Imaging of acute and chronic thromboembolic disease: state of the art.

Acute pulmonary embolism (PE) is a life-threatening condition that requires prompt diagnosis and treatment. Recent advances in imaging allow acute and rapid recognition even by the non-specialist radiologist. Most acute emboli resolve on anticoagulation without sequelae; however, some emboli fail to fully resolve becoming endothelialised with the development of chronic thromboembolic disease (CTED). Increased pulmonary vascular resistance arising from CTED may lead to chronic thromboembolic pulmonary hypertension (CTEPH) a debilitating disease affecting up to 5% of survivors of acute PE. Diagnostic evaluation is more complex in CTEPH/CTED than acute PE with subtle imaging features often being overlooked or misinterpreted. Differentiation of acute from chronic PE and from other forms of pulmonary hypertension has profound therapeutic implications. Diverse imaging techniques are available to diagnose and monitor PEs both in the acute and chronic setting. Broadly they include techniques that provide data on lung parenchymal perfusion (ventilation-perfusion [VQ] scintigraphy), angiographic techniques (computed tomography [CT], magnetic resonance imaging [MRI], and invasive angiography) or a combination of both (MR angiography and time-resolved angiography or dual-energy CT angiography). This review aims to describe state of the art imaging highlighting the strength and weaknesses of individual techniques in the diagnosis of acute and chronic PE.

UK Lung Cancer RCT Pilot Screening Trial: baseline findings from the screening arm provide evidence for the potential implementation of lung cancer screening.

BACKGROUND: Lung cancer screening using low-dose CT (LDCT) was shown to reduce lung cancer mortality by 20% in the National Lung Screening Trial. METHODS: The pilot UK Lung Cancer Screening (UKLS) is a randomised controlled trial of LDCT screening for lung cancer versus usual care. A population-based questionnaire was used to identify high-risk individuals. CT screen-detected nodules were managed by a pre-specified protocol. Cost effectiveness was modelled with reference to the National Lung Cancer Screening Trial mortality reduction. RESULTS: 247 354 individuals aged 50-75 years were approached; 30.7% expressed an interest, 8729 (11.5%) were eligible and 4055 were randomised, 2028 into the CT arm (1994 underwent a CT). Forty-two participants (2.1%) had confirmed lung cancer, 34 (1.7%) at baseline and 8 (0.4%) at the 12-month scan. 28/42 (66.7%) had stage I disease, 36/42 (85.7%) had stage I or II disease. 35/42 (83.3%) had surgical resection. 536 subjects had nodules greater than 50 mm(3) or 5 mm diameter and 41/536 were found to have lung cancer. One further cancer was detected by follow-up of nodules between 15 and 50 mm(3) at 12 months. The baseline estimate for the incremental cost-effectiveness ratio of once-only CT screening, under the UKLS protocol, was £8466 per quality adjusted life year gained (CI £5542 to £12 569). CONCLUSIONS: The UKLS pilot trial demonstrated that it is possible to detect lung cancer at an early stage and deliver potentially curative treatment in over 80% of cases. Health economic analysis suggests that the intervention would be cost effective-this needs to be confirmed using data on observed lung cancer mortality reduction. TRIAL REGISTRATION: ISRCTN 78513845.

Respiratory disease in common variable immunodeficiency and other primary immunodeficiency disorders.

Respiratory disease is a significant cause of morbidity and mortality amongst patients with primary immunodeficiency disorders. Computed tomography (CT) plays an important role in the multidisciplinary approach to these conditions, in detecting, characterizing, and quantifying the extent of lung damage and in directing treatment. The aim of this review is to classify the primary immunodeficiency disorders and describe the thoracic complications and the associated CT findings whilst discussing the role of radiology in diagnosis and surveillance.

Atrial septal defects: magnetic resonance and computed tomography appearances.

Atrial septal defects are associated with significant morbidity and mortality. Echocardiography is the first-line imaging modality, but MR and CT imaging can provide complimentary information, especially for the detection of associated anomalies and for assessing changes in the pulmonary vasculature. The aim of this pictorial essay is to review the spectrum of atrial septal defects, with particular reference to their cross-sectional imaging appearances and issues pertaining to management.

Congenital and acquired conditions of the aortic root: multidetector computed tomography features.

The aortic root links the left ventricle and ascending aorta and functions as a support structure for the aortic valve. It can be affected by a variety of congenital and acquired conditions, some of which are potentially life threatening. Echocardiography and cardiac magnetic resonance imaging are established non-invasive imaging techniques for assessing the aortic root. Recent technological advances have allowed multidetector computed tomography to emerge as an alternative means of assessing this aortic segment. This pictorial essay reviews the anatomy of the aortic root and illustrates the salient computed tomography imaging features of a range of congenital and acquired conditions that may affect it.

MDCT features of cardiothoracic sources of stroke.

Multidetector computed tomography (MDCT) is widely used in the assessment of cardiothoracic disease and provides high-resolution images of the heart, great vessels, and lungs. A range of cardiothoracic conditions can precipitate stroke, including intracardiac thrombus, right-to-left shunts, and diseases of the thoracic aorta. Many of these conditions may be identified on non-electrocardiogram (ECG)-gated studies, but the advent of high temporal resolution ECG-gated MDCT provides superior anatomical delineation. Radiologists should be familiar with the pathogenesis and CT features of cardiothoracic conditions that can precipitate stroke as their early identification to enables appropriate management and prognostic decisions.

Chronic left ventricular failure: the role of imaging in diagnosis and planning of conventional and novel therapies.

Heart failure is the leading cause of hospitalisation in the UK, and its prevalence is expected to increase further in the future due partly to an aging population. Although pharmacological agents remain the mainstay of therapy, an increasing number of surgical and novel minimally invasive interventions have been developed for the treatment of both acute and chronic heart failure. Imaging is essential for diagnosis, guiding therapeutic options, and monitoring therapy and its complications. As a result, radiologists should be familiar with the pathogenesis, treatment options, and imaging-related issues pertaining to the management of these patients.

Nontuberculous mycobacteria in bronchiectasis: Prevalence and patient characteristics.

The aim of the current study was to investigate the prevalence and clinical associations of nontuberculous mycobacteria (NTM) in a well-characterised cohort of patients with adult-onset bronchiectasis. The sputum of all patients attending a tertiary referral bronchiectasis clinic between April 2002 and August 2003 was examined for mycobacteria as part of an extensive diagnostic work-up. NTM-positive patients subsequently had further sputa examined. A modified bronchiectasis scoring system was applied to all high-resolution computed tomography (HRCT) scans from NTM-positive patients, and a matched cohort without NTM. Out of 98 patients attending the clinic, 10 had NTM in their sputum on first culture; of those, eight provided multiple positive cultures. Three patients were treated for NTM infection. A higher proportion of NTM-positive than -negative patients were subsequently diagnosed with cystic fibrosis (two out of nine versus two out of 75). On HRCT scoring, more patients in the NTM-positive group had peripheral mucus plugging than in the NTM-negative group. In the current prospective study of a large cohort of patients with bronchiectasis, 10% cultured positive for nontuberculous mycobacteria in a random clinic sputum sample. Few clinical parameters were helpful in discriminating between groups, except for a higher prevalence of previously undiagnosed cystic fibrosis and of peripheral mucus plugging on high-resolution computed tomography in the nontuberculous mycobacteria group.

Smoking related COPD and facial wrinkling: is there a common susceptibility?

BACKGROUND: Cigarette smoking causes accelerated facial wrinkling and predisposes to chronic obstructive pulmonary disease (COPD). However, it has long been recognised that there is a subgroup of susceptible smokers who are at increased risk of developing airflow obstruction. We have tested the hypothesis that there is a common susceptibility for the development of COPD and facial wrinkling in cigarette smokers. METHODS: One hundred and forty nine current and ex-smokers were recruited from a family based study of COPD genetics, 68 (45.6%) of whom fulfilled the definition of COPD. 124 (83.2%) had no or minor facial wrinkling (Daniell /=IV). Generalised estimating equations were used to adjust for familial correlations between related individuals and the potential confounding effects of age and pack years smoked. RESULTS: Forced expiratory volume in 1 second (FEV(1)) was significantly lower in those with wrinkles than in those without (mean difference in FEV(1) % predicted -13.7%, 95% CI -27.5 to 0.0, p = 0.05) and facial wrinkling was associated with a substantially increased risk of COPD (adjusted OR 5.0, 95% CI 1.3 to 18.5, p<0.02). The Daniell score correlated with the extent of emphysema on the CT scan (p<0.05) and facial wrinkling was also associated with a greater risk of more extensive emphysema (adjusted OR 3.0, 95% CI 1.0 to 9.3, p = 0.05). CONCLUSION: Facial wrinkling is associated with COPD in smokers, and both disease processes may share a common susceptibility. Facial wrinkling in smokers may therefore be a biomarker of susceptibility to COPD.

Lung volume reduction surgery for emphysema: What the radiologist needs to know.

Imaging plays a pivotal role in the selection of patients for the surgical treatment of emphysema. In this article, the imaging features of emphysema are reviewed along with the surgical options for treatment. Particular emphasis is given to lung volume reduction surgery as this technique has gained wide acceptance within the thoracic surgical community in recent years. Radiologists need to have an understanding of which patients may be potentially suitable for this technique.

Serial high resolution CT in non-specific interstitial pneumonia: prognostic value of the initial pattern.

AIM: To assess the relationship between initial CT pattern and serial changes in CT findings and pulmonary function tests (PFTs) in patients with non-specific interstitial pneumonia (NSIP). MATERIALS AND METHODS: Serial high resolution (HR) CTs and PFTs were retrospectively analyzed in 38 cases of histologically proven NSIP, including 4 with cellular NSIP, 13 with mixed cellular and fibrotic NSIP, and 21 with fibrotic NSIP. The presence and extent of various CT findings were assessed. A fibrosis index (defined as the ratio of the extent of a reticular/honeycomb pattern to the overall extent of abnormal parenchyma) was derived. RESULTS: The predominant CT pattern was reticular/honeycomb in 27 (84%) cases and ground-glass/consolidation in 6 (16%) cases. Between scans, mean disease extent reduced by 5.2%. Disease extent reduced by >10% in 13 (34%) and increased by >10% in 6 (16%) patients. Histopathological subtype of NSIP did not correlate with individual CT pattern, predominant pattern, fibrosis index or serial change in disease extent on CT or PFTs. Response on follow-up CT was associated with fibrosis index, predominant pattern and extent of consolidation on initial CT. CONCLUSION: In NSIP disease, progression on CT correlates with the predominant CT pattern, fibrosis index, and extent of consolidation but not with histopathological subtype. An inflammatory (ground-glass/consolidation) predominant pattern is associated with better outcome in terms of disease extent on HRCT.

The value of performing head CT in screening for cerebral metastases in patients with potentially resectable non-small cell lung cancer: experience from a UK cardiothoracic centre.

AIM: To evaluate the whether screening for cerebral metastases in neurologically intact patients with potentially resectable non-small cell lung cancer patients is both worthwhile and cost-effective. METHODS: We prospectively performed computed tomography (CT) of the head in 105 consecutive patients with potentially resectable lung cancer over an 18-month period. None of these patients had neurological symptoms or signs. RESULTS: Five patients (4.8%) with cerebral metastases were identified using CT. At our institution the financial saving of avoiding five thoracotomies was pound sterling 45,000, whilst the cost of performing 105 head CTs was pound sterling 16,000. This represented a substantial saving for the healthcare provider and preserved the quality of life in five patients. CONCLUSIONS: We conclude that screening for cerebral metastases in neurologically intact patients with potentially resectable non small cell lung cancer patients is both worthwhile and cost effective.

Transpleural ultrasound diagnosis of a pulmonary arteriovenous malformation.

Pulmonary arteriovenous malformations (PAVMs) are rare. We discuss a case of an 81-year-old female who attended hospital with a haemothorax. Ultrasound not only demonstrated an echogenic effusion in the right pleural space, but also identified an associated tubular structure. Doppler was applied to this structure, which exhibited pulsatile flow. This raised the possibility of a PAVM, which was subsequently confirmed on CT and angiography. Although, PAVM is a rare cause of haemothorax, the diagnosis should still be considered and transpleural ultrasound can detect these malformations non-invasively by the bedside.

Classification, staging and prognosis of lung cancer.

Lung cancer has increased in incidence throughout the twentieth century and is now the most common cancer in the Western World. It has a poor prognosis, only 10-15% of patients survive 5 years or longer. Outcome is dependent on clinical stage and cancer cell type. Lung cancer is broadly subclassified on the basis of histological features into squamous cell carcinoma, adenocarcinoma, large cell carcinoma and small cell carcinoma. The histopathological type of lung cancer correlates with tumour behaviour and prognosis. Staging based on prognosis is essential in clinical trials comparing different management strategies, and enables universal communication regarding the efficacy of different treatments in specific patient groups. The anatomic extent of disease determined either preoperatively using imaging supplemented by invasive procedures such as mediastinoscopy, and anterior mediastinotomy or following resection are described according to the T-primary tumour, N-regional lymph nodes, M-distant metastasis classification. The International System for Staging Lung Cancer attempts to group together patients with similar prognosis and treatment options. Various combinations of T, N, and M define different clinical or surgical-pathological stages (IA-IV) characterised by different survival characteristics. Refinements in staging based on imaging findings have enabled clinical staging to more accurately reflect the surgical-pathological stage and therefore more accurately predict prognosis. Recent advances including the use of positron emission tomography in combination with conventional staging promises to increase the accuracy of staging and therefore to reduce the number of invasive staging procedures and inappropriate thoracotomies.

Acute lung disease in the immunocompromised host.

The immunocompromised host is an individual with a decreased defense mechanism or immunity. Pulmonary complications commonly seen in these patients include infections, neoplasms, drug-induced lung disease, and pulmonary hemorrhage. High-resolution CT plays an invaluable role in confirming the presence of pulmonary disease and narrowing down the differential diagnosis in this group of patients. It also is helpful as a guide to the optimal type and site of biopsy. The pattern and prevalence of disease varies considerably between the AIDS and the non-AIDS group, and therefore, these two groups are considered separately.