Japanese Journal of Radiology最新文献

Background: Stroke, frequently associated with carotid artery disease, is evaluated using carotid computed tomography angiography (CTA). Dual-energy CTA (DE-CTA) enhances imaging quality but presents challenges in maintaining high image clarity with low-dose scans.

Objectives: To compare the image quality of 50 keV virtual monoenergetic images (VMI) generated using Deep Learning Image Reconstruction (DLIR) and Adaptive Statistical Iterative Reconstruction-V (ASIR-V) algorithms under a triple-low scanning protocol in carotid CTA.

Methods: A prospective study was conducted with 120 patients undergoing DE-CTA. The control group (Group 1), with a noise index (NI) of 4.0 and a contrast agent dose of 0.5 mL/kg, used the ASIR-V algorithm. The experimental group was divided into four subgroups: Group 2 (ASIR-V 50%), Group 3 (DLIR-L), Group 4 (DLIR-M), and Group 5 (DLIR-H), with a higher NI of 13.0 and a reduced contrast agent dose of 0.4 mL/kg. Objective image quality was assessed through signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and standard deviation (SD), while subjective quality was evaluated using a 5-point Likert scale. Radiation dose and contrast agent volume were also measured.

Results: The triple-low scanning protocol reduced radiation exposure by 53.2%, contrast agent volume by 19.7%, and injection rate by 19.8%. The DLIR-H setting outperformed ASIR-V, demonstrating superior image quality, better noise suppression, and improved contrast in small vessels. VMI at 50 keV showed enhanced diagnostic clarity with minimal radiation and contrast agent usage.

Conclusion: The DLIR algorithm, particularly at high settings, significantly enhances image quality in DE-CTA VMI under a triple-low scanning protocol, offering a better balance between radiation dose reduction and image clarity.

Objectives: The aim of our study was to evaluate the value of the fat attenuation index (FAI) as a tool for measuring plaque inflammation in perivascular adipose tissue (PVAT) and identifying symptomatic plaques in internal carotid atherosclerosis.

Methods: We conducted a retrospective analysis of patients with internal carotid atherosclerosis who underwent carotid artery computed tomography angiography (CTA). The patients were assigned to a symptomatic plaque group or asymptomatic plaque group on the basis of clinical diagnosis and neuroimaging. We measured perivascular FAIs at the maximum stenosis site with the plaque, the nonstenosis site adjacent to the maximum stenosis site, and the ipsilateral internal carotid artery (ICA). We subsequently compared these measurements between the two groups. Multivariable generalized estimating equation (GEE) analysis was performed to identify imaging predictors of symptomatic plaque in the ICA, and receiver operating characteristic (ROC) curves were used to assess the diagnostic accuracy for classifying symptomatic plaques.

Results: A total of 101 and 94 ICAs were included in the symptomatic plaque group and asymptomatic plaque group, respectively. Mild ICA stenosis resulted in a lower FAI at the maximum stenosis site than moderate or severe stenosis did (p = 0.001). A greater FAI of the ipsilateral ICA was observed in the symptomatic plaque group than in the asymptomatic plaque group (p = 0.002), as was the FAI at the maximum stenosis site of the ICA with the plaque (p = 0.038). Multivariable GEE analysis revealed that the stenosis severity (p = 0.004) and FAI at the maximum stenosis site of the ICA (p = 0.007) were capable of identifying symptomatic plaques. ROC analysis revealed that the FAI at the maximum stenosis site of the ICA, in combination with stenosis severity, resulted in a higher area under the curve (AUC) value (0.863) with moderate specificity (74%) and high sensitivity (89%).

Conclusion: The perivascular FAI at the maximum stenosis site of the ICA is useful for identifying symptomatic plaques by monitoring inflammation in patients with ICA atherosclerosis, which may provide a new inflammation marker for risk stratification of patients with stroke.

Purpose: This study evaluated the efficacy and safety of high-dose pelvic radiotherapy combined with chemotherapy, including bevacizumab and immune checkpoint inhibitors (ICI) in patients with stage IVB cervical cancer (CC) based on the 2018 International Federation of Gynecology and Obstetrics (FIGO) cervical cancer staging system.

Materials and methods: A retrospective analysis was conducted on 38 patients with stage IVB CC, as classified by the 2018 FIGO cervical cancer staging system, who received pelvic external beam radiotherapy (≥ 40 Gy) with or without brachytherapy and chemotherapy. Data were collected from two centers. The 2-year local control (LC), progression-free survival (PFS), and overall survival (OS) rates were analyzed using the Kaplan-Meier method. Symptom relief, including reductions in genital bleeding and pain from the primary lesion, was assessed. Acute and late adverse events were also evaluated.

Results: The median follow-up period was 17.5 months. The 2-year LC, PFS, and OS were 82%, 11%, and 47%, respectively. Although the evaluation method has limitations, most patients with genital bleeding and pain from the primary lesion showed improvement in symptoms. Late adverse events of grade ≥ 2 related to both pelvic radiotherapy and bevacizumab included one case of grade 3 gastrointestinal bleeding and two cases of grade 2 fistula.

Conclusion: This two-center study demonstrated that high-dose pelvic radiotherapy combined with chemotherapy, including bevacizumab and ICI, may achieve favorable local control and symptom relief in patients with stage IVB CC while maintaining an acceptable safety profile.

Modern breast cancer treatment has evolved significantly, integrating advanced imaging techniques and a variety of drug therapies, including endocrine therapy, chemotherapy, molecularly targeted drugs, and immune checkpoint inhibitors. This study discusses the interplay of drug treatments and imaging diagnostics in optimizing patient outcomes. Key findings emphasize the importance of personalized treatments based on intrinsic subtypes and imaging-guided decisions, as well as the management of treatment-related adverse effects.

Approximately 5% and 1% of global greenhouse gas emissions originate from the healthcare sector and medical imaging respectively. These are not insignificant. Despite this, the medical field has been slow to adopt sustainable practices. Green radiology is a sustainable, innovative, and responsible approach in radiological practice that focuses on minimising the negative environmental impact of our technologies and procedures. The Asian Oceanian Society of Radiology (AOSR) conducted a survey across Asia-Oceania to better understand current operations and identify opportunities for meaningful progress toward more sustainable radiological practices. From the 123 institutions that responded, it was found that collectively the carbon footprint of Asia-Oceania's radiological services are high in some of the countries/regions because of the high density of high energy consumption scanners (such as computed tomography and magnetic resonance imaging scanners). Our survey showed that less than half of the 15 societies that responded had specific academic or research activities related to sustainable radiology and less than a third reported that sustainability had been incorporated in the training curriculum. The AOSR is committed to facilitating the sharing of best practices in green radiology and recommends that Asia-Oceania use an "As Low As Reasonably Achievable" principle, traditionally used in radiation safety and extend this in the approach to the issues of environmental impact of radiological services. The AOSR as a cross-regional professional society, has the mandate to partner with our counterpart societies and industry stakeholders, to emphasise the importance of sustainability as a critical agenda, through our various activities. We foresee that influencing radiology leaders in the region to urgently formulate strategies, implement policies towards adopting eco-friendly approaches including reducing inappropriate imaging and encouraging academic efforts will help to reduce the environmental impact in each country/region. A checklist has been included to help kickstart the process.

Proper treatment of intra-articular tumor/tumor-like lesions (tenosynovial giant cell tumor, synovial chondromatosis, synovial hemangioma / intra-articular venous malformations, lipoma arborescens, etc.) depends on an accurate diagnosis. This review highlights the imaging findings of intra-articular tumor/tumor-like lesions and the other synovial diseases (gout, amyloid arthropathy, rheumatoid arthritis, ganglion, and postoperative intra-articular tumor) to determine whether they could help in establishing the correct diagnosis. Many synovial proliferative diseases have specific imaging characteristics and an awareness of these characteristics along with their pathological and anatomical features can allow for an accurate diagnosis. Even though a wide spectrum of diseases may involve the synovium, careful MRI assessment used in conjunction with clinical information can lead to a substantial narrowing of the differential diagnosis.