Ultrasound evaluation of the multifetal gestation

With the increasing incidence of multifetal gestations, it is essential for the clinician to appreciate the benefit of ultrasound evaluation in these pregnancies. Multifetal gestation pregnancies are at increased risk for a range of both antepartum and intrapartum complications, such as intrauterine growth restriction, premature delivery, congenital anomalies, cord accidents, malpresentations, placenta previa, and abruptio placentae. First-trimester ultrasonic evaluation, amniotic fluid assessment, monitoring of fetal growth, diagnosing the twin-to-twin transfusion syndrome, and assessment of fetal anomalies will be reviewed. An early and accurate assessment of amnionicity and chorionicity are paramount in these gestations. The impact of chorionicity, in particular, can have profound consequences in the management of multifetal gestations. The determination of chorionicity onultrasonic evaluation in a multifetal gestations. The determination of chorionicity on ultrasonic evaluation in a multifetal pregnancy should be determined in a systematic way between 10-14 weeks' gestation. The amniotic fluid volume should be routinely assessed when performing an ultrasonic evaluation in a multifetal pregnancy. Amniotic fluid changes may serve as the only useful indicator to a potential pathological condition. In addition, evaluation of fetal growth in twins is essential, because these pregnancies are at increased risk for growth restriction and increased perinatal mortality rates compared to singletons. Finally, a careful anatomical evaluation in mulitifetal gestation is important because twin pregnancies have higher rates of anomalies than their singleton counterparts.     

Treatment in the pediatric emergency department is evidence based: a retrospective analysis

Background  

Our goal was to quantify the evidence that is available to the physicians of a pediatric emergency department (PED) in making treatment decisions. Further, we wished to ascertain what percentage of evidence for treatment provided in the PED comes from pediatric studies.     

Traumatic brain injury and lifetime suicidality: Applying the interpersonal-psychological theory perspective

The present article investigates the traumatic brain injury (TBI)-suicide link, assessing whether (a) TBI accounts for variance in suicide risk, and (b) the interpersonal-psychological theory of suicide can be applied to TBI status. Matched case-control procedures applied to archival college student health data identified TBI and non-TBI subsamples (84 total). Individuals with a TBI possessed higher suicide risk than those without. Even accounting for the relative influence of strong suicide risk factors (i.e., depression, perceived burdensomeness, thwarted belongingness, and acquired capability), TBI was robustly associated with suicide risk. TBI history would be valuable to ascertain in assessing suicide risk.     

Accurate determination of blood–brain barrier permeability using dynamic contrast-enhanced T1-weighted MRI: a simulation and in vivo study on healthy subjects and multiple sclerosis patients

Dynamic contrast-enhanced magnetic resonance imaging (DCE–MRI) is increasingly used to estimate permeability in situations with subtle blood–brain barrier (BBB) leakage. However, the method''s ability to differentiate such low values from zero is unknown, and no consensus exists on optimal selection of total measurement duration, temporal resolution, and modeling approach under varying physiologic circumstances. To estimate accuracy and precision of the DCE–MRI method we generated simulated data using a two-compartment model and progressively down-sampled and truncated the data to mimic low temporal resolution and short total measurement duration. Model fit was performed with the Patlak, the extended Tofts, and the Tikhonov two-compartment (Tik-2CM) models. Overall, 17 healthy controls were scanned to obtain in vivo data. Long total measurement duration (15 minutes) and high temporal resolution (1.25 seconds) greatly improved accuracy and precision for all three models, enabling us to differentiate values of permeability as low as 0.1 ml/100 g/min from zero. The Patlak model yielded highest accuracy and precision for permeability values <0.3 ml/100 g/min, but for higher values the Tik-2CM performed best. Our results emphasize the importance of optimal parameter setup and model selection when characterizing low BBB permeability.     

Age related differences in maximal and rapid torque characteristics of the leg extensors and flexors in young,middle-aged and old men

The decline in maximal and rapid isometric torque characteristics may compromise functional living abilities in aging adults while loco-motor muscle groups, such as the leg extensors and flexors, may exhibit different torque–time age related decreases. The purpose of the present study was to examine the age-related differences in maximal and rapid torque characteristics of the leg extensor and flexor muscle groups in young, middle-aged, and old men. Sixty-five healthy men were categorized by age as young (n = 25; mean ± SD age = 24.9 ± 3.0 years), middle-aged (n = 22; age = 50.6 ± 4.0 years), and old (n = 18; age = 66.8 ± 4.5 years). Participants performed maximal voluntary contractions (MVCs) of the leg extensors and flexors and an estimated thigh cross sectional area (eThighCSA) assessment. Peak torque (PT), peak rate of torque development (RTDpeak), absolute RTD and the contractile impulse (IMPULSE) were calculated at time intervals of 30, 50, 100 and 200 ms from the torque–time curve. Relative RTD was calculated at 10, 20, 30, 40 and 50% of MVC from the normalized torque–time curves. PT, RTDpeak and later rapid torque variables (RTD100, RTD200, and IMPULSE200) were greater (P ≤ 0.05) in the young and middle-aged when compared to the old men for both muscle groups. Early (RTD30,50; IMPULSE30,50) and late (IMPULSE100) rapid torque variables were greater (P ≤ 0.05) for the young and middle-aged than the old men for the leg extensors but not the leg flexors, except for RTD30, in which there was no difference between young and old. There were no differences for all relative RTD variables between age groups (P > 0.05). eThighCSA was lower in the old compared to the young (P = 0.001) and middle-aged (P = 0.016) men. Maximal and rapid torque characteristics were preserved in middle-aged men but greatly reduced in older men with differential effects at early and late portions of the torque–time curve between the leg extensors and flexors. Significant decreases in absolute maximal and rapid torque production with no change in relative RTD across age groups and lower eThighCSA in old men may suggest that the loss of rapid torque producing capacities observed in older men may be largely a function of mechanisms associated with loss of muscle strength and muscle mass.