scholarly journals Infra-red tomography of port-wine-stain blood vessels in human skin

1996 ◽  
Vol 11 (3) ◽  
pp. 199-204 ◽  
Author(s):  
J. S. Nelson ◽  
T. E. Milner ◽  
B. S. Tanenbaum ◽  
D. M. Goodman ◽  
M. J. C. Van Gemert
Author(s):  
J. Stuart Nelson ◽  
Thomas E. Milner ◽  
Bahman Anvari ◽  
B. Samuel Tanenbaum ◽  
Lars O. Svaasand ◽  
...  

2004 ◽  
Vol 75 (6) ◽  
pp. 2048-2055 ◽  
Author(s):  
Bincheng Li ◽  
Boris Majaron ◽  
John A. Viator ◽  
Thomas E. Milner ◽  
J. Stuart Nelson

Author(s):  
John S. Viator ◽  
Steven L. Jacques ◽  
Guillermo Aguilar

Successful treatment of port wine stain (PWS) birthmarks in human skin utilizes cryogen spray cooling (CSC) in conjunction with laser treatment. CSC pre-cools the epidermis to protect it from subsequent laser irradiation which raises the temperature of both the epidermis and the deeper PWS. As the epidermal temperature is depressed by cryogen, damage to the skin surface is minimized while the PWS reaches temperatures sufficient to permanently damage the lesion. In order to optimize cooling and laser heating dosages and to properly guide laser therapy, the spatial relationship of epidermal melanin and PWS must be known. Photoacoustic depth profiling of human skin uses low energy, nanosecond pulses of laser light to induce acoustic waves in optically absorbing media, such as blood and melanin. We used a 532 nm Nd:YAG laser to measure total epidermal melanin content in human skin, comparing the results with visible reflectance spectroscopy. Furthermore, we performed numerical simulations of photoacoustic generation in skin, showing that a hemisperical acoustic sensor array could be used to reconstruct the rete pattern of epidermal melanin in the basal layer. Finally, we built a hemispherical probe for use in future experiments for imaging of human skin.


2019 ◽  
Vol 20 (9) ◽  
pp. 2243 ◽  
Author(s):  
Vi Nguyen ◽  
Marcelo Hochman ◽  
Martin C. Mihm ◽  
J. Stuart Nelson ◽  
Wenbin Tan

Port wine stain (PWS) is a congenital vascular malformation involving human skin. Approximately 15–20% of children a facial PWS involving the ophthalmic (V1) trigeminal dermatome are at risk for Sturge Weber syndrome (SWS), a neurocutaneous disorder with vascular malformations in the cerebral cortex on the same side of the facial PWS lesions. Recently, evidence has surfaced that advanced our understanding of the pathogenesis of PWS/SWS, including discoveries of somatic genetic mutations (GNAQ, PI3K), MAPK and PI3K aberrant activations, and molecular phenotypes of PWS endothelial cells. In this review, we summarize current knowledge on the etiology and pathology of PWS/SWS based on evidence that the activation of MAPK and/or PI3K contributes to the malformations, as well as potential futuristic treatment approaches targeting these aberrantly dysregulated signaling pathways. Current data support that: (1) PWS is a multifactorial malformation involving the entire physiological structure of human skin; (2) PWS should be pathoanatomically re-defined as “a malformation resulting from differentiation-impaired endothelial cells with a progressive dilatation of immature venule-like vasculatures”; (3) dysregulation of vascular MAPK and/or PI3K signaling during human embryonic development plays a part in the pathogenesis and progression of PWS/SWS; and (4) sporadic low frequency somatic mutations, such as GNAQ, PI3K, work as team players but not as a lone wolf, contributing to the development of vascular phenotypes. We also address many crucial questions yet to be answered in the future research investigations.


2013 ◽  
Vol 45 (10) ◽  
pp. 628-632 ◽  
Author(s):  
Gangjun Liu ◽  
Wangcun Jia ◽  
J. Stuart Nelson ◽  
Zhongping Chen

2005 ◽  
Vol 36 (2) ◽  
pp. 124-129 ◽  
Author(s):  
Guillermo Aguilar ◽  
Lars O. Svaasand ◽  
J. Stuart Nelson

2021 ◽  
Vol 4 (1) ◽  
pp. 457-458
Author(s):  
Prasanna Kumar Jha ◽  
Satyendra Kumar Singh

Acquired port wine stain though an uncommon entity that develops later in life, resembles congenital port wine stain morphologically and histologically. Congenital port wine stains are vascular lesions caused by progressive ectasia of blood vessels which is located in the vascular plexus of the dermis. Congenital port-wine stains may be associated with Sturge Weber syndrome causing neurological and eye abnormalities such as glaucoma. Here we report a 60-year-old male presenting with a complaint of asymptomatic reddish patches over the nose for 15 years.


2001 ◽  
Author(s):  
Guillermo Aguilar ◽  
Sergio H. Diaz Valdes ◽  
J. Stuart Nelson ◽  
Enrique J. Lavernia

Abstract Port wine stain (PWS) birthmarks are a congenital and progressive vascular malformation of the dermis, involving capillaries, which occurs in approximately 0.7% of children. The objective of laser surgery for this and similar conditions is to cause selective thermal damage, thrombosis, and, eventually, permanent photocoagulation in the PWS vessels. To achieve this, the radiated laser light is set at a specific wavelength, which is highly absorbed by the blood vessels’ hemoglobin (the major chromophore in blood). Unfortunately, the PWS vessels do not absorb all energy radiated — a significant amount is also absorbed by hemoglobin in the ectatic capillaries of the upper dermis. This unwanted absorption causes two problems: firstly, insufficient heat generation within the targeted vessels leads to poor clinical results, and, secondly, there is an increased risk of damage to the overlying epidermis. In current PWS laser therapy, cryogen spray cooling (CSC) is used effectively to cool and protect selectively the epidermis (tens of micrometers thick) prior to the laser pulse, while minimally cooling the blood vessels. The thermal response of the system is characterized by time and/or temperature dependent boundary conditions. However, in many recent studies, the boundary conditions induced by CSC are regarded as constant. In the present work we study the effects of time-dependent boundary conditions on the overall epidermal thermal damage after PWS laser therapy. We use computer models to simulate the laser light distribution, heat diffusion, and tissue damage, and introduce experimentally determined time-dependent boundary conditions measured for custom-made and commercial atomizing nozzles. We show that time-dependent boundary conditions have a significant effect in the optimal laser dose required to induce photocoagulation of PWS blood vessels while preserving the epidermis.


Author(s):  
Gerald W. Lucassen ◽  
Wim Verkruysse ◽  
Marleen Keijzer ◽  
Martin J.C. van Gemert

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