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Mirzaalian H, Hussein ME, Spinoulas L, May J, Abd-Almageed W. Explaining Face Presentation Attack Detection Using Natural Language. 2021 16th IEEE International Conference on Automatic Face and Gesture Recognition (FG 2021) 2021. [DOI: 10.1109/fg52635.2021.9667024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Majd A, AlJasser M, Mirzaalian H, Shapiro J, Hamarneh G, Lui H, Santos LDN, Chu T, Lee TK. A novel automated approach to rapid and precise in vivo measurement of hair morphometrics using a smartphone. Skin Res Technol 2021; 27:1128-1134. [PMID: 34251055 DOI: 10.1111/srt.13076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 06/09/2021] [Accepted: 06/24/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Although many hair disorders can be readily diagnosed based on their clinical appearance, their progression and response to treatment are often difficult to monitor, particularly in quantitative terms. We introduce an innovative technique utilizing a smartphone and computerized image analysis to expeditiously and automatically measure and compute hair density and diameter in patients in real time. METHODS A smartphone equipped with a dermatoscope lens wirelessly transmits trichoscopy images to a computer for image processing. A black-and-white binary mask image representing hair and skin is produced, and the hairs are thinned into single-pixel-thick fiber skeletons. Further analysis based on these fibers allows morphometric characteristics such as hair shaft number and diameters to be computed rapidly. The hair-bearing scalps of fifty participants were imaged to assess the precision of our automated smartphone-based device in comparison with a specialized trichometry device for hair shaft density and diameter measurement. The precision and operation time of our technique relative to manual trichometry, which is commonly used by hair disorder specialists, is determined. RESULTS An equivalence test, based on two 1-sided t tests, demonstrates statistical equivalence in hair density and diameter values between this automated technique and manual trichometry within a 20% margin. On average, this technique actively required 24 seconds of the clinician's time whereas manual trichometry necessitated 9.2 minutes. CONCLUSION Automated smartphone-based trichometry is a rapid, precise, and clinically feasible technique which can significantly facilitate the assessment and monitoring of hair loss. Its use could be easily integrated into clinical practice to improve standard trichoscopy.
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Affiliation(s)
- Ali Majd
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC, Canada
| | - Mohammed AlJasser
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC, Canada.,Division of Dermatology, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Hengameh Mirzaalian
- Medical Image Analysis Lab, School of Computing Science, Simon Fraser University, Burnaby, BC, Canada
| | - Jerry Shapiro
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC, Canada.,Vancouver Coastal Health Research Institute, Vancouver, BC, Canada.,The Ronald O. Perelman Department of Dermatology, NYU Grossman School of Medicine, NY, USA
| | - Ghassan Hamarneh
- Medical Image Analysis Lab, School of Computing Science, Simon Fraser University, Burnaby, BC, Canada
| | - Harvey Lui
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC, Canada.,Vancouver Coastal Health Research Institute, Vancouver, BC, Canada.,BC Cancer, Vancouver, BC, Canada
| | | | - Thomas Chu
- Department of Dermatology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Tim K Lee
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC, Canada.,Vancouver Coastal Health Research Institute, Vancouver, BC, Canada.,BC Cancer, Vancouver, BC, Canada
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AbdAlmageed W, Mirzaalian H, Guo X, Randolph LM, Tanawattanacharoen VK, Geffner ME, Ross HM, Kim MS. Assessment of Facial Morphologic Features in Patients With Congenital Adrenal Hyperplasia Using Deep Learning. JAMA Netw Open 2020; 3:e2022199. [PMID: 33206189 PMCID: PMC7675110 DOI: 10.1001/jamanetworkopen.2020.22199] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
IMPORTANCE Congenital adrenal hyperplasia (CAH) is the most common primary adrenal insufficiency in children, involving excess androgens secondary to disrupted steroidogenesis as early as the seventh gestational week of life. Although structural brain abnormalities are seen in CAH, little is known about facial morphology. OBJECTIVE To investigate differences in facial morphologic features between patients with CAH and control individuals with use of machine learning. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study was performed at a pediatric tertiary center in Southern California, from November 2017 to December 2019. Patients younger than 30 years with a biochemical diagnosis of classical CAH due to 21-hydroxylase deficiency and otherwise healthy controls were recruited from the clinic, and face images were acquired. Additional controls were selected from public face image data sets. MAIN OUTCOMES AND MEASURES The main outcome was prediction of CAH, as performed by machine learning (linear discriminant analysis, random forests, deep neural networks). Handcrafted features and learned representations were studied for CAH score prediction, and deformation analysis of facial landmarks and regionwise analyses were performed. A 6-fold cross-validation strategy was used to avoid overfitting and bias. RESULTS The study included 102 patients with CAH (62 [60.8%] female; mean [SD] age, 11.6 [7.1] years) and 59 controls (30 [50.8%] female; mean [SD] age, 9.0 [5.2] years) from the clinic and 85 controls (48 [60%] female; age, <29 years) from face databases. With use of deep neural networks, a mean (SD) AUC of 92% (3%) was found for accurately predicting CAH over 6 folds. With use of classical machine learning and handcrafted facial features, mean (SD) AUCs of 86% (5%) in linear discriminant analysis and 83% (3%) in random forests were obtained for predicting CAH over 6 folds. There was a deviation of facial features between groups using deformation fields generated from facial landmark templates. Regionwise analysis and class activation maps (deep learning of regions) revealed that the nose and upper face were most contributory (mean [SD] AUC: 69% [17%] and 71% [13%], respectively). CONCLUSIONS AND RELEVANCE The findings suggest that facial morphologic features in patients with CAH is distinct and that deep learning can discover subtle facial features to predict CAH. Longitudinal study of facial morphology as a phenotypic biomarker may help expand understanding of adverse lifespan outcomes for patients with CAH.
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Affiliation(s)
- Wael AbdAlmageed
- Information Sciences Institute, University of Southern California, Los Angeles
- Department of Electrical and Computer Engineering, University of Southern California, Los Angeles
| | - Hengameh Mirzaalian
- Information Sciences Institute, University of Southern California, Los Angeles
| | - Xiao Guo
- Information Sciences Institute, University of Southern California, Los Angeles
| | - Linda M. Randolph
- Division of Medical Genetics, Children’s Hospital Los Angeles, Los Angeles, California
- Keck School of Medicine of the University of Southern California, Los Angeles
| | | | - Mitchell E. Geffner
- Keck School of Medicine of the University of Southern California, Los Angeles
- Center for Endocrinology, Diabetes, and Metabolism, Children’s Hospital Los Angeles, Los Angeles, California
- The Saban Research Institute at Children’s Hospital Los Angeles, Los Angeles, California
| | - Heather M. Ross
- Center for Endocrinology, Diabetes, and Metabolism, Children’s Hospital Los Angeles, Los Angeles, California
| | - Mimi S. Kim
- Keck School of Medicine of the University of Southern California, Los Angeles
- Center for Endocrinology, Diabetes, and Metabolism, Children’s Hospital Los Angeles, Los Angeles, California
- The Saban Research Institute at Children’s Hospital Los Angeles, Los Angeles, California
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Guo X, Mirzaalian H, Abd-Almageed W, Randolph LM, Tanawattanacharoen VK, Geffner ME, Ross HM, Kim MS. SAT-087 Identifying Distinct Facial Dysmorphology in Youth with Congenital Adrenal Hyperplasia Using Deep Learning Techniques. J Endocr Soc 2020. [PMCID: PMC7208108 DOI: 10.1210/jendso/bvaa046.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
Purpose: Classical Congenital Adrenal Hyperplasia (CAH) due to 21-hydroxylase deficiency affects 1:15,000 newborns and involves adrenal insufficiency and androgen excess. These hormone abnormalities are evident as early as 7 weeks’ gestation and persist throughout pregnancy. Structural brain abnormalities are also known to occur in CAH, with abnormalities of brain and facial structure occurring together in conditions such as fetal alcohol spectrum disorder and holoprosencephaly. As well, sex differences in facial morphology are well described in healthy individuals. Thus, we aimed to study facial features using artificial intelligence in CAH youth. Methods: We studied frontal images of the face in 57 youth with severe salt-wasting CAH (60% female; 9.4±5.5y), and 38 controls (47% female, 9.7±5.1y), acquired with an iPad v12.1. We included 32 additional controls (43% female; 4-19y) from a publicly available face image dataset (1). Applying deep learning techniques, we converted 2-D facial photos to mathematical descriptors in order to differentiate features between groups. For a given test image, our pipeline output was a predicted “CAH score” between [0,1]. Due to our small dataset, we employed K-fold cross validation to train and test our deep neural network. At each of the K-9 folds, 88% of data (468 control and 531 CAH images) were used to train the network, with the remaining data (55 control and 63 CAH images) used to test the trained network. Test results were validated in terms of area under the curve (AUC) of receiver operating characteristic curves (generated from predicted CAH scores of test subjects), to analyze true and false positive rates. Our pipeline automatically detected face-bounding boxes and 68 facial landmarks (dlib toolkit) which were then used to compute 27 Euclidean (linear) facial features (2,3). We performed between group analyses of features with t-tests. Results: The averaged AUC of nine folds was 0.83±0.14, representing strong predictive power as a proxy to correlating facial dysmorphology with CAH. Predicted CAH scores were different between control (0.24±0.33) and CAH (0.69±0.37; p<0.0001) youth. Thirteen of 27 facial features were different between controls and CAH (p<0.05 for all) including 3 of 6 features related to sexual dimorphism. We also produced heat (i.e., saliency) maps showing the effect of CAH on facial features, and 2D t-SNE plot visualization of features showing well-defined separation between CAH and control group clusters. Conclusions: Utilizing deep learning, we have shown that CAH youth have facial features that can reliably distinguish them from controls. Further study is merited in regard to the etiology of affected facial morphology in CAH, and associations with disease severity, and/or brain and behavior abnormalities. (1) Masi I et al. Int J Comput Vis 2019. (2) Whitehouse AJ et al. Proc Biol Sci 2015. (3) Lefevre CE et al. Evol Hum Behav 2013
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Affiliation(s)
- Xiao Guo
- Information Sciences Institute USC, Los Angeles, CA, USA
| | | | | | | | | | | | | | - Mimi S Kim
- Children’s Hospital Los Angeles, Los Angeles, CA, USA
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Mirzaalian H, Hussein M, Abd-Almageed W. On the Effectiveness of Laser Speckle Contrast Imaging and Deep Neural Networks for Detecting Known and Unknown Fingerprint Presentation Attacks. 2019 International Conference on Biometrics (ICB) 2019. [DOI: 10.1109/icb45273.2019.8987428] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Cunningham TJ, Tabacchi M, Eliane JP, Tuchayi SM, Manivasagam S, Mirzaalian H, Turkoz A, Kopan R, Schaffer A, Saavedra AP, Wallendorf M, Cornelius LA, Demehri S. Randomized trial of calcipotriol combined with 5-fluorouracil for skin cancer precursor immunotherapy. J Clin Invest 2017. [PMID: 27869649 DOI: 10.1172/jci89820.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Actinic keratosis is a precursor to cutaneous squamous cell carcinoma. Long treatment durations and severe side effects have limited the efficacy of current actinic keratosis treatments. Thymic stromal lymphopoietin (TSLP) is an epithelium-derived cytokine that induces a robust antitumor immunity in barrier-defective skin. Here, we investigated the efficacy of calcipotriol, a topical TSLP inducer, in combination with 5-fluorouracil (5-FU) as an immunotherapy for actinic keratosis. METHODS The mechanism of calcipotriol action against skin carcinogenesis was examined in genetically engineered mouse models. The efficacy and safety of 0.005% calcipotriol ointment combined with 5% 5-FU cream were compared with Vaseline plus 5-FU for the field treatment of actinic keratosis in a randomized, double-blind clinical trial involving 131 participants. The assigned treatment was self-applied to the entirety of the qualified anatomical sites (face, scalp, and upper extremities) twice daily for 4 consecutive days. The percentage of reduction in the number of actinic keratoses (primary outcome), local skin reactions, and immune activation parameters were assessed. RESULTS Calcipotriol suppressed skin cancer development in mice in a TSLP-dependent manner. Four-day application of calcipotriol plus 5-FU versus Vaseline plus 5-FU led to an 87.8% versus 26.3% mean reduction in the number of actinic keratoses in participants (P < 0.0001). Importantly, calcipotriol plus 5-FU treatment induced TSLP, HLA class II, and natural killer cell group 2D (NKG2D) ligand expression in the lesional keratinocytes associated with a marked CD4+ T cell infiltration, which peaked on days 10-11 after treatment, without pain, crusting, or ulceration. CONCLUSION Our findings demonstrate the synergistic effects of calcipotriol and 5-FU treatment in optimally activating a CD4+ T cell-mediated immunity against actinic keratoses and, potentially, cancers of the skin and other organs. TRIAL REGISTRATION ClinicalTrials.gov NCT02019355. FUNDING Not applicable (investigator-initiated clinical trial).
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Cunningham TJ, Tabacchi M, Eliane JP, Tuchayi SM, Manivasagam S, Mirzaalian H, Turkoz A, Kopan R, Schaffer A, Saavedra AP, Wallendorf M, Cornelius LA, Demehri S. Randomized trial of calcipotriol combined with 5-fluorouracil for skin cancer precursor immunotherapy. J Clin Invest 2016; 127:106-116. [PMID: 27869649 DOI: 10.1172/jci89820] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/06/2016] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Actinic keratosis is a precursor to cutaneous squamous cell carcinoma. Long treatment durations and severe side effects have limited the efficacy of current actinic keratosis treatments. Thymic stromal lymphopoietin (TSLP) is an epithelium-derived cytokine that induces a robust antitumor immunity in barrier-defective skin. Here, we investigated the efficacy of calcipotriol, a topical TSLP inducer, in combination with 5-fluorouracil (5-FU) as an immunotherapy for actinic keratosis. METHODS The mechanism of calcipotriol action against skin carcinogenesis was examined in genetically engineered mouse models. The efficacy and safety of 0.005% calcipotriol ointment combined with 5% 5-FU cream were compared with Vaseline plus 5-FU for the field treatment of actinic keratosis in a randomized, double-blind clinical trial involving 131 participants. The assigned treatment was self-applied to the entirety of the qualified anatomical sites (face, scalp, and upper extremities) twice daily for 4 consecutive days. The percentage of reduction in the number of actinic keratoses (primary outcome), local skin reactions, and immune activation parameters were assessed. RESULTS Calcipotriol suppressed skin cancer development in mice in a TSLP-dependent manner. Four-day application of calcipotriol plus 5-FU versus Vaseline plus 5-FU led to an 87.8% versus 26.3% mean reduction in the number of actinic keratoses in participants (P < 0.0001). Importantly, calcipotriol plus 5-FU treatment induced TSLP, HLA class II, and natural killer cell group 2D (NKG2D) ligand expression in the lesional keratinocytes associated with a marked CD4+ T cell infiltration, which peaked on days 10-11 after treatment, without pain, crusting, or ulceration. CONCLUSION Our findings demonstrate the synergistic effects of calcipotriol and 5-FU treatment in optimally activating a CD4+ T cell-mediated immunity against actinic keratoses and, potentially, cancers of the skin and other organs. TRIAL REGISTRATION ClinicalTrials.gov NCT02019355. FUNDING Not applicable (investigator-initiated clinical trial).
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MESH Headings
- Administration, Topical
- Aged
- Aged, 80 and over
- Animals
- Antineoplastic Combined Chemotherapy Protocols/administration & dosage
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/pathology
- Calcitriol/administration & dosage
- Calcitriol/analogs & derivatives
- Carcinoma, Squamous Cell/drug therapy
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/immunology
- Carcinoma, Squamous Cell/pathology
- Cytokines/genetics
- Cytokines/immunology
- Female
- Fluorouracil/administration & dosage
- Humans
- Immunity, Cellular/drug effects
- Immunity, Cellular/genetics
- Keratosis, Actinic/drug therapy
- Keratosis, Actinic/genetics
- Keratosis, Actinic/immunology
- Keratosis, Actinic/pathology
- Male
- Mice
- Mice, Transgenic
- Middle Aged
- Precancerous Conditions/drug therapy
- Precancerous Conditions/genetics
- Precancerous Conditions/immunology
- Precancerous Conditions/pathology
- Skin Neoplasms/drug therapy
- Skin Neoplasms/genetics
- Skin Neoplasms/immunology
- Skin Neoplasms/pathology
- Thymic Stromal Lymphopoietin
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Cunningham T, Moradi Tuchayi S, Tabacchi M, Manivasagam S, Mirzaalian H, Turkoz A, Kopan R, Schaffer A, Wallendorf M, Cornelius L, Demehri S. 222 Topical 5-fluorouracil and calcipotriol combination: A potent immunotherapeutic for actinic keratosis. J Invest Dermatol 2016. [DOI: 10.1016/j.jid.2016.02.251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mirzaalian H, Ning L, Savadjiev P, Pasternak O, Bouix S, Michailovich O, Grant G, Marx CE, Morey RA, Flashman LA, George MS, McAllister TW, Andaluz N, Shutter L, Coimbra R, Zafonte RD, Coleman MJ, Kubicki M, Westin CF, Stein MB, Shenton ME, Rathi Y. Inter-site and inter-scanner diffusion MRI data harmonization. Neuroimage 2016; 135:311-23. [PMID: 27138209 DOI: 10.1016/j.neuroimage.2016.04.041] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 03/15/2016] [Accepted: 04/18/2016] [Indexed: 11/17/2022] Open
Abstract
We propose a novel method to harmonize diffusion MRI data acquired from multiple sites and scanners, which is imperative for joint analysis of the data to significantly increase sample size and statistical power of neuroimaging studies. Our method incorporates the following main novelties: i) we take into account the scanner-dependent spatial variability of the diffusion signal in different parts of the brain; ii) our method is independent of compartmental modeling of diffusion (e.g., tensor, and intra/extra cellular compartments) and the acquired signal itself is corrected for scanner related differences; and iii) inter-subject variability as measured by the coefficient of variation is maintained at each site. We represent the signal in a basis of spherical harmonics and compute several rotation invariant spherical harmonic features to estimate a region and tissue specific linear mapping between the signal from different sites (and scanners). We validate our method on diffusion data acquired from seven different sites (including two GE, three Philips, and two Siemens scanners) on a group of age-matched healthy subjects. Since the extracted rotation invariant spherical harmonic features depend on the accuracy of the brain parcellation provided by Freesurfer, we propose a feature based refinement of the original parcellation such that it better characterizes the anatomy and provides robust linear mappings to harmonize the dMRI data. We demonstrate the efficacy of our method by statistically comparing diffusion measures such as fractional anisotropy, mean diffusivity and generalized fractional anisotropy across multiple sites before and after data harmonization. We also show results using tract-based spatial statistics before and after harmonization for independent validation of the proposed methodology. Our experimental results demonstrate that, for nearly identical acquisition protocol across sites, scanner-specific differences can be accurately removed using the proposed method.
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Affiliation(s)
- H Mirzaalian
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA.
| | - L Ning
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA
| | - P Savadjiev
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA
| | - O Pasternak
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA
| | - S Bouix
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA
| | | | - G Grant
- Stanford University Medical Center, Palo Alto, CA, USA (Previously Duke University)
| | - C E Marx
- Duke University Medical Center and VA Mid-Atlantic MIRECC, NC, USA
| | - R A Morey
- Duke University Medical Center and VA Mid-Atlantic MIRECC, NC, USA
| | - L A Flashman
- Dartmouth University, Hanover and Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - M S George
- Medical University of South Carolina, Charleston, SC, USA, Ralph H. Johnson VA Medical Center, Charleston
| | - T W McAllister
- Geisel School of Medicine at Dartmouth (original) and Indiana University School of Medicine (current)
| | - N Andaluz
- Department of Neurosurgery, University of Cincinnati (UC) College of Medicine; Neurotrauma Center at UC Neuroscience Institute; and Mayfield Clinic, Cincinnati, OH
| | - L Shutter
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Previously Duke University)
| | - R Coimbra
- Department of Surgery, University of California, San Diego
| | - R D Zafonte
- Spaulding Rehabilitation Hospital and Harvard Medical School, Boston, USA
| | - M J Coleman
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA
| | - M Kubicki
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA
| | - C F Westin
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA
| | - M B Stein
- University of California, San Diego, San Diego, CA, USA
| | - M E Shenton
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA; VA Boston Healthcare System, Boston, MA, USA
| | - Y Rathi
- Harvard Medical School and Brigham and Women's Hospital, Boston, USA
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Wang CW, Huang CT, Hsieh MC, Li CH, Chang SW, Li WC, Vandaele R, Marée R, Jodogne S, Geurts P, Chen C, Zheng G, Chu C, Mirzaalian H, Hamarneh G, Vrtovec T, Ibragimov B. Evaluation and Comparison of Anatomical Landmark Detection Methods for Cephalometric X-Ray Images: A Grand Challenge. IEEE Trans Med Imaging 2015; 34:1890-900. [PMID: 25794388 DOI: 10.1109/tmi.2015.2412951] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Cephalometric analysis is an essential clinical and research tool in orthodontics for the orthodontic analysis and treatment planning. This paper presents the evaluation of the methods submitted to the Automatic Cephalometric X-Ray Landmark Detection Challenge, held at the IEEE International Symposium on Biomedical Imaging 2014 with an on-site competition. The challenge was set to explore and compare automatic landmark detection methods in application to cephalometric X-ray images. Methods were evaluated on a common database including cephalograms of 300 patients aged six to 60 years, collected from the Dental Department, Tri-Service General Hospital, Taiwan, and manually marked anatomical landmarks as the ground truth data, generated by two experienced medical doctors. Quantitative evaluation was performed to compare the results of a representative selection of current methods submitted to the challenge. Experimental results show that three methods are able to achieve detection rates greater than 80% using the 4 mm precision range, but only one method achieves a detection rate greater than 70% using the 2 mm precision range, which is the acceptable precision range in clinical practice. The study provides insights into the performance of different landmark detection approaches under real-world conditions and highlights achievements and limitations of current image analysis techniques.
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Mirzaalian H, Wels M, Heimann T, Kelm BM, Suehling M. Fast and robust 3D vertebra segmentation using statistical shape models. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2013:3379-82. [PMID: 24110453 DOI: 10.1109/embc.2013.6610266] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We propose a top-down fully automatic 3D vertebra segmentation algorithm using global shape-related as well as local appearance-related prior information. The former is brought into the system by a global statistical shape model built from annotated training data, i.e., annotated CT volumes. The latter is handled by a machine learning-based component, i.e., a boundary detector, providing a strong discriminative model for vertebra surface appearance by making use of local context-encoding features. This boundary detector, which is essentially a probabilistic boosting-tree classifier, is also learnt from annotated training data. Contextual information is taken into account by representing vertebra surface candidate voxels with high-dimensional vectors of 3D steerable features derived from the observed volume intensities. Our system does not only consider the body of the individual vertebrae but also the spinal processes. Before segmentation, the image parts depicting individual vertebrae are spatially normalized with respect to their bounding box information in terms of translation, orientation, and scale leading to more accurate results. We evaluate segmentation accuracy on 7 CT volumes each depicting 22 vertebrae. The results indicate a symmetric point-to-mesh surface error of 1.37 ± 0.37 mm, which matches the current state-of-the-art.
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Mirzaalian H, Lee TK, Hamarneh G. Hair enhancement in dermoscopic images using dual-channel quaternion tubularness filters and MRF-based multilabel optimization. IEEE Trans Image Process 2014; 23:5486-5496. [PMID: 25312927 DOI: 10.1109/tip.2014.2362054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Hair occlusion is one of the main challenges facing automatic lesion segmentation and feature extraction for skin cancer applications. We propose a novel method for simultaneously enhancing both light and dark hairs with variable widths, from dermoscopic images, without the prior knowledge of the hair color. We measure hair tubularness using a quaternion color curvature filter. We extract optimal hair features (tubularness, scale, and orientation) using Markov random field theory and multilabel optimization. We also develop a novel dual-channel matched filter to enhance hair pixels in the dermoscopic images while suppressing irrelevant skin pixels. We evaluate the hair enhancement capabilities of our method on hair-occluded images generated via our new hair simulation algorithm. Since hair enhancement is an intermediate step in a computer-aided diagnosis system for analyzing dermoscopic images, we validate our method and compare it to other methods by studying its effect on: 1) hair segmentation accuracy; 2) image inpainting quality; and 3) image classification accuracy. The validation results on 40 real clinical dermoscopic images and 94 synthetic data demonstrate that our approach outperforms competing hair enhancement methods.
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Abstract
A large number of pigmented skin lesions (PSLs) are a strong predictor of malignant melanoma. Many dermatologists advocate total body photography for high-risk patients because detecting new-appearing, disappearing, and changing PSL is important for early detection of the disease. However, manual inspection and matching of PSL is a subjective, tedious, and error-prone task. A computer program for tracking the corresponding PSL will greatly improve the matching process. In this paper, we describe the construction of the first human back template (atlas), which is used to facilitate spatial normalization of the PSL during the matching process. Four pairs of anatomically meaningful landmarks (neck, shoulder, armpit, and hip points) are used as reference points on the back image. Using the landmarks, a grid with longitudes and latitudes is constructed and overlaid on each subject-specific back image. To perform spatial normalization, the grid is registered into the back template, a unit-square rectilinear grid. To demonstrate the benefits of using the back template, we apply several state-of-the-art point-matching algorithms on 56 pairs of real dermatological images and show that utilizing spatially normalized coordinates improves the PSL matching accuracies.
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