Go Green in Neuroradiology: towards reducing the environmental impact of its practice.

Raising public awareness about the relevance of supporting sustainable practices is required owing to the phenomena of global warming caused by the rising production of greenhouse gases. The healthcare sector generates a relevant proportion of the total carbon emissions in developed countries, and radiology is estimated to be a major contributor to this carbon footprint. Neuroradiology markedly contributes to this negative environmental effect, as this radiological subspecialty generates a high proportion of diagnostic and interventional imaging procedures, the majority of them requiring high energy-intensive equipment. Therefore, neuroradiologists and neuroradiological departments are especially responsible for implementing decisions and initiatives able to reduce the unfavourable environmental effects of their activities, by focusing on four strategic pillars-reducing energy, water, and helium use; properly recycling and/or disposing of waste and residues (including contrast media); encouraging environmentally friendly behaviour; and reducing the effects of ionizing radiation on the environment. The purpose of this article is to alert neuroradiologists about their environmental responsibilities and to analyse the most productive strategic axes, goals, and lines of action that contribute to reducing the environmental impact associated with their professional activities.

Late/delayed gadolinium enhancement in MRI after intravenous administration of extracellular gadolinium-based contrast agents: is it worth waiting?

The acquisition of images minutes or even hours after intravenous extracellular gadolinium-based contrast agents (GBCA) administration ("Late/Delayed Gadolinium Enhancement" imaging; in this review, further termed LGE) has gained significant prominence in recent years in magnetic resonance imaging. The major limitation of LGE is the long examination time; thus, it becomes necessary to understand when it is worth waiting time after the intravenous injection of GBCA and which additional information comes from LGE. LGE can potentially be applied to various anatomical sites, such as heart, arterial vessels, lung, brain, abdomen, breast, and the musculoskeletal system, with different pathophysiological mechanisms. One of the most popular clinical applications of LGE regards the assessment of myocardial tissue thanks to its ability to highlight areas of acute myocardial damage and fibrotic tissues. Other frequently applied clinical contexts involve the study of the urinary tract with magnetic resonance urography and identifying pathological abdominal processes characterized by high fibrous stroma, such as biliary tract tumors, autoimmune pancreatitis, or intestinal fibrosis in Crohn's disease. One of the current areas of heightened research interest revolves around the possibility of non-invasively studying the dynamics of neurofluids in the brain (the glymphatic system), the disruption of which could underlie many neurological disorders.

The role of gadolinium-based contrast agents in magnetic resonance imaging structured reporting and data systems (RADS).

Among the 28 reporting and data systems (RADS) available in the literature, we identified 15 RADS that can be used in Magnetic Resonance Imaging (MRI). Performing examinations without using gadolinium-based contrast agents (GBCA) has benefits, but GBCA administration is often required to achieve an early and accurate diagnosis. The aim of the present review is to summarize the current role of GBCA in MRI RADS. This overview suggests that GBCA are today required in most of the current RADS and are expected to be used in most MRIs performed in patients with cancer. Dynamic contrast enhancement is required for correct scores calculation in PI-RADS and VI-RADS, although scientific evidence may lead in the future to avoid the GBCA administration in these two RADS. In Bone-RADS, contrast enhancement can be required to classify an aggressive lesion. In RADS scoring on whole body-MRI datasets (MET-RADS-P, MY-RADS and ONCO-RADS), in NS-RADS and in Node-RADS, GBCA administration is optional thanks to the intrinsic high contrast resolution of MRI. Future studies are needed to evaluate the impact of the high T1 relaxivity GBCA on the assignment of RADS scores.

Assessing teratogenic risks of gadolinium in freshwater environments: Implications for environmental health.

Gadolinium (Gd) is among the rare earth elements extensively utilized in both industrial and medical applications. The latter application appears to contribute to the rise in Gd levels in aquatic ecosystems, as it is excreted via urine from patients undergoing MRI scans and often not captured by wastewater treatment systems. The potential environmental and biological hazards posed by gadolinium exposure are still under investigation. This study aimed to assess the teratogenic risk posed by a gadolinium chelate on the freshwater cnidarian Hydra vulgaris. The experimental design evaluated the impact of pure Gadodiamide (25 µg/l, 50 µg/l, 100 µg/l, 500 µg/l) and its commercial counterpart compound (Omniscan®; 100 µg/l, 500 µg/l, 782.7 mg/l) at varying concentrations using the Teratogenic Risk Index (TRI). Here we showed a moderate risk (Class III of TRI) following exposure to both tested formulations at concentrations ≥ 100 µg/l. Given the potential for similar concentrations in aquatic environments, particularly near wastewater discharge points, a teratogenic risk assessment using the Hydra regeneration assay was conducted on environmental samples collected from three rivers (Tiber, Almone, and Sacco) in Central Italy. Additionally, chemical analysis of field samples was performed using ICP-MS. Analysis of freshwater samples revealed low Gd concentrations (≤ 0.1 µg/l), despite localized increases near domestic and/or industrial wastewater discharge sites. Although teratogenic risk in environmental samples ranged from high (Class IV of TRI) to negligible (Class I of TRI), the low Gd concentrations, particularly when compared to higher levels of other contaminants like arsenic and heavy metals, preclude establishing a direct cause-effect relationship between Gd and observed teratogenic risks in environmental samples. Nevertheless, the teratogenic risks observed in laboratory tests warrant further investigation.

Extrahepatic abscess and dropped gallstones: a case report and a narrative review of an unusual delayed complication of laparoscopic cholecystectomy.

BACKGROUND: Laparoscopic cholecystectomy is the most common minimally invasive abdominal surgery procedure performed in Western countries; it offers several advantages over laparotomy but still carries some risks, such as intraoperative spillage of bile and gallstones. Diagnosis of dropped gallstones could be challenging, it is frequently delayed, and this can lead to further complications such as abscesses formation. METHODS: We report the history of a 51-year-old male with persistent dull abdominal pain in association to appetite loss, vomiting episodes and changes in regular bowel habits, a past medical history of laparoscopic cholecystectomy for biliary lithiasis (1.5 years earlier) and minimum elevation of inflammatory markers and gamma-GT values. RESULTS: Ultrasound examination showed perihepatic stones and magnetic resonance imaging revealed the presence of multiple perihepatic abscesses, findings compatible with fibrotic-inflammatory phenomena from 'dropped gallstones'. A re-laparoscopy was then performed with an abscess collection containing multiple gallstones; a liver wedge resection was also required due to strong adhesions. At follow up, the patient had improved both on clinical and biochemical perspective. CONCLUSION: Dropped gallstones are an underreported cause of morbidity and diagnostic dilemmas in subjects who underwent to laparoscopic cholecystectomy, in relation to infectious complications that can occur even several months or years after surgery. Imaging represents a valuable aid in the correct non-invasive diagnostic process, but proper awareness of this insidious condition is necessary. Surgeons and radiologists should always consider this eventuality in the differential diagnosis of a patient presenting with abdominal abscesses and history of cholecystectomy.

Stress Cardiovascular Magnetic Resonance Imaging for the Detection of Coronary Artery Disease.

Stress cardiovascular magnetic resonance (CMR) imaging has received extensive validation for the assessment of ischemic heart disease. Without ionizing radiation exposure, it offers in-depth information regarding cardiac structure and function, presence and degree of myocardial ischemia and myocardial viability. When compared to other imaging modalities, it has demonstrated excellent sensitivity and specificity in detecting functionally relevant coronary artery stenosis, as well as strong prognostic value in clinical risk stratification. The current scientific data support a greater expansion of stress CMR. This review investigates the current stress CMR techniques and protocols, as well as its relevance in diagnosis and prognosis of coronary artery disease.

Neuroimages and Neuropathology of a Stroke-Like Cerebral Lymphomatoid Granulomatosis.

A 70-year-old man presented to the Emergency Department reporting the acute onset of non-fluent aphasia, hyposthenia, and hemi-anesthesia of the right body. Brain computerized tomography revealed a subcortical hypodense lesion in the middle cerebral artery territory. Neck ultrasounds of internal and external carotid arteries and of the vertebral arteries showed a focal moderate stenosis of the left internal carotid artery due to a soft atheromasic plaque. These findings that were initially consistent with a diagnosis of an ischemic stroke were not confirmed by magnetic resonance (MR). The latter showed an hyperintense lesion on FLAIR and T2-weighted sequences located in the left centrum semiovale, corona radiata, and thalamus, with a well-defined regular rim and a mild compressive effect on the lateral ventricle, with diffusivity restriction but without ADC reduction and with a punctate and serpiginous gadolinium enhancement on T1 sequences (Figure 1). Within the first day of observation, the patient started complaining progressive mental deterioration, in absence of any other possible causes, and a total body CT scan excluded any other organ involvement. Patient was then referred to the neurosurgeon in order to perform a brain biopsy. The neuropathology was compatible with the diagnosis of cerebral lymphomatoid granulomatosis (LG) (Figure 1).

Patterns of use, effectiveness and safety of gadolinium contrast agents: a European prospective cross-sectional multicentre observational study.

BACKGROUND: The EU gadolinium-based contrast agents (GBCA) market has changed in recent years due to the European Medicines Agency decision to suspend the marketing authorisation of linear GBCA and the marketing authorisation of new generic macrocyclic GBCA. The study aims to understand the patterns of (GBCA) use, and to study the effectiveness and safety of GBCA in routine practice across Europe. METHODS: Prospective, cross-sectional, multicentre, observational study in patients undergoing contrast-enhanced magnetic resonance. Reported usage patterns included indication, referral and examination details. Assessment of effectiveness included changes in radiological diagnosis, diagnostic confidence and image quality. Safety data were collected by spontaneous patient adverse event (AE) reporting. RESULTS: 2118 patients were included from 8 centres across 5 European countries between December 2018 and November 2019. Clariscan, Dotarem (gadoteric acid), Gadovist (gadobutrol) and ProHance (gadoteridol) were utilised in 1513 (71.4%), 356 (16.8%), 237 (11.2%) and 12 (0.6%) patients, respectively. Most were performed in CNS-related indications (46.2%). Mean GBCA doses were 0.10 mmol/kg body weight, except for Gadovist (mean 0.12 mmol/kg). GBCA use increased confidence in diagnosis in 96.2% of examinations and resulted in a change in radiological diagnosis in 73.9% of patients. Image quality was considered excellent or good in 96.1% of patients and across all GBCA. Four patients reported AEs (0.19%), with only 1 (0.05%) considered serious. CONCLUSIONS: This European study confirmed that GBCAs are used appropriately in Europe for a wide range of indications. The study demonstrated a significant increase in diagnostic confidence after GBCA use and confirmed the good safety profile of GBCAs, with comparable results for all agents used.

Gadolinium-based contrast agents: did we miss something in the last 25 years?

In the last 24 months, several clinical and experimental studies, suggested first and demonstrated later, a progressive concentration of Gadolinium in the brain of normal renal function patients, following repeated injections of some of the commercially approved Gadolinium-Based Contrast Agents. Although, till now, Gadolinium brain deposits have not been associated to any kind of neurological signs or symptoms, they oblige the radiology community to modify the actual approach in using Gadolinium contrast media in daily practice, to reduce unknown possible risks for patients.

Altered metal metabolism in patients with HCV-related cirrhosis and hepatic encephalopathy.

Dysfunctional metal homeostasis contributes to oxidative stress and neuronal damage. These have been implicated in hepatic encephalopathy pathogenesis. To investigate whether altered metal metabolism is associated with hepatic encephalopathy. Twenty-one controls and 34 HCV-cirrhotic patients (ENC/NEC patients according to presence/absence of previous overt episodes of hepatic encephalopathy) and a control group were studied. Serum iron, copper, ceruloplasmin, ceruloplasmin activity, transferrin, and ceruloplasmin/transferrin ratio were determined. Neuropsychological tests were performed by the repeatable battery of neuropsychological status. Magnetic resonance assessed basal ganglia volumes and metal deposition (pallidal index and T2*). Cirrhotic patients performed worse than controls at cognitive tests, especially ENC patients,. At biochemical analysis copper concentrations, ceruloplasmin activity and transferrin levels were lower in ENC than in NEC patients and controls (p < 0.05 and p < 0.01, respectively). Ceruloplasmin/transferrin ratio was higher in ENC compared to NEC patients (p < 0.05), and controls (p < 0.01). By brain magnetic resonance, ENC patients showed reduced caudate and globus pallidus volumes compared to controls (p < 0.05), and ENC and NEC patients an increased pallidal index compared to controls (p < 0.01). In ENC patients, ceruloplasmin activity correlated with caudate volume and pallidal index (ρ = 0.773 and ρ = -0.683, p < 0.05). Altered metal metabolism likely contributes to cirrhotic hepatic encephalopathy.

Inverse spatial distribution of brain metastases and white matter hyperintensities in advanced lung and non-lung cancer patients.

The aim of this study was to test by means of a voxel-based approach the hypothesis that there is a different spatial distribution of brain metastases (BM) and white matter hyperintensities (WMH) and that the presence of WMH affects the location of BM in lung and non-lung cancer patients. Two-hundred consecutive cancer patients at first diagnosis of BM were included. Images were acquired using a 1.5 Tesla MRI system (Magnetom Avanto B13, Siemens, Erlangen, Germany). Axial FLAIR T2 weighted images and gadolinium-enhanced T1 weighted images were post-processed for segmentation, co-registration and analysis. Binary lesion masks were created for WMH and BM, using Volumes of Interest. Lesion probability maps were generated and the voxel-based lesion-symptom mapping approach was used to model each voxel and to calculate a non parametric statistics (Brunner-Munzel test) describing the differences between the groups. In the lung cancer group we found higher frequency of BM in WMH- than in WMH+ patients in the occipital lobe and the cerebellum. In contrast, BM were more frequent in the right frontal lobe in WMH+ than in WMH- patients. We suggest that there exists an inverse brain spatial distribution between WMH and BM. In lung cancer patients, the presence of WMH seems to shift the distribution of BM toward locations different than what it is expected based on primary tumor.

Estimating the risk for symptomatic adjacent segment degeneration after lumbar fusion: analysis from a cohort of patients undergoing revision surgery.

PURPOSE: Aim of this study is to estimate the risk for symptomatic adjacent segment degeneration (ASD) and examine the association between spino-pelvic parameters and ASD. METHODS: 22 patients operated upon by instrumented lumbar or lumbosacral spinal fusion and re-operated upon for ASD were enrolled in the study. 83 consecutive patients with the same surgery and never re-operated upon were the controls. Pelvic incidence, sacral slope (SS), pelvic tilt (PT), and lumbar lordosis were calculated. RESULTS: Patients with ASD had significantly lower SS (p = 0.005) and higher PT values (p < 0.001). Patients with SS <39° or PT >21°, were at higher risk for symptomatic ASD (relative risk 1.73 for SS and 3.663 for PT). CONCLUSIONS: In patients re-operated upon for ASD, pelvic retroversion and hyperlordosis are the main mechanisms of compensation for the unbalanced spine. Patients with PT above 21° and SS below 39° are at higher risk for symptomatic ASD.

Bilateral remote cerebellar haemorrhage after spinal surgery: a case study and review of the literature.

BACKGROUND: Remote cerebellar haemorrhage is a rare and unpredictable complication after intracranial and spinal surgery, although less frequently found in the latter. The physiopathology of this phenomenon has not been definitely explained. OBJECTIVES: To describe and discuss the potential implications and pathomechanism of a bilateral remote cerebellar haemorrhage case after spinal surgery and review the literature related to this rare phenomenon. CASE REPORT: A 75 year-old man developed bilateral remote cerebellar haemorrhage after a lumbar laminectomy. Brain CT and MRI examinations showed chronic bilateral remote cerebellar haemorrhage, right haemoventricle and bilateral supratentorial subarachnoid haemorrhage. Subsequently, the patient underwent rehabilitation therapy with improvement of symptoms. CONCLUSION: When large cerebrospinal fluid loss is observed during spinal surgery, brain imaging study should be carried out. The pathogenetic hypothesis of microcirculation vessels tearing, the role of previous spinal surgery and of cerebellar atrophy should be considered and validated with further investigation.

The sensitivity of MIPs of 3D contrast-enhanced VIBE T1-weighted imaging for the detection of small brain metastases (≤ 5 mm) on 1.5 tesla MRI.

OBJECTIVES: To evaluate whether the use of Maximum Intensity Projection (MIP) images derived from contrast-enhanced 3D-T1-weighted volumetric interpolated breath-hold examination (VIBE) would allow more sensitive detection of small (≤5 mm) brain metastases (BM) compared with source as well as 2D-T1-weighted spin-echo (SE) images. METHODS: We performed a single center retrospective study on subjects with BM who underwent 1.5 tesla brain magnetic resonance imaging. Two readers counted the number of small BM for each of the seven sets of contrast-enhanced images created: axial 2D-T1-weighted SE, 3D-T1-weighted VIBE, 2.5 mm-thick-MIP T1-weighted VIBE, and 5 mm-thick-MIP T1-weighted VIBE; sagittal 3D-T1-weighted VIBE, 2.5 mm-thick-MIP T1-weighted VIBE, and 5 mm-thick-MIP T1-weighted VIBE. Total number of lesions detected on each image type was compared. Sensitivity, the average rates of false negatives and false positives, and the mean discrepancy were evaluated. RESULTS: A total of 403 small BM were identified in 49 patients. Significant differences were found: in the number of true positives and false negatives between the axial 2D-T1-weighted SE sequence and all other imaging techniques; in the number of false positives between the axial 2D-T1-weighted SE and the axial 3D-T1-weighted VIBE sequences. The two image types that combined offered the highest sensitivity were 2D-T1-weighted SE and axial 2.5 mm-thick-MIP T1-weighted VIBE. The axial 2D-T1-weighted SE sequence differed significantly in sensitivity from all other sequences. CONCLUSION: MIP images did not show a significant difference in sensitivity for the detection of small BM compared with native images.

Overview of the Current Knowledge and Conventional MRI Characteristics of Peri- and Para-Vascular Spaces.

Brain spaces around (perivascular spaces) and alongside (paravascular or Virchow-Robin spaces) vessels have gained significant attention in recent years due to the advancements of in vivo imaging tools and to their crucial role in maintaining brain health, contributing to the anatomic foundation of the glymphatic system. In fact, it is widely accepted that peri- and para-vascular spaces function as waste clearance pathways for the brain for materials such as ß-amyloid by allowing exchange between cerebrospinal fluid and interstitial fluid. Visible brain spaces on magnetic resonance imaging are often a normal finding, but they have also been associated with a wide range of neurological and systemic conditions, suggesting their potential as early indicators of intracranial pressure and neurofluid imbalance. Nonetheless, several aspects of these spaces are still controversial. This article offers an overview of the current knowledge and magnetic resonance imaging characteristics of peri- and para-vascular spaces, which can help in daily clinical practice image description and interpretation. This paper is organized into different sections, including the microscopic anatomy of peri- and para-vascular spaces, their associations with pathological and physiological events, and their differential diagnosis.

Impact of Sleeve Gastrectomy on Brain Structural Integrity.

INTRODUCTION: Potential brain structural differences in people with obesity (PwO) who achieve over or less than 50% excess weight loss (EWL) after sleeve gastrectomy (SG) are currently unknown. We compared measures of gray matter volume (GMV) and white matter (WM) microstructural integrity of PwO who achieved over or less than 50% EWL after SG with a group of controls with obesity (CwO) without a past history of metabolic bariatric surgery. METHODS: Sixty-two PwO underwent 1.5 T MRI scanning: 24 who achieved more than 50% of EWL after SG ("group a"), 18 who achieved less than 50% EWL after SG ("group b"), and 20 CwO ("group c"). Voxel-based morphometry and tract-based spatial Statistics analyses were performed to investigate GMV and WM differences among groups. Multiple regression analyses were performed to investigate relationships between structural and psychological measures. RESULTS: Group a demonstrated significantly lower GMV loss and higher WM microstructural integrity with respect to group b and c in some cortical regions and several WM tracts. Positive correlations were observed in group a between WM integrity and several psychological measures; the lower the WM integrity, the higher the mental distress, emotional dysregulation, and binge eating behavior. CONCLUSION: The present results gain a new understanding of the neural mechanisms of outcome in patients who undergo SG. We found limited GMV changes and extensive WM microstructural differences between PwO who achieved over or less than 50% EWL after SG, which may be due to higher vulnerability of WM to the metabolic dysfunction present in PwO.

Brain metastatic volume and white matter lesions in advanced cancer patients.

Brain white matter T2 hyperintensities (WMH) are a frequent MRI finding in adults, both in asymptomatic and in cancer patients. The aim of our study is to determine the relationship between quantitative measures of the volume of WMH and the volume of brain metastatic lesions at the first MRI diagnosis of brain metastases in a population of advanced cancer patients. Brain MRI examinations of 162 consecutive patients were included and 984 brain metastases at first diagnosis were studied. Axial FLAIR images were used to visualize peri-lesional edema and to segment WMH; multiplanar contrast-enhanced T1-weighted TSE images were used to detect, count, segment and measure metastatic lesions. Segmentation of WMH on FLAIR images was performed after linear image registration to eliminate peri-lesional edema from the WMH masks. The distribution of the volumes of metastatic lesions was significantly different (ANOVA, p = 0.003) among all patients and among lung cancer patients (ANOVA, p = 0.003), with higher volumes of metastatic lesions in a higher proportion of patients when WMH were absent. There were no significant differences among groups at the 10 cc threshold of WMH. We found that volumes of brain metastases at the first MR diagnosis in a sample of advanced cancer patients and in the group of lung cancer patients were significantly lower if WMH were present; we suggest that WMH may represent a clinical MRI bio-marker of brain micro-environment resistance to the occurrence of brain metastases.

MR differential diagnosis of acute deep grey matter pathology in paediatric patients.

A high metabolic demand, rich vascularization and high concentrations of ionic elements leading to the generation of oxygen free radicals, give to the deep grey matter (DGM) nuclei specific susceptibility to both acute and chronic insults, especially in paediatric patients. Reaching a diagnosis in the early stages of acute diseases in many patients is crucial for instigating prompt specific therapy leading to a favourable outcome. On the basis of a review of a 10-year in-house database and a review of the literature on CNS pathology involving the DGM nuclei in paediatric patients, we summarize the MR findings and clinical clues that may help the radiologist in the difficult differential diagnosis process. The terms "acute" and "chronic" refer to the clinical onset of the disease. MR imaging allows the detection of an injury, determination of its precise anatomical location and characterization of the signal changes. This, combined with a knowledge of specific MRI patterns, may be a roadmap to a definite diagnosis. Clinical history, physical and laboratory findings, timing of the MR examination and advanced MR imaging techniques (diffusion-weighted imaging and (1)H-MR spectroscopy), are crucial in some patients.