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Chronic liver disease (CLD) is a serious condition where various toxins present in the blood affect the brain leading to type C hepatic encephalopathy (HE). Both adults and children are impacted, while children may display unique vulnerabilities depending on the affected window of brain development.We aimed to use the advantages of high field proton Magnetic Resonance Spectroscopy (1H MRS) to study longitudinally the neurometabolic and behavioural effects of Bile Duct Ligation (animal model of CLD-induced type C HE) on rats at post-natal day 15 (p15) to get closer to neonatal onset liver disease. Furthermore, we compared two sets of animals (p15 and p21-previously published) to evaluate whether the brain responds differently to CLD according to age onset.We showed for the first time that when CLD was acquired at p15, the rats presented the typical signs of CLD, i.e. rise in plasma bilirubin and ammonium, and developed the characteristic brain metabolic changes associated with type C HE (e.g. glutamine increase and osmolytes decrease). When compared to rats that acquired CLD at p21, p15 rats did not show any significant difference in plasma biochemistry, but displayed a delayed increase in brain glutamine and decrease in total-choline. The changes in neurotransmitters were milder than in p21 rats. Moreover, p15 rats showed an earlier increase in brain lactate and a different antioxidant response. These findings offer tentative pointers as to which neurodevelopmental processes may be impacted and raise the question of whether similar changes might exist in humans but are missed owing to 1H MRS methodological limitations in field strength of clinical magnet.

Magnetic resonance spectroscopy is a powerful, non-invasive, quantitative imaging technique that allows for the measurement of brain metabolites that has demonstrated utility in diagnosing and characterizing a broad range of neurological diseases. Its impact, however, has been limited due to small sample sizes and methodological variability in addition to intrinsic limitations of the method itself such as its sensitivity to motion. The lack of standardization from a data acquisition and data processing perspective makes it difficult to pool multiple studies and/or conduct multisite studies that are necessary for supporting clinically relevant findings. Based on the experience of the ENIGMA MRS work group and a review of the literature, this manuscript provides an overview of the current state of MRS data harmonization. Key factors that need to be taken into consideration when conducting both retrospective and prospective studies are described. These include (1) MRS acquisition issues such as pulse sequence, RF and B0 calibrations, echo time, and SNR; (2) data processing issues such as pre-processing steps, modeling, and quantitation; and (3) biological factors such as voxel location, age, sex, and pathology. Various approaches to MRS data harmonization are then described including meta-analysis, mega-analysis, linear modeling, ComBat and artificial intelligence approaches. The goal is to provide both novice and experienced readers with the necessary knowledge for conducting MRS data harmonization studies.

Background Prognostic value of proton MR spectroscopy (H-MRS) in hypoxic–ischemic encephalopathy (HIE) is acknowledged; however, effects of gestational age (GA) and postnatal age (PA) on prediction and metabolite levels are unknown. Methods One hundred and sixty-nine newborns with moderate-to-severe HIE were studied, having ≥1 H-MRS scan during postnatal days 0–14 and known neurodevelopmental outcome (Bayley-II score/cerebral palsy/death). Initial scans were categorized by PA (day 1–3/4–6/≥7), and metabolite ratios were compared by predictive value. Metabolite dynamics were assessed in a total of 214 scans performed in the study population, using regression modeling, with predictors GA, PA, and outcome. Results N-acetyl-aspartate (NAA)/creatine (Cr) and myo-inositol (mI)/NAA height ratios were consistently associated with outcome throughout the first 14 days, with the highest predictive value in the late (≥7 days) period (AUC = 0.963 and 0.816, respectively). Neither GA nor PA had an overall effect on these metabolite ratios, which showed strongest association with outcome (p p = 0.0058 and 0.0002, respectively). However, this association disappeared in the poor outcome group. Conclusions In HIE, NAA/Cr and mI/NAA give most accurate outcome prediction throughout postnatal days 0–14. GA only affected metabolite levels in the good outcome group. Impact Proton MR spectroscopy metabolite ratios N-acetyl-aspartate/creatine and myo-inositol/N-acetyl-aspartate have persistently high predictive value throughout postnatal days 0–14 in newborns with hypoxic–ischemic encephalopathy, with the highest predictive power between postnatal days 7 and 14. Overall, neither metabolite ratio was affected by gestational age nor by postnatal age, while they showed the strongest association with neurological outcome. However, in newborns facing good outcome, metabolite ratios were associated with gestational age, whereas in cases facing poor outcome, this association disappeared. Proton MR spectroscopy provides valuable prognostic information in neonatal hypoxic–ischemic encephalopathy throughout the first 2 weeks of life, irrespective of the timing of MR scan.

Introduction. Conventional MR imaging provides highly detailed anatomic information with unrivalled soft tissue contrast making it the mainstay in the diagnosis of suspected brain lesions. Despite this, MRI alone at times cannot answer the diagnostic questions in quite a few patients. Proton MR Spectroscopy (H-MRS) provides information on the metabolic composition within an area under interrogation. By comparing the relative concentrations of specific metabolites, the neuroradiologist can deduce critical information regarding neuronal cell density and integrity, cell membrane turnover, metabolic fuel, and possible necrosis in the region of interest. This provides a biochemical picture of the underlying pathology and thus aids in the diagnosis. Methods. This was a cross-sectional comparative study. Results. Of the 63 patients examined by MRI and MRS for intracranial mass lesions, the radiologists were able to offer a single imaging diagnosis based on MRI alone in only 15 patients (23.8%) while when MRI imaging was combined with MR spectroscopy, a single imaging diagnosis was offered in 47 patients (74.6%). This was an overall statistically significant improvement. Conclusion. MRS aided the radiologist in offering a single diagnosis in high versus low-grade gliomas, high-grade gliomas versus tuberculomas, and recurrent tumours versus radiation necrosis.

In proton magnetic resonance (MR) spectroscopy (1H-MRS) of the breast cancer, choline peak could be detected. The purpose of this study was to evaluate the influences of the tumor volume, full width at half maximum (FWHM) of the water peak (FWHM), and T2* value of water (T2* value) on the detection rate of the choline peaks at 3.0 T-MRI. We measured FWHM and T2* value in 109 cases, and we evaluated the effect of tumor volume on the detection rate of the choline peaks and the effect of FWHM and T2* value on the detection of choline peaks. In 1H-MRS of breast cancer at 3.0 T-MRI, the detection rate of the choline peaks improved as the tumor volume was larger. As a shimming environment when acquiring 1H-MRS of breast cancer, FWHM is preferably 57.4 Hz or less and T2* value should be 11 ms or more, and T2* value has a great influence on the detection rate of the choline peaks.

Background The aim of our study was to determine the value of single-voxel proton MR spectroscopy (1HMRS) in distinguishing benign from malignant focal bone lesions in the peripheral skeleton. MRI and 1HMRS was performed in 50 focal lesions (> 1 cm size) detected on radiographs of peripheral skeleton.1HMRS was performed at 1.5 T with TE of 144 ms with automatic shimming and water suppression. Qualitative analysis for a discrete choline peak at 3.2 ppm was done. Significance of the presence of choline peak on 1HMRS in distinguishing benign from malignant lesions was calculated using histopathology as a gold standard. Chi-square test was used and p value Results Forty-one benign and 9 malignant lesions were confirmed by histopathological results. Amongst malignant lesions, choline peak was positive in all but 1 case of low-grade lymphoma. MR spectra of 11 benign lesions showed the presence of choline peak. All 7 benign giant cell tumors (GCT) were positive for choline peak. The sensitivity, specificity, PPV, NPV of proton MR spectroscopy in differentiating benign from malignant lesions were 87.5%,71%,38.8%, and 96.4% respectively. p value was significant ( Conclusion 1HMRS in focal bone lesions can help in the differentiation of malignant from benign musculoskeletal tumors. Although some benign lesions may show false-positive result, absence of choline peak is a reliable reassurance against malignancy. GCT is an exception amongst benign bone tumors as it consistently shows the presence of choline peak on 1HMRS.

Background The purpose of this study is to investigate the role of proton MR spectroscopy (1H-MRS) in the characterization and diagnosis of ovarian lesions. Results From October 2015 to October 2017, a total of 57 female patients (65 adnexal lesions; 8 cases were bilateral) were included. The examined lesions were classified according to their histopathological findings, (37 (57%) benign lesions, 4 (6%) borderline lesions, and 24 (37%) malignant lesions). The mean choline/creatinine (CHO/Cr) ratio was 1.29 ± 0.98 SD for malignant lesions, while the mean value in borderline lesions was 0.63 ± 0.15 SD, and the mean value for the benign lesions was 0.65 ± 0.34. Therefore, the mean CHO/Cr ratio was much higher in malignant than in benign lesions, which was statistically significant (P ≤ 0.001) as well as between the borderline and invasive lesions (P = 0.05), but not between the benign and borderline lesions. The diagnostic performance of conventional MRI in diagnosing adnexal lesions was 100%, specificity was 76%, and accuracy was 86%. However, MRS individual diagnostic performances are the following: sensitivity 89%, specificity, and 100% with an accuracy of 95%. Conclusion MRS proved to be an accurate and efficient method for the analysis of adnexal lesions and in differentiation between benign and malignant tumors.

In vivo MRS is a non-invasive measurement technique used not only in humans, but also in animal models using high-field magnets. MRS enables the measurement of metabolite concentrations as well as metabolic rates and their modifications in healthy animals and disease models. Such data open the way to a deeper understanding of the underlying biochemistry, related disturbances and mechanisms taking place during or prior to symptoms and tissue changes. In this work, we focus on the main preclinical (1)H, (31)P and (13)C MRS approaches to study brain metabolism in rodent models, with the aim of providing general experts’ consensus recommendations (animal models, anesthesia, data acquisition protocols). An overview of the main practical differences in preclinical compared with clinical MRS studies is presented, as well as the additional biochemical information that can be obtained in animal models in terms of metabolite concentrations and metabolic flux measurements. The properties of high-field preclinical MRS and the technical limitations are also described.

PURPOSE: The goal of this study was to propose a novel localized proton magnetic resonance spectroscopy (MRS) sequence that reduces signal loss due to J-modulation in the rat brain in vivo. METHODS: Sprague-Dawley rats were studied at 9.4 T. A semi-LASER sequence with evenly distributed echo-time (T(E)) was used, and a 90° J-refocusing pulse was inserted at T(E)/2. Proton spectra were acquired at two T(E)s (30 and 68 ms), with and without the J-refocused pulse. Data were processed in MATLAB and quantified with LCModel. RESULTS: The J-refocused spectrum acquired at T(E) = 30 ms did not show any signal losses due to J-modulation and had comparable spectral pattern to the one acquired with semi-LASER using the minimum achievable T(E). Higher signal amplitudes for glutamine, γ-aminobutyric acid and glutathione led to more reliable quantification precision for these metabolites. The refocused signal intensities at T(E) = 68 ms were also unaffected by J-modulation but were smaller than the signals at T(E) = 30 ms mainly due to transverse T(2) relaxation of metabolites. CONCLUSION: The proposed localized MRS sequence will be beneficial in both animal and human MRS studies when using ultra-short T(E) is not possible while also providing more reliable quantification precision for J-coupled metabolites.

Background Proton magnetic resonance spectroscopy (MRS) provides structural and metabolic information that is useful for the diagnosis of meningiomas with atypical radiological appearance. However, the metabolite that should be prioritized for the diagnosis of meningiomas has not been established. Purpose To evaluate the differences between the metabolic peaks of meningiomas and other intracranial enhanced mass lesions (non-meningiomas) using MR spectroscopy in short echo time (TE) spectra and the most useful metabolic peak for discriminating between the groups. Material and Methods The study involved 9 meningiomas, 22 non-meningiomas, intracranial enhancing tumors and abscesses, and 15 normal controls. The ranking of the peak at 3.8 ppm, peak at 3.8 ppm/Creatine (Cr), β-γ Glutamine-Glutamate (bgGlx)/Cr, N-acetyl compounds (NACs)/Cr, choline (Cho)/Cr, lipid and/or lactate (Lip-Lac) at 1.3 ppm/Cr, and the presence of alanine (Ala) were derived. The metabolic peaks were compared using the Mann-Whitney U test. ROC analysis was used to determine the cut-off values for differentiating meningiomas from non-meningiomas using statistically significant metabolic peaks. Results The ranking of the peak at 3.8 ppm among all the peaks, peak at 3.8 ppm/Cr, bgGlx/Cr, Lip-Lac/Cr, and the presence of Ala discriminated meningiomas from non-meningiomas with moderate to high accuracy. The highest accuracy was 96.9% at a threshold value of 3 for the rank of the peak at 3.8 ppm. Conclusion A distinct elevated peak at 3.8 ppm, ranked among the top three highest peaks, allowed the detection of meningiomas.

Accumulation of hepatic triacylglycerol (TG) is associated with obesity and metabolic syndrome, which are important pathogenic factors in the development of type 2 diabetes. In this narrative review, we summarize the effects of hepatic TG accumulation on hepatic glucose and insulin metabolism and the underlying molecular regulation in order to highlight the importance of hepatic TG accumulation for whole-body glucose metabolism. We find that liver fat accumulation is closely linked to impaired insulin-mediated suppression of hepatic glucose production and reduced hepatic insulin clearance. The resulting systemic hyperinsulinemia has a major impact on whole-body glucose metabolism and may be an important pathogenic step in the development of type 2 diabetes.

We combined magnetoencephalography (MEG), 7 T proton magnetic resonance spectroscopy (MRS), and 7 T fMRI during performance of a task in a group of 23 first episode psychosis (FEP) patients and 26 matched healthy controls (HC). We recorded both the auditory evoked response to 40 Hz tone clicks and the resting state in MEG. Neurometabolite levels were obtained from the anterior cingulate cortex (ACC). The fMRI BOLD response was obtained during the Stroop inhibitory control task. FEP showed a significant increase in resting state low frequency theta activity (p d = 0.69), but no significant difference in the 40 Hz auditory evoked response compared to HC. An across-groups whole brain analysis of the fMRI BOLD response identified eight regions that were significantly activated during task performance (p p = 0.0006; d = 1.19). In the combined FEP and HC group, there was a significant correlation between the BOLD signal during task performance and MEG resting state low frequency activity (p

Bone strength is affected not only by bone mineral density (BMD) and bone microarchitecture but also its microenvironment. Recent studies have focused on the role of marrow adipose tissue (MAT) in the pathogenesis of bone loss. Osteoblasts and adipocytes arise from a common mesenchymal stem cell within bone marrow and many osteoporotic states, including aging, medication use, immobility, over – and undernutrition are associated with increased marrow adiposity. Advancements in imaging technology allow the non-invasive quantification of MAT. This article will review magnetic resonance imaging (MRI)- and computed tomography (CT)-based imaging technologies to assess the amount and composition of MAT. The techniques that will be discussed are anatomic T1-weighted MRI, water-fat imaging, proton MR spectroscopy, single energy CT and dual energy CT. Clinical applications of MRI and CT techniques to determine the role of MAT in patients with obesity, anorexia nervosa, and type 2 diabetes will be reviewed.

Aim.Evaluation of proton MR spectroscopy in the diagnostics of non-alcoholic fatty liver disease.Materials and methods.70 patients (40 men, 30 women) with non-alcoholic fatty liver disease were included in the study. Average age of patients was 42 ± 11 years. All patients were divided in two groups. The first group included patients with liver steаthosis (n = 37). Patients with steatohepatitis detected by clinical data formed the second group (n = 33). All patients underwent MR spectroscopy for liver fat content evaluation in two time points (prescreening and after 6 months treatment).Results.MR spectroscopy showed fat content in patients with liver steatosis in the range from 7.5% to 58.4%, the median was 22.4% (lower and upper quartiles were 14.9% and 28.7%). After 6 months the liver fat content significantly decreased up to 1.5–43.7%, the median was 13.5% (the lower and upper quartiles were 5.54% and 18.9%). In patients with steatohepatitis the fat content calculated by MR spectroscopy ranged from 10.5% to 60%, the median was 28.8% (the lower and upper quartiles were 16.5% and 31.2%). There was no significant difference in fat content in this group after 6 months therapy (the median was 26.7%, the lower and upper quartiles were 14.2% and 28.7%, p = 0.22).Conclusion.Proton MR spectroscopy can be successfully used in patients with non-alcoholic fatty liver disease for liver fat content quantification in steatosis and steatohepatitis. MR spectroscopy can be discussed as a non-invasive biopsy alternative for dynamic evaluation during treatment.

Objective: The objective of this study was to evaluate intramedullary spinal cord lesions using magnetic resonance spectroscopy and correlate the results with histo-pathological examination (HPE). Materials and Methods: Approval for this study was obtained from our institute ethical committee. Overall, 50 patients were recruited (29 male and 21 female), with a maximum age of 53 years and minimum age of 7 years. The mean age group of the study was 33 years. Standard magnetic resonance imaging (MRI) spine was done on a Siemens Skyra 3Tesla MRI scanner. MR Spectroscopy (MRS) was performed for all patients with intramedullary spinal lesions after getting written consent. It was performed using single-voxel method. The change in the metabolite peak was observed in each case and the results were compared with HPE. These collected data were analyzed using SPSS 16.0 version. Descriptive statistics, frequency analysis, and percentage analysis were used for categorical variables; and for continuous variables, mean and standard deviation were analyzed. McNemar's test was used to find the significance between conventional MRI MRS. In the above statistical tool, the probability value 0.05 is considered as significant level. Results: From our study, we observed that by applying routine MRI sequences alone, we could only detect around 58% of the cases correctly. However, when MRS was done along with the conventional MR imaging, the number of cases detected significantly increased to 84%. By applying McNemar's test and comparing the conventional MRI and MRS with HPE, it was found that statistically significant difference exists with P value of 0.007. Conclusion: MRS of the spinal cord is a promising tool for research and diagnosis because it can provide additional information complementary to other non-invasive imaging methods. It is an emerging tool and adds new biomarker information for characterization of spinal cord tumors, to differentiate benign from malignant lesions and to prevent unnecessary biopsies and surgeries.

Objectives: The primary lymphoma of the central nervous system is a cancer rare. The diagnosis of this tumoral entity must be considered as an emergency considering the therapeutical involved. Therefore, we report this entity while reporting diagnostic challenges. Patients and Methods: Unfortunately, the conventional clinical and imaging signs can be confusing and might contribute to delay the diagnosis process of potentially curable pathological entity. The diagnosis confirmation in immunocompetent patients is based on a stereotaxic biopsy. Results and Conclusion: In this paper, we report a case illustrating the contribution of multimodal imaging including diffusion-weighted magnetic resonance imaging (MRI), diffusion tensor MRI, perfusion MRI, and proton MR spectroscopy to the diagnostic approach of the atypical primary lymphoma of the central nervous system.

BACKGROUND AND PURPOSE: Prognosis in glioma depends strongly on tumor grade and proliferation. In this prospective study of patients with untreated primary cerebral gliomas, we investigated whether amide proton transfer–weighted imaging could reveal tumor proliferation and reliably distinguish low-grade from high-grade gliomas compared with Ki-67 expression and proton MR spectroscopy imaging. MATERIALS AND METHODS: This study included 42 patients with low-grade (n = 28) or high-grade (n = 14) glioma, all of whom underwent conventional MR imaging, proton MR spectroscopy imaging, and amide proton transfer–weighted imaging on the same 3T scanner within 2 weeks before surgery. We assessed metabolites of choline and N-acetylaspartate from proton MR spectroscopy imaging and the asymmetric magnetization transfer ratio at 3.5 ppm from amide proton transfer–weighted imaging and compared them with histopathologic grade and immunohistochemical expression of the proliferation marker Ki-67 in the resected specimens. RESULTS: The asymmetric magnetization transfer ratio at 3.5 ppm values measured by different readers showed good concordance and were significantly higher in high-grade gliomas than in low-grade gliomas (3.61% ± 0.155 versus 2.64% ± 0.185, P = .0016), with sensitivity and specificity values of 92.9% and 71.4%, respectively, at a cutoff value of 2.93%. The asymmetric magnetization transfer ratio at 3.5 ppm values correlated with tumor grade (r = 0.506, P = .0006) and Ki-67 labeling index (r = 0.502, P = .002). For all patients, the asymmetric magnetization transfer ratio at 3.5 ppm correlated positively with choline (r = 0.43, P = .009) and choline/N-acetylaspartate ratio (r = 0.42, P = .01) and negatively with N-acetylaspartate (r = −0.455, P = .005). These correlations held for patients with low-grade gliomas versus those with high-grade gliomas, but the correlation coefficients were higher in high-grade gliomas (choline: r = 0.547, P = .053; N-acetylaspartate: r = −0.644, P = .017; choline/N-acetylaspartate: r = 0.583, P = .036). CONCLUSIONS: The asymmetric magnetization transfer ratio at 3.5 ppm may serve as a potential biomarker not only for assessing proliferation, but also for predicting histopathologic grades in gliomas.

Purpose To detect local cholinergic changes in human medial temporal lobe during configural working memory performance. Materials and Methods Proton magnetic resonance spectroscopy (1H-MRS) measurements were acquired at 3T from a 2 × 2 × 3 cm voxel in right medial temporal lobe from 36 subjects during performance of a configural visual working memory task (cWMT). In order to compensate for expected task-based blood oxygenation level-dependent (BOLD) T2* effects, resonance signal changes of unbound choline-containing metabolites (Cho) were referenced to an internal standard of creatine + phosphocreatine metabolites (Cre) and compared between four task blocks: rest, memorization, active memory maintenance, and recognition. An unannounced memory retention test was conducted in 21 subjects. Quality assurance analyses examined task-based Cho and Cre individually as well as referenced to resonance signal from N-acetylaspartate (NAA). Results Increases from a resting baseline in the Cho/Cre ratio were observed during 60-second blocks of active memory maintenance across the group (P = 0.0042). Behavioral accuracy during task performance correlated with memory retention (r = 0.48, P = 0.027). Quality assurance measures showed task-based changes in Cre resonance signal both individually (P = 0.00099) and when utilized as a noncholinergic internal reference (NAA/Cre, P = 0.00079). Conclusion Increases in human medial temporal lobe 1H-MRS Cho/Cre ratio occur during the maintenance of configural working memory information. However, interpretation of these results as driven by cholinergic activity cannot be assumed, as NAA, a noncholinergic metabolite, shows similar results when utilizing Cre as a reference. Caution is advised when considering Cre as an internal standard for task-based 1H-MRS measurements. Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017.

Objective Treatment response assessment in high-grade gliomas uses contrast enhanced T1-weighted MRI, but is unreliable. Novel advanced MRI techniques have been studied, but the accuracy is not well known. Therefore, we performed a systematic meta-analysis to assess the diagnostic accuracy of anatomical and advanced MRI for treatment response in high-grade gliomas. Methods Databases were searched systematically. Study selection and data extraction were done by two authors independently. Meta-analysis was performed using a bivariate random effects model when ≥5 studies were included. Results Anatomical MRI (five studies, 166 patients) showed a pooled sensitivity and specificity of 68% (95%CI 51–81) and 77% (45–93), respectively. Pooled apparent diffusion coefficients (seven studies, 204 patients) demonstrated a sensitivity of 71% (60–80) and specificity of 87% (77–93). DSC-perfusion (18 studies, 708 patients) sensitivity was 87% (82–91) with a specificity of 86% (77–91). DCE-perfusion (five studies, 207 patients) sensitivity was 92% (73–98) and specificity was 85% (76–92). The sensitivity of spectroscopy (nine studies, 203 patients) was 91% (79–97) and specificity was 95% (65–99). Conclusion Advanced techniques showed higher diagnostic accuracy than anatomical MRI, the highest for spectroscopy, supporting the use in treatment response assessment in high-grade gliomas. Key points • Treatment response assessment in high-grade gliomas with anatomical MRI is unreliable • Novel advanced MRI techniques have been studied, but diagnostic accuracy is unknown • Meta-analysis demonstrates that advanced MRI showed higher diagnostic accuracy than anatomical MRI • Highest diagnostic accuracy for spectroscopy and perfusion MRI • Supports the incorporation of advanced MRI in high-grade glioma treatment response assessment Electronic supplementary material The online version of this article (doi:10.1007/s00330-017-4789-9) contains supplementary material, which is available to authorized users.

Objective: To assess the impact of MR spectroscopy (MRS) on the detection of malignancy in ovarian masses. Methods: This prospective work included 230 females that had 245 adnexal/ovarian masses. Tumours were spotted by preliminary pelvic ultrasound. Masses assessed by MRI, multi- or single-voxel spectroscopy. Patients’ spectra were assessed for peaks of lactate (Lac, 1.31 ppm), lipid (Lip, 1.33 ppm), N-acetyl aspartate (2.0 ppm), acetone (A, 2.05 ppm), choline (Cho, 3.23 ppm) and creatinine (Cr, 3.4 ppm) and the mean values of the (Cho/Cr) ratios were performed by a semi-quantitative approach. The operative pathology served as the standard of reference. Results: Cho peak twofold higher than the average noise level was detected in 72% of the malignant and only 5.4% of the benign masses with an accuracy of 83%. Adding lactate to the choline enhanced the accuracy to 93%. The mean Cho/Cr ratios of the malignant ovarian masses (2.8) were significantly higher than that of the benign ones (1.2) . We used a receiver operating characteristic curve to determine the best cut-off value (1.7) for the mean Cho/Cr ratio to discriminate malignancy with sensitivity: 81.2%, specificity: 93.3 %, positive-predictive value: 92.9 %, negative-predictive value: 82.4% and accuracy: 87.1%. Conclusion: The simultaneous presence of choline and lactate peaks in MRS examination of the ovarian masses minimizes the overlap between benign and malignant categories. N-acetyl aspartate and acetone are the metabolites for diagnosing complex cystic masses as benign teratoma, endomterioma and tubo- ovarian abscess. Advances in knowledge: MRS is a non-contrast based and fast MR sequence that gives an idea about tissue components could be used to improve the sensitivity and the accuracy of detecting malignancy in ovarian masses.

Magnetic Resonance Spectroscopy (MRS) has at least two major roles in the evaluation of epileptic patients. First, MRS can help to understand the interaction between seizures and metabolic function. Thus, MRS is particularly interesting for basic science studies of seizures and epilepsy. Second, MRS can explain the nature of seizure control and/or provide localization information by measuring metabolic changes. So MRS can be used as a powerful complementary technique to structural MRI for diagnosis and assessment of response to therapy, and measurement of disease progression. The aim of this paper is to review the methodological aspects of 1H-MRS publications between 1994 to 2016, which utilized 1H-MRS in lateralizing the epileptogenic zone in lesional and non-lesional Temporal Lobe Epilepsy (TLE), Extra-Temporal Lobe Epilepsy (ETLE), and generalized epileptic patients to help the spectroscopist, magnetic resonance imaging technologists, and radiologists to improve the overall diagnostic sensitivity in epileptic patients.

BACKGROUND: Sleeve gastrectomy (SG) is the most common metabolic and bariatric surgery (MBS) procedure in adolescents and adults. Only few studies have assessed bone outcomes following SG and it is unknown whether skeletal changes differ by age group. Recent studies have identified marrow adipose tissue (MAT) as a novel biomarker for bone quality with studies in adults showing high MAT in those with visceral adiposity and a reciprocal increase in MAT with bone loss. OBJECTIVE: To determine the impact of SG on volumetric BMD (vBMD) and MAT in adolescents and adults with obesity. We hypothesized that SG would lead to a decrease in vBMD and increase in MAT but that these changes would be less pronounced in adolescents compared to adults. MATERIALS AND METHODS: The study was IRB-approved and HIPAA-compliant. Written informed consent/assent was obtained. We examined 10 adolescents (mean age 17.8±2.5 years, mean BMI 43.5±5.6 kg/m(2)) and 10 sex, race, and BMI-matched adults (mean age 49.5±13.6 years, mean BMI 43.7±5.9 kg/m(2)), before and 12 months after SG. At baseline and 12 months, subjects underwent quantitative CT of the lumbar spine (L1-L2) to assess trabecular vBMD, single voxel proton MR spectroscopy at 3T (PRESS pulse sequence without water suppression) at L1-L2 to quantify MAT, and MRI of the abdomen to assess visceral (VAT) and subcutaneous adipose tissue (SAT). RESULTS: At baseline, adolescents had lower MAT (p=0.0002) and higher vBMD (p=0.050) compared to adults. Adolescents and adults lost 27.9±6.5 vs. 25.0±11.2% of body weight (p

IDH mutation, a key factor in predicting glioma prognosis, alters the levels of some metabolites in brain, including 2-hydroxyglutarate (2HG), glutamine (Gln), and glutathione (GSH). While proton MR spectroscopy (1H-MRS) enables in-vivo detection of these metabolites, liquid chromatography-mass spectrometry (LC-MS/MS) is a sensitive in-vitro method to measure absolute metabolite concentrations. This study aims to examine the correlation of metabolic concentrations measured using 1H-MRS and LC-MS/MS in gliomas, and to detect IDH mutation with machine learning based on 1H-MRS and LC-MS/MS metabolic intensities. The patient cohort included 178 glioma patients (111M/67F, mean age:44.09±13.95 years, 100 IDH-mut, 78 IDH-wt). The patients were scanned pre-surgery by a 3T MR scanner with a 32-channel head coil. 1H-MRS was obtained from a manually placed region of interest with no necrosis, edema, and hemorrhage, using a Point Resolved Spectroscopy (PRESS) sequence (TR/TE=2000/30ms). LCModel software was used for quantification of eighteen metabolites of 1H-MRS data. Metabolite concentrations including creatine (Cr), choline (Cho), Gln, glutamate (Glu), gamma-aminobutyric acid (GABA), N-acetyl aspartate (NAA), myo-inositol (mIns), 2HG, and lactate (Lac) were also determined with LC-MS/MS for surgical specimen of the same patients. Spearman correlation coefficients were calculated between the metabolite concentrations measured with 1H-MRS and LC-MS/MS. Additionally, machine-learning algorithms were used to detect IDH mutation in gliomas based on metabolite concentrations obtained with 1H-MRS and LC-MS/MS. Consequently, there were statistically significant correlations between 1H-MRS and LC-MS/MS results for 2HG (p=0.036), Cr (p=0.009), mIns (p

Background Advanced MR imaging techniques provide physiologic information which complements the conventional MRI findings. Purpose To evaluate the role of dynamic contrast-enhanced perfusion MRI and proton MR spectroscopy (MRS) in differentiating grade-III from grade-IV glioma. Results 40 patients with preliminary diagnosis of glioma according to the conventional MRI study and the WHO classification and grading of glioma underwent dynamic MRI study which revealed, 19 patients (47.5%) are diagnosed as grade-III, and 21 cases (52.5%) are diagnosed as grade-IV. The tumor core relative cerebral blood volume (rCBV) was highly significant (P = 0.000) in differentiating grade III from grade IV with cutoff value of 6,sensitivity of 90.5%, specificity of 68.4%, PVP of 76% and NPV of 86.7%. In proton MR spectroscopy, (CHo/Cr) ratio was significant in differentiating grade III from grade IV glioma (P = 0.02), while CHo/NAA, NAA/Cr and MI/Cr ratios were not significant. Conclusion The rCBV estimation and the metabolite ratios separately or in combination increase the sensitivity of grading of glioma rather than the conventional MRI.