A small but significant number of mild traumatic brain injuries (mTBI) result in development of persistent prolonged symptoms, including cognitive deficits, headaches, and mental fatigue. 1 Such symptoms are called post-concussion syndrome (PCS), usually diagnosed according to the International Classification of Disease (ICD)-10 or the Diagnostic and Statistical Manual of Mental Disorder (DSM)-IV. However, the concept of PCS as one unique syndrome is debated, and it remains unclear clear why and who develops PCS. 2 The majority of studies use the term PCS to describe persistent concussion symptoms over 3 months following a non-penetrating direct or indirect blow to the head accompanied by loss of consciousness or alterations in mental state for <30 minutes. 1 Current management of PCS consists of a multidisciplinary approach of pharmaceutical treatment, vestibular and vision rehabilitation, cognitive behavioral therapy and physical therapy. A meta-analysis from 2018 of PCS intervention, however, found evidence of concussion treatment limited. 2 Treatment with low-frequency pulsating electromagnetic fields (PEMF) is a non-invasive, self-administered method best known from treatment of non-union long bone fractures where accelerated bone

Purpose: Diffuse low-grade gliomas (DLGGs) are low-malignancy brain tumors originating from the glial cells of the brain growing continuously and infiltratively along the neural axons and infiltrating the surrounding brain tissue. DLGGs usually transform into higher malignancy, causing progressive disability and premature death. MRI scans are valuable when assessing soft tissue abnormalities, but, due to the infiltrative properties of DLGGs, delineating the tumor borders is a challenging task. Therefore, the aim of this study was to explore the difference in gross tumor volume (GTV) of DLGGs delineated from 7 Tesla and 3 Tesla MRI scans. Method: Patients were recruited at the department of neurosurgery and were scanned in both a 7T and a 3T MRI scanner prior to the operation. Two observers delineated the tumors using semi-automatic delineation software. The results from each observer were blinded to the other observer’s delineation. Results: Comparing GTVs from 7T and 3T, the percentage difference varied up to 40.4% on the T2-weighted images. The percentage difference in GTV varied up to 15.3% on the fluid-attenuated inversion recovery (FLAIR) images. On the T2-weighted images, most cases varied by approximately 15%; on the FLAIR sequence, half of the cases varied by approximately 5% and the other half by approximately 15%. The overall inter-observer agreement was near perfect, with an intraclass correlation of 0.969. The intraclass correlation was better on the FLAIR sequence than on the T2 sequence. Conclusion: Overall, the GTVs delineated from 7T images were smaller. The increase in field strength improved the inter-observer agreement only on the FLAIR sequence.

Background and Purpose: Magnetic resonance spectroscopy (MRS) – a method to analyse metabolites in vivo – has been utilized in several studies of brain glioma biomarkers at lower fields strengths. At ultrahigh field strengths, MRS provides improved signal-to-noise-ratio and spectral resolution, but 7T studies on patients with gliomas are sparse. The purpose of this exploratory study was to evaluate the potential clinical implication of single-voxel MRS at 7T to assess metabolic information of lesions in a pilot cohort of patients with grade II and III gliomas. Methods: We scanned seven patients and seven healthy controls using the semi-localization by adiabatic-selective refocusing sequence on a Philips Achieva 7T system with a standard dual-transmit head coil. The metabolic ratios were calculated relative to water and total creatine. Additionally, 2-hydroxyglutarate (2-HG) MRS was carried out in four of the patients and 2-HG concentration was calculated relative to water. Results: When comparing tumour data to control regions in both patients and healthy controls, we found that choline/creatine and myo-inositol/creatine was significantly increased and that N-acetylaspartate/creatine and the neurotransmitter glutamate/creatine was significantly decreased. N-acetylaspartate/water and glutamate/water were also significantly decreased. Lactate/water and lactate/creatine showed an increase, although not significant. GABA/water was significantly decreased, but GABA/creatine was not. MRS spectra showed the presence of 2-HG in three of the four patients studied. Three of the patients, including the MRS 2-HG negative one, were operated and all of them had the IDH mutation. Conclusion: Our findings were consistent with existing literature on 3T- and 7T-MRS.

Purpose: Diffuse low-grade gliomas (DLGGs) are low malignancy brain tumors originating from the glial cells of the brain growing continuously and infiltratively along the neural axons and infiltrating the surrounding brain tissue. DLGG’s usually transforms to higher malignancy, are causing progressive disability and premature death. MRI scans are valuable when assessing soft tissue abnormalities, but due to the infiltrative properties of DLGGs delineating the tumor borders is a challenging task. The aim of this study was therefore to explore the difference in gross tumor volume (GTV) of DLGGs delineated from 3 Tesla and 7 Tesla MRI scans. Method: Patients were recruited at the department of neurosurgery and were scanned in both a 3T and a 7T MRI-scanner prior to operation. Two observers delineated the tumors using semi-automatic delineation software. The results from each observer were blinded to the other observer’s delineation. Results: Comparing GTVs from 7T and 3T the percentage difference varied up to 40.4% on the T2-weighted images. On the FLAIR images, the percentage difference in GTV varied up to 15.3%. On the T2-weighted images most cases varied approximately 15% and on the FLAIR sequence half of the cases varied approximately 5% and the other half approximately 15%. The overall interobserver agreement was near perfect with and intraclass correlation of 0.969. The intraclass correlation was better on the FLAIR sequence than on the T2 sequence. Conclusion: Overall, the GTVs delineated from 7T images were smaller. The increase in field strength improved the inter-observer agreement on the FLAIR sequence only.

Background and Purpose: Magnetic resonance spectroscopy (MRS)—a method of analysing metabolites in vivo—has been utilized in several studies of brain glioma biomarkers at lower field strengths. At ultra-high field strengths, MRS provides an improved signal-to-noise-ratio and spectral resolution, but 7T studies on patients with gliomas are sparse. The purpose of this exploratory study was to evaluate the potential clinical implication of the use of single-voxel MRS at 7T to assess metabolic information on lesions in a pilot cohort of patients with grade II and III gliomas. Methods: We scanned seven patients and seven healthy controls using the semi-localization by adiabatic-selective refocusing sequence on a Philips Achieva 7T system with a standard dual-transmit head coil. The metabolic ratios were calculated relative to water and total creatine. Additionally, 2-hydroxyglutarate (2-HG) MRS was carried out in four of the patients, and the 2-HG concentration was calculated relative to water. Results: When comparing the tumour data to control regions in both patients and healthy controls, we found that the choline/creatine and myo-inositol/creatine ratios were significantly increased and that the N-acetylaspartate/creatine and the neurotransmitter glutamate/creatine ratios were significantly decreased. The N-acetylaspartate/water and glutamate/water ratios were also significantly decreased. The lactate/water and lactate/creatine ratios showed increases, although not significant. The GABA/water ratio was significantly decreased, but the GABA/creatine ratio was not. MRS spectra showed the presence of 2-HG in three of the four patients studied. Three of the patients, including the MRS 2-HG-negative patient, were operated on, and all of them had the IDH mutation. Conclusion: Our findings were consistent with the existing literature on 3T and 7T MRS.