Determination of optimum pixel size and slice thickness for tractography and ulnar nerve diffusion tensor imaging at the cubital tunnel using 3T MRI.

BACKGROUND: Small peripheral nerve tractography is challenging because of the trade-off among resolution, image acquisition time, and signal-to-noise ratio. PURPOSE: To optimize pixel size and slice thickness parameters for fiber tractography and diffusion tensor imaging (DTI) of the ulnar nerve at the cubital tunnel using 3T magnetic resonance imaging (MRI). MATERIAL AND METHODS: Fifteen healthy volunteers (mean age 30 ± 6.8 years) were recruited prospectively. Axial T2-weighted and DTI scans were acquired, covering the cubital tunnel, using different pixel sizes and slice thicknesses. Three-dimensional (3D) nerve tractography was evaluated for the median number and length of the reconstructed fiber tracts and visual score from 0 to 5. Two-dimensional (2D) cross-sectional DTI was evaluated for fractional anisotropy (FA) values throughout the length of the ulnar nerve. RESULTS: A pixel size of 1.3 mm2 revealed the highest number of reconstructed nerve fibers compared to that of 1.1 mm2 (P = 0.048), with a good visual score. A slice thickness of 4 mm had the highest number of reconstructed nerve fibers and visual score compared with other thicknesses (all P < 0.05). In 2D cross-sectional images, the median FA values were in the range of 0.40-0.63 at the proximal, central, and distal portions of the cubital tunnel. Inter-observer agreement for all parameters was good to excellent. CONCLUSION: For fiber tractography and DTI of the ulnar nerve at the cubital tunnel, optimal image quality was obtained using a 1.3-mm2 pixel size and 4-mm slice thickness under MR parameters of this study at 3T.

Comparison of the diagnostic performance of CT Hounsfield unit histogram analysis and dual-energy X-ray absorptiometry in predicting osteoporosis of the femur.

PURPOSE: To evaluate the diagnostic performance of Hounsfield unit histogram analysis (HUHA) of precontrast abdominal-pelvic CT scans for predicting osteoporosis. MATERIALS AND METHODS: The study included 271 patients who had undergone dual X-ray absorptiometry (DXA) and abdominal-pelvic CT within 1 month. HUHA was measured using commercial 3D analysis software (Aquarius iNtuition v4.4.12Ⓡ, TeraRecon) and expressed as a percentage of seven HU range categories related to the ROI: A < 0, 0 ≤ B < 25, 25 ≤ C < 50, 50 ≤ D < 75, 75 ≤ E < 100, 100 ≤ F < 130, and 130 ≤ G. A coronal reformatted precontrast CT image containing the largest Ward's triangle was selected and then the ROI was drawn over the femoral neck. Correlation (r) and ROC curve analyses were used to assess diagnostic performance in predicting osteoporosis using the femur T-score as the reference standard. RESULTS: When the femur T-score was used as the reference, the rs of HUHA-A and HUHA-G were 0.74 and -0.57, respectively. Other HUHA values had moderate to weak correlations (r = -0.33 to 0.27). The correlation of HUHA-A was significantly higher than that of HUHA-G (p = 0.03). The area under the curve (0.95) of HUHA-A differed significantly from that of HUHA-G (0.90; p < 0.01). A HUHA-A threshold ≥ 27.7% was shown to predict osteoporosis based on a sensitivity and specificity of 95.6% and 81.7%, respectively. CONCLUSION: The HUHA-A value of the femoral neck is closely related to osteoporosis and may help predict osteoporosis. KEY POINTS: • HUHA correlated strongly with the DXA femur T-score (HUHA-A, r = 0.74). • The diagnostic performance of HUHA for predicting osteoporosis (AUC = 0.95) was better than that of the average CT HU value (AUC = 0.91; p < 0.05). • HUHA may help predict osteoporosis and enable semi-quantitative measurement of changes in bone mineral density.

Quantitative analysis of cochlear signal intensity on three-dimensional and contrast-enhanced fluid-attenuated inversion recovery images in patients with Meniere's disease: Correlation with the pure tone audiometry test.

PURPOSE: The purpose of this study was to correlate the quantitative analysis of cochlear signal intensity (SI) on 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and contrast-enhanced (CE) 3D-FLAIR images with results of the pure tone audiometry (PTA) test in patients with Meniere's disease (MD). MATERIALS AND METHODS: Over a 3-year period, 123 patients with MD underwent 3-Tesla (3 T) temporal magnetic resonance imaging (MRI), including 3D-FLAIR and CE-FLAIR sequences. The SI of membranous labyrinth of the cochlea in both ears of each patient was measured by drawing a region of interest (ROI) with a seed growing technique. The correlation between measured cochlear SIs on 3D-FLAIR and CE-FLAIR images, contrast enhancement index (CEI), and contrast enhancement ratio (CER) and clinical findings and pre- and post-treatment PTA results were assessed. RESULTS: Cochlear signal ratios of symptomatic ears on 3D-FLAIR and CE-FLAIR images were significantly higher than those of asymptomatic ears (P < 0.001). The area under the curve, from the receiver operating characteristic curve of cochlear SIs on 3D-FLAIR and CE-FLAIR images for discrimination between symptomatic and asymptomatic ears, was 0.729 and 0.728, respectively. Cochlear SIs on 3D-FLAIR and CE-FLAIR images were significantly correlated with patients' sex (P < 0.05 and P < 0.01, respectively), symptomatic ear (both P < 0.0001), and pre-treatment PTA (P < 0.0001 and P < 0.005, respectively), but were not significantly correlated with patients' age, post-treatment PTA or hearing threshold level at 0.5, 1.0, 2.0, or 4.0 kHz. CONCLUSION: Quantitative analysis of cochlear SI on 3D-FLAIR and CE-FLAIR images may be a helpful diagnostic adjunct for MD, but may be of little value in predicting the prognosis of MD.

The most-cited articles in pediatric imaging: a bibliometric analysis.

INTRODUCTION: The number of citations that an article has received reflects its impact on the scientific community. The purpose of our study was to identify and characterize the 51 most-cited articles in pediatric imaging. EVIDENCE ACQUISITION: Based on the database of Journal Citation Reports, we selected 350 journals that were considered as potential outlets for pediatric imaging articles. The Web of Science search tools were used to identify the most-cited articles relevant to pediatric imaging within the selected journals. EVIDENCE SYNTHESIS: The 51 most-cited articles in pediatric imaging were published between 1952 and 2011, with 1980-1989 and 2000-2009 producing 15 articles, each. The number of citations ranged from 576-124 and the number of annual citations ranged from 49.05-2.56. The majority of articles were published in pediatric and related journals (N.=26), originated in the USA (N.=23), were original articles (N.=45), used MRI as imaging modality (N.=27), and were concerned with the subspecialty of brain (N.=34). University College London School of Medicine (N.=6) and School of Medicine University of California (N.=4) were the leading institutions and Reynolds EO (N.=7) was the most voluminous author. CONCLUSIONS: Our study presents a detailed list and an analysis of the most-cited articles in the field of pediatric imaging, which provides an insight into historical developments and allows for recognition of the important advances in this field.

Validation of body composition using bioelectrical impedance analysis in children according to the degree of obesity.

This study aimed to validate body composition analysis using bioelectrical impedance analysis (BIA) against dual-energy X-ray absorptiometry (DXA) in children with obesity and to compare agreement between BIA and DXA according to their degree of obesity. Three hundred and sixteen children aged 6-17 years participated in the Intervention for Childhood and Adolescents Obesity via Activity and Nutrition study. We divided participants by body mass index (BMI) percentile (group 1: mild to moderate obesity; group 2: severe obesity) and compared body composition variables, eg, percentage of body fat (%BF), fat mass (FM), and fat-free mass (FFM) using BIA and DXA. The %BF and FM of BIA were significantly lower (-1.8% and -0.8 kg, respectively), and the FFM of BIA was significantly higher (1.4 kg) than those of DXA. There were significant negative relationships between the absolute value of differences from BIA and DXA and BMI z-scores in %BF, FM, and FFM (regression coefficient [ß]: -1.39, 95% confidence interval [CI]: -1.81 to -0.97; ß: -0.34, 95%CI: -0.61 to -0.06; ß: -0.73, 95%CI: -1.03 to -0.44, respectively). The gap of body compositions between BIA and DXA decreased as participants became more obese, and the differences of FM in boys with severe obesity and the differences of %BF and FFM in girls with severe obesity were much less than those in children with mild to moderate obesity. In conclusion, the agreement between DXA and BIA was better for children with severe obesity than for children with mild to moderate obesity.

The 100 most-cited articles in neuroimaging: A bibliometric analysis.

The purpose of our study was to identify and characterize the 100 most-cited articles in neuroimaging. Based on the database of Journal Citation Reports, we selected 669 journals that were considered as potential outlets for neuroimaging articles. The Web of Science search tools were used to identify the 100 most-cited articles relevant to neuroimaging within the selected journals. The following information was recorded for each article: publication year, journal, category and impact factor of journal, number of citations, number of annual citations, authorship, department, institution, country, article type, imaging technique used, and topic. The 100 most-cited articles in neuroimaging were published between 1980 and 2012, with 1995-2004 producing 69 articles. Citations ranged from 4384 to 673 and annual citations ranged from 313.1 to 24.9. The majority of articles were published in radiology/imaging journals (n=75), originated in the United States (n=58), were original articles (n=63), used MRI as imaging modality (n=85), and dealt with imaging technique (n=45). The Oxford Centre for Functional Magnetic Resonance Imaging of the Brain at John Radcliffe Hospital (n=10) was the leading institutions and Karl J. Friston (n=11) was the most prolific author. Our study presents a detailed list and an analysis of the 100 most-cited articles in the field of neuroimaging, which provides an insight into historical developments and allows for recognition of the important advances in this field.

Replaced common hepatic artery from the superior mesenteric artery: multidetector computed tomography (MDCT) classification focused on pancreatic penetration and the course of travel.

PURPOSE: We categorize the subtypes of the replaced common hepatic artery (RCHA) and evaluate the clinical implications. METHODS: Thirty-four cases of the RCHA were evaluated retrospectively using multidetector computed tomography. We categorized them into the three RCHA subtypes according to pancreatic penetration and the passing routes. The distance between the orifice of the superior mesenteric artery (SMA) and RCHA bifurcation (D SMA-RCHA) was measured using advanced 3D imaging software. Analysis of variance was used to evaluate the difference in D SMA-RCHA according to the RCHA subtype. RESULTS: Type A (n = 17, 50 %) referred to RCHA penetrating the pancreatic parenchyma, all crossing the dorsal aspect of the superior mesenteric vein (SMV). Among them, three cases were accompanied by the circumportal pancreas. Type B (n = 10, 29 %) referred to RCHA without penetration of the pancreatic parenchyma and crossing of the dorsal aspect of the main portal vein (MPV) or SMV. Type C (n = 7, 21 %) referred to RCHA without penetration of the pancreas parenchyma and crossing of the ventral aspect of the MPV or SMV. The mean D SMA-RCHA of each subtype was as follows: type A, 3.13 cm [95 % confidence interval (CI) 2.70-3.57]; type B, 2.04 cm [95 % CI 1.40-2.68]; and type C, 2.14 cm [95 % CI 2.23-2.92]. The D SMA-RCHA of the penetrating pancreatic parenchyma of the RCHA was significantly longer than that of the non-penetrating pancreatic parenchyma (P = 0.007). CONCLUSION: Half of RCHA show penetrating the pancreatic parenchyma, which was categorized as type A, and this type A takes off from the SMA more distally than RCHA without intrapancreatic penetration.

The role of US in finding intussusception and alternative diagnosis: a report of 100 pediatric cases.

BACKGROUND: The clinical diagnosis of intussusception remains challenging, because many children with intussusception may present with non-specific signs and symptoms, which overlap with other conditions. Therefore imaging, in particular ultrasonography (US), plays a significant role in the management of these patients. PURPOSE: To evaluate how US can contribute to the diagnosis in clinically suspected intussusception and finding alternative diagnosis. MATERIAL AND METHODS: We retrospectively reviewed reports of US examinations and medical records of 100 patients (51 boys, 49 girls; mean age, 23.0 ± 12.1 months) who underwent abdominal US for clinically suspected intussusception. Each US study was assessed for the presence or absence of intussusception and for a possible alternative diagnosis in cases interpreted as negative for intussusception. RESULTS: Thirty-seven patients had US findings consistent with intussusception, which was confirmed by air enema. In seven patients, US studies were normal. Alternative diagnoses were identified by US for each of the remaining 56 patients, including ileocolitis (n = 20), terminal ileitis (n = 18), mesenteric lymphadenitis (n = 13), choledochal cyst (n = 1), accessory spleen torsion (n = 1), small bowel ileus (n = 1), midgut volvulus with bowel ischemia (n = 1), and hydronephrosis (n = 1). CONCLUSION: With the high sensitivity and specificity of this study we conclude that US is valuable in detecting intussusception and finding the alternative diagnosis.

Risk factors for recurrence of right colonic uncomplicated diverticulitis after first attack.

PURPOSE: Most patients with acute right colonic uncomplicated diverticulitis can be managed conservatively. The aim of this study was to assess the clinical and radiologic risk factors for recurrence in patients with right colonic uncomplicated diverticulitis. METHODS: The present survey included 469 patients who were successfully managed conservatively for the first episode of right colonic uncomplicated diverticulitis between 2002 and 2012 in a referral center, and records were reviewed from collected data. Patients were divided into two groups: a nonrecurrent and a recurrent group. The clinical and radiologic features of all patients were analyzed to identify possible risk factors for recurrence. The Kaplan-Meier method and Cox regression were used. RESULTS: Seventy-four (15.8 %) patients had recurrence, and 15 (3.2 %) received surgery at recurrence within a median follow-up of 59 months. The mean recurrence interval after the first attack was 29 months. In univariate and multivariate analyses, risk factors for recurrence were confirmed multiple diverticula (relative risk [RR], 2.62; 95 % confidence interval [CI], 1.56-4.40) and intraperitoneally located diverticulitis (RR, 3.73; 95 % CI, 2.13-6.52). Of 66 patients with two risk factors, 36 (54.5 %) had recurrence and 10 (15.2 %) received surgery at recurrence. CONCLUSIONS: In patients with right colonic uncomplicated diverticulitis who have multiple diverticula and intraperitoneally located diverticulitis, the possibility of recurrence and surgical rate are high. Poor outcome may be cautioned in these patients.

Acute Ileal Diverticulitis: Computed Tomography and Ultrasound Findings.

BACKGROUND: Acute ileal diverticulitis is a rare disease mimicking acute appendicitis. Inaccurate diagnosis with a low prevalence and nonspecific symptoms leads to delayed or improper management. METHODS: This retrospective study aimed to investigate the characteristic sonographic (US) and computed tomography (CT) findings with clinical features in seventeen patients with acute ileal diverticulitis diagnosed between March 2002 and August 2017. RESULTS: The most common symptom was abdominal pain (82.3%, 14/17) localized to the right lower quadrant (RLQ) in 14 patients. The characteristic CT findings of acute ileal diverticulitis were ileal wall thickening (100%, 17/17), identification of inflamed diverticulum at the mesenteric side (94.1%, 16/17), and surrounding mesenteric fat infiltration (100%, 17/17). The typical US findings were outpouching diverticular sac connecting to the ileum (100%, 17/17), peridiverticular inflamed fat (100%, 17/17), ileal wall thickening with preserved layering pattern (94.1%, 16/17), and increased color flow to the diverticulum and surrounding inflamed fat on color Doppler imaging (100%, 17/17). The perforation group had a significantly longer hospital stay than non-perforation group (p = 0.002). In conclusion, acute ileal diverticulitis has characteristic CT and US findings that allow radiologists to accurately diagnose the disease.

How many times should we repeat measurements of the ultrasound-guided attenuation parameter for evaluating hepatic steatosis?

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.

Comparison between Two-Dimensional and Point Shear Wave Elastography Techniques in Evaluating Liver Fibrosis Using Histological Staging as the Reference Standard: A Prospective Pilot Study.

Evaluation of hepatic fibrosis is essential to prevent liver-related morbidity and mortality. Although various types of ultrasound shear wave elastography (SWE) have been used and validated, there are limited studies on the relatively newer technique, two-dimensional SWE (2D-SWE). Therefore, this study aimed to compare the diagnostic performances of 2D-SWE and point SWE (p-SWE) for evaluating liver fibrosis using histology as the reference standard. To measure liver stiffness (LS) values, 87 patients underwent 2D-SWE and p-SWE using the same machine. Technical failures and unreliable measurements were also evaluated. The diagnostic performances of 2D-SWE and p-SWE were compared using area under the receiver operating characteristic (AUROC) curve analysis. No technical failures were observed in either method; however, unreliable measurements were less frequent in 2D-SWE (1/87 [1.1%]) than in p-SWE (8/87 [9.2%]) (p < 0.001). The AUROC of the LS values of 2D-SWE were significantly higher than those of p-SWE for diagnosing significant fibrosis (0.965 vs. 0.872, p = 0.022) and cirrhosis (0.994 vs. 0.886, p = 0.042). In conclusion, 2D-SWE is more reliable and accurate than p-SWE for diagnosing hepatic fibrosis.

High-resolution computed tomography findings of swine-origin influenza A (H1N1) virus (S-OIV) infection: comparison with scrub typhus.

BACKGROUND: Swine-origin influenza A (H1N1) virus (S-OIV) infection and scrub typhus, also known as tsutsugamushi disease can manifest as acute respiratory illnesses, particularly during the late fall or early winter, with similar radiographic findings, such as a predominance of ground-glass opacity (GGO). PURPOSE: To differentiate S-OIV infection from scrub typhus using high-resolution computed tomography (HRCT). MATERIAL AND METHODS: We retrospectively reviewed the HRCT findings of 14 patients with S-OIV infection and 10 patients with scrub typhus. We assessed the location, cross-sectional distribution, and the presence of a peribronchovascular distribution of GGO and consolidations on HRCT. We also assessed the presence of interlobular septal thickening, bronchial wall thickening, pneumothorax, pneumomediastinum, pleural effusion, and mediastinal or axillary lymph node enlargement. RESULTS: Scrub typhus was more common than S-OIV in elderly patients (P < 0.001). The monthly incidences of S-OIV and scrub typhus infection reached a peak between October and November. About 86% of S-OIV patients and 80% of scrub typhus patients presented with GGO. About 67% of the GGO lesions in S-OIV had a peribronchovascular distribution, but this was absent in scrub typhus (P = 0.005). Consolidation (93% vs. 10%, P < 0.001) and bronchial wall thickening (43% vs. 0%, P = 0.024) were more frequent in S-OIV infection than scrub typhus. Interlobular septal thickening (90% vs. 36%, P = 0.013) and axillary lymphadenopathy (90% vs. 0%, P < 0.001) were more common in scrub typhus than S-OIV infection. CONCLUSION: There was considerable overlap in HRCT findings between S-OIV infection and scrub typhus. However, S-OIV showed a distinctive peribronchovascular distribution of GGO lesions. Consolidation and bronchial wall thickening were seen more frequently in S-OIV infection, whereas interlobular septal thickening and axillary lymphadenopathy were more common in scrub typhus. Thus, CT could be helpful for differential diagnosis between S-OIV infection and scrub typhus.

Diagnostic Performance of 2-D Shear Wave Elastography on the Evaluation of Hepatic Fibrosis with Emphasis on Impact of the Different Region-of-Interest Methods.

The purpose of this study was to evaluate the impact of the different region-of-interest (ROI) methods of 2-D shear wave elastography (2-D SWE) on hepatic fibrosis diagnosis. In this retrospective study, 83 patients who underwent 2-D SWE with three ROI methods (a circle ROI, a box ROI and multiple ROIs in an elastogram) and transient elastography (TE) were included. Liver stiffness (LS) was measured five times with each ROI method. These LS values were compared, and their correlation with those obtained from TE was evaluated. The LS values obtained using the three different ROI methods differed statistically (p < 0.001). However, the LS values obtained using each ROI method of 2-D SWE were highly correlated with those obtained using TE (r > 0.7, p < 0.001). All three ROI methods of 2-D SWE had high areas under the receiver operating characteristic curve in diagnosing significant fibrosis and cirrhosis (0.841, 0.820 and 0.840, respectively; 0.962, 0.946 and 0.945, respectively). There were no significant differences in area under the receiver operating characteristic curve among the ROI methods of 2-D SWE. Regardless of the ROI method, 2-D SWE had high performance in diagnosing hepatic fibrosis.

Unusual, but important, peri- and extra-articular manifestations of rheumatoid arthritis: a pictorial essay.

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.

Non-Pathological Opacification of the Cavernous Sinus on Brain CT Angiography: Comparison with Flow-Related Signal Intensity on Time-of-Flight MR Angiography.

Purpose: To investigate the non-pathological opacification of the cavernous sinus (CS) on brain computed tomography angiography (CTA) and compare it with flow-related signal intensity (FRSI) on time-of-flight magnetic resonance angiography (TOF-MRA). Methods: Opacification of the CS was observed in 355 participants who underwent CTA and an additional 77 participants who underwent examination with three diagnostic modalities: CTA, TOF-MRA, and digital subtraction angiography (DSA). Opacification of the CS, superior petrosal sinus (SPS), inferior petrosal sinus (IPS), and pterygoid plexus (PP) were also analyzed using a five-point scale. The Wilcoxon test was used to determine the frequencies of the findings on each side. Additionally, the findings on CTA images were compared with those on TOF-MRA images in an additional 77 participants without dural arteriovenous fistula (DAVF) using weighted kappa (κ) statistics. Results: Neuroradiologists identified non-pathological opacification of the CS (n = 100, 28.2%) on brain CTA in 355 participants. Asymmetry of opacification in the CS was significantly correlated with the grade difference between the right and left CS, SPS, IPS, and PP (p < 0.0001 for CS, p < 0.0001 for SPS, p < 0.0001 for IPS, and p < 0.05 for PP). Asymmetry of the opacification and FRSI in the CS was observed in 77 participants (CTA: n = 21, 27.3%; TOF-MRA: n = 22, 28.6%). However, there was almost no agreement between CTA and TOF-MRA (κ = 0.10, 95% confidence interval: -0.12-0.32). Conclusion: Asymmetry of non-pathological opacification and FRSI in the CS may be seen to some extent on CTA and TOF-MRA due to anatomical variance. However, it shows minimal reliable association with the FRSI on TOF-MRA.

Impact of respiratory motion on liver stiffness measurements according to different shear wave elastography techniques and region of interest methods: a phantom study.

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.

Ultrasound and MRI Findings of Giant Cell Fibroblastoma in the Abdominal Wall: Radiologic-Pathologic Correlations.

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.