Automatic registration of portal images and volumetric CT for patient positioning in radiation therapy

The efficacy of radiation therapy treatment depends on the patient setup accuracy at each daily fraction. A significant problem is reproducing the patient position during treatment planning for every fraction of the treatment process. We propose and evaluate an intensity based automatic registration method using multiple portal images and the pre-treatment CT volume. We perform both geometric and radiometric calibrations to generate high quality digitally reconstructed radiographs (DRRs) that can be compared against portal images acquired right before treatment dose delivery. We use a graphics processing unit (GPU) to generate the DRRs in order to gain computational efficiency. We also perform a comparative study on various similarity measures and optimization procedures. Simple similarity measure such as local normalized correlation (LNC) performs best as long as the radiometric calibration is carefully done. Using the proposed method, we achieved better than 1mm average error in repositioning accuracy for a series of phantom studies using two open field (i.e., 41 cm2) portal images with 90 degrees vergence angle.     

The effect of stretch rate and activation state on skeletal muscle force in the anatomical range

BACKGROUND: The effects of stretch rate and activation state on muscle mechanics require further clarification. This subject is of particular interest because of the role of skeletal muscle undergoing eccentric contractions in musculoskeletal injuries. METHODS: The present study investigated the force-displacement behavior of rabbit tibialis anterior muscle at three stretch rates (2.5, 10, 25 cm/s) and three activation states (passive, tetanic, denervated). A phenomenological power law model and a dynamic systems model were used to describe the mechanical responses. FINDINGS: The power law model showed excellent agreement with the passive and denervated responses to stretch (R(mean)=0.97). Repeated measures analysis of variance found a difference (P=0.042) in peak force between the passive and denervated states at a stretch rate of 2.5 cm/s. The dynamic systems model closely fit the tetanized muscle responses (R(mean)=0.95). There was no difference in the displacement at yield (P=0.83) for the three stretch rates of the tetanized muscle undergoing stretch. INTERPRETATION: Differences between the passive and denervated responses suggest that mechanoreceptors may play a role in stimulating the muscle as it is stretched through the anatomical range. The displacement at yield did not change significantly over a decade range of stretch velocities, suggesting that a strain threshold exists beyond which cross bridges cannot remain bound. The power law and dynamic systems models presented offer mathematically tractable approaches to interpret the response of lengthening skeletal muscle. These findings on active, passive, and denervated muscle point to a possible role of the muscle spindle to tissue mechanical behavior that should be accounted for in future studies of force-elongation behavior of skeletal muscle.     

Corrective effects of electromagnetic radiation in a millimeter wavelength range on the parameters of oxidative stress after standard anti-helicobacterial therapy in patients with ulcer disease

We assessed the possibilities of correction of oxidative stress parameters in the serum and gastroduodenal mucosa using electromagnetic radiation in a millimeter wavelength range in 127 patients with gastric and duodenal ulcer after eradication therapy. Control group included 230 healthy subjects. Parameter of lipid oxidation by free radicals were measured by direct methods (hemiluminescence and EPR-spectroscopy). The results show that standard eradication therapy does not influence parameters of oxidative stress. More pronounced effect of electromagnetic radiation in a millimeter wavelength range may be due to the correction of prooxidant-antioxidant and antioxidant disbalance. This observation provides pathogenetic substantiation for the inclusion of this physical method in modern therapeutic modalities.     

基于太赫兹谱检测血液卟啉的可行性研究

目的 探讨基于太赫兹谱测定人体血液中卟啉含量的可行性.方法 合成了3种卟啉化合物,用太赫兹时域频谱系统测量了它们的太赫兹透射谱.结果 卟啉化合物在0.1~1 THz频率范围内有较为丰富的吸收峰.结论 基于太赫兹谱检测卟啉从原理上讲是可行的.     

应用改进ELISA检测干血绵球HIV抗体的可行性研究

[目的]研讨以改进的ELISA法检测干血棉球HIV抗体的可行性。[方法]用包括20份S／CO比值在1～3在内的100份HIV抗体阳性血清,198份阴性血清样品进行研究,每份血清分为两部分,一部分血清置-20℃;另一部分血清制成干血棉球置37℃储存3周;然后,用于血棉球与血清样品进行HIV抗体检测对比试验。[结果]（1）血清样品按ELISA说明书方法检测,干血棉球用改进ELISA方法检测,干血棉球与相同的血清样品检测结果之间无显著性差异（P〉0．05）。（2）20份37℃储存3周S／CO比值在1～3的HIV抗体弱阳性干血棉球,用ELISA检测,有部分弱阳性样品出现了假阴性结果,而用改进ELISA法检测,全部阳性。[结论]可用干血棉球代替血清样品,用改进ELISA法进行HIV抗体检测。     

采用离心浓集法提高乙型肝炎病毒表面抗原检出率的可行性研究

目的 探讨离心浓集法预处理血清标本对提高乙型肝炎血清学标志物乙型肝炎表面抗原(HBsAg)检出率的可行性研究.方法 收集广州市内各大医院2009年52例HBsAg阳性者和疑似乙型肝炎感染者血清标本,分别用酶联免疫吸附试验(ELISA) 和化学发光免疫分析法(CLIA)测定HBsAg.再以PEG6000为沉淀剂,将标本进行高速离心浓集(30 000 r/min)25 ℃,40 min,取沉淀用TE Buffer溶解,采用上述相同方法分别进行测定,比较离心前后其HBsAg 的S/CO值与HBsAg定量值的上升情况,用SPSS统计学软件对数据进行非参数检验,分析其差别是否有统计学意义.结果 健康对照组与空白对照经高速离心处理前后的HBsAg 检测结果差异均无统计学意义(P>0.05),而疑似HBV感染组和HBV感染组患者血清经高速离心预处理后的测定结果均明显高于处理前(P<0.01).结论 离心浓集法预处理对于血清中有低水平乙型肝炎病毒颗粒的感染者有效,血清中的病毒颗粒可通过高速离心处理后得到浓缩,提高临床实验室常规诊断手段的灵敏度的范围,使隐匿型乙型肝炎的检出率有所提高.     

qRT-PCR法用于检测模拟环境表面载体HBV DNA的可行性研究

目的 探讨实时荧光定量PCR法(qRT-PCR法)用于检测模拟环境表面载体乙型肝炎病毒(HBV)DNA的可行性.方法 用4种浓度的HBV标准品5×106、5×105、5×104、5×103 IU/mL污染载体,放置3 d和7 d,采用qRT-PCR法,检测HBV载体表面HBV DNA浓度.结果 5×103 IU/mL标...     

调强放疗技术提高乳腺癌椎体转移治疗剂量临床研究

目的:探讨运用调强放疗和影像引导下的放疗技术进行乳腺癌椎体转移剂量提升治疗的临床价值。方法:乳腺癌椎体转移患者11例,在相同脊髓耐受剂量和保证常规适形放疗治疗剂量基础上,接受调强放疗和影像引导下的放疗,提高放疗剂量,观察治疗效果及不良反应。结果:调强放疗和影像引导下的放疗技术可提高椎体病灶治疗剂量约20%,短期临床疗效较好,无明显不良反应。结论:调强放疗和影像引导下的放疗技术可提高肿瘤病灶局部治疗剂量,更好地保护正常组织,提高患者生存质量。     

Effects of telephone call interventions on patients' well-being in a radiation therapy department

This study examined the effects of telephone call interventions by a collaborative team on patients' well-being. Fifty-five subjects undergoing radiation therapy for cure and who were able to communicate by telephone comprised the sample. Subjects were randomly assigned to a control group, who received the usual care or to an experimental group, who received a weekly telephone call intervention in addition to the usual care. Speilberger's State Trait Inventory, the Side Effects Profile, and the Coping Strategies Profile were used along with a telephone survey to collect data. Analysis of the data showed no significant differences between groups in anxiety, severity of side effects, helpfulness of self-care strategies, and coping strategies. However, the survey indicated that the telephone calls were clinically significant and provided a mechanism for demonstrating that the health care professionals cared about their patients and provided an opportunity for patients to talk about their concerns. The investigators believe that collaboration, caring, and communication are the essence of exemplary health care.     

The influence of patient positioning on radiation dose in CT imaging: A narrative review

Background and purposeAlthough it is fundamental for optimal scanner operation, it is generally accepted that accurate patient centring cannot always be achieved. This review aimed to examine the reported knowledge of the negative impact of patient positioning on radiation dose and image quality during CT imaging. Furthermore, the study evaluated the current optimisation tools and techniques used to improve patient positioning relative to the gantry iso-center.MethodologyA comprehensive search through the databases PubMed, Ovid, and Google Scholar was performed. Keywords included patient off-centring, patient positioning, localiser radiograph orientation, radiation dose, and automatic patient positioning (including synonyms). The search was limited to full-text articles that were written in English. After initial title and abstract screening, a total of 52 articles were identified to address the aim of the review. No limitations were imposed on the year of publication.ResultsVertical off-centring was reported in up to 95% of patients undergoing chest and abdominal CT examinations, showing a significant influence on radiation dose. Depending on the scanner model and vendor, localiser orientation, bowtie filter used, and patient size, radiation dose varied from a decrease of 36% to an increase of 91%. A significant dose reduction was demonstrated when utilising an AP localiser, aligning with the trend for radiographers to off-center patients below the gantry iso-centre. Utilizing a 3D camera for body contour detection allowed for more accurate patient positioning and promoted further dose reduction.ConclusionPatient positioning has shown significant effects on radiation dose and image quality in CT. Developing a good understanding of the key factors influencing patient dose (off-centring direction, localiser orientation, patient size and bowtie filter selection) is critical in optimising CT scanning practices. Utilising a 3D camera for body contour detection is strongly recommended to improve patient positioning accuracy, image quality and to minimise patient dose.     

危重症患者连续肾脏替代治疗液体容量耐受范围的临床研究

目的 探讨ICU患者累积液体差值与连续肾脏替代治疗CRRT预后之间的关系,帮助临床医师确定CRRT患者容量耐受的范围.方法 对ICU收治的2010年1月至2020年1月671例CRRT患者进行回顾性单中心队列研究,按照患者的基础疾病状态,分为心源性疾病CRRT组和非心源性疾病CRRT组,收集两组患者入院ICU后累积液体...     

"三穴五法"对腰椎间盘突出根性痛的镇痛作用

背景腰椎间盘突出症的治疗主要以手术为主,有研究表明通过非手术治疗可以有效地改善其临床症状.目的观察"三穴五法"对腰椎间盘突出根性痛的镇痛及腰部和下肢功能恢复的效果.设计以患者为研究对象,非随机化同期对照研究.单位一所大学的医院骨科和针灸推拿学院.对象选择1999-03/2003-06河南中医学院第一附属医院骨科、第三附属医院推拿科住院的腰椎疾病患者210例,随机分为实验组(n=108)和对照组(n=102).方法实验组采用"三穴五法"治疗.对照组采用传统手法治疗.分别于治疗后5,10,30 min,1,2……24 h进行疼痛和功能测评,并将评分结果统计分析.主要观察指标①两组患者镇痛效果.②两组患者综合功能测评结果.结果实验组总有效率为94.44%,平均镇痛时间(18.40±2.11)h;对照组总有效率为82.35%,平均镇痛时间(10.60±2.63)h.实验组镇痛效果及综合功能测评结果均优于对照组(t=4.86,4.42,P＜0.01).结论"三穴五法"对腰椎间盘突出根性痛患者具有缓解腰部疼痛、改善腰部症状,恢复下肢功能的作用.     

Papillary endothelial hyperplasia (Masson's tumor) developed in the capsule of the implant in a breast cancer patient treated with mastectomy and radiation therapy

Papillary endothelial hyperplasia (PEH) is an uncommon benign vascular proliferation appearing in soft tissues in different body areas including the breast, which may be related to radiation therapy. A 48-year-old woman previously treated for breast cancer with mastectomy followed by radiation therapy and reconstruction with an implant presented with a newly developing mass in the implant capsule. Pathological diagnosis was PEH. Imaging features of this rare entity are described, and lesions included in differential diagnosis are discussed.     

The effects of patient education in lithium therapy on quality of life and compliance

The purpose of this study was to show the effects of education on medication compliance, symptom level and quality of life of outpatients who were being treated with lithium for bipolar disorder. The study was performed comparing a total of 26 patients (14 study and 12 control) who were a patient group in lithium therapy. In the study one group was given a short education program about the disorder and lithium therapy in three sessions. Data were collected from both groups using a medication knowledge form, Brief Symptom Inventory, and WHO Quality of Life Scale before and after the intervention. At the end of 3 months whereas there was no difference seen in the scores of the control group; the study group had an increase in medication knowledge, a decrease in symptom level, an increase in quality of life, and a beginning of more regular medication use. Findings that were obtained show the importance of education about the disorder and medication in increasing the adaptation to society of patients who have bipolar disorder.     

癌症患者放化疗前后血小板参数的变化分析

目的分析探讨癌症患者放化疗前后血小板参数的变化及临床意义。方法用Sysmex XT-2000I全自动五分类血液分析仪测定31例癌症患者放化疗前后静脉血的血小板数（PLT）、血小板比积（PCT）、血小板平均体积（MPV）、血小板体积分布宽度（PDW）和大体积血小板比率（PLCR）,并与健康对照组比较。结果癌症患者放化疗前各参数与健康对照组间比较差异无统计学意义（P〉0．05）,而PLT、MPV、PCT、PLCR在放化疗后患者组均显著低于放化疗前（P〈0．01或P〈0．05）,PDW与放化疗前比较,差异无统计学意义（P〉0．05）。结论癌症患者放化疗后血小板参数的测定对观察其骨髓抑制状况和病情估计有一定的临床意义。     

Computerized detection of pulmonary nodules in chest radiographs based on morphological features and wavelet snake model

We have developed a new computer-aided diagnosis scheme for automated detection of lung nodules in digital chest radiographs based on a combination of morphological features and the wavelet snake. In our scheme, two processes were applied in parallel to reduce the false-positive detections after initial nodule candidates were selected. One process consisted of adaptive filtering for enhancement of nodules and suppression of normal lung structures, followed by extraction of conventional morphological features. The other process consisted of a novel approach for elimination of false positives called the edge-guided wavelet snake model. In the latter process, multiscale edges of the candidate nodules were extracted to yield parts of the nodule boundaries. A wavelet snake was then used for fitting of these multiscale edges for approximation of the true boundaries of nodules. A boundary feature called the weighted overlap between the snake and the multiscale edges was calculated and used for elimination of false positives. Finally, the weighted overlap and the morphological features were combined by use of an artificial neural network for efficient reduction of false positives. Our scheme was applied to a publicly available database of digital chest images for pulmonary nodules. Receiver operating characteristic analysis was employed for evaluation of the performance of each process in the scheme. The combined features yielded a large reduction of false positives, and thus achieved a high performance in discriminating between true and false positives. These results show that our new method, in particular the false-positive reduction method based on the wavelet snake, is effective in improving the performance of a computerized scheme for detection of pulmonary nodules in chest radiographs.     

Effects of functional electrical stimulation on dysphagia caused by radiation therapy in patients with nasopharyngeal carcinoma

Purpose  

This study aimed to assess the effectiveness of functional electrical stimulation on the swallowing function of irradiated nasopharyngeal carcinoma patients with dysphagia.