Aspects Of MRI Research Articles

Neuromelanin-sensitive MRI for mechanistic research and biomarker development in psychiatry.

Neuromelanin-sensitive MRI is a burgeoning non-invasive neuroimaging method with an increasing number of applications in psychiatric research. This MRI modality is sensitive to the concentration of neuromelanin, which is synthesized from intracellular catecholamines and accumulates in catecholaminergic nuclei including the dopaminergic substantia nigra and the noradrenergic locus coeruleus. Emerging data suggest the utility of neuromelanin-sensitive MRI as a proxy measure for variability in catecholamine metabolism and function, even in the absence of catecholaminergic cell loss. Given the importance of catecholamine function to several psychiatric disorders and their treatments, neuromelanin-sensitive MRI is ideally positioned as an informative and easy-to-acquire catecholaminergic index. In this review paper, we examine basic aspects of neuromelanin and neuromelanin-sensitive MRI and focus on its psychiatric applications in the contexts of mechanistic research and biomarker development. We discuss ongoing debates and state-of-the-art research into the mechanisms of the neuromelanin-sensitive MRI contrast, standardized protocols and optimized analytic approaches, and application of cutting-edge methods such as machine learning and artificial intelligence to enhance the feasibility and predictive power of neuromelanin-sensitive-MRI-based tools. We finally lay out important future directions to allow neuromelanin-sensitive-MRI to fulfill its potential as a key component of the research, and ultimately clinical, toolbox in psychiatry.

Absence of BOLD adaptation in chronic fatigue syndrome revealed by task functional MRI.

Neurological symptoms are central to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), yet its underlying neurophysiological mechanisms remain elusive. We examined a neglected aspect of task-based functional MRI, focusing on how blood oxygenation level-dependent (BOLD) signals alter during cognitive tasks in ME/CFS. This prospective observational study utilised MRI scans on ME/CFS participants and healthy controls (HCs) with sedentary lifestyles (ACTRN12622001095752). Participants completed two blocks of a Symbol Digit Modalities Test, with 30 trials per block split into two sets. The fMRI signal changes between blocks and sets were compared within and between groups. Thirty-four ME/CFS participants (38 years ± 10; 27 women) and 34 HCs (38 ± 10; 27 women), were evaluated. In the second task block, ME/CFS participants exhibited increased activation in the right postcentral gyrus, contrasting with decreased activation in multiple regions in HCs. These results were further confirmed by significantly higher bilateral dynamic changes (2nd vs 1st set) in the motor, sensory and cognitive cortex in ME/CFS compared to HCs and significant correlations between those changes in the left primary motor cortex with fatigue severities. BOLD adaptation, potentially improving energy economy, was absent in ME/CFS, which may provide an underlying neurophysiological process in ME/CFS.

The ageing central nervous system in multiple sclerosis: the imaging perspective.

The interaction between ageing and multiple sclerosis is complex and carries significant implications for patient care. Managing multiple sclerosis effectively requires an understanding of how ageing and multiple sclerosis impact brain structure and function. Ageing inherently induces brain changes, including reduced plasticity, diminished grey matter volume, and ischaemic lesion accumulation. When combined with multiple sclerosis pathology, these age-related alterations may worsen clinical disability. Ageing may also influence the response of multiple sclerosis patients to therapies and/or their side-effects, highlighting the importance of adjusted treatment considerations. Magnetic resonance MRI is highly sensitive to age- and multiple sclerosis-related processes. Accordingly, MRI can provide insights into the relationship between ageing and multiple sclerosis, enabling a better understanding of their pathophysiological interplay and informing treatment selection. This review summarizes current knowledge on the immuno-pathological and MRI aspects of ageing in the central nervous system in the context of multiple sclerosis. Starting from immunosenescence, ageing-related pathological mechanisms, and specific features like enlarged Virchow-Robin spaces, this review then explores clinical aspects, including late-onset multiple sclerosis, the influence of age on diagnostic criteria, and comorbidity effects on imaging features. The role of MRI in understanding neurodegeneration, iron dynamics, and myelin changes influenced by ageing and how MRI can contribute to defining treatment effects in ageing multiple sclerosis patients, are also discussed.

Knee Cysts and Pseudocysts: An Illustrated Review of the Different MRI Aspects

Knee Cysts and Pseudocysts: An Illustrated Review of the Different MRI Aspects

Data Format Standardization and DICOM Integration for Hyperpolarized 13C MRI.

Hyperpolarized (HP) 13C MRI has shown promise as a valuable modality for in vivo measurements of metabolism and is currently in human trials at 15 research sites worldwide. With this growth, it is important to adopt standardized data storage practices as it will allow sites to meaningfully compare data. In this paper, we (1) describe data that we believe should be stored and (2) demonstrate pipelines and methods that utilize the Digital Imaging and Communications in Medicine (DICOM) standard. This includes proposing a set of minimum set of information that is specific to HP 13C MRI studies. We then show where the majority of these can be fit into existing DICOM attributes, primarily via the "Contrast/Bolus" module. We also demonstrate pipelines for utilizing DICOM for HP 13C MRI. DICOM is the most common standard for clinical medical image storage and provides the flexibility to accommodate the unique aspects of HP 13C MRI, including the HP agent information but also spectroscopic and metabolite dimensions. The pipelines shown include creating DICOM objects for studies on human and animal imaging systems with various pulse sequences. We also show a python-based method to efficiently modify DICOM objects to incorporate the unique HP 13C MRI information that is not captured by existing pipelines. Moreover, we propose best practices for HP 13C MRI data storage that will support future multi-site trials, research studies, and technical developments of this imaging technique.

Normative body mass-adjusted reference ranges of magnetic resonance imaging signs commonly used in diagnosing idiopathic intracranial hypertension in a healthy standard population

Patients with chronic daily headaches (CDH) are often a diagnostic challenge and frequently undergo neuroimaging. One common underlying cause of CDH is idiopathic intracranial hypertension (IIH). However, certain neuroimaging abnormalities that suggest IIH, such as optic nerve sheath diameters (ONSD), pituitary gland height, and venous sinus diameter, require interpretation due to the absence of established normative values. Notably, intracranial pressure is known to varies with age, sex and weight, further complicating the determination of objectively abnormal findings within a specific patient group. This study aims to assist clinical neuroradiologists in differentiating neuroimaging results in CDH by providing weight-adjusted normative values for imaging characteristics of IIH. In addition to age and BMI we here assessed 1924 population-based T1-weighted MRI datasets of healthy participants for relevant MRI aspects of IIH. Association to BMI was analyzed using linear/logistic regression controlled for age and stratified for sex. ONSD was 4.3 mm [2.8; 5.9]/4.6 mm [3.6; 5.7] and diameter of transverse sinus was 4.67 mm [1.6; 6.5]/4.45 mm [3.0; 7.9]. Height of pituitary gland was 5.1 mm [2.2;8.1]/4.6 mm [1.9;7.1] for female and male respectively. Values generally varied with BMI with regression slopes spanning 0.0001 to 0.05 and were therefor presented as normative values stratified by BMI. Protrusion of ocular papilla, empty sella and transverse sinus occlusion were rare in total. Our data show an association between BMI and commonly used MRI features for diagnosing IIH. We provide categorized normative BMI values for ONSD, pituitary gland height, and transverse sinus diameter. This distinction helps objectively identify potential IIH indicators compared to regular population norms, enhancing diagnostic accuracy for suspected IIH patients. Notably, optic nerve head protrusion, empty sella, and transverse sinus occlusion are rare in healthy individuals, solidifying their importance as imaging markers regardless of BMI.

Present and Future Innovations in AI and Cardiac MRI.

Cardiac MRI is used to diagnose and treat patients with a multitude of cardiovascular diseases. Despite the growth of clinical cardiac MRI, complicated image prescriptions and long acquisition protocols limit the specialty and restrain its impact on the practice of medicine. Artificial intelligence (AI)-the ability to mimic human intelligence in learning and performing tasks-will impact nearly all aspects of MRI. Deep learning (DL) primarily uses an artificial neural network to learn a specific task from example data sets. Self-driving scanners are increasingly available, where AI automatically controls cardiac image prescriptions. These scanners offer faster image collection with higher spatial and temporal resolution, eliminating the need for cardiac triggering or breath holding. In the future, fully automated inline image analysis will most likely provide all contour drawings and initial measurements to the reader. Advanced analysis using radiomic or DL features may provide new insights and information not typically extracted in the current analysis workflow. AI may further help integrate these features with clinical, genetic, wearable-device, and "omics" data to improve patient outcomes. This article presents an overview of AI and its application in cardiac MRI, including in image acquisition, reconstruction, and processing, and opportunities for more personalized cardiovascular care through extraction of novel imaging markers.

Клинические и нейровизуальные варианты центральноканальных полостей спинного мозга

The article presents the results of a study involving 40 patients exhibiting cavitation in the area of the central canal. Clinical and MRI aspects of hydromyelia are examined. The authors provide their own data on the neurological and neurovisual dynamics of this condition. The article discusses the contentious and ambiguous nature of diagnostic criteria for one variant of spinal cord cavitation — hydromyelia, which complicates prognostic assessment.

Leigh syndrome: a must-know bilateral symmetrical basal ganglia affection

Leigh's syndrome also known as subacute necrotizing encephalomyopathy is a rare progressive neurological disease with a reserved prognosis affecting the brainstem and the basal nuclei, the symptomatology of which is revealed in the majority of cases during the first two years of life. In this article we report the case of an 4 years old child referred to our center following a consultation for delayed psychomotor acquisitions with axial hypotonia and elevated lactate levels. Brain MRI showed a characteristic appearance of this syndrome. This clinical case reports the MRI aspect of Leigh's syndrome, a rare and serious pathology responsible for bilateral and symmetrical lesions of the basal ganglia.

Assessment of undergraduates nursing students’ knowledge toward MRI safety: Cross-sectional study

IntroductionMagnetic resonance imaging (MRI) has been traditionally regarded as a relatively safe imaging modality due to the absence of ionizing radiation. However, considerable immediate safety risks are intrinsic to the MRI environment, necessitating comprehensive awareness and training among healthcare professionals, particularly nurses, who accompany their patients to the MRI department in most cases. This study was carried out to evaluate the level of knowledge and awareness of MRI safety issues among nursing students within the nursing faculty at Jazan University (JU). Materials and methodsA descriptive, cross-sectional survey encompassing 128 undergraduate nursing students was conducted. A structured questionnaire comprising 25 questions was employed and classified into three sections, encompassing demographic data and MRI safety awareness. Data were analyzed using Microsoft Excel, and frequencies and percentages of responses were calculated and summarized. ResultsOf the 128 participants, 111 were females, and 17 were males, distributed across the 2nd (41%), 3rd (20%), and 4th (39%) academic years. Participants exhibited a commendable grasp of MRI contraindications related to ferromagnetic materials such as oxygen cylinders and metal needles. However, their knowledge concerning the operational aspects of MRI, such as examination duration, was found to be lacking, indicating a significant deficiency in comprehension regarding the operational aspects of MRI technology. ConclusionThis study highlights the relatively high level of awareness regarding MRI safety among nursing students at JU. However, the identified lack of knowledge pertaining to the operational aspects of MRI technology emphasizes the need for further education and training in this area. To address this gap, we recommend the establishment of comprehensive MRI safety courses and training programs customized for undergraduate nursing students.

Ultrafast Dynamic Contrast-Enhanced MRI of the Breast: From Theory to Practice.

The development of ultrafast dynamic contrast-enhanced (UF-DCE) MRI has occurred in tandem with fast MRI scan techniques, particularly view-sharing and compressed sensing. Understanding the strengths of each technique and optimizing the relevant parameters are essential to their implementation. UF-DCE MRI has now shifted from research protocols to becoming a part of clinical scan protocols for breast cancer. UF-DCE MRI is expected to compensate for the low specificity of abbreviated MRI by adding kinetic information from the upslope of the time-intensity curve. Because kinetic information from UF-DCE MRI is obtained from the shape and timing of the initial upslope, various new kinetic parameters have been proposed. These parameters may be associated with receptor status or prognostic markers for breast cancer. In addition to the diagnosis of malignant lesions, more emphasis has been placed on predicting and evaluating treatment response because hyper-vascularity is linked to the aggressiveness of breast cancers. In clinical practice, it is important to note that breast lesion images obtained from UF-DCE MRI are slightly different from those obtained by conventional DCE MRI in terms of morphology. A major benefit of using UF-DCE MRI is avoidance of the marked or moderate background parenchymal enhancement (BPE) that can obscure the target enhancing lesions. BPE is less prominent in the earlier phases of UF-DCE MRI, which offers better lesion-to-noise contrast. The excellent contrast of early-enhancing vessels provides a key to understanding the detailed pathological structure of tumor-associated vessels. UF-DCE MRI is normally accompanied by a large volume of image data for which automated/artificial intelligence-based processing is expected to be useful. In this review, both the theoretical and practical aspects of UF-DCE MRI are summarized. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 2.

AliasNet: Alias artefact suppression network for accelerated phase-encode MRI

Sparse reconstruction is an important aspect of MRI, helping to reduce acquisition time and improve spatial-temporal resolution. Popular methods are based mostly on compressed sensing (CS), which relies on the random sampling of k-space to produce incoherent (noise-like) artefacts. Due to hardware constraints, 1D Cartesian phase-encode under-sampling schemes are popular for 2D CS-MRI. However, 1D under-sampling limits 2D incoherence between measurements, yielding structured aliasing artefacts (ghosts) that may be difficult to remove assuming a 2D sparsity model. Reconstruction algorithms typically deploy direction-insensitive 2D regularisation for these direction-associated artefacts. Recognising that phase-encode artefacts can be separated into contiguous 1D signals, we develop two decoupling techniques that enable explicit 1D regularisation and leverage the excellent 1D incoherence characteristics. We also derive a combined 1D + 2D reconstruction technique that takes advantage of spatial relationships within the image. Experiments conducted on retrospectively under-sampled brain and knee data demonstrate that combination of the proposed 1D AliasNet modules with existing 2D deep learned (DL) recovery techniques leads to an improvement in image quality. We also find AliasNet enables a superior scaling of performance compared to increasing the size of the original 2D network layers. AliasNet therefore improves the regularisation of aliasing artefacts arising from phase-encode under-sampling, by tailoring the network architecture to account for their expected appearance. The proposed 1D + 2D approach is compatible with any existing 2D DL recovery technique deployed for this application.

Advancements in Radiology and Diagnostic Imaging

Radiology and diagnostic imaging have undergone remarkable advancements in recent years, shaping the future of healthcare and improving patient outcomes. This review article provides an extensive overview of the developments and opportunities in various aspects of radiology, including CT, MRI, ultrasound, digital radiology, teleradiology, 3D printing, radiomics, radiogenomics, and nuclear radiology. It highlights the integration of artificial intelligence and machine learning in radiology, the emergence of theranostics, and the exploration of the human microbiome. The article also delves into advanced imaging techniques for cardiovascular diseases, hybrid imaging modalities in oncology, and optical imaging. The summary emphasizes the importance of continued innovation and development in radiology and diagnostic imaging to enhance patient care and global health outcomes.

Fetal MRI at 3 T: Principles to Optimize Success.

Fetal MRI has emerged as a cornerstone of prenatal imaging, helping to establish the correct diagnosis in pregnancies affected by congenital anomalies. In the past decade, 3 T imaging was introduced as an alternative to increase the signal-to-noise ratio (SNR) of the pulse sequences and improve anatomic detail. However, imaging at a higher field strength is not without challenges. Many artifacts that are barely appreciable at 1.5 T are amplified at 3 T. A systematic approach to imaging at 3 T that incorporates appropriate patient positioning, a thoughtful protocol design, and sequence optimization minimizes the impact of these artifacts and allows radiologists to reap the benefits of the increased SNR. The sequences used are the same at both field strengths and include single-shot T2-weighted, balanced steady-state free-precession, three-dimensional T1-weighted spoiled gradient-echo, and echo-planar imaging. Synergistic use of these acquisitions to sample various tissue contrasts and in various planes provides valuable information about fetal anatomy and pathologic conditions. In the authors' experience, fetal imaging at 3 T outperforms imaging at 1.5 T for most indications when performed under optimal circumstances. The authors condense the cumulative experience of fetal imaging specialists and MRI technologists who practice at a large referral center into a guideline covering all major aspects of fetal MRI at 3 T, from patient preparation to image interpretation. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Magnetic resonance imaging in neonates: a practical approach to optimize image quality and increase diagnostic yield.

Magnetic resonance imaging has emerged as a preferred modality in pediatric imaging because of its high soft-tissue contrast and the lack of ionizing radiation. It is important to recognize that despite its many advantages, several challenges to performing neonatal MRI arise from the lack of patient compliance and the small size of the anatomy. This manuscript presents the approach to patient preparation used at the authors' institution, summarizes general principles of image optimization and hardware selection, and reviews common indications across various organ systems. This manuscript also incorporates input from our pediatric-trained MRI technologists, in an attempt to compile a practical guideline covering all major aspects of neonatal MRI, from its execution to its interpretation.

Fetal brain MRI: neurometrics, typical diagnoses, and resolving common dilemmas.

This review presents a practical approach to imaging the fetal brain by MRI. Herein, we demonstrate how to measure brain structures and fluid spaces, and discuss the importance of comparing measurements to normative biometric references at a corresponding gestational age. We present some common imaging dilemmas of the technical aspects of fetal MRI with regard to typical regions of abnormality including the cerebrum, the ventricular system, and the posterior fossa, and discuss how to resolve them.

Initial PCV Chemotherapy Followed by Radiotherapy Is Associated With a Prolonged Response But Late Neurotoxicity in 20 Diffuse Low-Grade Glioma Patients.

BackgroundStudy RTOG 9802 in high-risk diffuse low-grade gliomas (DLGGs) showed the potential synergistic effect on survival of the procarbazine, CCNU, and vincristine (PCV) radiotherapy (RT) combination. Limited data on long-term neurocognitive impact and quality of life (QoL) have yet been reported.Patients and MethodsWe described a monocentric series of patients treated at first line by the combination of PCV immediately followed by RT between January 01, 1982 and January 01, 2017. Radiological data were collected and included volume, velocity of diametric expansion (VDE), and MRI aspects. Long-term neurocognitive and QoL were analyzed.ResultsTwenty patients fulfilled the eligibility criteria. The median response rate was 65.1% (range, 9.6%–99%) at the time of maximal VDE decrease corresponding to a median volume reduction of 79.7 cm3 (range, 3.1 to 174.2 cm3), which occurred after a median period of 7.2 years (range, 0.3–21.9) after the end of RT. An ongoing negative VDE was measured in 13/16 patients after the end of RT, with a median duration of 6.7 years (range, 9 months–21.9 years). The median follow-up since radiological diagnosis was 17.5 years (range, 4.8 to 29.5). Estimated median survival was 17.4 years (95% CI: 12; NR). After a long-term follow-up, substantial neurotoxicity was noticed with dementia in six progression-free patients (30%), leading to ventriculo-peritoneal shunt procedures in three, and premature death in five. Thirteen patients (65%) were unable to work with disability status. Successive longitudinal neurocognitive assessments for living patients showed verbal episodic memory deterioration.ConclusionsPCV-RT combination seems to have not only an oncological synergy but also a long-term neurotoxic synergy to consider before initial therapeutic decision.

MRI Aspects of Prenatal Brain Malformations about Three Cases and Literature Review

We report three cases of fetal malformations diagnosed by MRI in Abidjan. Patients were referred for suspicion of fetal malformations on ultrasound. They were young (average age of 29 years), primipares, without any particular antecedent. We used a 1.5 T MRI, T2 coronal, T2 axial, BTFE coronal, BTFE sagittal, BTFE axial, diffusion and ADC cartography were realised. MRI diagnosed an arachnoid cyst, posterior fossa kystique tumor, hydranencephaly. MRI is an excellent diagnostic tool for fetal malformations. Its use should be routine in management of fetal malformations.

Ultrafast Dynamic Contrast-enhanced MRI of the Breast: How Is It Used?

Ultrafast dynamic contrast-enhanced (UF-DCE) MRI is a new approach to capture kinetic information in the very early post-contrast period with high temporal resolution while keeping reasonable spatial resolution. The detailed timing and shape of the upslope in the time–intensity curve are analyzed. New kinetic parameters obtained from UF-DCE MRI are useful in differentiating malignant from benign lesions and in evaluating prognostic markers of the breast cancers. Clinically, UF-DCE MRI contributes in identifying hypervascular lesions when the background parenchymal enhancement (BPE) is marked on conventional dynamic MRI. This review starts with the technical aspect of accelerated acquisition. Practical aspects of UF-DCE MRI include identification of target hypervascular lesions from marked BPE and diagnosis of malignant and benign lesions based on new kinetic parameters derived from UF-DCE MRI: maximum slope (MS), time to enhance (TTE), bolus arrival time (BAT), time interval between arterial and venous visualization (AVI), and empirical mathematical model (EMM). The parameters derived from UF-DCE MRI are compared in terms of their diagnostic performance and association with prognostic markers. Pitfalls of UF-DCE MRI in the clinical situation are also covered. Since UF-DCE MRI is an evolving technique, future prospects of UF-DCE MRI are discussed in detail by citing recent evidence. The topic covers prediction of treatment response, multiparametric approach using DWI-derived parameters, evaluation of tumor-related vessels, and application of artificial intelligence for UF-DCE MRI. Along with comprehensive literature review, illustrative clinical cases are used to understand the value of UF-DCE MRI.

ECCO-ESGAR Topical Review on Optimizing Reporting for Cross-Sectional Imaging in Inflammatory Bowel Disease.

The diagnosis and follow up of patients with inflammatory bowel disease [IBD] requires cross-sectional imaging modalities, such as intestinal ultrasound [IUS], magnetic resonance imaging [MRI] and computed tomography [CT]. The quality and homogeneity of medical reporting are crucial to ensure effective communication between specialists and to improve patient care. The current topical review addresses optimized reporting requirements for cross-sectional imaging in IBD. An expert consensus panel consisting of gastroenterologists, radiologists and surgeons convened by the ECCO in collaboration with ESGAR performed a systematic literature review covering the reporting aspects of MRI, CT, IUS, endoanal ultrasonography and transperineal ultrasonography in IBD. Practice position statements were developed utilizing a Delphi methodology incorporating two consecutive rounds. Current practice positions were set when ≥80% of the participants agreed on a recommendation. Twenty-five practice positions were developed, establishing standard terminology for optimal reporting in cross-sectional imaging. Assessment of inflammation, complications and imaging of perianal CD are outlined. The minimum requirements of a standardized report, including a list of essential reporting items, have been defined. This topical review offers practice recommendations to optimize and homogenize reporting in cross-sectional imaging in IBD.