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Accurate evaluation of morphological changes in articular cartilage are necessary for early detection of osteoarthritis (OA). 3T magnetic resonance imaging (MRI) has highly sensitive contrast resolution and is widely used clinically to detect OA. However, synchrotron radiation phase-contrast imaging computed tomography (SR-PCI) can also provide contrast to tissue interfaces that do not have sufficient absorption differences, with the added benefit of very high spatial resolution. Here, MRI was compared with SR-PCI for quantitative evaluation of human articular cartilage. Medial tibial condyles were harvested from non-OA donors and from OA patients receiving knee replacement surgery. Both imaging methods revealed that average cartilage thickness and cartilage volume were significantly reduced in the OA group, compared to the non-OA group. When comparing modalities, the superior resolution of SR-PCI enabled more precise mapping of the cartilage surface relative to MRI. As a result, MRI showed significantly higher average cartilage thickness and cartilage volume, compared to SR-PCI. These data highlight the potential for high-resolution imaging of articular cartilage using SR-PCI as a solution for early OA diagnosis. Recognizing current limitations of using a synchrotron for clinical imaging, we discuss its nascent utility for preclinical models, particularly longitudinal studies of live animal models of OA. [ABSTRACT FROM AUTHOR]

Mandibular and medial retropharyngeal lymph nodes are routinely evaluated with CT when staging dogs with oral melanomas. While size alone is considered inadequate for detecting nodal metastasis, it is critical in evaluating treatment response, as clinical decisions are based on changes in size. It is common for different radiologists to measure the size of pre‐ and posttreatment lymph nodes in the same patient. The objective of this retrospective, observer agreement study was to evaluate the inter‐ and intraobserver agreement in measuring canine mandibular and medial retropharyngeal lymph nodes by a diverse population of veterinary radiologists and trainees. Fourteen dogs with documented oral melanoma and head CT studies identified from records of a single institution were included in this study. North American veterinary radiologists and trainees were recruited to measure the mandibular and medial retropharyngeal lymph nodes; in triplicate. Prior to performing the study measurements, participants completed a training tool demonstrating the lymph node measurements. Overall, interobserver intraclass correlation coefficient (ICC) was 0.961 (95% confidence interval [CI]: 0.946, 0.972) and intraobserver ICC was 0.977 (95% CI: 0.968, 0.983), indicating excellent agreement (ICC > 0.9 considered excellent). Similar findings were noted following sub‐analysis for most variables (experience, size, laterality, axis of measurement). These results suggest that follow‐up measurement of the long and short axis of the mandibular lymph nodes and short axis of the medial retropharyngeal lymph nodes in the transverse plane, performed by different veterinary radiologists using the same method of measure, should have minimal impact on clinical decision making. [ABSTRACT FROM AUTHOR]

Objective: X-ray phase contrast imaging generates contrast from refraction of X-rays, enhancing soft tissue contrast compared to conventional absorption-based imaging. Our goal is to develop a contrast agent for X-ray in-line phase contrast imaging (PCI) based on ultrasound microbubbles (MBs), by assessing size, shell material, and concentration. Methods: Polydisperse perfluorobutane-core lipid-shelled MBs were synthesized and size separated into five groups between 1 and 10 μm. We generated two size populations of polyvinyl-alcohol (PVA)-MBs, 2-3 μm and 3-4 μm, whose shells were either coated or integrated with iron oxide nanoparticles (SPIONs). Microbubbles were then embedded in agar at three concentrations: 5 × 107, 5 × 106 and 5 × 105 MBs/ml. In-line phase contrast imaging was performed at the Canadian Light Source with filtered white beam micro-computed tomography. Phase contrast intensity was measured by both counting detectable MBs, and comparing mean pixel values (MPV) in minimum and maximum intensity projections of the overall samples. Results: Individual lipid-MBs 6-10 μm, lipid-MBs 4-6 μm and PVA-MBs coated with SPIONs were detectable at each concentration. At the highest concentration, lipid-MBs 6-10 μm and 4-6 μm showed an overall increase in positive contrast, whereas at a moderate concentration, only lipid-MBs 6-10 μm displayed an increase. Negative contrast was also observed from two largest lipid-MBs at high concentration. Conclusion: These data indicate that lipid-MBs larger than 4 μm are candidates for PCI, and 5 × 106 MBs/ml may be the lowest concentration suitable for generating visible phase contrast in vivo. Significance: Identifying a suitable MB for PCI may facilitate future clinical translation. [ABSTRACT FROM AUTHOR]

Mycobacterium avium complex (MAC) is usually considered an opportunistic organism, which infects immunocompromised children or those with structural airway abnormalities. We present two cases of MAC infection affecting immune competent children, likely from hot tubs with primary involvement of pulmonary and urinary systems. These cases highlight the importance of asking about hot tub use in immune competent children with suspected or confirmed MAC infections. [ABSTRACT FROM AUTHOR]

A number of phase based X-ray imaging methods have been developed that derive contrast from phase effects from the object which make them particularly interesting because of the ability to visualize soft tissues. Shack–Hartmann is a wave-front diagnostic technique that emerged from optics which uses ray-line beams (beamlets) to interrogate the differences in the wave-front across a beam can also be used for X-ray imaging applications with phase sensitivity. This method, which has been applied in the X-ray regime, is very simple in that it only requires a screen to prepare an array of beamlets that then pass through the object and are allowed to propagate a distance onto a pixelated detector. Absorption and refraction information can be extracted from the detected beamlets. An untapped property is the additional ability to extract scatter distribution information based on the observed width of the detected spots. This paper describes experiments done at a synchrotron facility investigating the use of a Shack–Hartmann system for biomedical applications and include our method and examples of scatter contrast extraction from the method. [ABSTRACT FROM AUTHOR]

The Biomedical Imaging and Therapy (BMIT) beamlines at the Canadian Light Source (CLS) comprise a multi-modality synchrotron imaging facility capable of imaging objects with 2–200 μm resolution with beam sizes up to ~200 mm wide and ~10 mm high in the experimental hutches [1–3]. BMIT hosts two beamlines, a bend magnet 05B1-1 and an insertion device 05ID-2, with capabilities to apply absorption imaging, in-line phase contrast imaging (PCI), analyzer-based imaging (ABI) or diffraction-enhanced imaging (DEI), and K-Edge Subtraction (KES) imaging. Talbot or grating interferometry is under development. [ABSTRACT FROM PUBLISHER]

The article focuses on a pilot study that aims at evaluating lymph node enhancement in the head and neck of dogs with an indirect magnetic resonance (MR) lymphography. It describes the methodology of the study in which MR imaging was conducted on five dogs using gadoversetamide and Gadofluorine M contrast agents. It reveals the efficiency of indirect MR lymphography for diagnosing metastatic lymph nodes in dogs with cancer.

The bending magnet line (05B1-1) of the BioMedical Imaging and Therapy (BMIT) facility of the Canadian Light Source saw initial research application (Figure 1) during commissioning which began in December 2008 and continued intermittently through May 2010. Following an initial run based upon letters of intent (June-Dec. 2010), the bending magnet line is now available for regular user access. The mandate to advance research related to human and animal health, combined with an active bone imaging community at the University of Saskatchewan, has resulted in a strong representation of skeletal imaging during initial experiments at BMIT. To date, specific manifestations of bone imaging have ranged from micro-CT imaging of human cortical bone samples to in vitro diffraction enhanced imaging (DEI) of rat and pig bones and, ultimately, to in vivo DEI of bones within young chickens. In this article we focus on the diffraction enhanced imaging capabilities of BMIT and describe our efforts to apply this technology to human trabecular bone microarchitecture - a potential clinical application in the future. [ABSTRACT FROM AUTHOR]

The article cites a case of a 5-month-old girl who was diagnosed with subacute necrotizing encephalomyelopathy or Leigh disease. She was presented with failure to thrive, developmental regression, visual inattention, and nystagmus. The patient had transient episodes of stiffening of the arms and legs, and arching of the back. Magnetic resonance imaging and magnetic resonance spectroscopy were performed.

The article presents a case study of a 63 year old woman in the U.S. who was taken to the emergency department because of acute-onset epigastrc pain. She was physically examined and it shows that she has unbeatable blood pressure, peritonitis and has increased serum lactate level. The article discusses internal hernia. It also states that transomental hernia is a rare case and that the presence of small-bowel loops associated with stretched vascular pedicle indicates a sign of internal hernia.

The article presents a medical case of a 63-year-old woman with acute-onset epigastric pain who was presented to the emergency department. It mentions that physical examinations show an unstable blood pressure and peritonitis. It is stated that the patient had no history of previous or chronic illness, but past surgical history was noted with a hysterectomy.

The article discusses the medical examination of an infant patient with failure to thrive, developmental regression, visual inattention, and nystagmus. According to the study, the infant had transient episodes of stiffening of her arms and legs and arching of her back, wherein none of these symptoms were noted until she was three months of age. It has showed that the infant had been born at term by spontaneous vaginal delivery following an uncomplicated pregnancy.

Discusses the case of a 15-year-old girl presented with Ortner's syndrome, a left recurrent laryngeal nerve palsy associated with cardiovascular disease. History of the patient's medical condition; Clinical investigations and diagnosis; Management of the patient's case.

Describes the case of a 15-year-old girl presented with idiopathic pulmonary hypertension. History of the patient's medical condition; Medical examinations undergone; Diagnosis and treatment options for the condition.

The use of magnetic resonance imaging (MRI) during pregnancy is associated with concerns among patients and health professionals with regards to fetal safety. In this work, the Canadian Association of Radiologists (CAR) Working Group on MRI in Pregnancy presents recommendations for the use of MRI in pregnancy, derived from literature review as well as expert panel opinions and discussions. The working group, which consists of academic subspecialty radiologists and obstetrician-gynaecologists, aimed to provide updated, evidence-based recommendations addressing safety domains related to energy deposition, acoustic noise, and gadolinium-based contrast agent use based on magnetic field strength (1.5T and 3T) and trimester scanned, in addition to the effects of sedative use and occupational exposure. [ABSTRACT FROM AUTHOR]

The article reports on research which was conducted to investigate whether diffraction enhanced X-ray imaging would be effective in imaging the distal radius and would be a useful approach for visualizing the architecture of the trabecular bone. Researchers imaged human bone and tissue specimens. They found that diffraction enhanced X-ray imaging was an effective approach which improved visualization of bone architecture.

Abstract: Moiré pattern noise in Scanning Transmission X-ray Microscopy (STXM) imaging introduces significant errors in qualitative and quantitative image analysis. Due to the complex origin of the noise, it is difficult to avoid Moiré pattern noise during the image data acquisition stage. In this paper, we introduce a post-processing method for filtering Moiré pattern noise from STXM images. This method includes a semi-automatic detection of the spectral peaks in the Fourier amplitude spectrum by using a local median filter, and elimination of the spectral noise peaks using a Gaussian notch filter. The proposed median-Gaussian filtering framework shows good results for STXM images with the size of power of two, if such parameters as threshold, sizes of the median and Gaussian filters, and size of the low frequency window, have been properly selected. [Copyright &y& Elsevier]