Advances in radionuclide tracers have allowed for more accurate imaging that reflects the actions of numerous neurotransmitters, energy metabolism utilization, inflammation, and pathological protein accumulation. All of these achievements in molecular brain imaging have broadened our understanding of brain function in Parkinson's disease (PD). The implementation of molecular imaging has supported more accurate PD diagnosis as well as assessment of therapeutic outcome and disease progression. Moreover, molecular imaging is well suited for the detection of preclinical or prodromal PD cases. Despite these advances, future frontiers of research in this area will focus on using multi-modalities combining positron emission tomography and magnetic resonance imaging along with causal modeling with complex algorithms.
Brain ; diagnostic imaging ; Humans ; Molecular Imaging ; methods ; trends ; Neuroimaging ; methods ; trends ; Parkinson Disease ; diagnostic imaging

This study aimed to define the most consistent white matter microarchitecture pattern in Parkinson's disease (PD) reflected by fractional anisotropy (FA), addressing clinical profiles and methodology-related heterogeneity. Web-based publication databases were searched to conduct a meta-analysis of whole-brain diffusion tensor imaging studies comparing PD with healthy controls (HC) using the anisotropic effect size-signed differential mapping. A total of 808 patients with PD and 760 HC coming from 27 databases were finally included. Subgroup analyses were conducted considering heterogeneity with respect to medication status, disease stage, analysis methods, and the number of diffusion directions in acquisition. Compared with HC, patients with PD had decreased FA in the left middle cerebellar peduncle, corpus callosum (CC), left inferior fronto-occipital fasciculus, and right inferior longitudinal fasciculus. Most of the main results remained unchanged in subgroup meta-analyses of medicated patients, early stage patients, voxel-based analysis, and acquisition with 30 diffusion directions. The subgroup meta-analysis of medication-free patients showed FA decrease in the right olfactory cortex. The cerebellum and CC, associated with typical motor impairment, showed the most consistent FA decreases in PD. Medication status, analysis approaches, and the number of diffusion directions have an important impact on the findings, needing careful evaluation in future meta-analyses.
Anisotropy ; Brain/diagnostic imaging* ; Corpus Callosum ; Diffusion Tensor Imaging ; Humans ; Parkinson Disease/diagnostic imaging* ; White Matter/diagnostic imaging*

BACKGROUND: Reports evaluating the efficacy of transcranial sonography (TCS) for the differential diagnosis of Parkinson disease (PD) and other movement disorders in China are scarce. Therefore, this study aimed to assess the application of TCS for the differential diagnosis of PD, multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and essential tremor (ET) in Chinese individuals. METHODS: From 2017 to 2019, 500 inpatients treated at the Department of Dyskinesia, Beijing Tiantan Hospital, Capital Medical University underwent routine transcranial ultrasound examination. The cross-sections at the midbrain and thalamus levels were scanned, and the incidence rates of substantia nigra (SN) positivity and the incidence rates of lenticular hyperechoic area were recorded. The echo of the SN was manually measured. RESULTS: Of the 500 patients, 125 were excluded due to poor signal in temporal window sound transmission. Among the 375 individuals with good temporal window sound transmission, 200 were diagnosed with PD, 90 with ET, 50 with MSA, and 35 with PSP. The incidence rates of SN positivity differed significantly among the four patient groups (χ2 = 121.061, P < 0.001). Between-group comparisons were performed, and the PD group showed a higher SN positivity rate than the ET (χ2 = 94.898, P < 0.017), MSA (χ2 = 57.619, P < 0.017), and PSP (χ2 = 37.687, P < 0.017) groups. SN positivity showed a good diagnostic value for differentiating PD from the other three movement diseases, collectively or individually. The incidences of lenticular hyperechoic area significantly differed among the four patient groups (χ2 = 38.904, P < 0.001). Next, between-group comparisons were performed. The lenticular hyperechoic area was higher in the PD group than in the ET (χ2 = 6.714, P < 0.017) and MSA (χ2 = 18.680, P < 0.017) groups but lower than that in the PSP group (χ2 = 0.679, P > 0.017). CONCLUSION SN positivity could effectively differentiate PD from ET, PSP, and MSA in a Chinese population.
Diagnosis, Differential ; Humans ; Multiple System Atrophy/diagnostic imaging* ; Parkinson Disease/diagnostic imaging* ; Substantia Nigra/diagnostic imaging* ; Supranuclear Palsy, Progressive

Aged ; Electromyography ; Humans ; Imaging, Three-Dimensional ; Lumbar Vertebrae ; Lumbosacral Plexus ; diagnostic imaging ; Lumbosacral Region ; diagnostic imaging ; Magnetic Resonance Imaging ; Male ; Parkinson Disease ; complications ; Radiculopathy ; complications ; diagnostic imaging

Neuroinflammation is heavily associated with various neurological diseases including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and stroke. It is strongly characterized by the activation of microglia which can be visualized using position emission tomography (PET). Traditionally, translocator protein 18 kDa (TSPO) has been the preferred target for imaging the inflammatory progression of the microglial component. TSPO is expressed in the outer mitochondrial membrane and present in very low concentrations in the healthy human brain, but is markedly upregulated in response to brain injury and inflammation. Due to its value as a marker of microglial activation and subsequent utility for evaluating neuroinflammation in CNS disorders, several classes of TSPO radioligands have been developed and evaluated. However, the application of these second-generation TSPO radiotracers has been subject to several limiting factors, including a polymorphism that affects TSPO binding. This review focuses on recent developments in TSPO imaging, as well as current limitations and suggestions for future directions from a medical imaging perspective.
Alzheimer Disease ; Brain ; Brain Injuries ; Diagnostic Imaging ; Humans ; Inflammation ; Ligands ; Microglia ; Mitochondrial Membranes ; Molecular Imaging ; Multiple Sclerosis ; Parkinson Disease ; Stroke

Diffusion-tensor imaging (DTI) is a noninvasive medical imaging tool used to investigate the structure of white matter. The signal contrast in DTI is generated by differences in the Brownian motion of the water molecules in brain tissue. Postprocessed DTI scalars can be used to evaluate changes in the brain tissue caused by disease, disease progression, and treatment responses, which has led to an enormous amount of interest in DTI in clinical research. This review article provides insights into DTI scalars and the biological background of DTI as a relatively new neuroimaging modality. Further, it summarizes the clinical role of DTI in various disease processes such as amyotrophic lateral sclerosis, multiple sclerosis, Parkinson's disease, Alzheimer's dementia, epilepsy, ischemic stroke, stroke with motor or language impairment, traumatic brain injury, spinal cord injury, and depression. Valuable DTI postprocessing tools for clinical research are also introduced.
Amyotrophic Lateral Sclerosis ; Brain ; Brain Injuries ; Dementia ; Depression ; Diagnostic Imaging ; Disease Progression ; Epilepsy ; Multiple Sclerosis ; Nervous System Diseases* ; Neuroimaging ; Parkinson Disease ; Spinal Cord Injuries ; Stroke ; Water ; White Matter

Neurostimulation remarkably alleviates the symptoms in a variety of brain disorders by modulating the brain-wide network. However, how brain-wide effects on the direct and indirect pathways evoked by focal neurostimulation elicit therapeutic effects in an individual patient is unknown. Understanding this remains crucial for advancing neural circuit-based guidance to optimize candidate patient screening, pre-surgical target selection, and post-surgical parameter tuning. To address this issue, we propose a functional brain connectome-based modeling approach that simulates the spreading effects of stimulating different brain regions and quantifies the rectification of abnormal network topology in silico. We validated these analyses by pinpointing nuclei in the basal ganglia circuits as top-ranked targets for 43 local patients with Parkinson's disease and 90 patients from a public database. Individual connectome-based analysis demonstrated that the globus pallidus was the best choice for 21.1% and the subthalamic nucleus for 19.5% of patients. Down-regulation of functional connectivity (up to 12%) at these prioritized targets optimally maximized the therapeutic effects. Notably, the priority rank of the subthalamic nucleus significantly correlated with motor symptom severity (Unified Parkinson's Disease Rating Scale III) in the local cohort. These findings underscore the potential of neural network modeling for advancing personalized brain stimulation therapy, and warrant future experimental investigation to validate its clinical utility.
Adult ; Aged ; Brain Mapping ; Connectome ; Deep Brain Stimulation ; methods ; Female ; Humans ; Image Processing, Computer-Assisted ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neural Pathways ; diagnostic imaging ; physiology ; Oxygen ; blood ; Parkinson Disease ; diagnostic imaging ; pathology ; therapy ; ROC Curve ; United Kingdom

OBJECTIVETo investigate the role of 99mTc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathic Parkinson's disease (PD).

METHODSThirty-eight patients with primary, tentative diagnosis of PD and eighteen age-matched normal controls were studied with 99mTc-TRODAT-1 SPECT imaging. The regions of interests (ROIs) were drawn manually on cerebellum (CB), occipital cortex (OC) and three transverse plane slice-views of striatums, the semiquantitative BG (background)/[(OC+CB)/2] were then calculated.

RESULTSA lower uptake of 99mTc-TRODAT-1 in striatums were displayed in thirty-six out of thirty-eight PD patients by visual inspection, compared to controls. In twenty-four PD cases with (Hoehn and Yahr scale) HYS stage I, a greater loss of DAT uptake was found in striatum and its subregions contralateral striatum to the affected limbs than in the same regions of the controls, although the striatal uptake was bilaterally reduced. Using Spearman correlation analysis showed that the reduction of the uptake ratios significantly correlated with the UPDRS in striatum and all its subregions in the PD group (P<0.05), a similar change was also found in the putamen by using the rating scale of Hoehn and Yahr (P<0.05). However, analysis of variance (ANOVA) did not show any relationship between the decreasing uptake of 99mTc-TRODAT-1 and increasing severity of PD patients, although the specific uptake of 99mTc-TRODAT-1 was continuously decreased in the striatum by visual inspection with the progress of PD from HYS stage I to III.

CONCLUSION99mTc-TRODAT-1 SPECT imaging may serve as a useful method for improving the correct diagnosis of PD. In assessing the role of 99mTc-TRODAT-1 SPECT in disease severity of PD, UPDRS can offer a comprehensive index, although the Hoehn and Yahr assessment may be available in part.

Adult ; Aged ; Corpus Striatum ; diagnostic imaging ; metabolism ; Dopamine Plasma Membrane Transport Proteins ; Feasibility Studies ; Female ; Humans ; Male ; Membrane Glycoproteins ; metabolism ; Membrane Transport Proteins ; metabolism ; Middle Aged ; Nerve Tissue Proteins ; metabolism ; Organotechnetium Compounds ; pharmacokinetics ; Parkinson Disease ; diagnostic imaging ; metabolism ; Radiopharmaceuticals ; pharmacokinetics ; Reproducibility of Results ; Sensitivity and Specificity ; Severity of Illness Index ; Tomography, Emission-Computed, Single-Photon ; methods ; Tropanes ; pharmacokinetics

beta-CIT was labeled with 131I by the peracetic acid method. Cat model of Parkinsonism was set up with MPTP. Each of normal and PD model cats was given an injection of 74 MBq/0.5 ml 131I-beta-CIT into the femur vein. Then the blood samples were obtained at 4 h and 20 h, the radioactivity was counted with calibrator. The biodistribution data of 131I-beta-CIT in cat body was calculated (ID%/g). The cats were subjected to imaging at 0.5 h, 1 h, 2 h, 4 h, 20 h after the administration of radiopharmaceutical. The radioactivity in striatum and cerebellum was measured and striatal specific binding ratios were calculated. The Results showed that the radio chemical purity of 131I-beta-CIT was 97.62% +/- 0.31%. The 131I-beta-CIT remained stable for at least 4 h after incubation with water and serum respectively. Following intravenous administration in cats, 131I-beta-CIT showed high accumulation in striatum. The study of imaging in cats showed that striatal specific uptake of 131I-beta-CIT at 20 h after injection was 4.83 +/- 0.82 in normal cats and 2.92 +/- 0.66 in PD cats. There was a significant reduction of striatal tracer uptake in PD cats, compared to the controls. The results of biodistribution study was in agreement with the results of imaging study. These results suggest that beta-CIT is an ideal agent for dopamine transporter imaging and can be used for the diagnosis of Parkinson's disease.
Animals ; Brain ; metabolism ; Cats ; Cocaine ; analogs & derivatives ; metabolism ; Disease Models, Animal ; Dopamine Plasma Membrane Transport Proteins ; Female ; Male ; Membrane Glycoproteins ; metabolism ; Membrane Transport Proteins ; metabolism ; Mice ; Mice, Inbred Strains ; Nerve Tissue Proteins ; metabolism ; Parkinson Disease ; diagnostic imaging ; metabolism ; Tomography, Emission-Computed, Single-Photon