Strengthening preparedness against global health threats: A paradigm shift based on One Health approaches.

The implementation of preparedness strategies to prevent and mitigate the impact of global health threats poses several challenges. It should promptly identify cross-cutting drivers of pandemic threats, assess context-specific risks, engage multiple stakeholders, and translate complex data from multiple sources into accessible information for action. This requires a coordinated, multidisciplinary and multisectoral effort engaging systems that, most of the time, work in isolation. The One Health (OH) approach promotes the collaboration and communication among different disciplines and sectors, and could be applied across the preparedness phases at national and international level. We discuss here gaps and needs in preparedness strategies, which can benefit from the OH approach, and a set of actionable recommendations, as shared with the G20-2021 with a dedicated Policy Brief. The discussion adds to the current debate about OH operationalization and promotes a paradigm shift towards coordinated prevention and preparedness strategies for early assessment and management of global health threats.

Fibre post cementation: instrumental analysis.

The loss of dental substance due to the presence of decay, to wide conservative repairs, to the preparation of prosthetics or to enamel-dentine fractures, often causes an important structural weakening in the element that is endodontically treated (1-15). It is therefore necessary to use endocanal posts in the coronal reconstruction. Mineral fibre posts and epoxy resins that are available at present, fixed with resinous cements, thanks to their excellent integration, exceed the concept of reconstruction, meant as assembly of heterogeneous materials, arranging homogeneous materials according to a similar flexibility module (16-18). This allows to get a "post dentine cement monobloc", which is ideal for the morphofunctional tooth resetting (19-35). The aim of our experimental study was to analyse and compare the surface characteristics of same posts that are available at present by observing them in their relationship with cement and dental materials (36-44).

Comparative analysis of the peri-implant tissue response of standard versus short implants in smoker, non-smoker and former smoker patients: a one-year retrospective study.

The aim of this clinical study is to evaluate, through some clinical and radiographic tests, the different biological responses of hard and soft tissues adjacent to the standard or to reduced-length implants in smokers, non-smokers and former smokers. This study was a comparative analysis of three groups of patients. Patients were eligible if they needed an implant in the posterior areas of the maxilla and mandible, both with a sufficient amount of bone, using implants that are standard or with small heights, and using small implants so that they could avoid any regenerative bone therapy aimed at increasing vertical size. The clinical and X-ray assessment was performed after 4/6 months (T1) and after one year (T2). The main results were recordings of clinical aspects such as presence of inflammation, color and gum appearance assessments, and X-ray assessment differentiating maxilla and mandible implants. Averages were conducted to estimate differences between study groups. One-hundred patients were included, with a total of 200 implants: 100 standard sized implants and 100 short implants. In the individual study groups, there is no difference between the types of implants, and we have favorable and unfavorable conditions. The reported data and the analyzed studies are insufficient to define the influence of smoking in the assessment of the long-term predictability of implants.

Directional differences in head stabilisation in Acanthodactylus pardalis lizards.

Running inevitably causes the animal trunk to undulate. The consequential head rotations have to be stabilised in space for a steady gaze and an accurate sense of self-motion for balance. The ecology and anatomy of the species determine the necessity to stabilise the head in yaw, pitch, and roll direction. Terrestrial lizards, running with a sprawled body posture, are especially prone to undulations in the horizontal (yaw) plane. Measurements on an experimental oscillation platform show that Acanthodactylus pardalis lizards stabilise their head less in pitch direction (54% stabilisation) than in yaw and roll direction (66% and 64% stabilisation, respectively). Because we performed these experiments in darkness, the lizards based their head stabilisation on vestibular information. Hence, we hypothesised that their vestibular system is less sensitive in pitch direction than in yaw and roll direction. Yet, this was not confirmed by a detailed Fluid-Structure Interaction model of the membranous labyrinth, which showed that not pitch sensitivity (88% of yaw sensitivity), but roll sensitivity (73% of yaw sensitivity) is the lowest. So why is the head stabilisation in darkness almost as good in roll direction as in yaw direction? While this may be due to neurological nonlinearities, it seems worth noticing that the moment of inertia is lowest in roll direction due to the elongated head shape. Hence, less torque is needed to stabilise a head rotation in roll direction than in the other two directions.

Regional and Volumetric Parameters for Diffusion-Weighted WHO Grade II and III Glioma Genotyping: A Method Comparison.

BACKGROUND AND PURPOSE: Studies consistently report lower ADC values in isocitrate dehydrogenase (IDH) wild-type gliomas than in IDH mutant tumors, but their methods and thresholds vary. This research aimed to compare volumetric and regional ADC measurement techniques for glioma genotyping, with a focus on IDH status prediction. MATERIALS AND METHODS: Treatment-naïve World Health Organization grade II and III gliomas were analyzed by 3 neuroradiologist readers blinded to tissue results. ADC minimum and mean ROIs were defined in tumor and in normal-appearing white matter to calculate normalized values. T2-weighted tumor VOIs were registered to ADC maps with histogram parameters (mean, 2nd and 5th percentiles) extracted. Nonparametric testing (eta2 and ANOVA) was performed to identify associations between ADC metrics and glioma genotypes. Logistic regression was used to probe the ability of VOI and ROI metrics to predict IDH status. RESULTS: The study included 283 patients with 79 IDH wild-type and 204 IDH mutant gliomas. Across the study population, IDH status was most accurately predicted by ROI mean normalized ADC and VOI mean normalized ADC, with areas under the curve of 0.83 and 0.82, respectively. The results for ROI-based genotyping of nonenhancing and solid-patchy enhancing gliomas were comparable with volumetric parameters (area under the curve = 0.81-0.84). In rim-enhancing, centrally necrotic tumors (n = 23), only volumetric measurements were predictive (0.90). CONCLUSIONS: Regional normalized mean ADC measurements are noninferior to volumetric segmentation for defining solid glioma IDH status. Partially necrotic, rim-enhancing tumors are unsuitable for ROI assessment and may benefit from volumetric ADC quantification.

Implant-safe test in patients with peri-implantitis.

Matrix metalloproteases (MMPs) are a family of zinc-dependent endopeptidases, produced by numerous cell types including fibroblasts, endothelial cells, osteoblasts, macrophages, lymphocytes and neutrophils, and capable of degrading different components of the extracellular matrix (ECM), but also cytokines, receptors and factors that regulate cell motility (1). MMPs represent the main proteolytic enzymes involved in the remodeling and degradation of the components of the extracellular matrix, in the modifications of interactions between cells, and those between cells and the ECM that regulate, for example, the processes of cell migration (2, 3). Due to these characteristics, the MMPs are involved in numerous physiological processes (angiogenesis, apoptosis, bone remodeling, wound repair, morphogenesis, inflammation, immune response) response to incongruous conservative and endodontic treatments (29-37, 46, 47) and pathological (periodontitis, arthritis, cancer, cardiovascular diseases, neurological diseases, osteoporosis etc.) (5). Metalloproteinase-8 (MMP-8) is an important indicator of tissue decomposition and is present in case of periodontitis in the gingiva and in the sulcular fluid. The concentration of MMP-8 in the sulcular fluid of patients with chronic or aggressive periodontitis is higher than that found in healthy patients (4, 6). MMP-8 was also significantly correlated with gingivitis index, plaque index, probing and clinical attack level. For this reason, the concentration of MMP-8 in the sulcular fluid could constitute a useful index to monitor periodontitis activity and be used to predict disease progression, also because of orthodontic treatments (38-45). Patients with periodontitis had elevated concentrations of MMP-8 salivary compared to patients with gingivitis and healthy tissues. Through this experimentation we wanted to demonstrate the real effectiveness of using this test as a means of preventing peri-implant pathology.

Autotransplatation of immature third molars as substitutes for congenitally missing second premolars: an alternative solution in a young patient with oligodontia.

Auto transplantation of immature donor teeth can be a strategic therapeutic solution in young patients. It is preferable to choose this approach instead of prosthetic restorations because it offers a unique and definitive solution. Orthodontic space closure is not always deemed desirable, especially in non-extraction cases (53,54). Successful auto transplantations allow alveolar growth through eruption of donor teeth together with the adjacent dentition when skeletal and dental development is not yet completed. Auto transplantation of third molars is less well-recognised and less documented. The available literature shows promising success rates. Immature donor teeth are reportedly associated with better outcomes than mature donor teeth. Aim of this case report was to analyse the short-term outcomes of auto transplantation of immature maxillary third molars to replace the missing mandibular second premolars in a 17-year-old healthy female with oligodontia. The surgical procedure was performed as a single step. Left and right lower second deciduous molars (7.5-8.5), close to exfoliation, were extracted. Donor upper third molars with developing root were extracted as a traumatically as possible and immediately placed into the surgically modified recipient sites. They were stabilized by a sectional wire. One year after surgery, the survival of both transplanted teeth was achieved. They showed periodontal health, normal mobility and continuation of root development during the follow-up period. The upper left third molar responded to all success criteria, no signs of ankylosis, root resorption (infection or inflammatory), and pulp necrosis. The upper right third molar had long-standing evidence of not progressive cervical external inflammatory root resorption without any clinical signs. Further research is needed to determine their long-term survival and success rates.

Histomorphometric evaluation of bovine bone and equine bone matrix in maxillary sinus floor augmentation: a systematic review.

The aim of this study was to evaluate the efficiency of bovine and equine bone substitute materials used in sinus augmentation techniques. The research protocol was carried out using the PubMed database, including articles from October 2019 until February 2020 and those in English only. The search on PubMed (MED-LINE) was carried out with the following keywords: sinus augmentation OR sinus lift AND bovine bone graft OR equine bone matrix. The articles identified included randomised clinical trials, cross-sectional studies and case series. Outcomes were the percentage of newly formed bone, remaining graft particles and soft tissue in a follow-up at least of 5 months. The use of bovine bone graft (ABB) as a graft material in maxillary sinus elevation was evaluated in 9 studies. According to the quality assessment, 4 of the 9 studies were analysed and an arithmetic mean was performed showing the following results: newly formed bone (NFB 22.74%), residual grafts (RG 29.36%) and soft tissue percentage (SF 48.51%). The use of equine bone matrix (EBM) was assessed in four different studies including an RCT, a cross-sectional study and two case series; a mean percentage calculated by the extracted data of the four studies was estimated with newly formed bone (NFB 44.51%), residual grafts (RG 17.24%) and soft tissue percentage (SF 36.62%). EBM appears to be as effective as ABB for the maxillary sinus floor augmentation procedure.

The dentist's role in diagnosis and treatment of obstructive sleep apnea syndrome: a literature review.

The purpose of this work was to present a review of the literature concerning obstructive sleep apnea syndrome, and the role of the dentist in this pathology, both to identify elements useful for a good diagnosis and to apply the available therapeutic strategies. In literature there is no unanimous opinion on the treatment of OSAS. The multidisciplinary approach is necessary, creating teams made up of dentists, otolaryngologists and medical experts in sleep disorders, in order to develop a cooperation-based treatment plan for the disease. In this review, the importance of early diagnosis, orthodontic therapy in order to restore normal function is underlined, since OSAS is linked to a high risk of hypertension, cardiovascular diseases, daytime sleepiness, domestic and work accidents, with consequent deterioration of the quality of life.

Bruma MAD: a new way of treating OSAS patients.

The aim of this study was to introduce a new adjustable device in the treatment of obstructive sleep apnea syndrome (OSAS). The new appliance has a different way to regulate and move the mandible through the presence of two occlusal lifts, that can leave an open posterior space, and the complex system formed by the peduncle and the steel plate that can easily move forward the mandible. This system guarantees a posterior space for the tongue but mostly for the passage of air. The principal aim of Bruma MAD is to contrast the pharyngeal collapsing and to prevent hypopnea or apnea. Further clinical studies are needed to confirm and to evaluate the predictability of this new device.

Clinical practice of language fMRI in epilepsy centers: a European survey and conclusions by the ESNR Epilepsy Working Group.

PURPOSE: To assess current clinical practices throughout Europe with respect to acquisition, implementation, evaluation, and interpretation of language functional MRI (fMRI) in epilepsy patients. METHODS: An online survey was emailed to all European Society of Neuroradiology members (n = 1662), known associates (n = 6400), and 64 members of European Epilepsy network. The questionnaire featured 40 individual items on demographic data, clinical practice and indications, fMRI paradigms, radiological workflow, data post-processing protocol, and reporting. RESULTS: A total of 49 non-duplicate entries from European centers were received from 20 countries. Of these, 73.5% were board-certified neuroradiologists and 69.4% had an in-house epilepsy surgery program. Seventy-one percent of centers performed fewer than five scans per month for epilepsy. The most frequently used paradigms were phonemic verbal fluency (47.7%) and auditory comprehension (55.6%), but variants of 13 paradigms were described. Most centers assessed the fMRI task performance (75.5%), ensured cognitive-task adjustment (77.6%), trained the patient before scanning (85.7%), and assessed handedness (77.6%), but only 28.6% had special paradigms for patients with cognitive impairments. fMRI was post-processed mainly by neuroradiologists (42.1%), using open-source software (55.0%). Reporting was done primarily by neuroradiologists (74.2%). Interpretation was done mainly by visual inspection (65.3%). Most specialists (81.6%) were able to determine the hemisphere dominance for language in more than 75% of exams, attributing failure to the patient not performing the task correctly. CONCLUSION: This survey shows that language fMRI is firmly embedded in the preoperative management of epilepsy patients. The wide variety of paradigms and the use of non-CE-marked software underline the need for establishing reference standards.

Optical properties of GaN nanowires grown on chemical vapor deposited-graphene.

Optical properties of GaN nanowires (NWs) grown on chemical vapor deposited-graphene transferred on an amorphous support are reported. The growth temperature was optimized to achieve a high NW density with a perfect selectivity with respect to a SiO2 surface. The growth temperature window was found to be rather narrow (815°C ± 5°C). Steady-state and time-resolved photoluminescence from GaN NWs grown on graphene was compared with the results for GaN NWs grown on conventional substrates within the same molecular beam epitaxy reactor showing a comparable optical quality for different substrates. Growth at temperatures above 820 °C led to a strong NW density reduction accompanied with a diameter narrowing. This morphology change leads to a spectral blueshift of the donor-bound exciton emission line due to either surface stress or dielectric confinement. Graphene multi-layered micro-domains were explored as a way to arrange GaN NWs in a hollow hexagonal pattern. The NWs grown on these domains show a luminescence spectral linewidth as low as 0.28 meV (close to the set-up resolution limit).

First 3D imaging characterization of Pele's hair from Kilauea volcano (Hawaii).

In this work the morphologic features of Pele's hair formed during three different eruptions of Kilauea volcano have been investigated: fountaining from Kilauea Iki's 1959 Episode 1, weak explosive activity from Halemaumau lava lake and littoral explosions at Waikupanaha (2009). Morphological studies were performed by optical, stereo- and scanning electron microscopy. For the first time 3D image analysis was carried out by synchrotron radiation X-ray computed microtomography, which allowed a high-resolution 3D reconstruction of the internal structure of each Pele's hair, highlighting several differences in terms of number density, elongation and shape of the vesicles between the samples from the three eruptions. We identified three main parameters determining these differences: initial size of the magma droplet, ejection velocity and magma viscosity. Pele's hair erupted during the Kilauea Iki's fountaining shows the highest thickness and the least elongated shape of the vesicles, though it is related to fast ejection of a low viscosity magma. We therefore suggest that the size of magma droplets is the main parameter influencing the morphology and inner textures of the Pele's hair. The comparison with Pele's hair of similar eruptions elsewhere demonstrates that there is no univocal correspondence between eruptive style and Pele's hair texture.

HIDRAdisk: validation of an innovative visual tool to assess the burden of hidradenitis suppurativa.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic, relapsing, inflammatory skin disease characterized by painful inflamed nodules, recurrent abscesses and fistulas located in apocrine gland-bearing body sites. The negative impact of HS on patient's quality of life (QoL) has been reported to be greater than other dermatologic conditions as psoriasis and atopic eczema, and its improvement is an important goal in disease management. Nowadays, there are no specific validated QoL instruments available for HS and generic dermatologic questionnaires are used. OBJECTIVE: The objective of this study was to demonstrate the validity, reliability and responsiveness of HIDRAdisk, a new innovative tool designed for rapid assessment of HS burden and, at the same time, an intuitive graphic visualization of the measurement outcome. METHODS: A multicentre, longitudinal, observational study was conducted to validate the HIDRAdisk compared with other validated questionnaires [Skindex-16, Dermatology Life Quality Index (DLQI), Work Productivity and Activity Impairment-General Health (WPAI:GH)] and to evaluate its correlation with disease severity in Italian patients with any degree of HS severity, as measured by Hurley stage and HS Physician Global Assessment (HS-PGA). RESULTS: A total of 140 patients (59% women; mean age 34.9 ± 11.0 years) were enrolled in 27 dermatologic centres. HIDRAdisk showed a strong correlation with Skindex-16 and DLQI, and a good one with WPAI:GH (correlation coefficient: 0.7568, 0.6651 and 0.5947, respectively) and a statistically significant correlation with both Hurley stage and HS-PGA. Very good internal consistency (Cronbach coefficient >0.80; intraclass correlation coefficient >0.6), with correlation between the 10 items, good test-retest reliability (Spearman correlation coefficient, 0.8331; P < 0.0001) and responsiveness to changes were demonstrated. CONCLUSION: Our study shows that HIDRAdisk, a short and innovative visual HS QoL instrument, has been psychometrically validated in Italian language and it may help improve the management of HS once implemented in routine clinical practice.

Apparent diffusion coefficient for molecular subtyping of non-gadolinium-enhancing WHO grade II/III glioma: volumetric segmentation versus two-dimensional region of interest analysis.

OBJECTIVES: To investigate if quantitative apparent diffusion coefficient (ADC) measurements can predict genetic subtypes of non-gadolinium-enhancing gliomas, comparing whole tumour against single slice analysis. METHODS: Volumetric T2-derived masks of 44 gliomas were co-registered to ADC maps with ADC mean (ADCmean) calculated. For the slice analysis, two observers placed regions of interest in the largest tumour cross-section. The ratio (ADCratio) between ADCmean in the tumour and normal appearing white matter was calculated for both methods. RESULTS: Isocitrate dehydrogenase (IDH) wild-type gliomas showed the lowest ADC values throughout (p < 0.001). ADCmean in the IDH-mutant 1p19q intact group was significantly higher than in the IDH-mutant 1p19q co-deleted group (p < 0.01). A volumetric ADCmean threshold of 1201 × 10-6 mm2/s identified IDH wild-type with a sensitivity of 83% and a specificity of 86%; a volumetric ADCratio cut-off value of 1.65 provided a sensitivity of 80% and a specificity of 92% (area under the curve (AUC) 0.9-0.94). A slice ADCratio threshold for observer 1 (observer 2) of 1.76 (1.83) provided a sensitivity of 80% (86%), specificity of 91% (100%) and AUC of 0.95 (0.96). The intraclass correlation coefficient was excellent (0.98). CONCLUSIONS: ADC measurements can support the distinction of glioma subtypes. Volumetric and two-dimensional measurements yielded similar results in this study. KEY POINTS: • Diffusion-weighted MRI aids the identification of non-gadolinium-enhancing malignant gliomas • ADC measurements may permit non-gadolinium-enhancing glioma molecular subtyping • IDH wild-type gliomas have lower ADC values than IDH-mutant tumours • Single cross-section and volumetric ADC measurements yielded comparable results in this study.

EZH2 alterations in follicular lymphoma: biological and clinical correlations.

The histone methyltransferase EZH2 has an essential role in the development of follicular lymphoma (FL). Recurrent gain-of-function mutations in EZH2 have been described in 25% of FL patients and induce aberrant methylation of histone H3 lysine 27 (H3K27). We evaluated the role of EZH2 genomic gains in FL biology. Using RNA sequencing, Sanger sequencing and SNP-arrays, the mutation status, copy-number and gene-expression profiles of EZH2 were assessed in a cohort of 159 FL patients from the PRIMA trial. Immunohistochemical (IHC) EZH2 expression (n=55) and H3K27 methylation (n=63) profiles were also evaluated. In total, 37% of patients (59/159) harbored an alteration in the EZH2 gene (mutation n=46, gain n=23). Both types of alterations were associated with highly similar transcriptional changes, with increased proliferation programs. An H3K27me3/me2 IHC score fully distinguished mutated from wild-type samples, showing its applicability as surrogate for EZH2 mutation analysis. However, this score did not predict the presence of gains at the EZH2 locus. The presence of an EZH2 genetic alteration was an independent factor associated with a longer progression-free survival (hazard ratio 0.58, 95% confidence interval 0.36-0.93, P=0.025). We propose that the copy-number status of EZH2 should also be considered when evaluating patient stratification and selecting patients for EZH2 inhibitor-targeted therapies.

Diatoms in drowning cases in forensic veterinary context: a preliminary study.

In this preliminary study, a digestive method used in forensic context to extract diatoms has been applied in organs taken from ten wildlife animals belonging three species of mammals (a deer, a roe and five otters) and one species of birds (two magpies). Only four carcasses were recovered from aquatic environments (bath trough for animals, bathtub irrigation, river) and only in three cases out of ten that the cause of death was ruled out as drowning. In seven cases, the death was due to other causes: gunshot injuries for one otter, blunt trauma for a magpie, and traumatic injuries followed by motor vehicle collision in other four otters and a roe. Post-mortem examination was performed in all carcasses. The diatom test protocol was performed according to the Italian guidelines for analysis of benthic diatoms for ecological status assessment of inland waters. Five grams of lung, liver, and kidney was taken from all the animal carcasses. In some cases, additional tissue samples were also available among which brain, heart, spleen, and bone marrow. In all four cases found in water, the drowning medium was also available. Hydrogen peroxide (H2O2) digestion was performed, and identification of 21 genera of diatoms was obtained. The method proved to be suitable for the identification of diatoms in the organs of the animals drowned supporting the final diagnosis of drowning. Only in otters, all died for causes other than drowning, diatoms did not prove to be suitable for the diagnosis of drowning since their presence in the internal organs was mainly related to their main diet based on fishmeal. The authors believe that this first trial is very promising, and the results suggest that diatom test can be easily applied in forensic veterinary context.

Micro-CT evaluation of several glide path techniques and ProTaper Next shaping outcomes in maxillary first molar curved canals.

AIM: To evaluate the ability of ProGlider instruments, PathFiles and K-files to maintain canal anatomy during glide path preparation using X-ray computed micro-tomography (micro-CT). METHODOLOGY: Forty-five extracted maxillary first permanent molars were selected. Mesio-buccal canals were randomly assigned (n = 15) to manual K-file, PathFile or ProGlider groups for glide path preparation. Irrigation was achieved with 5% NaOCl and 10% EDTA. After glide path preparation, each canal was shaped with ProTaper Next X1 and X2 to working length. Specimens were scanned (isotropic voxel size 9.1 µm) for matching volumes and surface areas and post-treatment analyses. Canal volume, surface area, centroid shift, canal geometry variation through ratio of diameter ratios and ratio of cross-sectional areas were assessed in the apical and coronal levels and at the point of maximum canal curvature. One-way factorial anovas were used to evaluate the significance of instrument in the various canal regions. RESULTS: Post-glide path analysis revealed that instrument factor was significant at the apical level for both the ratio of diameter ratios and the ratio of cross-sectional areas (P < 0.001), with an improved maintenance of root canal geometry by ProGlider and PathFile. At the coronal level and point of maximum canal curvature, ProGlider demonstrated a tendency to pre-flare the root canal compared with K-file and PathFile. PathFile and ProGlider demonstrated a significantly lower centroid shift compared with K-file at the apical level (P = 0.023). Post-shaping analysis demonstrated a more centred preparation of ProGlider, compared with PathFile and K-files, with no significant differences for other parameters. CONCLUSIONS: Use of ProGlider instruments led to less canal transportation than PathFiles and K-files.

9.4 T MR microscopy of the substantia nigra with pathological validation in controls and disease.

BACKGROUND: The anatomy of the substantia nigra on conventional MRI is controversial. Even using histological techniques it is difficult to delineate with certainty from surrounding structures. We sought to define the anatomy of the SN using high field spin-echo MRI of pathological material in which we could study the anatomy in detail to corroborate our MRI findings in controls and Parkinson's disease and progressive supranuclear palsy. METHODS: 23 brains were selected from the Queen Square Brain Bank (10 controls, 8 progressive supranuclear palsy, 5 Parkinson's disease) and imaged using high field 9.4 Tesla spin-echo MRI. Subsequently brains were cut and stained with Luxol fast blue, Perls stain, and immunohistochemistry for substance P and calbindin. Once the anatomy was defined on histology the dimensions and volume of the substantia nigra were determined on high field magnetic resonance images. RESULTS: The anterior border of the substantia nigra was defined by the crus cerebri. In the medial half it was less distinct due to the deposition of iron and the interdigitation of white matter and the substantia nigra. The posterior border was flanked by white matter bridging the red nucleus and substantia nigra and seen as hypointense on spin-echo magnetic resonance images. Within the substantia nigra high signal structures corresponded to confirmed nigrosomes. These were still evident in Parkinson's disease but not in progressive supranuclear palsy. The volume and dimensions of the substantia nigra were similar in Parkinson's disease and controls, but reduced in progressive supranuclear palsy. CONCLUSIONS: We present a histologically validated anatomical description of the substantia nigra on high field spin-echo high resolution magnetic resonance images and were able to delineate all five nigrosomes. In accordance with the pathological literature we did not observe changes in the nigrosome structure as manifest by volume or signal characteristics within the substantia nigra in Parkinson's disease whereas in progressive supranuclear palsy there was microarchitectural destruction.