Magnetic Resonance Imaging Protocol Research Articles

Magnetic Resonance Imaging Parameters in the Subacute Phase after Traumatic Cervical Spinal Cord Injury: A Prospective, Observational Longitudinal Study. Part 1: Conventional Imaging Characteristics.

Magnetic resonance imaging (MRI) remains the gold standard for evaluating spinal cord tissue damage after spinal cord injury (SCI). Several MRI findings may have some prognostic potential, but their evolution over time, especially from the subacute to the chronic phase has not been studied extensively. We performed a prospective observational longitudinal study exploring the evolution of MRI parameters from the subacute to chronic phase after human traumatic cervical SCI. The study, conducted between 2016 and 2021, involved standardized neurological examinations and MRI scans 1 month, 3 months, and 1 year after SCI. The study cohort comprises 52 patients with cervical SCI. Patients were classified into AIS grades (American Spinal Injury Association Impairment Scale), and neurological recovery was assessed using the Integrated Neurological Change Score. The MRI protocol included various routine sequences, allowing the evaluation of established parameters such as intramedullary hemorrhage, lesion dimensions, maximum spinal cord compression, and various grading scales. The persistence of intramedullary hemorrhage one month after injury was associated with worse lower extremity motor scores and pinprick values after 3 months, and also in the chronic phase. In addition, dorsal column T2-weighted hyperintensities detected 3 months post-injury and in the chronic phase were related to lower pinprick sensory scores. The basic score and Sagittal Grade at 1 month were predictive for motor function 3 months after SCI and for neurological recovery between 1 and 3 months after injury. The study contributes valuable insights into the utility of routine MRI sequences for evaluating traumatic cervical SCI during the subacute to chronic phase. The identified MRI parameters and scores offer prognostic information and could support clinical decision-making.

A dynamic approach for MR T2-weighted pelvic imaging

T2-weighted 2D fast spin echo sequence serves as the standard sequence in
clinical pelvic MR imaging protocols. However, motion artifacts and blurring caused
by peristalsis present significant challenges. Patient preparation such as administering
antiperistaltic agents is often required before examination to reduce artifacts, which
discomfort the patients. This work introduce a novel dynamic approach for T2
weighted pelvic imaging to address peristalsis-induced motion issue without any patient
preparation.
Approach: A rapid dynamic data acquisition strategy with complementary sampling
trajectory is designed to enable highly undersampled motion-resistant data sampling,
and an unrolling method based on deep equilibrium model is leveraged to reconstruct
images from the dynamic sampled k-space data. Moreover, the fix-point convergence of
the equilibrium model ensures the stability of the reconstruction. The high acceleration
factor in each temporal phase, which is much higher than that in traditional static
imaging, has the potential to effectively freeze pelvic motion, thereby transforming
the imaging problem from conventional motion prevention or removal to motion
reconstruction.
Main results: Experiments on both retrospective and prospective data have
demonstrated the superior performance of the proposed dynamic approach in reducing
motion artifacts and accurately depicting structural details compared to standard static
imaging.
Significance: The proposed dynamic approach effectively captures motion states
through dynamic data acquisition and deep learning-based reconstruction, addressing
motion-related challenges in pelvic imaging.

Differentiation between high-grade gliomas and solitary brain metastases based on multidiffusion MRI model quantitative analysis.

Differentiating high-grade gliomas (HGGs) from solitary brain metastases (SBMs) using conventional magnetic resonance imaging (MRI) remains challenging due to their similar imaging features. This study aimed to evaluate the diagnostic performance of advanced diffusion models, such as neurite orientation dispersion and density imaging (NODDI) and mean apparent propagator magnetic resonance imaging (MAP-MRI), incomparison to traditional techniques like diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI) for distinguishing HGGs from SBMs. In total, 17 patients with HGGs and 26 patients with SBMs were prospectively recruited based on the established inclusion and exclusion criteria. Structural MRI sequences and diffusion spectrum imaging (DSI) were utilized to assess quantitative parameter models, including NODDI, MAP-MRI, DWI, DTI, and DKI. Quantitative parameters were measured for both the tumor parenchymal area and the peritumoral edema area. The quantitative parameters of the two patient groups were compared using either the independent Student's t-test or the Mann-Whitney U test. The effectiveness of each model was evaluated using receiver operating characteristic (ROC) curves and calculating the area under the curve (AUC). Finally, the DeLong test was employed to compare the diagnostic performance of each model through pairwise comparisons of ROC curves. Isotropic volume fraction (Viso) based on NODDI; mean squared displacement (MSD) and the return to plane probabilities (RTPP) based on MAP-MRI; radial diffusivity (RDk) and mean diffusivity (MDk) based on DKI; and axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) based on DTI of the peritumoral edema tumor were significantly different between HGGs and SBMs (p < 0.05). The optimal single discriminant parameters for each model are NODDI_Viso, MAP-MRI_MSD, DKI_MDk, and DTI_AD. Among these, the AUC of Viso (0.809) exceeds that of MSD (0.733), MDk (0.718), and AD (0.779). The combined model, which incorporates DTI_AD, DKI_RD, and NODDI_Viso, demonstrated superior diagnostic performance (0.897). Advanced diffusion MRI quantitative parameters derived from NODDI, such as Viso, have the potential to enhance the differentiation between HGGs and SBMs. The integrated utilization of these models is anticipated to enhance diagnostic accuracy and refine MRI protocols for brain tumor assessment.

MRI-Seed-Wizard: Combining Deep Learning Algorithms with Magnetic Resonance Imaging Enables Advanced Seed Phenotyping.

Evaluation of relevant seed traits is an essential part of most plant breeding and biotechnology programs. There is need for non-destructive, three-dimensional assessment of the morphometry, composition, and internal features of seeds. Here, we introduced a novel tool, MRI-Seed-Wizard, which integrates deep learning algorithms with non-invasive magnetic resonance imaging (MRI) for its use in the new domain - plant MRI. The tool enabled in vivo quantification of 23 grain traits, including volumetric parameters of inner seed structure. Several of these features cannot be assessed using conventional techniques, including X-ray computed tomography. MRI-Seed-Wizard was designed to automate the manual processes of identifying, labeling, and analyzing digital MRI data. We further provide advanced MRI protocols that allow the evaluation of multiple seeds simultaneously to increase throughput. The versatility of MRI-Seed-Wizard in seed phenotyping was demonstrated for wheat (Triticum aestivum) and barley (Hordeum vulgare) grains, and is applicable to a wide range of crop seeds. Thus, artificial intelligence, combined with the most versatile imaging modality - MRI, opens up new perspectives in seed phenotyping and crop improvement.

Assessment of chemical-shift and diffusion-weighted magnetic resonance imaging in differentiating malignant and benign vertebral lesions in oncologic patients. A single institution experience.

To analyze the contribution of two non-standard magnetic resonance imaging (MRI) techniques the chemical-shift image (CSI), and diffusion-weighted imaging (DWI) in distinguishing malignant and benign vertebral bone marrow lesions (VBMLs). Conventional spine MRI protocol, followed by CSI and DWI was performed with a 1.5 T system on 102 oncologic patients between January 2020 and December 2023. From the identified 325 VBMLs, 102 representative lesions (one per patient) were selected. VBMLs were divided into malignant (n = 74) and benign (n = 28) based on histopathology, or imaging follow-up. The quantitative parameters for VBMLs assessment were signal intensity ratio (SIR) derived from CSI and apparent diffusion coefficient (ADC) derived from DWI. The malignant VBMLs had significantly higher SIR values (p < 0.05) and lower ADC values compared to benign VBMLs (p < 0.05). The area under the curve (AUC) was 0.953 (p < 0.001) for SIR, and 0.894 for ADC (p < 0.001) (cut-off at > 0.82, and ≤ 1.57x10-3 mm2/s, respectively). The sensitivity and specificity for SIR were 93.6%, and 88.5%, while for ADC were 88.2% and 92.3% (respectively). The combined use of SIR and ADC improved the diagnostic accuracy to AUC of 0.988 (p < 0.001, cut-off at > 0.19), sensitivity, and specificity of 100.0% and 90.9% (respectively). Quantitative parameters, SIR and ADC, derived from two non-standard MRI techniques, CSI, and DWI, showed diagnostic strength in differentiating malignant and benign VBMLs. Combining both methods can further enhance the diagnostic performance and accuracy of spine MRI in clinical practice.

Overview of ADNI MRI.

The magnetic resonance imaging (MRI) Core has been operating since Alzheimer's Disease Neuroimaging Initiative's (ADNI) inception, providing 20 years of data including reliable, multi-platform standardized protocols, carefully curated image data, and quantitative measures provided by expert investigators. The overarching purposes of the MRI Core include: (1) optimizing and standardizing MRI acquisition methods, which have been adopted by many multicenter studies and trials worldwide and (2) providing curated images and numeric summary values from relevant MRI sequences/contrasts to the scientific community. Over time, ADNI MRI has become increasingly complex. To remain technically current, the ADNI MRI protocol has changed substantially over the past two decades. The ADNI 4 protocol contains nine different imaging types (e.g., three dimensional [3D] T1-weighted and fluid-attenuated inversion recovery [FLAIR]). Our view is that the ADNI MRI data are a greatly underutilized resource. The purpose of this paper is to educate the scientific community on ADNI MRI methods and content to promote greater awareness, accessibility, and use. HIGHLIGHTS: The MRI Core provides multi-platform standardized protocols, carefully curated image data, and quantitative analysis by expert groups. The ADNI MRI protocol has undergone major changes over the past two decades to remain technically current. As of April 25, 2024, the following numbers of image series are available: 17,141 3D T1w; 6877 FLAIR; 3140 T2/PD; 6623 GRE; 3237 dMRI; 2846 ASL; 2968 TF-fMRI; and 2861 HighResHippo (see Table 1 for abbreviations). As of April 25, 2024, the following numbers of quantitative analyses are available: FreeSurfer 10,997; BSI 6120; tensor based morphometry (TBM) and TBM-SYN 12,019; WMH 9944; dMRI 1913; ASL 925; TF-fMRI NFQ 2992; and medial temporal subregion volumes 2726 (see Table 4 for abbreviations). ADNI MRI is an underutilized resource that could be more useful to the research community.

The Douglas-Bell Canada Brain Bank Post-mortem Brain Imaging Protocol

Magnetic resonance imaging (MRI) is a valuable non-invasive tool that has been widely used for in vivo investigations of brain morphometry and microstructural characteristics. Post-mortem MRIs can provide complementary anatomical and microstructural information to in vivo imaging and ex vivo neuropathological assessments without compromising the sample for future investigations. We have developed a post-mortem MRI protocol for the brain specimens of the Douglas-Bell Canada Brain Bank (DBCBB), the largest brain bank in Canada housing over 3000 neurotypical and diseased brain specimens, that allows for acquisition of high-resolution 3T and 7T MRIs. Our protocol can be used to scan DBCBB specimens with minimal tissue manipulation, allowing for feasibly scanning large numbers of post-mortem specimens while retaining the quality of the tissue for downstream histology and immunohistochemistry assessments. We demonstrate the robustness of this protocol despite the dependency of image quality on fixation by acquiring data on the first day of extraction and fixation, to over twenty years post fixation. The acquired images can be used to perform volumetric segmentations, cortical thickness measurements, and quantitative analyses which can be potentially used to link MRI-derived and ex vivo histological measures, assaying both the normative organization of the brain and ex vivo measures of pathology.

304P Multi-modal magnetic resonance imaging protocols in the multi-site brain involvement in dystrophinopathies (BIND) study

304P Multi-modal magnetic resonance imaging protocols in the multi-site brain involvement in dystrophinopathies (BIND) study

Blood-Brain Barrier Integrity Decreases With Higher Blood Pressure: A 7T DCE-MRI Study.

Blood-brain barrier (BBB) integrity is presumed to be impaired in hypertension, resulting from cerebral endothelial dysfunction. Hypertension precedes various cerebrovascular diseases, such as cerebral small vessel disease, and is a risk factor for developing neurodegenerative diseases for which BBB disruption is a preceding pathophysiological process. In this cross-sectional study, we investigated the relation between hypertension, current blood pressure, and BBB leakage in human subjects. BBB leakage was determined in 22 patients with hypertension and 19 age- and sex-matched normotensive controls (median age [range], 65 [45-80] years; 19 men) using a sparsely time-sampled contrast-enhanced 7T magnetic resonance imaging protocol. Structural cerebral small vessel disease markers were visually rated. Multivariable regression analyses, adjusted for age, sex, cardiovascular risk factors, and cerebral small vessel disease markers, were performed to determine the relation between hypertension status, systolic and diastolic blood pressure, mean arterial pressure, drug treatment, and BBB leakage. Both hypertensive and normotensive participants showed mild scores of cerebral small vessel disease. BBB leakage did not differ between hypertensive and normotensive participants; however, it was significantly higher for systolic blood pressure, diastolic blood pressure, and mean arterial pressure in the cortex, and diastolic blood pressure and mean arterial pressure in the gray matter. Effectively treated patients showed less BBB leakage than those with current hypertension. BBB integrity in the total and cortical gray matter decreases with increasing blood pressure but is not related to hypertension status. These findings show that BBB disruption already occurs with increasing blood pressure, before the presence of overt cerebral tissue damage. Additionally, our results suggest that effective antihypertensive medication has a protective effect on the BBB. URL: https://trialsearch.who.int/; Unique identifier: NL7537.

Quantitative Evaluation of Knee Cartilage in Professional Martial Arts Athletes Using T2 Mapping: A Comparative Study.

Although the relationship between high-impact sports like football and basketball and the development of knee osteoarthritis is well established, the effect of martial arts on the knee joint remains unclear. To compare the imaging abnormalities of knee joints and T2 relaxation times of cartilage in professional martial arts athletes and healthy controls. Cross-sectional study. Hospital imaging center. Nine asymptomatic professional martial arts athletes and 18 healthy volunteers. We performed 3T magnetic resonance imaging of the knee on both legs of athletes and the dominant leg of controls. The magnetic resonance imaging protocol included conventional sequences used for morphological assessment (cartilage, meniscus, ligaments, joint effusion, and bone marrow edema) and T2 mapping used for quantitatively evaluating the cartilage. Knee cartilage was manually divided into 8 regions, and T2 relaxation times of the corresponding subregions were measured. Fisher exact test and t test were used to compare the frequency of lesions and cartilage T2 values both between groups and between the athletes' limbs. P < .05 was considered significant. Professional martial arts athletes exhibited significantly higher frequencies of cartilage (55.6% vs 11.1%, P = .023) and ligament lesions (66.7% vs 16.7%, P = .026) compared with the control group. Athletes showed higher T2 values in 3 distinct cartilage segments: the central weight-bearing segment of the medial femoral condyle (P = .006), the medial tibial plateau (P = .012), and the trochlea (P = .032), when compared with the controls. Additionally, the dominant leg of athletes showed significantly higher T2 values compared with the nondominant leg. The findings demonstrated the impact of martial arts on the knee joint, characterized by higher prevalence of lesions and elevated cartilage T2 values, particularly in the medial compartment. The dominant legs of martial arts athletes seem to have higher risk of cartilage degeneration due to the observed interlimb differences in T2 values.

Role of diffusion-weighted imaging in the diagnosis of pituitary region tumors.

This study aimed to assess the role of Diffusion-Weighted Imaging (DWI) in routine pituitary Magnetic Resonance Imaging (MRI) protocols for distinguishing sellar and parasellar tumors, addressing the lack of clear guidelines in contemporary literature. A retrospective analysis of 242 pituitary MRI scans with DWI sequences was conducted in a single-center study using a 1.5T scanner and standard DWI sequence parameters. Measurements of both absolute and relative mean apparent diffusion coefficient (ADC) values, along with minimal ADC values within tumors, were performed. The adopted region of interest (ROI) based method used for these measurements was validated. Invasive pituitary adenomas exhibited significantly lower min ADC and min rADC than meningiomas, with optimal cut-off points of 0.64 (sensitivity 73%, specificity 82%) and 0.78 (sensitivity 73%, specificity 89%), respectively. Post-hemorrhagic pituitary adenomas demonstrated lower ADC values than adamantinomatous craniopharyngiomas, with an AUC of 0.893 for min rADC = 1.07, and Rathke's Cleft Cysts with mucous content, AUC 0.8 for min rADC = 1.01. Specific differentiation with high sensitivity and specificity based on diffusion parameters was observed for these tumor groups. Cystic pituitary non-functional adenomas obtained significantly lower ADC values compared to the adamantinomatous type of craniopharyngiomas and serous Rathke's Cleft Cysts (AUC up to 0.942). The study concludes that integrating DWI into routine pituitary MRI protocols enhances diagnostic accuracy in distinguishing sellar and parasellar tumors. The short scan time of one minute makes DWI a valuable and precise tool, supporting its recommendation as a standard component of pituitary MRI examinations.

Comparative effectiveness of two abbreviated rectal MRI protocols in assessing tumor response to neoadjuvant chemoradiotherapy in patients with rectal cancer.

The present study aimed to compare the effectiveness of two abbreviated magnetic resonance imaging (MRI) protocols in assessing the response to neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer. Data from the examinations of 62 patients with rectal cancer who underwent neoadjuvant CRT and standard contrast-enhanced rectal MRI were retrospectively evaluated. Standard contrast-enhanced T2-weighted imaging (T2-WI), post-contrast T1-weighted imaging (T1-WI) and diffusion-weighted imaging (DWI) MRI, as well as two abbreviated protocols derived from these images, namely protocol AB1 (T2-WI and DWI) and protocol AB2 (post-contrast fat-suppressed (FS) T1-WI and DWI), were assessed. Measurements of lesion length and width, lymph node short-axis length, tumor staging, circumferential resection margin (CRM), presence of extramural venous invasion (EMVI), luminal mucin accumulation (MAIN), mucinous response, mesorectal fascia (MRF) involvement, and MRI-based tumor regression grade (mrTRG) were obtained. The reliability and compatibility of the AB1 and AB2 protocols in the evaluation of tumor response were analyzed. The imaging performed according to the AB1 and AB2 protocols revealed significant decreases in lesion length, width and lymph node size after CRT. These protocols also showed reductions in lymph node positivity, CRM, MRF, EMVI.Furthermore, both protocols were found to be reliable in determining lesion length and width. Additionally, compliance was observed between the protocols in determining lymph node size and positivity, CRM involvement, and EMVI after CRT. In conclusion, the use of abbreviated MRI protocols, specifically T2-WI with DWI sequences or post-contrast FS T1-WI with DWI sequences, is effective for evaluating tumor response in patients with rectal cancer following neoadjuvant CRT. The AB protocols examined in this study yielded similar results in terms of lesion length and width, lymph node positivity, CRM involvement, EMVI, MAIN, and MRF involvement.

Quantifying brain development in the HEALthy Brain and Child Development (HBCD) Study: The magnetic resonance imaging and spectroscopy protocol

The HEALthy Brain and Child Development (HBCD) Study, a multi-site prospective longitudinal cohort study, will examine human brain, cognitive, behavioral, social, and emotional development beginning prenatally and planned through early childhood. The acquisition of multimodal magnetic resonance-based brain development data is central to the study’s core protocol. However, application of Magnetic Resonance Imaging (MRI) methods in this population is complicated by technical challenges and difficulties of imaging in early life. Overcoming these challenges requires an innovative and harmonized approach, combining age-appropriate acquisition protocols together with specialized pediatric neuroimaging strategies. The HBCD MRI Working Group aimed to establish a core acquisition protocol for all 27 HBCD Study recruitment sites to measure brain structure, function, microstructure, and metabolites. Acquisition parameters of individual modalities have been matched across MRI scanner platforms for harmonized acquisitions and state-of-the-art technologies are employed to enable faster and motion-robust imaging. Here, we provide an overview of the HBCD MRI protocol, including decisions of individual modalities and preliminary data. The result will be an unparalleled resource for examining early neurodevelopment which enables the larger scientific community to assess normative trajectories from birth through childhood and to examine the genetic, biological, and environmental factors that help shape the developing brain.

Morphometry of medial temporal lobe subregions using high-resolution T2-weighted MRI in ADNI3: Why, how, and what's next?

This paper for the 20th anniversary of the Alzheimer's Disease Neuroimaging Initiative (ADNI) provides an overview of magnetic resonance imaging (MRI) of medial temporal lobe (MTL) subregions in ADNI using a dedicated high-resolution T2-weighted sequence. A review of the work that supported the inclusion of this imaging modality into ADNI Phase 3 is followed by a brief description of the ADNI MTL imaging and analysis protocols and a summary of studies that have used these data. This review is supplemented by a new study that uses novel surface-based tools to characterize MTL neurodegeneration across biomarker-defined AD stages. This analysis reveals a pattern of spreading cortical thinning associated with increasing levels of tau pathology in the presence of elevated amyloid beta, with apparent epicenters in the transentorhinal region and inferior hippocampal subfields. The paper concludes with an outlook for high-resolution imaging of the MTL in ADNI Phase 4. HIGHLIGHTS: As of Phase 3, the Alzheimer's Disease Neuroimaging Initiative (ADNI) magnetic resonance imaging (MRI) protocol includes a high-resolution T2-weighted MRI scan optimized for imaging hippocampal subfields and medial temporal lobe (MTL) subregions. These scans are processed by the ADNI core to obtain automatic segmentations of MTL subregions and to derive morphologic measurements. More detailed granular examination of MTL neurodegeneration in response to disease progression is achieved by applying surface-based modeling techniques. Surface-based analysis of gray matter loss in MTL subregions reveals increasing and spatially expanding patterns of neurodegeneration with advancing stages of Alzheimer's disease (AD), as defined based on amyloid and tau positron emission tomography biomarkers in accordance with recently proposed criteria. These patterns closely align with post mortem literature on spread of pathological tau in AD, supporting the role of tau pathology in the presence of elevated levels of amyloid beta as the driver of neurodegeneration.

The role of sacro-iliac joint magnetic resonance imaging in the diagnosis of axial spondyloarthritis: focus on differential diagnosis in women.

To review the role of sacro-iliac magnetic resonance imaging (MRI) in the diagnosis of axial spondyloarthritis (AxSpA), with a focus on gender differences. The experience of the authors and the results of an informal literature review are reported. Inflammatory changes of the sacro-iliac joint are the hallmark of AxSpA. Early, non-radiographic sacroiliitis may be diagnosed with MRI through the assessment of bone marrow edema (BMO) as well as concomitant structural damage. The MRI protocol should include three necessary sequences, i.e., fat-saturated T2-weighted sequences on two orthogonal planes, T1-weighted semi-coronal sequence, and fat-suppressed T1-weighted semi-coronal sequence. Inflammatory changes comprise required signs (BMO and/or osteitis) and additional signs, including synovitis (better defined as joint space enhancement), enthesitis, and capsulitis. Structural changes consist of erosions, sclerosis, fat metaplasia, and ankylosis. Due to mechanical axial strain, inflammatory changes in the sacro-iliac joint can be found in healthy individuals, runners, and patients with nonspecific low back pain. The prevalence of BMO is higher in women during pregnancy and postpartum, even 12 months after childbirth, but the extent and distribution of MRI findings may help in the differential diagnosis. Other challenges in the MRI diagnosis of sacroiliitis are subchondral T2 hyperintensity during developmental age, periarticular sclerosis in healthy subjects, or osteitis condensans ilii, and several pathological conditions that may mimic AxSpA, some of which are more frequently found in women. The described diagnostic challenges impose a multidisciplinary approach combining imaging findings with clinical and laboratory data.

Comprehensive MRI assessment reveals subtle brain findings in non-hospitalized post-COVID patients with cognitive impairment.

Impaired cognitive ability is one of the most frequently reported neuropsychiatric symptoms in the post-COVID phase among patients. It is unclear whether this condition is related to structural or functional brain changes. In this study, we present a multimodal magnetic resonance imaging study of 36 post-COVID patients and 36 individually matched controls who had a mild form of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infection from March 2020 to February 2022. This study aimed to investigate structural and functional brain alterations and their correlation with post-COVID symptoms and neurocognitive functions. The study protocol comprised an assessment of physical fatigue [Fatigue Severity Scale (FSS)], mental fatigue (Mental Fatigue Scale (MFS)], depression [Montgomery Asberg Depression Rating Scale (MADRS)], anxiety [Hospital Anxiety and Depression Scale (HAD)], post-COVID Symptoms Severity Score, and neurocognitive status [Repeatable Battery for the Assessment of Neuropsychological Status Update (RBANS)]. The magnetic resonance imaging protocol included morphological sequences, arterial spin labeling (ASL) and dynamic susceptibility contrast-enhanced (DSC) perfusion, diffusion tensor imaging (DTI), and resting-state functional magnetic resonance imaging (fMRI) sequences. Using these protocols, the assessments of macrostructural abnormalities, perfusion, gray matter density, white matter integrity, and brain connectivity were performed. Post-COVID patients had higher levels of physical fatigue, mental fatigue, depression, and anxiety than controls and showed cognitive impairment in all the RBANS domains except in Visuospatial/Construction. The subjective mental fatigue correlated with objective impaired cognitive ability in the RBANS test, particularly in the Attention domain. There were no differences between patients and controls regarding macrostructural abnormalities, regional volumes, regional perfusion metrics, gray matter density, or DTI parameters. We observed a significant positive correlation between RBANS Total Scale Index score and gray matter volume in the right superior/middle-temporal gyrus (p < 0.05) and a significant negative correlation between the white matter integrity and post-COVID symptoms (p < 0.05) in the same area. The connectivity differences were observed between patients and controls in a few regions, including the right middle frontal gyrus, an important area of convergence of the dorsal and ventral attention networks. We also noted a positive correlation between post-COVID symptoms and increased connectivity in the right temporoparietal junction, which is part of the ventral attention system. In non-hospitalized subjects with post-COVID, we did not find any structural brain changes or changes in perfusion, compared to controls. However, we noted differences in connectivity within an important area for attention processes, which may be associated with post-COVID brain fog.

Exploring the diagnostic landscape: A narrative review of the evolving role and advancement of MRI in the detection and characterization of lung câncer

This review aims to evaluate the diagnostic performance of magnetic resonance imaging (MRI) with respect to the detection of lung cancer. Many studies have shown that computed tomography (CT) has increased sensitivity and specificity for the treatment of cancer. The major drawback of CT is the radiation dose imparted by it. x. In most advanced scenarios, Positron emission tomography (PET/MRI) is used. Our goal was also to evaluate the reasons for MRI being the choice of modality. The publications considered in the review were obtained from PubMed/MEDLINE, the Cochrane Library and EMBASE. Only studies published in the English language with the subject modality being MRI or PET/MRI were included. Review articles, case reports and conference reports were excluded from the study. A total of 3140 articles were identified, of which 120 publications were considered. All these studies had an overall surface aim to evaluate the diagnostic performance of MRI in detecting lung cancer. By comparing these publications, we can conclude that MRI can be a potential alternative to CT in detecting cancer lesions 3 mm in diameter or greater. Smaller lesions undetected by MRI were found to be benign and stable during follow-up, indicating the use of this technique for acceptable clinical management. Compared with CT, MRI does not provide any added benefits for lung cancer detection. It offered high sensitivity to large nodules of 3 mm or greater. However, CT has emerged to be beneficial in evaluating small nodules. A multisequence MRI protocol may be helpful in diagnosing lung metastasis with a sensitivity comparable to that of CT.

NeuroMix with MRA: A Fast MR Protocol to Reduce Head and Neck CTA for Patients with Acute Neurologic Presentations.

Overuse of CT-based cerebrovascular imaging in the emergency department and inpatient settings, notably CTA of the head and neck for minor and nonfocal neurologic presentations, stresses imaging services and exposes patients to radiation and contrast. Furthermore, such CT-based imaging is often insufficient for definitive diagnosis, necessitating additional MR imaging. Recent advances in fast MRI may allow timely assessment and a reduced need for head and neck CTA in select populations. We identified inpatients or patients in the emergency department who underwent CTAHN (including noncontrast and postcontrast head CT, with or without CTP imaging) followed within 24 hours by a 3T MRI study that included a 2.5-minute unenhanced multicontrast sequence (NeuroMix) and a 5-minute intracranial time of flight MRA) during a 9-month period (April to December 2022). Cases were classified by 4 radiologists in consensus as to whether NeuroMix and NeuroMix + MRA detected equivalent findings, detected unique findings, or missed findings relative to CTAHN. One hundred seventy-four cases (mean age, 67 [SD, 16] years; 56% female) met the inclusion criteria. NeuroMix alone and NeuroMix + MRA protocols were determined to be equivalent or better compared with CTAHN in 71% and 95% of patients, respectively. NeuroMix always provided equivalent or better assessment of the brain parenchyma, with unique findings on NeuroMix and NeuroMix + MRA in 35% and 36% of cases, respectively, most commonly acute infarction or multiple microhemorrhages. In 8/174 cases (5%), CTAHN identified vascular abnormalities not seen on the NeuroMix + MRA protocol due to the wider coverage of the cervical arteries by CTAHN. A fast MR imaging protocol consisting of NeuroMix + MRA provided equivalent or better information compared with CTAHN in 95% of cases in our population of patients with an acute neurologic presentation. The findings provide a deeper understanding of the benefits and challenges of a fast unenhanced MR-first approach with NeuroMix + MRA, which could be used to design prospective trials in select patient groups, with the potential to reduce radiation dose, mitigate adverse contrast-related patient and environmental effects, and lessen the burden on radiologists and health care systems.

Development of fetal magnetic resonance imaging (MRI) phantom.

Anthropomorphic phantoms play an important role in routine clinical practice. They can be used to calibrate magnetic resonance imaging (MRI) scanners, control the diagnostic equipment quality, and reduce the acquisition time. The latter is especially critical for diagnosing fetal anomalies, which requires optimal image quality within the shortest possible time. This paper aims to develop an MRI fetal phantom and determine the materials that best mimic the magnetic resonance (MR) characteristics of its internal organs. Future phantom features will include simulations of fetal limb movements. A single MRI study of a pregnant woman at 20 weeks 3 days of gestation was used as a reference and for image segmentation. Anonymized Digital Imaging and Communication in Medicine (DICOM) files were imported into 3D Slicer v. 5.2.1 for segmentation of the uterus, fetus, and internal organs. Based on the performed segmentation, a three-dimensional model was obtained for printing on a 3D printer. The mold was 3D printed on an Anycubic Photon M3 Max printer. The paper showcases the selection and manufacturing of compositions to simulate the relaxation times of the fetal organs. Formulations for emulsions and carrageenan- and agar-based hydrogels are presented. The selected compositions were used to fill the 3D printed model. Statistical analysis showed no significant differences in absolute and relative signal values obtained from scans of a pregnant woman at 20 weeks and 3 days and a fetal phantom. During the study, an anthropomorphic fetal phantom was constructed, filled with compositions with relaxation times T1 and T2 similar to the control values of the corresponding tissues. The phantom can be used to set up and optimize fetal MRI protocols, train and educate medical students, residents, graduate students, and X-ray technicians, as well as to timely control image quality and equipment serviceability.

Evaluation of Lesion Burden in Pediatric Patients with Multiple Sclerosis by Computer Aided Algorithm and Comparison with Standard Detection Methods

Background: The aim of this retrospective study was to assess the lesion burden in pediatric patients with multiple sclerosis (pMS) using a computer-assisted algorithm, specifically the VolBrain program. The study aimed to compare the performance of this automated tool with traditional detection methods performed by neuroimaging analysts, providing valuable insights into the potential of automated tools for lesion quantification in pMS. Materials and Methods: The study cohort consisted of 20 PMS patients, aged 10-18 years, registered at Atatürk University Research Hospital. Lesion assessment was performed using the VolBrain program (by an anatomist) and standard detection methods (by a neuroradiologist) using T2 SPACE dark matter sequences. Statistical analysis included Wilcoxon and Pearson correlation tests, and the study adhered to ethical considerations and standardised magnetic resonance imaging (MRI) protocols. Results: In this study, pMS patients aged 10-18 years, the cohort consisted of 60% females (n=12) and 40% males (n=8). The mean age for females was 15.67±1.969 and for males 14.50±2.20 years (p=0.24). Plaque count analysis showed a statistically significant difference between radiologist and VolBrain assessment in all pMS patients (p=0.021). Significant differences were also observed in female pMS patients (p=0.034) but not in males (p=0.362). Correlations between radiologist and VolBrain assessments showed significant associations in both female and male patients, with strong correlations observed for plaque number, lesion burden and Expanded Disability Status Scale (EDSS) scores (p&amp;lt;0.01). Conclusions: This study demonstrates the potential of the VolBrain programme in assessing lesion burden in pMS patients. The observed correlations with traditional methods and clinical parameters support the concurrent validity of VolBrain and emphasise its potential clinical relevance. Incorporating automated tools into routine clinical practice could improve the accuracy of lesion quantification and thus contribute to improved monitoring and management of pMS.