271 research outputs found
Advances in imaging of the solitary pulmonary nodule
Objective. To review the radiological management of a solitary pulmonary nodule. Data sources. MEDLINE literature search (1958-2002). Study selection. All review articles and original articles. Key words for the literature search were 'solitary pulmonary nodule' and 'imaging'. Data extraction. All relevant information and data. Data synthesis. The solitary pulmonary nodule remains a perennial problem in radiological practice, particularly with current trends using low-dose computed tomography to screen for lung cancer. Determining the likelihood of malignancy forms the basis of the radiological approach of a solitary pulmonary nodule. Several factors that influence risk analysis include morphological and enhancement characteristics of the solitary pulmonary nodule on imaging, stability of the nodule, age of patient, smoking history, and history of malignant disease. Other ancillary procedures and imaging techniques that assist in the evaluation of a solitary pulmonary nodule include fluorodeoxyglucose positron-emission tomography, technetium Tc 99m depreotide imaging, bronchoscopy with bronchioloalveolar lavage and biopsy, image-guided transthoracic needle aspiration biopsy, video-assisted thorascopic surgery, and thoracotomy. Conclusions. The success of any radiological management of a solitary pulmonary nodule rests on careful clinical evaluation and risk stratification for malignancy before the implementation of appropriate imaging techniques.published_or_final_versio
A case of cerebellar hypoplasia in a Chinese infant with osteogenesis imperfecta
We report a unique case of unilateral cerebellar hypoplasia in a young Chinese girl with osteogenesis imperfecta type IV. Magnetic resonance imaging showed mild basilar invagination and impression. Although unilateral cerebellar hypoplasia and osteogenesis imperfecta may have been coincidental diagnoses, we propose possible mechanisms for unilateral cerebellar hypoplasia secondary to osteogenesis imperfecta. For example, cerebellar hypoplasia may have been because of vascular disruption or direct compression to the posterior circulation in utero. Foetuses with osteogenesis imperfecta are more susceptible to the above risks compared to the normal foetus because of associated craniocervical anomalies and a poorly ossified skull.published_or_final_versio
Partial rhombencephalosynapsis and Chiari II malformation
We report a rare case of partial rhombencephalosynapsis coexistent with Chiari II malformation in a 6-year-old girl and discuss the features of these entities on magnetic resonance imaging.published_or_final_versio
Population-based incidence of community-acquired pneumonia hospitalization in Hong Kong children younger than 5 years before universal conjugate pneumococcal immunization
Objectives: We sought to document the incidence of pediatric hospitalization for bacterial pneumonia before universal childhood conjugate pneumococcal vaccination using two different methods of diagnosis. Methods: By following the World Health Organization (WHO) chest radiography (CXR) protocol, two radiologists independently read the CXRs of a cohort of systematically recruited children younger than 5 years. The children had acute respiratory infections and were admitted to one of two hospitals that care for 72.5% of all pediatric admissions on Hong Kong Island. Medical records were reviewed for clinical manifestation and to identify bacterial pneumonia diagnosed by pediatricians. Results: In children younger than 5 years, the incidences of bacterial pneumonia, as diagnosed by pediatricians and by the WHO CXR standard, were 775.7 per 100,000 population [95% confidence interval (CI, 591.8-998.3)] and 439.5 per 100,000 population (95% CI, 304.6-614.5), respectively. The study period was from 2002 to 2004. Conclusion: This study provided a reliable baseline estimate of the hospitalization burden of pneumococcal pneumonia in Hong Kong children before the advent of universal conjugate pneumococcal vaccination. © 2014
CT features of advanced lymphoepithelioma-like carcinoma (LELC)
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Supervised and Unsupervised Detections for Multiple Object Tracking in Traffic Scenes: A Comparative Study
In this paper, we propose a multiple object tracker, called MF-Tracker, that
integrates multiple classical features (spatial distances and colours) and
modern features (detection labels and re-identification features) in its
tracking framework. Since our tracker can work with detections coming either
from unsupervised and supervised object detectors, we also investigated the
impact of supervised and unsupervised detection inputs in our method and for
tracking road users in general. We also compared our results with existing
methods that were applied on the UA-Detrac and the UrbanTracker datasets.
Results show that our proposed method is performing very well in both datasets
with different inputs (MOTA ranging from 0:3491 to 0:5805 for unsupervised
inputs on the UrbanTracker dataset and an average MOTA of 0:7638 for supervised
inputs on the UA Detrac dataset) under different circumstances. A well-trained
supervised object detector can give better results in challenging scenarios.
However, in simpler scenarios, if good training data is not available,
unsupervised method can perform well and can be a good alternative.Comment: Accepted for ICIAR 202
Diffusion tensor imaging for the evaluation of treatment-induced neurotoxicity in childhood medulloblastoma
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Diffusion tensor MR imaging in the evaluation of Wallerian degeneration in pediatric strokes: work-in-progress
Poster Session - Pediatric Brain MR Imaging: no. 2090We use DTI to detect and quantify Wallerian degeneration (WD) in pediatric MCA strokes. Fractional anisotropy (FA) and mean diffusivity (MD)of the
infarction, ipsilateral internal capsule (PLIC) and cerebral peduncle (CP) were measured in nine children and compared to the matched contralateral side. WD
was characterized by statistically significant differences in FA, but not MD, of the ipsilateral PLIC and CP compared to normal side. FA was reduced in all
children, whilst corresponding hyperintense signals on T2W were seen in five children. DTI is more sensitive than conventional MRI and can be used to detect
and quantify WD.published_or_final_versio
Factors associated with loss of white matter anisotropy in post-treatment medulloblastoma survivors
We evaluate effects of age at cranial irradiation, time interval since irradiation and irradiation dose on white matter anisotropy in childhood medulloblastoma
survivors by computing white matter fractional anisotropy (WM FA) using SPM post-processing functions. Mean percentage change in WM FA of patients
compared to controls was -4.4% (sd=7.6%). Using Spearmanís correlation, there were significant associations between percentage reduction of WM FA and
age at cranial irradiation (r=0.673, p=0.002) and irradiation dose (r=-0.723, p=<0.001), but not with time interval since irradiation. Multivariate regression
analysis confirmed that both factors correlated significantly with percentage reduction of WM FA (adjusted r2=0.516, p=0.001).published_or_final_versio
Lymph node density in silicosis: its relationship with lung function and clinical parameters
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