SU-E-T-210: Surviving a Visit by the Radiological Physics Center.

PURPOSE: To demonstrate an objective approach to determining if a negative report from the Radiological Physics Center (RPC) of greater than 10% error is valid or has clinical significance. METHODS: The discrepancy involved the clinical activity (mgRaEq) of Cs-137 sources, some manufactured by 3M and some by Amersham. Measurements were made in the proprietary RPC Well Counter calibrated by the MD Anderson ADCL and our Well Counter (CNMC, Model 44D) calibrated by the same laboratory as well as the University of Wisconsin ADCL. In addition, we possess an Amersham Cs-137 Check Source that had been calibrated by the UW-ADCL in 2002. All clinical sources were checked in both Well Counters on the first visit. One clinical source and the Check Source were measured in a second visit that occurred 51 days later. RESULTS: On the initial RPC visit, 9 of 25 sources had a minimum of an 8% discrepancy between the RPC and the Institution, with a maximum of 11%. Contributing errors included using the incorrect straw position by us, an unexplained 2.3% error in the RPC data identified 73 days post-visit, a 2% variation in Chamber Factors for our Well Counter from the two ADCL's. When we use the 2004 value of Air Kerma Strength for the Check Source to determine a Calibration Factor of the Well Counter, all sources were within 0.5% of their decayed value established in 2002. CONCLUSIONS: This work emphasizes the value of having simple Constancy Check systems in a Quality Assurance program as 'Accuracy' has error bars. The disagreement in calibration data between the ADCL Laboratories, which was at the 2% maximum quoted in their Calibration Reports, is a reminder that there is uncertainty in measurements. Constancy Checks allow one to sort out discrepancies and to answer challenges to the validity of your program.

Increased serum levels of interleukin 6 are associated with severe intraventricular haemorrhage in extremely premature infants.

BACKGROUND: Intraventricular haemorrhage (IVH) and periventricular leucomalacia (PVL) in premature infants presumably have many causes. It has been proposed that inflammatory processes in the fetomaternal unit play an important role in the pathogenesis of these lesions. OBJECTIVE: To study the correlation of postpartum serum interleukin 6 (IL6) concentration as a marker of inflammation and neonatal cerebral morbidity in preterm infants < 28 weeks of gestational age. METHODS: A total of 88 infants were grouped according to maximum serum IL6 levels within 12 hours post partum: group A (n = 50), < or = 100 pg/ml; group B (n = 38), > 100 pg/ml. Ultrasound studies and clinical assessment were performed routinely. RESULTS: IVH was noted significantly more often in group B (24/38; 63%) than in group A (19/50; 38%) (p = 0.02). In a multiple logistic regression model, raised serum IL6 independently predicted development of severe IVH (odds ratio 8.4; 95% confidence interval 2.85 to 24.9; p = 0.0001). CONCLUSIONS: Raised serum IL6 may serve as a marker for severe IVH in infants < 28 weeks of gestational age. Although cerebral morbidity in premature infants is determined by different variables, the identification of systemic inflammation can help to define the need for anti-inflammatory strategies to prevent cerebral morbidity.

[Invasive pressure measuring for the determination of the aortic opening surface in normal and stenotic left ventricular outflow tracts]. / Invasive Druckmessungen zur Bestimmung der Aorten-Offnungsfläche (AoOF) bei normalem und stenosiertem linksventrikulären Ausflusstrakt.

A method of evaluation of the aortic opening area in healthy dogs and dogs with aortic stenosis is described. Through right and left heart catheterisation intraventricular and intravascular pressures were measured. For the determination of cardiac output the thermodilution technique is used. The aortic opening area is calculated by using the GORLIN-formula. Values of normal and stenotic left ventricular outflow opening area are given.