The use of tissue electrical characteristics for breast cancer detection: a perspective review.

Breast cancer is the most frequently occurring malignancy in women. It is characterized by a high mortality rate. For the purpose of detecting this life threatening disease, research efforts are being made worldwide to exploit new technologies, to improve the detection accuracy of current devices and to develop new detection devices, comprehensive diagnostic procedures, and protocols. One such technology that is gaining popular attention over the recent years is the usage of electrical characteristics of the breast tissue to differentiate normal and cancerous tissues. Most of the devices using this technology are currently being used as adjunct diagnostic tools to improve the detection accuracy of established techniques like mammography and ultrasound. Also, early detection of breast cancer can help save many thousands of lives every year and can also reduce unnecessary healthcare expenditure caused by advanced stage treatment options. Hence, more research is also being done to adapt these devices into screening tools for early detection of breast cancer. The main objective of this review is to highlight the features of the currently available commercial devices that use this technology for breast cancer detection. The electrical behavior of normal and cancerous breast tissues is first presented. The various commercial devices that utilize electrical impedance or electropotentials for breast cancer detection are then described. Finally, conclusions and potential areas of research are highlighted.

Clinics in diagnostic imaging (58). Chronic cerebral paragonimiasis.

A 36-year-old Korean man presented with a history of epilepsy. MR imaging of the brain revealed multiple conglomerated round nodules that were hypointense on both T1-and-T2 weighted images. These were located at the left temporal and occipital lobes and had surrounding encephalomalacia. CT scan confirmed the presence of large calcified nodules in the corresponding regions. These imaging findings were typical of chronic cerebral paragonimiasis. The clinical, CT and MR features of cerebral paragonimiasis are reviewed.

An unusual case of nonspecific interstitial pneumonia treated initially with surgical resection.

Nonspecific interstitial pneumonia (NSIP) has been recently described as a distinct clinicopathologic entity. We describe an unusual case of a middle-aged man who presented with exertional dyspnoea, cough, radiographic airspace opacities in the left lung and previous history of right thoracotomy for suspected right lower lobe neoplasm. Histology at that time revealed "chronic inflammation". A course of high-dose steroids was given after failure of the airspace opacities to respond to a trial of antituberculous therapy. Improvement in symptoms and radiological appearance was noted subsequently. A diagnosis of nonspecific interstitial pneumonia was made on review of the initial open lung biopsy specimen. Seven months after tailing down to maintenance low-dose steroids, the NSIP relapsed. The NSIP subsequently responded again to high-dose steroids. This case illustrates that NSIP is a difficult diagnosis, may present as a focal lung opacity initially, and may relapse after steroid dose is tailed down.

Chest radiographic findings of a case of severe acute respiratory syndrome (SARS) in Singapore.

A new form of atypical pneumonia was reported in the East Asian region beginning from early 2003. This was later termed by the World Health Organisation as Severe Acute Respiratory Syndrome (SARS). The diagnosis of SARS relies on a combination of clinical features and chest radiographic findings. A preliminary review of SARS in Singapore shows chest radiographic findings of patchy airspace shadowing with severe cases progressing to diffuse air-space shadowing. We illustrate these findings with temporal correlation in our case report. As SARS is a contagious, rapidly progressive and potentially fatal condition, early diagnosis is crucial for prompt management and isolation of patients. Recognition of chest radiographic findings aids in the early diagnosis and containment of SARS.

Radiographic features of a case of severe acute respiratory syndrome with fatal outcome.

INTRODUCTION: Severe acute respiratory syndrome (SARS) is a new form of atypical pneumonia caused by a coronavirus. We present the clinical course and chest radiographic findings of a case of SARS with fatal outcome. CLINICAL PICTURE: A 39-year-old Chinese male presented with fever, sore throat and non-productive cough. During his illness, serial chest radiographs showed increasingly severe air-space shadowing in both lungs. TREATMENT AND OUTCOME: The patient was treated with supplemental oxygen, levofloxacin, oseltamivir, ribavirin and methylprednisolone. As his condition worsened, the required ventilatory and inotropic support. He later developed a myocardial infarct and coagulopathy, and succumbed to his illness. CONCLUSION: The reported case mortality of SARS is about 9% worldwide. In Singapore, the mortality is 15.5%. Acute respiratory distress syndrome (ARDS) is believed to be a contributory factor to our patient's demise. We report this case to show the radiographic changes of ARDS in a patient with SARS.

Radiological placement of 211 central venous catheters: outcome and complications.

A prospective study of 211 central venous catheters consecutively placed in 186 patients under radiological guidance was conducted over an 18-month period. The majority (64%) of our patients were at risk for acute complications or failure. These risks included bleeding tendency, distorted anatomy, or previous complicated lines and failed "blind" percutaneous attempts. We employed the subtraction angiographic technique for venous mapping or ultrasound localisation to guide our initial puncture. The accumulated catheter experience was 15,295 days and the median catheter survival time was 166 days. The success rate was 100%. Our acute complications included 1 case of arterial puncture (0.5%), 2 pneumothoraces (1.0%), and 13 patients (6.1%) with haematoma or prolonged oozing at the puncture site. The calculated infection rate was 0.25 episodes per 100 catheter days at risk. These results are comparable to those reported in the literature. We conclude that central venous catheterisation using imaging guidance is accurate and safe, and should be the method of choice especially in high-risk patients.

Remote consultation for computerized tomography and magnetic resonance studies by means of teleradiology--experience at the Singapore General Hospital.

A teleradiology link was established between Singapore General Hospital in Singapore and Stanford University in California, USA. Over eight months, a total of 28 cases (involving 27 magnetic resonance investigations and three computerized tomography scans) were transmitted by ISDN to California. Our initial experience with teleradiology for remote consultation was encouraging, although the data transmission cost was higher than we anticipated. however, costs could be reduced by using data compression. Long-distance telecommunication charges continue to fall, so intercontinental teleradiology of this type may be financially viable in future.

Evaluation of the efficiency of biofield diagnostic system in breast cancer detection using clinical study results and classifiers.

The division of breast cancer cells results in regions of electrical depolarisation within the breast. These regions extend to the skin surface from where diagnostic information can be obtained through measurements of the skin surface electropotentials using sensors. This technique is used by the Biofield Diagnostic System (BDS) to detect the presence of malignancy. This paper evaluates the efficiency of BDS in breast cancer detection and also evaluates the use of classifiers for improving the accuracy of BDS. 182 women scheduled for either mammography or ultrasound or both tests participated in the BDS clinical study conducted at Tan Tock Seng hospital, Singapore. Using the BDS index obtained from the BDS examination and the level of suspicion score obtained from mammography/ultrasound results, the final BDS result was deciphered. BDS demonstrated high values for sensitivity (96.23%), specificity (93.80%), and accuracy (94.51%). Also, we have studied the performance of five supervised learning based classifiers (back propagation network, probabilistic neural network, linear discriminant analysis, support vector machines, and a fuzzy classifier), by feeding selected features from the collected dataset. The clinical study results show that BDS can help physicians to differentiate benign and malignant breast lesions, and thereby, aid in making better biopsy recommendations.

The use of skin surface electropotentials for breast cancer detection--preliminary clinical trial results obtained using the biofield diagnostic system.

The purpose of this study is to evaluate the efficiency of the Biofield Diagnostic System (BDS) as an adjunct to established diagnostic techniques such as mammography and ultrasound in differentiating benign and malignant breast lesions. The clinical trial was conducted at the Tan Tock Seng hospital, Singapore. 103 women scheduled for mammography and/or ultrasound tests participated in the study. The BDS test recorded a sensitivity of 100%, specificity of 97.6%, and an accuracy of 98.1%. The area under the ROC curve was 0.988 which was slightly lower than that of ultrasound (0.994) and slightly higher than that of mammography (0.951). The BDS test has demonstrated high sensitivity and specificity values in the studied population. The accuracy is also comparable to that of diagnostic techniques like mammography and ultrasound. Thus, it is evident that BDS can be a fast and reliable adjunct tool for getting a secondary opinion on lesions with indeterminate mammographic and sonographic results.

Computer-based identification of breast cancer using digitized mammograms.

High-quality mammography is the most effective technology presently available for breast cancer screening. Efforts to improve mammography focus on refining the technology and improving how it is administered and X-ray films are interpreted. Computer-based intelligent system for identification of the breast cancer can be very useful in diagnosis and its management. This paper presents a comparative approach for classification of three kinds of mammogram namely normal, benign and cancer. The features are extracted from the raw images using the image processing techniques and fed to the two classifiers namely: the feedforward architecture neural network classifier, and Gaussian mixture model (GMM) for comparison.. Our protocol uses, 360 subjects consisting of normal, benign and cancer breast conditions. We demonstrate a sensitivity and specificity of more than 90% for these classifiers.

Erdheim-Chester disease: a rare cause of interstitial lung disease.

Erdheim-Chester disease is a non-Langerhans cell histiocytosis that is progressive and may lead on to multi-organ involvement. Pulmonary involvement is rare, its presentation is nonspecific, and it carries an adverse outcome. Several radiological features, when considered together, may point to the diagnosis. This condition should be considered in the differential diagnosis of interstitial lung disease. We describe a 39-year-old woman who presented with dry cough, malaise and progressive dyspnoea. She was diagnosed to have late stage interstitial lung disease due to Erdheim-Chester disease.

Analysis of IR thermal imager for mass blind fever screening.

BACKGROUND: Obtaining meaningful temperature for the human body requires identifying a body site that will provide reliable data across a large population. It is important to understand that skin temperature does not solely depend on body-core temperature and may be affected by other physiological and environmental factors. Currently, there is lack of empirical data in correlating facial surface temperature with body core temperature. Present IR systems in use at airports/immigration checkpoints have not been scientifically validated particularly in regards to the false-negative rate. As a result, they may create a false sense of security by underestimating the number of febrile (and possibly infected) individuals. This article evaluates the effectiveness of thermal scanner when it is being used for mass blind screening of potential fever subjects such as SARS or bird flu patients. METHODS: Bio-statistics with regression analysis and ROC is applied to analyse the data collected (502) from the SARS hospital in Singapore and conclusive results are drawn from them. The results are vital in determining two very important pieces of information: the best and yet practical region on the face to take readings and optimal pre-set threshold temperature for the thermal imager. RESULTS: (1) The thermal scanner can be used as a first line tool for the mass blind screening of hyperthermia, (2) the readings from the scanner suggest good correlation with the ear temperature readings, (3) an imager temperature threshold should be determined by the environmental factors, outdoor condition in particular, the physiological site offset and the performance characteristics of thermal imager to warrant the most accurate and reliable screening operation. CONCLUSIONS: The analysis suggested that the thermal imager used holds much promise for mass blind screening when the readings from a specific region have a good correlation with the ear temperature. From the regression analysis, the best reading is taken from the maximum temperature in the eye region, followed by the maximum temperature in the forehead region. With ROC analysis, a randomly selected individual from the fever group has a test value larger than that for a randomly selected individual from the normal group in 97.2% of the time. The test can distinguish between the normal and febrile groups and an optimum threshold temperature for the thermal imager can be found. The pre-set threshold cut-off temperature for the current thermal imager was found to be 36.3 degrees C with reference to the associated environmental condition. Any temperature readings that exceed this reading will trigger off the alarm and a thermometer will be used to verify the whether the person is having fever.

Pulmonary function and exercise capacity in survivors of severe acute respiratory syndrome.

The aim of this study was to investigate pulmonary function and exercise capacity in a group of survivors of the severe acute respiratory syndrome (SARS). At 3 months after hospital discharge, 46 survivors of SARS underwent the following evaluation: spirometry, static lung volumes and carbon monoxide transfer factor (TL,CO). In total, 44 of these patients underwent cardiopulmonary exercise testing. No abnormalities were detected in the pulmonary function tests in 23 (50%) of the patients. Abnormalities of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC and TL,CO were detected in seven (15%), 12 (26%), one (2%) and 18 (39%) patients, respectively. All of these abnormalities were mild except in one case. In 18 patients (41%), the maximum aerobic capacity was below the lower limit of the normal range. Breathing reserve was low in four patients and significant oxygen desaturation was detected in a further four patients. Comparison of the measured exercise capacity with resting pulmonary function tests showed many cases of discordance in impairment. In conclusion, pulmonary function defects were detected in half of the recovered severe acute respiratory syndrome patients 3 months after hospital discharge, but the impairment was mild in almost all cases. Many patients had reduced exercise capacity that cannot be accounted for by impairment of pulmonary function.