Planning and coordination of the radiological response to the coronavirus disease 2019 (COVID-19) pandemic: the Singapore experience.

Coronavirus disease 2019 (COVID-19) has spread fast and extensively around the world, with significant mortality and morbidity. As this is a respiratory infection, chest radiography and computed tomography (CT) are important imaging techniques in the work-up of this disease. Given its highly infectious nature, cross-infection within the healthcare setting and radiology departments needs to be addressed actively and prevented. We describe the response of radiology departments in Singapore to this pandemic, in terms of diagnosis, re-configuration of the department, re-organisation and segregation of staff, infection control, managerial, and leadership issues.

Ultrasonography of the hand and wrist.

Musculoskeletal ultrasonography (US) of the hands and wrist has recently been increasing in popularity. Recent rapid technical advances in the US, such as new ultra-high frequency probes and smaller probe sizes, have led to improved image quality. This, in turn, has accelerated the growth of musculoskeletal US. Known advantages of US are its lack of ionising radiation, noninvasiveness, portability and low cost. Dynamic and real-time assessment and Doppler imaging are additional benefits of this modality, especially in the imaging of the hands and wrist. Superficial structures of the hands and wrist, including the tendons, ligaments, nerves and vessels, are amenable to imaging with high frequency US. In this article, we demonstrate a spectrum of hand and wrist pathology using US, including entrapment neuropathy, inflammatory conditions, traumatic injury and masses. Ultrasound-guided procedures applicable to the hand and wrist are also briefly discussed.

The reliability, validity and sensitivity to change of the Chinese version of SF-36 in oriental patients with rheumatoid arthritis.

OBJECTIVE: To assess the reliability, validity and sensitivity to change of a Chinese version of the 36-item Short-Form Health Survey (SF-36) in Chinese-speaking patients with rheumatoid arthritis (RA) in Singapore. METHODS: The psychometric properties of the Chinese Hong Kong standard version of the SF-36 were assessed in 401 RA patients. The construct validity of the Chinese SF-36 was assessed by comparison with the American College of Rheumatology (ACR) functional status, a validated Chinese Health Assessment Questionnaire (C-HAQ) and markers of RA activity and severity. RESULTS: The overall Cronbach's coefficient alpha was 0.921, reflecting excellent internal consistency. The instrument showed reasonable test-retest reliability except in the social functioning (SF) subscale. There was a significant ceiling effect in the role physical (RP), SF and role emotional (RE) subscales and a floor effect in the RP and RE subscales. Physical function (PF) and SF were strongly correlated with C-HAQ and patient's assessment of RA activity [Pearson's correlation coefficient (r) ranging from -0.41 to -0.53] and moderately correlated with ACR functional status (r = -0.35 and -0.3, respectively). Weak correlations were also found between the Chinese SF-36 and markers of RA activity, deformed joint count and radiographic damage. PF and SF were the subscales most responsive to change in quality of life (QOL). CONCLUSION: The Chinese SF-36 showed reasonable reliability, criterion validity and responsiveness with limitations in certain subscales. Overall, the physical domains and PF in particular may be the most ideal psychometric measures of QOL in RA.

Cartilage injury and repair: assessment with magnetic resonance imaging.

Articular cartilage damage plays a major role in joint degeneration and dysfunction. Accurate assessment of the morphology and degree of cartilage wear is important in diagnosis, prognosis and management, particularly as many of these patients are young or participate in high-performance sports. Magnetic resonance imaging is able to directly evaluate such injuries, due to its high spatial resolution and excellent soft-tissue contrast resolution. This pictoral essay aims to demonstrate normal and damaged articular cartilage on MR imaging, as well as surgically-repaired cartilage.

Clinics in diagnostic imaging (107).

A 90-year-old woman was admitted for progressively increasing lower abdominal pain. There was no history of prior surgery, and physical examination was non-specific. The supine abdominal radiograph revealed an abnormal collection of air over the right obturator foramen. Computed tomography showed a right obturator hernia with incarcerated bowel in the hernial sac, and a right sciatic hernia containing the right ovary. The anatomy of obturator and inguinal hernias is reviewed, and the use of various imaging modalities in evaluation of abdominal hernias is discussed.

Avascular necrosis of the triquetrum: a case report.

A case of total ischemia of the triquetrum after a crushing injury to the right wrist by a dumbbell is reported. He was treated conservatively with splinting and analgesia. There was complete clinical and radiological recovery after a follow-up of one year.

Clinics in diagnostic imaging (94). Undisplaced occult subcapital fracture of the right femoral neck.

An 84-year-old woman, who sustained a fall in the nursing home, complained of right hip pain and inability to bear weight. Radiographs showed no fracture or cortical break. MR imaging showed an undisplaced subcapital fracture of the right femoral neck for which a hemiarthroplasty was performed. The patient was then discharged 10 days post-operation. Effectiveness of MR imaging for assessing occult hip fracture, a more superior imaging modality as compared to radiographs, is discussed. Early diagnosis can also expedite appropriate treatment and promote recovery, which can reduce the cost of prolonged or inpatient care. The role of MR imaging in detection of other causes of pain in the hip region is also discussed, drawing on examples in our local experience.

Radiographic features of a case of severe acute respiratory syndrome with fatal outcome.

INTRODUCTION: Severe acute respiratory syndrome (SARS) is a new form of atypical pneumonia caused by a coronavirus. We present the clinical course and chest radiographic findings of a case of SARS with fatal outcome. CLINICAL PICTURE: A 39-year-old Chinese male presented with fever, sore throat and non-productive cough. During his illness, serial chest radiographs showed increasingly severe air-space shadowing in both lungs. TREATMENT AND OUTCOME: The patient was treated with supplemental oxygen, levofloxacin, oseltamivir, ribavirin and methylprednisolone. As his condition worsened, the required ventilatory and inotropic support. He later developed a myocardial infarct and coagulopathy, and succumbed to his illness. CONCLUSION: The reported case mortality of SARS is about 9% worldwide. In Singapore, the mortality is 15.5%. Acute respiratory distress syndrome (ARDS) is believed to be a contributory factor to our patient's demise. We report this case to show the radiographic changes of ARDS in a patient with SARS.

Chest radiographic findings of a case of severe acute respiratory syndrome (SARS) in Singapore.

A new form of atypical pneumonia was reported in the East Asian region beginning from early 2003. This was later termed by the World Health Organisation as Severe Acute Respiratory Syndrome (SARS). The diagnosis of SARS relies on a combination of clinical features and chest radiographic findings. A preliminary review of SARS in Singapore shows chest radiographic findings of patchy airspace shadowing with severe cases progressing to diffuse air-space shadowing. We illustrate these findings with temporal correlation in our case report. As SARS is a contagious, rapidly progressive and potentially fatal condition, early diagnosis is crucial for prompt management and isolation of patients. Recognition of chest radiographic findings aids in the early diagnosis and containment of SARS.

Penile colour duplex ultrasonography as a screening tool for venogenic erectile dysfunction.

INTRODUCTION: Vasculogenic impotence is one of the major causes of erectile dysfunction. Cavernosometry and cavernosography is traditionally the gold standard for evaluation of venogenic impotence. However, it is invasive and there are potentially significant complications. Penile colour flow Doppler imaging (PCDI) is non-invasive and can be used to assess venous incompetence. MATERIALS AND METHODS: One hundred and sixty-eight patients were referred for PCDI assessment from March 1998 to February 2001. Forty-three of these also had cavernosogram and cavernosometry done and were included in the study. RESULTS: The sensitivity was 93.9%, the specificity was 90.0%, the accuracy was 93.0% with a negative predictive value of 81.8% and a positive predictive value of 96.9%. Kappa value of 0.81 was obtained, indicating excellent agreement between PCDI and cavernosogram and cavernometry. CONCLUSIONS: Penile colour flow Doppler imaging is accurate in the assessment of venogenic erectile dysfunction. It can replace cavernometry and cavernosogram as a screening tool. Cavernometry and cavernosogram should only be done in cases when PCDI suggests venogenic impotence, and when surgery is contemplated.

Percutaneous vertebroplasty in the management of osteoporotic vertebral compression fractures: initial experience.

INTRODUCTION: Vertebral compression fractures related to osteoporosis may cause persistent pain which impairs mobility and reduces the quality of life. Percutaneous vertebroplasty is a therapeutic interventional radiology procedure which is used in the management of pain relief in such fractures. It involves the injection of bone cement [polymethylmethacrylate (PMMA)] into the collapsed vertebrae under radiological guidance. This provides pain relief as well as increases the strength and stability of the vertebra. MATERIALS AND METHODS: A total of 16 patients with 17 osteoporotic compression fractures which were treated with percutaneous vertebroplasty over an 18-month period were studied. There were all women with the exception of 1 male patient. Their ages ranged from 61 to 87 years. The fracture sites were at the thoracolumbar junction from T12 to L3 levels. The majority of cases only required a unipedicular injection, with bipedicular injections in 3 cases. All cases were performed in the angiographic suite in the radiology departments, with biplanar fluoroscopy in one hospital. PMMA was injected in a semi-solid state under radiological guidance and screening into the collapsed vertebrae. RESULTS: All cases showed good technical success with no mortality or major complications. Only 2 cases had minor complications of cement leakage into the soft tissues of the back and adjacent disc space, respectively. There was sufficient pain relief in all patients and they were well enough to be discharged within 1 to 5 days after the procedure. Patients were followed up to evaluate the degree of long-term pain relief as well as analgesic usage. CONCLUSION: Percutaneous vertebroplasty is a new and minimally-invasive modality of treating pain in patients with osteoporotic compression fractures who are refractory to medical therapy. Under adequate imaging guidance, the risks of complications are minimal while the potential benefit to patients and their care-givers are significant.

The Bone and Joint Decade 2000-2010: for prevention and treatment of musculoskeletal disease.

The Bone and Joint Decade 2000-2010 has been established to increase awareness of the scale and impact of musculoskeletal disorders on the individual, health care systems and the society. It is a multi-disciplinary initiative involving professional bodies, patient care groups, research organisations and the community.

Differentiation of malignant vertebral collapse from osteoporotic and other benign causes using magnetic resonance imaging.

INTRODUCTION: Elderly patients presenting with backache and vertebral collapse are a diagnostic challenge. Plain X-rays, computed tomography and radionuclide bone scans have not always reliably distinguished between benign and malignant causes. Magnetic resonance imaging (MRI) may be able to do so. MATERIALS AND METHODS: Patients who underwent MRI evaluation for vertebral collapse were retrospectively studied. Over a 21-month period from January 1995 to September 1996, 47 patients with 58 vertebral collapses were studied. Benign and malignant aetiologies were established by serial imaging, clinical outcome and histology. Imaging was performed with T1 and T2-weighted sequences, with contrast enhancement in some patients. Collapsed vertebrae were examined for appearance of marrow on T1 and T2-weighted sequences and after contrast administration, signal intensity of adjacent discs, degree of marrow involvement, involvement of posterior elements, presence or absence of paraspinal mass and end-plate integrity. Agreement between the final and radiological diagnosis was evaluated. RESULTS: There were 36 benign vertebral collapses (20 osteoporotic, 7 post-traumatic, 9 infective) and 22 malignant ones (20 metastatic carcinoma, 2 multiple myeloma). Features which pointed to malignant cause were hypointense marrow on T1-weighted images, marrow enhancement after intravenous contrast, greater than 50% marrow involvement and involvement of posterior elements. Of the vertebral collapses due to infection, 78% showed end-plate disruption. CONCLUSIONS: This study shows that MRI can be used to accurately differentiate between benign and malignant causes of vertebral collapse. Further differentiation between an osteoporotic, traumatic or infective cause can be done with the help of clinical history and evaluation of end-plate integrity.

Clinics in diagnostic imaging (63). Flipped bucket-handle tear of the lateral meniscus posterior horn.

Tears of the menisci in the knee are common after trauma, especially following sports injuries. A 21-year-old Chinese man with a flipped bucket-handle tear of the posterior horn of the lateral meniscus is reported. The MR imaging findings were confirmed at surgery. The classification and different types of meniscal tears, and the role of MR imaging in the diagnosis of meniscal lesions, are discussed.

Overview of imaging in rheumatologic diseases.

The role of radiology in rheumatologic diseases has for many years been confined to conventional radiography alone. The advances in medicine placed great demands on earlier and more accurate evaluation of these diseases. Conventional radiographs have been used as diagnostic aids and radiographic features and measurements are well established. However, the newer technologies, such as ultrasound, computed tomography and magnetic resonance imaging (MRI) have recently influenced accuracy of diagnosis and allowed for earlier detection and a more comprehensive evaluation of the results of therapy. One leading example is the significant role MRI plays in the early detection of avascular necrosis, especially of the hips. The clinical benefits of the newer modalities in radiology are being increasingly recognised and its full potential realised by both rheumatologists and radiologists.

The lumbosacral lucent cleft.

BACKGROUND: The lumbosacral lucent cleft was first described in association with traumatic injuries to the neck. However, we have observed this sign to be present in patients with no precursor of trauma, and we reviewed the incidence of lucent cleft sign in our local population and any characteristic features of the lucent cleft. METHODS: Four-hundred and thirty lumbosacral spine radiographs were examined prospectively over an 8-month period, with correlation with clinical findings. Follow-up radiographs were obtained at 1, 3 and 6 months for patients with the lucent cleft sign. FINDINGS: Nineteen patients (4.4%) were found to have lucent clefts in their lumbosacral spine X-rays. No significant change in the number and features to the lucent clefts was noted even when the symptoms had resolved after 6 months. All the lucent clefts were linear, horizontally oriented and located at the anterior edge of the adjacent vertebral body. CONCLUSION: The lucent cleft sign in the spine, which has so far been described in association with has spinal trauma may be completely innocuous in patients with little or no symptoms.