Publications by authors named "Antonios Tzortzakakis"

Background High-quality translations of radiology reports are essential for optimal patient care. Because of limited availability of human translators with medical expertise, large language models (LLMs) are a promising solution, but their ability to translate radiology reports remains largely unexplored. Purpose To evaluate the accuracy and quality of various LLMs in translating radiology reports across high-resource languages (English, Italian, French, German, and Chinese) and low-resource languages (Swedish, Turkish, Russian, Greek, and Thai).

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β-amyloid (Aβ) pathology is not always coupled with Alzheimer's disease (AD) relevant cognitive decline. We assessed the accuracy of tau PET to identify Aβ(+) individuals who show prospective disease progression. 396 cognitively unimpaired and impaired individuals with baseline Aβ and tau PET and a follow-up of ≥ 2 years were selected from the Alzheimer's Disease Neuroimaging Initiative dataset.

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Article Synopsis
  • The study focuses on developing a machine-learning model to predict anastomotic leakage (AL) after esophagectomy for esophageal cancer, as this complication poses significant risks post-surgery.
  • 471 patients' preoperative CT and clinical data were analyzed to create and test the model using an XGBoost algorithm, with performance metrics measured using ROC curves.
  • The model showed a noteworthy accuracy, achieving a 79.2% area under the curve, which can aid in identifying patients at risk of AL, particularly where clinical indicators suggest low probability.*
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  • Fibroblast activation protein (FAPI) is gaining attention as a target for imaging various cancers using radiolabeled inhibitors, but no clear imaging protocols have been established yet.
  • This study aimed to determine if the time required for FAPI PET/CT imaging could be shortened from 4 minutes to 3 minutes per bed position without compromising image quality or diagnostic capability.
  • Results showed that while images taken at 3 minutes had acceptable quality, those taken at 1 and 2 minutes were significantly worse than those at 4 minutes, indicating that a reduction in acquisition time could be feasible but with limits to maintain image integrity.
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Patients with HER2-low metastatic breast cancer (mBC), defined as an immunohistochemistry (IHC) score of 1+ or 2+ without HER2 gene amplification, may benefit from HER2 antibody-drug conjugates. Identifying suitable candidates is a clinical challenge because of spatial and temporal heterogeneity in HER2 expression and discrepancies in pathologic reporting. We aimed to investigate the feasibility and safety of HER2-specific PET imaging with [Ga]Ga-ABY-025 for visualization of HER2-low mBC.

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Objectives: To increase understanding of optimal imaging parameters [ 18 F]PSMA-1007 when imaging patients with prostate cancer and to determine interrater agreement using [ 18 F]PSMA-1007.

Methods: In this observational study, four independent physicians read reconstruction sets using bedtimes of 1, 2 and 3 minutes of patients undergoing [ 18 F]PSMA-1007. positron emission topography.

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Objectives: To use convolutional neural networks (CNNs) for the differentiation between benign and malignant renal tumors using contrast-enhanced CT images of a multi-institutional, multi-vendor, and multicenter CT dataset.

Methods: A total of 264 histologically confirmed renal tumors were included, from US and Swedish centers. Images were augmented and divided randomly 70%:30% for algorithm training and testing.

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Purpose: To determine the relationship between postoperative C-reactive protein (CRP) as an early indicator of anastomotic leakage (AL) after esophagectomy for esophageal cancer.

Methods: We reviewed patients diagnosed with esophageal or esophagogastric junctional cancer who underwent esophagectomy between 2006 and 2022 at the Karolinska University Hospital, Stockholm, Sweden. Multivariable logistic regression models estimated relative risk for AL by calculating the odds ratio (OR) with a 95% confidence interval (CI).

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Background: Masticatory parameters, such as reduced number of teeth and posterior contacts, have been shown to be associated with reduced cognitive status. The underlying mechanisms that affect these associations, are however, not well understood.

Objectives: The study aims to investigate the association between masticatory dysfunction and cognition and explore the mediating effect of brain structure.

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Differentiating benign renal oncocytic tumors and malignant renal cell carcinoma (RCC) on imaging and histopathology is a critical problem that presents an everyday clinical challenge. This manuscript aims to demonstrate a novel methodology integrating metabolomics with radiomics features (RF) to differentiate between benign oncocytic neoplasia and malignant renal tumors. For this purpose, thirty-three renal tumors (14 renal oncocytic tumors and 19 RCC) were prospectively collected and histopathologically characterised.

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Article Synopsis
  • The study aims to enhance the diagnosis of oncocytic renal tumors using a combined approach of radiomics analysis and Tc Sestamibi SPECT/CT imaging to distinguish benign tumors from more aggressive renal cell carcinoma.
  • A total of 57 renal tumors were analyzed, and the combined SPECT/radiomics model showed superior diagnostic accuracy (95%) compared to both the radiomics-only (71.67%) and visual evaluation of SPECT/CT alone (90.8%).
  • The results suggest that incorporating radiomics with SPECT/CT imaging can significantly improve preoperative assessment, with the Tc Sestamibi uptake being the most critical factor in achieving better diagnostic performance and reducing false positives and negatives.
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Multiple myeloma (MM) is one of the most common hematological malignancies affecting the bone marrow. Radiomics analysis has been employed in the literature in an attempt to evaluate the bone marrow of MM patients. This manuscript aimed to systematically review radiomics research on MM while employing a radiomics quality score (RQS) to accurately assess research quality in the field.

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Background: Expanding therapeutic possibilities have improved disease-related prospects for breast cancer patients. Pathological analysis on a tumor biopsy is the current reference standard biomarker used to select for treatment with targeted anticancer drugs. This method has, however, several limitations, related to intra- and intertumoral as well as spatial heterogeneity in receptor expression as well as the need to perform invasive procedures that are not always technically feasible.

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Predicting brain aging can help in the early detection and prognosis of neurodegenerative diseases. Longitudinal cohorts of healthy subjects scanned through magnetic resonance imaging (MRI) have been essential to understand the structural brain changes due to aging. However, these cohorts suffer from missing data due to logistic issues in the recruitment of subjects.

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Breast cancer is the most common form of cancer among women in Sweden. Several decades ago it was recognized that the Human epidermal growth factor receptor 2 (HER2) is involved in a critical growth system for breast cancer cells. Overexpression of HER2 (immunohistochemistry [IHC] 2+/3+, in situ hybridization [ISH] positive) is present in 15 percent of all breast cancers.

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Objectives: To compare the dynamic changes in future liver remnant (FLR) function and volume after hepatectomy and to evaluate the associations between three modalities in assessment of liver function.

Methods: Liver function and volume were quantified pre-operatively, at post-operative day (POD) 7 and POD 28 in 10 patients with colorectal liver metastases undergoing hemihepatectomy using the indocyanine green retention (ICG) test, hepatobiliary scintigraphy (HBS) and gadoxetic acid-enhanced MRI. The Tc mebrofenin uptake rate in the FLR was applied as a reference of liver function.

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Background: Tc-Sestamibi Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) contributes to the non-invasive differentiation of renal oncocytoma (RO) from renal cell carcinoma (RCC) by characterising renal tumours as Sestamibi positive or Sestamibi negative regarding their Tc-Sestamibi uptake compared to the non-tumoral renal parenchyma.

Purpose: To determine whether Tc- Sestamibi uptake in renal tumour and the non-tumoral renal parenchyma measured using Standard Uptake Value (SUV) SPECT, has a beneficial role in differentiating RO from RCC.

Material And Methods: Fifty-seven renal tumours from 52 patients were evaluated.

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Background: This is the study plan of the Karolinska NeuroCOVID study, a study of neurocognitive impairment after severe COVID-19, relating post-intensive care unit (ICU) cognitive and neurological deficits to biofluid markers and MRI. The COVID-19 pandemic has posed enormous health challenges to individuals and health-care systems worldwide. An emerging feature of severe COVID-19 is that of temporary and extended neurocognitive impairment, exhibiting a myriad of symptoms and signs.

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Surgical resection of the esophagus remains a critical component of the multimodal treatment of esophageal cancer. Anastomotic leakage (AL) is the most significant complication following esophagectomy, in terms of clinical implications. Identifying risk factors for AL is important for modifying patient management and improving surgical outcomes.

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Background: Definite noninvasive characterisation of renal tumours positive on Tc-sestamibi single photon emission computed tomography/computed tomography (SPECT/CT) examination including renal oncocytomas (ROs), hybrid oncocytic chromophobe tumours (HOCTs), and chromophobe renal cell carcinoma (chRCC) is currently not feasible.

Objective: To investigate whether combined Tc-sestamibi SPECT/CT and in situ metabolomic profiling can accurately characterise renal tumours exhibiting Tc-sestamibi uptake.

Design Setting And Participants: A tissue microarray analysis of 33 tumour samples from 28 patients was used to investigate whether their in situ metabolomic status correlates with their features on Tc-sestamibi SPECT/CT examination.

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Definitive, pre-operative differentiation of solid renal lesions by ultrasound, contrast-enhanced multiphasic CT or MRI examinations is often not possible. An increasing amount of literature indicates the added value of Tc-Sestamibi SPECT/CT, CT perfusion and contrast-enhanced ultrasound in the pre-operative characterisation of solid renal tumours. This case report presents the diagnostic approach of a solid renal tumour that turned out to be a hybrid oncocytic chromophobe tumour in a patient with Stage 3 renal failure by combining the three aforementioned modern examination techniques.

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To optimize diagnostic workup of the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, we systematically reviewed neurological and neuroradiological manifestations of SARS-CoV-2 and all other known human coronavirus species (HCoV). Which lessons can we learn? We identified relevant publications (until 26 July 2020) using systematic searches in PubMed, Web of Science, and Ovid EMBASE with predefined search strings. A total of 4571 unique publications were retrieved, out of which 378 publications were selected for in-depth analysis by two raters, including a total of 17549 (out of which were 14418 SARS-CoV-2) patients.

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Background Neurologic complications in coronavirus disease 2019 (COVID-19) have been described, but the understanding of their pathophysiologic causes and neuroanatomical correlates remains limited. Purpose To report on the frequency and type of neuroradiological findings in COVID-19. Materials and Methods In this retrospective study, all consecutive adult hospitalized patients with polymerase chain reaction positivity for severe acute respiratory syndrome coronavirus 2 and who underwent neuroimaging at Karolinska University Hospital between March 2 and May 24, 2020, were included.

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Quantification tools for SPECT/CT are a field of ongoing research among hybrid imaging techniques. A recent multicenter study evaluating SUV SPECT software on phantoms showed that quantitative SPECT/CT is reproducible in Hybrid Viewer software. The aim of our study was to evaluate the intra- and interobserver agreement of quantitative SUV SPECT measurements in clinical settings for patients with solid renal tumors.

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Purpose To develop and evaluate a triple arterial phase CT liver protocol with a similar radiation dose to that of standard single arterial phase CT in study subjects suspected of having hepatocellular carcinoma (HCC). Materials and Methods The study consisted of a retrospective part A for protocol development (n = 15) and a prospective part B to evaluate diagnostic accuracy (n = 38). All 53 participants underwent perfusion CT with 50 mL contrast material between August 2013 and September 2014.

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