Faculty Bibliography

Ultrasound has become popular in clinical/surgical applications, both as the primary image guidance modality and also in conjunction with other modalities like CT or MRI. Three dimensional ultrasound (3DUS) systems have also demonstrated usefulness in image-guided therapy (IGT). At the same time, however, current lack of open-source and open-architecture multi-modal medical visualization systems prevents 3DUS, from fulfilling its potential. Several standalone 3DUS systems, like Stradx or In-Vivo exist today. Although these systems have been found to be useful in real clinical setting it is difficult to augment their functionality and integrate them in versatile IGT systems. To address these limitations, a robotic/freehand 3DUS open environment (CISUS) is being integrated into the 3D Slicer, an open-source research tool developed for medical image analysis and surgical planning. In addition, the system capitalizes on generic application programming interfaces (APIs) for tracking devices and robotic control. The resulting platform-independent open-source system may serve as a valuable tool to the image guided surgery community. Other researchers could straightforwardly integrate the generic CISUS system along with other functionalities (i.e. dual view visualization, registration, real-time tracking, segmentation, etc. .) to rapidly create their medical/surgical applications. Our current driving clinical application is robotically assisted and freehand 3DUS-guided liver ablation, which is fully being integrated under the CISUS-3D Slicer. Initial functionality and pre-clinical feasibility are demonstrated on phantom and ex-vivo animal models.

Our research is intended to develop ultrasonic methods for characterizing cancerous prostate tissue and thereby to improve the effectiveness of biopsy guidance, therapy targeting, and treatment monitoring. We acquired radio frequency (RF) echo-signal data and clinical variables, e.g., PSA, during biopsy examinations. We computed spectra of the RF signals in each biopsied region, and trained neural network classifiers with over 3,000 sets of data using biopsy data as the gold standard. For imaging, a lookup table returned scores for cancer likelihood on a pixel-by-pixel basis from spectral-parameter and PSA values. Using ROC analyses, we compared classification performance of artificial neural networks (ANNs) to conventional classification with a leave-one-patient-out approach intended to minimize the chance of bias. Tissue-type images (TTIs) were compared to prostatectomy histology to further assess classification performance. ROC-curve areas were greater for ANNs than for the B-mode-based classification by more than 20%, e.g., 0.75 +/- 0.03 for neural-networks vs. 0.64 +/- 0.03 for B-mode LOSs. ANN sensitivity was 17% better than the sensitivity range of ultrasound-guided biopsies. TTIs showed tumors that were entirely unrecognized in conventional images and undetected during surgery. We are investigating TTIs for guiding prostate biopsies, and for planning radiation dose-escalation and tissue-sparing options, and monitoring prostate cancer

A number of studies have demonstrated a relationship between depression and low perceived social support and increased cardiac morbidity and mortality in patients with coronary heart disease. There is also evidence that depression increases the risk of acute myocardial infarction and morbidity and mortality following it. This review examines those studies that have investigated these relationships as well as those that have attempted to explain them on the basis of various pathophysiologic mechanisms. Among the latter are studies that have shown that selective serotonin reuptake inhibitors are beneficial in the treatment of depression and that they appear to reverse the enhanced platelet activity observed in depressed patients with acute myocardial infarction. Depression increases hospital length of stay, procedures, readmission rates, and the cost of medical care. Much remains to be elucidated concerning the roles of depression and low perceived social support in predisposing to acute myocardial infarction and to increased morbidity and mortality following it. However, sufficient scientific evidence exists for physicians to make efforts to diagnose and treat depression to reduce the concurrent risk of acute myocardial infarction and morbidity and mortality following it

Understanding clinical phenotypes through their corresponding genotypes is one of the principal goals of genetic research. Though achieving this goal is relatively simple with single gene syndromes, more complex diseases often consist of varied clinical phenotypes that may be the result of interactions among multiple genetic loci. Microarray technology has brought the phenotype -genotype relationship to the molecular level, using differently behaving cancers, for example, as the basis for comparing patterns of gene expression. With this feasibility study, we attempted to use similar methods of analysis at the clinical level, in order to evaluate our hypothesis that the clustering of clinical phenotypes would provide information that would be useful in elucidating their underlying genotypes. Because of its breadth of content and detailed descriptions, we used OMIM as our source material for phenotypic and genetic information. After processing the source material, we then performed self-organizing map and hierarchical clustering analysis on representative diseases by phenotypic category. Through pre-determined queries over this analysis, we made two findings of potential clinical significance, one concerning diabetes and another concerning progressive neurologic diseases. Our methods provide a formal approach to analyzing phenotypes among diverse diseases, and may help indicate fruitful areas for further research into their underlying genetic causes

Contrary to what The Medical Letter said on May 24, 2004, the topical drug imiquimod (Aldara) which is used to treat actinic keratosis and superficial basal cell cancer, apparently can cause systemic effects, including fatigue and influenza-like illness; exfoliative dermatitis and angioedema have been reported. These may be related less to the drug itself than to the local reaction the drug causes

This year's vaccine includes new influenza A (H3N2) and B strains, and has expanded indications for children. Immunization should proceed as soon as vaccine is available