Evidence of Added Value of Chest CT in Coronavirus Disease (COVID-19) Pneumonia with Initial Negative RT-PCR Results.
Chan LL, Tan EK
We read with interest the article by Chen et al. , who retrospectively examined the chest CT findings of 21 patients with confirmed coronavirus disease (COVID-19) pneumonia and found differences in CT features between the groups with negative and positive initial reverse transcription–polymerase chain reaction (RT-PCR) results. The swab RT-PCR tests were all performed within 3 days of CT. The authors concluded that CT showed less pulmonary consolidation in the group with negative initial RT-PCR results. They highlighted that CT is useful for patient screening if COVID-19 is clinically suspected.
A Rare Case of Acute Hemorrhagic Leukoencephalitis in a COVID-19 Patient.
Yong MH, Chan YFZ, Liu J, Sanamandra SK, Kheok SW, Lim KC, Sewa DW
Dear Editor, Neurological manifestations associated with severe COVID-19 infection in the current SARS-CoV-2 pandemic have been gaining attention, with encephalopathy and stroke [1,2] featuring prominently, and a recent account of acute necrotizing encephalopathy . We report a rare case of a Singaporean male with severe COVID-19 pneumonia who developed Acute Hemorrhagic Leukoencephalitis.
Chest Radiographs and CTs in the Era of COVID-19: Indications, Operational Safety Considerations and Alternative Imaging Practices
Chia AQX, Cheng LTE, Wijaya L, Png MA, Sim WY, Hong WL, Chen RC
Coronavirus disease-19 (COVID-19) is a pathogen that has shown an ability for sustained community transmission. To ensure utmost safety, radiology services will need to adapt to this disease in the coming months and possibly years ahead. This will include learning how to perform radiographs and CT in a safe and sustainable manner. Due to the risk of nosocomial spread of disease, the judicious use and implementation of strict infection protocols is paramount to limit healthcare worker and patient transmission. Between 28 January 2020 and 8 June 2020, our institution performed 12,034 radiographs and 178 CT scans for suspected or confirmed COVID-19 patients. As of 8 June 2020, there have been no documented instances of healthcare staff acquiring COVID-19 during the course of work. In this article, we present the indications and operational considerations used by our institution to safely image patients with suspected or confirmed COVID-19. Alternative practices for imaging radiographs are also discussed.
Evaluation of trigeminal nerve tractography using two-fold-accelerated simultaneous multi-slice readout-segmented echo planar diffusion tensor imaging
Koh YH, Shih YC, Lim SL, Kiew YS, Lim EW, Ng SM, Ooi LQR, Tan WQ, Chung YC, Rumpel H, Tan EK, Chan LL.
Adapting lessons from SARS for the COVID-19 pandemic - Perspectives from Radiology Nursing in Singapore.
Wong ASK, Ooi CC, Leow MQH, Kiew YS, Yeo KCW, Tan SG, Tay KH
Radiographic Features of Coronavirus Disease 2019 (COVID-19) Based on an Initial Cohort of 96 Patients in Singapore.
Khoo HW, Hui TCH, Haja Mohideen S, Liew CJY, Kok SSX, Young BE, Ong SWX, Kalimuddin S, Tan SY, Loh J, Chan LP, Poh ACC, Wong SBS, Leo Y, Lye DC, Kaw GJL, Tan CH.
Introduction: Chest radiographs (CXR) are widely used for the screening and management of the coronavirus disease 2019 (COVID-19). This paper determinates the radiographic features of COVID-19 based on an initial national cohort of patients.
Clinical placements for undergraduate diagnostic radiography students amidst the COVID-19 pandemic in Singapore: Preparation, challenges and strategies for safe resumption.
Tay YX, Sng LH, Chow HC, Zainuldin MR.
Introduction: The COVID-19 pandemic resulted in the suspension of clinical training for undergraduate radiography students in Singapore. Coordinated preparation plans and strategies between the university and hospitals were needed to safely resume clinical placements within national and hospitals’ risk control measures against COVID-19 transmission.
Messaging Fatigue and Desensitisation to Information During Pandemic.
Koh PK, Chan LL, Tan EK.
To the editor, the current COVID-19 pandemic which has afflicted more than 6 million people has led to many mental, societal and economic consequences. The physical and mental fatigue of frontline workers in places constrained by manpower shortage are well recognized. Public healthcare communication has played a crucial role in engaging the public to partake in this crisis. However, the challenges and repercussions of messaging fatigue has received little attention.
Chest CT in asymptomatic COVID-19: benefits and concerns.
We read with interest the paper by Liu et al. who argued that it is not justified to use Chest CT as a screening Tool for COVID-19 in unrelated patients and symptomatic subjects without contact history. The authors highlighted that a number of hospitals outside Wuhan in China used chest CT scan to screen for COVID-19 for hospitalized patients with illnesses un-related to COVID-19 and without respiratory symptoms.
Clinical utility of chest radiography for severe COVID-19
Hui, T., Khoo, H. W., Young, B. E., Haja Mohideen, S. M., Lee, Y. S., Lim, C. J., Leo, Y. S., Kaw, G., Lye, D. C., & Tan, C. H.
Background: Chest radiography (CXR) is performed more widely and readily than CT for the management of coronavirus disease (COVID-19), but there remains little data on its clinical utility. This study aims to assess the diagnostic performance of CXR, with emphasis on its predictive value, for severe COVID-19 disease.
Fully Automated Hybrid Approach to Predict the IDH Mutation Status of Gliomas via Deep Learning and Radiomics
Choi YS, Bae S, Chang JH, Kang S, Kim SH, Kim J, Rim TH, Choi SH, Jain R, Lee S
Background: Glioma prognosis depends on isocitrate dehydrogenase (IDH) mutation status. We aimed to predict the IDH status of gliomas from preoperative MR images using a fully automated hybrid approach with convolutional neural networks (CNNs) and radiomics.
Olfactory Loss of Function as a Possible Symptom of COVID-19
Kheok SW, Teo WYN.
To the Editor There is increasing interest in the cause of anosmia in patients with coronavirus disease 2019 (COVID-19), and the article written by Dr Eliezer et al,1 presents an interesting finding of a patient with bilateral obstruction of the olfactory clefts. This is different from another report of a COVID-19 patient with isolated anosmia whose magnetic resonance imaging results showed normal olfactory bulb and no corresponding inflammation in the olfactory clefts or paranasal sinuses.
Cryptic Asymptomatic Parasellar High Signal on Time-of-Flight MR Angiography: How to Resolve the Clinical Conundrum
Lim KC, Santhosh RS, Kee TP, Sim S, Ho MI, Ho JXM, Mcadory LE, Lim WEH, Chan LL
Purpose: Hyperintense parasellar signal on time-of-flight MR angiography (TOF-MRA) in asymptomatic patients may be due to a variety of nonpathological causes and mimic parasellar high flow signal in pathological arteriovenous shunts at the cavernous sinus (CSAVS). This creates a clinical conundrum between diagnosing an aggressive yet asymptomatic CSAVS subtype against exposing patients without CSAVS to potential complications of an invasive angiographic evaluation…
Appropriateness of MRI Brain Orders: Application of American and British Guidelines
Lim JLL, McAdory LE, Tang PH, Conceicao EP, Lim WEH, De Silva DA, Tan EK, Chan LL
Machine Learning and Radiomic Phenotyping of Lower Grade Gliomas: Improving Survival Prediction
Choi YS, Ahn SS, Chang JH, Kang S, Kim EH, Kim SH, Jain R, Lee S
Background and purpose: Recent studies have highlighted the importance of isocitrate dehydrogenase (IDH) mutational status in stratifying biologically distinct subgroups of gliomas. This study aimed to evaluate whether MRI-based radiomic features could improve the accuracy of survival predictions for lower grade gliomas over clinical and IDH status.
Ong EZ, Chan YFZ, Leong WY, Lee NMY, Kalimuddin S, Haja Mohideen S, Chan KS, Tan AT, Bertoletti A, Ooi EE, Low JGH
The inflammatory response to SARS-coronavirus-2 (SARS-CoV-2) infection is thought to underpin COVID-19 pathogenesis. We conducted daily transcriptomic profiling of three COVID-19 cases and found that the early immune response in COVID-19 patients is highly dynamic. Patient throat swabs were tested daily for SARS-CoV-2, with the virus persisting for 3 to 4 weeks in all three patients. Cytokine analyses of whole blood revealed increased cytokine expression in the single most severe case. However, most inflammatory gene expression peaked after respiratory function nadir…
Evaluating Potential Deceased Donor Renal Transplant Recipients for Asymptomatic COVID-19
Ho QY, Chung SJ, Low SCS, Chen RC, Tee SP, Chan FZY, Tan BH, Kee TYS
We present a case of asymptomatic coronavirus disease 2019 (COVID-19) diagnosed in a hemodialysis patient during deceased donor renal transplantation (DDRT) evaluation and discuss the challenges of excluding COVID-19 before transplantation.Effect of Myocardial Viability Assessed by Cardiac Magnetic Resonance on Survival in Patients With Severe Left Ventricular Dysfunction
Yap J, Lim FY, Gao F, Wang SZ, Low SCS, Le TT, Tan R
Background: Myocardial viability assessment in revascularization of ischemic heart failure remains controversial. This study evaluated the prognostic utility of cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) in ischemic heart failure.
Touch me not: safe distancing in Radiology during Coronavirus Disease 2019 (COVID-19)
Chen RC, Cheng LTE, Lim JLL, Gogna A, Ng DCE, Teo LZY, Tan BS
In the era of COVID-19, "social distancing" has become a buzzword. Strictly speaking, social distancing refers to physically distancing by 1 to 2 m, but the overall concept is more important: disrupting the infectious chain by separating those with the disease from those without. Epidemiologists have espoused the term, believing in its ability to "flatten the curve." By reducing the exponential rise in cases, the health care system is not overwhelmed and can function sustainably over the long term. Although this concept’s main intention is to control disease, in the hospital setting, it provides the equally important added benefit of ensuring continuity of vital services should intrahospital transmission occur. We are part of a 1,700-bed hospital, with a radiological service strength of over 600 (41 residents, 77 attending physicians [nuclear medicine, interventional, diagnostic], 273 radiographers, and 240 nurses and administrative support staff). This article describes our measures and early experiences with safe distancing in our radiology service.
Radiological retrograde ureteric stent exchange in women: a single-centre review
Lai AL, Choong M, Toh LMHW, Irani FG, Damodharan K, Chan SXJM, Too CW, Patel A, Gogna A, S Chandramohan
AIM: To evaluate the safety and efficacy of modified wire loop technique for retrograde stent exchange. MATERIALS AND METHODS: All patients were from the KK Women and Children's Hospital where there is no on-site urology service. Patients were identified retrospectively from the institutional radiological information system (RIS) database. In total, 270 stents were removed and 238 replaced for 79 patients between January 2012 to December 2016. Success rates for stent removal and exchange as well as skin dose and fluoroscopy time were assessed…
Tison NRR, Leong L, Tan PH, Tan VKM.
A 39-year-old premenopausal woman presented with a self-palpated right breast mass. Clinical examination revealed a stiff, turgid right breast with a palpable 5 cm mass with indistinct margins at the upper outer quadrant. The overlying skin and nipple areolar complex was normal. The left breast was unremarkable, and no clinically palpable lymph nodes were noted bilaterally.Multiparametric MRI-Ultrasound Software Fusion Prostate Biopsy - Initial Results Using A Stereotactic Robotic Assisted Transperineal Prostate Biopsy Platform Comparing Systematic Versus Targeted Biopsy
Lee AY, Yang XY, Lee HJ, Law YM, Hong HH, Lau WK, Lee LS, Ho HS, Tay KJ, Cheng CW, Yuen JS, Chen K.
Objective: To compare the detection rates of prostate cancer between systematic biopsy and targeted biopsy using a stereotactic robot‐assisted transperineal prostate platform…
Multinodular and vacuolating neuronal tumour of the cerebrum: an incidental diagnosis in a child presenting with absence seizures
Tan TSE, Sanamandra SK.
A previously well 7-year-old boy presents with recurrent absence seizures, comprising sudden activity arrest and staring episodes lasting 10–20 s, occurring several times daily. There were no other associated symptoms or history of head trauma, infection or epilepsy. Neurological and electroencephalogram assessment were unremarkable. Further work-up with cranial MRI incidentally revealed several benign-appearing coalescent nodules in the left parietal lobe without any other significant intracranial abnormality (figure 1), consistent with multinodular and vacuolating neuronal tumour (MVNT) of the cerebrum.
Sim WY, Chen RC, Aw LP, Abu Bakar Rafidah, Tan CC, Heng AL, Ooi CC
Objectives: This paper aims to share our experience in reorganising our general radiography service during the coronavirus disease (COVID-19) pandemic from the viewpoint of a large tertiary referral medical centre.
Parkinson Disease and the Immune System - Associations, Mechanisms and Therapeutics
Tan EK, Chao Y, West A, Chan LL, Poewe W, Jankovic J
Chan LL, Tan EK.
We read with interest the neuroimaging findings of the first presumptive case of encephalitis associated with COVID-19 infection in the Mar 2020 issue of Radiology by Dr Neo Poyiadji and thank the authors for documenting and sharing their important findings with the community in the current pandemic…
Tan BP, Lim KC, Goh YG, Kok SXS, Teo SY, Poh CCA, Kaw JLG, Quek ST, Wong BSS, Chan LP, Tan BS
The coronavirus disease 2019 (COVID-19) pandemic presents an unprecedented challenge to the healthcare systems of the world. In Singapore, the Radiology community’s early experience on managing this pandemic was shaped by lessons learnt from the earlier SARS outbreak in 2003. This article surveys the operational responses of radiology departments from 6 public hospitals in Singapore.
Adapting to a new normal? Adapting to a New Normal? Key Operational responses of a Radiology service during the COVID-19 epidemic
Chen RC, Tan TT, Chan LP
Diffusion Tensor Imaging Radiomics in Lower-grade Glioma: Improving Subtyping of Isocitrate Dehydrogenase Mutation Status
Park CJ, Choi YS, Park YW, Ahn SS, Kang S, Chang J, Kim SH, Lee S
Purpose: To evaluate whether diffusion tensor imaging (DTI) radiomics with machine learning improves the prediction of isocitrate dehydrogenase (IDH) mutation status of lower-grade gliomas beyond radiomic features from conventional MRI and DTI histogram parameters. Methods: A total of 168 patients with pathologically confirmed lower-grade gliomas were retrospectively enrolled. A total of 158 and 253 radiomic features were extracted from DTI (DTI radiomics) and conventional MRI (T1-weighted image with contrast enhancement, T2-weighted image, and FLAIR [conventional radiomics]), respectively…
AI-based Prognostic Imaging Biomarkers for Precision Neuro-oncology: the ReSPOND consortium
Davatzikos C, Barnholtz-Sloan JS, Bakas S, Colen R, Mahajan A, Quintero CB, Font JC, Puig J, Jain R, Sloan AE, Badve C, Marcus DS, Choi YS, Lee S, Chang JH, Poisson LM, Griffith B, Dicker AP, Flanders AE, Booth TC, Rathore S, Akbari H, Sako C, Bilello M, Shukla G, Kazerooni AF, Brem S, Lustig R, Mohan S, Bagley S, Nasrallah M, O'Rourke DM
Artificial intelligence (AI) and machine learning (ML) methods have begun to reveal that complex imaging patterns can provide individualized biomarkers for diagnosis and prognosis. However, AI methods have been challenged by insufficient training, heterogeneity of imaging protocols across hospitals, and lack of generalization to new patient data. These challenges prompted the development of the ReSPOND (Radiomics Signatures for PrecisiON Diagnostics) consortium on glioblastoma (GBM). This collaboration of over 10 institutions, across 3 continents, is positioned to pool, harmonize, and analyze brain MRIs…
Rapid Progression to Acute Respiratory Distress Syndrome: Review of Current Understanding of Critical Illness from COVID-19 Infection
Goh KJ, Choong MC, Cheong EH, Kalimuddin S, Duu Wen S, Phua GC, Chan KS, Haja Mohideen S
The coronavirus disease 2019 (COVID-19) outbreak that started in Wuhan, Hubei province, China in December 2019 has now extended across the globe with >100,000 cases and 3,000 deaths reported in 93 countries as of 7 March 2020. We report a case of COVID-19 infection in a 64-year-old man who developed rapidly worsening respiratory failure and acute respiratory distress syndrome (ARDS) that required intubation. As the clinical spectrum of COVID-19 ranges widely from mild illness to ARDS with a high risk of mortality, there is a need for more research to identify early markers of disease severity. Current evidence suggests that patients with advanced age, pre-existing comorbidities or dyspnoea should be closely monitored, especially at 1-2 weeks after symptom onset. It remains to be seen if laboratory findings such as lymphopenia or elevated lactate dehydrogenase may serve as early surrogates for critical illness or markers of disease recovery. Management of ARDS in COVID-19 remains supportive while we await results of drug trials. More studies are needed to understand the incidence and outcomes of ARDS and critical illness from COVID-19, which will be important for critical care management and resource planning.
Quality of Prostate MRI: Is the PI-RADS Standard Sufficient?
Sackett J, Shih JH, Reese SE, Brender JR, Harmon SA, Barrett T, Coskun M, Madariaga M, Marko J, Law YM, Turkbey EB, Mehralivand S, Sanford T, Lay N, Pinto PA, Wood BJ, Choyke PL, Turkbey B
Rationale and Objective: The Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) published a set of minimum technical standards (MTS) to improve image quality and reduce variability in multiparametric prostate MRI. The effect of PIRADSv2 MTS on image quality has not been validated. We aimed to determine whether adherence to PI-RADSv2 MTS improves study adequacy and perceived quality.
Huang X, Wen MC, Ng SYE, Hartono S, Chia NSY, Choi X, Tay KY, Au WL, Chan LL, Tan EK, Tan LCS
Stereotactic robot-assisted transperineal prostate biopsy under local anaesthesia and sedation: moving robotic biopsy from operating theatre to clinic
Yang X, Lee AY, Law YM, Sim ASP, Tay KJ, Lau WKO, Ho HSS, Yuen JSP, Chen K.
Lipid Fraction Derived From MRI In- and Opposed-Phase Sequence as a Novel Biomarker for Predicting Survival Outcome of Glioma.
Seow P, Narayanan V, Romelean RJ, Wong JHD, Win MT, Chandran H, Chinna K, Rahmat K, Ramli N
Rationale and purpose: Our study evaluated the capability of magnetic resonance imaging in- and opposed-phase (IOP) derived lipid fraction as a novel prognostic biomarker of survival outcome in glioma. Materials and methods: We analyzed 46 histologically proven glioma (WHO grades II-IV) patients using standard 3T magnetic resonance imaging brain tumor protocol and IOP sequence. Lipid fraction was derived from the IOP sequence signal-loss ratio. The lipid fraction of solid nonenhancing region of glioma was analyzed, using a three-group analysis approach based on volume under surface of receiver-operating characteristics to stratify the prognostic factors into three groups of low, medium, and high lipid fraction. The survival outcome was evaluated, using Kaplan-Meier survival analysis and Cox regression model.
MR Image Phenotypes may Add Prognostic Value to Clinical Features in IDH Wild-type Lower-grade Gliomas
Park CJ, Han K, Shin H, Ahn SS, Choi YS, Park YW, Chang JH, Kim SH, Jain R, Lee S
Purpose: To identify significant prognostic magnetic resonance imaging (MRI) features and their prognostic value when added to clinical features in patients with isocitrate dehydrogenase wild-type (IDHwt) lower-grade gliomas. Materials and methods: Preoperative MR images of 158 patients (discovery set = 112, external validation set = 46) with IDHwt lower-grade gliomas (WHO grade II or III) were retrospectively analyzed using the Visually Accessible Rembrandt Images feature set. Radiologic risk scores (RRSs) for overall survival were derived from the least absolute shrinkage and selection operator and elastic net…
Large Solitary Lytic Skull Vault Lesions in Adults: Radiological Review with Pathological Correlation
Kee TP, Liauw L, Sathiyamoorthy S, Lee HY, Tan GSL, Yu WY
Déjà vu or Jamais Vu? How the Severe Acute Respiratory Syndrome Experience Influenced a Singapore Radiology Department's Response to the Coronavirus Disease (COVID-19) Epidemic
Cheng LTE, Chan LP, Tan BH, Chen RC, Tay KH, Ling ML, Tan BS
OBJECTIVE. This article shares the ground operational perspective of how a tertiary hospital radiology department in Singapore is responding to the coronavirus disease (COVID-19) epidemic. This same department was also deeply impacted by the severe acute respiratory syndrome (SARS) outbreak in 2003.
Microstructural abnormalities found in uncinate fasciculus and superior cerebellar tracts in children with global developmental delay: a feasibility study
Ramli N, Yap A, Muridan R, Seow P, Rahmat K, Fong CY, Tan LK, Ong LC.
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