ABSTRACT
Objective To study the practicability of measurement of abdominal wall tension (AWT) for noninvasive monitoring of intra-abdominal pressure in ICU patients.Methods Patients with indwelling urethral catheter admitted to ICU from April 2011 to March 2013 were enrolled for a prospective study.Exclusion criteria were patients with muscular relaxants,abdominal operation in three months,acute peritonitis,abdominal mass,acute injury of urinary bladder,acute cystitis,neurogenic bladder,intrapelvis hematoma,and pelvic fracture.The AWT (N/mm) and urinary bladder pressure (UBP) (mm Hg) of all patients were measured.Statistical analysis was performed by SPSS 13.0 statistical software.The correlation of AWT and UBP were analyzed using linear regression analysis.The effects of respiration and body position on AWT were analyzed using the Paired-samples t test,and the effects of gender and body mass index (BMI) on basic level of AWT (IAP ＜ 12 mm Hg) were analyzed using the One-way ANOVA.Results A total of 51 patients were recruited in study.A significantly linear correlation between AWT and UBP were observed (R =0.986,P ＜ 0.01),the regression equation was Y =1.369 + 9.57X (P ＜ 0.01).Under the supine-flat positioning,the intra-abdominal pressures at the end of inspiration and the end of expiration were (1.65 ± 0.52) N/mm and (1.45 ± 0.54) N/mm,respectively,and under body straight up 30° supine positioning,the intra-abdominal pressures at the end of inspiration and the end of expiration were (1.25 ± 0.30) N/mm and (1.07 ± 0.35) N/mm,respectively.There were significant differences in intra-abdominal pressure between different respiratory phases and body positions (P ＜ 0.01).Basic levels of AWT in male and female were (1.09 ± 0.29) N/mm and (1.01 ± 0.34) N/mm.The basic levels of AWT in patients with BMI ＜ 18.5,18.5 ≤ BMI ≤25 and BMI ＞ 25 were (0.91 ± 0.30) N/mm,(1.02 ±0.35) N/mm and (1.16 ±0.28) N/mm respectively,but gender and BMI had no significant effects on basic level of AWT (P =0.457 and 0.313,respectively).Conclusions There was a significantly linear correlation between AWT and UBP,and respiratory phase and body position had significant effects on AWT,but gender and BMI had no significant impacts on basic level of AWT.AWT could be served as a simple,easy,and accurate method to monitor the IAP in critical ill patients.
ABSTRACT
Objective To compare positional and volumetric differences of internal gross tumor volume (IGTV) delineated separately by three approaches based on four-dimensional CT (4DCT) for the primary tumor of non-small cell lung cancer (NLCLC). Methods Twenty-one patients with NLCLC underwent big bore 4DCT simulation scan of the thorax. IGTVs of the primary tumor of NSCLC were tumor on the MIP images were delineated to produce IGTVMIP. The position of the target center, the volume of target, the degree of inclusion (DI) and the matching index (MI) were compared reciprocally between IGTV10, IGTVEI+EE and IGTVMIP. Results Average differences between the position of the center of IGTVs on direction of x,y and z axes were less than 1 mm, with no statistically significant difference. The volume of IGTV10 was larger than that of IGTVEI+EE, the difference was statistically significant (t=2.37,P=0.028);the volume of IGTV10 was larger than that of IGTVMIP, but the difference was not statistically significant(t=1.95 ,P=0.065). The ratio of IGTVEI+EE with IGTV10, IGTVMIP with IGTV10 were 0.85±0.08 and 0.92±0.11, respectively. DI of IGTVEI+EE in IGTV10, IGTVMIP in IGTV10 were 84.78% ± 8. 95% and 88.47% ±9.04%. MI between IGTV10 and IGTVEI+EE, IGTV10 and IGTVMIP were 0.85 ±0.09, 0.86±0. 09, respectively. Conclusions The center displacement of the IGTVs delineated separately by the three different techniques based on 4DCT images are not obvious; IGTVEI+EE and IGTVMIP can not replace IGTV10 , however , IGTVMIP is more close to IGTV10 comparing to IGTVEI+EE . The ratio of GTVEI+EE with IGTV10 is correlated to the tumor motion vector. As the vector increases, the ratio of GTVEI+EE with IGTV10decreases, especially for small tumors.
ABSTRACT
Objective To evaluate the respiratory movement of the both lungs with four-dimensional CT(4DCT), and determine the optimal respiratory phase series CT images for radiation dose calculation. Methods From November 2005 to November 2006,thirty patients with lung cancer who received 4DCT scan were enrolled,including 15 left and 15 right lung cancer cases,25 men and 5 women. The media age was 55 (35-78) years old. After 4DCT scanning, the image was treated with Advantage 4D workstation,and then transmitted into Pinnacle station( Adac 7.4). The both lungs were automatically outlined using Pinnacle station with CT recognition value of-900 to-200 Hu. Then-the same physician examined the unreasonable parts and revised them. After the delineation was completed,the volume of 10 respiratory phases of lung was obtained. Results The average respiratory phase in inspiratory and expiratory phases was 78.87%±2.71% and 26.32%±3.17% in the tumor located lung,77.55%±2.81% and 24.73%±2.55% in the healthy lung. The maximum and minimum mean volume was 106.48%±3.00% and 94.23%±2.78% in the tumor located lung,107.47%±2.43% and 93.65%±2.32% in the healthy lung. The volume at the end of inspiratory and expiratory was 106.43%±3.07% and 94.63%±2.71% in the tumor located lung, 107.37%±4.62% and 93.98%±2.34% in the healthy lung. Conclusions The series CT images scan on 20% ,30% and 80% respiratory phases are reasonable for radiation dose calculation. The maximum and minimum average lung volumes are almost equal to those at the end of inspiratory and expiratory.