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Fundamento: A avaliação da área valvar mitral por meio da reconstrução multiplano na ecocardiografia tridimensional é restrita a softwares específicos e à experiência dos ecocardiografistas. Eles precisam selecionar manualmente o frame do vídeo que contenha a área de abertura máxima da valva mitral, dimensão fundamental para a identificação de estenose mitral. Objetivo: Automatizar o processo de determinação da área de abertura máxima da valva mitral, por meio da aplicação de Processamento Digital de Imagens (PDI) em exames de ecocardiograma, desenvolvendo um algoritmo aberto com leitura de vídeo no formato avi. Método: Este estudo piloto observacional transversal foi realizado com vinte e cinco exames diferentes de ecocardiograma, sendo quinze com abertura normal e dez com estenose mitral reumática. Todos os exames foram realizados e disponibilizados por dois especialistas, com autorização do Comitê de Ética em Pesquisa, que utilizaram dois modelos de aparelhos ecocardiográficos: Vivid E95 (GE Healthcare) e Epiq 7 (Philips), com sondas multiplanares transesofágicas. Todos os vídeos em formato avi foram submetidos ao PDI através da técnica de segmentação de imagens. Resultados: As medidas obtidas manualmente por ecocardiografistas experientes e os valores calculados pelo sistema desenvolvido foram comparados utilizando o diagrama de Bland-Altman. Observou-se maior concordância entre valores no intervalo de 0,4 a 2,7 cm². Conclusão: Foi possível determinar automaticamente a área de máxima abertura das valvas mitrais, tanto para os casos advindos da GE quanto da Philips, utilizando apenas um vídeo como dado de entrada. O algoritmo demonstrou economizar tempo nas medições quando comparado com a mensuração habitual. (AU)
Background: The evaluation of mitral valve area through multiplanar reconstruction in 3-dimensional echocardiography is restricted to specific software and to the experience of echocardiographers. They need to manually select the video frame that contains the maximum mitral valve opening area, as this dimension is fundamental to identification of mitral stenosis. Objective: To automate the process of determining the maximum mitral valve opening area, through the application of digital image processing (DIP) in echocardiography tests, developing an open algorithm with video reading in avi format. Method: This cross-sectional observational pilot study was conducted with 25 different echocardiography exams, 15 with normal aperture and 10 with rheumatic mitral stenosis. With the authorization of the Research Ethics Committee, all exams were performed and made available by 2 specialists who used 2 models of echocardiographic devices: Vivid E95 (GE Healthcare) and Epiq 7 (Philips), with multiplanar transesophageal probes. All videos in avi format were submitted to DIP using the image segmentation technique. Results: The measurements obtained manually by experienced echocardiographers and the values calculated by the developed system were compared using a Bland-Altman diagram. There was greater agreement between values in the range from 0.4 to 2.7 cm². Conclusion: It was possible to automatically determine the maximum mitral valve opening area, for cases from both GE and Philips, using only 1 video as input data. The algorithm has been demonstrated to save time on measurements when compared to the usual method. (AU)
Subject(s)
Humans , Heart Valve Diseases/mortality , Mitral Valve/physiopathology , Mitral Valve/diagnostic imaging , Mitral Valve Stenosis/etiology , Image Processing, Computer-Assisted/methods , Doxorubicin/radiation effects , Echocardiography, Transesophageal/methods , Echocardiography, Three-Dimensional/methods , Transcatheter Aortic Valve Replacement/methods , Isoproterenol/radiation effects , Mitral Valve/surgeryABSTRACT
Objective:To investigate the changes in gray matter volume (GMV) and abnormalities in structural covariant network (SCN) patterns in patients with chronic pontine infarction (PI).Methods:Patients with unilateral chronic PI (case group) with the first onset admitted to the First Affiliated Hospital of Zhengzhou University and Tianjin Medical University General Hospital from October 2014 to June 2021 were prospectively included. At the same time, healthy subjects matched with age, gender and education years (normal control group) were included. High-resolution three-dimensional T 1 structural MRI images and behavioral scores of the subjects were collected. The voxel-based morphometry and two-sample t test were used to explore the differences in GMV between the groups. Using GMV differential brain regions as seed points, SCN was constructed to explore the abnormality of structural covariant patterns in patients with PI. Spearman rank correlation analysis was used to analyze the correlation between GMV in differential brain regions and behavioral scores. Results:A total of 60 patients with PI were enrolled, including 33 left PI and 27 right PI, while 34 healthy controls were also enrolled. Compared with the normal control group, the GMV in bilateral posterior cerebellar lobe decreased significantly in the left PI group, and the GMV in left anterior and posterior cerebellar lobes and the right posterior cerebellar lobe decreased significantly in the right PI group (Gaussian random field correction with voxel level P<0.001 and cluster level P<0.05, cluster voxel >20), and there was a significant correlation between GMV values in the left anterior and posterior cerebellar lobes and the right posterior cerebellar lobe and the motor function score ( P<0.05). In addition, compared with the normal control group, the right PI group had broader covariate brain regions and a significant increase in the number of structural connections between covariate brain regions (family-wise error correction with voxel level P<0.05, cluster voxel >20). Conclusions:The GMV in bilateral posterior cerebellar lobe decreases significantly in patients with chronic PI, and were secondary to broader covariate brain regions and structural connections. This may be the neural mechanism of impaired behavioral function in patients with PI.
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Objective:To study the impact of different scattering correction algorithms in the reconstruction of PET/CT images on image artifacts and the precision of quantitative parameters.Methods:The phantom as described in the National Electrical Manufacturers Association (NEMA) NU2 standard was filled with 18F. The background activity was fixed, and the activity of the solution in the spheres was adjusted to obtain several configurations, including the normal ratio group (4.08∶1) and the extreme ratio group (200∶1). The surface contamination group with the same ratio as the extreme ratio group contained a small radioactive source with different doses of 18F (74, 37, 3.7 and 0.37 MBq) placed at the surface of the phantom. PET/CT images of 30 patients (21 males, 9 females, age: (44.5±10.2) years) from Peking University Cancer Hospital & Institute between July 2012 and December 2021 were retrospectively analyzed, including 10 with normal images ( 18F-FDG) and 20 with abnormal images (10 with dislocation during acquisition, 10 with surface contamination). The images were reconstructed with relative and absolute scattering correction. The phantom was evaluated using the target to background ratio (TBR) and the artifact classification. CV as well as the artifact classification were used to compare the clinical image quality. Mann-Whitney U test and χ2 test were used to analyze data. Results:In the normal ratio group and the extreme ratio group, the TBRs of phantom images reconstructed with relative correction were significantly higher than those with absolute correction (normal ratio group: 3.30(1.94, 4.53) vs 2.72(1.56, 3.56); z=-2.20, P=0.028; extreme ratio group: 105.47(45.62, 162.82) vs 101.36(43.96, 155.57); z=-1.99, P=0.046). In the surface contamination group, with the increase of the activity of the small source, the artifact became more obvious, and the artifact classification score of absolute correction was significantly better than that of relative correction (1.5(1.0, 2.0) vs 2.5(2.0, 3.0); z=-2.00, P=0.046). In the 10 normal 18F-FDG PET/CT patients, the CVliver of the relative correction (9.67%(8.00%, 11.00%)) was significantly lower than that of absolute correction (11.00%(9.00%, 12.00%); z=-2.57, P=0.010), indicating the higher image quality of images with relative correction. In abnormal images, the image quality of absolute correction was significantly higher than that of relative correction with fewer and less severe artifacts (dislocation cases: 9/10 vs 4/10; χ2=5.50, P=0.019; surface contamination cases: 9/10 vs 4/10; χ2=5.50, P=0.019). Conclusions:The relative scattering correction is suitable for normal situations in clinical PET acquisition. However, with dislocation or surface contamination, the absolute scattering correction helps to reduce the artifacts and improve the image quality.
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Objective:To explore values and differences of multi-modality image registration and normalization methods in 18F-AV45 PET quantitative analysis of Alzheimer′s disease (AD). Methods:Twenty AD patients (10 males, 10 females; age (77.0±5.8) years) and 20 normal controls (NC; 8 males, 12 females; age (75.2±4.8) years) from the AD neuroimaging initiative (ADNI) open database of the National Institute on Aging were analyzed. β-amyloid (Aβ) deposition (positive/negative) was assessed by visual analysis. The SUV ratio (SUVr) in each brain region and individual average SUVr were calculated using template normalization method (M1), normalization after registration with 18F-FDG PET or MRI image (M2 or M3) respectively with the cerebellum as the reference area. The intra-class correlation coefficient (ICC) was used to complete the reliability between methods, and independent-sample t test and one-way repeated measures analysis of variance were used to compare the differences of quantitative indexes between different groups and different methods. ROC curve analysis was used to compare the diagnostic efficacy in distinguishing AD and NC, Aβ positive and negative cases. Results:There were 15 and 6 patients with positive Aβ deposition in AD group and in NC group respectively by visual analysis. The SUVrs of three methods were with good consistency (ICC=0.82, P<0.001), and the differences among individual average SUVrs (1.29±0.17, 1.36±0.23, 1.45±0.24) were significant ( F=68.78, P<0.001). There were significant differences between AD group (1.39±0.17, 1.48±0.24, 1.58±0.25) and NC group (1.20±0.10, 1.24±0.15, 1.33±0.16; t values: 3.55-4.33, all P<0.05), Aβ positive group (1.39±0.16, 1.50±0.21, 1.59±0.23) and negative group (1.19±0.11, 1.21±0.14, 1.31±0.15; t values: 4.58, 5.11, 4.41, all P<0.001), and the individual average SUVr of M3 was higher (both P<0.001). The AUCs of distinguishing Aβ positive and negative deposition of M1-M3 were 0.86, 0.88, 0.84 and the thresholds of SUVrs were 1.29, 1.37, 1.52, respectively. Conclusion:The three multi-modality registration and normalization methods are reliable methods for quantitation of 18F-AV45 PET imaging with certain differences, and should be selected carefully based on data conditions in practice.
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Objective:To investigate the effects of silicon photomutipliers (SiPM) detector and Bayesian penalized likelihood (BPL) reconstruction algorithm on semiquantitative parameters of 18F-FDG PET/CT and diagnostic efficiency for solitary pulmonary nodules/masses compared with traditional photomultiplier tube (PMT) and ordered subsets expectation maximization (OSEM). Methods:From March 2020 to January 2022, 118 patients (76 males, 42 females, age (63.0±10.1) years) newly diagnosed with solitary pulmonary nodules/masses in First Hospital of Shanxi Medical University were prospectively enrolled and underwent 18F-FDG PET/CT imaging with two different PET/CT scanners successively. The images were divided into PMT+ OSEM, SiPM+ OSEM and SiPM+ BPL groups according to PET detector and reconstruction algorithms. The SUV max, SUV mean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of pulmonary nodules/masses were measured, then signal-to-noise ratio (SNR) and signal-to-background ratio (SBR) were calculated. One-way analysis of variance and Kruskal-Wallis rank sum test were performed to compare differences of above parameters among groups. ROC curve analysis was used to analyze the optimal threshold of SUV max for the differential diagnosis of pulmonary nodules/masses and AUCs were obtained. Results:There were 83 malignant nodules and 35 benign nodules. The image quality of SiPM+ BPL group (4.23±0.64) was better than that of SiPM+ OSEM group (3.57±0.50) or PMT+ OSEM group (3.58±0.51; F=54.85, P<0.001). There were significant differences in SUV max (7.57(3.86, 15.61) vs 4.95(2.22, 10.48)), SUV mean (4.43(2.28, 9.12) vs 2.84(1.21, 5.71)), MTV (3.54(1.57, 7.67) vs 5.09(2.83, 11.79)), SNR (28.12(12.55, 54.38) vs 20.16(8.29, 41.45)) and SBR (4.03(1.83, 7.75) vs 2.32(0.96, 5.03)) between SiPM+ BPL and SiPM+ OSEM groups ( H values: 16.63-37.05, all P<0.001). The optimal threshold values of SUV max in SiPM+ BPL, SiPM+ OSEM and PMT+ OSEM were 3.31, 2.21, 2.05 with AUCs of 0.686, 0.689, 0.615 for nodules < 2 cm, and were 10.29, 6.49, 4.33 with AUCs of 0.775, 0.782, 0.774 for nodules/masses ≥2 cm. Conclusions:Image quality and parameters of pulmonary nodules/masses are mainly affected by the reconstruction algorithms. BPL can improve SUV max, SUV mean, SBR and SNR, but reduce MTV without significant effect on liver parameters. SiPM+ BPL has a higher diagnostic threshold of SUV max than SiPM+ OSEM and PMT+ OSEM.
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Objective:To establish standard spatial brain template and ROIs template of 11C-methyl- N-2β-carbomethoxy-3β-(4-fluorophenyl)tropane (CFT) PET images for automated quantitative analysis of dopamine transporter (DAT) distribution. Methods:From May 2014 to December 2015, 11C-CFT PET and MRI T 1 brain images of 16 healthy volunteers (3 males, 13 females; age (63.3±6.9) years) from Huashan Hospital, Fudan University were co-registered and smoothed using statistical parametric mapping(SPM)5 software based on MATLAB to create a standard spatial brain template. The ROIs template was established by ScAnVp procedures. These templates were clinically verified by using 11C-CFT PET images of 37 healthy volunteers (23 males, 14 females; age (61.7±7.1) years), 32 Parkinson′s disease (PD) patients (20 males, 12 females; age (61.1±5.4) years), 10 multiple system atrophy with predominant parkinsonism (MSA-P) patients (7 males, 3 females; age (60.8±7.1) years) and 10 progressive supranuclear palsy (PSP) patients (5 males, 5 females; age (58.4±6.1) years) from Huashan Hospital, Fudan University between January 2014 and March 2019. One-way analysis of variance was used to analyze data. Results:Based on the 11C-CFT PET images and MRI T 1 images of healthy volunteers, a standard spatial brain template for normalization of 11C-CFT PET images was created. The ROIs template was established including seven regions: bilateral caudate, anterior putamen, posterior putamen (along the long axis) and the occipital cortex. The ROIs template was accurately aligned in each verification group. The normal reference values of semi-quantitative DAT distribution in caudate, anterior putamen and posterior putamen were obtained (1.84±0.13, 2.18±0.16, 1.77±0.11). The semi-quantitative values of 11C-CFT uptake in each ROI in patients were significantly lower than those in healthy volunteers ( F values: 49.79-283.83, all P<0.05). Conclusion:The established brain templates with accurate spatial alignment for 11C-CFT image analysis can provide foundational tools for the application of 11C-CFT PET imaging in clinical practice and scientific research.
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Objective:To explore the added value of T 1-weighted stack-of-stars volumetric interpolated body examination (StarVIBE) sequence on PET/MR image quality. Methods:A retrospective analysis was performed on 60 patients (42 males, 18 females; age 11-86 (58±12) years) who underwent 18F-FDG PET/MR examination and with positive PET results in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from April 2020 to April 2021. All patients completed StarVIBE sequence collection, and volumetric interpolated body examination (VIBE) sequence was used as control. StarVIBE and VIBE sequence images were evaluated independently using five-point method by two physicians. The evaluation was carried out from six aspects: lesion display, lesion boundary display, vascular around lesions display, fusion level with PET image, image artifact and overall image quality. Wilcoxon signed rank test was used to compare the image quality of the two sequences, and Kappa test was performed to assess the consistency of the image quality scores between the two physicians. Results:There were 26 cases with cervical lesions, 14 cases with chest lesions, 7 cases with abdomen lesions and 13 cases with pelvic lesions. The scores of lesion display (4.0(3.8, 4.5) vs 3.5(3.0, 4.0)), lesion boundary display (4.0(4.0, 4.0) vs 3.0(3.0, 3.5)), vascular around lesions display (5.0(4.0, 5.0) vs 4.0(3.5, 4.5)), fusion level with PET image (5.0(5.0, 5.0) vs 4.5(4.0, 5.0)), image artifact (4.5(4.0, 5.0) vs 4.5(4.0, 5.0)) and overall image quality (5.0(4.0, 5.0) vs 4.0(4.0, 4.0)) of StarVIBE sequences were better than those of VIBE sequences ( z values: 3.77-6.54, all P<0.001). On the vascular around the lesions display, the scores of StarVIBE were significantly better than those of VIBE sequence in the neck (5.0(4.5, 5.0) vs 3.0(2.7, 3.5); z=4.49, P<0.001) and chest (4.5(4.3, 4.7) vs 4.0(3.6, 4.3); z=3.10, P=0.002). As for image quality, the scores of StarVIBE were also significantly better than those of VIBE in neck (5.0(4.5, 5.0) vs 4.0(3.7, 4.5); z=4.36, P<0.001) and chest (5.0(5.0, 5.0) vs 4.0(4.0, 4.5); z=3.02, P=0.003). In abdominal lesions, the score of StarVIBE was higher than that of VIBE in blood vessels (4.5(3.5, 5.0) vs 4.0(3.5, 4.5); z=2.07, P=0.038), and there was no difference between score of overall image quality (4.0(3.7, 4.5) vs 4.0(3.5, 4.5); z=0.27, P=0.785). The score of overall image quality of pelvic StarVIBE sequence was better than that of VIBE sequence (5.0(4.5, 5.0) vs 4.0(4.0, 4.5); z=2.12, P=0.034). Kappa value of image quality score between two physicians was 0.554, indicating moderate consistency. Conclusion:In whole-body PET/MR imaging, StarVIBE sequence can significantly improve the image quality of cervical, thoracic and pelvic lesions when comparing with VIBE sequence.
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Objective:To explore the impact of different segmentation methods on differential diagnostic efficiency of 18F-FDG PET/MR radiomics to distinguish Parkinson′s disease (PD) from multiple system atrophy (MSA). Methods:From December 2017 to June 2019, 90 patients (60 with PD and 30 with MSA; 37 males, 53 females; age (55.8±9.5) years) who underwent 18F-FDG PET/MR in Union Hospital, Tongji Medical College, Huazhong University of Science and Technology were retrospectively collected. Patients were randomized to training set and validation set in a ratio of 7∶3. The bilateral putamina and caudate nuclei, as the ROIs, were segmented by automatic segmentation of brain regions based on anatomical automatic labeling (AAL) template and manual segmentation using ITK-SNAP software. A total of 1 172 radiomics features were extracted from T 1 weighted imaging (WI) and 18F-FDG PET images. The minimal redundancy maximal relevance (mRMR) and least absolute shrinkage and selection operator (LASSO) algorithm were used for features selection and radiomics signatures (Radscore) construction, with 10-fold cross-validation for preventing overfitting. The diagnostic performance of the models was assessed by ROC curve analysis, and the differences between models were calculated by Delong test. Results:There were 63 cases in training set (42 PD, 21 MSA) and 27 cases in validation set (18 PD, 9 MSA). The Radscore values were significantly different between the PD group and the MSA group in all training set and validation set of radiomics models ( 18F-FDG_Radscore and T 1WI_Radscore) based on automatic or manual segmentation methods ( z values: from -5.15 to -2.83, all P<0.05). ROC curve analysis showed that AUCs of 18F-FDG_Radscore and T 1WI_Radscore based on automatic segmentation in training and validation sets were 0.848, 0.840 and 0.892, 0.877, while AUCs were 0.900, 0.883 and 0.895, 0.870 based on manual segmentation. There were no significant differences in training and validation sets between Radiomics models based on different segmentation methods ( z values: 0.04-0.77, all P>0.05). Conclusions:The 18F-FDG PET/MR radiomics models based on different segmentation methods achieve promising diagnostic efficacy for distinguishing PD from MSA. The radiomics analysis based on automatic segmentation shows greater potential and practical value in the differential diagnosis of PD and MSA in view of the advantages including time-saving, labor-saving, and high repeatability.
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Objective:To investigate the diagnostic value of thin-layer three-dimensional reconstruction technology combined with personalized scanning for benign and malignant solid solitary pulmonary nodules.Methods:The clinical data of 140 patients with solid solitary pulmonary nodules admitted to Jiangshan People's Hospital form January 2020 to July 2021 were retrospectively analyzed. These patients consisted of 40 patients with benign solid solitary pulmonary nodules (benign group) and 100 patients with malignant solid solitary pulmonary nodules (malignant group). All patients underwent thin-layer three-dimensional reconstruction combined with personalized scanning. The pulmonary nodule signs achieved by thin-layer three-dimensional reconstruction combined with personalized scanning and the diagnostic performance of the combined technology were compared between benign and malignant groups.Results:The proportions of patients with lung cavity sign, lobular sign, vascular convergence sign, vacuole sign, emphysema distribution sign, split pleura sign, and distal perforating vascular sign in the malignant group were 11.0%, 81.0%, 77.0%, 49.0%, 6.0%, 10.0% and 31.0%, respectively, and they were 42.5%, 62.5%, 55.0%, 27.5%, 20.0%, 32.5%, and 5.0%, respectively in the benign group ( χ2 = 15.80, 5.00, 5.66, 4.55, 4.76, 8.96, 9.33, all P < 0.05). The most sensitive sign was lobular sign, which had the highest efficiency, up to 82.0%, in differentiating benign and malignant pulmonary nodules. Conclusion:Lung cavity sign, lobular sign, vascular convergence sign, vacuole sign, emphysema distribution sign, split pleura sign, and distal perforating vascular sign differ greatly between patients with benign and malignant solid solitary pulmonary nodules. Lobular sign has the highest sensitivity in differentiating benign and malignant solid solitary pulmonary nodules. Thin-layer three-dimensional reconstruction combined with personalized scanning has a diagnostic value for benign and malignant solid solitary pulmonary nodules.
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RESUMEN Fundamento: el procesamiento de imágenes es clave en la planificación de tratamientos de radioterapia con haces externos. En su ejecución pueden ocurrir errores humanos y fallos de equipos, que conllevan, entre otros efectos, a interpretaciones erróneas de imágenes diagnósticas, errores de contorneo de blancos, sobredosis a tejidos sanos o subdosis a tejidos tumorales, lo cual significa poner en riesgo a los pacientes sometidos a estas prácticas. Objetivo: caracterizar los riesgos asociados a los factores tecnológicos y humanos relacionados con el procesamiento de imágenes que pueden afectar a los pacientes sometidos a tratamientos de radioterapia con haces externos. Métodos: como base de estudio se empleó la práctica de radioterapia de intensidad modulada. Para caracterizar los iniciadores y las medidas de defensa relacionados con este procesamiento, se emplearon modelos de riesgo basados en análisis de modos y efectos de fallo y matriz de riesgo de la práctica de referencia, que fueron procesados con el software SECURE-MR-FMEA. Resultados: los análisis de sensibilidad sobre los modelos de radioterapia de intensidad modulada mostraron los efectos sobre el riesgo de los fallos asociados al procesamiento de imágenes. Conclusiones: se confirmó la importancia de aplicar el análisis de riesgo en el procesamiento de imágenes para elevar la seguridad de los pacientes durante los tratamientos de radioterapia con haces externos.
ABSTRACT Background: image processing is the key in planning external beam radiotherapy treatments. In its execution, human errors and equipment failures can occur, which lead, among other effects, to erroneous interpretations of diagnostic images, target contouring errors, overdose of healthy tissues or underdose of tumor tissues, which means putting patients at risk patients subjected to these practices. Objective: to characterize the risks associated with technological and human factors related to image processing that can affect patients undergoing radiotherapy treatments with external beams. Methods: intensity modulated radiotherapy was used as the basis of the study. To characterize the initiators and defense measures related to this processing, risk models were used based on analysis of failure modes and effects and the risk matrix of the reference practice, which were processed with the SECURE-MR-FMEA software. Results: the sensitivity analyzes on the intensity-modulated radiotherapy models showed the effects on the risk of failures associated with image processing. Conclusions: the importance of applying risk analysis in image processing to increase patient safety during external beam radiotherapy treatments was confirmed.
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RESUMEN Fundamento: en los laboratorios de microbiología, la identificación y conteo de microorganismos es un procedimiento habitual. Aunque existen en el mercado equipos que posibilitan su realización de manera automática o semiautomática, son muy costosos, por lo cual esta tarea, difícil e irritante para los ojos, la siguen realizando los expertos de manera tradicional mediante la observación de las muestras en los microscopios, con la consiguiente variabilidad entre ellos. Objetivo: proponer un nuevo método para el conteo de bacterias y levaduras en imágenes digitales, bajo diferentes magnificaciones, tomadas a bioproductos de origen microbiano obtenidos por fermentación. Métodos: el sensor empleado para la toma de imágenes de las muestras fue una cámara digital modelo HDCE-X, con un sensor CMOS de ½", con una resolución de 2592 píxeles por 1944 píxeles (5 Mp). Se emplearon dos tipos de magnificaciones: magnificación 40x (PL40, 0.65 apertura numérica and 0.17 de distancia de trabajo) y magnificación 100x (HI plan 100/1.25 con inmersión de aceite). El método propuesto se basa en técnicas de procesamiento digital de imágenes, utilizando herramientas como la detección de contornos, operaciones morfológicas y análisis estadístico, y fue desarrollado en lenguaje Python con empleo de la biblioteca OpenCV. Resultados: la detección y conteo de bacterias se logró con una exactitud y precisión aceptable, en ambos casos por encima de 0,95; no en el caso de las levaduras cuya exactitud y precisión fueron menores, alrededor de 0,78 y 0,86 respectivamente. Se proponen flujos de trabajo basados en técnicas de procesamiento digital de imágenes, fundamentalmente en detección de contornos, operaciones morfológicas y análisis estadístico. Conclusiones: el método posee una efectividad aceptable para el contexto y depende de las características que presenten las imágenes.
ABSTRACT Background: In microbiology laboratories, the identification and counting of microorganisms is a common procedure; and although there is a variety of equipment on the market that possibility to carry out these processes automatically or semi-automatically, it is usually expensive to many laboratories. These are some of the reasons why this arduous and difficult task is still performed in many laboratories by experts in the traditional way, through the observation of samples in microscope, consuming a great time and having variations in the results between experts. Objective: The present work aims to propose a new method for counting bacteria and yeasts in digital images, taken under different magnifications, of microbial bioproducts obtained by fermentation. Methods: The sensor used to take images of the samples was a digital camera model HDCE-X, with a ½" CMOS sensor, with a resolution of 2592 pixels by 1944 pixels (5 Mp). Two types of magnifications were used: 40x magnification (PL40, 0.65 numerical aperture and 0.17 working distance) and 100x magnification (HI plan 100/1.25 with oil immersion). The proposed method is based on digital image processing technics, using tools as contour detection, morphological operations and statistical analysis, and was developed in Python language using the OpenCV library. The work also presents a comparison with the results obtained using ImageJ software for the same purpose. Results: the detection and count of bacteria was achieved with an acceptable accuracy and precision, in both cases above 0.95; not in the case of yeasts whose accuracy and precision was lower, around 0.78 for accuracy and 0.86 for precision. Workflows based on digital image processing techniques are proposed, using tools as contour detection, morphological operations and statistical analysis. Conclusions: the method has an acceptable effectiveness for the context and depends on the characteristics presented by the images.
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RESUMEN Fundamento: la segmentación del hígado utilizando datos de tomografía computarizada es el primer paso para el diagnóstico de enfermedades hepáticas. Actualmente la segmentación de estructuras y órganos, basado en imágenes, que se realiza en los hospitales del país, dista de tener los niveles de precisión que se obtienen de los modernos sistemas 3D, por lo que se requiere buscar alternativas viables utilizando el PDI sobre ordenador. Objetivo: determinar una variante eficaz y eficiente desde el punto de vista computacional en condiciones de rutina hospitalaria, para la segmentación de imágenes hepáticas con fines clínicos. Métodos: se compararon dos métodos modernos de segmentación (Graph Cut y EM/MPM) aplicándolos sobre imágenes de tomografía de hígado. Se realizó un análisis evaluativo y estadístico de los resultados obtenidos en la segmentación de las imágenes a partir de los coeficientes de Dice, Vinet y Jaccard. Resultados: con el método Graph Cut, en todos los casos, se segmentó la región deseada, incluso cuando la calidad de las imágenes era baja, se observó gran similitud entre la imagen segmentada y la máscara de referencia. El nivel de detalles visuales es bueno y la reproducción de bordes permanece fiel a la máscara de referencia. La segmentación de las imágenes por el método de EM/MPM, no siempre fue satisfactoria. Conclusiones: el método de segmentación Graph Cut obtuvo mayor precisión para segmentar imágenes de hígado.
ABSTRACT Background: liver segmentation using computed tomography data is the first step for the diagnosis of liver diseases. Currently, the segmentation of structures and organs, based on images, which is carried out in the country's hospitals, is far from having the levels of precision obtained from modern 3D systems, it is necessary to search for viable alternatives using the PDI on a computer. Objective: to determine an effective and efficient variant from the computational point of view in routine hospital conditions, for the segmentation of liver images for clinical purposes. Methods: Two modern segmentation methods (Graph Cut and EM/MPM) were compared by applying them to liver tomography images. An evaluative and statistical analysis of the results obtained in the segmentation of the images from the Dice, Vinet and Jaccard coefficients was carried out. Results: with the Graph Cut method, in all cases, the desired region was segmented, even when the quality of the images was low, great similarity was observed between the segmented image and the reference mask. The level of visual detail is good, and edge reproduction remains true to the reference skin. Image segmentation by the EM/MPM method was not always satisfactory. Conclusions: the Graph Cut segmentation method obtained greater precision to segment liver images.
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Objective:To investigate the clinical value of digital technology in repair of soft tissue defect in hand by anterior tibial artery perforator flap.Methods:From January 2015 to February 2021, 9 patients with soft tissue defects in hand were repaired with anterior tibial artery perforator flap assisted by digital technology in flap design, including 6 males and 3 females aged from 19 to 63 years with a mean age of 33 years. The size of defects varied from 2.0 cm×1.5 cm to 4.0 cm×3.0 cm, with exposed bones or tendons. Preoperative CTA scan of lower limb was performed and three-dimensional image was reconstructed with Mimics 20.0. The anterior tibial artery perforator flap was designed according to the shape and size of the defect, then the resection of flap was digitally simulated. The flap based on the digital design was harvested and the defect was repaired in the operation. The size of flap was 2.5 cm×2.0 cm~4.5 cm×3.5 cm. Outpatient clinic follow-up was performed to evaluate the survival of flaps. Disability of Arm, Shoulder and Hand(DASH) was used for function evaluation.Results:All flaps were harvested successfully and all donor sites were closed directly. After surgery, 8 flaps survived completely. One flap developed venous occlusion that showed partial necrosis of the flap, and it was rescued after exploration and re-anastomosis. The follow-up period ranged from 6 to 21 months, with an average of 13 months. The DASH scores of the affected limb were 2 to 15 points at the last follow-up, with an average of 6.4 points. Mild scar hyperplasia occurred at donor site in 1 case without sensory abnormality.Conclusion:The digital technology is able to accurately locate the perforators by allowing an individualised design of the anterior tibial artery perforator flap. The flap is suitable for repair of small and medium-sized soft tissue defect in hand, and the digital technology has certain value in clinical application.
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Objective:To investigate differences in cardiac function and perfusion parameters measured by IQ-SPECT and low energy high-resolution (LEHR)-SPECT, as well as effects of scattering correction (SC) and CT attenuation correction (AC) on myocardial perfusion imaging.Methods:From May 2020 to September 2020, 80 patients (58 males, 22 females, age (57±10) years) who underwent SPECT myocardial perfusion imaging were retrospectively enrolled in Fuwai Hospital. According to the standardized left ventricular end-diastolic diameter of body surface measured by two-dimensional echocardiography, patients were divided into 2 groups: A group ( n=34) with significantly enlarged left ventricle and B group ( n=46) with no significant enlargement of left ventricle. LEHR-SPECT and IQ-SPECT gated myocardial perfusion imaging were performed in all patients. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), summed rest score (SRS) and total perfusion defect (TPD) were measured. Parameters measured by two methods and differences before and after SC and AC were compared by using paired t test and Wilcoxon signed rank test. The correlation was analyzed by Pearson correlation or Spearman rank correlation analyses, and the consistency was analyzed by Bland-Altman analysis. Results:In A group, EDV, EF and SRS measured by IQ-SPECT were significantly lower than those assessed by LEHR-SPECT after SC and AC (EDV: (257±137) vs (276±154) ml, EF: (21±11)% vs (26±13)%, SRS: 17(6, 25) vs 18(8, 28); t values: -2.63, -7.46, z=-2.14, all P<0.05); all parameters measured by LEHR-SPECT and IQ-SPECT had well correlation ( r values: 0.965, 0.969, 0.967, rs values: 0.920, 0.960, all P<0.001) and consistency. In B group, EDV and EF measured by IQ-SPECT were significantly lower than those assessed by LEHR-SPECT after SC and AC (EDV: (96±40) vs (107±39) ml, EF: (46±15)% vs (54±16)%; t values: -6.23, -10.71, both P=0.001); SRS and TPD measured by IQ-SPECT after SC and AC were significantly lower than non-SC and non-AC (SRS: 2(1, 4) vs 5(3, 11), TPD: (3%(1%, 5%) vs 7%(3%, 12%); z values: -4.11, -4.16, both P<0.001); all parameters measured by LEHR-SPECT and IQ-SPECT had well correlation ( r values: 0.956, 0.978, 0.958, rs values: 0.926, 0.944, all P<0.001) and consistency. Conclusions:There are good correlation and consistency of left ventricular function and myocardial perfusion parameters acquired by IQ-SPECT and LEHR-SPECT. Moreover, IQ-SPECT is able to shorten acquisition time, resulting in great potential in clinical application.
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Objective:To investigate the effect of motion correction (MC) on the calculated values of myocardial blood flow (MBF) and myocardial flow reserve (MFR) based on cadmium-zinc-telluride SPECT (CZT SPECT) images.Methods:Twenty-eight consecutive patients (10 males, 18 females, age: (60.75±11.62) years) with suspected or known coronary artery disease who underwent myocardial perfusion imaging (MPI) with dynamic CZT SPECT between June 2019 and August 2019 in TEDA International Cardiovascular Hospital were retrospectively analyzed. The MBF and MFR during rest imaging and stress imaging were quantitatively analyzed. Corridor 4DM software was used to calculate the stress MBF (sMBF) and MFR of the coronary artery branches and left ventricular (LV) before and after MC. The paired t test and Pearson correlation were used for data analysis. Results:The sMBF and MFR of LV before MC were (0.82±0.49) ml·min -1·g -1 and 1.69±0.68 respectively. After MC the two parameters increased to (1.05±0.64) ml·min -1·g -1 and 2.12±0.77 respectively ( t values: -4.87, -6.01, both P<0.001). The sMBF and MFR in left anterior descending (LAD), left circumflex (LCX), right coronary artery (RCA) and LV before MC were correlated with those after MC ( r values: 0.69-0.96, all P<0.001). If MFR <2.0 was used as the reference of impaired MFR, data before MC showed 19 patients (67.9%, 19/28) had impaired MFR, while 13 patients (46.4%, 13/28) had impaired MFR based on MFR values after MC. Conclusion:For MPI quantitative imaging with CZT SPECT, the calculated values of sMBF and MFR after MC is higher than those before MC, suggesting that MC is helpful to reduce the false positive results which may be caused by the " creep" effect of the heart.
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Objective:To study the morphology of dorsal medial talar neck osteophyte (DMTNO) and its association with anteromedial ankle impingement syndrome (AAIS) using CT 3D reconstruction images.Methods:The present retrospective study included 23 patients with AAIS due to DMTNO (case group) and 23 patients with DMTNO but without AAIS (control group) who had been admitted from February 2019 to June 2021. Multi-slice CT data (DICOM) of DMTNO in both groups were collected and imported into Arigin 3D Pro 3D reconstruction software to reconstruct and observe the 3D morphology of DMTNO. The dorsal convex distance, medial convex distance and anterior convex distance of DMTNO were measured to find their association with AAIS.Results:In the case group, DMTNO clearly showed a flat polyhedral shape with a large base and a small top; in the control group, DMTNO showed various shapes that were different mainly in an irregular top but similar in a large, long and narrow base. The dorsal convex distance [(8.07±2.30) mm] and medial convex distance [(6.70±2.62) mm] in the case group were significantly larger than those in the control group [(3.59±1.10) mm and (1.98±0.93) mm] ( P<0.05), but there was no significant difference between the 2 groups in the anterior convex distance ( P>0.05). Conclusions:The DMTNO leading to AAIS shows a flat polyhedral shape with a large base and a small top. No correlation is found between the anterior convex and AAIS whereas the dorsal convex and medial convex of DMTNO may be closely associated with AAIS.
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Objective:To investigate a rapid protocol for the acquisition of a three-dimensional (3D) image of corneal nerve distribution and its various parameters.Methods:Four SPF female C57BL/6 mice were selected and four corneal samples with complete limbi were obtained using a dissecting microscope after the sacrifice of mice euthanized by ether.After conventional fixation, permeabilization, and immunostaining by an anti-β-Ⅲ tubulin fluorescent-conjugated antibody, a whole-nerve image of the whole-mount cornea was captured under a 60X oil lens using a scientific complementary metal-oxide-semiconductor detector and a high-resolution deconvolution microscope.The 3D image of the corneal nerve fiber was obtained after 3D deconvolution processing, Z-axis data projection, and automatic stitching using the self-contained image processing software of the microscope system.The corneal nerve density in different areas was analyzed using the automatic detection mode in the Filament Tracer module and the manual Autopath module of the interactive microscopic image analysis software Imaris.The use and care of animals complied with the statement of the Association for Research in Visual and Ophthalmology, and the study protocol was approved by an Experimental Animal Welfare Committee of Jinan University (No.JN-A-2002-01).Results:It was found that stromal nerve fibers in a dense network entered the Bowman membrane near the limbus, and branches of stromal nerve fibers formed subbasal nerve plexus, which stretched toward the center of the cornea to form a dense neural network-like structure and converged into a vortex-like structure at the apex of the cornea.Some subbasal nerves entered the epithelial layer vertically and some branches of nerve endings were found.Through the automatic detection mode of Imaris software, a gradual increase of the density from (2 488.88±282.84)μm/μm 2 at the limbus to (5 766.66±298.55)μm/μm 2 at the center of the cornea of the subbasal nerve branches, and a decrease of the density from (40.99±0.99)μm/μm 2 at the limbus to (34.57±1.28)μm/μm 2 at the center of the stromal nerves were found.It was also found that the stromal nerves at the limbus entered the Bowman membrane for about 151 μm and then began to branch to form subbasal nerves. Conclusions:The high-resolution deconvolution microscope system can be used to study the 3D distribution of the whole corneal nerve.Additionally, Imaris can be used for obtaining various parameters of the corneal nerves automatically and quickly.
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Objective:To investigate the effects of total-body PET/CT imaging with short acquisition time on image quality and lesion detectability in lungs and parenchymal organs.Methods:Sixty patients (31 males, 29 females, age (61.1±11.8) years) with pulmonary nodules (PN) and 53 patients (29 males, 24 females, age (56.7±17.2) years) with parenchymal organ lesions (POL) who underwent total-body PET/CT imaging in the First Affiliated Hospital of Shandong First Medical University between October 2021 and April 2022 were retrospectively analyzed. The acquisition time with PET was 600 s, and the reconstructed images were divided into 6 groups based on different duration (30, 60, 120, 180, 300 and 600 s), namely G30, G60, G120, G180, G300 and G600 groups. The subjective analysis was carried out with the 5-point Likert scale in 3 aspects: the overall impression of image quality, noise, and lesion conspicuity. The objective analysis indicators included the SUV mean of the mediastinal blood pool (MBP); the SUV mean, standard deviation (SD) and signal-to-noise ratio (SNR) of the liver; SUV max and target-to-background ratio (TBR) of the lesions. Differences of the indicators among 6 groups were analyzed by Friedman test with Bonferroni correction. G600 served as the reference for the other 5 groups to test their lesion detectability. Results:The subjective image quality of different groups for PN and that of G120, G180, G300 groups for POL could meet the needs of clinical diagnosis in terms of the overall image quality, noise, and lesion conspicuity (all scores>3). There was no significant difference in the SUV mean of MBP among different time groups (median for PN: 1.52-1.56, median for POL: 1.35-1.47; χ2 values: 10.23, 11.02, both P>0.05). Difference was not found in SUV mean of the liver either (median for PN: 2.51-2.56, median for POL: 2.33-2.40; χ2 values: 8.35, 8.93, both P>0.05). The liver SD significantly increased along with the shortened acquisition time ( χ2 values: 400.99, 400.00, both P<0.001; z values: from -16.90 to -3.15, all P<0.003). The SNR significantly decreased along with the shortened acquisition time ( χ2 values: 397.32, 400.00, both P<0.001; z values: 2.98-16.90, all P<0.003). The SUV max (median for PN: 3.55-4.01, median for POL: 5.77-6.08; χ2 values: 8.58, 3.02, both P>0.05) and TBR (median for PN: 2.42-2.81, median for POL: 2.36-2.45; χ2 values: 9.83, 3.69, both P>0.05) of lesion were not significantly different among 6 groups. Taking G600 group as a reference, the lesion detection rates were 100% in G30 group and other 4 groups for PN (81/81) and in G120, G180, G300 groups for POL (80/80). Conclusion:Total-body PET/CT imaging with acquisition time of 30 s for lungs and that with acquisition time of 120 s for parenchymal organs are feasible for clinical use, with the PET image quality and lesion detectability maintained.
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Objective:To investigate the value of generative adversarial networks-based PET image reconstruction in improving the quality of low-dose 18F-FDG PET images and lesion detection in pediatric patients. Methods:Retrospective analysis of 61 PET images of children (38 males, 23 females, age (4.0±3.5) years) who underwent 18F-FDG total-body PET/CT imaging in Beijing Friendship Hospital, Capital Medical University from August 2021 to December 2021 was performed. The low-dose images (30 s, 20 s, 10 s) of all children extracted by list mode were input into the generative adversarial networks for deep learning (DL) reconstruction to obtain the corresponding simulated standard full-dose images (DL-30 s, DL-20 s, DL-10 s). The semi-quantitative parameters of the liver blood pool and primary lesion of standard full-dose 120 s, 30 s, 20 s, 10 s, DL-30 s, DL-20 s, and DL-10 s images were measured. The target-to-background ratio (TBR), contrast-to-noise ratio (CNR), and CV were calculated. The 5-point Likert scale was used for subjective scoring of image quality, and the detective abilities for positive lesions of each groups were compared. The sensitivities and positive predictive values of positive lesions detection were calculated. Mann-Whitney U test and Kruskal-Wallis rank sum test and χ2 test were used for data analyses. Results:CNR of the 30 s, 20 s, and 10 s groups were lower than those of DL-30 s, DL-20 s, and DL-10 s groups, respectively ( z values: -3.58, -3.20, -3.65, all P<0.05). Score of DL-10 s group was significantly lower than those of 120 s, DL-30 s and DL-20 s groups (4(3, 4), 5(4, 5), 4(4, 5), 4(4, 5); H=97.70, P<0.001). There were no significant differences in TBR, CNR, CV, SUV max and SUV mean of lesions and liver blood pool in 120 s, DL-30 s, DL-20 s, and DL-10 s groups ( H values: 0.00-6.76, all P>0.05). The sensitivities of positive lesion detection in DL-30 s, DL-20 s, and DL-10 s groups were 97.83%(225/230), 96.96%(223/230), 95.65%(220/230), respectively, and the positive predictive values were 96.57%(225/233), 93.70%(223/238), 84.94%(220/259), respectively. The positive predictive value in DL-10 s group was lower than those in DL-30 s and DL-20 s groups ( χ2=23.51, P<0.001). There were more false-positive and false-negative lesions detected by DL-10 s group than those of DL-30 s and DL-20 s groups in different sites. Conclusion:Based on the generative adversarial networks, the image quality of DL-20 s group is high and can meet the clinical diagnostic requirements.
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Abstract Objective: To evaluate the degree of similarity between manual and semiautomatic segmentation of soft-tissue sarcomas on magnetic resonance imaging (MRI). Materials and Methods: This was a retrospective study of 15 MRI examinations of patients with histopathologically confirmed soft-tissue sarcomas acquired before therapeutic intervention. Manual and semiautomatic segmentations were performed by three radiologists, working independently, using the software 3D Slicer. The Dice similarity coefficient (DSC) and the Hausdorff distance were calculated in order to evaluate the similarity between manual and semiautomatic segmentation. To compare the two modalities in terms of the tumor volumes obtained, we also calculated descriptive statistics and intraclass correlation coefficients (ICCs). Results: In the comparison between manual and semiautomatic segmentation, the DSC values ranged from 0.871 to 0.973. The comparison of the volumes segmented by the two modalities resulted in ICCs between 0.9927 and 0.9990. The DSC values ranged from 0.849 to 0.979 for intraobserver variability and from 0.741 to 0.972 for interobserver variability. There was no significant difference between the semiautomatic and manual modalities in terms of the segmentation times (p > 0.05). Conclusion: There appears to be a high degree of similarity between manual and semiautomatic segmentation, with no significant difference between the two modalities in terms of the time required for segmentation.
Resumo Objetivo: Verificar a similaridade entre as segmentações manual e semiautomática de sarcomas de tecidos moles na ressonância magnética (RM) e a similaridade interobservador e intraobservador entre as segmentações manuais. Materiais e Métodos: Estudo retrospectivo que incluiu 15 exames de RM de pacientes com diagnóstico de sarcoma de tecidos moles realizados antes de intervenções terapêuticas. As segmentações manual e semiautomática foram realizadas por três radiologistas utilizando o software 3D Slicer. O coeficiente de similaridade Dice (CSD) e a distância de Hausdorff foram utilizados para avaliar a similaridade das segmentações. Análise estatística descritiva e coeficiente de correlação intraclasse (CCI) foram realizados para comparar volumes tumorais. Resultados: A comparação dos métodos manual e semiautomático obteve valores de CSD entre 0,871 e 0,973. A comparação dos volumes segmentados pelos dois métodos de segmentação mostrou CCI entre 0,9927 e 0,9990. As análises intraobservador e interobservador obtiveram valores de CSD, respectivamente, de 0,849 a 0,979 e de 0,741 a 0,972. Não houve diferença significativa entre os tempos de segmentação dos métodos semiautomático e manual (p > 0,05). Conclusão: Houve alta similaridade entre as segmentações de sarcomas de tecidos moles obtidas pelos métodos manual e semiautomático, sem diferença significativa para o tempo despendido para as segmentações.