Diagnostic utility of additional whole-chest CT as part of an acute abdominal pain CT imaging pathway during the COVID-19 pandemic.

AIM: To evaluate the diagnostic utility of additional whole-chest computed tomography (CT) in identifying otherwise unheralded COVID-19 lung disease as part of an acute abdominal pain CT imaging pathway in response to the COVID-19 pandemic. MATERIALS AND METHODS: Consecutive patients (n=172) who underwent additional whole-chest CT via a COVID-19 acute abdominal pain CT imaging pathway between 27 March and 3 May 2020 were evaluated in this retrospective single-centre study. Chest CT examinations were graded as non-COVID-19, indeterminate for, or classic/probable for COVID-19. CT examinations in the latter two categories were further divided into one of three anatomical distributions (lung base, limited chest [below carina], whole chest [above carina]) based on location of findings. Reverse transcriptase-polymerase chain reaction (RT-PCR) results and clinical features of COVID-19 were assessed to determine if COVID-19 was clinically suspected at the time of CT referral. RESULTS: Twenty-seven of the 172 (15.7%) patients had CT features potentially indicative of COVID-19 pneumonia, 6/27 (3.5%) demonstrating a classic/probable pattern and 21/27 (12.2%) demonstrating an indeterminate pattern. After correlation with clinical features and RT-PCR 8/172 (4.7%) were defined as COVID-19 positive, of which only 1/172 (0.6%) was clinically unsuspected of COVID-19 at the time of CT referral. All COVID-19 positive cases could be identified on review of the lung base alone. CONCLUSION: Whole-chest CT as part of an acute abdominal pain CT imaging pathway has a very low diagnostic yield for our cohort of patients. All COVID-19-positive patients in our cohort were identified on review of the lung bases on the abdominal CT and this offers an alternative imaging approach in this patient group.

Cardiac MR assessment of cardiac myxomas.

Cardiac myxomas are the most common benign primary cardiac tumour to present in adulthood. While most patients present with symptoms of cardiac obstruction, embolic phenomena or constitutional impairment, up to a fifth of patients remain asymptomatic and are incidentally diagnosed on imaging. Although echocardiography is usually the initial imaging modality used to evaluate these patients, cardiac MRI (CMR) has emerged over the past decade as the primary imaging modality in the assessment of patients with cardiac tumours. The superior tissue characterization capability of CMR means that it is able to determine the nature of some tumours pre-operatively and performs well in differentiating myxomas from thrombus. We present a pictorial review highlighting the key CMR features of myxomas and show how these lesions can be differentiated from thrombus and other cardiac masses.

Cardiac MR assessment of microvascular obstruction.

Microvascular obstruction (MVO) is usually seen in a proportion of patients with acute myocardial infarction following reperfusion therapy of an occluded coronary artery. It is characterized by damage and dysfunction of the myocardial microvasculature with a no-reflow phenomenon within the infarct zone. While MVO may be demonstrated via a number of different imaging modalities, cardiac MR (CMR) enables accurate identification of MVO and also permits assessment of infarct extent and overall left ventricular function during the same imaging examination. We present a pictorial review of the characteristic appearances of MVO on CMR and highlight the importance of this imaging diagnosis for patient outcome following acute myocardial infarction.

The role of multidetector-row CT in the diagnosis, classification and management of acute aortic syndrome.

The term "acute aortic syndrome" (AAS) encompasses several non-traumatic life-threatening pathologies of the thoracic aorta presenting in patients with a similar clinical profile. These include aortic dissection, intramural haematoma and penetrating atherosclerotic ulcers. These different pathological entities can be indistinguishable on clinical grounds alone and may be confused with other causes of chest pain, including myocardial infarction. Multidetector-row CT (MDCT) is the current modality of choice for imaging AAS with a sensitivity and specificity approaching 100%. Early diagnosis and accurate radiological classification is associated with improved clinical outcomes in AAS. We review the characteristic radiological features of the different pathologies that encompass AAS and highlight the vital role of MDCT in determining the management of these life-threatening conditions.

Pericardial disease--anatomy and function.

Imaging of patients with suspected or known pericardial disease remains challenging. Echocardiography is the first-line investigation for pericardial disease but it has specific limitations in terms of its abilities to visualise the pericardium fully and to identify extracardiac pathology. Cardiac cross-sectional imaging by both MRI and CT has developed significantly and now has an important role in the investigation of pericardial disease. This article examines the appearances of both healthy and diseased pericardium using CT and MRI. The typical imaging findings across a wide range of conditions are illustrated and the roles of CT and MRI are reviewed. The relative merits and weaknesses of each modality are explored and the specific functional techniques that are available are introduced.

Cross-sectional imaging appearances of cardiac aneurysms.

Cardiac aneurysms are an uncommon presentation of cardiac disease, but are important to identify and accurately characterise. Traditionally, these aneurysms have been investigated with plain radiography, angiography and echocardiography. With the significant recent technical improvements in cross-sectional cardiac imaging, computed tomography (CT) and magnetic resonance imaging (MRI) are now becoming established as the definitive investigations. This article reviews the spectrum of locations of cardiac aneurysms and their appearance with particular reference to CT and MRI. We describe the relative merits of each technique and discuss how they may be used to direct clinical practice.

Giant left anterior descending coronary artery aneurysm.

Small atherosclerotic coronary artery aneurysms are a relatively frequent incidental finding at angiography. We report an unusual case in that the aneurysm found was extremely large and therefore potentially at risk of rupture.

Endobronchial ultrasound to assess airway wall thickening: validation in vitro and in vivo.

Endobronchial ultrasound (EBUS) allows identification of airway wall structures and could potentially be utilised for in vivo studies of airway thickening in asthma. The present study investigated whether inflation of the fluid-filled balloon sheath over the transducer (necessary to provide sonic coupling with the airway wall) influenced in vitro measurements. In vivo comparability of EBUS with high resolution computed tomography scanning (HRCT), an established method for measuring wall thickness, was determined in control subjects. The airway diameter and wall thickness were studied using EBUS in 24 cartilaginous airways obtained from four sheep, before and after balloon sheath inflation during immersion in saline. To assess EBUS versus HRCT comparability of airway measures in vivo, 12 control subjects underwent imaging of the posterior basal bronchus of the right lower lobe by both techniques. Intra- and interobserver agreement were also assessed. Results with and without the balloon sheath gave comparable measures of airway internal diameter and wall thickness in vitro. Statistical analysis showed agreement between EBUS and HRCT, and intra- and interobserver variability in vivo. The current study concludes that endobronchial ultrasound, which does not present a radiation risk, could be utilised in the in vivo study of cartilaginous airway wall remodelling in respiratory diseases, such as asthma.

'Cable-maker's clavicle': stress fracture of the medial clavicle.

A 50-year-old man presented with a non-traumatic painful swelling over the medial clavicle. Radiographs showed a poorly defined fracture and the possibility of an underlying pathology was raised. Computed tomography suggested a stress fracture. This prompted a further, more detailed occupational history to be obtained from the patient, which revealed a hitherto undescribed cause of clavicular stress fracture and obviated the need for further imaging or biopsy.

Endoparasites of plethodontid salamanders from Paradise Brook, New Hampshire.

Totals of 52 dusky salamanders Desmognathus fuscus, 51 two-lined salamanders Eurycea bislineata, 54 red-backed salamanders Plethodon cinereus, and 3 spring salamanders Gyrinophilus porphyriticus (Plethodontidae) collected in June and August 1995 from Paradise Brook, a tributary to Hubbard Brook, New Hampshire, were examined for parasites. Parasites found were Brachycoelium storeriae, Brachycoelium sp., Bothriocephalus rarus, Falcaustra sp., Omeia sp., Batracholandros magnavulvaris, and Cepedietta michiganensis. Eighty-six percent of the red-backed salamanders, a terrestrial species, harbored 1 or more parasites. Among the aquatic and semiaquatic species, 27% of the dusky and 45% of the two-lined salamanders were infected with 1 or more parasites.

Parasites of the deepwater sculpin, Myoxocephalus thompsoni (Cottidae), from Lake Michigan and Lake Huron.

A total of 190 deepwater sculpins, Myoxocephalus thompsoni, collected in 1995 from Michigan waters of Lake Michigan and Lake Huron was examined for parasites. Five parasite species occurred in sculpins from Lake Michigan with Echinorhynchus salmonis being most common. Six parasite species infected sculpins from Lake Huron, with Haplonema sp. the most common. Haplonema sp. is the only gravid helminth species reported from deepwater sculpins. Pleistophora sp. and Trichodina sp. infected sculpins from Lake Huron and Lake Michigan. Parasite species richness for sculpins at the 3 locations ranged from 5 to 6; mean values ranged from 1.18 to 1.39 for examined fish. The restricted diet of deepwater sculpin, which may be related to the depth of its habitat, appears to determine its helminth fauna. Deepwater sculpin may be an important transport host for E. salmonis, Cyathocephalus truncatus, and Eubothrium salvelini to lake trout and burbot that commonly feed on them.