Diseases of the Chest, Breast, Heart and Vessels 2019-2022

This open access book focuses on diagnostic and interventional imaging of the chest, breast, heart, and vessels. It consists of a remarkable collection of contributions authored by internationally respected experts, featuring the most recent diagnostic developments and technological advances with a highly didactical approach. The chapters are disease-oriented and cover all the relevant imaging modalities, including standard radiography, CT, nuclear medicine with PET, ultrasound and magnetic resonance imaging, as well as imaging-guided interventions. As such, it presents a comprehensive review of current knowledge on imaging of the heart and chest, as well as thoracic interventions and a selection of "hot topics". The book is intended for radiologists, however, it is also of interest to clinicians in oncology, cardiology, and pulmonology

Diseases of the Chest, Breast, Heart and Vessels 2019-2022

This open access book focuses on diagnostic and interventional imaging of the chest, breast, heart, and vessels. It consists of a remarkable collection of contributions authored by internationally respected experts, featuring the most recent diagnostic developments and technological advances with a highly didactical approach. The chapters are disease-oriented and cover all the relevant imaging modalities, including standard radiography, CT, nuclear medicine with PET, ultrasound and magnetic resonance imaging, as well as imaging-guided interventions. As such, it presents a comprehensive review of current knowledge on imaging of the heart and chest, as well as thoracic interventions and a selection of "hot topics". The book is intended for radiologists, however, it is also of interest to clinicians in oncology, cardiology, and pulmonology

Evaluation of Quantitative Imaging Biomarkers in Interstitial Lung Disease

Despite evidence that hyperpolarised 129-Xenon (129Xe) MRI, combined with proton MRI, is able to provide useful structural and functional data, its clinical application has been relatively limited in the field of interstitial lung disease (ILD). However, the insensitivity of pulmonary function tests (PFTs) in early disease, and the ability of hyperpolarised 129Xe MRI to assess regional lung function makes it an appealing tool to explore the diagnosis and monitoring of ILD. CT involves ionising radiation and is unable to provide functional data. It has some advantages over MRI in terms of its speed, image contrast and spatial resolution. Various automated, computer based, quantitative CT (QCT) analysis methods have been reported in ILD. The findings reported in this thesis represent the first known longitudinal data combining hyperpolarised 129Xe MRI and dynamic contrast enhanced (DCE) MRI with QCT alongside PFTs in various ILD subtypes. It also expands upon previous work involving these novel MRI techniques in idiopathic pulmonary fibrosis (IPF). 129Xe spectroscopy derived red blood cell / tissue plasma ratio (RBC:TP) was used in the assessment of alveolar gas exchange, showing a statistically significant change over 6 and 12 months in IPF subjects, despite relatively stable PFTs. 129Xe diffusion-weighted (DW) MRI techniques demonstrate increased Brownian gas diffusion in fibrotic ILD. This is likely due to microstructural changes in the distal airways and alveoli as a result of honeycombing and/or traction bronchiectasis. There was also evidence that DW-MRI measurements may have utility in the monitoring and prediction of disease progression. Changes in pulmonary perfusion over short time periods were found using DCE-MRI in subjects with hypersensitivity pneumonitis, suggesting potential value in demonstrating an early inflammation response to steroid therapy. As new drug treatments are developed, the ability to quantify subtle changes using QCT and functional lung MRI could be particularly valuable

THE EXPLORATION OF THE VALIDITY OF QUANTITATIVE 2-DEOXY-2-[FLUORINE-18] FLUORO-D-GLUCOSE (18F-FDG) POSITRON EMISSION TOMOGRAPHY/COMPUTED TOMOGRAPHY (PET/CT) TO ASSESS LUNG INFLAMMATION

Lung diseases are one of the leading causes of death in the UK; responsible for 20% of all deaths each year. Inflammation is thought to be an important driver of the pathogenesis and progression of several lung diseases. Positron emission tomography/computed tomography (PET/CT) is an imaging modality capable of providing functional and molecular imaging through detection of trace quantities of a radioactive tracer. 18F-FDG is the most widely available tracer and in several small studies has been used to investigate diffuse lung diseases such as chronic obstructive pulmonary disease (COPD). These studies rely on quantification of the PET image. Static acquisitions provide information on the biodistribution of the tracer at a single time point after administration, the standardised uptake value (SUV) is the most widely used measure of 18F-FDG uptake. Dynamic acquisitions provide information on the spatial and temporal distribution of the tracer; linear and non-linear modelling techniques allow estimation of the metabolic rate of 18F-FDG in the lung. Previous studies have used a linear method called Patlak graphical analysis, whilst non-linear compartmental models have been used more recently to estimate metabolism. However, these contending measures of pulmonary 18F-FDG uptake, which are putative biomarkers of lung inflammation, have so far been disparately applied. Further, there is nascent understanding that these imaging endpoints are affected by pulmonary air and blood volume; the importance of this effect will likely depend on the disease and its severity. These issues are exacerbated by the presence of respiratory motion and the low signal- to-noise ratio achieved in PET studies. This has led to questions regarding the utility of quantitative 18F-FDG PET to assess lung inflammation. In this work, prospective and retrospective clinical studies were used to assess the clinical, biological and technical validity of 18F-FDG PET imaging endpoints in several clinically relevant diseases. The central hypothesis was that pulmonary inflammation can be assessed using quantitative 18F-FDG. Using retrospective data from two complementary imaging studies, pulmonary 18F- FDG uptake was investigated in COPD patients, α1ATD patients, smokers without COPD and heathy non-smokers. The results demonstrate that the different 18F-FDG imaging endpoints produce disparate findings, and this is exacerbated by the presence of varying blood and air volumes due to emphysema. Nevertheless, measures derived from Patlak analysis revealed elevated uptake consistent with the pathophysiologi- cal understanding of the disease process and further demonstrated correlation with other putative markers of inflammation hence, one could speculate that it relates to inflammation. Further, 18F-FDG imaging outcomes assessed using Patlak analysis were shown to be more reliable than compartmental modelling outcomes. However, the Patlak outcomes are composite measures, not only driven by inflammation but also by pulmonary blood and air. In circumstances where differences in pulmonary blood and air volume between subjects are substantial, it may not be a suitable biomarker of inflammation, but it could be a useful marker of disease activity. Further tissue validation and independent measures of pulmonary blood are required to support its role as a marker of inflammation. In a prospective study, dynamic 18F-FDG PET scans were used to evaluate pulmonary inflammation in sarcoidosis patients and healthy controls. The results show that 18F-FDG uptake was increased in sarcoidosis using Patlak analysis, whilst no difference was found using SUV or compartmental models. Preliminary findings suggest that the signal relates to inflammatory cell counts (macrophages and lymphocytes were most numerous) rather than any one specific cell line; however, further evidence is required to determine if 18F-FDG uptake is driven by underlying inflammation. Consistent with previous findings, mismatch in CT and PET lung images has substantial effect on the quantitative 18F-FDG outcomes; notably, Patlak outcomes were less influenced than compartmental modelling. In summary, the observations made in this work demonstrate the substantial challenges of using 18F-FDG PET/CT to assess diffuse lung disease. Given the incongruity between the different imaging outcomes, these data highlight that future studies should be carefully planned with particular justification of the acquisition and analysis methods. The results of this work suggest that Patlak measures may have the most utility in diffuse lung disease. However, differences in Patlak measures should be interpreted judiciously, as they may be driven by differences in pulmonary blood and air along with inflammation; further study is required to determine if it may be a useful marker of disease activity. In contrast, no differences in pulmonary 18F-FDG uptake between patients and controls were found using compartmental modelling across all studies. Equally, the SUV was found to have poor utility across studies. Future efforts to expedite the use of novel tracers that are more specific to inflammation combined with the development of improved noise reduction techniques may improve the utility of quantitative PET/CT in the context of lung inflammation

Prediction and prognostication in interstitial lung disease associated pulmonary hypertension using baseline and longitudinal trends in non-invasive variables

Pulmonary hypertension (PH) commonly occurs in patients with interstitial lung disease (ILD) and is associated with worsening of symptoms and an adverse prognosis. The onset of PH is extremely difficult to predict due to the very similar symptomology of the two conditions and confounding of common screening tests for PH in patients with ILD. It is not clear what invasive and non-invasive variables predict mortality in ILD-PH patients, or whether existing mortality prediction tools used in ILD patients are valid in ILD-PH. I hypothesised that the prediction of PH occurring in ILD patients was possible using non invasive screening tests, and that baseline and longitudinal change in non-invasive variables would predict mortality in ILD-PH patients. The integration of echocardiographic, brain natriuretic peptide (BNP), pulmonary function tests and CT variables showed that prediction of PH occurring in ILD patients was possible, although false positives were common. Echocardiographic variables best correlated with invasive right heart catheter (RHC) pressures. A score was developed to predict severe PH using echocardiographic variables, and was effective even when blinding the most powerful predictor which is commonly unavailable in patients with ILD-PH. CT is commonly employed in suspected ILD-PH patients to exclude co-existent pulmonary emboli and assess parenchymal disease progression. The right ventricle to left ventricle measured at CT pulmonary angiography was superior to both echocardiographic and RHC derived variables at predicting mortality. The presence of PH confounds commonly used mortality prediction tools in ILD. A multi modality mortality prediction model was developed to predict mortality using baseline demographics, lung function and ILD diagnosis. Longitudinal change in pulmonary function tests and BNP were shown to predict mortality. A longitudinal model using demographics and change in gas transfer was developed. External validation of the mortality prediction tools is necessary before its utility is demonstrated.Open Acces

Cardiovascular and Thoracic Imaging: Trends, Perspectives and Prospects

Radiology is evolving at a fast pace, and the specific field of cardiovascular and thoracic imaging is no stranger to that trend. While it could, at first, seem unusual to gather these two specialties in a common Issue, the very fact that many of us are trained and exercise in both is more than a hint to the common grounds these fields are sharing. From the ever-increasing role of artificial intelligence in the reconstruction, segmentation, and analysis of images to the quest of functionality derived from anatomy, their interplay is big, and one innovation developed with the former in mind could prove useful for the latter. If the coronavirus disease 2019 (COVID-19) pandemic has shed light on the decisive diagnostic role of chest CT and, to a lesser extent, cardiac MR, one must not forget the major advances and extensive researches made possible in other areas by these techniques in the past years. With this Issue, we aim at encouraging and wish to bring to light state-of-the-art reviews, novel original researches, and ongoing discussions on the multiple aspects of cardiovascular and chest imaging

Case series of breast fillers and how things may go wrong: radiology point of view

INTRODUCTION: Breast augmentation is a procedure opted by women to overcome sagging breast due to breastfeeding or aging as well as small breast size. Recent years have shown the emergence of a variety of injectable materials on market as breast fillers. These injectable breast fillers have swiftly gained popularity among women, considering the minimal invasiveness of the procedure, nullifying the need for terrifying surgery. Little do they know that the procedure may pose detrimental complications, while visualization of breast parenchyma infiltrated by these fillers is also deemed substandard; posing diagnostic challenges. We present a case series of three patients with prior history of hyaluronic acid and collagen breast injections. REPORT: The first patient is a 37-year-old lady who presented to casualty with worsening shortness of breath, non-productive cough, central chest pain; associated with fever and chills for 2-weeks duration. The second patient is a 34-year-old lady who complained of cough, fever and haemoptysis; associated with shortness of breath for 1-week duration. CT in these cases revealed non thrombotic wedge-shaped peripheral air-space densities. The third patient is a 37‐year‐old female with right breast pain, swelling and redness for 2- weeks duration. Previous collagen breast injection performed 1 year ago had impeded sonographic visualization of the breast parenchyma. MRI breasts showed multiple non- enhancing round and oval shaped lesions exhibiting fat intensity. CONCLUSION: Radiologists should be familiar with the potential risks and hazards as well as limitations of imaging posed by breast fillers such that MRI is required as problem-solving tool

Characterization of alar ligament on 3.0T MRI: a cross-sectional study in IIUM Medical Centre, Kuantan

INTRODUCTION: The main purpose of the study is to compare the normal anatomy of alar ligament on MRI between male and female. The specific objectives are to assess the prevalence of alar ligament visualized on MRI, to describe its characteristics in term of its course, shape and signal homogeneity and to find differences in alar ligament signal intensity between male and female. This study also aims to determine the association between the heights of respondents with alar ligament signal intensity and dimensions. MATERIALS & METHODS: 50 healthy volunteers were studied on 3.0T MR scanner Siemens Magnetom Spectra using 2-mm proton density, T2 and fat-suppression sequences. Alar ligament is depicted in 3 planes and the visualization and variability of the ligament courses, shapes and signal intensity characteristics were determined. The alar ligament dimensions were also measured. RESULTS: Alar ligament was best depicted in coronal plane, followed by sagittal and axial planes. The orientations were laterally ascending in most of the subjects (60%), predominantly oval in shaped (54%) and 67% showed inhomogenous signal. No significant difference of alar ligament signal intensity between male and female respondents. No significant association was found between the heights of the respondents with alar ligament signal intensity and dimensions. CONCLUSION: Employing a 3.0T MR scanner, the alar ligament is best portrayed on coronal plane, followed by sagittal and axial planes. However, tremendous variability of alar ligament as depicted in our data shows that caution needs to be exercised when evaluating alar ligament, especially during circumstances of injury