Objective Vascular optical tomographic imaging (VOTI) is a novel imaging modality that is capable of detecting hemoglobin concentrations in tissue. VOTI is non-invasive, non-ionizing and does not require contrast injection. We applied this technology to diagnosing peripheral arterial disease (PAD) within lower extremities of diabetic patients with calcified arteries. This could be of substantial benefit as these patients suffer from comorbidities such as arterial incompressibility, which complicates diagnosis and monitoring. Methods Forty subjects (10 non-diabetic patients with PAD, 10 diabetic patients with PAD, and 20 healthy volunteers) were enrolled in a diagnostic pilot study using the VOTI system. The patients were imaged during a thigh pressure cuff occlusion. Results The VOTI system was capable of quantifying the blood volume changes within the foot during the thigh cuff occlusion and outputting diagnostic parameters, such as change in hemoglobin concentration, enabling the assessment of foot perfusion. This study resulted in a statistically significant difference between the healthy cohort and both the non-diabetic and the diabetic PAD cohorts (P=0.006, P=0.006). Receiver operating characteristic (ROC) curve analysis showed that PAD diagnosis could be made with over 80% sensitivity or specificity depending on the characteristic cut-off point. In addition, VOTI was capable of providing the locations of under-perfused regions within the foot and evaluating the severity of arterial disease, even within diabetic patients with calcified arteries, which are traditionally difficult to diagnose. Conclusion VOTI can effectively diagnose PAD independently of arterial compressibility, making it very useful for assessing vascular disease in diabetic patients.

To simulate the hemodynamic effects in the feet in response to a thigh cuff occlusion, we have developed a multi-compartmental model in which the circulatory system for the leg is represented by its electrical equivalents. Dynamic vascular optical tomographic imaging data previously obtained from 20 patients with peripheral artery disease (PAD) and 20 healthy subjects is used to test the model. Analyzing the clinical data with the support of the model yields diagnostic specificity and sensitivity in the 90-95% range, significantly higher than previously reported.

Background Infantile hemangiomas (IHs) are vascular tumors with potential for significant morbidities. There is a lack of validated objective tools to assess IH severity and response to treatment. Diffuse Optical Spectroscopy (DOS), a non-invasive, non-ionizing imaging modality can measure total hemoglobin concentration [THb] and tissue oxygen saturation (%StO2) to assess IH vascularity and response to treatment. Objective Our objective is to evaluate the utility of a wireless, handheld DOS system to assess IH characteristics at selected points during their clinical course. Methods Thirteen subjects (initial age 5.8±2.0 months) with fifteen IHs were enrolled. IHs were classified as proliferative, plateau-phase, or involuting. Nine patients with 11 IHs were untreated; four patients (with 4 IHs) were treated with timolol or propranolol. Each IH was evaluated by placing the DOS system directly on the lesion and a normal contralateral skin site. IH vascularity and oxygenation were scored by a newly defined Normalized Hypoxia Fraction coefficient. Measurements were recorded at intervals from initial visit to 1–2 years of age. Results For the 9 untreated IHs the NHF was highest at 6 months of age, during proliferation. Differences in NHFs between the proliferation and the plateau and involuting stages were statistically significant (p=0.02, p=0.0005). In treated patients, the NHF normalize up to 60% after 2 months. One treated IH came within 5% of the NHF for normal skin after 12 months. Conclusions Evidence is provided that DOS can be used to assess the vascularity and tissue oxygenation of IHs and monitor their progression and response to treatment.

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A novel multi-view non-contact dynamic diffuse optical tomographic imaging system for the clinical evaluation of vasculature in the lower extremities is presented. The system design and implementation are described in detail, including methods for simultaneously obtaining and reconstructing diffusely reflected and transmitted light using a system of mirrors and a single CCD camera. The system and its performance using numeric simulations and optical phantoms. Measurements of a healthy foot in vivo demonstrates the potential of the system in assessing perfusion within the foot.