Publications by authors named "Takahiro Tsuboyama"

Purpose: To examine magnetic resonance imaging (MRI) features of mesonephric-like adenocarcinoma (MLA) of the uterine corpus.

Method: MRI features of 19 patients with pathologically proven MLA of the uterine corpus were retrospectively compared with those of 95 patients with endometrial endometrioid carcinoma (EEC).

Results: Most patients with MLA were postmenopausal.

View Article and Find Full Text PDF

Purpose: To compare the image quality and diagnostic performance of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER), reduced field-of-view (rFOV), and conventional diffusion-weighted imaging (cDWI) combined with deep learning reconstruction (DLR) for evaluating rectal tumors.

Methods: This prospective study included 42 MRI examinations of 38 patients with rectal tumors who underwent initial staging and/or restaging MRI. PROPELLER-DWI, rFOV-DWI, and cDWI obtained with DLR were reviewed by two radiologists and compared for image quality and diagnostic performance for local tumor extent at staging and restaging and response to chemoradiotherapy at restaging.

View Article and Find Full Text PDF

Objectives: To assess the MRI findings of endometrial cancer with microcystic, elongated, and fragmented (MELF) pattern invasion and to evaluate the optimal sequences to detect deep myometrial invasion with MELF.

Materials And Methods: This retrospective single-center case-control study included 85 patients with endometrial cancer, including 17 patients with MELF, between December 2020 and January 2023. Preoperative MRI, including T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) with equilibrium phase contrast-enhanced (CE) MRI were reviewed by three radiologists.

View Article and Find Full Text PDF

The objective of this article is to provide a comprehensive overview of the imaging characteristics of various renal cell tumors using 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET), based on the latest WHO-2022 classification. Due to the physiological accumulation of FDG in the kidneys, the clinical utility of FDG-PET in the evaluation of renal tumors has traditionally been considered limited. However, recent studies have re-evaluated its potential value.

View Article and Find Full Text PDF

The advances in artificial intelligence (AI) technology in recent years have been remarkable, and the field of radiology is at the forefront of applying and implementing these technologies in daily clinical practice. Radiologists must keep up with this trend and continually update their knowledge. This narrative review discusses the application of artificial intelligence in the field of musculoskeletal imaging.

View Article and Find Full Text PDF

Purpose: To investigate the age-related changes in magnetic resonance imaging (MRI) findings of lobular endocervical glandular hyperplasia (LEGH) during long-term follow-up.

Materials And Methods: This multicenter study included 91 patients who underwent preoperative MRI and had a histopathological diagnosis of LEGH, atypical LEGH, or adenocarcinoma in situ (AIS) with LEGH after surgical resection. Thirty patients underwent follow-up MRIs at intervals of more than 3 months.

View Article and Find Full Text PDF

Intramural pregnancy (IMP) is an extremely rare form of ectopic pregnancy (EP), typically associated with previous uterine trauma, adenomyosis, or assisted reproductive technology (ART), such as embryo transfer (ET). Despite its potentially life-threatening nature, the absence of definitive preoperative diagnostic criteria for IMP complicates its early detection and management, especially in patients without known risk factors. Additionally, management becomes more challenging when there is an elevated risk of hemorrhage.

View Article and Find Full Text PDF

Ventricular tachycardia (VT) is a severe arrhythmia commonly treated with implantable cardioverter defibrillators, antiarrhythmic drugs and catheter ablation (CA). Although CA is effective in reducing recurrent VT, its impact on survival remains uncertain, especially in patients with extensive scarring. Stereotactic arrhythmia radioablation (STAR) has emerged as a novel treatment for VT in patients unresponsive to CA, leveraging techniques from stereotactic body radiation therapy used in cancer treatments.

View Article and Find Full Text PDF

Purpose: The purposes of the study are to assess the diagnostic performance of preoperative imaging for staging factors in gastric-type endocervical adenocarcinoma (GEA) and to compare the performance for GEA with that of usual-type endocervical adenocarcinoma (UEA) among patients preoperatively deemed locally early stage (DLES) (< T2b without distant metastasis).

Materials And Methods: For this multi-center retrospective study, 58 patients were enrolled. All had undergone MRI with or without CT and FDG PET-CT preoperatively and had been pathologically diagnosed with GEA at five institutions.

View Article and Find Full Text PDF

In this narrative review, we review the applications of artificial intelligence (AI) into clinical magnetic resonance imaging (MRI) exams, with a particular focus on Japan's contributions to this field. In the first part of the review, we introduce the various applications of AI in optimizing different aspects of the MRI process, including scan protocols, patient preparation, image acquisition, image reconstruction, and postprocessing techniques. Additionally, we examine AI's growing influence in clinical decision-making, particularly in areas such as segmentation, radiation therapy planning, and reporting assistance.

View Article and Find Full Text PDF

Purpose: To compare image quality and visibility of anatomical structures on contrast-enhanced thin-slice abdominal CT images reconstructed using super-resolution deep learning reconstruction (SR-DLR), deep learning-based reconstruction (DLR), and hybrid iterative reconstruction (HIR) algorithms.

Materials And Methods: This retrospective study included 54 consecutive patients who underwent contrast-enhanced abdominal CT. Thin-slice images (0.

View Article and Find Full Text PDF

The integration of deep learning (DL) in breast MRI has revolutionized the field of medical imaging, notably enhancing diagnostic accuracy and efficiency. This review discusses the substantial influence of DL technologies across various facets of breast MRI, including image reconstruction, classification, object detection, segmentation, and prediction of clinical outcomes such as response to neoadjuvant chemotherapy and recurrence of breast cancer. Utilizing sophisticated models such as convolutional neural networks, recurrent neural networks, and generative adversarial networks, DL has improved image quality and precision, enabling more accurate differentiation between benign and malignant lesions and providing deeper insights into disease behavior and treatment responses.

View Article and Find Full Text PDF
Article Synopsis
  • Interventional oncology uses image-guided therapies like tumor embolization and ablation to treat malignant tumors minimally invasively, and AI is gaining traction in this field.
  • Recent literature shows a spike in studies exploring AI applications for tasks such as automatic segmentation, treatment simulation, and predicting treatment outcomes, with the latter being the most researched area.
  • Although many AI methods are still in the research phase and not widely used in clinical settings, the rapid advancements indicate that AI technologies will likely be integrated into interventional oncology practices soon.
View Article and Find Full Text PDF
Article Synopsis
  • - This review investigates the role of Large Language Models (LLMs) in nuclear medicine, particularly focusing on imaging techniques like PET and SPECT, highlighting recent advancements in both fields.
  • - It discusses current developments in nuclear medicine and how LLMs are being used in related areas like radiology for tasks such as report generation and image interpretation, with the potential to improve medical practices.
  • - Despite the promise of LLMs, challenges like reliability, explainability, and ethical concerns need to be addressed, making further research essential for integrating these technologies into nuclear medicine effectively.
View Article and Find Full Text PDF

Objectives: To create prediction models (PMs) for distinguishing between benign and malignant liver lesions using quantitative data from dual-energy CT (DECT) without contrast agents.

Materials And Methods: This retrospective study included patients with liver lesions who underwent DECT, including non-contrast-enhanced scans. Benign lesions included hepatic hemangioma, whereas malignant lesions included hepatocellular carcinoma, metastatic liver cancer, and intrahepatic cholangiocellular carcinoma.

View Article and Find Full Text PDF

Purpose: Minimal misregistration of fused PET and MRI images can be achieved with simultaneous positron emission tomography/magnetic resonance imaging (PET/MRI). However, the acquisition of multiple MRI sequences during a single PET emission scan may impair fusion precision of each sequence. This study evaluated the diagnostic utility of time-synchronized PET/MRI using an MR active trigger and a Bayesian penalized likelihood reconstruction algorithm (BPL) to assess the locoregional extension of endometrial cancer.

View Article and Find Full Text PDF
Article Synopsis
  • Placental site trophoblastic tumor (PSTT) is a rare type of tumor arising from the placenta, and this study documented MRI findings in four cases, highlighting a specific feature known as "pseudo-myometrial thinning."
  • The researchers analyzed MRIs and pathology results, measuring the thickness of myometrium (the muscular layer of the uterus) beneath the tumor compared to normal myometrium, finding that the MRI measurements showed significant thinning.
  • Results indicated that while tumors appeared to invade deeply into the myometrium on imaging, they were actually localized within the superficial layer, suggesting that MRI could misrepresent the extent of tissue invasion, potentially due to compression effects.
View Article and Find Full Text PDF
Article Synopsis
  • MRI is crucial for diagnosing pelvic issues related to organs like the prostate, bladder, and uterus, and uses RADS to standardize the process.
  • AI technologies, including machine learning, are being integrated into pelvic MRI to enhance various steps of diagnosis, especially for prostate imaging.
  • Recent multi-center studies highlight how AI can improve the effectiveness and reliability of pelvic MRI diagnostics by making findings more generalizable across different healthcare settings.
View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to assess how well 50-keV virtual monoenergetic images (VMI) can visualize abdominal arteries using photon-counting detector CT compared to 70-keV VMI.
  • Fifty patients who had abdominal scans were analyzed for signal-to-noise and contrast-to-noise ratios across various arteries, along with 3D imaging to evaluate arterial lengths and visibility.
  • Results showed that 50-keV VMI provided significantly better image quality and visibility of arterial branches than 70-keV VMI, indicating its potential benefits for clinical imaging of abdominal arteries.
View Article and Find Full Text PDF
Article Synopsis
  • * This review examines the environmental challenges associated with AI systems, such as greenhouse gas emissions from data centers and electronic waste, while also proposing solutions like energy-efficient models and renewable energy usage.
  • * It highlights the need for sustainable practices in AI deployment, suggesting policies, collaboration, and eco-friendly approaches, to ensure that AI advancements do not compromise environmental health.
View Article and Find Full Text PDF

Photon-counting CT has a completely different detector mechanism than conventional energy-integrating CT. In the photon-counting detector, X-rays are directly converted into electrons and received as electrical signals. Photon-counting CT provides virtual monochromatic images with a high contrast-to-noise ratio for abdominal CT imaging and may improve the ability to visualize small or low-contrast lesions.

View Article and Find Full Text PDF
Article Synopsis
  • Deep Learning (DL) has advanced diagnostic radiology by improving image analysis, and the introduction of Transformer architecture and Large Language Models (LLMs) has further transformed this area.* -
  • LLMs can streamline the radiology workflow, aiding in tasks like report generation and diagnostics, especially when combined with multimodal technology for enhanced applications.* -
  • However, challenges like information inaccuracies and biases remain, and radiologists need to understand these technologies better to maximize their benefits while ensuring medical safety and ethical standards.*
View Article and Find Full Text PDF