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.

Analysis of normal and dysplastic glenohumeral morphology at magnetic resonance imaging in children with neonatal brachial plexus palsy.

BACKGROUND: Glenoid version and percentage of the humeral head anterior to the scapular line are commonly used 2-D measures to assess deformity of the glenohumeral joint of children with neonatal brachial plexus palsy. OBJECTIVE: To assess whether glenoid version and percentage of the humeral head anterior to the scapular line would be altered by standardizing the measurements to the orientation of the scapula. MATERIALS AND METHODS: Twenty-one bilateral magnetic resonance imaging (MRI) scans were evaluated by four reviewers. Measurements were performed on the axial image slices and again after applying 3-D reformatting. RESULTS: Three-dimensional reformatting led to intrapatient corrections up to 25° for version and -30% for percentage of the humeral head anterior to the scapular line. The mean difference on the involved side between clinical and anatomical version across all subjects from all reviewers was 2.2° ± 3.9° (range: -4.5° to 11.5°). The mean difference in the percentage of the humeral head anterior to the scapular line after reformatting was -1.8% (range: -15.9% to 5.2%). CONCLUSION: Measurements can differ greatly for the same child depending on technical factors of image acquisition and presentation in the clinical setting. With this study, we present a clinically accessible protocol to correct for scapular orientation from MRI data of children with neonatal brachial plexus palsy.

Glenoid version by CT scan: an analysis of clinical measurement error and introduction of a protocol to reduce variability.

OBJECTIVE: Recent studies have challenged the accuracy of conventional measurements of glenoid version. Variability in the orientation of the scapula from individual anatomical differences and patient positioning, combined with differences in observer measurement practices, have been identified as sources of variability. The purpose of this study was to explore the utility and reliability of clinically available software that allows manipulation of three-dimensional images in order to bridge the variance between clinical and anatomic version in a clinical setting. MATERIALS AND METHODS: Twenty CT scans of normal glenoids of patients who had proximal humerus fractures were measured for version. Four reviewers first measured version in a conventional manner (clinical version), measurements were made again (anatomic version) after employing a protocol for reformatting the CT data to align the coronal and sagittal planes with the superior-inferior axis of the glenoid, and the scapular body, respectively. RESULTS: The average value of clinical retroversion for all reviewers and all subjects was -1.4° (range, -16° to 21°), as compared to -3.2° (range, -21° to 6°) when measured from reformatted images. The mean difference between anatomical and clinical version was 1.9° ± 5.6° but ranged on individual measurements from -13° to 26°. In no instance did all four observers choose the same image slice from the sequence of images. CONCLUSIONS: This study confirmed the variation in glenoid version dependent on scapular orientation previously identified in other studies using scapular models, and presents a clinically accessible protocol to correct for scapular orientation from the patient's CT data.

Sonographic evaluation of palpable superficial masses.

Palpable soft tissue masses are common and are often referred for imaging evaluation. Ultrasonography is an attractive way to image these lesions because it is inexpensive, readily available, and does not rely on ionizing radiation. Ultrasonography can easily confirm the presence of a mass, differentiate solid from cystic lesions, define the anatomic extent of the lesion, and detect vascular lesions with high sensitivity. In most cases, ultrasonography can accurately characterize the lesion, obviating biopsy and reducing unnecessary further work-up. This article reviews the capabilities of ultrasonography in evaluating superficial soft tissue lesions and the sonographic appearance of disease entities.

Bayesian assessment of overtriage and undertriage at a level I trauma centre.

We analysed the trauma triage system at a specific level I trauma centre to assess rates of over- and undertriage and to support recommendations for system improvements. The triage process is designed to estimate the severity of patient injury and allocate resources accordingly, with potential errors of overestimation (overtriage) consuming excess resources and underestimation (undertriage) potentially leading to medical errors.We first modelled the overall trauma system using risk analysis methods to understand interdependencies among the actions of the participants. We interviewed six experienced trauma surgeons to obtain their expert opinion of the over- and undertriage rates occurring in the trauma centre. We then assessed actual over- and undertriage rates in a random sample of 86 trauma cases collected over a six-week period at the same centre. We employed Bayesian analysis to quantitatively combine the data with the prior probabilities derived from expert opinion in order to obtain posterior distributions. The results were estimates of overtriage and undertriage in 16.1 and 4.9% of patients, respectively. This Bayesian approach, which provides a quantitative assessment of the error rates using both case data and expert opinion, provides a rational means of obtaining a best estimate of the system's performance. The overall approach that we describe in this paper can be employed more widely to analyse complex health care delivery systems, with the objective of reduced errors, patient risk and excess costs.

Carotid artery fibromuscular dysplasia.

Extracranial carotid artery fibromuscular dysplasia (FMD) is a rare finding that is frequently incidental and asymptomatic. It usually occurs in middle-age women and is secondary to medial fibrodysplasia or, less commonly, intimal fibrodysplasia. The carotid artery may be elongated or kinked and associated aneurysms have been reported. Symptoms including transient ischemic attack or stroke are uncommon and are due to low flow or embolization of platelet aggregates. Digital subtraction angiography demonstrates high-grade stenosis with the characteristic "string of beads" pattern. Antiplatelet medication with sequential imaging is the accepted therapy for asymptomatic lesions. Graduated endoluminal dilation under direct vision should be reserved for patients with documented lateralizing symptoms.