Tesla MRI Research Articles

Comparison between 1.5 and 3-Tesla MRI findings in Ménière’s disease

Introduction3 T-MRI of the inner ear has been used to identify the endolymphatic hydrops (EH) phenomenon, and less frequently 1.5 T-MRI. The aim of this study was to assess whether there was agreement between findings of EH at 1.5 T MRI and those obtained at 3.0 T MRI in patients clinically diagnosed with definite Meniere disease (MD).MethodsCross-sectional, blinded study was conducted in a tertiary neurotology ambulatory practice. Thirty patients with clinical diagnosis of unilateral definite MD was included. Two MRI exams (1.5 T and 3.0 T) were performed for each patient and were evaluated by two examiners (E1, E2) who were blinded to the symptomatic ear. An analysis of intra-and inter-examiner agreement was performed. It was determined whether there was an association between MRI findings and disease duration, symptom severity, and MD clinical stage.ResultsE1 found EH at 3 T-MRI in 26 (86.66%) patients and at 1.5 T-MRI in 25 (83.33%). E2 found EH in 25 (83.33%) patients in 3 T-MRI and in 22 (73.33%) at 1.5 T-MRI. The agreement between the examiners’ assessments in relation to the EH was high (0.844) for the 3 T MRI and substantial for the 1.5 T, both statistically significant. There was no statistically significant relationship between EH imaging findings and clinical disease severity and course.Discussion1.5 T and 3.0 T MRI images agreed regarding the findings of absence or presence of cochlear hydrops (CH) and vestibular hydrops (VH). The degrees of CH and VH found at 3.0 T MRI in symptomatic ear were not associated with clinical aspects and the stage of disease.

Investigation of intrafractional spinal cord and spinal canal movement during stereotactic MR-guided online adaptive radiotherapy for kidney cancer.

This study aimed to investigate the intrafractional movement of the spinal cord and spinal canal during MR-guided online adaptive radiotherapy (MRgART) for kidney cancer. All patients who received stereotactic MRgART for kidney cancer between February 2022 and February 2024 were included in this study. Patients received 30-42 Gy in 3-fraction MRgART for kidney cancer using the Elekta Unity, which is equipped with a linear accelerator and a 1.5 Tesla MRI. MRI scans were performed at three points during each fraction: for online planning, position verification, and posttreatment assessment. The spinal cord was contoured from the upper edge of Th12 to the medullary cone, and the spinal canal was contoured from Th12 to L3, using the first MRI. These contours were adjusted to the second and third MR images via deformable image registration, and movements were measured. Margins were determined via the formula "1.3×Σ+0.5×σ" and 95% prediction intervals. A total of 22 patients (66 fractions) were analyzed. The median interval between the first and third MRI scans were 38 minutes. The mean ± standard deviation of the spinal cord movements after this interval were -0.01 ± 0.06 for the x-axis (right-left), 0.01 ± 0.14 for the y-axis (caudal-cranial), 0.07 ± 0.05 for the z-axis (posterior-anterior), and 0.15 ± 0.08 for the 3D distance, respectively. The correlation coefficients of the 3D distance between the spinal cord and the spinal canal was high (0.92). The calculated planning organ at risk volume margin for all directions was 0.11 cm for spinal cord. The 95% prediction intervals for the x-axis, y-axis, and z-axis were -0.11-0.09 cm, -0.23-0.25 cm and -0.14-0.03 cm, respectively. Margins are necessary in MRgART to compensate for intrafractional movement and ensure safe treatment delivery.

Integrating Diffusion-weighted and Perfusion-weighted Imaging for Improved Grading and Characterization of Brain Tumors

Objective: This study aims to evaluate the role of Diffusion-Weighted Imaging (DWI) and Perfusion-Weighted Imaging (PWI) in the detection, characterization, and grading of brain tumors, focusing on their correlation with histopathological findings. Materials and Methods: A total of 40 patients with intracranial mass lesions underwent DWI, PWI, and conventional MRI using a 1.5 Tesla MRI scanner. Apparent Diffusion Coefficient (ADC) values were calculated for tumor core, peritumoral edema, and normal brain tissue. Cerebral Blood Volume (CBV), Cerebral Blood Flow (CBF), and Mean Transit Time (MTT) were analyzed using PWI. Data were statistically analyzed, with a p-value ≤ 0.05 considered significant. Results: The study included 38 neoplastic lesions and 2 tuberculomas. DWI showed distinct ADC values for different tumors, with meningiomas having a mean ADC of 0.84 ± 0.3 × 10⁻³ mm²/s and schwannomas a higher ADC of 2.14 × 10⁻³ mm²/s. PWI revealed elevated relative CBV in high-grade gliomas (mean: 2.1 ± 0.76), while lower rCBV was observed in metastases (mean: 0.5 ± 0.26). Tuberculomas exhibited intermediate perfusion characteristics. Conclusion: DWI and PWI, in conjunction with conventional MRI, enhance the diagnostic accuracy for brain tumors by providing valuable information on tumor cellularity and vascularity. These techniques aid in distinguishing between tumor types, grades, and associated edema, thus improving clinical decision-making and treatment planning.

Integrating standard epilepsy protocol, ASL-perfusion, MP2RAGE/EDGE and the MELD-FCD classifier in the detection of subtle epileptogenic lesions: a 3 Tesla MRI pilot study.

Malformations of cortical development (MCDs) in children with focal epilepsy pose significant diagnostic challenges, and a precise radiological diagnosis is crucial for surgical planning. New MRI sequences and the use of artificial intelligence (AI) algorithms are considered very promising in this regard, yet studies evaluating the relative contribution of each diagnostic technique are lacking. The study was conducted using a dedicated "EPI-MCD MR protocol" with a 3 Tesla MRI scanner in patients with focal epilepsy and previously negative MRI. MRI sequences evaluated included 3D FLAIR, 3D T1 MPRAGE, T2 Turbo Spin Echo (TSE), 3D T1 MP2RAGE, and Arterial Spin Labelling (ASL). Two paediatric neuroradiologists scored each sequence for localisation and extension of the lesion. The MELD-FCD AI classifier's performance in identifying pathological findings was also assessed. We only included patients where a diagnosis of MCD was subsequently confirmed on histology and/or sEEG. The 3D FLAIR sequence showed the highest yield in detecting epileptogenic lesions, with 3D T1 MPRAGE, T2 TSE, and 3D T1 MP2RAGE sequences showing moderate to low yield. ASL was the least useful. The MELD-FCD classifier achieved a 69.2% true positive rate. In one case, MELD identified a subtle area of cortical dysplasia overlooked by the neuroradiologists, changing the management of the patient. The 3D FLAIR sequence is the most effective in the MRI-based diagnosis of subtle epileptogenic lesions, outperforming other sequences in localisation and extension. This pilot study emphasizes the importance of careful assessment of the value of additional sequences.

3D Creatine Kinase Imaging (CKI) for In Vivo Whole-Brain Mapping of Creatine Kinase Reaction Rates with 31P-Magnetization Transfer MR Fingerprinting.

The creatine kinase (CK) is a key enzyme involved in brain bioenergetics, but imaging its activity noninvasively in the human brain remains a significant challenge. This study aims to advance the magnetization transfer (MT)-31P magnetic resonance fingerprinting (MRF) framework for 3D Creatine Kinase Imaging (CKI), delivering the first whole-brain CK reaction rate maps. The method was implemented and validated on a clinical 7 Tesla MRI scanner with a 49:30-minute acquisition time and the within-session reproducibility was assessed. The CKI method successfully enables the whole-brain mapping of CK reaction rates, showing robust reproducibility with coefficients of variation (CV) below 11% for 25-minute scan sessions. Furthurmore, CKI acquisition provided simultaneous mapping of adenosine triphosphate (ATP) and phosphocreatine (PCr) concentrationratios, PCr longitudinal relaxation time (T 1 PCr ), and phosphorus-based B0 maps at a 7.2 × 7.2 × 20 mm 3 resolution. CKI provides, for the first time,3D whole-brain mapping of k CK rates in high resolution, using a user-friendly, push-button approach. A functional CKI (fCKI) study demonstrated the first CK activation cluster map in response to visual stimulation, revealing a mean 17% increase in CK rates in the visual cortex. The novel imaging modalities, CKI and fCKI, have the potential to offer new insights into brain bioenergetics both at rest and during activity.

ECCENTRIC: A fast and unrestrained approach for high-resolution in vivo metabolic imaging at ultra-high field MR

Abstract A novel method for fast and high-resolution metabolic imaging, called ECcentric Circle ENcoding TRajectorIes for Compressed sensing (ECCENTRIC), has been developed at 7 Tesla MRI. ECCENTRIC is a non-Cartesian spatial-spectral encoding method designed to accelerate magnetic resonance spectroscopic imaging (MRSI) with high signal-to-noise at ultra-high field. The approach provides flexible and random sampling of the Fourier space without temporal interleaving to improve spatial response function and spectral quality. ECCENTRIC enables the implementation of spatial-spectral MRSI with reduced gradient amplitudes and slew-rates, thereby mitigating electrical, mechanical, and thermal stress of the scanner hardware. Moreover, it exhibits robustness against timing imperfections and eddy-current delay. Combined with a model-based low-rank reconstruction, this approach enables simultaneous imaging of up to 14 metabolites over the whole brain at 2–3 mm isotropic resolution in 4–10 min. MRSI ECCENTRIC was performed on four healthy volunteers, yielding high-resolution spatial mappings of neurochemical profiles within the human brain. This innovative tool introduces a novel approach to neuroscience, providing new insights into the exploration of brain activity and physiology.

Reduced neurovascular coupling of the visual network in migraine patients with aura as revealed with arterial spin labeling MRI: is there a demand-supply mismatch behind the scenes?

BackgroundAlthough neuroimaging investigations have consistently demonstrated that “hyperresponsive” and “hyperconnected” visual cortices may represent the functional substrate of cortical spreading depolarization in patients with migraine with aura, the mechanisms which underpin the brain “tendency” to ignite the cortical spreading depolarization and, consequently, aura phenomenon are still matter of debate. Considering that triggers able to induce aura phenomenon constrain brain to increase global (such as physical activity, stressors and sleep abnormalities) or local (such as bright light visual stimulations) energy demand, a vascular supply unable to satisfy the increased energy requirement could be hypothesized in these patients.MethodsTwenty-three patients with migraine with aura, 25 patients with migraine without aura and 20 healthy controls underwent a 3-Tesla MRI study. Cerebral blood flow and local functional connectivity (regional homogeneity) maps were obtained and registered to the MNI space where 100 cortical regions were derived using a functional local-global normative parcellation. A surrogate estimate of the regional neurovascular coupling for each subject was obtained at each parcel from the correlation coefficient between the z-scored ReHo map and the z-scored cerebral blood flow maps.ResultsA significantly higher regional cerebral blood flow across the visual cortex of both hemispheres (i.e. fusiform and lingual gyri) was detected in migraine with aura patients when compared to patients with migraine without aura (p < 0.05, corrected for multiple comparisons). Concomitantly, a significantly reduced neurovascular coupling (p < 0.05, false discovery rate corrected) in the primary visual cortex parcel (VIS-4) of the large-scale visual network was observed in the left hemisphere of patients with migraine with aura (0.23±0.03), compared to both patients with migraine without aura (0.32±0.05) and healthy controls (0.29±0.05).ConclusionsVisual cortex neurovascular “decoupling” might represent the “link” between the exposure to trigger factors and aura phenomenon ignition. While physiological vascular oversupply may compensate neurovascular demand-supply at rest, it becomes inadequate in case of increased energy demand (e.g. when patients face with trigger factors) paving the way to the aura phenomenon ignition in patients with migraine with aura. Whether preventive treatments may exert their therapeutic activity on migraine with aura restoring the energy demands and cerebral blood flow trade-off within the visual network should be further investigated.

Multicenter validation of automated detection of paramagnetic rim lesions on brain MRI in multiple sclerosis.

Paramagnetic rim lesions (PRLs) are an MRI biomarker of chronic inflammation in people with multiple sclerosis (MS). PRLs may aid in the diagnosis and prognosis of MS. However, manual identification of PRLs is time-consuming and prone to poor interrater reliability. To address these challenges, the Automated Paramagnetic Rim Lesion (APRL) algorithm was developed to automate PRL detection. The primary objective of this study is to evaluate the accuracy of APRL for detecting PRLs in a multicenter setting. We applied APRL to a multicenter dataset, which included 3-Tesla MRI acquired in 92 participants (43 with MS, 14 with clinically isolated syndrome [CIS]/radiologically isolated syndrome [RIS], 35 without RIS/CIS/MS). Subsequently, we assessed APRL's performance by comparing its results with manual PRL assessments carried out by a team of trained raters. Among the 92 participants, expert raters identified 5637 white matter lesions and 148 PRLs. The automated segmentation method successfully captured 115 (78%) of the manually identified PRLs. Within these 115 identified lesions, APRL differentiated between manually identified PRLs and non-PRLs with an area under the curve (AUC) of.73 (95% confidence interval [CI]: [.68,.78]). At the subject level, the count of APRL-identified PRLs predicted MS diagnosis with an AUC of.69 (95% CI: [.57,.81]). Our study demonstrated APRL's capability to differentiate between PRLs and lesions without paramagnetic rims in a multicenter study. Automated identification of PRLs offers greater efficiency over manual identification and could facilitate large-scale assessments of PRLs in clinical trials.

Utility of diffusion-weighted imaging in differentiating benign and malignant breast lesions

Background: Breast cancer presents a significant global health burden. An accurate differentiation between benign and malignant lesions is imperative for timely intervention. While dynamic contrast enhanced MRI (DCE-MRI) is highly sensitive, its specificity is limited. This has led to the exploration of diffusion-weighted imaging (DWI) in distinguishing between benign and malignant breast lesions.Objectives: The study aimed to explore the diagnostic utility of DWI in distinguishing between benign and malignant breast lesions.Method: Assessment of 38 breast lesions using DWI with a b value of 800 s/mm2, performed with 3 Tesla MRI. The diagnostic performance of two different region of Interest (ROI) placement approaches was compared to obtain a feasible cut-off value of apparent diffusion coefficient (ADC) to differentiate between malignant and benign lesions. The histopathological reports were used as the gold standard.Results: ADC values of malignant lesions were significantly lower than those of benign lesions (0.84 × 10−3 mm2/s vs. 1.54 × 10−3 mm2/s). The average ADC measured using a small-sized 2D ROI including the darkest part in the ADC map, performed better than the large 2D ROI covering the entire lesion.Conclusion: Using a cut-off value of 0.98 × 10−3 mm2/s, ADC obtained high sensitivity (90%) and specificity (88.9%) in distinguishing between benign and malignant breast lesions.Contribution: Utilising quantitative analysis of DWI with ADC value measurement, reliably distinguished between benign and malignant breast lesions in this cohort, especially when employing a higher b value of 800 s/mm2.

229 - Evaluation of image quality in 1.5 tesla MRI scanner in Nepal

229 - Evaluation of image quality in 1.5 tesla MRI scanner in Nepal

REVOLUTIONIZING ONCOLOGY IMAGING: A PARADIGM SHIFT THROUGH STANDARDIZED MRI PROTOCOLS: VOLUME 2

Introduction: Oncology imaging is always developing, thus rapid and precise diagnosis are essential for cancer therapy. Recognizing the importance of Magnetic Resonance Imaging, our Mahamana Pandit Madan Mohan Malaviya Cancer Centre is standardizing MRI protocols to improve inspection and interpretation. This project aims to standardize, eliminate variance, and speed up patient care choices. Methods: Our standardized MRI procedures summarize scan parameters, sequences, modes, matrix and other data by body part. A 3 Tesla MRI machine was used to study how scanner differences affect parameters. Detailing appropriate pathological visualization sequences allowed diagnostic versatility. Localiser or scanogram was emphasized for exact scan plane alignment, ensuring uniform pictures for smooth comparisons. Results:Specific procedures were established for certain anatomical locations, with a focus on precise patient placement. Optimizing the localizer setup and selecting the appropriate coil can enhance the quality of images and increase diagnostic accuracy. Discussion: The conversation emphasizes the crucial need of standardizing MRI methods to ensure prompt and precise cancer diagnosis. The benefits of using this technology, such as maintaining consistency, saving time, and improving picture quality, help speed up the diagnostic process and lead to better outcomes for patients. Conclusion: Standardizing MRI procedures is a major step toward efficient and patient-centered cancer imaging, addressing varied oncological issues and improving consistency, time efficiency, and picture quality. Staff training and cooperation put our institution at the forefront of technology advances to improve cancer patient outcomes. We aim to enhance cancer care and treatment via cooperation, improvement, and a patient-centric approach.

Structural connectivity of dopaminergic pathways in major depressive disorder: An ultra-high resolution 7-Tesla diffusion MRI study

Accumulating evidence points to imbalanced dopamine (DA) signaling and circulating levels in the pathophysiology of major depressive disorder (MDD). However, the use of conventional MRI scanners and acquisition techniques has prevented a thorough examination of DA neural pathways in MDD. We uniquely employed ultra-high field diffusion MRI at 7.0 Tesla to map the white matter architecture and integrity of several DA pathways in MDD patients. Fifty-three MDD patients and 12 healthy controls (HCs) were enrolled in the final analysis. Images were acquired using a 7.0 Tesla MRI scanner. FreeSurfer was used to segment components of DA pathways, and MRtrix was used to perform preprocessing and tractography of mesolimbic, mesocortical, nigrostriatal, and unconventional DA pathways. Bayesian analyses assessed the impact of MDD and clinical features on DA tracts. MDD was associated with perturbed white matter microstructural properties of the nigrostriatal pathway, while several MDD features (severity of depression/age of onset/insomnia) related to connectivity changes within mesocortical, nigrostriatal, and unconventional pathways. MDD is associated with microstructural differences in the nigrostriatal pathway. The findings provide insight into the structural architecture and integrity of several DA pathways in MDD, and implicate their involvement in the clinical manifestation of MDD.

The transepicondylar distance is a reliable and easily measured parameter for estimating femoral cartilage surface area using MRI.

Different cartilage repair techniques are widely used to regenerate cartilage, such as autologous chondrocyte implantation (ACI), osteochondral autograft transfer, microfracturing and minced cartilage. Defect size is a key parameter for selecting the best procedure to repair cartilage. However, the defect's size is not related to the patient's total cartilage surface. This is because assessing the femoral cartilage surface area is time-consuming and therefore unsuitable in the daily clinical routine. It has been proposed that the femur's total cartilage area correlates positively with the transepicondylar distance (TEA). The knees of 40 subjects were analysed. Their average age was 30.1 ± 8.6 years. Twenty-four female and 16 male subjects were examined. Their mean body height was 176.2 ± 8.8 cm. MRI scans were performed via 3-Tesla MRI. These data were postprocessed and quantified using the browser-based, customizable SATORI platform (Fraunhofer MEVIS). This software computed the femoral cartilage surface area (FeCA), the patella cartilage surface area (PCA), the TEA and the patella length. Body height reveals a good correlation (r = 0.722, p < 0.001) with the distal femur's cartilage area surface. However, regression analysis shows only moderate dependence (R2: 0.514). A very good correlation (r = 0.830, p < 0.001) was observed between the TEA distance and the total cartilage surface area of the distal femur. The regression analysis yields a good value (R2: 0.684). The cranio-caudal length of the patella was chosen as a suitably measurable two-dimensional parameter for correlation analysis with the patella's total cartilage surface area. Those results yield a poor correlation (r = 0.577, p < 0.001) between the two parameters, and regression analysis reveals a low value (R2: 0.384). The TEA is a reliable parameter for estimating the femur's cartilage area using MRI. A simple determination of this parameter allows the estimation of the femur's total cartilage area as well as the surface-corrected defect size (SCDS) in daily routine. Level II.

Analysis of myocardial T1, T2, and T2* values by age, sex, and cardiac segments in normal population: a prospective study.

This study examines myocardial T1, T2, and T2* values in a sizable cohort of healthy volunteers, analyzing variations by age, sex, and cardiac segments. It offers a novel approach to defining normal parametric mapping boundaries and represents the first comprehensive study of its kind in Turkey. Our prospective study was conducted between August 2021 and August 2022. Healthy volunteers aged 20-80 were grouped, with at least eight females and eight males per decade. Cardiac MRI examination measured T1 and T2 times in 16 left ventricle segments using parametric mapping techniques on a 1.5 Tesla MRI device. T2* mapping was also performed on the mid-section interventricular septum. The data analysis considered the impact of age, sex, and segments. One hundred eighteen cases were included in the study. Female volunteers observed significantly higher T1, T2, and T2* values than male volunteers. For the T2* and T1 times, significantly lower values were detected in women over 50 than those under 50. It was observed that the Midventricular approach (middle section) gave closer results than the Midventricular Septal approach (septal region of middle section) in predicting Global times. We present the normal reference ranges for cardiac T1, T2, and T2* times in a large cohort of healthy volunteers with homogeneous sex and age distribution. Sex was the most influential factor in our study. Therefore, we suggest using separate reference values for males, and females above and below 50 years old, instead of the standard reference intervals that do not account for specified sex in current guidelines.

Characteristics of Alzheimer’s Disease and Mild Cognitive Impairment Influenced by the Time of Onset

Introduction: Although the prevalence of Alzheimer’s disease (AD) is higher in older people compared to younger people, dementia has also been documented in younger adults. Although early-onset dementia and late-onset dementia had been considered a single disease in pathological investigations, many studies revealed differences in cognitive and neuroimaging changes between them. We evaluated differences in cognitive and neuroimaging changes among the following groups: individuals with early-onset AD (EOAD), late-onset AD (LOAD), early-onset mild cognitive impairment (EOMCI), or late-onset MCI (LOMCI), and healthy controls (HCs). Methods: Patients underwent both a 1.5 Tesla magnetic resonance imaging scan and the Mini-Mental State Examination (MMSE). Differences in regional gray matter volumes and MMSE subscales were investigated among the five diagnostic groups. Results: Compared to the EOAD group, the LOAD group had significantly higher scores on orientation in place. Compared to the LOMCI patients, the EOMCI patients achieved significantly higher recall scores. The LOAD and LOMC groups showed significant volume reductions in bilateral medial temporal regions compared to the HCs. The EOAD and EOMCI groups did not show significant atrophy of the medial temporal region compared to the HC group. Conclusions: The hippocampal volume and memory were preserved in the patients with EOMCI or EOAD compared to those with LOMCI or LOAD. These findings may indicate that the distinct and differing patterns of neuropsychological changes between EOAD and LOAD are also common in MCI, which is intermediate between normal cognition and AD.

Patterns of cortical thickness alterations in degenerative cervical myelopathy: associations with dexterity and gait dysfunctions.

Degenerative cervical myelopathy (DCM) can lead to significant brain structural reorganization. The association between the cortical changes and specific motor symptoms in DCM has yet to be fully elucidated. We investigated the associations between cortical thickness changes with neurological symptoms, such as dexterity and gait abnormalities, in patients with DCM in a case-control study. A 3 Tesla MRI scanner was used to acquire high-resolution T1-weighted structural scans from 30 right-handed patients with DCM and 22 age-matched healthy controls. Pronounced cortical thinning was observed in DCM patients relative to healthy controls, particularly in the bilateral precentral and prefrontal gyri, left pars triangularis, left postcentral gyrus, right transverse temporal and visual cortices (P ≤ 0.04). Notably, cortical thickness in these regions showed strong correlations with objective motor deficits (P < 0.0001). Specifically, the prefrontal cortex, premotor area and supplementary motor area exhibited significant thickness reductions correlating with diminished dexterity (R2 = 0.33, P < 0.0007; R2 = 0.34, P = 0.005, respectively). Similarly, declines in gait function were associated with reduced cortical thickness in the visual motor and frontal eye field cortices (R2 = 0.39, P = 0.029, R2 = 0.33, P = 0.04, respectively). Interestingly, only the contralateral precuneus thickness was associated with the overall modified Japanese Orthopaedic Association (mJOA) scores (R2 = 0.29, P = 0.003). However, the upper extremity subscore of mJOA indicated an association with the visual cortex and the anterior prefrontal (R2 = 0.48, P = 0.002, R2 = 0.33, P = 0.0034, respectively). In conclusion, our findings reveal patterns of cortical changes correlating with motor deficits, highlighting the significance of combining objective clinical and brain imaging assessments for understanding motor network dysfunction in DCM.

The use of 7T MRI in multiple sclerosis: review and consensus statement from the North American Imaging in Multiple Sclerosis Cooperative.

The use of ultra-high-field 7-Tesla (7T) MRI in multiple sclerosis (MS) research has grown significantly over the past two decades. With recent regulatory approvals of 7T scanners for clinical use in 2017 and 2020, the use of this technology for routine care is poised to continue to increase in the coming years. In this context, the North American Imaging in MS Cooperative (NAIMS) convened a workshop in February 2023 to review the previous and current use of 7T technology for MS research and potential future research and clinical applications. In this workshop, experts were tasked with reviewing the current literature and proposing a series of consensus statements, which were reviewed and approved by the NAIMS. In this review and consensus paper, we provide background on the use of 7T MRI in MS research, highlighting this technology's promise for identification and quantification of aspects of MS pathology that are more difficult to visualize with lower-field MRI, such as grey matter lesions, paramagnetic rim lesions, leptomeningeal enhancement and the central vein sign. We also review the promise of 7T MRI to study metabolic and functional changes to the brain in MS. The NAIMS provides a series of consensus statements regarding what is currently known about the use of 7T MRI in MS, and additional statements intended to provide guidance as to what work is necessary going forward to accelerate 7T MRI research in MS and translate this technology for use in clinical practice and clinical trials. This includes guidance on technical development, proposals for a universal acquisition protocol and suggestions for research geared towards assessing the utility of 7T MRI to improve MS diagnostics, prognostics and therapeutic efficacy monitoring. The NAIMS expects that this article will provide a roadmap for future use of 7T MRI in MS.

Age-related differences in human cortical microstructure depend on the distance to the nearest vein

Abstract Age-related differences in cortical microstructure are used to understand the neuronal mechanisms that underlie human brain ageing. The cerebral vasculature contributes to cortical ageing, but its precise interaction with cortical microstructure is poorly understood. In a cross-sectional study, we combine venous imaging with vessel distance mapping to investigate the interaction between venous distances and age-related differences in the microstructural architecture of the primary somatosensory cortex, the primary motor cortex and additional areas in the frontal cortex as non-sensorimotor control regions. We scanned 18 younger adults and 17 older adults using 7 Tesla MRI to measure age-related changes in longitudinal relaxation time (T1) and quantitative susceptibility mapping (QSM) values at 0.5 mm isotropic resolution. We modelled different cortical depths using an equi-volume approach and assessed the distance of each voxel to its nearest vein using vessel distance mapping. Our data reveal a dependence of cortical quantitative T1 values and positive QSM values on venous distance. In addition, there is an interaction between venous distance and age on quantitative T1 values, driven by lower quantitative T1 values in older compared to younger adults in voxels that are closer to a vein. Together, our data show that the local venous architecture explains a significant amount of variance in standard measures of cortical microstructure and should be considered in neurobiological models of human brain organisation and cortical ageing.

Optimizing prostate cancer detection in transition zone: an analysis of apparent diffusion coefficient values in prostate magnetic resonance imaging evaluation with Prostate Imaging Reporting and Data System (PI-RADS) assessment.

Multiparametric magnetic resonance imaging (mpMRI) is increasingly used for the early detection of clinically significant prostate cancer (csPCa). However, the achievement of accurate detection rates, particularly for transition zone (TZ) lesions, remains challenging. We investigated the relationship between apparent diffusion coefficient (ADC) values in Prostate Imaging Reporting and Data System (PI-RADS) 3-5 lesions and csPCa within the TZ. We retrospectively evaluated TZ lesions in patients who underwent 3.0 Tesla MRI followed by MRI-targeted/transrectal ultrasound fusion biopsies (MRI-FBx). Fusion biopsies were performed for potentially cancerous lesions, defined as lesions with PI-RADS scores 3-5. We analyzed 196 lesions for which fusion biopsies were performed. The overall prostate cancer (PCa) detection rate was 53.6% (105/196); csPCa constituted 33.7% (66/196) of cases. The minimum ADC value was significantly lower for patients with csPCa (484.9±112.3 µm2/s) than for patients with benign histology or non-csPCa (P<0.001). Older age, higher initial prostate-specific antigen level, larger region of interest, and minimum and mean ADC values were associated with the presence of csPCa. Multivariate analysis indicated that only the minimum ADC value was an independent predictor of csPCa. Using a cutoff minimum ADC value <561 µm2/s to detect csPCa in TZ lesions increased the detection rate to 57.4% (54/94). The minimum ADC value provides substantial additional information regarding the presence of csPCa in the TZ, potentially improving the detection rates for lesions rated as PI-RADS 3-5 and informing the need for follow-up biopsies in areas that are initially cancer-free.

Radiofrequency Lesion in the Atrial Wall: How Variable Is It? 9.4 Tesla MRI Analysis of Radiofrequency Lesion Volume in a Swine Model.

Background/Objectives: Most data on radiofrequency (RF) effects come from ex vivo or in vitro studies that quantify lesions using width and/or depth, while electrophysiologists use manufacturers' indirect indices. The objective of this study was to evaluate RF lesion volume by high-resolution MRI of excised lesions in an in vivo porcine model, comparing a low-energy long-duration (LE) (20 W, 50 s) RF application strategy with a high-energy short-duration (HE) (50 W, 20 s) one. Methods: Eighteen piglets were divided into LE (n = 9) and HE groups (n = 9). RF applications were performed at four locations in both atria. Animals were sacrificed after 5-7 days, and RF lesion specimens were excised, fixed, and analyzed by 9.4 Tesla MRI. RF lesion volume, variability (variance), depth, and any extracardiac lesions were compared between the groups. Results: Seventy RF applications were performed (36 LE, 34 HE). MRI analyzed 26 LE and 28 HE samples. The HE group showed 35% higher volume than the LE group (100.2 mm3 (±81.2) in LE vs. 178.3 mm3 (±163.7) in HE, p = 0.033). RF volume variance was 6.6 mm3 in LE and 40.3 mm3 in HE. The HE group had more complications (seven vs. zero, p = 0.02) and extracardiac lesions (18 vs. 14, p = 0.613). Conclusions: There was large and unpredictable variability in RF injury on the atrial wall, even under controlled conditions, which could explain arrhythmia recurrences. The greatest lesion variability was found during HE applications. The dose/effect relationship of RF needs careful study for treating cardiac arrhythmias.