High Frequency Ultrasound for High Resolution Skin Imaging

High frequency and broadband ultrasound in the frequency range above 20 MHz is an efficient modality for the non invasive and high resolution imaging of skin structures and skin diseases like skin tumors and inflammatory processes. However, special system designs and signal processing strategies have to be applied to account for the strong and frequency dependent attenuation of high frequency ultrasound in tissue. In this paper the design of an ultrasound imaging system with a minimum spatial resolution of about 9 , utilizing the frequency range from 30 to 150 MHz, is presented. This system enables the high resolution visualization of the uppermost skin layers, which is of great interest in dermatology and cosmetics. To quantify the imaging properties of the system reference measurements were performed by imaging a glass plate and a wire phantom. Furthermore, image processing techniques for the analysis of three dimensional data sets were adapted to investigate the topology of skin structures like skin layers. Results from in vivo measurements on healthy skin and skin tumors are presented. Übersicht Hochfrequenter und breitbandiger Ultraschall im Frequenzbereich oberhalb von 20 MHz stellt eine leistungsfähige Modalität zur nichtinvasiven und hochauflösenden Abbildung von Hautstrukturen und Hauterkrankungen wie Hauttumoren und entzündlichen Prozessen dar. Es müssen jedoch spezielle Systemkonzepte und Signalverarbeitungstechniken angewandt werden, um der starken und frequenzabhängigen Dämpfung des hochfrequenten Ultraschalls im Gewebe Rechnung zu tragen. In dieser Arbeit wird der Entwurf eines Ultraschallabbildungssystems, das den Frequenzbereich von 30 bis 150 MHz nutzt, mit einer kleinsten räumlichen Auflösung von etwa 9 vorgestellt. Dieses System erlaubt die hochauflösende Darstellung der obersten Hautschichten, was von großem Interesse in der Dermatologie und der Kosmetik ist. Zur Quantifizierung der Abbildungseigenschaften des Systems wurden Referenzmessungen durch Abbildung einer Glasplatte und eines Drahtphantoms durchgeführt. Femer wurden Bildverarbeitungstechniken für die Analyse dreidimensionaler Datensätze adaptiert, um die Topologie von Hautstrukturen (Hautschichten, Haarfollikel) zu untersuchen. Es werden Ergebnisse von Messungen in vivo an gesunder Haut und an Hauttumoren vorgestellt. Für die Dokumentation Hochfrequenter Ultraschall / Ultraschallabbildung / Medizin / Dermatologie / Haut / B/D-scan

[1]  150 Mhz Adaptive Ultrasound Imaging of the Eye and Skin , 1996 .

[2]  B. Gusterson,et al.  Correlation between Histology and High Resolution Echographic Images of Small Skin Tumours , 1992 .

[3]  J W Hunt,et al.  Measurement of the ultrasonic properties of vascular tissues and blood from 35-65 MHz. , 1991, Ultrasound in medicine & biology.

[4]  J. Serup,et al.  Non‐invasive quantification of psoriasis plaques–measurement of skin thickness with 15 mHz pulsed ultrasound , 1984, Clinical and experimental dermatology.

[5]  K. Hoffmann,et al.  Ultrasound in Dermatology , 1988 .

[6]  H Ermert,et al.  Sonography of the skin at 100 MHz enables in vivo visualization of stratum corneum and viable epidermis in palmar skin and psoriatic plaques. , 1999, The Journal of investigative dermatology.

[7]  H. Ermert,et al.  Structural analysis of the skin using high frequency, broadband ultrasound in the range from 30 to 140 MHz , 1998, 1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102).

[8]  Brian G. Starkoski,et al.  Ultrasound backscatter microscope for skin imaging , 1993 .

[9]  D. A. Christopher,et al.  40-MHZ echocardiography scanner for cardiovascular assessment of mouse embryos. , 1998, Ultrasound in medicine & biology.

[10]  H. Ermert,et al.  Hochfrequentes Ultraschallsystem für die Untersuchung von Hauterkrankungen und zur Tumordiagnostik in der Dermatologie , 1989 .

[11]  H. Ermert,et al.  150 MHz in vivo ultrasound of the skin: imaging techniques and signal processing procedures targeting homogeneous resolution , 1994, 1994 Proceedings of IEEE Ultrasonics Symposium.

[12]  F. Foster,et al.  A realtime 200 MHz ultrasound B-scan imager , 1997, 1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118).

[13]  Daniel H. Turnbull,et al.  BEYOND 30 MHZ , 1996 .

[14]  Michael Vogt,et al.  High-frequency ultrasonic imaging and its applications in skin , 1999, Medical Imaging.

[15]  H. Ermert,et al.  A 50 MHz ultrasonic imaging system for dermatalogic application , 1989, Proceedings., IEEE Ultrasonics Symposium,.

[16]  Helmut Ermert,et al.  In vivo imaging of the skin in the 100 MHz region using the synthetic aperture concept , 1995, 1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium.

[17]  H. Ermert,et al.  A 100-MHz ultrasound imaging system for dermatologic and ophthalmologic diagnostics , 1996, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[18]  H Ermert,et al.  [100 MHz ultrasound of psoriasis vulgaris plaque]. , 2008, Ultraschall in der Medizin.

[19]  D. A. Christopher,et al.  Advances in ultrasound biomicroscopy. , 2000, Ultrasound in medicine & biology.

[20]  Helmut Ermert,et al.  Adaptive 150 MHz ultrasound imaging of the skin and the eye using an optimal combination of short pulse mode and pulse compression mode , 1995, 1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium.

[21]  F Patat,et al.  High-resolution real-time ultrasonic scanner. , 1992, Ultrasound in medicine & biology.

[22]  B. Querleux,et al.  In vivo cross-sectional ultrasonic imaging of human skin. , 1988, Dermatologica.

[23]  F. S. Foster,et al.  Ultrasound Biomicroscopy of the Eye , 1994, Springer New York.

[24]  J. Serup.  Localized scleroderma (morphoea): thickness of sclerotic plaques as measured by 15 MHz pulsed ultrasound. , 1984, Acta dermato-venereologica.

[25]  Helmut Ermert,et al.  In vivo ultrasound biomicroscopy , 1993 .

[26]  Helmut Ermert,et al.  Signal Processing in High-Frequency Broadband Imaging Systems for Dermatologic Application , 1992 .

[27]  Helmut Ermert,et al.  Adaptive Wiener filtering for B-mode image improvement , 1992, IEEE 1992 Ultrasonics Symposium Proceedings.

[28]  J. Serup,et al.  Ultrasound for assessment of allergic and irritant patch test reactions , 1987, Contact dermatitis.

[29]  S Murakami,et al.  Human skin histology using high‐resolution echography , 1989, Journal of clinical ultrasound : JCU.