Eladio Rodriguez-Diaz

Preoperative discrimination of benign from malignant disease in thyroid nodules with indeterminate cytology using elastic light-scattering spectroscopy.

Thyroid nodules are common and often require fine needle aspiration biopsy (FNAB) to determine the presence of malignancy to direct therapy. Unfortunately, approximately 15-30% of thyroid nodules evaluated by FNAB are not clearly benign or malignant by cytology alone. These patients require surgery for the purpose of diagnosis alone; most of these nodules ultimately prove to be benign. Elastic light scattering spectroscopy (ESS) that measures the spectral differences between benign and malignant thyroid nodules has shown promise in improving preoperative determination of benign status of thyroid nodules. We describe the results of a large, prospective, blinded study validating the ESS algorithm in patients with thyroid nodules. An ESS system was used to acquire spectra from human thyroid tissue. Spectroscopic results were compared to the histopathology of the biopsy samples. Sensitivity and specificity of the ESS system in the differentiation of benign from malignant thyroid nodules are 74% and 90% respectively, with a negative predictive value of 97%. These data suggest that ESS has the potential for use in real time diagnosis of thyroid nodules as an adjunct to FNAB cytology.

Elastic Scattering Spectroscopy as an Optical Marker of Inflammatory Bowel Disease Activity and Subtypes

Background:In 10% to 15% of individuals, inflammatory bowel disease (IBD) is difficult to classify as ulcerative colitis (UC) or Crohns disease (CD). Previous work has demonstrated that probe-based elastic scattering spectroscopy (ESS) can produce spectra, informed by parameters like tissue ultrastructure and hemoglobin content, capable of differentiating pathologies. This study investigates whether ESS is an in vivo optical biomarker for the presence, activity, and type of IBD in the colon. Methods:Pilot study, a retrospective data analysis. ESS spectra of endoscopically normal and inflamed colon were obtained from 48 patients with IBD and 46 non-IBD controls. Measurements from patients with IBD were categorized as CD or UC based on clinical diagnosis. Spectra were analyzed using high-dimensional methods. Leave-one-patient-out cross-validation was used to obtain diagnostic performance estimates. Results:Patients with IBD were distinguishable from non-IBD controls with a sensitivity of 0.93 and specificity of 0.91 based on readings from endoscopically normal mucosa, and 0.94 and 0.93 from inflamed mucosa. In patients with IBD, histologically normal and inflamed colon were distinguishable with per-class accuracies of 0.83 and 0.89, respectively; histologically normal from inactive inflammation with accuracies of 0.73 and 0.89, respectively; and inactive from active colitis with accuracies of 0.87 and 0.84, respectively. The diagnosis of CD versus UC was made with per-class accuracies of 0.92 and 0.87 in normal and 0.87 and 0.85 in inflamed mucosa, respectively. Conclusions:ESS, a simple, low-cost clinically friendly optical biopsy modality, has the potential to enhance the endoscopic assessment of IBD and its activity in real time and may help to distinguish CD from UC.

Optical Sensing of Field Carcinogenesis in Colonic Mucosa Using Elastic-Scattering Spectroscopy

G A A b st ra ct s RESULTS: At standard endoscopy, anal lesions were observed in 11/15 (73.3%) patients. At CLE, 9 (60%) patients showed irregular arrangements of epithelial cells (inhomogeneous cells with irregular and unclear border demarcation and presence of increased cell concentration). Long branching IPCLs and irregular shaped IPCLs/leakage were recorded in 14 (93.3%) and 8 (53.3%) patients, respectively. At standard histology, HG-AIN/carcinoma was diagnosed in 8 (53.3%) patients (AIN-3 in 4, AIN-2 in one, carcinoma in 3). LG-AIN was present in 4 (AIN-1 in 3, condyloma in one), while in the rest of patients histology showed normal squamous epithelium. HG-AIN/carcinoma could be predicted with a positive predictive value of 89%. CONCLUSION: Our preliminary data show that irregular cellular and irregular shaped IPCLs/leakage confocal patterns are pathognomonic features of neoplastic changes. On the other hand, long branching IPCLs are not a pathological feature. CLE could be an alternative tool to HRA and could improve the surveillance of AIN lesions. The small size of our population sample requires further studies for the results to be confirmed.

The color of cancer: Margin guidance for oral cancer resection using elastic scattering spectroscopy

To evaluate the usefulness of elastic scattering spectroscopy (ESS) as a diagnostic adjunct to frozen section analysis in patients with diagnosed squamous cell carcinoma of the oral cavity.

Probe-based confocal laser endomicroscopy quantitative morphometric markers associated with portal hypertension in duodenal mucosa.

Early detection of portal hypertension (PH) may help to prevent the morbidity of late‐stage cirrhosis by stratifying disease severity and enabling disease‐modifying interventions in potentially reversible conditions like non‐alcoholic fatty liver disease and alcoholic hepatitis. This study seeks to correlate morphometric features by confocal endomicroscopy with established surrogate clinical markers of PH.

Recognition of rotated images using the multi-valued neuron and rotation-invariant 2D Fourier descriptors

The Fourier descriptors paradigm is a well-established approach for affine-invariant characterization of shape contours. In the work presented here, we extend this method to images, and obtain a 2D Fourier representation that is invariant to image rotation. The proposed technique retains phase uniqueness, and therefore structural image information is not lost. Rotation-invariant phase coefficients were used to train a single multi-valued neuron (MVN) to recognize satellite and human face images rotated by a wide range of angles. Experiments yielded 100% and 96.43% classification rate for each data set, respectively. Recognition performance was additionally evaluated under effects of lossy JPEG compression and additive Gaussian noise. Preliminary results show that the derived rotation-invariant features combined with the MVN provide a promising scheme for efficient recognition of rotated images.

Optically Sectioned Fluorescence Imaging with HiLo

HiLo is a wide-field fluorescence imaging technique that provides optical sectioning by processing two images acquired sequentially using illumination with and without high contrast structure. We present the latest implementations of the technique.