Biomedical subjects

Sarah Lenington

Publications and source records attributed to Sarah Lenington.

4 recordsLinked to original sources

PubMed2005

Electrical impedance scanning for the early detection of breast cancer in young women: preliminary results of a multicenter prospective clinical trial.

PURPOSE: To evaluate the feasibility and patient satisfaction with electrical impedance scanning (EIS) for early detection of breast cancer in young women. METHODS: Women undergoing screening clinical breast examination, imaging, or biopsy were eligible for EIS examination with T-Scan 2000ED (Mirabel Medical Systems, Austin, TX). Multiple logistic regression analysis evaluated the association between clinical variables and EIS performance. Patients completed a screening EIS satisfaction questionnaire (1 = least satisfied to 5 = most satisfied). RESULTS: Twenty-nine cancers were identified among 1,103 women. Sixty-six percent (19 of 29) of cancers were nonpalpable and 55% (16 of 29) were in women age < or = 50 years. EIS sensitivity and specificity in women younger than 40 years was 50% and 90%, respectively. Exogenous estrogen use (P < .001) and menopausal status (P = .007) correlated significantly with EIS performance. False-positive rates were increased in postmenopausal women and those taking exogenous hormones. No correlation was evident between EIS performance and family history, prior breast cancer, breast density, or palpability. EIS-positive women younger than age 40 were 4.5 times more likely to have breast carcinoma than were women randomly selected from the general population. Patients were highly satisfied with the comfort, speed, and reporting of EIS screening (mean score, 4.8). CONCLUSION: EIS seems promising for early detection of breast cancer, and identification of young women at increased risk for having the disease at time of screening. Positive EIS-associated breast cancer risk compares favorably with relative risks of conditions commonly used to justify early breast cancer screening. Patients are satisfied with a screening paradigm involving breast EIS.

Adult↗

PubMed2005

Electrical impedance scanning of thyroid nodules before thyroid surgery: a prospective study.

BACKGROUND: Electrical impedance scanning (EIS) is a novel imaging technique based on differential electrical conductivity and capacitance of malignant and normal human tissues. The aim of this study was to evaluate the accuracy of EIS in the detection of thyroid malignancies. METHODS: Patients with thyroid nodules scheduled for thyroid surgery were eligible for the study. Enrolled patients underwent EIS with a T-Scan 2000ED. Nodule location, size, and type (cystic vs. solid) measured by ultrasound, cytology results, thyroid conductivity, and capacitance calculated by EIS were recorded. EIS results were interpreted as positive or negative for malignancy and compared with final histopathology results. Study end points included EIS accuracy, sensitivity, specificity, negative and positive predictive values, and false-positive and false-negative rates. RESULTS: Sixty-four patients were enrolled onto the study, and all underwent either lobectomy-isthmusectomy (20%) or total thyroidectomy (80%). The mean tumor diameter was 2.64 +/- 14.8 mm. Thyroid cancers were identified by histology in 30 patients (46.9%). There were 11 false-positive and four false-negative cases. The overall diagnostic accuracy of EIS was 76.6% (49 of 64 correct diagnoses). The sensitivity and specificity of EIS were 86.7% (26 of 30 true positive) and 67.6% (23 of 34 true negative), respectively. The corresponding positive and negative predictive values were 70.3% and 85.2%. CONCLUSIONS: EIS is a potentially useful imaging modality for differentiating thyroid neoplasms. If these results are confirmed in large-scale trials, EIS may be an important part of the evaluation of thyroid nodules.

Adolescent↗

PubMed2002

Breast electrical impedance and estrogen use in postmenopausal women.

OBJECTIVES: To examine the potential for using electrical impedance measurements on the breast as an indicator of estrogen activity in breast tissue. METHODS: Eighty-six postmenopausal women were examined with TS2000, a device that measures electrical capacitance and conductance on the breast. Seventy women had undergone natural menopause (NM) and 16 had had a hysterectomy/ovarectomy. Twenty-one women were using estrogen replacement therapy (ERT). Each woman had electrical impedance measured over several frequencies on the nipple sector of both breasts. We analyzed capacitance and conductance at 200 and 1100 Hz and the slopes and intercepts of regression lines relating capacitance and conductance to the natural log of frequency. RESULTS: Type of menopause (natural or induced) was not statistically related to any measured variable. The number of years since the start of menopause was statistically related to all measured variables. Overall, levels of capacitance and conductance decreased as the number of years since the start of menopause increased. Women who used ERT had a statistically higher level of nipple conductance at 200 Hz than did women who did not use ERT. CONCLUSIONS: The pattern of electrical measurements on the nipple (and in particular conductance at 200 Hz) is correlated with the pattern of estrogen changes after menopause. These data indicate that electrical measurements might be a useful, non-invasive assay of estrogen activity in breast tissue.

Breast↗

PubMed2002

Novel EIS postprocessing algorithm for breast cancer diagnosis.

A new postprocessing algorithm was developed for the diagnosis of breast cancer using electrical impedance scanning. This algorithm automatically recognizes bright focal spots in the conductivity map of the breast. Moreover, this algorithm discriminates between malignant and benign/normal tissues using two main predictors: phase at 5 kHz and crossover frequency, the frequency at which the imaginary part of the admittance is at its maximum. The thresholds for these predictors were adjusted using a learning group consisting of 83 carcinomas and 378 benign cases. In addition, the algorithm was verified on an independent test group including 87 carcinomas, 153 benign cases and 356 asymptomatic cases. Biopsy was used as gold standard for determining pathology in the symptomatic cases. A sensitivity of 84% and a specificity of 52% were obtained for the test group.

Algorithms↗