Determination of mean ionization potential using magnetic resonance imaging for the reduction of proton beam range uncertainties: theory and application.

We present a novel model to accurately calculate mean ionization potential from measurements acquirable by MRI and show its feasibility in a phantom. PMID: 29077570 [PubMed - in process]
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research

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Publication date: Available online 14 September 2019Source: Academic RadiologyAuthor(s): Valentin Quack, Marcel Betsch, Julian Hellmann, Jörg Eschweiler, Simone Schrading, Matthias Gatz, Björn Rath, Markus Tingart, Markus Laubach, Christiane K. Kuhl, Timm DirrichsRationale and ObjectivesUp to now, the diagnosis of tendinopathies is based on conventional B-mode-ultrasound (B-US), Power Doppler-ultrasound (PD-US), and magnetic resonance imaging. In the past decade, Shear Wave Elastography (SWE) has been introduced in tendon imaging, for example in athletes or patients suffering from tendinopathy. SWE allows real-ti...
Source: Academic Radiology - Category: Radiology Source Type: research
The objective of this study was to look for compensatory foot and ankle behaviours during gait in paediatric patients with symptomatic ACL deficiency.HypothesisCompensation for ACL deficiency during gait occurs at the foot and ankle in children, because compensation at the hip and pelvis would require greater energy expenditure.Material and methodsWe included 47 patients, 33 males and 14 females, ranging in age from 9 to 17 years (mean, 14.1 years). The patients had a history of unilateral ACL injury documented by MRI and initially treated by immobilisation and physical therapy. They were allowed to walk with full weight-b...
Source: Orthopaedics and Traumatology: Surgery and Research - Category: Orthopaedics Source Type: research
Publication date: 15 November 2019Source: NeuroImage, Volume 202Author(s): Emma Christiaen, Marie-Gabrielle Goossens, Robrecht Raedt, Benedicte Descamps, Lars Emil Larsen, Erine Craey, Evelien Carrette, Kristl Vonck, Paul Boon, Christian VanhoveAbstractEpilepsy is a neurological disorder characterized by recurrent epileptic seizures. Electrophysiological and neuroimaging studies in patients with epilepsy suggest that abnormal functional brain networks play a role in the development of epilepsy, i.e. epileptogenesis, resulting in the generation of spontaneous seizures and cognitive impairment. In this longitudinal study, we...
Source: NeuroImage - Category: Neuroscience Source Type: research
Publication date: 15 November 2019Source: NeuroImage, Volume 202Author(s): Michalis Kassinopoulos, Georgios D. MitsisAbstractFunctional magnetic resonance imaging (fMRI) is widely viewed as the gold standard for studying brain function due to its high spatial resolution and non-invasive nature. However, it is well established that changes in breathing patterns and heart rate strongly influence the blood oxygen-level dependent (BOLD) fMRI signal and this, in turn, can have considerable effects on fMRI studies, particularly resting-state studies. The dynamic effects of physiological processes are often quantified by using co...
Source: NeuroImage - Category: Neuroscience Source Type: research
Publication date: Available online 12 September 2019Source: Joint Bone SpineAuthor(s): Shoji Baba, Goro Motomura, Satoshi Ikemura, Yusuke Kubo, Takeshi Utsunomiya, Hiroyuki Hatanaka, Koichiro Kawano, Yasuharu NakashimaAbstractObjectives: To quantify the volume of bone-resorptive lesions in post-collapse osteonecrosis of the femoral head (ONFH) using micro-computed tomography (micro-CT) and assess their characteristics in post-collapse ONFH.Methods: We investigated 35 femoral heads resected from 35 patients with ONFH (20 men and 15 women; mean age, 47.2 years). On each of seven coronal high-resolution micro-CT slices of the...
Source: Joint Bone Spine - Category: Orthopaedics Source Type: research
Authors: Daida K, Nishioka K, Takanashi M, Kobayashi M, Yoshikawa K, Kusunoki S, Yokoyama K, Hattori N Abstract A healthy 28-year-old woman presented suddenly with intractable status epilepticus: a focal seizure evolved into a generalized seizure preceded by a high fever. Brain magnetic resonance imaging indicated bilateral hyperintensities in the hippocampus on T2-weighted imaging. Electroencephalograms continuously demonstrated diffuse sharp waves and poly-spikes. Comprehensive immunomodulation therapies and anti-epileptic drugs did not lead to any improvements. We therefore diagnosed her with cryptogenic limbic ...
Source: Internal Medicine - Category: Internal Medicine Tags: Intern Med Source Type: research
Every year, tens thousands of men in the United States are diagnosed with low-risk prostate cancer. Most are told that they don ’t need treatment other than “active surveillance” to monitor their slow-growing tumors. Now, UCLA physicians have shown that the best way to proceed with this is by starting out with an MRI-guided prostate biopsy.In the past, doctors relied on ultrasound to guide a biopsy needle into the prostate. However, ultrasound doesn ’t allow the visualization of prostate tumors, so a biopsy may have missed a tumor. Over the past decade, it’s become possible to instead perform ...
Source: UCLA Newsroom: Health Sciences - Category: Universities & Medical Training Source Type: news
AbstractAlthough intramyocardial hemorrhage (IMH) is a poor prognostic factor caused by ischemia reperfusion injury, little evidence is available regarding the association between IMH volume and biomarkers. In the present study, we measured IMH volume using three-dimensional (3D) T1-weighted magnetic resonance imaging (T1-MRI) and investigated its association with biomarkers. Moreover, the accuracy of semi-automatic measurement of IMH volume was validated. We retrospectively enrolled 33 consecutive patients (mean age 67  ± 11 years) who underwent cardiac MRI after reperfusion therapy for acute myo...
Source: The International Journal of Cardiovascular Imaging - Category: Radiology Source Type: research
AbstractIndividuals at high risk for pancreatic cancer are recommended surveillance and healthy lifestyle behaviours and patient experience with recommendations are understudied. To describe engagement and experience with surveillance, tobacco and alcohol use, health beliefs and motivation (Champion Health Belief Measure) and the relationship with personal, psychosocial (Impact of Event Scale), and familial characteristics. Interest in integrative therapies (complementary therapies) are described. A multi-site cross-sectional survey including individuals at high risk for pancreatic cancer with no diagnosis of pancreatic ca...
Source: Familial Cancer - Category: Cancer & Oncology Source Type: research
In this study, iron oxide (γ-Fe2O3) nanoparticles (IONs) were successfully synthesized using sol-gel method, and characterized by XRD and VSM. The potential application of the differently sized IONs (22 nm and 30 nm) as magnetic resonance imaging (MRI) contrast agents was investigated. The relaxation time (T2) of the IONs was measured at room temperature and concentration range of 9-84 µg/ml using fast spin echo sequence with six echoes. The size was found to affect the contrast enhancement of the MRI image, with the T2 for 22 nm sized γ-Fe2O3 nanoparticles exhibiting a shorter dephasing compared to the 3...
Source: Results in Physics - Category: Physics Source Type: research
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