73 research outputs found
The standing fixed flexion view detects narrowing of the joint space better than the standing extended view in patients with moderate osteoarthritis of the knee
A characteristic time sequence of epileptic activity in EEG during dynamic penicillin-induced focal epilepsy—A preliminary study
AbstractPenicillin-induced focal epilepsy is a well-known model in experimental epilepsy. However, the dynamic evolution of waveforms, DC-level changes, spectral content and coherence are rarely reported. Stimulated by earlier fMRI findings, we also seek for the early signs preceding spiking activity from frequency domain of EEG signal. In this study, EEG data is taken from previous EEG/fMRI series (six pigs, 20–24kg) of an experimental focal epilepsy model, which includes dynamic induction of epileptic activity with penicillin (6000IU) injection into the somatosensory cortex during deep isoflurane anaesthesia. No ictal discharges were recorded with this dose. Spike waveforms, DC-level, time–frequency content and coherence of EEG were analysed. Development of penicillin induced focal epileptic activity was not preceded with specific spectral changes. The beginning of interictal spiking was related to power increase in the frequencies below 6Hz or 20Hz, and continued to a widespread spectral increase. DC-level and coherence changes were clear in one animal. Morphological evolution of epileptic activity was a collection of the low-amplitude monophasic, bipolar, triple or double spike-wave forms, with an increase in amplitude, up to large monophasic spiking. In conclusion, in the time sequence of induced epileptic activity, immediate shifts in DC-level EEG are plausible, followed by the spike activity-related widespread increase in spectral content. Morphological evolution does not appear to follow a clear continuum; rather, intermingled and variable spike or multispike waveforms generally lead to stabilised activity of high-amplitude monophasic spikes
Syndesmotic Fixation in Supination-External Rotation Ankle Fractures: A Prospective Randomized Study
Article Ankle fractures are the most common injuries treated operatively by orthopedic surgeons
Impact of constitutional TET2 haploinsufficiency on molecular and clinical phenotype in humans
Clonal hematopoiesis driven by somatic heterozygous TET2 loss is linked to malignant degeneration via consequent aberrant DNA methylation, and possibly to cardiovascular disease via increased cytokine and chemokine expression as reported in mice. Here, we discover a germline TET2 mutation in a lymphoma family. We observe neither unusual predisposition to atherosclerosis nor abnormal pro-inflammatory cytokine or chemokine expression. The latter finding is confirmed in cells from three additional unrelated TET2 germline mutation carriers. The TET2 defect elevates blood DNA methylation levels, especially at active enhancers and cell-type specific regulatory regions with binding sequences of master transcription factors involved in hematopoiesis. The regions display reduced methylation relative to all open chromatin regions in four DNMT3A germline mutation carriers, potentially due to TET2-mediated oxidation. Our findings provide insight into the interplay between epigenetic modulators and transcription factor activity in hematological neoplasia, but do not confirm the putative role of TET2 in atherosclerosis.Peer reviewe
Temporal Trends in Vertebral Size and Shape from Medieval to Modern-Day
Human lumbar vertebrae support the weight of the upper body. Loads lifted and carried by the upper extremities cause significant loading stress to the vertebral bodies. It is well established that trauma-induced vertebral fractures are common especially among elderly people. The aim of this study was to investigate the morphological factors that could have affected the prevalence of trauma-related vertebral fractures from medieval times to the present day. To determine if morphological differences existed in the size and shape of the vertebral body between medieval times and the present day, the vertebral body size and shape was measured from the 4th lumbar vertebra using magnetic resonance imaging (MRI) and standard osteometric calipers. The modern samples consisted of modern Finns and the medieval samples were from archaeological collections in Sweden and Britain. The results show that the shape and size of the 4th lumbar vertebra has changed significantly from medieval times in a way that markedly affects the biomechanical characteristics of the lumbar vertebral column. These changes may have influenced the incidence of trauma- induced spinal fractures in modern populations
Genetic susceptibility of intervertebral disc degeneration among young Finnish adults
<p>Abstract</p> <p>Background</p> <p>Disc degeneration (DD) is a common condition that progresses with aging. Although the events leading to DD are not well understood, a significant genetic influence has been found. This study was undertaken to assess the association between relevant candidate gene polymorphisms and moderate DD in a well-defined and characterized cohort of young adults. Focusing on young age can be valuable in determining genetic predisposition to DD.</p> <p>Methods</p> <p>We investigated the associations of existing candidate genes for DD among 538 young adults with a mean age of 19 belonging to the 1986 Northern Finland Birth Cohort. Nineteen single nucleotide polymorphisms (SNP) in 16 genes were genotyped. We evaluated lumbar DD using the modified Pfirrmann classification and a 1.5-T magnetic resonance scanner for imaging.</p> <p>Results</p> <p>Of the 538 individuals studied, 46% had no degeneration, while 54% had DD and 51% of these had moderate DD. The risk of DD was significantly higher in subjects with an allele G of <it>IL6 </it>SNPs rs1800795 (OR 1.45, 95% CI 1.07-1.96) and rs1800797 (OR 1.37, 95% CI 1.02-1.85) in the additive inheritance model. The role of <it>IL6 </it>was further supported by the haplotype analysis, which resulted in an association between the GGG haplotype (SNPs rs1800797, rs1800796 and rs1800795) and DD with an OR of 1.51 (95% CI 1.11-2.04). In addition, we observed an association between DD and two other polymorphisms, <it>SKT </it>rs16924573 (OR 0.27 95% CI 0.07-0.96) and <it>CILP </it>rs2073711 in women (OR 2.04, 95% CI 1.07-3.89).</p> <p>Conclusion</p> <p>Our results indicate that <it>IL6</it>, <it>SKT </it>and <it>CILP </it>are involved in the etiology of DD among young adults.</p
Diffusion-weighted MRI and delayed contrast enhancement of degenerated intervertebral disc
Abstract
Magnetic resonance imaging (MRI) provides methods to study the microstructure and functional properties of tissues that can be utilized to acquire information about the degenerative processes in the spine. The purpose of the current study was to evaluate the value of diffusion-weighted MRI and quantification of delayed gadolinium enhancement in assessing intervertebral disc degeneration.
An experimental degeneration model was used to evaluate the sensitivity of diffusion-weighted MRI and T2 relaxation time measurements in detecting early degenerative changes in the disc. In six pigs, an annular disc lesion was induced surgically, after which the discs were repeatedly MR imaged for up to eight weeks. T2 relaxation time of the lesioned discs decreased postoperatively, whereas apparent diffusion coefficient (ADC) initially increased, but at eight weeks decreased when compared to the control discs.
The value of ADC in degeneration of human discs was evaluated by imaging 228 voluntary middle-aged men. ADC values of the three lowest lumbar intervertebral discs were measured and disc degeneration was visually graded. The reduction in ADC between visually normal and moderately degenerated discs was 4%, whereas severely degenerated discs showed 5% higher ADC values than normal discs. T2 signal intensity of the discs was significantly correlated with the ADC values. Because of a considerable overlap between ADC values of normal and degenerated discs the clinical relevance of the ADC measurements of lumbar intervertebral discs remains questionable.
A method to quantify delayed enhancement of the nucleus pulposus after intravenous gadolinium contrast agent injection was developed to evaluate the diffusion of small solutes into the disc. Twenty male volunteers were imaged in order to correlate the measured change in the T1 relaxation rate with visually evaluated degenerative changes. The percentual change of T1 relaxation rate for individual discs was up to 126%, and a positive trend was observed between the delayed enhancement and the disc degeneration grades.
In order to study the factors that determine the intensity of delayed enhancement, T1 relaxation rate measurements were further correlated with lumbar artery stenosis, bone marrow changes adjacent to endplates, endplate defects, and ADC of the disc. Lumbar artery stenosis and ADC values of the discs were not correlated with enhancement, while disc space narrowing and the presence of degenerative endplate changes had a strong correlation, suggesting an important role for the endplate in maintaining the integrity of the disc
Emergence of teleradiology, PACS, and other radiology IT solutions in Acta Radiologica
Abstract
For this historical review, we searched a database containing all the articles published in Acta Radiologica during its 100-year history to find those on the use of information technology (IT) in radiology. After reading the full texts, we selected the presented articles according to major radiology IT domains such as teleradiology, picture archiving and communication systems, image processing, image analysis, and computer-aided diagnostics in order to describe the development as it appeared in the journal. Publications generally follow IT megatrends, but because the contents of Acta Radiologica are mainly clinically oriented, some technology achievements appear later than they do in journals discussing mainly imaging informatics topics
Retrograde intramedullary nailing of the radius in children:a pilot magnetic resonance imaging study of soft-tissue findings
Abstract
Purpose: Unstable forearm shaft fractures in children are preferably treated surgically using elastic stable intramedullary nails. The radius is nailed retrograde from the distal metaphysis. There is a risk of surgery-related soft-tissue complications during the operation. Close evaluation of occult surgery-related soft-tissue lesions has not been possible previously, due to the titanium alloy hardware used in the process. The aim of the present study was to evaluate the potential findings in the surrounding soft tissues after intramedullary nailing of the radius, by using magnetic resonance imaging.
Methods: The study population comprised 15 pediatric patients with forearm shaft fractures treated by polylactide-co-glycolide biodegradable intramedullary nails and postoperatively evaluated via magnetic resonance imaging. The main outcome was signal abnormality in any tendon at the entry point postoperatively. Secondarily, other changes in the soft tissues related to nailing were determined. Furthermore, the precise location of the entry point and the anatomic characteristics of the soft-tissue tunnel were described.
Results: In total, 5 of 15 patients (33.3%) had transient signal pathology in a tendon postoperatively. Edema around the superficial radial nerve was detected in 13 of 15 patients (86.7%). The most common surgical approach was between the extensor pollicis brevis and the extensor carpi radialis longus tendons, which was applied in 10 of 15 patients (66.7%).
Conclusions: One in three patients exhibited transient and occult surgery-related intraparenchymal signal pathology in a tendon, after forearm intramedullary nailing. Caution with surgical prepare of the soft-tissue cleavage is recommended
Lumbosacral transitional vertebrae are associated with lumbar degeneration:retrospective evaluation of 3855 consecutive abdominal CT scans
Abstract
Objectives: To assess the prevalence of lumbosacral transitional vertebra (LSTV) and associated spinal degenerative changes on abdominal CT scans in Caucasian population.
Material and methods: A total of 3855 abdominal CT scans of the year 2017 from a single hospital were retrospectively assessed for LSTV, disc degeneration (DD), and facet joint degeneration (FD). An age- and sex-matched 150-subject control group without LSTV was picked at random. Multivariable logistic regression was used for the analysis.
Results: LSTV was found in 1101 (29%) scans: Castellvi type I in 68%, type II in 16%, type III in 13%, and type IV in 3% of scans. Age- and sex-adjusted prevalence of DD was significantly higher in Castellvi type II and III groups at multiple lumbar levels, and in IV group at L4/5 than in control group (p < 0.001–0.034). At L5/S1, the prevalence of DD was significantly higher in the control group than in type II, III, or IV groups (p < 0.001–0.017). After combining Castellvi types II, III, and IV into one group, significant differences were found at all lumbar levels except L2/3 (p < 0.001–0.016). Prevalence of FD was significantly higher at L4/5 in Castellvi groups I, II, and III than in the control group (p < 0.001–0.002). When Castellvi types II, III, and IV were combined into one group, significant differences were found at lumbar levels L2/3, L3/4, and L4/5 (p < 0.001–0.021).
Conclusion: Lumbosacral vertebrae of Castellvi types II, III, and IV are associated with greater lumbar degeneration, warranting meticulous evaluation of spinal anatomy, even on CT
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