In vivo neuropil density from anatomical MRI and machine learning.

Brain energy budgets specify metabolic costs emerging from underlying mechanisms of cellular and synaptic activities. While current bottom-up energy budgets use prototypical values of cellular density and synaptic density, predicting metabolism from a person's individualized neuropil density would be ideal. We hypothesize that in vivo neuropil density can be derived from magnetic resonance imaging (MRI) data, consisting of longitudinal relaxation (T1) MRI for gray/white matter distinction and diffusion MRI for tissue cellularity (apparent diffusion coefficient, ADC) and axon directionality (fractional anisotropy, FA). We present a machine learning algorithm that predicts neuropil density from in vivo MRI scans, where ex vivo Merker staining and in vivo synaptic vesicle glycoprotein 2A Positron Emission Tomography (SV2A-PET) images were reference standards for cellular and synaptic density, respectively. We used Gaussian-smoothed T1/ADC/FA data from 10 healthy subjects to train an artificial neural network, subsequently used to predict cellular and synaptic density for 54 test subjects. While excellent histogram overlaps were observed both for synaptic density (0.93) and cellular density (0.85) maps across all subjects, the lower spatial correlations both for synaptic density (0.89) and cellular density (0.58) maps are suggestive of individualized predictions. This proof-of-concept artificial neural network may pave the way for individualized energy atlas prediction, enabling microscopic interpretations of functional neuroimaging data.

Multicenter Quantification of Radiation Exposure and Associated Risks for Prostatic Artery Embolization in 1476 Patients.

Background Prostatic artery embolization (PAE) is a safe, minimally invasive angiographic procedure that effectively treats benign prostatic hyperplasia; however, PAE-related patient radiation exposure and associated risks are not completely understood. Purpose To quantify radiation dose and assess radiation-related adverse events in patients who underwent PAE at multiple centers. Materials and Methods This retrospective study included patients undergoing PAE for any indication performed by experienced operators at 10 high-volume international centers from January 2014 to May 2021. Patient characteristics, procedural and radiation dose data, and radiation-related adverse events were collected. Procedural radiation effective doses were calculated by multiplying kerma-area product values by an established conversion factor for abdominopelvic fluoroscopy-guided procedures. Relationships between cumulative air kerma (CAK) or effective dose and patient body mass index (BMI), fluoroscopy time, or radiation field area were assessed with linear regression. Differences in radiation dose stemming from radiopaque prostheses or fluoroscopy unit type were assessed using two-sample t tests and Wilcoxon rank sum tests. Results A total of 1476 patients (mean age, 69.9 years ± 9.0 [SD]) were included, of whom 1345 (91.1%) and 131 (8.9%) underwent the procedure with fixed interventional or mobile fluoroscopy units, respectively. Median procedure effective dose was 17.8 mSv for fixed interventional units and 12.3 mSv for mobile units. CAK and effective dose both correlated positively with BMI (R2 = 0.15 and 0.17; P < .001) and fluoroscopy time (R2 = 0.16 and 0.08; P < .001). No radiation-related 90-day adverse events were reported. Patients with radiopaque implants versus those without implants had higher median CAK (1452 mGy [range, 900-2685 mGy] vs 1177 mGy [range, 700-1959 mGy], respectively; P = .01). Median effective dose was lower for mobile than for fixed interventional systems (12.3 mSv [range, 8.5-22.0 mSv] vs 20.4 mSv [range, 13.8-30.6 mSv], respectively; P < .001). Conclusion Patients who underwent PAE performed with fixed interventional or mobile fluoroscopy units were exposed to a median effective radiation dose of 17.8 mSv or 12.3 mSv, respectively. No radiation-related adverse events at 90 days were reported. © RSNA, 2024 See also the editorial by Mahesh in this issue.

Aspm knockout ferret reveals an evolutionary mechanism governing cerebral cortical size.

The human cerebral cortex is distinguished by its large size and abundant gyrification, or folding. However, the evolutionary mechanisms that drive cortical size and structure are unknown. Although genes that are essential for cortical developmental expansion have been identified from the genetics of human primary microcephaly (a disorder associated with reduced brain size and intellectual disability) 1 , studies of these genes in mice, which have a smooth cortex that is one thousand times smaller than the cortex of humans, have provided limited insight. Mutations in abnormal spindle-like microcephaly-associated (ASPM), the most common recessive microcephaly gene, reduce cortical volume by at least 50% in humans2-4, but have little effect on the brains of mice5-9; this probably reflects evolutionarily divergent functions of ASPM10,11. Here we used genome editing to create a germline knockout of Aspm in the ferret (Mustela putorius furo), a species with a larger, gyrified cortex and greater neural progenitor cell diversity12-14 than mice, and closer protein sequence homology to the human ASPM protein. Aspm knockout ferrets exhibit severe microcephaly (25-40% decreases in brain weight), reflecting reduced cortical surface area without significant change in cortical thickness, as has been found in human patients3,4, suggesting that loss of 'cortical units' has occurred. The cortex of fetal Aspm knockout ferrets displays a very large premature displacement of ventricular radial glial cells to the outer subventricular zone, where many resemble outer radial glia, a subtype of neural progenitor cells that are essentially absent in mice and have been implicated in cerebral cortical expansion in primates12-16. These data suggest an evolutionary mechanism by which ASPM regulates cortical expansion by controlling the affinity of ventricular radial glial cells for the ventricular surface, thus modulating the ratio of ventricular radial glial cells, the most undifferentiated cell type, to outer radial glia, a more differentiated progenitor.

Performance and reliability assessment of a lower dose, task-based scoliosis radiography protocol in pediatric patients.

BACKGROUND: Follow-up scoliosis radiographs are performed to assess the degree of spinal curvature and skeletal maturity, which can be done at lower radiation exposures than those in standard-dose radiography. OBJECTIVE: Describe and evaluate a protocol that reduced the radiation in follow-up frontal-view scoliosis radiographs. MATERIALS AND METHODS: We implemented a postero-anterior lower dose modified-technique for scoliosis radiography with task-based definition of adequate image quality and use of technique charts based on target exposure index and patient's height and weight. We subsequently retrospectively evaluated 40 consecutive patients who underwent a follow-up radiograph using the modified-technique after an initial standard-technique radiograph. We evaluated comparisons of proportions for subjective assessment with chi-squared tests, and agreements of reader's scores with intraclass correlation coefficients and Bland-Altman plots. We determined incident air kerma, exposure index, deviation index/standard deviation, dose-area product (DAP), and effective dose for each radiograph. We set statistical significance at P<0.05. RESULTS: Forty patients (65% female), aged 4-17 years. Median effective dose was reduced from 39 to 10 µSv (P<0.001), incident air kerma from 139 to 29 µSv (P<0.001), and DAP from 266 to 55 mGy*cm2 (P<0.001). All modified-technique parameters were rated with a mean score of acceptable or above. All modified-technique measurements obtained inter- and intra-observer correlation coefficient agreements of 0.86 ("Good") or greater. CONCLUSION: Substantial dose reduction on follow-up scoliosis imaging with existing radiography units is achievable through task-based definition of adequate image quality and tailoring of radiation to each patient's height and weight, while still allowing for reliable assessment and reproducible measurements.

Machine Learning Models for Prediction of Posttreatment Recurrence in Early-Stage Hepatocellular Carcinoma Using Pretreatment Clinical and MRI Features: A Proof-of-Concept Study.

BACKGROUND. Posttreatment recurrence is an unpredictable complication after liver transplant for hepatocellular carcinoma (HCC) that is associated with poor survival. Biomarkers are needed to estimate recurrence risk before organ allocation. OBJECTIVE. This proof-of-concept study evaluated the use of machine learning (ML) to predict recurrence from pretreatment laboratory, clinical, and MRI data in patients with early-stage HCC initially eligible for liver transplant. METHODS. This retrospective study included 120 patients (88 men, 32 women; median age, 60.0 years) with early-stage HCC diagnosed who were initially eligible for liver transplant and underwent treatment by transplant, resection, or thermal ablation between June 2005 and March 2018. Patients underwent pretreatment MRI and posttreatment imaging surveillance. Imaging features were extracted from postcontrast phases of pretreatment MRI examinations using a pretrained convolutional neural network. Pretreatment clinical characteristics (including laboratory data) and extracted imaging features were integrated to develop three ML models (clinical model, imaging model, combined model) for predicting recurrence within six time frames ranging from 1 through 6 years after treatment. Kaplan-Meier analysis with time to recurrence as the endpoint was used to assess the clinical relevance of model predictions. RESULTS. Tumor recurred in 44 of 120 (36.7%) patients during follow-up. The three models predicted recurrence with AUCs across the six time frames of 0.60-0.78 (clinical model), 0.71-0.85 (imaging model), and 0.62-0.86 (combined model). The mean AUC was higher for the imaging model than the clinical model (0.76 vs 0.68, respectively; p = .03), but the mean AUC was not significantly different between the clinical and combined models or between the imaging and combined models (p > .05). Kaplan-Meier curves were significantly different between patients predicted to be at low risk and those predicted to be at high risk by all three models for the 2-, 3-, 4-, 5-, and 6-year time frames (p < .05). CONCLUSION. The findings suggest that ML-based models can predict recurrence before therapy allocation in patients with early-stage HCC initially eligible for liver transplant. Adding MRI data as model input improved predictive performance over clinical parameters alone. The combined model did not surpass the imaging model's performance. CLINICAL IMPACT. ML-based models applied to currently underutilized imaging features may help design more reliable criteria for organ allocation and liver transplant eligibility.

Cryoablation of Venous Malformations: A Systematic Review.

This study aimed to review systematically the efficacy, safety, and technical aspects of cryoablation in the treatment of venous malformations (VMs) and to provide the groundwork for future studies. A literature search for clinical studies utilizing percutaneous cryoablation of VMs was performed. All clinical studies related to primary or secondary treatment of VMs with percutaneous cryoablation were included in this review. These selected studies were evaluated for patient characteristics, cryoablation technique, technical success, lesion size and pain scores before and after cryoablation, and adverse outcomes. Random effects analysis of postprocedural changes in lesion volume and pain scores was performed. There were 54 patients with 55 cases of cryoablation of VMs. Of these cases, 27 recorded changes in lesion volume and 31 recorded changes in pain scores. The weighted mean postprocedural decrease in lesion size was 92.0% (raw average, 71.7%). The weighted mean reduction in pain score was 77% (raw average, 78.2%). Considering all treated cases (55), complete resolution of symptoms was seen in 35 cases (63.6%) and overall (complete or partial) improvement in 52 cases (94.5%). Common postprocedural symptoms included pain, bruising, swelling and numbness lasting less than 2 weeks. There were two major adverse events (3.7%), with both cases due to persistent dysesthesia. Patients with a history of prior sclerotherapy demonstrated lower preprocedural and postprocedural pain scores (4.7 and 1.3) than patients without prior treatments (5.8 and 2.8). Cryoablation of VMs appears to be potentially safe and effective on limited short-interval follow-up.

MR Imaging Biomarkers for the Prediction of Outcome after Radiofrequency Ablation of Hepatocellular Carcinoma: Qualitative and Quantitative Assessments of the Liver Imaging Reporting and Data System and Radiomic Features.

PURPOSE: To assess the Liver Imaging Reporting and Data System (LI-RADS) and radiomic features in pretreatment magnetic resonance (MR) imaging for predicting progression-free survival (PFS) in patients with nodular hepatocellular carcinoma (HCC) treated with radiofrequency (RF) ablation. MATERIAL AND METHODS: Sixty-five therapy-naïve patients with 85 nodular HCC tumors <5 cm in size were included in this Health Insurance Portability and Accountability Act-compliant, institutional review board-approved, retrospective study. All patients underwent RF ablation as first-line treatment and demonstrated complete response on the first follow-up imaging. Gadolinium-enhanced MR imaging biomarkers were analyzed for LI-RADS features by 2 board-certified radiologists or by analysis of nodular and perinodular radiomic features from 3-dimensional segmentations. A radiomic signature was calculated with the most informative features of a least absolute shrinkage and selection operator Cox regression model using leave-one-out cross-validation. The association between both LI-RADS features and radiomic signatures with PFS was assessed via the Kaplan-Meier analysis and a weighted log-rank test. RESULTS: The median PFS was 19 months (95% confidence interval, 16.1-19.4) for a follow-up period of 24 months. Multifocality (P = .033); the appearance of capsular continuity, compared with an absent or discontinuous capsule (P = .012); and a higher radiomic signature based on nodular and perinodular features (P = .030) were associated with poorer PFS in early-stage HCC. The observation size, presence of arterial hyperenhancement, nonperipheral washout, and appearance of an enhancing "capsule" were not associated with PFS (P > .05). CONCLUSIONS: Although multifocal HCC clearly indicates a more aggressive phenotype even in early-stage disease, the continuity of an enhancing capsule and a higher radiomic signature may add value as MR imaging biomarkers for poor PFS in HCC treated with RF ablation.

Sparse Data-Driven Learning for Effective and Efficient Biomedical Image Segmentation.

Sparsity is a powerful concept to exploit for high-dimensional machine learning and associated representational and computational efficiency. Sparsity is well suited for medical image segmentation. We present a selection of techniques that incorporate sparsity, including strategies based on dictionary learning and deep learning, that are aimed at medical image segmentation and related quantification.

The cavernous carotid inferolateral trunk and persistent primitive maxillary arteries: analysis of dissected arterially injected fetal specimens and high-resolution micro-CT of the dog's anastomotic arteries.

PURPOSE: The presence of a persistent primitive maxillary artery is described in the literature dealing with the development of the cavernous carotid inferolateral trunk, and the relevant similarities of the cranial circulation of the human and dog. The literature includes no dissection photographs of the above-mentioned two human fetal arteries, only diagrammatic representations. This study's objectives were to analyze photographs of fetal dissections for the presence of these two arteries, and also investigate the possibility of obtaining, in preserved dog specimens, high-resolution micro-CT imaging of arteries homologous with the above-mentioned two human arteries. METHODS: The literature describing the embryologic development of the cavernous carotid inferolateral trunk, the persistent primitive maxillary arteries, and their homologies in the dog was reviewed. Relevant dissections of fetal specimens were analyzed. High-resolution micro-CT images of un-dissected dog arteries were produced and analyzed. RESULTS: Photographs of fetal specimen dissections demonstrate the cavernous carotid inferolateral trunk. A separate persistent primitive maxillary artery was not present in the dissected specimens. High-resolution micro-CT images of the dog demonstrate homologous arteries with segments of the human inferolateral trunk, and other skull base and brain arteries. CONCLUSION: This investigation provides the only photographs in the literature of dissected human fetal cavernous carotid inferolateral trunks. A persistent primitive maxillary artery was not present in the dissected specimens and is a non-existent structure, likely a previously misidentified carotid inferolateral trunk. High-resolution micro-CT images of the dog visualized arteries that are homologous to segments of the human cavernous carotid inferolateral trunk artery.

Prostatic Artery Embolization Using 100-300-µm Trisacryl Gelatin Microspheres to Treat Lower Urinary Tract Symptoms Attributable to Benign Prostatic Hyperplasia: A Single-Center Outcomes Analysis with Medium-Term Follow-up.

PURPOSE: To report medium-term outcomes of prostatic artery embolization (PAE) using 100-300-µm trisacryl gelatin microspheres to treat lower urinary tract symptoms (LUTS) from benign prostatic hyperplasia (BPH) and to evaluate how cone-beam computed tomography-measured prostate gland volume (PGV), median lobe enlargement (MLE), age, and Charlson Comorbidity Index (CCI) affect these results. MATERIALS AND METHODS: Seventy-four consecutive patients who underwent PAE from April 2014 through August 2018 were retrospectively reviewed. Patients had International Prostate Symptom Score (IPSS) >12, Quality of Life (QoL) score >2, prostate gland volume (PGV) >40 mL, age older than 45 years, and medical therapy failure. Twelve patients were excluded for bladder pathology or prostate cancer. Patients (n = 62, age = 71.8 ± 9.3 years, CCI = 3.5 ± 1.7, PGV = 174 ± 110 mL) had pre-procedure IPSS = 22.4 ± 5.6, QoL score = 4.4 ± 0.9, and post-void residual (PVR) = 172 ± 144 mL. Post-procedure values were compared to baseline at 1, 3, 6, 12, and 24 months. Associations between outcomes and PGV, MLE, age, and CCI were evaluated. Adverse event recording used Clavien-Dindo classification. RESULTS: One month after PAE (n = 37), IPSS improved to 7.6 ± 5.2 (P < .0001) and QoL score improved to 1.7 ± 1.4 (P < .0001). At 3 months (n = 32), improvements continued, with IPSS = 6.4 ± 5.1 (P < .0001), QoL score = 1.2 ± 1.2 (P < .0001), PVR = 53 ± 41 mL (P < .001), and PGV = 73 ± 38 mL (P < .0001). Results were sustained at 6 months (n = 35): IPSS = 6.4 ± 4.1 (P < .0001), QoL score = 1.2 ± 1.2 (P < .0001), PVR = 68 ± 80 mL (P < .0001), PGV = 60 ± 19 mL (P < .001). At 12 months, patients (n = 26) had IPSS = 7.3 ± 5.5 (P < .0001), QoL score = 1.2 ± 0.8 (P <.0001), PVR = 89 ± 117 mL (P < .0001), PGV = 60 ± 48 mL (P < .01). At 24 months, patients (n = 8) had IPSS = 8.0 ± 5.4 (P < .0001), QoL score = 0.7 ± 0.5 (P < .0001), PVR = 91 ± 99mL (P = 0.17), and PGV = 30 ± 5mL (P = .11). Improvements were independent of PGV, MLE, age, and CCI. Two grade II urinary infections occurred. CONCLUSIONS: PAE with 100-300-µm microspheres produced sustained substantial improvements in LUTS, PGV, and PVR, which were independent of baseline PGV, MLE, age, or CCI.

Regional myocardial strain analysis via 2D speckle tracking echocardiography: validation with sonomicrometry and correlation with regional blood flow in the presence of graded coronary stenoses and dobutamine stress.

BACKGROUND: Quantitative regional strain analysis by speckle tracking echocardiography (STE) may be particularly useful in the assessment of myocardial ischemia and viability, although reliable measurement of regional strain remains challenging, especially in the circumferential and radial directions. We present an acute canine model that integrates a complex sonomicrometer array with microsphere blood flow measurements to evaluate regional myocardial strain and flow in the setting of graded coronary stenoses and dobutamine stress. We apply this unique model to rigorously evaluate a commercial 2D STE software package and explore fundamental regional myocardial flow-function relationships. METHODS: Sonomicrometers (16 crystals) were implanted in epicardial and endocardial pairs across the anterior myocardium of anesthetized open chest dogs (n = 7) to form three adjacent cubes representing the ischemic, border, and remote regions, as defined by their relative locations to a hydraulic occluder on the mid-left anterior descending coronary artery (LAD). Additional cardiac (n = 3) and extra-cardiac (n = 3) reference crystals were placed to define the cardiac axes and aid image registration. 2D short axis echocardiograms, sonometric data, and microsphere blood flow data were acquired at baseline and in the presence of mild and moderate LAD stenoses, both before and during low-dose dobutamine stress (5 µg/kg/min). Regional end-systolic 2D STE radial and circumferential strains were calculated with commercial software (EchoInsight) and compared to those determined by sonomicrometry and to microsphere blood flow measurements. Post-systolic indices (PSIs) were also calculated for radial and circumferential strains. RESULTS: Low-dose dobutamine augmented both strain and flow in the presence of mild and moderate stenoses. Regional 2D STE strains correlated moderately with strains assessed by sonomicrometry (Rradial = 0.56, p < 0.0001; Rcirc = 0.55, p < 0.0001) and with regional flow quantities (Rradial = 0.61, Rcirc = 0.63). Overall, correspondence between 2D STE and sonomicrometry was better in the circumferential direction (Bias ± 1.96 SD: - 1.0 ± 8.2% strain, p = 0.06) than the radial direction (5.7 ± 18.3%, p < 0.0001). Mean PSI values were greatest in low flow conditions and normalized with low-dose dobutamine. CONCLUSIONS: 2D STE identifies changes in regional end-systolic circumferential and radial strain produced by mild and moderate coronary stenoses and low-dose dobutamine stress. Regional 2D STE end-systolic strain measurements correlate modestly with regional sonomicrometer strain and microsphere flow measurements.

Scoring of Coronary Artery Disease Characteristics on Coronary CT Angiograms by Using Machine Learning.

Background Coronary CT angiography contains prognostic information but the best method to extract these data remains unknown. Purpose To use machine learning to develop a model of vessel features to discriminate between patients with and without subsequent death or cardiovascular events. Performance was compared with that of conventional scores. Materials and Methods Coronary CT angiography was analyzed by radiologists into four features for each of 16 coronary segments. Four machine learning model types were explored. Five conventional vessel scores were computed for comparison including the Coronary Artery Disease Reporting and Data System (CAD-RADS) score. The National Death Index was retrospectively queried from January 2004 through December 2015. Outcomes were all-cause mortality, coronary heart disease deaths, and coronary deaths or nonfatal myocardial infarctions. Score performance was assessed by using area under the receiver operating characteristic curve (AUC). Results Between February 2004 and November 2009, 6892 patients (4452 men [mean age ± standard deviation, 51 years ± 11] and 2440 women [mean age, 57 years ± 12]) underwent coronary CT angiography (median follow-up, 9.0 years; interquartile range, 8.2-9.8 years). There were 380 deaths of all causes, 70 patients died of coronary artery disease, and 43 patients reported nonfatal myocardial infarctions. For all-cause mortality, the AUC was 0.77 (95% confidence interval: 0.76, 0.77) for machine learning (k-nearest neighbors) versus 0.72 (95% confidence interval: 0.72, 0.72) for CAD-RADS (P < .001). For coronary artery heart disease deaths, AUC was 0.85 (95% confidence interval: 0.84, 0.85) for machine learning versus 0.79 (95% confidence interval: 0.78, 0.80) for CAD-RADS (P < .001). When deciding whether to start statins, if the choice is made to tolerate treating 45 patients to be sure to include one patient who will later die of coronary disease, the use of the machine learning score ensures that 93% of patients with events will be administered the drug; if CAD-RADS is used, only 69% will be treated. Conclusion Compared with Coronary Artery Disease Reporting and Data System and other scores, machine learning methods better discriminated patients who subsequently experienced an adverse event from those who did not. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Schoepf and Tesche in this issue.

Case-Control Comparison of Conventional End-Hole versus Balloon-Occlusion Microcatheter Prostatic Artery Embolization for Treatment of Symptomatic Benign Prostatic Hyperplasia.

PURPOSE: To compare procedural metrics and clinical improvement for prostatic artery embolization (PAE) performed with a balloon-occlusion (BO) versus end-hole (EH) microcatheter in patients with benign prostatic hyperplasia. MATERIALS AND METHODS: Retrospective review was performed of 129 patients undergoing PAE with 100-300 µm Embosphere microspheres from April 2013 through August 2018. Microcatheter selection was nonrandom, based on prostatic artery anatomy. Five technical failures and 5 microcatheter crossover cases were excluded. BO group (n = 46, age 72.8 y ± 9.0, gland volume 184 mL ± 83, 42% in retention) and EH group (n = 73, age 76.0 y ± 9.0, gland volume 190 mL ± 116, 44% in retention) were compared using procedural metrics (excluding 30 EH learning-curve cases); symptomatic improvement at 3, 6, and 12 months after PAE; voiding trial success; and adverse events (reported used Clavien-Dindo classification). RESULTS: Procedural and fluoroscopy times were lower in the BO group (n = 46) vs EH group (n = 43) (152.0 min ± 34.0 vs 172.8 min ± 47.9, P < .02; 37.8 min ± 12.9 vs 50.3 min ± 18.9, P < .001). Collaterals coiled, contrast material used, and injected particle volume were similar for both groups (P = NS). International Prostate Symptom Score improvement was similar for BO group (n = 25) (before PAE 23.5 ± 6.5, 12 months after PAE 7.6 ± 6.8) and EH group (n = 30) (before PAE 20.9 ± 5.9, 12 months after PAE 6.6 ± 5.2) (P = NS). Quality-of-life improvements were also similar (BO: before PAE 4.5 ± 1.2, 12 months after PAE 1.4 ± 0.9; EH: before PAE 4.1 ± 1.0, 12 months after PAE 0.9 ± 0.7), as were 12-month postvoid residual improvements, voiding trial failure rates (EH 12%, BO 8%), and adverse event rates (grade II, III: EH 15%, BO 11%) (P = NS for all). CONCLUSIONS: BO microcatheter use in PAE did not affect injected particle volume, contrast material use, or protective coiling and did not impact symptomatic improvement, postvoid residual improvement, voiding trial success, or adverse events after PAE. Lower procedure and fluoroscopy times with BO microcatheter were likely due to selection bias.

Effect of Reader and Patient Parameters on the Performance of Last-Image-Hold for Fluoroscopic Grading of Vesicoureteric Reflux.

OBJECTIVE. The purpose of this study is to determine the effect of different reader and patient parameters on the degree of agreement and the rate of misclassification of vesicoureteric reflux grading on last-image-hold frames in relation to spot-exposed frames from voiding cystourethrography (VCUG) as well as to determine the nature of reflux misclassification on last-image-hold frames. MATERIALS AND METHODS. Blinded readers conducted a retrospective evaluation of last-image-hold and spot-exposed frames of the renal fossae from 191 sequential VCUG examinations performed during a five-year period. Kappa tests were used to determine the agreement between reflux gradings and to assess the impact of reader and patient parameters. Pearson product-moment correlations were used to evaluate the effect of patient parameters on reader level of certainty regarding reflux grading. RESULTS. We measured almost perfect overall agreement for more experienced readers and substantial overall agreement for less experienced readers. Point estimates of overall misclassification were less than 2% for more experienced readers and less than 4% for less experienced readers. The readers' level of certainty about reflux grading had a positive impact on agreement values and misclassification rates. Experienced readers' most common misclassification was assigning reflux a grade of 3 on a spot-exposed frame and a grade of 2 on an equivalent last-image-hold frame. Inexperienced readers' most common misclassification involved missing reflux altogether. CONCLUSION. Instances of grade 2 reflux on last-image-hold frames may warrant supplemental evaluation with spot-exposed frames. Otherwise, a reader's level of certainty regarding reflux grading on a last-image-hold frame may help determine whether a supplemental spot-exposed frame would be beneficial.

Benefit of a Visual Aid in the Management of Moderate-Severity Contrast Media Reactions.

OBJECTIVE: The purpose of this study was to compare management of moderate-severity reactions with and without a visual aid or flowchart in contrast medium reaction simulations. SUBJECTS AND METHODS: All attending radiologists and trainees were requested to participate in a contrast medium reaction simulation program, including a moderate-severity reaction scenario, and were randomized to groups having or not having a visual aid. The time to administer intramuscular (IM) epinephrine via automated injector and errors in administration were recorded. After the simulation, all participants completed a survey assessing their comfort in treating reactions to contrast media with and without a visual aid. RESULTS: A total of 138 participants were divided into 21 sessions in the program, with 68 participants in the moderate-severity reaction scenario. Eleven groups were provided a visual aid; 10 groups were not. Errors in management occurred in 18.2% (2 of 11) of groups with visual aids versus 40% (4 of 10) in groups without (p = 0.35), with epinephrine self-administration reflecting the most common error. Excluding the groups with errors, the mean time to administration of IM epinephrine was 97 seconds with versus 152 seconds without the visual aid (p = 0.04). Of the 138 participants, 97.8% agreed that the poster would aid in medication administration, and 87% agreed that it would help decrease time to administer medications. CONCLUSION: A visual aid increased the subjective confidence of radiologists in the dose and route of medication administration in the contrast medium reaction simulation and led to faster administration of epinephrine. Self-administration IM epinephrine errors were common and seen in both groups.

JOURNAL CLUB: Benefit of Epinephrine Autoinjector for Treatment of Contrast Reactions: Comparison of Errors, Administration Times, and Provider Preferences.

OBJECTIVE: Given the rarity of contrast reactions in practice, most radiologists have little to no experience in their management, and errors are common. The purpose of this study was to compare treatment of a moderate-severity reaction with intramuscular epinephrine by either the traditional manual method of drawing up and delivering epinephrine with a needle and syringe or the use of an epinephrine autoinjector. SUBJECTS AND METHODS: All diagnostic radiologists at the study institution were requested to participate in an annual contrast reaction simulation program, which consisted of three simulation scenarios in a high-fidelity simulation laboratory. During the moderate-severity simulation scenario, the time to administer intramuscular epinephrine and any errors in administration were recorded. Groups were randomized to use an autoinjector device or manual delivery. All participants completed a survey assessing the experience with epinephrine and their comfort in treating contrast reactions using a traditional manual approach versus an epinephrine autoinjector. RESULTS: Among 189 participants in the contrast reaction simulation program, 76 participated in a moderate-severity reaction simulation two to five at a time in 25 sessions. Mean total time to administration was significantly longer for manual (108.8 seconds) than for autoinjector (38.7 seconds) delivery (p < 0.001). There were 11 errors in the manual group and one error in the autoinjector group (p = 0.005). Ninety-four percent of participants reported feeling very comfortable or comfortable with the autoinjector as opposed to 60% for manual delivery (p < 0.001). Overall, 96% of participants thought the autoinjector was easier to use. CONCLUSION: Use of an epinephrine autoinjector for treatment of contrast reactions was associated with a significantly greater degree of provider comfort, shorter time to administration, and fewer errors.

Knowledge of Density and Screening Ultrasound.

To determine breast density awareness and attitudes regarding supplemental breast ultrasound screening since implementation of the nation's first breast density notification law, Connecticut Public Act 09-41. A self-administered survey was distributed at a Connecticut academic breast imaging center between February 2013 and February 2014. Women with prior mammography reports describing heterogeneous or extremely dense breast tissue were invited to participate when presenting for screening mammography, screening ultrasound, or both. Data were collected on breast density awareness, history of prior ultrasounds, attitudes toward ultrasound and breast-cancer risk, and demographics. Data were collected from 950 completed surveys. The majority of surveyed women (92%) were aware of their breast density, and 77% had undergone a prior screening ultrasound. Forty-three percent of participants who were aware of their breast density also expressed increased anxiety about developing breast cancer due to having dense breast tissue. Caucasian race and higher education were significantly associated (p < 0.05) with knowledge of personal breast density (93% and 95%, respectively) and having a prior screening breast ultrasound (79% and 80%, respectively). Patients with less than a college degree (82%) were significantly more likely to rely exclusively on their provider's recommendation regarding obtaining screening ultrasound (p < 0.05). Breast density awareness is strongly associated with higher education, higher income, and Caucasian race. Non-Caucasian patients and those with less than a college education rely more heavily on their physicians' recommendations regarding screening ultrasound. Among women aware of their increased breast density, nearly half reported associated increased anxiety regarding the possibility of developing breast cancer.

Assessment of a modified technique for air delivery during fluoroscopic-monitored pneumatic intussusception reduction.

BACKGROUND: Intussusception is one of the most common causes of acute abdominal emergency in children. Image-monitored pressure reduction is the first line of treatment. OBJECTIVE: We report on a modified technique of air delivery during fluoroscopic-monitored pneumatic intussusception reductions, and compare it with an established technique. MATERIALS AND METHODS: We modified the Shiels intussusception reduction device so that the air used for intussusception reduction is delivered not by the device's insufflator bulb, but rather by the hospital medical air supply system, eliminating the need for continuous pumping of the insufflator bulb during the procedure. Subsequently, we retrospectively compared sequential fluoroscopy-monitored pneumatic intussusception reduction procedures performed in patients younger than 18 years using either the standard or modified devices, evaluating technical procedure parameters (i.e. median procedure time length, fluoroscopy time length and radiation dose) and patient outcomes (i.e. number of complete intussusception reductions, number of incomplete intussusception reductions, number of intussusception recurrences within 3 days of the procedure, number of procedures followed by surgery). RESULTS: We found no statistically significant differences between procedures performed with the standard and modified techniques. CONCLUSION: The device modification allows for increased operator comfort. Evaluated procedure parameters and patient outcomes appear similar to those of the standard technique.

The Role of Report Comparison, Analysis, and Discrepancy Categorization in Resident Education.

OBJECTIVE: The purpose of this study was to show the value of automated radiology report comparison and analysis in resident education by providing qualitative and quantitative feedback on the discrepancies between preliminary and finalized reports. MATERIALS AND METHODS: Anonymous surveys on dictation practices and the process of reviewing reports were completed by consenting radiology residents and faculty. All 277 reports obtained across all modalities during the 4-week study were retrieved from the dictation server in both their preliminary and finalized states, for a total of 544 reports. Disparities between these reports were automatically compared side by side and were categorized according to clinical relevance, report quality, or report structure. The frequency of report corrections was compared between junior (postgraduate years [PGYs] 2 and 3) and senior (PGYs 4 and 5) residents. Residents were surveyed regarding the usefulness of the feedback. RESULTS: Eighty-six reports (31%) were verified as unchanged, with no statistically significant difference noted between junior and senior residents (33.2% and 25.9%, respectively; p = 0.03). Of the 370 discrepancies noted in the 191 edited reports, 81 (21.9%) were discrepancies in clinically relevant findings; 106 (28.6%) were discrepancies in report quality; and 183 (49.5%) were discrepancies in report structure, syntax, or both. Although senior residents had a lower rate of discrepancies in the clinical relevance category than did junior residents (12.8% and 26.5%; p = 0.004), they had a higher rate of discrepancies in the report quality category (58.4% and 44.9%; p = 0.02). Surveys of both residents and faculty showed strong support for the project. CONCLUSION: Categorization of corrections was deemed useful by residents and can be helpful in assessing elements of reporting accuracy for individual feedback. Quantitative report comparison and analysis show promise in tailoring resident education at the programmatic level as cumulative data are gathered and trends are analyzed.

Magnetic Resonance Imaging and Sonography in the Diagnosis of Placental Invasion.

OBJECTIVES: To compare older and newer magnetic resonance imaging (MRI) criteria for placental invasion and to compare the sensitivity, specificity, and accuracy of MRI and sonography in determining the depth of placental invasion. METHODS: Forty pregnant patients at high risk for morbidly adherent placenta based on prenatal sonography underwent MRI evaluations. Two reviewers, who were blinded to the original MRI and sonographic interpretations, clinical history, and obstetric/pathologic findings, reviewed the MRI examinations. The MRI and sonographic scans were analyzed for the presence and depth of invasion. The MRI scans were tabulated for the presence of dark intraplacental T2 bands, bulging of the myometrium, increased vascularity, and indistinct myometrium, loss of the dark T2 myometrial/placental interface, and a thin myometrium. The obstetric/pathologic results served as the reference standards. RESULTS: Eighteen of 40 patients had a morbidly invasive placenta. The sensitivity, specificity, and accuracy of MRI and sonography were not significantly different. The accuracy rates for determining the depth of placental invasion by readers 1 and 2 were 0.65 and 0.55, respectively (P > .05). According to the Cohen κ statistic, there was a good inter-reader agreement between the MRI readers in assessing the depth of placental invasion (κ = 0.45). The features most commonly seen were dark T2 bands, bulging of the uterus, and loss of the dark T2 interface, which were all associated with the presence of placental invasion. CONCLUSIONS: The diagnosis of placental invasion remains challenging on sonography and MRI, which perform similarly. The presence of 2 or more criteria adds specificity to the diagnosis of placental invasion on MRI.