Radiomic analysis of lung cancer for the assessment of patient prognosis and intratumor heterogeneity / Análise radiômica do câncer de pulmão para avaliação prognóstica do paciente e da heterogeneidade intratumoral

Abstract Objective: To determine whether the radiomic features of lung lesions on computed tomography correlate with overall survival in lung cancer patients. Materials and Methods: This was a retrospective study involving 101 consecutive patients with malignant neoplasms confirmed by biopsy or surgery. On computed tomography images, the lesions were submitted to semi-automated segmentation and were characterized on the basis of 2,465 radiomic variables. The prognostic assessment was based on Kaplan-Meier analysis and log-rank tests, according to the median value of the radiomic variables. Results: Of the 101 patients evaluated, 28 died (16 dying from lung cancer), and 73 were censored, with a mean overall survival time of 1,819.4 days (95% confidence interval [95% CI]: 1,481.2-2,157.5). One radiomic feature (the mean of the Fourier transform) presented a difference on Kaplan-Meier curves (p < 0.05). A high-risk group of patients was identified on the basis of high values for the mean of the Fourier transform. In that group, the mean survival time was 1,465.4 days (95% CI: 985.2-1,945.6), with a hazard ratio of 2.12 (95% CI: 1.01-4.48). We also identified a low-risk group, in which the mean of the Fourier transform was low (mean survival time of 2,164.8 days; 95% CI: 1,745.4-2,584.1). Conclusion: A radiomic signature based on the Fourier transform correlates with overall survival, representing a prognostic biomarker for risk stratification in patients with lung cancer.

Resumo Objetivo: Associar características radiômicas de lesões pulmonares em imagens de tomografia computadorizada com a sobrevida global de pacientes com câncer de pulmão. Materiais e Métodos: Estudo retrospectivo composto por 101 pacientes consecutivos com neoplasia maligna confirmada por biópsia/cirurgia. As lesões foram semiautomaticamente segmentadas e caracterizadas por 2.465 variáveis radiômicas. A avaliação prognóstica foi baseada na análise de Kaplan-Meier e no teste log-rank, de acordo com a mediana dos valores das variáveis. Resultados: Vinte e oito pacientes faleceram (16 por câncer de pulmão) e 73 foram censurados, com tempo médio de sobrevida de 1.819,4 dias (intervalo de confiança 95% [IC 95%]: 1.481,2-2.157,5). Uma característica radiômica (média de Fourier) apresentou diferença nas curvas de Kaplan-Meier (p < 0,05). Um grupo de pacientes de maior risco foi identificado a partir de valores altos da variável: sobrevida de 1.465,4 dias (IC 95%: 985,2-1.945,6) e razão de risco de 2,12 (IC 95%: 1,01-4,48). Um grupo de menor risco foi identificado a partir de valores baixos da variável (sobrevida de 2.164,8 dias; IC 95%: 1.745,4-2.584,1). Conclusão: Este estudo apresentou uma assinatura radiômica em imagens de tomografia computadorizada, baseada na transformada de Fourier, correlacionada com a sobrevida global de pacientes com câncer de pulmão, representando assim um biomarcador prognóstico.

Advances in clinical assessment of bone healing / 中华创伤骨科杂志

The process of bone healing is absolutely complicated and affected by a wide variety of factors. The quality of bone healing directly determines management approaches. Therefore, it is crucial to evaluate accurately outcomes of bone healing. The assessments of bone healing mostly used in current clinical practice are a combination of clinical manifestations and X-ray examination while computed tomography (CT) and ultrasound may be applied alternatively for particular parts and populations. As understanding of bone healing process and bone biomechanical structure is deepening in recent years, both traditional and novel assessments of bone healing have been well refined. This review will expound on the advantages, disadvantages and clinical indications of various assessments, as well as their future development trends, to provide useful information for clinicians.

Radiomic feature analysis of computed tomography images for the diagnosis of invasive pulmonary adenocarcinoma appearing as ground-glass nodules / 中国基层医药

Objective:To investigate the value of radiomic features of computed tomography (CT) images in the diagnosis of invasive pulmonary adenocarcinoma appearing as part-solid ground-glass nodules.Methods:The clinical data of 100 part-solid ground-glass nodules from 88 patients with pulmonary adenocarcinoma confirmed by pathological diagnosis who received surgical treatment in Taizhou Tumor Hospital, China between February 2016 and April 2019 were retrospectively analyzed. Among these 100 part-solid ground-glass nodules, 56 from 53 patients were diagnosed as invasive pulmonary adenocarcinoma and 44 from 35 patients as non-invasive pulmonary adenocarcinoma. A set of regular risk factors and visually-assessed qualitative CT imaging features were compared with the radiomic features using logistic regression analysis. Three diagnostic models, i.e., a basis model using the clinical risk factors and qualitative CT features, a radiomics model using significant radiomic features, and a nomogram model combining all significant features, were established and their diagnostic efficacy was compared based on receiver operating characteristic (ROC) curves. Decision curve analysis was performed for the nomogram model to explore its potential clinical benefit.Results:Multiple logistic regression analysis showed that three qualitative CT imaging features (pleural traction ( P = 0.006), solid component size ( P = 0.045) and solid component proportion ( P = 0.020)) and quantitative Rad score ( P = 0.046) were significantly correlated with invasive pulmonary adenocarcinoma. The adjusted ratios were 7.189, 0.075, 194.786 and 2.016, respectively. The diagnostic nomogram model based on these four features showed that the area under the ROC curve (AUC) was 0.903 (95% CI: 0.845, 0.975). The diagnostic nomogram model showed a significantly higher performance (AUC = 0.903) in differentiating invasive pulmonary adenocarcinoma from non-invasive pulmonary adenocarcinoma than either the basis model (AUC = 0.853, P = 0.000) or the radiomics model (AUC = 0.769, P < 0.001). Decision curve analysis indicated a potential benefit of using such a nomogram model in clinical diagnosis. Conclusion:Quantitative radiomic features provide additional information regarding clinically-assessed qualitative features for differentiating invasive pulmonary adenocarcinoma from non-invasive pulmonary adenocarcinoma appearing as ground-glass nodules, and a diagnostic nomogram model including all these significant features may be clinically useful in preoperative strategy planning.

Soft Tissue Cephalometric Measurements Among Malaysian Malays and Chinese

Abstract Objective: To obtain the standardized values of individuals of Malaysian Malay and Chinese for further relevant research, such as treatment planning and aesthetical considerations. Material and Methods: In this retrospective study, 440 (305 were Malays and 135 were Chinese) standardized lateral cephalometric radiographs of orthodontic patients selected through simple random sampling are profiled using Holdaway's analysis. The independent t-test was used to assess the disparities in race and gender. The significant level was p<0.05. Results: Significant differences were found between the Malays and Chinese in their skeletal profile convexity, superior sulcus depth, inferior sulcus to the H line and nose prominence. Between Malay females and males, there are significant differences in superior sulcus depth, soft tissue subnasale to H line, basic upper lip thickness, upper lip thickness and nose prominence. Between Chinese males and females, there were differences in their skeletal profile convexity, upper lip to H line, basic upper lip thickness and upper lip thickness. Conclusion: The findings demonstrated the difference between standardized norms and the unique profiles of Malaysian Malays and Chinese. There are significant gender disparities in the soft tissue cephalometric measurements among Malaysian Malay and Chinese subjects.

Quantification of Metal Artefacts from Orthodontic Brackets in CT Images: A Modified Method

@#Any metallic object within the CT scanning field can produce metal artefacts, which will degrade the diagnostic image quality. Previous methods described for quantifying this kind of artefacts were complicated and difficult to reproduce. The purpose of this study was to introduce a new rapid method for quantifying the artefacts produced in craniofacial CT images. This is an in-vitro experimental study. Four different compositions of orthodontic brackets were bonded consecutively in the tooth surfaces of a cadaveric skull head. All scans were performed by a single operator using the same CT machine followed by a standard scanning protocol. Artefact intensity for all data sets was quantified by following a modified method with a freely available open-source software ImageJ. All datasets were duplicated where metal artefacts were quantified according to the previous conventional method. Statistical analysis included independent samples t-test for validation and intraclass correlation coefficient (ICC) with a 95% confidence interval for both intra- and inter-examiner reliability. The modified method of measuring artefact score exhibited excellent intra (0.997–0.941) and inter-rater (0.996–0.905) reliability. In addition, no significant difference (p = 0.072) of mean artefact score was noted between the groups measured by the modified method and the conventional method. This modified method for measuring the artefact intensity is valid and reliable.

Application of quantitative imaging technique in the diagnosis of pancreatic cancer / 中国基层医药

Pancreatic cancer is a malignant tumor,and the clinical manifestations are not characteristic,so it is difficult to diagnose at an early stage, and it has a poor prognosis. Image technology has been widely used in clinical,with mature technology,and the application of image technology not only confined to the image display,but also has become a hot spot of research, including dynamic contrast enhancement magnetic resonance imaging (DCE－MRI),intravoxel incoherent motion ( IVIM),CT perfusion imaging,which could analyze quantitatively the permeability and microvascular of lesions,to improve the sensitivity of diagnosis,and to assess quantitatively the effect of drugs,radiation and chemotherapy.

Risk assessment of hepatocellular carcinoma development for indeterminate hepatic nodules in patients with chronic hepatitis B

BACKGROUND/AIMS: A risk prediction model for the development of hepatocellular carcinoma (HCC) from indeterminate nodules detected on computed tomography (CT) (Rad(CT) score) in patients with chronic hepatitis B (CHB)-related cirrhosis was proposed. We validated this model for indeterminate nodules on magnetic resonance imaging (MRI).METHODS: Between 2013 and 2016, Liver Imaging Reporting and Data System (LI-RADS) 2/3 nodules on MRI were detected in 99 patients with CHB. The Rad(CT) score was calculated.RESULTS: The median age of the 72 male and 27 female subjects was 58 years. HCC history and liver cirrhosis were found in 47 (47.5%) and 44 (44.4%) patients, respectively. The median Rad(CT) score was 112. The patients with HCC (n=41, 41.4%) showed significantly higher Rad(CT) scores than those without (median, 119 vs. 107; P=0.013); the Chinese university-HCC and risk estimation for HCC in CHB (REACH-B) scores were similar (both P>0.05). Arterial enhancement, T2 hyperintensity, and diffusion restriction on MRI were not significantly different in the univariate analysis (all P>0.05); only the Rad(CT) score significantly predicted HCC (hazard ratio [HR]=1.018; P=0.007). Multivariate analysis showed HCC history was the only independent HCC predictor (HR=2.374; P=0.012). When the subjects were stratified into three risk groups based on the Rad(CT) score (<60, 60–105, and >105), the cumulative HCC incidence was not significantly different among them (all P>0.05, log-rank test).CONCLUSIONS: HCC history, but not Rad(CT) score, predicted CHB-related HCC development from LI-RADS 2/3 nodules. New risk models optimized for MRI-defined indeterminate nodules are required.

Correlation between ahlbäck classification and gonarthrosis risk factors / Correlação entre a classificacão de ahlbäck e fatores de risco da gonartrose

ABSTRACT Objective: To demonstrate whether or not there is a correlation between the risk factors for gonarthrosis and the radiographic classification of Ahlbäck. Methods: We studied patients with primary gonarthrosis attended at the knee outpatient clinic of the General Hospital of Vila Penteado during their routine visit. We collected data on patient age (years), weight (kg), height (meters), body mass index (BMI = patient weight/height2), personal history of hypertension or diabetes mellitus (positive or negative), sedentarism (physical activity less than three times per week, 30 minutes per session), functional demand (how many blocks walked weekly), time of onset of symptoms (in years) and laterality or bilaterality. The data were correlated with the Ahlbäck classification applied to the radiographs performed at the time of the consultation. Results: A sample of 108 patients was studied. We did not find an association between the Ahlbäck classification and the patient's age, smoking, sedentary lifestyle, laterality, number of blocks walked per week, diabetes mellitus, and sex; however, a positive association was observed in hypertensive patients as well as a weak correlation with height and weight of the patient and moderate correlation with BMI. Conclusion: The Ahlbäck classification is unrelated to most of the risk factors for primary gonarthrosis. Level of evidence III, Case-control study.

RESUMO Objetivo: Demonstrar se existe ou não correlação entre os fatores de risco de gonartrose e a classificação radiográfica de Ahlbäck. Métodos: Estudamos pacientes com gonartrose primária, assistidos no ambulatório de joelho do Hospital Geral de Vila Penteado em sua consulta de rotina. Foram coletados dados referentes a idade do paciente (anos), peso do paciente (kg), altura (metros), índice de massa corporal (IMC= peso do paciente/altura2), antecedente pessoal de hipertensão ou diabetes mellitus (positivo ou negativo), sedentarismo (se pratica atividade física menos de três vezes por semana, 30 minutos por sessão), demanda funcional (quantas quadras caminha semanalmente), tempo do início dos sintomas (em anos) e lateralidade ou bilateralidade. Os dados foram correlacionados com a classificação de Ahlbäck aplicada às radiografias realizadas no momento da consulta. Resultados: Uma amostra de 108 pacientes foi estudada. Não encontramos associação entre a classificação de Ahlbäck e a idade do paciente, tabagismo, sedentarismo, lateralidade, quantidade de quadras percorridas por semana, diabetes mellitus e sexo do paciente, porém verificou-se associação positiva em pacientes hipertensos e correlação fraca com altura e peso do paciente e correlação moderada com IMC. Conclusão: A classificação de Ahlbäck não apresenta relação com a maioria dos fatores de risco de gonartrose primária. Nível de evidência III, Estudo caso-controle.

Pedicle exposure technique for atlas screw fixation:a radiological research / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the meaning of pedicle exposure technique for screw fixation on atlas with the vertebral groove height less than 4 mm by using reconstructive computed tomography.</p><p><b>METHODS</b>From April 2015 to June 2015, 84 pedicles of 51 patients with groove heights less than 4 mm were studied by digital reconstruction respectively. Parameters of atlas pedicle screw fixation were measured.</p><p><b>RESULTS</b>Among the 51 cases, the vertebral groove height was (3.28±0.51) mm. Lateral mass heights, lateral mass widths and the transition area heights between lateral mass and posterior arch were fit for 3.5 mm screw implanting. Ideal pedicle screw trajectory lengths from 0° to 15° (0°, 5°, 10°, 15°) were (27.36±1.81), (27.01±1.68), (27.07±1.75), (27.48±1.72) mm, exposed trajectory lengths from 0° to 15°(0°, 5°, 10°, 15°) were(23.44±1.79), (23.87±1.84), (24.58±1.89), (25.56±2.01) mm, trajectory length of lateral mass was (20.78±2.05) mm. The mean CT values on 5 sections through pedicle trajectory and lateral mass trajectory were (701.89±141.48) HU and (599.11±137.33) HU, respectively. There were no significant differences between ideal pedicle trajectory lengths from 0° to 15°(>0.05). Exposed trajectory lengths was significantly increased accompanying with medial angles increasing (<0.05), and was longer than trajectory lengths of lateral mass (<0.05). CT value of pedicle screws was higher than CT value of lateral mass screws significantly (<0.01).</p><p><b>CONCLUSIONS</b>Screws can be implanted in atlas with vertebral groove height less than 4 mm by using pedicle exposure technique. Few trajectory lengths will be sacrificed with favorable pull out strength due to adequate bone mass purchased.</p>

New method of assessing the relationship between buccal bone thickness and gingival thickness

PURPOSE: The aim of this study was to determine the relationship between buccal bone thickness and gingival thickness by means of a noninvasive and relatively accurate digital registration method. METHODS: In 20 periodontally healthy subjects, cone-beam computed tomographic images and intraoral scanned files were obtained. Measurements of buccal bone thickness and gingival thickness at the central incisors, lateral incisors, and canines were performed at points 0–5 mm from the alveolar crest on the superimposed images. The Friedman test was used to compare buccal bone and gingival thickness for each depth between the 3 tooth types. Spearman's correlation coefficient was calculated to assess the correlation between buccal bone thickness and gingival thickness. RESULTS: Of the central incisors, 77% of all sites had a buccal thickness of 0.5–1.0 mm, and 23% had a thickness of 1.0–1.5 mm. Of the lateral incisors, 71% of sites demonstrated a buccal bone thickness <1.0 mm, as did 63% of the canine sites. For gingival thickness, the proportion of sites <1.0 mm was 88%, 82%, and 91% for the central incisors, lateral incisors, and canines, respectively. Significant differences were observed in gingival thickness at the alveolar crest level (G0) between the central incisors and canines (P=0.032) and between the central incisors and lateral incisors (P=0.013). At 1 mm inferior to the alveolar crest, a difference was found between the central incisors and canines (P=0.025). The lateral incisors and canines showed a significant difference for buccal bone thickness 5 mm under the alveolar crest (P=0.025). CONCLUSIONS: The gingiva and buccal bone of the anterior maxillary teeth were found to be relatively thin (<1 mm) overall. A tendency was found for gingival thickness to increase and bone thickness to decrease toward the root apex. Differences were found between teeth at some positions, although the correlation between buccal bone thickness and soft tissue thickness was generally not significant.

Iterative reconstruction improves imaging quality of low er -radiation CT perfusion in patients w ith acute ischemic stroke / 国际脑血管病杂志

Objective To investigate w hether the iterative reconstruction (iDose 4 ) technique improves imaging quality of the low-radiation-dose w hole brain CT perfusion (CTP). Methods Thirty-five consecutive patients w ith clinical y suspected ischemic stroke w ere col ected. Bril iance 256 iCT w as used to perform low-radiation-dose w hole brain CTP, and the filtered back projection (FBP) and iDose 4 algorithm w ere used to conduct image reconstruction. The noise and signal to noise ratio of the 2 kinds of reconstruction algorithms, as w el as the imaging quality of each parameter map w ere compared. Results The effective dose of the w hole brain CTP w as 2.2 mSv. Compared w ith FBP, the noise of each region of interest in the iDose4 Tmax map was decreased significantly ( P<0.05) and the signal to noise ratio was increased significantly (P<0.05). The imaging quality scores (median, interquartile range) reconstructed by FPB group w ere significantly low er than by iDose 4 for cerebral blood flow (CBF) map ( 5.00 [3.00-6.00]vs. 6.00 [5.00-6.00]; Z= -2.784, P=0.005), cerebral blood volume (CBV) map ( 6.00 [5.00-6.00] vs. 6.00 [6.00-7.00]; Z= -3.674, P<0.001), and mean transit time (MTT) map (4.00 [3.00-5.00] vs. 5.00 [4.00-6.00]; Z=3.394, P=0.001). The proportions of the poor quality in CBF map ( 34.3%vs. 11.4%;χ2 =7.036, P=0.030), CBV map (11.4%vs.2.9%; χ2 =7.485, P=0.024 ) and MTT map (28.6%vs.11.4%;χ2 =5.318, P=0.070) reconstructed by FBP w ere significantly higher than by iDose 4 . Conclusions The iDose4 technique may improve imaging quality of low er-radiation-dose CTP.

Mammographic Breast Density Evaluation in Korean Women Using Fully Automated Volumetric Assessment

The purpose was to present mean breast density of Korean women according to age using fully automated volumetric assessment. This study included 5,967 screening normal or benign mammograms (mean age, 46.2 +/- 9.7; range, 30-89 years), from cancer-screening program. We evaluated mean fibroglandular tissue volume, breast tissue volume, volumetric breast density (VBD), and the results were 53.7 +/- 30.8 cm3, 383.8 +/- 205.2 cm3, and 15.8% +/- 7.3%. The frequency of dense breasts and mean VBD by age group were 94.3% and 19.1% +/- 6.7% for the 30s (n = 1,484), 91.4% and 17.2% +/- 6.8% for the 40s (n = 2,706), 72.2% and 12.4% +/- 6.2% for the 50s (n = 1,138), 44.0% and 8.6% +/- 4.3% for the 60s (n = 89), 39.1% and 8.0% +/- 3.8% for the 70s (n = 138), and 39.1% and 8.0% +/- 3.5% for the 80s (n = 12). The frequency of dense breasts was higher in younger women (n = 4,313, 92.3%) than older women (n = 1,654, 59.8%). Mean VBD decreased with aging or menopause, and was about 16% for 46-year-old-Korean women, much higher than in other countries. The proportion of dense breasts sharply decreases in Korean women between 40 and 69 years of age.

Clinical and radiological features of hypertensive brainstem encephalopathy / 解放军医学杂志

Objective To discuss the diagnosis and treatment of hypertensive brainstem encephalopathy. Methods The clinical and imaging data of 3 cases of hypertensive brainstem encephalopathy were summarized and analyzed for the purpose of improving the acumen in diagnosis and treatment. Results All the 3 patients showed relatively mild clinical symptoms, and they were misdiagnosed in different degrees during the treatment, but their clinical symptoms were improved by rapid and effective antihypertensive therapy. Cerebral CT and MRI scans revealed extensive abnormal signals in brain stem, with or without supratentorial lesions and brain stem hemorrhage. The lesions as revealed by imaging were improved significantly after treatment. Conclusions Clinical-radiographic dissociation is the classic feature of hypertensive brainstem encephalopathy. The clinical symptoms and lesions as shown by imaging could be improved after active treatment.

Distance learning in dental radiology: immediate impact of the implementation / Educação à distância em radiologia odontológica: Impacto imediato da implantação

Objective: This study assessed the immediate impact in terms of learning dento-maxillomandibular radiographic anatomy in intraoral periapical radiographs after entire replacement of the method of classroom learning by the distance learning using the Moodle platform. Material and Methods: Teaching of this subject by traditional educational setting in classroom was made until the first semester of 2011, “A class” (AC), using radiographic slabs from duplicated films with imprints indicating anatomical structures in images that is accompanied by textbook with its description and support teacher, who works closely with the classroom to support student learning. In the second semester of 2011, “B class” (BC), these same radiographic slabs were digitalized, including description of textbook, creating the Moodle e-course about dentomaxillomandibular anatomy in intraoral radiographs for distance learning. The impact was assessed by comparison of scores of students from two distinct classes, AC (N = 60) and BC (N = 62), after application of a similar test with all content of the topic of dento-maxillomandibular anatomy, using T-Student unpaired test (α = 0.05). A voluntary and unidentified questionnaire with 12 questions, developed in Google Docs spreadsheets, was used to evaluate the acceptance of students for this e-course. Results: No significant differences (p > 0.05) were observed in scores of the students from two classes. Among other questions, all students of BC who completed the questionnaire had interest in content of the available material in e-course, and their satisfaction level on a scale from 0 to 10 had a mean of 8.47 (SD = 1.69). Conclusion: The method of distance learning of this subject using the Moodle platform can be utilized with same educational results as of those obtained from a traditional educational setting...

Objetivo: Este estudo avaliou o impacto imediato em termos de aprendizagem da anatomia radiográfica dento-maxilo-mandibular em radiografias periapicais intrabucais, após toda a substituição do método de ensino em sala de aula pela educação a distância com a plataforma Moodle. Material e Métodos: O ensino desta disciplina no ambiente educacional tradicional em sala de aula foi feito até o primeiro semestre de 2011, classe A (AC), utilizando pranchas de filmes radiográficos duplicados com marcações que indicavam estruturas anatômicas nas imagens eum livro texto com a descrição da referida estrutura, além de professor de apoio, que trabalhava na sala de aula junto com os alunos como apoio de aprendizagem. No segundo semestre de 2011, para a “classe B” (BC), essas mesmas pranchas radiográficas foram digitalizadas, incluindo a descrição do livro texto, para criar o curso digital Moodle sobre anatomia dentomaxilo- mandibular em radiografias intra-orais para educação a distância. O impacto dessa substituição foi avaliado pela comparação das notas dos alunos dessas duas classes distintas, AC (N= 60) e BC (N = 62), após a aplicação de uma prova semelhante com todo o conteúdo do tema da anatomia dentomaxilo- mandibular, utilizando teste T-Student não pareado (α = 0,05). Um questionário voluntário e não identificado com 12 questões, desenvolvido em planilhas do Google Docs, foi utilizado para avaliar a aceitação dos alunos em relação ao curso digital. Resultados: Não houve diferença significativa (p > 0,05) entre as notas dos alunos das duas classes. Em relação às respostas do questionário, todos os alunos da BC que responderam ao questionário tinham interesse no conteúdo do material disponível no curso digital e o nível de satisfação medido em uma escala de 0 a 10 obteve média de 8,47 (DP = 1,69)...

Computer-aided detection system for masses in automated whole breast ultrasonography: development and evaluation of the effectiveness

PURPOSE: The aim of this study was to evaluate the performance of a proposed computer-aided detection (CAD) system in automated breast ultrasonography (ABUS). METHODS: Eighty-nine two-dimensional images (20 cysts, 42 benign lesions, and 27 malignant lesions) were obtained from 47 patients who underwent ABUS (ACUSON S2000). After boundary detection and removal, we detected mass candidates by using the proposed adjusted Otsu's threshold; the threshold was adaptive to the variations of pixel intensities in an image. Then, the detected candidates were segmented. Features of the segmented objects were extracted and used for training/testing in the classification. In our study, a support vector machine classifier was adopted. Eighteen features were used to determine whether the candidates were true lesions or not. A five-fold cross validation was repeated 20 times for the performance evaluation. The sensitivity and the false positive rate per image were calculated, and the classification accuracy was evaluated for each feature. RESULTS: In the classification step, the sensitivity of the proposed CAD system was 82.67% (SD, 0.02%). The false positive rate was 0.26 per image. In the detection/segmentation step, the sensitivities for benign and malignant mass detection were 90.47% (38/42) and 92.59% (25/27), respectively. In the five-fold cross-validation, the standard deviation of pixel intensities for the mass candidates was the most frequently selected feature, followed by the vertical position of the centroids. In the univariate analysis, each feature had 50% or higher accuracy. CONCLUSION: The proposed CAD system can be used for lesion detection in ABUS and may be useful in improving the screening efficiency.

Anterior and medial angulations of the styloid process in subjects with TMD: clinical and radiographic findings

This study investigated the existence of association between the angulation of the styloid process on the anterior and medial directions with the intensity of temporomandibular dysfunction (TMD) symptoms. Fifty patients (8 men and 42 women) aged 25 to 70 years, with relevant TMD symptoms were evaluated. Clinical examinations were performed to determine the severity of TMD symptoms (orofacial pain, headache, tinnitus and dizziness) based on the RDC/TMD criteria and the visual analogue scale (VAS), and digital radiographic images of the styloid process were obtained: lateral cephalometric skull radiograph (analysis of anterior angulation) and posteroanterior skull radiograph (reverse Towne's projection) (analysis of medial angulation). The anterior angulation average of the styloid process was 20.89° while the medial angulation average was 19.1° in the right side and 19.04° in the left side. There was no statistically significant difference among the patient groups (severe, moderate and mild symptoms) associating the TMD symptoms and the anterior or medial angulation of the styloid process (p>0.05). There was no correlation between the intensity of the TMD symptoms and the measurements of anterior and medial angulation of the styloid process using either lateral cephalometric or posteroanterior radiographs (reverse Towne's projection).

Este estudo investigou a existência de associação entre a angulação do processo estiloide nas direções anterior e medial e a intensidade dos sintomas de disfunção temporomandibular. Cinquenta pacientes (8 homens e 42 mulheres) com idade entre 25 a 70 anos, com sintomas relevantes de DTM foram avaliados. Os exames clínicos foram realizados para determinar a severidade dos sintomas da DTM (dor orofacial, cefaleia, zumbido e tontura) com base nos critérios do RDC / DTM e na escala visual analógica (EVA), e imagens de radiografias digitais do processo estiloide foram obtidas: cefalométrica lateral com incidência reversa (análise de angulação anterior), e póstero-anterior do crânio (projeção reversa de Towne) (análise de angulação medial). A média de angulação anterior do processo estilóide foi 20,89°, enquanto a média da angulação medial foi 19,1° no lado direito e 19,04° no lado esquerdo. Não houve diferença estatisticamente significativa entre os grupos de pacientes (sintomas severos, moderados ou leves) em associação com os sintomas de DTM e as angulações anterior ou medial do processo estiloide (p>0,05). Não houve correlação entre a intensidade dos sintomas de DTM e as medidas das angulações anterior e medial do processo estiloide utilizando a radiografia cefalométrica lateral ou a póstero-anterior (projeção reversa de Towne).

Radiopacity of restorative composites by conventional radiograph and digital images with different resolutions

PURPOSE: This study was performed to evaluate and compare the radiopacity of dentin, enamel, and 8 restorative composites on conventional radiograph and digital images with different resolutions. MATERIALS AND METHODS: Specimens were fabricated from 8 materials and human molars were longitudinally sectioned 1.0 mm thick to include both enamel and dentin. The specimens and tooth sections were imaged by conventional radiograph using #4 sized intraoral film and digital images were taken in high speed and high resolution modes using a phosphor storage plate. Densitometric evaluation of the enamel, dentin, restorative materials, a lead sheet, and an aluminum step wedge was performed on the radiographic images. For the evaluation, the Al equivalent (mm) for each material was calculated. The data were analyzed using one-way ANOVA and Tukey's test (p<0.05), considering the material factor and then the radiographic method factor, individually. RESULTS: The high speed mode allowed the highest radiopacity, while the high resolution mode generated the lowest values. Furthermore, the high resolution mode was the most efficient method for radiographic differentiation between restorative composites and dentin. The conventional radiograph was the most effective in enabling differentiation between enamel and composites. The high speed mode was the least effective in enabling radiographic differentiation between the dental tissues and restorative composites. CONCLUSION: The high speed mode of digital imaging was not effective for differentiation between enamel and composites. This made it less effective than the high resolution mode and conventional radiographs. All of the composites evaluated showed radiopacity values that fit the ISO 4049 recommendations.

Quantitative Measurement Method for Possible Rib Fractures in Chest Radiographs / 대한의료정보학회지

OBJECTIVES: This paper proposes a measurement method to quantify the abnormal characteristics of the broken parts of ribs using local texture and shape features in chest radiographs. METHODS: Our measurement method comprises two steps: a measurement area assignment and sampling step using a spline curve and sampling lines orthogonal to the spline curve, and a fracture-ness measurement step with three measures, asymmetry and gray-level co-occurrence matrix based measures (contrast and homogeneity). They were designed to quantify the regional shape and texture features of ribs along the centerline. The discriminating ability of our method was evaluated through region of interest (ROI) analysis and rib fracture classification test using support vector machine. RESULTS: The statistically significant difference was found between the measured values from fracture and normal ROIs; asymmetry (p < 0.0001), contrast (p < 0.001), and homogeneity (p = 0.022). The rib fracture classifier, trained with the measured values in ROI analysis, detected every rib fracture from chest radiographs used for ROI analysis, but it also classified some unbroken parts of ribs as abnormal parts (8 to 17 line sets; length of each line set, 2.998 +/- 2.652 mm; length of centerlines, 131.067 +/- 29.460 mm). CONCLUSIONS: Our measurement method, which includes a flexible measurement technique for the curved shape of ribs and the proposed shape and texture measures, could discriminate the suspicious regions of ribs for possible rib fractures in chest radiographs.

Chitosan-based biomaterials used in critical-size bone defects: radiographic study in rat's calvaria / Biomateriais a base de quitosana na correção de defeitos ósseos críticos criados em calvaria de ratos: avaliação radiográfica

Objetivo: Este estudo avaliou através de imagens radiográficas digitais, a ação de biomateriais de quitosana e de cloridrato de quitosana, com baixo e alto peso molecular, utilizados na correção de defeitos ósseos de tamanho crítico (DOTC)em calvária de ratos. Material e MétodoO: DOTCs com 8 mm de diâmetro foram criados cirurgicamente na calvária de 50 ratos Holtzman. Em 10 animais o defeito foi preenchido foram preenchidos com coágulo sanguíneo (controle negativo). Os 40 animais restantes foram divididos de acordo com o biomaterial utilizado no preenchimento do defeito (quitosana de baixo peso e de alto peso molecular, e cloridrato de quitosana de baixo e de alto peso molecular), e foram avaliados em dois períodos experimentais (15 e 60 dias), totalizando 5 animais/biomaterial/período de avaliação. Resultado: A avaliação radiográfica foi feita utilizando duas radiografias digitais do crânio do animal: uma tomada logo após o defeito ósseo ser criado e a outra no momento do sacrifício. Nessas imagens, foi avaliada a densidade óssea radiográfica inicial e a final na área do defeito, que foram comparadas. As análises na densidade óssea radiográfica indicaram aumento da densidade óssea radiográfica dos DOTCs tratados para todos os biomateriais testados, em ambos os períodos. Resultados semelhantes foram encontrados no grupo controle. Conclusão: Conclui-se que os biomateriais de quitosana testados não foram capazes de aumentar a densidade radiográfica em DOTC realizados em calvária de ratos.

Objective: This study evaluated, using digital radiographic images, the action of chitosan and chitosan hydrochloride biomaterials, with both low and high molecular weight, used in the correction of critical-size bone defects (CSBD's) in rat's calvaria. Material and Method: CSBD's with 8 mm in diameter were surgically created in the calvaria of 50 Holtzman rats and these were filled with a blood clot (Control), low molecular weight chitosan, high molecular weight chitosan, low molecular weight chitosan hydrochloride and high molecular weight chitosan hydrochloride, for a total of 10 animals, which were divided into two experimental periods (15 and 60 days), for each biomaterial. The radiographic evaluation was made using two digital radiographs of the animal's skull: one taken right after the bone defect was created and the other at the moment of the sacrifice, providing the initial and the final radiographic bone density in the area of the defect, which were compared. Result: Analysis of radiographic bone density indicated that the increase in the radiographic bone density of the CSBD's treated with the proposed biomaterials, in either molecular weight, in both observed periods, where similar to those found in control group. Conclusion: Tested chitosan-based biomaterials were not able to enhance the radiographic density in the CSBD's made in rat's calvaria.

Evaluating the Accuracy of Emergency Medicine Resident Interpretations of Abdominal CTs in Patients with Non-Traumatic Abdominal Pain

Abdominal computed tomography (CT) is widely used as a diagnostic tool in emergency medicine (EM) to accurately diagnose abdominal pain. EM residents must be able to offer preliminary interpretations of CT imaging. In this study, we evaluated the preliminary interpretation ability of a sample of emergency residents presented with adult abdominal CT images, and compared their results with those of radiology residents. We conducted a prospective observational study from November 16, 2008 to June 30, 2009. During this time, we gathered preliminary interpretations of consecutive abdominal CT made by emergency and radiology residents. We assessed the discrepancy rates of both samples by comparing their findings to the final reports from attending radiologists. A total of 884 cases were enrolled in the present study. The discrepancy rates of emergency and radiology residents were 16.7% and 12.2%, respectively. When female genital organs, peritoneum, adrenal glands, or the musculoskeletal system were abnormal, we found that emergency residents' preliminary interpretations of CT images were insufficient compared to those of radiology residents. Therefore more formal education is needed to emergency residents. If possible, the preliminary interpretations of radiology attending physicians are ideal until improving the ability of interpretations of emergency residents in abdomen CT.