Purpose: This retrospective study aimed to determine the number of times the ultrasound-guided attenuation parameter (UGAP) should be measured during the evaluation of hepatic steatosis. Methods: Patients with suspected nonalcoholic fatty liver disease who underwent two UGAP repetition protocols (six-repetition [UGAP_6] and 12-repetition [UGAP_12]) and measurement of the controlled attenuation parameter (CAP) using transient elastography between October 2020 and June 2021 were enrolled. The mean attenuation coefficient (AC), interquartile range (IQR)/median, and coefficient of variance (CV) of the two repetition protocols were compared using the paired t test. Moreover, the diagnostic performances of UGAP_6 and UGAP_12 were compared using the area under the receiver operating characteristic (AUROC) curve, considering the CAP value as a reference standard. Results: The study included 160 patients (100 men; mean age, 50.9 years). There were no significant differences between UGAP_6 and UGAP_12 (0.731±0.116 dB/cm/MHz vs. 0.734±0.113 dB/cm/MHz, P=0.156) and mean CV (7.6±0.3% vs. 8.0±0.3%, P=0.062). However, the mean IQR/median of UGAP_6 was significantly lower than that of UGAP_12 (8.9%±6.0% vs. 9.8%±5.2%, P=0.012). In diagnosing the hepatic steatosis stage, UGAP_6 and UGAP_12 yielded comparable AUROCs (≥S1, 0.908 vs. 0.897, P=0.466; ≥S2, 0.883 vs. 0.897, P=0.126; S3, 0.832 vs. 0.834, P=0.799). Conclusion UGAP had high diagnostic performance in diagnosing hepatic steatosis, regardless of the number of repetitions (six repetitions vs. 12 repetitions), with maintained reliability. Therefore, six UGAP measurements seem sufficient for evaluating hepatic steatosis using UGAP.

Purpose: This study quantified the impact of respiratory motion on liver stiffness measurements according to different shear wave elastography (SWE) techniques and region of interest (ROI) methods, using liver fibrosis phantoms. Methods: Three operators measured stiffness values in four phantoms with different stiffness on a moving platform with two SWE techniques (point-SWE [pSWE] and 2-dimensional SWE [2D-SWE]), three types of motion (static mode and moving mode at low and high speeds), and four ROI methods in 2D-SWE (circle, point, box, and multiple). The circular ROI method was used to compare the two SWE techniques. The occurrence of technical failure and unreliable measurements, stiffness values, and measurement time were evaluated. Results: Technical failure was observed only in moving mode for pSWE and 2D-SWE (n=1 for both). Unreliable measurements were also only observed in moving mode and were significantly less common in 2D-SWE (n=1) than in pSWE (n=12) (P<0.001). No statistically significant differences in the technical failure rate or stiffness values were noted between the static and moving modes for both SWE techniques. The technical failure and unreliable measurement rates were not significantly different among the ROI methods for 2D-SWE. Stiffness values did not differ significantly according to the ROI method used in any moving mode. However, the multiple ROI method had significantly shorter measurement times than the circular ROI method for all moving modes. Conclusion 2D-SWE may be preferable for evaluating liver fibrosis in patients with poor breath-hold. Furthermore, 2D-SWE with multiple ROIs enables rapid measurements, without affecting liver stiffness values.

Ultrasonography is a useful technique to detect soft tissue changes of rheumatoid arthritisnot only synovitis, but also tenosynovitis, bursitis, and enthesitis-even at a subclinical stage. However, radiologists tend to focus on synovitis in daily practice, and unusual peri- or extraarticular manifestations of rheumatoid arthritis are difficult to detect at the initial presentation. This pictorial essay describes a broad spectrum of ultrasonographic findings in tendons, bursae, ligaments, subcutaneous tissues, bones, and nerves to assist in the accurate diagnosis of rheumatoid arthritis.

Purpose: This study aimed to assess the technical performance of ElastQ Imaging compared with ElastPQ and to investigate the correlation between liver stiffness (LS) values obtained using these two techniques. Methods: This retrospective study included 249 patients who underwent LS measurements using both ElastPQ and ElastQ Imaging equipped on the same machine. The applicability, repeatability (coefficient of variation [CV]), acquisition time, and LS values were compared using the chi-square or Wilcoxon signed-rank tests. In the development group, the correlation between the LS values obtained by the two techniques was assessed with Spearman correlation coefficients and linear regression analysis. In the validation group, the agreement between the estimated and real LS values was evaluated using a Bland-Altman plot. Results: ElastQ Imaging had higher applicability (94.0% vs. 78.3%, P<0.001) and higher repeatability, with a lower median CV (0.127 vs. 0.164, P<0.001) than did ElastPQ. The median acquisition time of ElastQ Imaging was significantly shorter than that of ElastPQ (45.5 seconds vs. 96.5 seconds, P<0.001). The median LS value obtained using ElastQ Imaging was significantly higher than that obtained using ElastPQ (5.60 kPa vs. 5.23 kPa, P<0.001). The LS values between the two techniques exhibited a strong positive correlation (r=0.851, P<0.001) in the development group. The mean difference and 95% limits of agreement were 0.0 kPa (-3.9 to 3.9 kPa) in the validation group. Conclusion ElastQ Imaging may be more reliable and faster than ElastPQ, with strongly correlated LS measurements.

Giant cell fibroblastoma (GCF) is a rare soft-tissue sarcoma of fibroblastic origin. To the best of our knowledge, only one brief description of the MRI findings of GCF exists in the pathologic literature. Herein, we report a case of histologically proven GCF in a 3-year-old boy who underwent ultrasonography and MRI of a superficial mass in the abdominal wall.

PURPOSE: The purpose of this study was to evaluate the ultrasonographic findings of secondary appendicitis (SA) and to discuss the differential findings compared with primary appendicitis. METHODS: In this study, we analyzed the ultrasonographic findings of 94 patients under 15 years old of age treated at our institution from May 2005 to May 2014 who had bowel inflammation and an inflamed appendix with a maximal outer diameter >6 mm that improved with nonsurgical treatment (the SA group). Ninety-nine patients with pathologically proven acute appendicitis (the primary appendicitis [PA] group) from June 2013 to May 2014 and 44 patients with pathologically negative appendectomy results from May 2005 to May 2014 were also included to compare the ultrasonographic features of these conditions. A retrospective review of the ultrasonographic findings was performed by two radiologists. The clinical and laboratory findings were also reviewed. The results were statically analyzed using analysis of variance, the Pearson chi-square test, and the two-tailed Fisher exact test. RESULTS: Compared with PA, cases of SA had a smaller diameter (9.8 mm vs. 6.6 mm, P < 0.001), and were less likely to show periappendiceal fat inflammation (98% vs. 6%, P < 0.001) or an appendicolith (34% vs. 11%, P < 0.001). SA showed mural hyperemia on color Doppler ultrasonography as frequently as PA (P=0.887). CONCLUSION: The ultrasonographic features of SA included an increased diameter compared to a healthy appendix and the same level of hyperemia as in PA. However, the diameter was commonly in the equivocal range (mean diameter, 6.6 mm), and periappendiceal fat inflammation was rarely present in SA.
Appendectomy ; Appendicitis* ; Appendix ; Humans ; Hyperemia ; Inflammation ; Pediatrics ; Retrospective Studies ; Ultrasonography* ; Ultrasonography, Doppler, Color

Renal artery injury is a rare complication in blunt trauma, but can cause devascularization of the kidney, leading to renal failure. It requires early diagnosis and management. The treatment of renal artery injury still remains controversial, but recent studies have reported the successful treatment outcome with endovascular stent placement. Nevertheless, there is no standard treatment strategy in cases of pediatric patients. We report a case of a 16-year-old girl with right renal artery occlusion associated with a grade IV liver laceration. She was treated with only balloon angioplasty, and the kidney showed marked improvement of parenchymal perfusion with normalized renal function. Treatment with only balloon angioplasty can be a treatment option in pediatric patients with renal artery injury.

Orbitofacial angioedema is one of the common contrast-induced adverse reactions. The symptoms are recognized, based on the patient's clinical complaints. Based on prior research findings, there were no reports about contrast-induced orbitofacial angioedema that was confirmed on image findings. The researchers herein report on contrast-induced orbitofacial angioedema presented on enhanced computed tomography, following intravenous administration of iodine contrast media.

Spinal meningiomas account for 12% of all the meningiomas and are usually located in the intradural extramedullary space. In some cases, they are associated with some extradural extensions. However, purely extradural spinal meningiomas are rare. Additionally, it is difficult to make an accurate preoperative diagnosis. We report a case of pathologically confirmed atypical meningioma, presented as a posterior epidural mass on the thoracic spine. We review the case, clinical symptoms, radiologic findings and the histologic features.

Subependymomas are rare benign central nervous system tumor which account of 0.7% of all intracranial tumors. Subependymomas show characteristic MR findings according to their location. However, sometimes atypical findings could be found. In addition, subependymomas can occur very rarely in the spinal cord. We report two cases of pathologically confirmed subependymoma, one of which shows atypical appearances in spite of their intraventicular location and the other of which shows rare case of spinal intramedullary subependymoma. We review the clinical symptoms and radiologic findings of two cases