Evaluation of Compressed SENSE on Image Quality and Reduction of MRI Acquisition Time: A Clinical Validation Study.

RATIONALE AND OBJECTIVES: To evaluate the effect of compressed SENSE (CS) in clinical settings on scan time reduction and image quality. MATERIALS AND METHODS: Ninety-five magnetic resonance imaging (MRI) scans from different anatomical regions were acquired, consisting of a standard protocol sequence (SS) and sequence accelerated with CS. Anonymized paired sequences were randomly displayed and rated by six blinded subspecialty radiologists. Side-by-side evaluation on perceived sharpness, perceived signal-to-noise-ratio (SNR), lesion conspicuity, and artifacts were compared and scored on a five-point Likert scale, and individual image quality was evaluated on a four-point Likert scale. RESULTS: CS reduced overall scan time by 32% while maintaining acceptable MRI quality for all regions. The largest time savings were seen in the spine (mean = 68 seconds, 44% reduction) followed by the brain (mean = 86 seconds, 37% reduction). The sequence with maximum time savings was intracranial 3D-time-of-flight magnetic resonance angiography (202 seconds, 56% reduction). CS was mildly inferior to SS on perceived sharpness, perceived SNR, and lesion conspicuity (mean scores = 2.32-2.96, P < .001 [1: SS superior; 3: equivalent; 5: CS superior]). CS was equivalent to SS for joint and body scans on overall image quality (CS = 3.02-3.37, SS = 3.04-3.68, P > .05, [1: lowest quality and 4: highest quality]). The overall image quality of CS was slightly less for brain and spine scans (mean CS = 2.79-3.05, mean SS = 3.13-3.43, P = .021) but still diagnostic. Good overall clinical acceptance for CS (88%) was noted with full clinical acceptance for body scans (100%) and high acceptance for other regions (68%-95%). CONCLUSION: CS significantly reduced MR acquisition time while maintaining acceptable image quality. The implementation of CS may improve departmental workflows and enhance patient care.

Reconfiguring the radiology leadership team for crisis management during the COVID-19 pandemic in a large tertiary hospital in Singapore.

The coronavirus 2019 (COVID-19) outbreak poses a serious public health risk. To date, the disease has affected almost all countries in the world. The enormous scale of the outbreak and the relative lack of knowledge and information regarding a new virus, as well as the unpredictability of events, make it challenging for leadership teams to respond. This paper shares how we have reconfigured our radiology leadership team into a smaller disease outbreak task force (DOTF) to respond and coordinate all related efforts during this ongoing COVID-19 pandemic. The DOTF format is modelled after the military with domain groups looking at manpower, intelligence, operations, and logistics matters on a daily basis so that timely decisions can be made and action plans executed promptly. In managing the DOTF, discipline, flexibility, and teamwork are key principles, and these are built upon a strong foundation of focus on infection prevention and control, and patient and staff safety as well as staff well-being. The DOTF has positioned us well to confront the many challenges to date. We believe it will also help us navigate the complex issues that will arise with future surges in cases and in formulating strategies to manage exit from the present and future lockdowns. KEY POINTS: • In a pandemic, regular and directed meetings by a smaller leadership core group are required, for prompt decision making and execution of action plans. • The military format, with domain groups to look at manpower, intelligence, operations, and logistics matters, is useful in managing a pandemic. • Discipline, flexibility, and teamwork with strong focus on infection prevention and control, and patient and staff safety as well as staff well-being are key principles for leadership teams managing a pandemic.

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.

Implementation of an Artificial Intelligence-Based Double Read System in Capturing Pulmonary Nodule Discrepancy in CT Studies.

Studies show that up to 80% of all radiology errors are due to errors in perception. Early detection is critical for good outcomes in patients with primary lung cancer and lung metastasis. However, pulmonary nodules can be easily missed due to their small size. We prospectively applied a machine vision algorithm to CT studies containing lung parenchyma to detect pulmonary nodules, as well as a natural language processing algorithm to the text of the report to identify documentation of pulmonary nodules. Apparent discrepancies in perception - instances where a pulmonary nodule was not reported - were flagged for a secondary review by a radiologist. Four thousand and nine hundred studies were prospectively processed, of which 450 cases with potential discrepancies were detected. Preliminary manual analysis was performed to analyze the base error rate and to optimize thresholds for the machine vision and natural language processing algorithms, and 104 cases were flagged for final review. Of these 104 cases, 50 cases contained undocumented pulmonary nodules. Among these cases, 7 cases were classified as likely to be significant, where report addendums were done and the clinicians notified. We have successfully implemented an automated double read system to detect pulmonary nodule discrepancies, with minimal disruption to the radiology workflow and while keeping personal health information on-premises. This successful implementation demonstrates the viability of using an automated and secure radiology double-read system to improve patient safety in radiology workflows, either at a health system or an independent radiology practice.

Graduates’ and Employers’ Perceptions on Competencies Obtained from An Undergraduate Dental Curriculum Persepsi Graduan dan Majikan terhadap Kompetensi yang Diperolehi dari Kurikulum Program Pergigian Prasiswazah / Jurnal Sains Kesihatan Malaysia

@#The effectiveness of a dental curriculum as reflected by the competencies of the graduates is paramount in ensuring its relevance in the rapidly evolving field of dentistry. This work aimed to assess the competencies of dental graduates of the Faculty of Dentistry, Universiti Kebangsaan Malaysia (UKM) as perceived by the graduates and their employers on the basis of the core competencies listed in the undergraduate dental curriculum. A self-administered questionnaire consisting of 43 questions based on eight competency domains were sent to all UKM dental graduates of years 2012 to 2015 and to senior dental officers who represented their employers. The eight domains assessed were as follows: 1) gathering information at chair-side, 2) diagnosis, 3) treatment planning, 4) treatment and prevention, 5) communitybased, 6) management and administrative, 7) communication and 8) personal management and professional development. a total of 132 graduates (75%) and 18 employers (55%) responded. Only domain E on community-based skills was collectively rated ‘satisfactory’ while the rest of the seven domains had an ‘excellent’ rating by all respondents. With regard to individual skill, basic life support was rated very low for both groups (38.6% graduates and 23.5% employers). A strong association was found between the scores given by the graduates and their employers (p= 0.00). Generally, no difference was found between the scores of graduates from different years. The findings allow an evaluation of the curriculum in a myriad of angles. Although the graduates reported a good level of competency in most domains, the employers were reserved on the community-based skills. Poor competency in the key skill of basic life support in medical emergencies was highlighted and must be addressed in the curriculum or during training at the workplace.

Managing a Renal Transplant Programme During the COVID-19 Pandemic: Practical Experience from a Singapore Transplant Centre.

INTRODUCTION: Coronavirus Disease 2019 (COVID-19) has significantly affected the way healthcare is delivered in Singapore. Healthcare services such as renal transplantation had to rapidly adjust and meet the needs to (1) protect patients and staff, (2) ramp up, conserve or redeploy resources while (3) ensuring that critical services remained operational. This paper aims to describe the experience of the renal transplant programme at the Singapore General Hospital (SGH) in responding to the risks and constraints posed by the pandemic. METHODS AND MATERIALS: This is a review and summary of the SGH renal transplant programme's policy and protocols that were either modified or developed in response to the COVID-19 Pandemic. RESULTS: A multi-pronged approach was adopted to respond to the challenges of COVID-19. These included ensuring business continuity by splitting the transplant team into different locations, adopting video and tele-consults to minimise potential patient exposure to COVID-19, streamlining work processes using electronic forms, ensuring safe paths for patients who needed to come to hospital, ring-fencing and testing new inpatients at risk for COVID-19, enhancing precautionary measures for transplant surgery, ensuring a stable supply chain of immunosuppression, and sustaining patient and staff education programmes via video conferencing. CONCLUSIONS: Though the COVID-19 pandemic has reduced access to kidney transplantation, opportunities arose to adopt telemedicine into mainstream transplant practice as well as use electronic platforms to streamline work processes. Screening protocols were established to ensure that transplantation could be performed safely, while webinars reached out to empower patients to take precautions against COVID-19.

Computed tomography-based diagnosis of occult fragility hip fractures offer shorter waiting times with no inadvertent missed diagnosis.

PURPOSE: Surgical delay due to the wait for advanced cross-sectional imaging in occult fragility hip fracture management is not well studied. Our study aims to investigate computed tomography (CT) as an alternative to the gold standard magnetic resonance imaging (MRI) in occult hip fracture workup to decrease surgical delay. METHODS: We conducted a retrospective review of all CTs and MRIs performed between 2015 and 2017 for patients with clinically suspected fragility hip fractures and negative plain radiographs to investigate surgical delay resulting from the wait for advanced imaging and representations due to missed fractures. RESULTS: A total of 243 scans (42 CTs and 201 MRIs) were performed for occult hip fracture workup over the study timeframe, of which 49 patients (20%) had occult hip fractures [CT: 6 (14%), MRI: 43 (21%), p = 0.296)]. There were no readmissions for fracture in the 12 months following a negative scan. The CT group had shorter waiting times (CT: 29 ± 24 h, MRI: 44 ± 32 h, p = 0.004) without significantly reducing surgical delay (CT: 82 ± 36 h, MRI: 128 ± 58 h, p = 0.196). The MRI group had a higher number of patients with a cancer history (p = 0.036), reflective of the practice for workup of possible metastases as a secondary intention. CONCLUSION: Advanced cross-sectional imaging wait times in occult hip fracture workup contribute significantly to surgical delay. Modern CT techniques are not inferior to MRI in detecting occult fractures and may be a suitable alternative in the absence of a cancer history if MRI cannot be obtained in a timely fashion or is contraindicated. Clinicians should utilize the more readily available imaging modality to reduce surgical delay.

Diagnostic Ultrasound Services During the Coronavirus Disease (COVID-19) Pandemic.

OBJECTIVE. Nosocomial transmission of coronavirus disease (COVID-19) to frontline health care workers is well known, and health care workers may inadvertently become vectors for onward transmission. Ultrasound (US) service providers are at significant risk because scanning usually requires prolonged close patient contact. The bulky US equipment may also facilitate fomite transmission of disease. With increasing use of point-of-care and portable diagnostic US services, the risk is substantial. CONCLUSION. Our experience and protocols may help service providers with their own effective response against COVID-19.

Adapting to a new normal? 5 key operational principles for a radiology service facing the COVID-19 pandemic.

KEY POINTS: • Radiology services encountering the coronavirus disease-19 pandemic will need to modify their daily operational practices.• Leadership, patient risk stratification, adequate manpower, operational workflow clarity, and workplace/social responsibility will help Radiology services safely and sustainably deal with the current disease outbreak.

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.

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. CONCLUSION. Though similar to SARS, the COVID-19 outbreak has several differences. We share how lessons from 2003 are applied and modified in our ongoing operational response to this evolving novel pathogen.

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.

Use of magnetic resonance imaging in detecting subclinical synovitis in rheumatoid arthritis and correlation of imaging findings with interleukin-18 levels.

AIM: We studied the usefulness of magnetic resonance imaging (MRI) in detecting subclinical inflammation in patients with asymptomatic RA and tested the hypothesis of interleukin (IL)-18 as a marker of disease activity. METHODS: Thirteen RA patients with Disease Activity Score of 28 joints (DAS28) < 2.6 were evaluated. The patients underwent clinical evaluation, laboratory tests and MRI assessment. Imaging of bilateral hands and wrists was performed using validated acquisition and scoring techniques. Serum IL-18 levels were concurrently measured. RESULTS: MRI assessments showed that 92.3% and 76.9% of patients had synovitis and bone marrow edema, respectively, despite being in clinical remission. Eight out of 12 patients (66.7%) had erosions on MRI which were not visualised on plain radiographs. Of all the 182 joints studied for synovitis on MRI, only one had clinical evidence of joint swelling. Comparison of the total sum scores of synovitis between the right and left hand and wrist joints of individual patients showed a significant difference between the two sides. Measurements of IL-18 indicated that a large proportion (54%) of the patients had undetectable or very low levels of the cytokine. CONCLUSION: MRI is more sensitive in detecting erosions compared with X-rays, and is superior in its ability to detect subclinical inflammation in RA patients. Despite being in clinical remission, a large majority of patients had imaging-detected synovitis and bone marrow edema. Our study highlights the usefulness of MRI for the accurate evaluation of disease activity. In the utility of MRI, it may be important to assess bilateral hands and wrists, instead of limiting to the dominant side.

Dynamic imaging with dual-source gated Computed Tomography (CT): implications of motion parameters on image quality for wrist imaging.

OBJECTIVE: Dynamic Computed Tomography (CT) promises insights into the pathophysiology of carpal instability by recording images of the carpus while it is in motion. The purpose of this study was to investigate the effect of motion velocity on image quality for dynamic carpal imaging applications using a clinical dual-source CT (DSCT) scanner. METHODS: A phantom with targets in the axial, coronal and sagittal planes was attached to a motion simulator and imaged using a 64-slice DSCT scanner. Data was acquired when the phantom was stationary and during periodic linear motion. Spatial resolution, motion artifacts and banding artifacts were assessed. RESULTS: Mean spatial resolution was 0.82 mm at 36 mm/s and 0.79 mm at 18 mm/s. Banding artifacts were mild at 36 mm/s and minimal at 18 mm/s. Motion artifacts were minimal at motion velocity of up to 36 mm/s in both the coronal and sagittal planes. Axial plane motion artifacts were moderate at 36 mm/s and mild at 18 mm/s. DISCUSSION: Sub-millimeter resolution is achievable with commercially available DSCT scanners with mild to moderate amounts of motion artifacts at velocities of 18 mm/s and 36 mm/s respectively.

Vertebrae adjacent to spinal bone lesion are inconsistent reference markers: a magnetic resonance spectroscopic viewpoint.

PURPOSE: To ascertain the suitability of vertebrae adjacent to spinal bone lesions as a signal intensity reference on MRI, and compare the MR spectroscopic appearance of vertebral body compression fractures due to malignant tumor infiltration, bone weakening (e.g., osteoporosis), and/or minor trauma. MATERIALS AND METHODS: Twenty-five patients with spinal compression fractures underwent routine spinal MRI with an additional 1H MRS study protocol to assess the percent fat fraction of the compressed vertebrae as well as the adjacent bony environment. Peak areas for water and total lipid were calculated from short-TE single-voxel 1H MR spectra using the LCModel analyzing tool. RESULTS: There were consistent water-only patterns in the fractured vertebra suggesting either near complete marrow replacement by malignant tissue or local edematous fluid/hemorrhage within the marrow spaces. However, the adjacent vertebrae showed a wide range of patterns from a dominant lipid signal to the inverse of a pronounced water level. These results far exceed the normal variation expected based on age and sex. CONCLUSION: The results suggest that the adjacent vertebrae may not be an accurate reference, especially in diffusion-weighted imaging (DWI), because of the large difference between the two compartments. Furthermore, in the case of gradient-echo measurements, the in-phase vs. opposed-phase effects are significant.

Imaging features of fat necrosis.

OBJECTIVE: We describe five cases of biopsy-proven fat necrosis and review the imaging with an emphasis on MRI. CONCLUSION: MRI showed the classically reported finding of central globular high signal intensity with a low-signal-intensity rim in only two of the five cases. We noted peripheral contrast enhancement, which to our knowledge has not been reported previously, in three of our five cases. Other patterns such as amorphous, cloudlike stranding and a serpentine appearance were also encountered. In reviewing the literature, we found that the MRI appearance of fat necrosis is more varied than previously thought.