Outcomes of COVID-19 Disease in Comparison with Influenza in Renal Transplant Recipients: Results from a Large Nationwide Research Network in the United States.

COVID-19 infection has worse outcomes in immunocompromised individuals. This includes those with diabetes mellitus, cancer, chronic autoimmune diseases requiring immunomodulatory therapy, and solid-organ transplant recipients on chronic immunosuppression. Using the National Inpatient Sample Database, this study retrospectively compared 14,915 renal transplant recipients who were hospitalized with either COVID-19 or Influenza virus infection in the US at any point between 1st January 2020 and 31st December 2020. We found that compared to renal transplant recipients with influenza infection, recipients with COVID-19 infection were more likely to require mechanical ventilation and vasopressor support and develop acute kidney injury requiring hemodialysis. COVID-19 patients also had significantly longer length of hospital stay. Renal transplant recipients with COVID-19 had significantly higher in-hospital mortality compared to recipients with influenza infection (14.09% vs 2.61%, adjusted odds ratio [aOR] 9.73 [95% CI (5.74-16.52)], P < .001). Our study clearly demonstrates the severe outcomes of high mortality and morbidity in renal transplant recipients with COVID-19. Further research should be undertaken to focus on the key areas noted to reduce morbidity and mortality in this population.

Colon and Rectal Surgery Fellowship Applicant and Matching Trends in the United States: An Analysis of National Resident Matching Program Data.

BACKGROUND: Colon and Rectal Surgery fellowships are training programs that aim to train surgeons in the management of small bowel, colon, rectal, and anal pathologies. OBJECTIVE: We investigated trends in Colon and Rectal Surgery fellowship match to help applicants anticipate future fellowship application cycles. DESIGN: This was a retrospective cohort study of applicants in the Colon and Rectal Surgery match from 2009 to 2023. Proportion of positions filled, match rates, and rank-order lists were collected. The impact of US-MD, non-US-MD, and DO status on match rate was assessed. We used the Mann Kendall trend test to obtain tau statistic and P-value for temporal trends over time, while associations between categorical variables were investigated by a chi-square test. RESULTS: Fellowship programs increased from 43 to 67, positions increased from 78 to 110, and number of applicants rose from 113 to 135. Nearly all positions were filled from 2009 to 2023 (range: 96.3%-100%). The overall match rate fluctuated between 67.3% and 80.7%. The match rate over the past 5 years was 72.0%. The match rate for US-MDs was 80.0%, while non-US-MDs had a 56.2% match rate. The percentage matching at each rank were first choice 28.0%, second choice 10.4%, third choice 6.9%, and fourth choice or lower 23.5%. CONCLUSION: Despite an increase in Colon and Rectal Surgery fellowship positions, the overall match rate has not changed significantly over the years, mainly as a result of increased applicants.

Use of National Institute for Health and Care Excellence head injury guidelines among patients with delayed presentation after head trauma can lead to missed traumatic brain injury: a 5-year institutional review.

Introduction: In 2014, traumatic brain injury (TBI) caused 3 million ER visits, hospitalizations, and deaths in the US. The National Institute for Health and Care Excellence (NICE) guidelines, initially generated using data from patients presenting within 24 h of head trauma, are used to determine the need for head computed tomography (CT) scan in patients after 24 h. The authors wanted to determine the proportion of CT scans for head trauma performed at our center in late presenters (>24 h after head trauma), the incidence of intracranial pathology in early (24 h) versus late (>24 h) presenters, and the sensitivity of the NICE guidelines for TBI in these two subpopulations. Methods: A retrospective chart review was conducted at a tertiary care center in Karachi. All people (>16) who had a head CT for head trauma from 2010 to 2015 were included. Age, sex, primary diagnosis, comorbid disorders, mechanism-of-injury, duration (in hours) from head trauma to presentation, site, and extent of injury (injury severity scale), hospital stay, number and details of surgical procedures, CT scan findings, other injuries, and mortality were recorded. Means were compared using the Independent Sample t-test, while categorical variables were compared using χ2. Multivariate logistic regression analyses were used to identify TBI predictors. Results: The authors found 2009 eligible patients; seven were excluded due to incomplete medical records. The final statistical analysis comprised 2002 head trauma patients. Overall, 52% of early and late presenters had severe injuries, and 2.3% died. 32.2% of patients with head trauma had CT after 24 h. Early presenters were 46.7% traumatized, while late presenters were 63%. The NICE guidelines were 93% sensitive for early presenters and 83% for late presenters with traumatic intracranial injury. Conclusion: Patients coming to the emergency department after 24 h of head trauma are a large proportion of the overall head trauma population. The NICE guidelines for late-presenting head injuries are less sensitive and may overlook intracranial injuries if imaging is not performed.

Sonographic Characteristics and Pathology Correlation of Breast Imaging Reporting and Data System (BI-RADS) Category 4 Lesions.

INTRODUCTION: The Breast Imaging-Reporting and Database System (BI-RADS) category 4 is designated for breast lumps that do not display the typical features of malignancy but still raise enough suspicion to warrant a recommendation for a biopsy, as malignancy cannot be ruled out through imaging alone. The main objective of this study was to investigate the sonographic characteristics and pathology correlation of BI-RADS 4 breast lesions and determine the positive predictive rate of BI-RADS 4 lesions in diagnosing breast cancer, using histopathology as the gold standard. METHODS: This was a cross-sectional study conducted at the Department of Radiology, Aga Khan University Hospital in Karachi, spanning from May 2021 to August 2022, with a duration of 15 months. The study focused on female patients over the age of 18 who presented with suspicious breast lesions on ultrasound. Both mammography and ultrasound-guided core needle biopsy were performed on these patients, followed by a detailed histopathological evaluation of the biopsy specimens. To calculate the positive predictive value (PPV), true positive cases were identified through both histopathology and ultrasonography. RESULTS: A total of 227 cases were categorized as BI-RADS 4 lesions, with the patients' mean age being 47.8 ± 14.3 years (range: 17 - 88). Among the biopsied lesions, 101 cases were confirmed to be true positive for breast malignancies, resulting in a PPV for malignancy of 44.9%. Conversely, there were 124 false positive cases out of the 227 BI-RADS 4 category lesions (54.63%). The primary indication for presentation was a breast lump, and out of the 101 confirmed malignant cases, 70 (69.3%) were associated with malignancy. CONCLUSION: BI-RADS 4 can be utilized to assess suspicious breast lumps; however, for more reliable results and to avoid false negatives, histopathological confirmation should complement the imaging findings.

A Dynamically Consistent Nonstandard Difference Scheme for a Discrete-Time Immunogenic Tumors Model.

This manuscript deals with the qualitative study of certain properties of an immunogenic tumors model. Mainly, we obtain a dynamically consistent discrete-time immunogenic tumors model using a nonstandard difference scheme. The existence of fixed points and their stability are discussed. It is shown that a continuous system experiences Hopf bifurcation at one and only one positive fixed point, whereas its discrete-time counterpart experiences Neimark-Sacker bifurcation at one and only one positive fixed point. It is shown that there is no chance of period-doubling bifurcation in our discrete-time system. Additionally, numerical simulations are carried out in support of our theoretical discussion.

Deep learning techniques for liver and liver tumor segmentation: A review.

Liver and liver tumor segmentation from 3D volumetric images has been an active research area in the medical image processing domain for the last few decades. The existence of other organs such as the heart, spleen, stomach, and kidneys complicate liver segmentation and tumor identification task since these organs share identical properties in terms of shape, texture, and intensity values. Many automatic and semi-automatic techniques have been presented in recent years, in an attempt to establish a system for the reliable diagnosis and detection of liver illnesses, specifically liver tumors. With the evolution of deep learning techniques and their exceptional performance in the field of medical image processing, medical image segmentation in volumetric images using deep learning techniques has received a great deal of emphasis. The goal of this study is to provide an overview of the available deep learning approaches for segmenting liver and detecting liver tumors, as well as their evaluation metrics including accuracy, volume overlap error, dice coefficient, and mean square distance. This research also includes a detailed overview of the various 3D volumetric imaging architectures, designed specifically for the task of semantic segmentation. The comparison of approaches offered in earlier challenges for liver and tumor segmentation, as well as their dice scores derived from respective site sources, is also provided.

Erratum to: Hepatocellular carcinoma with extrahepatic blood supply from right renal artery.

[This corrects the article DOI: 10.1093/jscr/rjab391.].

Brain MR Image Enhancement for Tumor Segmentation Using 3D U-Net.

MRI images are visually inspected by domain experts for the analysis and quantification of the tumorous tissues. Due to the large volumetric data, manual reporting on the images is subjective, cumbersome, and error prone. To address these problems, automatic image analysis tools are employed for tumor segmentation and other subsequent statistical analysis. However, prior to the tumor analysis and quantification, an important challenge lies in the pre-processing. In the present study, permutations of different pre-processing methods are comprehensively investigated. In particular, the study focused on Gibbs ringing artifact removal, bias field correction, intensity normalization, and adaptive histogram equalization (AHE). The pre-processed MRI data is then passed onto 3D U-Net for automatic segmentation of brain tumors. The segmentation results demonstrated the best performance with the combination of two techniques, i.e., Gibbs ringing artifact removal and bias-field correction. The proposed technique achieved mean dice score metrics of 0.91, 0.86, and 0.70 for the whole tumor, tumor core, and enhancing tumor, respectively. The testing mean dice scores achieved by the system are 0.90, 0.83, and 0.71 for the whole tumor, core tumor, and enhancing tumor, respectively. The novelty of this work concerns a robust pre-processing sequence for improving the segmentation accuracy of MR images. The proposed method overcame the testing dice scores of the state-of-the-art methods. The results are benchmarked with the existing techniques used in the Brain Tumor Segmentation Challenge (BraTS) 2018 challenge.

Machine learning classification of texture features of MRI breast tumor and peri-tumor of combined pre- and early treatment predicts pathologic complete response.

PURPOSE: This study used machine learning classification of texture features from MRI of breast tumor and peri-tumor at multiple treatment time points in conjunction with molecular subtypes to predict eventual pathological complete response (PCR) to neoadjuvant chemotherapy. MATERIALS AND METHOD: This study employed a subset of patients (N = 166) with PCR data from the I-SPY-1 TRIAL (2002-2006). This cohort consisted of patients with stage 2 or 3 breast cancer that underwent anthracycline-cyclophosphamide and taxane treatment. Magnetic resonance imaging (MRI) was acquired pre-neoadjuvant chemotherapy, early, and mid-treatment. Texture features were extracted from post-contrast-enhanced MRI, pre- and post-contrast subtraction images, and with morphological dilation to include peri-tumoral tissue. Molecular subtypes and Ki67 were also included in the prediction model. Performance of classification models used the receiver operating characteristics curve analysis including area under the curve (AUC). Statistical analysis was done using unpaired two-tailed t-tests. RESULTS: Molecular subtypes alone yielded moderate prediction performance of PCR (AUC = 0.82, p = 0.07). Pre-, early, and mid-treatment data alone yielded moderate performance (AUC = 0.88, 0.72, and 0.78, p = 0.03, 0.13, 0.44, respectively). The combined pre- and early treatment data markedly improved performance (AUC = 0.96, p = 0.0003). Addition of molecular subtypes improved performance slightly for individual time points but substantially for the combined pre- and early treatment (AUC = 0.98, p = 0.0003). The optimal morphological dilation was 3-5 pixels. Subtraction of post- and pre-contrast MRI further improved performance (AUC = 0.98, p = 0.00003). Finally, among the machine-learning algorithms evaluated, the RUSBoosted Tree machine-learning method yielded the highest performance. CONCLUSION: AI-classification of texture features from MRI of breast tumor at multiple treatment time points accurately predicts eventual PCR. Longitudinal changes in texture features and peri-tumoral features further improve PCR prediction performance. Accurate assessment of treatment efficacy early on could minimize unnecessary toxic chemotherapy and enable mid-treatment modification for patients to achieve better clinical outcomes.

Morel-Lavallée Lesion in a 35-year Female.

Morel-Lavallée lesion is a post-traumatic degloving cyst, usually filled with blood, lymph or necrotic tissue, which mostly develops in the area around greater trochanter. Early diagnosis and prompt treatment is essential to prevent further complications, such as compression of surrounding structures. X-rays have limited use and magnetic resonance imaging (MRI) is the modality of choice in diagnosing the lesion. We report a case of a 35-year female presenting with left thigh pain after a fall from motorcycle almost 21/2 years ago. Ultrasound and MRI confirmed the presence of Morel-Lavallée lesion involving the left pelvis and upper thigh. Given the chronicity of lesion and extensive tissue involvement, the patient underwent surgical excision of the lesion with favourable long-term outcomes. In this case report and literature review, we discuss the pathophysiology, clinical presentation, radiological findings and management options for Morel-Lavallée lesion. Key Words: Morel-Lavallée lesion, Post-traumatic cyst, Degloving Injury, Tangential cyst.

Glomuvenous Malformation of the Neck.

The cells in glomus body regulate blood flow to the skin and play a role in temperature regulation. Glomuvenous malformations (GVMs), previously reported in literature as glomus tumors or glomangiomas, are usually present in the nail bed. In 1972, Carroll and Berman described the triad of paroxysmal stabbing pain, point tenderness, and cold hypersensitivity associated with these malformations. We present an unusual case of GVM in the neck of a 17-year-old female presenting with a painful right-sided neck mass. Physical examination revealed an approximately 2.5 × 2 cm right-sided tender neck mass; pain was exacerbated by probing with a pinhead. Computed tomography identified multiple rounded masses in the neck, with the delayed contrast filling. The patient underwent excisional biopsy of the lesion and samples were sent for histopathological examination. The histopathology report, along with the radiological findings and the clinical presentation, confirmed the diagnosis of GVM. The patient remained symptom-free on long-term follow-up. Despite absence of previous reports, GVM can occur in neck. Surgical excision can lead to complete resolution of symptoms.

Primary esophageal tuberculosis mimicking esophageal carcinoma on computed tomography: A case report.

BACKGROUND: Tuberculosis (TB) has a rare extrapulmonary manifestation known as esophageal tuberculosis, accounting for 0.2% of total TB patients. Esophageal TB typically presents with dysphagia, with retrosternal pain or odynophagia, but generalized symptoms such as low-grade fever, decreased appetite, and weight loss are also observed. Esophageal carcinoma and Crohn's disease of the esophagus are important differential diagnoses with similar presentation. CASE SUMMARY: We present a case of a 25-year-old male, who presented with esophageal TB mimicking an esophageal carcinoma. Lab work-up, Mantoux test, and chest X-ray were normal. Barium-swallow examination showed moderate dilatation of distal esophagus with a nodular and irregular mucosa. Computed tomography showed significant thickening of thoracic and distal esophagus with infiltration into the lesser omentum and large, centrally necrotic lymph nodes on gastro-hepatic ligament suggestive of a possible malignancy. Esophagoscopy was performed and a biopsy of mural thickening was performed and sent for histopathological examination. The histopathology report and TB-polymerase chain reaction confirmed the diagnosis of esophageal TB. The patient was started on anti-tuberculous therapy (ATT), and complete resolution of symptoms and disease was achieved in 6 mo. CONCLUSION: Esophageal TB is an extremely rare, yet important differential diagnosis in a patient presenting with dysphagia. Esophageal TB can mimic esophageal carcinoma on computed tomography scan. The patient responded well to a complete course of ATT.

Primary intracranial extraosseous Ewing's sarcoma.

INTRODUCTION: Common sites of occurrence of extraosseous Ewing's sarcoma include the soft tissues and bones of the lower extremity, 12 paravertebral, and retroperitoneal regions. Primary intracranial Ewing's sarcoma/pPNET is usually intraparenchymal located 13 when supratentorially, and an extraaxial epidural tumor radiographically mimicking a meningioma is extremely rare. CASE PRESENTATION: A 20-year14 old male presented to the emergency department with a 1-day history of drowsiness, headache, and fever. Neurological exam15 ination revealed decreased muscle strength (4/5) in the left lower limb. Head computed tomography scan showed an epidural 16 space-occupying lesion in the right temporoparietal region, which was assumed to be a meningioma by radiographic criteria. However, the surgical specimen was diagnosed as Ewing's sarcoma. CONCLUSION: Primary intracranial extraosseous Ewing's sarcoma is a rare condition that may mimic a meningioma on imaging. Physicians must be cognizant of this possibility, particularly in any young individual with a solitary contrast-enhancing dural-based lesion.

Enteroenteric Fistulae in Acute Bowel Ischemia.

Gastrointestinal fistulae are classified as enteroenteric or enterocutaneous. Most gastrointestinal fistulae are formed after surgical procedures for inflammatory bowel disease or malignancy. For spontaneous enteroenteric fistulae, ischemia has been reported as a possible etiology. We report two cases of spontaneous enteroenteric fistulae arising after bowel ischemia; a 38-year male with a 10-day history of severe abdominal pain with fever and vomiting, and a 22-year female with a one-week history of abdominal pain and diarrhea. Arterial and venous thrombi in association with enteroenteric fistulae were identified on computed tomography. These cases point towards acute mesenteric ischemia as a rare cause of spontaneous enteroenteric fistulae. Surgical management of these fistulae can be effective in resolving this complication.

Dopamine Detection using Mercaptopropionic Acid and Cysteamine for Electrodes Surface Modification.

Gold electrodes are often not suitable for dopamine measurements as dopamine creates a non-conducting polymer layer on the surface of the electrodes, which leads to increased amount of electrode passivity with the gradual increase in voltammograms measurement. This work presents the impedance spectroscopy and cyclic-voltammetry comparative study for dopamine detection with two modifications for the surface of Au electrodes; cysteamine and mercaptopropionic acid for thermally bonded and ultrasonically welded microfluidic chips, respectively. The effects of optimized tubing selection, bonding techniques, and cleaning methods of the devices with KOH solution played crucial role for improvements in dopamine detection, which are observed in the results. Furthermore, comparison for the modification with unmodified chips, and finding the unknown concentration of dopamine solution using flow injection techniques, is also illustrated.

Design and Simulation of Microfluidic Device for Metabolite Screening and Quantitative Monitoring of Drug Uptake in Cancer Cells.

Although liquid-liquid extraction methods are currently being applied in many areas such as analytical chemistry, biochemical engineering, biochemistry, and biological applications, accessibility and usability of microfluidics in practical daily life fields are still bounded. Suspended microfluidic devices have the potential to lessen the obstacles, but the absence of robust design rules have hampered their usage. The primary objective of this work is to design and fabricate a microfluidic device to quantitatively monitor the drug uptake of cancer cells. Liquid-liquid extraction is used to quantify the drug uptake. In this research work, designs and simulations of two different microfluidic devices for carrying out multiplex solution experiments are proposed to test their efficiency. These simplified miniaturized chips would serve as suspended microfluidic metabolites extraction platform as it allows extracting the metabolites produced from the cancer cells as a result of applying a specific drug type for a certain period of time. These devices would be fabricated by making polydimethylsiloxane (PDMS) molds from the negative master mold using soft lithography. Furthermore, it can leverage to provide versatile functionalities like high throughput screening, cancer cell invasions, protein purification, and small molecules extractions. As per previous studies, PDMS has been depicting better stability with various solvents and has proved to be a reliable and cost effective material to be used for fabrication, though the sensitivity of the chip would be analyzed by cross contamination and of solvents within the channels of device.

Diagnostic Accuracy of Ultrasound in Detecting Retained Products of Conception: A Study from a Tertiary Care Hospital in Karachi, Pakistan.

Introduction Retained products of conception (RPOC) are a known complication after abortion or childbirth. To improve clinical evaluation and avoid unnecessary surgery, transvaginal scan is performed in suspected cases. However, both RPOC and blood clots appear isoechoic on ultrasound, and false positives can lead to unnecessary intervention. In this study, the ultrasound findings have been correlated with the histopathology (as a gold standard) to determine the diagnostic value of sonography in the detection of RPOC in postpartum or post-abortion patients. Methods This cross-sectional study was carried out to determine the diagnostic accuracy of ultrasound in the detection of the retained products of conception in relation with the histopathological findings at the Department of Radiology, Aga Khan University Hospital (AKUH), Karachi. A total of 193 patients with suspicion of RPOC undergoing a transvaginal scan in the Department of Radiology, AKUH, were enrolled. The study was conducted for a period of 12 months from October 2014 to October 2015. Results Our results yielded that out of 193 cases, 113 cases (87.05%) had histopathology positive for RPOC, while 107 (55.44%) RPOC cases were identified by ultrasound as having RPOC. The mean endometrial thickness of the patients included in the study was 13.5 mm. According to our results, ultrasound has a sensitivity of 75.22%, specificity of 72.50%, a positive predictive value (PPV) of 79.44%, a negative predictive value (NPV) of 67.44%, and a diagnostic accuracy of 74.09%. Conclusion Transvaginal ultrasound is a modality that can be used for early diagnosis of the retained products of conception including fetal parts and could prove to be lifesaving. However, the operator and equipment variables need to be looked at, and a uniform criterion needs to be agreed on.

Chest Wall Schwannoma: Case Report and a Review of Imaging Findings.

A chest wall schwannoma arises from peripheral nerve sheath Schwann cells of the intercostal nerves. We describe the presentation and imaging findings of a patient who presented with a chest wall swelling. The imaging findings were highly suspicious for a chest wall schwannoma and the histopathology confirmed the diagnosis following surgical excision. Imaging findings are reviewed in detail.