ABSTRACT
This work presents a method for constructing phantoms suitable for diffuse optical mammography. They are based on Polydimethylsiloxane silicones, with the characteristic of being anthropomorphic, and having similar mechanical and optical properties as a real breast. These phantoms are useful for testing the performance of diffuse optical imaging devices in the near infrared, both in transmittance and reflectance geometries, since they can be constructed containing inclusions, to simulate breast tumors. An alternative component to be used as scattering agent, that is easier to handle than traditional scattering agents, is also studied. The optical properties of the phantoms were tested varying the concentration of scattering and absorbing agents, while their mechanical properties were modified by adding a silicone fluid to the basic mixture. Finally, the phantoms were tested by Diffuse Optical Imaging experiments, and these images were compared to the ones obtained by conventional ultrasound techniques. Results show that the constructed anthropomorphic phantoms properly reproduce the optical and mechanical characteristics of human breasts, and are suitable to be used in Diffuse Optical Imaging.
ABSTRACT
This cross-sectional, concurrent and descriptive study presents the decisions regarding patients referred to our Lung Transplantation Unit (LTxU). Each patient is discussed in a multidisciplinary clinical session (phase I), rejecting some and accepting others for assessment in our LTxU (phase II) according to criteria of the National and International Guidelines for Transplantation. A protocol assessment in phase II, leads to a decision to reject, accept, or follow-up the candidate for LTx. Among 214 evaluation requests received in our unit from May 2008 to December 2011, 37 patients (17%) were rejected based on the information sent to our LTxU. Among the patients evaluated in phase II, 62 (28.9%) were put on the waiting list, 125 (58.4%) were rejected, and twenty-seven (12.6%) were postponed for future reconsideration, results that were similar to those described in the literature. The main disease referred for LTx was obstructive airflow (n = 98; 45.7%), followed by interstitial lung disease (ILD; n = 66; 30.8%), cystic fibrosis or bronchiectasis (n = 20; 9.3%), or primary pulmonary hypertension group 1 (n = 20; 9.3%). Ten patients (4.6%) were diagnosed with other respiratory diseases. Most patients (n = 165; 77.1%) lived in the region of our hospital (Madrid). The main reasons to reject patients for LTx were malnutrition, severe disease in other organs, toxic habits, and refusal of treatment. Finally, one out of four referred patients was accepted for LTx. In addition to serious comorbidities in various organs, a high percentage of patients who were not accepted for LTx because of these factors might have been of accepted had these conditions been corrected before patient referral.