Color Doppler and Microvascular Flow Imaging to Evaluate the Degree of Inflammation in a Case of Hidradenitis Suppurativa

Microvascular Flow Imaging is a new ultrasound technique with better ability than Color Doppler Imaging to identify small vessels that have slow blood flow, and it permits better evaluation of the features, especially microvascular architecture, of various lesions. We describe a case of inguinal hidradenitis suppurativa in a patient with positive risk factors (young age, female, smoker, and obese), diagnosed by ultrasonography using B-Mode, Color Doppler, and finally also with Microvascular Flow Imaging. Our aim is to demonstrate the usefulness of this new technique in characterization of lesions.

Imaging microvasculature network evolution and neurodegeneration with precise photothrombosis approach

In the cerebral cortex, the vasculature plays important homeostatic functions, especially at the highly connected complex capillary networks. The association of focal capillary ischemia with the neurodegenerative disease as well as the laminar vascular dynamics have prompted studies of vascular micro-occlusion via photothrombosis. However, technical challenges of this approach remain, including increased temporal precision of occlusion, increasing the depth of vascular occlusion, understanding how such micro-occlusion impacts local blood flow, and ultimately the neuronal effects of such changes. Here, we have developed a novel approach that employs ultra-fast multiphoton light to induce focal Rose Bengal-induced photothrombosis. We demonstrated induction of highly precise and fast occlusion of microvessels at various types and depths. The change of the microvascular architecture and hemodynamics after occlusion revealed the autoregulation and significant difference between upstream vs downstream in layer 2/3. Further, we found that micro-occlusion at two different layers within the same vascular arbor results in distinct effects on the acute flow redistribution mechanism. To examine neuronal effects of such micro-occlusion, we produced infarct of capillaries surrounding a labeled target neuron and found this induces dramatic and rapid lamina-specific degeneration in neuronal dendritic architecture. In sum, our technique enhanced the precision and power of the photothrombotic study of microvascular function. The current results pointed to the importance of laminar scale regulation within the microvascular network, a finding which may be relevant for models of neurovascular disease.

Physiological MRI Biomarkers in the Differentiation Between Glioblastomas and Solitary Brain Metastases

Purpose Glioblastomas (GB) and solitary brain metastases (BM) are the most common brain tumors in adults. GB and BM may appear similar in conventional magnetic resonance imaging (cMRI). Their management strategies, however, are quite different with significant consequences on clinical outcome. The aim of this study was to evaluate the usefulness of a previously presented physiological MRI approach scoping to obtain quantitative information about microvascular architecture and perfusion, neovascularization activity, and oxygen metabolism to differentiate GB from BM. Procedures Thirty-three consecutive patients with newly diagnosed, untreated, and histopathologically confirmed GB or BM were preoperatively examined with our physiological MRI approach as part of the cMRI protocol. Results Physiological MRI biomarker maps revealed several significant differences in the pathophysiology of GB and BM: Central necrosis was more hypoxic in GB than in BM (30 %; P = 0.036), which was associated with higher neovascularization activity (65 %; P = 0.043) and metabolic rate of oxygen (48 %; P = 0.004) in the adjacent contrast-enhancing viable tumor parts of GB. In peritumoral edema, GB infiltration caused neovascularization activity (93 %; P = 0.018) and higher microvascular perfusion (30 %; P = 0.022) associated with higher tissue oxygen tension (33 %; P = 0.020) and lower oxygen extraction from vasculature (32 %; P = 0.040). Conclusion Our physiological MRI approach, which requires only 7 min of extra data acquisition time, might be helpful to noninvasively distinguish GB and BM based on pathophysiological differences. However, further studies including more patients are required.