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BACKGROUND: Colonoscopy difficulty and procedure time can vary between cases, posing challenges for daily scheduling in endoscopy units. In the literature, cecal intubation time (CIT) is commonly used to assess colonoscopy difficulty, yet there is debate regarding the factors influencing CIT. This prospective observational study aimed to evaluate the factors influencing CIT. METHODS: In this single-center, prospective, observational study, 915 patients who underwent colonoscopy between July 2023 and April 2024 were evaluated. Failure to achieve cecal intubation due to poor bowel preparation and a history of colorectal surgery were considered as exclusion criteria. Patients with a CIT ≥ 11 min or those with technically failed cecal intubation were categorized into the prolonged CIT subgroup, while those with a CIT < 11 min were analyzed in the normal CIT subgroup. Patients were evaluated based on demographic characteristics, clinical parameters, and colonoscopy results. RESULTS: A total of 902 patients included in the final analysis. The median age was 55 years and 55.4% of them were women. The cecal intubation rate was 97.5% (892 patients). The polyp, adenoma, and malignancy detection rate were 27.4, 20.7, and 1.9%, respectively. Median cecal intubation time (CIT) was 6 min (Interquartile range: 4-8). In multivariate analysis, body mass index ≤ 18.5, previous abdominal surgery, increased Wexner Constipation Score, and lesser endoscopist experience were associated with prolonged CIT. CONCLUSIONS: BMI, previous abdominal surgery, severity of constipation, and the experience of endoscopist may affect CIT. Considering these factors during daily planning in the endoscopy unit can lead to more efficient facility utilization.
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BACKGROUND: The requirement for routine biopsy sampling in esophagogastroduodenoscopy (EGD) with normal endoscopic findings is a subject of debate. In this study, patients who had normal endoscopic findings in EGD and underwent biopsy sampling were retrospectively analyzed. METHODS: This single-center retrospective cohort study included 671 patients who underwent EGD between 2021 and 2023 in the Sisli Hamidiye Etfal Training and Research Hospital Surgical Endoscopy Unit. All patients had normal endoscopic findings and a sampling biopsy was performed on all patients included. Patients were evaluated based on demographic and clinicopathologic findings. This study was registered to ClinicalTrials.gov (NCT06269380). RESULTS: Two hundred sixty patients (38.7%) have abnormal histopathologic findings. Helicobacter pylori positivity was detected in 200 (29.8%) patients. Intestinal metaplasia (IM) was present in 80 of 260 patients (30.8%). The frequency of IM was higher in older age groups and cases with mild gastritis ( P <0.001). The frequency and severity of gastritis were associated with increased H. pylori positivity and density ( P <0.001). CONCLUSIONS: The biopsy sampling may contribute to the diagnosis and treatment process in cases where normal endoscopic findings are observed during EGD.
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Endoscopia do Sistema Digestório , Gastrite , Infecções por Helicobacter , Helicobacter pylori , Humanos , Estudos Retrospectivos , Feminino , Masculino , Pessoa de Meia-Idade , Biópsia/métodos , Endoscopia do Sistema Digestório/métodos , Infecções por Helicobacter/patologia , Infecções por Helicobacter/diagnóstico , Helicobacter pylori/isolamento & purificação , Adulto , Gastrite/patologia , Gastrite/microbiologia , Gastrite/diagnóstico , Idoso , Antro Pilórico/patologia , Antro Pilórico/microbiologia , Metaplasia/patologia , Adulto JovemRESUMO
Laparoscopic totally extraperitoneal inguinal hernia repair is considered a common and safe procedure. Here, we present the case of a 31-year-old male with right indirect inguinal hernia and no medical history. The patient underwent laparoscopic totally extraperitoneal inguinal hernia repair and the operation was completed successfully. During extubation, subcutaneous emphysema was noted at the neck, chest, and above the nipples. Tracheal injury was excluded by the anaesthesiologists and otorhinolaryngologists. On arterial blood gas, the patient's oxygen saturation was 95% with nasal oxygen support. The patient was followed-up closely in the general surgery inpatient clinic. Computed tomography was performed, on which bilateral pneumothorax and pneumomediastinum were noted. Conservative management was planned and the patient was discharged on the fourth postoperative day. Laparoscopic totally extraperitoneal inguinal hernia repair is considered a routinely applied safe procedure, however, appropriate care should be taken to avoid possible complications.
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Hérnia Inguinal , Laparoscopia , Enfisema Mediastínico , Pneumotórax , Enfisema Subcutâneo , Masculino , Humanos , Adulto , Hérnia Inguinal/cirurgia , Hérnia Inguinal/complicações , Laparoscopia/efeitos adversos , Enfisema Mediastínico/diagnóstico por imagem , Enfisema Mediastínico/etiologia , Enfisema Mediastínico/terapia , Pneumotórax/terapia , Pneumotórax/cirurgia , Enfisema Subcutâneo/terapia , Enfisema Subcutâneo/complicações , Herniorrafia/efeitos adversos , Herniorrafia/métodosRESUMO
Gastric malignancies constitute the sixth most common cancer with regards to incidence and have the fifth most mortality rates. Extended lymph-node dissection is the surgical modality of choice while treating advanced stage gastric cancer. It is yet a topic of debate, whether or not the amount of positive lymph nodes after a pathological examination following the surgical intervention is of prognostic value. In this study, it is aimed to evaluate the prognostic significance of positive lymph nodes following the surgery. A total of 193 patients who underwent curative gastrectomy between January 2011 and December 2015 have been considered for a retrospective data collection. The cases with R1-R2 resections, palliative or emergent surgeries are excluded. Metastatic to total number of lymph nodes, corresponded a ratio which was analyzed in this survey and practiced as a predictive parameter of disease outcome. This survey includes 138 male (71.5%) and 55 female (28.5%) patients treated between 2011 and 2015 in our clinic. The survey follow-up duration of the cases range between 0, 2, and 72 months, corresponding an average of 23.24 ± 16.99 months. We calculated cutoff value of 0.09 with, sensitivity is 76.32% for positive to total number of lymph nodes ratio, whereas specivity applies for 64.10%, positive predictive value for 58% and negative predictive value for 80.6%. Positive lymph node ratio has a prognostic value in terms of predicting the prognosis of the patients with gastric adenocarcinoma following a curative gastrectomy. This might in long term contribute to the prognostic analysis of patients if integrated in the current staging system.
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Neoplasias Gástricas , Humanos , Masculino , Feminino , Prognóstico , Neoplasias Gástricas/patologia , Estudos Retrospectivos , Estadiamento de Neoplasias , Razão entre Linfonodos , Excisão de Linfonodo , Linfonodos/cirurgia , Linfonodos/patologia , GastrectomiaRESUMO
Aim: The aim of this study was to investigate the effect of the largest metastatic lymph node (MLN) size on postoperative outcomes of patients with stage II-III gastric cancer (GC). Methods: A total of 163 patients with stage II/III GC who underwent curative surgery were included in this single-center retrospective study. The lymph nodes were counted, each lymph node was analyzed for metastatic involvement by histopathological examination, and the diameter of the largest metastatic lymph node was recorded. The severity of postoperative complications was assessed by Clavien-Dindo classification system. Two groups of 163 patients were defined according to ROC analysis with cut-off value of histopathologically maximum MLN diameter. A comparative analysis of demographic and clinicopathological characteristics of the patients and their postoperative outcomes were performed. Results: The median hospital stay was significantly longer in patients with major complications compared to patients without major complications [18 days (IQR: 13-24) vs. 8 days (IQR: 7-11); (p < 0.001)]. The median MLN size was significantly larger in deceased patients compared to survived [1.3â cm (IQR: 0.8-1.6) vs. 0.9â cm (IQR: 0.6-1.2), respectively; (p < 0.001)]. The cut-off value of MLN size predicting mortality was found as 1.05â cm. MLN size ≥1.05â cm had nearly 3.5 times more negative impact on survival. Conclusions: The largest metastatic lymph node size had a significant association with survival outcomes. Particularly, MLN size over 1.05â cm was associated with worse survival outcomes. However, the largest MLN was not shown to have any effect on major complications. Further prospective and large-scale studies are required to draw more precise conclusions.
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Background: The metastatic lymph nodes (MLN) are interpreted to be correlated with prognosis of the colorectal cancers (CRC). The present retrospective study aimed to investigate the clinical significance of the largest MLN size in terms of postoperative outcomes and its predictive value in the prognosis of the patients with stage III CRC. Methods: Between May 2013 and December 2018, a total of 101 patients who underwent curative resection for stage III CRC retrospectively reviewed. All patients were divided into two groups regarding cut-off value (<1.05 cm and ≥1.05 cm) of maximum MLN diameter measured histopathologically. A comparative analysis of demographic and clinicopathological characteristics of the patients and their postoperative outcomes were performed. Results: Two groups carried similar demographic data and preoperative laboratory variables except the lymphocyte count, hematocrit (HCT) ratio, hemoglobin level and mean corpuscular volume (MCV) value (p<0.05). The patients with MLN diameter ≥1.05 cm (n=46) needed more erythrocyte suspension and were hospitalized longer than the patients with a diameter <1.05 cm (n=55) (p=0.006 and 0.0294, respectively). Patients with MLN diameter < 1.05 cm had a significantly longer overall survival than patients with MLN diameter ≥ 1.05 cm (75,29 vs. 52,57 months, respectively). Regarding the histopathologic features, the patients with MLN diameter ≥1.05 cm had larger tumor size and higher number of MLN than those with diameter <1.05 cm (p=0.049 and 0.001). Conclusion: The size of MLN larger than 1.05 cm may be predictive for a poor prognosis and lower survival of stage III CRC patients. The largest MLN size may be a proper alternative factor to the number of MLNs in predicting prognosis or in staging CRC patients.
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AIM: This study aimed to evaluate the surgical procedures, outcomes, and prognostic factors in patients with ischemic heart disease who were operated on due to nonocclusive mesenteric ischemia (NOMI). MATERIAL AND METHODS: This research contains all patients diagnosed with congestive heart failure and NOMI between January 2011 to January 2020. The patients who had angiography or CT that showed occlusion of more than 50% in any of the main branches of the mesenteric artery or patients who presented with symptoms in correlation with a total occlusion were excluded from the study. Patients who underwent coronary heart surgery but were not diagnosed with congestive heart failure and those with atrial fibrillation also were excluded from the study. Patients divided into two groups, according to a medical database. RESULTS: A significant difference was found between the surviving and non-survivor groups in minutes, in terms of median time to segmenter intestinal resection (P = 0.042). CONCLUSION: An early diagnosis and surgical segmental intestinal resection before peritonitis worsens can be the key to better prognosis for NOMI patients.
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Procedimentos Cirúrgicos Cardíacos , Insuficiência Cardíaca , Isquemia Mesentérica , Humanos , Isquemia Mesentérica/diagnóstico , Isquemia Mesentérica/cirurgia , PrognósticoRESUMO
When given a series of sinusoidal oscillations in which the two hemicycles have equal amplitude but asymmetric velocity, healthy subjects lose perception of the slower hemicycle (SHC), reporting a drift towards the faster hemicycle (FHC). This response is not reflected in the vestibular-ocular reflex, suggesting that the adaptation is of higher order. This study aimed to define EEG correlates of this adaptive response. Twenty-five subjects underwent a series of symmetric or asymmetric oscillations and reported their perceived head orientation at the end using landmarks in the testing room; this was converted into total position error (TPE). Thirty-two channel EEG was recorded before, during and after adaptation. Spectral power and coherence were calculated for the alpha, beta, delta and theta frequency bands. Linear mixed models were used to determine a region-by-condition effect of the adaptation. TPE was significantly greater in the asymmetric condition and reported error was always in the direction of the FHC. Regardless of condition, alpha desynchronised in response to stimulation, then rebounded back toward baseline values. This pattern was accelerated and attenuated in the prefrontal and occipital regions, respectively, in the asymmetric condition. Functional connectivity networks were identified in the beta and delta frequency bands; these networks, primarily comprising frontoparietal connections, were more coherent during asymmetric stimulation. These findings suggest that the temporary vestibulo-perceptual 'neglect' induced by asymmetric vestibular stimulation may be mediated by alpha rhythms and frontoparietal attentional networks. The results presented further our understanding of brain rhythms and cortical networks involved in vestibular perception and adaptation. KEY POINTS: Whole-body asymmetric sinusoidal oscillations, which consist of hemicycles with equal amplitude but differing velocities, can induce transient 'neglect' of the slower hemicycle in the vestibular perception of healthy subjects. In this study, we aimed to elucidate EEG correlates of this 'neglect', thereby identifying a cortical role in vestibular perception and adaptation. We identified a desynchronisation-resynchronisation response in the alpha frequency band (8-14 Hz) that was accelerated in the prefrontal region and attenuated in the occipital region when exposed to asymmetric, as compared to symmetric, rotations. We additionally identified functional connectivity networks in the beta (14-30 Hz) and delta (1-4 Hz) frequency bands consisting primarily of frontoparietal connections. These results suggest a prominent role of alpha rhythms and frontoparietal attentional networks in vestibular perception and adaptation.
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Reflexo Vestíbulo-Ocular , Vestíbulo do Labirinto , Adaptação Fisiológica/fisiologia , Eletroencefalografia , Humanos , Percepção , Reflexo Vestíbulo-Ocular/fisiologia , Vestíbulo do Labirinto/fisiologiaRESUMO
Perioperative chemotherapy provides advantage for gastric cancer patients in terms of survival. A 56-year male with a diagnosis of locally advanced gastric carcinoma presented with complaints of acute abdominal pain; and was diagnosed as gastric tumor perforation during neoadjuvant therapy. Gastric perforation may occur during neoadjuvant chemotherapy for gastric cancer. While the treatment of choice for these perforations was surgery in the past, it is now shifting towards a minimally invasive or non-invasive approach. We used the minimally invasive treatment approach with nasogastric drainage, intravenous antibiotics and proton pump inhibitors, which was effective in the treatment of perforation. Althrough, conservative treatment approach may be an effective management option in selected patients with gastric cancer perforation. Key Words: Gastric cancer, Neoadjuvant chemotherapy, Perforation.
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Terapia Neoadjuvante , Neoplasias Gástricas , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimioterapia Adjuvante , Tratamento Conservador , Humanos , Masculino , Neoplasias Gástricas/tratamento farmacológicoRESUMO
AIM: The incidence of invasive lobular carcinoma (ILC), a breast cancer type comprising several variants with distinct morphological and molecular features and clinical behaviors, has been increasing in recent years. Unlike the well-defined classical lobular carcinoma, the most common ILC variant, some uncertainties remain regarding the features of other ILC variants. Therefore, we investigated the clinicopathological features and survival outcomes of specific ILC variants. MATERIAL AND METHODS: This retrospective study compared the tumor and patient characteristics and outcomes according to specific ILC variants in 77 patients who underwent surgery for ILC between January 2010 and December 2016 at a single center in Turkey. RESULTS: The mean patient age was 54.58 ± 11.7 years. The ILC variants were classical, pleomorphic, tubulolobular, solid, and signet ring cell in 49(63.6%), 14(18.2%), 10(12.8%), 2(2.7%), and 2(2.7%) patients, respectively. The mean tumor diameter, histological grade, Ki-67 proliferation index, nodal metastasis, E-cadherin expression, lymphovascular invasion, and type of surgery were significantly different among the variants. However, there were no significant differences in the rates of local recurrence, distant metastasis, and overall survival among the variants. CONCLUSIONS: Despite the good prognostic characteristics and good response to treatment, several studies have reported that ILC is associated with poor long-term outcomes. Therefore, significant challenges remain in the management of ILC. Although it is believed to be a specific histological type, ILC is clinically and pathologically heterogenous. Therefore, the identification of patients with poor prognostic variants should aid in the implementation of efficient and personalized treatment options. KEY WORDS: Breast cancer, Invasive cancer, Invasive lobuler carcinoma, Prognosis, Variants of lobuler carcinoma.
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Neoplasias da Mama , Carcinoma Ductal de Mama , Carcinoma Lobular , Adulto , Idoso , Mama , Neoplasias da Mama/cirurgia , Carcinoma Lobular/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Estudos RetrospectivosRESUMO
Aims: Type 2 diabetes caused by obesity is increasing globally. Bariatric surgical procedures are known to have positive effects on glucose homeostasis through neurohormonal action mechanisms. In the present study, we aimed to investigate the factors influencing glucose homeostasis independent of weight loss after the laparoscopic sleeve gastrectomy (LSG). Methods: Patients who underwent LSG for morbid obesity in a 3-year period were evaluated. Data on demographics, clinical characteristics (duration of diabetes, resected gastric volume, antral resection margin) and laboratory parameters (preoperative and postoperative blood glucose on fasting, preoperative HbA1c levels and first-year HbA1c levels) were retrospectively reviewed. Effect of patients' body mass index (<50 kg/m2, ≥50 kg/m2), first-year excess weight loss (EWL%) rates, age (≥50 years, <50 years), duration of diabetes (≥5 years, <5 years) and antral resection margin (≥3 cm, <3 cm) on postoperative blood glucose profile and diabetic resolution status were investigated. Results: Total of 61 patients constituted the study group. There were 40 female and 21 male patients with an average age of 43.8 ± 10.5 years (19-67 years). Preoperatively, mean BMI, blood glucose levels and HbA1c were 48.8 ± 8.5 kg/m2, 133.6 ± 47.4 mg/dL and 7.4 ± 1.1, respectively. The mean blood glucose level at the postoperatively 5th day was 88.0 ± 16.3 mg/dL (median: 84 mg/dL) (P < .001). Fifty-nine out of 61 patients improved their glycaemic control. Conclusions: It is noteworthy that LSG can control blood glucose levels in short term after surgery regardless of weight loss. Therefore, LSG should be preferred at earlier stages in the treatment of obesity-related T2DM in order to prevent T2DM-related complications.
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Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/cirurgia , Gastrectomia/métodos , Homeostase , Laparoscopia/métodos , Adulto , Idoso , Biomarcadores/sangue , Complicações do Diabetes/etiologia , Complicações do Diabetes/prevenção & controle , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/etiologia , Feminino , Hemoglobinas Glicadas , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/complicações , Obesidade Mórbida/cirurgia , Estudos Retrospectivos , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVE: To evaluate the treatment options applied to solitary caecal diverticulitis patients, and to explore the possibility of non-operative treatments. METHODS: The retrospective study was conducted a tertiary referral centre, and comprised data of patients who presented with acute abdominal pain and were diagnosed either preoperatively or intraoperatively as cases of solitary caecal diverticulitis between January 2009 and December 2017. Data on demographics, physical examination findings, laboratory results, treatment modalities and outpatient clinical records was noted, and analysed analysed using SPSS 21. RESULTS: Of the 580 patients whose medical records were reviewed, 11(1.89%) were diagnosed as cases of solitary caecal diverticulitis. Of them, 6(54.5%) patients were treated conservatively, and 5(45.4%) surgically. The disease recurred in 1(9%) patient who was treated conservatively. Among those treated surgically, 1(20%) patient had hemicolectomy, and the rest had appendectomy and/or diverticulectomy and drainage procedures. There were no major complications during the follow- up. CONCLUSIONS: With accurate diagnosis during preoperative period, the spread of the pathology helps to choose the best suitable surgical technique. Appendectomy should be performed to avoid future diagnostic confusion.
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Apendicite , Doenças do Ceco , Diverticulite , Apendicite/diagnóstico , Apendicite/cirurgia , Doenças do Ceco/diagnóstico , Doenças do Ceco/cirurgia , Diagnóstico Diferencial , Diverticulite/diagnóstico , Diverticulite/cirurgia , Humanos , Estudos RetrospectivosRESUMO
BACKGROUND: Blood is the first tissue contacting the implant surface and starting the biological interactions to enhance osseointegration and stimulate bone formation with the progenitor cytokines, chemokines, and growth factors. The coagulation cascade initiates the first step of osseointegration between implant and neighboring tissues. The wound healing may be inadequate unless the blood wets the implant surface properly. Wettability is one of the most important features of the implant surface while lipid level constitutes a milestone that may change the energy of blood, which determines its distribution on implant material. Thus, the aim of this study was to evaluate the effect of lipid component of blood as cholesterol and its treatment on their wetting behavior of titanium surfaces. METHODS: Five surface groups were formed including grade 4 titanium-machined, grade 4 titanium-SLA, grade 4 titanium-SLActive, Roxolid-SLA, and Roxolid-SLActive. In healthy, hyperlipidemic, and treatment situations, blood was taken from eight rabbits and dropped to the disc surfaces. Contact angles were measured between the blood samples and disc surfaces. RESULTS: A significant difference was found between both machined and SLActive surfaces, SLA and SLActive surfaces in the hyperlipidemic period, and only Roxolid-SLA and SLActive surfaces during the treatment period. When evaluated according to time, only grade 4-machined and Grade 4-SLA surfaces showed a significant difference. CONCLUSIONS: Our findings indicated that each period has its own characteristics and showed the importance of cholesterol in blood structure on applicability of implant surfaces.
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Cortical involvement in postural control is well recognized, however the role of non-visual afferents remains unclear. Parietal cortical areas are strongly implicated in vestibulo-spatial functions, but topographical localization during balance tasks remains limited. Here, we use electroencephalography (EEG) during continuous balance tasks of increasing difficulty at single electrode positions. Twenty-four healthy, right-handed individuals performed four balance tasks of increasing difficulty (bipedal and unipedal) and a seated control condition with eyes closed. Subjective ratings of task difficulty were obtained. EEG was recorded from 32 electrodes; 5 overlying sensory and motor regions of interest (ROIs) were chosen for further investigation: C3, Cz, C4, P3, P4. Spectral power and coherence during balance tasks were analyzed in theta (4-8â¯Hz) and alpha (8-12â¯Hz) bands. Alpha power reduced as task difficulty increased and this reduction correlated with subjective difficulty ratings. Alpha coherence increased with task difficulty between C3-Cz-C4 electrode pairs. Differential changes in power were observed in Cz, suggestive of a distinct role at this electrode location, which captures lower limb cortical representation. Hemispheric asymmetry was observed, as reflected by greater reductions in theta and alpha power in right-sided areas. Our results demonstrate the functional importance of bilateral central and parietal cortices in continuous balance control. The hemispheric asymmetry observed implies that the non-dominant hemisphere is involved with online monitoring of postural control. Although the posterior parietal asymmetry found may relate to vestibular, somatosensory or multisensory feedback processing, we argue that the finding relates to active balance control rather than simple sensory-intake or reflex circuit activation.
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Encéfalo/fisiologia , Lateralidade Funcional/fisiologia , Equilíbrio Postural/fisiologia , Postura/fisiologia , Adulto , Mapeamento Encefálico , Eletroencefalografia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
BACKGROUND: The conventional radiologic features that differentiate benign from malignant bone lesions were originally described using radiography (x-ray [XR]). When evaluating sectional imaging studies such as magnetic resonance imaging (MRI) and computed tomography (CT), one may apply these principles to identify malignant bone lesions. The aim of this study was to evaluate the performances of these radiographic features for detecting malignity when applied to CT and MRI. MATERIALS AND METHODS: This retrospective study was approved by our institutional ethical board. Thirty-nine patients with histopathologic proof of a high-grade bone malignancy and preoperative imaging data obtained with a minimum of two different modalities were included in the study. Four radiologists reviewed the images and scored the lesions for distinctness of margins, presence and type of periosteal reaction, matrix mineralization, and presence of soft tissue mass. The average score for each modality was then tested for accuracy with regard to the histopathology. RESULTS: When lesion margins were considered, XR was the best modality to detect a high-grade malignancy. MRI, especially postcontrast T1-weighted sequence, was the least helpful in this regard. There was no significant difference between CT and XR and between CT and MRI. When the periosteal reaction was considered, XR was the best modality to detect the malignant type of periosteal reaction. In this regard, MRI and CT were misleading; either by not detecting or undergrading periosteal reaction. MRI was the best modality to detect soft tissue mass. CONCLUSION: Conventional imaging criteria for bone malignancy can be misleading when applied to MRI or CT. When cross-sectional imaging features contradict those from XR, the latter should be the guide for clinical management.
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Neoplasias Ósseas/diagnóstico por imagem , Adolescente , Adulto , Neoplasias Ósseas/patologia , Criança , Pré-Escolar , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Imagem Multimodal , Gradação de Tumores , Periósteo/diagnóstico por imagem , Radiografia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Adulto JovemRESUMO
This Letter presents a novel, computationally efficient interpolation method that has been optimised for use in electrocardiogram baseline drift removal. In the authors' previous Letter three isoelectric baseline points per heartbeat are detected, and here utilised as interpolation points. As an extension from linear interpolation, their algorithm segments the interpolation interval and utilises different piecewise linear equations. Thus, the algorithm produces a linear curvature that is computationally efficient while interpolating non-uniform samples. The proposed algorithm is tested using sinusoids with different fundamental frequencies from 0.05 to 0.7 Hz and also validated with real baseline wander data acquired from the Massachusetts Institute of Technology University and Boston's Beth Israel Hospital (MIT-BIH) Noise Stress Database. The synthetic data results show an root mean square (RMS) error of 0.9 µV (mean), 0.63 µV (median) and 0.6 µV (standard deviation) per heartbeat on a 1 mVp-p 0.1 Hz sinusoid. On real data, they obtain an RMS error of 10.9 µV (mean), 8.5 µV (median) and 9.0 µV (standard deviation) per heartbeat. Cubic spline interpolation and linear interpolation on the other hand shows 10.7 µV, 11.6 µV (mean), 7.8 µV, 8.9 µV (median) and 9.8 µV, 9.3 µV (standard deviation) per heartbeat.