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Radiomic analysis of imaging heterogeneity in tumours and the surrounding parenchyma based on unsupervised decomposition of DCE-MRI for predicting molecular subtypes of breast cancer
摘要： Objectives This study aimed to predict the molecular subtypes of breast cancer via intratumoural and peritumoural radiomic analysis with subregion identification based on the decomposition of contrast-enhanced magnetic resonance imaging (DCE-MRI). Methods The study included 211 women with histopathologically confirmed breast cancer. We utilised a completely unsupervised convex analysis of mixtures (CAM) method by unmixing dynamic imaging series from heterogeneous tissues. Each tumour and the surrounding parenchyma were thus decomposed into multiple subregions, representing different vascular characterisations, from which radiomic features were extracted. A random forest model was trained and tested using a leave-one-out cross-validation (LOOCV) method to predict breast cancer subtypes. The predictive models from tumoural and peritumoural subregions were fused for classification. Results Tumour and peritumour DCE-MR images were decomposed into three compartments, representing plasma input, fast-flow kinetics, and slow-flow kinetics. The tumour subregion related to fast-flow kinetics showed the best performance among the subregions for differentiating between patients with four molecular subtypes (area under the receiver operating characteristic curve (AUC) = 0.832), exhibiting an AUC value significantly (p < 0.0001) higher than that obtained with the entire tumour (AUC = 0.719). When the tumour- and parenchyma-based predictive models were fused, the performance, measured as the AUC, increased to 0.897; this value was significantly higher than that obtained with other tumour partition methods. Conclusions Radiomic analysis of intratumoural and peritumoural heterogeneity based on the decomposition of image time-series signals has the potential to more accurately identify tumour kinetic features and serve as a valuable clinical marker to enhance the prediction of breast cancer subtypes.
关键词： Magnetic resonance imaging,Diagnostic imaging,Breast neoplasms
更新于2025-09-23 15:23:52
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A prospective study on dual time 18F-FDG-PET/CT in high-risk prostate cancer patients
摘要： Objective: This proof of concept study investigated whether dual time point FDG-PET/CT with image acquisition after 1 and 3 h could be useful in preoperative staging of patients undergoing robot-assisted radical prostatectomy and extended pelvic lymph node dissection for high-risk prostate cancer. Results: Twenty patients with high-risk prostate cancer underwent dual time point FDG-PET/CT before undergoing surgery. Histologically confirmed lymph node metastases were found in 9/20 (45%). A median of 19 (range 10–41; n = 434) lymph nodes were removed per patient. Pelvic lymph nodes with detectable FDG uptake were seen in two patients only, but the FDG-avid lesion on PET did not correspond with pathological findings in either patient. We found a significant increase in maximal standardized uptake value of the prostate of around 30% between early and late imaging. We found no correlation between clinical findings after radical prostatectomy and PET measurements.
关键词： Prostatic neoplasms,Diagnostic imaging,Positron emission tomography,Fluorodeoxyglucose
更新于2025-09-23 15:22:29
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Experimental evaluation of seven quality control phantoms for digital breast tomosynthesis
摘要： Keywords: Breast, Diagnostic imaging, Digital breast tomosynthesis, Quality control, Screening. Purposes: The introduction of digital breast tomosynthesis (DBT) into the French breast cancer screening program is forecast by the authorities. The aim of the present study was to evaluate image quality phantoms to be used as internal quality controls. Methods: Seven breast phantoms dedicated to quality control in mammography were evaluated on reconstructed DBT images: ACR Model 015, BR3D, DBT QC model 021, Mam/Digi-EPQC, MTM100, TOMOMAM? and TOMOPHAN?. Two representative image parameters of DBT images were studied: image score and z-resolution, when inserts were included in the phantom, on five DBT systems of three different brands. Three observers were involved. Results: The MTM100, Mam/Digi-EPQC, BR3D, DBT QC model 021 phantoms' images presented artefacts affecting the image score. The ACR Model 015, TOMOMAM? and TOMOPHAN? phantoms appeared to be pertinent for DBT image score analysis. Due to saturation artefacts, Z-resolution results were not coherent with the theory for all phantoms except by using aluminium beads in the TOMOMAM? phantom. Conclusions: Phantom manufacturers should be encouraged to collaborate with DBT system manufacturers in order to design universal phantoms suitable for all systems for more complete quality control. From our study we can propose several specifications for an ideal and universal phantom designed for internal quality control in DBT. Phantoms should allow sensitive image score measurements. The background structure should be realistic to avoid artefacts. Phantoms should have a standard breast-like shape and size.
关键词： Breast,Digital breast tomosynthesis,Screening,Diagnostic imaging,Quality control
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 8th International Conference on Consumer Electronics - Berlin - Berlin (2018.9.2-2018.9.5)] 2018 IEEE 8th International Conference on Consumer Electronics - Berlin (ICCE-Berlin) - Development of a Mobile App for training health professionals in diagnostic imaging: a progress report
摘要： The paper discusses the development and application of a Noble Metal Alloy (NMA) for enhancing heat transfer processes in diagnostic imaging, specifically designed for use in optoelectronics. It presents a novel approach to improving the efficiency and reliability of imaging devices through advanced material science.
关键词： Noble Metal Alloy,Heat Transfer,Optoelectronics,Material Science,Diagnostic Imaging
更新于2025-09-23 15:22:29
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Guided wave inspection of dissimilar material joints using time reversal techniques
摘要： Dissimilar material bonding has recently gained a lot of attention in automotive, marine and defense applications. Nevertheless, a major hurdle limiting the full acceptance of such structural components is the lack of non-destructive evaluation (NDE) technique to evaluate their strength, which depends on the integrity of the bonding layer. In this work, guided wave (GW) inspection with surface-mounted piezoelectric sensors (PZT) was employed along with time reversal for Structural Health Monitoring (SHM) of dissimilar material lap-joints. Baseline-free probability imaging was used to identify the location of artificial disbond. The results of GW inspection were further validated with ultrasonic C-scan. Overall, the technique shows great potential in detection of defects in bonded joints.
关键词： guided waves,time reversal,diagnostic imaging,SHM,Dissimilar material joints
更新于2025-09-23 15:22:29
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Novel real-time optical imaging modalities for the detection of neoplastic lesions in urology: a systematic review
摘要： Background Current optical diagnostic techniques for malignancies are limited in their diagnostic accuracy and lack the ability to further characterise disease, leading to the rapidly increasing development of novel imaging methods within urology. This systematic review critically appraises the literature for novel imagining modalities, in the detection and staging of urological cancer and assesses their effectiveness via their utility and accuracy. Methods A systematic literature search utilising MEDLINE, EMBASE and Cochrane Library Database was conducted from 1970 to September 2018 by two independent reviewers. Studies were included if they assessed real-time imaging modalities not already approved in guidelines, in vivo and in humans. Outcome measures included diagnostic accuracy and utility parameters, including feasibility and cost. Results Of 5475 articles identified from screening, a final 46 were included. Imaging modalities for bladder cancer included optical coherence tomography (OCT), confocal laser endomicroscopy, autofluorescence and spectroscopic techniques. OCT was the most widely investigated, with 12 studies demonstrating improvements in overall diagnostic accuracy (sensitivity 74.5–100% and specificity 60–98.5%). Upper urinary tract malignancy diagnosis was assessed using photodynamic diagnosis (PDD), narrow band imaging, optical coherence tomography and confocal laser endomicroscopy. Only PDD demonstrated consistent improvements in overall diagnostic accuracy in five trials (sensitivity 94–96% and specificity 96.6–100%). Limited evidence for optical coherence tomography in percutaneous renal biopsy was identified, with anecdotal evidence for any modality in penile cancer. Conclusions Evidence supporting the efficacy for identified novel imaging modalities remains limited at present. However, OCT for bladder cancer and PDD in upper tract malignancy demonstrate the best potential for improvement in overall diagnostic accuracy. OCT may additionally aid intraoperative decision making via real-time staging of disease. Both modalities require ongoing investigation through larger, well-conducted clinical trials to assess their diagnostic accuracy, use as an intraoperative staging aid and how to best utilise them within clinical practice.
关键词： Urological malignancy,Optical imaging,Neoplasm,Diagnostic imaging
更新于2025-09-09 09:28:46
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Noninvasive diagnostic imaging using machine-learning analysis of nanoresolution images of cell surfaces: Detection of bladder cancer
摘要： We report an approach in diagnostic imaging based on nanoscale-resolution scanning of surfaces of cells collected from body fluids using a recent modality of atomic force microscopy (AFM), subresonance tapping, and machine-leaning analysis. The surface parameters, which are typically used in engineering to describe surfaces, are used to classify cells. The method is applied to the detection of bladder cancer, which is one of the most common human malignancies and the most expensive cancer to treat. The frequent visual examinations of bladder (cytoscopy) required for follow-up are not only uncomfortable for the patient but a serious cost for the health care system. Our method addresses an unmet need in noninvasive and accurate detection of bladder cancer, which may eliminate unnecessary and expensive cystoscopies. The method, which evaluates cells collected from urine, shows 94% diagnostic accuracy when examining five cells per patient’s urine sample. It is a statistically significant improvement (P < 0.05) in diagnostic accuracy compared with the currently used clinical standard, cystoscopy, as verified on 43 control and 25 bladder cancer patients.
关键词： diagnostic imaging,cancer diagnostics,atomic force microscopy,machine learning,noninvasive methods
更新于2025-09-09 09:28:46
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100 kVp Low-Tube Voltage Abdominal CT in Adults: Radiation Dose Reduction and Image Quality Comparison of 120 kVp Abdominal CT
摘要： Purpose: To compare image quality and the effect of radiation dose reduction after decreasing tube voltage from 120 kVp to 100 kVp for abdominal CT in adults. Materials and Methods: A total of 200 patients who underwent abdominal CT at 120 kVp (n = 100) or 100 kVp (n = 100) were enrolled. Automatic tube current modulation was applied with other scan parameters being constant. Radiation dose was calculated based on CT dosimetry index. The image quality of abdominal organs and image noise were assessed quantitatively and qualitatively. Results: A radiation dose reduction of 13.3% was found in the 100 kVp group. On quantitative analysis, image noise was increased up to 47% in the 100 kVp group. CT numbers of liver, pancreas, renal cortex, aorta, portal vein, and psoas muscle in the 100 kVp group were significantly (p < 0.05) higher than those in the 120 kVp group. Signal-to-noise ratio was significantly higher (p < 0.05) in the 120 kVp group. Contrast-to-noise ratio (CNR) of the liver was higher in the 120 kVp group. However, no significant (p > 0.05) difference was observed in the CNR of other organs between the two groups. On qualitative analysis, noise texture of abdominal organs, artifact, and diagnostic acceptability were not significantly (p > 0.05) different. Conclusion: 100 kVp abdominal CT reduced radiation dose by 13.3% without sacrificing image quality compared to 120 kVp abdominal CT.
关键词： Tomography, X-ray Computed,Adult,Diagnostic Imaging,Technology, Radiologic,Abdomen
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE 7th Global Conference on Consumer Electronics (GCCE) - Nara, Japan (2018.10.9-2018.10.12)] 2018 IEEE 7th Global Conference on Consumer Electronics (GCCE) - Shape-aware Medical Image Enhancement by Weighted Total Variation
摘要： In this paper, we propose a sharpening method for medical images combining weights on each pixel and Total Variation regularization. When weighting properly on each pixel in Total Variation regularization, information loss in optimization can be prevented. In the proposed method, weighting for each pixel is calculated from emphasis processing on an image and edge information, and Total Variation regularization is performed using weight information. As a result, noise removal and sharpening can be performed at the same time. Moreover, by comparing the proposed method with the conventional method, qualitative evaluation is carried out, and the effectiveness is shown.
关键词： Image enhancement,Image denoising,Medical diagnostic imaging,Biomedical imaging
更新于2025-09-04 15:30:14
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Concurrent pituitary and adrenocortical lesions on computed tomography imaging in dogs with spontaneous hypercortisolism
摘要： Background: Spontaneous hypercortisolism or Cushing's syndrome in dogs is either pituitary or adrenal dependent, but concurrent pituitary and adrenal hypercortisolism also has been reported. Objective: To determine how often concurrent pituitary and adrenal lesions are present in dogs with spontaneous hypercortisolism. Animals: Two hundred one client-owned dogs with spontaneous hypercortisolism. Methods: Retrospective study. Pre- and post-contrast computed tomography (CT) scans of the pituitary and adrenal glands were performed in dogs with confirmed hypercortisolism. Results: In dogs with dexamethasone-suppressible hypercortisolism (122/201), 78 dogs (64%) had an enlarged pituitary gland (median pituitary height/brain area [P/B], 0.43 × 10?2 mm?1; range, 0.32-1.21 × 10?2 mm?1). Two of these 78 dogs had concurrent adrenal lesions. In the remaining dogs (44/122; 36%), the pituitary gland was not enlarged. In the dexamethasone-resistant group (79/201), the pituitary gland was enlarged in 47 dogs (59%; median P/B, 0.57 × 10?2; range, 0.32-1.50 × 10?2 mm?1). Eight of these 47 dogs (17%) had concurrent adrenal lesions. In the remaining 32 dexamethasone-resistant dogs (41%), the pituitary gland was not enlarged. Among them, 27 dogs had adrenal lesions and suppressed ACTH concentrations consistent with adrenal-dependent hypercortisolism and 5 dogs were diagnosed with pituitary-dependent hypercortisolism. Conclusions and Clinical Importance: Concurrent pituitary and adrenal lesions were present in 5% of all dogs with hypercortisolism and in 10% of the dexamethasone-resistant dogs. Diagnostic imaging of both pituitary and adrenal glands should be included in the diagnostic evaluation of every dog with spontaneous hypercortisolism to obtain information needed for estimation of prognosis and choosing the optimal treatment.
关键词： CT scan,diagnostic imaging,Cushing's,ACTH
更新于2025-09-04 15:30:14