Objectives: Choosing an acceptance radius or proximity criterion is necessary to analyse free-response receiver operating characteristic (FROC) observer performance data. This is currently subjective, with little guidance in the literature about what is an appropriate acceptance radius. We evaluated varying acceptance radii in a nodule detection task in chest radiography ...

For many years, the right ventricle (RV) was considered less relevant in cardiac disease than its left counterpart, partly because of limited ability to noninvasively evaluate the RV with accuracy. From an earlier period when chest x-ray and invasive contrast ventriculography were the only available imaging modalities, the development of ...

Bedside chest radiography is a frequent X-ray examination when patients are physically incapacitated. An X-ray cassette with an imaging plate is inserted below the patient's body, and the image orientation of the radiograph is determined by the direction of insertion. Therefore, an incorrect direction of insertion would yield an incorrect ...

The purpose of this work is twofold: (i) to develop a CAD system for the assessment of emphysema by digital chest radiography and (ii) to test it against CT imaging. The system is based on the analysis of the shape of lung silhouette as imaged in standard chest examination. Postero-anterior ...

Purpose: Our previous study indicated that multiprojection chest radiography could significantly improve radiologists' performance for lung nodule detection in clinical practice. In this study, the authors further verify that multiprojection chest radiography can greatly improve the performance of a computer-aided diagnostic (CAD) scheme.Methods: Our database consisted of 59 subjects, including ...

In this study, a radio frequency phased array coil was built to image the breast in conjunction with a magnetic resonance guided high-intensity focused ultrasound (MRgHIFU) device designed specifically to treat the breast in a treatment cylinder with reduced water volume. The MRgHIFU breast coil was comprised of a 10-channel ...

The respiratory system is often affected by complications of immunodeficiency, typically manifesting clinically as acute respiratory illness. Ongoing literature reviews regarding the appropriateness of imaging in these patients are critical, as advanced medical therapies such as stem cell transplantation, chemotherapy, and immunosuppressive therapies for autoimmune disease continue to keep high ...

The bedside chest x-ray (CXR) is an indispensible diagnostic tool for monitoring seriously ill patients in the intensive care unit. The CXR often reveals abnormalities that may not be detected clinically. In addition, bedside CXRs are an irreplaceable tool with which to detect the malposition of tubes and lines and ...

PURPOSE:: To determine the repeat rate (RR) of chest radiographs acquired with portable computed radiography (CR) and installed direct radiography (DR) and to develop and assess strategies designed to decrease the RR. MATERIALS AND METHODS:: The RR and reasons for repeated digital chest radiographs were documented over the course of ...

A retrospective study of digital chest radiography was performed to compare the image quality and dose parameters from two X-ray rooms in different areas of the same hospital using identical X-ray units but different local protocol for obtaining chest PA and lateral radiographs. Image quality of radiographs was assessed from ...

A 63-year-old asymptomatic woman with cured Hodgkin diseases presented for restaging. The chest computed tomography showed a mass at the right side of the upper mediastinum. The benignity and the origin of the tissue were unknown. First, we performed a bronchoscopy-guided biopsy but without success. In the next step, we ...

Prenatal imaging with high-resolution US and rapid acquisition MRI plays a key role in the accurate diagnosis of congenital chest masses. Imaging has enhanced our understanding of the natural history of fetal lung masses, allowing for accurate prediction of outcome, parental counseling, and planning of pregnancy and newborn management. This ...

In order to provide a precise radiography for diagnosis, it is required that we avoid radiography with defects by having enough evaluation. Conventionally, evaluation was performed only by observation of a radiological technologist (RT). The evaluation support system was developed for providing a high quality assurance without depending on RT ...

Regadenoson (REG) is a A2a receptor selective pharmacologic SPECT imaging agent. Its safety in unselected chronic obstructive pulmonary disease (COPD) or asthma (AM) undergoing SPECT imaging has not been well evaluated. We retrospectively identified 228 patients (COPD n = 126 and AM n = 102, Grp 1) undergoing REG SPECT from Jan to Nov ...

Selective adenosine receptor agonists have several advantages for use as stress agents in conjunction with myocardial perfusion imaging compared to the non selective agents such as adenosine and dipyridamole. This review will summarize the pre-clinical and clinical data on the selective adenosine agonist stress agents regadenoson (Lexiscan(®)), binodenoson (CorVue™) and ...

Computer-aided Diagnosis (CAD) systems can assist radiologists in several diagnostic tasks. Lung segmentation is one of the mandatory steps for initial detection of lung cancer in Posterior-Anterior chest radiographs. On the other hand, many CAD schemes in projection chest radiography may benefit from the suppression of the bony structures that ...

Pixel accuracy in images from high-resolution computed tomography (HRCT) is ultimately limited by reconstruction error and noise. While for visual analysis this may not be relevant, for computer-aided quantitative analysis in either densitometric, or shape studies aiming at accurate results, the impact of pixel uncertainty must be taken into consideration. ...

INTRODUCTION: Assessment of the motion of the cerebellar tonsils is of interest in diseases affecting the CSF flow at the foramen magnum. Cardiac-gated balanced steady-state free-precession technique, which has recently been shown to demonstrate the pulsatile motion of neural structures, appears well suited to allow direct measurement of craniocaudal translation ...

OBJECTIVES/HYPOTHESIS: Several techniques of endoscopic repair of cerebrospinal fluid (CSF) rhinorrhea were prescribed. Defect localization was mandatory for all. STUDY DESIGN: Prospective study. METHODS: A prospective study was conducted on nonaccidental CSF rhinorrhea. The sensitivity and specificity of image-guided navigation in localizing the defect were studied. The feasibility and reliability ...

Denoising algorithms can alleviate the trade-off between noise-level and acquisition time that still exists for certain image types. Nonlocal means, a recently proposed technique, outperforms other methods in removing noise while retaining image structure, albeit at prohibitive computational cost. Modifications have been proposed to reduce the cost, but the method ...

A 32x32 Sb-based Geiger-mode (GM) avalanche photodiode array, operating at 2 μm with three-dimensional imaging capability, is presented. The array is interfaced with a ROIC (readout integrated circuit) in which each pixel can detect a photon and record the arrival time. The hybridized unit for the 1000-element focal plane array, ...

To evaluate a prototype fast spin-echo (FSE) triple-echo Dixon (FTED) technique for T2-weighted spine imaging with and without fat suppression compared to conventional T2-weighted fast recovery (FR) FSE and short-tau inversion recovery (STIR) imaging. Sixty-one patients were referred for spine magnetic resonance imaging (MRI) including sagittal FTED (time 2:26), STIR ...

OBJECTIVE: To introduce a new grading system of lumbar central canal stenosis, evaluate its reliabilities, and compare it to the cross-sectional area and anterior-posterior diameter of the dural sac. MATERIALS AND METHODS: Lumbar central canal stenosis is defined as obliteration of the anterior CSF space in front of the cauda ...

The resorption pit assay is classically used to evaluate osteoclast activity on bone or dentine slices that can be eroded by these cells. Two different types of cells were generated from peripheral blood mononuclear cells cultured in the presence of M-CSF + sRANKL or with M-CSF + LPS. At the ...

Positron-emission tomography (PET) imaging of amyloid with Pittsburgh Compound B (PIB) and Aβ42 levels in the cerebrospinal fluid (CSF Aβ42) demonstrate a highly significant inverse correlation. Both these techniques are presumed to measure brain Aβ amyloid load. The objectives of this study were to develop a method to transform CSF ...

Image quality assessment (IQA) aims to use computational models to measure the image quality consistently with subjective evaluations. The well-known structural-similarity (SSIM) index brings IQA from pixel-based stage to structure-based stage. In this paper, a novel feature-similarity (FSIM) index for full reference IQA is proposed based on the fact that ...

OBJECTIVE: Susceptibility-weighted MR imaging (SWI) is usually obtained without administration of intravenous gadolinium (Gd). However, it is occasionally necessary to perform SWI after Gd is injected. The effects of Gd on SWI have not been systematically examined. The aim of this prospective study was to investigate whether performing SWI after ...

To investigate non-Gaussian water diffusion using diffusional kurtosis imaging (DKI) to assess age effects on gray matter (GM) and white matter (WM) microstructural changes in the prefrontal cortex (PFC) of adolescents with attention-deficit hyperactivity disorder (ADHD) compared to typically developing controls (TDC). In this preliminary cross-sectional study, T1-weighted magnetization-prepared rapid ...

This study describes the tactics used by Cyprian honeybees (Apis mellifera cypria) to defend their colonies against hornet (Vespa orientalis orientalis) attacks. We use simulated hornet attacks and a combination of video recordings and image analysis to reveal, for the first time, contrasted intra-subspecies defensive tactics that operate at the ...

Triple-quantum-filtered (TQF) sodium MRI can be used to separate sodium NMR signals from different physiological compartments. Although three-pulse triple-quantum filtering has been demonstrated to be better suited for in vivo imaging, the absence of the refocusing pulse in the filter increases its sensitivity to magnetic field inhomogeneities. Therefore, several TQF ...

The authors present a computationally efficient technique for maximum a posteriori (MAP) estimation of images in the presence of both blur and noise. The image is divided into statistically independent regions. Each region is modelled with a WSS Gaussian prior. Classical Wiener filter theory is used to generate a set ...

To study the effect of a nonlinear noise filter on the detection of simulated endoleaks in a phantom with 80- and 100-kVp multidetector computed tomographic (CT) angiography. An aortic aneurysm phantom, including iodinated endoleaks, was constructed. Multidetector CT angiography with use of 80-, 100-, and 120-kVp tube voltages was performed ...

The fiber bundle density (FBD) calculated from ultrasound B-scan images of the equine superficial digital flexor tendon (SDFT) can serve as an objective measurement to characterize the three metacarpal sites of normal SDFTs, and also to discriminate a healthy SDFT from an injured one. In this paper, we propose a ...

A combined system of microwave imaging reflectometry and electron cyclotron emission (ECE) imaging has been developed for the Large Helical Device. This system includes a wide-band two-dimensional horn-antenna mixer array (HMA). The HMA consists of horn antennas, waveguides, mixers, and intermediate frequency circuits. The frequency response of the HMA is ...

The aim of this report is to illustrate a method for the precise placement of chemotherapeutic delivery catheters with the aid of computer-assisted navigation systems. We have developed a cannula which can be referenced to our navigation system (BrainLab (®)) to advance and position catheters. The cannula has a length ...

The traditional Hessian-related vessel filters often suffer from detecting complex structures like bifurcations due to an over-simplified cylindrical model. To solve this problem, we present a shape-tuned strain energy density function to measure vessel likelihood in 3D medical images. This method is initially inspired by established stress-strain principles in mechanics. ...

In this paper, we present a novel framework that exploits an informative reference channel in the processing of another channel. We formulate the problem as a maximum a posteriori estimation problem considering a reference channel and develop a probabilistic model encoding the interchannel correlations based on Markov random fields. Interestingly, ...

A color filter array (CFA) used in a digital camera is a mosaic of spectrally selective filters, which allows only one color component to be sensed at each pixel. The missing two components of each pixel have to be estimated by methods known as demosaicking. The demosaicking algorithm and the ...

The non-local means (NLM) filter removes noise by calculating the weighted average of the pixels in the global area and shows superiority over existing local filter methods that only consider local neighbor pixels. This filter has been successfully extended from 2D images to 3D images and has been applied to ...

Our goal in this study was to compare magnetic resonance images and volumes of brain structures obtained alive versus postmortem of California sea lions Zalophus californianus exhibiting clinical signs of domoic acid (DA) toxicosis and those exhibiting normal behavior. Proton density-(PD) and T2-weighted images of postmortem-intact brains, up to 48 ...

We derive the fourth-order oriented partial-differential equations (PDEs) for noise removal of two-photon fluorescence images. We consider it from two aspects: one is based on a variational method; the other is based on controlling the diffusion direction. Our filtering model makes the diffusion along only the special orientation--decided via all ...

Automated firearms identification systems will correlate a reference bullet with all evidence bullets without a selection procedure to exclude the bullets having insufficient bullet identifying signature. Correlations that include such bullets increase the workload and may affect the correlation accuracy. In this article, a parameter called striation density is proposed ...

It is known that visual information is processed separately and based on multiple spatial frequencies. Therefore, integration of information is important for categorization of natural scenes. To clarify the time course of visual integration, we examined categorization accuracies for spatially filtered images as a function of image exposure duration. Results ...

Colour and spectral imaging systems typically use filters and glass prisms to disperse light of different wavelengths. With the miniaturization of integrated devices, current research on imaging sensors focuses on novel designs aiming at high efficiency, low power consumption and slim dimension, which poses great challenges to the traditional colourant-based ...

Speckle noise negatively affects medical ultrasound image shape interpretation and boundary detection. Speckle removal filters are widely used to selectively remove speckle noise without destroying important image features to enhance object boundaries. In this article, a fully automatic bilateral filter tailored to ultrasound images is proposed. The edge preservation property ...

High-fidelity color image acquisition with a multispectral camera utilizes optical filters to separate the visible electromagnetic spectrum into several passbands. This is often realized with a computer-controlled filter wheel, where each position is equipped with an optical bandpass filter. For each filter wheel position, a grayscale image is acquired and ...

This paper presents a new three-dimensional (3D) ultrasound reconstruction algorithm for generation of 3D images from a series of two-dimensional (2D) B-scans acquired in the mechanical linear scanning framework. Unlike most existing 3D ultrasound reconstruction algorithms, which have been developed and evaluated in the freehand scanning framework, the new algorithm ...

This correspondence proposes an efficient semidefinite programming (SDP) method for the design of a class of linear phase finite impulse response triplet halfband filter banks whose filters have optimal frequency selectivity for a prescribed regularity order. The design problem is formulated as the minimization of the least square error subject ...

A first-principles task-based approach to the design of medical ultrasonic imaging systems for breast lesion discrimination is described. This study explores a new approximation to the ideal Bayesian observer strategy that allows for object heterogeneity. The new method, called iterative Wiener filtering, is implemented using echo data simulations and a ...

This paper deals with the theory and applications of spatially-variant discrete mathematical morphology. We review and formalize the definition of spatially variant dilation/erosion and opening/closing for binary and gray-level images using exclusively the structuring function, without resorting to complement. This theoretical framework allows to build morphological operators whose structuring elements ...