This study evaluated the feasibility of using texture analysis and machine learning to distinguish radiographic lung patterns. A total of 1200 regions of interest (ROIs) including four specific lung patterns (normal, alveolar, bronchial, and unstructured interstitial) were obtained from 512 thoracic radiographs of 252 dogs and 65 cats. Forty-four texture parameters based on eight methods of texture analysis (first-order statistics, spatial gray-level-dependence matrices, gray-level-difference statistics, gray-level run length image statistics, neighborhood gray-tone difference matrices, fractal dimension texture analysis, Fourier power spectrum, and Law's texture energy measures) were used to extract textural features from the ROIs. The texture parameters of each lung pattern were compared and used for training and testing of artificial neural networks. Classification performance was evaluated by calculating accuracy and the area under the receiver operating characteristic curve (AUC). Forty texture parameters showed significant differences between the lung patterns. The accuracy of lung pattern classification was 99.1% in the training dataset and 91.9% in the testing dataset. The AUCs were above 0.98 in the training set and above 0.92 in the testing dataset. Texture analysis and machine learning algorithms may potentially facilitate the evaluation of medical images.
Animals ; Area Under Curve ; Cats ; Classification ; Dataset ; Dogs ; Fourier Analysis ; Fractals ; Lung ; Machine Learning ; Neural Networks (Computer) ; Pattern Recognition, Visual ; Radiography, Thoracic ; Residence Characteristics ; ROC Curve

OBJECTIVES: The purpose of this study was to investigate whether the neural activity of autism spectrum disorder (ASD) patients is different from that of normal individuals when performing aesthetic judgments. METHODS: We recruited typical ASD patients without savant skills (ASD group, n=17) and healthy controls (HC group, n=19) for an functional magnetic resonance imaging study. All subjects were scanned while performing aesthetic judgment tasks on two kinds of artwork (magnificent landscape images and fractal images). Differences in brain activation between the two groups were assessed by contrasting neural activity during the tasks. RESULTS: The aesthetic judgment score for all images was significantly lower in the ASD group than in the HC group. During the aesthetic judgment tasks, the ASD group showed less activation than the HC group in the anterior region of the superior frontal gyrus, and more activation in the temporoparietal area and insula, regardless of the type of images being judged. In addition, during the aesthetic judgment task for the fractal images, the ASD group exhibited greater neural activity in the amygdala and the posterior region of the middle/inferior temporal gyrus (Brodmann area 37) than the HC group. CONCLUSION: The results of this study suggest that the brain activation patterns associated with aesthetic experiences in ASD patients may differ from those of normal individuals.
Amygdala ; Autism Spectrum Disorder* ; Autistic Disorder* ; Beauty* ; Brain ; Fractals ; Humans ; Judgment ; Magnetic Resonance Imaging ; Prefrontal Cortex ; Temporal Lobe

OBJECTIVE: Prior functional magnetic resonance imaging (fMRI) work has revealed that children/adolescents with disruptive behavior disorders (DBDs) show dysfunctional reward/non-reward processing of non-social reinforcements in the context of instrumental learning tasks. Neural responsiveness to social reinforcements during instrumental learning, despite the importance of this for socialization, has not yet been previously investigated. METHODS: Twenty-nine healthy children/adolescents and 19 children/adolescents with DBDs performed the fMRI social/non-social reinforcement learning task. Participants responded to random fractal image stimuli and received social and non-social rewards/non-rewards according to their accuracy. RESULTS: Children/adolescents with DBDs showed significantly reduced responses within the caudate and posterior cingulate cortex (PCC) to non-social (financial) rewards and social non-rewards (the distress of others). Connectivity analyses revealed that children/adolescents with DBDs have decreased positive functional connectivity between the ventral striatum (VST) and the ventromedial prefrontal cortex (vmPFC) seeds and the lateral frontal cortex in response to reward relative to non-reward, irrespective of its sociality. In addition, they showed decreased positive connectivity between the vmPFC seed and the amygdala in response to non-reward relative to reward. CONCLUSION: These data indicate compromised reinforcement processing of both non-social rewards and social non-rewards in children/adolescents with DBDs within core regions for instrumental learning and reinforcement-based decision-making (caudate and PCC). In addition, children/adolescents with DBDs show dysfunctional interactions between the VST, vmPFC, and lateral frontal cortex in response to rewarded instrumental actions potentially reflecting disruptions in attention to rewarded stimuli.
Amygdala ; Attention Deficit and Disruptive Behavior Disorders ; Conditioning, Operant ; Fractals ; Frontal Lobe ; Gyrus Cinguli ; Learning ; Magnetic Resonance Imaging* ; Prefrontal Cortex ; Problem Behavior* ; Reinforcement, Social* ; Reward ; Socialization ; Ventral Striatum

OBJECTIVE: In the current study we investigated neurodevelopmental changes in response to social and non-social reinforcement. METHODS: Fifty-three healthy participants including 16 early adolescents (age, 10–15 years), 16 late adolescents (age, 15–18 years), and 21 young adults (age, 21–25 years) completed a social/non-social reward learning task while undergoing functional magnetic resonance imaging. Participants responded to fractal image stimuli and received social or non-social reward/non-rewards according to their accuracy. ANOVAs were conducted on both the blood oxygen level dependent response data and the product of a context-dependent psychophysiological interaction (gPPI) analysis involving ventromedial prefrontal cortex (vmPFC) and bilateral insula cortices as seed regions. RESULTS: Early adolescents showed significantly increased activation in the amygdala and anterior insula cortex in response to non-social monetary rewards relative to both social reward/non-reward and monetary non-rewards compared to late adolescents and young adults. In addition, early adolescents showed significantly more positive connectivity between the vmPFC/bilateral insula cortices seeds and other regions implicated in reinforcement processing (the amygdala, posterior cingulate cortex, insula cortex, and lentiform nucleus) in response to non-reward and especially social non-reward, compared to late adolescents and young adults. CONCLUSION: It appears that early adolescence may be marked by: (i) a selective increase in responsiveness to non-social, relative to social, rewards; and (ii) enhanced, integrated functioning of reinforcement circuitry for non-reward, and in particular, with respect to posterior cingulate and insula cortices, for social non-reward.
Adolescent ; Amygdala ; Fractals ; Gyrus Cinguli ; Healthy Volunteers ; Humans ; Learning ; Magnetic Resonance Imaging* ; Oxygen ; Prefrontal Cortex ; Reinforcement, Social* ; Reward ; Young Adult

In this study, we investigated where the sex differences of object-location binding memory performance were influenced by the cognitive load. We used the fractal objects version of the ‘What was where?’ task to measure object memory, location memory and objection-location binding memory. Cognitive load was controlled by task difficulty presented two sessions: one session randomly displayed three or four fractal objects (Session 34) and the other session four or five objects (Session 45). The results showed that females outperformed males on object-location binding memory. Interestingly, even when the four object trials were compared between Session 34 and Session 45, in which we believed that the level of difficulty was similar while cognitive load varied, the swap error of males was significantly increased in Session 45 compared to females. In conclusion, there may be sex differences in object-location binding memory and the males could be more sensitive about the cognitive load than females.
Female ; Fractals ; Humans ; Male ; Memory* ; Sex Characteristics*

PURPOSE: The aim of this study was to know whether there is significant difference of peri-implant bone density according to the state of antagonist region. MATERIALS AND METHODS: 51 patients who had implant operation in Daejeon Dental Hospital of Wonkwang University participated in this study and total of 51 implants were analyzed. Implants were classified depending on opposing antagonist region, gender, age and location of jaw. The opposing antagonist region was divided into four groups; natural tooth, implant, pontic and edentulous region. Fractal analysis was performed using two periapical radiographs; one after implant placement and the other after 10 weeks following prosthetic restoration. The analysis was done by Image J. The data was statistically analyzed using one-way ANOVA and Tukey multiple comparison test. RESULTS: The mean value of fractal difference was 0.009 +/- 0.048 with opposing natural tooth, 0.026 +/- 0.080 with opposing implant, 0.025 +/- 0.068 with opposing pontic and 0.093 +/- 0.171 with opposing edentulous area. There was a statistically significant difference in fractal value between opposing implant and opposing edentulous state. And there was no statistically significant difference according to age, gender and location of jaw. CONCLUSION: There was no statistically significant difference between 3 groups except opposing edentulous region and there was a statistically significant difference between opposing implant and edentulous region. And there was no statistically significant difference according to age, gender and location of jaw.
Bone Density* ; Denture, Partial, Fixed ; Fractals* ; Humans ; Jaw ; Tooth

The linear analysis for heart rate variability (HRV), including time domain method, frequency domain method and time-frequency analysis, has reached a lot of consensus. The non-linear analysis has also been widely applied in biomedical and clinical researches. However, for non-linear HRV analysis, especially for short-term non-linear HRV analysis, controversy still exists, and a unified standard and conclusion has not been formed. This paper reviews and discusses three short-term non-linear HRV analysis methods (fractal dimension, entropy and complexity) and their principles, progresses and problems in clinical application in detail, in order to provide a reference for accurate application in clinical medicine.
Electrocardiography ; Entropy ; Fractals ; Heart Rate ; Humans

OBJECTIVE: The purpose of this study was to determine whether the results of fractal analysis can be used as criteria for midpalatal suture maturation evaluation. METHODS: The study included 131 subjects aged over 18 years of age (range 18.1–53.4 years) who underwent cone-beam computed tomography. Skeletonized images of the midpalatal suture were obtained via image processing software and used to calculate fractal dimensions. Correlations between maturation stage and fractal dimensions were calculated using Spearman's correlation coefficient. Optimal fractal dimension cut-off values were determined using a receiver operating characteristic curve. RESULTS: The distribution of maturation stages of the midpalatal suture according to the cervical vertebrae maturation index was highly variable, and there was a strong negative correlation between maturation stage and fractal dimension (−0.623, p < 0.001). Fractal dimension was a statistically significant indicator of dichotomous results with regard to maturation stage (area under curve = 0.794, p < 0.001). A test in which fractal dimension was used to predict the resulting variable that splits maturation stages into ABC and D or E yielded an optimal fractal dimension cut-off value of 1.0235. CONCLUSIONS: There was a strong negative correlation between fractal dimension and midpalatal suture maturation. Fractal analysis is an objective quantitative method, and therefore we suggest that it may be useful for the evaluation of midpalatal suture maturation.
Cervical Vertebrae ; Cone-Beam Computed Tomography ; Evaluation Studies as Topic* ; Female ; Fractals* ; Methods ; ROC Curve ; Skeleton ; Sutures*

Adipose derived stem cells (ADSC) are good candidates for the replacement of bone marrow derived mesenchymal stem cells due to their abundance, multipotency property, and easier accessibility. In order to explore the behavior of these cells in response to mechanical stimulation, in this study we have investigated the effects of uniaxial dynamic mechanical loading on ADSC's morphology. Stem cells derived from the fat tissue of human and after an overnight culture were seeded on a silicone rubber strips. Afterwards, cells were subjected to a uniaxial dynamic loading in three different groups. Cell images were evaluated considering different morphological parameters. Fractal dimension decreased significantly after loading while in control groups there were a significant increase (p<0.05), approving that cyclic strain would lead to more aligned and organized cells. Cell orientation also increased significantly (p<0.05). Moreover cells' orientation angle, 24 hour after loading does not change compared to the observations immediately after loading, which attests to the practicality of the cyclic strain in functional tissue engineering. Cell width decreased and cell length increased which led to a significant increase in cell shape index (p<0.05). Results confirmed that uniaxial dynamic loading affects cell morphological parameters comparing their values before and after loading. In addition, the number of cycles are also an important factor since different number of cycles lead to different amounts of certain morphological parameters. Conclusively, cyclic strain can be a practical method in the field of functional tissue engineering.
Bone Marrow ; Cell Shape ; Fractals ; Humans ; Mesenchymal Stromal Cells ; Methods ; Silicone Elastomers ; Stem Cells* ; Tissue Engineering

PURPOSE: Prostate cancer is the most frequent cancer in men in Europe. A major focus in urology is the identification of new biomarkers with improved accuracy in patients with low-risk prostate cancer. Here, we evaluated two-dimensional neovascular complexity in prostate tumor and nontumor biopsy cores by use of a computer-aided image analysis system and assessed the correlations between the results and selected clinical and pathological parameters of prostate carcinoma. MATERIALS AND METHODS: A total of 280 prostate biopsy sections from a homogeneous series of 70 patients with low-risk prostate cancer (Gleason score 3+3, prostate-specific antigen [PSA]<10 ng/mL, and clinical stage T1c) who underwent systematic biopsy sampling and subsequent radical prostatectomy were analyzed. For each biopsy, 2-microm sections were treated with CD34 antibodies and were digitized by using an image analysis system that automatically estimates the surface fractal dimension. RESULTS: Our results showed that biopsy sections without cancer were significantly more vascularized than were tumors. No correlations were found between the vascular surface fractal dimension and patient's age, PSA and free-to-total PSA ratios, pathological stage, Gleason score, tumor volume, vascular invasion, capsular penetration, surgical margins, and biochemical recurrence. CONCLUSIONS: The value of angiogenesis in prostate cancer is still controversial. Our findings suggest that low-risk prostate cancer tissues are less vascularized than are nontumor tissues. Further studies are necessary to understand whether angiogenesis is a hallmark of intermediate- and high-risk prostate cancer.
Adult ; Aged ; Biopsy, Needle ; Fractals ; Humans ; Image Processing, Computer-Assisted/methods ; Kallikreins/blood ; Male ; Middle Aged ; Neoplasm Grading ; Neoplasm Staging ; Neovascularization, Pathologic/*pathology ; Prostate/*blood supply ; Prostate-Specific Antigen/blood ; Prostatectomy ; Prostatic Neoplasms/*blood supply/pathology/surgery ; Retrospective Studies