Risultati per: L'imaging nella urolitiasi

Stroke, Ahead of Print. Vascular cognitive impairment is common after stroke, in memory clinics, medicine for the elderly services, and undiagnosed in the community. Vascular disease is said to be the second most common cause of dementia after Alzheimer disease, yet vascular dysfunction is now known to predate cognitive decline in Alzheimer disease, and most dementias at older ages are mixed. Neuroimaging has a major role in identifying the proportion of vascular versus other likely pathologies in patients with cognitive impairment. Here, we aim to provide a pragmatic but evidence-based summary of the current state of potential imaging biomarkers, focusing on magnetic resonance imaging and computed tomography, which are relevant to diagnosing, estimating prognosis, monitoring vascular cognitive impairment, and incorporating our own experiences. We focus on markers that are well-established, with a known profile of association with cognitive measures, but also consider more recently described, including quantitative tissue markers of vascular injury. We highlight the gaps in accessibility and translation to more routine clinical practice.

Objectives
During a precommissioning inspection of a new biocontainment centre, radiographers noted structural features of quarantine rooms that could compromise staff and patient safety and the X-ray image quality, even after significant modifications had been made to an earlier radiography protocol. The aim of this study was to explore the safety and effectiveness of the modified protocol, in the new space, and identify improvements, if required.

Design
A qualitative study using in situ simulation and video-reflexive methods.

Setting
A newly built biocontainment centre, prior to its commissioning in 2021, in a large, tertiary hospital in Sydney, Australia.

Participants
Five radiographers, and a nurse and a physician from the biocontainment centre, consented to participate. All completed the study.

Interventions
Two simulated mobile X-ray examinations were conducted in the unit prior to its commissioning; simulations were videoed. Participants and other stakeholders analysed video footage, collaboratively, and sessions were audio recorded, transcribed and analysed thematically. Problems and potential solutions identified were collated and communicated to the hospital executive, for endorsement and actioning, if possible.

Results
Four themes were identified from the data: infection exposure risks, occupational health and exposure risks, communication and X-ray image quality. Facilitated group reviews of video footage identified several important issues, across these four areas of risk, which had not been identified previously.

Conclusions
In situ simulation is used, increasingly, to evaluate and improve healthcare practices. This study confirmed the added value of video-reflexive methods, which provided experienced participants with a richer view of a familiar protocol, in a new setting. Video footage can be examined immediately, or later if required, by a broader group of stakeholders, with diverse experience or expertise. Using video reflexivity, clinicians identified potential safety risks, which were collated and reported to the hospital executive, who agreed to implement modifications.

Introduction
Positron emission tomography (PET) imaging can be used to evaluate arterial wall inflammation in extracranial vascular diseases. However, the application of PET imaging in unruptured intracranial aneurysms (UIA) remains unexplored. Our objective is to investigate feasibility of PET imaging using 18F-FDG and 68Ga-DOTANOC tracers to evaluate arterial wall inflammation in UIA.

Methods and analysis
This PET imaging feasibility study will enrol patients scheduled for surgical treatment of UIA. The study subjects will undergo PET imaging of the intracranial arteries within 1 month before planned surgery. The imaging protocol includes 18F-FDG PET MRI, MRA with gadolinium enhancement, and 68Ga-DOTANOC PET CT. The study will also involve preoperative blood samples, intraoperative cerebrospinal fluid (CSF) samples, and aneurysm sac biopsy. Planned sample size is at least 18 patients. Primary outcome is uptake of 18F-FDG or 68Ga-DOTANOC in intracranial arterial aneurysms compared with contralateral normal vessel as maximum standardised uptake value or target-to-blood pool ratio and correlation of uptake of 18F-FDG or 68Ga-DOTANOC to aneurysm histological findings. Secondary outcomes include estimating the correlations between uptake of 18F-FDG or 68Ga-DOTANOC and histological findings with blood and CSF miRNA-levels, arterial wall enhancement in gadolinium enhanced MRA, aneurysm size and shape, smoking, hypertension, and location of the aneurysm.

Ethics and dissemination
This study is approved by the Human Research Ethics Committee of the Hospital District of Southwest Finland, Finnish Medicines Agency Fimea, and Turku University Hospital. Findings will be disseminated through peer-reviewed journal articles and presentations at national and international conferences.

Trial registration number
NCT04715503

Circulation, Volume 149, Issue 7, Page 542-544, February 13, 2024.

New England Journal of Medicine, Ahead of Print.

Introduction
Cystic fibrosis (CF) is a life-limiting autosomal recessive genetic condition. It is caused by mutations in the gene that encodes for a chloride and bicarbonate conducting transmembrane channel. X-ray velocimetry (XV) is a novel form of X-ray imaging that can generate lung ventilation data through the breathing cycle. XV technology has been validated in multiple animal models, including the β-ENaC mouse model of CF lung disease. It has since been assessed in early-phase clinical trials in adult human subjects; however, there is a paucity of data in the paediatric cohort, including in CF. The aim of this pilot study was to investigate the feasibility of performing a single-centre cohort study in paediatric patients with CF and in those with normal lungs to demonstrate the appropriateness of proceeding with further studies of XV in these cohorts.

Methods and analysis
This is a cross-sectional, single-centre, pilot study. It will recruit children aged 3–18 years to have XV lung imaging performed, as well as paired pulmonary function testing. The study will aim to recruit 20 children without CF with normal lungs and 20 children with CF. The primary outcome will be the feasibility of recruiting children and performing XV testing. Secondary outcomes will include comparisons between XV and current assessments of pulmonary function and structure.

Ethics and dissemination
This project has ethical approval granted by The Women’s and Children’s Hospital Human Research Ethics Committee (HREC ID 2021/HRE00396). Findings will be disseminated through peer-reviewed publication and conferences.

Trial registration number
ACTRN12623000109606.

Stroke, Volume 55, Issue Suppl_1, Page A128-A128, February 1, 2024. Background and aims:Portable, low-field (LF) MRI has the potential to improve access to expeditious, definitive brain imaging and facilitate diagnosis of acute stroke. Currently available diffusion-weighted imaging (DWI) protocols at LF are limited to a single diffusion direction due to acquisition duration. However, single-direction diffusion has reduced sensitivity for detecting acute ischemic infarcts, particularly small lesions residing in white matter tracts. The purpose of this study was to establish the feasibility of acquiring multi-direction DWI compared with single-direction counterparts on LF-MRI.Methods:Patients presenting with a diagnosis of acute ischemic stroke between July and September 2023 were eligible. Consented patients underwent DWI acquisition on a 0.064T LF-MRI (Mk1.9; Hyperfine Research Inc). Three diffusion directions (x, y, and z) were acquired with abweighting of 900 s/mm2and a single acquisition with ab0 s/mm2. Theb900 images were co-registered to theb0, trace and apparent diffusion coefficient (ADC) maps calculated, and the final images interpolated at 1 mm3.Results:Ten patients presenting to the Massachusetts General Hospital with acute ischemic stroke were consented and imaged within 72 hours of last known well. The total acquisition time was 14 minutes, with all subjects able to tolerate the scan duration. Ischemic lesions as small as 0.1 mL were detectable on the LF-MRI (17.5 +/- 18.2 mL). An example of each diffusion direction individually, the combined trace, and corresponding ADC maps are shown in Figure 1, compared with conventional high-field (HF) diffusion images acquired within 30 minutes of the LF acquisition.Conclusion:Multi-direction DWI imaging is feasible on a 0.064T LF-MRI scanner. Our experience suggests further modifications to the pulse sequence and scanner configuration may facilitate a reduction in acquisition time, improve resolution, or both.

Stroke, Volume 55, Issue Suppl_1, Page ATMP49-ATMP49, February 1, 2024. Background:Red blood cells (RBC)-rich thrombus are more easily retrieved via endovascular procedures while platelet-rich thrombus are more resistant to recanalization. Our aim was to generate a radiomics model able to identify both RBC and platelet-rich thrombus at CT admission in patients undergoing mechanical thrombectomy.Methods:We included consecutive patients that received mechanical thrombectomy due to a large vessel occlusion in which thrombi was obtained. Thrombi obtained during the procedure were hematoxiline-eosine processed and proportions of RBC were determined. Relative proportion of the platelets in the thrombi was quantified by using a immunohistochemical staining recognizing CD61. We considered RBC-rich thrombi those with a content of RBC >30% and platelet-rich thrombi those with a content of CD61 >70%. Thrombi were segmented manually on co-registered non-contrast CT (NCCT) and CT angiography (CTA) at admission (30% was 0.938 (sensitivity 86%, specificity 86%, PPV 84%). Regarding platelet-rich thrombus, the area under the curve for detecting CD61 >70% was 0.89 (sensitivity 83%, specificity 84%, PPV 74%). Feature importance by imaging type for RBC-rich and platelet rich thrombus was 70.33% and 69.8% for NCCT and 29.67% and 30% for CTA, respectively. The most important feature types for RBC-rich thrombus were histograms (51%) and first order (27%) while the most important features for platelet rich-thrombus were histograms (94%) followed by texture (5.94%). No information about shape improved any model.Conclusion:Our radiomics model can reliably identify RBC and platelet-rich thrombi. Fast identification of thrombus histological components on CT at arrival can help to design the preferred therapeutic strategy

Stroke, Volume 55, Issue Suppl_1, Page A28-A28, February 1, 2024. Introduction:ACTIMIS (NCT03803007) was a randomized phase 1b/2a clinical trial evaluating glenzocimab, a monoclonal antibody fragment targeting platelet receptor glycoprotein VI in patients with acute ischemic stroke treated by thrombolysis. Primary analysis demonstrated a reduction in intracranial hemorrhage occurrence stroke-related mortality. In this sub-analysis, volumetric imaging biomarkers were used to assess efficacy of glenzocimab.Methods:In the phase 2a study, patients were randomized (1:1) with 1000mg glenzocimab or placebo. CT or MRI was acquired at baseline with CT at 24 hours and MRI at 7 days for safety and efficacy analysis. Baseline and follow up imaging were processed as post-hoc analysis using AI core lab software (Brainomix, Oxford, UK). Automated output was reviewed for accuracy by an expert clinician (DC) blinded to treatment allocation.Results and Conclusions:Follow up imaging data were available from 103/106 patients (51 glenzocimab, 52 placebo) at 24 hours. Of these, 54 underwent mechanical thrombectomy (MT, 27 glenzocimab, 27 placebo). Day-7 imaging was available for 9 fewer placebo patients and 1 glenzocimab patient. All except 2 patients (1 placebo, 1 glenzocimab) with missing data at Day-7 died during the study. Preliminary analysis showed smaller volume of hemorrhagic transformation (HT) in the glenzocimab group at 24 hours compared to placebo and a trend towards smaller volume of ischemic injury. Exploratory analysis also highlighted an interaction effect between risk of HT following MT and glenzocimab (lower risk in patients treated with glenzocimab). The full results of the imaging sub-analysis of the ACTIMIS study will be presented at the conference and discussed in the context of current literature.

Stroke, Volume 55, Issue Suppl_1, Page ATMP53-ATMP53, February 1, 2024. Introduction:Digital subtraction angiography (DSA) is the gold standard investigation for the diagnosis and prognostication of moyamoya disease (MMD). Magnetic resonance arterial spin labelling (MR-ASL) is a newer non-invasive technique that can predict the perfusion reliably. Our study aims at prediction of collaterals with MR-ASL in addition to parenchymal perfusion deficit.Methodology:It is an observational single centre cohort study where consecutive MMD patients with both DSA and MR-ASL done within 3 months of each other were included in the study. Images were reviewed by 2 radiologists independently. MMD severity was graded using Suzuki staging and collaterals were graded using DSA and MR-ASL in 7 different regions [4 areas in basal ganglia level – basal ganglia, M1, A1 and P1], 3 areas at superficial cortical level above basal ganglia [M2, A2, P2]. DSA collateral grading used was: grade 0 – no collaterals visible (absence of any capillary blush) with perfusion deficit, grade 1 – mild to moderate collaterals with some perfusion deficit, grade 2 – extensive collaterals with no perfusion deficit, grade 3 – normal antegrade flow. Collateral grading used on MR-ASL was: grade 0 – no or minimal ASL signal; grade 1 – moderate ASL signal with arterial transit artefact (ATA), grade 2 – high ASL signal with ATA, grade 3 – normal perfusion without ATA.Results:Of the 46 MMD patients (males – 22), 92 hemispheres were included. 4 hemispheres were excluded as the patient underwent revascularisation in the corresponding hemisphere. Among the remaining 88 hemispheres, 7 were normal on angiography. At various Suzuki grades, the degree of collaterals graded on ASL changed according to Suzuki staging (p

Stroke, Volume 55, Issue Suppl_1, Page AWP119-AWP119, February 1, 2024. Introduction:Magnetic resonance imaging (MRI) and computed tomography (CT) is useful for the evaluation of the ischemic core and penumbra. The indication for mechanical thrombectomy (MT) for acute ischemic stroke is determined by either or both imaging modalities. The selection of initial imaging modality is differed by the institute, and it is uncertain which imaging modality is superior before MT. In this study, we compared the clinical outcomes after MT by imaging modality in the K-NET registry (Kanagawa intravenous and endovascular treatment of acute ischemic stroke registry).Methods:The K-NET registry is a Japanese multicenter prospective registry study of patients treated with Intravenous thrombolysis with recombinant tissue plasminogen activator, endovascular treatment, or both for acute ischemic stroke. The present study is based on patients’ data in the K-NET registry between January 2018 and June 2021. The inclusion criteria for the current analysis were as follows: (1) pre-modified Rankin score (mRS) 0-2; (2) patients transferred directly to primary stroke centers; (3) treated with MT; and (4) performed only CT or MRI for diagnosis of acute ischemic stroke before MT. The patients who performed both CT and MRI at admission were excluded. Unbalanced cohorts with a nonrandom distribution of patients were accounted for by using propensity score matching.Results:2348 patients were enrolled in the registry during the period, and 753 patients were eligible for inclusion criteria. 498 (249 matched pairs) were included after propensity score-matched analysis. The baseline characteristics were well-balanced between the two groups. There was no difference in the final mTICI grade between the two groups. The time from image to puncture in the MRI group was significantly shorter than the CT group (52min versus 38min), and the time from image to recanalization was also significantly shorter in the MRI group (108min versus 88.5min). The rate of functional independence (90 days mRS 0-2) was higher in the MRI group versus the CT group (54.4% versus 43.8%, p=0.017).Conclusions:The selection of MRI before MT was associated with a shorter time from image to puncture and recanalization and a favorable outcome compared with CT.

Stroke, Volume 55, Issue Suppl_1, Page ATP147-ATP147, February 1, 2024. Background:White matter disease is a common phenomenon in patients with sickle cell disease, that has been linked to cognitive impairment. However, there is no standardized approach for quantification of the cerebral disease burden. The Fazekas score is widely used to quantify the burden of white matter disease in chronic small vessel disease. However, its utility in sickle cell disease has not yet been established. We aimed to assess its, interrater reliability in this patient population.Methods:A patient cohort was compiled for the purpose of a research ethics board (REB) approved retrospective study of consecutive adult patients with sickle cell disease, each of whom underwent MRI/MRA between the year 2017 and 2019. All MRI/MRA studies were performed on 3-Tesla MRI. Two neuroradiologists independently assessed the axial FLAIR MRI brain sequence, for all patients, with the sole focus of assigning a Fazekas score (0-3) to each study, as a means of quantifying the burden of ischemic white matter lesions. The neuroradiologists were blinded to the scoring assigned by their counterpart and to the clinical information. Cohen’s weighted Kappa was used as a measure of agreement between readers.Results:Ninety patients with a median age of 31 and 45/90 (50%) women were included. The expected agreement was 74.65%, with an observed agreement of 94.44% between readers, with a weighted Kappa of 0.7808.Conclusion:On the basis of this study, there is good inter-rater reliability of Fazekas scoring on axial FLAIR MRI brain sequence in patients with sickle cell disease, even though the underlying pathophysiology of white matter lesions in this patient population might vary compared to individuals with chronic small vessel disease. The Fazekas is a promising measure that could easily be integrated in systematic evaluation of cerebrovascular lesions of adults with sickle cell disease.

Stroke, Volume 55, Issue Suppl_1, Page ATMP79-ATMP79, February 1, 2024. Introduction:Incident intracerebral hemorrhage (ICH) is an uncommon medical event that can lead to devastating outcomes, including death. Small vessel disease (SVD), as measured by cerebral microbleeds (CMBs) and white matter hyperintensities (WMH), has been associated with risk factors and might be a predictor of incident ICH. CMBs result from irregularities in brain vessel structure due to chronic hypertension and cerebral amyloid angiopathy. These microhemorrhages are a possible risk factor for ICH.Methods:A cohort of ARIC (Atherosclerosis Risk in Communities) participants underwent 3T MRI at visit 5 (2011-2013). CMBs were assessed using a T2* gradient echo. CMBs are homogenous hypointense lesions ≤10 mm in diameter. WMH volumes were derived from FLAIR images using an automated program to measure the volumetric burden of leukoaraiosis. During 10 years of follow-up, incident ICH was noted in 7 (0.4%) out of 1,656 participants were dichotomized based on the presence of CMB and the median of WMH volume.Results:ARIC subjects (n=1656, mean age=76±5 years; 40% men; 26% African American race) underwent MRI. CMBs were present in 385 (23.25%) patients out of 1656. ICH occurred in 0.16% and 1.30% of patients without CMBs and with CMBs, respectively. Kaplan Meier (KM) survival analysis between CMBs and ICH was significant (logrank p=0.002). Cox Regression yielded a significant crude hazards ratio (HR 8.7, 95% CI 1.7-44.7, p=0.010). Adjustment for age, gender, race, and hypertension was also significant (HR 9.9, 95% CI 1.9-52.0, p=0.07). KM survival analysis between WMH median (11.68 cm3) and ICH was significant (logrank p=0.006). Figure 1 displays the KM curves of those with and without CMBs and the incidence of ICH as well as those below and above WMH median and incidence of ICH.Conclusion:CMBs and WMH detected by MRI appear to be an important predictor for the occurrence of incident ICH. Further research is needed to observe if MRI could be used to screen subjects at high-risk for elevated risk of incident ICH.

Stroke, Volume 55, Issue Suppl_1, Page ATP141-ATP141, February 1, 2024. Background:Computerized tomography perfusion (CTP) imaging serves as a valuable modality for the assessment of individuals with a large vessel anterior circulation stroke. Current literature proposes that employing CTP imaging in patients within the initial time frame of less than 8 hours, may lead to an overestimation of the projected infarct core, specifically when utilizing cerebral blood flow (CBF) less than 30%. The hypoperfusion intensity ratio (HIR) may result in overestimation. We sought to further investigate the interplay of CTP parameters in patients presenting within 8 hours of symptom onset of stroke, to assess the accuracy of core infarct estimation.Methods:A retrospective cohort study analyzing patients with large vessel anterior occlusion (LVAO) who underwent CTP and mechanical thrombectomy within 24 hours of symptom onset between January 2017 to December 2022. RAPID software estimates the infarct core using CBF

Stroke, Volume 55, Issue Suppl_1, Page ATP131-ATP131, February 1, 2024. Background:Large vessel occlusion (LVO) stroke patients are often transferred from regional hospitals to comprehensive stroke centers (CSC) for thrombectomy. The need for repeat imaging at CSCs prior to intervention is unclear. We compared regional hospital and CSC perfusion imaging results for interfacility transfers in a single health system.Methods:We analyzed a cohort of patients in western Michigan who received CT perfusion imaging before and after transfer to a CSC. Perfusion mismatch (MM), core infarct volume (CIV), and favorability of imaging for mechanical thrombectomy (MT) candidacy were compared between the regional and CSC studies. A favorable imaging profile was defined as the presence of LVO, MM volume >10 mL, and MM/CIV ratio of >1.2. Linear regression was used to examine predictors of infarct growth during transfer.Results:Over a 10-month period, 25 patients met inclusion criteria. The median age was 76 (IQR 66-81), 60% were male, median NIHSS was 11 (IQR 2-18), and most patients had occlusion of the internal carotid or middle cerebral arteries (72%). The median time from last known well to initial CT was 250 minutes (IQR 85-620). Regional median MM volume was 52 mL (IQR 8-97), CIV was 0 mL (IQR 0-13), and hypoperfusion intensity ratio (HIR) was 0.25 (IQR 0-0.34). The median time between CTs was 152 minutes (IQR 139-226). The median change in MM volume was -3 mL (IQR -27-3) and median CIV growth rate was 0 mL/hr (IQR 0-2.0). In a multivariable regression model, higher HIR (β=23.2, p=0.012) and minutes between imaging studies (β=0.10, p=0.021) were associated with CIV growth. Sixteen patients (64%) had favorable imaging profiles for MT at the regional hospital. Of these, 15 (93.8%) continued to have a favorable CSC imaging profiles and 9 (56.2%) underwent MT. Of the 9 patients without favorable regional imaging profiles, 1 (11.1%) had a favorable CSC imaging profile and 2 (22.2%) underwent MT.Conclusion:In our sample, regional and CSC perfusion imaging patterns were similar and patients infrequently crossed thresholds for MT candidacy between studies. Initial HIR and longer delays between were independently associated with infarct growth during transfers, however overall infarct growth was very small.

Stroke, Volume 55, Issue Suppl_1, Page ATP52-ATP52, February 1, 2024. Background:Delays in IV thrombolytic and thrombectomy treatments are associated with worse outcomes after ischemic stroke. The objective of our study was to compare door-to-CT imaging times among Code Stroke patients who presented by private vehicle and were evaluated by a physician in the emergency department (ED) either in the triage hallway or the emergency department room.Methods:We prospectively collected real-time data on Code Stroke patients presenting by private vehicle to a primary stroke center from May 1, 2022 through September 18, 2022. A Code Stroke was activated for all patients presenting to the emergency room with positive BE-FAST symptoms occurring within 24 hours from last known normal time. Patients were evaluated by a physician either in the triage hallway or an ED room prior to CT imaging. We compared baseline demographic data, NIHSS scores and door-to-CT times in patients evaluated by the physician in the ED triage hallway versus the ED room.Results:Of 55 patients who presented to the ED by private vehicle during the study period, the mean age was 54 ± 15 years, 53% were female and 45% non-white. The median NIHSS score was 1 [IQR 0-4]. There were 27 (49%) patients who underwent physician evaluation in the triage hallway and the remaining went into a patient room before going to CT. The median NIHSS scores for evaluations in the room were higher than in the triage hallway (2 vs 0, p=0.037). Overall, median time from door-to-CT was 11 minutes for patients who went directly from the triage hallway to CT and 21 minutes for patients who were roomed prior to CT (p=0.005).Conclusions:This study found that Code Stroke patients presenting by private vehicle and evaluated by an emergency physician in the triage hallway saved 10 minutes in door-to-CT time compared with physician evaluation in a room.