Diagnostic Value of Sarcopenia Computed Tomography Metrics for Older Patients with or without Cancers with Gastrointestinal Disorders

ObjectivesThe diagnostic utility of poor body composition measures in sarcopenia remains unclear. We hypothesize that the skeletal muscle gauge [combination of skeletal muscle index (SMI) and skeletal muscle density (SMD); SMG = SMI × SMD] would have significant diagnostic and predictive value in certain muscle regions and populations.DesignProspective cross-sectional study.Setting and ParticipantsWe examined inpatients age ≥60 years with or without cancer and with gastrointestinal disorders.MethodsWe used computed tomography (CT) image metrics in the 12th thoracic (T12), third lumbar (L3), erector spinae muscle (ESM), and psoas muscle (PM) regions to establish correlations with the 2019 Asian Working Group for Sarcopenia Consensus and used receiver operating characteristic area under the curve (AUC) to compare differences between metrics. Associations between CT metrics and mortality were reported as relative risk after adjustments.ResultsWe evaluated 385 patients (median age, 69.0 years; 60.8% men) and found consistent trends in cancer (49.6%) and noncancer (50.4%) cohorts. SMG had a stronger correlation with muscle mass than SMD [mean rho: 0.68 (range, 0.59?0.73) vs 0.39 (range, 0.28?0.48); all P < .01] in T12, L3, and PM regions and a stronger correlation with muscle function than SMI [mean rho: 0.60 (range, 0.50?0.77) vs 0.36 (range, 0.22?0.58); all P < .05] in T12, ESM, and L3 regions. SMG outperformed SMI in diagnostic accuracy in all regions, particularly for L3 (AUC: 0.87?0.88 vs 0.80?0.82; both P < .05). PMG (PM gauge) and L3SMG did not differ, whereas EMG (ESM gauge) or T12SMG and L3SMG did (AUC: 0.80?0.82 vs 0.87?0.88; all P < .05). L3SMI, L3SMD, T12SMG, EMG, and PMG showed no association with 1-year cancer-related mortality after adjusting for confounders; however, L3SMG [relative risk = 0.92 (0.85?0.99); P = .023) was.Conclusions and ImplicationsL3SMG covers all features of sarcopenia with more diagnostic value than other metrics, allowing a complete sarcopenia assessment with CT alone and not just in populations with cancer.     

Diagnosing Sarcopenia in Male Patients With Cirrhosis by Dual‐Energy X‐Ray Absorptiometry Estimates of Appendicular Skeletal Muscle Mass

Background: Ascites in cirrhotic patients interfere with accurate assessment of skeletal muscle when diagnosing sarcopenia. We hypothesized measurement of appendicular skeletal muscle index (ASMI) with dual‐energy x‐ray absorptiometry (DXA) improves the diagnosis of sarcopenia in cirrhotic patients as ASMI does not include the fluid‐filled abdominal compartment. Objective: To evaluate if ASMI is influenced by ascites, lower limb edema (LLE) and predicts mortality alone or combined with handgrip strength (HGS) in cirrhotic patients. Design: ASMI, HGS, and 36‐month mortality were obtained in 144 men with cirrhosis. ASMI was compared before and after paracentesis in 20 men with ascites and to results from 20 matched controls. The prognostic value of ASMI alone and with HGS was tested in a survival. Survival probabilities were obtained for sarcopenia diagnosed by standard ASMI and HGS European Working Group on Sarcopenia in Older People (EWGSOP) cutoffs and a new cutoff calculated from our ASMI + HGS tertiles. Results: ASMI did not change after paracentesis, was lower in patients than in controls (P < .001), and was not influenced by LLE (D = 0.30 kg/m2, P = .068; R² = 2.40%). Mortality was influenced by ASMI and HGS (P_interaction = 0.028). Sarcopenia diagnosed by EWGSOP was also diagnosed by our new cutoff; both predicted mortality with the latter more sensitive for mortality risk prediction (P = .011). Conclusions: DXA‐measured ASMI is not influenced by ascites or LLE in cirrhotic patients; can diagnose low skeletal muscle/sarcopenia; and predicts mortality, particularly when combined with HGS.     

基于Bayesian非局部先验的低剂量X-射线CT成像

目的降低病人在CT扫描中所受的辐射剂量。方法在低剂量的扫描条件下,由于有效投影信息的缺少,CT图像易受到量子噪声的影响。本文提出了一种新的非局部先验Bayesian重建算法来提高CT图像重建质量。结果与传统的图像重建方法比较,本文提出的重建方法,能够利用目标图像中更多形态结构的全局信息来构建先验项,从而克服了传统图像重建信息局限性的缺点。结论试验证明本文所提出的CT图像重建方法在低剂量扫描条件下具有很好的表现。     

医用计算机断层扫描技术专利状况分析

基于计算机断层扫描技术领域的产业状况和专利文献数据的基础上,给出了全球和中国范围内的CT技术的专利状况进行了定性和定量分析,并就我国企业发展提出了建议。     

MDCT冠状动脉CTA检查中辐射剂量的优化控制

随着多排螺旋CT（MDCT）血管造影检查（CTA）越来越多地应用于冠心病的诊断与治疗随访中，病人所受辐射剂量增加问题也日益受到关注。本文系统地介绍了辐射剂量的概念、MDCT的剂量表征、辐射剂量与扫描参数的关系，并结合最新临床实践结果提出了在保证图像质量前提下降低辐射剂量的具体措施，从而达到对MDCT冠状动脉CTA检查中辐射剂量的优化控制。     

Bioelectrical Impedance Analysis for the Assessment of Body Composition in Sarcopenia and Type 2 Diabetes

Sarcopenia is emerging as a severe complication in type 2 diabetes (T2DM). On the other hand, it has been documented that nutritional aspects, such as insufficient protein or total energy intake, increase sarcopenia risk. The analysis of body composition is a relevant approach to assess nutritional status, and different techniques are available. Among such techniques, bioelectrical impedance analysis (BIA) is particularly interesting, since it is non-invasive, simple, and less expensive than the other techniques. Therefore, we conducted a review study to analyze the studies using BIA for body composition analysis in T2DM patients with sarcopenia or at risk of catching it. Revised studies have provided important information concerning relationships between body composition parameters (mainly muscle mass) and other aspects of T2DM patients’ conditions, including different comorbidities, and information on how to avoid muscle mass deterioration. Such relevant findings suggest that BIA can be considered appropriate for body composition analysis in T2DM complicated by sarcopenia/muscle loss. The wide size of the patients’ cohort in many studies confirms that BIA is convenient for clinical applications. However, studies with a specific focus on the validation of BIA, in the peculiar population of patients with T2DM complicated by sarcopenia, should be considered.     

螺旋CT在86例肠梗阻诊断中的临床应用

目的探讨多层CT及重建技术在肠梗阻的诊断及其临床上的应用价值。方法回顾性分析荣昌县人民医院2007年6月-2011年5月期间住院的各类型肠梗阻患者86例,将术前CT检查与术后结果相对照。结果术前CT的病因诊断率为93.02%,实际病因诊断率为82.56%,假阳性率为12.79%,假阴性率为16.28%。结论多层CT检查不仅能提高肠梗阻确诊率,而且可以提高肠梗阻的病因诊断率。     

The Associations of Body Image Perception with Serum Resistin Levels in Highly Trained Adolescent Estonian Rhythmic Gymnasts

Rhythmic gymnasts (RGs) are more likely to be dissatisfied with their body mass and shape compared to untrained controls (UCs). However, due to the lack of information, the aim of this study was to investigate the associations of body image perception (BIP) with body composition, daily energy consumption and different blood biochemical markers in adolescent RGs compared to UCs. Thirty-three highly trained RG girls and 20 UC girls aged 14–18 years participated in this cross-sectional study. Height, body mass, body composition, energy intake, resting energy expenditure, training volume and different blood biochemical markers were measured. The body attitude test (BAT) was used to evaluate the BIP of the participants. There were no differences in the total BAT scores between the groups. In RGs, the BAT score correlated positively with the serum resistin level (r = 0.35; p = 0.047). A stepwise multiple regression analysis showed that 40.8% of the variability in the BAT score was determined by resistin and BMI. The association of BIP with resistin values was observed only in RGs. In conclusion, our findings add to the increasing evidence that resistin may be a link between BIP and body composition, most likely through fat mass, in adolescent female RGs.     

基于图像分析技术的舌象分析仪研究

目的：研制一种舌象分析仪，该分析仪主要用于解决目前传统中医舌象诊断过程中存在的主客观误差等问题。方法：采用软硬件相结合的架构，以专门设计的舌图像采集装置与通用计算机为主要组成部分，通过数字图像分析技术的运用，完成舌图像的采集控制、舌图像校正预处理、舌图像分割以及舌图像特征分析识别等功能。结果：通过一定量样本的学习训练，舌型特征的识别准确率接近90％。结论：舌象分析仪在一定程度上实现了舌诊的客观性分析，该设备可应用于中医舌诊的临床与教学等，具有广阔的发展前景。     

双源CT图像质量与辐射剂量的关系与分析

目的：研究双源CT设备在自动管电流调节下扫描对图像质量的影响,分析辐射剂量与图像质量之间的关系。方法：在双源CT对胸部、腹部扫描时进行剂量测量,探讨辐射剂量与图像质量的协调关系,在二者之间找到了最佳的平衡点。结果：双源CT设备在自动管电流调节下扫描,可平均降低15％的辐射剂量。结论：在保证图像质量的前提下．双源CT设备既能为临床提供准确的影像诊断信息,又能最大程度地降低辐射剂量。     

医用X线CT关键性指标的质量控制研究

本文介绍如何在医院内应用Barracude多功能X线分析仪,对X线CT主要指标进行质量检测的方法,以方便临床工程师对CT的日常质量控制。     

肺癌DCE-CT技术与肿瘤血管生成的相关研究

目的用动态增强CT功能成像(DCE-CT)的方法观察肺癌肿瘤血管生成。方法对28例肺癌进行DCE-CT扫描,记录强化峰值(PH)、肿块强化达到峰值时间(Tp),计算肿块与主动脉强化峰值之比(M/A)、灌注值、相对血管容积(rBV)和毛细血管通透值(Pm),将各值分别与肺癌微血管密度(MVD)做相关性分析。将28例肺癌分为血管内皮生长因子(VEGF)表达阳性组和VEGF表达阴性组,分析2组MVD、各成像参数以及淋巴结转移情况的差异。结果 PH、M/A、灌注值、rBV、Pm分别为(27.03±8.89)HU、0.13±0.07、(0.33±0.06)μL.min-1.ml-1、(27.00±10.95)%、(188.90±133.10)μL.min-1.ml-1。PH、M/A、灌注值、rBV与MVD呈正相关,其中,灌注值与MVD相关性最高(r=0.78,P<0.0001),Pm值与MVD无相关性(r=0.29,P>0.05);VEGF阳性组MVD和CT功能成像参数高于VEGF阴性组,两组淋巴结转移情况差异有统计学意义(χ2=9.389,P<0.05)。结论 DCE—CT可得到比较全面的肺癌血供情况,能为肺癌肿瘤血管生成的评估提供新方法。     

Measuring Abdominal Circumference and Skeletal Muscle From a Single Cross‐Sectional Computed Tomography Image

Diagnostic computed tomography (CT) scans provide numerous opportunities for body composition analysis, including quantification of abdominal circumference, abdominal adipose tissues (subcutaneous, visceral, and intermuscular), and skeletal muscle (SM). CT scans are commonly performed for diagnostic purposes in clinical settings, and methods for estimating abdominal circumference and whole‐body SM mass from them have been reported. A supine abdominal circumference is a valid measure of waist circumference (WC). The valid correlation between a single cross‐sectional CT image (slice) at third lumbar (L3) for abdominal SM and whole‐body SM is also well established. Sarcopenia refers to the age‐associated decreased in muscle mass and function. A single dimensional definition of sarcopenia using CT images that includes only assessment of low whole‐body SM has been validated in clinical populations and significantly associated with negative outcomes. However, despite the availability and precision of SM data from CT scans and the relationship between these measurements and clinical outcomes, they have not become a routine component of clinical nutrition assessment. Lack of time, training, and expense are potential barriers that prevent clinicians from fully embracing this technique. This tutorial presents a systematic, step‐by‐step guide to quickly quantify abdominal circumference as a proxy for WC and SM using a cross‐sectional CT image from a regional diagnostic CT scan for clinical identification of sarcopenia. Multiple software options are available, but this tutorial uses ImageJ, a free public‐domain software developed by the National Institutes of Health.     

Sarcopenia and Appendicular Muscle Mass as Predictors of Impaired Fasting Glucose/Type 2 Diabetes in Elderly Women

Elderly women exhibit a high risk of type 2 diabetes (T2D), but no definitive data exist about the possible role of postmenopausal increases in visceral adiposity, the loss of lean body mass, or decreases in the sum of the lean mass of arms and legs (appendicular skeletal muscle mass (ASMM)). This retrospective, longitudinal study investigated whether body composition (bioelectrical impedance analysis) predicted the development of impaired fasting glucose (IFG) or T2D in a cohort of 159 elderly women (age: 71 ± 5 years, follow-up: 94 months) from southern Italy (Clinical Nutrition and Geriatric Units of the “Mater Domini” University Hospital in Catanzaro, Calabria region, and the “P. Giaccone ”University Hospital in Palermo, Sicily region). Sarcopenia was defined in a subgroup of 128 women according to the EWGSOP criteria as the presence of low muscle strength (handgrip strength <16 kg) plus low muscle mass (reported as appendicular skeletal muscle mass <15 kg). Participants with a low ASMM had a higher IFG/T2D incidence than those with a normal ASMM (17% vs. 6%, p-adjusted = 0.044); this finding was independent of BMI, fat mass, waist circumference, and habitual fat intake (OR = 3.81, p = 0.034). A higher incidence of IFG/T2D was observed in the subgroup with sarcopenia than those without sarcopenia (33% vs. 7%, p-adjusted = 0.005) independent of BMI and fat mass (OR = 6.75, p = 0.007). In conclusion, this study demonstrates that elderly women with low ASMM had a higher probability of developing IFG/T2D. Further studies are needed to confirm these results in men and in other age groups.     

利用OSC迭代方法混合重建去除CT金属伪影

目的：提出一种高速有效去除CT金属伪影的混合重建算法。方法：首先将带有金属伪影的CT体模图像分割成金属部分和非金属部分,然后利用混合重建方法,对非金属部分采用FBP重建,对金属部分采用OSC迭代重建,最后将所获得的金属部分图像与非金属部分图像进行融合得到结果。结果：单纯的迭代重建对128×128的矩阵从图像读入到结果得出共用时9 min左右,效率非常低下;混合重建对相同的矩阵的重建时间只需8 s。结论：利用OSC迭代混合重建算法可以有效地抑制金属伪影,提高运算效率。     

基于VTK的任意平面CT图像二维交互分割初步研究

研究利用VC＋＋6.0进行基于VTK（Visualization Toolkit）的三维CT图像任意平面的二维交互分割软件的开发。用VTK实现了从三维显示中选取任意方位平面以及该平面对应图像的三维与二维显示,研究在VC＋＋6.0创建的二维视图中进行轮廓勾画和区域生长的功能,实现了在三维图像中将区域生长结果叠加于原二维图像的功能。