ABSTRACT
CONTENTS 4.1 Skin .............................................................................................................. 124
4.1.1 Skin Lesion ...................................................................................... 125 4.1.2 Psoriasis ........................................................................................... 125
4.2 Thickness Assessment of Skin Lesions .................................................. 129 4.2.1 Subjective Assessment .................................................................. 129 4.2.2 Objective Assessment .................................................................... 129
4.2.2.1 Light Microscope ............................................................ 130 4.2.2.2 X-ray .................................................................................. 131 4.2.2.3 Ultrasound ....................................................................... 132 4.2.2.4 Digital Imaging ............................................................... 133
4.2.3 Problem Statement and Formulation .......................................... 134 4.3 Development of a 3D Thickness Algorithm........................................... 135
4.3.1 Data Acquisition Setup ................................................................. 135 4.3.1.1 3D Imaging Equipment .................................................. 135 4.3.1.2 3D Scanner Setup ............................................................ 136 4.3.1.3 Ambient Illumination ..................................................... 136 4.3.1.4 3D Image Capture ........................................................... 137
4.3.2 Development of the Lesion Thickness Algorithm .................... 139 4.3.2.1 3D Segmentation of Normal Skin ................................. 140 4.3.2.2 3D Estimation of the Lesion Base ................................. 147 4.3.2.3 Determination of Lesion Surface Elevation for
Thickness .......................................................................... 151 4.4 Results and Analysis ................................................................................. 152
4.4.1 Validation and Analysis of the Lesion Thickness Algorithm ....152 4.4.1.1 Analysis of 3D Normal Skin Segmentation ................ 154 4.4.1.2 Analysis of 3D Lesion Base Estimation ....................... 156 4.4.1.3 Analysis of the Thickness Algorithm .......................... 157
4.4.2 Clinical Study Results and Analysis of the Lesion Thickness Algorithm ..................................................................... 159 4.4.2.1 Thickness Data and PASI Thickness Classication ... 159 4.4.2.2 Analysis of PASI Thickness Scoring ............................. 162 4.4.2.3 Reliability of the Lesion Thickness Algorithm and
PASI Scoring ..................................................................... 163
The skin is the largest organ of the human body and it protects a human being’s inner organs from the environment [1]. The skin consists of three layers: from outer to inner they are the epidermis, dermis, and subcutaneous fat layer. Figure 4.1 shows the structure of the skin, in which the epidermal layer is colored red, the dermis is colored pink, and the subcutaneous fat layer is colored yellow [2].
