Publications by authors named "Piotr Radojewski"

Purpose: To develop and validate a novel analytical approach simplifying , , proton density (PD), and off-resonance quantifications from phase-cycled balanced steady-state free precession (bSSFP) data. Additionally, to introduce a method to correct aliasing effects in undersampled bSSFP profiles.

Theory And Methods: Off-resonant-encoded analytical parameter quantification using complex linearized equations (ORACLE) provides analytical solutions for bSSFP profiles.

View Article and Find Full Text PDF

Imaging can help to diagnose CNS vasculitis. Yet so far, no imaging studies of CNS vasculitis at 7T are available. We share our experience of vessel wall imaging (VWI) at 7T in patients with suspected vasculitis.

View Article and Find Full Text PDF

Background: Ultra-high-field magnetic resonance imaging (MRI) at a field strength of 7 Tesla (T) has marked a significant milestone in diagnostic imaging since it was approved for clinical use in 2017. Despite the potential to improve image analysis by advances in signal-to-noise ratio, and improved spatial resolution and metabolic imaging, the clinical implementation of 7-T MRI remains limited. Factors that contribute to this limited availability are the high price, the operating costs, the need for specifically educated personnel, and lack of evidence of clinical benefit.

View Article and Find Full Text PDF

Over the past decades, morphometric analysis of brain MRI has contributed substantially to the understanding of healthy brain structure, development and aging as well as to improved characterisation of disease related pathologies. Certified commercial tools based on normative modeling of these metrics are meanwhile available for diagnostic purposes, but they are cost intensive and their clinical evaluation is still in its infancy. Here we have compared the performance of "ScanOMetrics", an open-source research-level tool for detection of statistical anomalies in individual MRI scans, depending on whether it is operated on the output of FreeSurfer or of the deep learning based brain morphometry tool DL + DiReCT.

View Article and Find Full Text PDF

Phenylketonuria is a rare metabolic disease resulting from a deficiency of the enzyme phenylalanine hydroxylase. Recent cross-sectional evidence suggests that early-treated adults with phenylketonuria exhibit alterations in cortical grey matter compared to healthy peers. However, the effects of high phenylalanine exposure on brain structure in adulthood need to be further elucidated.

View Article and Find Full Text PDF

Background: Reporting of sex-specific analyses in multiple sclerosis (MS) is sparse. Disability accrual results from relapses (relapse-associated worsening) and independent thereof (progression independent of relapses).

Objectives: A population of MS patients during relapse treated per standard of care was analyzed for sex differences and short-term relapse outcome (3-6 months) as measured by Expanded Disability Status Scale (EDSS) change.

View Article and Find Full Text PDF

GABA+ and Glx (glutamate and glutamine) are widely studied metabolites, yet the commonly used magnetic resonance spectroscopy (MRS) techniques have significant limitations, including sensitivity to B and B-inhomogeneities, limited bandwidth of MEGA-pulses, high SAR which is accentuated at 7T. To address these limitations, we propose SLOW-EPSI method, employing a large 3D MRSI coverage and achieving a high resolution down to 0.26 ml.

View Article and Find Full Text PDF
Article Synopsis
  • Cerebral small vessel disease (SVD) is a key cause of intracerebral hemorrhage (ICH), and researchers created a new MRI-based classification system, known as CADMUS, to categorize ICH subtypes associated with SVD.
  • A retrospective study analyzed data from two patient cohorts to classify ICH types based on MRI findings, assessing reliability and tracking subsequent strokes or hemorrhages.
  • The findings revealed a diverse distribution of ICH phenotypes among patients, with the CADMUS classification showing good reliability and potential for enhancing clinical and research practices in identifying SVD-related ICH types.
View Article and Find Full Text PDF

Background: Phenylketonuria (PKU) represents a congenital metabolic defect that disrupts the process of converting phenylalanine (Phe) into tyrosine. Earlier investigations have revealed diminished cognitive performance and changes in brain structure and function (including the presence of white matter lesions) among individuals affected by PKU. However, there exists limited understanding regarding cerebral blood flow (CBF) and its potential associations with cognition, white matter lesions, and metabolic parameters in patients with PKU, which we therefore aimed to investigate in this study.

View Article and Find Full Text PDF

Objective: To evaluate the influence of quantitative reports (QReports) on the radiological assessment of hippocampal sclerosis (HS) from MRI of patients with epilepsy in a setting mimicking clinical reality.

Methods: The study included 40 patients with epilepsy, among them 20 with structural abnormalities in the mesial temporal lobe (13 with HS). Six raters blinded to the diagnosis assessed the 3T MRI in two rounds, first using MRI only and later with both MRI and the QReport.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the impact of phenylketonuria (PKU) on white matter microstructure in adults, focusing on how it correlates with metabolic control and cognitive performance.
  • Using diffusion tensor imaging and H spectroscopy, researchers analyzed 30 PKU patients and 54 healthy controls, revealing significant reductions in white matter metrics like mean diffusivity and fractional anisotropy in patients.
  • The findings indicate that these microstructural changes are linked to cognitive functions such as inhibition and cognitive flexibility, suggesting that PKU may have broader effects on brain structure and function than previously understood.
View Article and Find Full Text PDF

Volumetric assessment based on structural MRI is increasingly recognized as an auxiliary tool to visual reading, also in examinations acquired in the clinical routine. However, MRI acquisition parameters can significantly influence these measures, which must be considered when interpreting the results on an individual patient level. This Technical Note shall demonstrate the problem.

View Article and Find Full Text PDF

Changes in brain glucose metabolism occur in many neurological disorders as well as during aging. Most studies on the uptake of glucose in the brain use positron emission tomography, which requires injection of a radioactive tracer. Our study shows that ultra-high-field H-MRS can be used to measure α-D-glucose at 5.

View Article and Find Full Text PDF

Purpose: Differentiating normal anatomical variants such as an infundibulum or a vascular loop from true intracranial aneurysms is crucial for patient management. We hypothesize that high-resolution 7 T magnetic resonance imaging (MRI) improves the detection and characterization of normal anatomical variants that may otherwise be misdiagnosed as small unruptured aneurysms.

Methods: This is a retrospective, single-center study.

View Article and Find Full Text PDF

Deep learning (DL) models have provided state-of-the-art performance in various medical imaging benchmarking challenges, including the Brain Tumor Segmentation (BraTS) challenges. However, the task of focal pathology multi-compartment segmentation (e.g.

View Article and Find Full Text PDF

Epileptic seizures require a rapid and safe diagnosis to minimize the time from onset to adequate treatment. Some epileptic seizures can be diagnosed clinically with the respective expertise. For more subtle seizures, imaging is mandatory to rule out treatable structural lesions and potentially life-threatening conditions.

View Article and Find Full Text PDF

Background: 2-hydroxy-glutarate (2HG) is a metabolite that accumulates in isocitrate dehydrogenase (IDH)-mutated gliomas and can be detected noninvasively using MR spectroscopy. However, due to the low concentration of 2HG, established magnetic resonance spectroscopic imaging (MRSI) techniques at the low field have limitations with respect to signal-to-noise and to the spatial resolution that can be obtained within clinically acceptable measurement times. Recently a tailored editing method for 2HG detection at 7 Tesla (7 T) named SLOW-EPSI was developed.

View Article and Find Full Text PDF

Introduction: Data on structural brain changes after infection with SARS-CoV-2 is sparse. We postulate multiple sclerosis as a model to study the effects of SARS-CoV-2 on brain atrophy due to the unique availability of longitudinal imaging data in this patient group, enabling assessment of intraindividual brain atrophy rates.

Methods: Global and regional cortical gray matter volumes were derived from structural MRIs using FreeSurfer.

View Article and Find Full Text PDF

Purpose: Studies at 3T have shown that T relaxometry enables characterization of brain tissues at the single-subject level by comparing individual physical properties to a normative atlas. In this work, an atlas of normative T values at 7T is introduced with 0.6 mm isotropic resolution and its clinical potential is explored in comparison to 3T.

View Article and Find Full Text PDF
Article Synopsis
  • Machine learning can work well, but it often struggles to make accurate predictions on new data, which is called out-of-sample generalizability.
  • To solve this problem, researchers are using a method called Federated ML that allows computers to share information about how well they're learning without actually sharing the data itself.
  • In a big study with 71 locations around the world, scientists created a model to help detect brain tumors more accurately, showing a significant improvement compared to older methods and hoping to help with rare illnesses and data sharing in healthcare.
View Article and Find Full Text PDF
Article Synopsis
  • Neuronal autoantibodies, specifically anti-neurochondrin antibodies, play a crucial role in diagnosing primary autoimmune cerebellar ataxia (PACA), a condition that still lacks extensive knowledge and documentation.
  • A case study of a 33-year-old man revealed significant symptoms including gait imbalance and cerebellar atrophy over time, leading to a confirmed PACA diagnosis through various tests.
  • Early diagnosis and treatment with immunotherapy showed positive outcomes, suggesting that PACA cases associated with anti-neurochondrin antibodies may be underreported, and recognizing them can lead to important therapeutic interventions.
View Article and Find Full Text PDF

Brain morphometry is usually based on non-enhanced (pre-contrast) T1-weighted MRI. However, such dedicated protocols are sometimes missing in clinical examinations. Instead, an image with a contrast agent is often available.

View Article and Find Full Text PDF

Introduction: About 80% of all non-traumatic intracerebral hemorrhage (ICH) are caused by the sporadic cerebral small vessel diseases deep perforator arteriopathy (DPA, also termed hypertensive arteriopathy or arteriolosclerosis) and cerebral amyloid angiopathy (CAA), though these frequently co-exist in older people. Contemporary neuroimaging (MRI and CT) detects an increasing spectrum of hemorrhagic and non-hemorrhagic imaging biomarkers of small vessel disease which may identify the underlying arteriopathies.

Areas Covered: We discuss biomarkers for cerebral small vessel disease subtypes in ICH, and explore their implications for clinical practice and research.

View Article and Find Full Text PDF

Purpose: At ultra-high field (UHF), B -inhomogeneities and high specific absorption rate (SAR) of adiabatic slice-selective RF-pulses make spatial resolved spectral-editing extremely challenging with the conventional MEGA-approach. The purpose of the study was to develop a whole-brain resolved spectral-editing MRSI at UHF (UHF, B  ≥ 7T) within clinical acceptable measurement-time and minimal chemical-shift-displacement-artifacts (CSDA) allowing for simultaneous GABA/Glx-, 2HG-, and PE-editing on a clinical approved 7T-scanner.

Methods: Slice-selective adiabatic refocusing RF-pulses (2π-SSAP) dominate the SAR to the patient in (semi)LASER based MEGA-editing sequences, causing large CSDA and long measurement times to fulfill SAR requirements, even using SAR-minimized GOIA-pulses.

View Article and Find Full Text PDF