Baseline MRI Research Articles

DDDR-24. REAL WORLD EXPERIENCE USING THE IDH INHIBITOR IVOSIDENIB IN IDH MUTANT GLIOMA: TOLERABILITY AND OUTCOMES

Abstract BACKGROUND Mutant isocitrate dehydrogenase (IDHm) inhibitors represent a novel therapeutic strategy for treating IDHm glioma, though their optimal use outside of clinical trials remains undefined. This study describes real world utilization of the IDH1 inhibitor, ivosidenib, in patients with IDHm glioma. METHODS We retrospectively reviewed clinical and radiographic data from IDHm glioma patients treated with ivosidenib monotherapy at Dana-Farber Cancer Institute and Massachusetts General Hospital from 2020-2024. Patients with a baseline MRI at ivosidenib initiation and at least 2 subsequent scans while on ivosidenib were included in radiographic response analysis (452 scans). RESULTS This cohort included 77 patients (39 males) age 17-75 years (median 41). Thirty-eight patients (49%) had astrocytomas and 39 (51%) had oligodendrogliomas; 48 (62%) had grade 2, 26 (34%) grade 3, and 3 (4%) grade 4 gliomas. Twenty-four patients (31%) received ivosidenib as first-line therapy and 53 (69%) received ivosidenib after failing prior treatments. Among those in the radiographic analysis, 4 (6%) demonstrated partial response, 4 (6%) minor response, 44 (62%) stable disease, and 19 (27%) progressive disease (PD). Significantly higher PD rates were seen in those with enhancing disease (p<0.001) or received ivosidenib as subsequent-line therapy (p=0.002); PD rate was similar between grades 2 and 3 in the first-line group (p=0.64). One-year progression free survival was 100% in the first-line group and 66% in the subsequent-line group. At the time of our analyses, 4 patients (5%) had died (all in the subsequent-line group). Infrequent side effects included CK elevation, QTc prolongation, transaminitis, and diarrhea. One patient (1%) was dose reduced and 3 (4%) discontinued drug due to side effects. CONCLUSIONS In this real world IDHm glioma cohort, ivosidenib was well-tolerated. Better response rates were seen in patients without enhancing disease at ivosidenib initiation and those who received the drug as first-line therapy.

NIMG-29. EARLY REDUCTION IN MRI DIFFUSION APPARENT DIFFUSION COEFFICIENT (ADC) STRONGLY PREDICTS LONG TERM RESPONSE TO ONC201 THERAPY IN PATIENTS WITH H3K27M-DMG

Abstract ONC201 is the first monotherapy to improve outcomes in H3K27M- diffuse midline glioma (DMG) beyond radiation. Despite impressive early efficacy in H3K27M-DMG, individual response to ONC201 is variable and no radiographic biomarkers predict long term response. Previous studies demonstrated baseline MRI diffusion apparent diffusion coefficient (ADC) is lower in DMG with H3K27M compared to wildtype but change after radiation therapy was not correlated with improved OS or PFS. We hypothesize ADC will enable stratification of patients more likely to respond to ONC201. Imaging and clinical data were abstracted from chart review of patients treated with ONC201 at University of Michigan. Two neuroradiologists performed centralized review for RAPNO measurements and mean ADC was assessed using ROI measured in consistent anatomic locations, with areas of cystic degeneration or necrosis excluded. Sixty-one patients were identified for review. Preliminary analysis was performed on twenty-three patients, with upfront ONC201 therapy, median age 14.8 years old (5-25yo), primary site includes pontine (n=15), thalamic (n=7). Baseline characteristics of age, ADC and size at diagnosis or follow-up RAPNO scored size were not statistically significant. Patients with longer than median survival (334 days) demonstrated increased ADC (+58.25x10-6mm2/s) from baseline to cycle 2 whereas patients with shorter than median survival demonstrated decreased ADC (-174.8x10-6mm2/s) (p = 0.0076). Further, patients with decreased ADC demonstrated mean OS of 302.8 days and patients with increased ADC had mean OS of 588.0 (p = 0.0054). In H3K27M-DMG patients treated with ONC201, increased ADC after two cycles of ONC201 was strongly predictive of longer overall survival. Our recent work demonstrated that ONC201 disrupts metabolic and epigenetic pathways to restore pathognomonic H3K27me3 reduction, which may underline greater change in ADC. Ongoing work will validate these findings in an independent external cohort and integrate histogram analysis, parametric assessments, MRI perfusion and liquid biopsy biomarkers (cf-tDNA and metabolomics).

Association of renal biomarkers with fast progressor phenotype and related outcomes in anterior circulation large vessel occlusion stroke

BackgroundRenal dysfunction is a known predictor of long-term functional dependency after anterior circulation large vessel occlusion (ACLVO) stroke. However, the impact of renal dysfunction on early infarct growth rate (IGR) has not been previously demonstrated. The objective of this study was to define the association of creatinine-based renal biomarkers with fast or slow progressor phenotypes and related clinical outcomes in ACLVO stroke.MethodsThis retrospective study examined patients with acute intracranial internal carotid artery or middle cerebral artery-M1 occlusions admitted between 2014 and 2019. Patients were included if they received baseline CT perfusion (CTP) or MRI on presentation within 24 h of estimated stroke onset. Infarct growth rate (IGR) was determined by ischemic core volume on CTP or MRI divided by time from stroke onset to imaging. IGR was used to stratify fast progressor (IGR ≥10 mL/h) and slow progressor (IGR < 10 mL/h) status. Renal dysfunction was assessed based on serum creatinine and estimated glomerular filtration rate (eGFR) on presenting laboratories. Logistic regression models, adjusted for significant covariates, identified independent associations between renal dysfunction biomarkers, progressor status, and clinical outcomes based on modified Rankin Scale (mRS) at 90 days.ResultsAmong 230 patients with ACLVO, 29% were fast progressors, with median serum creatinine levels higher than slow progressors (1.1 vs. 0.9 mg/dL, p < 0.05) and lower median eGFR (66.2 vs. 69.0 mL/min/1.73m2, p < 0.05). Elevated creatinine (≥1.2 mg/dL) was independently associated with fast progressor status (adjusted OR 2.37, 95% CI 1.18–4.77), worse 90-day mRS (adjusted OR 1.88, 95% CI 1.01–3.51) and mortality (adjusted OR 2.57, 95% CI 1.14–5.79). Reduced eGFR (<60 mL/min/1.73m2) was independently associated with fast progressor status (adjusted OR 2.38, 95% CI 1.14–4.94), but not with 90-day mRS or mortality.ConclusionSerum creatinine-based biomarkers of renal dysfunction were associated with fast progressor phenotype of ACLVO stroke, and worse clinical outcomes, which may help identify such patients earlier during emergency evaluation for expedited access to EVT. Future prospective studies are warranted to confirm and test implementation of these findings.

Mechanisms affecting the neutrophil to lymphocyte ratio in heart failure: a prospective CMR study

Abstract Background The neutrophil-to-lymphocyte ratio (NLR) is a simple measure of inflammation defined as the ratio of the neutrophils to lymphocytes as measured in the full blood count. It is well known that patients with heart failure (HF) have elevated levels of pro-inflammatory cytokines. It has been demonstrated in a recent meta-analysis that elevated NLR in heart failure is significantly associated with worse outcomes including all-cause mortality, heart failure readmissions and cardiovascular death. Purpose Given this association between NLR and adverse prognosis in HF, we aim to identify which factors are associated with an elevated NLR. This may help to recognise patients at higher risk and guide management. Methods Patients with newly diagnosed HF and left ventricular ejection fraction <50% on referral echocardiogram were prospectively recruited at the time of referral for cardiovascular magnetic resonance (CMR). Exclusion criteria included prior revascularisation, myocardial infarction, anginal chest pain, congenital heart disease and suspected myocarditis. In one appointment patients (N=599) underwent clinical assessment, medication review, full blood count and CMR. The CMR protocol included quantitative assessment myocardial blood flow at stress and rest, assessment of ischaemic and non-ischaemic fibrosis by late gadolinium enhancement imaging and T1 and T2 mapping. Guideline directed medical therapy was determined by the referring physician. Baseline demographic data, medication and MRI results were recorded for all patients. NLR was calculated from full blood count and split into tertiles. Clinical and CMR parameters were compared between tertiles by analysis of variance and chi squared test. Results See Table 1 The factors which were found to be significantly associated with an elevated NLR were age, atrial fibrillation, NTproBNP, diuretic dose, inducible ischaemia and ischaemic fibrosis. Of note there was no significant difference between groups in terms of guideline directed medical therapy use or other CMR parameters. Conclusion NLR is increasingly recognised as a marker of adverse risk in patients with heart failure. This prospective study of 599 heart failure patients with reduced ejection fraction has identified that an elevated NLR is associated with: 1. Evidence of congestion as evidenced by NTproBNP results and increased diuretic doses. 2. Occult coronary artery disease as shown by greater levels of inducible ischaemia and ischaemic fibrosis. These findings suggest that the adverse prognosis associated with elevated NLR in heart failure may be mediated by worsening congestion and occult coronary artery disease. Importantly there was no association between myocardial inflammation or oedema (measured as native T1 and T2) and NLR. Whether NLR improves with medical therapy of heart failure remains to be established and our findings need to be validated in more varied cohorts of patients with heart failure.

Inhibition of fractalkine signalling in patients with acute myocardial infarction - First results from the FRACTAL trial

Abstract Background We have previously demonstrated a strong association between expression of the fractalkine receptor CX3CR1 on lymphocytes and microvascular obstruction (MVO) in patients undergoing primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction. Our pre-clinical studies also found an improvement in infarct size, inflammation and intramyocardial haemorrhage (IMH) when rats were pre-treated with the fractalkine inhibitor KAND567. Purpose FRACTAL (FRACTalkine inhibition in Acute myocardial infarction) study was a phase IIa, pilot, randomized, 2-arm parallel group, placebo-controlled, double blinded, multi-centre trial. Its primary aim was to assess the safety and tolerability of intravenous and oral administration of the fractalkine inhibitor KAND567 as well as reducing signs of reperfusion injury in STEMI patients undergoing PPCI. Methods Patients with a new diagnosis of anterior STEMI, who had index chest pain within 5 hours and angiographic occlusion of the LAD, were randomised on a 1:1 basis to receive either KAND567 or placebo over a period of 72 hours. All patients then underwent a baseline MRI scan at 3 days with a follow-up scan at 3 months, paralleled by longitudinal deep immuno­phenotyping over 9 time points. Results A total of 71 patients were enrolled into the study with 64 (90.1%) being male patients. The mean age of patients was 59.2 years. 37 patients received KAND567, whilst 34 received placebo over 72-hour period. Throughout the 3-month follow-up period, 23 (62%) patients from the KAND567 arm as compared to 24 (71%) patients in the placebo arm had reported adverse events. There was no statistical difference in serious adverse events (SAEs) between both arms with 9 documented in the placebo arm and 12 in the KAND567 arm. Safety bloods also demonstrated no significant differences between the two groups across all time points. There was a higher incidence of left ventricular (LV) thrombus in the placebo arm as compared to the KAND567 arm (17.6% vs. 2.7%; p=0.049). Additionally, the study also demonstrated a lower occurrence of IMH in the KAND567 arm compared to the placebo arm (35.5% vs. 55.2%; p=0.19). Deep immunephenotyping suggested clear target engagement in the KAND567 arm in natural killer cells as well as in cytotoxic T-lymphocytes. Conclusion This first in-man study demonstrates that inhibition of the fractalkine pathway in STEMI patients appears safe and well-tolerated, while demonstrating a promising potential in preventing LV thrombus and IMH. The results suggest a new mechanism and class of drug to target reperfusion injury, clearly warranting a larger phase III study.LV thrombus and IMH

Fractalkine Inhibition in Acute Myocardial Infarction leads to reduced intramyocardial haemorrhage

Abstract Background The fractalkine receptor CX3CR1 has been linked to the development of microvascular obstruction (MVO) in ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI). Pre-clinical studies have demonstrated a reduction in infarct size, inflammation and intramyocardial haemorrhage (IMH) with inhibition of CX3CR1. Purpose The FRACTAL study is a phase IIa, pilot, randomized, 2-arm parallel group, placebo-controlled, double blinded, multi-centre trial. In addition to assessing the safety and tolerability of the fractalkine inhibitor KAND567 in STEMI patients, a subgroup exploratory analysis was performed. We investigated into the translation of MRI and blood samples characteristics between the two groups. Methods Patients with an anterior STEMI who had an occluded proximal to mid left anterior descending (LAD) artery were recruited. These patients had to present within 5 hours of the onset of their chest pain. They were subsequently randomised on a 1:1 basis to receive either KAND567 or placebo. Patients then underwent an MRI at day 3, and subsequently a comparator at 3 months. Additionally, throughout the period of their follow-up, patients would regularly undergo blood sampling to assess multiple parameters. Results Of the 71 patients recruited into the study, 29 patients in the KAND567 arm and 28 patients in the placebo arm received both MRIs. The KAND567 arm had shown a similar troponin rise at day 1 compared to placebo (4357 vs 4286). Baseline MRI demonstrated an identical infarct size between both arms. The presence and absence of IMH was then analysed defining IMH+ as presence of IMH and IMH- as IMH absence. The presence of IMH in patients showed a larger infarct size. The infarct size of IMH+ were the same between KAND567 and placebo, which was a similar finding in the IMH- arm too. However, when compared to day 90 MRI demonstrated a numerically smaller infarct size in the KAND567 group with a smaller percentage of IMH. This was consistent with a lower rate of IMH in the KAND567 arm too, when compared between the groups (35.5% vs 55.2%; p=0.15) (see table below). This seemed to be related to the smaller distribution IMH+, as the IMH+ infarcts were much larger in both arms, whilst overall infarct size in IMH subgroup were identical. Conclusion KAND567 appears to prevent the transition from IMH- to IMH+, while it doesn’t change infarct size in the respective subgroups of IMH+ or IMH-.MRI Comparator Table

Frequency and outcomes of new or suspicious MRI findings on breast MRI for patients on neoadjuvant therapy.

To assess the frequency and outcomes of indeterminate enhancing findings on breast MRI unrelated to the index primary tumor(s) in patients on neoadjuvant therapy (NAT). This retrospective review identified all diagnostic breast MRIs performed to evaluate response to NAT at our institution between 2017 and 2020. All exams with indeterminate enhancing findings (BI-RADS 3-5) unrelated to the index tumor(s) for which follow-up imaging or tissue diagnosis was recommended were included. Cases lacking a pre-treatment MRI or those with insufficient follow-up were excluded. Imaging of all post-NAT breast MRIs were re-reviewed. The electronic medical record was reviewed to evaluate patient and lesion characteristics and outcomes. Between 2017 and 2020, 614/4042 (15.2%) breast MRIs were performed to evaluate response to NAT. After exclusions, 38 of these exams (6.2%) identified 42 indeterminate enhancing findings unrelated to the index tumor for which follow-up imaging (15 exams) or tissue diagnosis (23 exams) was recommended. Fifteen of 42 (35.7%) of the findings were new compared to the pre-treatment baseline MRI, 8/42 (19.0%) increased and 19/42 (45.2%) were present on pre-treatment MRI. Most findings were contralateral to the index tumor (28, 66.7%). Findings were masses (17, 40.4%), focus (15, 35.7%), and non-mass enhancement (10, 23.8%). Of the 42 findings, 19 (45.2%) underwent percutaneous biopsy, 10 (23.8%) underwent surgical biopsy or mastectomy, and 13 (31%) were followed by imaging. Thirty-seven were benign, 4 were high-risk lesions without upgrade (atypical ductal hyperplasia, atypical lobular hyperplasia, and papillomatosis with atypical ductal hyperplasia), and one (2.4%) was malignant (invasive lobular carcinoma), which was non-mass enhancement present on the pre-treatment MRI. Indeterminate enhancing lesions unrelated to the index tumor(s) on breast MRIs performed to assess response to neoadjuvant chemotherapy are uncommon. When present, these lesions have an extremely low likelihood of malignancy, especially when new compared to the pre-treatment MRI. Because incidental indeterminate enhancing lesions on breast MRI at post-NAT follow-up are rarely malignant, radiologists should be judicious in recommending follow-up or tissue diagnosis for such lesions after NAT.

Dimensional assessment on baseline MRI of soft-tissue sarcomas: longest diameter, sum and product of diameters, and volume-which is the best measurement method to predict patients' outcomes?

The longest diameter (LD) is a strong prognostic factor for patients with soft-tissue sarcoma (STS). Other dimensional assessments, such as the sum of diameters (SoD), product of diameters (PoD), and volume (3D-COG - proposed by the Children Oncology Group), can be rapidly performed; however, their prognostic values have never been compared to LD. Our goal was to investigate their performance in improving patients' prognostication for STS of the lower limbs. All consecutive adults managed with curative intent at our sarcoma reference center for a newly diagnosed STS of the lower limbs between 2000 and 2017, with pre-treatment MRI, were included in this retrospective study. Multivariable Cox regression models were trained to predict metastasis-free survival (MFS) in a Training cohort of 66.7% patients based on LD, PoD, SoD, or 3D-COG (and systematically including age, histologic grade, histotype, radiotherapy, chemotherapy, and surgical margins as covariables). The models were then compared on a validation cohort of 33.3% patients using concordance indices (c-index). The same approach was applied for overall survival (OS) and local relapse-free survival (LFS). Measurement reproducibility among three readers was evaluated with an intraclass correlation coefficient (ICC). 382 patients were included in the survival modeling (72/253 [28.5%] metastatic relapses in Training and 36/129 [27.9%] metastatic relapses in Validation). Higher dimensions were associated with lower MFS (multivariable hazard ratio [HR] = 2.44 and P = 0.0018 for LD; HR = 1.88 and P = 0.0009 for PoD, HR = 1.52 and P = 0.0041 for SoD; and HR = 1.08 and P = 0.0195 for 3D-COG). Higher c-indices were obtained with PoD model in Training (c-index = 0.772) and Validation (c-index = 0.688), but they were not significantly higher thanthose obtained with LD model. None of the measurements was associated with LFS or OS. All measurements demonstrated excellent ICC (> 0.95). Regarding its simplicity and good performance, LD appeared as the best metric to incorporate in prognostic models and nomograms for MFS.

Greater baseline cortical atrophy in the dorsal attention network predicts faster clinical decline in Posterior Cortical Atrophy.

Posterior Cortical Atrophy (PCA) is a clinical syndrome characterized by progressive visuospatial and visuoperceptual impairment. As the neurodegenerative disease progresses, patients lose independent functioning due to the worsening of initial symptoms and development of symptoms in other cognitive domains. The timeline of clinical progression is variable across patients, and the field currently lacks robust methods for prognostication. Here, evaluated the utility of MRI-based cortical atrophy as a predictor of longitudinal clinical decline in a sample of PCA patients. PCA patients were recruited through the Massachusetts General Hospital Frontotemporal Disorders Unit PCA Program. All patients had cortical thickness estimates from baseline MRI scans, which were used to predict longitudinal change in clinical impairment assessed by the CDR Sum-of-Boxes (CDR-SB) score. Multivariable linear regression was used to estimate the magnitude of cortical atrophy in PCA patients relative to a group of amyloid-negative cognitively unimpaired participants. Linear mixed-effects models were used to test hypotheses about the utility of baseline cortical atrophy for predicting longitudinal clinical decline. Data acquired from 34 PCA patients (mean age = 65.41 ± 7.90, 71% females) and 24 controls (mean age = 67.34 ± 4.93, 50% females) were analyzed. Sixty-two percent of the PCA patients were classified as having mild cognitive impairment (CDR 0.5) at baseline, with the rest having mild dementia (CDR 1). Each patient had at least one clinical follow-up, with the mean duration of 2.78 ± 1.62 years. Relative to controls, PCA patients showed prominent baseline atrophy in the posterior cortical regions, with the largest effect size observed in the visual network of the cerebral cortex. Cortical atrophy localized to the dorsal attention network, which supports higher-order visuospatial function, selectively predicted the rate of subsequent clinical decline. These results demonstrate the utility of a snapshot measure of cortical atrophy of the dorsal attention network for predicting the rate of subsequent clinical decline in PCA. If replicated, this topographically-specific MRI-based biomarker could be useful as a clinical prognostication tool that facilitates personalized care planning.

Baseline and Longitudinal MRI Markers Associated With 16-Year Mortality in Patients With Cerebral Small Vessel Disease.

Information on whether small vessel disease (SVD) reduces life expectancy is limited. Moreover, the excess mortality risk attributed specifically to SVD compared with controls from the general population has not been evaluated. This study aimed to investigate the baseline and progression of MRI markers of SVD associated with mortality in a 16-year follow-up cohort study and to determine the excess long-term mortality risk of patients with SVD. Participants with SVD from the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Imaging Cohort (RUN DMC) study (with MRI assessments in 2006, 2011, 2015, and 2020) were followed until their death or December 1, 2021. Adjusted Cox regression analyses and linear mixed-effect regression models were used to investigate the association between MRI markers of SVD and mortality. The excess mortality risk of SVD was calculated by comparing mortality data of the RUN DMC study with the general population matched by sex, age, and calendar year. 200 of 503 (39.9%) participants died during a follow-up period of 15.9 years. Cause of death was available for 182 (91%) participants. Baseline white matter hyperintensity volume (HR 1.3 per 1-SD increase [95% CI 1.1-1.5], p = 0.010), presence of lacunes (1.5 [95% CI 1.1-2.0], p = 0.008), mean diffusivity (HR 1.1 per 1-SD increase [95% CI 1.1-1.2], p = 0.001), and total brain volume (HR 1.5 per 1-SD decrease [95% CI 1.3-1.9], p < 0.001) were associated with all-cause mortality after adjusting for age, sex, and vascular risk factors. Total brain volume decrease over time was associated with all-cause mortality after adjusting for age, sex, and vascular risk factors (HR 1.3 per 1-SD decrease [95% CI 1.1-1.7], p = 0.035), and gray matter volume decrease remained significant after additionally adjusting for its baseline volume (1.3 per 1-SD decrease [1.1-1.6], p = 0.019). Participants with a Fazekas score of 3, presence of lacunes, or lower microstructural integrity had an excess long-term mortality risk (21.8, 15.7, 10.1 per 1,000 person-years, respectively) compared with the general population. Excess long-term mortality risk only exists in patients with severe SVD (Fazekas score of 3, presence of lacunes, or lower microstructural integrity). This could help in assisting clinicians to predict the clinical outcomes of patients with SVD by severity.

B - 109 Long-Term Cognitive Effects of Combined Opioid/Non-Opioid Use

Abstract Objective Chronic pain is estimated to afflict 25–50% of community-dwelling older adults (Cravello et al., 2019). Despite the growing epidemic, opioids remain commonly prescribed analgesics, and approximately 10% of older adults with intermittent opioid use become chronic users (Ramachandran et al., 2021). This is concerning given an observed association between cognitive decline and prescription opioid use within this population (Warner et al., 2022). In efforts to reduce opioid consumption, opioid/non-opioid combinations have been used (Pergolizzi et al., 2023); however, the long-term cognitive impact of such alternatives has not been investigated. Thus, the current case report investigates the neurocognitive outcome following longtime opioid/non-opioid combination cessation in the context of chronic pain. Method A 69-year-old Black woman with approximate 30-year history of chronic pain underwent neuropsychological re-evaluation 2 years post-initial assessment and 1.5 years after stopping combined hydromorphone/clonidine use via intrathecal pump. Baseline MRI brain revealed mild diffuse atrophy and punctate nonspecific T2 white matter hyperintensities. CT head approximately 1 year later was unremarkable. Results Neuropsychological re-assessment approximately 2 years post-baseline evaluation revealed significantly declined performances on speed-mediated tasks (e.g., oral numeric sequencing, fluency) amid an otherwise grossly stable, albeit globally impaired, cognitive profile. Conclusions This study elucidates the impact of a 1.5-year period of abstinence from 13 years of combined intrathecal opioid/non-opioid use. Overall, results suggest that cognitive performance, even following this abstinence period, is not improved. Thus, while opioid/non-opioid therapies may reduce opioid exposure, deleterious cognitive effects persist. This study highlights the importance of non-opioid analgesics in efforts to attenuate cognitive impairment risk.

Long-term disability trajectories in multiple sclerosis: a group-based trajectory analysis of the AusLong cohort

BackgroundPrevious natural history studies highlighted a consistent heterogeneity of disability trajectories among individuals with primary or secondary progressive multiple sclerosis (MS). However, evidence on disability progression in relapsing onset MS...

MRI Accurately Visualizes RF Ablation Delivery Targeted to MRI-Defined Arrhythmia Substrates in the Left Ventricle.

Investigate the capacity of MRI to evaluate efficacy of radiofrequency (RF) ablations delivered to MRI-defined arrhythmogenic substrates. Baseline MRI was performed at 3T including 3D LGE in a swine model of chronic myocardial infarct (N=8). MRI-derived maps of scar and heterogeneous tissue channels (HTCs) were generated using ADAS 3D. Animals underwent electroanatomic mapping and ablation of the left ventricle in CARTO3, guided by MRI-derived scar maps. Post-ablation MRI (in vivo at 3T in 5/8 animals; ex vivo at 1.5T in 3/8) included 3D native T1-weighted IR-SPGR (TI=700-800ms) to visualize RF lesions. T1-derived RF lesions were compared against excised tissue. The locations of T1-derived RF lesions were compared against CARTO ablation tags, and segment-wise sensitivity and specificity of lesion detection were calculated within the AHA 17-segment model. RF lesions were clearly visualized in HTCs, scar, and myocardium. Ablation patterns delivered in CARTO matched T1-derived RF lesion patterns with high sensitivity (88.9%) and specificity (94.7%), and were closely matched in registered MR-EP data sets, with a displacement of 5.4 ±3.8mm (N=152 ablation tags). Integrating MRI into ablative procedures for RF lesion assessment is feasible. Patterns of RF lesions created using a standard 3D EAM system are accurately reflected by MRI visualization in healthy myocardium, scar, and HTCs comprising the MRI-defined arrhythmia substrate. MRI visualization of RF lesions can provide near-immediate (<24h) assessment of ablation, potentially indicating whether critical MRI-defined ventricular tachycardia substrates have been adequately ablated.

Progression of Bone Marrow Lesions and the Development of Knee Osteoarthritis: Osteoarthritis Initiative Data.

Background Bone marrow lesions (BMLs) are a known risk factor for incident knee osteoarthritis (OA), and deep learning (DL) methods can assist in automated segmentation and risk prediction. Purpose To develop and validate a DL model for quantifying tibiofemoral BML volume on MRI scans in knees without radiographic OA and to assess the association between longitudinal BML changes and incident knee OA. Materials and Methods This retrospective study included knee MRI scans from the Osteoarthritis Initiative prospective cohort (February 2004-October 2015). The DL model, developed between August and October 2023, segmented the tibiofemoral joint into 10 subregions and measured BML volume in each subregion. Baseline and 4-year follow-up MRI scans were analyzed. Knees without OA at baseline were categorized into three groups based on 4-year BML volume changes: BML-free, BML regression, and BML progression. The risk of developing radiographic and symptomatic OA over 9 years was compared among these groups. Results Included were 3869 non-OA knees in 2430 participants (mean age, 59.5 years ± 9.0 [SD]; female-to-male ratio, 1.3:1). At 4-year follow-up, 2216 knees remained BML-free, 1106 showed an increase in BML volume, and 547 showed a decrease in BML volume. BML progression was associated with a higher risk of developing radiographic knee OA compared with remaining BML-free (hazard ratio [HR] = 3.0; P < .001) or BML regression (HR = 2.0; P < .001). Knees with BML progression also had a higher risk of developing symptomatic OA compared with BML-free knees (HR = 1.3; P < .001). Larger volume changes in BML progression were associated with a higher risk of developing both radiographic OA (HR = 2.0; P < .001) and symptomatic OA (HR = 1.7; P < .001). In almost all subchondral plates, especially the medial femur and tibia, BML progression was associated with a higher risk of developing both radiographic and symptomatic OA compared with remaining BML-free. Conclusion Knees with BML progression, according to subregion and extent of volume changes, were associated with an increased risk of OA compared with BML-free knees and knees with BML regression, highlighting the potential utility of monitoring BML volume changes in evaluating interventions to prevent OA development. ClinicalTrials.gov Identifier: NCT00080171 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Said and Sakly in this issue.

Baseline MRI predictors of successful organ preservation in the Organ Preservation in Rectal Adenocarcinoma (OPRA) trial.

Prospective randomized trials have not yet identified baseline features predictive of organ preservation in locally advanced rectal cancers treated with total neoadjuvant therapy and a selective watch-and-wait strategy. This was a secondary analysis of the OPRA trial, which randomized patients with stage II-III rectal adenocarcinoma to receive either induction or consolidation total neoadjuvant therapy. Patients were recommended for total mesorectal excision, or watch and wait based on clinical response at 8 ± 4 weeks after completing treatment. Standardized baseline clinical and radiological variables were collected prospectively. Survival outcomes, including total mesorectal excision-free survival, disease-free survival, and overall survival, were assessed by intention-to-treat analysis. Cox proportional hazards models were used to evaluate associations between baseline variables and survival outcomes. Of the 324 patients randomized for the OPRA trial, 38 (11.7%) had cT4 tumours, 230 (71.0%) cN-positive disease, 101 (32.5%) mesorectal fascia involvement, and 64 (19.8%) extramural venous invasion. Several baseline features were independently associated with recommendation for total mesorectal excision on multivariable analysis: nodal disease (HR 1.66, 95% c.i. 1.12 to 2.48), extramural venous invasion (HR 1.57, 1.07 to 2.29), mesorectal fascia involvement (HR 1.45, 1.01 to 2.09), and tumour length (HR 1.11, 1.00 to 1.22). Of these, nodal disease (HR 2.02, 1.15 to 3.53) and mesorectal fascia involvement (HR 2.02, 1.26 to 3.26) also predicted worse disease-free survival. Age (HR 1.03, 1.00 to 1.06) was associated with overall survival. Baseline MRI features, including nodal disease, extramural venous invasion, mesorectal fascia involvement, and tumour length, independently predict the likelihood of organ preservation after completion of total neoadjuvant therapy. Mesorectal fascia involvement and nodal disease are associated with disease-free survival.

External validation of the MAGNIFI-CD index in patients with complex perianal fistulising Crohn's disease.

There is an increasing need for objective treatment monitoring in perianal fistulising Crohn's disease (pfCD). Therefore, the magnetic resonance novel index for fistula imaging in CD (MAGNIFI-CD) index has been designed and internally validated on the ADMIRE-CD trial cohort. The aim of this study was to externally validate the MAGNIFI-CD index to monitor response to medical and surgical treatment regimens in pfCD. A retrospective longitudinal cohort was established of consecutive patients with complex pfCD treated with surgical and/or medical therapy and a baseline and follow-up MRI between January 2007 and May 2021. The MAGNIFI-CD index was scored by two independent, abdominal radiologists blinded for time points and clinical outcomes. Responsiveness, reliability, and test accuracy regarding clinically important improvement were assessed. Cut-offs for response and remission were selected classified on fistula drainage assessment and physician global assessment. A total of 65 patients (51% female, median age 32 years) were included. A clinically relevant responsiveness of the MAGNIFI-CD was shown, with a significant decrease in clinical remitters and responders with a median MAGNIFI-CD of 18.0 [7.5-20.0] to 9.0 [0.8-16.0] (p < 0.001) and non-significant change in non-responders with a median MAGNIFI-CD of 20.0 [12.0-23.0] to 18.0 [13.0-21.0] (p = 0.22). There was an 'almost perfect' interobserver agreement (ICC = 0.87; 95% CI 0.80-0.92) for the MAGNIFI-CD index. An optimal cut-off value was defined as a decrease of 2 points for clinical response, and a MAGNIFI-CD ≤ 6 for remission at follow-up MRI. The MAGNIFI-CD index is a responsive and reliable MRI scoring instrument for treatment monitoring in perianal fistulising Crohn's disease. The MAGNIFI-CD index is a well-structured, responsive scoring instrument to assess fistula severity and activity that allows quantitative detection of changes in therapy response in patients with perianal fistulising Crohn's disease, thereby facilitating endpoints in clinical trials. Well-defined cut-offs for response and remission are needed for objective treatment monitoring of perianal fistulising Crohn's disease (pfCD). Cut-off values for remission and for response at 6 months follow-up were defined. Interobserver agreement was good. The MAGNIFI-CD index is responsive and reliable for treatment monitoring and is suitable for use in clinical trials.

Relationships of hematocrit concentration with dementia from a multiethnic population-based study.

Red blood cell (RBC) concentration impacts cerebrovascular disease, yet it is unclear whether RBC concentrations relate to dementia risk, particularly in racially/ethnically diverse cohorts. We investigated whether RBC concentrations associate with incident dementia risk in a diverse population of stroke-free individuals and explored whether cerebral small vessel disease (CSVD) mediates this relationship. A longitudinal observational analysis was performed using a population-based cohort of stroke-free, older adult participants (>50 years) from the Northern Manhattan Study (NOMAS) enrolled between 2003-2008. Participants received baseline hematocrit testing, MRI neuroimaging, and cognitive assessments at baseline and long-term follow-up. Associations of baseline hematocrit as a categorical variable (low, normal [reference], and high based on laboratory reference levels) with incident dementia were assessed using Cox models adjusting for relevant covariates. Separate analyses investigated whether MRI CSVD mediated these relationships. We studied 1207 NOMAS participants (mean age 71±9 years, 60% female, 66% Hispanic). Mean hematocrit was 41.2% (±3.8) with 16% of participants developing incident dementia. Lower hematocrit associated with increased dementia risk (adjusted hazard ratio 1.81 [1.01-3.23]) after adjusting for age, sex, race/ethnicity, education, APOE status, and comorbidities. High hematocrit was not associated with dementia risk. No interactions by sex or race/ethnicity were seen and baseline CSVD did not mediate relationships between hematocrit and dementia. Low hematocrit associated with dementia risk in our diverse population cohort. Further work is needed to assess mechanisms behind anemia's relationship with dementia to assess whether this can serve as a trackable, preventable/treatable risk factor for dementia.

Biologically interpretable multi-task deep learning pipeline predicts molecular alterations, grade, and prognosis in glioma patients

Deep learning models have been developed for various predictions in glioma; yet, they were constrained by manual segmentation, task-specific design, or a lack of biological interpretation. Herein, we aimed to develop an end-to-end multi-task deep learning (MDL) pipeline that can simultaneously predict molecular alterations and histological grade (auxiliary tasks), as well as prognosis (primary task) in gliomas. Further, we aimed to provide the biological mechanisms underlying the model’s predictions. We collected multiscale data including baseline MRI images from 2776 glioma patients across two private (FAHZU and HPPH, n = 1931) and three public datasets (TCGA, n = 213; UCSF, n = 410; and EGD, n = 222). We trained and internally validated the MDL model using our private datasets, and externally validated it using the three public datasets. We used the model-predicted deep prognosis score (DPS) to stratify patients into low-DPS and high-DPS subtypes. Additionally, a radio-multiomics analysis was conducted to elucidate the biological basis of the DPS. In the external validation cohorts, the MDL model achieved average areas under the curve of 0.892–0.903, 0.710–0.894, and 0.850–0.879 for predicting IDH mutation status, 1p/19q co-deletion status, and tumor grade, respectively. Moreover, the MDL model yielded a C-index of 0.723 in the TCGA and 0.671 in the UCSF for the prediction of overall survival. The DPS exhibits significant correlations with activated oncogenic pathways, immune infiltration patterns, specific protein expression, DNA methylation, tumor mutation burden, and tumor-stroma ratio. Accordingly, our work presents an accurate and biologically meaningful tool for predicting molecular subtypes, tumor grade, and survival outcomes in gliomas, which provides personalized clinical decision-making in a global and non-invasive manner.

Non-invasive prediction of axillary lymph node dissection exemption in breast cancer patients post-neoadjuvant therapy: A radiomics and deep learning analysis on longitudinal DCE-MRI data

PurposeIn breast cancer (BC) patients with clinical axillary lymph node metastasis (cN+) undergoing neoadjuvant therapy (NAT), precise axillary lymph node (ALN) assessment dictates therapeutic strategy. There is a critical demand for a precise method to assess the axillary lymph node (ALN) status in these patients. Materials and methodsA retrospective analysis was conducted on 160 BC patients undergoing NAT at Fujian Medical University Union Hospital. We analyzed baseline and two-cycle reassessment dynamic contrast-enhanced MRI (DCE-MRI) images, extracting 3668 radiomic and 4096 deep learning features, and computing 1834 delta-radiomic and 2048 delta-deep learning features. Light Gradient Boosting Machine (LightGBM), Support Vector Machine (SVM), RandomForest, and Multilayer Perceptron (MLP) algorithms were employed to develop risk models and were evaluated using 10-fold cross-validation. ResultsOf the patients, 61 (38.13 %) achieved ypN0 status post-NAT. Univariate and multivariable logistic regression analyses revealed molecular subtypes and Ki67 as pivotal predictors of achieving ypN0 post-NAT. The SVM-based “Data Amalgamation” model that integrates radiomic, deep learning features, and clinical data, exhibited an outstanding AUC of 0.986 (95 % CI: 0.954–1.000), surpassing other models. ConclusionOur study illuminates the challenges and opportunities inherent in breast cancer management post-NAT. By introducing a sophisticated, SVM-based “Data Amalgamation” model, we propose a way towards accurate, dynamic ALN assessments, offering potential for personalized therapeutic strategies in BC.

Magnetic resonance imaging insights from active surveillance of women with ductal carcinoma in situ

New approaches are needed to determine which ductal carcinoma in situ (DCIS) is at high risk for progression to invasive ductal carcinoma (IDC). We retrospectively studied DCIS patients who declined surgery (2002–2019), and received endocrine therapy (ET) and breast MRI. Baseline MRI and changes at 3 months and 6 months were analyzed by recursive partitioning to stratify IDC risk. Sixty-two patients (63 DCIS; 1 bilateral) with a mean follow-up of 8.5 years were included. Fifty-one percent remained on active surveillance (AS) without evidence of IDC, with a mean duration of 7.6 years. A decision tree based on MRI features of lesion distinctness and background parenchymal enhancement (BPE) at baseline and change after 3 months of ET stratified patients into low, intermediate, and high risk for progression to IDC. MRI imaging features in patients treated with ET and undergoing AS, may help determine which DCIS lesions are at low versus high risk for IDC.