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NeuroImage Jul 2008In this paper, we propose a new automated procedure for lesion identification from single images based on the detection of outlier voxels. We demonstrate the utility of...
In this paper, we propose a new automated procedure for lesion identification from single images based on the detection of outlier voxels. We demonstrate the utility of this procedure using artificial and real lesions. The scheme rests on two innovations: First, we augment the generative model used for combined segmentation and normalization of images, with an empirical prior for an atypical tissue class, which can be optimised iteratively. Second, we adopt a fuzzy clustering procedure to identify outlier voxels in normalised gray and white matter segments. These two advances suppress misclassification of voxels and restrict lesion identification to gray/white matter lesions respectively. Our analyses show a high sensitivity for detecting and delineating brain lesions with different sizes, locations, and textures. Our approach has important implications for the generation of lesion overlap maps of a given population and the assessment of lesion-deficit mappings. From a clinical perspective, our method should help to compute the total volume of lesion or to trace precisely lesion boundaries that might be pertinent for surgical or diagnostic purposes.
Topics: Algorithms; Brain; Brain Diseases; Brain Edema; Cerebral Ventricles; Data Interpretation, Statistical; Fuzzy Logic; Humans; Image Processing, Computer-Assisted; Models, Statistical; ROC Curve
PubMed: 18482850
DOI: 10.1016/j.neuroimage.2008.03.028 -
Seminars in Vascular Surgery 2018The angiosome concept of foot perfusion was conceived based on anatomical studies of arterial circulation and used for planning surgical procedures, tissue... (Review)
Review
The angiosome concept of foot perfusion was conceived based on anatomical studies of arterial circulation and used for planning surgical procedures, tissue reconstruction, and amputation. Its application is relevant in diabetic patients with critical limb ischemia and nonhealing foot ulcer or amputation. An understanding of foot angiosome anatomy is useful for predicting healing and planning arterial revascularization. A review of the literature, including the most recent systematic reviews and meta-analyses, indicates improved wound healing is achieved when the angiosome concept is followed. The greatest value of angiosome-based revascularization is in patients with lesion(s) limited to a single angiosome, or to achieve optimal healing of amputation sites. Future research should focus on proper identification of (imaging) modalities to determine the hemodynamic and functional changes before and after revascularization, thus identifying the "real" angiosome and directing optimal therapy.
Topics: Amputation, Surgical; Angiography; Clinical Decision-Making; Critical Illness; Diabetic Foot; Foot; Humans; Ischemia; Limb Salvage; Models, Cardiovascular; Patient Selection; Peripheral Arterial Disease; Predictive Value of Tests; Regional Blood Flow; Treatment Outcome; Vascular Surgical Procedures; Wound Healing
PubMed: 30876642
DOI: 10.1053/j.semvascsurg.2018.12.002 -
Journal of Clinical Medicine Jul 2023The amount of coronary calcium strongly correlates with the degree of atherosclerosis and, therefore, with the rate of future cardiac events. Calcified coronary lesions... (Review)
Review
The amount of coronary calcium strongly correlates with the degree of atherosclerosis and, therefore, with the rate of future cardiac events. Calcified coronary lesions still represent a challenge for interventional cardiologists, bringing not only a higher risk of immediate complications during percutaneous coronary interventions (PCI), but also a higher risk of late stent failure due to under-expansion and/or malapposition, and therefore, have a relevant prognostic impact. Accurate identification of the calcified plaques together with the analysis of their distribution pattern within the vessel wall by intracoronary imaging is important to improve the successful treatment of these lesions. The aim of this review is to guide readers through the assessment of the calcified plaque distribution using intracoronary imaging in order to select the best devices and strategies for plaque debulking and lesion preparation.
PubMed: 37510959
DOI: 10.3390/jcm12144844 -
Dermatologic Therapy Mar 2021In this systematic review, we anticipated in summarizing clinical features, histopathological hallmarks, and possible pathology behind the maculopapular skin eruptions... (Review)
Review
In this systematic review, we anticipated in summarizing clinical features, histopathological hallmarks, and possible pathology behind the maculopapular skin eruptions occurring in Covid-19 patients. A literature search was executed using MEDLINE/PubMed and Embase databases for articles published till 20 November 2020. All eligible articles including observational studies, case reports, and case series reporting the maculopapular skin lesion in Covid-19 patients were included. Data were obtained for 354 Covid-19 patients presenting with maculopapular lesions from 40 studies. The mean age of these patients was 53 years, and with 42% of them being male. These maculopapular lesions differed considerably in terms of distribution and appearance, ranging from diffuse erythematous maculopapular lesions to scattered erythematous macules coalescing into papules to maculopapular lesions in plaques. The mean duration of the lesion was 8 days. These lesions were frequently localized on trunks and extremities. Superficial perivascular dermatitis with lymphocytic infiltrate was a histopathological hallmark of these lesions. As these skin lesions may have a possible association with diagnosis, management, prognosis, and severity of the disease, all health practitioners need to be well acquainted with these Covid-19 skin lesions. Also, in the middle of this worldwide pandemic, early identification of this eruption may help manage this infection's further spread.
Topics: COVID-19; Drug Eruptions; Exanthema; Humans; Male; Middle Aged; Pandemics; SARS-CoV-2
PubMed: 33481314
DOI: 10.1111/dth.14788 -
Bioengineering (Basel, Switzerland) Sep 2023Accurate identification of lesions and their use across different medical institutions are the foundation and key to the clinical application of automatic diabetic...
Accurate identification of lesions and their use across different medical institutions are the foundation and key to the clinical application of automatic diabetic retinopathy (DR) detection. Existing detection or segmentation methods can achieve acceptable results in DR lesion identification, but they strongly rely on a large number of fine-grained annotations that are not easily accessible and suffer severe performance degradation in the cross-domain application. In this paper, we propose a cross-domain weakly supervised DR lesion identification method using only easily accessible coarse-grained lesion attribute labels. We first propose the novel lesion-patch multiple instance learning method (LpMIL), which leverages the lesion attribute label for patch-level supervision to complete weakly supervised lesion identification. Then, we design a semantic constraint adaptation method (LpSCA) that improves the lesion identification performance of our model in different domains with semantic constraint loss. Finally, we perform secondary annotation on the open-source dataset EyePACS, to obtain the largest fine-grained annotated dataset EyePACS-pixel, and validate the performance of our model on it. Extensive experimental results on the public dataset FGADR and our EyePACS-pixel demonstrate that compared with the existing detection and segmentation methods, the proposed method can identify lesions accurately and comprehensively, and obtain competitive results using only coarse-grained annotations.
PubMed: 37760202
DOI: 10.3390/bioengineering10091100 -
Journal of Neurology, Neurosurgery, and... Feb 2002From a series of glimpses, we perceive a seamless and richly detailed visual world. Cerebral damage, however, can destroy this illusion. In the case of Bálint's... (Review)
Review
OBJECTIVES
From a series of glimpses, we perceive a seamless and richly detailed visual world. Cerebral damage, however, can destroy this illusion. In the case of Bálint's syndrome, the visual world is perceived erratically, as a series of single objects. The goal of this review is to explore a range of psychological and anatomical explanations for this striking visual disorder and to propose new directions for interpreting the findings in Bálint's syndrome and related cerebral disorders of visual processing.
METHODS
Bálint's syndrome is reviewed in the light of current concepts and methodologies of vision research.
RESULTS
The syndrome affects visual perception (causing simultanagnosia/visual disorientation) and visual control of eye and hand movement (causing ocular apraxia and optic ataxia). Although it has been generally construed as a biparietal syndrome causing an inability to see more than one object at a time, other lesions and mechanisms are also possible. Key syndrome components are dissociable and comprise a range of disturbances that overlap the hemineglect syndrome. Inouye's observations in similar cases, beginning in 1900, antedated Bálint's initial report. Because Bálint's syndrome is not common and is difficult to assess with standard clinical tools, the literature is dominated by case reports and confounded by case selection bias, non-uniform application of operational definitions, inadequate study of basic vision, poor lesion localisation, and failure to distinguish between deficits in the acute and chronic phases of recovery.
CONCLUSIONS
Studies of Bálint's syndrome have provided unique evidence on neural substrates for attention, perception, and visuomotor control. Future studies should address possible underlying psychoanatomical mechanisms at "bottom up" and "top down" levels, and should specifically consider visual working memory and attention (including object based attention) as well as systems for identification of object structure and depth from binocular stereopsis, kinetic depth, motion parallax, eye movement signals, and other cues.
Topics: Agnosia; Attention; Brain Mapping; Cerebrovascular Disorders; Dominance, Cerebral; Humans; Occipital Lobe; Perceptual Disorders; Psychomotor Disorders; Visual Cortex; Visual Perception
PubMed: 11796765
DOI: 10.1136/jnnp.72.2.162 -
Journal of Clinical Imaging Science 2014Vascular lesions of the head and neck region in children constitute an interesting group of lesions that benefit immensely from imaging techniques. Imaging is essential... (Review)
Review
Vascular lesions of the head and neck region in children constitute an interesting group of lesions that benefit immensely from imaging techniques. Imaging is essential for identification, characterization, and delineation of the extent of lesion and subsequent follow-up. Infantile hemangiomas, which are vascular tumors with a specific evolution pattern, constitute a large majority of these lesions. On the other hand, there are vascular malformations, which are anomalies of the vascular system, consisting of a range of vascular tissues associated with various flow patterns. When diagnosis is clinically evident, imaging should utilize non-radiation techniques and address the issues necessary for management. Timing and interpretation of imaging methods employed in assessing childhood vascular lesion should also take into consideration the natural history so that imaging is performed to address a specific question. This review highlights the typical appearance of a hemangioma and a group of vascular malformations of the head and neck. For descriptive purpose, an attempt has been made to group lesions into specific subsites, with each one having specific clinical significance. Cases included illustrate the spectrum of the disease ranging from classical form in young children to slightly differing manifestations of the disease in adolescents and adults. The illustrations also provide a novel way of presenting image data using volume-rendering techniques of 3D data. Multi-modality team interaction and management strategies of these complex lesions are also emphasized.
PubMed: 25161800
DOI: 10.4103/2156-7514.135179 -
Indian Journal of Ophthalmology Oct 2021In this article we focus on a systematic approach to assess common orbital lesions on magnetic resonance imaging (MRI). The identification of the probable compartment or... (Review)
Review
In this article we focus on a systematic approach to assess common orbital lesions on magnetic resonance imaging (MRI). The identification of the probable compartment or structure of origin helps narrow the differential diagnosis of a lesion. Analyzing the morphology, appearance, and signal intensity on various sequences, the pattern, and degree of contrast enhancement are key to characterize lesions on MRI. Imaging features suggesting cellularity and vascularity can also be determined to help plan for biopsy or surgery of these lesions. MRI can also distinguish active from chronic disease in certain pathologies and aids in selecting appropriate medical management. MRI may thus serve as a diagnostic tool and help in guiding therapeutic strategies and posttreatment follow-up.
Topics: Contrast Media; Diagnosis, Differential; Humans; Magnetic Resonance Imaging; Orbit; Orbital Neoplasms
PubMed: 34571598
DOI: 10.4103/ijo.IJO_904_21 -
Acta Neuropathologica May 2007Silver-staining methods are helpful for histological identification of pathological deposits. In spite of some ambiguities regarding their mechanism and interpretation,... (Review)
Review
Silver-staining methods are helpful for histological identification of pathological deposits. In spite of some ambiguities regarding their mechanism and interpretation, they are widely used for histopathological diagnosis. In this review, four major silver-staining methods, modified Bielschowsky, Bodian, Gallyas (GAL) and Campbell-Switzer (CS) methods, are outlined with respect to their principles, basic protocols and interpretations, thereby providing neuropathologists, technicians and neuroscientists with a common basis for comparing findings and identifying the issues that still need to be clarified. Some consider "argyrophilia" to be a homogeneous phenomenon irrespective of the lesion and the method. Thus, they seek to explain the differences among the methods by pointing to their different sensitivities in detecting lesions (quantitative difference). Comparative studies, however, have demonstrated that argyrophilia is heterogeneous and dependent not only on the method but also on the lesion (qualitative difference). Each staining method has its own lesion-dependent specificity and, within this specificity, its own sensitivity. This "method- and lesion-dependent" nature of argyrophilia enables operational sorting of disease-specific lesions based on their silver-staining profiles, which may potentially represent some disease-specific aspects. Furthermore, comparisons between immunohistochemical and biochemical data have revealed an empirical correlation between GAL+/CS-deposits and 4-repeat (4R) tau (corticobasal degeneration, progressive supranuclear palsy and argyrophilic grains) and its complementary reversal between GAL-/CS+deposits and 3-repeat (3R) tau (Pick bodies). Deposits containing both 3R and 4R tau (neurofibrillary tangles of Alzheimer type) are GAL+/CS+. Although no molecular explanations, other than these empiric correlations, are currently available, these distinctive features, especially when combined with immunohistochemistry, are useful because silver-staining methods and immunoreactions are complementary to each other.
Topics: Animals; History, 20th Century; History, 21st Century; Humans; Nervous System Diseases; Silver Staining
PubMed: 17401570
DOI: 10.1007/s00401-007-0200-2 -
Environmental Health Perspectives Apr 1990The nasal passages of laboratory animals and man are complex, and lesions induced in the delicate nasal lining by inhaled air pollutants vary considerably in location... (Review)
Review
The nasal passages of laboratory animals and man are complex, and lesions induced in the delicate nasal lining by inhaled air pollutants vary considerably in location and nature. The distribution of nasal lesions is generally a consequence of regional deposition of the inhaled material, local tissue susceptibility, or a combination of these factors. Nasal uptake and regional deposition are are influenced by numerous factors including the physical and chemical properties of the inhaled material, such as water solubility and reactivity; airborne concentration and length of exposure; the presence of other air contaminants such as particulate matter; nasal metabolism, and blood and mucus flow. For certain highly water-soluble or reactive gases, nasal airflow patterns play a major role in determining lesion distribution. Studies of nasal airflow in rats and monkeys, using casting and molding techniques combined with a water-dye model, indicate that nasal airflow patterns are responsible for characteristic differences in the distribution of nasal lesions induced by formaldehyde in these species. Local tissue susceptibility is also a complex issue that may be a consequence of many factors, including physiologic and metabolic characteristics of the diverse cell populations that comprise each of the major epithelial types lining the airways. Identification of the principal factors that influence the distribution and nature of nasal lesions is important when attempting the difficult process of determining potential human risks using data derived from laboratory animals. Toxicologic pathologists can contribute to this process by carefully identifying the site and nature of nasal lesions induced by inhaled materials.
Topics: Air Pollutants; Animals; Cricetinae; Disease Susceptibility; Dogs; Guinea Pigs; Humans; Macaca fascicularis; Mice; Models, Anatomic; Nasopharyngeal Diseases; Pulmonary Ventilation; Rabbits; Rats; Risk Factors
PubMed: 2200663
DOI: 10.1289/ehp.85-1568327