Cinematic versus volume rendered imaging for the depiction of complex congenital heart disease.

INTRODUCTION: Planning for surgical intervention for patients with complex congenital heart disease requires a comprehensive understanding of the individual's anatomy. Cinematic rendering (CR) is a novel technique that purportedly builds on traditional volume rendering (VR) by converting CT image data into clearly defined 3D reconstructions through the stimulation and propagation of light rays. The purpose of this study was to compare CR to VR for the understanding of critical anatomy in unoperated complex congenital heart disease. METHODS: In this retrospective study, CT data sets from 20 sequential scanned cases of unoperated paediatric patients with complex congenital heart disease were included. 3D images were produced at standardised and selected orientations, matched for both VR and CR. The images were then independently reviewed by two cardiologists, two radiologists and two surgeons for overall image quality, depth perception and the visualisation of surgically relevant anatomy, the coronary arteries and the pulmonary veins. RESULTS: Cinematic rendering demonstrated significantly superior image quality, depth perception and visualisation of surgically relevant anatomy than VR. CONCLUSION: Cinematic rendering is a novel 3D CT-rendering technique that may surpass the traditionally used volumetric rendering technique in the provision of actionable pre-operative anatomical detail for complex congenital heart disease.

Correlation between hepatorenal index and attenuation imaging for assessing hepatic steatosis.

Introduction: Hepatic steatosis screening is required to assess high-risk populations, identify those for intervention, monitor response and prevent disease progression and complications. Liver biopsy and magnetic resonance imaging proton density fat fraction are current gold standards, but are limited by biopsy risk factors, patient tolerance and cost. Non-invasive, cost-effective, semi-quantitative and quantitative ultrasound assessment exists. The aim of this study was to assess the correlation between the semi-quantitative hepatorenal index (HRI) to assess hepatic steatosis using the quantitative attenuation imaging (ATI) as a reference standard, in adults with varied suspected liver pathologies. Methods: Data were collected prospectively between April 2019 and March 2020 at a tertiary institution on any patient >18 years referred to US assessment of suspected liver pathology. The only exclusion criteria were absent or invalid HRI or ATI measurements. Three hundred fifty eight patients were included. Results: There was a significant weak positive correlation between HRI and ATI (r = 0.351, P < 0.001) and between HRI steatosis grade (SG) and ATI SG (r = 0.329, P < 0.001), using previously established cut-off values. With ATI as the reference standard, there was no significant correlation between HRI and hepatic steatosis within steatosis grades, nor for no (SG = 0) or any (SG > 0) hepatic steatosis. Conclusions: Our study in a typical heterogeneous clinical population suggests the semi-quantitative HRI is of limited use in hepatic steatosis imaging. As HRI is the objective measure of the subjective brightness (B)-mode assessment, this imaging feature may not be as reliable as previously thought. Quantitative ATI may be the preferred non-invasive technique for hepatic steatosis assessment.

Sabre-sheath trachea: An underused diagnostic weapon in the thoracic armoury.

INTRODUCTION: A sabre-sheath trachea is a highly specific sign for chronic obstructive pulmonary disease. It also correlates well with the degree of disease. We hypothesized that the term is vastly under-utilized in radiologic reporting, despite its high diagnostic value. METHODS: We interrogated our multisite metropolitan-wide radiology information system to find the number of CT reports containing the phrase 'sabre-sheath trachea' and conceivable variants thereof, over the 10 years to present. We compared this with the entire number of CT chest reports in the same time period in order to estimate the utilization of the sign. RESULTS: The results confirmed our hypothesis that the sign is rarely invoked, likely around 1 in 41 times relative to opportunity. CONCLUSIONS: This highly specific sign of chronic obstructive small airway disease should be reinforced in training and utilized by radiologists.