引导超声聚焦热消融的超高场磁共振射频电磁场匀场技术及人体组织比吸收率安全分析

目的 探究在超高场磁共振引导下的高强度聚焦超声手术中射频电磁场B1场匀场技术及人体组织比吸收率(SAR)安全性.方法 建立包含温度梯度的女性盆腔模型,分别仿真计算在正常模型匀场系数激励以及在温度梯度模型的匀场系数激励下的射频电磁场B1场的均匀性和局部比吸收率.结果 对包含温度梯度的女性盆腔模型采用正常模型的匀场系数激励,组织局部SAR最大值达到10.24 W/kg,超出了国际电工委员会(IEC)对局部SAR值规定的10 W/kg的安全阈值;对包含温度梯度的女性盆腔模型采用温度梯度模型的匀场系数激励,组织局部SAR最大值为9.65 W/kg在IEC的安全阈值内.结论 在进行超高场磁共振引导下的高强度聚焦超声手术时,需要考虑超声能量在人体形成的温度分布,在温度梯度的基础上重新进行匀场优化能将组织局部SAR值降低到安全阈值内.     

In vivo feasibility of image-guided transvaginal focused ultrasound therapy for the treatment of intracavitary fibroids

OBJECTIVE: To determine the feasibility of uterine tissue ablation in vivo using a transvaginal focused ultrasound applicator guided by ultrasound imaging. DESIGN: Randomized in vivo animal study. SETTING: Academic research environment. ANIMAL(S): Healthy anesthetized sheep. INTERVENTION(S): Uterine treatment location was determined using a computerized targeting system. Five sonications 10 seconds in duration and averaging 2,000 W/cm(2) of focal ultrasound intensity were applied in each animal's uterus. Animals were euthanized either immediately or 2, 7, or 30 days post-treatment. MAIN OUTCOME MEASURE(S): Gross and microscopic analysis of the dissected uterus was used to quantitatively and qualitatively determine the ablated region and treatment side effects. RESULT(S): Treatments resulted in coagulative necrosis. Histopathological analysis showed that over 7 days, inflammatory cells appeared and smooth muscle bundles regenerated. By day 30, treated tissues healed and scar tissue formed. None of the animals showed abnormal behavior or medical problems. Complications in three animals were damage to the vaginal wall and colon, possibly due to inadequate applicator cooling and an empty bladder during treatment. CONCLUSION(S): Transvaginal image-guided high-intensity focused ultrasound has potential for treating uterine fibroids. Further safety testing of this treatment will prepare it for human use.     

The possible combinatory effects of acute consumption of caffeine,creatine, and amino acids on the improvement of anaerobic running performance in humans

Preexercise nutritional investigations have recently become a popular avenue of examining the interaction of multiple ingredients on exercise and training methods. The critical velocity (CV) test is used to quantify the relationship between total running distance and time to exhaustion (TTE), yielding aerobic (CV) and anaerobic parameters (anaerobic running capacity [ARC]). The purpose of this study was to examine the hypothesis that a preexercise supplement containing caffeine, creatine, and amino acids (Game Time; Corr-Jen Laboratories Inc, Aurora, CO) would positively impact CV and ARC in college-aged men and women. In a single-blind crossover design, 10 participants consumed the preexercise supplement (ACT) or placebo (PL) before each testing session. Each participant completed runs to exhaustion on a treadmill at 110%, 90% (day 1), and 105% and 100% (day 2) of the peak velocity (PV) determined from a graded exercise test. The ACT elicited a 10.8% higher ARC (P = .02) compared with the PL, whereas no difference was found in CV (0.6%, P = .38). The TTE was greater for the ACT than the PL at 110% (ACT = 125.7 ± 9.6 seconds, PL = 117.3 ± 12.6 seconds), 105% (ACT = 156.9 ± 11.0 seconds, PL = 143.8 ± 12.9 seconds), and 100% PV (ACT = 185.7 ± 10.7 seconds, PL = 169.7 ± 12.8 seconds) (P = .01-.04); but there was no difference for the TTE at 90% PV (ACT = 353.5 ± 52.7 seconds, PL = 332.7 ± 54.0 seconds) (P = .08). These findings suggest that the acute ingestion of this preexercise supplement may be an effective strategy for improving anaerobic performance, but appears to have no effect on aerobic power.     

Intoxication and binge and high-intensity drinking among US young adults in their mid-20s

ABSTRACT

Background: Alcohol use is a key risk factor for young adult mortality and disease, but limited research has focused on high-risk alcohol use among individuals moving from early young adulthood into building and maintaining an initial structure of adult life. This study estimated the prevalence of a range of alcohol use behaviors among US young adults aged 25/26, examined evidence for historical change in prevalence rates, and estimated associations between alcohol use and key demographic, substance use, and adult social role characteristics. Methods: Data were obtained from 3542 individuals selected for follow-up from the nationally representative 12th-grade student Monitoring the Future study. Respondents self-reported alcohol use behaviors at age 25/26 during calendar years 2005–2014. Results: Two fifths (39.9%) of young adults aged 25/26 reported being intoxicated at least once in the past 30 days; 25.6% reported usually experiencing a sustained high of 3 or more hours when drinking alcohol. Past-2-week binge drinking (5+ drinks in a row) was reported by 36.3% of respondents. Past-2-week high-intensity drinking (10+ drinks in a row) was reported by 12.4%. These age 25/26 alcohol use prevalence rates remained stable over the 10 years of data examined, in contrast to significant declines over historical time in alcohol prevalence rates among these same individuals at age 18. High-risk drinking was particularly associated with being male, white, unmarried, employed, a nonparent, and an alcohol user before finishing high school. Conclusions: Among US young adults in their mid-20s, alcohol use was highly normative and frequently included participation in high-risk drinking behaviors. High-risk alcohol use prevention approaches developed specifically to reach young adults in their mid-20s are needed, as well as efforts to increase proactive clinician screening to identify young adults participating in high-risk alcohol use.     

Establishment of a scoring system for predicting the difficulty level of high-intensity focussed ultrasound ablation of uterine fibroids

Purpose: To establish a scoring system that predicts the difficulty level of high-intensity focussed ultrasound (HIFU) ablation of uterine fibroids.

Materials and methods: Four hundred and twenty-two patients with fibroids were enrolled. The energy efficiency factor (EEF) and sonication time were set as dependent variables, with factors possibly affecting EEF and sonication time including age, body mass index (BMI), the volume of fibroids, the location of the uterus, the type of fibroids, the signal intensity on the T2-weighted imaging (T2WI), the enhancement type, the thickness of the rectus abdominis and the subcutaneous fat layer, the distance from the anterior/posterior surface of the fibroid to the skin, and the abdominal wall scars were set as predictors for building optimal scaling regression models.

Results: The volume of the fibroids, the location of the uterus, the signal intensity on T2WI, enhancement type, rectus abdominis thickness, subcutaneous fat thickness, and distance from the anterior surface of fibroid to the skin were related to EEF. Signal intensity on T2WI, the volume of fibroids, distance from the posterior surface of fibroid to the skin, and enhancement type were related to sonication time. Models that can predict the difficulty level of HIFU for fibroids have been established: for EEF, y?′?=?0.338X?′₁???0.231X?′₂+0.156X?′₃+0.167X?′₄?; for sonication time, y?=?0.227X₁+0.321X₂+0.157X₃+0.194X₄.

Conclusions: A scoring system for predicting the difficulty level of HIFU treatment for uterine fibroids has been established and it can be used to help select patients and to predict the sonication time for a given fibroid.     

3.0 TMRI对子宫肌瘤高强度聚焦超声治疗后的早期效果评价

目的 采用3.0 TMRI平扫及增强扫描对子宫肌瘤高聚焦超声(HIFU)早期疗效评价.方法 33例子宫肌瘤患者,其中单发肌瘤20例,多发肌瘤13例,共59个,患者平均年龄(34.3±8.7)岁,所有患者均于HIFU术前及术后1 d行MRI平扫、增强扫描检查,观察并定量测定肌瘤、肌壁HIFU术前、后T2压脂、T2WI、T1WI平扫及增强扫描信号值,并计算肌瘤最大消融区面积,对其疗效进行评估.结果 59个肌瘤于HIFU术后在T1WI增强扫描序列均出现无强化的消融区,平均消融率达70.9%.MRI增强扫描消融区T1信号值与术前比较明显减低(P<0.01).术后消融区在T1平扫像上呈不同程度高信号,T2像上消融区范围显示不明确,但T2信号值较术前明显升高(P<0.01).MRI平扫所见术后T1信号增高区1.0 cm)肌壁T2压脂信号各组间均无统计学差别.结论 3.0 TMRI增强扫描可以直观、准确的显示肌瘤消融区,T1术后高信号区可以显示肌瘤HIUF术后坏死区,可以评价消融范围.     

高强度聚焦超声治疗门静脉癌栓的初步临床观察

目的:探讨高强度聚焦超声(high intensity focused ultrasound,HIFU)治疗门静脉癌栓(portal vein tumor thrombosis, PVTT)的安全性和有效性。方法:应用FEP-BY01型肿瘤超声治疗机对42例原发性肝癌合并的门静脉癌栓进行HIFU治疗。结果:HIFU治疗后31％(13／42)癌栓消失;33．3％(14／42)癌栓部分消失; 35．7％癌栓不消失。未发生皮肤烧伤、出血和胃肠道穿孔等并发症。结论:HIFU治疗PVTT是一种新的和安全有效的局部治疗方法。     

高强度聚焦超声与替吉奥联合治疗晚期胰腺癌的临床观察

目的:探讨高强度聚焦超声肿瘤消融与口服替吉奥联合治疗晚期胰腺癌的疗效。方法:将43例晚期胰腺癌患者随机分为高强度聚焦超声治疗组和高强度聚焦超声＋替吉奥治疗组,观察不良反应和疗效。结果:高强度聚焦超声、高强度聚焦超声＋替吉奥的近期有效率分别为: 22.73％（5/22）和52.38%（11/21）,联合治疗的效果明显优于单纯治疗（P<0.05）;临床获益反应率分别为81.82％（18/22）和76.19%（16/21）,两组无明显差异（P>0.05）;不良反应方面,接受高强度聚焦超声治疗的患者明显少于联合使用替吉奥的患者（P<0.05）;中位生存期分别为7.6和13.6个月,接受联合使用替吉奥治疗的患者生存期明显优于仅接受高强度聚焦超声治疗的患者（P<0.05）。结论:在高强度聚焦超声治疗的基础上,联合口服替吉奥治疗晚期胰腺癌患者治疗效果更好。