In vivo analyses of the correlates of cortical and white matter pathology in patients with multiple sclerosis by quantitative 7 Tesla and 3 Tesla MRI and molecular imaging.

This thesis is divided in two sections. The first reports the results from a project regarding the application of ultra-high-field quantitative MRI for the study of cortical grey matter pathology in patients with early multiple sclerosis (MS). Applying a Combined Myelin Estimation method, obtained by 7 Tesla magnetic resonance imaging, we aimed at characterizing cortical microstructural abnormalities related to myelin content in cortical lesions and normal-appearing cortex, to assess their evolution at 1-year follow-up and to relate cortical myelin changes to clinical and radiological disease burden. Data obtained from 25 patients with early MS and 19 healthy volunteers showed overall abnormally low myelin content in cortical lesions and several areas of normal-appearing cortex. Myelin content along the cortex correlated with neurological impairment. Individual cortical lesion analysis revealed heterogenous patterns, ranging from extensive to partial demyelination, or even measurements comparable to the healthy group. At 1-year follow-up, cortical myelin was overall decreased in cortical lesions and scattered areas in the normal-appearing cortex. Diffusion metrics obtained in the same regions did not show the presence of cortical neural loss accompanying early demyelination. The second section reports results from a study in which we combined 11C-PBR28 positron-emission tomography, marking activated microglia, with the more recently validated synthetic magnetic resonance imaging for myelin content assessment, aiming at researching the presence of correlates of pathology in the white matter of patients with multiple sclerosis at different disease stages, and assessing the interplay between neuroinflammation and demyelination. We found abnormal increase of microglia activation in MS patients compared to healthy volunteers in several areas across the white matter, correlating with clinical and radiological disease burden. An individual analysis of white matter lesions showed the presence of active lesions in the early phases of the disease, evolving in inactive or peripherally active lesions in the late disease phases, the latter correlating with clinical disability. Myelin content in the normal-appearing white matter of MS patients correlated with neurological impairment and lesion load. Higher microglia activation in the white matter lesions was related to lower myelin content in the non-lesioned white matter

An Interpretable Machine Learning Model to Predict Cortical Atrophy in Multiple Sclerosis

To date, the relationship between central hallmarks of multiple sclerosis (MS), such as white matter (WM)/cortical demyelinated lesions and cortical gray matter atrophy, remains unclear. We investigated the interplay between cortical atrophy and individual lesion-type patterns that have recently emerged as new radiological markers of MS disease progression. We employed a machine learning model to predict mean cortical thinning in whole-brain and single hemispheres in 150 cortical regions using demographic and lesion-related characteristics, evaluated via an ultrahigh field (7 Tesla) MRI. We found that (i) volume and rimless (i.e., without a "rim" of iron-laden immune cells) WM lesions, patient age, and volume of intracortical lesions have the most predictive power; (ii) WM lesions are more important for prediction when their load is small, while cortical lesion load becomes more important as it increases; (iii) WM lesions play a greater role in the progression of atrophy during the latest stages of the disease. Our results highlight the intricacy of MS pathology across the whole brain. In turn, this calls for multivariate statistical analyses and mechanistic modeling techniques to understand the etiopathogenesis of lesions

Relationship between prolactin plasma levels and white matter volume in women with multiple sclerosis

BACKGROUND: The role of prolactin (PRL) on tissue injury and repair mechanisms in multiple sclerosis (MS) remains unclear. The aim of this work was to investigate the relationship between PRL plasma levels and brain damage as measured by magnetic resonance imaging (MRI). METHODS: We employed a chemiluminescence immunoassay for measuring plasma levels of PRL. We used a 1.5 T scanner to acquire images and Jim 4.0 and SIENAX software to analyse them. RESULTS: We included 106 women with relapsing remitting (RR) MS and stable disease in the last two months. There was no difference in PRL plasma levels between patients with and without gadolinium enhancement on MRI. PRL plasma levels correlated with white matter volume (WMV) (rho = 0.284, p = 0.014) but not with grey matter volume (GMV). Moreover, PRL levels predicted changes in WMV (Beta: 984, p = 0.034). CONCLUSIONS: Our data of a positive association between PRL serum levels and WMV support the role of PRL in promoting myelin repair as documented in animal models of demyelination. The lack of an increase of PRL in the presence of gadolinium enhancement, contrasts with the view considering this hormone as an immune-stimulating and detrimental factor in the inflammatory process associated with MS

An Interpretable Machine Learning Model to Predict Cortical Atrophy in Multiple Sclerosis

To date, the relationship between central hallmarks of multiple sclerosis (MS), such as white matter (WM)/cortical demyelinated lesions and cortical gray matter atrophy, remains unclear. We investigated the interplay between cortical atrophy and individual lesion-type patterns that have recently emerged as new radiological markers of MS disease progression. We employed a machine learning model to predict mean cortical thinning in whole-brain and single hemispheres in 150 cortical regions using demographic and lesion-related characteristics, evaluated via an ultrahigh field (7 Tesla) MRI. We found that (i) volume and rimless (i.e., without a “rim” of iron-laden immune cells) WM lesions, patient age, and volume of intracortical lesions have the most predictive power; (ii) WM lesions are more important for prediction when their load is small, while cortical lesion load becomes more important as it increases; (iii) WM lesions play a greater role in the progression of atrophy during the latest stages of the disease. Our results highlight the intricacy of MS pathology across the whole brain. In turn, this calls for multivariate statistical analyses and mechanistic modeling techniques to understand the etiopathogenesis of lesions

Interferon beta failure predicted by EMA criteria or isolated MRI activity in multiple sclerosis.

Objective :The objective of this paper is to investigate four-year outcomes of interferon beta (IFNB)-treated patients with multiple sclerosis (MS) according to their clinical or magnetic resonance imaging (MRI) activity status at first year of treatment. METHODS: A total of 370 patients with MS duration ≤5 years before IFNB start were followed-up for four years. The optimal threshold for one-year MRI activity that more accurately predicted subsequent relapses or disability worsening was identified. The risk of relapses and disability worsening after the first year was then estimated by propensity score (PS)-adjusted analyses in patients fulfilling European Medicines Agency (EMA) criteria for second-line escalation and in those with isolated MRI activity. RESULTS: A total of 192 (51.9%) patients relapsed, and 66 (17.8%) worsened in disability from year 1 to 4 of follow-up. The more accurate threshold for one-year MRI activity was the occurrence of ≥1 enhancing or ≥2 new T2-lesions. An increased risk of relapses and disability worsening was found in either patients fulfilling EMA criteria (hazard ratio (HR) = 3.69, and HR = 6.02) and in those experiencing isolated MRI activity (HR = 3.15, and HR = 5.31) at first year of treatment, when compared with stable patients (all p values <0.001). CONCLUSION: The four-year outcomes of patients with isolated MRI activity did not differ from those fulfilling EMA criteria at first year of IFNB treatment

Evidence of diffuse cerebellar neuroinflammation in multiple sclerosis by 11 C-PBR28 MR-PET

Background: Activated microglia, which can be detected in vivo by 11 C-PBR28 positron emission tomography (PET), represent a main component of MS pathology in the brain. Their role in the cerebellum is still unexplored, although cerebellar involvement in MS is frequent and accounts for disability progression. Objectives: We aimed at characterizing cerebellar neuroinflammation in MS patients compared to healthy subjects by combining 11 C-PBR28 MRI-Positron Emission Tomography (MR-PET) with 7 Tesla (T) MRI and assessing its relationship with brain neuroinflammation and clinical outcome measures. Methods: Twenty-eight MS patients and 16 healthy controls underwent 11 C-PBR28 MR-PET to measure microglia activation in normal appearing cerebellum and lesions segmented from 7 T scans. Patients were evaluated using the Expanded Disability Status Scale and Symbol Digit Modalities Test. 11 C-PBR28 binding was assessed in regions of interest using 60–90 minutes standardized uptake values normalized by a pseudo-reference region in the brain normal appearing white matter. Multilinear regression was used to compare tracer uptake in MS and healthy controls and assess correlations with clinical scores. Results: In all cerebellar regions examined, MS patients showed abnormally increased tracer uptake, which correlated with cognitive and neurological disability. Conclusion: Neuroinflammation is widespread in the cerebellum of patients with MS and related to neurological disability and cognitive impairment

Organization and Activity of Italian Echocardiographic Laboratories: A Survey of the Italian Society of Echocardiography and Cardiovascular Imaging

Background: The Italian Society of Echocardiography and Cardiovascular Imaging (SIECVI) conducted a national survey to understand better how different echocardiographic modalities are used and accessed in Italy. Methods: We analyzed echocardiography laboratory activities over a month (November 2022). Data were retrieved via an electronic survey based on a structured questionnaire, uploaded on the SIECVI website. Results: Data were obtained from 228 echocardiographic laboratories: 112 centers (49%) in the northern, 43 centers (19%) in the central, and 73 (32%) in the southern regions. During the month of observation, we collected 101,050 transthoracic echocardiography (TTE) examinations performed in all centers. As concern other modalities there were performed 5497 transesophageal echocardiography (TEE) examinations in 161/228 centers (71%); 4057 stress echocardiography (SE) examinations in 179/228 centers (79%); and examinations with ultrasound contrast agents (UCAs) in 151/228 centers (66%). We did not find significant regional variations between the different modalities. The usage of picture archiving and communication system (PACS) was significantly higher in the northern (84%) versus central (49%) and southern (45%) centers (P &lt; 0.001). Lung ultrasound (LUS) was performed in 154 centers (66%), without difference between cardiology and noncardiology centers. The evaluation of left ventricular (LV) ejection fraction was evaluated mainly using the qualitative method in 223 centers (94%), occasionally with the Simpson method in 193 centers (85%), and with selective use of the three-dimensional (3D) method in only 23 centers (10%). 3D TTE was present in 137 centers (70%), and 3D TEE in all centers where TEE was done (71%). The assessment of LV diastolic function was done routinely in 80% of the centers. Right ventricular function was evaluated using tricuspid annular plane systolic excursion in all centers, using tricuspid valve annular systolic velocity by tissue Doppler imaging in 53% of the centers, and using fractional area change in 33% of the centers. When we divided into cardiology (179, 78%) and noncardiology (49, 22%) centers, we found significant differences in the SE (93% vs. 26%, P &lt; 0.001), TEE (85% vs. 18%), UCA (67% vs. 43%, P &lt; 0001), and STE (87% vs. 20%, P &lt; 0.001). The incidence of LUS evaluation was similar between the cardiology and noncardiology centers (69% vs. 61%, P = NS). Conclusions: This nationwide survey demonstrated that digital infrastructures and advanced echocardiography modalities, such as 3D and STE, are widely available in Italy with a notable diffuse uptake of LUS in the core TTE examination, a suboptimal diffusion of PACS recording, and conservative use of UCA, 3D, and strain. There are significant differences between northern and central-southern regions and echocardiographic laboratories that pertain to the cardiac unit. This inhomogeneous distribution of technology represents one of the main issues that must be solved to standardize the practice of echocardiography