Radiographic features of COVID-19 based on an initial cohort of 96 patients in Singapore.

INTRODUCTION: Chest radiographs (CXRs) are widely used for the screening and management of COVID-19. This article describes the radiographic features of COVID-19 based on an initial national cohort of patients. METHODS: This is a retrospective review of swab-positive patients with COVID-19 who were admitted to four different hospitals in Singapore between 22 January and 9 March 2020. Initial and follow-up CXRs were reviewed by three experienced radiologists to identify the predominant pattern and distribution of lung parenchymal abnormalities. RESULTS: In total, 347 CXRs of 96 patients were reviewed. Initial CXRs were abnormal in 41 (42.7%) out of 96 patients. The mean time from onset of symptoms to CXR abnormality was 5.3 ± 4.7 days. The predominant pattern of lung abnormality was ground-glass opacity on initial CXRs (51.2%) and consolidation on follow-up CXRs (51.0%). Multifocal bilateral abnormalities in mixed central and peripheral distribution were observed in 63.4% and 59.2% of abnormal initial and follow-up CXRs, respectively. The lower zones were involved in 90.2% of initial CXRs and 93.9% of follow-up CXRs. CONCLUSION: In a cohort of swab-positive patients, including those identified from contact tracing, we found a lower incidence of CXR abnormalities than was previously reported. The most common pattern was ground-glass opacity or consolidation, but mixed central and peripheral involvement was more common than peripheral involvement alone.

Bacteria-ball in the urinary tract: a rare entity.

A bacterial mass in the urinary tract is a very rare entity. We report the first case of a bacterial ball within the urinary tract of a patient with diabetic cystopathy on long term urinary indwelling catheter. She presented with fever and gross haematuria. CT scan of abdomen and pelvis revealed a gas containing hyperdense mass within the bladder suspicious of bladder stone. The lesion was resected, and histopathology revealed a matrix of acellular materials with bacteria colony.

A practical and adaptive approach to lung cancer screening: a review of international evidence and position on CT lung cancer screening in the Singaporean population by the College of Radiologists Singapore.

Lung cancer is the leading cause of cancer-related death around the world, being the top cause of cancer-related deaths among men and the second most common cause of cancer-related deaths among women in Singapore. Currently, no screening programme for lung cancer exists in Singapore. Since there is mounting evidence indicating a different epidemiology of lung cancer in Asian countries, including Singapore, compared to the rest of the world, a unique and adaptive approach must be taken for a screening programme to be successful at reducing mortality while maintaining cost-effectiveness and a favourable risk-benefit ratio. This review article promotes the use of low-dose computed tomography of the chest and explores the radiological challenges and future directions.

Accuracy and clinical outcomes of coronary CT angiography for patients with suspected coronary artery disease: a single-centre study in Singapore.

INTRODUCTION: This study aimed to assess the accuracy and outcomes of coronary computed tomography angiography (CCTA) performed in a regional hospital in Singapore. METHODS: The Changi General Hospital CCTA database was retrospectively analysed over a 24-month period. Electronic hospital records, catheter coronary angiography (CCA) and CCTA electronic databases were used to gather data on major adverse cardiovascular events (MACE) and CCA results. CCTA findings were deemed positive if coronary artery stenosis ≥ 50% was reported or if the stenosis was classified as moderate or severe. CCA findings were considered positive if coronary artery stenosis ≥ 50% was reported. RESULTS: The database query returned 679 patients who had undergone CCTA for the evaluation of suspected coronary artery disease. Of the 101 patients in the per-patient accuracy analysis group, there were six true negatives, one false negative, 81 true positives and 13 false positives, resulting in a negative predictive value of 85.7% and positive predictive value of 86.2%. The mean age of the study sample was 53 ± 13 years and 255 (37.6%) patients were female. Mean duration of patient follow-up was 360 days. Of the 513 negative CCTA patients, none developed MACE during the follow-up period, and of the 164 positive CCTA patients, 19 (11.6%) developed MACE (p < 0.001). CONCLUSION: Analysis of CCTA studies suggested accuracy and outcomes that were consistent with published clinical data. There was a one-year MACE-free warranty period following negative CCTA findings.

Clinics in diagnostic imaging (182). Acute descending aortic dissection with aortic root retrograde extension.

A 77-year-old man presented with acute-onset severe chest pain radiating to the back and elevated blood pressure. Multiphasic computed tomography of the aorta revealed an intimal tear in the descending thoracic aorta which extended both retrograde to the aortic root and antegrade to the infra-renal abdominal aorta. The initial impression, that the images showed a Stanford type B aortic dissection, was because the portion of the false lumen that extended beyond the aortic arch remained unopacified even on delayed phases, making it challenging to assess the extent of the dissection flap. Bedside transthoracic echocardiography revealed a pericardial effusion. Cardiac tamponade ensued and the patient passed away shortly after presentation. This case highlights the need for early and accurate imaging assessment of acute aortic dissection, including accurate identification of the site of intimal tear and the extent of the dissection flap.

Saccular Kommerell aneurysm, a potential pitfall on MDCT imaging - A review of imaging features and potential mimics.

Saccular Kommerell aneurysm represents a potential pitfall on Multidetector CT (MDCT) imaging, mimicking conditions such as saccular aneurysm of the thoracic aorta, ductus diverticulum and dilated Kommerell diverticulum. Accurate diagnosis of this condition is critical in the management of this potentially fatal condition. This paper reviews the MDCT imaging features of Kommerell aneurysms and its mimics and demonstrates how to make an accurate diagnosis through a series of four cases. MDCT features of Kommerell aneurysms, either saccular or fusiform types arising from a Kommerell diverticulum with atherosclerotic plaque and mural thrombus are discussed.

Imaging findings and clinical features of abdominal vascular compression syndromes.

OBJECTIVE: This article describes the typical imaging findings and clinical features that are associated with four abdominal vascular compression syndromes. We explain the underlying pathophysiology that results in these clinical syndromes so that the patient subset who will benefit from treatment can be identified. CONCLUSION: The abdominal vascular compression syndromes discussed here are uncommon and are potentially easily missed on a cursory review of radiologic examinations, particularly in a nonspecific and vague clinical setting. Hence, knowledge of the typical imaging findings and associated clinical symptoms is essential so that the they can be carefully sought and excluded. However, because these findings may also exist in healthy individuals as anatomic variants, it is important to correlate radiologic findings with clinical symptoms to identify the subset of patients who will benefit from treatment.

Finding nemo: imaging findings, pitfalls, and complications of ingested fish bones in the alimentary canal.

In Asian cuisine, fish is often prepared whole with the bones. Accidental fish bone (FB) ingestion is not an infrequently encountered condition in the emergency department. An impacted FB in the alimentary canal can lead to potentially life-threatening complications. For impacted FBs that cannot be visualized clinically, radiographs and multidetector computed tomography are helpful in localizing the FB, evaluating for complications, and planning treatment. In this pictorial essay, we illustrate the spectrum of radiological findings of impacted FBs, common imaging pitfalls, and complications. Finally, we highlight the imaging findings that are important to the clinician in planning treatment.

Pitfalls in multidetector computed tomography imaging of traumatic spinal injuries.

The advent of multidetector computed tomography (MDCT) has largely supplanted plain radiography as the recommended primary imaging modality for the evaluation of acute spinal injuries. Although MDCT is highly sensitive and specific for bony injuries, errors in diagnosis can still occur. Knowledge of the possible imaging pitfalls on MDCT, leading to either misdiagnosis of fractures or missed fractures, is vital in ensuring an accurate diagnosis. This paper serves to highlight conditions that can mimic or reduce the sensitivity for the detection of acute spinal injuries, as well as demonstrate imaging findings which aid in the detection and diagnosis of subtle spinal injuries. Review areas for clinically relevant extra-spinal findings in the context of trauma will also be discussed.