The Future Is Beyond Bright: The Evolving Role of Quantitative US for Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is a common cause of morbidity and mortality. Nonfocal liver biopsy is the historical reference standard for evaluating NAFLD, but it is limited by invasiveness, high cost, and sampling error. Imaging methods are ideally situated to provide quantifiable results and rule out other anatomic diseases of the liver. MRI and US have shown great promise for the noninvasive evaluation of NAFLD. US is particularly well suited to address the population-level problem of NAFLD because it is lower-cost, more available, and more tolerable to a broader range of patients than MRI. Noninvasive US methods to evaluate liver fibrosis are widely available, and US-based tools to evaluate steatosis and inflammation are gaining traction. US techniques including shear-wave elastography, Doppler spectral imaging, attenuation coefficient, hepatorenal index, speed of sound, and backscatter-based estimation have regulatory clearance and are in clinical use. New methods based on channel and radiofrequency data analysis approaches have shown promise but are mostly experimental. This review discusses the advantages and limitations of clinically available and experimental approaches to sonographic liver tissue characterization for NAFLD diagnosis as well as future applications and strategies to overcome current limitations.

Shear-Wave Elastography of the Breast: Impact of Technical Image Quality Parameters on Diagnostic Accuracy.

OBJECTIVE. The purpose of this study is to determine the impact of shear-wave elastography (SWE) image quality parameters on the diagnostic performance of elasticity measurements in classifying breast lesions. MATERIALS AND METHODS. This retrospective study included 281 breast lesions that underwent SWE and ultrasound-guided biopsy performed between October 1, 2017, and August 31, 2018. Three readers who were blinded to pathologic outcomes independently scored the image quality of each SWE image (with low quality denoted by a score of 0 and high quality indicated by a score of 1) on the basis of five parameters: B-mode visualization of the lesion on a dual-panel display, SWE red pattern (denoting high stiffness) in the near field of the FOV, appearance of the surrounding tissue, FOV placement, and ROI placement for the maximum (Emax), minimum (Emin), mean (Emean), and SD (ESD) of Young modulus elasticity measurements. Using ROC analysis, we compared the performance of Emax, Emean, and ESD in diagnosing malignancy on low- and high-quality images on the basis of consensus (i.e., majority) scores for each individual quality parameter as well as two models combining a few of the quality parameters. RESULTS. Three quality parameters (B-mode visualization of the lesion, presence of a near-field red pattern, and the appearance of the surrounding tissue) showed moderate-to-substantial interobserver agreement. SWE images were considered high quality (n = 167) if both B-mode visualization and near-field red pattern received a consensus score of 1, and they were considered low quality (n = 114) if either parameter received a consensus score of 0. High-quality images had a statistically higher AUC value than low-quality images when Emax (p < .001), Emean (p = .002), and ESD (p < .001) were used as classifiers of malignancy. CONCLUSION. Quality parameters can support radiologists who are performing and interpreting breast SWE images. These quality parameters have the potential to improve the accuracy of SWE in differentiating malignant from benign breast lesions.

Cervical Extension of the Normal Thymus in Children and Adolescents: Sonographic Features and Prevalence.

OBJECTIVE: This study aims to confirm the prevalence of incidental cervical extension of normal thymus in children and adolescents undergoing neck ultrasound and describe the ultrasound appearance to minimize future misdiagnosis. MATERIALS AND METHODS: This retrospective study was conducted in a single institution. Thyroid and lower neck ultrasound images of the consecutive pediatric subjects between January 1, 2011 and September 30, 2017 were independently reviewed by 2 radiologists for the presence of cervical thymus. When identified on sonographic images, cervical thymus was described on the basis of echogenicity, location, and shape. RESULTS: In 278 consecutive cases, the 2 reviewers identified 105 (37.8%) and 103 (37.1%) cases respectively as having sonographically visible tissue in the expected location of cervical extension of the thymus. The internal echotexture was variable with 38.1% of cases being hypoechoic, 37.1% mixed, and 24.8% hyperechoic. Cervical extension of the thymus was most commonly (65.0%) to the left of the trachea or (30.9%) bilateral/anterior to the trachea; isolated right paratracheal thymus was uncommon. Thymic shape was variable: quadrilateral (30.9%), oval (29.9%), triangular (25.8%), and other (13.4%). The logistic regression model including age, gender, and BMI z-scores showed that, when controlled for sex and BMI z-scores, younger age was a predictor for the presence of cervical thymic extension (p < .001). CONCLUSION: Cervical thymic extension is sonographically visible as a soft tissue mass of variable appearance in about a third of children and adolescents undergoing neck ultrasonography with decreasing prevalence with age. Sonographically visible cervical thymic tissue is more common in younger patients.

Normal Liver Stiffness Measured with MR Elastography in Children.

Background Stiffness thresholds for liver MR elastography in children vary between studies and may differ from thresholds in adults. Normative liver stiffness data are needed to optimize diagnostic thresholds for children. Purpose To determine normal liver stiffness, and associated normal ranges for children, as measured with MR elastography across vendors and field strengths. Materials and Methods This was a prospective multicenter cohort study (ClinicalTrials.gov identifier: NCT03235414). Volunteers aged 7-17.9 years without a known history of liver disease were recruited at four sites for a research MRI and blood draw between February 2018 and October 2019. MRI was performed on three vendor platforms and at two field strengths (1.5 T and 3.0 T). All MRI scans were centrally analyzed; stiffness, proton density fat fraction (PDFF), and R2* values were expressed as means of means. Mean and 95% confidence intervals (CIs) for liver stiffness were calculated. Pearson correlation coefficient (r), two-sample t test, or analysis of variance was used to assess univariable associations. Results Seventy-one volunteers had complete data and no documented exclusion criterion (median age, 12 years; interquartile range [IQR], 10-15 years; 39 female participants). Median body mass index percentile was 54% (IQR, 32.5%-69.5%). Mean liver stiffness was 2.1 kPa (95% CI: 2.0, 2.2 kPa) with mean ± 1.96 kPa standard deviation of 1.5-2.8 kPa. Median liver PDFF was 2.0% (IQR, 1.7%-2.6%). There was no association between liver stiffness and any patient variable or MRI scanner factor. Conclusion Mean liver stiffness measured with MR elastography in children without liver disease was 2.1 kPa (similar to that in adults). The 95th percentile of normal liver stiffness was 2.8 kPa. Liver stiffness was independent of sex, age, or body mass index and did not vary with MRI scanner vendor or field strength. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Yin in this issue.

Portal Venous Pulsatility Index: A Novel Biomarker for Diagnosis of High-Risk Nonalcoholic Fatty Liver Disease.

OBJECTIVE. The purpose of this study was to assess the accuracy of portal vein pulsatility for noninvasive diagnosis of high-risk nonalcoholic fatty liver disease (NAFLD). MATERIALS AND METHODS. This retrospective study included patients with biopsy-proven diagnosis of NAFLD who underwent duplex Doppler ultrasound assessment of the main portal vein within 1 year of liver biopsy (January 2014 to February 2018). Doppler ultrasound images were reviewed. The spectral waveform was used to measure the maximum (Vmax) and minimum (Vmin) velocity of blood in the portal veins. Venous pulsatility index (VPI) defined as (Vmax - Vmin) / Vmax was calculated. ROC curve analysis was used to calculate AUC as a measure of accuracy to determine the value of this index for diagnosis of high-risk NAFLD and compared with that of the following four clinical decision aids: NAFLD fibrosis score (FS), fibrosis-4 index (FIB-4), BARD score (body mass index, aspartate aminotransferase [AST]-to-alanine aminotransferase ratio, diabetes mellitus), and AST-to-platelet ratio index (APRI). The value of adding VPI to these indexes was also investigated. RESULTS. Of 123 study subjects, 33 (26.8%) had high-risk NAFLD and were found to have a lower VPI than the other 90 subjects (0.19 vs 0.32; p < 0.001). VPI, NAFLD FS, FIB-4, and APRI had statistically significant diagnostic values for high-risk NAFLD. VPI had the highest optimism-corrected AUC (VPI, 0.84 [95% CI, 0.77-0.91]; NAFLD FS, 0.74 [95% CI, 0.63-0.83]; FIB-4, 0.81 [95% CI, 0.72-0.89]; APRI, 0.73 [95% CI, 0.61-0.82]). Addition of VPI to any of the four scoring systems significantly improved the diagnostic value of the score for high-risk NAFLD. CONCLUSION. VPI may be an accurate noninvasive biomarker for diagnosis of high-risk NAFLD.

Potential diagnostic and prognostic value of serum and cerebrospinal fluid biomarkers in traumatic spinal cord injury: A systematic review.

It remains unclear whether biomarkers in the serum or CSF can be used for diagnosis or prognosis of spinal cord injuries (SCI). Therefore, a systematic review was undertaken to evaluate the prognostic or diagnostic value of serum and CSF biomarkers in assessing the severity of SCI and the outcome of patients. Two independent reviewers summarized the human studies retrieved from the electronic databases of Medline, Embase, Scopus and ISI Web of Science until April 2018. Seventeen studies were included (1065 patients aged 16-94 years old). Although the findings of the included studies suggest that inflammatory and structural proteins may be useful in assessing the severity of SCI and prediction of neurological outcome, the level of evidence is generally low. Given limitations to the available evidence, further investigation in this field is required using large prospective data sets with rigorous analysis of sensitivity, specificity and prediction.

Clinical application of ultrasound-guided percutaneous microwave ablation for benign breast lesions: a prospective study.

BACKGROUND: Background: Benign breast lesions are the most common diseases in adult women, which have been treated with minimally invasive therapies in recent years. Little is known about the feasibility of Microwave ablation (MWA) for benign breast lesion treatment. The primary aim of this prospective study was to evaluate the safety and efficiency of MWA as a potential therapeutic option for benign breast lesions in a single-center cohort study. METHODS: Women with possibly benign breast lesions based on an ultrasound (US) assessment who were scheduled to undergo MWA between November 2014 to July 2018 were included in the study. The patients underwent conventional US to measure the size of the lesion, Doppler US to assess the vascularity of the lesion, elastography to evaluate the stiffness of the mass, core needle biopsy of suspicious lesions, contrast-enhanced US to help determine the treatment plan and eventually MWA of the lesion. Lesions were followed at one, three, six, twelve and eighteen months after treatment to with the same imaging modalities. RESULTS: A total of 314 women aged 17 to 69 years old (mean = 36.9 ± 9.9 years) with 725 benign breast lesions (mean of maximum diameter = 10.86 ± 5.40 mm) were included. The frequency of palpable mass, pain and nipple discharge significantly decreased after treatment. Complete ablation rate was 97.8%, immediately after ablation, which increased to 100% after supplementary ablation of the 15 cases with incomplete ablation. Blood flow classification and lesion's volume also showed a significant decrease, while both volume reduction ratio and disappearance rate significantly increased following treatment. The elasticity score of the lesions showed fluctuations across different follow-up intervals. None of the patients experienced major complications and the 1% who had mild symptoms were successfully treated. CONCLUSION: MWA treatment is shown to be safe and efficient and has the potential to be considered as an alternative first line treatment for benign breast lesions.

Accuracy of cystatin C in prediction of acute kidney injury in children; serum or urine levels: which one works better? A systematic review and meta-analysis.

BACKGROUND: There is still an ongoing discussion on the prognostic value of cystatin C in assessment of kidney function. Accordingly, the present study aimed to conduct a meta-analysis to provide evidence for the prognostic value of this biomarker for acute kidney injury (AKI) in children. METHODS: An extensive search was performed in electronic databases of Medline, Embase, ISI Web of Science, Cochrane library and Scopus until the end of 2015. Standardized mean difference (SMD) with a 95% of confidence interval (95% CI) and the prognostic performance characteristics of cystatin C in prediction of AKI were assessed. Analyses were stratified based on the sample in which the level of cystatin C was measured (serum vs. urine). RESULTS: A total of 24 articles were included in the meta-analysis [1948 children (1302 non-AKI children and 645 AKI cases)]. Serum (SMD = 0.96; 95% CI: 0.68-1.24; p < 0.0001) and urine (SMD = 0.54; 95% CI:0.34-0.75; p < 0.0001) levels of cystatin C were significantly higher in children with AKI. Overall area under the curve of serum cystatin C and urine cystatin C in prediction of AKI were 0.83 (95% CI: 0.80-0.86) and 0.85 (95% CI: 0.81-0.88), respectively. The best sensitivity (value = 0.85; 95% CI: 0.78-0.90) and specificity (value = 0.61; 95% CI: 0.48-0.73), were observed for the serum concentration of this protein and in the cut-off points between 0.4-1.0 mg/L. CONCLUSION: The findings of the present study showed that cystatin C has an acceptable prognostic value for prediction of AKI in children. Since the serum level of cystatin C rises within the first 24 h of admission in patients with AKI, this biomarker can be a suitable alternative for traditional diagnostic measures.

A randomized controlled trial of smoking cessation methods in patients newly-diagnosed with pulmonary tuberculosis.

BACKGROUND: Tuberculosis (TB) and tobacco use are two major alarming global health issues that tend to be co-prevalent in many developing countries and various surveys have provided evidence on their entangled associations. Accordingly, it is strongly suggested that smoking cessation be incorporated in TB control programs. Therefore, we aimed to evaluate the effectiveness of two smoking cessation methods among newly-diagnosed pulmonary TB patients. METHODS: A total of 210 newly-diagnosed pulmonary TB patients from Tehran, Iran with smoking habits were included in this randomized clinical trial during 2012-2013. Patients were assigned to three groups of control (just TB medical treatment), brief advice (TB medical treatment plus individualized counseling sessions of quitting behavioral therapy) and combined intervention (TB medical treatment plus individualized counseling sessions of quitting behavioral therapy plus medical treatment with slow release bupropion). Patients' abstinence was followed at six time point during six months. Data were analyzed by SPSS v.22 using Generalized Estimating Equations (GEE) model. RESULTS: Abstinance rate at the end of six months were 71.7 % for combined intervention group, 33.9 % for brief advice group and 9.8 % for the control group (p < 0.001). Combined intervention group and brief advice group respectively had 35 times (p < 0.001, OR = 35.26, 95 % CI = 13.77-90.32) and 7 times (p < 0.001, OR = 7.14, 95 % CI = 2.72-18.72) more odds of not being an active smoker at each time point, compared to the control group. CONCLUSION: Considering the prevalence and importance of TB and the substantial influence of these preventive measures on controlling tobacco use, application of such programs is recommended. TRIAL REGISTRATION: The survey was registered in the Iranian registry of clinical trials website (irct.ir) in August 31, 2013 with IRCT ID: IRCT2013062613783N1 .

Artificial Intelligence for Breast US.

US is a widely available, commonly used, and indispensable imaging modality for breast evaluation. It is often the primary imaging modality for the detection and diagnosis of breast cancer in low-resource settings. In addition, it is frequently employed as a supplemental screening tool via either whole breast handheld US or automated breast US among women with dense breasts. In recent years, a variety of artificial intelligence systems have been developed to assist radiologists with the detection and diagnosis of breast lesions on US. This article reviews the background and evidence supporting the use of artificial intelligence tools for breast US, describes implementation strategies and impact on clinical workflow, and discusses potential emerging roles and future directions.

Prevalence of Hypertension among Children Based on the New American Academy of Pediatrics Clinical Practice Guidelines.

Background: In 2017, the American Academy of Pediatrics (AAP) updated clinical practice guidelines for the diagnosis and management of hypertension in children. The present study aimed to assess the prevalence of hypertension in Iranian children based on the latest guidelines. Methods: Data on 7301 student participants (3589 boys and 3712 girls) aged between 7-12 yr were assessed. The data were extracted from the fifth Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable Disease (CASPIAN V) school-based study conducted in the 30 provinces of Iran in 2015. Blood pressure (BP) was classified as normal, elevated BP, and stage 1 and 2 hypertension using weighted analysis and the 2017 AAP guidelines. All analyses were performed in STATA 14.0 statistical software, with findings presented in terms of prevalence. Results: The overall prevalence of high BP in Iranian children was 14.7%. In addition, 15.1% of boys had high BP, with 9.4% and 1.7% of them with stage 1 and 2 hypertension, respectively. Moreover, 14.3% of girls had high BP, of which 10% had stage 1 and 1.3% with stage 2 hypertension. For elevated hypertension, it was observed in 4% of boys and 3% of girls. Conclusion: Using the 2017 AAP guidelines demonstrated a higher prevalence of hypertension in children (14.7%) in Iran. The prevalence of hypertension in boys was slightly higher compared to girls.

Prevalence of Posttraumatic Stress Disorder Symptoms Following Traumatic Spinal Cord Injury: A Systematic Review and Meta-analysis.

BACKGROUND: Limited evidence is currently available on the prevalence of posttraumatic stress disorder (PTSD) following traumatic spinal cord injury (SCI). This systematic review and meta-analysis aims to assess the prevalence and geographic distribution of PTSD symptoms after SCI. METHODS: After a search in the MEDLINE, Embase, Scopus, and Web of Science databases, two reviewers independently summarized relevant studies published through 20 October 2021. Observational studies were included. The studies were eligible if they assessed PTSD symptoms using standard self-report or clinician-based instruments. Data and results were reported using the overall prevalence and the odds ratio (OR), with 95% confidence intervals (CIs). RESULTS: 24 articles (5646 patients) met the inclusion criteria. The prevalence of PTSD symptoms ranged from 6.33% (95% CI, 2.73-13.97) to 61.76% (95% CI, 52.07-70.61). Pooled analysis demonstrated that the overall prevalence of PTSD symptoms in SCI patients was significantly higher in developing countries (41.64%; 95% CI, 31.11-52.55) than in developed countries (19.35%; 95% CI, 14.66-24.51) (OR = 1.24; 95% CI, 1.08-1.42; p = .003). The highest prevalence of PTSD symptoms was reported in South Africa (56.25%; 95% CI, 47.01-65.08), followed by Sri Lanka (45.71%; 95% CI, 30.47-61.81), and Greece (43.55%; 95% CI, 31.94-55.91). By contrast, Norway (6.33%; 95% CI, 2.73-13.97), Switzerland/Germany (8.65%; 95% CI, 4.8-13.42), and Denmark (10.71%; 95% CI, 6.89-16.30) were found to have the lowest prevalence of PTSD symptoms after SCI. CONCLUSION: Many traumatic SCI patients suffer from PTSD symptoms, and their prevalence seems to be higher in developing countries than in developed countries. These findings underscore the need to consider the psychological aspects of traumatic SCI.

Role of a Chest X-ray Severity Score in a Multivariable Predictive Model for Mortality in Patients with COVID-19: A Single-Center, Retrospective Study.

Predicting the mortality risk of patients with Coronavirus Disease 2019 (COVID-19) can be valuable in allocating limited medical resources in the setting of outbreaks. This study assessed the role of a chest X-ray (CXR) scoring system in a multivariable model in predicting the mortality of COVID-19 patients by performing a single-center, retrospective, observational study including consecutive patients admitted with a confirmed diagnosis of COVID-19 and an initial CXR. The CXR severity score was calculated by three radiologists with 12 to 15 years of experience in thoracic imaging, based on the extent of lung involvement and density of lung opacities. Logistic regression analysis was used to identify independent predictive factors for mortality to create a predictive model. A validation dataset was used to calculate its predictive value as the AUROC. A total of 628 patients (58.1% male) were included in this study. Age (p < 0.001), sepsis (p < 0.001), S/F ratio (p < 0.001), need for mechanical ventilation (p < 0.001), and the CXR severity score (p = 0.005) were found to be independent predictive factors for mortality. We used these variables to develop a predictive model with an AUROC of 0.926 (0.891, 0.962), which was significantly higher than that of the WHO COVID severity classification, 0.853 (0.798, 0.909) (one-tailed p-value = 0.028), showing that our model can accurately predict mortality of hospitalized COVID-19 patients.

Age, Period and Cohort Analysis of Smoking Prevalence in Iranian Population over a 25-Year Period.

BACKGROUND: Current and daily smoking prevalence rates have been have investigated in several cross-sectional studies. However, analyses in terms of age-period-cohort (APC) have not been carried out. We assessed daily smoking dynamics over a 25-year period using the APC model. METHODS: In our analyses, we used data from 214,652 people aged 15 to 64 years, collected by national health surveys conducted in 1990-1991, 1999, 2005, 2007, 2011 and 2016. The Intrinsic Estimator model was used to analyze the impact of APC on daily smoking prevalence. RESULTS: Males were found to exhibit a higher prevalence of smoking compared to females (26.0% against 2.7%). Prevalence of smoking increased by age, peaking at the age groups of 40-44 in men and 45-49 in women, followed by a decreasing trend. The 1990 period had the highest prevalence in both genders, and the 2016 period had the lowest. The coefficients of birth cohort effects showed different patter19s of fluctuations in the two genders with the maximum and minimum coefficients for men calculated in the 1966-1970 and 1991-95 birth cohorts, and for females the 1931-1935 and 1971-1975 birth cohorts, respectively. CONCLUSION: We showed the impact of APC on daily tobacco smoking prevalence, and these factors should be considered when dealing with smoking.

Effect of vitamins C and E on recovery of motor function after spinal cord injury: systematic review and meta-analysis of animal studies.

CONTEXT: Many animal studies have evaluated the role of vitamins in the recovery of motor function after spinal cord injury, but their results have been contradictory and no consensus has been reached. OBJECTIVE: This meta-analysis aimed to investigate the effects of vitamin C and vitamin E on recovery of motor function after spinal cord injury in animal models. DATA SOURCES: Two authors independently collected the records of relevant articles published in MEDLINE, Embase, Scopus, and Web of Science through November 2018. STUDY SELECTION: All studies conducted in animal models to evaluate the therapeutic effects of vitamin C or vitamin E or both on recovery of motor function after spinal cord injury were included. Studies that lacked a control group or a standard treatment, lacked an assessment of motor function, included genetically modified/engineered animals, included animals pretreated with vitamin C or vitamin E, or combined vitamin treatment with other methods, such as cell therapies, were excluded. DATA EXTRACTION: Data from 10 articles met the inclusion criteria for meta-analysis, conducted in accordance with PRISMA guidelines. RESULTS: Daily supplementation with vitamin C (P < 0.0001) and vitamin E (P < 0.0001) significantly improved the recovery of motor function in animals affected by spinal cord injury. Vitamin C supplementation is effective only when administered intraperitoneally (P < 0.0001). Concurrent supplementation with both vitamins does not show better efficacy than treatment with either one alone. CONCLUSION: Administration of vitamin C and vitamin E in animal models of spinal cord injury significantly improves the recovery of motor function.

Age-Period-Cohort Analysis of Abdominal Obesity in Iranian Children and Adolescents: The CASPIAN Study.

BACKGROUND: The assessment of the trend of changes in the prevalence of abdominal obesity can provide useful health information. OBJECTIVES: This study aimed to conduct an age-period-cohort (APC) analysis to provide the trend of the prevalence of abdominal obesity in the Iranian pediatric population through the three temporal dimensions of age, period, and cohort. METHODS: Data were gathered from a total number of 53,962 Iranian children and adolescents aged 5 to 19 years through four surveys of a national surveillance program (the CASPIAN study) conducted in 2003, 2007, 2011, and 2015. Abdominal obesity was defined as a waist-to-height ratio of ≥ 0.5. The APC analysis was performed using the "apc_ie"command in STATA software. RESULTS: A significant correlation existed between age, period, and cohort effects and the prevalence of abdominal obesity in children and adolescents. With increasing age, regardless of considerable fluctuations, the prevalence of abdominal obesity followed an overall increasing trend in both genders. The age effect coefficient increased from -2.1 in the age group of 5 - 9 years to 1.1 in the age group of 10 - 14 years and then decreased to 1.0 in the age group of 15 - 19 years among boys; figures followed an increasing trend in girls from -2.2 to 0.8 and 1.5, respectively. As for the period effect, in both boys and girls, the prevalence of abdominal obesity followed an increasing trend when coming from the earlier periods to the recent ones (from -4.6 to 4.0 in boys and from -4.1 to 2.4 in girls). Likewise, this prevalence increased from earlier birth cohorts to the recent ones in both genders. CONCLUSIONS: The prevalence of abdominal obesity is increasing among Iranian children and adolescents and this rising trend is affected by age, period, and birth cohort effects. The findings of this study emphasize the necessity of implementing comprehensive interventions for tackling the epidemic of childhood obesity.

Magnetic resonance imaging/transrectal ultrasonography fusion guided seed placement in a phantom: Accuracy between 2-seed versus 1-seed strategies.

PURPOSE: To investigate whether the 2-seed placement per Magnetic Resonance Imaging (MRI) suspicious lesion yields a higher seed placement accuracy than a 1-seed strategy on a phantom. METHODS: Eight olives embedded in gelatin, each simulating a prostate, underwent MRI. Three virtual spherical lesions (3, 5, and 8 mm diameters) were marked in each olive on the MRI images and co-registered to the MRI/Transrectal Ultrasonography (TRUS) fusion biopsy system. Two radiologists placed 0.5 mm fiducials, targeting the center of each virtual lesion under fusion image guidance. Half of the 8 olives in each phantom were assigned either to the 1-seed or 2-seeds per lesion strategy. Post-procedure Computed Tomography (CT) images identified each seed and were fused with MR to localize each virtual lesion and collected the seed placement error - distance between the virtual target and the corresponding seed (using the closer seed for the 2-seed strategy). Seed placement success is defined as fiducial placement within a lesion boundary. RESULTS: Each operator repeated the procedure on three different phantoms, and data from 209 seeds placed for 137 lesions were analyzed, with an overall error of 3.03 ±â€¯1.52 mm. The operator skill, operator phantom procedural experience, lesion size, and number of seeds, were independently associated with the seed placement error. Seed placement success rate was higher for the 2-seed group compared to 1-seed, although the difference was not statistically significant. CONCLUSIONS: Placing 2 seeds per MRI lesion yielded a significantly lower error compared to 1-seed strategy, although seed placement success rate was not significantly different.

Development of a generalized model for kidney depth estimation in the Chinese population: A multi-center study.

PURPOSE: To establish an accurate and reliable equation for kidney depth estimation in adult patients from different Chinese geographical regions. METHOD: This multicenter study enrolled Eastern Asian Chinese patients with abdominal PET/CT scans at 26 imaging centers from six macro-regions across China in 3 years. Age, gender, height, weight, primary disease and its extent on PET scans of the participants were collected as potential predictive factors. Kidney depth on CT, defined as the average of the vertical distances from the posterior skin to the farthest anterior and closest posterior surfaces of each kidney, was measured as the standard reference. The new kidney depth model was constructed using a multiple regression model, and its performance was compared to those of three established models by computing the absolute value of estimation errors in comparison with CT-measured kidney depth. RESULTS: A total of 2502 patients were enrolled and classified into training (n=1653) and testing (n = 849) subsets. In the training subset, two kidney depth models were constructed: Left (cm): 0.013×age+0.117×gender-0.044×height+0.087×weight+7.951, Right (cm): 0.005×age+0.013×gender-0.035×height+0.082×weight+7.266 (weight: kg, height: cm, gender = 0 if female, 1 if male). In the testing subset, one-way analysis of variance showed that the estimation errors of the new models did not significantly differ among the 6 regions. Bland-Altman analysis determined that new equations had lower estimated biases (left: 0.039 cm, right: 0.018 cm) compared with other existing models. CONCLUSION: The new equations were highly accurate for kidney depth estimation in adults from all over China, with lower estimation errors compared to other established models.

Differentiation of Benign from Malignant Adnexal Masses by Dynamic Contrast-Enhanced MRI (DCE-MRI): Quantitative and Semi-quantitative analysis at 3-Tesla MRI

Background: To evaluate the utility of the pharmacokinetic modeling derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in differentiating benign from malignant adnexal masses. Methods: A total of 43 patients with 49 complex adnexal masses (27 benign, 3 borderline, and 19 malignant lesions) underwent preoperative DCE-MRI examinations on a 3 Tesla MRI. Using extended Tofts' model, quantitative analysis was performed in the solid components of all tumors. Three pharmacokinetic parameters were defined as volume transfer coefficient (Ktrans), the rate constant (Kep), and the plasma volume (Vp). Semi-quantitative analysis was also performed and the values of relative signal intensity (SI rel) wash-in-rate (WIR), the initial area under the curve (iAUC60), time-to-peak (TTP) and wash-out-rate (WOR) were calculated. Receiver operating characteristic (ROC) curve analysis was performed to evaluate diagnostic characteristics of each DCE-MRI parameter in differentiating borderline/malignant tumors from benign lesions and to provide the optimal cutoff values for these variables. Results: SI rel had the highest diagnostic value (AUC=0.872; p<0.001; cut-off=121.4 associated with an overall accuracy=79.6%, sensitivity=95.5%, specificity=66.7%, NPV=94.8% and PPV=70.0%). Ktrans had the second highest AUC=0.836 (p<0.001; cut-off=0.034 associated with an overall accuracy=79.6%, sensitivity=86.4%, specificity=74.1%, NPV=87.0% and PPV=73.1%). The other factors found to be acceptable diagnostic parameters for borderline/malignant lesions included WIR (AUC=0.816; p<0.001), iAUC60 (AUC=0.808; p<0.001), Vp (AUC=0.795; p<0.001), SI max (AUC=0.737, p=0.005), SI peak (AUC=0.737; p=0.005) and Kep (AUC=0.681; p=0.031). Conclusion: Quantitative DCE-MRI is a relevant tool for differentiating benign from malignant adnexal masses. Among all the DCE parameters, SI rel and Ktrans are the most accurate discriminators.