Radiology

Chest radiography and computed tomography (CT) have a crucial role to play in the diagnosis and management of acute respiratory distress syndrome (ARDS). The identification of pulmonary opacification is a requirement for the definition of ARDS on the chest radiograph, while CT has a role to play, not only in the diagnosis of ARDS, but also in the identification of complications. This paper reviews the radiological appearances of ARDS that have been documented for some time, and also more recent research that has identified a role for CT in directing ventilation and in prognostication.

Early lung cancers associated with cystic airspaces are increasingly being recognized as a cause of delayed diagnoses-owing to data gathered from screening trials and encounters in routine clinical practice as more patients undergo serial imaging. Several morphologic subtypes of cancers associated with cystic airspaces exist and can exhibit variable patterns of progression as the solid elements of the tumor grow. Current understanding of the pathogenesis of these malignancies is limited, and the numbers of cases reported in the literature are small. However, several tumor cell types are represented in these lesions, with adenocarcinoma predominating. The features of cystic airspaces differ among cases and include emphysematous bullae, congenital or fibrotic cysts, subpleural blebs, bronchiectatic airways, and distended distal airspaces. Once identified, these cystic lesions pose management challenges to radiologists in terms of distinguishing them from benign mimics of cancer that a...

We present a case of iatrogenic extensive air embolism in the peripheral pulmonary arterial tree following intravenous contrast injection for a CT pulmonary angiogram performed to investigate chest pain in a 25-year-old female patient. Small volumes of iatrogenic air embolism following contrast injection are not infrequently encountered incidentally in the central vasculature (brachiocephalic veins, superior vena cava, right cardiac chambers and main pulmonary arteries). To our knowledge, however, this is the only case of extensive peripheral pulmonary arterial air embolism on CT that has been reported in the literature. Despite the extent of peripheral air, this potentially clinically significant complication was relatively inconspicuous at CT interpretation. A new radiological sign, the "double bronchus sign", is proposed as a useful diagnostic tool. In addition to discussing the imaging features, important safety considerations and principles of immediate management, relevant to all radiologists, are addressed.

The accurate identification and characterization of small pulmonary nodules at low-dose CT is an essential requirement for the implementation of effective lung cancer screening. Individual reader detection performance is influenced by nodule characteristics and technical CT parameters but can be improved by training, the application of CT techniques, and by computer-aided techniques. However, the evaluation of nodule detection in lung cancer screening trials differs from the assessment of individual readers as it incorporates multiple readers, their inter-observer variability, reporting thresholds, and reflects the program accuracy in identifying lung cancer. Understanding detection and interpretation errors in screening trials aids in the implementation of lung cancer screening in clinical practice. Indeed, as CT screening moves to ever lower radiation doses, radiologists must be cognisant of new technical challenges in nodule assessment. Screen detected lung cancers demonstrate di...

Background Cystic fibrosis (CF) is a chronic, life-limiting disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene leading to abnormal airway surface ion transport, chronic lung infections, inflammation and eventual respiratory failure. With the exception of the small-molecule potentiator, ivacaftor (Kalydeco®, Vertex Pharmaceuticals, Boston, MA, USA), which is suitable for a small proportion of patients, there are no licensed therapies targeting the basic defect. The UK Cystic Fibrosis Gene Therapy Consortium has taken a cationic lipid-mediated CFTR gene therapy formulation through preclinical and clinical development. Objective To determine clinical efficacy of the formulation delivered to the airways over a period of 1 year in patients with CF. Design This was a randomised, double-blind, placebo-controlled Phase IIb trial of the CFTR gene–liposome complex pGM169/GL67A. Randomisation was performed via InForm™ version 4.6 (Phase Forward Incorporated, ...

Modern computed tomography (CT) machines have the capability to perform thoracic CT for a range of clinical indications at increasingly low radiation doses. This article reviews several factors, both technical and patient-related, that can affect radiation dose and discusses current dose-reduction methods relevant to thoracic imaging through a review of current techniques in CT acquisition and image reconstruction. The fine balance between low radiation dose and high image quality is considered throughout, with an emphasis on obtaining diagnostic quality imaging at the lowest achievable radiation dose. The risks of excessive radiation dose reduction are also considered. Inappropriately low dose may result in suboptimal or non-diagnostic imaging that may reduce diagnostic confidence, impair diagnosis, or result in repeat examinations incurring incremental ionising radiation exposure.

Background: Diagnostic capacity and suboptimal logistics are consistently identified as barriers to timely diagnosis of cancer, especially lung cancer. Immediate chest X-ray (CXR) reporting for patients referred from general practice is advocated in the National Optimal Lung Cancer Pathway to improve time to diagnosis of lung cancer and to reduce inappropriate urgent respiratory medicine referral for suspected cancer (2WW) referrals. The aim of radioX is to examine the impact of immediate reporting by radiographers of CXRs requested by general practice (GP) on lung cancer patient pathways. Methods: A two-way comparative study that will compare the time to diagnosis of lung cancer for patients. Internal comparison will be made between those who receive an immediate radiographer report of a GP CXR compared to standard radiographer GP CXR reporting over a 12-month period. External comparison will be made with a similar, neighbouring hospital trust that does not have radiographer CXR reporting. Primary outcome is the effect on the speed of the lung cancer pathway (diagnosis of cancer or discharge). Secondary outcomes include the effect of the pathway on efficiency including the number of repeat CXRs performed in a timely fashion for suspected infection and the effect of immediate reporting of GP CXRs on patient satisfaction. Discussion: The radioX trial will examine the hypothesis that immediate reporting of CXRs referred from GP reduces the time to diagnosis of lung cancer or discharge from the lung cancer pathway.

To review the clinical features of nine patients with pulmonary light-chain deposition disease (LCDD) and record their high-resolution CT (HRCT) and histopathological findings. Patients with a diagnosis of LCDD on lung biopsy specimen were retrospectively identified. The HRCT characteristics of nodules, cysts, and ancillary findings; change at follow-up; and histopathological findings were documented. Features common to all nine cases were thin-walled cysts. In seven cases, vessels traversing the cysts were identified. The majority of patients (8/9) had at least one pulmonary nodule. There was no zonal predominance of either cysts or nodules. The disease appeared stable in the majority of cases with no serial change in HRCT appearances (5/6 cases with follow-up data, mean duration 29 months). To the authors' knowledge, this is the largest series of pulmonary LCDD patients in the literature, and the first systematic assessment of HRCT findings. Pulmonary cysts are a unifying feat...

We present a case of iatrogenic extensive air embolism in the peripheral pulmonary arterial tree following intravenous contrast injection for a CT pulmonary angiogram performed to investigate chest pain in a 25-year-old female patient. Small volumes of iatrogenic air embolism following contrast injection are not infrequently encountered incidentally in the central vasculature (brachiocephalic veins, superior vena cava, right cardiac chambers and main pulmonary arteries). To our knowledge, however, this is the only case of extensive peripheral pulmonary arterial air embolism on CT that has been reported in the literature. Despite the extent of peripheral air, this potentially clinically significant complication was relatively inconspicuous at CT interpretation. A new radiological sign, the "double bronchus sign", is proposed as a useful diagnostic tool. In addition to discussing the imaging features, important safety considerations and principles of immediate management, relevant to all radiologists, are addressed.

Chest radiography and computed tomography (CT) have a crucial role to play in the diagnosis and management of acute respiratory distress syndrome (ARDS). The identification of pulmonary opacification is a requirement for the definition of ARDS on the chest radiograph, while CT has a role to play, not only in the diagnosis of ARDS, but also in the identification of complications. This paper reviews the radiological appearances of ARDS that have been documented for some time, and also more recent research that has identified a role for CT in directing ventilation and in prognostication.