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1.
Hum Mol Genet ; 31(9): 1531-1543, 2022 05 04.
Article in English | MEDLINE | ID: mdl-34791242

ABSTRACT

The interocular distance, or orbital telorism, is a distinctive craniofacial trait that also serves as a clinically informative measure. While its extremes, hypo- and hypertelorism, have been linked to monogenic disorders and are often syndromic, little is known about the genetic determinants of interocular distance within the general population. We derived orbital telorism measures from cranial magnetic resonance imaging by calculating the distance between the eyeballs' centre of gravity, which showed a good reproducibility with an intraclass correlation coefficient of 0.991 (95% confidence interval 0.985-0.994). Heritability estimates were 76% (standard error = 12%) with a family-based method (N = 364) and 39% (standard error = 2.4%) with a single nucleotide polymorphism-based method (N = 34 130) and were unaffected by adjustment for height (model II) and intracranial volume (model III) or head width (model IV). Genome-wide association studies in 34 130 European individuals identified 56 significantly associated genomic loci (P < 5 × 10-8) across four different models of which 46 were novel for facial morphology, and overall these findings replicated in an independent sample (N = 10 115) with telorism-related horizontal facial distance measures. Genes located nearby these 56 identified genetic loci were 4.9-fold enriched for Mendelian hypotelorism and hypertelorism genes, underlining their biological relevance. This study provides novel insights into the genetic architecture underlying interocular distance in particular, and the face in general, and explores its potential for applications in a clinical setting.


Subject(s)
Genome-Wide Association Study , Hypertelorism , Genetic Loci , Genome-Wide Association Study/methods , Humans , Hypertelorism/genetics , Polymorphism, Single Nucleotide/genetics , Reproducibility of Results
2.
Neurol Neurochir Pol ; 58(2): 176-184, 2024.
Article in English | MEDLINE | ID: mdl-38324117

ABSTRACT

INTRODUCTION: Cognitive impairment occurs from the earliest stages of multiple sclerosis (MS) and progresses over time. The introduction of disease modifying therapies (DMTs) has changed the prognosis for MS patients, offering a potential opportunity for improvement in the cognitive arena as well. MATERIAL AND METHODS: 41 patients with relapsing-remitting multiple sclerosis (MS) were recruited to the study. Thirty patients were available for final follow-up and were included in the analysis. Baseline (BL) brain MRI including volumetry and neuropsychological tests were performed. Blood samples were collected at BL and follow-up (FU) and were tested for: vascular endothelial growth factor (VEGF), soluble vascular cell adhesion molecule-1 (sVCAM1), soluble platelet-endothelial CAM-1 (sPECAM1), and soluble intercellular CAM-1 (sICAM-1). Patients were invited for a final neuropsychological follow-up after a median of 6 years. Disease activity (relapses, EDSS increase, new/active brain lesions on MRI) was analysed between BL and FU. RESULTS: The study group deteriorated in the Rey-Osterrieth Complex Figure (ROCF) test (p = 0.001), but improved significantly in three other tests, i.e. semantic fluency test (p = 0.013), California Verbal Learning Test (CVLT, p = 0.016), and Word Comprehension Test (WCT, p < 0.001). EDSS increase correlated negatively with semantic fluency and WCT scores (r = -0.579, p = 0.001 and r = -0.391, p = 0.033, respectively). Improvements in semantic fluency test and WCT correlated positively with baseline deep grey matter, grey matter, and cortical volumes (p < 0.05, r > 0). Higher EDSS on FU correlated significantly negatively with baseline left and right pallidum, right caudate, right putamen, right accumbens, and cortical volume (p < 0.05, r < 0). No significant relationship was found between the number of relapses and EDSS on FU or neuropsychological deteriorations. Improvements in WCT and CVLT correlated positively with baseline sPECAM1 and sVCAM1 results, respectively (r > 0, p < 0.05). Deterioration in ROCF test correlated significantly with higher levels of baseline VEGF and sVCAM1 (p < 0.05). CONCLUSIONS: Brain volume is an important predictor of future EDSS and cognitive functions outcome. MS patients have a potential for improving in neuropsychological tests over time. It remains to be established whether this is related to successful disease modification with immunotherapy. Baseline volumetric measures are stronger predictors of cognitive performance than relapse activity, which yet again highlights the importance of atrophy in MS prognosis.


Subject(s)
Cognitive Dysfunction , Disease Progression , Magnetic Resonance Imaging , Multiple Sclerosis, Relapsing-Remitting , Neuropsychological Tests , Humans , Multiple Sclerosis, Relapsing-Remitting/diagnostic imaging , Multiple Sclerosis, Relapsing-Remitting/complications , Multiple Sclerosis, Relapsing-Remitting/physiopathology , Multiple Sclerosis, Relapsing-Remitting/blood , Multiple Sclerosis, Relapsing-Remitting/psychology , Female , Male , Adult , Follow-Up Studies , Cognitive Dysfunction/etiology , Middle Aged , Prognosis , Vascular Endothelial Growth Factor A/blood
3.
Mult Scler ; 28(14): 2212-2220, 2022 12.
Article in English | MEDLINE | ID: mdl-36017870

ABSTRACT

BACKGROUND: White matter lesions (WMLs) on brain magnetic resonance imaging (MRI) in multiple sclerosis (MS) may contribute to misdiagnosis. In chronic active lesions, peripheral iron-laden macrophages appear as paramagnetic rim lesions (PRLs). OBJECTIVE: To evaluate the sensitivity and specificity of PRLs in differentiating MS from mimics using clinical 3T MRI scanners. METHOD: This retrospective international study reviewed MRI scans of patients with MS (n = 254), MS mimics (n = 91) and older healthy controls (n = 217). WMLs, detected using fluid-attenuated inversion recovery MRI, were analysed with phase-sensitive imaging. Sensitivity and specificity were assessed for PRLs. RESULTS: At least one PRL was found in 22.9% of MS and 26.1% of clinically isolated syndrome (CIS) patients. Only one PRL was found elsewhere. The identification of ⩾1 PRL was the optimal cut-off and had high specificity (99.7%, confidence interval (CI) = 98.20%-99.99%) when distinguishing MS and CIS from mimics and healthy controls, but lower sensitivity (24.0%, CI = 18.9%-36.6%). All patients with a PRL showing a central vein sign (CVS) in the same lesion (n = 54) had MS or CIS, giving a specificity of 100% (CI = 98.8%-100.0%) but equally low sensitivity (21.3%, CI = 16.4%-26.81%). CONCLUSION: PRLs may reduce diagnostic uncertainty in MS by being a highly specific imaging diagnostic biomarker, especially when used in conjunction with the CVS.


Subject(s)
Demyelinating Diseases , Multiple Sclerosis , Humans , Multiple Sclerosis/diagnostic imaging , Retrospective Studies , Diagnostic Imaging , Biomarkers
4.
Pediatr Blood Cancer ; 67(6): e28224, 2020 06.
Article in English | MEDLINE | ID: mdl-32196935

ABSTRACT

AIM: The aim of the study was to assess long-term consequences of central nervous system (CNS) prophylaxis in patients with high-risk ALL (HR-ALL) treated according to ALL IC-BFM 2002 and to compare observed abnormalities in patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) with those who received only prophylactic CNS irradiation (12 Gy) and with control group. PATIENTS AND METHODS: We studied 29 patients with HR-ALL in CR1 after treatment according to protocol ALL IC-BFM 2002 (14 with allo-HSCT conditioned with fractionated total body irradiation [FTBI] and 15 without HSCT) and 16 children with newly diagnosed ALL (control group). The median time from therapy completion to evaluation was 5 years. To assess brain status, volumetric T1-weighted sequences of magnetic resonance imaging were used. Neuropsychological assessment based on battery neuropsychological tests. RESULTS: Transplanted patients had significantly lower volumes of white and gray matter (P = .048 and P < .001) and also of subcortical structures, including the thalamus (P < .001), the hippocampus (P = .007), the putamen (P = .011), the globus pallidus (P = .001), and the accumbens (P < .001). In addition, these patients had generally lower cognitive performance, especially in vocabulary (P = .011), visuospatial ability (P = .047), executive functions and attention (P = .034; P = .002; P = .048), and processing speed (P = .049 and P = .037). The thalamus volume is correlated with neuropsychological performance in verbal functions (P < .001), executive functions (P < .001 and P = .024), and processing speed (P < .001). CONCLUSIONS: In pediatric patients treated for ALL, FTBI-based preparative regimen preceding allo-HSCT causes reduction of subcortical structure volumes and decline in cognitive performance. The observed long-term structural and functional CNS sequelae are significantly more pronounced in transplanted HR-ALL patients than in those treated with prophylactic CNS- radiotherapy only.


Subject(s)
Brain/pathology , Cognitive Dysfunction/etiology , Hematopoietic Stem Cell Transplantation/adverse effects , Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy , Whole-Body Irradiation/adverse effects , Adolescent , Case-Control Studies , Child , Child, Preschool , Cognitive Dysfunction/pathology , Combined Modality Therapy , Female , Follow-Up Studies , Humans , Male , Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology , Prognosis , Transplantation, Homologous
5.
Neurol Neurochir Pol ; 53(1): 18-25, 2019.
Article in English | MEDLINE | ID: mdl-30742302

ABSTRACT

AIM: The aim of this study was to assess degenerative lesion localisation in the course of relapsing-remitting multiple sclerosis (RRMS) and to identify the association between localisation and the frequency of T1-hypointense lesions (black holes) with cognitive dysfunction. We also searched for neuroradiological predictors of cognitive dysfunction in patients. The clinical rationale for the study was previous research, and our own findings suggest that lesion localisation plays an important role in cognitive performance and neurological disability of MS patients. MATERIAL AND METHODS: Forty-two patients were included in the study. All subjects underwent neuropsychological examination using Raven's Coloured Progressive Matrices, a naming task from the Brief Repeatable Battery of Neuropsychological Tests, and attention to detail tests. Magnetic resonance imaging (MRI) was acquired on 1.5 Tesla scanner and black holes were manually segmented on T1-weighted volumetric images using the FMRIB Software Library. Linear regression was applied to establish a relationship between black hole volume per lobe and cognitive parameters. Bonferroni correction of voxelwise analysis was used to correct for multiple comparisons. RESULTS: The following associations between black hole volume and cognition were identified: frontal lobes black hole volume was associated with phonemic verbal fluency (t = -4.013, p < 0.001), parietal black hole volume was associated with attention (t = -3.776, p < 0.001), and parietal and temporal black hole volumes were associated with nonverbal intelligence (p < 0.001). The volume of parietal black holes was the best predictor of cognitive dysfunction. CONCLUSIONS: Our approach, including measurement of focal axonal loss based on T1-volumetric MRI sequence and brief neuropsychological assessment, might improve personalised diagnostic and therapeutic decisions in clinical practice.


Subject(s)
Cognitive Dysfunction , Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , White Matter , Brain , Humans , Magnetic Resonance Imaging , Neuropsychological Tests
6.
Neurol Neurochir Pol ; 52(4): 483-489, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29643001

ABSTRACT

Although neurons are the main source of neurotrophins in the healthy brain, neurotrophins can also be expressed in the immune system. We have previously shown that in relapsing-remitting multiple sclerosis (RRMS) lower immune-cell neurotrophin levels are associated with brain atrophy and cognitive impairment. The aim of the present study was to assess if immune-cell neurotrophin expression is impaired in MS as compared with the healthy controls, and to describe if these levels change in treatment-naïve RRMS patients, following one year of immunomodulation. Fifty treatment-naïve RRMS patients were assessed at baseline and after one year of immunomodulation (beta-interferons/glatiramer acetate). The control group included 39 healthy subjects matched according to age and gender. Peripheral blood mononuclear cells (PBMCs) were isolated from heparinized blood using Ficoll-Histopaque gradient. The levels of brain-derived-neurotrophic-factor (BDNF), beta-nerve-growth-factor (beta-NGF), neurotrophin-3 (NT-3) and neurotrophin-4/5 (NT-4/5) were measured in PBMC lysates with ELISA. BDNF levels were significantly lower in MS than in the healthy controls (median 613 vs. 1657pg/mg protein, p<0.001). After one year of immunomodulation, BDNF expression did not change significantly (p=0.06) on the group level. In 70% of patients there was no increase in BDNF level, and in 30% it increased. We observed no differences between treatment groups. Other neurotrophins were detected in a minority of MS samples (as opposed to the controls). To conclude, we have shown that immune-cell production of neurotrophins is impaired in MS patients. In our MS cohort standard immunomodulation failed to restore normal BDNF levels in PBMCs within one year of therapy.


Subject(s)
Brain-Derived Neurotrophic Factor/metabolism , Multiple Sclerosis, Relapsing-Remitting , Humans , Immunomodulation , Leukocytes, Mononuclear , Multiple Sclerosis, Relapsing-Remitting/metabolism , Nerve Growth Factors
7.
Neuroimmunomodulation ; 24(6): 320-330, 2017.
Article in English | MEDLINE | ID: mdl-29539621

ABSTRACT

OBJECTIVE: Central nervous system (CNS) involvement in systemic lupus erythematosus (SLE) remains poorly understood. Damage within the CNS is driven by the autoimmune response; however, immunopathophysiology of neuropsychiatric (NP) SLE is multifactorial. Immune cell neurotrophin production could be neuroprotective against autoimmunity-driven CNS damage, as has been shown in multiple sclerosis. The aim of this study was to establish whether immune cell neurotrophin production is associated with damage severity in NPSLE. METHODS: Selected neurotrophins (BDNF, NGF, NT-3, and NT-4/5) were measured with ELISA within peripheral blood mononuclear cells (PBMCs) isolated from 38 NPSLE patients matched with 39 healthy controls. Subcortical and cortical structure volumes were segmented with the Freesurfer 5.3 pipeline on T1-weighted isotropic images acquired on a 1.5-T MRI scanner. RESULTS: BDNF and NGF levels in PBMCs were reduced in NPSLE compared to the healthy population. The PBMC BDNF level was associated with reduced thalamus, caudate, and putamen volumes. The NGF level correlated with lateral ventricles enlargement and thalamic volume loss. CONCLUSIONS: In NPSLE, immune cell BDNF and NGF levels are linked with subcortical atrophy. Higher BDNF levels are associated with higher midsagittal atrophy, which may reflect compensatory mechanisms, upregulating BDNF when neuroprotection is needed. These data require further confirmation.


Subject(s)
Brain-Derived Neurotrophic Factor/metabolism , Brain/diagnostic imaging , Brain/metabolism , Immunity, Cellular/physiology , Leukocytes, Mononuclear/metabolism , Nerve Growth Factor/metabolism , Adult , Atrophy , Brain/immunology , Brain-Derived Neurotrophic Factor/immunology , Case-Control Studies , Cross-Sectional Studies , Female , Humans , Leukocytes, Mononuclear/immunology , Lupus Vasculitis, Central Nervous System , Magnetic Resonance Imaging/methods , Male , Middle Aged , Nerve Growth Factor/immunology , Nerve Growth Factors/biosynthesis , Prospective Studies , Young Adult
8.
Neuroradiology ; 59(2): 147-156, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28074235

ABSTRACT

INTRODUCTION: The aim of this study was to assess the long-term side effects of central nervous system prophylaxis (high-dose chemotherapy alone vs chemotherapy and CNS radiotherapy) according to the ALL IC-BFM 2002. METHODS: Thirty-tree children aged 6.7-19.9 years have been studied. The control group consisted of 12 children newly diagnosed with acute lymphoblastic leukemia. We assessed subcortical gray matter volume using automatic MRI segmentation and cognitive performance to identify differences between two therapeutic schemes and patients prior to treatment. RESULTS: Patients treated with chemotherapy and CNS radiotherapy had smaller hippocampi than two other subgroups and lower IQ score than patients treated with chemotherapy alone. Both treated groups, whether with chemotherapy only or in combination with CNS radiotherapy, had significantly lower volumes of caudate nucleus and performed significantly worse on measures of verbal fluency in comparison with patients prior to treatment. There were no differences in the mean volumes of total white matter, total gray matter, thalamus, putamen, and amygdala between the studied groups. CONCLUSION: In all children treated according to the ALL IC-BFM 2002 with high-dose chemotherapy, both decreased volume of selected subcortical structures and cognitive impairment was observed, especially in children who received chemotherapy in combination with reduced dose CNS radiotherapy. In all children treated according to the ALL IC-BFM 2002 with high-dose chemotherapy, both decreased volume of selected subcortical structures and cognitive impairment were observed, especially in children who received chemotherapy in combination with CNS radiotherapy.


Subject(s)
Antimetabolites, Antineoplastic/therapeutic use , Cognition Disorders/etiology , Cranial Irradiation/methods , Magnetic Resonance Imaging/methods , Methotrexate/therapeutic use , Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnostic imaging , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/radiotherapy , Adolescent , Child , Combined Modality Therapy , Female , Humans , Male , Radiotherapy Dosage , Treatment Outcome , Young Adult
11.
Cell Rep Med ; 5(5): 101529, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38703765

ABSTRACT

The size of the human head is highly heritable, but genetic drivers of its variation within the general population remain unmapped. We perform a genome-wide association study on head size (N = 80,890) and identify 67 genetic loci, of which 50 are novel. Neuroimaging studies show that 17 variants affect specific brain areas, but most have widespread effects. Gene set enrichment is observed for various cancers and the p53, Wnt, and ErbB signaling pathways. Genes harboring lead variants are enriched for macrocephaly syndrome genes (37-fold) and high-fidelity cancer genes (9-fold), which is not seen for human height variants. Head size variants are also near genes preferentially expressed in intermediate progenitor cells, neural cells linked to evolutionary brain expansion. Our results indicate that genes regulating early brain and cranial growth incline to neoplasia later in life, irrespective of height. This warrants investigation of clinical implications of the link between head size and cancer.


Subject(s)
Genome-Wide Association Study , Head , Neoplasms , Humans , Head/anatomy & histology , Neoplasms/genetics , Neoplasms/pathology , Female , Male , Polymorphism, Single Nucleotide/genetics , Genetic Variation , Organ Size/genetics , Signal Transduction/genetics , Adult , Genetic Predisposition to Disease
12.
Med Biol Eng Comput ; 61(6): 1343-1361, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36698030

ABSTRACT

Understanding the 3D cerebral vascular network is one of the pressing issues impacting the diagnostics of various systemic disorders and is helpful in clinical therapeutic strategies. Unfortunately, the existing software in the radiological workstation does not meet the expectations of radiologists who require a computerized system for detailed, quantitative analysis of the human cerebrovascular system in 3D and a standardized geometric description of its components. In this study, we show a method that uses 3D image data from magnetic resonance imaging with contrast to create a geometrical reconstruction of the vessels and a parametric description of the reconstructed segments of the vessels. First, the method isolates the vascular system using controlled morphological growing and performs skeleton extraction and optimization. Then, around the optimized skeleton branches, it creates tubular objects optimized for quality and accuracy of matching with the originally isolated vascular data. Finally, it optimizes the joints on n-furcating vessel segments. As a result, the algorithm gives a complete description of shape, position in space, position relative to other segments, and other anatomical structures of each cerebrovascular system segment. Our method is highly customizable and in principle allows reconstructing vascular structures from any 2D or 3D data. The algorithm solves shortcomings of currently available methods including failures to reconstruct the vessel mesh in the proximity of junctions and is free of mesh collisions in high curvature vessels. It also introduces a number of optimizations in the vessel skeletonization leading to a more smooth and more accurate model of the vessel network. We have tested the method on 20 datasets from the public magnetic resonance angiography image database and show that the method allows for repeatable and robust segmentation of the vessel network and allows to compute vascular lateralization indices.


Subject(s)
Imaging, Three-Dimensional , Magnetic Resonance Angiography , Humans , Imaging, Three-Dimensional/methods , Magnetic Resonance Imaging , Algorithms
13.
Commun Biol ; 6(1): 691, 2023 07 04.
Article in English | MEDLINE | ID: mdl-37402774

ABSTRACT

Skull bone mineral density (SK-BMD) provides a suitable trait for the discovery of key genes in bone biology, particularly to intramembranous ossification, not captured at other skeletal sites. We perform a genome-wide association meta-analysis (n ~ 43,800) of SK-BMD, identifying 59 loci, collectively explaining 12.5% of the trait variance. Association signals cluster within gene-sets involved in skeletal development and osteoporosis. Among the four novel loci (ZIC1, PRKAR1A, AZIN1/ATP6V1C1, GLRX3), there are factors implicated in intramembranous ossification and as we show, inherent to craniosynostosis processes. Functional follow-up in zebrafish confirms the importance of ZIC1 on cranial suture patterning. Likewise, we observe abnormal cranial bone initiation that culminates in ectopic sutures and reduced BMD in mosaic atp6v1c1 knockouts. Mosaic prkar1a knockouts present asymmetric bone growth and, conversely, elevated BMD. In light of this evidence linking SK-BMD loci to craniofacial abnormalities, our study provides new insight into the pathophysiology, diagnosis and treatment of skeletal diseases.


Subject(s)
Bone Density , Craniosynostoses , Animals , Bone Density/genetics , Genome-Wide Association Study , Zebrafish/genetics , Skull , Craniosynostoses/genetics , Transcription Factors/genetics
14.
Cortex ; 145: 315-326, 2021 12.
Article in English | MEDLINE | ID: mdl-34781092

ABSTRACT

Orbital telorism, the interocular distance, is clinically informative and in extremes is considered a minor physical anomaly. While its extremes, hypo- and hypertelorism, have been linked to disorders often related to cognitive ability, little is known about the neural correlates of normal variation of telorism within the general population. We derived measures of orbital telorism from cranial magnetic resonance imaging (MRI) by calculating the distance between the eyeball center of gravity in two population-based datasets (N = 5,653, N = 29,824; mean age 64.66, 63.75 years). This measure was found to be related to grey matter tissue density within numerous regions of the brain, including, but surprisingly not limited to, the frontal regions, in both positive and negative directions. Additionally, telorism was related to several cognitive functions, such as Purdue pegboard test (Beta, P-value (CI95%) -.02, 1.63 × 10-7 (-.03:-.01)) and fluid intelligence (.02, 4.75 × 10-6 (.01:0.02)), with some relationships driven by individuals with a smaller orbital telorism. This is reflective of the higher prevalence of hypotelorism in developmental disorders, specifically those that accompany lower cognitive lower functioning. This study suggests, despite previous links only made in clinical extremes, that orbital telorism holds some relation to structural brain development and cognitive function in the general population. This relationship is likely driven by shared developmental periods.


Subject(s)
Brain , Gray Matter , Cognition , Frontal Lobe , Humans , Magnetic Resonance Imaging , Neuropsychological Tests
15.
Int J MS Care ; 23(6): 261-268, 2021.
Article in English | MEDLINE | ID: mdl-35035297

ABSTRACT

BACKGROUND: One of the major objectives of the Multiple Sclerosis Data Alliance (MSDA) is to enable better discovery of multiple sclerosis (MS) real-world data (RWD). METHODS: We implemented the MSDA Catalogue, which is available worldwide. The current version of the MSDA Catalogue collects descriptive information on governance, purpose, inclusion criteria, procedures for data quality control, and how and which data are collected, including the use of e-health technologies and data on collection of COVID-19 variables. The current cataloguing procedure is performed in several manual steps, securing an effective catalogue. RESULTS: Herein we summarize the status of the MSDA Catalogue as of January 6, 2021. To date, 38 data sources across five continents are included in the MSDA Catalogue. These data sources differ in purpose, maturity, and variables collected, but this landscaping effort shows that there is substantial alignment on some domains. The MSDA Catalogue shows that personal data and basic disease data are the most collected categories of variables, whereas data on fatigue measurements and cognition scales are the least collected in MS registries/cohorts. CONCLUSIONS: The Web-based MSDA Catalogue provides strategic overview and allows authorized end users to browse metadata profiles of data cohorts and data sources. There are many existing and arising RWD sources in MS. Detailed cataloguing of MS RWD is a first and useful step toward reducing the time needed to discover MS RWD sets and promoting collaboration.

16.
Biomed Opt Express ; 11(3): 1336-1353, 2020 Mar 01.
Article in English | MEDLINE | ID: mdl-32206414

ABSTRACT

The retinal volumetric flow rate contains useful information not only for ophthalmology but also for the diagnosis of common civilization diseases such as diabetes, Alzheimer's disease, or cerebrovascular diseases. Non-invasive optical methods for quantitative flow assessment, such as Doppler optical coherence tomography (OCT), have certain limitations. One is the phase wrapping that makes simultaneous calculations of the flow in all human retinal vessels impossible due to a very large span of flow velocities. We demonstrate that three-dimensional Doppler OCT combined with three-dimensional four Fourier transform fast phase unwrapping (3D 4FT FPU) allows for the calculation of the volumetric blood flow rate in real-time by the implementation of the algorithms in a graphics processing unit (GPU). The additive character of the flow at the furcations is proven using a microfluidic device with controlled flow rates as well as in the retinal veins bifurcations imaged in the optic disc area of five healthy volunteers. We show values of blood flow rates calculated for retinal capillaries and vessels with diameters in the range of 12-150 µm. The potential of quantitative measurement of retinal blood flow volume includes noninvasive detection of carotid artery stenosis or occlusion, measuring vascular reactivity and evaluation of vessel wall stiffness.

17.
Radiology ; 251(2): 525-34, 2009 May.
Article in English | MEDLINE | ID: mdl-19401577

ABSTRACT

PURPOSE: To establish reference values of the ratios of flow velocity in the middle cerebral artery (V(MCA)) and the terminal portion of the internal carotid artery (V(tICA)) to flow velocity in the extracranial portion of internal carotid artery (V(ICA)) in children with sickle cell disease (SCD). MATERIALS AND METHODS: Institutional ethics committee approval and parental informed consent were obtained for this prospective HIPAA-compliant study. Sixty-eight children (38 female; mean age, 7.7 years +/- 3.3; range, 2-14 years) with HbSS genotype, without neurologic deficits and no history of stroke, were enrolled. Final study population comprised 56 (mean age 8.0 +/- 3.3 years, 26 females) children who underwent magnetic resonance (MR) angiography, which excluded intracranial arterial narrowing, transcranial color-coded duplex ultrasonography (US), and carotid US to determine V(MCA)/V(ICA) and V(tICA)/V(ICA) ratios from angle-corrected and uncorrected velocities. Tolerance interval estimates were used to calculate reference ranges and linear regression was used to quantify associations of Doppler parameters with age adjusted for hemoglobin and hematocrit. RESULTS: Reference ranges in centimeters per second for mean angle-corrected V(MCA) on the left and right sides were 62-198 and 69-153; those for V(tICA) were 30-196 and 36-175; and those for V(ICA) were 18-116 and 15-95, respectively. Reference ranges for mean angle-corrected V(MCA)/V(ICA) ratio on the left and right sides were 1.2-4.0 and 0.4-3.4 and those for V(tICA)/V(IC)(A) ratio were 0.5-2.9 and 0.5-2.7, respectively. V(MCA), V(tICA), and V(tICA)/V(ICA) ratio were not age dependent, contrary to V(ICA) and V(MCA)/V(ICA) ratio, after controlling for hematocrit and hemoglobin. CONCLUSION: The study provides reference limits for V(MCA), V(tICA), V(ICA), and velocity ratios obtained from children with SCD.


Subject(s)
Anemia, Sickle Cell/physiopathology , Blood Flow Velocity , Carotid Arteries/physiopathology , Cerebrovascular Circulation , Image Interpretation, Computer-Assisted/methods , Middle Cerebral Artery/physiopathology , Ultrasonography, Doppler, Transcranial/methods , Adolescent , Anemia, Sickle Cell/diagnostic imaging , Child , Child, Preschool , Female , Humans , Male , Pilot Projects
18.
Radiology ; 250(3): 887-96, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19244052

ABSTRACT

PURPOSE: To determine the accuracy of relative cerebral blood volume (rCBV) fraction for distinguishing high-grade recurrent neoplasm from treatment-related necrosis (TRN) in enhancing masses identified on surveillance magnetic resonance (MR) images following treatment for primary or secondary brain neoplasm. MATERIALS AND METHODS: This institutional review board approved and HIPAA-compliant retrospective study included 30 patients undergoing resection of recurrent enhancing mass appearing after treatment with surgery and radiation, with or without chemotherapy. The enhancing mass volume was manually segmented on three-dimensional T1-weighted images. The rCBV maps were created by using T2-weighted dynamic susceptibility contrast perfusion MR imaging and registered to T1-weighted images, and the fraction of enhancing mass with rCBV above a range of thresholds was calculated. A receiver operating characteristic (ROC) curve was created by calculating sensitivity-specificity pairs at each threshold for rCBV fraction (< or = 20% or > 20%) by using percentage of malignant features at histologic evaluation as the reference criterion. Relationships between rCBV and probability of recurrence were estimated by using logistic regression analysis. RESULTS: ROC analysis showed excellent discriminating accuracy of rCBV fraction (area under the ROC curve, 0.97 +/- 0.03 [standard error]) and high efficiency (93%) with an rCBV threshold of 1.8 times that of normal-appearing white matter. Logistic regression analysis showed that a unit increase of rCBV is associated with a 254-fold increase (95% confidence interval: 43, 1504, P < .001) of the odds that enhanced tissue is recurrence, adjusting for age, treatment, volume of enhancing tissue, and time to suspected recurrence. CONCLUSION: The fraction of malignant histologic features in enhancing masses recurring after treatment for brain neoplasms can be predicted by using the rCBV fraction, with improved differentiation between recurrent neoplasm and TRN.


Subject(s)
Blood Volume , Brain Neoplasms/diagnosis , Brain Neoplasms/therapy , Cerebrovascular Circulation , Magnetic Resonance Imaging/methods , Neoplasm Recurrence, Local/diagnosis , Neoplasm Recurrence, Local/prevention & control , Adult , Aged , Discriminant Analysis , Female , Humans , Male , Middle Aged , Prognosis , Reproducibility of Results , Retrospective Studies , Sensitivity and Specificity , Treatment Outcome
19.
JAMA Neurol ; 76(12): 1446-1456, 2019 12 01.
Article in English | MEDLINE | ID: mdl-31424490

ABSTRACT

Importance: The central vein sign has been proposed as a specific imaging biomarker for distinguishing between multiple sclerosis (MS) and not MS, mainly based on findings from ultrahigh-field magnetic resonance imaging (MRI) studies. The diagnostic value of the central vein sign in a multicenter setting with a variety of clinical 3 tesla (T) MRI protocols, however, remains unknown. Objective: To evaluate the sensitivity and specificity of various central vein sign lesion criteria for differentiating MS from non-MS conditions using 3T brain MRI with various commonly used pulse sequences. Design, Setting, and Participants: This large multicenter, cross-sectional study enrolled participants (n = 648) of ongoing observational studies and patients included in neuroimaging research databases of 8 neuroimaging centers in Europe. Patient enrollment and MRI data collection were performed between January 1, 2010, and November 30, 2016. Data analysis was conducted between January 1, 2016, and April 30, 2018. Investigators were blinded to participant diagnosis by a novel blinding procedure. Main Outcomes and Measures: Occurrence of central vein sign was detected on 3T T2*-weighted or susceptibility-weighted imaging. Sensitivity and specificity were assessed for these MRI sequences and for different central vein sign lesion criteria, which were defined by the proportion of lesions with central vein sign or by absolute numbers of lesions with central vein sign. Results: A total of 606 participants were included in the study after exclusion of 42 participants. Among the 606 participants, 413 (68.2%) were women. Patients with clinically isolated syndrome and relapsing-remitting MS (RRMS) included 235 women (66.6%) and had a median (range) age of 37 (14.7-61.4) years, a median (range) disease duration of 2 (0-33) years, and a median (range) Expanded Disability Status Scale score of 1.5 (0-6.5). Patients without MS included 178 women (70.4%) and had a median (range) age of 54 (18-83) years. A total of 4447 lesions were analyzed in a total of 487 patients: 690 lesions in 98 participants with clinically isolated syndrome, 2815 lesions in 225 participants with RRMS, 54 lesions in 13 participants with neuromyelitis optica spectrum disorder, 54 lesions in 14 participants with systemic lupus erythematosus, 121 lesions in 29 participants with migraine or cluster headache, 240 lesions in 20 participants with diabetes, and 473 lesions in 88 participants with other types of small-vessel disease. The sensitivity was 68.1% and specificity was 82.9% for distinguishing MS from not MS using a 35% central vein sign proportion threshold. The 3 central vein sign lesion criteria had a sensitivity of 61.9% and specificity of 89.0%. Sensitivity was higher when an optimized T2*-weighted sequence was used. Conclusions and Relevance: In this study, use of the central vein sign at 3T MRI yielded a high specificity and a moderate sensitivity in differentiating MS from not MS; international, multicenter studies may be needed to ascertain whether the central vein sign-based criteria can accurately detect MS.


Subject(s)
Brain/diagnostic imaging , Cerebral Veins/diagnostic imaging , Multiple Sclerosis, Relapsing-Remitting/diagnostic imaging , Adolescent , Adult , Aged , Aged, 80 and over , Case-Control Studies , Cluster Headache/diagnostic imaging , Cross-Sectional Studies , Demyelinating Diseases/diagnostic imaging , Female , Humans , Lupus Vasculitis, Central Nervous System/diagnostic imaging , Magnetic Resonance Imaging , Male , Middle Aged , Migraine Disorders/diagnostic imaging , Multiple Sclerosis/diagnostic imaging , Neuromyelitis Optica/diagnostic imaging , Sensitivity and Specificity , Young Adult
20.
Ann Neurol ; 62(5): 481-92, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17702036

ABSTRACT

OBJECTIVE: To identify dysfunctional brain regions critical for impaired reading/spelling of words/pseudowords by evaluating acute stroke patients on lexical tests and magnetic resonance imaging, before recovery or reorganization of structure-function relationships. METHODS: A series of 106 consenting patients were administered oral reading and spelling tests within 24 hours of left supratentorial stroke onset. Patients underwent diffusion- and perfusion-weighted magnetic resonance examination the same day to identify regions of hypoperfusion/infarct of 16 Brodmann areas. RESULTS: Simultaneous logistic regression analysis demonstrated that dysfunction of left Brodmann areas 40 (supramarginal gyrus) and 37 (posterior-inferior temporal/fusiform gyrus) best predicted impairment in reading words (odds ratio [OR], 6.20 [95% confidence interval (CI), 1.54-24.96] and 2.71 [95% CI, 0.87-8.45], respectively), reading pseudowords (OR, 39.65 [95% CI 3.9-400.78] and 4.41 [95% CI, 1.1-17.51], respectively), spelling words (OR, 14.11 [95% CI 1.37-144.93] and 7.41 [95% CI, 1.48-37.24], respectively), and spelling pseudowords (OR, 4.84 [95% CI, 0.73-32.13] and 7.74 [95% CI, 1.56-38.51], respectively). Whole-brain voxel-wise analyses demonstrated voxel clusters within these regions that were most strongly associated with task deficits. INTERPRETATION: Results indicate that a shared network of regions including parts of left Brodmann areas 37 and 40 is necessary for reading and spelling of words and pseudowords. Further studies may define the precise roles of these brain regions in language. Identification of any neural regions specific to one of these tasks or one type of stimuli will require study of more patients with selective deficits.


Subject(s)
Brain/physiology , Language Tests , Language , Reading , Acoustic Stimulation/methods , Adult , Aged , Aged, 80 and over , Brain Mapping/methods , Humans , Middle Aged , Nerve Net/physiology , Stroke/complications , Stroke/pathology
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