Radiologie (Heidelberg, Germany)最新文献

Nondegenerative disorders involving the basal ganglia frequently do not present clinically as a primary parkinsonian syndrome, but rather in the context of acute or subacute neurological symptoms such as altered level of consciousness, epileptic seizures, encephalopathy, or newly emerging hyperkinetic movement disorders. In these clinical scenarios, neuroimaging is often performed without a clear etiological hypothesis and primarily serves as an initial diagnostic orientation. Due to their end-arterial vascular supply, high metabolic demand, and central role within distributed motor and cognitive networks, the basal ganglia are particularly vulnerable to vascular, metabolic-toxic, inflammatory, and genetic insults. Accordingly, nondegenerative disorders often exhibit characteristic-and in some cases highly specific-patterns of involvement, the systematic analysis of which allows for rapid etiological stratification. This article provides a structured overview of the most relevant nondegenerative causes of movement disorders with basal ganglia involvement and describes typical neuroradiological patterns observed in vascular, metabolic-toxic, genetic, neoplastic, and infectious-inflammatory conditions. In addition, current developments in magnetic resonance imaging are discussed with respect to their potential and inherent limitations. Neuroradiological imaging remains a central tool in the evaluation of nondegenerative movement disorders, guiding etiological classification, and directing further diagnostic work-up.

Magnetic resonance imaging (MRI) plays a pivotal role in the diagnostic work-up of dementia. In addition to excluding secondary and potentially treatable causes, MRI enables the identification of characteristic neuroanatomical patterns that support the differentiation between major dementia entities. In daily clinical practice, the diagnostic value of MRI relies primarily on systematic visual assessment and semiquantitative evaluation of regional atrophy patterns and accompanying vascular pathology. In recent years, automated morphometric analyses and artificial intelligence (AI)-based approaches have gained increasing attention. While these techniques promise objective quantification of structural brain changes, their clinical utility on an individual patient level remains limited. High interindividual variability of brain volumes, technical dependencies, and normative database issues restrict their diagnostic accuracy and may lead to overinterpretation of numerical results if used outside the appropriate context. This review provides a clinically oriented overview of MRI in dementia imaging. Emphasis is placed on pattern-based visual assessment, the role of established semiquantitative rating scales and a critical appraisal of automated morphometry. A practical imaging algorithm is proposed that integrates visual analysis, rating scales and quantitative tools in a structured manner. The aim is to highlight the realistic clinical value of MRI and to emphasize its role as an interpretative rather than a purely numerical diagnostic modality.

Alzheimer's disease is one of the most common causes of dementia in older adults. Since 2024, monoclonal antibody therapy has been available, which can slow disease progression at certain stages. During therapy, magnetic resonance imaging changes called amyloid-related imaging abnormalities (ARIA)-edema (ARIA-E) and hemorrhage (ARIA-H)-must be monitored at specific points during treatment; depending on severity, therapy may need to be paused. Cerebral amyloid angiopathy (CAA) and its inflammatory form (CAA-I) should be considered in the differential diagnosis.

Background: Parkinson's disease (PD) and atypical Parkinsonian syndromes (APS), including multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD), are increasing worldwide. Early differential diagnosis is challenging due to overlapping symptoms and the often delayed appearance of pathognomonic signs.

Objective: Presentation of the role of structural magnetic resonance imaging (MRI) in the differential diagnosis of neurodegenerative Parkinsonian syndromes.

Material and methods: Literature review of current guidelines and studies on T1-weighted and T2-weighted sequences, susceptibility-weighted imaging (SWI), diffusion-weighted imaging, volumetry and multiparametric approaches. The focus was on disease-specific atrophy patterns, quantitative methods and automated analyses.

Results: Structural changes in PD are usually subtle; the nigrosome‑1 (swallowtail) sign on SWI can provide diagnostic clues. The PSP shows pronounced midbrain atrophy, MSA demonstrates putaminal, pontine and cerebellar atrophy and CBD exhibits asymmetric cortical atrophy. Volumetric and multiparametric analyses increase the diagnostic accuracy, especially in early disease stages, although widespread clinical implementation remains limited.

Conclusion: Structural MRI provides early indicators of APS and aids the differential diagnosis. Quantitative and multiparametric methods improve objectivity and sensitivity, particularly for subtle or rare syndromes and could play an increasingly more important role in clinical practice.

The diagnostics of small bowel diseases represent a special challenge as this intestinal segment is not readily accessible endoscopically and the clinical symptoms are often nonspecific. The assessment is further complicated by the bowel motility and the dependency on contrast agent administration and luminal distension. Modern cross-sectional imaging techniques, particularly computed tomography (CT) and magnetic resonance (MR) enterography, have revolutionized the diagnostics of inflammatory, neoplastic and vascular small bowel diseases. The precise differentiation of the various small bowel pathologies requires thorough knowledge of characteristic imaging patterns. Bowel wall thickening, the extent, distribution and pattern of contrast enhancement uptake, mesenteric vascular changes and associated extraintestinal findings provide crucial diagnostic indications. The integration of clinical parameters with morphological and functional imaging criteria enables timely and targeted treatment planning.

Prions are unprecedented infectious pathogens that cause a group of rare and inevitably fatal neurodegenerative diseases, affecting approximately 1 person per 1 million inhabitants worldwide each year. These diseases include Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), kuru, fatal insomnia (FI) and variably protease-sensitive prionopathy (VPSPr), all of which involve a conformational change of normal cellular prion protein (PrPC) into abnormal scrapie prion protein (PrPSc) through a posttranslational process. This structural change is associated with profound alterations in the physicochemical properties of PrPC, making the molecule resistant to proteolysis. The conformational alteration of PrPC can occur either due to spontaneous conversion, dominant mutations in the prion protein gene (PRNP) which codes for PrPC or due to an infection with the pathogenic isoform PrPSc from exogenous sources. There is general consensus that PrPC serves as the substrate for the conversion to abnormal PrPSc. The latter multiplies exponentially and accumulates in the brain, forming deposits which are associated with the neurodegenerative changes. Although the understanding of the main causes of prion-induced neurodegeneration is still limited, the spread of PrPSc and neurotoxic signal transfer in the pathogenic process of prions appear to show an interaction. Prion diseases sometimes have long incubation times but also short clinical trajectories. Sporadic and genetic forms occur worldwide of which genetic forms are associated with mutations in PRNP. Zoonotic forms of prion diseases are also associated with bovine diseases. Substantial progress has been made in the diagnosis of these disorders and the diagnostics include magnetic resonance imaging (MRI) and laboratory investigations, particularly of the cerebrospinal fluid.

Background: Motor neuron diseases (MND) affect the upper and/or lower motor neurons. Radiological diagnostics primarily serve to systematically exclude treatable mimics and support the clinical and electrophysiological diagnosis. The focus is on amyotrophic lateral sclerosis (ALS); supplementary progressive muscular atrophy (PMA, purely lower motor neuron, LMN disease) and spinal muscular atrophy (SMA).

Objective: Which imaging signs support the diagnosis of ALS, how do electromyography/magnetic resonance imaging (EMG/MRI) fit into the Gold Coast criteria and which other motor neuron diseases are relevant?

Material and methods: Overview of clinical criteria (Gold Coast), genetics and typical MRI findings of the brain, spinal cord and musculature.

Results: Gold Coast core: progressive motor deterioration, upper motor neuron (UMN) and LMN signs in ≥ 1 region or LMN in ≥ 2 regions and exclusion of alternative causes.

Imaging: susceptibility-weighted imaging (SWI) motor band sign as UMN marker; T2/fluid-attenuated inversion recovery (FLAIR) hyperintensities along the corticospinal tract with low sensitivity, moderate specificity; T1 bright tongue as an indication of chronic denervation in bulbar involvement. EMG: detection of subclinical LMN involvement, sometimes limited in UMN-dominant/bulbar courses. PMA: Pure purely LMN symptoms, often continuum to ALS. SMA: Autosomal autosomal recessive (SMN1 deletion).

Discussion: The diagnosis remains primarily clinical; EMG and MRI are supportive. The radiological priority is the exclusion of mimics. The UMN markers increase diagnostic certainty in the context of clinical/EMG findings but do not replace them. Clear findings facilitate classification according to Gold Coast. The PMA and SMA require careful differential diagnostics; characteristic MRI patterns support progression and treatment planning.

Movement disorders are a frequent yet diagnostically unspecific reason for referral in routine neuroradiological practice. Hypokinetic syndromes with parkinsonism in particular regularly raise the question of an underlying neurodegenerative disorder, while requiring careful differentiation from atypical parkinsonian syndromes and secondary causes. This first part of the review focuses on the neuroradiological assessment of degenerative movement disorders, with an emphasis on the parkinsonian spectrum. It is grounded in the functional anatomy of the basal ganglia and their integration into motor networks. Building on this framework, a practice-oriented diagnostic approach is presented in which clinical phenotypes, temporal evolution, and accompanying symptoms serve as guiding criteria for targeted image interpretation. The article addresses idiopathic Parkinson's disease as well as atypical parkinsonian syndromes, in particular progressive supranuclear palsy, multiple system atrophy, and corticobasal syndrome. Typical and atypical magnetic resonance imaging (MRI) patterns, established morphometric markers, and the diagnostic limitations of visual signs such as the swallow-tail sign are critically discussed. In addition, neuromelanin-sensitive MRI, susceptibility-based techniques, and artificial intelligence (AI)-supported approaches are reviewed, with explicit consideration of their current limitations. The aim of this contribution is to enable a structured and clinically robust neuroradiological assessment of parkinsonism and to use imaging in a targeted manner for differential diagnosis and guidance of further diagnostic work-up.