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Piotr Kalinowski

Bio: Piotr Kalinowski is an academic researcher from Medical University of Warsaw. The author has contributed to research in topics: Liver transplantation & Medicine. The author has an hindex of 10, co-authored 33 publications receiving 504 citations.

Papers
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Journal ArticleDOI
TL;DR: A neural network-based approach for nonalcoholic fatty liver disease assessment in ultrasound that is efficient and in comparison with other methods does not require the sonographers to select the region of interest.
Abstract: The nonalcoholic fatty liver disease is the most common liver abnormality. Up to date, liver biopsy is the reference standard for direct liver steatosis quantification in hepatic tissue samples. In this paper we propose a neural network-based approach for nonalcoholic fatty liver disease assessment in ultrasound. We used the Inception-ResNet-v2 deep convolutional neural network pre-trained on the ImageNet dataset to extract high-level features in liver B-mode ultrasound image sequences. The steatosis level of each liver was graded by wedge biopsy. The proposed approach was compared with the hepatorenal index technique and the gray-level co-occurrence matrix algorithm. After the feature extraction, we applied the support vector machine algorithm to classify images containing fatty liver. Based on liver biopsy, the fatty liver was defined to have more than 5% of hepatocytes with steatosis. Next, we used the features and the Lasso regression method to assess the steatosis level. The area under the receiver operating characteristics curve obtained using the proposed approach was equal to 0.977, being higher than the one obtained with the hepatorenal index method, 0.959, and much higher than in the case of the gray-level co-occurrence matrix algorithm, 0.893. For regression the Spearman correlation coefficients between the steatosis level and the proposed approach, the hepatorenal index and the gray-level co-occurrence matrix algorithm were equal to 0.78, 0.80 and 0.39, respectively. The proposed approach may help the sonographers automatically diagnose the amount of fat in the liver. The presented approach is efficient and in comparison with other methods does not require the sonographers to select the region of interest.

164 citations

Journal ArticleDOI
TL;DR: Ghrelin levels decrease after SG and increase after RYGB, but this difference does not affect similar outcomes of these procedures during 1-year follow-up.

88 citations

Journal ArticleDOI
TL;DR: Both LSG and RYGB are comparably safe techniques with no significant differences in minor and major complication rates at 6 and 12 months of follow-up and the procedures are equally effective with regard to %EWL, reduction in BMI and amelioration of comorbidities in the Polish population.
Abstract: Introduction: Roux-en-Y gastric bypass (RYGB) is considered the gold standard bariatric procedure with documented safety and effectiveness. Laparoscopic sleeve gastrectomy (LSG) is a newer procedure being done with increasing fre - quency. Randomized comparisons of LSG and other bariatric procedures are limited. We present the results of the first prospective randomized trial comparing LSG and RYGB in the Polish population. Aim: To assess the efficacy and safety of LSG versus RYGB in the treatment of morbid obesity and obesity-related comorbidities. Material and methods: Seventy-two morbidly obese patients were randomized to RYGB (36 patients) or LSG (36 patients). Both groups were comparable regarding age, gender, body mass index (BMI) and comorbidities. The fol - low-up period was at least 12 months. Baseline and 6 and 12 month outcomes were analyzed including assessment of percent excess weight lost (%EWL), reduction in BMI, morbidity (minor, major, early and late complications), mor - tality, reoperations, comorbidities and nutritional deficiencies. Results: There was no 30-day mortality and no significant difference in major complication rate (0% after RYGB and 8.3% after LSG, p > 0.05) or minor complication rate (16.6% after RYGB and 10.1% after LSG, p > 0.05). There were no early reoperations after RYGB and 2 after LSG (5.5%) (p > 0.05). Weight loss was significant after RYGB and LSG but there was no difference between both groups at 6 and 12 months of follow-up. At 12 months %EWL in RYGB and LSG groups reached 64.2% and 67.6% respectively (p > 0.05). There was no significant difference in the overall prevalence of comorbidities and nutritional deficiencies. Conclusions: Both LSG and RYGB produce significant weight loss at 6 and 12 months after surgery. The procedures are equally effective with regard to %EWL, reduction in BMI and amelioration of comorbidities at 6 and 12 months of fol - low-up. Laparoscopic sleeve gastrectomy and RYGB are comparably safe techniques with no significant differences in minor and major complication rates at 6 and 12 months.

86 citations

Journal ArticleDOI
TL;DR: Patients with NASH undergoing RYGB are more susceptible to early transient deterioration of liver function than after SG, suggesting that rapid weight loss and mal absorption after bariatric surgery in patients with NAFLD or steatohepatitis may impair liver function.
Abstract: Objectives:The aim of the study was to compare the influence of sleeve gastrectomy (SG) versus Roux-en-Y gastric bypass (RYGB) on liver function in bariatric patients with non-alcoholic fatty liver disease (NAFLD) in a randomized clinical trial (NCT01806506).Background:Rapid weight loss and malabsor

65 citations

Journal ArticleDOI
TL;DR: Both RYGB and LSG lead to nutritional deficiencies despite different properties of operations and similar %EWL during follow-up, according to analysis of incidence and severity of malnutrition after bariatric surgery in patients submitted to RY GB or LSG during 12 months of follow- up.
Abstract: Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are the two most frequently performed bariatric operations. These two types of metabolic surgery alter the anatomy and function of digestive tract producing significant weight loss in morbidly obese patients but may lead to malnutrition. Analysis of incidence and severity of malnutrition after bariatric surgery in patients submitted to RYGB or LSG during 12 months of follow-up. Retrospective study of 98 patients after RYGB (n = 47) or LSG (n = 51) assessed for nutritional deficiencies during 12 months after surgery was conducted. The differences in body mass index (BMI) and blood tests including erythrocytes, haemoglobin, total protein, albumin, iron, ferritin, transferrin, vitamin B12, folic acid, calcium and phosphorus concentrations were compared between groups before the operations and at 1 and 12 months. Nutritional deficiencies were common before surgery with prevalence up to 19.6% for albumin in the LSG group. Median preoperative BMI levels and albumin concentrations were higher in the RYGB group compared to the LSG group, but there was no difference in percent excess weight loss (%EWL) at 1 and 12 months between LSG and RYGB. One month after LSG erythrocyte count, haemoglobin, iron, ferritin and transferrin levels were significantly higher than in the RYGB group. These differences subsided at 12 months. At 12 months, only the prevalence of vitamin B12 deficiency was significantly higher in the RYGB group. Both RYGB and LSG lead to nutritional deficiencies despite different properties of operations and similar %EWL during follow-up.

47 citations


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TL;DR: All seven RCTs comparing surgery with non-surgical interventions found benefits of surgery on measures of weight change at one to two years follow-up and Improvements for some aspects of health-related quality of life (QoL) and diabetes were also found; the overall quality of the evidence was moderate.
Abstract: Background: bariatric (weight loss) surgery for obesity is considered when other treatments have failed. The effects of the available bariatric procedures compared with medical management and with each other are uncertain. This is an update of a Cochrane review first published in 2003 and most recently updated in 2009. Objectives: to assess the effects of bariatric surgery for overweight and obesity, including the control of comorbidities. Search methods: studies were obtained from searches of numerous databases, supplemented with searches of reference lists and consultation with experts in obesity research. Date of last search was November 2013. Selection criteria: randomised controlled trials (RCTs) comparing surgical interventions with non-surgical management of obesity or overweight or comparing different surgical procedures. Data collection and analysis: data were extracted by one review author and checked by a second review author. Two review authors independently assessed risk of bias and evaluated overall study quality utilising the GRADE instrument. Main results: twenty-two trials with 1798 participants were included; sample sizes ranged from 15 to 250. Most studies followed participants for 12, 24 or 36 months; the longest follow-up was 10 years. The risk of bias across all domains of most trials was uncertain; just one was judged to have adequate allocation concealment. All seven RCTs comparing surgery with non-surgical interventions found benefits of surgery on measures of weight change at one to two years follow-up. Improvements for some aspects of health-related quality of life (QoL) (two RCTs) and diabetes (five RCTs) were also found. The overall quality of the evidence was moderate. Five studies reported data on mortality, no deaths occurred. Serious adverse events (SAEs) were reported in four studies and ranged from 0% to 37% in the surgery groups and 0% to 25% in the no surgery groups. Between 2% and 13% of participants required reoperations in the five studies that reported these data. Three RCTs found that laparoscopic Roux-en-Y gastric bypass (L)(RYGB) achieved significantly greater weight loss and body mass index (BMI) reduction up to five years after surgery compared with laparoscopic adjustable gastric banding (LAGB). Mean end-of-study BMI was lower following LRYGB compared with LAGB: mean difference (MD) -5.2 kg/m² (95% confidence interval (CI) -6.4 to -4.0; P Open RYGB, LRYGB and laparoscopic sleeve gastrectomy (LSG) led to losses of weight and/or BMI but there was no consistent picture as to which procedure was better or worse in the seven included trials. MD was -0.2 kg/m² (95% CI -1.8 to 1.3); 353 participants; 6 trials; low quality evidence) in favour of LRYGB. No statistically significant differences in QoL were found (one RCT). Six RCTs reported mortality; one death occurred following LRYGB. SAEs were reported by one RCT and were higher in the LRYGB group (4.5%) than the LSG group (0.9%). Reoperations ranged from 6.7% to 24% in the LRYGB group and 3.3% to 34% in the LSG group. Effects on comorbidities, complications and additional surgical procedures were neutral, except gastro-oesophageal reflux disease improved following LRYGB (one RCT). One RCT of people with a BMI 25 to 35 and type 2 diabetes found laparoscopic mini-gastric bypass resulted in greater weight loss and improvement of diabetes compared with LSG, and had similar levels of complications. Two RCTs found that biliopancreatic diversion with duodenal switch (BDDS) resulted in greater weight loss than RYGB in morbidly obese patients. End-of-study mean BMI loss was greater following BDDS: MD -7.3 kg/m² (95% CI -9.3 to -5.4); P One RCT comparing laparoscopic duodenojejunal bypass with sleeve gastrectomy versus LRYGB found BMI, excess weight loss, and rates of remission of diabetes and hypertension were similar at 12 months follow-up (very low quality evidence). QoL, SAEs and reoperation rates were not reported. No deaths occurred in either group. One RCT comparing laparoscopic isolated sleeve gastrectomy (LISG) versus LAGB found greater improvement in weight-loss outcomes following LISG at three years follow-up (very low quality evidence). QoL, mortality and SAEs were not reported. Reoperations occurred in 20% of the LAGB group and in 10% of the LISG group. One RCT (unpublished) comparing laparoscopic gastric imbrication with LSG found no statistically significant difference in weight loss between groups (very low quality evidence). QoL and comorbidities were not reported. No deaths occurred. Two participants in the gastric imbrication group required reoperation. Authors' conclusions: surgery results in greater improvement in weight loss outcomes and weight associated comorbidities compared with non-surgical interventions, regardless of the type of procedures used. When compared with each other, certain procedures resulted in greater weight loss and improvements in comorbidities than others. Outcomes were similar between RYGB and sleeve gastrectomy, and both of these procedures had better outcomes than adjustable gastric banding. For people with very high BMI, biliopancreatic diversion with duodenal switch resulted in greater weight loss than RYGB. Duodenojejunal bypass with sleeve gastrectomy and laparoscopic RYGB had similar outcomes, however this is based on one small trial. Isolated sleeve gastrectomy led to better weight-loss outcomes than adjustable gastric banding after three years follow-up. This was based on one trial only. Weight-related outcomes were similar between laparoscopic gastric imbrication and laparoscopic sleeve gastrectomy in one trial. Across all studies adverse event rates and reoperation rates were generally poorly reported. Most trials followed participants for only one or two years, therefore the long-term effects of surgery remain unclear.

1,228 citations

Journal ArticleDOI
TL;DR: Five pre-trained convolutional neural network-based models have been proposed for the detection of coronavirus pneumonia-infected patient using chest X-ray radiographs and it has been seen that the pre- trained ResNet50 model provides the highest classification performance.
Abstract: The 2019 novel coronavirus disease (COVID-19), with a starting point in China, has spread rapidly among people living in other countries, and is approaching approximately 34,986,502 cases worldwide according to the statistics of European Centre for Disease Prevention and Control. There are a limited number of COVID-19 test kits available in hospitals due to the increasing cases daily. Therefore, it is necessary to implement an automatic detection system as a quick alternative diagnosis option to prevent COVID-19 spreading among people. In this study, five pre-trained convolutional neural network based models (ResNet50, ResNet101, ResNet152, InceptionV3 and Inception-ResNetV2) have been proposed for the detection of coronavirus pneumonia infected patient using chest X-ray radiographs. We have implemented three different binary classifications with four classes (COVID-19, normal (healthy), viral pneumonia and bacterial pneumonia) by using 5-fold cross validation. Considering the performance results obtained, it has seen that the pre-trained ResNet50 model provides the highest classification performance (96.1% accuracy for Dataset-1, 99.5% accuracy for Dataset-2 and 99.7% accuracy for Dataset-3) among other four used models.

1,040 citations

Journal ArticleDOI
TL;DR: In this paper, five pre-trained convolutional neural network-based models were proposed for the detection of coronavirus pneumonia-infected patient using chest X-ray radiographs.
Abstract: The 2019 novel coronavirus disease (COVID-19), with a starting point in China, has spread rapidly among people living in other countries and is approaching approximately 101,917,147 cases worldwide according to the statistics of World Health Organization. There are a limited number of COVID-19 test kits available in hospitals due to the increasing cases daily. Therefore, it is necessary to implement an automatic detection system as a quick alternative diagnosis option to prevent COVID-19 spreading among people. In this study, five pre-trained convolutional neural network-based models (ResNet50, ResNet101, ResNet152, InceptionV3 and Inception-ResNetV2) have been proposed for the detection of coronavirus pneumonia-infected patient using chest X-ray radiographs. We have implemented three different binary classifications with four classes (COVID-19, normal (healthy), viral pneumonia and bacterial pneumonia) by using five-fold cross-validation. Considering the performance results obtained, it has been seen that the pre-trained ResNet50 model provides the highest classification performance (96.1% accuracy for Dataset-1, 99.5% accuracy for Dataset-2 and 99.7% accuracy for Dataset-3) among other four used models.

769 citations

Journal ArticleDOI
TL;DR: The data suggest that patients undergoing bariatric surgery should not expect a cure of OSA after surgical weight loss, and will likely need continued treatment for OSA to minimize its complications.

347 citations

Journal ArticleDOI
TL;DR: These updated clinical practice guidelines for bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity and clinical decision-making should be evidence-based within the context of a chronic disease.

302 citations