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Magnetic Resonance in Medicine Jan 2019To develop a black blood heart-rate adaptive T -prepared balanced steady-state free-precession (BEATS) sequence for myocardial T mapping.
PURPOSE
To develop a black blood heart-rate adaptive T -prepared balanced steady-state free-precession (BEATS) sequence for myocardial T mapping.
METHODS
In BEATS, blood suppression is achieved by using a combination of preexcitation and double inversion recovery pulses. The timing and flip angles of the preexcitation pulse are auto-calculated in each patient based on heart rate. Numerical simulations, phantom studies, and in vivo studies were conducted to evaluate the performance of BEATS. BEATS T maps were acquired in 36 patients referred for clinical cardiac MRI and in 1 swine with recent myocardial infarction. Two readers assessed all images acquired in patients to identify the presence of artifacts associated with slow blood flow.
RESULTS
Phantom experiments showed that the BEATS sequence provided accurate T values over a wide range of simulated heart rates. Black blood myocardial T maps were successfully obtained in all subjects. No significant difference was found between the average T measurements obtained from the BEATS and conventional bright-blood T ; however, there was a decrease in precision using the BEATS sequence. A suppression of the blood pool resulted in sharper definition of the blood-myocardium border and reduced partial voluming effect. The subjective assessment showed that 16% (18 out of 108) of short-axis slices have residual blood artifacts (12 in the apical slice, 4 in the midventricular slice, and 2 in the basal slice).
CONCLUSION
The BEATS sequence yields dark blood myocardial T maps with better definition of the blood-myocardium border. Further studies are warranted to evaluate diagnostic accuracy of black blood T mapping.
Topics: Adult; Aged; Aged, 80 and over; Algorithms; Animals; Artifacts; Blood Flow Velocity; Computer Simulation; Female; Heart; Heart Rate; Humans; Image Enhancement; Image Interpretation, Computer-Assisted; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Models, Theoretical; Myocardium; Phantoms, Imaging; Signal Processing, Computer-Assisted; Swine; Young Adult
PubMed: 30058162
DOI: 10.1002/mrm.27360 -
Diagnostics (Basel, Switzerland) Nov 2022When we talk about visualization methods in surgery, it is important to mention that the diagnosis of tumors and how we define tumor borders intraoperatively in a... (Review)
Review
When we talk about visualization methods in surgery, it is important to mention that the diagnosis of tumors and how we define tumor borders intraoperatively in a correct way are two main things that would not be possible to achieve without this grand variety of visualization methods we have at our disposal nowadays. In addition, histopathology also plays a very important role, and its importance cannot be neglected either. Some biopsy specimens, e.g., frozen sections, are examined by a histopathologist and lead to tumor diagnosis and the definition of its borders. Furthermore, surgical resection is a very important point when it comes to prognosis and life survival. Confocal laser endomicroscopy (CLE) is an imaging technique that provides microscopic information on the tissue in real time. CLE of disorders, such as head, neck and brain tumors, has only recently been suggested to contribute to both immediate tumor characterization and detection. It can be used as an additional tool for surgical biopsies during biopsy or surgical procedures and for inspection of resection margins during surgery. In this review, we analyze the development, implementation, advantages and disadvantages as well as the future directions of this technique in neurosurgical and otorhinolaryngological disciplines.
PubMed: 36359540
DOI: 10.3390/diagnostics12112697 -
Dento Maxillo Facial Radiology Mar 2017To detect and determine image error and artefact types in intraoral radiographs obtained with photostimulable phosphor (PSP) technology, place them in an appropriate...
OBJECTIVES
To detect and determine image error and artefact types in intraoral radiographs obtained with photostimulable phosphor (PSP) technology, place them in an appropriate classification and retrospectively analyze the PSP-specific image errors and artefacts. The causes and solutions of PSP-specific errors and artefacts have also been discussed.
METHODS
The radiographic database of Ondokuz Mayis University, Faculty of Dentistry, Department of Dentomaxillofacial Radiology, was used for this study. Different types of image errors and artefacts observed on intraoral radiographs during 2014-15 were detected and defined. A total of 2100 intraoral radiographs were individually evaluated for the distribution of PSP-specific image artefacts.
RESULTS
There were 34 image error and artefact types detected and classified into 4 groups according to the causative factors. The most common PSP-specific image artefacts were found in fading with a ratio of 44.1% for the ambient light-related group, peeling of the plate borders with a ratio of 53.4% for the PSP plate-related group and straight line with a ratio of 42.2% for the scanner-related group.
CONCLUSIONS
The determination and definition of the image errors and artefacts with clarification of their causes and solutions are important for the improvement of radiographic quality and the reduction of the retake ratio.
Topics: Artifacts; Diagnostic Errors; Luminescent Agents; Radiographic Image Enhancement; Radiography, Dental; Retrospective Studies
PubMed: 27883287
DOI: 10.1259/dmfr.20160188 -
Scandinavian Journal of Trauma,... Jul 2017In 2002, the World Congress on Drowning developed a uniform definition for drowning. The aim of this study is to determine the prevalence of "non-uniform drowning... (Review)
Review
BACKGROUND
In 2002, the World Congress on Drowning developed a uniform definition for drowning. The aim of this study is to determine the prevalence of "non-uniform drowning terminology" (NUDT) and "non-uniform drowning definitions" (NUDD) in peer-reviewed scientific literature from 2010 to 2016, and compare these findings with those from our unpublished study performing a similar analysis on literature from 2003 to 2010.
METHODS
A systematic review was performed using drowning-specific search terms in Pubmed and Web of Science. Titles and abstracts published between July 2010 and January 2016 were screened for relevance to the study focus. Articles meeting screening criteria were reviewed for exclusion criteria to produce the final group of studies. These articles were reviewed by four reviewers for NUDT and NUDD. The Fisher exact test was used to determine any statistically significant changes.
RESULTS
The final group of studies included 167 articles. A total of 53 articles (32%) utilized NUDT, with 100% of these including the term "near drowning". The proportion of articles utilizing NUDT was significantly less than reported by our previous study (p < 0.05). In addition, 32% of the articles included a definition for drowning (uniform or non-uniform), with 15% of these utilizing NUDD.
DISCUSSION
Our study reveals a statistically significant improvement over the past thirteen years in the use of uniform drowning terminology in peer-reviewed scientific literature, although year-to-year variability over the current study period does not yield an obvious trend.
CONCLUSIONS
Of the articles reviewed during the 2010-2016 study period, 32% included outdated and non-uniform drowning terminology and definitions. While this reveals an absolute decrease of 11% as compared with the previous study period (2003-2010), there is still significant room for improvement.
Topics: Drowning; Follow-Up Studies; Humans; Terminology as Topic
PubMed: 28716063
DOI: 10.1186/s13049-017-0405-x -
NeuroImage Oct 2009Due to its crucial role for memory processes and its relevance in neurological and psychiatric disorders, the hippocampus has been the focus of neuroimaging research for... (Review)
Review
Due to its crucial role for memory processes and its relevance in neurological and psychiatric disorders, the hippocampus has been the focus of neuroimaging research for several decades. In vivo measurement of human hippocampal volume and shape with magnetic resonance imaging has become an important element of neuroimaging research. Nevertheless, volumetric findings are still inconsistent and controversial for many psychiatric conditions including affective disorders. Here we review the wealth of anatomical protocols for the delineation of the hippocampus in MR images, taking into consideration 71 different published protocols from the neuroimaging literature, with an emphasis on studies of affective disorders. We identified large variations between protocols in five major areas. 1) The inclusion/exclusion of hippocampal white matter (alveus and fimbria), 2) the definition of the anterior hippocampal-amygdala border, 3) the definition of the posterior border and the extent to which the hippocampal tail is included, 4) the definition of the inferior medial border of the hippocampus, and 5) the use of varying arbitrary lines. These are major sources of variance between different protocols. In contrast, the definitions of the lateral, superior, and inferior borders are less disputed. Directing resources to replication studies that incorporate characteristics of the segmentation protocols presented herein may help resolve seemingly contradictory volumetric results between prior neuroimaging studies and facilitate the appropriate selection of protocols for manual or automated delineation of the hippocampus for future research purposes.
Topics: Algorithms; Artificial Intelligence; Hippocampus; Humans; Image Enhancement; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Pattern Recognition, Automated; Reproducibility of Results; Sensitivity and Specificity
PubMed: 19447182
DOI: 10.1016/j.neuroimage.2009.05.019 -
Advances in Experimental Medicine and... 2014The International League Against Epilepsy (ILAE) defined a seizure as "a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal... (Review)
Review
The International League Against Epilepsy (ILAE) defined a seizure as "a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain." This definition has been used since the era of Hughlings Jackson, and does not take into account subsequent advances made in epilepsy and neuroscience research. The clinical diagnosis of a seizure is empirical, based upon constellations of certain signs and symptoms, while simultaneously ruling out a list of potential imitators of seizures. Seizures should be delimited in time, but the borders of ictal (during a seizure), interictal (between seizures) and postictal (after a seizure) often are indistinct. EEG recording is potentially very helpful for confirmation, classification and localization. About a half-dozen common EEG patterns are encountered during seizures. Clinicians rely on researchers to answer such questions as why seizures start, spread and stop, whether seizures involve increased synchrony, the extent to which extra-cortical structures are involved, and how to identify the seizure network and at what points interventions are likely to be helpful. Basic scientists have different challenges in use of the word 'seizure,' such as distinguishing seizures from normal behavior, which would seem easy but can be very difficult because some rodents have EEG activity during normal behavior that resembles spike-wave discharge or bursts of rhythmic spiking. It is also important to define when a seizure begins and stops so that seizures can be quantified accurately for pre-clinical studies. When asking what causes seizures, the transition to a seizure and differentiating the pre-ictal, ictal and post-ictal state is also important because what occurs before a seizure could be causal and may warrant further investigation for that reason. These and other issues are discussed by three epilepsy researchers with clinical and basic science expertise.
Topics: Action Potentials; Electrodes; Electroencephalography; Epilepsy; Humans; Monitoring, Physiologic
PubMed: 25012363
DOI: 10.1007/978-94-017-8914-1_1 -
Gland Surgery Oct 2019Mastectomy without immediate reconstruction leaves us with a population of women who may need a new breast in a delayed fashion. These women are often elderly, not fit...
Mastectomy without immediate reconstruction leaves us with a population of women who may need a new breast in a delayed fashion. These women are often elderly, not fit for major flap surgery or reluctant to have long scars or implants. Free fat grafting has mainly been used as an adjunct to other reconstructive methods. We present an option for delayed full breast reconstruction with free fat grafting alone. In some cases, we utilize the lateral excess as a flap in combination with fat grafting. Patient selection is crucial. A lady fitting this reconstruction method should have fat to donate, preferably in several different regions as well as redundant skin on the chest-wall and only minor radiation damage. Also, breast size requirements need to be sensible. The Fat is harvested in a closed system under general or local anesthesia. Following a few minutes decantation, the fat is put into syringes and injected from 4-6 entrance points into 3-4 layers with a blunt cannula. Depending on the width, height and thickness of the receiving chest wall, the transferred volume varies between 150-300 cc/operation. In general, 2-5 operations are needed to reconstruct a breast with fat alone. If the patient presents with lateral excess tissue, this can be utilized as a local, fasciocutaneous flap, de-epithelialized and rotated 180 degrees to support the inferior border of the new breast. This enables inferolateral definition and control of the breast footprint. The secret behind success in free fat grafting for full breast reconstruction lies in the small technical details and works safely and efficiently in a selected group of patients.
PubMed: 31709171
DOI: 10.21037/gs.2019.05.07 -
Journal of Advances in Medical... Apr 2016Systems-Based Practice (SBP) is one of the six competencies introduced by the ACGME for physicians to provide high quality of care and also the most challenging of them...
INTRODUCTION
Systems-Based Practice (SBP) is one of the six competencies introduced by the ACGME for physicians to provide high quality of care and also the most challenging of them in performance, training, and evaluation of medical students. This concept analysis clarifies the concept of SBP by identifying its components to make it possible to differentiate it from other similar concepts. For proper training of SBP and to ensure these competencies in physicians, it is necessary to have an operational definition, and SBP's components must be precisely defined in order to provide valid and reliable assessment tools.
METHODS
Walker & Avant's approach to concept analysis was performed in eight stages: choosing a concept, determining the purpose of analysis, identifying all uses of the concept, defining attributes, identifying a model case, identifying borderline, related, and contrary cases, identifying antecedents and consequences, and defining empirical referents.
RESULTS
Based on the analysis undertaken, the attributes of SBP includes knowledge of the system, balanced decision between patients' need and system goals, effective role playing in interprofessional health care team, system level of health advocacy, and acting for system improvement. System thinking and a functional system are antecedents and system goals are consequences. A case model, as well as border, and contrary cases of SBP, has been introduced.
CONCLUSION
he identification of SBP attributes in this study contributes to the body of knowledge in SBP and reduces the ambiguity of this concept to make it possible for applying it in training of different medical specialties. Also, it would be possible to develop and use more precise tools to evaluate SBP competency by using empirical referents of the analysis.
PubMed: 27104198
DOI: No ID Found -
Clinical, Cosmetic and Investigational... 2015Pyoderma gangrenosum (PG) is a rare disease, but commonly related to important morbidity. PG was first assumed to be infectious, but is now considered an inflammatory... (Review)
Review
Pyoderma gangrenosum (PG) is a rare disease, but commonly related to important morbidity. PG was first assumed to be infectious, but is now considered an inflammatory neutrophilic disease, often associated with autoimmunity, and with chronic inflammatory and neoplastic diseases. Currently, many aspects of the underlying pathophysiology are not well understood, and etiology still remains unknown. PG presents as painful, single or multiple lesions, with several clinical variants, in different locations, with a non specific histology, which makes the diagnosis challenging and often delayed. In the classic ulcerative variant, characterized by ulcers with inflammatory undermined borders, a broad differential diagnosis of malignancy, infection, and vasculitis needs to be considered, making PG a diagnosis of exclusion. Moreover, there are no definitively accepted diagnostic criteria. Treatment is also challenging since, due to its rarity, clinical trials are difficult to perform, and consequently, there is no "gold standard" therapy. Patients frequently require aggressive immunosuppression, often in multidrug regimens that are not standardized. We reviewed the clinical challenges of PG in order to find helpful clues to improve diagnostic accuracy and the treatment options, namely topical care, systemic drugs, and the new emerging therapies that may reduce morbidity.
PubMed: 26060412
DOI: 10.2147/CCID.S61202 -
Journal of Advances in Medical... Jul 2017Considering the pervasiveness of social accountable medical education concept around the world and the growing trend of literature in this regard as well as various...
INTRODUCTION
Considering the pervasiveness of social accountable medical education concept around the world and the growing trend of literature in this regard as well as various interpretations made about this concept, we found it necessary to analyze the concept of social accountable medical education.
METHODS
In this study, the modified version of McKenna's approach to concept analysis was used to determine the concept, explain structures and substructures and determine the border concepts neighboring and against social accountability in medical education.
RESULTS
By studying the selected sources,the components of the concept were obtained to identify it and express an analytic definition of social accountability in medical education system. Then, a model case with all attributes of the given concept and the contrary and related concepts were mentioned to determine the boundary between the main concept and auxiliary ones.
CONCLUSION
According to the results of this study in the field of social accountability, the detailed and transparent analytical definition of social accountable medical education can be used in future studies as well as the function and evaluation of medical education system.
PubMed: 28761884
DOI: No ID Found