Multifunctional patch for use during laser procedures: Optimization and feasibility testing.

OBJECTIVE: The objective of this study was to develop a patch that can be placed on the skin during laser hair removal and similar procedures, that serves to reduce the laser-induced plume, provides a ready indicator to the laser surgeon of where pulses have been applied, and cools the skin. METHODS: A two-layer patch composed of a cooling hydrogel layer and an indicator layer was optimized and tested ex vivo. The hydrogel was composed of gelatin and glycerin. The concentration of each hydrogel component was optimized to determine the minimum gelatin concentration at which the gel can be handled without breakage and the minimum glycerin concentration that allows for storage at -20°C without crystallization. This is the temperature of a conventional freezer; application of the cooling layer to the skin would help prevent epidermal injury. The indicator layer was composed of a plastic transparency sheet with small dots of black ink particles printed onto its surface. Transparency sheets were printed from templates created in Adobe Photoshop in which dots are at a specified density; additionally, Photoshop's opacity function was used to vary the opacity of the dots themselves. Performance was tested using a 755 nm alexandrite laser used clinically for hair removal by measuring light transmission through the patch and observing the sheet's ability to indicate the location of laser exposures. The transmittance of patch components across a broad spectrum was also measured using a microplate reader. Several adhesives, including a two-part epoxy, silicone rubber, and cyanoacrylate, were tested for their ability to adhere to the hydrogel and indicator layers. Assembled patches composed of the hydrogel layer, indicator layer, and adhesive were tested ex vivo for their ability to mitigate the laser hair removal plume by measuring airborne particulate matter during simulated laser hair removal. RESULTS: A minimum gelatin concentration of 5% was found to enable easy handling of the hydrogel. A mixture composed of 60% water and 40% glycerin by volume consistently allowed storage at -20°C without crystallization. For the indicator layer, ink particle density of 50% and opacity of 5% provided a readily apparent indicator function following laser exposure. Transmission through the sheet measured during alexandrite laser exposures was 90% and was not different than transmission through the sheet alone without ink particles. A cyanoacrylate glue was found to adhere to the hydrogel and indicator layers, while the other adhesives proved inadequate. Measurements using a microplate reader confirmed that the reflection from the transparency sheet itself was the primary contributor to energy loss. In experiments exposing hair clippings to the laser with and without the patch, the patch allowed an increase of 5000 particles/cc relative to baseline particles in the environmental air, while the absence of the patch allowed an increase of 150,000 particles/cc relative to baseline, indicating that the patch decreased particle debris in the plume by 97%. CONCLUSIONS: A two-layer patch composed of hydrogel and plastic indicator layer with cyanoacrylate adhesive can be stored in a conventional freezer without crystallization, then placed over an area of skin to be treated for laser hair removal. The patch clearly indicates the pattern and sites of laser exposure, while blocking almost all (97%) of particles in the laser-induced plume. Future work will include safety validation and in vivo testing of efficacy, as these were not undertaken in this study.

Gaseous and Particulate Content of Laser Tattoo Removal Plume.

BACKGROUND: There is increasing awareness of the potential hazards of surgical plumes. The plume associated with laser tattoo removal remains uncharacterized. OBJECTIVE: To determine the gaseous, particulate, and microbiological content of the laser tattoo removal plume. MATERIALS AND METHODS: Air sampling was performed during laser tattoo removal from pig skin and from patients. Measurement of metals, volatile organic compounds (VOCs), carbon monoxide (CO), hydrogen sulfide (HS), and ultrafine particulates (UPs) as well as bacterial 16S ribosomal DNA sequencing were performed. RESULTS: Metals were identified in the plume from both pig and human skin. Volatile organic compounds were found at similar levels within and outside the treatment room. Several bacterial phyla were detected in the treatment room, but not outside. High levels of UPs were measured throughout the treatment room during tattoo removal from pig skin. Ultrafine particulates were detected at low levels in the room periphery during tattoo removal from human skin, but at higher levels in the immediate treatment zone. HS and CO were not detected. CONCLUSION: Metals, VOCs, HS, and CO were found at levels below applicable occupational exposure limits. The presence of bacteria is of uncertain significance, but may be hazardous. High levels of UPs require further investigation.

Quantification of liver iron with MRI: state of the art and remaining challenges.

Liver iron overload is the histological hallmark of hereditary hemochromatosis and transfusional hemosiderosis, and can also occur in chronic hepatopathies. Iron overload can result in liver damage, with the eventual development of cirrhosis, liver failure, and hepatocellular carcinoma. Assessment of liver iron levels is necessary for detection and quantitative staging of iron overload and monitoring of iron-reducing treatments. This article discusses the need for noninvasive assessment of liver iron and reviews qualitative and quantitative methods with a particular emphasis on magnetic resonance imaging (MRI). Specific MRI methods for liver iron quantification include signal intensity ratio as well as R2 and R2* relaxometry techniques. Methods that are in clinical use, as well as their limitations, are described. Remaining challenges, unsolved problems, and emerging techniques to provide improved characterization of liver iron deposition are discussed.

Effect of echo-sampling strategy on the accuracy of out-of-phase and in-phase multiecho gradient-echo MRI hepatic fat fraction estimation.

PURPOSE: To assess the effect of echo-sampling strategy on the accuracy of out-of-phase (OP) and in-phase (IP) multiecho gradient-echo magnetic resonance imaging (MRI) hepatic fat fraction (FF) estimation, using MR spectroscopy (MRS) proton density FF (PDFF) as a reference standard. MATERIALS AND METHODS: In this Institutional Review Board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant prospective study, 84 subjects underwent proton MRS and non-T1 -weighted gradient-echo imaging of the liver at 3T. Imaging data were collected at 16 nominally OP and IP echo times (TEs). MRI-FF was estimated while varying two echo-sampling parameters (number of consecutive echoes, starting echo number). For each combination of these parameters, MRI-FF estimation accuracy was assessed with slope, intercept, average bias, and R2 from a linear regression of MRS-PDFF on MRI-FF. The relationship between accuracy metrics and echo-sampling parameters was assessed by Spearman rank correlation. RESULTS: For FF calculations using 3-16 echoes and a starting echo number of 1, the intercept ranged from 0.0046 to 0.0124, slope from 0.941 to 0.96, average bias from 0.0034 to 0.0078, and R2 from 0.968 to 0.976. All four accuracy metrics were the best with the 3- and 4-echo calculations and worsened progressively with an increasing number of echoes. For a given number of echoes, there was an overall trend toward decreasing accuracy as starting echo number increased. Spearman correlation coefficients between starting echo number and intercept, slope, average bias, and R2 were 0.911, -0.64, -0.889, and -0.954, respectively, indicating progressive loss of accuracy in each case. CONCLUSION: Multiecho OP and IP imaging provided high FF estimation accuracy. Accuracy was highest using the earliest 3 or 4 echoes. Incorporation of additional echoes or delaying the starting echo number progressively reduced accuracy.

Updates in the Management of Congenital Melanocytic Nevi.

Congenital melanocytic nevi (CMN) carry an increased risk of melanoma and may be disfiguring, and consensus regarding treatment recommendations is lacking. While clinical monitoring is the standard of care, many caregivers are interested in its removal to prevent psychosocial burden or to decrease risk. Although melanoma can occur regardless of CMN removal, there are a variety of treatments that may offer improved cosmesis or local symptom control, including surgical excision, laser therapy, and other superficially destructive techniques. Regardless of the selected management, these patients are monitored for ongoing melanoma risk. An extensive discussion with families regarding the risks and benefits of observation versus active intervention is essential. To facilitate these discussions, we herein summarize current CMN management strategies and considerations.

Innovating on innovation training with the Virtual Magic Wand (VMW) program: a qualitative study.

To identify and solve unmet needs and bring new therapies to patients, clinicians at all levels must engage in innovation. The Magic Wand Initiative, a program based at Massachusetts General Hospital-Wellman Center for Photomedicine, created a 10-months course called the Virtual Magic Wand (VMW) program that is a curriculum that teaches the biomedical innovation pathway to dermatologists and engages them in this creative process. This study aims to identify the impact of the VMW program on participants and consider the potential benefits of an innovation curriculum. The authors conducted semi-structured interviews in which alumni of the VMW program were asked about their experiences with innovation before, during, and after the program. Using grounded theory methodology, data were analyzed using deductive coding methods. The most cited benefit of the program was the opportunity to network (n = 12, 100%)-specifically, the mentorship opportunities (n = 10, 83%) and specialty-specific peer groups (n = 9, 75%). Other benefits included a change in mindset regarding their clinical work (n = 11, 92%) and learning the process of innovation (83%). Among barriers, lack of time (n = 7, 58%), knowledge (n = 6, 50%), and resources (n = 5, 42%), were the most mentioned. All alumni interviewed have stayed engaged in the field of biomedical innovation after their completion of the VMW program. These findings show that the VMW program positively impacted the lives and careers of participants. This study identified some of the systemic reasons that deter physicians from regularly engaging in innovation and provides guidance for how to design other innovation programs and further support the advancement of medicine.

Cosmetic dermatology in menopause.

ABSTRACT: Skin changes that accompany aging lead many to seek treatments that restore a more youthful appearance. Common issues of concern include skin tone, wrinkles, skin thinning, sagging, laxity and decreased elasticity, and hollowing of the face. This work discusses these concerns and their anatomic bases and highlights evidence for a causal role played by menopause-associated hormonal changes where such evidence exists. In addition, treatment options are discussed, with an emphasis on minimally invasive approaches. A variety of modalities are discussed, including botulinum toxins, fillers, multiple types of lasers, radiofrequency devices, focused ultrasound, chemical peels, and thread lifts. These interventions, often in combination, can achieve goals of patients seeking aesthetic rejuvenation.

Methods for metabolic evaluation of prostate cancer cells using proton and (13)C HR-MAS spectroscopy and [3-(13)C] pyruvate as a metabolic substrate.

Prostate cancer has been shown to undergo unique metabolic changes associated with neoplastic transformation, with associated changes in citrate, alanine, and lactate concentrations. (13)C high resolution-magic angle spinning (HR-MAS) spectroscopy provides an opportunity to simultaneously investigate the metabolic pathways implicated in these changes by using (13)C-labeled substrates as metabolic probes. In this work, a method to reproducibly interrogate metabolism in prostate cancer cells in primary culture was developed using HR-MAS spectroscopy. Optimization of cell culture protocols, labeling parameters, harvesting, storage, and transfer was performed. Using [3-(13)C] pyruvate as a metabolic probe, (1)H and (13)C HR-MAS spectroscopy was used to quantify the net amount and fractional enrichment of several labeled metabolites that evolved in multiple cell samples from each of five different prostate cancers. Average enrichment across all cancers was 32.4 +/- 5.4% for [3-(13)C] alanine, 24.5 +/- 5.4% for [4-(13)C] glutamate, 9.1 +/- 2.5% for [3-(13)C] glutamate, 25.2 +/- 5.7% for [3-(13)C] aspartate, and 4.2 +/- 1.0% for [3-(13)C] lactate. Cell samples from the same parent population demonstrated reproducible fractional enrichments of alanine, glutamate, and aspartate to within 12%, 10%, and 10%, respectively. Furthermore, the cells produced a significant amount of [4-(13)C] glutamate, which supports the bioenergetic theory for prostate cancer. These methods will allow further characterization of metabolic properties of prostate cancer cells in the future. Magn Reson Med, 2009. (c) 2009 Wiley-Liss, Inc.

The Stanford University experience with conventional-dose, total skin electron-beam therapy in the treatment of generalized patch or plaque (T2) and tumor (T3) mycosis fungoides.

OBJECTIVE: To review the Stanford University experience with total skin electron-beam therapy (TSEBT) of 30 Gy or greater as monotherapy in patients with mycosis fungoides (MF) and compare with subgroups receiving adjuvant nitrogen mustard (HN2), and further update our experience with repeated courses of TSEBT. DESIGN: Retrospective study. SETTING: Academic referral center, multidisciplinary clinic. PATIENTS: A total of 180 patients with MF treated from 1970 through 2007 with T2 MF (103 with generalized patch or plaque disease) or T3 MF (77 with tumor disease). Patients with extracutaneous disease were excluded. INTERVENTIONS: Total skin electron-beam therapy with or without adjuvant topical HN2. MAIN OUTCOME MEASURE: Clinical response rate, freedom from relapse (FFR), overall survival (OS), and progression-free survival (PFS) after TSEBT. RESULTS: The overall response rate (ORR) was 100%; 60% of patients achieved a complete clinical response (patients with T2 MF = 75%, those with T3 MF = 47%). The 5- and 10-year OS rates of the entire cohort were 59% and 40%, respectively. There were no significant differences in FFR (P = .30 for T2 disease; P = .50 for T3 disease), PFS (P = .10 for T2 disease; P = .40 for T3 disease), or OS (P = .30 for T2 disease; P = .50 for T3 disease) between adjuvant HN2 and TSEBT monotherapy cohorts. The ORR was 100% in patients receiving a second course of TSEBT with median FFR of 6 months. CONCLUSIONS: A TSEBT of 30 Gy or greater is highly effective in treating T2-T3 MF, with better outcomes in T2 disease. There was no clinical advantage to adjuvant HN2 as used in our cohort. Second courses of TSEBT are safe and efficacious and provide clinically meaningful palliation for select patients.

In vivo application of sub-second spiral chemical shift imaging (CSI) to hyperpolarized 13C metabolic imaging: comparison with phase-encoded CSI.

A fast spiral chemical shift imaging (CSI) has been developed to address the challenge of the limited acquisition window in hyperpolarized (13)C metabolic imaging. The sequence exploits the sparsity of the spectra and prior knowledge of resonance frequencies to reduce the measurement time by undersampling the data in the spectral domain. As a consequence, multiple reconstructions are necessary for any given data set as only frequency components within a selected bandwidth are reconstructed "in-focus" while components outside that band are severely blurred ("spectral tomosynthesis"). A variable-flip-angle scheme was used for optimal use of the longitudinal magnetization. The sequence was applied to sub-second metabolic imaging of the rat in vivo after injection of hyperpolarized [1-(13)C]-pyruvate on a clinical 3T MR scanner. The comparison with conventional CSI based on phase encoding showed similar signal-to-noise ratio (SNR) and spatial resolution in metabolic maps for the substrate and its metabolic products lactate, alanine, and bicarbonate, despite a 50-fold reduction in scan time for the spiral CSI acquisition. The presented results demonstrate that dramatic reductions in scan time are feasible in hyperpolarized (13)C metabolic imaging without a penalty in SNR or spatial resolution.

Teledermatology: a review of reliability and accuracy of diagnosis and management.

In this article, the authors summarize the published literature on the reliability and accuracy of teledermatology. The first section reports on the diagnostic reliability of teledermatology compared with face-to-face clinic consultation. In the second section, the authors report on the "intragroup" diagnostic agreement between either clinic dermatologists or teledermatologists. The third section discusses the diagnostic accuracy for those studies that include definitive histopathologic diagnosis. The last section summarizes the literature comparing clinical management decisions by clinic dermatologists to those made by teledermatologists.

Fast metabolic imaging of systems with sparse spectra: application for hyperpolarized 13C imaging.

A fast spiral chemical shift imaging (spCSI) sequence was developed for application to hyperpolarized (13)C imaging. The sequence exploits sparse spectra, which can occur in such applications, and prior knowledge of resonance frequencies to reduce the measurement time by undersampling the data in the spectral domain. As a consequence, multiple reconstructions of a given data set have to be computed in which only components with frequencies within a certain bandwidth are reconstructed "in focus" while others are severely blurred ("spectral tomosynthesis"). The sequence was tested at 3 T on a phantom containing approximately 1.5-M solutions of alanine (Ala), lactate (Lac), and pyruvate-pyruvate hydrate C1-C2 ester (with two resonances, PPE1 and PPE2) at thermal equilibrium polarization, all enriched to 99% (13)C in the C1 carbonyl positions. Results from spCSI with a single spatial interleaf (single-shot spCSI) and three interleaves (three-shot spCSI) were compared with those obtained by phase-encoded free induction decay CSI (FIDCSI). The metabolic maps of all four resonances for three-shot spCSI, and of PPE1 and PPE2 for single-shot spCSI demonstrate resolution and localization properties similar to those of the FIDCSI images. The metabolic maps of Ala and Lac for single-shot spCSI contain minor artifacts due to signal overlap of aliased resonances.

Estimation of renal extraction fraction based on postcontrast venous and arterial differential T1 values: an error analysis.

An error analysis for quantifying single kidney extraction fraction (EF) via differential T1 measurements in the renal vein (RV) and renal artery (RA) is presented. Sources of error include blood flow effects, the effect of a short repetition time (TR), and the impact of uncertainties in the T1 estimates on the final EF calculations. Blood flow effects were investigated via simulation. For a range of blood velocities in the renal vein that may be found in kidney disease, incomplete refreshment of blood between readouts results in significant errors in T1 estimation. For a .5-cm slice, 110-ms sampling interval, and T1 of 600 ms, T1 estimation to within 5% of true T1 requires an average through-plane velocity of 6.75 cm/s for parabolic flow, and 3.5 cm/s for plug flow. Improvement can be achieved by accurately estimating the fraction of blood that has not refreshed between readouts (f(old)), while the quality of the T1 estimate varies with the accuracy of f(old) estimation. Shortening of the TR was investigated using phantom and in vivo studies. T1 was estimated to within 3% of the true value on phantoms, and within 5% of the true value for flowing blood for TR = 2T1. The estimated EF is shown to be very sensitive to the difference between T(1RA) and T(1RV). To achieve 10% or 20% uncertainty in the EF estimate, T1 in the renal vein and renal artery must be estimated to within approximately 1% or 2%. Because of limitations on measurement accuracy and precision, this method appears to be impractical at this time.