Baseline MRIs Research Articles

PREDICTING TIME TO COGNITIVE IMPAIRMENT USING BRAIN AGE

Abstract The neurological changes that occur during the asymptomatic pre-clinical phase of cognitive impairment (CI) can be quantified using brain age (BA) measures and leveraged to identify those at risk of clinical manifestation. We employ a machine learning survival model to predict future CI among healthy older adults using cognitive, demographic, genetic, and neuroimaging data including regional brain volume and anatomically specific measures of BA. Participants were 2,718 adults from NACC (1,795 females, mean age=69.14±10.91). Converters (N=343) were diagnosed with CI during the study, and non-converters (N=2,375) were CN across all visits. We predicted time to conversion (days) from baseline MRIs (185 brain volumes and regional BA measures) and 69 clinical variables. The model was trained on 1,846 converters and 252 non-converters, validated on 32 converters and 238 non-converters, and tested on 150 converters and 200 non-converters with 5-fold cross-validation. The model’s predictive accuracy (c-index) was 0.82 for training, 0.83 for validation, and 0.78 in the test set. Important features for prediction included age, neurocognitive test scores, education, history of hypertension and stroke, BA, and volumes of the right hippocampus, right precentral gyrus, bilateral white matter, and left inferior temporal gyrus. Products of this model allow us to compare a) the risk, and b) the BA biomarkers across population subgroups with heightened CI risk such as racial minorities and people with fewer years of education. The ability to accurately predict future cognitive impairment (CI) benefits those most in need of therapeutic interventions and reduces the burden of CI on healthcare systems.

Temporal atrophy together with verbal encoding impairment is highly predictive for cognitive decline in typical Alzheimer's dementia - a retrospective follow-up study.

The increasing prevalence of Alzheimer's disease (AD) has created an urgent need for rapid and cost-effective methods to diagnose and monitor people at all stages of the disease. Progressive memory impairment and hippocampal atrophy are key features of the most common so-called typical variant of AD. However, studies evaluating detailed cognitive measures combined with region of interest (ROI)-based imaging markers of progression over the long term in the AD dementia (ADD) stage are rare. We conducted a retrospective longitudinal follow-up study in patients with mild to moderate ADD (aged 60-92 years). They underwent magnetic resonance imaging (MRI; 3 Tesla, MPRAGE) as well as clinical and neuropsychological examination (Consortium to Establish a Registry for Alzheimer's Disease [CERAD] -Plus test battery) at baseline and at least one follow-up visit. ROI-based brain structural analysis of baseline MRIs was performed using the Computational Anatomy Toolbox (CAT) 12. Clinical dementia progression (progression index [PI]) was measured by the annual decline in the Mini Mental State Examination (MMSE) scores. MRI, demographic, and neuropsychological data were included in univariate and multiple linear regression models to predict the PI. 104 ADD patients (age 63 to 90 years, 73% female, mean MMSE score 22.63 ± 3.77, mean follow-up 4.27 ± 2.15 years) and 32 age- and gender-matched cognitively intact controls were included. The pattern of gray matter (GM) atrophy and the cognitive profile were consistent with the amnestic/typical variant of ADD in all patients. Deficits in word list learning together with temporal lobe GM atrophy had the highest predictive value for rapid cognitive decline in the multiple linear regression model, accounting for 25.4% of the PI variance. Our results show that temporal atrophy together with deficits in the encoding of verbal material, rather than in immediate or delayed recall, is highly predictive for rapid cognitive decline in patients with mild to moderate amnestic/typical ADD. These findings point to the relevance of combining detailed cognitive and automated structural imaging analyses to predict clinical progression in patients with ADD.

Effect of arthroscopic partial meniscectomy on structural degeneration of the knee – A 5-year MRI-based follow-up of the placebo-surgery controlled FIDELITY (Finnish Degenerative Meniscus Lesion Study) trial

ObjectiveTo assess the 5-year effects of arthroscopic partial meniscectomy (APM) vs. placebo-surgery on the development of the structural changes of the knee by MRI. DesignThis multicentre, randomized, participant- and outcome-assessor-blinded, placebo-surgery-controlled trial was carried out in Finland. We randomized 146 adults, mean age 52 years (range 35 to 65) to undergo either APM or placebo surgery. The subjects had symptoms of degenerative medial meniscus tear, a tear verified in MRI and arthroscopy, and no advanced osteoarthritis at baseline. We compared the baseline and 5-year follow-up MRIs using MRI Osteoarthritis Knee Score (MOAKS) scoring to derive subregional data on cartilage damage, osteophytes and bone marrow lesions (BMLs). Progression of structural cartilage changes analysed per subregion was the main outcome, that of osteophytes and BMLs secondary outcomes. We analysed the progression with multilevel logistic regression model on subregion level data, adjusted for randomization stratification factors, and using robust standard errors. ResultsSixty-three (90%) subjects in the APM and 73 (96%) in the placebo-surgery group had MRI at both time points. The adjusted odds ratio (APM vs. placebo-surgery) was 1.31 (95% confidence interval 0.81, 1.94) for progression of cartilage damage, 2.86 (1.16, 6.21) for osteophytes, and 1.43 (0.84, 2.43) for BMLs. ConclusionsWe found a slightly greater risk for progression of osteophytes in the APM group compared to the placebo-surgery group at 5 years after surgery. Trial registrationClinicalTrials.gov (NCT01052233 and NCT00549172).

Disability independent of cerebral white matter demyelination in progressive multiple sclerosis

The pathogenic mechanisms contributing to neurological disability in progressive multiple sclerosis (PMS) are poorly understood. Cortical neuronal loss independent of cerebral white matter (WM) demyelination in myelocortical MS (MCMS) and identification of MS patients with widespread cortical atrophy and disability progression independent of relapse activity (PIRA) support pathogenic mechanisms other than cerebral WM demyelination. The three-dimensional distribution and underlying pathology of myelinated T2 lesions were investigated in postmortem MCMS brains. Postmortem brain slices from previously characterized MCMS (10 cases) and typical MS (TMS) cases (12 cases) were co-registered with in situ postmortem T2 hyperintensities and T1 hypointensities. T1 intensity thresholds were used to establish a classifier that differentiates MCMS from TMS. The classifier was validated in 36 uncharacterized postmortem brains and applied to baseline MRIs from 255 living PMS participants enrolled in SPRINT-MS. Myelinated T2 hyperintensities in postmortem MCMS brains have a contiguous periventricular distribution that expands at the occipital poles of the lateral ventricles where a surface-in gradient of myelinated axonal degeneration was observed. The MRI classifier distinguished pathologically confirmed postmortem MCMS and TMS cases with an accuracy of 94%. For SPRINT-MS patients, the MRI classifier identified 78% as TMS, 10% as MCMS, and 12% with a paucity of cerebral T1 and T2 intensities. In SPRINT-MS, expanded disability status scale and brain atrophy measures were similar in MCMS and TMS cohorts. A paucity of cerebral WM demyelination in 22% of living PMS patients raises questions regarding a primary role for cerebral WM demyelination in disability progression in all MS patients and has implications for clinical management of MS patients and clinical trial outcomes in PMS. Periventricular myelinated fiber degeneration provides additional support for surface-in gradients of neurodegeneration in MS.

Binge drinking and progression of white matter hyperintensities of presumed vascular origin in older men

BackgroundInformation on trajectories of diffuse subcortical brain damage of vascular origin associated with binge drinking in older adults is limited. We sought to evaluate the impact of this drinking pattern on the progression of white matter hyperintensities (WMH) of presumed vascular origin in individuals aged ≥60 years taken from the community. MethodsFollowing a longitudinal prospective design, participants of the Atahualpa Project Cohort received interviews to assess patterns of alcohol intake as well as baseline and follow-up brain MRIs. Only men were included because alcohol consumption in women is negligible and tend not to engage in binge drinking in our studied population. Poisson regression models were fitted to assess the incidence rate ratio of WMH progression by patterns of alcohol use (binge drinking or not), after adjusting for demographics, level of education and cardiovascular risk factors. ResultsThe study included 114 men aged ≥60 years (mean age: 65.1±5.4 years). Thirty-seven participants (32%) reported binge drinking for more than 30 years. Follow-up MRIs revealed WMH progression in 45 participants (39%) after a median of 7.2 years. In unadjusted analysis, the risk of WMH progression among individuals with binge drinking was 2.08 (95% C.I.: 1.16–3.73). After adjustment for age, education level and vascular risk factors, participants with this drinking pattern were 2.75 times (95% C.I.: 1.42–5.30) more likely to have WMH progression than those who did not. ConclusionsStudy results show an independent association between binge drinking and WMH progression in community-dwelling older men.

CP-14. VOLUMETRIC ANALYSIS OF PAEDIATRIC CRANIOPHARYNGIOMAS: CLINICAL-RADIOLOGICAL CORRELATION STUDY

Abstract BACKGROUND Craniopharyngioma are heterogeneous hypothalamopituitary tumours with solid and cystic components which have a distinct natural history. Neuroimaging follow-up and the definition of progressive disease is challenging due to unpredictable growth of the inflammatory cystic component. METHODS This multicentre retrospective observational study aimed to describe the clinical-radiological correlation of craniopharyngiomas at two paediatric neurosurgery units (GOSH,UK and USP,Brazil). Craniopharyngiomas treated over a 20-year period were identified and standardized clinical outcomes recorded. Baseline MRIs were reviewed and volumetric T1-weighted images segmented by a board-certified paediatric neuroradiologist. RESULTS Of 123 patients, 92 baseline MRIs were available for image analysis (USP=32; GOSH=60). No differences between series were identified in either demography (mean age: USP=9.2±4.6; GOSH=8.2±4.1 years) or tumour characteristics, with tumours being predominantly cystic (USP=75%; GOSH=76%), localised to the sellar/suprasellar region (USP=84%; GOSH: 88%), and on pre-chiasmatic (USP=34%; GOSH=22%) or retro-chiasmatic (USP=59%; GOSH=67%) locations. Pre-chiasmatic tumours were associated with an increased prevalence of visual symptoms at presentation (p=0.006) and worse recovery of visual acuity at long-term follow-up (p=0.021). Regarding volumetric analysis, mean volumes were 16.6±25.1cm3 for the cystic component and 38.3±10cm3 for the solid component. Volumes of the solid and cystic components had no correlation with each other. Larger cystic tumour volumes were correlated with a greater prevalence of diabetes insipidus at presentation (p=0.06). Larger solid tumours were significantly related to younger ages (p=0.02) and had worse PFS in our series. In terms of long-term outcomes, high volume cystic tumours were related to worse hypothalamic outcomes. In multivariate analysis (n=92), Paris classification did not predict long-term outcomes. CONCLUSIONS Volumetric analysis of craniopharyngiomas showed significant correlation with the onset of diabetes insipidus and hypothalamic long-term outcomes. Larger cystic craniopharyngioma were more common in younger patients. The Paris classification did not predict long-term outcomes in multivariate analysis.

Comparison of intra- and inter-reader agreement of abbreviated versus comprehensive MRCP for pancreatic cyst surveillance.

To retrospectively compare inter- and intra-reader agreement of abbreviated MRCP (aMRCP) with comprehensive MRI (cMRCP) protocol for detection of worrisome features, high-risk stigmata, and concomitant pancreatic cancer in pancreatic cyst surveillance. 151 patients (104 women, mean age: 69[10] years) with baseline and follow-up contrast-enhanced MRIs were included. This comprised 138 patients under cyst surveillance with 5-year follow-up showing no pancreatic ductal adenocarcinoma (PDAC), 6 with pancreatic cystic lesion-derived malignancy, and 7 with concomitant PDAC. The aMRCP protocol used four sequences (axial and coronal Half-Fourier Single-shot Turbo-spin-Echo, axial T1 fat-saturated pre-contrast, and 3D-MRCP), while cMRCP included all standard sequences, including post-contrast. Three blinded abdominal radiologists assessed baseline cyst characteristics, worrisome features, high-risk stigmata, and PDAC signs using both aMRCP and cMRCP, with a 2-week washout period. Intra- and inter-reader agreement were calculated using Fleiss' multi-rater kappa and Intra-class Correlation Coefficient (ICC). 95% confidence intervals (CI) were calculated. Cyst size, growth, and abrupt main pancreatic duct transition had strong intra- and inter-reader agreement. Intra-reader agreement was ICC = 0.93-0.99 for cyst size, ICC = 0.71-1.00 for cyst growth, and kappa = 0.83-1.00 for abrupt duct transition. Inter-reader agreement for cyst size was ICC = 0.86 (aMRCP) and ICC = 0.83 (cMRCP), and for abrupt duct transition was kappa = 0.84 (aMRCP) and kappa = 0.69 (cMRCP). Thickened cyst wall, mural nodule and cyst-duct communication demonstrated varying intra-reader agreements and poor inter-reader agreements. aMRCP showed high intra- and inter-reader agreement for most pancreatic cyst parameters that highly rely on T2-weighted sequences.

Longitudinal Free-Water Changes in Dementia with Lewy Bodies.

Diffusion-weighted magnetic resonance imaging (dMRI) examines tissue microstructure integrity in vivo. Prior dementia with Lewy bodies (DLB) diffusion tensor imaging studies yielded mixed results. We employed free-water (FW) imaging to assess DLB progression and correlate with clinical decline in DLB. Baseline and follow-up MRIs were obtained at 12 and/or 24 months for 27 individuals with DLB or mild cognitive impairment with Lewy bodies (MCI-LB). FW was analyzed using the Mayo Clinic Adult Lifespan Template. Primary outcomes were FW differences between baseline and 12 or 24 months. To compare FW change longitudinally, we included 20 cognitively unimpaired individuals from the Alzheimer's Disease Neuroimaging Initiative. We followed 23 participants to 12 months and 16 participants to 24 months. Both groups had worsening in Montreal Cognitive Assessment (MoCA) and Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) scores. We found significant FW increases at both time points compared to baseline in the insula, amygdala, posterior cingulum, parahippocampal, entorhinal, supramarginal, fusiform, retrosplenial, and Rolandic operculum regions. At 24 months, we found more widespread microstructural changes in regions implicated in visuospatial processing, motor, and cholinergic functions. Between-group analyses (DLB vs. controls) confirmed significant FW changes over 24 months in most of these regions. FW changes were associated with longitudinal worsening of MDS-UPDRS and MoCA scores. FW increased in gray and white matter regions in DLB, likely due to neurodegenerative pathology associated with disease progression. FW change was associated with clinical decline. The findings support dMRI as a promising tool to track disease progression in DLB. © 2024 International Parkinson and Movement Disorder Society.

Abstract TP29: Neurodegenerative Plasma Biomarker Associations With Cognitive Resilience in Adults With High White Matter Hyperintensity Volume: A Post-Hoc Analysis of Systolic Blood Pressure Intervention Trial Memory & Cognition in Decreased Hypertension (SPRINT MIND)

Introduction: Although high cerebral white matter hyperintensity volume (WMHv) is associated with cognitive decline, many adults with high WMHv show no cognitive deficits. Neurodegenerative plasma biomarkers may be associated with cognitive decline via vascular processes causing higher WMHv such as cerebral amyloid angiopathy & inflammatory small vessel disease. We determined associations of plasma amyloid β 42 (AB42), amyloid β 40 (AB40), AB42/AB40, total tau, & neurofilament light chain (NfL) with cognitive resilience (CR) in adults with high WMHv using baseline MRIs & measurements from SPRINT MIND. Methods: This study included baseline data from 186 SPRINT MIND participants who were in the highest WMHv tertile & had available plasma biomarker concentrations & Montreal Cognitive Assessment (MoCA) scores. We defined CR two ways: A) MoCA score >25 or B) MoCA score >22. We determined univariate & adjusted odds ratios (OR) & 90% confidence intervals (CI) for each aforementioned plasma biomarker with CR. Confounders in adjusted models were: age, sex, race-ethnicity (Non-Hispanic white, Non-Hispanic Black, Hispanic, or other) education (no college education, college education, or post-graduate education), smoking history (never smoker, prior smoker, or current smoker) physical activity (0, 1-4, or ≥ 5 days of vigorous physical activity), diabetes, having insurance, & average systolic blood pressure. Residual confounding and effect modification by WMHv were tested in sensitivity analyses. Results: In our sample, the mean age was 72.6 years, 45.7% were female & 66% were Non-Hispanic white. The median WMHv was 10.0 cm 3 (25%-75% range: 6.3 - 16.9 cm 3 ). . CR defined as MoCA scores > 25 & >22 was present in 28.5% & 56.5% of participants respectively. Lower plasma AB40 was marginally associated with CR using a MoCa cutoff of >25 (OR 1.003, 90% CI: 1.001-1.006) in univariate analyses. There were no other significant (P>0.1) univariate or adjusted associations between plasma biomarkers with CR using either MoCa cutoff, nor significant confounding or effect modification by WMHv (P> 0.1). Conclusion: There were no significant adjusted associations between any plasma biomarker with CR. Future work should identify factors associated with CR in adults with high WMHv.

Different inflammatory signatures based on CSF biomarkers relate to preserved or diminished brain structure and cognition

Neuroinflammation is a hallmark of Alzheimer’s disease (AD) and both positive and negative associations of individual inflammation-related markers with brain structure and cognitive function have been described. We aimed to identify inflammatory signatures of CSF immune-related markers that relate to changes of brain structure and cognition across the clinical spectrum ranging from normal aging to AD. A panel of 16 inflammatory markers, Aβ42/40 and p-tau181 were measured in CSF at baseline in the DZNE DELCODE cohort (n = 295); a longitudinal observational study focusing on at-risk stages of AD. Volumetric maps of gray and white matter (GM/WM; n = 261) and white matter hyperintensities (WMHs, n = 249) were derived from baseline MRIs. Cognitive decline (n = 204) and the rate of change in GM volume was measured in subjects with at least 3 visits (n = 175). A principal component analysis on the CSF markers revealed four inflammatory components (PCs). Of these, the first component PC1 (highly loading on sTyro3, sAXL, sTREM2, YKL-40, and C1q) was associated with older age and higher p-tau levels, but with less pathological Aβ when controlling for p-tau. PC2 (highly loading on CRP, IL-18, complement factor F/H and C4) was related to male gender, higher body mass index and greater vascular risk. PC1 levels, adjusted for AD markers, were related to higher GM and WM volumes, less WMHs, better baseline memory, and to slower atrophy rates in AD-related areas and less cognitive decline. In contrast, PC2 related to less GM and WM volumes and worse memory at baseline. Similar inflammatory signatures and associations were identified in the independent F.ACE cohort. Our data suggest that there are beneficial and detrimental signatures of inflammatory CSF biomarkers. While higher levels of TAM receptors (sTyro/sAXL) or sTREM2 might reflect a protective glia response to degeneration related to phagocytic clearance, other markers might rather reflect proinflammatory states that have detrimental impact on brain integrity.

Rates of change of pons and middle cerebellar peduncle diameters are diagnostic of multiple system atrophy of the cerebellar type.

Definitive diagnosis of multiple system atrophy of the cerebellar type (MSA-C) is challenging. We hypothesized that rates of change of pons and middle cerebellar peduncle diameters on MRI would be unique to MSA-C and serve as diagnostic biomarkers. We defined the normative data for anterior-posterior pons and transverse middle cerebellar peduncle diameters on brain MRI in healthy controls, performed diameter-volume correlations and measured intra- and inter-rater reliability. We studied an Exploratory cohort (2002-2014) of 88 MSA-C and 78 other cerebellar ataxia patients, and a Validation cohort (2015-2021) of 49 MSA-C, 13 multiple system atrophy of the parkinsonian type (MSA-P), 99 other cerebellar ataxia patients and 314 non-ataxia patients. We measured anterior-posterior pons and middle cerebellar peduncle diameters on baseline and subsequent MRIs, and correlated results with Brief Ataxia Rating Scale scores. We assessed midbrain:pons and middle cerebellar peduncle:pons ratios over time. The normative anterior-posterior pons diameter was 23.6 ± 1.6 mm, and middle cerebellar peduncle diameter 16.4 ± 1.4 mm. Pons diameter correlated with volume, r = 0.94, P < 0.0001. The anterior-posterior pons and middle cerebellar peduncle measures were smaller at first scan in MSA-C compared to all other ataxias; anterior-posterior pons diameter: Exploratory, 19.3 ± 2.6 mm versus 20.7 ± 2.6 mm, Validation, 19.9 ± 2.1 mm versus 21.1 ± 2.1 mm; middle cerebellar peduncle transverse diameter, Exploratory, 12.0 ± 2.6 mm versus 14.3 ±2.1 mm, Validation, 13.6 ± 2.1 mm versus 15.1 ± 1.8 mm, all P < 0.001. The anterior-posterior pons and middle cerebellar peduncle rates of change were faster in MSA-C than in all other ataxias; anterior-posterior pons diameter rates of change: Exploratory, -0.87 ± 0.04 mm/year versus -0.09 ± 0.02 mm/year, Validation, -0.89 ± 0.48 mm/year versus -0.10 ± 0.21 mm/year; middle cerebellar peduncle transverse diameter rates of change: Exploratory, -0.84 ± 0.05 mm/year versus -0.08 ± 0.02 mm/year, Validation, -0.94 ± 0.64 mm/year versus -0.11 ± 0.27 mm/year, all values P < 0.0001. Anterior-posterior pons and middle cerebellar peduncle diameters were indistinguishable between Possible, Probable and Definite MSA-C. The rate of anterior-posterior pons atrophy was linear, correlating with ataxia severity. Using a lower threshold anterior-posterior pons diameter decrease of -0.4 mm/year to balance sensitivity and specificity, area under the curve analysis discriminating MSA-C from other ataxias was 0.94, yielding sensitivity 0.92 and specificity 0.87. For the middle cerebellar peduncle, with threshold decline -0.5 mm/year, area under the curve was 0.90 yielding sensitivity 0.85 and specificity 0.79. The midbrain:pons ratio increased progressively in MSA-C, whereas the middle cerebellar peduncle:pons ratio was almost unchanged. Anterior-posterior pons and middle cerebellar peduncle diameters were smaller in MSA-C than in MSA-P, P < 0.001. We conclude from this 20-year longitudinal clinical and imaging study that anterior-posterior pons and middle cerebellar peduncle diameters are phenotypic imaging biomarkers of MSA-C. In the correct clinical context, an anterior-posterior pons and transverse middle cerebellar peduncle diameter decline of ∼0.8 mm/year is sufficient for and diagnostic of MSA-C.

Cerebral microbleeds and asundexian in non-cardioembolic ischemic stroke: Secondary analyses of the PACIFIC-STROKE randomized trial.

Cerebral microbleeds are magnetic imaging resonance (MRI) markers of hemorrhage-prone cerebral small vessel disease that predict future risk of ischemic stroke and intracranial hemorrhage (ICrH). There exist concerns about the net benefit of antithrombotic therapy in patients with microbleeds. We aimed to investigate the effects of an oral factor-XIa inhibitor (asundexian), that is hypothesized to inhibit thrombosis without compromising hemostasis, on the development of new microbleeds over time and interactions between microbleeds and asundexian treatment on clinical outcomes. We additionally assessed associations between baseline microbleeds and the risks of clinical and neuroimaging outcomes in patients with non-cardioembolic ischemic stroke. This is a secondary analysis of the PACIFIC-STROKE, international, multi-center Phase 2b double-blind, randomized clinical trial. PACIFIC-STROKE enrolled patients aged ⩾ 45 years with mild-to-moderate non-cardioembolic ischemic stroke who presented within 48 h of symptom onset for whom antiplatelet therapy was intended. Microbleeds were centrally adjudicated, and participants with an interpretable T2*-weighted sequence at their baseline MRI were included in this analysis. Patients were randomized to asundexian (10/20/50 mg daily) versus placebo plus standard antiplatelet treatment. Regression models were used to estimate the effects of (1) all pooled asundexian doses and (2) asundexian 50 mg daily on new microbleed formation on 26-week MRIs. Cox proportional hazards or regression models were additionally used to estimate interactions between treatment assignment and microbleeds for ischemic stroke/transient ischemic attack (TIA) (primary outcome), and ICrH, all-cause mortality, hemorrhagic transformation (HT), and new microbleeds (secondary outcomes). Of 1746 participants (mean age, 67.0 ± 10.0; 34% female) with baseline MRIs, 604 (35%) had microbleeds. During a median follow-up of 10.6 months, 7.0% (n = 122) had ischemic stroke/TIA, 0.5% (n = 8) ICrH, and 2.1% (n = 37) died. New microbleeds developed in 10.3% (n = 155) of participants with adequate follow-up MRIs and HT in 31.4% (n = 345). In the total sample of patients with adequate baseline and 26-week follow-up MRIs (n = 1507), new microbleeds occurred in 10.2% of patients assigned to any asundexian dose and 10.5% of patients assigned to placebo (OR, 0.96; 95% CI, 0.66-1.41). There were no interactions between microbleeds and treatment assignment for any of the outcomes (p for interaction > 0.05). The rates of new microbleeds, HT, and ICrH were numerically less in patients with microbleeds assigned to asundexian relative to placebo. The presence of microbleeds was associated with a higher risk of HT (aOR, 1.6; 95% CI, 1.2-2.1) and new microbleeds (aOR, 4.4; 95% CI, 3.0-6.3). Factor XIa inhibition with asundexian appears safe in patients with non-cardioembolic ischemic stroke and hemorrhage-prone cerebral small vessel disease marked by microbleeds on MRI. These preliminary findings will be confirmed in the ongoing OCEANIC-STROKE randomized trial. ClinicalTrials.gov Identifier: NCT04304508.

Prevalence of Cerebral Microhemorrhages and Cortical Superficial Siderosis in APOE4/4 Homozygotes with Early Alzheimer’s disease: Baseline Findings from Phase 3 Trial of Oral ALZ‐801 in APOE4/4 Homozygotes (APOLLOE4)

AbstractBackgroundPlaque clearing amyloid antibodies show an increased risk of amyloid‐related imaging abnormalities with edema or hemorrhages (ARIA‐E or ARIA‐H). ARIA risk increases with number of APOE4 alleles, with APOE4/4 homozygotes showing the highest risk related to high burden of Aβ plaque in microvessels (cerebral amyloid angiopathy, CAA). To decrease the risk of ARIA, amyloid antibody trials exclude subjects with CAA‐related lesions such as &gt;4 microhemorrhages (MH) or superficial siderosis. ALZ‐801 (valiltramiprosate), an oral drug that inhibits formation of neurotoxic Aβ oligomers, shows promising efficacy in APOE4 carriers with no observed ARIA‐E (Abushakra 2017, 2022). Two ALZ‐801 trials are currently ongoing in APOE4 carriers with Early AD. A Phase 2 study enrolled APOE4 carriers, and a Phase 3 trial enrolled APOE4/4 patients. Both studies allow &gt;10 MH and/or some siderosis lesions at baseline.MethodThe fully‐enrolled Phase 3 trial (APOLLOE4) included 325 homozygotes with Early AD (MMSE ≥22). We evaluated prevalence of microhemorrhages (MH), macrohemorrhages and superificial siderosis (CAA lesions). Baseline MRIs acquired from 1.5T/3T scanners were centrally evaluated by Clario, and the number/location of these CAA lesions is reported.ResultSubjects had mean age 69 years, 51% female, MMSE 26, 82% white, 65% with MCI. Of 325 subjects, 313 had baseline MRIs that showed &gt; 1 MH in 32%, including 9% with &gt; 4 MH. A total of 9% had ≥ 1 superficial siderosis, and 2 subjects had macrohemorrahages. Occipital and frontal lobes were most common locations of CAA lesions. Most subjects had white matter disease (Fazekas = 1).ConclusionAPOE4/4 homozygotes show high prevalence of CAA lesions with 32% and 9% having lobar microhemorrhages and superificial siderosis respectively. This high burden of CAA lesions most likely underlies the high incidence of ARIA in APOE4/4 patients treated with the approved amyloid antibodies (30%‐60%). ARIA‐E is also reported in APOE4/4 patients treated with placebo in lecanemab &amp; gantenerumab trials (4%‐6%). This background ARIA likely reflects spontaneous CAA‐related inflammation commonly reported in APOE4 carriers (CAA‐RI, Regendhardt 2020). Oral ALZ‐801 in the ongoing studies has not shown increased ARIA risk, and has safety advantage over amyloid antibodies especially for APOE4/4 homozygous patients.

A deep learning-based comparative MRI model to detect inflammatory changes in rheumatoid arthritis

Rheumatoid Arthritis (RA) is an autoimmune disease that mainly affects joints in the wrist and hands. It typically results in inflamed and painful joints. MRI is one of the most common imaging modalities to detect and monitor possible inflamed RA-related areas, enabling rheumatologists to treat patients more timely and efficiently. Despite the importance of finding and tracking inflamed areas associated with RA in MRI, there is no previously published work on finding pixel-by-pixel changes related to RA between baseline and follow-up MRIs. Therefore, this paper proposes a hypothesis-free deep learning-based model to discover changes in wrist MRIs on a pixel level to detect changes in inflamed areas related to RA without using prior anatomical information. To do this, a combination of a U-Net-based network and image thresholding was utilised to find pixel-level non-trivial changes between baseline and follow-up MRI images. A wrist MRI dataset including 99 individual pairs of MRI images (each pair constructed of baseline and follow-up images) was used to evaluate the proposed model. Data were collected from patients with clinically suspected arthralgia (CSA), defined as patients at risk of developing RA according to their rheumatologist and already had subclinical inflammation on MRI but could not be diagnosed with RA (yet) since they had not developed clinically detectable arthritis. The obtained results were evaluated using an observer study. The evaluation showed that our proposed model is a promising first step toward developing an automatic model to find RA-related inflammatory changes.

Predicting Neurocognitive Decline in Multiple Brain Metastases Patients Undergoing Distributed Stereotactic Radiosurgery

Stereotactic radiosurgery (SRS) is the standard of care for treating a limited number (<3) of brain metastasis (BMs), which offers reduced neurotoxicity compared to whole brain radiotherapy (WBRT). Contemporary advancements in SRS made it possible to also commonly treat multiple (>4) BMs (mBMs). Emphasizing the value of preserving quality of life (QoL) after SRS, there is an urgent need for a systematic study of potential neurocognitive decline in patients receiving SRS treatment for mBMs. The purpose of this study is to use routine MRIs to predict neurocognitive decline for patients treated with distributed SRS, allowing for timely and effective treatment strategy design. This study uses data from an institutional phase I/II clinical trial to determine the neurocognitive decline in patients with (>6) mBMs treated with distributed SRS. In the first 12 months post-SRS, participants are followed and evaluated with routine MRIs and the Hopkins Verbal Learning Test-Revised (HVLT-R) at 2 to 3-month intervals. Changes in HVLT-Delayed Recall scores between two visits are used to define neurocognitive decline. For each visit, an in-house deep learning model segments 66 cortical and 55 subcortical brain regions of interest (ROIs) from the T1 structural MRI and extracts 253 ROI features, including the surface area and thickness of cortical ROIs, and the volume of all ROIS. The difference in ROI features between two visits, together with other clinical factors (e.g., prescription, number of BMs, etc.), is considered as one sample. The study included 22 subjects with 91 visits, resulting in 171 samples with neurocognitive decline labels. The entire sample set is split into 10 folds on patient level for cross validation. In each fold, feature engineering is conducted to remove redundancy and to select the most-important features. The top 20% most frequently selected features are applied with Support Vector Machine to predict the neurocognitive decline label of each sample. As a preliminary result, the proposed method achieves an accuracy of 76%, with an area under the curve (AUC) of 0.75, sensitivity of 0.65 and specificity of 0.83 for predicting neurocognitive decline in mBMs SRS patients using only routine T1 MRIs. The volume of lateral occipital complex, the thickness of inferior parietal lobe and postcentral gyrus, and the surface area of lateral orbitofrontal cortex and pars triangularis are identified as the 5 most important features for this task. Our method shows promising findings for post-SRS neurocognitive decline prediction solely based on routine baseline and follow-up MRIs. In addition, it can identify critical brain ROIs associated with the post-SRS cognitive function. This method has the potential to assist treatment planning strategy to help preserve patients' QoL.

Longitudinal assessment of hepatocellular carcinoma response to stereotactic body radiation using gadoxetate-enhanced MRI: A case series

PurposeTo describe the longitudinal response in patients with hepatocellular carcinoma (HCC) treated with stereotactic body radiation therapy (SBRT) and who underwent liver transplant (LT) using gadoxetate-enhanced MRI. MethodsFive men (median age 61y, range 57–64y) with 6 HCCs treated with SBRT (median dose 50 Gy) who subsequently underwent LT were included in this retrospective study. Patients underwent gadoxetate-enhanced MRI before and after SBRT over a period of 3–18 months. Response was assessed using RECIST1.1, mRECIST, LI-RADS and image subtraction, by 2 observers in consensus. Percentage of pathologic tumor necrosis was evaluated. ResultsLT was performed 278 days (IQR, 148–418d) after completion of SBRT and 48d after the last MRI. Histopathology demonstrated tumor necrosis of 48 ± 42% (range, 10–100%). Mean tumor size at baseline and last post-treatment MRIs pre-LT were 2.6 ± 0.8 cm and 2.4 ± 0.9 cm. Enhancing tumor component size at baseline MRI and last post-treatment MRI pre-LT were 1.6 ± 0.8 cm and 0.9 ± 1.0 cm. Responses assessed at the last LRI pre-LT were: partial response (PR, n = 3), stable disease (SD, n = 3) using RECIST1.1; complete response (CR, n = 2), partial response (PR, n = 2), stable disease (SD, n = 2) using mRECIST; and LR-TR viable (n = 4), LR-TR non-viable (n = 2) using LI-RADS. At the last MRI pre-LT, per-lesion features of arterial phase hyperenhancement (APHE, 4/6), portal venous washout (3/6) and capsule (3/6) were observed. 5/6 lesions displayed a hypointense perilesional halo on hepatobiliary phase with a mean delay of 3.1 months post-SBRT. ConclusionsThis case-series showed decreased size, persistent APHE, and incomplete pathologic necrosis in most HCCs treated with SBRT undergoing transplant.

MRI in rectal cancer patients on 'watch and wait': patterns of response and their evolution.

Evaluate MR patterns of response and their evolution in rectal cancer patients on watch and wait (WW). We retrospectively reviewed 337 MRIs of 60 patients (median follow-up: 12 months; range: 6-49 months). Baseline MRIs (available in 34/60 patients) were evaluated for tumor morphology, location, thickness, circumferential involvement, nodal status and EMVI. First post-treatment MRIs (in all patients) were additionally evaluated for pattern of response on T2 and DWI. Change in post-treatment scar thickness and scar depth angle between the first and second post-treatment scans was also evaluated. Evolution of the response pattern/recurrence were evaluated till the last available scan. On the baseline scans, 20/34 (59%) patients had polypoidal tumor with 12/20 having ≤ 25% circumferential wall involvement. We saw five patterns of response-normalized rectal wall (2/60-3%), minimal fibrosis (23/60-38%), full thickness fibrosis (16/60-27%), irregular fibrosis (11/60-18%) and split scar (6/60-10%), with 2/60 (3%) showing possible residual disease. On the first post-treatment scans, 12/60 (20%) had restricted diffusion, with 3/12 having persistent restriction till last follow-up. Post-treatment fibrosis/split scar remained stable in 44/60 (73%) cases and improved further in the rest. 9/60 (15%) patients developed regrowth/recurrence. Patients with recurrence had < 10 mm scar thickness and < 21° change in scar angle between the first and second post-treatment MRIs. Most patients on WW protocol developed minimal or full thickness fibrosis, majority of which remained stable on follow-up.

Predicting response to chemoradiotherapy in rectal cancer via visual morphologicassessmentand staging on baseline MRI: a multicenter and multireader study.

Pre-treatment knowledge of the anticipated response of rectal tumors to neoadjuvant chemoradiotherapy (CRT) could help to further optimize the treatment. Van Griethuysen et al. proposed a visual 5-point confidence score to predict the likelihood of response on baseline MRI. Aim wasto evaluatethis scorein a multicenter and multireader study setting and compare it to two simplified (4-point and 2-point) adaptations in terms of diagnostic performance, interobserver agreement (IOA), and reader preference. Twenty-two radiologists from 14 countries (5 MRI-experts,17 general/abdominal radiologists) retrospectively reviewed 90 baseline MRIs to estimate if patients would likely achieve a (near-)complete response (nCR); first using the 5-point score by van Griethuysen (1=highly unlikely to 5=highly likely to achieve nCR), second using a 4-point adaptation (with 1-point each for high-risk T-stage, obvious mesorectal fascia invasion, nodal involvement, and extramural vascular invasion), and third using a 2-point score (unlikely/likely to achieve nCR). Diagnostic performance was calculated using ROC curves and IOA using Krippendorf's alpha (α). Areas under the ROC curve to predict the likelihood of a nCR were similar for the three methods (0.71-0.74). IOA was higher for the 5- and 4-point scores (α=0.55 and 0.57 versus 0.46 for the 2-point score) with best results for the MRI-experts (α=0.64-0.65). Most readers (55%) favored the 4-point score. Visual morphologic assessment and stagingmethods can predictneoadjuvant treatment response with moderate-good performance. Compared to a previously published confidence-based scoring system, study readers preferred a simplified 4-point risk score based on high-risk T-stage, MRF involvement, nodal involvement, and EMVI.

Evaluating novel imaging-based mathematical modeling prediction of immunotherapy response by individual melanoma brain metastasis and patient prognosis.

e14013 Background: Ipilimumab/Nivolumab (Ipi/Nivo) significantly transformed outcomes for patients with melanoma brain metastases (MBM), however inter- and intra-patient responses can vary widely. The purpose of this study is to develop and calibrate an imaging-based mathematical model to predict lesion-specific immune response to Ipi/Nivo in patients with MBM to guide early local treatments such as radiotherapy and evaluate the prognostic value of identifying treatment resistant lesions. Methods: Baseline and follow-up 3D T1-W contrast MRIs of patients who solely received Ipi/Nivo after diagnosis with MBM were used to segment individual brain metastases and track serial volumetric data for each lesion to develop a mechanistic model (eq 1). After applying appropriate assumptions to our model, tumor burden ( ρ), intrinsic lesion growth rate ( α 0), Ipi/Nivo-induced kill rate ( μ) and immune response strength ( Λ) were quantified for each lesion. Growth rate shortly after the start of treatment ( α 1 ) was calculated using the short-term model solution (eq 2). dρ/dt= (α0- μ+μ.Λ).ρ - μ.Λ.ρ2 (eq 1) ρ(t)≈eα1.t (eq 2) Change in BM volume between baseline and last follow-up was used to classify each lesion as either ‘responder’ or ‘non-responder’; these were compared with the Wilcoxon-rank-sum test. The highest α1 value for any one BM within a patient tumor was evaluated for its potential to sort patient overall survival (OS). Because the median survival was not reached for this cohort, we determined the α1 threshold of 0.005 to sort patients using an optimization routine that generates the maximum AUC to separate the cohort into 2 groups on an ROC curve. Kaplan-Meier (KM) curves were compared between these 2 groups. Results: In 23 patients, we evaluated 61 lesions. At the lesion level, model parameters representing μ and Λ were significantly different between responder and non-responder lesions (p-values &lt;0.0001 and 0.0004, respectively). The highest α1value for any one BM within a patient tumor was used to sort patient overall survival (OS) into prognostically ‘favorable’ or ‘unfavorable’ groups based on patient survival to ±1,200 days. In this limited cohort, OS KM curves by most aggressive lesion for favorable (α1 &lt; 0.005) vs. unfavorable (α1 &gt; 0.005) were not significant by log-rank test (p = 0.3263). Conclusions: In this limited cohort, we demonstrate feasibility to leverage serial conventional imaging and tumor volumetric data to calibrate a mechanistic model to predict per-lesion treatment response of MBM to Ipi/Nivo. Although the p-value between groups was found to be insignificant when predicting survival using α1, this is likely because of the small number of patients included in this study (n=23). Furthermore, when taken together with the notable AUC (=0.7917) observed in the ROC curve, this promising result supports further investigation in a larger cohort.

Prevalence of Amyloid-Related Imaging Abnormalities in APOE4/4 Homozygotes with Early Alzheimer’s Disease: Baseline Findings from Ongoing Clinical Trials of Oral Anti-Amyloid Agent ALZ-801 (Valiltramiprosate) (P5-6.003)

Prevalence of Amyloid-Related Imaging Abnormalities in APOE4/4 Homozygotes with Early Alzheimer’s Disease: Baseline Findings from Ongoing Clinical Trials of Oral Anti-Amyloid Agent ALZ-801 (Valiltramiprosate) (P5-6.003)