Added Value of Cone-Beam Computed Tomography for Detecting Hepatocellular Carcinomas and Feeding Arteries during Transcatheter Arterial Chemoembolization Focusing on Radiation Exposure.

Background and Objectives: This study aimed to evaluate the added value of cone-beam computed tomography (CBCT) for detecting hepatocellular carcinomas (HCC) and feeding arteries during transcatheter arterial chemoembolization (TACE). Material and methods: Seventy-six patients underwent TACE and CBCT. We subcategorized patients into groups I (61 patients: possible superselection of tumor/feeding arteries) and II (15 patients: limited superselection of tumor/feeding arteries). We evaluated fluoroscopy time and radiation dose during TACE. Two blinded radiologists independently performed an interval reading based on digital subtraction angiography (DSA) imaging only and DSA combined with CBCT in group I. Result: The mean total fluoroscopy time was 1456.3 ± 605.6 s. The mean dose-area product (DAP), mean DAP of CBCT, and mean ratio of DAP of CBCT to total DAP was 137.1 ± 69.2 Gy cm2, 18.3 ± 7.1 Gy cm2, and 13.3%, respectively. The sensitivity for detecting HCC increased after the additional CBCT reading, from 69.6% to 97.3% and 69.6% to 96.4% for readers 1 and 2, respectively. The sensitivity for detecting feeding arteries increased from 60.3% to 96.6% and 63.8% to 97.4% for readers 1 and 2, respectively. Conclusions: CBCT can increase sensitivity for detecting HCCs and feeding arteries without significantly increasing the radiation exposure.

Accelerated Pancreatobiliary MRI for Pancreatic Cancer Surveillance in Patients With Pancreatic Cystic Neoplasms.

BACKGROUND: Pancreatobiliary MRI is often recommended for patients at risk of developing pancreas cancer. But the surveillance MRI protocol has not yet been widely accepted. PURPOSE: To establish an accelerated MRI protocol targeting the table time of 15 minutes for pancreatic cancer surveillance and test its performance in lesion characterization. STUDY TYPE: Prospective. POPULATION: A total of 30 participants were enrolled, who were undergoing follow-up care for intraductal papillary mucinous neoplasms or newly diagnosed pancreatic cysts (≥10 mm) and were scheduled for or had recently undergone contrast-enhanced CT (CECT). FIELD STRENGTH/SEQUENCE: A 3 T; heavily T2WI, 3D MRCP, DWI, dynamic T1WI, two-point Dixon. ASSESSMENT: In-room time and table time were measured. Seven radiologists independently reviewed image quality of MRI and then the presence of high-risk stigmata and worrisome features in addition to diagnostic confidence for accelerated MRI, CECT, and the noncontrast part of accelerated MRI (NC-MRI). STATISTICAL ANALYSIS: Fisher's exact test was used for categorical variables and either the Student's t-test or Mann-Whitney test was performed for continuous variables. The generalized estimated equation was used to compare the diagnostic performance of examinations on a per-patient basis. Interobserver agreement was evaluated via Fleiss kappa. A P value of <0.05 was considered to be statistically significant. RESULTS: The in-room time was 18.5 ± 2.6 minutes (range: 13.7-24.9) and the table time was 13.9 ± 1.9 minutes (range: 10.7-17.5). There was no significant difference between the diagnostic performances of the three examinations (pooled sensitivity: 75% for accelerated MRI and CECT, 68% for NC-MRI, P = 0.95), with the highest significant diagnostic confidence for accelerated MRI (4.2 ± 0.1). With accelerated MRI, the interobserver agreement was fair to excellent for high-risk stigmata (κ = 0.34-0.98). DATA CONCLUSION: Accelerated MRI protocol affords a table time of 15 minutes, making it potentially suitable for cancer surveillance in patients at risk of developing pancreatic cancer. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY STAGE: 2.

Gastrointestinal Air Motion Artifact Which Can Be Mistaken for Active Gastrointestinal Bleeding in Multidetector Computed Tomography: Phantom and Clinical Study.

OBJECTIVES: We investigated the computed tomographic characteristics of gastrointestinal air motion artifact (GIAMA), which can be misinterpreted as active gastrointestinal bleeding. METHODS: We simulated GIAMA using 3 types of air-ball phantoms (air-ball in water, air-ball in oil, air-water-ball in oil) and a bovine intestine in oil phantom. We also performed a retrospective clinical review of precontrast abdominal computed tomography images of 76 patients to investigate the frequency, location, shape, and maximum density of hyperdense GIAMA. RESULTS: In phantom studies, air motion artifacts appeared as dark and bright streak artifacts at the borders of a moving air-ball and water or oil. In the clinical study, hyperdense GIAMA was visualized in 60 (79.0%) of 76 patients. The small intestine was most commonly affected (46.4%), and the intramural type had the highest frequency (58.0%). CONCLUSION: Knowing the radiologic features of GIAMA can assists radiologists in identifying active gastrointestinal bleeding sites accurately.

Ultrasonographic Quantitative Analysis of Fatty Pancreas in Obese Children: Its Correlation with Metabolic Syndrome and Homeostasis Model Assessment of Insulin Resistance.

OBJECTIVES: To evaluate pancreatic echogenicity on transabdominal ultrasonography and the correlation of fatty pancreas with metabolic syndrome (MetS), as well as insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]). STUDY DESIGN: This retrospective study included 135 obese children and adolescents who underwent transabdominal ultrasonography from January 2015 to December 2015. Fatty pancreas was quantitatively analyzed using the pancreato-perihepatic fat index (PPHFI). The correlation between the PPHFI and HOMA-IR was analyzed, and multivariate logistic regression analysis was used to determine factors that were independently correlated with MetS. Receiver operating characteristic curve analysis was performed to determine the best cut-off value of the PPHFI for diagnosing MetS. RESULTS: The PPHFI and the HOMA-IR value were significantly higher in subjects with MetS than in those without MetS (P < .0001). The PPHFI also showed an association with the HOMA-IR value (r = 0.70; P <.0001). The PPHFI was an independent factor for diagnosing MetS (OR 4.36; P = .032). The best cut-off value for the PPHFI for a diagnosis of MetS was 2.34 with a sensitivity of 0.96 and specificity 0.70. CONCLUSIONS: These results suggest that an increased PPHFI is significantly correlated with MetS and insulin resistance, and that the PPHFI may be a useful indicator for diagnosing MetS in obese children and adolescents. The impact of the presence of fatty pancreas in obese children and adolescents must be evaluated.

Diagnostic accuracy of transabdominal high-resolution US for staging gallbladder cancer and differential diagnosis of neoplastic polyps compared with EUS.

PURPOSE: To compare the diagnostic accuracy of transabdominal high-resolution ultrasound (HRUS) for staging gallbladder cancer and differential diagnosis of neoplastic polyps compared with endoscopic ultrasound (EUS) and pathology. MATERIALS AND METHODS: Among 125 patients who underwent both HRUS and EUS, we included 29 pathologically proven cancers (T1 = 7, T2 = 19, T3 = 3) including 15 polypoid cancers and 50 surgically proven polyps (neoplastic = 30, non-neoplastic = 20). We reviewed formal reports and assessed the accuracy of HRUS and EUS for diagnosing cancer as well as the differential diagnosis of neoplastic polyps. Statistical analyses were performed using chi-square tests. RESULTS: The sensitivity, specificity, PPV, and NPV for gallbladder cancer were 82.7 %, 44.4 %, 82.7 %, and 44 % using HRUS and 86.2 %, 22.2 %, 78.1 %, and 33.3 % using EUS. HRUS and EUS correctly diagnosed the stage in 13 and 12 patients. The sensitivity, specificity, PPV, and NPV for neoplastic polyps were 80 %, 80 %, 86 %, and 73 % using HRUS and 73 %, 85 %, 88 %, and 69 % using EUS. Single polyps (8/20 vs. 21/30), larger (1.0 ± 0.28 cm vs. 1.9 ± 0.85 cm) polyps, and older age (52.5 ± 13.2 vs. 66.1 ± 10.3 years) were common in neoplastic polyps (p < 0.05). CONCLUSION: Transabdominal HRUS showed comparable accuracy for diagnosing gallbladder cancer and differentiating neoplastic polyps compared with EUS. HRUS is also easy to use during our routine ultrasound examinations. KEY POINTS: • HRUS showed comparable diagnostic accuracy for GB cancer compared with EUS. • HRUS and EUS showed similar diagnostic accuracy for differentiating neoplastic polyps. • Single, larger polyps and older age were common in neoplastic polyps. • HRUS is less invasive compared with EUS.

Comparison of push-out bond strength of fiber-reinforced composite resin posts according to cement thickness.

STATEMENT OF PROBLEM: Post space size and cement thickness can differ because of variations in root canal morphology, such as an oval shape, and because the entire canal space cannot be included in the post space preparation. As a result, increased cement thickness around the post may affect the bond strength between the post and the dentin. PURPOSE: The purpose of this in vitro study was to evaluate the push-out bond strength of fiber-reinforced composite resin posts to root dentin with cement layers of varying thickness. MATERIAL AND METHODS: Thirty human premolars were endodontically treated and restored with fiber-reinforced composite resin posts. Post space was prepared using a drill with a 1.5-mm diameter and diameters of 1.25 mm (small [S] group), 1.375 mm (medium [M] group), and 1.5 mm (large [L] group) were cemented. The specimens were sectioned horizontally into 1-mm-thick slices, and the push-out bond strengths of the apical and coronal fragments were evaluated. Bond strength was compared using analysis of variance and 2-sample t tests (α=.05). RESULTS: No significant differences were found in the debonding force and push-out bond strength among fiber-reinforced composite posts of different sizes (P>.05). The mean debonding force and standard deviation of the posts were 25.05 ±9.52 N for the S group, 28.17 ±11.38 N for the M group, and 33.78 ±12.47 N for the L group. The corresponding push-out bond strength values were 3.11 ±1.54 MPa, 3.39 ±1.4 MPa, and 4.15 ±1.75 MPa. The differences in debonding force between the apical (26.43 ±10.72 N) and coronal (31.57 ±12.03 N) areas were not significant (P>.05). However, the differences in push-out bond strength between the apical (4.27 ±1.73 MPa) and coronal areas (2.83 ±1.08 MPa) were significant (P<.05). CONCLUSIONS: The widening of post spaces and, consequently, the increased cement thickness do not significantly affect the bond strength of fiber-reinforced composite resin posts to root dentin.

Diagnostic accuracy of liver imaging reporting and data system (LI-RADS) v2014 for intrahepatic mass-forming cholangiocarcinomas in patients with chronic liver disease on gadoxetic acid-enhanced MRI.

PURPOSE: To investigate the utility of Liver Imaging Reporting and Data System (LI-RADS) v2014 for intrahepatic mass-forming cholangiocarcinomas (IMCC) on gadoxetic acid-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: This retrospective study was approved by our Institutional Review Board with waiver of informed consent. Pathologically confirmed IMCCs (n = 35) and hepatocellular carcinomas (HCCs) (n = 71) in patients with chronic hepatitis B or cirrhosis who had undergone gadoxetic acid-enhanced 3.0T or 1.5T MRI were included. Three radiologists independently assigned LI-RADS categories for each IMCC or HCC. Diagnostic performances of LR-M (probable malignancy, not specific for HCC) and LR-5/5v (definitely HCC) were investigated, and imaging features were compared between IMCCs of LR-M and non-LR-M. RESULTS: In all, 88.6% (31/35), 80.0% (28/35), and 74.3% (26/35) of IMCCs and 12.7% (9/71), 22.5% (16/71), and 16.9% (12/71) of HCCs were assigned as LR-M by the three reviewers with substantial interobserver agreements (kappa = 0.664-0.741). Among IMCCs, 2.9% (1/35), 5.7% (2/35), and 11.4% (4/35) were categorized as LR-5/5v. IMCCs of non-LR-M (n = 8, using the consensus method) were significantly smaller (24.1 ± 17.4 vs. 62.8 ± 30.6 mm, P = 0.002) and showed higher frequencies of arterial hyperenhancement (75.0% (6/8) vs. 7.4% (2/27), P < 0.001) and lower frequencies of non-HCC malignancy-favoring features such as peripheral enhancement (12.5% (1/8) vs. 77.8% (21/27), P = 0.002) or the target appearance on the hepatobiliary phase (0% (0/8) vs. 81.5% (22/27), P < 0.001) than IMCCs of LR-M (n = 27). CONCLUSION: Using LI-RADS, the majority of IMCCs can be accurately categorized as LR-M on gadoxetic acid-enhanced MRI; however, caution is warranted, as some atypical IMCCs may be assigned as LR-5/5v resulting in a false-positive diagnosis of HCC. J. Magn. Reson. Imaging 2016;44:1330-1338.

Acute invasive small-bowel Anisakiasis: clinical and CT findings in 19 patients.

PURPOSE: To evaluate the clinical and CT findings in patients with small-bowel Anisakiasis. MATERIALS AND METHODS: Nineteen patients with small-bowel Anisakiasis and who underwent abdominal CT between 2005 and 2012 were enrolled in our study. All of these patients were diagnosed using either a serologic test for Anisakiasis (n = 18) or by pathology (n = 1). Their medical records were reviewed in order to determine the clinical findings. CT images were retrospectively reviewed by two radiologists to evaluate the characteristics of the involved bowel wall and the ancillary findings. RESULTS: All patients had presented with the acute onset of severe abdominal pain as well as a history of having recently eaten raw fish. The mean time interval from eating the fish to the onset of abdominal pain was 1.7 days. Eighteen patients were treated conservatively and experienced resolution of their symptoms within seven days of hospitalization. One patient underwent surgical exploration for presumed small-bowel ischemia. The sites of involvement included the ileum (16/19, 84%) and jejunum (3/19, 16%). All patients had circumferential bowel-wall thickening (mean, 0.8 cm) with an intermediate length of involved bowel (mean, 7.9 cm). Small-bowel obstruction occurred in 16 patients (84%). The target sign was present in 17 patients (89%), ascites, particularly in the perilesional area, in 16 patients (84%), and mesenteric edema in 15 patients (79%). CONCLUSION: Small-bowel Anisakiasis should be considered in the differential diagnosis of acute abdomen in order to avoid unnecessary surgery when patients present with abdominal pain after having recently eaten raw fish, concentric bowel-wall thickening with the target sign in the ileum, perilesional ascites, as well as bowel obstruction seen on CT.

Comparison of Image Quality and Radiation Dose in Pediatric Temporal Bone CT Using Photon-Counting Detector CT and Energy-Integrating Detector CT.

BACKGROUND AND PURPOSE: Currently, there is a lack of research directly comparing photon-counting detector CT (PCD-CT) and energy-integrating detector CT (EID-CT) in pediatric temporal bone CT imaging. The purpose of this study was to compare the image quality and radiation dose of temporal bone CT scans in pediatric patients acquired with PCD-CT and EID-CT. MATERIALS AND METHODS: The retrospective study included a total of 110 pediatric temporal bone CT scans (PCD-CT, n = 52; EID-CT, n = 58). Two independent readers evaluated the spatial resolution of 4 anatomic structures (tympanic membrane, incudostapedial joint, stapedial crura, and cochlear modiolus) and overall image quality by using a 4-point scale. Interreader agreement was assessed. Dose-length product for each CT was compared, and subgroup analyses were performed based on age (younger than 3 years, 3-5 years, 6-11 years, and 12 years and above). RESULTS: PCD-CT demonstrated statistically significantly higher scores than EID-CT for all items (tympanic membrane, 2.9 versus 2.4; incudostapedial joint, 3.6 versus 2.6; stapedial crura, 3.2 versus 2.4; cochlear modiolus, 3.4 versus 2.8; overall image quality, 3.6 versus 2.8; P < .05). Interreader agreement ranged from good to excellent (interclass correlation coefficients, 0.6-0.81). PCD-CT exhibited a 43% dose reduction compared with EID-CT, with a particularly substantial reduction of over 70% in the subgroups of children younger than 6 years. CONCLUSIONS: PCD temporal bone CT achieves significantly superior imaging quality at a lower radiation dose compared with EID-CT.

Safety and efficacy of fluoroscopy-guided urethral catheterization in case of failed blind or cystoscopy-assisted urethral catheterization.

This retrospective study evaluated the safety and efficacy of fluoroscopy-guided urethral catheterization in patients who failed blind or cystoscopy-assisted urethral catheterization. We utilized our institutional database between January 2011 and March 2023, and patients with failed blind or cystoscopy-assisted urethral catheterization and subsequent fluoroscopy-guided urethral catheterization were included. A 5-Fr catheter was inserted into the urethral orifice, and the retrograde urethrography (RGU) was acquired. Subsequently, the operator attempted to pass a hydrophilic guidewire to the urethra. If the guidewire and guiding catheter could be successfully passed into the bladder, but the urethral catheter failed pass due to urethral stricture, the operator determined either attempted again with a reduced catheter diameter or performed balloon dilation according to their preference. Finally, an appropriately sized urethral catheter was selected, and an endhole was created using an 18-gauge needle. The catheter was then inserted over the wire to position the tip in the bladder lumen and ballooned to secure it. We reviewed patients' medical histories, the presence of hematuria, and RGU to determine urethral abnormalities. Procedure-related data were assessed. Study enrolled a total of 179 fluoroscopy-guided urethral catheterizations from 149 patients (all males; mean age, 73.3 ± 13.3 years). A total of 225 urethral strictures were confirmed in 141 patients, while eight patients had no strictures. Urethral rupture was confirmed in 62 patients, and hematuria occurred in 34 patients after blind or cystoscopy-assisted urethral catheterization failed. Technical and clinical success rates were 100%, and procedure-related complications were observed in four patients (2.2%). The mean time from request to urethral catheter insertion was 129.7 ± 127.8 min. The mean total fluoroscopy time was 3.5 ± 2.5 min and the mean total DAP was 25.4 ± 25.1 Gy cm2. Balloon dilation was performed in 77 patients. Total procedure time was 9.2 ± 7.6 min, and the mean procedure time without balloon dilation was 7.1 ± 5.7 min. Fluoroscopy-guided urethral catheterization is a safe and efficient alternative in patients where blind or cystoscopy-assisted urethral catheterization has failed or when cystoscopy-urethral catheterization cannot be performed.

Acupuncture-Induced Abscess in the Retroperitoneal Cavity and Thigh Muscle: A Case Report.

Acupuncture is increasingly being used in Asian countries and is generally considered a relatively safe procedure. However, adverse events have been reported consistently. Therefore, clinicians should be aware of the possibility of acupuncture-related complications and should actively treat serious cases. We report a case of an acupuncture-induced large abscess in the retroperitoneal cavity and thigh muscles treated with percutaneous catheter drainage, surgical incision, and drainage.

Detection and position evaluation of chest percutaneous drainage catheter on chest radiographs using deep learning.

PURPOSE: This study aimed to develop an algorithm for the automatic detecting chest percutaneous catheter drainage (PCD) and evaluating catheter positions on chest radiographs using deep learning. METHODS: This retrospective study included 1,217 chest radiographs (proper positioned: 937; malpositioned: 280) from a total of 960 patients underwent chest PCD from October 2017 to February 2023. The tip location of the chest PCD was annotated using bounding boxes and classified as proper positioned and malpositioned. The radiographs were randomly allocated into the training, validation sets (total: 1,094 radiographs; proper positioned: 853 radiographs; malpositioned: 241 radiographs), and test datasets (total: 123 radiographs; proper positioned: 84 radiographs; malpositioned: 39 radiographs). The selected AI model was used to detect the catheter tip of chest PCD and evaluate the catheter's position using the test dataset to distinguish between properly positioned and malpositioned cases. Its performance in detecting the catheter and assessing its position on chest radiographs was evaluated by per radiographs and per instances. The association between the position and function of the catheter during chest PCD was evaluated. RESULTS: In per chest radiographs, the selected model's accuracy was 0.88. The sensitivity and specificity were 0.86 and 0.92, respectively. In per instance, the selected model's the mean Average Precision 50 (mAP50) was 0.86. The precision and recall were 0.90 and 0.79 respectively. Regarding the association between the position and function of the catheter during chest PCD, its sensitivity and specificity were 0.93 and 0.95, respectively. CONCLUSION: The artificial intelligence model for the automatic detection and evaluation of catheter position during chest PCD on chest radiographs demonstrated acceptable diagnostic performance and could assist radiologists and clinicians in the early detection of catheter malposition and malfunction during chest percutaneous catheter drainage.

Fluoroscopy-Guided Percutaneous Transthoracic Pleural Forceps Biopsy in Patients With Exudative Pleural Effusion.

OBJECTIVE: This study aimed to evaluate the diagnostic performance and procedural characteristics of fluoroscopy-guided percutaneous transthoracic pleural forceps biopsy (PTPFB) in patients with exudative pleural effusion. MATERIALS AND METHODS: Patients with exudative pleural effusion who underwent PTPFB between May 1, 2014, and February 28, 2023, were included in this retrospective study. The interval between percutaneous catheter drainage (PCD) and PTPFB, number of biopsies, procedural time, and procedure-related complications were evaluated. The sensitivity, specificity, and accuracy of diagnosing malignancy were computed for pleural cytology using PCD drainage, PTPFB, and combined PTPFB and pleural cytology. RESULTS: Seventy-one patients, comprising 50 male and 21 female (mean age, 69.5 ± 15.3 years), were included in this study. The final diagnoses were benign lesions in 48 patients (67.6%) and malignant in 23 patients (32.4%). The overall interval between PCD and biopsy was 2.4 ± 3.7 days. The interval between PCD and biopsy in the group that underwent delayed PTPFB was 5.2 ± 3.9 days. The mean number of biopsies was 4.5 ± 1.3. The mean procedural time was 4.4 ± 2.1 minutes. Minor bleeding complications were reported in one patient (1.4%). The sensitivity, specificity, and accuracy for pleural cytology, PTPFB, and combined PTPFB and pleural cytology were 47.8% (11/23), 100% (48/48), and 83.1% (59/71), respectively; 65.2% (15/23), 100% (48/48), and 88.7% (63/71), respectively; and 78.3% (18/23), 100% (48/48), and 93.0% (66/71), respectively. The sensitivity and accuracy of cytology combined with PTPFB were significantly higher than those of cytological testing alone (P = 0.008 and 0.001, respectively). CONCLUSION: Fluoroscopy-guided PTPFB is an accurate and safe diagnostic technique for patients with exudative pleural effusion, with acceptable diagnostic performance, low complication rates, and reasonable procedural times.

[Delayed Bilateral Common Femoral Pseudoaneurysm after Percutaneous Access with Interventional Management: A Case Report]. / ê²½í”¼ì  ì ‘ê·¼ì„ 통한 ì‹œìˆ í›„ì— 발생한 지연성 양측 총대퇴 가성동맥류 및 ì¸í„°ë²¤ì ˜ 치료: 증례 ë³´ê³ .

Common femoral artery pseudoaneurysm is a potentially serious complication of peripheral angiography. There have been few prior reports of simultaneous pseudoaneurysm in both common femoral arteries after percutaneous access. Here we report the case of a 58-year-old male patient who presented with phlegmon or abscess a few days after bilateral femoral access, after which newly developed bilateral femoral pseudoaneurysm with wide neck was observed on CT angiography 2 months after infection treatment. Because the patient refused surgery for pseudoaneurysm, a stent-graft was inserted in the left side, and percutaneous thrombin injection under US guidance with balloon occlusion was performed for the right side. Most pseudoaneurysms occur immediately after the causative procedure. However, there have been some cases in which pseudoaneurysms may occur several weeks or months later; it is therefore necessary to check the risk factors and to carefully observe the hemostasis site.

Reversible Ortner's Syndrome as a Presenting Feature of Thyrotoxicosis in an Adolescent: A Rare Case Report.

Ortner's or cardiovocal syndrome is hoarseness attributable to left recurrent laryngeal nerve (RLN) palsy associated with mechanical compression of the nerve by pathologically enlarged cardiovascular structures. Ortner's syndrome is a rare condition, and to our knowledge, only a few cases have been reported in Korea. Furthermore, this condition is extremely uncommon in pediatric patients with thyrotoxicosis-related RLN paralysis. We report a case of reversible Ortner's syndrome in an adolescent who presented with secondary pulmonary hypertension related to thyrotoxicosis.

[Comparison of True and Virtual Non-Contrast Images of Liver Obtained with Single-Source Twin Beam and Dual-Source Dual-Energy CT]. / 간의 ë‹¨ì¼ì„ ì› Twin Beamê³¼ ì´ì¤‘ì„ ì› 이중에너지 ì „ì‚°í™”ë‹¨ì¸µì´¬ì˜ì˜ 비조영증강 영상과 가상 비조영증강 영상의 비교 연구.

Purpose: To assess the magnitude of differences between attenuation values of the true non-contrast image (TNC) and virtual non-contrast image (VNC) derived from twin-beam dual-energy CT (tbDECT) and dual-source DECT (dsDECT). Materials and Methods: This retrospective study included 62 patients who underwent liver dynamic DECT with tbDECT (n = 32) or dsDECT (n = 30). Arterial VNC (AVNC), portal VNC (PVNC), and delayed VNC (DVNC) were reconstructed using multiphasic DECT. Attenuation values of multiple intra-abdominal organs (n = 11) on TNCs were subsequently compared to those on multiphasic VNCs. Further, we investigated the percentage of cases with an absolute difference between TNC and VNC of ≤ 10 Hounsfield units (HU). Results: For the mean attenuation values of TNC and VNC, 33 items for each DECT were compared according to the multiphasic VNCs and organs. More than half of the comparison items for each DECT showed significant differences (tbDECT 17/33; dsDECT 19/33; Bonferroni correction p < 0.0167). The percentage of cases with an absolute difference ≤ 10 HU was 56.7%, 69.2%, and 78.6% in AVNC, PVNC, and DVNC in tbDECT, respectively, and 70.5%, 78%, and 78% in dsDECT, respectively. Conclusion: VNCs derived from the two DECTs were insufficient to replace TNCs because of the considerable difference in attenuation values.

Renal Epithelioid Angiomyolipoma with Epithelial Cysts Mimicking Cystic Renal Cell Carcinoma: A Case Report of Combination of Two Rare Entities.

Renal angiomyolipomas (AMLs) are typically solid tumors, but there have been few reports of a rare cystic variant of AML. AML with epithelial cysts, where the epithelial cyst has a cuboidal epithelial lining, account for the majority of them. Next, epithelioid AML (EAML) with cystic changes due to hemorrhage and necrosis, which is composed of epithelioid cells with abundant eosinophilic cytoplasm, have also been reported. These rare cystic types of AML can be mistaken for other cystic tumors, such as cystic renal cell carcinoma, in preoperative imaging. We report the imaging findings of a rare case of EAML with epithelial cysts.

Quantitative Analysis of Pancreatic Fat in Children with Obesity Using Magnetic Resonance Imaging and Ultrasonography.

PURPOSE: The aim of this study was to evaluate the pancreatic fat fraction (PFF) using magnetic resonance imaging (MRI) in children with and without obesity and to correlate PFF with body mass index (BMI) z-score, hepatic fat fraction (HFF), and ultrasonography-derived pancreato-perihepatic fat index (PPHFI). METHODS: This prospective study included 45 children with obesity and 19 without obesity (control group). PFF and HFF were quantitatively assessed using the abdominal multi-echo Dixon method for MRI. The PPHFI was assessed using transabdominal ultrasonography. Anthropometric, MRI, and ultrasonographic characteristics were compared between the two groups. Correlations between PFF, HFF, PPHFI, and BMI z-scores in each group were also analyzed. RESULTS: The PFF, HFF, PPHFI, and BMI z-score were higher in the group with obesity than in the control group (PFF: 6.65±3.42 vs. 1.78±0.55, HFF: 19.5±13.0 vs. 2.31±1, PPHFI: 3.65 ±1.63 vs. 0.94±0.31, BMI z-score: 2.27±0.56 vs. 0.42±0.54, p<0.01, respectively). PFF was correlated with BMI z-scores, PPHFI, and HFF in the obesity group, and multivariate analysis showed that PFF was strongly correlated with BMI z-score and PPHFI (p<0.05). The BMI z-score was strongly correlated with PFF in the control group (p<0.01). CONCLUSION: These results suggest that MRI-derived PFF measures are associated with childhood obesity. PFF and PPHFI were also highly correlated in the obesity group. Therefore, PFF may be an objective index of pancreatic fat content and has the potential for clinical utility as a non-invasive biomarker for the assessment of childhood obesity.

[Multicentric Florid Cystic Endosalpingiosis in Different Anatomical Spaces: A Case Report]. / 서로 다른 í•´ë¶€í•™ì  공간에 발생한 다발성 개화성 낭성 ë‚´ë‚œê´€ì¢ : 증례 ë³´ê³ .

Endosalpingiosis is a condition that causes the non-neoplastic proliferation of ectopic tubal epithelium. Florid cystic endosalpingiosis is an atypical subtype that is very rarely reported. It presents as a mass-like feature and therefore needs to be differentiated from tumorous conditions. Here, we report the imaging findings of a case of multicentric florid cystic endosalpingiosis in the extraperitoneal pelvic cavity and the retroperitoneal spaces.

Iodine Uptake in Retroperitoneal Cysts after Radioactive Iodine Treatment.

Radioactive iodine ablation has long-lasting effects on remnant thyroid tissue and metastasis from well-differentiated thyroid cancer. After radioactive iodine treatment, scintigraphy is a major imaging modality for detecting metastasis and assessing its management. False-positive iodine uptake can be found in many aberrant locations, including cysts. This report describes iodine uptake in retroperitoneal cysts in a 62-year-old woman diagnosed with papillary thyroid carcinoma. Radioiodine scintigraphy was performed after iodine therapy. Abnormally increased iodine activity was noted in the left upper abdomen. Additional radiologic examinations helped in preventing invasive biopsy.