J-difference GABA-edited MRS reveals altered cerebello-thalamo-cortical metabolism in patients with hepatic encephalopathy.

Hepatic encephalopathy (HE) is a common neurological manifestation of liver cirrhosis and is characterized by an increase of ammonia in the brain accompanied by a disrupted neurotransmitter balance, including the GABAergic and glutamatergic systems. The aim of this study is to investigate metabolic abnormalities in the cerebello-thalamo-cortical system of HE patients using GABA-edited MRS and links between metabolite levels, disease severity, critical flicker frequency (CFF), motor performance scores, and blood ammonia levels. GABA-edited MRS was performed in 35 participants (16 controls, 19 HE patients) on a clinical 3 T MRI system. MRS voxels were placed in the right cerebellum, left thalamus, and left motor cortex. Levels of GABA+ and of other metabolites of interest (glutamine, glutamate, myo-inositol, glutathione, total choline, total NAA, and total creatine) were assessed. Group differences in metabolite levels and associations with clinical metrics were tested. GABA+ levels were significantly increased in the cerebellum of patients with HE. GABA+ levels in the motor cortex were significantly decreased in HE patients, and correlated with the CFF (r = 0.73; p < .05) and motor performance scores (r = -0.65; p < .05). Well-established HE-typical metabolite patterns (increased glutamine, decreased myo-inositol and total choline) were confirmed in all three regions and were closely linked to clinical metrics. In summary, our findings provide further evidence for alterations in the GABAergic system in the cerebellum and motor cortex in HE. These changes were accompanied by characteristic patterns of osmolytes and oxidative stress markers in the cerebello-thalamo-cortical system. These metabolic disturbances are a likely contributor to HE motor symptoms in HE. In patients with hepatic encephalopathy, GABA+ levels in the cerebello-thalamo-cortical loop are significantly increased in the cerebellum and significantly decreased in the motor cortex. GABA+ levels in the motor cortex strongly correlate with critical flicker frequency (CFF) and motor performance score (pegboard test tPEG), but not blood ammonia levels (NH3).

Evaluation of Sodium Relaxation Times and Concentrations in the Achilles Tendon Using MRI.

Sodium magnetic resonance imaging (MRI) can be used to evaluate the change in the proteoglycan content in Achilles tendons (ATs) of patients with different AT pathologies by measuring the 23Na signal-to-noise ratio (SNR). As 23Na SNR alone is difficult to compare between different studies, because of the high influence of hardware configurations and sequence settings on the SNR, we further set out to measure the apparent tissue sodium content (aTSC) in the AT as a better comparable parameter. Ten healthy controls and one patient with tendinopathy in the AT were examined using a clinical 3 Tesla (T) MRI scanner in conjunction with a dual tuned 1H/23Na surface coil to measure 23Na SNR and aTSC in their ATs. 23Na T1 and T2* of the AT were also measured for three controls to correct for different relaxation behavior. The results were as follows: 23Na SNR = 11.7 ± 2.2, aTSC = 82.2 ± 13.9 mM, 23Na T1 = 20.4 ± 2.4 ms, 23Na T2s* = 1.4 ± 0.4 ms, and 23Na T2l* = 13.9 ± 0.8 ms for the whole AT of healthy controls with significant regional differences. These are the first reported aTSCs and 23Na relaxation times for the AT using sodium MRI and may serve for future comparability in different studies regarding examinations of diseased ATs with sodium MRI.

Proof-of-Concept Double-Blind Placebo-Controlled Trial Measuring Cartilage Composition in Early Rheumatoid Arthritis under TNF-α-Inhibitor Therapy.

Low levels of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) values are indicative of cartilage degeneration. Patients with early rheumatoid arthritis are known to have low dGEMRIC values due to inflammatory activity. The additional effect of biological disease-modifying antirheumatic drug (bDMARD) and conventional synthetic disease-modifying antirheumatic drug (csDMARD) treatment on cartilage status is still unclear. In this prospective, double-blinded, randomized proof-of-concept clinical trial, patients with early rheumatoid arthritis (disease duration less than 12 months from symptoms onset) were treated with methotrexate + adalimumab (10 patients: 6/4 (f/m)). A control group with methotrexate alone (four patients: 2/2 (f/m)) was used. Cartilage integrity in the metacarpophalangeal joints was compared using dGEMRIC at baseline, 12, and 24 weeks after treatment initiation. A statistically significant increase in dGEMRIC levels was found in the adalimumab group considering the results after 12 and 24 weeks of therapy (p < 0.05) but not in the control group (p: non-significant). After 24 weeks, a tendency towards increased dGEMRIC values under combination therapy was observed, whereas methotrexate alone showed a slight decrease without meeting the criteria of significance (dGEMRIC mean change: +85.8 ms [-156.2-+346.5 ms] vs. 30.75 ms [-273.0-+131.0 ms]; p: non-significant). After 24 weeks of treatment with a combination of methotrexate and adalimumab, a trend indicating improvement in cartilage composition is seen in patients with early rheumatoid arthritis. However, treatment with methotrexate alone showed no change in cartilage composition, as observed in dGEMRIC sequences of metacarpophalangeal joints.

Endovascular coil-embolization of an unruptured, true UAA during early pregnancy- a case report.

BACKGROUND: True uterine artery aneurysms, especially during pregnancy, are a rare entity and not well understood. Clinical symptoms are unspecific pelvic pain and pressure. Diagnosis can be confirmed by transvaginal color-coded-sonography and/or magnetic resonance imaging. Because of potential risk of rupture, immediate interdisciplinary discussion and treatment planning in the best interests of both mother and child is crucial. CASE PRESENTATION: We present a 31-year-old pregnant woman with increasing pelvic pain and pressure. Diagnosis of an unruptured uterine artery aneurysm was confirmed by color-coded-sonography and magnetic resonance angiography. After interdisciplinary consultation, successful endovascular super-selective coil-embolization was performed by using X-ray fluoroscopy. Thus, fetal radiation dose during treatment with 4.33 mGy (VirtualDoseTM) was as low as possible with no immediate harm to the fetus. CONCLUSIONS: Unruptured true uterine artery aneurysms can be successfully treated by endovascular super-selective coil-embolization during early pregnancy with no immediate harm to the fetus.

To Contrast or Not to Contrast? On the Role of Contrast Enhancement in Hand MRI Studies of Patients with Rheumatoid Arthritis.

Currently, clinical indications for the application of gadolinium-based contrast agents (GBCA) in magnetic resonance imaging (MRI) are increasingly being questioned. Consequently, this study aimed to evaluate the additional diagnostic value of contrast enhancement in MRI of the hand in patients with rheumatoid arthritis (RA). Thirty-one patients with RA (mean age, 50 ± 14 years (range, 18-72 years)) underwent morphologic MRI scans on a clinical 3 T scanner. MRI studies were analyzed based on (1) the Rheumatoid Arthritis Magnetic Resonance Imaging Score (RAMRIS) and (2) the GBCA-free RAMRIS version, termed RAMRIS Sine-Gadolinium-For-Experts (RAMRIS-SAFE), in which synovitis and tenosynovitis were assessed using the short-tau inversion-recovery sequence instead of the post-contrast T1-weighted sequence. The synovitis subscores in terms of Spearman's ρ, as based on RAMRIS and RAMRIS-SAFE, were almost perfect (ρ = 0.937; p < 0.001), while the tenosynovitis subscores were less strongly correlated (ρ = 0.380 p = 0.035). Correlation between the total RAMRIS and RAMRIS-SAFE was also almost perfect (ρ = 0.976; p < 0.001). Inter-rater reliability in terms of Cohen's κ was high (0.963 ≤ κ ≤ 0.925). In conclusion, RAMRIS-SAFE as the GBCA-free version of the well-established RAMRIS is a patient-friendly and resource-efficient alternative for assessing disease-related joint changes in RA. As patients with RA are subject to repetitive GBCA applications, non-contrast imaging protocols should be considered.

Quantification of Sodium Relaxation Times and Concentrations as Surrogates of Proteoglycan Content of Patellar CARTILAGE at 3T MRI.

Sodium MRI has the potential to depict cartilage health accurately, but synovial fluid can influence the estimation of sodium parameters of cartilage. Therefore, this study aimed to reduce the impact of synovial fluid to render the quantitative compositional analyses of cartilage tissue technically more robust. Two dedicated protocols were applied for determining sodium T1 and T2* relaxation times. For each protocol, data were acquired from 10 healthy volunteers and one patient with patellar cartilage damage. Data recorded with multiple repetition times for T1 measurement and multi-echo data acquired with an additional inversion recovery pulse for T2* measurement were analysed using biexponential models to differentiate longitudinal relaxation components of cartilage (T1,car) and synovial fluid (T1,syn), and short (T2s*) from long (T2l*) transversal relaxation components. Sodium relaxation times and concentration estimates in patellar cartilage were successfully determined: T1,car = 14.5 ± 0.7 ms; T1,syn = 37.9 ± 2.9 ms; c(T1-protocol) = 200 ± 48 mmol/L; T2s* = 0.4 ± 0.1 ms; T2l* = 12.6 ± 0.7 ms; c(T2*-protocol) = 215 ± 44 mmol/L for healthy volunteers. In conclusion, a robust determination of sodium relaxation times is possible at a clinical field strength of 3T to quantify sodium concentrations, which might be a valuable tool to determine cartilage health.