Quantitative Discrimination of Pigmented Lesions Using Three-Dimensional High- Resolution Ultrasound Reflex Transmission Imaging  Deepak Rallan, Nigel L. Bush, Jeff C. Bamber, Chris C. Harland  Journal of Investigative Dermatology  Volume 127, Issue 1, Pages 189-195 (January 2007) DOI: 10.1038/sj.jid.5700554 Copyright © 2007 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 1 Ultrasound beam and image planes for three image types. The RTI is an attenuation image, LBI is a lesion reflection image, and EEI is a surface reflectance image. The transducer moves in two horizontal directions and data are integrated from multiple horizontal slices. The images therefore depict three-dimensional volume data. Journal of Investigative Dermatology 2007 127, 189-195DOI: (10.1038/sj.jid.5700554) Copyright © 2007 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 2 Quantitative differences between melanoma, benign melanocytic SKs, and other benign-pigmented lesions (BN) on three parameters. The dashed lines mark the value ranges beyond which melanoma was excluded. The error bars show the 95% confidence interval about the mean. Exclusion was one tailed in order to assess the most conservative result for specificity. The category labelled as BN above contained five benign lentigos and one dermatofibroma as well. Journal of Investigative Dermatology 2007 127, 189-195DOI: (10.1038/sj.jid.5700554) Copyright © 2007 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 3 Examples of the appearance of the three lesion types and the three scan types are shown. Although SKs can sometimes be recognized on RTI by visual inspection, we noted this is not the case with acanthotic keratoses. Similarly, lesions in the BPL category cannot be reliably differentiated from melanoma upon visual inspection of the images. Although elusive to the human eye, the acoustic differences were numerically quantifiable making differentiation entirely objective. Journal of Investigative Dermatology 2007 127, 189-195DOI: (10.1038/sj.jid.5700554) Copyright © 2007 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 4 Inter- and intra-group comparison of acoustic parameters. MM – malignant melanoma, SK- seborrheic keratoses, BN – other benign-pigmented lesions. (a) Significant correlation between surface reflectance and surface heterogeneity exists for the SK group but not for the BN and MM groups. (b) Intra-lesional contrast correlates with intra-lesional heterogeneity in all three groups. The relationship is weakest for MM. (c) Heterogeneity of attenuation increases with overall tumor attenuation. The relationship is weakest for the BN group. Journal of Investigative Dermatology 2007 127, 189-195DOI: (10.1038/sj.jid.5700554) Copyright © 2007 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 5 RTI and corresponding photograph of a melanoma are shown. Eo – mean echo value in normal skin, Ei – mean echo value within tumor boundary, Ho – SD of echoes in normal skin, and HA – SD of values within tumor boundary. The lesion is not visible on this RTI and is defined using the optical boundary of the transformed photograph (right). Lesion contrast is calculated as (Eo–Ei)/Eo. Similarly, relative heterogeneity is calculated as (Ho–HA)/Ho. Marker and bubble artifacts are excluded from calculations. The two features were calculated on EEI and LBI as well for each lesion. Journal of Investigative Dermatology 2007 127, 189-195DOI: (10.1038/sj.jid.5700554) Copyright © 2007 The Society for Investigative Dermatology, Inc Terms and Conditions