Objective To evaluate the accuracy of a three-dimensional (3D) magnetic position sensor system in the quantification of ventricular stroke volumes in a dynamic model. Methods A latex balloon model of the left ventricle was suspended in a water bath connected to a pump producing 10 different pulsatile stroke volumes (15-65mi/beat). Scanning was performed using a 5.0 mHz transducer mounted with a Flock of Birds (FOB) magnetic receiver (GE System Five). The probe was scanned to sweep continuously across and over the balloon volume over 3 - 7 seconds. Digital loops were stored on magneto-optical disks and reviewed retrospectively using 3D Echopac software (GE) based on Simpson's method and compared with a two-dimensional (2D) biplane area-length method (1/2 L x R) measurements at end systole and end diastole. Both 3D and 2D derived stroke volumes were compared with the reference stroke volume calculated by direct measurement of balloon capacity. Results There was an improved correlation between 3D stroke volume and reference stroke volume ( y = 0.91 x + 0.41, r = 0.97, SEE = 2.83 ml, P = 0.0001 ) compared to 2D stroke volume and reference stroke volume (y=0.49x+8.68, r=0.87, SEE=3.87 ml, P=0.0011, difference between 2D and 3D P＜0.003). Conclusion 3D magnetic FOB scanning is practical, accurate and should facilitate assessment of left ventricular function.

Objective To develop the Sino-Nasal Outcome Test-20 Chinese Version (SNOT-20 CV). Methods By introducing, translating, pretesting, adjusting, and performance testing of SNOT-20 inventory, a Chinese draft scale came into being. On the basis of the clinical applications and feedbacks from ten domestic hospitals, the scale was further modified and was more strictly tested in sixty patients with chronic rhinosinusitis, and then its psychometric properties were compared with that of the original edition. Results The SNOT-20 CV showed the following psychometric properties: The scale was easily accepted and answered in patients, showing a satisfactory feasibility. The split-half reliability, Cronbach' alpha and intraclass correlation coefficient were 0. 95, 0. 88, and 0. 98, respectively. The content validity was approved by experts of working group. The criteria validity calculated between SNOT-20 and SF-36 was - 0. 67. Factor analysis of construct validity showed that the comparative fit index was 0. 93 and the 20 items were classified into 4 domains which were accorded with the designed constructs. The category rating system was of reasonable additivity and comparability. Every domain was of sensitivity to effectively discriminate between patient population and healthy population ( P < 0. 01 ). The standardized response mean of twenty items and five important items at three months postoperatively was respectively 0. 48 and 0. 57, suggesting moderate responsibility to clinical change. SNOT-20 CV passed the tests of feasibility, reliability, validity, scalability, sensitivity, and responsibility, showing good properties comparable to that of the original edition. Conclusions SNOT-20 CV passes the psychometric and clinimetric tests and can be used for measuring rhinosinusitis-specific quality of life in China.