Biomedical subjects

A T Ahuja

Publications and source records attributed to A T Ahuja.

At least 19 recordsLinked to original sources

PubMed2007

Features discriminating SARS from other severe viral respiratory tract infections.

This study investigated the discriminatory features of severe acute respiratory syndrome (SARS) and severe non-SARS community-acquired viral respiratory infection (requiring hospitalization) in an emergency department in Hong Kong. In a case-control study, clinical, laboratory and radiological data from 322 patients with laboratory-confirmed SARS from the 2003 SARS outbreak were compared with the data of 253 non-SARS adult patients with confirmed viral respiratory tract infection from 2004 in order to identify discriminatory features. Among the non-SARS patients, 235 (93%) were diagnosed as having influenza infections (primarily H3N2 subtype) and 77 (30%) had radiological evidence of pneumonia. In the early phase of the illness and after adjusting for baseline characteristics, SARS patients were less likely to have lower respiratory symptoms (e.g. sputum production, shortness of breath, chest pain) and more likely to have myalgia (p < 0.001). SARS patients had lower mean leukocyte and neutrophil counts (p < 0.0001) and more commonly had "ground-glass" radiological changes with no pleural effusion. Despite having a younger average age, SARS patients had a more aggressive respiratory course requiring admission to the ICU and a higher mortality rate. The area under the receiver operator characteristic curve for predicting SARS when all variables were considered was 0.983. Using a cutoff score of >99, the sensitivity was 89.1% (95%CI 82.0-94.0) and the specificity was 98.0% (95%CI 95.4-99.3). The area under the receiver operator characteristic curve for predicting SARS when all variables except radiological change were considered was 0.933. Using a cutoff score of >8, the sensitivity was 80.7% (95%CI 72.4-87.3) and the specificity was 94.5% (95%CI 90.9-96.9). Certain clinical manifestations and laboratory changes may help to distinguish SARS from other influenza-like illnesses. Scoring systems may help identify patients who should receive more specific tests for influenza or SARS.

Adolescent↗

PubMed2006

Biopsy of deep-seated head and neck lesions under intraoral ultrasound guidance.

Although transcutaneous ultrasound combined with fine-needle aspiration is often used as initial modality for evaluating superficial neck masses, its role in management of deep-seated neck masses is limited. Intraoral ultrasound and guided biopsy helps in obtaining tissue from deep-seated neck masses for an accurate histologic diagnosis, providing useful information in treatment planning. This article discusses the role of intraoral ultrasound and presents 3 cases in which biopsy of deep-seated neck masses under intraoral ultrasound guidance helped in diagnosis and management.

Adenoma, Pleomorphic↗

PubMed2005

Determinants of prestroke cognitive impairment in stroke associated with small vessel disease.

Understanding the determinants of prestroke cognitive impairment (PCI) in stroke associated with small vessel disease (SVD) may shed light on how to prevent further cognitive deterioration after stroke. We administered the Informant Questionnaire on Cognitive Decline (IQCODE) to close informants of 78 consecutive stroke patients who had SVD. PCI, as defined by an average score of IQCODE > or =3.4 was found in 19 (24%) patients. Regression analyses were performed on the following risk factors for PCI: age, years of education, gender, previous stroke, volume of white matter changes, measures of silent lacunes, cerebral atrophy index, medial temporal lobe atrophy and frontal lobe atrophy. Multivariate regression analyses revealed that only cerebral atrophy index (OR 1.5, CI 1.2-1.9, p < 0.001) predicted PCI among patients with SVD.

Aged↗

PubMed2005

Computed tomography for cervical spine trauma. The impact of MDCT on fracture detection and dose deposition.

A multidetector computed tomography (MDCT) was installed in our department. Referral rates, examination protocols and detection rates of abnormal findings in CT examinations for cervical spine trauma 6 months before and 6 months after MDCT installation were compared to look for changes in practice. Retrospective analysis of all CT cervical spine examinations in patients with multiple trauma over two contiguous 6-month periods: from July 2003 to December 2003 (helical CT) and from January 2004 to June 2004 (MDCT). Variables recorded were number of CT examinations performed, scan plane coverage and traumatic abnormalities detected. Phantom dosimetry measurements for cervical spine examination in both helical CT and MDCT were compared. One hundred and fifty four patients underwent cervical spine CT during these periods. Helical CT period: of 91 patients undergoing CT cervical spine examination for trauma, 65 (71%) were complete cervical examinations and 26 (29%) were level-specific examinations. Eight patients (9%) had cervical spine fracture, six of which were apparent on radiographs. Dose estimations for thyroid, lens and breast were 24.76, 1.86 and 0.21 mGy, respectively, for complete cervical spine examinations. MDCT period: of 63 patients who underwent CT cervical spine examination for trauma, 61 (97%) were complete examinations and 2 (3%) were level-specific examinations. Six patients (11%) had cervical spine fracture, three of which were apparent on radiographs. Dose estimations for thyroid, lens and breast were 75.8, 9.7 and 0.7 mGy, respectively, for complete cervical spine examinations, which were notably higher than those for helical CT. After installation of MDCT, clinical requests for complete examination of the cervical spine following trauma increased. This changing trend resulted in a significantly higher radiation dose to thyroid, lens and breast.

Accidental Falls↗

PubMed2005

Imaging for thyroglossal duct cyst: the bare essentials.

Thyroglossal duct cyst is the most common congenital cyst in the head and neck, and imaging features have been well documented in the literature. However, there are several practical important points to bear in mind during preoperative imaging, which are often overlooked. This review aims to summarize the imaging findings and emphasize important points for trainees and radiologists, particularly those who may encounter this lesion infrequently.

Adult↗

PubMed2005

Human cervical lymphadenopathy: evaluation with in vivo 1H-MRS at 1.5 T.

AIM: To evaluate the feasibility of performing in vivo proton magnetic resonance spectroscopy ((1)H-MRS) of cervical lymph nodes, and the clinical usefulness of the technique in the characterization of cervical lymphadenopathy. MATERIALS AND METHODS: Cervical lymphadenopathy was examined in 20 individuals with malignant disease, i.e. 10 with squamous cell carcinoma (SCC), 6 with undifferentiated carcinoma (UDC) and 4 with non-Hodgkin's lymphoma (NHL). Cervical lymphadenopathy was also examined in 4 individuals with benign disease, i.e. 3 with tuberculosis (TB) and 1 with Castleman's disease. A point-resolved spectroscopic sequence with echo times (TE) of 136 and 272 ms and a time-domain spectral fitting procedure were used to estimate peak amplitude of choline (Cho), creatine (Cr) and unsuppressed water. Cho/Cr and Cho/water ratios were measured for each lesion. The mean ratio for each lesion group was obtained and results were compared statistically. RESULTS: At TE of 136 ms, spectra were interpretable in all 24 cases and a Cr peak was identified with post-processing in 15 cases. The Cho/Cr and Cho/water ratios for NHL were 9.1 +/- 5.2 and 1.7 +/- 0.2 x 10(-3), for UDC were 4.4 +/- 0.9 and 1.2 +/- 0.4 x 10(-3), and for SCC were 2.1 +/- 0.6 and 0.5 +/- 0.3 x 10(-3), respectively. Both Cho/Cr and Cho/water ratios for UDC were significantly higher than SCC (p = 0.002 and 0.026, respectively). At TE of 272 ms, spectra were interpretable in 22 of 24 cases and a Cr peak was identified with post-processing in 11 cases. Cho/Cr and Cho/water ratios for NHL were 5.4 and 4.6 +/- 1.4 x 10(-3), for UDC were 4.2 +/- 1.5 and 2.6 +/- 1.0 x 10(-3) and for SCC were 2.5 +/- 1.1 and 1.3 +/- 0.6 x 10(-3), respectively. The Cho/water ratio for UDC was significantly higher than for SCC (p = 0.04). The Cho/Cr ratio for UDC was also higher than for SCC, but this difference was not statistically significant (p = 0.07). Neither Cho nor Cr was detected in the 3 cases of TB. CONCLUSION: In vivo (1)H-MRS is a feasible technique for the evaluation of cervical lymph nodes and it offers potential as a clinical tool in the investigation of cervical lymphadenopathy. However, further studies with larger patient cohorts are needed to validate the findings of this initial report.

Adult↗

PubMed2005

Impact of severe acute respiratory syndrome (SARS) on pulmonary function, functional capacity and quality of life in a cohort of survivors.

OBJECTIVE: To examine the impact of severe acute respiratory syndrome (SARS) on pulmonary function, exercise capacity, and health-related quality of life (HRQoL) among survivors. METHODS: 110 survivors with confirmed SARS were evaluated at the Prince of Wales Hospital, HK at the end of 3 and 6 months after symptom onset. The assessment included lung volumes (TLC, VC, RV, FRC), spirometry (FVC, FEV1), carbon monoxide transfer factor (TLCO adjusted for haemoglobin), inspiratory and expiratory respiratory muscle strength (Pimax and Pemax), 6 minute walk distance (6MWD), chest radiographs, and HRQoL by SF-36 questionnaire. RESULTS: There were 44 men and 66 women with a mean (SD) age of 35.6 (9.8) years and body mass index of 23.1 (4.8) kg/m2. Seventy (64%) were healthcare workers. At 6 months 33 subjects (30%) had abnormal chest radiographs; four (3.6%), eight (7.4%), and 17 (15.5%) patients had FVC, TLC, and TLCO below 80% of predicted values; and 15 (13.9%) and 24 (22.2%) had Pimax and Pemax values below 80 cm H2O, respectively. The 6MWD increased from a mean (SD) of 464 (83) m at 3 months to 502 (95) m (95% CI 22 to 54 m, p<0.001), but the results were lower than normal controls in the same age groups. There was impairment of HRQoL at 6 months. Patients who required ICU admission (n = 31) had significantly lower FVC, TLC, and TLCO than those who did not. CONCLUSION: The exercise capacity and health status of SARS survivors was considerably lower than that of a normal population at 6 months. Significant impairment in surface area for gas exchange was noted in 15.5% of survivors. The functional disability appears out of proportion to the degree of lung function impairment and may be related to additional factors such as muscle deconditioning and steroid myopathy.

Adult↗

PubMed2005

Diseases of the submandibular gland as demonstrated using high resolution ultrasound.

In this review the high resolution ultrasound appearances of the normal anatomy and pathology involving the submandibular gland are demonstrated. The submandibular gland is affected by a number of disease processes that may be difficult to distinguish clinically. Its superficial location makes it ideal for ultrasound evaluation and a useful adjunct to clinical examination. In the assessment of submandibular pathology ultrasound allows intraglandular and extraglandular lesions to be localized and differentiated. These lesions can be further characterized as being benign or malignant and the extent of any extraglandular extension determined. Ultrasound is the first-line investigation in the assessment of sialolithiasis due to its high specificity and sensitivity. In severe infective sialadenitis ultrasound can confirm the presence and guide drainage of abscesses. Ultrasound also has an important role in the assessment of chronic inflammatory disorders such as sarcoidosis and Sjogren's syndrome.

Acute Disease↗

PubMed2004

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 > or =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.

Aged↗

PubMed2004

Frequency and determinants of prestroke dementia in a Chinese cohort.

Pre-existing dementia among patients with acute stroke is common, and adversely affects outcomes. Only a few studies have been published on prestroke dementia (PSD), none of which have investigated a consecutive stroke cohort in an Asian patient population. The objective of this study was to examine the prevalence and clinical correlates of PSD in Chinese stroke patients in Hong Kong. Close and reliable informants of 289 stroke patients who were consecutively admitted to the medical wards of a university-affiliated regional hospital completed the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) within 1 week after their relative's admission. The presence of PSD was defined as an average IQCODE score of >or= 4.00. In addition, a wide range of demographic and clinical variables were examined and recorded.Twenty-two participants (7.6%) had PSD. The frequency of PSD in the group of subjects (n = 73) who were assessed within 48 hours after their admission was 12.3%. Univariate analysis found that PSD was associated with age, marital status, atrial fibrillation (AF), previous transient ischaemic attack (TIA), leukoaraiosis, and cerebral atrophy index (CAI). Multivariate logistic regression suggested that CAI, age, AF, and past TIA were independent risk factors for PSD. The low prevalence of PSD in Chinese patients in comparison with their Caucasian counterparts may be due to the difference in the time frame of the assessment. Comparative studies involving both Caucasian and Chinese stroke patients are required to further explore the role of AF and TIA in the development of PSD in both Chinese and Caucasian patients.

Adolescent↗

PubMed2004

Does Doppler analysis of musculoskeletal soft-tissue tumours help predict tumour malignancy?

AIM: To investigate whether analysing vascularity of soft-tissue tumours on ultrasound assists differentiating benign from malignant tumours. MATERIALS AND METHODS: One hundred and forty-eight vascular soft-tissue tumours in 148 patients (88 males, mean age 45.6 years) were studied. Final diagnosis was established histologically in 95 (64%) of cases. For each tumour, three-colour Doppler imaging features (vascularity, vascular density, vascular organization) and 13 pulsed Doppler (spectral analysis) parameters were assessed. Data analysis was performed to isolate optimal discriminatory criteria for differentiating benign from malignant tumours. RESULTS: Significantly more benign soft-tissue tumours had an organized vascular pattern on colour Doppler imaging. If the vascular pattern is organized, this is a good indicator of tumour benignity. However, this pattern was apparent in less then one-third of the soft-tissue tumours. Benign tumours also had significantly higher minimum end diastolic velocity (EDVmin) and lower mean ratio of resistive index (RImean) than malignant soft-tissue tumours, though considerable overlap existed between the two groups. CONCLUSION: Colour Doppler imaging analysis of soft-tissue tumours is of limited value when differentiating benign from malignant tumours. If an organized vascular pattern is present, the tumour is more likely to be benign. Flow characteristics were not specific enough to be applicable in clinical practice.

Adolescent↗

PubMed2004

Imaging for primary hyperparathyroidism--what beginners should know.

For patients with primary hyperparathyroidism surgical removal of the hyperfunctioning parathyroid gland is curative. With advances in minimally invasive surgery, accurate pre-operative localization of the hyperfunctioning parathyroid tissue is essential to aid successful surgical treatment. The onus of identifying this hyperfunctioning parathyroid tissue therefore falls on imaging techniques such as high-resolution ultrasound, radionuclide imaging, computed tomography and magnetic resonance imaging. This article is not an exhaustive review, and its main aim is to familiarize the general radiologist, trainee radiologists and clinicians with the basics of various imaging techniques and their roles in practical management of patients with primary hyperparathyroidism.

Diagnostic Imaging↗

PubMed2004

Sonographic assessment of the submandibular space.

There is a wide variety of pathological processes which may present with swelling in the submandibular space. Although the submandibular gland is the most important structure in this region, there are a number of extraglandular causes of swelling which frequently mimic submandibular gland enlargement. In this review the use of high-resolution ultrasound in the assessment of the submandibular gland and adjacent structures is discussed and illustrated.

Humans↗

PubMed2004

Computer-assisted detection as a second reader in symptomatic Asian women with palpable breast cancer.

PURPOSE: To determine the potential role of a computer-assisted detection (CAD) algorithm as a second reader for experienced and inexperienced radiologists in mammography reading in Asian women. MATERIAL AND METHODS: Two-view mammograms performed in 124 consecutive patients who presented with palpable breast cancer masses were retrospectively evaluated by two experienced breast radiologists (7 and 10 years' experience). The original reports of the session radiologists with variable experience of reading mammograms (2 to more than 10 years) were also evaluated. The number of suspicious masses and microcalcification clusters detected in each patient by both groups of radiologists were recorded. The radiologists then re-evaluated the films with the CAD system as a second reader. Any improvement in the detectability of breast pathology by either the experienced radiologists and/or by the session radiologists was then assessed. A total of 127 breasts had biopsy-proven carcinoma; 74 breasts had mastectomy performed. All the imaging results were correlated with tru-cut biopsy or mastectomy histology. RESULTS: With CAD-aided interpretation, there were altogether 95 visible masses and 77 suspicious microcalcification clusters in 109 mammographically detectable cancers correlated with histology results. There was a 7.4% (7/95) and 10.4% (8/77) increase in the number of masses and microcalcification clusters detected, respectively, by the experienced radiologists after application of CAD, whereas the increase was 13.7% (13/95) and 27.3% (21/77) for detection of masses and microcalcifications by the session radiologists, respectively. In 9 patients, a secondary focus detected by CAD was confirmed by histology. Three patients had contralateral breast tumors, 1 had a satellite invasive tumor while 5 had ductal carcinoma in situ on the same breast. Based on the biopsies and 74 mastectomies, the true-positive and false-positive detection rate of CAD was 92.6% and 31.8% for detection of carcinomas. The true-positive and false-positive detection rates were 100% and 58.8% for microcalcification clusters. CONCLUSION: The current generation CAD algorithm helped to improve the detection rate of carcinomas, calcifications and multifocality in Asian breasts.

Adult↗

PubMed2004

Severe acute respiratory syndrome: report of treatment and outcome after a major outbreak.

BACKGROUND: The outcome is reported of a prospective uncontrolled study based on a stepwise treatment protocol during an outbreak of severe acute respiratory syndrome (SARS) in Hong Kong. METHOD: One hundred and thirty eight patients were treated with broad spectrum antibiotics, a combination of ribavirin and low dose corticosteroid, and then intravenous high dose methylprednisolone according to responses. Sustained response to treatment was defined as (1) defervescence for > or =4 consecutive days, (2) resolution of lung consolidation by >25%, and (3) oxygen independence by the fourth day without fever. Patients with defervescence who achieved either criterion 2 or 3 were classified as partial responders. Patients who fell short of criteria 2 and 3 were non-responders. RESULTS: Laboratory confirmation of SARS coronavirus infection was established in 132 (95.7%). None responded to antibiotics but 25 (18.1%) responded to ribavirin + low dose corticosteroid. Methylprednisolone was used in 107 patients, of whom 95 (88.8%) responded favourably. Evidence of haemolytic anaemia was observed in 49 (36%). A high level of C-reactive protein at presentation was the only independent predictor for use of methylprednisolone (odds ratio 2.18 per 10 mg/dl increase, 95% confidence interval 1.12 to 4.25, p = 0.02). Thirty seven patients (26.8%) required admission to the intensive care unit and 21 (15.2%) required invasive mechanical ventilation. There were 15 deaths (mortality rate 10.9%), most with significant co-morbidities, whereas 122 (88.4%) had been discharged home 4 months after the outbreak onset. CONCLUSION: The use of high dose pulse methylprednisolone during the clinical course of a SARS outbreak was associated with clinical improvement, but randomised controlled trials are needed to ascertain its efficacy in this condition.

Adult↗

PubMed2004

Vascular lesions of parotid gland in adult patients: diagnosis with high-resolution ultrasound and MRI.

Three adult patients with rare vascular lesions in the parotid gland including pseudoaneurysm, arteriovenous fistula and haemangioma are discussed. All patients presented with non-specific unilateral parotid mass. In all cases high-resolution ultrasound and MRI allowed accurate diagnosis and delineation of the extent of lesion. Conventional angiogram was utilized for planning definitive surgical or endovascular treatment.

Adult↗

PubMed2004

MRI of neck nodes in non-Hodgkin's lymphoma of the head and neck.

The aim of this study is to describe the imaging features of neck nodes in non-Hodgkin's lymphoma (NHL). The MR scans of 61 patients undergoing staging of a primary extranodal NHL of the head and neck were reviewed retrospectively. Those MR images with nodal disease were assessed for (a) the pattern of nodal disease, (b) presence of nodal necrosis and (c) presence of extracapsular neoplastic spread (ENS) and nodal matting. The features of the nodal disease were analysed in relationship to the sites of the primary NHL (palatine tonsil (PT) n=23, nasal cavity (NC) n=24, nasopharynx (NP) n=6, other extralymphatic sites (OES) n=8), and histology (natural killer/T-cell (NK/T) n=26, diffuse large cell (DLC) n=24, other subtypes (OS) n=11). Nodal disease was present in 26 patients (43%) and occurred in NHL of the PT n=16 (70%), NP n=3 (50%), NC n=5 (21%) and OES n=2 (25%) and in DLC n=15 (63%), NK/T n=6 (23%) and OS n=5 (45%). Nodal disease was significantly more frequent in DLC than NK/T lymphomas (p=0.0053). Nodal disease spread in a contiguous fashion in 25 (96%) patients with nodes. Necrosis was present in 7 of 26 (27%) being present in DLC of the PT in 5, NK/T of the NP in one and NK/T of the NC in one. ENS and matting were present in 19 (73%) and 13 (50%) patients with nodes, respectively. ENS was found in DLC, NK/T, OS, NC, NP, PT, OES (11, 4, 4,1, 2, 14, 2, respectively) and matting was found in DLC, NK/T, OS, NC, NP, PT, OES (9, 3, 1, 0, 2, 10, 1, respectively). Nodal NHL spreads in a contiguous fashion and is most commonly associated with DLC lymphoma of the NP and PT in Waldeyer's ring. Extracapsular nodal spread is frequent and found in most histological subtypes especially those arising from Waldeyer's ring. Necrosis is more common than previously believed.

Adolescent↗

PubMed2004

Clinics in diagnostic imaging (101): Multinodular accessory thyroid tissue.

A 71-year-old woman with a strong family history of thyroid cancer presented with 3 months of constipation. A carcinoid tumour of the rectum was found at colonoscopy. On physical examination, she had a large goitre and there was a 3-4 cm firm submental mass. The differential diagnosis was accessory thyroid tissue or a carcinoma metastasis. Staging computed tomography was performed to include the neck, followed by ultrasonography and aspiration biopsy of the submental mass, which confirmed the diagnosis of multinodular accessory thyroid tissue. Differences in aetiology and pathophysiology of accessory thyroid tissue and ectopic thyroid glands are discussed.

Aged↗