European Respiratory Society
Imaging

Imaging is key to the screening and diagnosis of many respiratory conditions. It is also an area of significant debate, particularly with regard to questions surrounding safety and overuse. This Monograph will be of interest to pulmonologists in all areas of respiratory medicine. The book covers two main areas: imaging methodology and safety; and imaging use in specific respiratory conditions. Chapters include: safety issues in CT and MRI, MRI methods, radionuclide imaging, chest radiography, COPD, cystic fibrosis, asthma, lung cancer, pulmonary hypertension, and much more.

  • ERS Monograph
  1. Page v
  2. Page vi
  3. Page 1
    Abstract
    Jim M. Wild, Academic Unit of Radiology, C Floor, Royal Hallamshire Hospital, Sheffield, S10 2JF, UK. E-mail: j.m.wild@sheffield.ac.uk

    Despite the inherent challenges of MRI of the lungs, a number of quantitative techniques with high functional sensitivity have been established for regional assessment of multiple aspects of pulmonary structure and physiology. Conventional proton-based magnetic resonance methods provide noninvasive anatomical imaging and diagnostic measures of pulmonary perfusion, ventilation and gas-exchange functions. Multinuclear MRI of the lung, including hyperpolarised noble gas MRI with 3He and 129Xe, has matured into a sensitive functional tool for visualisation of pulmonary ventilation, quantification of gas diffusion and evaluation of alveolar microstructure. These minimally invasive, safe and nonionising radiation-based methods are well-suited to longitudinal assessment of disease progression and treatment response, and recent technological and methodological advances are facilitating the dissemination of previously unconventional techniques on a broader clinical scale. In this article, we review the established and developing procedures for proton and multinuclear MRI of the pulmonary system, with applicable clinical examples.

  4. Page 20
    Abstract
    Frank M. Bengel, Klinik für Nuklearmedizin, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany. E-mail: bengel.frank@mh-hannover.de

    Radionuclide imaging techniques provide noninvasive information about global and regional lung function, physiology and biology. The ventilation/perfusion scan is an established test for detecting pulmonary embolism. Its clinical role has shifted from the acute setting towards the workup of CTEPH. Other routine clinical applications include quantification prior to lung surgery and assessment of right-left shunting. In lung cancer, PET with the glucose analogue 18F deoxyglucose currently serves as a first line staging tool and may be used more extensively for monitoring of therapy in the future. Other imaging markers of molecular mechanisms are penetrating the clinical arena, e.g. in inflammatory conditions, and those are expected to lead to further molecular imaging applications in lung disease. Finally, the advent of hybrid imaging devices such as SPECT-CT, PET-CT and, more recently, PET/magnetic resonance, has led to the convergence of tomographic imaging techniques towards a multi-modality, multi-parametric environment for precise, integrated imaging of lung morphology, physiology and molecular function. This is expected to aid in the personalisation of pulmonary medicine.

  5. Page 34
    Abstract
    Dag Wormanns, Evangelische Lungenklinik Berlin, Lindenberger Weg 27, D-13125 Berlin, Germany. E-mail: dag.wormanns@elk-berlin.de

    This chapter provides information on basic technical aspects concerning acquisition of chest radiography. Different patient positions for chest radiography and their specifics are discussed, especially the limitations of portable chest radiography. Indications for chest radiography of intensive care unit patients are presented, and some specific aspects regarding interpretation of these chest radiographs are reviewed. The Fleischer Society proposed a glossary of terms for chest imaging. Some of the definitions that are especially important to reporting chest radiography are explained and illustrated.

  6. Page 47
    Abstract
    Theresa C. McLoud, Dept of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA. E-mail: tmcloud@partners.org

    Lung cancer screening has become a reality in the USA. Results of the National Lung Screening Trial showed a 20% mortality benefit in a defined population for annual screening with CT. However, the benefits of CT screening in high-risk individuals was accompanied by a very high false-positive rate, which in most cases resulted in multiple short-term additional follow-up CT examinations. In the USA, screening and insurance reimbursement are required by federal law for eligible current and former smokers with both private and public insurance. The American College of Radiology has developed a reporting system (Lung-RADS) that associates findings with guideline-based management decisions. The most recently revised seventh edition of the lung cancer TNM staging system correlates with patient prognosis and is now utilised for small cell lung cancer, nonsmall cell lung cancer and bronchopulmonary carcinoid tumours. The assignment of correct tumour (T), nodal (N) and metastasis (M) classifications is crucial not only to allow for clear physician communication across specialties, but also to direct appropriate therapy in this patient population.

  7. Page 60
    Abstract
    Nicholas Screaton, Dept of Radiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK. E-mail: Nicholas.screaton@papworth.nhs.uk

    Pulmonary embolism is a common condition that has significant associated morbidity and mortality. Anticoagulation is an effective treatment, but is not without significant complications. Pulmonary embolism often presents nonspecifically and imaging is central to establishing a diagnosis. CT pulmonary angiography is now the standard imaging test, benefiting from availability, rapid acquisition, high accuracy in identifying pulmonary embolism and complementary roles in patient risk stratification. In patients not found to have pulmonary embolism CT pulmonary angiography may offer an alternative diagnosis.

    A rapid increase in CT pulmonary angiography numbers have been mirrored by a falling diagnostic yield and have led to concerns of overuse both from a resource and radiation exposure perspective. To avoid unnecessary imaging adherence to guidelines, appropriate use of clinical scoring systems and D-dimer tests are essential. Technological developments, e.g. dual-energy CT pulmonary angiography pulmonary blood volume imaging, can improve CT pulmonary angiography sensitivity and risk stratification.

    Perfusion scintigraphy is widely used in pregnancy, benefiting from a high negative predictive value and significant reduction in maternal radiation dose compared with CT pulmonary angiography. Magnetic resonance pulmonary angiography offers benefits of no radiation exposure and additional functional information, but limited availability and variable diagnostic quality has limited its use.

  8. Page 80
    Abstract
    Robert A. Stockley, University Hospitals Birmingham NHS Foundation Trust, Lung Function Dept, Mindelsohn Way, Edgbaston, Birmingham, B15 2GW, UK. E-mail: r.a.stockley@bham.ac.uk

    Routine radiological investigation has long been part of the regular assessment of patients with a diagnosis of COPD. However, practical interpretation and use (especially of newer radiological techniques) can often provide confusion and identify unexpected pathology. Recent advances in understanding the radiological as well as clinical phenotypes of COPD patients and the frequency of incidental findings will lead to more focused patient management and appropriate subsequent investigations.

  9. Page 99
    Abstract
    Cornelia Schaefer-Prokop, Meander Medical Center, Maatweg 3, 3813 TZ Amersfoort, The Netherlands. E-mail: cornelia.schaeferprokop@gmail.com

    Until recently, CT has been regarded as the most important and valuable radiological modality for detecting, analysing and diagnosing diffuse interstitial lung disease, based on the unsurpassed morphological detail provided by HRCT.

    Volumetric HRCT offers a number of advantages over discontinuous axial thin-section CT slices, of which the most important are improved detection of subtle disease, better and more accurate comparability, and superior quantitative measures. A number of processing options, such as maximum and minimum intensity projections, ease analysis of HRCT patterns. The most recent developments in detector and reconstruction technology have made up for the disadvantages of continuous versus discontinuous data acquisition of the past, allowing for substantial dose savings. In addition to technical aspects, this chapter outlines the principles of HRCT interpretation using a four-pattern approach, and lists key findings to differentiate the most frequent interstitial lung diseases.

  10. Page 116
    Abstract
    Fergus Gleeson, Dept of Radiology, Churchill Hospital, Old Road, Headington, Oxford, UK. E-mail: fergus.gleeson@ouh.nhs.uk

    A chest radiograph is the most common means of identifying pleural disease; however, physician-performed ultrasound is now frequently performed prior to other investigations. As experience with this technique improves, ultrasound will be used more commonly to identify pleural and diaphragmatic thickening and nodularity, and for the diagnosis of pneumothorax and, potentially, cardiac failure. Ultrasound can guide intervention and can also be used to assess treatment success post-pleurodesis. Multislice CT (MSCT) remains a common investigation for the detection of mediastinal and extrapleural disease, and provides an excellent overview of the volume of pleural disease. MSCT remains the technique of choice in differentiating benign from malignant disease, but new developments in MRI and PET/CT suggest they may also have a role. Both MRI and PET/CT may also play a role in helping differentiate different malignancies or subtypes of malignancies, and may be used as biomarkers for prognosis and disease response.

  11. Page 141
    Abstract
    Emma J. Helm, University Hospital Coventry and Warwickshire, Clifford Bridge Road, Coventry, CV2 2DX, UK. E-mail: emma.helm@uhcw.nhs.uk

    Radiology has an essential role in the diagnosis, characterisation, management and follow-up of both pneumonia and acute respiratory distress syndrome (ARDS). When imaging is used in conjunction with clinical and laboratory findings, the differential list can be significantly reduced. In the majority of cases, chest radiography provides more than adequate information to manage the patient with pneumonia or ARDS appropriately; however, CT is useful when there is a discrepancy between clinical findings and radiographic findings or when the patient fails to respond to empirical therapies. CT also has a particular role trying to optimise ventilation strategies in the patient with ARDS.

  12. Page 158
    Abstract
    Anton Vonk Noordegraaf, Dept of Pulmonary Medicine, VU University Medical Center, De Boelelaan 1117, ZH 4F004, 1007 MB Amsterdam, PO Box 7057, The Netherlands. E-mail: a.vonk@vumc.nl

    Pulmonary hypertension (PH) is a haemodynamic condition that leads to a progressive increase in pulmonary vascular resistance and mean pulmonary artery pressure. Irrespective of its aetiology, the main cause of death in PH patients is right ventricular (RV) failure. Noninvasive imaging techniques play an essential role in diagnosing PH and monitoring disease progression. This chapter provides an overview of the most important noninvasive imaging tools for assessing pulmonary pressures, RV function and monitoring.

  13. Page 171
    Abstract
    Sumit Gupta, Dept of Infection, Inflammation and Immunity, Institute for Lung Health, University of Leicester, Leicester LE3 9QP, UK. E-mail: drsumitgupta@yahoo.com

    Asthma imaging is undergoing an exciting transformation. From simply being a tool to assess for asthma mimics and conditions associated with asthma, imaging in asthma is now being used to provide quantitative assessment of morphology, function and pathogenic processes at the molecular level, opening up a variety of research and clinical prospects. Imaging in asthma can be used to obtain detailed structural and functional information, which can help in understanding pathophysiology, identify at-risk patients, monitor disease progression and assess response to therapy. Current and emerging imaging techniques in asthma are discussed in this chapter.

  14. Page 188
    Abstract
    Mark O. Wielpütz, Diagnostic and Interventional Radiology, Subdivision of Pulmonary Imaging, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany. E-mail: mark.wielpuetz@med.uni-heidelberg.de

    Repetitive imaging is required in cystic fibrosis (CF) lung disease in order to provide detailed information on regional distribution for severity assessment and therapy monitoring in clinical routine as well as interventional trials. CT has long overtaken the use of chest radiography because it provides higher morphological detail with respect to airway and parenchymal changes. This is closely linked to an increase in radiation exposure in CF individuals, who are referred for imaging procedures from a critically susceptible young age and may accumulate relevant doses during their lifetime. MRI, as an ionising radiation-free cross-sectional imaging modality, has taken the first step into the clinical arena in CF. MRI can depict the morphological hallmarks of CF lung disease such as bronchial wall thickening, bronchiectasis, mucus plugging, small airways disease and infiltrates at lower spatial resolution compared to CT but excels due to enhanced tissue characterisation and comprehensive functional imaging capabilities. These include imaging of respiratory mechanics, ventilation and, in particular, lung perfusion, of which four-dimensional perfusion imaging is currently most valuable. These tools make MRI an ideal modality to monitor potentially reversible lung abnormalities such as ventilation and perfusion impairment (air trapping), which could sensitively react to therapy and might even be regarded as precursor lesions to irreversible bronchiectatic destruction.

  15. Page 207
    Abstract
    Andrew J. Swift, Unit of Academic Radiology, University of Sheffield, C Floor, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF, UK. E-mail: a.j.swift@shef.ac.uk

    The cardiopulmonary unit is necessary for the supply of oxygen to tissues of the body and elimination of carbon dioxide. Good coordination of both ventricles and the lungs is necessary to achieve and maintain this process. Cardiopulmonary interactions are occurring all the time, with every heartbeat maintaining optimal efficiency of the unit. This chapter will provide a brief overview of the history of cardiopulmonary circulation and a basic description of the anatomy and physiology of the right ventricle and pulmonary circulation. Several ways in which the heart, pulmonary vasculature and lungs influence each other in health and disease will also be described, including mechanical interplay between the left and right ventricles, pulmonary arterial and right ventricular coupling, and the influences of respiration and lung disease on cardiac function.

  16. Page 216
    Abstract
    Harvey O. Coxson, Centre for Heart Lung Innovation, St Paul's Hospital, Burrard Building, 1081 Burrard Street – Room 166, Vancouver, BC, V6Z 1Y6, Canada. E-mail: harvey.coxson@hli.ubc.ca

    Much of our understanding of both healthy and diseased lung is based on quantitative morphological assessment using pathology. However, the development of new therapies for lung disease requires measurements and tools that can noninvasively measure lung structure and function both on a global and a regional scale. Medical imaging technologies allow us to “see” the complex internal structures of the lung in three dimensions so that detailed anatomical measurements can be taken, while other imaging modalities can also measure how the lung functions. In this chapter we highlight three techniques that have impacted pulmonary imaging research with an emphasis on quantitative measurements: CT, hyperpolarised noble gas MRI and OCT. For each of these imaging modalities, we discuss the quantitative measurements that can be derived as well as discussing the pulmonary diseases where each technique has demonstrated utility, some drawbacks that are unique to each technique and some important directions for future research.

  17. Page 233
    Abstract
    Laura Fregonese, European Medicines Agency, 30 Churchill Place, Canary Wharf, London, E14 5EU, UK. E-mail: Laura.Fregonese@ema.europa.eu

    In recent years the development of new imaging techniques and advanced imaging processing methods have improved the sensitivity, specificity, and reproducibility of imaging biomarkers for use in clinical monitoring. Imaging also offers the potential to improve the drug development process, from the early phases of compound discovery and confirmation of pharmacology, to preclinical studies in animal models and clinical studies for regulatory approval. This chapter will discuss the application of anatomical and molecular imaging techniques to drug development and monitoring of specific targets in respiratory medicine, outlining the current applications of imaging measures in preclinical and clinical development. The chapter will also discuss the regulatory approval process and provide a regulatory perspective on why the use of imaging end-points remains limited in preclinical and clinical development.

  18. Page 253
    Abstract
    Jonathan Goldin, Division of Thoracic Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. E-mail: jgoldin@mednet.ucla.edu

    One of the quintessential applications of CT is the detection and evaluation of thoracic pathology. CT examinations of the chest are likely to increase with the advent of screening for lung cancer and the increasing role of CT in parenchymal disease assessments and cardiac CT applications. There are risks associated with undergoing CT related to radiation dose and the use of iodine based contrast agents. The actual risk is a subject of much discussion and debate. At all times, the risk–benefit of a CT study should be considered in terms of the information likely to be derived and the benefit to the patient versus the risks albeit very small. With the advent of novel CT reconstruction techniques, dual-source CT machines and attention to basic principles of CT scanning, the radiation dose of CT is set to be lowered dramatically in the future. In this chapter we will focus on the two main sources of risk related to the use of iodinated contrast agents and radiation dose.

  19. Page 263
    Abstract
    Alex Frydrychowicz, Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, 23562 Lübeck, Germany. E-mail: alex.frydrychowicz@uksh.de

    In general, MRI is a safe method if used with indispensable precaution. The long-term effects of a static magnetic field on human tissue at typical diagnostic field strengths are not known, but the topic remains somewhat controversial due to sparse scientific data [1, 2]. However, there are additional possible sources of risk, which have the potential for harm if the technique is used imprudently. Continuous technician training, consistent patient instruction, society recommendations [3] and safety protocols implemented by vendors have contributed to the wide acceptance and mostly uneventful use of MRI.

    This chapter aims to introduce the clinician to the relevant safety issues and precautionary measures relating to MRI use. The necessary physical background will be introduced for each safety topic. Also, perceived uncertainties by referring physicians and staff regarding medical implants and the use of contrast agents will be addressed. Consequently, this chapter should enable physicians to confidently triage and advise patients scheduled for MRI.