Jun Wang, Shutian An, Zhen Wang, Zichen Hu, Yueyue Zhang, Daiwang Jia, Yong Cheng, Yang Xiang, Ruan Fang, Peiyang Zheng, Zijun Zheng, Zhanglei Li, Yewen Jiang, Yongqiang Yu, Ren Zhao, Xiaohu Li
Cardiac magnetic resonance elastography (MRE) is a non-invasive technique that quantifies myocardial stiffness by tracking shear wave propagation through the heart. Shear waves are generated externally and delivered to the thorax through a passive driver placed on the chest. Passive driver position is a critical yet underexplored determinant of measurement quality. To compare two passive driver positions in 3.0 T cardiac MRE — the apical surface projection (ASP) and the left lateral chest wall (LCW) — and to determine which yields more reliable left ventricular (LV) myocardial stiffness measurements. Twenty-three healthy volunteers (mean age 43.0 ± 17.0 years; 14 men, 9 women) underwent two cardiac MRE acquisitions, with the passive driver placed first at the ASP and then at the LCW. LV myocardial stiffness and the octahedral shear strain signal-to-noise ratio (OSS-SNR) were measured at both positions. Differences between positions were analyzed using paired t-tests with Cohen's d. Inter- and intra-observer reproducibility were assessed using intraclass correlation coefficients (ICC) and Bland–Altman analysis. Myocardial stiffness was significantly lower at the ASP than at the LCW (9.0 ± 1.7 kPa vs. 14.7 ± 3.0 kPa; mean difference −5.8 kPa, 95% CI −7.2 to −4.3; P < 0.001; Cohen's d = − 1.73). OSS-SNR was significantly higher at the ASP (1.72 ± 0.48 vs. 1.25 ± 0.29; P < 0.001; Cohen's d = 0.85). At the ASP, stiffness measurements demonstrated excellent intra- and inter-observer agreement, with ICCs of 0.962 and 0.963, respectively. At the LCW, stiffness measurements demonstrated good inter-observer agreement and excellent intra-observer agreement, with ICCs of 0.839 and 0.914, respectively. Passive driver placement at the ASP resulted in significantly higher OSS-SNR and superior reproducibility for LV myocardial stiffness measurements compared with LCW placement. Therefore, the ASP should be considered the preferred driver position for cardiac MRE in clinical and research settings.
Wenyan Wei, Lin Lu, Yan Wu, Qianye Fang, Yuankun Li, Junyue Zhou, Runmeng Li, Dan Han, Tengfei Ke, Wen Zhao
To compare the clinical value of true electrocardiogram-gated and virtual electrocardiogram-gated coronary computed tomography angiography (CCTA), and to provide a reasonable and effective imaging strategy for patients with acute chest pain. A total of 254 patients with acute chest pain and suspected coronary artery disease who underwent CCTA were prospectively enrolled. Patients were alternately assigned according to examination date to the virtual ECG-gated group (n = 126), or the true ECG-gated group (n = 128). Examination time and radiation dose were recorded. Objectiveand subjective image quality parameters were evaluated. Objective parameters included image background noise, CT values of the aorta and coronary artery branches, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Subjective image quality was assessed using a 5-point scale. In patients who underwent invasive coronary angiography (ICA) within 30 days after CCTA, diagnostic agreement was evaluated using ICA as the reference standard. Diagnostic performance was assessed at the vessel level using receiver operating characteristic (ROC) curve analysis, with the four major coronary arteries from each patient considered as the units of analysis. (1) The virtual ECG-gated group demonstrated significantly improved examination efficiency compared with the true ECG-gated group, with a shorter total examination time (2.83 ± 0.37 min vs. 4.15 ± 0.49 min, P < 0.001) and positioning time (0.89 ± 0.26 min vs. 2.03 ± 0.35 min, P < 0.001). However, the radiation dose was higher in the virtual ECG-gated group than in the true ECG-gated group (3.58 ± 0.69 mSv vs. 3.18 ± 0.54 mSv, P < 0.001). (2) Image quality analysis showed that the virtual ECG-gated group had lower image noise than the true ECG-gated group, as well as higher SNR and CNR values for the aorta and coronary artery branches (all P < 0.001). However, CT values and subjective image quality scores were comparable between the two groups (all P > 0.05). (3) In the ICA-validated subgroup, the virtual ECG-gated group showed a higher diagnostic agreement rate than the true ECG-gated group (92.00% vs. 85.58%), with corresponding vessel-level AUC values of 0.89 and 0.82, respectively. However, the virtual ECG-gated group was associated with a higher radiation dose than the true ECG-gated group (3.58 ± 0.69 mSv vs. 3.18 ± 0.54 mSv), representing a trade-off for achieving an ECG-independent acquisition strategy and maintaining diagnostic image quality. Virtual ECG-gated CCTA can significantly improve examination efficiency while maintaining comparable image quality and diagnostic performance to true ECG-gated CCTA. Although this approach was associated with a modest increase in radiation dose, this represents a trade-off for reducing dependence on real-time ECG acquisition and simplifying the CCTA workflow. Therefore, virtual ECG-gated CCTA may serve as a feasible and efficient imaging strategy for selected patients with acute chest pain, particularly in clinical scenarios requiring rapid evaluation or simplified workflow.
Diyou Chen, Wei Ma, Li Zhan, Hui Zhao, Kunlin Xiong
Existing CT-based prognostic models for traumatic brain injury (TBI) are not tailored to specific injury mechanisms and lack sensitivity to cerebral oedema changes. This study aimed to develop an assessment method for cerebral oedema and compare it with conventional CT scoring systems in predicting long-term outcomes in patients with TBI following road traffic accidents (RTAs). A retrospective analysis was conducted on 227 patients with TBI following RTAs admitted to a single center (2019.1-2023.12). A clinical prognostic model (IMPACT) was defined, comprising age, motor score, and pupillary light reflex. The A5 (+1) CT classification was defined based on the involvement of cerebral lobes by oedema and the resulting mass effect. The Marshall CT classification, Rotterdam CT score, Helsinki CT score, and A5 (+1) CT classification were added to the IMPACT model to assess their value in predicting outcomes using area under the curve (AUC). The AUC for A5 (+1) CT classification reached 0.849, surpassing Marshall CT classification (0.720, p < 0.001), Rotterdam CT score (0.745, p = 0.004), and Helsinki CT score (0.746, p = 0.002). Adding A5 (+1) CT classification to IMPACT model increased the AUC by 0.076 (p = 0.001). Adding Rotterdam CT score increased the AUC by 0.038 (p = 0.028), while incorporating Marshall CT classification and Helsinki CT score yielded no significant changes (p = 0.138, p = 0.057). The A5 (+1) CT classification outperforms conventional CT scoring systems in assessing long-term outcomes for patients with TBI following RTAs. Its inclusion in the IMPACT model enhances predictive performance.
Rubén Fernández de la Rosa, Gonzalo Cuesta Domingo, Pedro Nespral, Elena Marcos-Macías, Marta Vaillant, Luis García-García, Miguel Ángel Pozo, Jordi A. Matias-Guiu, María Nieves Cabrera-Martin, Mirjam Brackhan, Pablo Bascuñana
Metformin is one of the most widely used drugs to control diabetes type 2. However, there is no indication of pausing metformin treatment before an 18 F-FDG PET scan. The aim of this study is to evaluate if metformin, in both patients and mice, can alter brain 18 F-FDG uptake. In vivo 18 F-FDG PET scans were carried out in male mice. Animals were treated with saline or metformin (300 mg/kg) 10 min before 18 F-FDG or chronically (3 weeks) in drinking water. Separately, patients with non-pathological 18 F-FDG brain scans were distributed into two groups: metformin-treated (n = 12) and control patients (n = 27). PET images were structurally normalized to brain templates, corrected to whole-brain activity, and compared using SPM12. In mice, acute treatment induced a significant hypermetabolism in several brain regions including hippocampus (1.07 ± 0.07 vs 0.94 ± 0.08; p = 0.0002) and thalamus (1.17 ± 0.08 vs 1.00 ± 0.08; p = 0.0002). Chronic treatment increased tracer uptake only in cortical regions. Similarly, treated patients showed hypermetabolism in the temporal lobe (1.03 ± 0.04 vs 0.97 ± 0.04; p < 0.0001) and white matter and lower uptake in frontal cortical regions (1.24 ± 0.04 vs 1.28 ± 0.06; p = 0.0165). Linear regression to HbA1c showed a negative correlation to 18 F-FDG uptake in frontal and parietal cortical subregions, but no correlation to temporal lobe uptake. Our results show that metformin treatment might modify 18 F-FDG uptake in temporal lobe structures. On the other hand, lower uptake in frontal cortex might be attributable to the diabetic condition. Thus, new studies modifying the treatment regimen in diabetic patients prior to performing an 18 F-FDG PET are warranted.
Florian Awin Stolz, Andrei Manzhurtsev, Marlene Bönstrup, Daniel Groener, Nico Melzer, Felix Rosenow, Elke Hattingen, Christophe Théo Arendt
Central nervous system involvement is uncommon in systemic sclerosis, and inflammatory temporomesial syndromes in this context are rarely reported. We present a 58-year-old man with systemic sclerosis who developed subacute cognitive impairment and dialeptic seizures arising from the right temporal lobe. Video electroencephalography confirmed a right temporal seizure onset zone. Brain magnetic resonance imaging demonstrated enlargement and subtle T2 hyperintensity of the right hippocampus and amygdala, while fluorodeoxyglucose-positron emission tomography/computed tomography images showed focal hypermetabolism of the enlarged right amygdala. Proton magnetic resonance spectroscopy demonstrated bilateral reduction of total N-acetylaspartate compared with an age-matched healthy reference subject, with a more pronounced difference on the right, a pattern compatible with bilateral, right-accentuated neuronal dysfunction or injury. MR relaxometry demonstrated significant bilateral T2 prolongation in the amygdalae and hippocampal heads, whereas T1 abnormalities were more region-dependent, involving the right amygdala and both hippocampal heads. Serum testing detected anti-pyruvate dehydrogenase antibodies, whereas routine clinical neural antibody testing was negative. The patient became seizure-free under antiseizure medication and immunosuppressive therapy with cyclophosphamide. Notably, although the unilateral conventional imaging findings did not meet the bilateral mesial temporal criterion required by current consensus criteria for definite autoimmune limbic encephalitis, MR relaxometry revealed bilateral temporomesial abnormalities. This finding is consistent with available neuropathological and experimental evidence and suggests that routine imaging may underestimate disease extent. This case highlights a rare presentation of antibody-atypical limbic encephalitis in the setting of systemic sclerosis and illustrates how multimodal imaging can support diagnosis and tissue characterization when routine antibody testing is unrevealing.
