Towards multi-phase postmortem CT angiography in children: a study on a porcine model

Pediatric postmortem CT angiography: validation of vascular access for PMCT angiography in stillbirths, babies and toddlers

PURPOSE

The use of angiography in postmortem CT angiography (PMCTA) has several advantages. In adults, femoral vascular access is well established. Due to the small and specific anatomy in fetuses and infants, the technique has to be adapted, especially regarding the vascular access. The aim of this study was to evaluate vascular access for pediatric PMCTA (pedPMCTA).

MATERIALS AND METHODS

Ten pedPMCTAs were performed in stillbirths, babies, and one toddler. A femoral approach by cannulation of the femoral artery and vein, an umbilical approach by cannulation of the umbilical vessels, and an intraosseous approach by an intraosseous needle were evaluated by handling and resulting imaging.

RESULTS

The insertion of a cannula with a size of 18-20 G in the femoral vessels was possible in babies. An umbilical access with peripheral venous cannulas with a size of 14-20 G was feasible in stillbirths and newborns. An intraosseous access is advisable as equal alternative to umbilical and in cases where a femoral access is not possible. The most significant problem with the vascular access is the extravasation of contrast media, but this can be reduced significantly with practice.

CONCLUSION

When performing pedPMCTA, an umbilical vascular access is recommended if an umbilical cord with open vessels is still present. Otherwise, a bone marrow access should be preferred in the presence of an arteriovenous shunt or if only the venous system needs to be shown. If that is not the case, the femoral access with the possibility to separate venous and arterial scan should be used.

How to report perinatal and paediatric postmortem CT

Postmortem CT (PMCT) has become increasingly accepted alongside skeletal surveys as a critical part of investigation in childhood deaths, either as part of a suite of non-invasive investigations through parental choice, or comprehensive evaluation in a forensic setting. Whilst CT image acquisition and protocols have been published and are relatively standardised, CT imaging reporting remains highly variable, largely dependent upon reporter experience and expertise. The main "risk" in PMCT is the over-interpretation of normal physiological changes on imaging as pathological, potentially leading to misdiagnosis or overdiagnosis of the disease. In this article, we present a pragmatic standardised reporting framework, developed over a decade of PMCT reporting in children in our institution, with examples of positive and negative findings, so that it may aid in the interpretation of PMCT images with those less experienced in paediatric findings and postmortem imaging. CRITICAL RELEVANCE STATEMENT: Standardised reporting using a common framework with a sound understanding of normal postmortem changes that occur in children are crucial in avoiding common reporting errors at postmortem CT. KEY POINTS: Familiarity with postmortem imaging is required for useful image reporting, and reporting standards vary. Understanding normal postmortem change from significant abnormalities requires training and experience. Following a template may remind reporters what to include and help improve performance.

Role of 3D Volumetric and Perfusion Imaging for Detecting Early Changes in Pancreatic Adenocarcinoma

Purpose

There is a major shortage of reliable early detection methods for pancreatic cancer in high-risk groups. The focus of this preliminary study was to use Time Intensity-Density Curve (TIDC) and Marley Equation analyses, in conjunction with 3D volumetric and perfusion imaging to demonstrate their potential as imaging biomarkers to assist in the early detection of Pancreatic Ductal Adenocarcinoma (PDAC).

Experimental Designs

A quantitative retrospective and prospective study was done by analyzing multi-phase Computed Tomography (CT) images of 28 patients undergoing treatment at different stages of pancreatic adenocarcinoma using advanced 3D imaging software to identify the perfusion and radio density of tumors.

Results

TIDC and the Marley Equation proved useful in quantifying tumor aggressiveness. Perfusion delays in the venous phase can be linked to Vascular Endothelial Growth Factor (VEGF)-related activity which represents the active part of the tumor. 3D volume analysis of the multiphase CT scan of the patient showed clear changes in arterial and venous perfusion indicating the aggressive state of the tumor.

Conclusion

TIDC and 3D volumetric analysis can play a significant role in defining the response of the tumor to treatment and identifying early-stage aggressiveness.

Post-mortem thermal angiography: a pilot study on swine coronary circulation

Thermal imaging (TI) allows the detection of thermal patterns emitted from objects as a function of their temperature in the long-infrared spectrum and produces visible images displaying temperature differences. The aim of this pilot study was to test TI to visualize the coronary circulation of swine hearts. Thirty swine hearts were prepared for ex situ coronarography, and thermal images were acquired through a FlirOne thermal camera (FLIR Systems®) paired with a Google Android Smartphone. Coronary arteries were cannulated, namely the anterior interventricular artery, the circumflex branch of the left coronary artery, and the right coronary artery. The heart was cooled, and contrast medium (CM) consisting of distilled water heated to 40 °C was injected in a coronary vessel, while thermal images were captured. These steps were repeated for each coronary vessel and under experimentally simulated coronary heart disease. Thermal imaging coronarography (TIC) allowed a clear representation of the morphology and course of the coronary vessels and of experimentally simulated coronary heart disease, moreover, demonstrated to be easy to perform during or after autopsies on ex situ hearts, non-destructive, reproducible, and cheap. On the basis of these preliminary results, TIC might allow a subsequent more focused and comprehensive cardiopathological examination of the heart, which remains mandatory for the definitive diagnosis of coronary heart disease. Although these preliminary results seem encouraging, further systematic studies on human hearts, both normal and pathological, are necessary for estimating the sensitivity and specificity of the proposed method and to draw any definitive conclusion.