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Biomedical subjects

C Metreweli

Publications and source records attributed to C Metreweli.

At least 163 records · Page 9Linked to original sources

A practical approach to ultrasound of cervical lymph nodes.

Although the role of high resolution ultrasound (US) in evaluating cervical nodes is well established, it is often combined with fine needle aspiration cytology (FNAC). As a result, US appearances that help in distinguishing the various causes of cervical adenopathy are often overlooked and not emphasized. The aim of this study is to re-emphasize to the sonologist the US clues that may help in differentiating the aetiology of abnormal cervical nodes. We, therefore, present the spectrum of US appearances of lymph nodes. One hundred and forty patients (702 abnormal nodes) with known pathology were compared with 100 normal subjects (1211 nodes). After identifying an abnormal nodes, US features that further help in distinguishing between the various pathologies are the distribution of lymphadenopathy, echogenicity, calcification, distal enhancement, intranodal cystic necrosis, matting and soft tissue oedema.

Adolescent↗

Sonographic evaluation of hip effusion in children. Improved visualization with the hip in extension and abduction.

PURPOSE: To assess the difference in the sonographic appearance of hip effusions when the hip was placed in the extended and abducted position as compared to a neutral position. MATERIAL AND METHODS: Twenty-one consecutive children (aged 2-14 years) with hip pain or limping were examined for hip effusions by means of ultrasound. The capsule-femoral-neck distance, the presence of joint fluid, and the shape of the anterior capsule were compared in hips in slight extension and abduction with those in hips in a neutral position. RESULTS: Of the 11 positive hip effusions, the maximal distance between the capsule and femoral neck was significantly larger (p < 0.005) in the extended and abducted hip position than in the neutral hip position, with a mean difference of 1.6 mm. Convex bulging of the anterior capsule was more confidently diagnosed in 3 hip effusions in the extended and abducted hip, and better visualization of fluid between the capsule and femoral neck was achieved in 4 joint in this posture. CONCLUSION: The study demonstrated an improvement in the sonographic detection of hip effusion in the extended and abducted position compared to the neutral position.

Adolescent↗

Plain radiography and computed tomography of invasive thymomas: clinico-radiologic-pathologic correlation.

Fifteen computed tomography (CT) scans in nine patients with invasive thymoma are presented. The CT findings were an anterior mediastinal mass (89%), pleural deposits (78%), local infiltration of the mediastinum (100]), invasion of the cardiovascular structures (22%), lung invasion (11%) and diaphragmatic or subdiaphragmatic deposits (33%). Radiologic-pathologic correlation available in six patients showed a sensitivity of 89.5%, specificity of 87.5% and accuracy of 88.6% for CT. We conclude that CT is superior to plain radiography in the diagnosis of invasive thymoma. It provides an accurate pre-operative assessment by better demonstration of the full extent of abnormalities, and is useful in surgical planning, monitoring of therapeutic response and detecting recurrence.

Adult↗

The role of ultrasound in the diagnosis of a large, rapidly growing, thyroid mass.

The value of ultrasound in the diagnosis of a large rapidly growing thyroid mass was assessed in a study of 42 patients with a large (> 3 cm) rapidly growing (< two months) solitary mass. Haemorrhage into a thyroid nodule was present in 31 patients and thyroid malignancy in 11. Ultrasound of haemorrhage into a thyroid nodule revealed a large cystic mass in all 31 patients containing internal debris (22), septations (three), or a combination of both (six). The malignant causes of a large rapidly growing mass were lymphoma (two), anaplastic carcinoma (four) and metastasis (five). Ultrasound of these thyroid malignancies revealed a mass with a smooth, well-defined margin and strikingly low homogeneous echogenicity in all cases. Patients with thyroid metastases had evidence of widespread metastatic disease elsewhere. Lymphoma was differentiated from anaplastic carcinoma on fine-needle aspiration cytology or surgical biopsy. Ultrasound was of value in differentiating between a benign haemorrhagic nodule and a malignant tumour. The various malignant tumours had similar appearances, however, and could not be distinguished on ultrasound.

Adult↗

Uncommon features of abdominal aortoiliac disease.

This pictorial review illustrates the cross-sectional imaging of several less common manifestations of aortoiliac disease. Despite their varying clinical features, the imaging appearances with ultrasound, CT and MRI will allow a correct assessment in most cases.

Adult↗

In vivo demonstration of microcalcification in breast cancer using high resolution ultrasound.

84 patients with 89 primary breast cancers underwent high resolution ultrasound, mammography and histological evaluation. Pathological specimens and hard copy images of both imaging modalities were reviewed in order to document the amount of microcalcification present in each tumour. A total of 44, 40 and 46 tumours had visible microcalcification using high resolution ultrasound, mammography and histology, respectively. Using mammography as the gold standard, ultrasound achieved a sensitivity of 95%, specificity of 87.8% and accuracy of 91% in the detection of microcalcification. Histology had a sensitivity of 80%, specificity of 71.4% and accuracy of 75.3%. We conclude that ultrasound is sensitive in the detection of microcalcification in breast cancer when they are within a mass lesion, and is a reliable diagnostic sign of carcinoma when present.

Adult↗

Ultrasound assessment of swallowing in malnourished disabled children.

Oral motor dysfunction is common in children with neurological impairment. Nutritional advice depends upon an accurate assessment of feeding potential in these cases. Videofluoroscopic assessment of oral motor function has been the accepted "gold standard" investigation for several years but has significant drawbacks, including the time constraints set by the use of ionizing radiation and the problems posed by the cumbersome equipment needed in mimicking the child's normal feeding situation. Ultrasonography (US) has been suggested as an alternative or additional investigation of oral motor function in children with neurological impairment. We prospectively evaluated a scoring system derived from US assessment of oral motor function in 32 malnourished disabled children with feeding problems by comparing them with a group of matched control children without neurological impairment. US imaging provided useful information with regard to the oral cavity and the soft tissue structures, capturing the salient features of tongue/hyoid/palate activity and bolus transport across the tongue and through the hypopharyngeal area. The mean percentage score obtained by US assessment of oral motor function in children with neurological impairment was 54.3 +/- 23.2 and from children without neurological impairment 91.9 +/- 12.7 (p < 0.0001). Scores for the oral and pharyngeal phases of swallowing were also very significantly lower than that in the control group, both phases being equally impaired in the disabled children. This study has demonstrated that a scoring system based on US assessment of different components of oral motor activity detects statistically significant differences in the feeding capabilities of children with neurological impairment.

Adolescent↗

Comparison of T2 weighted fat suppressed turbo spin echo and contrast enhanced T1 weighted spin echo MRI in nasopharyngeal carcinoma.

Fat suppressed T2 weighted fast imaging sequences have recently been favoured in MRI of head and neck tumours. The purpose of this study was to evaluate the use of T2 weighted fat suppressed turbo spin echo (T2W SPIR) and compare it with our standard technique, the gadolinium-enhanced T1 weighted spin echo (Gd-T1W SE). The MR images of 36 patients with nasopharyngeal carcinoma were analysed for local tumour extent. T2W SPIR was better in evaluating tumour extension into the clivus and fascia. In all other regions Gd-T1W SE was either better (nasopharyngeal walls, small parapharyngeal muscles, parapharyngeal fat space, paranasal sinuses, pterygomaxillary fissure and pterygoid process) or equal (nasal cavity, oropharynx, cranial fossa and cavernous sinus) to T2W SPIR. T2W SPIR was unable to replace Gd-T1W SE in evaluation of tumour extent because of loss of signal from magnetic susceptibility artefact, poor delineation of anatomical detail and reduced tumour conspicuity. The use of T2W SPIR as an additional sequence may be warranted in selected cases but cannot replace Gd-T1W SE.

Adult↗

Sonography of peripheral nerve tumors of the neck.

OBJECTIVE: Peripheral nerve tumors (PNTs) of the neck are uncommon and are frequently mistaken for lymph nodes. The purpose of this study is to describe the sonographic appearance of PNTs in the neck and determine features useful in differentiating PNTs from lymph nodes. CONCLUSION: PNTs of the neck have features that should alert the sonographer to the correct diagnosis. Features of value in differentiating PNTs from lymph nodes include a solitary, oval, hypoechoic mass with posterior enhancement and absence of an echogenic hilum. These features should lead to a careful search for the associated nerve to confirm the diagnosis. In addition, schwannomas have a vascular pattern indicating marked hypervascularity that can be obliterated with light pressure from the probe.

Adolescent↗

Visceral fat and cardiovascular risk factors in Chinese NIDDM patients.

OBJECTIVE: The interrelations between obesity, glucose intolerance, hypertension, dyslipidemia, and insulin resistance are well recognized. These relationships are of particular interest in Hong Kong's Chinese population, in whom increasing affluence has coincided with a marked increase in the prevalence of NIDDM. We designed a pilot study to examine the relationships between visceral fat and cardiovascular risk factors in Chinese NIDDM patients. RESEARCH DESIGN AND METHODS: We studied 21 Chinese NIDDM patients whose visceral fat was quantified by magnetic resonance imaging. Cardiovascular risk factors including plasma lipids and 24-h ambulatory blood pressure (BP) were measured. In addition, insulin resistance was determined by a short insulin tolerance test (SITT). RESULTS: Increased visceral adiposity was significantly correlated with plasma triglycerides (r = 0.63, P = 0.004), the total cholesterol/HDL cholesterol ratio (r = 0.61, P = 0.008), the urinary albumin/creatinine ratio (r = 0.49, P = 0.04), and decreased insulin sensitivity as measured by the SITT (r = 0.47, P = 0.03). When the data were analyzed by tertiles, increasing visceral fat area was associated with higher plasma triglycerides, lower HDL cholesterol, and a smaller plasma glucose decrement during the SITT. In addition, the diurnal rhythm in BP and heart rate tended to be best preserved in those with the least visceral obesity. CONCLUSIONS: This pilot study demonstrates that visceral fat accumulation is associated with dyslipidemia, hypertension, insulin resistance, and albuminuria in Chinese patients with NIDDM.

Adipose Tissue↗

Sonographic features of head and neck hemangiomas and vascular malformations: review of 23 patients.

The sonographic features of 23 head and neck hemangiomas and vascular malformations are presented. A focal mass lesion was seen in all patients. The predominant sonographic features were a well-defined hypoechoic mass lesion with heterogeneous echotexture and the presence of cystic and sinusoidal spaces within, as well as the occasional presence of phleboliths. Color Doppler imaging demonstrated flow in 12 of 13 lesions. When performing sonography on soft tissue masses in the head and neck, the presence of color Doppler signal in a well-defined hypoechoic mass with heterogeneous echotexture should raise the possibility of an hemangioma.

Adolescent↗

Sonographic, magnetic resonance imaging, and mammographic assessments of preoperative size of breast cancer.

High resolution sonographic (39 cases), magnetic resonance imaging (32 cases), and mammographic (35 cases) measurements of preoperative size of breast cancer were correlated with the pathologic size in 39 patients with breast carcinoma to determine the most accurate imaging technique for breast cancer size. There were nine T1, 21 T2, four T3, and four T4 tumors. Sonographic and magnetic resonance imaging measurements of tumor size demonstrated correlation coefficients of 0.92 and 0.93, respectively, both of which were superior to that of mammography (0.84). Sonographic tumor size evaluation thus is shown to be equivalent to magnetic resonance imaging in this study. Three of nine (33%), four of seven (57%), and four of eight (50%) T1 tumors would have been overstaged by ultrasonography, magnetic resonance imaging, and mammography, respectively. Three of 21 (14.3%), one of 16 (6.3%), and two of 18 (11.1%) T2 tumors would have been understaged by ultrasonography, magnetic resonance imaging, and mammography, respectively. We therefore found ultrasonography to be of value in the diagnosis and staging of breast cancer.

Aged↗

Sonographic features of benign papillary neoplasms of the breast: review of 22 patients.

The sonographic features of 22 patients with histologically benign intraductal papillomas are presented, with clinical, mammographic, galactographic, and histopathologic correlation. The most common presenting feature in this series is a palpable central breast mass in an elderly woman. Sonography was abnormal in all 22 patients. The typical sonographic features include a well-defined, smooth-walled, solid, hypoechoic nodule or a lobulated, smooth-walled, cystic lesion with solid components. Dilated ducts are a common feature, often with visible solid intraluminal echoes. These findings suggest the diagnosis of an intraductal papilloma. The differential diagnosis includes fibroadenoma and phyllodes tumor (for large solid lesions) and intracystic carcinoma (for complex cystic lesions). Mammograms are frequently normal (36% of patients). When abnormal, the mammographic features are of a smooth-walled, well-defined mass or increased retroareolar opacity. Contrary to the reported literature, calcification was seen infrequently. We conclude that ultrasonography is useful in the detection and delineation of intraductal papillomas.

Adolescent↗

Normal splenic size in a Chinese population.

To establish the normal range for the length of the spleen in the Hong Kong Chinese population we used ultrasonography to examine 783 patients not known to have any condition likely to be associated with splenic enlargement. The results show a rapid growth in splenic length up to age 20 years, followed by a mild decrease. A statistically significant difference is seen between male and female subjects from about 15 to 40 years with spleens of men being about 0.5 cm longer. Using 2 standard deviations above the mean as a guide, we recommend 12 cm as the upper limit of normal in this population.

Adolescent↗