Japanese Journal of Radiology最新文献

Objective: To evaluate the association of asymmetrical cortical vein sign (ACVS) and asymmetrical medullary vein sign (AMVS) on susceptibility-weighted imaging (SWI) with 90-day poor outcomes in patients with unilateral middle cerebral artery acute ischemic stroke (AIS) after conservative drug treatment.

Methods: Clinical data for the participants included age, sex, smoking, alcohol, hypertension, diabetes, hyperlipidemia, coronary heart disease, NHISS-admission, and NHISS-discharge scores. Participants underwent magnetic resonance imaging (MRI) within 12 h of hospital admission, including conventional scan sequences and a SWI sequence. Poor prognosis was defined as a modified Rankin scale (mRS) ≥ 3 at 90 days.

Results: A total of 108 patients were included from January 2021 to March 2022. Twenty-seven (25%) patients had a poor outcome at 90 days. Univariate analysis indicated that diabetes, NHISS-admission, NHISS-discharge, DWI-ASPECTS, SWI-ASPECTS, FLAIR-ASPECTS, and AMVS + were associated with 90-day poor outcome. Multivariate regression analysis showed that AMVS + was associated with 90-day poor outcome from the three models (OR = 3.57, P = 0.006; OR = 3.74, P = 0.005; OR = 5.14, P = 0.0057). However, no significant association was found between ACVS + and 90-day poor outcome.

Conclusions: AMVS might be a helpful neuroimaging predictor for poor outcome at 90 days compared to ACVS in drug-conserving treatment of patients with unilateral middle cerebral artery ischemic stroke.

Purpose: The computed tomography angiography (CTA) spot sign is a validated predictor of 30-day mortality in intracerebral hemorrhage (ICH). However, its role in predicting unfavorable functional outcomes remains unclear. This study explores the frequency of the spot sign and its association with functional outcomes, hematoma expansion, and length of hospital stay among survivors of ICH.

Materials and methods: This was a retrospective analysis of consecutive patients with primary ICH who received CTA within 24 h of admission to two medical centers between January 2007 and August 2022. Patients who died before discharge and those referred from other hospitals were excluded. Spot signs were assessed by an experienced neuroradiologist. Functional outcomes were determined by modified Rankin Scale (mRS) scores and the Barthel Index (BI).

Results: In total, 98 patients were included; 14 (13.64%) had a spot sign. No significant differences were observed in the baseline characteristics between the patients with and without a spot sign. Higher spot sign scores were associated with higher odds of experiencing hematoma expansion (p = 0.013, 95% CI = 1.16-3.55), undergoing surgery (p = 0.012, 95% CI = 0.19-1.55), and having longer hospital stay (p = 0.02, 95% CI = 1.22-13.92). However, higher spot sign scores were not associated with unfavorable functional outcomes (p = 0.918 for BI, and p = 0.782 for mRS).

Conclusion: Spot signs are common findings among patients with ICH, and higher spot sign scores were associated with subsequent hematoma expansion and longer hospital stays but not unfavorable functional outcomes.

Purpose: This study evaluates the impact of the 2021 revision of Japan's Ordinance on the Prevention of Ionizing Radiation Hazards on radiation protection practices, focusing on the deployment of radiation protection devices and the involvement of radiology technologists in Japanese hospitals.

Methods: A two-phase web-based questionnaire survey was conducted among hospitals registered as training facilities with the Japanese Radiological Society. The survey included 53 questions covering facility information, radiation worker management, training, and working environment.

Results: The use of lens-specific dosimeters significantly increased post-revision (p = 0.005). Protective eyewear availability showed minor improvements, particularly in angiographic rooms (p = 0.019). The involvement of radiology technologists remained high in angiographic rooms but showed no significant changes in endoscopy and fluoroscopy rooms. Larger hospitals exhibited better compliance with protective measures, though gaps in resource allocation persisted.

Conclusion: The ordinance revision led to significant improvements in dosimeter usage but only minor changes in protective eyewear deployment and technologist involvement.

Purpose: To evaluate the behavior of n-butyl cyanoacrylate-Lipiodol-iopamidol at a ratio of 2:3:1 (NLI231) with and without microcoils and/or flow control in embolization of medium-sized arteries in an in vitro vascular model.

Materials and methods: A vessel model representing a common hepatic artery was prepared. Six scenarios were set for embolization, each ran three times: 1) NLI231 injected alone with flow control to 0 ml/min during and up to 5 min after embolization; 2) NLI231 injected into a mesh of microcoil of 5% density with the flow control; 3) NLI231 injected into a microcoil of 10% density with the flow control; 4) NLI231 injected alone without the flow control; 5) NLI231 injected into microcoil of 5% density without the flow control; 6) NLI231 injected into a microcoil of 10% density without the flow control. The microcoils were delivered to the embolization site, and NLI231 was injected. After 1 h of observation, distal filters were collected, and grades of migration (I = none, II = partial, III = almost all-all) were assessed for each scenario.

Results: Embolization was achieved in scenarios with NLI231 and microcoils regardless of flow control (p < 0.01). NLI231 did not migrate in scenarios with microcoils and flow control (p < 0.05). NLI231 with microcoils without flow control can embolize the vessel, but partial migration occurred, and the distal distance of the NLI231 complex from the embolization site was longer (p < 0.01).

Conclusion: Combining sparse coiling with NLI231 may be feasible but is limited to use when flow control is available, or where distal embolization is permissible to some extent.

Purpose: To investigate the added value of using contrast-enhanced magnetic resonance imaging (MRI) in conjunction with contrast-enhanced computed tomography (CT) for differentiating malignant and benign ampullary strictures.

Materials and methods: The present retrospective study included 90 patients with ampullary strictures who underwent preoperative contrast-enhanced CT and contrast-enhanced MRI at two tertiary institutions. The image sets (i.e., CT alone vs. combined CT and MRI) were evaluated by three abdominal radiologists, who used a five-point Likert scale to score their confidence for diagnosing malignancy in patients with ampullary strictures. Diagnostic accuracy was calculated using receiver-operating characteristic (ROC) curve analysis, sensitivity, specificity, and accuracy. Additionally, interobserver agreement regarding the scoring of potential malignancies of the ampullary strictures was assessed.

Results: The addition of contrast-enhanced MRI to contrast-enhanced CT showed a significant improvement in predicting malignant ampullary strictures in all three observers (p = 0.007, 0.001, and 0.002) using ROC curve analysis, and a significant improvement was observed in diagnostic sensitivity and accuracy for predicting malignancy (p = 0.016 and 0.029 for observer 1; p = 0.023 and 0.010 for observer 2; and p = 0.010 and 0.011 for observer 3). The interobserver agreement for the five-point scale in determining malignancies of the ampullary strictures was 0.86 for CT alone and 0.93 for the combined set of CT and MRI.

Conclusion: The addition of contrast-enhanced MRI to CT provided added value for differentiating malignant from benign ampullary strictures.

Purpose: Transarterial radioembolization (TARE) is effective for unresectable hepatocellular carcinoma; however, it awaits approval in Japan. This study aimed to simulate the cost-effectiveness of TARE over chemoembolization when TARE is approved in Japan and identify the requirements for cost-effectiveness.

Materials and methods: A Markov model was constructed to analyze the costs and effectiveness associated with TARE and transarterial chemoembolization with drug-eluting beads (DEB-TACE) for 2-month cycles over 5 years. In the primary analysis, the intention-to-treat survival data were used to calculate transition probabilities, whereas the ancillary analysis assessed the per-protocol survival data. DEB-TACE costs were calculated using the Japanese nationwide claims Diagnosis Procedure Combination database between April 2018 and March 2022, whereas TARE costs were estimated using database and international sources. The incremental cost-effectiveness ratio (ICER) was determined based on the payer's perspective and compared with the Japanese willingness-to-pay threshold of 5 million Japanese yen (JPY) (31,250 USD) per quality-adjusted life years (QALY).

Results: From the claims database, 6,986 patients with hepatocellular carcinoma who received DEB-TACE were identified. In the primary analysis, the ICER was 5,173,591 JPY (32,334 USD)/QALY, surpassing the Japanese willingness-to-pay threshold. However, the ancillary analysis showed a lower ICER of 4,156,533 JPY (25,978 USD)/QALY, falling below the threshold. The one-way deterministic sensitivity analysis identified progression-free survival associated with TARE and DEB-TACE, DEB-TACE costs, and radioactive microsphere reimbursement price as key ICER influencers. The primary analysis suggested that setting the reimbursement price of radioactive microspheres below 1.399 million JPY (8,744 USD), approximately 2.8% lower than the price in the United Kingdom, would place the ICER below the Japanese willingness-to-pay threshold.

Conclusions: Under specific conditions, TARE can be a more cost-effective treatment than DEB-TACE. If the reimbursement price of radioactive microspheres is set approximately 2.8% lower than that in the United Kingdom, TARE could be cost-effective compared with DEB-TACE.

Purpose: The purpose of this study was to evaluate the cost-effectiveness of comprehensive treatment strategy, including segmental adrenal venous sampling (sAVS) and radiofrequency ablation (RFA), versus medication-only strategy for primary aldosteronism.

Materials and methods: A Markov decision model was developed to compare the cost-effectiveness of a comprehensive treatment strategy and a medication-only strategy for 50-year-old men and women with stage I-III hypertension. The comprehensive treatment strategy included aldosterone/renin ratio measurement, two loading tests, computed tomography, sAVS, drugs, surgery, and RFA. We built a model with a yearly cycle over 32- and 38-year time horizons for men and women, respectively, and four health states: hypertension, heart failure, stroke, and death. The incremental cost-effectiveness ratio (ICER), expressed as Japanese yen per quality-adjusted life-years (QALYs), was estimated, and strategy preference was determined on the basis of 5 million Japanese yen per QALY societal willingness-to-pay threshold.

Results: The ICERs of the comprehensive treatment strategy over the medication-only strategy were 201,482 and 3,399 JPY per QALY for men and women, respectively. The resultant ICER was less than the 5 million JPY societal willingness-to-pay threshold. Deterministic sensitivity analysis and probabilistic sensitivity analysis revealed that the results varied with the input values, but the comprehensive strategy was likely to be more cost-effective than the medication-only strategy.

Conclusion: This cost-effectiveness study revealed that a comprehensive treatment strategy including sAVS and RFA was favorable compared with the medication-only strategy for managing stage I-III hypertension in 50-year-old men and women, with acceptable willingness-to-pay thresholds. This cost-effectiveness study revealed that a comprehensive treatment strategy for primary aldosteronism that included segmental adrenal sampling and radiofrequency ablation was favorable compared with the medication-only strategy for managing stage I-III hypertension in 50-year-old men and women, with acceptable willingness-to-pay thresholds.

Purpose: To evaluate deep learning-reconstructed (DLR)-fluid-attenuated inversion recovery (FLAIR) images generated from undersampled data, compare them with fully sampled and rapidly acquired FLAIR images, and assess their potential for white matter hyperintensity evaluation.

Materials and methods: We examined 30 patients with white matter hyperintensities, obtaining fully sampled FLAIR images (standard FLAIR, std-FLAIR). We created accelerated FLAIR (acc-FLAIR) images using one-third of the fully sampled data and applied deep learning to generate DLR-FLAIR images. Three neuroradiologists assessed the quality (amount of noise and gray/white matter contrast) in all three image types. The reproducibility of hyperintensities was evaluated by comparing a subset of 100 hyperintensities in acc-FLAIR and DLR-FLAIR images with those in the std-FLAIR images. Quantitatively, similarities and errors of the entire image and the focused regions on white matter hyperintensities in acc-FLAIR and DLR-FLAIR images were measured against std-FLAIR images using structural similarity index measure (SSIM), regional SSIM, normalized root mean square error (NRMSE), and regional NRMSE values.

Results: All three neuroradiologists evaluated DLR-FLAIR as having significantly less noise and higher image quality scores compared with std-FLAIR and acc-FLAIR (p < 0.001). All three neuroradiologists assigned significantly higher frontal lobe gray/white matter visibility scores for DLR-FLAIR than for acc-FLAIR (p < 0.001); two neuroradiologists attributed significantly higher scores for DLR-FLAIR than for std-FLAIR (p < 0.05). Regarding white matter hyperintensities, all three neuroradiologists significantly preferred DLR-FLAIR (p < 0.0001). DLR-FLAIR exhibited higher similarity to std-FLAIR in terms of visibility of the hyperintensities, with 97% of the hyperintensities rated as nearly identical or equivalent. Quantitatively, DLR-FLAIR demonstrated significantly higher SSIM and regional SSIM values than acc-FLAIR, with significantly lower NRMSE and regional NRMSE values (p < 0.0001).

Conclusions: DLR-FLAIR can reduce scan time and generate images of similar quality to std-FLAIR in patients with white matter hyperintensities. Therefore, DLR-FLAIR may serve as an effective method in traditional magnetic resonance imaging protocols.

Lung cancer has a poor prognosis, and further improvements in outcomes are needed. Radiotherapy plays an important role in the treatment of unresectable lung cancer, and there have been recent developments in the field of radiotherapy for the management of lung cancer. However, to date, there have been few reviews on the improvement in treatment outcomes associated with high precision radiotherapy for lung cancer. Thus, this review aimed to summarize the recent developments in radiotherapy techniques and indicate the future directions in the use of radiotherapy for lung cancer. Stereotactic body radiotherapy (SBRT) for unresectable stage I lung cancer has been reported to improve local control rates without severe adverse events, such as radiation pneumonitis. For locally advanced lung cancer, a combination of chemoradiotherapy and adjuvant immune checkpoint inhibitors dramatically improves treatment outcomes, and intensity-modulated radiotherapy (IMRT) enables safer radiation therapy with less frequent pneumonitis. Particle beam therapy, such as carbon-ion radiotherapy and proton beam therapy, has been administered as advanced medical care for patients with lung cancer. Since 2024, it has been covered under insurance for early stage lung cancer with tumors ≤ 5 cm in size in Japan. In addition to chemotherapy, local ablative radiotherapy improves treatment outcomes in patients with oligometastatic stage IV lung cancer. A particular problem with radiotherapy for lung cancer is that the target location changes with respiratory motion, and various physical methods have been used to control respiratory motion. Recently, coronavirus disease has had a major impact on lung cancer treatment, and cancer treatment during situations, such as the coronavirus pandemic, must be performed carefully. To improve treatment outcomes for lung cancer, it is necessary to fully utilize evolving radiotherapy modalities, and the role of radiotherapy in lung cancer treatment is expected to increase.

The skull base and orbit have complicated anatomical structures where various tumors can occur. The tumor may present with neurological symptoms; however, its diagnosis is clinically difficult owing to accessibility issues. Therefore, diagnostic imaging is crucial in assessing tumors in the skull base and orbit and guiding subsequent management. Notably, some tumors have a predilection for a specific site of origin, and identifying the site of origin on imaging can help narrow the differential diagnosis. At the skull base, chordomas typically occur in the clivus, chondrosarcomas in the paramedian areas, paragangliomas in the jugular foramen, neurogenic tumors, and perineural spread in the neural foramen. Among orbital tumors, cavernous hemangiomas usually occur in the intraconal space, and pleomorphic adenomas and adenoid cystic carcinomas occur in the lacrimal glands. Some skull base and orbital tumors exhibit distinctive imaging features. Chordomas and chondrosarcomas of the skull base show high signal intensities on T2-weighted images, with chondrosarcomas often displaying cartilaginous calcifications. Paragangliomas are characterized by their hypervascular nature. In the orbit, cavernous hemangiomas and pleomorphic adenomas present unique dynamic patterns. Immunoglobulin G4-related disease forms lesions along the nerves. Identifying the tumor origin and its imaging characteristics can help narrow the differential diagnosis of skull base and orbital tumors.