Structural magnetic resonance imaging in dystonia: A systematic review of methodological approaches and findings

Cerebellar pathology in forensic and clinical neuroscience

Recent research underscores the cerebellum's growing importance in forensic science and neurology, showing its functions extend beyond motor control, especially in identifying causes of death. Critical neuropathological markers including alpha-synuclein and tau protein aggregates, cellular degeneration, inflammation, and vascular changes are vital for identifying neurodegenerative diseases, injuries, and toxic exposures. Advanced forensic methods, such as Magnetic resonance imaging (MRI), immunohistochemistry, and molecular analysis, have greatly improved the accuracy of diagnoses. Promising new therapies, including neuroprotective agents like resveratrol and transcranial magnetic stimulation (TMS), offer potential in treating cerebellar disorders. The cerebellum's vulnerability to toxins, drugs, and traumatic brain injuries (TBIs) highlights its forensic relevance. Moreover, advancements in genetic diagnostics, such as next-generation sequencing and CRISPR-Cas9, are enhancing the understanding and treatment of genetic conditions like Joubert syndrome and Dandy-Walker malformation. These findings emphasize the need for further research into cerebellar function and its broader significance in both forensic science and neurology.

Somato-cognitive action network in laryngeal and focal hand dystonia sensorimotor dysfunction

The central pathology causing idiopathic focal dystonia remains unclear, limiting effective treatment targets. The recently identified somato-cognitive action network (SCAN) with its role in coordinating physiologic processes and coarse movements has been implicated in dystonia dysfunction. SCAN is thought to interface between the phylogenetically newer primary motor regions that control fine movements and the cingulo-opercular network (CON) that putatively conveys cognitive intentions for action. We hypothesized that the effector-agnostic nature of SCAN may constitute a central pathology shared across focal dystonia subtypes affecting different body parts. Additionally, the effector-specific areas in the primary sensorimotor cortex may show distinct functional changes depending on the dystonic body region. We collected functional MRI from patients with either of two subtypes of focal dystonia (laryngeal dystonia or LD, N =24, and focal hand dystonia or FHD, N =18) and healthy control participants ( N =21). Regions of interest were selected based on prior work that suggested dystonia-related abnormality within the basal-ganglia-thalamo-cortical and cerebello-thalamo-cortical sensorimotor circuitries. We investigated if focal dystonia is associated with resting-state functional connectivity changes 1) between SCAN and other cortical regions (effector-specific areas and CON), 2) between cortical and non-cortical regions, or 3) between non-cortical (subcortical and cerebellar) regions. Cortical regions were individualized based on resting-state data. Separately, individualized hand and mouth/larynx regions were also generated from task-based MRI (finger-tapping and phonation, respectively) for comparison. There was a shared interaction effect in both focal dystonia subtypes ( p =0.048 for LD, p =0.017 for FHD) compared to controls, which was driven by SCAN's higher functional connectivity to task-derived mouth/larynx region and concomitantly lower connectivity to CON. This dystonia-dependent interaction was not observed with the resting-state mouth/larynx region. No significant resting-state functional changes were observed involving subcortical and cerebellar regions when LD and FHD were modeled as independent groups. However, exploratory analysis combining LD and FHD suggested a dystonia-dependent asynchronization between SCAN and sensorimotor cerebellum ( p =0.010) that may indicate a pathological rather than compensatory process. For the first time, our study systematically tested circuitry-based functional connectivity changes in two focal dystonias. Our results show that SCAN is uniquely associated with dystonia dysfunction beyond the dystonic effector regions, potentially offering insights on pathophysiology and treatments.

No reliable gray matter alterations in idiopathic dystonia

Background

The structural brain abnormalities associated with idiopathic dystonia (ID) remain inadequately understood. Previous voxel-based morphometry (VBM) studies examining whole-brain gray matter (GM) volume alterations in patients with ID have reported inconsistent and occasionally contradictory findings.

Methods

We performed a coordinate-based meta-analysis (CBMA) using the latest seed-based d mapping with permutation of subject images (SDM-PSI) technique to identify consistent GM alterations in patients with ID at the whole-brain level. Additionally, meta-regression analyses were conducted to explore the potential moderating effects of age, gender, and disease duration on GM volume.

Results

The CBMA incorporated 27 VBM studies, comprising 32 datasets with a total of 840 patients with ID and 834 healthy controls. Our analysis did not identify consistent or reliable GM alterations in patients with ID. The robustness of these findings was confirmed through a jackknife sensitivity analysis. Meta-regression analyses revealed that disease duration significantly influenced GM volume in the right insula.

Conclusion

Based on the best practice guidelines for CBMA, we utilized the most recent SDM-PSI algorithm to perform a new CBMA that included a larger group of individuals with ID. However, in contrast to previous CBMAs, we did not observe any consistent alterations in GM in ID. The findings suggest that using GM volume assessed by VBM as an imaging marker for ID may not be reliable. This could be attributed to ID being a functional disorder, or the inconsistency in GM alterations may be influenced by demographic and clinical variations, differences in imaging protocols and analysis methods, or small sample sizes. It is imperative to control for subject characteristics, employ standardized VBM methodologies, and enhance sample sizes in future research.

Joint and distinct neural structure and function deficits in major depressive disorder with suicidality: a multimodal meta-analysis of MRI studies

BACKGROUND

Suicide risk is a major concern for patients with major depressive disorder (MDD). Neuroimaging studies have demonstrated that patients with MDD with suicidal ideation or suicide attempt (MDD-S) are accompanied by neurostructural or functional abnormalities, but there is no consensus of opinion on neural substrate alterations involved in MDD-S.

METHODS

We performed a whole-brain multimodal meta-analysis of existing magnetic resonance imaging (MRI) studies to identify conjoint and separate alterations of grey matter volume (GMV) and spontaneous brain activity characteristics (regional homogeneity and amplitude of low-frequency fluctuations) between patients with MDD-S and patients with MDD without suicidal ideation or suicidal attempt (MDD-NS) via the seed-based d mapping software. We excluded studies that used other modalities, had overlapping data, or had insufficient information.

RESULTS

Our systematic search identified 13 structural MRI studies (471 patients with MDD-S and 508 patients with MDD-NS) and 16 resting-state functional MRI studies (704 patients with MDD-S and 554 patients with MDD-NS) published up to Dec. 5, 2023. Compared with patients with MDD-NS, those with MDD-S showed increased GMV with hypoactivity in the left postcentral gyrus, decreased GMV with hypoactivity in the right inferior parietal gyri, decreased GMV with hyperactivity in the right insula, and separate GMV and functional changes within the bilateral parietal, occipital, and frontal lobes, and the left thalamus.

LIMITATIONS

We were unable to analyze the association between brain features and clinical detail because of a lack of data. Included studies showed considerable heterogeneity and publication bias.

CONCLUSION

These findings provide a comprehensive overview of brain morphological and spontaneous functional impairments linked to impulsivity, impaired positive reward modulation, emotional disturbances, abnormal emotional processing, and cognitive deficits in MDD-S. These results support an understanding of the relationship between neural substrates and clinical symptoms in MDD-S, and these alterations provide useful insight into pathophysiological mechanisms and intervention strategies to decrease suicide risk in MDD.

Advanced Magnetic Resonance Imaging for Early Diagnosis and Monitoring of Movement Disorders

Advanced magnetic resonance imaging (MRI) techniques are transforming the study of movement disorders by providing valuable insights into disease mechanisms. This narrative review presents a comprehensive overview of their applications in this field, offering an updated perspective on their potential for early diagnosis, disease monitoring, and therapeutic evaluation. Emerging MRI modalities such as neuromelanin-sensitive imaging, diffusion-weighted imaging, magnetization transfer imaging, and relaxometry provide sensitive biomarkers that can detect early microstructural degeneration, iron deposition, and connectivity disruptions in key regions like the substantia nigra. These techniques enable earlier and more accurate differentiation of movement disorders, including Parkinson's disease, progressive supranuclear palsy, multiple system atrophy, corticobasal degeneration, Lewy body and frontotemporal dementia, Huntington's disease, and dystonia. Furthermore, MRI provides objective metrics for tracking disease progression and assessing therapeutic efficacy, making it an indispensable tool in clinical trials. Despite these advances, the absence of standardized protocols limits their integration into routine clinical practice. Addressing this gap and incorporating these techniques more systematically could bring the field closer to leveraging advanced MRI for personalized treatment strategies, ultimately improving outcomes for individuals with movement disorders.

Emerging Molecular-Genetic Families in Dystonia: Endosome-Autophagosome-Lysosome and Integrated Stress Response Pathways

Advances in genetic technologies and disease modeling have greatly accelerated the pace of introducing and validating molecular-genetic contributors to disease. In dystonia, there is a growing convergence across multiple distinct forms of the disease onto core biological processes. Here, we discuss two of these, the endosome-autophagosome-lysosome pathway and the integrated stress response, to highlight recent advances in the field. Using these two pathomechanisms as examples, we further discuss the opportunities that molecular-genetic grouping of dystonias present to transform dystonia care. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Biomarkers and Rehabilitation for Functional Neurological Disorder

Functional neurological disorder, or FND, is widely misunderstood, particularly when considering recent research indicating that the illness has numerous biological markers in addition to its psychiatric disorder associations. Nonetheless, the long-held view that FND is a mental illness without a biological basis, or even a contrived (malingered) illness, remains pervasive both in current medical care and general society. This is because FND involves intermittent disability that rapidly and involuntarily alternates with improved neurological control. This has in turn caused shaming, perceived low self-efficacy, and social isolation for the patients. Until now, biomarker reviews for FND tended not to examine the features that are shared with canonical neurological disorders. This review, in contrast, examines current research on FND biomarkers, and in particular their overlap with canonical neurological disorders, along with the encouraging outcomes for numerous physical rehabilitation trials for FND. These findings support the perspective endorsed here that FND is unquestionably a neurological disorder that is also associated with many biological markers that lie outside of the central nervous system. These results suggest that FND entails multiple biological abnormalities that are widely distributed in the body. General healthcare providers would benefit their care for their patients through their improved understanding of the illness and recourses for support and treatment that are provided in this review.

White Matter Microstructural Changes Using Ultra-Strong Diffusion Gradient MRI in Adult-Onset Idiopathic Focal Cervical Dystonia

BACKGROUND AND OBJECTIVES

Adult-onset idiopathic focal cervical dystonia (AOIFCD) involves abnormal posturing of the cervical musculature and, in some individuals, an associated head tremor. Existing neuroimaging studies have implicated key motor networks. However, measures used to date lack specificity toward underlying pathophysiologic differences. We aim to assess white matter motor pathways for localized, microstructural differences, which may aid in understanding underlying mechanisms.

METHODS

Individuals diagnosed with AOIFCD and an age- and sex-matched control group were prospectively recruited through the Welsh Movement Disorders Research Network. All participants underwent in-depth clinical phenotyping and MRI (structural and diffusion sequences) using ultra-strong diffusion gradients. Tractography (whole-tract median values) and tractometry (along tract profiling) were performed for key white matter motor pathways assessing diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging (NODDI), and standard model parameters. Groups were compared using linear model analysis with Bonferroni multiple comparison correction.

RESULTS

Fifty participants with AOIFCD and 30 healthy control participants were recruited, with 46 with AOIFCD and 30 healthy controls included for analysis (33 without head tremor, 13 with head tremor). Significant differences were observed in the anterior thalamic radiations (lower mid-tract fractional anisotropy [estimate = -0.046, p = 3.07 × 10-3], radial kurtosis [estimate = -0.165, p = 1.42 × 10-4], f-intra-axonal signal fraction [estimate = -0.044, p = 2.78 × 10-3], p2 orientation coherence [estimate = -0.043, p = 1.64 × 10-3], higher Orientation Dispersion Index [ODI, estimate = 0.023, p = 2.22 × 10-3]) and thalamopremotor tracts (higher mid-tract mean kurtosis [estimate = 0.064, p = 7.56 × 10-4], lower Neurite Density Index [estimate = 0.062, p = 2.1 × 10-3], higher distal tract ODI [estimate = 0.062, p = 3.1 × 10-3], lower f [estimate = -0.1, p = 2.3 × 10-3], and striatopremotor tracts [proximal lower f: estimate = -0.075, p = 1.06 × 10-3]). These measures correlated with clinical measures: dystonia duration (right thalamopremotor distal ODI: r = -0.9, p = 1.29 × 10-14), psychiatric symptoms (obsessive compulsive symptoms: left anterior thalamic radiation p2 r = 0.92, p = 2.797 × 10-11), sleep quality (Sleep Disorders Questionnaire Score: left anterior thalamic radiation ODI: r = -0.84, p = 4.84 × 10-11), pain (left anterior thalamic radiation ODI: r = -0.89, p = 1.4 × 10-13), and cognitive functioning (paired associated learning task p2, r = 0.94, p = 6.68 × 10-20).

DISCUSSION

Overall, localized microstructural differences were identified within tracts linking the prefrontal and premotor cortices with thalamic and basal ganglia regions, suggesting pathophysiologic processes involve microstructural aberrances of motor system modulatory pathways, particularly involving intra-axonal and fiber orientation dispersion measures.

Multimodal neuroimaging to characterize symptom-specific networks in movement disorders

Movement disorders, such as Parkinson's disease, essential tremor, and dystonia, are characterized by their predominant motor symptoms, yet diseases causing abnormal movement also encompass several other symptoms, including non-motor symptoms. Here we review recent advances from studies of brain lesions, neuroimaging, and neuromodulation that provide converging evidence on symptom-specific brain networks in movement disorders. Although movement disorders have traditionally been conceptualized as disorders of the basal ganglia, cumulative data from brain lesions causing parkinsonism, tremor and dystonia have now demonstrated that this view is incomplete. Several recent studies have shown that lesions causing a given movement disorder occur in heterogeneous brain locations, but disrupt common brain networks, which appear to be specific to each motor phenotype. In addition, findings from structural and functional neuroimaging in movement disorders have demonstrated that brain abnormalities extend far beyond the brain networks associated with the motor symptoms. In fact, neuroimaging findings in each movement disorder are strongly influenced by the constellation of patients' symptoms that also seem to map to specific networks rather than individual anatomical structures or single neurotransmitters. Finally, observations from deep brain stimulation have demonstrated that clinical changes, including both symptom improvement and side effects, are dependent on the modulation of large-scale networks instead of purely local effects of the neuromodulation. Combined, this multimodal evidence suggests that symptoms in movement disorders arise from distinct brain networks, encouraging multimodal imaging studies to better characterize the underlying symptom-specific mechanisms and individually tailor treatment approaches.

Unilateral Stereotactic Radiofrequency Lesioning as a Surgical Treatment Option for Meige Syndrome

Background Meige syndrome is a segmental dystonia affecting the head and neck, with bilateral blepharospasm as the primary symptom. First-line treatment typically involves Botox injections. For cases resistant to this treatment, bilateral deep brain stimulation of the globus pallidus internus (GPi) is considered. This study explores the efficacy of unilateral radiofrequency (RF) lesioning as an alternative surgical treatment for Meige syndrome. Methods We investigated six cases of medically refractory Meige syndrome treated with unilateral RF lesioning between October 2022 and August 2023. The procedures utilized the Leksell Stereotactic System (Elekta, Stockholm, Sweden) and the StealthStation S8 system (Medtronic, Dublin, Ireland). Target coordinates were initially set at 8-9 mm lateral and 1-2 mm inferior to the mid-commissure point (MCP) for the pallidothalamic tract (PTT), and 20 mm lateral, 2 mm anterior, and 3.0-4.5 mm inferior to the MCP for GPi, with fine adjustments based on MRI findings. Results The mean age of patients was 53. 3 ±16.5 years. Five patients underwent PTT RF lesioning, while one received GPi RF lesioning (pallidotomy). No surgical complications were reported. The Burke-Fahn-Marsden Dystonia Rating Scale scores were 32.9 ± 19.4 preoperatively and 17.7 ± 13.9 three months postoperatively, reflecting an average improvement of 42.7%. The Jankovic Rating Scale scores were 7.17 ± 0.76 preoperatively, 2.33 ± 2.34 the day after surgery (average improvement of 67%), and 3.50 ± 1.64 three months postoperatively (average improvement of 51%). Bilateral facial symptoms improved in four patients (67%). Conclusion Unilateral RF lesioning for Meige syndrome demonstrated the potential to improve bilateral symptoms and may be considered a viable treatment option for patients with refractory cases.

Structural brain heterogeneity underlying symptomatic and asymptomatic genetic dystonia: a multimodal MRI study

BACKGROUND

Most of DYT genotypes follow an autosomal dominant inheritance pattern with reduced penetrance; the mechanisms underlying the disease development remain unclear. The objective of the study was to investigate cortical thickness, grey matter (GM) volumes and white matter (WM) alterations in asymptomatic (DYT-A) and symptomatic dystonia (DYT-S) mutation carriers.

METHODS

Eight DYT-A (four DYT-TOR1A and four DYT-THAP1), 14 DYT-S (seven DYT-TOR1A, and seven DYT-THAP1), and 37 matched healthy controls underwent 3D T1-weighted and diffusion tensor (DT) MRI to study cortical thickness, cerebellar and basal ganglia GM volumes and WM microstructural changes.

RESULTS

DYT-S showed thinning of the frontal and motor cortical regions related to sensorimotor and cognitive processing, together with putaminal atrophy and subcortical microstructural WM damage of both motor and extra-motor tracts such as cerebral peduncle, corona radiata, internal and external capsule, temporal and orbitofrontal WM, and corpus callosum. DYT-A had cortical thickening of middle frontal areas and WM damage of the corona radiata.

CONCLUSIONS

DYT genes phenotypic expression is associated with alterations of both motor and extra-motor WM and GM regions. Asymptomatic genetic status is characterized by a very subtle affection of the WM motor pathway, together with an increased cortical thickness of higher-order frontal regions that might interfere with phenotypic presentation and disease manifestation.

Macro- and micro-structural insights into primary dystonia: a UK Biobank study

BACKGROUND

Dystonia is a hyperkinetic movement disorder with key motor network dysfunction implicated in pathophysiology. The UK Biobank encompasses > 500,000 participants, of whom 42,565 underwent brain MRI scanning. This study applied an optimized pre-processing pipeline, aimed at better accounting for artifact and improving data reliability, to assess for grey and white matter structural MRI changes between individuals diagnosed with primary dystonia and an unaffected control cohort.

METHODS

Individuals with dystonia (n = 76) were identified from the UK Biobank using published algorithms, alongside an age- and sex-matched unaffected control cohort (n = 311). Grey matter morphometric and diffusion measures were assessed, together with white matter diffusion tensor and diffusion kurtosis metrics using tractography and tractometry. Post-hoc Neurite Orientation and Density Distribution Imaging (NODDI) was also undertaken for tracts in which significant differences were observed.

RESULTS

Grey matter tremor-specific striatal differences were observed, with higher radial kurtosis. Tractography identified no white matter differences, however segmental tractometry identified localised differences, particularly in the superior cerebellar peduncles and anterior thalamic radiations, including higher fractional anisotropy and lower orientation distribution index in dystonia, compared to controls. Additional tremor-specific changes included lower neurite density index in the anterior thalamic radiations.

CONCLUSIONS

Analysis of imaging data from one of the largest dystonia cohorts to date demonstrates microstructural differences in cerebellar and thalamic white matter connections, with architectural differences such as less orientation dispersion potentially being a component of the morphological structural changes implicated in dystonia. Distinct tremor-related imaging features are also implicated in both grey and white matter.

Blood neurofilament light chain as a surrogate marker for dystonia

BACKGROUND AND PURPOSE

Dystonia is a heterogeneous movement disorder, and it remains unclear whether neurodegeneration is involved. Neurofilament light chain (NfL) is a biosignature of neurodegeneration. We aimed to investigate whether plasma NfL levels were elevated and associated with disease severity in patients with dystonia.

METHOD

We enrolled 231 unrelated dystonia patients (isolated dystonia n = 203; combined dystonia n = 28) and 54 healthy controls from movement disorder clinics. Clinical severity was evaluated using the Fahn Marsden Dystonia Rating Scale, the Unified Dystonia Rating Scale, and the Global Dystonia Rating Scale. Blood NfL levels were measured by single-molecule array.

RESULTS

Plasma NfL levels were significantly higher in those with generalized dystonia compared to those with focal dystonia (20.1 ± 8.8 vs. 11.7 ± 7.2 pg/mL; p = 0.01) or controls (p < 0.01), while the level was comparable between the focal dystonia group and controls (p = 0.08). Furthermore, the dystonia combined with parkinsonism group had higher NfL levels than the isolated dystonia group (17.4 ± 6.2 vs. 13.5 ± 7.5 pg/mL; p = 0.04). Notably, whole-exome sequencing was performed in 79 patients and two patients were identified as having likely pathogenic variants: one had a heterozygous c.122G>A (p.R41H) variant in THAP1 (DYT6) and the other carried a c.1825G>A (p.D609N) substitution in ATP1A3 (DYT12). No significant correlation was found between plasma NfL levels and dystonia rating scores.

CONCLUSION

Plasma NfL levels are elevated in patients with generalized dystonia and dystonia combined with parkinsonism, suggesting that neurodegeneration is involved in the disease process of this subgroup of patients.

Cell-specific Dyt1 ∆GAG knock-in to basal ganglia and cerebellum reveal differential effects on motor behavior and sensorimotor network function

Dystonia is a neurological movement disorder characterized by repetitive, unintentional movements and disabling postures that result from sustained or intermittent muscle contractions. The basal ganglia and cerebellum have received substantial focus in studying DYT1 dystonia. It remains unclear how cell-specific ∆GAG mutation of torsinA within specific cells of the basal ganglia or cerebellum affects motor performance, somatosensory network connectivity, and microstructure. In order to achieve this goal, we generated two genetically modified mouse models: in model 1 we performed Dyt1 ∆GAG conditional knock-in (KI) in neurons that express dopamine-2 receptors (D2-KI), and in model 2 we performed Dyt1 ∆GAG conditional KI in Purkinje cells of the cerebellum (Pcp2-KI). In both of these models, we used functional magnetic resonance imaging (fMRI) to assess sensory-evoked brain activation and resting-state functional connectivity, and diffusion MRI to assess brain microstructure. We found that D2-KI mutant mice had motor deficits, abnormal sensory-evoked brain activation in the somatosensory cortex, as well as increased functional connectivity of the anterior medulla with cortex. In contrast, we found that Pcp2-KI mice had improved motor performance, reduced sensory-evoked brain activation in the striatum and midbrain, as well as reduced functional connectivity of the striatum with the anterior medulla. These findings suggest that (1) D2 cell-specific Dyt1 ∆GAG mediated torsinA dysfunction in the basal ganglia results in detrimental effects on the sensorimotor network and motor output, and (2) Purkinje cell-specific Dyt1 ∆GAG mediated torsinA dysfunction in the cerebellum results in compensatory changes in the sensorimotor network that protect against dystonia-like motor deficits.

Dystonia and Parkinson's disease: Do they have a shared biology?

Parkinsonism and dystonia co-occur across many movement disorders and are most encountered in the setting of Parkinson's disease. Here we aim to explore the shared neurobiological underpinnings of dystonia and parkinsonism through the clinical lens of the conditions in which these movement disorders can be seen together. Foregrounding the discussion, we briefly review the circuits of the motor system and the neuroanatomical and neurophysiological aspects of motor control and highlight their relevance to the proposed pathophysiology of parkinsonism and dystonia. Insight into shared biology is then sought from dystonia occurring in PD and other forms of parkinsonism including those disorders in which both can be co-expressed simultaneously. We organize these within a biological schema along with important questions to be addressed in this space.

Cortico-Subcortical White Matter Bundle Changes in Cervical Dystonia and Blepharospasm

Dystonia is thought to be a network disorder due to abnormalities in the basal ganglia-thalamo-cortical circuit. We aimed to investigate the white matter (WM) microstructural damage of bundles connecting pre-defined subcortical and cortical regions in cervical dystonia (CD) and blepharospasm (BSP). Thirty-five patients (17 with CD and 18 with BSP) and 17 healthy subjects underwent MRI, including diffusion tensor imaging (DTI). Probabilistic tractography (BedpostX) was performed to reconstruct WM tracts connecting the globus pallidus, putamen and thalamus with the primary motor, primary sensory and supplementary motor cortices. WM tract integrity was evaluated by deriving their DTI metrics. Significant differences in mean, radial and axial diffusivity between CD and HS and between BSP and HS were found in the majority of the reconstructed WM tracts, while no differences were found between the two groups of patients. The observation of abnormalities in DTI metrics of specific WM tracts suggests a diffuse and extensive loss of WM integrity as a common feature of CD and BSP, aligning with the increasing evidence of microstructural damage of several brain regions belonging to specific circuits, such as the basal ganglia-thalamo-cortical circuit, which likely reflects a common pathophysiological mechanism of focal dystonia.

Neural Network in the Analysis of the MR Signal as an Image Segmentation Tool for the Determination of T1 and T2 Relaxation Times with Application to Cancer Cell Culture

Artificial intelligence has been entering medical research. Today, manufacturers of diagnostic instruments are including algorithms based on neural networks. Neural networks are quickly entering all branches of medical research and beyond. Analyzing the PubMed database from the last 5 years (2017 to 2021), we see that the number of responses to the query "neural network in medicine" exceeds 10,500 papers. Deep learning algorithms are of particular importance in oncology. This paper presents the use of neural networks to analyze the magnetic resonance imaging (MRI) images used to determine MRI relaxometry of the samples. Relaxometry is becoming an increasingly common tool in diagnostics. The aim of this work was to optimize the processing time of DICOM images by using a neural network implemented in the MATLAB package by The MathWorks with the patternnet function. The application of a neural network helps to eliminate spaces in which there are no objects with characteristics matching the phenomenon of longitudinal or transverse MRI relaxation. The result of this work is the elimination of aerated spaces in MRI images. The whole algorithm was implemented as an application in the MATLAB package.