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Biomedical subjects

W T Yang

Publications and source records attributed to W T Yang.

At least 55 records · Page 3Linked to original sources
PubMed1997

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1996

Detection of axillary lymph node metastases in breast carcinoma by technetium-99m sestamibi breast scintigraphy, ultrasound and conventional mammography.

Axillary lymph node status is important in the staging of breast carcinoma. To evaluate the accuracy of technetium-99m sestamibi breast scintigraphy in detecting metastatic axillary lymph nodes as compared with other accepted imaging modalities, we performed 99mTc-sestamibi breast scintigraphy, conventional mammography and ultrasound in 36 patients with primary untreated breast carcinoma. With histopathology as the gold standard, 99mTc-sestamibi breast scintigraphy was found to yield true-positive results in 7 of 11 cases (64%) of axillary lymph node metastases and true-negative results in 18 of 20 cases (90%); it has an accuracy of 81%, a positive predictive value of 77.8% and a negative predictive value of 81.8%.

Axilla↗
PubMed1996

Paraffinomas of the breast: mammographic, ultrasonographic and radiographic appearances with clinical and histopathological correlation.

Paraffinomas are uncommon lesions occasionally encountered in the breast. The clinical and radiological (mammographic, ultrasound and plain film) features are presented in five patients with breast paraffinomas, one of whom had synchronous infiltrative ductal carcinoma. Histopathological correlation was available in two patients. Women with a history of paraffin injections into the breast may present decades later with hard, nodular breast masses simulating breast cancer. Dense fibrosis particularly in the retroglandular midbreast region causing streaky opacities and bizarre architectural distortion on mammography suggests the diagnosis. Flocculent, amorphous, ring or rounded calcifications may also be present within the breast and axilla. Migration of liquid paraffin through the tissue planes can result in diffuse conglomerate calcification in the chest and abdominal walls.

Aged↗
PubMed1996

The use of sonography in differentiating cervical lymphomatous lymph nodes from cervical metastatic lymph nodes.

Lymphoma and metastases are common causes of cervical lymphadenopathy. Clinical examination alone is unable to differentiate the two. Ultrasound (US) with its high sensitivity and specificity when combined with a find needle aspiration cytology (FNAC) is therefore the ideal initial investigation. We present the spectrum of findings in 19 patients with non Hodgkins lymphoma (NHL), 15 patients with pharyngeal, laryngeal and oesophageal (PLO) carcinomas, 22 patients with oral cavity tumours and 12 patients with infraclavicular carcinomas. The US features found consistently useful in differentiating NHL from other metastases were the distribution of the nodes, distal enhancement and lack of intranodal necrosis. Other US features of abnormal nodes helped identify abnormality but did not help in differentiation.

Adolescent↗
PubMed1996

Transrectal ultrasound in the evaluation of cervical carcinoma and comparison with spiral computed tomography and magnetic resonance imaging.

38 women with biopsy proven untreated cervical carcinoma were prospectively studied with transrectal ultrasound (TRUS), spiral computed tomography (SCT) and magnetic resonance imaging (MRI). 20 women had radical hysterectomy and pelvic lymphadenectomy with detailed histological evaluation of the parametra. The echographic features of cervical carcinoma on TRUS are a hypoechoic (60%) or isoechoic (40%) (relative to normal uterine muscle/cervical stroma), poorly defined mass lesion with indistinct margins in an enlarged cervix. This relatively high percentage of isoechoic tumours and relative lack of contrast resolution may pose a problem in the identification of some tumours, and to our knowledge has not been previously reported. Further limitations of TRUS are in the evaluation of advanced cervical cancer, due to bulky tumours rendering poor access to the parametrium and pelvic sidewall. The overall accuracy in staging of early cervical cancer (less than stage 2b) was 85% for examination under anaesthesia (EUA), 75% for TRUS, 65% for MRI and 50% for SCT. The positive predictive value in evaluating the parametra in this group of patients was also lower for SCT (14%) and MRI (33%) compared with TRUS (100%). In the evaluation of advanced cervical cancer (stage 2b or higher), there was poor correlation between TRUS and EUA, with MRI showing the best correlation with EUA. We conclude that SCT is inferior to both TRUS and MRI in the staging of early stage cervical cancer.

Adult↗
PubMed1996

Role of MIBI breast scintigraphy in evaluation of palpable breast lesions.

The sensitivity and specificity of MIBI breast scintigraphy, conventional mammography and ultrasound in differentiating malignant and benign palpable breast lesions was compared in 48 women. MIBI breast scintigraphy had a sensitivity of 97% a specificity of 69%, a positive predictive value of 87.5% and a negative predictive value of 91.7%. Ultrasound and mammography had comparable results with accuracy rates of approximately 93%. We conclude that MIBI breast scintigraphy may have a complementary role in the evaluation of palpable breast lesions, but is not specific enough to replace current imaging modalities.

Adult↗
PubMed1996

Assessment of factors affecting palpability of breast masses using ultrasonography in Chinese women.

Five hundred and twenty-nine women with self-discovered or clinically palpable breast lumps had physical examination followed by high-resolution ultrasonographic examination of the breast. A total of 482 palpable and 146 nonpalpable masses were discovered by ultrasonography. The median values of the breast stromal, premammary, and retromammary fat thickness measurements were 1.3 cm, 0.1 cm, and 0.1 cm, respectively. The median depths of the lesions and the distance of the lesions from the pectoralis muscle were 0.5 cm and 0.2 cm, respectively. The median size of all breast masses was 1.5 cm. These measurements (of the tissue characteristics of the breast, location of the breast mass, and size of the breast lesion) were correlated with palpability or nonpalpability of the breast lesions. Multivariate logistic regression performed for all breast masses showed the only significant factors affecting palpability to be the size (anteroposterior and transverse diameters) and the depth of a breast mass. This is expressed by the following equation: [formula: see text] where z = -0.8759 + 0.9691 (g) + 2.2770 (e)-1.5332 (d), and d represents depth of lesion from the cutaneous surface and e and g represent anteroposterior and transverse diameters of the breast mass, respectively. The nature of the breast tissue (i.e., the premammary fat, retromammary fat, or breast stromal thickness as determined by ultrasonography) does not affect palpability. This study would therefore strongly support the recommendation of breast self-examination, irrespective of breast structure.

Breast Neoplasms↗
PubMed1996

High resolution sonographic detection of axillary lymph node metastases in breast cancer.

Axillary lymph node status is crucial in the evaluation of prognosis and in treatment planning of breast cancer. High-resolution real-time sonographic scans of the breast and both axillae were performed on 114 patients with breast carcinoma, all of whom had axillary lymph node dissection and histologic assessment. The sensitivity of high-resolution ultrasonography in the detection of axillary nodal metastases was 84.1%, with a specificity of 97.1%, accuracy of 92.1%, positive predictive value of 94.9%, and negative predictive value 90.7%. Ultrasonography of the axilla provides good information on anatomy and pathology and may have a potential role in the prognostic work-up of patients who are not surgical candidates.

Adult↗
PubMed1996

Role of high frequency ultrasonography in the evaluation of palpable breast masses in Chinese women: alternative to mammography?

We prospectively assessed the accuracy of high resolution breast ultrasonography in the diagnosis of palpable breast masses in comparison to clinical palpation and x-ray mammography. Four hundred and eight Chinese women with palpable breast lumps had clinical assessment followed by ultrasonography of the breast, mammography (for women over 35 years), and fine needle aspiration cytology. Excisional biopsy or surgery was performed for suggestive lesions. The clinical, mammographic and ultrasound diagnoses were compared with the final pathologic diagnosis. In the determination of whether a lesion was malignant, the sensitivity, specificity, and positive predictive values were 97%, 97%, and 85%, respectively, for ultrasonography; 92%, 94%, and 84%, respectively, for mammography; and 88%, 92%, and 67%, respectively, for clinical evaluation. The specificity for combined clinical palpation and ultrasonography was higher (99%) than that for combined clinical palpation and mammography (96%). Addition of ultrasonography to combined clinical palpation and mammography increased specificity. Mammography in addition to combined clinical palpation and ultrasonography did not significantly improve the sensitivity, specificity, or positive predictive value. This limited usefulness raises the question as to whether it should be eliminated in the workup of a palpable mass in the average Chinese patient. Its main advantage is the detection of extended foci of carcinoma in situ related to a palpable mass, which often is undetected by ultrasonography.

Adult↗
PubMed1996

Clinics in diagnostic imaging (11). Ductal carcinoma of the breast.

A 39-year-old Chinese woman presented with a palpable breast lump which was increasing in size. No overlying skin change or axillary lymph nodes were palpable. Mammograms and ultrasound showed a malignant left breast lesion, suspicious of ductal carcinoma. Following excision biopsy which confirmed infiltrative ductal carcinoma, a left modified radical mastectomy was performed. The role of mammographic screening is discussed. Diagnostic mammography in conjunction with ultrasound is emphasised.

Adult↗
PubMed1996

Clinics in diagnostic imaging (20). Masseter muscle haemangioma.

A 13-year-old Chinese girl presented with a hard mass over the angle of the left jaw. No overlying skin change was evident and no cervical lymph nodes were palpable. Ultrasound showed dense calcific foci within the left masseter muscle, suspicious of phleboliths. This was confirmed on plain radiography. A 99mTc red cell scintigram showed an haemangioma. The patient was treated conservatively in view of these findings. The multimodality approach to imaging of lesions in the angle of the jaw using radiography, sialography, ultrasound, ultrasound guided fine-needle aspiration and computed tomography is discussed.

Adolescent↗
PubMed1995

Case report: neonatal adrenal haemorrhage presenting as an acute right scrotal swelling (haematoma)--value of ultrasound.

Acute scrotal swelling resulting from remote intra-abdominal pathology is a well recognized but rare entity. The present report relates to such a case in a neonate who presented with an acute right scrotal haematoma, adrenal haemorrhage not being suspected clinically, but detected ultrasonographically. In the imaging of neonatal scrotal swellings, abdominal ultrasound is important in excluding a primary intra-abdominal event.

Adrenal Gland Diseases↗