Focal Changes Research Articles

Thalamic pathology in frontotemporal dementia: Predilection for specific nuclei, phenotype-specific signatures, clinical correlates, and practical relevance.

Frontotemporal dementia (FTD) phenotypes are classically associated with distinctive cortical atrophy patterns and regional hypometabolism. However, the spectrum of cognitive and behavioral manifestations in FTD arises from multisynaptic network dysfunction. The thalamus is a key hub of several corticobasal and corticocortical circuits. The main circuits relayed via the thalamic nuclei include the dorsolateral prefrontal circuit, the anterior cingulate circuit, and the orbitofrontal circuit. In this paper, we have reviewed evidence for thalamic pathology in FTD based on radiological and postmortem studies. Original research papers were systematically reviewed for preferential involvement of specific thalamic regions, for phenotype-associated thalamic disease burden patterns, characteristic longitudinal changes, and genotype-associated thalamic signatures. Moreover, evidence for presymptomatic thalamic pathology was also reviewed. Identified papers were systematically scrutinized for imaging methods, cohort sizes, clinical profiles, clinicoradiological associations, and main anatomical findings. The findings of individual research papers were amalgamated for consensus observations and their study designs further evaluated for stereotyped shortcomings. Based on the limitations of existing studies and conflicting reports in low-incidence FTD variants, we sought to outline future research directions and pressing research priorities. FTD is associated with focal thalamic degeneration. Phenotype-specific thalamic traits mirror established cortical vulnerability patterns. Thalamic nuclei mediating behavioral and language functions are preferentially involved. Given the compelling evidence for considerable thalamic disease burden early in the course of most FTD subtypes, we also reflect on the practical relevance, diagnostic role, prognostic significance, and monitoring potential of thalamic metrics in FTD. Cardinal manifestations of FTD phenotypes are likely to stem from thalamocortical circuitry dysfunction and are not exclusively driven by focal cortical changes.

Electroconvulsive therapy induced large-scale grey matter increases do not lead to any significant functional brain changes

Abstract Electroconvulsive therapy (ECT) is an effective treatment for severe depression and induces gray matter increases in the brain. Small-scale studies suggest that ECT also leads to changes in brain functioning, but findings are inconsistent. In this talk, we will discuss our recent publication where we investigated the influence of ECT on changes in both brain structure and multiple measures of brain function and their relation to clinical improvement using multicenter neuroimaging data from the Global ECT-MRI Research Collaboration (GEMRIC). We found wide-spread increases in gray matter volume in patients following ECT. In contrast, no significant changes in any of the functional measures were observed, and there were no visible differences in structural or functional changes between ECT responders and non-responders. Multimodal analysis revealed that volume increases in the striatum, supplementary motor area and fusiform gyrus were associated with local changes in brain function. These results confirm wide-spread increases in GM volume, and suggest that this is not accompanied by functional changes or associated with clinical response. While focal changes in brain function appear related to individual differences in brain volume increases, we emphasize the need for approaches beyond standard activity measures of fMRI to investigate the working mechanism of ECT. Research Category and Technology and Methods Clinical Research: 2. Electroconvulsive Therapy (ECT) Keywords: Electroconvulsive Therapy, Gray matter, Brain Function, Neuroimaging

Method of surgical treatment of recurrent pleural empyema with bronchial fistula after right pneumonectomy for destructive drug-resistant pulmonary tuberculosis

Introduction. The treatment of patients with recurrent empyema of the pleural cavity associated with bronchial fistula of the main bronchus has been an urgent problem in phthisiosurgery for many decades. There are non-radi-cal methods of treatment using various variants of bron-cho-obturators and radical methods of treatment, but ac-companied by high trauma due to chest decostation. The authors proposed an original method for the elimination of recurrent bronchial fistula and pleural empyema after right pneumonectomy while preserving the frame of the chest. Materials and methods. A retrospective study for the period from 2016 to 2023 included 9 patients who were operated on for empyema of the pleural cav-ity with a fistula of the right main bronchus according to the original method after previous pneumonecto-my. The duration of the fistula before surgery ranged from 4 to 42 months. Bacterial excretion in sputum was preserved in 3 (33.4%) patients. 8 (88.8%) patients had pre-XDR MTB and only 1 (11.1%) had MDR MTB. In all patients, a mixed (specific and non-specific) flora was determined in the pleural fluid. The surgical strategy was multi-staged. At the first stage, upper-posterior thoracoplasty, thoracotomy, resection of the stump of the right main bronchus, its suturing and myoplasty were performed. At the second stage, an open cleaning of the pleural cavity was performed with tamponage of the residual empyema cavity from the thoracostomy, after that vacuum asssisted closure system was applied to the thoracostomy. At the third stage, myoplastic closure of the thoracostomy was performed. The im-mediate and long-term results of treatment of patients were evaluated. Results. All patients were operated on by the same surgical team. In all cases, resection of the stump of the right main bronchus was performed, for a length of 2 mm to 5 mm. Histological examination of the bronchial resection margin did not reveal tubercu-lous lesions. In the postoperative period, surgical com-plications requiring invasive interventions to eliminate them occurred in 22.2%. In 8 (88.8%) patients, the result of treatment was regarded as satisfactory (persistent absence of fistula, absence of progression of pleural empyema). In a patient with persistent recurrence of the fistula, the result of treatment is regarded as unsat-isfactory. In the long-term period, all patients with satis-factory surgical treatment were removed from the dis-pensary register, data for recurrence of empyema and bronchial fistula were not obtained during the control examination. Against the background of anti-tuberculo-sis chemotherapy, a clinical cure of tuberculosis of the sole lung was achieved with the formation of metatu-berculous fibrotic focal changes without destruction. All patients were persistently abacillated. Conclusion. The proposed multi-stage therapeutic surgical tactics for recurrent empyema of the pleural cavity associated with bronchial fistula of the main bronchus is an optimal alternative to supertraumatic and non-radical methods, since it allows reliable elimination of chronic, often re-current, bronchial fistula with successful treatment of empyema of the residual pleural cavity, and is also ac-companied by low traumatism and the best cosmetic effect while maintaining the frame of the chest wall

Clinical characteristics and short-term outcomes of autoimmune encephalitis in adults

To characterize clinical, paraclinical features and short-term outcomes in different types of autoimmune encephalitis (AE) in a one-center cohort of Russian patients, as well as to evaluate the frequency and significance of the joint expression of antineuronal and anti-glial antibodies (Abs) in AE. Forty-one patients were diagnosed with AE at the Research Center of Neurology from November 2020 to December 2022. Demographic, clinical characteristics, results of laboratory tests, MRI of brain, treatment and outcomes of disease were analyzed. The analysis of Abs to glial antigens (myelin-oligodendrocyte glycoprotein - MOG, glial fibrillar acidic protein - GFAP, aquaporin 4 - AQP-4) was performed by indirect immunofluorescence assay (Euroimmun, Germany). In 24 (58.5%) patients was established definite AE, confirmed by specific Abs detection; in 2 (4.9%) - definite limbic encephalitis, in 15 (36.6%) - seronegative probable AE (including 3 cases of Hashimoto's encephalitis). GFAP-Abs in cerebrospinal fluid (CSF) were detected only in two patients - with clinical and MRI-picture of autoimmune GFAP-astrocytopathy (A-GFAP-A). GFAP- and MOG-Abs in the blood were detected in 25.7% and 6%, respectively, AQP-4-Abs were not detected. There were no correlations between co-expression with glial Abs and clinical characteristics. Systemic and antithyroid Abs were present in 15% and 31%, respectively. Paraneoplastic AE accounted for 22%. For the first time in the Russian population, 2 cases of A-GFAP-A, 6 cases of AE associated with COVID-19 were described. The most common first syndrome were epileptic seizure (34%), psychiatric (29%) and cognitive (14%) disorders. Relapses of AE was observed in 22%. Inflammatory changes in CSF were detected in 41%, focal changes on MRI in 68%. First-line immune therapy was performed in all patients, 85% of cases received pulse therapy with methylprednisolone. Second-line immune therapy (rituximab or cyclophosphamide intravenously) was performed in 19.5%, 78% of patients achieved significant improvement during treatment (scores ≤2 on the modified Rankin scale). The results allow us to consider COVID-19 as a trigger of AE. The absence of detection of GFAP-Abs in CSF in patients with other types of AE contributes to the confirmation of the specificity of GFAP-seropositivity of CSF for the diagnosis of A-GFAP-A. The expression of GFAP- and MOG-Abs in AE can serve as confirmation of the immuno-mediated etiology of the disease, which is especially important for the AE diagnosis in the absence of antineuronal Abs.

Metastaze timoma u jetri - prikaz slučaja brzorastuće abdominalne mase kod trudnice

Introduction: Thymomas are the most common primary mediastinal tumors originating from epithelial cells of the thymus, demonstrating epithelial differentiation. Pathologically, thymomas exhibit relatively slow growth and typically spread directly, with extremely rare occurrences of distant dissemination to extrathoracic organs. The precise incidence of such dissemination remains unknown. Distant metastases, particularly to the liver, are exceptionally rare, with only a few cases documented in the literature. Case Report: A 39-year-old woman, in her 31st week of gestation, presented with abdominal pain and discomfort. She underwent ultrasonography, followed by an urgent MRI of the abdomen due to a protruding tumor mass in the liver. Shortly after delivering a healthy baby via cesarean section, she was admitted to the hospital for a CT scan of the abdomen. The imaging revealed multiple focal changes in the liver parenchyma, exhibiting radiological characteristics consistent with focal nodular hyperplasia. Less likely differential diagnoses included adenomas or hemangiomas. Subsequently, she underwent staged hepatectomy, and the results of the pathological analysis confirmed the presence of type B thymoma metastases in the liver. Conclusion: According to the available data in the literature, metastatic thymomas are often identified in patients who have previously undergone treatment for the primary disease. Our patient did not have a history of thymectomy, as confirmed by postoperative chest scans. Onset of symptoms during late pregnancy guided our diagnosis, relying on overall clinical and radiological findings of the detected tumor. Our treatment involved staged hepatectomy post-childbirth, followed by adjuvant chemotherapy. Further comprehensive studies are essential to precisely understand neoplasm behaviors like thymoma for timely detection and effective treatment.

CLINICAL AND PATHOHISTOLOGICAL MANIFESTATIONS OF ACUTE KIDNEY INJURY AMONG PATIENTS WITH ACUTE DRUG POISONING (OVERDOSE).

The aim: To investigate clinical and pathohistological manifestations of acute kidney injury among patients with drug poisoning (overdose). Materials and methods: A cohort retrospective analysis of medical data of 86 patients treated in 2017-2021 with a diagnosis of "acute drug poisoning" com¬plicated by the development of acute kidney injury syndrome was conducted. A forensic medical examination of deceased patients (7 persons) was carried out. Histological samples were examined using an microscope OPTON Axioskop (Germany) in transmitted light, at magnifications of 100 and 400 times. Statistical analysis of the obtained data was carried out using the IBM SPSS Statistics 29.0.0.0 program, Pearson's correlation analysis was used, p≤0.05. Results: Acute renal failure in drug poisoning occurs under the influence of prerenal (hypoxia, r=0,66, р=0,0021; hypovolemia, r=0,61, р=0,0333) and renal factors (toxic effect of chemical components of the drug and rhabdomyolysis, r=0,743, р=0,0034). In the tissue samples, erythrocyte stasis in the capillaries, general fullness of blood vessels, signs of the sludge effect and small diapedesis hemorrhages were found; vasculitis and perivascular sclerosis are noted; foci of mononuclear infiltration of the stroma, focal edema, necrosis and interstitial fibrosis; desquamation, degenerative-dystrophic changes of the nephrothelium, tubular atrophy were found; hyaline casts in separate tubules; focal glomerular changes with segmental increase of the mesangial matrix and proliferation of endothelial cells, atrophy and hyalinosis of individual glomeruli were noted. Conclusions: The multifactorial effect of opioids is confirmed by microcirculation disorders, vascular, interstitial, tubular and glomerular changes in the kidneys.

Oxalate Nephropathy.

Oxalate Nephropathy.

Design of a High-Resolution Multifocal LIDAR: Enabling Higher Resolution Beyond the Laser Pulse Rise Time

3D imaging is increasingly impacting areas such as space, defense, automation, medical and automotive industries. The most well-known optical 3D imaging systems are LIDAR systems that rely on Time of Flight (ToF) measurement. The depth resolution of the LIDAR systems is limited by the rise time of the illumination signal, bandwidth of the detector systems, and the signal-to-noise ratio. The focal gradients can be utilized to obtain 3D images from 2D camera captures. In this study, we combine the basic LIDAR techniques with a physical measurement of focal gradient changes that are caused by the depth of field, to obtain a high-resolution 3D image using spatially separated single-pixel detectors. The system that we introduce here enables depth resolution that goes beyond the rise time of the incident laser pulse.

Honeycomb-like Structured Film, a Novel Therapeutic Device, Suppresses Tumor Growth in an In Vivo Ovarian Cancer Model.

Ovarian cancer cell dissemination can lead to the mortality of patients with advanced ovarian cancer. Complete surgery for no gross residual disease contributes to a more favorable prognosis than that of patients with residual disease. HCFs have highly regular porous structures and their 3D porous structures act as scaffolds for cell adhesion. HCFs are fabricated from biodegradable polymers and have been widely used in tissue engineering. This study aimed to show that HCFs suppress tumor growth in an in vivo ovarian cancer model. The HCF pore sizes had a significant influence on tumor growth inhibition, and HCFs induced morphological changes that rounded out ovarian cancer cells. Furthermore, we identified gene ontology (GO) terms and clusters of genes downregulated by HCFs. qPCR analysis demonstrated that a honeycomb structure downregulated the expression of CXCL2, FOXC1, MMP14, and SNAI2, which are involved in cell proliferation, migration, invasion, angiogenesis, focal adhesion, extracellular matrix (ECM), and epithelial-mesenchymal transition (EMT). Collectively, HCFs induced abnormal focal adhesion and cell morphological changes, subsequently inhibiting the differentiation, proliferation and motility of ovarian cancer cells. Our data suggest that HCFs could be a novel device for inhibiting residual tumor growth after surgery, and could reduce surgical invasiveness and improve the prognosis for patients with advanced ovarian cancer.

Early onset of age-related changes in the retina of cystine/glutamate antiporter knockout mice

To determine the role of the cystine/glutamate antiporter on retinal structure and function, retinas of C57Bl/6J wild-type and xCT knockout mice, lacking the xCT subunit of the cystine/glutamate antiporter were examined from 6 weeks to 12 months of age. Fundoscopy, optical coherence tomography (OCT), and whole mount retinal autofluorescence imaging were used to visualise age-related retinal spots. Glial fibrillary acidic protein (GFAP) immunolabelling was used to assess retinal stress. Retinal function was evaluated using full-field and focal electroretinograms. Examinations revealed retinal spots in both wild-type and xCT knockout mice with the number of spots greater at 9 months in the knockout compared to wild-type. OCT confirmed these discrete spots were located at the retinal pigment epithelium (RPE)–photoreceptor junction and did not label with drusen markers. Whole mount lambda scans of the 9 month xCT knockout retinas revealed that the photoreceptor autofluorescence matched the spots, suggesting these spots were retinal debris. GFAP labelling was increased in knockout retinas compared to wild-type indicative of retinal stress, and the discrete spots were associated with migration of microglia/macrophages to the RPE-retina intersection. OCT revealed that the superior retina was thinner at 9 months in knockout compared to wild-type mice due to changes to the outer nuclear and photoreceptor layers. While global retinal function was not affected by loss of xCT, focal changes in retinal function were detected in areas where spots were present. Tother these results suggest that the xCT KO mice exhibit features of accelerated ageing and suggests that this mouse model may be useful for studying the underlying cellular pathways in retinal ageing.

Early Uterine Transplant Graft Loss Due to Thrombosis: Single-Center Experience With Causes, Prevention, Diagnosis, and Treatment

Uterus transplantation (UTx) is a promising treatment option for women who wish to give birth but suffer from absolute uterine factor infertility. This paper presents an interim analysis of a trial focusing on the causes, prevention, diagnosis, and management of graft thrombosis. Our team analyzed 10 cases of UTx (recipients numbered 1 to 10). Early thrombosis developed in 2 of 10 (20 %) recipients, and thrombectomy and temporary viability preservation were achieved in both cases. However, re-thrombosis developed in both cases, and a graft hysterectomy was carried out. In recipient number 2, vascular changes might have contributed to graft thrombosis. The histopathological finding of the explant revealed subintimal excentric fibrosis with focal sclerotic changes. In recipient number 8, thrombosis was facilitated by external compression of the vascular pedicles by the hematoma as well as production of de novo donor-specific antibodies. Thrombosis led to graft loss in both cases despite an attempt at a thrombectomy. Therefore, the focus must be on prevention including a thorough evaluation of the donor candidate. In the postoperative course, perfusion is closely followed-up with an ultrasound, Doppler flow monitoring, and macroscopic evaluation of the cervix. In the event that findings are unclear, a relaparotomy should be promptly indicated. If thrombosis is revealed, a thrombectomy and an attempt to salvage the graft are indicated; however, the role of this strategy is questionable due to the low chance of long-term success. The indication of upfront graft removal and early re-transplantation in the treatment of uterine graft remains debatable.

Компьютерная томография при диагностике COVID-19-ассоциированной пневмонии в медицинском центре «Мед-Арт»

Given the gained experience, the algorithm of spiral computed tomography in the diagnosis of focal changes in the lungs caused by the new coronavirus infection Covid-19 (SARS-CоV-2) is described in the article

Ultrasound appearance of regenerative peripheral nerve interface with clinical correlation.

To describe the ultrasound (US) appearance of regenerative peripheral nerve interfaces (RPNIs) in humans, and correlate clinically and with histologic findings from rat RPNI. Patients (≥ 18years) who had undergone RPNI surgery within our institution between the dates of 3/2018 and 9/2019 were reviewed. A total of 21 patients (15 male, 6 female, age 21-82years) with technically adequate US studies of RPNIs were reviewed. Clinical notes were reviewed for the presence of persistent pain after RPNI surgery. Histologic specimens of RPNIs in a rat model from prior studies were compared with the US findings noted in this study. There was a variable appearance to the RPNIs including focal changes involving the distal nerve, nerve-muscle graft junction, and area of the distal sutures. The muscle grafts varied in thickness with accompanying variable echogenic changes. No interval change was noted on follow-up US studies. Diffuse hypoechoic swelling with loss of the fascicular structure of the nerve within the RPNI and focal hypoechoic changes at the nerve-muscle graft junction were associated with clinical outcomes. US findings corresponded to histologic findings in the rat RPNI. Ultrasound imaging can demonstrate various morphologic changes involving the nerve, muscle, and interface between these two biological components of RPNIs. These changes correspond to expected degenerative and regenerative processes following nerve resection and muscle reinnervation and should not be misconstrued as pathologic in all cases. N5 and N1 morphologic type changes of the RPNI were found to be associated with symptoms.

A unified framework for focal intensity change detection and deformable image registration. Application to the monitoring of multiple sclerosis lesions in longitudinal 3D brain MRI.

Registration is a crucial step in the design of automatic change detection methods dedicated to longitudinal brain MRI. Even small registration inaccuracies can significantly deteriorate the detection performance by introducing numerous spurious detections. Rigid or affine registration are usually considered to align baseline and follow-up scans, as a pre-processing step before applying a change detection method. In the context of multiple sclerosis, using deformable registration can be required to capture the complex deformations due to brain atrophy. However, non-rigid registration can alter the shape of appearing and evolving lesions while minimizing the dissimilarity between the two images. To overcome this issue, we consider registration and change detection as intertwined problems that should be solved jointly. To this end, we formulate these two separate tasks as a single optimization problem involving a unique energy that models their coupling. We focus on intensity-based change detection and registration, but the approach is versatile and could be extended to other modeling choices. We show experimentally on synthetic and real data that the proposed joint approach overcomes the limitations of the sequential scheme.

Evaluation of Retinal Vascularity Index in Patients with COVID-19: A Case-Control Study.

The purpose of this study was to evaluate the impact of COVID-19 infection on retinal microvasculature by topographically mapping the retinal arteriole-to-venule ratio (AVR). In a comparative cross-sectional case-control study, fundus photos were obtained in COVID-19-infected patients and healthy controls. AVT was measured over 16 points across the retina using retinal vascularity index (RVI)-a novel semi-automated computerized parameter based on retinal vasculature. A total of 51 COVID-19-positive patients and 65 healthy controls were enrolled in the study. Overall, the mean RVI of all 16 points across the retina was 0.34 ± 0.02 in patients with COVID-19 and 0.33 ± 0.02 in control subjects (p = 0.64). Out of the 16 points being measured, three points had a statistically significant greater value in patients with COVID compared to normal controls. Localised greater RVI values were found in some of the points in COVID-19-positive patients, which likely indicates a more focal change of the vasculature.

UNRAVELING THE AMBIGUITY BETWEEN COGNITION AND DEPRESSION: A LONGITUDINAL ANALYSIS OF OLDER ADULTS

Abstract Research on directionality of the relationship between cognitive functioning and depression is ambiguous, especially when considering implications for patients with mild cognitive impairment or Alzheimer disease (AD). Previous research suggests that depression in late life could be a pre-clinical manifestation of AD before other cognitive symptoms are detectable. Some research supports the hypothesis that level of depression can independently predict level of cognition. Other research suggests that depression is a risk factor for developing dementia or AD late in life. Further research on the impact of subjective cognitive decline versus objective cognitive performance in association with depressive symptoms is a critical area to explore. Using data from the Social Networks in Alzheimer Disease (SNAD) study and the Indiana Alzheimer Disease Research Center (IADRC), we conducted a preliminary longitudinal analysis of 196 focal subjects (Mage = 71.6 years, Pfemale = 63%). Interviews conducted one year apart were leveraged to elucidate the bidirectional relationship between depressive symptomology and cognition. Using a lagged dependent variable approach controlling for age, sex, race, and education, the results indicate that only executive function predicts depression at timepoint 2 (-0.31 SD, p< 0.001). However, depression predicts focal Cognitive Change Index (CCI) (0.06 SD, p< 0.05), processing speed (-0.04 SD, p< 0.05), and episodic memory (-0.04 SD, p< 0.05). Other cognitive domains examined, including attention, language, visual/spatial skills, MoCA score, and informant-rated CCI, were not significant as predictors or as outcomes. These results suggest that depression may be a more robust predictor of cognition than cognition is of depression.

Superficial and Deep Capillary Plexuses: Potential Biomarkers of Focal Retinal Defects in Eyes Affected by Macular Idiopatic Epiretinal Membranes? A Pilot Study.

Inner macular layers are the most involved in the retinal distortion caused by idiopathic epiretinal membrane (iERM). They represent the anatomical structures in which the superficial (SCP) and deep (DCP) capillary plexus are embedded. We quantified flow signal (FS) in these capillary plexuses using Swept Source OCT angiography to identify possible markers for postoperative outcome. The software ImageJ was used to quantify the FS in a 150 µm radius area around each point analyzed by MAIA microperimeter. In 16 patients with unilateral iERM, focal light sensitivity (FLS) in the para- and perimacular areas was measured to evaluate macular function in 24 points overlapping macular plexuses and compared with normal fellow eyes (FEs). t-Test for independent samples iERM eyes (iERMEs) vs. fellow eyes (FEs) and Pearson correlation coefficient of FS vs. FLS in each point were calculated. A level of p < 0.05 was accepted as statistically significant. As a whole, FLS was significantly higher in FEs vs. ERMEs (p < 0.001); FS in both SCP and DCP was not significantly different between ERMEs and FEs (p = 0.827, p = 0.791). Correlation in focal retinal areas between FLS and FS in ERMEs was significant in SCP (p = 0.002) and not significant in DCP (p = 0.205); in FEs was significant in both SCP (p < 0.001) and DCP (p = 0.022). As previously described, these defective areas were located mainly in sites of distortion of retinal layers; therefore, it can be hypothesized that a focal change in FS, occurring mostly in SCP, could be involved in the onset of the functional defect.

Dark Current Noise Correction Method Based on Dark Pixels for LWIR QWIP Detection Systems

The long-wave infrared (LWIR) quantum-well photodetector (QWIP) operates at low temperatures, but is prone to focal plane temperature changes when imaging in complex thermal environments. This causes dark current changes and generates low-frequency temporal dark current noise. To address this, a dark current noise correction method based on dark pixels is proposed. First, dark pixels were constructed in a QWIP system and the response components of imaging pixels and dark pixels were analyzed. Next, the feature data of dark pixels and imaging pixels were collected and preprocessed, after which a recurrent neural network (RNN) was used to fit the dark current response model. Target data were collected and input into the dark current response model to obtain dark level correction values and correct the original data. Finally, after calculation and correction, temporal noise was reduced by 49.02% on average. The proposed method uses the characteristics of dark pixels to reduce dark current temporal noise, which is difficult using conventional radiation calibrations; this is helpful in promoting the application of QWIPs in LWIR remote sensing.

ИЗМЕНЕНИЯ АУТОФЛЮОРЕСЦЕНЦИИ ГЛАЗНОГО ДНАУ МОЛОДЫХ ЛИЦ С РАЗНЫМИ ВИДАМИ РЕФРАКЦИИ. СООБЩЕНИЕ 1

Purpose:to assess the state of the macular region of the retina using the study of autofluorescence (AF) of theeye fundus in young subjects with high visual acuity and different types of clinical refraction.Material and methods.104 healthy volunteers (208 eyes), 70 females and 34 males, aged 20 to 30 years, average age (24,5± 0,4) годаy.о., were examined. All patients had high visual acuity (1,0 and higher) and there were no signs of pathology in the macular region, which was established ophthalmoscopically and confirmed by optical coherence tomography (OCT) data. Such methods of the examination were performed in all subjects as visometry with correction, refractometry, ophthalmobiomi-ocroscopy with Goldmann's lens, OCT in the 3D mode of the macular region of the fundus and the study of fundus-AF with typing on known patterns: normal pattern, minimal changes, focal changes and reticular pattern. The analysis was carried outin10 subgroups depending on the type, the degree of clinical refraction and the presence of astigmatism.Results.4 main patterns of AF were identified in the examined subjects: normal, minimal changes, focal changes and reticular. The most common pattern in all refractive groups was the reticular pattern, the frequency of which ranged from 41,7 to 88,9%. The least common pattern was normal, the frequency of which ranged from 4,2 to 33,3%. A significant differencebetween the values of the thickness of the retina in the foveal zone with the reticular pattern and its average group value in different refractive groups was not found.Conclusion.In young subjects with high visual acuity without clinical manifestation of pathology of the macular zone, AF-patterns other than the normal picture may be present. The reticular pattern is noted as the most common in all analyzed groups with various types of refraction. Further studies of early changes in fundus AF may make it possible to determine thepredictors of the development of dystrophic pathology of the macular zone.

Longitudinal hippocampal diffusion-weighted imaging and T2 relaxometry demonstrate regional abnormalities which are stable and predict subfield pathology intemporallobeepilepsy.

High-resolution (1 mm isotropic) diffusion tensor imaging (DTI) of the hippocampus in temporal lobe epilepsy (TLE) patients has shown patterns of hippocampal subfield diffusion abnormalities, which were consistent with hippocampal sclerosis (HS) subtype on surgical histology. The objectives of this longitudinal imaging study were to determine the stability of focal hippocampus diffusion changes over time in TLE patients, compare diffusion and quantitative T2 abnormalities of the sclerotic hippocampus, and correlate presurgical mean diffusivity (MD) and T2 maps with postsurgical histology. Nineteen TLE patients and 19 controls underwent two high-resolution (1 mm isotropic) DTI and 1.1 × 1.1 × 1 mm3 T2 relaxometry scans (in a subset of 16 TLE patients and 9 controls) of the hippocampus at 3T, with a 2.6 ± 0.8 year inter-scan interval. Within-participant hippocampal volume, MD and T2 were compared between the scans. Contralateral hippocampal changes 2.3 ± 1.0 years after surgery and ipsilateral preoperative MD maps versus postoperative subfield histopathology were evaluated in eight patients who underwent surgical resection of the hippocampus. Reduced volume and elevated MD and T2 of sclerotic hippocampi remained unchanged between longitudinal scans. Focal regions of elevated MD and T2 in bilateral hippocampi of HS TLE were detected consistently at both scans. Regions of high MD and T2 correlated and remained consistent over time. Volume, MD, and T2 remained unchanged in postoperative contralateral hippocampus. Regional elevations of MD identified subfield neuron loss on postsurgical histology with 88% sensitivity and 88% specificity. Focal T2 elevations identified subfield neuron loss with 75% sensitivity and 88% specificity. Diffusion and T2 abnormalities in ipsilateral and contralateral hippocampi remained unchanged between the scans suggesting permanent microstructural alterations. MD and T2 demonstrated good sensitivity and specificity to detect hippocampal subfield neuron loss on postsurgical histology, supporting the potential that high-resolution hippocampal DTI and T2 could be used to diagnose HS subtype before surgery.