In vivo comparison of two through-plane MR velocity mapping methods: Fast fourier encoding and phase mapping

Magnetic resonance imaging maps of velocity were acquired with a 1.5-T system in 10 subjects in a plane perpendicular to the main pulmonary artery. Velocity images were successively acquired with a method developed from Fourier-encoding velocity imaging (FEVI) principles with eight gradient steps and one excitation, and with two-point phase-subtraction mapping. Reconstruction in FEVI was implemented by zero-filling interpolation around the eight gradient steps and then around the four central steps. The methods were compared by using estimates of noise in velocity measurements based on the difference between the experimental map and a smooth fitted map. For the same acquisition time, FEVI with four encoding steps was more precise in velocity measurements than phase mapping. Precision was further increased by the use of eight encoding steps, but acquisition time was doubled.     

Correlation of unilateral thoracoscopic lung volume reduction with improvement in lung function and exercise performance in patients with severe pulmonary emphysema

1 ), forced vital capacity, static compliance, and maximal oxygen uptake. The functional residual capacity as measured by the gas dilution method (FRC_gas), was unchanged; however, it was found to be decreased significantly when measured by body plethysmograph (FRC_box). Positive correlations existed between the reduction in FRC_box and the increase in FEV₁ (r = 0.586, P = 0.0042) and maximal oxygen uptake (r = 0.550, P = 0.018). Pulmonary ventilation and exercise ability in patients with pulmonary emphysema were improved in a volume-dependent manner by thoracoscopic lung volume reduction. These findings indicate that patients with a preoperative trapped gas volume level exceeding 1 l would be ideal candidates for thoracoscopic lung volume reduction. (Received for publication on Mar. 4, 1998; accepted on Jan. 7, 1999)     

口内进路下颌角及咬肌肥大矫正术

为了避免面部留有切口疤痕,寻找出一种简单方便的回内进路手术方式。方法：口内进路、用skruber摆动锯截除肥大的下颌角,来复锯经日内补充截除骨断面下部骨突起及部分骨下绿,再用长柄骨磨头进一步磨改。结果：12例患者面形改善明显。结论：下颌角及咬肌肥大采用正颌外科技术经单纯的日内进路不需作辅加切口即能达到良好的手术效果。     

Body growth in early diagnosed vesicoureteric reflux

Body growth was studied in 32 subjects with vesicoureteric reflux (VUR), diagnosed following the prenatal finding of urinary tract dilatation, who had normal renal filtration function and who received antibacterial prophylaxis by the first few days of life. They were followed for 1–5 years (mean 2.3 years). Most had persistent VUR during the 1st year of life. Body growth performance was compared with that of 94 subjects with VUR diagnosed and treated by us after the neonatal period. During the follow-up period, none of the patients with prenatally detected VUR had a height Z score below –2, nor a weight-for-height index below 90%, and 1 had variations in height Z score ≥1. The difference in the percentage of patients with prenatally detected VUR (1/32) and those with VUR diagnosed and treated after the neonatal period (20/94) who had variations in height Z score ≥1 was significant (P=0.035). Patients with prenatally detected VUR and normal renal filtration function, given antibacterial prophylaxis by the first few days of life, have normal body growth, although VUR still persists. Received: 19 March 1998 / Revised: 10 February 1999 / Accepted: 10 February 1999     

矩形外固定器治疗桡骨远端粉碎性骨折

本文报告一种新的矩形外固定器,１９９２年以来,治疗５例桡骨远端粉碎性骨折,经临床观察和随访,治疗结果较满意。外固定针固定在２～３掌骨和桡骨干上。根据需要,闭合复位后,可利用外固定器行加压或撑开固定,该固定器具有操作简单和固定牢固等优点,很适宜治疗桡骨远端粉碎性骨折     

以H835-50氨基酸分析仪测定肌氨酸

研究了用氨基酸分析仪测定肌氨酸含量时的最大吸收波长、最佳浓度等,验证了分析短程序的可靠性并用于实践,为高转化率合成Ｎ－酰基肌氨酸钠提供准确的测定结果     

Radiation Dose Reduction via Sinogram Affirmed Iterative Reconstruction and Automatic Tube Voltage Modulation (CARE kV) in Abdominal CT

Objective

To evaluate the feasibility of sinogram-affirmed iterative reconstruction (SAFIRE) and automated kV modulation (CARE kV) in reducing radiation dose without increasing image noise for abdominal CT examination.

Materials and Methods

This retrospective study included 77 patients who received CT imaging with an application of CARE kV with or without SAFIRE and who had comparable previous CT images obtained without CARE kV or SAFIRE, using the standard dose (i.e., reference mAs of 240) on an identical CT scanner and reconstructed with filtered back projection (FBP) within 1 year. Patients were divided into two groups: group A (33 patients, CT scanned with CARE kV); and group B (44 patients, scanned after reducing the reference mAs from 240 to 170 and applying both CARE kV and SAFIRE). CT number, image noise for four organs and radiation dose were compared among the two groups.

Results

Image noise increased after CARE kV application (p < 0.001) and significantly decreased as SAFIRE strength increased (p < 0.001). Image noise with reduced-mAs scan (170 mAs) in group B became similar to that of standard-dose FBP images after applying CARE kV and SAFIRE strengths of 3 or 4 when measured in the aorta, liver or muscle (p ≥ 0.108). Effective doses decreased by 19.4% and 41.3% for groups A and B, respectively (all, p < 0.001) after application of CARE kV with or without SAFIRE.

Conclusion

Combining CARE kV, reduction of mAs from 240 to 170 mAs and noise reduction by applying SAFIRE strength 3 or 4 reduced the radiation dose by 41.3% without increasing image noise compared with the standard-dose FBP images.     

Assessment of buccal marginal alveolar peri-implant and periodontal defects using a cone beam CT system with and without the application of metal artefact reduction mode

Objectives:

To investigate the accuracy of cone beam CT (CBCT) images obtained with and without artefact reduction (AR) in detecting simulated buccal peri-implant and buccal periodontal defects.

Methods:

42 implants inserted into edentulous mandibles, and 38 teeth present in dry mandibles were used. Simulated buccal peri-implant defects (n = 22) and buccal periodontal defects (n = 22) were prepared. 20 implants and 18 teeth without simulated defects were the control group. Images of the mandibles were obtained using a Planmeca ProMax^® 3D Max CBCT unit (Planmeca Oy, Helsinki, Finland). Image reconstructions were prepared without and with low, medium and high AR modes. Images were viewed randomly by six observers twice for the presence of defects. Kappa coefficient was calculated. F2_LD_F1 design for non-parametric analysis of longitudinal data was used. Area under curves (AUCs) were calculated for each observer. Significance level was taken as α = 0.05.

Results:

Intraobserver kappa ranged from 0.140 to 0.792 for peri-implant and from 0.189 to 1.0 for periodontal defects. All factors were statistically significant (p < 0.001), except for image mode and implant brand. Pairwise interactions were found between periodontal defects and peri-implant defects (p < 0.001), observers (p < 0.001), observer and image mode (p < 0.001), defect model and observer (p < 0.001) and defect model, image mode and observer (p = 0.04). AUC values ranged from 0.39 to 0.52 for peri-implant and from 0.45 to 0.71 for periodontal defects. Higher AUC values were found for periodontal defects than for peri-implant defects.

Conclusions:

Buccal peri-implant defects were more difficult to detect than buccal periodontal defects. No difference was found among CBCT images obtained with and without AR modes.     

运动员减体重期维生素代谢的改变及其补充

对３４名摔跤运动员减体重期维生素代谢的研究表明,运动员减体重期摄入的ＶＡ、ＶＢ１、ＶＢ２、ＰＰ、ＶＣ都明显低于运动员供给量标准。血中ＶＡ浓度减重前后基本一致,暗适应时间稍延长,２４ｈ尿中ＶＢ１;、ＶＢ２、ＶＣ排出量减体重后明显低于减体重前。尿中ＰＰ排出量减体重前后基本一样,任意克肌酐尿中ＶＢ１、ＶＢ２、ＰＰ、ＶＣ排出量与２４ｈ尿中这几种维生素排出量结果基本一致,进一步说明了结果的可靠性。服用减重营养饼干后,血中ＶＡ含量减体重后高于减前,适应时间减体重前后基本一致,但短于普通饼干组。尿中ＶＢ１、ＶＢ２、ＰＰ、ＶＣ排出量减体重后高于减重前,且均高于吃普通饼干对照组。说明减体重营养饼干补充了运动员减体重造成的各种维生素的不足和丢失,满足了运动员减体重对维生素的需要。     

切开复位内固定结合外固定治疗肘关节恐怖三联征

2005年1月～2011年12月,我科对12例肘关节恐怖三联征患者采用切开复位内固定结合外支架固定治疗,疗效满意,报道如下。1材料与方法1.1病例资料本组12例,男7例,女5例,年龄29～67岁。桡骨小头骨折按改良Mason分型:Ⅰ型6例,Ⅱ型5例,Ⅲ型1例;尺骨冠状突骨折按Regan-Morrey分型:Ⅰ型6例,Ⅱ型3例,Ⅲ型3例。12例患者均合并内、外侧副韧带损伤。伤后至手术时间2 h～8 d。