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The primary aim of this study, is to assess whether ADC-based intensity weighted lesion volume is more associated with functional outcome than total lesion volume alone in post-EVT anterior circulation LVO stroke patients. The secondary aim is to investigate whether other ADC intensity based biomarkers (infarct density and mean intensity) are more associated with functional outcome than total lesion volume alone. Lastly, we will investigate the influence of intravenous alteplase before EVT on weighted lesion volume, infarct density and mean ADC. Research questions 1. Does ADC-based intensity weighted lesion volume provide additional information on functional outcomes beyond total lesion volume in anterior circulation LVO stroke patients? 2. Do previously established ADC-based biomarkers (infarct density and mean intensity) provide additional information on functional outcome beyond total lesion volume in anterior circulation LVO stroke patients? 3. How do infarct density, weighted lesion volume and total lesion volume differ between patients who received EVT alone and those who received both EVT and intravenous alteplase?

Magnetic resonance imaging (MRI) is a non-destructive technique for determining the quality of fruits which, with different protocols, shows the density and structure of hydrogen atoms in the fruit in which it is placed. This study compared MRI images of healthy and bruised apple flesh tissues, both with and without pests, using various protocols to identify the best one. For this purpose, magnetic resonance imaging (MRI) using two protocols: T 1 (Spin-lattice relaxation time) and T 2 (Spin-spin relaxation time), was carried out on 200 apple fruits that were loaded during storage. The loading of fruits was performed at four levels: 150, 300, 450, and 600 N in a quasi-static manner, and then stored for periods of 25, 50, and 75 days at 4 °C. At the end of each storage period, imaging was carried out. Then, the contrast of T 1 and T 2 images of healthy and bruised tissue of apple fruit with and without pests using ImageJ software was determined. It was concluded that the healthy tissue of apple fruit without pests was clearer in T 1 images than in T 2 images. It has also been seen that the bruised area of fruits without pests in T 2 images is more recognizable than in T 1 images.

Magnetic resonance imaging (MRI) is a non-destructive technique for determining the quality of fruits which, with different protocols, shows the density and structure of hydrogen atoms in the fruit in which it is placed. This study compared MRI images of healthy and bruised apple flesh tissues, both with and without pests, using various protocols to identify the best one. For this purpose, magnetic resonance imaging (MRI) using two protocols: T 1 (Spin-lattice relaxation time) and T 2 (Spin-spin relaxation time), was carried out on 200 apple fruits that were loaded during storage. The loading of fruits was performed at four levels: 150, 300, 450, and 600 N in a quasi-static manner, and then stored for periods of 25, 50, and 75 days at 4 °C. At the end of each storage period, imaging was carried out. Then, the contrast of T 1 and T 2 images of healthy and bruised tissue of apple fruit with and without pests using ImageJ software was determined. It was concluded that the healthy tissue of apple fruit without pests was clearer in T 1 images than in T 2 images. It has also been seen that the bruised area of fruits without pests in T 2 images is more recognizable than in T 1 images.

Magnetic resonance imaging (MRI) is a non-destructive technique for determining the quality of fruits which, with different protocols, shows the density and structure of hydrogen atoms in the fruit in which it is placed. This study compared MRI images of healthy and bruised apple flesh tissues, both with and without pests, using various protocols to identify the best one. For this purpose, magnetic resonance imaging (MRI) using two protocols: T 1 (Spin-lattice relaxation time) and T 2 (Spin-spin relaxation time), was carried out on 200 apple fruits that were loaded during storage. The loading of fruits was performed at four levels: 150, 300, 450, and 600 N in a quasi-static manner, and then stored for periods of 25, 50, and 75 days at 4 °C. At the end of each storage period, imaging was carried out. Then, the contrast of T 1 and T 2 images of healthy and bruised tissue of apple fruit with and without pests using ImageJ software was determined. It was concluded that the healthy tissue of apple fruit without pests was clearer in T 1 images than in T 2 images. It has also been seen that the bruised area of fruits without pests in T 2 images is more recognizable than in T 1 images.

This article is from PLoS ONE , volume 9 . Abstract Background: Previous studies demonstrated that primary open angle glaucoma (POAG) is associated with abnormal brain structure; however, little is known about the changes in the local synchronization of spontaneous activity. The main objective of this study was to investigate spontaneous brain activity in patients with POAG using regional homogeneity (ReHo) analysis based on resting state functional magnetic resonance imaging (rs-fMRI). Methodology/Principal Findings: Thirty-nine POAG patients and forty-one age- and gender- matched healthy controls were finally included in the study. ReHo values were used to evaluate spontaneous brain activity and whole brain voxel-wise analysis of ReHo was carried out to detect differences by region in spontaneous brain activity between groups. Compared to controls, POAG patients showed increased ReHo in the right dorsal anterior cingulated cortex, the bilateral medial frontal gyrus and the right cerebellar anterior lobe, and decreased ReHo in the bilateral calcarine, bilateral precuneus gryus, bilateral pre/postcentral gyrus, left inferior parietal lobule and left cerebellum posterior lobe. A multiple linear regression analysis was performed to explore the relationships between clinical measures and ReHo by region showed significant group differences in the POAG group. Negative correlations were found between age and the ReHo values of the superior frontal gyrus (r = −0.323, p = 0.045), left calcarine (r = −0.357, p = 0.026) and inferior parietal lobule (r = −0.362, p = 0.024). A negative correlation was found between the ReHo values of the left precuneus and the cumulative mean defect (r = −0.400, p = 0.012). Conclusions: POAG was associated with abnormal brain spontaneous activity in some brain regions and such changed regional activity may be associated with clinical parameters. Spontaneous brain activity may play a role in POAG initiation and progression.

This article is from PLoS ONE , volume 9 . Abstract Chronic neuropathic pain following surgery represents a serious worldwide health problem leading to life-long treatment and the possibility of significant disability. In this study, neuropathic pain was modeled using the chronic constriction injury (CCI). The CCI rats exhibit mechanical hypersensitivity (typical neuropathic pain symptom) to mechanical stimulation of the affected paw 11 days post surgery, at a time when sham surgery animals do not exhibit hypersensitivity. Following a similar time course, TRPV1 gene expression appears to rise with the hypersensitivity to mechanical stimulation. Recent studies have shown that immune cells play a role in the development of neuropathic pain. To further explore the relationship between neuropathic pain and immune cells, we hypothesize that the infiltration of immune cells into the affected sciatic nerve can be monitored in vivo by molecular imaging. To test this hypothesis, an intravenous injection of a novel perfluorocarbon (PFC) nanoemulsion, which is phagocytosed by inflammatory cells (e.g. monocytes and macrophages), was used in a rat CCI model. The nanoemulsion carries two distinct imaging agents, a near-infrared (NIR) lipophilic fluorescence reporter (DiR) and a 19F MRI (magnetic resonance imaging) tracer, PFC. We demonstrate that in live rats, NIR fluorescence is concentrated in the area of the affected sciatic nerve. Furthermore, the 19F MRI signal was observed on the sciatic nerve. Histological examination of the CCI sciatic nerve reveals significant infiltration of CD68 positive macrophages. These results demonstrate that the infiltration of immune cells into the sciatic nerve can be visualized in live animals using these methods.

This article is from Breast Cancer Research : BCR , volume 15 . Abstract None

This article is from Journal of Cardiovascular Magnetic Resonance , volume 16 . Abstract None

This article is from Journal of Cardiovascular Magnetic Resonance , volume 16 . Abstract None

This article is from Journal of Cardiovascular Magnetic Resonance , volume 16 . Abstract None

This article is from Cerebrovascular Diseases Extra , volume 4 . Abstract Background: The type of neuroimaging for the evaluation of transient ischemic attack (TIA) is debatable. Many patients undergo head computed tomography (CT) with or without CT angiogram (CTA) while being at the emergency department (ED) and later magnetic resonance imaging (MRI) with MR angiogram (MRA) during admission. We hypothesized that evaluation with only one imaging modality (CT/CTA or MRI/MRA) is sufficient to formulate a treatment plan. We looked for the most cost-effective way to evaluate TIA patients. Methods: We performed a retrospective chart review of 82 patients with TIA. All patients had completely resolved neurological deficit at the time of their evaluation in the ED. We divided the patients into two groups. In group 1, the evaluation included CT with CTA of the head and neck. In group 2, the evaluation included brain MRI with MRA or CTA of the head and neck. We compared these two groups for clinical characteristics and etiological evaluations of stroke/TIA. The outcomes were measured by the number of therapeutic adjustments for the prevention of another ischemic stroke/TIA at the time of discharge from the hospital and revascularization procedures. We counted the following as therapeutic adjustment: (1) antiplatelet therapy was started de novo; (2) anticoagulation was started; (3) arterial revascularization procedure was performed, and (4) one antiplatelet agent was substituted for another. We performed a cost-effectiveness analysis if the outcomes of the two groups were different and a cost-minimization analysis if there was no difference in the outcomes. All cost calculations were made based on Medicare CPT codes. Results: Group 1 included 23 patients and group 2 59 patients. The patients in both groups had similar demographic and clinical characteristics. There was no difference in other etiological evaluations in groups 1 and 2. All patients underwent head CT as the first tool of evaluation whether MRI was done later or not. Therapeutic adjustments and revascularization procedures did not differ between the two groups. All head CTs showed no acute changes. MRI showed small ischemic infarcts in 44% of the patients in group 2. The average per-patient cost of neuroimaging with CT/CTA was USD 1,460.00, with CT and MRI/MRA USD 1,569 and with CT/CTA and brain MRI USD 2,090.00 (p < 0.01). Conclusion: Either MRI/MRA or CT/CTA might be sufficient for the evaluation of patients with TIA or small asymptomatic strokes. If head CT at the ED is bypassed, a brain MRI with MRA of the head and neck would be the most informative tool at the lowest cost. Prospective studies with larger numbers of patients are needed for a better understanding of the safety and cost of imaging tools used for patients with TIA.

This article is from Cerebrovascular Diseases Extra , volume 4 . Abstract Background: The type of neuroimaging for the evaluation of transient ischemic attack (TIA) is debatable. Many patients undergo head computed tomography (CT) with or without CT angiogram (CTA) while being at the emergency department (ED) and later magnetic resonance imaging (MRI) with MR angiogram (MRA) during admission. We hypothesized that evaluation with only one imaging modality (CT/CTA or MRI/MRA) is sufficient to formulate a treatment plan. We looked for the most cost-effective way to evaluate TIA patients. Methods: We performed a retrospective chart review of 82 patients with TIA. All patients had completely resolved neurological deficit at the time of their evaluation in the ED. We divided the patients into two groups. In group 1, the evaluation included CT with CTA of the head and neck. In group 2, the evaluation included brain MRI with MRA or CTA of the head and neck. We compared these two groups for clinical characteristics and etiological evaluations of stroke/TIA. The outcomes were measured by the number of therapeutic adjustments for the prevention of another ischemic stroke/TIA at the time of discharge from the hospital and revascularization procedures. We counted the following as therapeutic adjustment: (1) antiplatelet therapy was started de novo; (2) anticoagulation was started; (3) arterial revascularization procedure was performed, and (4) one antiplatelet agent was substituted for another. We performed a cost-effectiveness analysis if the outcomes of the two groups were different and a cost-minimization analysis if there was no difference in the outcomes. All cost calculations were made based on Medicare CPT codes. Results: Group 1 included 23 patients and group 2 59 patients. The patients in both groups had similar demographic and clinical characteristics. There was no difference in other etiological evaluations in groups 1 and 2. All patients underwent head CT as the first tool of evaluation whether MRI was done later or not. Therapeutic adjustments and revascularization procedures did not differ between the two groups. All head CTs showed no acute changes. MRI showed small ischemic infarcts in 44% of the patients in group 2. The average per-patient cost of neuroimaging with CT/CTA was USD 1,460.00, with CT and MRI/MRA USD 1,569 and with CT/CTA and brain MRI USD 2,090.00 (p < 0.01). Conclusion: Either MRI/MRA or CT/CTA might be sufficient for the evaluation of patients with TIA or small asymptomatic strokes. If head CT at the ED is bypassed, a brain MRI with MRA of the head and neck would be the most informative tool at the lowest cost. Prospective studies with larger numbers of patients are needed for a better understanding of the safety and cost of imaging tools used for patients with TIA.

This article is from Experimental and Therapeutic Medicine , volume 7 . Abstract The aim of the present study was to establish a novel animal model of osteonecrosis of the femoral head (ONFH) using a magnetic resonance imaging (MRI)-guided argon-helium cryotherapy system. A total of 48 rabbits were used to generate the ONFH models. In group I, the left femoral head of the rabbits received two cycles of argon-helium freezing-thawing under MRI guidance, while in group II, the right femoral head of each rabbit received only one cycle of argon-helium freezing-thawing. X-ray and histological examinations were performed. The percentages of lacunae in the femoral heads of group I at weeks 4, 8 and 12 following surgery (49.75±3.17, 62.06±4.12 and 48.25±2.76%, respectively) were higher than those in group II (39.13±4.48, 50.69±3.84 and 37.50±3.86%, respectively). In addition, the percentage of empty lacunae in group I was 62.06% at week 8 following surgery. Therefore, an animal model of ONFH was successfully established using an argon-helium cryotherapy system. The percentage of empty lacunae in group I was higher than that in group II at weeks 4, 8 and 12 after surgery.

This article is from Psychiatry Investigation , volume 9 . Abstract Here, we report psychotic symptoms together with a right cerebellopontine-angle lesion. A37-year-old female patient presented with a trigeminal Schwannoma occupying the right cerebellopontine angle. Her psychotic symptoms included auditory hallucinations and delusions of persecution. T1- and T2-weighted images on magnetic resonance imaging (MRI) revealed hyperintense and hypointense areas in the right cerebellopontine angle, respectively. The clinical and neuroimaging reviews in this case suggest that sudden onset of psychotic symptoms at a mature age may be associated with a right cerebellopontine-angle lesion and that MRI should be used to evaluate possible organic bases in patients that present with psychosis.

This article is from World Journal of Surgical Oncology , volume 12 . Abstract Background: The purpose of this study was to assess the magnetic resonance imaging findings of alveolar soft part sarcoma. Methods: Magnetic resonance images of pathologically proven alveolar soft part sarcoma in 14 patients were retrospectively reviewed, including lesion location, size and shape, border definition, signals on T1-weighted and T2-weighted images, presence or absence of peritumoral and intratumoral flow voids, and enhancement pattern. Results: Patients included five women and nine men, ranging in age from 27 to 54 years, with a mean age of 36 years. A slow-growing mass without pain was the chief complaint. Eight patients had pulmonary metastases at presentation. Ten lesions arose from the extremities, two were located in the gluteal regions, one affected the presacral space and one occurred in the back. The mean maximal size of the lesions was 9.8 cm, ranging from 6.2 to 16 cm. All lesions appeared as a round (n = 2), ovoid (n = 8) or irregular (n = 4) shape with ill-defined margins. The lesions mainly demonstrated isointense or mildly hyperintense compared to muscle on T1-weighted images, and heterogeneous high signal intensity on T2-weighted images. Peritumoral edemas were observed in six patients. Ten lesions showed intense inhomogeneous enhancement after contrast. Intra- and peritumoral tubular flow voids representing tortuous dilated vessels with rapid blood flow were present in all cases. Conclusions: Alveolar soft part sarcoma has some distinctive magnetic resonance imaging features including a slow-growing, large mass in the soft tissue of the extremities in young adults, with numerous signal voids on T1-weighted and T2-weighted images, and strong enhancement after contrast.

This article is from Korean Journal of Radiology , volume 15 . Abstract We report a case of a 74-year-old female with myxoid adrenocortical adenoma which showed different magnetic resonance imaging findings compared to those of a typical adrenocortical adenoma. The myxoid change in the adrenocortical adenoma is a rare form of degeneration. It presents a considerable diagnostic challenge to both radiologists and clinicians because it can mimic other adrenal tumor types on imaging. The MRI findings of the presented case included a high signal intensity on T2-weighted images similar to that of fluid and delayed progressive enhancement.

This article is from Croatian Medical Journal , volume 55 . Abstract Previously there have been no methods for directly tracing the flow of cerebrospinal fluid (CSF) under physiological conditions, and the circulation of CSF has therefore been studied and visualized by injecting a radioactively labeled tracer or contrast medium visible in x-ray images. The newly developed Time-Spatial Inversion Pulse (Time-SLIP) method makes it possible to directly visualize the flow of CSF using magnetic resonance imaging (MRI), permitting CSF dynamics to be depicted in a certain time frame. The CSF dynamics visualized using Time-SLIP has been found to differ markedly from the classical CSF circulation theory described in medical textbooks. It can be said that research on CSF dynamics has advanced to the next stage with the use of this innovative imaging method. Obtaining a more accurate understanding of normal CSF physiology and pathophysiology should lead to improved diagnostic accuracy, permit the identification of new etiological factors in a variety of diseases, and promote the development of new therapeutic approaches.

This article is from BMC Neurology , volume 14 . Abstract Background: Some studies reported that cerebral developmental venous anomaly (DVA) is often concurrent with cavernous malformation (CM). But there is lack of statistical evidence and study of bulk cases. The factors associated with concurrency are still unknown. The purpose of this study was to determine the prevalence of concomitant DVA and CM using observational data on Chinese patients and analyze the factors associated with the concurrency. Methods: The records of all cranial magnetic resonance imaging (MRI) performed between January 2001 and December 2012 in Beijing Tiantan Hospital were reviewed retrospectively. The DVA and CM cases were selected according to imaging reports that met diagnostic criteria. Statistical analysis was performed using the Pearson chi-square statistic for binary variables and multivariable logistic regression analysis for predictors associated with the concurrent CM. Results: We reviewed a total of 165,230 cranial MR images performed during the previous 12 year period, and identified 1,839 cases that met DVA radiographic criteria. There were 205 patients who presented concomitant CM among the 1,839 DVAs. The CM prevalence in DVA cases (11.1%) was significantly higher than that in the non-DVA cases (2.3%) (P

This article is from Brain , volume 137 . Abstract Temporal lobe surgery can control seizures in drug-resistant epilepsy, but its impact on working memory is poorly understood. Using functional MRI, Stretton et al. reveal improvements in working memory post-surgery, which depend upon the functional capacity of the hippocampal remnant and the functional reserve of the contralateral hippocampus.

This article is from Journal of Cardiovascular Magnetic Resonance , volume 16 . Abstract None

This article is from World Journal of Surgical Oncology , volume 11 . Abstract Background: The management of cancer in the axillary area depends on the etiology of the tumor. Case Report: A 37-year-old woman presented with a 2 cm mass in the axillary fossa. Core needle biopsy revealed adenocarcinoma. There were no abnormal breast findings on physical examination, mammography, or ultrasonography. However, enhanced magnetic resonance imaging (MRI) and positron emission tomography (PET) showed a segmentally-distributed, abnormal area in the upper-outer quadrant, continuous with the axillary mass. Samples of this area obtained by vacuum-assisted biopsy showed intraductal carcinoma. These findings indicated that the axillary lesion was a part of primary breast cancer originating from the axillary tail. Based on these results, the patient underwent total mastectomy with sentinel lymph node biopsy. Pathological examination of the specimen showed invasive ductal carcinoma accompanied by intraductal carcinoma extending up to 8.5 cm. Our case suggests that enhanced MRI and PET can provide useful preoperative information for the management of axillary breast lesions.

This article is from Frontiers in Human Neuroscience , volume 7 . Abstract Transcranial direct-current stimulation (tDCS) is showing increasing promise as an adjunct therapy in stroke rehabilitation. However questions still remain concerning its mechanisms of action, which currently limit its potential. Magnetic resonance (MR) techniques are increasingly being applied to understand the neural effects of tDCS. Here, we review the MR evidence supporting the use of tDCS to aid recovery after stroke and discuss the important open questions that remain.

This article is from Frontiers in Neurology , volume 5 . Abstract Stroke continues to be a significant cause of death and disability worldwide. Although major advances have been made in the past decades in prevention, treatment, and rehabilitation, enormous challenges remain in the way of translating new therapeutic approaches from bench to bedside. Thrombolysis, while routinely used for ischemic stroke, is only a viable option within a narrow time window. Recently, progress in stem cell biology has opened up avenues to therapeutic strategies aimed at supporting and replacing neural cells in infarcted areas. Realistic experimental animal models are crucial to understand the mechanisms of neuronal survival following ischemic brain injury and to develop therapeutic interventions. Current studies on experimental stroke therapies evaluate the efficiency of neuroprotective agents and cell-based approaches using primarily rodent models of permanent or transient focal cerebral ischemia. In parallel, advancements in imaging techniques permit better mapping of the spatial-temporal evolution of the lesioned cortex and its functional responses. This review provides a condensed conceptual review of the state of the art of this field, from models and magnetic resonance imaging techniques through to stem cell therapies.

This article is from Oncology Letters , volume 8 . Abstract The aim of the present study was to evaluate the value of systematic 12- and 13-core biopsies, guided by transrectal ultrasound (TRUS) or magnetic resonance imaging (MRI), with regard to the prostate cancer detection rate (PCDR). Between July 1999 and June 2012, 2,707 patients were recruited to the Department of Urology, The First Affiliated Hospital of Nanjing Medical University (Nanjing, China). Prostate biopsies were performed via systematic 12- or 13-core biopsy and guided by either TRUS or MRI. The PCDR was established by retrospectively analyzing the distribution of positive cores, and it was assumed that all patients had undergone four biopsy schemes: Medial 6-core, lateral 6-core, 12-core and entire 13-core. In addition, the positive rate of the biopsies with the extra 13th core and the mean positive rate of systematic 12-core biopsies were compared. The PCDR of an entire 13-core biopsy was significantly higher than that of a lateral 6-core biopsy. The positive rate of the extra 13th core, which identified abnormal TRUS or MRI findings, was significantly higher when compared with that of the mean positive rate of the systematic 12-core biopsy. The results of the present study demonstrated that the entire 13-core biopsy was superior to the 6-core biopsy with regard to the PCDR. Therefore, the systematic 12-core biopsy with an extra 13th core is considered to be beneficial towards improving the PCDR.

This article is from Journal of Cardiovascular Magnetic Resonance , volume 16 . Abstract None

This article is from Journal of Cardiovascular Magnetic Resonance , volume 16 . Abstract None

This article is from Journal of Cardiovascular Magnetic Resonance , volume 16 . Abstract None

Magnetic Resonance Imaging 1991: Volume 9 , Issue Contents. Digitized from IA1652604-05 . Previous issue: sim_magnetic-resonance-imaging_1990_8_supplement-1 . Next issue: sim_magnetic-resonance-imaging_1991_9_index .

Magnetic Resonance Imaging 2001: Volume 19 , Issue Contents. Digitized from IA1652604-05 . Previous issue: sim_magnetic-resonance-imaging_2000-12_18_10 . Next issue: sim_magnetic-resonance-imaging_2001-01_19_1 .

Magnetic Resonance Imaging 2001: Volume 19 , Issue Contents. Digitized from IA1652604-05 . Previous issue: sim_magnetic-resonance-imaging_2000-12_18_10 . Next issue: sim_magnetic-resonance-imaging_2001-01_19_1 .

The analytical expression for the signal-to-noise ratio of a slotted surface coil with an arbitrary number of slots was derived using the quasi-static approach. This surface coil based on the vane-type magnetron tube. To study the coil perfomance, the theoretical signal-to-noise ratio predictions of this coil design were computed using a different number of slots. Results were also compared with theoretical results obtained for a circular coil with similar dimensions. It can be appreciated that slotted surface coil performance improves as the number of coils increases and, outperformed the circular-shaped coil. This makes it a good candidate for other MRI applications involving coil array techniques.

The analytical expression for the signal-to-noise ratio of a slotted surface coil with an arbitrary number of slots was derived using the quasi-static approach. This surface coil based on the vane-type magnetron tube. To study the coil perfomance, the theoretical signal-to-noise ratio predictions of this coil design were computed using a different number of slots. Results were also compared with theoretical results obtained for a circular coil with similar dimensions. It can be appreciated that slotted surface coil performance improves as the number of coils increases and, outperformed the circular-shaped coil. This makes it a good candidate for other MRI applications involving coil array techniques.

The analytical expression for the signal-to-noise ratio of a slotted surface coil with an arbitrary number of slots was derived using the quasi-static approach. This surface coil based on the vane-type magnetron tube. To study the coil perfomance, the theoretical signal-to-noise ratio predictions of this coil design were computed using a different number of slots. Results were also compared with theoretical results obtained for a circular coil with similar dimensions. It can be appreciated that slotted surface coil performance improves as the number of coils increases and, outperformed the circular-shaped coil. This makes it a good candidate for other MRI applications involving coil array techniques.

This article is from Journal of Cardiovascular Magnetic Resonance , volume 16 . Abstract None

This article is from Clinical and Experimental Otorhinolaryngology , volume 5 . Abstract Objectives: In this study, we compared the magnetic resonance (MR) image artifacts caused by a conventional metal-based cochlear implant and a newly developed liquid crystal polymer (LCP)-based device. Methods: The metal-based cochlear implant system (Nurobiosys Co.) was attached to side of the head of a subject and the LCP-based device was attached to opposite side. In both devices, alignment magnets were removed for safety. Magnetic resonance imaging (MRI) was performed on a widely used 3.0 T and an ultra-high 7.0 T MRI machine. 3.0 and 7.0 T MR images were acquired using T1- and T2*-weighted gradient echo sequences, respectively. Results: In the 3.0 T images, the metal-based device on the left side generated the significant amount of artifacts. The MR images in the proximity of the metal package were obscured by the artifacts in both axial and sagittal views. On the other hand, the MR images near the LCP-based device were relatively free from the artifacts and clearly showed the brain structures. 7.0 T MR images showed the more severe distortion in the both sides but the metal-based cochlear implant system caused a much larger obscure area than the LCP-based system. Conclusion: The novel LCP-based cochlear implant provides a good MRI compatibility beyond present-day cochlear implants. Thus, MR images can be obtained from the subjects even with the implanted LCP-based neural prosthetic systems providing useful diagnostic information. Furthermore, it will be also useful for functional MRI studies of the auditory perception mechanism after cochlear implantations as well as for positron emission tomography-MRI hybrid imaging.

This article is from PLoS ONE , volume 8 . Abstract Background: The purpose of the present study was to compare the image quality of spinal magnetic resonance (MR) imaging performed on a high-field horizontal open versus a short-bore MR scanner in a randomized controlled study setup. Methods: Altogether, 93 (80% women, mean age 53) consecutive patients underwent spine imaging after random assignement to a 1-T horizontal open MR scanner with a vertical magnetic field or a 1.5-T short-bore MR scanner. This patient subset was part of a larger cohort. Image quality was assessed by determining qualitative parameters, signal-to-noise (SNR) and contrast-to-noise ratios (CNR), and quantitative contour sharpness. Results: The image quality parameters were higher for short-bore MR imaging. Regarding all sequences, the relative differences were 39% for the mean overall qualitative image quality, 53% for the mean SNR values, and 34–37% for the quantitative contour sharpness (P

Bed rest has been widely used as a simulation of weightlessness in studying the effects of microgravity exposure on human physiology and cognition. Changes in muscle function and functional mobility have been reported to be associated with bed rest. Understanding the effect of bed rest on neural control of movement would provide helpful information for spaceflight. In the current study, we evaluated how the brain activation for foot movement changed as a function of bed rest. Eighteen healthy men (aged 25 to 39 years) participated in this HDBR study. They remained continuously in the 6deg head‐down tilt position for 70 days. Functional MRI was acquired during 1‐Hz right foot tapping, and repeated at 7 time points: 12 days pre‐, 8 days pre‐, 7 days in‐, 50 days in‐, 70 days in‐, 8 days post‐, and 12 days post‐ HDBR. In all 7 sessions, we observed increased activation in the left motor cortex, right cerebellum and right occipital cortex during foot movement blocks compared to rest. Compared to the pre‐HDBR baseline (1st and 2nd sessions), foot movement‐induced activation in the left hippocampus increased during HDBR. This increase emerged in the 4th session, enlarged in the 5th session, and remained significant in the 6th and 7th sessions. Furthermore, increased activation relative to the baseline in left precuneus was observed in the 5th, 6th and 7th sessions. In addition, in comparison with baseline, increased activation in the left cerebellum was found in the 4th and 5th sessions, whereas increased activation in the right cerebellum was observed in the 4th, 6th and 7th sessions. No brain region exhibited decreased activation during bed rest compared to baseline. The increase of foot movement related brain activation during HDBR suggests that in a long‐term head‐down position, more neural control is needed to accomplish foot movements. This change required a couple of weeks to develop in HDBR (between 3rd and 4th sessions), and did not return to baseline even 12 days after HDBR. The observed effect of bed rest on brain activation during a foot tapping task could be linked to HDBR related changes in brain structure that we have recently reported. The relationship between pre‐ and post‐ HDBR changes in brain activation and performance in a functional mobility test will also be presented.

Introduction : “Dynamic traction therapy” (DTT) is a new standardized conservative treatment option in lumbar disc herniation. This study aimed to evaluate the therapeutic effect of DTT in lumbar disc herniation, by correlating both clinical and magnetic resonance imaging (MRI) outcomes. Materials and methods: In a total of 27 patients (mean age 50.5±9.1), who underwent standardized DTT, MRI was performed before and after therapy and evaluated by two independent radiologists individually and blindly; both grading intervertebral discs according to Pfirrmann classification in terms of degeneration, morphology, localization and nerve root affectation. The effect of standardized DTT on painful herniated discs was correlated with numerical pain rating (NPR) scale from 0 to 10 and clinical outcome. Results: Significant MRI changes were found in images after therapy compared to before therapy regarding morphology and nerve root affectation (p < 0.05), but disc degeneration grading showed only a tendency towards improvement (p> 0.05), interestingly showing a better disc hydration after therapy. Patients’ NPR decreased from a mean value of 10 to 1 after completed therapy, thus showing a significant change in pain (p < 0.001). Clinical outcome measurements improved significantly after therapy (P 0.05). Conclusion: Lumbar disc herniation grading showed a positive correlation with patients’ decreased NPR after undergoing standardized DTT, therefore our preliminary results might impact in the therapeutic management of patients complaining of lumbar disc pathology, however further longitudinal studies are recommended.

Introduction : “Dynamic traction therapy” (DTT) is a new standardized conservative treatment option in lumbar disc herniation. This study aimed to evaluate the therapeutic effect of DTT in lumbar disc herniation, by correlating both clinical and magnetic resonance imaging (MRI) outcomes. Materials and methods: In a total of 27 patients (mean age 50.5±9.1), who underwent standardized DTT, MRI was performed before and after therapy and evaluated by two independent radiologists individually and blindly; both grading intervertebral discs according to Pfirrmann classification in terms of degeneration, morphology, localization and nerve root affectation. The effect of standardized DTT on painful herniated discs was correlated with numerical pain rating (NPR) scale from 0 to 10 and clinical outcome. Results: Significant MRI changes were found in images after therapy compared to before therapy regarding morphology and nerve root affectation (p < 0.05), but disc degeneration grading showed only a tendency towards improvement (p> 0.05), interestingly showing a better disc hydration after therapy. Patients’ NPR decreased from a mean value of 10 to 1 after completed therapy, thus showing a significant change in pain (p < 0.001). Clinical outcome measurements improved significantly after therapy (P 0.05). Conclusion: Lumbar disc herniation grading showed a positive correlation with patients’ decreased NPR after undergoing standardized DTT, therefore our preliminary results might impact in the therapeutic management of patients complaining of lumbar disc pathology, however further longitudinal studies are recommended.

Magnetic Resonance Imaging 1996: Volume 14 , Issue Contents. Digitized from IA1652604-05 . Previous issue: sim_magnetic-resonance-imaging_1995_13_8 . Next issue: sim_magnetic-resonance-imaging_1996_14_1 .

Magnetic Resonance Imaging 1996: Volume 14 , Issue Contents. Digitized from IA1652604-05 . Previous issue: sim_magnetic-resonance-imaging_1995_13_8 . Next issue: sim_magnetic-resonance-imaging_1996_14_1 .

Quantum control of individual spins in condensed matter systems is an emerging field with wide-ranging applications in spintronics, quantum computation, and sensitive magnetometry. Recent experiments have demonstrated the ability to address and manipulate single electron spins through either optical or electrical techniques. However, it is a challenge to extend individual spin control to nanoscale multi-electron systems, as individual spins are often irresolvable with existing methods. Here we demonstrate that coherent individual spin control can be achieved with few-nm resolution for proximal electron spins by performing single-spin magnetic resonance imaging (MRI), which is realized via a scanning magnetic field gradient that is both strong enough to achieve nanometric spatial resolution and sufficiently stable for coherent spin manipulations. We apply this scanning field-gradient MRI technique to electronic spins in nitrogen-vacancy (NV) centers in diamond and achieve nanometric resolution in imaging, characterization, and manipulation of individual spins. For NV centers, our results in individual spin control demonstrate an improvement of nearly two orders of magnitude in spatial resolution compared to conventional optical diffraction-limited techniques. This scanning-field-gradient microscope enables a wide range of applications including materials characterization, spin entanglement, and nanoscale magnetometry.

Quantum control of individual spins in condensed matter systems is an emerging field with wide-ranging applications in spintronics, quantum computation, and sensitive magnetometry. Recent experiments have demonstrated the ability to address and manipulate single electron spins through either optical or electrical techniques. However, it is a challenge to extend individual spin control to nanoscale multi-electron systems, as individual spins are often irresolvable with existing methods. Here we demonstrate that coherent individual spin control can be achieved with few-nm resolution for proximal electron spins by performing single-spin magnetic resonance imaging (MRI), which is realized via a scanning magnetic field gradient that is both strong enough to achieve nanometric spatial resolution and sufficiently stable for coherent spin manipulations. We apply this scanning field-gradient MRI technique to electronic spins in nitrogen-vacancy (NV) centers in diamond and achieve nanometric resolution in imaging, characterization, and manipulation of individual spins. For NV centers, our results in individual spin control demonstrate an improvement of nearly two orders of magnitude in spatial resolution compared to conventional optical diffraction-limited techniques. This scanning-field-gradient microscope enables a wide range of applications including materials characterization, spin entanglement, and nanoscale magnetometry.

We propose a novel compressed sensing technique to accelerate the magnetic resonance imaging (MRI) acquisition process. The method, coined spread spectrum MRI or simply s2MRI, consists of pre-modulating the signal of interest by a linear chirp before random k-space under-sampling, and then reconstructing the signal with non-linear algorithms that promote sparsity. The effectiveness of the procedure is theoretically underpinned by the optimization of the coherence between the sparsity and sensing bases. The proposed technique is thoroughly studied by means of numerical simulations, as well as phantom and in vivo experiments on a 7T scanner. Our results suggest that s2MRI performs better than state-of-the-art variable density k-space under-sampling approaches

This article is from Pediatric Rheumatology Online Journal , volume 11 . Abstract None

This article is from NeuroImage : Clinical , volume 4 . Abstract Background: Multiple sclerosis (MS) is a heterogeneous disorder with a progressive course that is difficult to predict on a case-by-case basis. Natural history studies of MS have demonstrated that age influences clinical progression independent of disease duration. Objective: To determine whether age would be associated with greater CNS injury as detected by magnetization transfer MRI. Materials and methods: Forty MS patients were recruited from out-patient clinics into two groups stratified by age but with similar clinical disease duration as well as thirteen controls age-matched to the older MS group. Images were segmented by automated programs and blinded readers into normal appearing white matter (NAWM), normal appearing gray matter (NAGM), and white matter lesions (WMLs) and gray matter lesions (GMLs) in the MS groups. WML and GML were delineated on T2-weighted 3D fluid-attenuated inversion recovery (FLAIR) and T1 weighted MRI volumes. Mean magnetization transfer ratio (MTR), region volume, as well as MTR histogram skew and kurtosis were calculated for each region. Results: All MTR measures in NAGM and MTR histogram metrics in NAWM differed between MS subjects and controls, as expected and previously reported by several studies, but not between MS groups. However, MTR measures in the WML did significantly differ between the MS groups, in spite of no significant differences in lesion counts and volumes. Conclusions: Despite matching for clinical disease duration and recording no significant WML volume difference, we demonstrated strong MTR differences in WMLs between younger and older MS patients. These data suggest that aging-related processes modify the tissue response to inflammatory injury and its clinical outcome correlates in MS.

This article is from International Journal of General Medicine , volume 7 . Abstract Objective: The purpose of this research was to assess the functional brain activity and perceptual rating of innocuous somatic pressure stimulation before and after exercise rehabilitation in patients with chronic pain. Materials and methods: Eleven chronic pain patients and eight healthy pain-free controls completed 12 weeks of supervised aerobic exercise intervention. Perceptual rating of standardized somatic pressure stimulation (2 kg) on the right anterior mid-thigh and brain responses during functional magnetic resonance imaging (fMRI) were assessed at pre- and postexercise rehabilitation. Results: There was a significant difference in the perceptual rating of innocuous somatic pressure stimulation between the chronic pain and control groups (P=0.02) but no difference following exercise rehabilitation. Whole brain voxel-wise analysis with correction for multiple comparisons revealed trends for differences in fMRI responses between the chronic pain and control groups in the superior temporal gyrus (chronic pain > control, corrected P=0.30), thalamus, and caudate (control > chronic, corrected P=0.23). Repeated measures of the regions of interest (5 mm radius) for blood oxygen level-dependent signal response revealed trend differences for superior temporal gyrus (P=0.06), thalamus (P=0.04), and caudate (P=0.21). Group-by-time interactions revealed trend differences in the caudate (P=0.10) and superior temporal gyrus (P=0.29). Conclusion: Augmented perceptual and brain responses to innocuous somatic pressure stimulation were shown in the chronic pain group compared to the control group; however, 12-weeks of exercise rehabilitation did not significantly attenuate these responses.

This article is from International Journal of General Medicine , volume 7 . Abstract Objective: The purpose of this research was to assess the functional brain activity and perceptual rating of innocuous somatic pressure stimulation before and after exercise rehabilitation in patients with chronic pain. Materials and methods: Eleven chronic pain patients and eight healthy pain-free controls completed 12 weeks of supervised aerobic exercise intervention. Perceptual rating of standardized somatic pressure stimulation (2 kg) on the right anterior mid-thigh and brain responses during functional magnetic resonance imaging (fMRI) were assessed at pre- and postexercise rehabilitation. Results: There was a significant difference in the perceptual rating of innocuous somatic pressure stimulation between the chronic pain and control groups (P=0.02) but no difference following exercise rehabilitation. Whole brain voxel-wise analysis with correction for multiple comparisons revealed trends for differences in fMRI responses between the chronic pain and control groups in the superior temporal gyrus (chronic pain > control, corrected P=0.30), thalamus, and caudate (control > chronic, corrected P=0.23). Repeated measures of the regions of interest (5 mm radius) for blood oxygen level-dependent signal response revealed trend differences for superior temporal gyrus (P=0.06), thalamus (P=0.04), and caudate (P=0.21). Group-by-time interactions revealed trend differences in the caudate (P=0.10) and superior temporal gyrus (P=0.29). Conclusion: Augmented perceptual and brain responses to innocuous somatic pressure stimulation were shown in the chronic pain group compared to the control group; however, 12-weeks of exercise rehabilitation did not significantly attenuate these responses.