K.T. Wong

Imaging of salivary gland tumours

Salivary gland neoplasms account for <3% of all tumors. Most of them are benign and parotid gland is the commonest site. As a general rule, the smaller the involved salivary gland, the higher is the possibility of the tumor being malignant. The role of imaging in assessment of salivary gland tumour is to define intra-glandular vs. extra-glandular location, detect malignant features, assess local extension and invasion, detect nodal metastases and systemic involvement. Image guided fine needle aspiration cytology provides a safe means to obtain cytological confirmation. For lesions in the superficial parotid and submandibular gland, ultrasound is an ideal tool for initial assessment. These are superficial structures accessible by high resolution ultrasound and FNAC which provides excellent resolution and tissue characterization without a radiation hazard. Nodal involvement can also be assessed. If deep tissue extension is suspected or malignancy confirmed on cytology, an MRI or CT is mandatory to evaluate tumour extent, local invasion and perineural spread. For all tumours in the sublingual gland, MRI should be performed as the risk of malignancy is high. For lesions of the deep lobe of parotid gland and the minor salivary glands, MRI and CT are the modalities of choice. Ultrasound has limited visualization of the deep lobe of parotid gland which is obscured by the mandible. Minor salivary gland lesions in the mucosa of oral cavity, pharynx and tracheo-bronchial tree, are also not accessible by conventional ultrasound. Recent study suggests that MR spectroscopy may differentiate malignant and benign salivary gland tumours as well as distinguishing Warthins tumor from pleomorphic adenoma. However, its role in clinical practice is not well established. Similarly, the role of nuclear medicine and PET scan, in imaging of parotid masses is limited. Sialography is used to delineate the salivary ductal system and has limited role in assessment of tumour extent.

Ultrasound of malignant cervical lymph nodes

Abstract Malignant lymph nodes in the neck include metastases and lymphoma. Cervical nodal metastases are common in patients with head and neck cancers, and their assessment is important as it affects treatment planning and prognosis. Neck nodes are also a common site of lymphomatous involvement and an accurate diagnosis is essential as its treatment differs from other causes of neck lymphadenopathy. On ultrasound, grey scale sonography helps to evaluate nodal morphology, whilst power Doppler sonography is used to assess the vascular pattern. Grey scale sonographic features that help to identify metastatic and lymphomatous lymph nodes include size, shape and internal architecture (loss of hilar architecture, presence of intranodal necrosis and calcification). Soft tissue oedema and nodal matting are additional grey scale features seen in tuberculous nodes or in nodes that have been previously irradiated. Power Doppler sonography evaluates the vascular pattern of nodes and helps to identify the malignant nodes. In addition, serial monitoring of nodal size and vascularity are useful features in the assessment of treatment response.

High Morbidity and Mortality in Adults Hospitalized for Respiratory Syncytial Virus Infections

BACKGROUND Better understanding of complications and outcomes of adults hospitalized with respiratory syncytial virus (RSV) infection is necessary. METHODS A retrospective cohort study was conducted on all adults (≥ 18 years) admitted to 3 acute care general hospitals in Hong Kong with virologically confirmed RSV infection during 2009-2011 (N = 607). Adults hospitalized for seasonal influenza during the period were used for comparison (n = 547). Both infections were prospectively diagnosed following a standard protocol. Independent reviews of chest radiographs were performed by radiologists. Main outcome measures were all-cause death, respiratory failure requiring ventilatory support, and hospitalization duration. Cox proportional hazards models were used for analyses. RESULTS The mean age of RSV patients was 75 (SD, 16) years; 87% had underlying conditions. Lower respiratory and cardiovascular complications were diagnosed in 71.9% (pneumonia, 42.3%; acute bronchitis, 21.9%; chronic obstructive pulmonary disease/asthma exacerbation, 27.3%) and 14.3% of patients, respectively; 12.5% had bacterial superinfections. Supplemental oxygen and ventilatory support were required in 67.9% and 11.1%, respectively. Crude all-cause mortality was 9.1% and 11.9% within 30 days and 60 days, respectively; mean length of stay of survivors was 12 (SD, 13) days. Advanced age, radiographic pneumonia, requirement for ventilation, bacterial superinfection, and elevated urea level and white blood cell count were independently associated with poorer survival. Systemic corticosteroid use was associated with longer hospitalization and secondary infections. The overall outcomes of survival and length of stay were not significantly different from those in influenza. CONCLUSIONS RSV can cause severe lower respiratory complications in older adults, resulting in respiratory failure, prolonged hospitalization, and high mortality similar to seasonal influenza. Corticosteroids did not seem to improve outcomes. The unmet need for antiviral therapy and vaccination against RSV in adults should be promptly addressed.

Ultrasound of thyroid cancer

The management of thyroid nodules is multi-disciplinary and involves head and neck surgeons, pathologists and radiologists. Ultrasound is easy to perform, widely available, does not involve ionizing radiation and is readily combined with fine needle aspiration cytology (FNAC). It is therefore an ideal investigation of choice for evaluating thyroid nodules. It evaluates specific features that help in identifying the nature of the nodule and FNAC helps in diagnostic accuracy. In addition, following treatment for thyroid cancer ultrasound provides a safe tool for disease surveillance. This paper discusses the role of ultrasound in the management of patients with thyroid cancer.

Frequency and Determinants of Poststroke Dementia in Chinese

Background and Purpose— Both dementia and stroke are major health problems in Chinese societies. Stroke is a frequent cause of dementia. Only a few studies have been published on poststroke dementia (PSDE), none of which has investigated a consecutive stroke cohort in Asian patient populations. The objective of this study was to examine the prevalence and clinical correlates of PSDE in Chinese stroke patients in Hong Kong. Methods— Two hundred eighty stroke patients consecutively admitted to the medical wards of a university-affiliated regional hospital were interviewed by a psychiatrist 3 months after stroke. The presence of dementia and vascular dementia was diagnosed according to the Diagnostic and Statistical Manual, 4th edition. In addition, a wide range of demographic and clinical variables were examined. Results— Fifty-five participants (20%) had PSDE. Univariate analysis found that PSDE was associated with age; level of education; prestroke Rankin Scale score; prestroke Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) score; National Institutes of Health Stroke Scale (NIHSS) best language score, dysarthria score, and total score; urinary incontinence; cortical infarct; leukoaraiosis; bilateral lesions; number of lesions; involvement of middle cerebral artery circulation; and cerebral atrophy index. Multivariate logistic regression suggested that prestroke IQCODE score, NIHSS total score, leukoaraiosis, involvement of middle cerebral artery territory, and cerebral atrophy index were independent risk factors of PSDE. After removal of 22 patients with prestroke dementia, which was defined as a prestroke IQCODE score ≥4.0, the frequency of PSDE dropped to 15.5%. Furthermore, involvement of the middle cerebral artery territory and cerebral atrophy index were replaced by level of education and bilateral lesions as independent predictors in the final logistic model. Conclusions— PSDE is common among Chinese stroke patients in Hong Kong. Its frequency is comparable to that in white populations. The clinical determinants of PSDE, after the exclusion of patients with prestroke dementia, include premorbid level of cognitive function, severity of stroke, leukoaraiosis, level of education, and bilateral lesions.

Poststroke Depression in Chinese Patients: Frequency, Psychosocial, Clinical, and Radiological Determinants:

This study attempted to evaluate the psychosocial, clinical, and radiological predictors of poststroke depression (PSD) in Chinese patients. One hundred eighty-nine patients participated in the study. Three months after the index stroke, a psychiatrist administered the Structured Clinical Interview for DSM-IV to all of the patients and made a DSM-IV diagnosis of depression. In addition, a host of demographic, clinical, and radiological variables were examined. Thirty-one (16.4%) of the patients had a diagnosis of PSD that included major depression (n = 11, 5.8%,), minor depression (n = 16, 8.5%), or dysthymia (n = 4, 2.1%). Univariate analysis revealed that PSD was associated with female gender, a lower level of education, a lower Lubben Social Network Scale (LSNS) score, subcortical infarcts, and lesions in the anterior cerebral artery (ACA) territory, and the Modified Life Event Scale (MLES) score was borderline for statistical significance. Multivariate logistic regression analysis suggested that female gender, a high MLES score, and subcortical and ACA lesions were independent risk factors for PSD and that a high LSNS score was a protective factor. (J Geriatr Psychiatry Neurol 2005; 18:45-51)

Socioeconomic burden of psoriatic arthritis in Hong Kong: direct and indirect costs and the influence of disease pattern.

Objective. To estimate the direct costs and indirect costs of patients with psoriatic arthritis (PsA) in Hong Kong. Methods. A retrospective cost-of-illness study was performed on 125 patients with PsA. Participants completed questionnaires on demographics, employment status, and out of pocket expenses. Health resources consumption was recorded by chart review and patient self-report questionnaire. Patients were grouped according to disease pattern, i.e., peripheral and axial disease. Multiple regression was used to determine the predictors of the costs. Results. The average annual direct costs were

Imaging of cystic or cyst-like neck masses.

4,141 (2006 US dollars) per patient. Costs of inpatient care accounted for 27% of direct costs, followed by costs of visits to healthcare providers (25%). The estimated average indirect costs were

Frequency and determinants of prestroke dementia in a Chinese cohort

3,127 per patient-year. Forty-eight (42%) patients had no indirect costs. Sixty percent of patients with peripheral disease were still employed, compared to 39% of patients with axial disease. Patients with axial disease had almost twice the indirect costs compared to those with peripheral disease (p = 0.005). Increased pain and poor function were independently associated with increased direct costs. Worse physical health status, determined by indirect costs borne by the patient, and poor function and old age predicted high costs. Conclusion. PsA imposes substantial economic burden. Pain and function are significantly associated with costs. Improvements in treatments to reduce pain and restore function are likely to reduce the costs incurred by these patients.

Frequency and clinical determinants of poststroke cognitive impairment in nondemented stroke patients.

Cystic or cyst-like neck masses form a unique category within head and neck radiology with unique differential diagnoses. The precise anatomical location and imaging appearances are important for accurate diagnosis and formulating the differential diagnoses of cystic lesions in the neck. In vast majority of cases ultrasound, sometimes supplemented by fine-needle aspiration cytology (FNAC), is adequate for pre-treatment assessment. For large, deep-seated lesions assessment using magnetic resonance imaging (MRI) or computed tomography (CT) often provides useful supplementary information. Radiologists should be aware of imaging findings of common cystic neck masses to help in their appropriate management.