A basic step toward understanding skin surface temperature distributions caused by internal heat sources

This study uses numerical solutions of a bio-heat transfer equation to investigate the relationship between skin surface temperature distributions and internal heat sources under various physiological and environmental conditions. It is found that although a surface temperature distribution depends on all heat source parameters, the properly normalized distribution is primarily affected only by the depth of the heat source. This study provides a physical basis for determining the depth and type of an internal heat source from a thermogram acquired in various environmental conditions and an understanding of the basic relationship between skin surface temperature distributions and internal heat sources.     

Information needs and sources of information among cancer patients: a systematic review of research (1980-2003)

Understanding what cancer patients need to know and from whom they receive information during the course of care is essential to ensuring quality care. We reviewed 112 articles published from 1980 to 2003 and developed a typology summarizing cancer patients' information needs and the sources from which they receive information. The majority of articles focused on information needs and sources during the diagnosis and treatment phase. Thus, the most frequent information need was treatment-related (38.1%). The most frequent information source was health professionals (27.3%). We examined patients' information needs and sources along the continuum of care and found that during diagnosis and treatment, information needs about the stage of disease, treatment options, and side-effects of treatment were prominent; during post-treatment, patients continued to need information about treatment, and information about recovery was also important. Future research should examine cancer patients' information needs and sources throughout their cancer journey.     

Analytical calculation of the skin temperature distribution due to subcutaneous heat production in a spherical heat source.

An analytical solution of the thermal conductivity equation describing the surface temperature distribution over a buried heat source is given in tabular form. The solution is applicable to experimental models for studies of the surface temperature over an implanted artificial heat source. The results can also be used for the analysis of the skin temperature over biological heat sources such as breat tumours.     

Skin temperature over an artificial heat source implanted in man.

The medical application of infrared thermography makes use of the skin temperature as an indication of an underlying pathological process. In order to study the relation between the heat production from a source in living tissue and the overlying skin temperature, artificial heat sources were implanted subcutaneously in human volunteers. The experimental results show that a detectable surface temperature increase over the heat sources presupposes high power output or superficial implantation. The effect of forced convective heat loss from the skin surface and lowered ambient temperature was studied. Forced convection markedly decreased the temperature contrast. An implicit conclusion from experimental and theoretical work is that a localized 'hot spot' can only exceptionally be attributed to metabolic heat production conducted to the skin surface from a buried pathological process. The thermal pattern over a breast tumour, a septic or aseptic inflammation or a tissue injury mainly reflects the vascular reaction.     

Computerized detection of breast cancer with artificial intelligence and thermograms

This paper shows the concurrent use of thermography and artificial neural networks (ANN) for the diagnosis of breast cancer, a disease that is growing in prominence in women all over the world. It has been reported that breast thermography itself could detect breast cancer up to 10 years earlier than the conventional golden methods such as mammography, in particular in the younger patient. However, the accuracy of thermography is dependent on many factors such as the symmetry of the breasts' temperature and temperature stability. A woman's body temperature is known to be stable in certain periods after menstruation and it was found that the accuracy of thermography in women whose thermal images are taken in a suitable period (5th - 12th and 21st day of menstruation) is higher (80%) than the total population of patients (73%). The stability of the body temperature will depend on physiological state. This paper examines the use of ANN to complement the infrared heat radiating from the surface of the body with other physiological data. Four backpropagation neural networks were developed and trained using the results from the Singapore General Hospital patients' physiological data and thermographs. Owing to the inaccuracies found in thermography and the low population size gathered for this project, the networks developed could only accurately diagnose about 61.54% of the breast cancer cases. Nevertheless, the basic neural network framework has been established and it has great potential for future development of an intelligent breast cancer diagnosis system. This would be especially useful to the teenagers and young adults who are unsuitable for mammography at a young age. An intelligent breast thermography-neural network will be able to give an accurate diagnosis of breast cancer and can make a positive impact on breast disease detection.     

Influence of angle between the nozzle and skin surface on the heat flux and overall heat extraction during cryogen spray cooling

High speed video imaging and an inverse heat conduction problem algorithm were used to observe and measure the effect of the angle between the nozzle and surface of a skin phantom on: (a) surface temperature; (b) heat flux q; and (c) overall heat extraction Q during cryogen spray cooling (CSC). A skin phantom containing a fast-response temperature sensor was sprayed with 50 ms cryogen spurts from a commercial nozzle placed 30 mm from the surface. The nozzle was systematically positioned at angles ranging from 5 to 90 degrees (perpendicular) with respect to the phantom surface. It is shown that angles as low as 15 have an insignificant impact on the surface temperature, q and Q. Only exaggerated angles of 5 show up to 10% lower q and 30% lower Q with respect to the maximal values measured when nozzles are aimed perpendicularly. This study proves that the slight angle that many commercial nozzles have does not affect significantly the CSC efficiency.     

Altered expression of syndecan-1 in prostate cancer

Syndecan-1 is a cell surface heparan sulfate proteoglycan expressed by epithelial cells. It interacts with growth factors, matrix components, and other extracellular proteins, and is thought to be involved in processes such as cell growth, differentiation and adhesion. The expression of syndecan-1 appears generally downregulated in human carcinomas and in experimental cancer models, whereas transfectional expression of syndecan-1 in cultured cancer cells has been shown to inhibit their growth and other aspects of malignant behavior. These findings suggest that analysis of syndecan-1 expression might be of prognostic value in cancer diagnosis, and studies on some carcinomas indeed point to an inverse correlation between syndecan-1 expression and cancer prognosis. So far, little information has been available on the expression of syndecan-1 in human prostate and prostate disease. We have generated and characterized novel antibodies against syndecan-1 and applied them to immunohistochemical staining of specimens representing normal prostate as well as benign and malignant (n=23) prostate disease. The results indicate that syndecan-1 expression is altered but not uniformly absent in prostate cancer, which is in contrast to the expression of high-molecular-weight cytokeratins. The data initially suggest an inverse correlation between syndecan-1 expression and Gleason grade of the tumor, and warrant a larger study to assess the potential prognostic value of analysing syndecan-1 expression in prostate carcinoma.     

基于有限元法的生物体三维温度场无损重构

医学热诊断技术是一种无创的新型功能影像技术,其独特的诊断机理使其成为一种有潜力的医学影像辅助诊断手段。但是目前的热诊断大多根据热像图进行表观上的判断,主要依靠定性分析。本研究基于有限元法,通过求解Pennes生物传热方程,只需提取生物体的表面温度来重构三维生物体温度分布。利用通用有限元软件ANSYS的APDL二次开发功能和图形显示功能,得到直观的三维温度图像,特别是通过优化算法提取出体内的单个或多个异常热源信息,包括位置和强度,从而为医生的热诊断提供定量的分析。     

Fast temperature optimization of multi-source hyperthermia applicators with reduced-order modeling of 'virtual sources'

The goal of this work is to build the foundation for facilitating real-time magnetic resonance image guided patient treatment for heating systems with a large number of physical sources (e.g. antennas). Achieving this goal requires knowledge of how the temperature distribution will be affected by changing each source individually, which requires time expenditure on the order of the square of the number of sources. To reduce computation time, we propose a model reduction approach that combines a smaller number of predefined source configurations (fewer than the number of actual sources) that are most likely to heat tumor. The source configurations consist of magnitude and phase source excitation values for each actual source and may be computed from a CT scan based plan or a simplified generic model of the corresponding patient anatomy. Each pre-calculated source configuration is considered a 'virtual source'. We assume that the actual best source settings can be represented effectively as weighted combinations of the virtual sources. In the context of optimization, each source configuration is treated equivalently to one physical source. This model reduction approach is tested on a patient upper-leg tumor model (with and without temperature-dependent perfusion), heated using a 140 MHz ten-antenna cylindrical mini-annular phased array. Numerical simulations demonstrate that using only a few pre-defined source configurations can achieve temperature distributions that are comparable to those from full optimizations using all physical sources. The method yields close to optimal temperature distributions when using source configurations determined from a simplified model of the tumor, even when tumor position is erroneously assumed to be approximately 2.0 cm away from the actual position as often happens in practical clinical application of pre-treatment planning. The method also appears to be robust under conditions of changing, nonlinear, temperature-dependent perfusion. The proposed approach of using virtual sources reduces the number of variables that must be optimized to achieve a tumor-focused temperature distribution, thereby reducing the calculation time required in real-time control applications to about 1/3 to 1/4 of that required for full optimization.     

Information acquisition for women facing surgical treatment for breast cancer: influencing factors and selected outcomes

OBJECTIVE: To examine, summarize, and critically assess the literature focusing on information use by early-stage breast cancer patients. METHODS: Empirical articles reporting the information needs, sources used/preferred, and intervention-related outcomes experienced by patients in the context of making a treatment choice were chosen. Several healthcare databases were searched. Articles were limited to those published in English between January 1, 1986 and March 31, 2006. RESULTS: A total of 25 articles met the inclusion criteria. Information needs were consistent, and highest rankings were for (in order): information about chances for a cure, stage of disease, and treatment options. Results were equivocal regarding the factors found to influence information need: age, time since diagnosis, and preferred role in decision-making. The highest ranked information sources accessed and preferred were physicians. Age, education, and type of treatment chosen influenced source choice. Patients using consumer decision aids (CDAs) had less decisional conflict, higher satisfaction with the decision made and the decision process, and higher knowledge levels. CONCLUSION: Information needs and source use were influenced by several personal and contextual factors. PRACTICE IMPLICATIONS: A better understanding of source use could provide more effective ways of disseminating information to patients.     

基于红外技术的人体异常热源的探测研究

采用红外测温技术及改进蚁群算法求解导热反问题中的内热源强度及表面换热系数。通过建立含有内热源的二维稳态导热反问题实验模型,用红外热像仪测量试件的表面温度,并选用若干点温度作为求解反问题的补充条件,来反演热源强度及表面换热系数,并讨论了测点布置方式对反演结果的影响。计算结果表明：采用红外热像仪测温,结合改进蚁群算法可准确地对热源强度和表面换热系数进行反演识别。在整个边界上均匀布置测点的个数越多,则反演时计算步数越少,反演结果越精确;在测点个数相同时,在整个边界上均匀布置测点比在部分边界上均匀布置测点,更容易反演计算出准确的结果。     

Computerized detection of breast cancer with artificial intelligence and thermograms

This paper shows the concurrent use of thermography and artificial neural networks (ANN) for the diagnosis of breast cancer, a disease that is growing in prominence in women all over the world. It has been reported that breast thermography itself could detect breast cancer up to 10 years earlier than the conventional golden methods such as mammography, in particular in the younger patient. However, the accuracy of thermography is dependent on many factors such as the symmetry of the breasts' temperature and temperature stability. A woman's body temperature is known to be stable in certain periods after menstruation and it was found that the accuracy of thermography in women whose thermal images are taken in a suitable period (5th - 12th and 21st day of menstruation) is higher (80%) than the total population of patients (73%). The stability of the body temperature will depend on physiological state. This paper examines the use of ANN to complement the infrared heat radiating from the surface of the body with other physiological data. Four backpropagation neural networks were developed and trained using the results from the Singapore General Hospital patients' physiological data and thermographs. Owing to the inaccuracies found in thermography and the low population size gathered for this project, the networks developed could only accurately diagnose about 61.54% of the breast cancer cases. Nevertheless, the basic neural network framework has been established and it has great potential for future development of an intelligent breast cancer diagnosis system. This would be especially useful to the teenagers and young adults who are unsuitable for mammography at a young age. An intelligent breast thermography-neural network will be able to give an accurate diagnosis of breast cancer and can make a positive impact on breast disease detection.     

非接触式灸疗温度场的估计

目的研究非接触性艾灸的温度场分布,为调控灸疗过程和提高灸疗效果提供依据。方法根据生物传热的相关理论,建立描述人体组织内部在非接触性艾灸时的温度场理论模型,并据此推导当艾灸强度确定时,影响该温度场分布的体内异常热源深度与施灸处皮肤温度的对应关系。结果在不同艾灸强度下,根据对应关系计算出的结果与有限元的分析结果进行比较,结果显示对体内异常热源深度的估测结果与有限元仿真分析结果十分接近。而组织内部温度场理论模型的正确性也得到了物理实验的验证。结论本文提出的根据人体皮肤表面温度和艾灸强度估计体内异常热源的深度信息,继而估计出组织内温度场的方法具有一定的适用性,将有助于临床灸疗的方案设计。     

Thermal and scatter effects on the radiation sensitivity of well chambers used for high dose rate Ir-192 calibrations.

High dose rate (HDR) iridium sources must be calibrated regularly because of the short half-life of Ir-192. High dose rate sources can now be calibrated using a new well-type chamber that allows easy, reproducible source calibrations. The chamber includes a styrofoam insulator that surrounds the source in the well. A study of the radiation sensitivity of the well chamber exposed to an HDR Ir-192 source at two different activities (300 and 230 GBq) revealed that the sensitivity of the chamber varies by as much as 1.1% as the chamber is moved toward a scattering surface. Second, with the styrofoam insulator removed, the air temperature within the ion collecting volume increased during exposure, causing a gradual decrease in chamber sensitivity of 0.15% in 30 min. This temperature increase was caused by heat transfer from radiation emitted by the Ir-192 source, and diminished as the source decayed. However, with the styrofoam insulator around the central aluminum tube in the well, the source cannot heat the collecting volume and thus thermal equilibrium between the ion collecting volume and its environment is maintained throughout an exposure. The radiation sensitivity of the commercial well chamber was found to be constant for exposure times of 30 min.     

Study of hot stress dynamic IR thermography for detecting surface cancerous tissue

Abstract

The early diagnosis of cancer at any location of the human body can help in enhancing the survival rate and in reducing the cost of the treatment. Among the several techniques, the conventional infra-red (IR) thermography suffers from several limitations, including higher patient discomfort and longer time for tumour detection based on the temperature difference between tumour and adjacent healthy tissues. Hence, in this work, a novel non-invasive hot stress dynamic IR thermography system is proposed to detect surface tumour without severe discomfort to the patient. The system is designed to detect the surface tumour under 3?min within a temperature range of 42 and 37?°C. A two-dimensional numerical model based on the bio-heat transfer of tissue consists of cancerous and healthy cells is developed and validated to analysis the thermal contrast arises due to the presence of cancerous and healthy cells while cooling naturally. A light source is introduced with appropriate intensity to achieve a suitable temperature contrast. Moreover, the effects of natural convective heat loss from the tissue to the ambient and the scanning speed of IR Thermography on the tissue are investigated. A temperature difference of about 1.5?°C is found after cooling of tissues for 140?s, which can be detected using a thermographic camera. Finally, a sensitivity study is conducted to access the importance of the individual parameter over the final temperature field. The results predict the blood perfusion rate as the most significant parameter that significantly influences the temperature distribution in the considered domain.     

Temperature distribution in atherosclerotic coronary arteries: influence of plaque geometry and flow (a numerical study)

Intravascular coronary thermography is a method that may detect vulnerable, atherosclerotic plaques and is currently evaluated in a clinical setting. Active macrophages or enzymatic heat releasing processes in vulnerable plaques may act as heat sources. To better understand the parameters of influence on thermographic measurements, numerical simulations have been performed on a model of a coronary artery segment containing a heat source. Heat source parameters and flow were varied to study their influence on temperatures at the lumen wall. Maximal temperature differences at the lumen wall increased when the source volume increased and they differ with the source geometry. The simulations showed that blood flow acts as a coolant to the lumen wall. Blood flow decreased maximal temperatures depending on the source geometry, source volume and the maximal flow velocity. Influence of flow was highest for circumferentially extended sources, up to a factor 3.7, and lowest for longitudinally extended sources, down to a factor 1.9. When cap thickness increased, maximal temperatures decreased and the influence of flow increased. This study shows that correct interpretation of intravascular thermographic measurements requires data on the flow and on the morphologic characteristics of the atherosclerotic plaque.     

肺癌肿瘤干细胞表面标志物的研究

背景：对肿瘤干细胞表面标志物进行检测及跟踪监测研究,可为肿瘤的诊断及生物治疗如免疫治疗等提供重要的帮助。 目的：对肺癌的肿瘤干细胞表面标志物的研究进行文献检索分析,为提高肿瘤的诊断率、改善治疗方法、提高患者的生活质量提供可借鉴的理论依据。 方法：检索SCI数据库2002/2011肺癌肿瘤干细胞表面标志物研究相关文献,采用检索词为“肿瘤干细胞(cancer stem cell);肺癌(lung cancer)”,共检索110篇文献,选取符合标准的18篇文献进行数据分析。 结果与结论：肺癌是目前世界上发病率和死亡率最高的恶性肿瘤之一,检测肺癌肿瘤干细胞表面标志物CD133可深入研究肿瘤发生、发展及增殖、维持过程,同时CD133可以为肺癌的靶向生物治疗提供相关信息。随着研究的不断深入,肿瘤干细胞表面标志物不仅可以应用于肿瘤的早期诊断,还将应用于肿瘤的生物治疗。     

Comparison of modelled and observed in vivo temperature elevations induced by focused ultrasound: implications for treatment planning

Two numerical models for predicting the temperature elevations resulting from focused ultrasound heating of muscle tissue were tested against experimental data. Both models use the Rayleigh-Sommerfeld integral to calculate the pressure field from a source distribution. The first method assumes a source distribution derived from a uniformly radiating transducer whereas the second uses a source distribution obtained by numerically projecting pressure field measurements from an area near the focus backward toward the transducer surface. Both of these calculated ultrasound fields were used as heat sources in the bioheat equation to calculate the temperature elevation in vivo. Experimental results were obtained from in vivo rabbit experiments using eight-element sector-vortex transducers at 1.61 and 1.7 MHz and noninvasive temperature mapping with MRI. Results showed that the uniformly radiating transducer model over-predicted the peak temperature by a factor ranging from 1.4 to 2.8, depending on the operating mode. Simulations run using the back-projected sources were much closer to experimental values, ranging from 1.0 to 1.7 times the experimental results, again varying with mode. Thus, a significant improvement in the treatment planning can be obtained by using actual measured ultrasound field distributions in combination with backward projection.     

Morphological clues to the appropriate recognition of hereditary renal neoplasms

An important emerging role of the surgical pathologist besides the traditional tasks of establishment of the diagnosis and documentation of prognostic and predictive factors, is to recognize the possibility of a hereditary condition in cases where the histology is suggestive for a familial cancer syndrome. In recent years, the knowledge regarding all of the above roles, including the role of recognition of familial cancer, has particularly expanded in renal neoplasms with the close scrutiny to morphology, molecular correlates and clinical features of the different sub-types of renal cell carcinoma. Awareness of these clinically distinctive sub-types and their associated histologic clues will prompt the pathologist for further immunohistochemical or molecular work up, to look for clinical information to support the suspected diagnosis of familial cancer, to alert managing physician/s to look for stigmata of history of familial cancer, which will permit triaging patients and their families for appropriate genetic counseling. This review provides a comprehensive review of the known sub-types of renal cell carcinoma that have a predilection to occur in the setting of hereditary disease; examples include renal cancers occurring in the background of von Hippel Lindau disease, hereditary leiomyomatosis and renal cell carcinoma syndrome, tuberous sclerosis, Birt Hogg Dube syndrome and succinate dehydrogenase deficiency. Herein we focus on diagnostic clues for renal tumors occurring in a non-pediatric setting that should prompt their correct recognition and reiterate the importance of the correct diagnosis.     

A tyrosine sulfated human glycoprotein with an unusual cell distribution.

We describe a human integral cell surface glycoprotein (Mr 142 kD), recognized by monoclonal antibody M2B3. This glycoprotein is absent from resting peripheral blood lymphocytes, but becomes expressed in significant levels with mitogen activation. The M2B3 glycoprotein is present on epithelial cells in the basal layer of epidermal and esophageal tissue as well as in several fresh tumors examined. In addition, it is present on smooth muscle tissue throughout the gastrointestinal tract, but is absent from smooth muscle from several other tissue sources, skeletal muscle and cardiac muscle. The M2B3 glycoprotein is similar, but not identical, in apparent Mr to a transformation-associated glycoprotein, Q14. Further, the M2B3 and Q14 species are related antigenically. Nonetheless, M2B3 and Q14 are distinct glycoproteins based on clear differences in cell distribution and in partial peptide mapping. The M2B3 antigen described herein is sulfated on tyrosine, and represents one of the few cell surface proteins described to date that is sulfated on tyrosine residues. Our studies suggest the function of the M2B3 glycoprotein is likely to be associated with cell proliferation of cell adhesion.