Safety of Gadoxetate Disodium for Hepatobiliary MRI in Children and Adolescents.

Background Despite a proven role in the characterization of liver lesions, use of the gadolinium-based contrast agent (GBCA) gadoxetate disodium at MRI is limited in children due to a lack of comparative safety data. Purpose To evaluate the safety of the GBCA gadoxetate disodium (a linear ionic hepatobiliary contrast agent [HBA]) in children and adolescents, compared with extracellular contrast agents (ECA). Materials and Methods A retrospective analysis was conducted in children and adolescents aged 18 years or younger who underwent HBA-enhanced MRI at one of three tertiary hospitals from January 2010 to December 2022. The incidence of GBCA-associated acute adverse events was compared between MRI examinations with a HBA and those with ECA. Severity was categorized according to American College of Radiology guidelines (mild, moderate, or severe). (a) Propensity score matching using multivariable logistic regression models and (b) inverse probability of treatment weighting analysis based on nine covariates (age, sex, asthma, allergic rhinitis, chronic urticaria or atopy, food allergy, drug allergy, premedication, and history of GBCA-associated adverse events) were used for confounder adjustment. Results A total of 1629 MRI examinations (ECA, n = 1256; HBA, n = 373) in 1079 patients were included (mean age, 8.6 years ± 6.5; 566 girls). The per-examination incidence of GBCA-associated acute adverse events showed no evidence of a difference, with rates of 0.9% (11 of 1256 examinations) for ECA and 1.3% (five of 373 examinations) for HBA (odds ratio [OR], 1.55 [95% CI: 0.54, 4.46]; P = .42). Acute adverse events were all mild with ECA, whereas with HBA, they were mild for four patients and moderate for one patient. There was no evidence of a difference in the incidence of acute adverse events, even in propensity score matching (OR, 1.33 [95% CI: 0.30, 5.96]; P = .71) and inverse probability of treatment weighting analysis (OR, 0.84 [95% CI: 0.25, 2.86]; P = .78). Conclusion Gadoxetate disodium showed no difference in acute adverse events compared with ECA in children and adolescents, with further large-scale pediatric studies required to confirm its safety. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Otero in this issue.

Comparing Diagnostic Accuracy of Radiologists versus GPT-4V and Gemini Pro Vision Using Image Inputs from Diagnosis Please Cases.

Background The diagnostic abilities of multimodal large language models (LLMs) using direct image inputs and the impact of the temperature parameter of LLMs remain unexplored. Purpose To investigate the ability of GPT-4V and Gemini Pro Vision in generating differential diagnoses at different temperatures compared with radiologists using Radiology Diagnosis Please cases. Materials and Methods This retrospective study included Diagnosis Please cases published from January 2008 to October 2023. Input images included original images and captures of the textual patient history and figure legends (without imaging findings) from PDF files of each case. The LLMs were tasked with providing three differential diagnoses, repeated five times at temperatures 0, 0.5, and 1. Eight subspecialty-trained radiologists solved cases. An experienced radiologist compared generated and final diagnoses, considering the result correct if the generated diagnoses included the final diagnosis after five repetitions. Accuracy was assessed across models, temperatures, and radiology subspecialties, with statistical significance set at P < .007 after Bonferroni correction for multiple comparisons across the LLMs at the three temperatures and with radiologists. Results A total of 190 cases were included in neuroradiology (n = 53), multisystem (n = 27), gastrointestinal (n = 25), genitourinary (n = 23), musculoskeletal (n = 17), chest (n = 16), cardiovascular (n = 12), pediatric (n = 12), and breast (n = 5) subspecialties. Overall accuracy improved with increasing temperature settings (0, 0.5, 1) for both GPT-4V (41% [78 of 190 cases], 45% [86 of 190 cases], 49% [93 of 190 cases], respectively) and Gemini Pro Vision (29% [55 of 190 cases], 36% [69 of 190 cases], 39% [74 of 190 cases], respectively), although there was no evidence of a statistically significant difference after Bonferroni adjustment (GPT-4V, P = .12; Gemini Pro Vision, P = .04). The overall accuracy of radiologists (61% [115 of 190 cases]) was higher than that of Gemini Pro Vision at temperature 1 (T1) (P < .001), while no statistically significant difference was observed between radiologists and GPT-4V at T1 after Bonferroni adjustment (P = .02). Radiologists (range, 45%-88%) outperformed the LLMs at T1 (range, 24%-75%) in most subspecialties. Conclusion Using direct radiologic image inputs, GPT-4V and Gemini Pro Vision showed improved diagnostic accuracy with increasing temperature settings. Although GPT-4V slightly underperformed compared with radiologists, it nonetheless demonstrated promising potential as a supportive tool in diagnostic decision-making. © RSNA, 2024 See also the editorial by Nishino and Ballard in this issue.

N-(2,3-dihydroxypropyl) carbamoyl side chain: a potentially significant factor for recurrent iodinated contrast medium-related adverse drug reactions.

PURPOSE: To determine whether switching to contrast media based on the sharing of N-(2,3-dihydroxypropyl) carbamoyl side chain reduces the recurrence of iodinated contrast media (ICM)-associated adverse drug reactions (ADRs). MATERIALS AND METHODS: This single-center retrospective study included 2133 consecutive patients (mean age ± SD, 56.1 ± 11.4 years; male, 1052 [49.3%]) who had a history of ICM-associated ADRs and underwent contrast-enhanced CT examinations. The per-patient and per-exam-based recurrence ADR rates were compared between cases of switching and non-switching the ICM from ICMs that caused the previous ADRs, and between cases that used ICMs with common and different carbamoyl side chains from ICMs that caused the previous ADRs. Downgrade rates (no recurrence or the occurrence of ADR less severe than index ADRs) were also compared. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) analysis were additionally performed. RESULTS: In per-patient analysis, switching of ICM showed a lower recurrence rate (switching, 10.4% [100/965] vs. non-switching, 28.4% [332/1168]), with the adjusted odds ratio (OR) of 0.27 (95% CI: 0.21, 0.34; p < 0.001). The result was consistent in PSM (OR, 0.29 [95% CI: 0.22, 0.39]; p < 0.001), IPTW (OR, 0.28 [95% CI: 0.22, 0.36]; p < 0.001), and in per-exam analysis (5.5% vs. 13.8%; OR, 0.32 [95% CI: 0.27, 0.37]; p < 0.001). There was lower per-exam recurrence (5.0% [195/3938] vs. 7.8% [79/1017]; OR, 0.63 [95% CI: 0.47, 0.83]; p = 0.001) and higher downgrade rates (95.6% [3764/3938] vs. 93.3% [949/1017]; OR, 1.51 [95% CI: 1.12, 2.03]; p = 0.006) when using different side chain groups. CONCLUSION: Switching to an ICM with a different carbamoyl side chain reduced the recurrent ADRs and their severity during subsequent examinations. CLINICAL RELEVANCE STATEMENT: Switching to an iodinated contrast media with a different carbamoyl side chain reduced the recurrent adverse drug reactions and their severity during subsequent examinations.

Chemoembolization versus radiofrequency ablation for single small (≤ 3 cm) hepatocellular carcinoma: a propensity score matching analysis.

OBJECTIVES: To compare the efficacy of transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) for patients with single small (≤ 3 cm) hepatocellular carcinoma (HCC) and preserved liver function (Child-Pugh class A). MATERIALS AND METHODS: The clinical features of treatment-naïve patients who underwent TACE and RFA as first-line treatment were balanced through propensity score matching (PSM). The primary endpoint was overall survival (OS), and the secondary endpoints were local tumor recurrence (LTR) and recurrence-free survival (RFS). RESULTS: The analysis included 440 patients who received TACE, and 430 patients who received RFA. After PSM adjustment (323 pairs), the 5- and 10-year OS rates were 81% and 61%, respectively, in patients who underwent RFA, and 77% and 51%, respectively, for patients who underwent TACE (p = 0.021). Subgroup analyses showed that OS, LTR, and RFS were homogeneously better in the RFA group. CONCLUSION: RFA was associated with better survival outcomes than TACE in patients with single small HCC and preserved liver function. CLINICAL RELEVANCE STATEMENT: This large-scale comparative study provides evidence that radiofrequency ablation has a better overall survival rate than chemoembolization for small (≤ 3 cm) hepatocellular carcinomas. KEY POINTS: • The relative effectiveness of transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) for early HCC is unclear. • Overall survival rate was significantly higher in the RFA group. • The effects of RFA on overall survival, local tumor recurrence, and recurrence-free survival were homogeneously better in all subgroups.

Diagnostic performance of the 2021 Korean thyroid imaging reporting and data system in pediatric thyroid nodules.

OBJECTIVES: To evaluate the diagnostic performance of 2021 K-TIRADS biopsy criteria for detecting malignant thyroid nodules in a pediatric population, making comparisons with 2016 K-TIRADS. METHODS: This retrospective study included pediatric patients with histopathologically confirmed diagnoses. The diagnostic performance of 2021 K-TIRADS was compared with that of 2016 K-TIRADS. Simulation studies were performed by changing biopsy cut-off sizes for K-TIRADS 5 to 1.0 cm (K-TIRADS5-1.0cm) and 0.5 cm (K-TIRADS5-0.5cm), and for K-TIRADS 4 to 1.0 cm (K-TIRADS4-1.0cm) and 1.0-1.5 cm (K-TIRADS4-1.0~1.5cm). Subgroup analysis was performed in small (< 1.5 cm) and large nodules (≥ 1.5 cm). RESULTS: Two hundred seventy-seven thyroid nodules (54.9% malignant) from 221 pediatric patients were analyzed. All simulated 2021 K-TIRADS showed higher accuracy than 2016 K-TIRADS. Compared with 2021 K-TIRADS5-1.0cm, 2021 K-TIRADS5-0.5cm showed lower specificity (51.6% vs. 47.9%; p = 0.004) but higher sensitivity (77.2% vs. 90.3%; p < 0.001) and accuracy (62.7% vs. 68.9%; p < 0.001). Compared with 2021 K-TIRADS4-1.0cm, 2021 K-TIRADS4-1.0~1.5cm showed higher specificity (44.9% vs. 47.9%; p = 0.018) without significant difference in other diagnostic measures. Compared with 2016 K-TIRADS, 2021 K-TIRADS (biopsy cut-offs, 0.5 cm for K-TIRADS 5; 1.0-1.5 cm for K-TIRADS 4) showed higher sensitivity (34.0% vs. 67.3%; p < 0.001) while maintaining specificity (89.4% vs. 88.2%; p = 0.790) in small nodules, and higher specificity (5.9% vs. 25.4%; p < 0.001) while maintaining sensitivity (100% vs. 98.7%; p = 0.132) in large nodules. CONCLUSIONS: In pediatric patients, 2021 K-TIRADS showed superior diagnostic accuracy to 2016 K-TIRADS, especially with a biopsy cut-off of 0.5 cm for K-TIRADS 5 and 1.0-1.5 cm for K-TIRADS 4. KEY POINTS: • All simulated 2021 K-TIRADS showed higher accuracy than 2016 K-TIRADS. • 2021 K-TIRADS with cut-off size for K-TIRADS 5 of 0.5 cm showed lower specificity but higher sensitivity and accuracy than that of 1.0 cm. • Compared with 2016 K-TIRADS, 2021 K-TIRADS (biopsy cut-offs, 0.5 cm for K-TIRADS 5; 1.0-1.5 cm for K-TIRADS 4) showed higher sensitivity while maintaining specificity in small nodules, and higher specificity while maintaining sensitivity in large nodules.

Diagnostic Performance of Five Adult-based US Risk Stratification Systems in Pediatric Thyroid Nodules.

Background The validation of adult-based US risk stratification systems (RSSs) in the discrimination of malignant thyroid nodules in a pediatric population remains lacking. Purpose To estimate and compare the diagnostic performance of pediatric US RSSs based on five adult-based RSSs in the discrimination of malignant thyroid nodules in a pediatric sample. Materials and methods Pediatric patients (age ≤18 years) with histopathologically confirmed US-detected thyroid nodules at a tertiary referral hospital between January 2000 and April 2020 were analyzed retrospectively. The diagnostic performance of US-based fine-needle aspiration biopsy (FNAB) criteria in thyroid cancer detection was estimated. The following sensitivity analyses were performed: (a) scenario 1: nodules smaller than 1 cm, with the highest category additionally biopsied; (b) scenario 2, application of American College of Radiology Thyroid Imaging Reporting and Data System nodule size cutoffs to other RSSs; (c) scenario 3, scenarios 1 and 2 together. Generalized estimating equations (GEEs) were used for estimation. Results A total of 277 thyroid nodules in 221 pediatric patients (median age, 16 years [interquartile range {IQR}, 13-17]; 172 female; 152 of 277 patients [55%] malignant) were analyzed. The GEE-estimated sensitivity and specificity ranged from 70% to 78% (104 to 119 of 152 patients, based on each reader's interpretation) and from 42% to 78% (49 of 124 patients to 103 of 125 patients). In scenario 1, the missed malignancy rate was reduced from 32%-38% (41 of 134 patients to 34 of 83 patients) to 15%-21% (eight of 59 patients to 28 of 127 patients). In scenario 2, the unnecessary biopsy rate was reduced from 35%-39% (60 of 176 patients to 68 of 175 patients) to 20%-34% (18 of 109 patients to 62 of 179 patients). The highest accuracy was noted in scenario 3 (range, 71%-81%; 199 of 277 patients to 216 of 262 patients). Conclusion The diagnostic performances of the fine-needle aspiration biopsy criteria of five adult-based risk stratification systems were acceptable in the pediatric population and were improved by applying the American College of Radiology Thyroid Imaging Reporting and Data System size cutoff for nodules 1 cm or larger and allowing biopsy of the highest category nodules smaller than 1 cm. © RSNA, 2022 Online supplemental material is available for this article.

Postnatal Imaging for Prediction of Outcome in Patients with Left-sided Congenital Diaphragmatic Hernia.

OBJECTIVE: To evaluate associations between postnatal imaging features and outcome of left-sided congenital diaphragmatic hernia, as defined by overall survival and a requirement for extracorporeal membrane oxygenation (ECMO). STUDY DESIGN: Newborns diagnosed prenatally with left-sided congenital diaphragmatic hernia between January 2013 and September 2021 were studied retrospectively. The esophageal deviation index was newly defined as the largest diameter from the midline to deviated gastric tube divided by the largest transverse diameter of the thoracic cavity on the radiograph. Regression analyses were performed to identify postnatal imaging features associated with overall survival and a requirement for ECMO. The predictive power (ie, area under the curve [AUC] of a time-dependent receiver operating characteristic curve) of prenatal, postnatal, and intraoperative findings for predicting survival were calculated. RESULTS: Ninety-seven patients (54 males; mean gestational age, 38.3 ± 1.9 weeks; mean birth weight, 2956.5 ± 540.0 g) were analyzed. The esophageal deviation index (adjusted hazard ratio [HR], moderate [≥0.19 to <0.24], 6.427 [P = .029]; severe [≥0.24], 33.007 [P < .001]) and right pneumothorax (adjusted HR, 8.763; P = .002) were associated with overall survival and with a requirement for ECMO. Liver herniation on postnatal ultrasound also was associated with overall survival (P < .001) and need for ECMO (P = .001). In addition, the AUC for prediction of 1-year survival from postnatal ultrasound was comparable with that of prenatally or intraoperatively detected liver herniation (0.93; 95% CI, 0.88-0.97). CONCLUSIONS: The esophageal deviation index, right pneumothorax, and liver herniation observed by postnatal imaging have prognostic value in patients with left-sided congenital diaphragmatic hernia.

Ultrasound-guided sclerotherapy for the treatment of ovarian endometrioma: an updated systematic review and meta-analysis.

OBJECTIVE: To determine the efficacy and safety of ultrasound (US)-guided sclerotherapy for the treatment of ovarian endometrioma through a systematic review and meta-analysis. METHODS: MEDLINE and EMBASE databases were searched for studies reporting outcomes in patients with endometrioma who were treated with US-guided sclerotherapy. Meta-analyses of recurrence, pain resolution, pregnancy, technical success, and complication rates were analyzed. Subgroup analyses were conducted regarding the indwelling time of sclerotherapy (≤ 10 min vs > 10 min). RESULTS: Twenty-eight studies (1301 patients) were included. The pooled technical efficacy was 98.3%. The pooled estimates of recurrence, pain resolution, and pregnancy rate were 13.8%, 85.9%, and 37.6%, respectively. The pooled major complication rate was 1.7%. A sclerotherapy time > 10 min had a lower pooled recurrence rate than a time ≤ 10 min (11.2% vs 20.9%; p = 0.106). Direct comparisons showed that the recurrence rate was significantly lower with sclerotherapy > 10 min than with sclerotherapy ≤ 10 min (OR, 0.2; p = 0.015). Regarding pregnancy rates, sclerotherapy of > 10 min showed no significant difference compared with sclerotherapy of ≤ 10 min (35.9% vs 38.8%; p = 0.664). Direct comparisons with surgery showed that sclerotherapy increased the pregnancy rate compared with surgery (OR, 2.0; p = 0.042). There was no significant difference in AMH level before and after sclerotherapy (p = 0.951). There was no significant difference in major complication rates between sclerotherapy > 10 min and ≤ 10 min (p = 0.837). CONCLUSION: US-guided sclerotherapy seems to be an effective and safe therapeutic option regarding recurrence, pain resolution, and pregnancy for patients with ovarian endometrioma. KEY POINTS: • US-guided sclerotherapy seems to be an effective and safe therapeutic option regarding recurrence, pain resolution, and pregnancy for patients with ovarian endometrioma. • Sclerotherapy of more than 10 min had a lower recurrence rate than sclerotherapy less than or equal to 10 min. There was no significant difference in major complication rates between sclerotherapy of > 10 min and ≤ 10 min. • Future randomized controlled trials are warranted to compare the outcomes of US-guided sclerotherapy with surgery.

Thermal ablation in the treatment of intrahepatic cholangiocarcinoma: a systematic review and meta-analysis.

OBJECTIVE: To summarize the efficacy and safety of thermal ablation for the treatment of intrahepatic cholangiocarcinoma (ICC). METHODS: MEDLINE, EMBASE, Cochran Library, and Web of Science databases were searched for studies reporting outcomes in patients with ICC treated with thermal ablation. Meta-analyses of cumulative overall survival (OS) and recurrence-free survival (RFS), Kaplan-Meier survival rates according to time to local tumor progression (TTLTP), technical efficacy, and incidence of complications were analyzed. Pooled hazard ratios of common variables were calculated to explore factors associated with OS. RESULTS: Twenty observational studies comprising 917 patients were reviewed (primary ICC [n = 502]; post-surgical recurrent ICC [n = 355]; information not available [n = 60]). The pooled proportion of technical efficacy was 91.9% (95% CI, 87.3-94.9%). The pooled 1-, 3-, and 5-year OS rates were 82.4% (95% CI, 75.1-88.9%), 42.1% (95% CI, 36.0-48.4%), and 28.5% (95% CI, 21.2-36.2%). Primary tumors showed higher 3-year OS rates than recurrent ones, with borderline significance (p = 0.072). The pooled 1- and 3-year RFS rates were 40.0% (95% CI, 33.6-46.4%) and 19.2% (95% CI, 8.4-32.7%). The pooled 1-, 3-, and 5-year TTLTP rates were 79.3% (95% CI, 65.1-90.9%), 59.5% (95% CI, 49.1-69.4%), and 58.2% (95% CI, 44.9-70.9%). The pooled incidence of major complications was 5.7% (95% CI, 4.1-7.8%). Tumor size (> 3 cm), multiple tumors, and age (> 65 years) were factors associated with shorter OS. CONCLUSION: Thermal ablation is a successful alternative with a good safety profile, especially for a single ICC smaller than 3 cm. KEY POINTS: • The pooled 1-, 3-, and 5-year OS rates following thermal ablation for the treatment of intrahepatic cholangiocarcinoma were 82.4%, 42.1%, and 28.5%. • The pooled incidence of major complications was 5.7%. • A tumor size > 3 cm (HR: 2.12, p = 0.006), multiple tumors (HR: 1.67, p = 0.004), and age > 65 years (HR: 1.67, p = 0.006) were factors associated with shorter OS.

Diagnostic performance of loss of nigral hyperintensity on susceptibility-weighted imaging in parkinsonism: an updated meta-analysis.

OBJECTIVES: To evaluate diagnostic performance of loss of nigral hyperintensity on SWI in differentiating idiopathic Parkinson's disease (IPD) or primary parkinsonism (including IPD and Parkinson-plus syndrome) from healthy/disease controls. METHODS: MEDLINE/PubMed and EMBASE databases were searched to identify original articles investigating the diagnostic performance of loss of nigral hyperintensity for differentiating IPD or primary parkinsonism from healthy/disease control, up to April 3, 2020. Pooled sensitivity and specificity were calculated using a bivariate random-effects model. The proportion of nondiagnostic scan, inter- and intrareader agreement, and the proportion of concordance between clinical laterality and imaging asymmetry were also pooled. RESULTS: Nineteen articles covering 2125 patients (1097 with primary parkinsonism, 1028 healthy/disease controls) were included. For discrimination between IPD and healthy/disease controls, pooled sensitivity and specificity were 0.96 (95% CI, 0.91-0.98) and 0.95 (95% CI, 0.92-0.97). For discrimination between primary parkinsonism and healthy/disease controls, pooled sensitivity and specificity were 0.87 (95% CI, 0.75-0.94) and 0.93 (95% CI, 0.85-0.97). The pooled proportion of non-diagnostic scans on random-effects modeling was 4.2% (95% CI, 2.5-6.9%). The inter- and intrareader agreements were almost perfect, with the pooled coefficients being 0.84 (95% CI, 0.78-0.89) and 0.96 (95% CI, 0.89-0.99), respectively. The pooled proportion of concordant cases was 69.3% (95% CI, 58.4-78.4%). CONCLUSIONS: Loss of nigral hyperintensity on SWI can differentiate IPD or primary parkinsonism from a healthy/disease control group with high accuracy. However, the proportion of non-diagnostic scans is not negligible and must be taken into account. KEY POINTS: • For discrimination between idiopathic Parkinson's disease and healthy/disease controls, pooled sensitivity and specificity of loss of nigral hyperintensity were 0.96 and 0.95. • For discrimination between primary parkinsonism and healthy/disease controls, pooled sensitivity and specificity of loss of nigral hyperintensity were 0.87 and 0.93. • The pooled proportion of non-diagnostic scans on random-effects modeling was 4.2%.

Diagnostic performance of adult-based ATA and ACR-TIRADS ultrasound risk stratification systems in pediatric thyroid nodules: a systematic review and meta-analysis.

OBJECTIVES: To evaluate the diagnostic performance of adult-based "American College of Radiology- Thyroid Imaging Reporting And Data System" (ACR-TIRADS) and "American Thyroid Association" (ATA) in the pediatric population. METHODS: MEDLINE/PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched for articles investigating the diagnostic performance of each stratification system (ACR-TIRADS or ATA) and evaluated them according to three aspects: (a) the risk of malignancy in each category; (b) diagnostic performance using the classic indicators (sensitivity, specificity); and (c) diagnostic performance regarding fine needle aspiration/biopsy recommendation. In addition to pathologic diagnosis, we allowed imaging follow-up as the reference standard for benign nodules. RESULTS: Eight articles (1036 thyroid nodules) were included. For ACR-TIRADS, the pooled risk of malignancy in category was as follows: category 5 (59.3%); 4 (20.7%); 3 (11.0%); 2 (6.0%), and 1 (5.5%). For nodules of high suspicion of malignancy (category 4 or 5), the pooled sensitivity and specificity were 0.84 and 0.64. For ATA, the pooled risk of malignancy was as follows: category 5 (55.4%); 4 (34.2%); 3 (12.2%); and 2 (7.5%). For nodules of high suspicion of malignancy (category 4 or 5), the pooled sensitivity and specificity were 0.90 and 0.50. For category 5 nodules, the pooled specificity was significantly higher in ACR-TIRADS (p = 0.02). For ACR-TIRADS, the missed malignancy rate was 21.7% and the unnecessary biopsy rate was 62.7%. Information was not sufficient for this calculation with ATA. CONCLUSIONS: The diagnostic performance of ACR-TIRADS and ATA in the pediatric population was somewhat modest. Large studies are mandatory for further validation and future amendments. KEY POINTS: • The pooled sensitivity and specificity for highly suspicious nodules (category 4 or 5) for ACR-TIRADS were 0.84 and 0.64, and for ATA were 0.90 and 0.50, respectively. • When applying ACR-TIRADS for children, the pooled missed malignancy rate (21.7%) and unnecessary biopsy rates (62.7%) are still reasonably high. Insufficient information was available to perform these calculations for the ATA system. • Current risk stratification systems, especially ACR-TIRADS, require modification by focusing more on increasing the sensitivity and decreasing the missed malignancy rate. Lowering size cut-off for biopsy would be a reasonable option.

Predictors of failed enema reduction in children with intussusception: a systematic review and meta-analysis.

OBJECTIVE: To identify predictors of failed enema reduction in children with intussusception. METHODS: PubMed and EMBASE were searched for all studies published over a 20-year time frame, prior to March 25, 2020. Original articles that reported predictors of failed enema reduction were included. The pooled odds ratio (OR) for successful enema reduction according to various features was calculated. The combined estimates were meta-analytically pooled by random-effects modeling. The risk of bias was assessed using the National Institute of Health Quality Assessment Tool. This review was registered to the PROSPERO (CRD42020190178). RESULTS: A total of 38 studies, comprising 40,133 cases, were included. The shorter duration of symptoms (< 24 h; combined OR, 3.812; 95% CI, 2.150-6.759) and abdominal pain (combined OR, 2.098; 95% CI, 1.405-3.133) were associated with the success (all p < 0.001). Age < 1 year (combined OR, 0.385; 95% CI, 0.166-0.893; p = 0.026), fever (combined OR, 0.519; 95% CI, 0.371-0.725; p < 0.001), rectal bleeding (combined OR, 0.252; 95% CI, 0.165-0.387; p < 0.001), and vomiting (combined OR, 0.497; 95% CI, 0.372-0.664; p < 0.001) were associated with the failed reduction. The ascites (combined OR, 0.127; 95% CI, 0.044-0.368; p = 0.001), left-sided intussusception (combined OR, 0.121; 95% CI, 0.058-0.252; p < 0.001), and trapped fluid (combined OR, 0.179; 95% CI, 0.061-0.525; p = 0.017) on US were associated with the failed reduction. CONCLUSIONS: Successful predictors for intussusception reduction have been summarized. This evidence can help identify patients who are more likely to fail non-operative reduction and could be potential surgical candidates. KEY POINTS: • A shorter duration of symptoms and presence of abdominal pain were associated with increased probability of success. • Age (less than 1 year), presence of fever, rectal bleeding, vomiting, and presence of ascites, left-sided intussusception, or trapped fluid on ultrasonography were associated with decreased probability of success. • This study suggests that various clinical and ultrasonography predictors would help identify patients who are more likely to fail nonoperative reduction and identify potential preoperative candidates.

A prediction model for overall survival after transarterial chemoembolization for hepatocellular carcinoma invading the hepatic vein or inferior vena cava.

OBJECTIVES: An effective therapeutic option has not yet been established for hepatocellular carcinoma (HCC) invading the hepatic vein (HV) or inferior vena cava (IVC). This study aimed to determine the therapeutic effect of transarterial chemoembolization (TACE) in HCC patients with HV or IVC invasion, and to build a risk prediction model. METHODS: Data from patients who underwent TACE as a first-line treatment for HCC invading the HV or IVC between 1997 and 2019 were retrospectively evaluated. RESULTS: Data from 296 patients were included (1997-2006 comprised the training cohort, n = 174; 2007-2019 comprised the validation cohort, n = 122). The median post-TACE survival was 7.3 months and an objective tumor response was achieved in 34.1% of patients. Multivariable Cox analysis of the training cohort identified five pretreatment factors (maximal tumor size > 10 cm, infiltrative HCC, combined portal vein invasion, extrahepatic metastasis, and ECOG performance status 1), which were used to create predictive models for overall survival. Median overall survival times in the validation cohort were 14 and 4.2 months for the low (sum of risk score: 0-3)- and high-risk (sum of risk score: 4-7) groups, respectively (p < 0.001). Time-dependent ROC curves for the predictive models for overall survival applied to the validation cohort showed acceptable AUC values (0.723 and 0.667 at 6 months and 1 year). CONCLUSIONS: TACE seems effective for selected patients with HCC invading the HV or IVC. The predictive model may help to identify candidates most likely to benefit from TACE. KEY POINTS: • To develop a risk prediction model for patients with HCC with HV or IVC invasion treated with TACE, five factors were selected from a multivariate Cox regression model for overall survival. • The combination of these factors helped to identify two prognostic categories: low- and high-risk. • The predictive model can help to select candidates who will benefit most from TACE in this patient group.

Unnecessary thyroid nodule biopsy rates under four ultrasound risk stratification systems: a systematic review and meta-analysis.

OBJECTIVES: To summarize and compare unnecessary biopsy rates and diagnostic performance in the examination of thyroid nodules according to four representative US-based risk stratification systems. METHODS: MEDLINE/PubMed and EMBASE databases were searched to identify original articles investigating unnecessary biopsy rates according to at least one of the following guidelines: ACR-TIRADS, ATA, EU-TIRADS, and K-TIRADS. The unnecessary biopsy rates for each risk stratification system were pooled using a random-effects model. Meta-regression analyses were performed to explore heterogeneity. Diagnostic odds ratios (DORs) for the appropriate selection of thyroid nodules for fine-needle aspiration were also pooled using a bivariate random-effects model. RESULTS: Eight articles including 13,092 thyroid nodules met the eligibility criteria and were included. The pooled unnecessary biopsy rates of ACR-TIRADS, ATA, EU-TIRADS, and K-TIRADS were 25% (95% CI, 22-29%), 51% (95% CI, 44-58%), 38% (95% CI, 16-66%), and 55% (95% CI, 42-67%), respectively. The pooled unnecessary biopsy rate of ACR-TIRADS was significantly lower than that of ATA (p < .001) and K-TIRADS (p < .001), and also lower than that of EU-TIRADS, but not reaching statistical significance (p = .087). The pooled DORs of ACR-TIRADS, ATA, and K-TIRADS were 5.9 (95% CI, 3.6-9.6), 6.3 (95% CI, 4.5-8.8), and 4.5 (95% CI, 1.7-11.6), respectively, with the differences not being statistically significant. CONCLUSIONS: ACR-TIRADS showed a lower unnecessary biopsy rate than the other risk stratification systems albeit DOR was comparable between ACR-TIRADS, ATA, and K-TIRADS. Future revisions of each system should be made by referring to ACR-TIRADS to reduce unnecessary biopsy rates. KEY POINTS: • The pooled unnecessary biopsy rates of ACR-TIRADS, ATA, EU-TIRADS, and K-TIRADS were 25% (95% CI, 22-29%), 51% (95% CI, 44-58%), 38% (95% CI, 16-66%), and 55% (95% CI, 42-67%), respectively. • The pooled unnecessary biopsy rate of ACR-TIRADS was significantly lower than that of ATA (p < .001) and K-TIRADS (p < .001). • The pooled DORs of ACR-TIRADS, ATA, and K-TIRADS were 5.9 (95% CI, 3.6-9.6), 6.3 (95% CI, 4.5-8.8), and 4.5 (95% CI, 1.7-11.6), respectively, with the differences not being statistically significant.

Immune checkpoint inhibitor therapy may increase the incidence of treatment-related necrosis after stereotactic radiosurgery for brain metastases: a systematic review and meta-analysis.

OBJECTIVES: To compare the incidence of treatment-related necrosis between combination SRS+ICI therapy and SRS therapy alone in patients with brain metastases from melanoma and non-small cell lung cancer (NSCLC). METHODS: A systematic literature search of Ovid-MEDLINE and EMBASE was performed up to August 10, 2020. The difference in the pooled incidence of treatment-related necrosis after SRS+ICI or SRS alone was evaluated. The cumulative incidence of treatment-related necrosis at the specific time point after the treatment was calculated and plotted. Subgroup and meta-regression analyses were additionally performed. RESULTS: Sixteen studies (14 on melanoma, 2 on NSCLC) were included. In NSCLC brain metastasis, the reported incidences of treatment-related necrosis in SRS+ICI and SRS alone ranged 2.9-3.4% and 0-2.9%, respectively. Meta-analysis was conducted including 14 studies on melanoma brain metastasis. The incidence of treatment-related necrosis was higher in SRS+ICI than SRS alone (16.0% vs. 6.5%; p = 0.065; OR, 2.35). The incidence showed rapid increase until 12 months after the SRS when combined with ICI therapy (14%; 95% CI, 8-22%) and its pace of increase slowed thereafter. Histopathologic diagnosis as the reference standard for treatment-related necrosis and inclusion of only symptomatic cases were the source of heterogeneity in SRS+ICI. CONCLUSIONS: Treatment-related necrosis tended to occur 2.4 times more frequently in the setting of combination SRS+ICI therapy compared with SRS alone in melanoma brain metastasis showing high cumulative incidence within the first year. Treatment-related necrosis should be considered when SRS+ICI combination therapy is used for melanoma brain metastasis, especially in the first year. KEY POINTS: • Treatment-related necrosis occurred 2.4 times more frequently in the setting of combination SRS+ICI therapy compared with SRS alone in melanoma brain metastasis. • Treatment-related necrosis more frequently occurred in brain metastases from melanoma than NSCLC. • Reference standard for treatment-related necrosis and inclusion of only symptomatic treatment-related necrosis were a significant source of heterogeneity, indicating varying definitions of treatment-related necrosis in the literature need to be unified.

Outcome of staging chest CT and identification of factors associated with lung metastasis in children with hepatoblastoma.

OBJECTIVES: To evaluate the outcome of staging chest CT and to identify clinicoradiological factors predictive of lung metastasis in patients with hepatoblastoma based on the 2017 PRE-Treatment EXTent of tumor (PRETEXT) system. METHODS: This bi-center study retrospectively identified patients diagnosed with hepatoblastoma between January 1998 and September 2019 in two tertiary hospitals. The primary outcome was the proportion of the patients who had lung metastasis at staging chest CT. The diagnostic accuracy of staging chest CT was calculated based on the 2017 PRETEXT criteria. The secondary outcome was the identification of factors predictive of lung metastasis using multivariable logistic regression. RESULTS: In total, 123 patients (median age, 1 year; interquartile range, 0-4 years; 59 female) were included. Among those, 28% (35/123; 95% confidence interval [CI], 21-37%) had lung metastasis at staging chest CT. The overall accuracy of staging chest CT was 96.8%. The proportion of lung metastasis in patients with stage I, II, III, and IV was 0%, 24% (12 of 49; 95% CI, 14-38%), 23% (9 of 40; 95% CI, 12-38%), and 56% (14 of 25; 95% CI, 37-73%), respectively. Multifocality (adjusted odds ratio, 6.7; 95% CI, 2.7-17.5; p < .001) and male sex (adjusted odds ratio, 3.1; 95% CI, 1.2-8.6; p = .02) were associated with the presence of lung metastasis. CONCLUSIONS: Twenty-eight percent of the patients with hepatoblastoma had lung metastasis at staging chest CT. Multifocality and male sex were predictive factors for lung metastasis on staging chest CT. KEY POINTS: • The proportion of lung metastasis in patients with hepatoblastoma was 28%. • The overall accuracy of staging chest CT was 97% based on the 2017 PRETEXT system. • Hepatic tumor multifocality and male sex were predictors of lung metastasis.

Technical Performance of Acoustic Radiation Force Impulse Imaging for Measuring Renal Parenchymal Stiffness: A Systematic Review and Meta-Analysis.

OBJECTIVES: To estimate the technical performance of acoustic radiation force impulse (ARFI) imaging (two-dimensional shear wave elastography [2D-SWE] and point shear wave elastography [p-SWE]) for measuring renal parenchymal stiffness. METHODS: EMBASE and PubMed databases were searched for studies reporting technical performance of ARFI imaging in terms of technical failure, interobserver agreement, and/or intraobserver agreement. The proportion of technical failure and intraclass correlation coefficients (ICCs) for interobserver and intraobserver agreement was pooled. The pooled estimates of native and transplanted kidneys were obtained separately. Meta-regression and subgroup analyses were conducted to explore heterogeneity. RESULTS: Twenty-four studies (2993 patients) were included. The pooled proportions of technical failure were 4.3% (95% confidence interval [CI] 2.2-8.5%) and 6.6% (95% CI 4.0-10.7%) in native and transplanted kidneys, respectively. The pooled ICCs of interobserver agreement were 0.70 (95% CI 0.68-0.83) and 0.81 (95% CI 0.68-0.89), indicating moderate and good agreement in native and transplanted kidneys, respectively. The pooled ICC showed good (0.77; 95% CI 0.49-0.91) intraobserver agreement in native kidneys. Regarding interobserver agreement in transplanted kidneys, ROI location (mid pole only versus others) was a significant factor of heterogeneity (P = .04). CONCLUSIONS: The ARFI-based SWE techniques show good technical performance for measuring renal parenchymal stiffness. The wide range of SWE protocols necessitates development of standardized guidelines on the use of renal ARFI imaging.

The safety and efficacy of haemostasis with a catechol-conjugated, chitosan-based haemostatic dressing versus a chitosan-based haemostatic dressing after transfemoral approach for transcatheter arterial chemoembolization: a randomized controlled trial.

PURPOSE: To compare the haemostatic efficacy (i.e. efficacy to prevent access site complications) of the InnoSEAL haemostatic pad and Clo-Sur PLUS P.A.D. after femoral arterial puncture for transcatheter arterial chemoembolization (TACE). MATERIAL AND METHODS: This randomized controlled trial compared the safety and efficacy of an InnoSEAL haemostatic pad (n = 48) and a Clo-Sur PLUS P.A.D. (n = 52) for haemostasis of arterial puncture sites after TACE with femoral arterial access using a 5-Fr sheath. Primary endpoints were incidence of major (necessitating surgery) and moderate access site complications (ASC) (necessitating blood transfusion/thrombin injection). Secondary endpoints were incidence of minor ASC (no therapy required) and time to haemostasis. RESULTS: No major or moderate ASC was seen with either device. Minor ASC (6.3% [3/48] vs. 19.2% [10/52], p = 0.075) and ecchymosis (classified as minor ASC; 4.2% [2/48] vs. 17.3% [9/52]; p = 0.053, p-value cut-off after Bonferroni correction = 0.025) were less frequently observed with the InnoSEAL haemostatic pad. The time to haemostasis did not differ significantly between the 2 devices (5.6 ± 1.0 vs. 5.3 ± 0.7 minutes; p = 0.118). Multivariable logistic regression analysis showed a lower risk of ASC with the InnoSEAL pad (adjusted OR, 0.174; 95% CI: 0.034-0.890; p = 0.036). CONCLUSIONS: No major ASC was seen with either pad, and no significant difference of minor ASC was observed between 2 pads.

Supplementary Anal Imaging by Magnetic Resonance Enterography in Patients with Crohn's Disease Not Suspected of Having Perianal Fistulas.

BACKGROUND & AIMS: Few data are available to guide the use of anal imaging for patients with Crohn's disease (CD) who are not suspected of having perianal fistulas. We aimed to evaluate the role of anal imaging supplementary to magnetic resonance enterography (MRE) in these patients. METHODS: In a prospective study, we added a round of anal MR imaging (MRI), collecting axial images alone, to MRE evaluation of 451 consecutive adults who were diagnosed with or suspected of having CD but not believed to have perianal fistulas. Images were examined for perianal tracts; if present, colorectal surgeons reexamined patients to identify external openings or perianal inflammation or abscess. Patients were followed and data were collected on dedicated treatment for perianal fistulas or abscess. We calculated the diagnostic yield for anal MRI, associated factors, and outcomes of MRI-detected asymptomatic perianal tracts. RESULTS: A total of 440 patients (mean age, 29.6±8.9 years) met the inclusion criteria. Anal MRI revealed perianal tracts in 53 patients (12%; 95% CI, 9.3%-15.4%). Surgeons however did not identify any lesions that required treatment. The asymptomatic tracts were mostly single unbranched (83%), inter-sphincteric (72%), or had a linear dark signal at the tract margin (79%). Younger age at MRE, female sex, and CD activity index scores of 220-450 were independently associated with detection of perianal tracts. MRI detection of asymptomatic tracts was independently associated with later development of perianal fistulas or abscess that required treatment: 17.8% cumulative incidence at 37 months and an adjusted hazard ratio of 3.06 (95% CI, 1.01-9.27; P = .048). CONCLUSIONS: In a prospective study of patients with CD, we found that adding anal MRI evaluation to MRE resulted in early identification of patients at risk for perianal complications.

The safety and efficacy of balloon-occluded transcatheter arterial chemoembolization for hepatocellular carcinoma refractory to conventional transcatheter arterial chemoembolization.

OBJECTIVES: To evaluate the safety and efficacy of balloon-occluded transcatheter arterial chemoembolization (B-TACE) for the treatment of HCC refractory to conventional TACE (C-TACE). METHODS: This single-center retrospective analysis included 60 consecutive patients who underwent B-TACE (mean age, 61.4 years; male:female ratio, 4.5:1) for the treatment of residual viable (n = 40) or recurrent HCC (n = 20) refractory to C-TACE between November 2017 and November 2018. Technical success, radiologic response rate (proportion of the patients achieving complete response [CR] or partial response [PR] on first follow-up CT according to m-RECIST), major complication rate, and time to progression (TTP) were evaluated. The TTP of B-TACE was also compared with that of the last C-TACE. Factors associated with achieving CR and TTP were explored. RESULTS: B-TACE resulted in 100% technical success and radiologic response rate (CR in 45 and PR in 15 patients). The major complication rate was 6.7% (4/60). The median TTP after B-TACE was 5.3 months (95% confidence interval [CI], 4.0-6.9 months). The TTP of B-TACE for treating residual HCC was significantly longer than that of the last C-TACE (median [95% CI], 4.4 [3.2-6.9] vs. 2.7 [2.3-4.4] months; p = 0.013). BCLC stage C (adjusted OR, 4.448; 95% CI, 1.691-11.700; p = 0.002) and multiplicity of HCC (adjusted OR, 2.746; 95% CI, 1.206-6.251; p = 0.016) were significantly associated with tumor progression after B-TACE. CONCLUSIONS: B-TACE is safe and effective for the treatment of HCC refractory to C-TACE. BCLC stage C and multiplicity of HCC were independent factors associated with TTP after B-TACE. KEY POINTS: • B-TACE for the treatment of HCC refractory to C-TACE showed a 100% radiologic response at first follow-up and a significantly longer TTP than the last C-TACE when treating residual tumor. • The major complication rate after B-TACE was 6.7%. Although AST, ALT, and total bilirubin increase were more profound in B-TACE than in the last C-TACE, these were normalized at the first follow-up. • Tumor size, multiplicity of HCC, and hepatic arterial injury were independent factors associated with achieving a complete response. BCLC stage C and multiplicity of HCC were significantly associated with TTP after B-TACE.