specific MR temperature measurement techniques and will accelerate the two goups' respective goals of using MRgHIFU to treat tumors in breast and liver.