Various methods are now available for clinical exploration of the breast. The most commonly used methods provide information essentially on morphology and structure, including macroscopic data (palpation, radiography, echography) and microscopic data (cytology, histology). By contrast, the thermal methods, among them skin thermography using infrared scanners or liquid crystals films, offer the advantage of giving information on thermophysiology. The superficial thermal pattern of the breast is in fact related to metabolism and vascularization within the underlying tissues. It may therefore be changed significantly as a result of normal phenomena (e.g., the menstrual cycle or pregnancy) or pathological processes. Because cancers vary so widely, not only in their histologic features but also in their physiological properties (e.g., the doubling time of tumors ranges from approximately 50 to 700 days), it would be regrettable to ignore the thermological dimension, which is related to the temporal properties of cancer. In spite of continuous progress in thermographic techniques as well as in standardization of examining conditions and image analysis, however, many physicians still hesitate to consider thermography as a useful tool in clinical practice. This attitude is somewhat amazing for those who have a long experience in thermography. It may be explained considering that physical and biological bases are not familiar to the physicians. All other methods of investigation refer to topics of medical teaching, e.g., radiography and echography to anatomy, or scintigraphy and biochemical assays to metabolic physiology. On the contrary, thermodynamics and thermokinetics are, for most physicians, strange sciences, though man is more or less unconsciously experiencing heat production and heat exchanges in every situation that he is undergoing. In the present state of the art, all options should be considered for developing research and teaching in thermopathology, starting from the basic knowledge of thermophysics and thermophysiology. This is certainly the only way of improving the acceptance of thermography by physicians and consequently by the health care authorities. Since we started with thermography 14 years ago, clinical and fundamental research have been simultaneously developed in our Laboratory of Biomedical

Thermopathology of breast cancer: measurement and analysis of in vivo temperature and blood flow

Thermography at centimeter and millimeter wavelengths can measure subsurface temperatures of the human body. Radiative and bio-heat transfer influence the wavelength dependent subcutaneous temperature and spatial resolution. Recent clinical results in treatment monitoring of arthritis, detection of tumors in the neck and brain area, and breast cancer are reviewed.

Centimeter- and millimeter-wave thermography--a survey on tumor detection.

Publisher Summary This chapter discusses the applications and principles of open-ended waveguides. Open-ended waveguides are used for a variety of applications, such as simple antennas, elements radiating in a plasma, diathermy and hyperthermia applicators, thermography detectors, or probes for the measurement of distances. The basic mode of structure consists of a waveguide; it is diagrammatically represented in the chapter. The waveguides are metallic with any cross-section, including closed two-conductor lines—such as coaxial lines. The general theoretical development and particular applications to circular and rectangular waveguides and to coaxial lines are also discussed in the chapter. The chapter provides a general survey of the present state of the art in the area of microwaves. Several different approaches are available to measure the reflection in a waveguide, such as slotted-line techniques, reflectometry, and resonant cavities. Theoretical development for a flanged waveguide radiating into an infinite homogenous medium is also considered by normalization, moment method, or variational principles. The application of various structures, such as coaxial line, is also discussed in the chapter.

Open-Ended Waveguides: Principles and Applications

This review is concerned principally with the physical aspects of the various methods of breast imaging that may be used to assist in the diagnosis of primary breast disease, and with the way in which they relate to each other.

http://iopscience.iop.org/article/10.1088/0031-9155/27/4/001/pdf

Methods of breast imaging

The thermal emission of human skin at micrometer wavelengths has been used in clinical infrared thermography for over one decade. Recently, the emission of the human body at centimeter and millimeter wavelengths has been studied for clinical applicat ions.'4 The advantage of these long wavelengths is their good depth-viewing capabilities; they can directly measure subcutaneous temperatures, in contrast to conventional infrared thermography, which is limited to the measurement of skin temperatures only. This paper will briefly review emission characteristics of the human body, describe thermographic imaging instrumentation operating at several different wavelengths, and present preliminary clinical findings on treatment monitoring of arthritis, detection of tumors in the brain and thyroid, and detection of breast cancer.

Imaging thermograms at centimeter and millimeter wavelengths

Thermographic studies of 14 patients with breast carcinoma were performed using two millimeter wave scanners for 30 and 68 GHz. Small correlation with infrared thermograms was observed indicating the depth sensing capabilities of millimeter waves. Correlation with mammographic and other clinical findings was good for tumors with medium subcutaneous depth. These preliminary results indicate a need for a statistically more significant number of cases, extension towards lower sensing frequencies and experiments on postoperative specimens and phantom models.

J. L. Guerguin-Kern

Papers

Millimeter-wave thermography--application to breast cancer.