Detecting anomalous growth of skin lesion using threshold-based segmentation algorithm and Fuzzy K-Nearest Neighbor classifier

Context: Skin cancer is a complex and life-threatening disease caused primarily by genetic instability and accumulation of multiple molecular alternations. Aim: Currently, there is a great interest in the prospects of image processing to provide quantitative information about a skin lesion, that can be relevance for the clinical images and also used as a stand-alone cautioning tool. Setting and Design: To accomplish a powerful approach to recognize skin cancer without performing any unnecessary skin biopsies, this article presents a new hybrid technique for the classification of skin images using Firefly with K-Nearest Neighbor algorithm (FKNN). Materials and Methods: FKNN classifier is used to predict and classify skin cancer along with threshold-based segmentation and ABCD feature extraction. Image preprocessing and feature extraction techniques are mandatory for any image-based applications. Statistical Analysis Used: Initially, it is essential to eliminate the illumination variation and the other unwanted shadow areas present in the skin image, which is done by homomorphic filtering called preprocessing. Results: The comparison of our proposed method with other existing methods and a comprehensive discussion is explored based on the obtained results. Conclusion: The proposed FKNN provides a quantitative information about a skin lesion through hybrid KNN and firefly optimization that helps for recognizing the skin cancer efficiently than other technique with low computational complexity and time

Semiautomatic Three-Dimensional Threshold-Based Cardiac Computed Tomography Ventricular Volumetry in Repaired Tetralogy of Fallot: Comparison with Cardiac Magnetic Resonance Imaging

OBJECTIVE: To assess the accuracy and potential bias of computed tomography (CT) ventricular volumetry using semiautomatic three-dimensional (3D) threshold-based segmentation in repaired tetralogy of Fallot, and to compare them to those of two-dimensional (2D) magnetic resonance imaging (MRI). MATERIALS AND METHODS: This retrospective study evaluated 32 patients with repaired tetralogy of Fallot who had undergone both cardiac CT and MRI within 3 years. For ventricular volumetry, semiautomatic 3D threshold-based segmentation was used in CT, while a manual simplified contouring 2D method was used in MRI. The indexed ventricular volumes were compared between CT and MRI. The indexed ventricular stroke volumes were compared with the indexed arterial stroke volumes measured using phase-contrast MRI. The mean differences and degrees of agreement in the indexed ventricular and stroke volumes were evaluated using Bland-Altman analysis. RESULTS: The indexed end-systolic (ES) volumes showed no significant difference between CT and MRI (p > 0.05), while the indexed end-diastolic (ED) volumes were significantly larger on CT than on MRI (93.6 ± 17.5 mL/m² vs. 87.3 ± 15.5 mL/m² for the left ventricle [p < 0.001] and 177.2 ± 39.5 mL/m² vs. 161.7 ± 33.1 mL/m² for the right ventricle [p < 0.001], respectively). The mean differences between CT and MRI were smaller for the indexed ES volumes (2.0–2.5 mL/m²) than for the indexed ED volumes (6.3–15.5 mL/m²). CT overestimated the stroke volumes by 14–16%. With phase-contrast MRI as a reference, CT (7.2–14.3 mL/m²) showed greater mean differences in the indexed stroke volumes than did MRI (0.8–3.3 mL/m²; p < 0.005). CONCLUSION: Compared to 2D MRI, CT ventricular volumetry using semiautomatic 3D threshold-based segmentation provides comparable ES volumes, but overestimates the ED and stroke volumes in patients with repaired tetralogy of Fallot.

Computed Tomography Pulmonary Vascular Volume Ratio Can Be Used to Evaluate the Effectiveness of Pulmonary Angioplasty in Peripheral Pulmonary Artery Stenosis

OBJECTIVE: To explore whether computed tomography (CT) pulmonary vascular volume ratio can be used to evaluate the effectiveness of pulmonary artery angioplasty in patients with peripheral pulmonary artery stenosis. MATERIALS AND METHODS: Changes in CT pulmonary vascular volume ratio between serial cardiothoracic CT examinations were calculated in 38 patients. Fifteen patients underwent interim pulmonary artery angioplasty (group 1), while 23 did not (group 2). According to the effectiveness of pulmonary artery angioplasty, patients in group 1 were further divided into group 1A (improved or aggravated) and group 1B (ineffective). Changes in the pulmonary vascular volume percentages among the three groups (group 1A, group 1B, and group 2) on serial CT examinations were compared. RESULTS: Pulmonary artery angioplasty on serial CT examinations was successful in seven patients, ineffective in seven patients, and aggravated in one patient. As a result, eight patients were included in group 1A and seven were included in group 1B. Changes in the CT pulmonary vascular volume percentages in group 1A were statistically significantly greater than those in group 1B (11.6 ± 5.6% vs. 2.7 ± 1.6%, p 0.1). CONCLUSION: CT pulmonary vascular volume ratio can be used to evaluate the effectiveness of pulmonary artery angioplasty in patients with peripheral pulmonary artery stenosis.

Computed Tomography-Based Ventricular Volumes and Morphometric Parameters for Deciding the Treatment Strategy in Children with a Hypoplastic Left Ventricle: Preliminary Results

OBJECTIVE: To determine the utility of computed tomography (CT) ventricular volumes and morphometric parameters for deciding the treatment strategy in children with a hypoplastic left ventricle (LV). MATERIALS AND METHODS: Ninety-four consecutive children were included in this study and divided into small LV single ventricle repair (SVR) (n = 28), small LV biventricular repair (BVR) (n = 6), disease-matched control (n = 19), and control (n = 41) groups. The CT-based indexed LV volumes, LV-to-right-ventricular (LV/RV) volume ratio, left-to-right atrioventricular valve (AVV) area ratio, left-to-right AVV diameter ratio, and LV/RV long dimension ratio were compared between groups. Proportions of preferred SVR in the small LV SVR group suggested by the parameters were evaluated. RESULTS: Indexed LV end-systolic (ES) and end-diastolic (ED) volumes in the small LV SVR group (6.3 ± 4.0 mL/m² and 14.4 ± 10.2 mL/m², respectively) were significantly smaller than those in the disease-matched control group (16.0 ± 4.7 mL/m² and 37.7 ± 12.0 mL/m², respectively; p < 0.001) and the control group (16.0 ± 5.5 mL/m² and 46.3 ± 10.8 mL/m², respectively; p < 0.001). These volumes were 8.3 ± 2.4 mL/m² and 21.4 ± 5.3 mL/m², respectively, in the small LV BVR group. ES and ED indexed LV volumes of < 7 mL/m² and < 17 mL/m², LV/RV volume ratios of < 0.22 and < 0.25, AVV area ratios of < 0.33 and < 0.24, and AVV diameter ratios of < 0.52 and < 0.46, respectively, enabled the differentiation of a subset of patients in the small LV SVR group from those in the two control groups. One patient in the small LV biventricular group died after BVR, indicating that this patient might not have been a good candidate based on the suggested cut-off values. CONCLUSION: CT-based ventricular volumes and morphometric parameters can suggest cut-off values for SVR in children with a hypoplastic LV.

Comparison between Three-Dimensional Navigator-Gated Whole-Heart MRI and Two-Dimensional Cine MRI in Quantifying Ventricular Volumes

OBJECTIVE: To test whether the method utilizing three-dimensional (3D) whole-heart MRI has an additional benefit over that utilizing conventional two-dimensional (2D) cine MRI in quantifying ventricular volumes. MATERIALS AND METHODS: In 110 patients with congenital heart disease, a navigator-gated, 3D whole-heart MRI during end-systole (ES) and end-diastole (ED), 2D short-axis cine MRI, and phase contrast MRI of the great arteries were acquired. Ventricular volumes were measured by using a 3D threshold-based segmentation for 3D whole-heart MRI and by using a simplified contouring for 2D cine MRI. The cardiac trigger delays of 3D whole-heart MRI were compared with those of a 2D cine MRI. The stroke volumes calculated from the ventricular volumes were compared with the arterial flow volumes, measured by phase contrast MRI. RESULTS: The ES and ED trigger delays of whole-heart MRI were significantly less than cine MRI for both the left ventricle (−16.8 ± 35.9 ms for ES, −59.0 ± 90.4 ms for ED; p < 0.001) and the right ventricle (−58.8 ± 30.6 ms for ES, −104.9 ± 92.7 ms for ED; p < 0.001). Compared with the arterial flow volumes, 2D cine MRI significantly overestimated the left ventricular stroke volumes (8.7 ± 8.9 mL, p < 0.001) and the 3D whole-heart MRI significantly underestimated the right ventricular stroke volumes (−22.7 ± 22.9 mL, p < 0.001). CONCLUSION: Three-dimensional whole-heart MRI is often subject to early timing of the ED phase, potentially leading to the underestimation of the right ventricular stroke volumes.