Ten years of gadolinium retention and deposition: ESMRMB-GREC looks backward and forward.

In 2014, for the first time, visible hyperintensities on unenhanced T1-weighted images in the nucleus dentatus and globus pallidus of the brain were associated with previous Gadolinium-based contrast agent (GBCA) injections and gadolinium deposition in patients with normal renal function. This led to a frenzy of retrospective studies with varying methodologies that the European Society of Magnetic Resonance in Medicine and Biology Gadolinium Research and Educational Committee (ESMRMB-GREC) summarised in 2019. Now, after 10 years, the members of the ESMRMB-GREC look backward and forward and review the current state of knowledge of gadolinium retention and deposition. CLINICAL RELEVANCE STATEMENT: Gadolinium deposition is associated with the use of linear GBCA but no clinical symptoms have been associated with gadolinium deposition. KEY POINTS : • Traces of Gadolinium-based contrast agent-derived gadolinium can be retained in multiple organs for a prolonged time. • Gadolinium deposition is associated with the use of linear Gadolinium-based contrast agents. • No clinical symptoms have been associated with gadolinium deposition.

Use of gadolinium-based contrast agents in multiple sclerosis: a review by the ESMRMB-GREC and ESNR Multiple Sclerosis Working Group.

Magnetic resonance imaging (MRI) is the most sensitive technique for detecting inflammatory demyelinating lesions in multiple sclerosis (MS) and plays a crucial role in diagnosis and monitoring treatment effectiveness, and for predicting the disease course. In clinical practice, detection of MS lesions is mainly based on T2-weighted and contrast-enhanced T1-weighted sequences. Contrast-enhancing lesions (CEL) on T1-weighted sequences are related to (sub)acute inflammation, while new or enlarging T2 lesions reflect the permanent footprint from a previous acute inflammatory demyelinating event. These two types of MRI features provide redundant information, at least in regular monitoring of the disease. Due to the concern of gadolinium deposition after repetitive injections of gadolinium-based contrast agents (GBCAs), scientific organizations and regulatory agencies in Europe and North America have proposed that these contrast agents should be administered only if clinically necessary. In this article, we provide data on the mode of action of GBCAs in MS, the indications of the use of these agents in clinical practice, their value in MS for diagnostic, prognostic, and monitoring purposes, and their use in specific populations (children, pregnant women, and breast-feeders). We discuss imaging strategies that achieve the highest sensitivity for detecting CELs in compliance with the safety regulations established by different regulatory agencies. Finally, we will briefly discuss some alternatives to the use of GBCA for detecting blood-brain barrier disruption in MS lesions. CLINICAL RELEVANCE STATEMENT: Although use of GBCA at diagnostic workup of suspected MS is highly valuable for diagnostic and prognostic purposes, their use in routine monitoring is not mandatory and must be reduced, as detection of disease activity can be based on the identification of new or enlarging lesions on T2-weighted images. KEY POINTS: • Both the EMA and the FDA state that the use of GBCA in medicine should be restricted to clinical scenarios in which the additional information offered by the contrast agent is required. • The use of GBCA is generally recommended in the diagnostic workup in subjects with suspected MS and is generally not necessary for routine monitoring in clinical practice. • Alternative MRI-based approaches for detecting acute focal inflammatory MS lesions are not yet ready to be used in clinical practice.

Visceral adiposity in patients with lipomatous hypertrophy of the interatrial septum.

Lipomatous hypertrophy of the interatrial septum (LHIS) is a benign cardiac mass determined by abnormal deposition of adipose tissue in the interatrial septum. The quantitative relationship between LHIS and visceral adiposity has not been explored to date.In this retrospective study, three groups of consecutive patients undergoing CT imaging were enrolled: L + with LHIS, L- without LHIS, and LO- without both LHIS and history of malignancies. Areas of total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and LHIS areas were calculated on CT images. The relationship between LHIS and abdominal fat distribution was investigated with linear regression models. Bonferroni correction was applied to account for multiple testing. Statistical significance was set at 5%. In this study we enrolled a total of 175 subjects: 58 (33.14%) with LHIS (L +), 51(29.14%) without LHIS (L-) and 66 (37.71%) without both LHIS and medical history of malignancies (LO-). VAT (coeff: 105.82; 95% CI 59.37-152.27), SAT (coeff: 74.59; 95% CI 31.63-117.54), and TAT (coeff: 190.37; 95% CI 115.02-265.72), were significantly higher in L + patients. Moreover, VAT (coeff: 24.95; 95% CI 6.94-42.96) and TAT (coeff: 36.58; 95% CI 8.75-64.41) were statistically significant linear predictors for LHIS area. Here, we report a novel association between LHIS and visceral adiposity using a quantitative CT-based imaging approach. The results are of great importance also because they might drive early identification of subjects with LHIS at risk for visceral obesity, and trigger lifestyle interventions aimed at weight loss.

Brain functional connectivity differences between responders and non-responders to sleeve gastrectomy.

PURPOSE: To compare resting-state functional connectivity (RSFC) of obese patients responders or non-responders to sleeve gastrectomy (SG) with a group of obese patients with no past medical history of metabolic or bariatric surgery. METHODS: MR images were acquired at 1.5 Tesla. Resting-state fMRI data were analyzed with statistical significance threshold set at p < 0.05, family-wise error (FWE) corrected. RESULTS: Sixty-two subjects were enrolled: 20 controls (age range 25-64; 14 females), 24 responders (excess weight loss > 50%; age range 23-68; 17 females), and 18 non-responders to sleeve gastrectomy (SG) (excess weight loss < 50%; age range 23-67; 13 females). About within-network RSFC, responders showed significantly lower RSFC with respect to both controls and non-responders in the default mode and frontoparietal networks, positively correlating with psychological scores. Non-responders showed significantly higher (p < 0.05, family-wise error (few) corrected) RSFC in regions of the lateral visual network as compared to controls. Regarding between-network RSFC, responders showed significantly higher anti-correlation between executive control and salience networks (p < 0.05, FWE corrected) with respect to both controls and non-responders. Significant positive correlation (Spearman rho = 0.48, p = 0.0012) was found between % of excess weight loss and executive control-salience network RSFC. CONCLUSION: There are differences in brain functional connectivity in either responders or non-responders patients to SG. The present results offer new insights into the neural correlates of outcome in patients who undergo SG and expand knowledge about neural mechanisms which may be related to surgical response.

Computed tomography density changes of bone metastases after concomitant denosumab.

OBJECTIVE: To evaluate bone density changes at the level of normal trabecular bone and bone metastases (BMs) after denosumab (DM) treatment in oncologic patients. MATERIALS AND METHODS: We retrospectively evaluated 31 consecutive adult patients with histologically confirmed solid tumors with at least one newly diagnosed bone metastatic lesion detected at CT. Patients received treatment with DM, 120 mg subcutaneous every 28 days for at least 6 months. Bone density was determined at the level of BMs and at the level of normal trabecular bone of lumbar vertebrae using a region of interest (ROI)-based approach. RESULTS: A progressive increase in CT bone density was demonstrated at the level of normal trabecular bone at 6 months (18% ± 5%) and 12 months (23% ± 7%) after the treatment begins. BMs showed a significant increase in CT bone density (p < 0.05) as compared to baseline after 6 months (57% ± 15%) and 12 months (1.06 ± 0.25 times higher) after treatment. CONCLUSION: We have found that long-term treatment with DM increases bone density progressively in oncologic patients. This effect can be observed not only at the level of secondary lesions but also at the level of apparently normal trabecular bone and is more pronounced for osteolytic metastases.

Large language models for structured reporting in radiology: performance of GPT-4, ChatGPT-3.5, Perplexity and Bing.

Structured reporting may improve the radiological workflow and communication among physicians. Artificial intelligence applications in medicine are growing fast. Large language models (LLMs) are recently gaining importance as valuable tools in radiology and are currently being tested for the critical task of structured reporting. We compared four LLMs models in terms of knowledge on structured reporting and templates proposal. LLMs hold a great potential for generating structured reports in radiology but additional formal validations are needed on this topic.

Bilateral MCP Infarct Due to Vertebral Giant Cell Arteritis.

We present the case of an 83-year-old woman with an isolated bilateral middle cerebellar peduncles stroke caused by complete occlusion of the right vertebral artery and focal occlusion of the left vertebral artery due to giant cell arteritis. The diagnosis was achieved by integrating MRI, ultrasound study, laboratory data and subsequent pathology analysis after biopsy of the temporal artery.

Effect of Exposure to Gadodiamide and Brain Irradiation on T1 -Weighted Images and ADC Maps of the Dentate Nucleus.

BACKGROUND: Brain irradiation is considered a cofactor influencing the dentate nucleus (DN) signal intensity (SI) on unenhanced T1 -weighted images in patients exposed to gadolinium-based contrast agents (GBCAs). PURPOSE: To assess the effect of gadodiamide and whole-brain radiation therapy (WBRT) on T1 -weighted images and on apparent diffusion coefficient (ADC) maps of DN. STUDY TYPE: Single-center retrospective. POPULATION: In all, 125 patients who underwent brain MRIs were classified into four groups: 1) patients who did neither receive intravenous GBCAs injections nor irradiation (controls); 2) patients having ≥3 GBCAs-enhanced scans and no WBRT; 3) patients having WBRT and < 3 GBCAs-enhanced scans; and 4) patients having WBRT and ≥ 3 GBCAs-enhanced scans. FIELD STRENGTH/SEQUENCE: 1.5T magnet, echo-planar diffusion weighted imaging (DWI) and unenhanced T1 -weighted sequences. ASSESSMENT: The DN-to-pons SI ratio on unenhanced T1 -weighted images and ADC values of the DN were calculated. Values were compared between groups and relative to the cumulative gadolinium dose and to the time delay after WBRT. STATISTICAL TESTS: Statistical analysis included the Mann-Whitney U-test and Spearman's rank-order correlation. RESULTS: DN ADC values were not significantly different (P = 0.34) between patients exposed to gadodiamide (0.81 ± 0.06) and controls (0.83 ± 0.07). There were no differences in DN ADC values (P = 0.28) and DN-to-pons SI ratios (P = 0.42) between patients exposed to WBRT (ADC values: 0.85 ± 0.09; SI ratio: 1.11 ± 0.10) and controls (ADC values: 0.83 ± 0.06; SI ratio: 1.09 ± 0.06). There was a significant negative correlation between DN ADC values and the time (days) since the end of WBRT (r = - 0.33; 95% confidence interval [CI]: -0.55, -0.06; P < 0.05). DATA CONCLUSION: We did not find changes suggestive of gadolinium-related tissue microstructural damage of the DN. The ADC values of the DN are associated with the time from WBRT. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 5.

Exposure to gadolinium and neurotoxicity: current status of preclinical and clinical studies.

PURPOSE: Gadolinium is a rare-earth lanthanide metal that is known to have a direct neurotoxic effect. The scope of the present review is to summarize the current preclinical and clinical evidence on the association between exposure to gadolinium of the central nervous system and neurotoxicity. METHODS: A literature review was performed by searching for original research papers investigating on gadolinium exposure and neurotoxicity. RESULTS: Gadolinium is neurotoxic through multiple mechanisms, mainly involving Ca++ homeostasis and mitochondrial functions, as shown by preclinical in vitro studies. The available evidence related to the four different classes of gadolinium-based contrast agents commonly applied in clinical practice (i.e., linear and macrocyclic based on ligand structure, and ionic and non-ionic based on their net molecular charge) suggests that serial intravenous injections of gadolinium-based contrast agents and gadolinium brain depositions are not associated to histological changes, as confirmed by preclinical animal and human (MR imaging and autopsy) studies. CONCLUSION: To date, no cause-effect relationship has been demonstrated in patients between brain gadolinium exposure and clinical consequences specific to neurological toxicity.

Within-network brain connectivity in Crohn's disease patients with gadolinium deposition in the cerebellum.

PURPOSE: Patients with Crohn's disease (CD) undergo multiple gadolinium-based contrast agent injections across their lifespan to enhance signal intensity of the intestinal wall and differentiate active from quiescent inflammatory disease. Thus, CD patients are prone to gadolinium accumulation in the brain and represent a non-neurological population to explore gadolinium-related brain toxicity. Possible effects are expected to be greater on the cerebellar network due to the high propensity of the dentate nucleus to accumulate gadolinium. Herein, we provide a whole-brain network analysis of resting-state fMRI dynamics in long-term quiescent CD patients with normal renal function and MRI evidence of gadolinium deposition in the brain. METHODS: Fifteen patients with CD and 16 healthy age- and gender-matched controls were enrolled in this study. Relevant resting-state networks (RSNs) were identified using independent component analysis (ICA) from functional magnetic resonance imaging data. An unpaired two-sample t test (with age and sex as nuisance variables) was used to investigate between different RSNs. Clusters were determined by using threshold-free cluster enhancement and a family-wise error corrected cluster significance threshold of p < 0.05. RESULTS: Patients showed significantly decreased resting-state functional connectivity (p < 0.05, FWE corrected) of several regions of the right frontoparietal (FPR) and the dorsal attention (DAN) RSNs. No differences between the two groups were found in the functional connectivity maps of all the other RSNs, including the cerebellar network. CONCLUSION: Our findings suggest a non-significant impact of gadolinium deposition on within-network cerebellar functional connectivity of long-term quiescent CD patients.

Absence of dentate nucleus resting-state functional connectivity changes in nonneurological patients with gadolinium-related hyperintensity on T1 -weighted images.

BACKGROUND: The dentate nuclei of the cerebellum are the areas where gadolinium predominantly accumulates. It is not yet known whether gadolinium deposition affects brain functions. PURPOSE/HYPOTHESIS: To assess whether gadolinium-dependent high signal intensity of the cerebellum on T1 -weighted images of nonneurological adult patients with Crohn's disease is associated with modifications of resting-state functional connectivity (RSFC) of the cerebellum and dentate nucleus. STUDY TYPE: Observational, cross-sectional. POPULATION: Fifteen patients affected by Crohn's disease were compared with 16 healthy age- and gender-matched control subjects. All participants underwent neurological, neurocognitive-psychological assessment, and blood sampling. FIELD STRENGTH/SEQUENCE: 1.5-T magnet blood oxygenation level-dependent (BOLD) functional MRI. ASSESSMENT: High signal intensity on T1 -weighted images, cerebellum functional connectivity, neurocognitive performance, and blood circulating gadolinium levels. STATISTICAL TESTS: An unpaired two-sample t-test (age and sex were nuisance variables) was used to investigate between-group differences in cerebellar and dentate nucleus functional connectivity. Z-statistical images were set using clusters determined by Z > 2.3 and a familywise error (FWE)-corrected cluster significance threshold of P = 0.05. RESULTS: Dentate nuclei RSFC was not different (P = n.s.) between patients with gadolinium-dependent high signal intensity on T1 -weighted images and controls. Pre- and postcentral gyrus bilaterally and the right supplementary motor cortex showed a decrease of RSFC with the cerebellum hemispheres (P < 0.05 FWE-corrected) and was related to disease duration but not to gadodiamide cumulative doses (P = n.s.). DATA CONCLUSION: Crohn's disease patients with gadolinium-dependent hyperintense dentate nuclei on unenhanced T1 -weighted images do not show dentate nucleus RSFC changes. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2019;50:445-455.

Exploring the interplay between paraspinal muscular status and bone health in osteoporosis and fracture risk: a comprehensive literature review on computed tomography (CT) and magnetic resonance imaging (MRI) studies.

Background and Objective: Computed tomography (CT) and magnetic resonance imaging (MRI) of the spine are fundamental non-invasive tools to investigate the status of the bone and soft tissue in vivo. A novel and promising approach is to investigate the quality and quantity of paraspinal muscles even beyond the clinical question. The aim of the present review is to summarize current evidence on CT and MRI about the relationship between paraspinal muscular status and bone health in osteoporosis (OP) and fracture risk. Methods: Literature research was carried out on September 2023 using PubMed, Scopus, and Cochrane databases. Key Content and Findings: Research investigating the intricate interplay between musculature and bone health reveals that degenerating paraspinal muscles, characterized by shrinking and fatty infiltration, are associated with lower bone mineral density (BMD) and the development of OP. Additionally, research indicates that weaker paraspinal muscles are linked to a higher risk of fractures, including those at the spine. Conclusions: The findings suggest that paraspinal muscle health may be a significant factor in identifying individuals at risk for OP and fractures. Further investigation is needed to explore the potential of paraspinal muscles in preventing these conditions.

Retrolabyrinthine approach to the lateral skull base: The value of preoperative temporal bone CT analysis.

PURPOSE: The most used neurosurgical approach to reach cerebellar-pontine angle is the retrosigmoid route. This article describes the presigmoid approach which requires excellent knowledge of the labyrinthine block together with quantitative analysis of temporal bone CT. METHODS: CT-based quantitative measurements were obtained in patients undergoing vestibular neurectomy with a presigmoid approach. Eighteen patients were enrolled, and five measures were taken: Trautmann's area, the petro-clival angle, presigmoid dura length and its angle. The relationship between these measurements and hospitalization days, operating times, and complications was explored. RESULTS: The posterior semicircilar canal (PSC)-sigmoid sinus (SS) distance, presigmoid dura- internal auditory canal (IAC)-PSC angle, and duration of surgery are predictors of complications. Specifically, a PSC-sigmoid sinus distance <11 mm, a dura presig-IAC-PSC angle <14 are associated with the highest risk of complications. CONCLUSION: Preoperative temporal bone CT scan can guide the surgeon through the narrowest areas of the surgical approach. Trautmann's triangle area and petro-clival angle reduction are challenging and can be faced with combined microscopic-endoscopic technique, and with optics angulation-rotation. The retrolabyrinthine approach can enable hearing preservation and minimal cerebellar retraction.

The importance of psoas muscle on low back pain: a single-center study on lumbar spine MRI.

Background: Low back pain (LBP) is the most frequent indication to magnetic resonance imaging (MRI) examinations of the lumbosacral spine. The individual role of soft tissues, including muscles, on LBP is not fully understood and the contribution of each MRI-derived parameter of soft tissues status on the intensity of LBP has not been investigated in detail. Methods: The study design was observational retrospective, single center carried out at a University Hospital. Images were acquired using a using a 1.5 Tesla scanner. Patients completed a symptom questionnaire and rated their pain intensity using the Visual Analogue Scale (VAS). The VAS scores ​​were categorized as mild, moderate, and severe using cutoff values of 3.8 and 5.7, based on the literature. Biometric data, including weight and height, were also recorded to calculate the body mass index (BMI). The ratios between intramuscular fat infiltration and net muscle area were also calculated. Patient sample included 94 patients with LBP underwent MRI of the lumbosacral spine. Results: The stepwise analysis revealed that increasing psoas net area was associated with lower VAS levels (odds ratio [OR]: 0.94: 95% confidence interval [CI]: 0.90-0.98; p=.005), and an increase of one square centimeter of total psoas area resulted in a greater probability of reporting a mild (+1.21%; 95% CI: 0.37, 2.05%) or a moderate VAS (+0.40%; 95% CI: -0.02, 0.82%), Furthermore, a more severe VAS was associated with a higher BMI (OR: 1.13; 95% CI: 1.00-1.27). Conclusion: Our study demonstrates a relationship between LBP and MRI parameters of paravertebral and psoas muscles status. The psoas muscle is extremely important for spine stabilization and is linked to clinical symptoms of patients affected by LBP. These findings could contribute to future studies and improve treatment options in patients with LBP, possibly reducing the impact on disability, quality of life and socioeconomical burden.

Posterior Subcutaneous Edema at Lumbar Spine MRI: A Systematic Review.

RATIONALE AND OBJECTIVES: Edema in the subcutaneous soft tissue of the lumbar spine is a frequent incidental finding in spinal magnetic resonance imaging, however, its exact explanation is yet to be determined. The aim of this paper is to provide a systematic literature review on posterior lumbar subcutaneous edema (LSE). MATERIALS AND METHODS: The present systematic literature search was carried out in October 2023 using electronic databases: PubMed, Cochrane library, and Scopus. RESULTS: The current evidence suggests that lumbar edema is correlated with clinical data such as weight and age, and potentially female sex. Moreover, LSE is related to several specific conditions, including both systemic and spinal disorders, such as heart or kidney disorders, as well as low back pain and degenerative and/or inflammatory diseases. CONCLUSION: It is important to be aware that there is an association between LSE and a variety systemic and spinal disorders.