Publications by authors named "Hiroyuki Uetani"

Subependymoma is a benign, slow-growing tumor that arises from the ventricular wall. Although often asymptomatic, it can obstruct cerebrospinal fluid flow, leading to hydrocephalus. Most subependymomas are unilateral, typically located in the fourth ventricle, followed by the lateral ventricles.

View Article and Find Full Text PDF

Objective: Aimed to evaluate the potential of large language models (LLMs) in differentiating intra-axial primary brain tumors using structured magnetic resonance imaging (MRI) reports and compare their performance with radiologists.

Materials And Methods: Structured reports of preoperative MRI findings from 137 surgically confirmed intra-axial primary brain tumors, including Glioblastoma (n = 77), Central Nervous System (CNS) Lymphoma (n = 22), Astrocytoma (n = 9), Oligodendroglioma (n = 9), and others (n = 20), were analyzed by multiple LLMs, including GPT-4, Claude-3-Opus, Claude-3-Sonnet, GPT-3.5, Llama-2-70B, Qwen1.

View Article and Find Full Text PDF

Background And Purpose: To evaluate the effects of super-resolution deep learning-based reconstruction (SR-DLR) on thin-slice T2-weighted hippocampal MR image quality using 3 T MRI, in both human volunteers and phantoms.

Materials And Methods: Thirteen healthy volunteers underwent hippocampal MRI at standard and high resolutions. Original (standard-resolution; StR) images were reconstructed with and without deep learning-based reconstruction (DLR) (Matrix = 320 × 320), and with SR-DLR (Matrix = 960 × 960).

View Article and Find Full Text PDF

Gastric neuroendocrine carcinoma (small cell neuroendocrine carcinoma [small cell NEC]) is a rare type of gastric cancer that is rarely encountered in clinical practice. Although solitary brain metastasis from gastric cancer is exceptionally rare, we present a case of solitary brain metastasis of gastric NEC. The patient was a 71-year-old man who had undergone surgery and chemotherapy for gastric NEC two years prior.

View Article and Find Full Text PDF

Rationale And Objectives: This study evaluates the performance, cost, and processing time of OpenAI's reasoning large language models (LLMs) (o1-preview, o1-mini) and their base models (GPT-4o, GPT-4o-mini) on Japanese radiology board examination questions.

Materials And Methods: A total of 210 questions from the 2022-2023 official board examinations of the Japan Radiological Society were presented to each of the four LLMs. Performance was evaluated by calculating the percentage of correctly answered questions within six predefined radiology subspecialties.

View Article and Find Full Text PDF

Background: This study aimed to optimize the fusion of quantitative maps and morphological images to improve late iodine enhancement (LIE) imaging using cardiac dual-energy computed tomography (DECT).

Methods And Results: We retrospectively analyzed 15 patients with suspected old myocardial infarction who underwent cardiac DECT. Virtual monochromatic images (VMI) ranging from 40 to 200 keV and quantitative maps (e.

View Article and Find Full Text PDF

Purpose: Pituitary abscess is a rare condition that can be challenging to distinguish from other sellar cystic lesions (OSCLs) due to no specific symptoms and overlapping imaging features. Accurate differentiation is crucial for appropriate treatment planning. This study aimed to evaluate the usefulness of 3T split acquisition fast spin-echo diffusion-weighted imaging (SPLICE-DWI) in differentiating pituitary abscesses from OSCLs.

View Article and Find Full Text PDF

Objective: Duplication of extracranial cerebral arteries is a rare anatomical variant, most commonly observed in the vertebral artery. However, duplication of the cervical internal carotid artery (ICA) is extremely rare. We present a unique case of a patient diagnosed with a right facial artery aneurysm, in whom a right duplicated ICA, ipsilateral persistent stapedial artery (PSA), and contralateral aberrant ICA were incidentally identified.

View Article and Find Full Text PDF

Spinal arteriovenous fistula (SAVF), including spinal dural arteriovenous fistula and spinal extradural arteriovenous fistula (SEAVF), is a rare spinal vascular disorder characterized by abnormal intradural and extradural arteriovenous shunting, often resulting in progressive motor, sensory, and autonomic dysfunction. Due to its nonspecific presentation and overlapping imaging findings with other spinal diseases, SAVF is frequently misdiagnosed, delaying appropriate treatment and increasing the risk of neurological deterioration. Here, we present a case in which heavily T2-weighted imaging and dynamic contrast-enhanced magnetic resonance angiography at 3T were valuable for the diagnosis of SEAVF.

View Article and Find Full Text PDF

Objective: This preliminary study aims to assess the image quality of enhanced-resolution deep learning reconstruction (ER-DLR) in magnetic resonance cholangiopancreatography (MRCP) and compare it with non-ER-DLR MRCP images.

Methods: Our retrospective study incorporated 34 patients diagnosed with biliary and pancreatic disorders. We obtained MRCP images using a single breath-hold MRCP on a 3T MRI system.

View Article and Find Full Text PDF

Objective: Discriminating between hemorrhage and iodine extravasation can pose challenges in conventional computed tomography (CCT) images following preoperative embolization for meningioma. This study aimed to assess the efficacy of dual-energy computed tomography (DECT) in differentiating hemorrhage from iodine extravasation after preoperative embolization for meningioma.

Methods: Twenty-one consecutive meningioma patients who underwent CCT before and DECT immediately after preoperative embolization were included in this study.

View Article and Find Full Text PDF

Purpose: In the 2016 WHO Classification of Lymphoid Tissue Neoplasms, co-expression of MYC and BCL2 is newly designated as double expressor lymphoma. Patients with primary central nervous system lymphoma with double expressor (DE-PCNSL) have been reported to have a higher risk of recurrence and a worse prognosis than those with PCNSL without double expressor (non-DE-PCNSL). The aim of this study was to determine whether DE-PCNSL has characteristic clinical and MR imaging features compared to non-DE-PCNSL.

View Article and Find Full Text PDF

Purposes: This study aimed to assess the effectiveness of Super-Resolution Deep Learning Reconstruction (SR-DLR) -a deep learning-based technique that enhances image resolution and quality during MRI reconstruction- in improving the image quality of thin-slice 3D T2-weighted imaging (T2WI) and Prostate Imaging-Reporting and Data System (PI-RADS) assessment in prostate Magnetic Resonance Imaging (MRI).

Methods: This retrospective study included 33 patients who underwent prostate MRI with SR-DLR between November 2022 and April 2023. Thin-slice 3D-T2WI of the prostate was obtained and reconstructed with and without SR-DLR (matrix: 720 × 720 and 240 × 240, respectively).

View Article and Find Full Text PDF

Background: This study aimed to determine whether spectral imaging with dual-energy computed tomography (CT) can improve diagnostic performance for coronary plaque characterization.

Methods And Results: We conducted a retrospective analysis of 30 patients with coronary plaques, using coronary CT angiography (dual-layer CT) and intravascular ultrasound (IVUS) studies. Based on IVUS findings, patients were diagnosed with either vulnerable or stable plaques.

View Article and Find Full Text PDF

Purpose: The purpose of this study is to estimate the extent to which the implementation of deep learning reconstruction (DLR) may reduce the risk of radiation-induced cancer from CT examinations, utilizing real-world clinical data.

Methods: We retrospectively analyzed scan data of adult patients who underwent body CT during two periods relative to DLR implementation at our facility: a 12-month pre-DLR phase (n = 5553) using hybrid iterative reconstruction and a 12-month post-DLR phase (n = 5494) with routine CT reconstruction transitioning to DLR. To ensure comparability between two groups, we employed propensity score matching 1:1 based on age, sex, and body mass index.

View Article and Find Full Text PDF

Rationale And Objectives: To evaluate the performance of various multimodal large language models (LLMs) in the Japanese Diagnostic Radiology Board Examinations (JDRBE) both with and without images.

Materials And Methods: Five multimodal LLMs-GPT-4o, Claude 3 Opus, GPT-4 Vision, Gemini Flash 1.5, and Gemini Pro 1.

View Article and Find Full Text PDF
Article Synopsis
  • Efficient communication is essential for managing high-risk incidental CT findings (ICTFs), and a new system called APCFS was introduced for better coordination between radiologists and ordering clinicians.
  • The study analyzed 52,331 CT scans from 2019 to 2021, finding that 507 cases (about 1%) had high-risk ICTFs, predominantly affecting the lungs, with many requiring follow-up or therapeutic interventions.
  • Key risk factors linked to these high-risk findings included specific imaging protocols, the area being imaged, and the clinical department involved, such as cardiology.
View Article and Find Full Text PDF

Objectives: This study aims to assess the effectiveness of super-resolution deep-learning-based reconstruction (SR-DLR), which leverages k-space data, on the image quality of lumbar spine magnetic resonance (MR) bone imaging using a 3D multi-echo in-phase sequence.

Materials And Methods: In this retrospective study, 29 patients who underwent lumbar spine MRI, including an MR bone imaging sequence between January and April 2023, were analyzed. Images were reconstructed with and without SR-DLR (Matrix sizes: 960 × 960 and 320 × 320, respectively).

View Article and Find Full Text PDF

Objective: The purpose of this study was to evaluate the usefulness of the injection pressure-to-injection rate (IPIR) ratio for the early detection of contrast extravasation at the venipuncture site during contrast-enhanced computed tomography.

Methods: We retrospectively enrolled 57,528 patients who underwent contrast-enhanced computed tomography examinations in a single hospital. The power injector recorded the contrast injection pressure at 0.

View Article and Find Full Text PDF
Article Synopsis
  • The study evaluates various catheter techniques used to completely occlude different types of renal arteriovenous malformations (rAVMs) in 18 patients over 11 years, analyzing outcomes based on specific classification criteria.
  • Among the patients, 83% achieved complete rAVM occlusion, with some experiencing asymptomatic small renal infarctions, but no major complications were reported.
  • All patients with symptoms saw improvement, and there were no cases of recurrence or growth of the rAVMs during a follow-up period averaging 32 months.
View Article and Find Full Text PDF

Purpose: We aimed to evaluate the effect of deep learning-based reconstruction (DLR) on high-spatial-resolution three-dimensional T2-weighted fast asymmetric spin-echo (HR-3D T2-FASE) imaging in the preoperative evaluation of cerebellopontine angle (CPA) tumors.

Methods: This study included 13 consecutive patients who underwent preoperative HR-3D T2-FASE imaging using a 3 T MRI scanner. The reconstruction voxel size of HR-3D T2-FASE imaging was 0.

View Article and Find Full Text PDF

Objective: The aim of this study was to assess the utility of the combined use of 3D wheel sampling and deep learning-based reconstruction (DLR) for intracranial high-resolution (HR)-time-of-flight (TOF)-magnetic resonance angiography (MRA) at 3 T.

Methods: This prospective study enrolled 20 patients who underwent head MRI at 3 T, including TOF-MRA. We used 3D wheel sampling called "fast 3D" and DLR for HR-TOF-MRA (spatial resolution, 0.

View Article and Find Full Text PDF
Article Synopsis
  • * This study analyzed 23 patients who underwent stereotactic radiotherapy (SRT) after surgery for craniopharyngiomas from 2006 to 2021, showing excellent long-term survival rates of 100% at 10 years and 85.7% at 20 years.
  • * SRT proved to be safe and effective, with high local control rates and no significant adverse effects on vision or pituitary function, suggesting that planning for SRT during surgery can lead to better patient
View Article and Find Full Text PDF
Article Synopsis
  • Leptomeningeal enhancement (LME) in glioblastoma patients can indicate the spread of tumor cells, but its presence doesn't always mean the disease is untreatable, particularly given some cases where LME disappears post-surgery.
  • In a study of glioblastoma patients with preoperative LME, 8% showed LME at the brainstem, with larger tumor size linked to its presence and a trend toward significance for deep tumor location.
  • Post-surgery, four out of six patients had significant LME disappearance, suggesting that LME might stem from different factors like impaired blood flow rather than leptomeningeal dissemination, potentially leading to better prognosis than expected.
View Article and Find Full Text PDF

Chordoma is a rare tumor that arises from chordal tissue during fetal life. Recently, the concept of poorly differentiated chordoma, a subtype of chordoma characterized by loss of / with a poorer prognosis than conventional chordomas, was established. It predominantly occurs in children and is rare in adults.

View Article and Find Full Text PDF