Japanese Journal of Radiology最新文献

Purpose: This is a preliminary analysis of one of the secondary endpoints in the prospective study cohort. The aim of this study is to assess the image quality and diagnostic confidence for lung cancer of CT images generated by using cadmium-zinc-telluride (CZT)-based photon-counting-detector-CT (PCD-CT) and comparing these super-high-resolution (SHR) images with conventional normal-resolution (NR) CT images.

Materials and methods: Twenty-five patients (median age 75 years, interquartile range 66-78 years, 18 men and 7 women) with 29 lung nodules overall (including two patients with 4 and 2 nodules, respectively) were enrolled to undergo PCD-CT. Three types of images were reconstructed: a 512 × 512 matrix with adaptive iterative dose reduction 3D (AIDR 3D) as the NR_AIDR3D image, a 1024 × 1024 matrix with AIDR 3D as the SHR_AIDR3D image, and a 1024 × 1024 matrix with deep-learning reconstruction (DLR) as the SHR_DLR image. For qualitative analysis, two radiologists evaluated the matched reconstructed series twice (NR_AIDR3D vs. SHR_AIDR3D and SHR_AIDR3D vs. SHR_DLR) and scored the presence of imaging findings, such as spiculation, lobulation, appearance of ground-glass opacity or air bronchiologram, image quality, and diagnostic confidence, using a 5-point Likert scale. For quantitative analysis, contrast-to-noise ratios (CNRs) of the three images were compared.

Results: In the qualitative analysis, compared to NR_AIDR3D, SHR_AIDR3D yielded higher image quality and diagnostic confidence, except for image noise (all P < 0.01). In comparison with SHR_AIDR3D, SHR_DLR yielded higher image quality and diagnostic confidence (all P < 0.01). In the quantitative analysis, CNRs in the modified NR_AIDR3D and SHR_DLR groups were higher than those in the SHR_AIDR3D group (P = 0.003, <0.001, respectively).

Conclusion: In PCD-CT, SHR_DLR images provided the highest image quality and diagnostic confidence for lung tumor evaluation, followed by SHR_AIDR3D and NR_AIDR3D images. DLR demonstrated superior noise reduction compared to other reconstruction methods.

In pediatric oncology, ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) is valuable as a tool for noninvasive imaging and monitoring. While many reports have reviewed the use of PET and PET/CT in pediatrics, considerable variations in age, body size, and metabolism are seen during different stages of childhood development. Neonates (from birth to one month old) and infants (from 1 month to 1 year) present unique challenges for FDG-PET/CT examination due to their small body size, the immaturity of organs, the need for specialized patient preparation, and support requirements during scanning. In addition, differences in metabolic activity can lead to distinct differences in patterns of physiological FDG uptake on PET/CT imaging between neonates and infants. These factors differ significantly from those encountered in older children, who may be treated similarly to adults during imaging procedures. This review, based on both the literature and clinical experience, explores the specific characteristics, challenges, and considerations for FDG-PET/CT imaging from neonates to infants, with a focus on optimizing imaging protocols and interpreting physiological variations in this growth period.

Objectives: To investigate the frequency and patterns of calcification in ovarian tumours and evaluate their association with various histological types and malignancy grades.

Methods: This retrospective study included patients who underwent non-contrast CT between March 2015 and March 2024 and had pathologically confirmed ovarian tumours. CT scans were reviewed for the presence and patterns of calcification (punctate, linear, coarse, and amorphous) by three radiologists. Statistical analysis was performed using the Fisher-Freeman-Halton exact test with Bonferroni correction.

Results: This study included 328 patients (mean age, 55 years; range, 18-88 years). Significant differences in calcification frequency were observed among major tumour categories (p < 0.001), with with germ cell tumours being more calcified and metastases less calcified. Similarly, a significant difference was also found among epithelial tumours (p = 0.005), where mucinous and Brenner tumours were more calcified, whereas serous tumours were less calcified. Benign epithelial tumours showed a significantly higher frequency of calcification than borderline tumours and carcinomas (p < 0.001). When comparing the calcification patterns observed among epithelial tumours, significant differences were found for all calcification patterns: punctate (p = 0.024), linear (p < 0.001), coarse (p < 0.001), and amorphous (p < 0.001). The linear pattern was more common in mucinous tumours, whereas the amorphous pattern was more common in serous and Brenner tumours. Among non-epithelial tumours, germ cell tumours frequently exhibited liner and many calcifications, and immature teratomas were characterised by a mixture of punctate, linear, and coarse calcifications. Granulosa cells and metastatic tumours did not exhibit calcification.

Conclusions: Among epithelial tumours, mucinous and Brenner tumours had a significantly higher frequency of calcification, and benign tumours had a significantly higher frequency of calcification. Amorphous patterns were significantly more common in serous and Brenner tumours, while linear patterns were significantly more common in mucinous tumours.

Purpose: To assess the utility of dual-type deep learning (DL)-based image reconstruction with DL-based image denoising and super-resolution processing by comparing images reconstructed with the conventional method in head and neck fat-suppressed (Fs) T2-weighted imaging (T2WI).

Materials and methods: We retrospectively analyzed the cases of 43 patients who underwent head/neck Fs-T2WI for the assessment of their head and neck lesions. All patients underwent two sets of Fs-T2WI scans with conventional- and DL-based reconstruction. The Fs-T2WI with DL-based reconstruction was acquired based on a 30% reduction of its spatial resolution in both the x- and y-axes with a shortened scan time. Qualitative and quantitative assessments were performed with both the conventional method- and DL-based reconstructions. For the qualitative assessment, we visually evaluated the overall image quality, visibility of anatomical structures, degree of artifact(s), lesion conspicuity, and lesion edge sharpness based on five-point grading. In the quantitative assessment, we measured the signal-to-noise ratio (SNR) of the lesion and the contrast-to-noise ratio (CNR) between the lesion and the adjacent or nearest muscle.

Results: In the qualitative analysis, significant differences were observed between the Fs-T2WI with the conventional- and DL-based reconstruction in all of the evaluation items except the degree of the artifact(s) (p < 0.001). In the quantitative analysis, significant differences were observed in the SNR between the Fs-T2WI with conventional- (21.4 ± 14.7) and DL-based reconstructions (26.2 ± 13.5) (p < 0.001). In the CNR assessment, the CNR between the lesion and adjacent or nearest muscle in the DL-based Fs-T2WI (16.8 ± 11.6) was significantly higher than that in the conventional Fs-T2WI (14.2 ± 12.9) (p < 0.001).

Conclusion: Dual-type DL-based image reconstruction by an effective denoising and super-resolution process successfully provided high image quality in head and neck Fs-T2WI with a shortened scan time compared to the conventional imaging method.

Purpose: To assess the added value of artificial intelligence (AI) for radiologists and emergency physicians in the radiographic detection of pelvic fractures.

Materials & methods: In this retrospective study, one junior radiologist reviewed 940 X-rays of patients admitted to emergency for a fall with suspicion of pelvic fracture between March 2020 and June 2021. The radiologist analyzed the X-rays alone and then using an AI system (BoneView). In a random sample of 100 exams, the same procedure was repeated alongside five other readers (three radiologists and two emergency physicians with 3-30 years of experience). The reference diagnosis was based on the patient's full set of medical imaging exams and medical records in the months following emergency admission.

Results: A total of 633 confirmed pelvic fractures (64.8% from hip and 35.2% from pelvic ring) in 940 patients and 68 pelvic fractures (60% from hip and 40% from pelvic ring) in the 100-patient sample were included. In the whole dataset, the junior radiologist achieved a significant sensitivity improvement with AI assistance (Se_-PELVIC = 77.25% to 83.73%; p < 0.001, Se_-HIP 93.24 to 96.49%; p < 0.001 and Se_{-PELVIC RING} 54.60% to 64.50%; p < 0.001). However, there was a significant decrease in specificity with AI assistance (Spe_-PELVIC = 95.24% to 93.25%; p = 0.005 and Spe_-HIP = 98.30% to 96.90%; p = 0.005). In the 100-patient sample, the two emergency physicians obtained an improvement in fracture detection sensitivity across the pelvic area + 14.70% (p = 0.0011) and + 10.29% (p < 0.007) respectively without a significant decrease in specificity. For hip fractures, E1's sensitivity increased from 59.46% to 70.27% (p = 0.04), and E2's sensitivity increased from 78.38% to 86.49% (p = 0.08). For pelvic ring fractures, E1's sensitivity increased from 12.90% to 32.26% (p = 0.012), and E2's sensitivity increased from 19.35% to 32.26% (p = 0.043).

Conclusion: AI improved the diagnostic performance for emergency physicians and radiologists with limited experience in pelvic fracture screening.

Objective: To determine whether apparent diffusion coefficient (ADC) measurements at term equivalent age (TEA) are useful for assessment of major abnormalities revealed by MRI.

Materials and methods: Of 405 neonates who underwent MRI during the period 2016-2022, 101 low birth weight (LBW) infants (birth weight < 1500 g) were imaged at TEA. ADC values were measured in the thalamus, basal ganglia, anterior and posterior centrum semiovale, pons, and cerebellar hemisphere. The ADC values in LBW infants with and without major abnormalities evident on MRI were compared at the above six sites. Abnormal findings included IVH-3 IVH-4, more than six punctate white matter lesion, white matter injury (cystic or non-cystic), and major cerebellar hemorrhage. LBW infants overall (N = 101) and an extreme LBW (ELBW) group (< 1000 g) (N = 55) were compared and area under the curve was calculated using ROC analysis.

Result: There were no difference in ADC values between LBW infants with and without major abnormalities. In ELBW infants, ADC values in the cerebellum were higher when major abnormalities were present (p = 0.045). ROC analysis yielded AUC < 0.7 for both LBW cases overall and ELBW cases.

Conclusion: For LBW infants overall, ADC measurements alone at TEA are not very useful for differentiation between individuals with and without major abnormalities, but ELBW infants with major abnormalitiesshowed higher ADC values in the cerebellum, suggesting that the normal reduction of ADC occurring with maturation between preterm birth and TEA may be impaired.

Purpose: This study aimed to evaluate the clinical significance of four-dimensional dynamic ventilation CT (4DCT) for assessing resectability in borderline resectable locally advanced esophageal cancer (BR-LAEC) and confirmed the pathological validity of the 4DCT results in surgery without prior treatment.

Materials and methods: We retrospectively reviewed 128 patients (107 men; median age, 68 [range, 43-89] years) diagnosed with BR-LAEC on initial conventional CT (i-CT). These patients were initially classified into three categories: BR1 (closer to resectable), BR2 (resectability not assessable), or BR3 (closer to unresectable). Subsequent 4DCT reclassified patients as either resectable or unresectable within 1 week of i-CT. We analyzed the diagnostic shift induced by 4DCT. Additionally, 18 patients who underwent surgery without prior treatment were evaluated using 4DCT and pathological outcomes.

Results: 4DCT reclassified patients with BR-LAEC as resectable (57.0%; 73/128) and unresectable (43.0%; 55/128). Of 53 patients initially classified as BR1, 32.1% (17/53) were reclassified as unresectable, and of 47 patients initially classified as BR3, 46.8% (22/47) were reclassified as resectable. Among 28 patients initially classified as BR2, 53.6% (15/27) were reclassified as resectable and 46.4% (13/27) as unresectable. In the surgery-only cohort of 18 patients, 9 were initially classified as BR1 and 9 as BR2, and all were reclassified as resectable. These patients were pathologically confirmed to have resectable disease.

Conclusions: 4DCT may provide information complementary to that provided by initial conventional CT in assessing resectability among patients with BR-LAEC, and could be a useful adjunct tool for guiding clinical decisions in this patient population.

Purpose: Placenta previa complicated by placenta accrete spectrum (PAS) is a life-threatening obstetrical condition; therefore, preoperative diagnosis of PAS is important to determine adequate management. Although several MRI features that suggest PAS has been reported, the diagnostic importance, as well as optimal use of each feature has not been fully evaluated.

Materials and methods: The occurrence of 11 PAS-related MRI features was investigated in MR images of 145 patients with placenta previa. The correlation between each MRI feature and pathological diagnosis of PAS was evaluated using univariate analysis. A decision tree model was constructed according to a random forest machine learning model of variable selection.

Results: Eight MRI features showed a significant correlation with PAS in univariate analysis. Among these features, placental/uterine bulge and myometrial thinning showed high odds ratios: 138.2 (95% CI: 12.7-1425.6) and 66.0 (95% CI: 18.01-237.1), respectively. A decision tree was constructed based on five selected MRI features: myometrial thinning, placental bulge, serosal hypervascularity, placental ischemic infarction/recess, and intraplacental T2 dark bands. The decision tree predicted the presence of PAS in the randomly assigned validation cohort with significance (p < 0.001). The sensitivity and the specificity of the decision tree for detecting PAS were 90.0% (95%CI: 53.2-98.9) and 95.5% (95%CI: 89.9-96.8), respectively.

Conclusion: Among PAS-related MRI features, placental/uterine bulge and myometrial thinning showed high diagnostic values. In addition, the present decision tree model was shown to be effective in predicting the presence of PAS in cases with placenta previa.

Sarcopenia, defined as skeletal muscle loss, is thought to be a hallmark of cancer cachexia. It has an impact on mortality, especially in cancer patients. There are also opposing views regarding the relationship between definitive concurrent chemoradiotherapy (CRT) and sarcopenia in locally advanced lung cancer. Our aim was to investigate the prognostic effect of sarcopenia in our patients with locally advanced stage III non-small cell lung cancer (NSCLC) who received definitive concurrent CRT by using many markers, and to determine the overall survival (OS). The study was designed as a retrospective cohort. 54 patients with stage III NSCLC who received definitive concurrent CRT at the Radiation Oncology Unit of Health Sciences University Izmir Dr Suat Seren Chest Diseases and Surgery Training Hospital, between January 1, 2018 and December 31, 2019, were included in the study.92% of our patients were sarcopenic with international L3-skeletal muscle index (SMI) and Psoas muscle index (PMI) threshold values. The mean OS time was 32.4 months, and the 4-year survival rate was 38.9%. While the new threshold values specific to our patient group were 26.21 for SMI and 2.94 for PMI, SMI and PMI did not indicate OS with these values. Even with the new values, most proposed criteria for sarcopenia did not indicate OS. However, low BMI (≤21.30), low serum albumin (≤4.24 mg/dl) and low visceral fat tissue area (≤37) in univariate analysis, and low visceral fat tissue area (≤37) in multivariate analysis indicated OS. OS was poor in patients with low fat tissue area. In patients with stage III NSCLC who received definitive concurrent CRT, low visceral fat tissue area (≤37) indicated OS, rather than SMI, PMI and other sarcopenia indices.

Objectives: Given increasing research suggesting the utility of positron emission tomography/magnetic resonance imaging (PET/MRI) in identifying the pain generator of low back pain, our study aims to assess its effectiveness in evaluating the source of pain in patients with failed back surgery syndrome (FBSS) by comparing the performance of fluorine-18-labeled fluorodeoxyglucose (¹⁸F-FDG) PET/MRI with conventional MRI.

Methods: We retrospectively analyzed data from patients with FBSS who underwent ¹⁸F-FDG PET and MRI of the lumbar vertebrae and lower extremities for undetermined sources of pain. We assessed 1) The diagnostic reliability and efficacy of MRI and ¹⁸F-FDG PET/MRI according to correct differential diagnosis, affected level, and affected side of the pain source compared to the findings of selective root or peripheral nerve block or revision lumbar spine surgery; and 2) The association between standardized uptake value (SUV) and standardized uptake value ratio (SUVR) threshold and accuracy of the suspected pathology on ¹⁸F-FDG PET/MRI.

Results: Among 30 included patients, the diagnostic accuracy of pain source recognition was higher for ¹⁸F-FDG PET/MRI than for MRI alone (1.0 vs. 0.4 in spinal disease and 0.8 vs. 0 in lower extremity disease, both p < 0.05). SUVR values of 1.4-1.5 showed the highest accuracy (0.93), higher than the accuracy obtained using the SUV threshold (0.87).

Conclusion: ¹⁸F-FDG PET/MRI added value to MRI alone in detecting of hypermetabolic activity associated with pain from spinal and non-spinal sources.