Explore the vast range of titles available.

BackgroundBreast cancer remains a leading cause of death in women and novel imaging biomarkers are urgently required. Here, we demonstrate the diagnostic and treatment-monitoring potential of non-invasive sodium (23Na) MRI in preclinical models of breast cancer.MethodsFemale Rag2−/−Il2rg−/− and Balb/c mice bearing orthotopic breast tumours (MDA-MB-231, EMT6 and 4T1) underwent MRI as part of a randomised, controlled, interventional study. Tumour biology was probed using ex vivo fluorescence microscopy and electrophysiology.Results23Na MRI revealed elevated sodium concentration ([Na+]) in tumours vs non-tumour regions. Complementary proton-based diffusion-weighted imaging (DWI) linked elevated tumour [Na+] to increased cellularity. Combining 23Na MRI and DWI measurements enabled superior classification accuracy of tumour vs non-tumour regions compared with either parameter alone. Ex vivo assessment of isolated tumour slices confirmed elevated intracellular [Na+] ([Na+]i); extracellular [Na+] ([Na+]e) remained unchanged. Treatment with specific inward Na+ conductance inhibitors (cariporide, eslicarbazepine acetate) did not affect tumour [Na+]. Nonetheless, effective treatment with docetaxel reduced tumour [Na+], whereas DWI measures were unchanged.ConclusionsOrthotopic breast cancer models exhibit elevated tumour [Na+] that is driven by aberrantly elevated [Na+]i. Moreover, 23Na MRI enhances the diagnostic capability of DWI and represents a novel, non-invasive biomarker of treatment response with superior sensitivity compared to DWI alone.

Objectives To evaluate whole-body MRI (WB-MRI) parameters significantly associated with treatment response in multiple myeloma (MM). Methods Twenty-one MM patients underwent WB-MRI at diagnosis and after two cycles of chemotherapy. Scans acquired at 3.0 T included T2, diffusion-weighted-imaging (DWI) and mDixon pre- and post-contrast. Twenty focal lesions (FLs) matched on DWI and post-contrast mDixon were selected for each time point. Estimated tumour volume (eTV), apparent diffusion coefficient (ADC), enhancement ratio (ER) and signal fat fraction (sFF) were derived. Clinical treatment response to chemotherapy was assessed using conventional criteria. Significance of temporal parameter change was assessed by the paired t test and receiver operating characteristics/area under the curve (AUC) analysis was performed. Parameter repeatability was assessed by interclass correlation (ICC) and Bland–Altman analysis of 10 healthy volunteers scanned at two time points. Results Fifteen of 21 patients responded to treatment. Of 254 FLs analysed, sFF ( p  < 0.0001) and ADC ( p  = 0.001) significantly increased in responders but not non-responders. eTV significantly decreased in 19/21 cases. Focal lesion sFF was the best discriminator of treatment response (AUC 1.0). Bone sFF repeatability was excellent (ICC 0.98) and better than bone ADC (ICC 0.47). Conclusion WB-MRI derived focal lesion sFF shows promise as an imaging biomarker of treatment response in newly diagnosed MM. Key Points • Bone signal fat fraction using mDixon is a robust quantifiable parameter • Fat fraction and ADC significantly increase in myeloma lesions responding to treatment • Bone lesion fat fraction is the best discriminator of myeloma treatment response

Although free‐water diffusion reconstruction for diffusion‐weighted imaging (DWI) data can be applied to both single‐shell and multishell data, recent finding in synthetic data suggests that the free‐water indices from single‐shell acquisition should be interpreted with care, as they are heavily influenced by initialization parameters and cannot discriminate between free‐water and mean diffusivity modifications. However, whether using a longer multishell acquisition protocol significantly improve reconstruction for real human MRI data is still an open question. In this study, we compare canonical diffusion tensor imaging (DTI), single‐shell and multishell free‐water imaging (FW) indices derived from a short, clinical compatible diffusion protocol (b = 500 s/mm2, b = 1,000 s/mm2, 32 directions each) on their power to predict brain age. Age was chosen as it is well‐known to be related to widespread modification of the white matter and because brain‐age estimation has recently been found to be relevant to several neurodegenerative diseases. We used a previously developed and validated data‐driven whole‐brain machine learning pipeline to directly compare the precision of brain‐age estimates in a sample of 89 healthy males between 20 and 85 years old. We found that multishell FW outperform DTI indices in estimating brain age and that multishell FW, even when using low (500 ms2) b‐values secondary shell, outperform single‐shell FW. Single‐shell FW led to lower brain‐age estimation accuracy even of canonical DTI indices, suggesting that single‐shell FW indices should be used with caution. For all considered reconstruction algorithms, the most discriminant indices were those measuring free diffusion of water in the white matter. Multishell but not single‐shell free‐water diffusion imaging predicts brain age better than canonical diffusion imaging. Multishell free‐water in isolation performs similarly to more complex models including FA, MD, RD and AD.

ObjectivesWe tested whether FLAIR vascular hyperintensities (FVH)–DWI mismatch could identify candidates for thrombectomy most likely to benefit from revascularization.MethodsWe retrospectively reviewed 100 patients with proximal MCA occlusion from 18 stroke centers randomized in the IV-thrombolysis plus mechanical thrombectomy arm of the THRACE trial (2010–2015). We tested the associations between successful revascularization on digital subtraction angiography (modified Thrombolysis in Cerebral Infarction 2b/3) and 3-month favorable outcome (modified Rankin Scale score ≤ 2), stratified on FVH–DWI mismatch status, with secondary analyses adjusted on National Institutes of Health Stroke Scale (NIHSS) and DWI lesion volume.ResultsFVH–DWI mismatch was present in 79% of patients, with a similar prevalence at 1.5 T (80%) and 3 T (78%). Successful revascularization (74%) was more frequent in patients with FVH–DWI mismatch (63/79, 80%) than in patients without (11/21, 52%), p = 0.01. The OR of favorable outcome for revascularization were 15.05 (95% CI 3.12–72.61, p < 0.001) in patients with FVH–DWI mismatch and 0.83 (95% CI 0.15–4.64, p = 0.84) in patients without FVH–DWI mismatch (p = 0.011 for interaction). Similar results were observed after adjustment for NIHSS (OR = 12.73 [95% CI 2.69–60.41, p = 0.001] and 0.96 [95% CI 0.15–6.30, p = 0.96]) or for DWI volume (OR = 12.37 [95% CI 2.76–55.44, p = 0.001] and 0.91 [95% CI 0.16–5.33, p = 0.92]) in patients with and without FVH–DWI mismatch, respectively.ConclusionsThe FVH–DWI mismatch identifies patients likeliest to benefit from revascularization, irrespective of initial DWI lesion volume and clinical stroke severity, and could serve as a useful surrogate marker for penumbral evaluation.Key Points• The FVH–DWI mismatch, defined by FLAIR vascular hyperintensities (FVH) located beyond the boundaries of the DWI lesion, is associated with large penumbra.• Among stroke patients with proximal middle cerebral artery occlusion referred for thrombectomy, those with FVH–DWI mismatch are most likely to benefit from revascularization.• FVH–DWI mismatch provides an alternative to PWI–DWI mismatch in order to select patients who are candidates for thrombectomy.

Introduction The effect of diffusion-weighted magnetic resonance imaging (DWI)-guided dose-painting intensity-modulated radiation therapy (DP-IMRT) on locally advanced recurrent nasopharyngeal carcinoma (NPC) remains unclear. This study aimed to compare the outcomes and toxicities of DWI-guided DP-IMRT in patients with locally recurrent NPC. Methods In this prospective trial, 150 patients with locally advanced recurrent NPC were randomly assigned (1:1) to receive reirradiation with DWI-guided DP-IMRT (DWI group, n  = 75) or conventional MRI-based IMRT (MRI group, n  = 75). In the DWI group, DWI-guided gross tumor volume received escalation to 65.4 Gy/30 fx in 2.18 Gy per fraction, while in the MRI group, the planning target volume was irradiated at 60 Gy/30fx in 2.0 Gy per fraction. The trial was registered at Chictr.org.cn (ChiCTR2100052340) on October 24, 2021. Survival rates were compared, and multivariate analyses were conducted. Results The median follow-up duration was 16 months. Compared with the MRI group, patients in the DWI group had better 18-month progression-free survival (PFS) 75.1% vs. 53.6%; P  = 0.006), local recurrence-free survival (LRFS) (83.4% vs. 61.8%; P  = 0.010), and locoregional recurrence-free survival (73.1% vs. 64.9%; P  = 0.025). Grade 3–4 toxicities between the two groups showed no significant difference. Multivariate analysis revealed that DWI-guided DP-IMRT was an independent prognostic factor for PFS and LRFS. Conclusion Compared with conventional MRI-based IMRT, DWI-guided DP-IMRT improved PFS in patients with recurrent NPC without increasing acute and late toxic effects.

Background The ability to lie still in an MRI scanner is essential for obtaining usable image data. To reduce motion, young children are often sedated, adding significant cost and risk. Objective We assessed the feasibility of using a simple and affordable behavioral desensitization program to yield high-quality brain MRI scans in sedation-free children. Materials and methods 222 children (4–9.9 years), 147 with type 1 diabetes and 75 age-matched non-diabetic controls, participated in a multi-site study focused on effects of type 1 diabetes on the developing brain. T1-weighted and diffusion-weighted imaging (DWI) MRI scans were performed. All children underwent behavioral training and practice MRI sessions using either a commercial MRI simulator or an inexpensive mock scanner consisting of a toy tunnel, vibrating mat, and video player to simulate the sounds and feel of the MRI scanner. Results 205 children (92.3%), mean age 7 ± 1.7 years had high-quality T1-W scans and 174 (78.4%) had high-quality diffusion-weighted scans after the first scan session. With a second scan session, success rates were 100% and 92.5% for T1-and diffusion-weighted scans, respectively. Success rates did not differ between children with type 1 diabetes and children without diabetes, or between centers using a commercial MRI scan simulator and those using the inexpensive mock scanner. Conclusion Behavioral training can lead to a high success rate for obtaining high-quality T1-and diffusion-weighted brain images from a young population without sedation.

The International Carotid Stenting Study (ICSS) of stenting and endarterectomy for symptomatic carotid stenosis found a higher incidence of stroke within 30 days of stenting compared with endarterectomy. We aimed to compare the rate of ischaemic brain injury detectable on MRI between the two groups. Patients with recently symptomatic carotid artery stenosis enrolled in ICSS were randomly assigned in a 1:1 ratio to receive carotid artery stenting or endarterectomy. Of 50 centres in ICSS, seven took part in the MRI substudy. The protocol specified that MRI was done 1–7 days before treatment, 1–3 days after treatment (post-treatment scan), and 27–33 days after treatment. Scans were analysed by two or three investigators who were masked to treatment. The primary endpoint was the presence of at least one new ischaemic brain lesion on diffusion-weighted imaging (DWI) on the post-treatment scan. Analysis was per protocol. This is a substudy of a registered trial, ISRCTN 25337470. 231 patients (124 in the stenting group and 107 in the endarterectomy group) had MRI before and after treatment. 62 (50%) of 124 patients in the stenting group and 18 (17%) of 107 patients in the endarterectomy group had at least one new DWI lesion detected on post-treatment scans done a median of 1 day after treatment (adjusted odds ratio [OR] 5·21, 95% CI 2·78–9·79; p<0·0001). At 1 month, there were changes on fluid-attenuated inversion recovery sequences in 28 (33%) of 86 patients in the stenting group and six (8%) of 75 in the endarterectomy group (adjusted OR 5·93, 95% CI 2·25–15·62; p=0·0003). In patients treated at a centre with a policy of using cerebral protection devices, 37 (73%) of 51 in the stenting group and eight (17%) of 46 in the endarterectomy group had at least one new DWI lesion on post-treatment scans (adjusted OR 12·20, 95% CI 4·53–32·84), whereas in those treated at a centre with a policy of unprotected stenting, 25 (34%) of 73 patients in the stenting group and ten (16%) of 61 in the endarterectomy group had new lesions on DWI (adjusted OR 2·70, 1·16–6·24; interaction p=0·019). About three times more patients in the stenting group than in the endarterectomy group had new ischaemic lesions on DWI on post-treatment scans. The difference in clinical stroke risk in ICSS is therefore unlikely to have been caused by ascertainment bias. Protection devices did not seem to be effective in preventing cerebral ischaemia during stenting. DWI might serve as a surrogate outcome measure in future trials of carotid interventions. UK Medical Research Council, the Stroke Association, Sanofi-Synthélabo, European Union, Netherlands Heart Foundation, and Mach-Gaensslen Foundation.

Whether brain stimulation could modulate brain structure in autism remains unknown. This study explored the impact of continuous theta burst stimulation (cTBS) over the left dorsolateral prefrontal cortex (DLPFC) on white matter macro/microstructure in intellectually able children and emerging adults with autism. Sixty autistic participants were randomized (30 active) and received active or sham cTBS for eight weeks twice per week, 16 total sessions using a double-blind (participant-, rater-, analyst-blinded) design. All participants received high-angular resolution diffusion MR imaging at baseline and week 8. Twenty-eight participants in the active group and twenty-seven in the sham group with good imaging quality entered the final analysis. With longitudinal fixel-based analysis and network-based statistics, we found no significant difference between the active and sham groups in changes of white matter macro/microstructure and connections following cTBS. In addition, we found no association between baseline white matter macro/microstructure and autistic symptom changes from baseline to week 8 in the active group. In conclusion, we did not find a significant impact of left DLPFC cTBS on white matter macro/microstructure and connections in children and emerging adults with autism. These findings need to be interpreted in the context that the current intellectually able cohort in a single university hospital site limits the generalizability. Future studies are required to investigate if higher stimulation intensities and/or doses, other personal factors, or rTMS parameters might confer significant brain structural changes visible on MRI in ASD.

Purpose Concerns of imaging-related radiation exposure in young patients with high survival rates have increased the use of magnetic resonance imaging (MRI) in testicular cancer (TC) stage I. However, computed tomography (CT) is still preferred for metastatic TC. The purpose of this study was to compare whole-body MRI incl. diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) with contrast-enhanced, thoracoabdominal CT in metastatic TC. Methods A prospective, non-inferiority study of 84 consecutive patients (median age 33 years) with newly diagnosed metastatic TC (February 2018–January 2021). Patients had both MRI and CT before and after treatment. Anonymised images were reviewed by experienced radiologists. Lesion malignancy was evaluated on a Likert scale (1 benign–4 malignant). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated on patient and lesion level. The primary outcome was demonstrating non-inferiority regarding sensitivity of MRI compared to CT. The non-inferiority margin was set at 5%. ROC curves and interobserver agreement were calculated. Results On patient level, MRI had 98% sensitivity and 75% specificity compared to CT. On lesion level within each modality, MRI had 99% sensitivity and 78% specificity, whereas CT had 98% sensitivity and 88% specificity. MRI sensitivity was non-inferior to CT (difference 0.57% (95% CI − 1.4–2.5%)). The interobserver agreement was substantial between CT and MRI. Conclusion MRI with DWIBS was non-inferior to contrast-enhanced CT in detecting metastatic TC disease. Trial registration www.clinicaltrials.gov NCT03436901, finished July 1st 2021.

Cerebral embolization during transcatheter aortic valve implantation (TAVI) can lead to a spectrum of clinically relevant manifestations, ranging from overt stroke to mild neurologic or cognitive deficits and subclinical cerebral infarcts. This study sought to determine the frequency of neurologic injury, cerebral ischemic lesions, and cognitive dysfunction in subjects undergoing contemporary commercial TAVI in the United States. Neuro-TAVR is the first prospective, multicenter study to use serial systematic neurologic and cognitive assessments and diffusion-weighted magnetic resonance imaging (at 4 ± 2 days after procedure) to investigate the incidence and severity of neurologic injury after contemporary unprotected TAVI in the United States. A total of 44 consecutive patients underwent TAVI at 5 US sites. Diffusion-weighted magnetic resonance imaging lesions were detected in 94%, with a mean of 10.4 ± 15.3 lesions per subject and a median total lesion volume of 295 mm3 (interquartile range 71.6 to 799.6 mm3). New neurologic impairment (worsening in National Institutes of Health Stroke Scale score from baseline with new cerebral lesions) occurred in 22.6% (7 of 31) of subjects at discharge and 14.8% (4 of 27) at 30 days. In addition, cognitive decrements from baseline were identified by the Montreal Cognitive Assessment in 33% (12 of 36) of subjects at discharge and 41% (13 of 32) at 30 days. In conclusion, this contemporary cohort of US patients confirms that TAVI results in cerebral infarction in most patients and that 1 in 5 patients have measurable neurologic impairment and 1 in 3 patients have decrease in cognitive measures by Montreal Cognitive Assessment score after TAVI, reinforcing the need for methods to mitigate the risk of brain injury during TAVI.