Radiology Preparedness in the Ongoing Battle against COVID-19: Experiences from Large to Small Public Hospitals in Singapore.

The coronavirus disease 2019 (COVID-19) pandemic presents an unprecedented challenge to the health care systems of the world. In Singapore, early experiences of the radiology community on managing this pandemic was shaped by lessons learned from the severe acute respiratory syndrome outbreak in 2003. This article surveys the operational responses of radiology departments from six public hospitals in Singapore. © RSNA, 2020.

Single coronary artery arising from the right sinus of Valsalva presenting with chest pain.

Single coronary artery is a rare anomaly, with a reported incidence of 0.024%. It can be diagnosed on coronary computed tomography angiography, where the presence of ostial narrowing and compression between the great vessels must be carefully excluded, since these malignant forms can lead to sudden cardiac death and other ischemic complications. We describe a case of single coronary artery arising from the right sinus of Valsalva presenting with symptoms of ischemic chest pain.

The iPad tablet computer for mobile on-call radiology diagnosis? Auditing discrepancy in CT and MRI reporting.

Tablet computers such as the iPad, which have a large format, improved graphic display resolution and a touch screen interface, may have an advantage compared to existing mobile devices such as smartphones and laptops for viewing radiological images. We assessed their potential for emergency radiology teleconsultation by reviewing multi-image CT and MRI studies on iPad tablet computers compared to Picture Archival and Communication Systems (PACS) workstations. Annonymised DICOM images of 79 CT and nine MRI studies comprising a range of common on-call conditions, reported on full-featured diagnostic PACS workstation by one Reporting Radiologist, were transferred from PACS to three iPad tablet computers running OsiriX HD v 2.02 DICOM software and viewed independently by three reviewing radiologists. Structured documentation was made of major findings (primary diagnosis or other clinically important findings), minor findings (incidental findings), and user feedback. Two hundred and sixty four readings (88 studies read by three reviewing radiologists) were compared, with 3.4 % (nine of 264) major discrepancies and 5.6 % (15 of 264) minor discrepancies. All reviewing radiologists reported favorable user experience but noted issues with software stability and limitations of image manipulation tools. Our results suggest that emergency conditions commonly encountered on CT and MRI can be diagnosed using tablet computers with good agreement with dedicated PACS workstations. Shortcomings in software and application design should be addressed if the potential of tablet computers for mobile teleradiology is to be fully realized.

MDCT evaluation of central airway and vascular complications of lung transplantation.

OBJECTIVE: The purpose of this article is to illustrate the spectrum of central airway and vascular complications in lung transplantation using MDCT, with an emphasis on the usefulness of advanced postprocessing techniques. CONCLUSION: MDCT is an invaluable tool in the diagnosis, evaluation, and posttreatment assessment of central airway and vascular complications in lung transplant recipients. Advanced postprocessing techniques provide complementary information that is visually accessible and anatomically meaningful for the clinician.

Primitive neuroectodermal tumour of the kidney: radiologic-pathological correlations.

A primitive neuroectodermal tumour of the kidney is a rare malignancy. We report the computed tomographic features and the histopathological correlation of such a tumour occurring in a middle-aged man. Although the radiological appearance has significant overlap with other renal tumours, this tumour should be included in the differential diagnosis of a large renal mass in younger patients.

Endocardial irregularities of the left atrial roof as seen on coronary CT angiography.

OBJECTIVE: To describe and characterize morphological characteristics of endocardial irregularities in the roof of the left atrium as seen on coronary CT angiography. METHODS: We retrospectively evaluated the left atrium in 50 consecutive coronary CT patients with multiplanar reformatting, volume rendering, and virtual endoscopy. RESULTS: Twenty-one of the 50 patients had an endocardial irregularity at the roof of the left atrium. The most common finding (n = 14) was a smooth diverticulum, arising near the venoatrial junction of the right superior pulmonary vein. CONCLUSION: Endocardial irregularities of the left atrium can be identified on coronary CT and may be more common than previously considered. The findings probably represent remnants of the cardinal venous system during embryological development. Further work should focus on the true prevalence and potential clinical significance.

Routine pelvic and lower extremity CT venography in patients undergoing pulmonary CT angiography.

OBJECTIVE: The purpose of our study was to assess the utility of performing routine pelvic and lower extremity CT venography (CTV) along with pulmonary CT angiography (CTA) in all patients evaluated for pulmonary embolism. MATERIALS AND METHODS: Eight hundred twenty-nine consecutive patients (281 men and 548 women) underwent CTA-CTV for pulmonary embolism. Reports were evaluated as follows: positive or negative for pulmonary embolism with or without deep venous thrombosis (DVT) or with nondiagnostic CTV. Coexisting factors of malignancy, previous venous thromboembolism (VTE), recent surgery, and cardiovascular disease comprised the high-risk group of 446 patients. The remaining 383 patients formed the low-risk group. Statistical analysis included four binary predictors (previous VTE, malignancy, cardiovascular disease, and surgery) and three binary outcome variables (pulmonary embolism, DVT, and VTE). Chi-square test and univariate and multivariate regression analyses were performed. RESULTS: VTE, pulmonary embolism, and DVT occurred in 152 (18.3%), 124 (15.0%), and 61 (7.3%) of 829 patients, respectively. Between the high-risk and low-risk groups, prevalence of VTE was 114 (25.6%) of 446 and 38 (9.9%) of 383 patients, respectively (p < 0.001); prevalence of pulmonary embolism was 92 (20.6%) of 446 and 32 (8.3%) of 383 patients, respectively (p < 0.001). Isolated DVT was found in 28 (3.4%) of 829 patients. The incremental value of CTV for the entire cohort was 3.4%, 0.72% in the low-risk group (six of 829) and 2.6% (22 of 829) in the high-risk group. For outcome variable VTE, malignancy and previous VTE were statistically significant (p = 0.04 and p < 0.001, respectively); for pulmonary embolism, malignancy and previous VTE were statistically significant (p = 0.03 and p = 0.005, respectively); for DVT, only previous VTE was statistically significant (p < 0.001). CONCLUSION: CTV should not be performed routinely in all patients evaluated for pulmonary embolism and may only be useful in patients with a high probability of pulmonary embolism, including those with a history of VTE and possible malignancy.

Sudden deafness due to intralabyrinthine haemorrhage: a possible rare late complication of head and neck irradiation.

INTRODUCTION: Radiation injury resulting in sudden, late onset sensorineural hearing loss is a recognised complication in patients who have received head and neck irradiation. We describe the magnetic resonance imaging (MRI) of the internal acoustic canal (IAC) of 3 such patients and postulate a cause for these findings. CLINICAL PICTURE: A total of 63 patients were referred for MRI IAC for sudden-onset sensorineural hearing loss. Of these patients, only 5 patients had abnormal MRI finding in the affected ear and the remaining patients had normal studies. Two patients had acoustic neuromas. Three patients demonstrated high T1-weighted signal in the labyrinths of the affected ears and had past histories of head and neck irradiation. The MRI findings and medical records of these 3 patients were reviewed and described in this case series. OUTCOME: High labyrinthine signal on unenhanced T1-weighted images in the symptomatic ear of these patients was observed, suggesting the possibility of haemorrhage. In the patient who had a history of brain tumour, susceptibility artifacts were also seen in the right hemipons on the gradient-echo images, indicating the presence of paramagnetic substances from previous therapy. CONCLUSION: We postulate that labyrinthine haemorrhage is a rare, late complication of head and neck irradiation, resulting in sudden sensorineural hearing loss.