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Labuda C, Lawler BC, Hoffmeister BK, Harbert SC, Viano AM, Myat PSM. Ultrasonic Characterization of Human Scalp. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:2489-2496. [PMID: 37716831 DOI: 10.1016/j.ultrasmedbio.2023.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 09/18/2023]
Abstract
OBJECTIVE The ultrasonic properties of scalp may be relevant to a variety of applications including transcranial ultrasound. However, there is no information about the ultrasonic properties of scalp available in the literature. While ultrasonic studies of skin from other anatomic regions have been previously reported, scalp tissue is generally thicker with a higher density of hair follicles, blood vessels and sebaceous glands. Thus, it is unknown if the ultrasonic properties of scalp are similar to skin from other regions. The goal of this study was to measure the ultrasonic properties of human scalp. METHODS Pulse-echo measurements were performed with a 7.5 MHz ultrasound transducer to determine the speed of sound (SOS), frequency slope of attenuation (FSA) and integrated backscatter coefficient (IBC) of 32 specimens of formalin-fixed human scalp from four donors. RESULTS The means ± standard deviations for these three ultrasonic quantities measured in the frequency range 2.83-7.74 MHz over all specimens were SOS = 1525 ± 16.92 m/s, FSA = 2.59 ± 0.724 dB/cm/MHz and IBC = 0.122 ± 0.0746 cm-1 Sr-1. CONCLUSION These values are comparable to reported values for human skin from other parts of the body, but some differences in SOS and IBC exist.
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Affiliation(s)
- Cecille Labuda
- Department of Physics and Astronomy/National Center for Physical Acoustics, University of Mississippi, University, MS, USA.
| | | | | | | | - Ann M Viano
- Department of Physics, Rhodes College, Memphis, TN, USA
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Mofid Y, Faleweei G, Chartier C, Machet L, Vierron E, Gissot V, Tauveront V, Georgescou G, Dujardin PA, Machet MC, Kervarrec T, Patat F, Ossant F, Maruani A. High-Frequency Transient Elastography Prototype to Assess Skin (Dermis) Fibrosis: A Diagnostic Study in Patients with Venous Insufficiency and Controls. ULTRASCHALL IN DER MEDIZIN (STUTTGART, GERMANY : 1980) 2021; 42:503-513. [PMID: 32187631 DOI: 10.1055/a-1047-3146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
PURPOSE High-frequency transient elastography (HF-TE) is a noninvasive technique for assessing shear-wave speed and finally elasticity in thin tissue such as the skin. It has never been validated for monitoring fibrotic skin diseases. The purpose was to evaluate the potential of HF-TE to assess skin fibrosis in patients with chronic venous disorders (CVD). MATERIALS AND METHODS This clinical study enrolled 48 patients at various stages of CVD and 48 paired healthy volunteers. Subjects underwent a clinical examination with an evaluation of Rodnan's fibrosis skin score. We studied the dermis thickness measured using ultrasound (US) and elasticity measurements using cutometer and HF-TE studied according to 3 cutaneous zones positioned on the leg. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the diagnosis performance for a combined parameter (PRL) based on a logistic regression model using both elasticity and dermal thickness. RESULTS Patients with CVD had significantly higher values of skin elasticity than healthy subjects, 134.5 kPa and 132.1 kPa vs. 91.3 kPa, respectively. The dermis thickness also increased with escalation in CVD stage for all studied zones. The PRL parameter had an AUC value of 0.79 for all zones and stages of CVD clustered. The discriminating power of PRL increased with escalation of the CVD stage; with an AUC value of up to 0.89 for evolved stages, and a sensitivity and specificity of 0.79 and 0.89, respectively. CONCLUSION HF-TE, coupled with a US measurement of dermis thickness, made it possible to propose a new biomarker, which proved to be a good diagnostic tool for skin fibrosis.
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Affiliation(s)
- Yassine Mofid
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | | | | | - Laurent Machet
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
- Department of Dermatology, CHRU Tours, France
| | | | | | | | | | | | | | | | - Frédéric Patat
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
- CHRU Tours, CIC 1415, Tours, France
| | - Frederic Ossant
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
- CHRU Tours, CIC 1415, Tours, France
| | - Annabel Maruani
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
- Department of Dermatology, CHRU Tours, France
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Hu Y, Yang M, Huang H, Shen Y, Liu H, Chen X. Controlled Ultrasound Erosion for Transdermal Delivery and Hepatitis B Immunization. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1208-1220. [PMID: 30803825 DOI: 10.1016/j.ultrasmedbio.2019.01.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 01/05/2019] [Accepted: 01/15/2019] [Indexed: 06/09/2023]
Abstract
Although ultrasound is effective for transdermal delivery, it remains difficult to control the position, shape and size of localized skin transport regions. We developed an ultrasound erosion protocol to generate a single-site, circular delivery region with controlled size at the center of patched skin. We found that (i) shorter ultrasound pulses (25 cycles) with higher pulse repetition frequency (4 kHz) and higher peak negative pressure (17.0 MPa) resulted in larger (0.995 mm2) and deeper (∼300 µm) skin delivery regions with a higher success rate (94.44%); and (ii) temperature elevation of the skin increased with ultrasound exposure time, with a 30-s safety threshold. Furthermore, we found that hair follicles decreased the delivery controllability of ultrasound erosion. Therefore, we selected the skin of the hind legs of mice without dense hair follicles to deliver more than 1 μL of vaccine solution and successfully elicit immune responses against hepatitis B surface antigen.
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Affiliation(s)
- Yaxin Hu
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China; National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Shenzhen, China
| | - Mei Yang
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China; National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Shenzhen, China
| | - Haoqiang Huang
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China; National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Shenzhen, China
| | - Yuanyuan Shen
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China; National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Shenzhen, China
| | - Haitao Liu
- Vaccine Research Department, Shenzhen Kangtai Biological Products Company Ltd., Shenzhen, China
| | - Xin Chen
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China; National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Shenzhen, China.
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Chartier C, Mofid Y, Bastard C, Miette V, Maruani A, Machet L, Ossant F. High-Resolution Elastography for Thin-Layer Mechanical Characterization: Toward Skin Investigation. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:670-681. [PMID: 28043724 DOI: 10.1016/j.ultrasmedbio.2016.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/03/2016] [Accepted: 11/10/2016] [Indexed: 06/06/2023]
Abstract
Interest in elasticity estimation for thin layers is increasing because of the various potential applications, including dermatology and cosmetology. In this context, we propose a dedicated elastographic system using 1-D high-frequency transient elastography (HF-TE) to estimate the 1-D Young's modulus through the dermis and hypodermis, which are the two human skin layers of interest in this study. An experimental validation of the HF-TE method was first carried out on two homogeneous tissue-mimicking hard and soft phantoms. The Young's modulus values obtained in these phantoms were compared with those obtained by two complementary shear wave propagation techniques: shear wave-induced resonance elastography (SWIRE) and supersonic shear imaging (SSI). A third two-layer thin phantom, with mechanical properties similar to those of skin, was used to validate the ability of HF-TE to distinguish layers and measure elasticity. Finally, preliminary in vivo experiments conducted on forearm and cheek skin revealed the promising performance of HF-TE in measuring elasticity in the dermis and hypodermis.
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Affiliation(s)
- Caroline Chartier
- Université François-Rabelais de Tours, Inserm, Imagerie et Cerveau UMR U930, Tours, France
| | - Yassine Mofid
- Université François-Rabelais de Tours, Inserm, Imagerie et Cerveau UMR U930, Tours, France.
| | | | | | | | | | - Frédéric Ossant
- Université François-Rabelais de Tours, Inserm, Imagerie et Cerveau UMR U930, Tours, France; CHRU de Tours, Tours, France; INSERM CIC 1415, Tours, France
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Dalecki D, Mercado KP, Hocking DC. Quantitative Ultrasound for Nondestructive Characterization of Engineered Tissues and Biomaterials. Ann Biomed Eng 2015; 44:636-48. [PMID: 26581347 DOI: 10.1007/s10439-015-1515-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/13/2015] [Indexed: 12/15/2022]
Abstract
Non-invasive, non-destructive technologies for imaging and quantitatively monitoring the development of artificial tissues are critical for the advancement of tissue engineering. Current standard techniques for evaluating engineered tissues, including histology, biochemical assays and mechanical testing, are destructive approaches. Ultrasound is emerging as a valuable tool for imaging and quantitatively monitoring the properties of engineered tissues and biomaterials longitudinally during fabrication and post-implantation. Ultrasound techniques are rapid, non-invasive, non-destructive and can be easily integrated into sterile environments necessary for tissue engineering. Furthermore, high-frequency quantitative ultrasound techniques can enable volumetric characterization of the structural, biological, and mechanical properties of engineered tissues during fabrication and post-implantation. This review provides an overview of ultrasound imaging, quantitative ultrasound techniques, and elastography, with representative examples of applications of these ultrasound-based techniques to the field of tissue engineering.
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Affiliation(s)
- Diane Dalecki
- Department of Biomedical Engineering, University of Rochester, 310 Goergen Hall, P.O. Box 270168, Rochester, NY, 14627, USA.
| | - Karla P Mercado
- Department of Internal Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267, USA
| | - Denise C Hocking
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Box 711, Rochester, NY, 14642, USA
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Piotrzkowska-Wroblewska H, Litniewski J, Szymanska E, Nowicki A. Quantitative sonography of basal cell carcinoma. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:748-759. [PMID: 25638309 DOI: 10.1016/j.ultrasmedbio.2014.11.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 10/29/2014] [Accepted: 11/23/2014] [Indexed: 06/04/2023]
Abstract
A 30-MHz ultrasonic scanner was used to collect B-scan images together with appropriate radiofrequency echoes from diseased and healthy skin regions of patients with diagnosed basal cell carcinoma and pre-cancerous lesions (actinic keratosis). Radiofrequency data were processed to obtain the attenuation coefficient and statistics of the backscattered echo signal determination (K-distribution and effective density of scatterers [EDS]). The attenuation coefficient was significantly higher for patients with basal cell carcinoma than for healthy patients. Also, the pre-cancerous skin lesions had increased attenuation. The averaged EDS values for cancer lesions were significantly lower than those for pre-cancerous lesions and healthy skin. The successful differentiation between the tissue groups examined suggests the potential value of the attenuation coefficient and EDS for carcinoma characterization.
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Affiliation(s)
| | - Jerzy Litniewski
- Department of Ultrasound, Institute of Fundamental Technological Research, Warsaw, Poland
| | | | - Andrzej Nowicki
- Department of Ultrasound, Institute of Fundamental Technological Research, Warsaw, Poland
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Melchor J, Rus G. Torsional ultrasonic transducer computational design optimization. ULTRASONICS 2014; 54:1950-1962. [PMID: 24882020 DOI: 10.1016/j.ultras.2014.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 04/29/2014] [Accepted: 05/01/2014] [Indexed: 06/03/2023]
Abstract
A torsional piezoelectric ultrasonic sensor design is proposed in this paper and computationally tested and optimized to measure shear stiffness properties of soft tissue. These are correlated with a number of pathologies like tumors, hepatic lesions and others. The reason is that, whereas compressibility is predominantly governed by the fluid phase of the tissue, the shear stiffness is dependent on the stroma micro-architecture, which is directly affected by those pathologies. However, diagnostic tools to quantify them are currently not well developed. The first contribution is a new typology of design adapted to quasifluids. A second contribution is the procedure for design optimization, for which an analytical estimate of the Robust Probability Of Detection, called RPOD, is presented for use as optimality criteria. The RPOD is formulated probabilistically to maximize the probability of detecting the least possible pathology while minimizing the effect of noise. The resulting optimal transducer has a resonance frequency of 28 kHz.
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Affiliation(s)
- J Melchor
- Dpt. of Structural Mechanics, University of Granada, Politécnico de Fuentenueva, 18071 Granada, Spain.
| | - G Rus
- Dpt. of Structural Mechanics, University of Granada, Politécnico de Fuentenueva, 18071 Granada, Spain.
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Petrella LI, de Azevedo Valle H, Issa PR, Martins CJ, Machado JC, Pereira WCA. Statistical analysis of high frequency ultrasonic backscattered signals from basal cell carcinomas. ULTRASOUND IN MEDICINE & BIOLOGY 2012; 38:1811-1819. [PMID: 22920547 DOI: 10.1016/j.ultrasmedbio.2012.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 04/21/2012] [Accepted: 06/04/2012] [Indexed: 06/01/2023]
Abstract
A statistical approach was implemented in the study of histologic characteristics from ex vivo basal cell carcinomas, based on the properties of backscattered acoustic waves, for the purpose of evaluating the method as a diagnostic tool. The study was developed using an ultrasound biomicroscope working at a frequency of 45 MHz. The parameters examined were signal-to-noise ratio (SNR), and shape parameters from the Weibull (b(W)) and generalized gamma (c(GG) and υ(GG)) probability density functions. Twenty-seven carcinomatous skin samples were obtained from volunteer patients and classified into two groups (BCC1 and BCC2) based on the distribution patterns of their tumor nests; also, seven non-tumoral samples were used for comparative purposes. Significant differences between groups were obtained for all studied parameters. The successful differentiation between some tissue groups suggests its potential use for carcinoma characterization.
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Affiliation(s)
- Lorena Itatí Petrella
- Laboratory of Ultrasound, National Institute of Metrology, Quality and Technology, Duque de Caxias, RJ, Brazil.
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Turlier V, Rouquier A, Black D, Josse G, Auvergnat A, Briant A, Dahan S, Gassia V, Saint-Martory C, Zakaria W, Queille-Roussel C, Grognard-Gourdon C, Thioly-Bensoussan D, Degouy A, Schmitt AM. Assessment of the clinical efficacy of a hyaluronic acid-based deep wrinkle filler using new instrumental methods. J COSMET LASER THER 2010; 12:195-202. [PMID: 20653347 DOI: 10.3109/14764172.2010.502461] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The efficacy of numerous hyaluronic acid (HA)-based fillers has been demonstrated by semi-quantitative and qualitative methods, useful in clinical practice, but poorly reliable. OBJECTIVE To objectively evaluate the efficacy of a HA gel in treating nasolabial folds (NLFs) over a 9-12-month follow-up period. METHODS A total of 47 adult patients with moderate to severe NLFs received one or two injections of HA gel. Efficacy was assessed by measuring NLF depth at time intervals up to 12 months subjectively by blind and open clinical scoring using the Lemperle scale, and objectively using skin replicas and in vivo 3D imaging methods. Tissue characterization and dermal thickness were also assessed using radiofrequency ultrasonography and high-resolution ultrasound imaging, respectively. RESULTS The filler injection highly significantly decreased the depth of NLFs (p < 0.0001) at all time points, with an improvement of at least 1 grade in the Lemperle score in 77% and 89% of the subjects at 9 and 12 months, respectively. NLF volume measured on replicas and 3D images significantly decreased after injection and this improvement was maintained over 12 months. CONCLUSION This HA gel is well tolerated and provides a significant and long-lasting correction of moderate to severe NLFs, as objectively demonstrated by instrumental methods.
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Affiliation(s)
- Virginie Turlier
- Centre de Recherche sur la Peau Pierre Fabre, Hôtel Dieu, Toulouse, France.
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Josse G, Rouvrais C, Mas A, Haftek M, Delalleau A, Ferraq Y, Ossant F, George J, Lagarde JM, Schmitt AM. A multitechnique evaluation of topical corticosteroid treatment. Skin Res Technol 2009; 15:35-9. [DOI: 10.1111/j.1600-0846.2008.00326.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Vogt M, Ermert H. In vivo ultrasound biomicroscopy of skin: spectral system characteristics and inverse filtering optimization. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2007; 54:1551-9. [PMID: 17703658 DOI: 10.1109/tuffc.2007.425] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
High-frequency ultrasound (HFUS) in the 20 MHz to 100 MHz range has to meet the opposite requirements of good spatial resolution and of high penetration depth for in vivo ultrasound biomicroscopy (UBM) of skin. The attenuation of water, which serves as sound propagation medium between utilized single element transducers and the skin, becomes very eminent with increasing frequency. Furthermore, the spectra of acquired radio frequency (rf) echo signals change over depth because of the diffracted sound field characteristics. The reduction of the system's center frequency and bandwidth causes a significant loss of spatial resolution over depth. In this paper, the spectral characteristics of HFUS imaging systems and the potential of inverse echo signal filtering for the optimization of pulse-echo measurements is analyzed and validated. A Gaussian model of the system's transfer function, which takes into account the frequency-dependent attenuation of the water path, was developed. Predictions of system performance are derived from this model and compared with measurement results. The design of a HFUS skin imaging system with a 100 MHz range transducer and a broadband driving electronics is discussed. A time-variant filter for inverse rf echo signal filtering was designed to compensate the system's depth-dependent imaging properties. Results of in vivo measurements are shown and discussed.
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Affiliation(s)
- Michael Vogt
- Institute of High Frequency Engineering, Department of Electrical Engineering and Information Technology, Ruhr-University, 44780 Bochum, Germany.
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Mofid Y, Ossant F, Imberdis C, Josse G, Patat F. In-vivo imaging of skin under stress: potential of high-frequency (20 MHz) static 2-D elastography. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2006; 53:925-35. [PMID: 16764447 DOI: 10.1109/tuffc.2006.1632683] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The aim of this study was to evaluate the potential of high-frequency static two-dimensional (2-D) elastography for in vivo exploration of the mechanical behavior of skin. Our device was based on the combination of a 20 MHz sonographer and a patented extensiometer device able to apply calibrated uniaxial stretching of the skin. We used a new algorithm to compute elastograms that improve elastographic signal-to-noise ratio (SNRe) without sacrificing resolution. Mechanical behavior was described according to the axial strain and lateral displacements induced in the tissue. The efficacy of the strain anpolyvinyl alcohol first evaluated in polyvinyl alcohol (PVA)-cryogel phantoms. Several in vivo experiments then were conducted, mainly with the multistretching averaging method, and demonstrated the potential of this technique in the evaluation of mechanical behavior of the dermis and the hypodermis under stress.
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Affiliation(s)
- Yassine Mofid
- Laboratoire UltraSons, Signaux et Instrumentation, Formation de Recherche en Evolution 2448, Centre National de la Recherche Scientifique, Tours, France
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Bridal SL, Fournier C, Coron A, Leguerney I, Laugier P. Ultrasonic backscatter and attenuation (11-27 MHz) variation with collagen fiber distribution in ex vivo human dermis. ULTRASONIC IMAGING 2006; 28:23-40. [PMID: 16924880 DOI: 10.1177/016173460602800103] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This ex vivo study explores the relationship of ultrasonic attenuation and backscatter to dermal microarchitecture by comparing ultrasonic measurements of these parameters (11-27 MHz) to a microscopic analysis of three parameters describing the collagen distribution (mean thickness and spacing of collagen bundles along the insonification direction and the percent area occupied by collagen). Skin samples (N= 31) were obtained from patients undergoing breast or abdominal reduction surgery. Radio-frequency (rf) signals were acquired in a B-scan format using an ultrasound system developed for skin imaging (Ultrasons Technologies, Tours, France). Ultrasonic data were analyzed to calculate average integrated backscatter (IBS in dB) and frequency dependence of backscatter (n, dimensionless) of each specimen at depths centered approximately 370,620 and 880 microm beneath the skin surface. Average integrated attenuation coefficient (IA in dB.cm(-1)) and frequency dependence of attenuation coefficient (beta in dB.cm(-1).MHz(-1)) were estimated across the depth between 240 and 1,000 microm. The three collagen distribution parameters were estimated using digitized microcopic fields from matched regions of histological sections stained with hematoxylin-eosin-saffron. No significant correlation was identified between collagen distribution parameters and IA or beta. For the most superficial depth studied in abdominal skin, n was inversely correlated to collagen bundle thickness (r = -0.67,p = 0.002) and percent area (r = -0.65,p = 0.003). At the same depth, IBS was inversely correlated to percent area of collagen (r = -0.51,p = 0.03). The rather high collagen packing (48 to 82% area) measured in histological sections and the inverse relationship observed between IBS and percent area of collagen suggest that a packing factor should be included in models relating skin collagen distribution to ultrasound spectral parameters. A better understanding of the relationship between ultrasound parameters and the microarchitecture of the dermis should help to interpret changes in ultrasonic parameters observed during in vivo ultrasonic skin examinations.
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Affiliation(s)
- S Lori Bridal
- CNRS, UMR7623, Laboratoire d'Imagerie Paramétrique, Paris, France.
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