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Chui-Mei Tiu

Publications and source records attributed to Chui-Mei Tiu.

34 records · Page 2Linked to original sources
PubMed2003

Breast lesions on sonograms: computer-aided diagnosis with nearly setting-independent features and artificial neural networks.

PURPOSE: To develop a computer-aided diagnosis (CAD) algorithm with setting-independent features and artificial neural networks to differentiate benign from malignant breast lesions. MATERIALS AND METHODS: Two sets of breast sonograms were evaluated. The first set contained 160 lesions and was stored directly on the magnetic optic disks from the ultrasonographic (US) system. Four different boundaries were delineated by four persons for each lesion in the first set. The second set comprised 111 lesions that were extracted from the hard-copy images. Seven morphologic features were used, five of which were newly developed. A multilayer feed-forward neural network was used as the classifier. Reliability, extendability, and robustness of the proposed CAD algorithm were evaluated. Results with the proposed algorithm were compared with those with two previous CAD algorithms. All performance comparisons were based on paired-samples t tests. RESULTS: The area under the receiver operating characteristic curve (A(z)) was 0.952 +/- 0.014 for the first set, 0.982 +/- 0.004 for the first set as the training set and the second set as the prediction set, 0.954 +/- 0.016 for the second set as the training set and the first set as the prediction set, and 0.950 +/- 0.005 for all 271 lesions. At the 5% significance level, the performance of the proposed CAD algorithm was shown to be extendible from one set of US images to the other set and robust for both small and large sample sizes. Moreover, the proposed CAD algorithm was shown to outperform the two previous CAD algorithms in terms of the A(z) value. CONCLUSION: The proposed CAD algorithm could effectively and reliably differentiate benign and malignant lesions. The proposed morphologic features were nearly setting independent and could tolerate reasonable variation in boundary delineation.

Adolescent↗
PubMed2003

Duplex Doppler ultrasound of hepatic Schistosomiasis japonica: a study of 47 patients.

This study describes the ultrasound (US) appearances of the liver with hepatic schistosomiasis japonica (HSJ), and studies the portal hemodynamics in 47 patients with HSJ using duplex Doppler US over a period of 15 years. All patients but two were Chinese war veterans seen in Taiwan about 35-55 years after their presumed infection in Mainland China. The US presentations were reviewed. The data from Doppler portal flow studies were available for 39 patients with HSJ, and compared to data from Doppler portal flow studies in 40 normal healthy volunteers and to this data in 40 patients with postnecrotic cirrhosis. A typical "coarse reticular pattern" due to fibrosis in the whole liver was noted in 40 patients (85%). Other findings included periportal fibrosis (15%), septum-like fibrous bands extending to the liver capsule (32%), and an apparent nodular liver surface (19%). Splenomegaly was noted in seven patients. While coexisting hepatocellular carcinomas (HCC) were evident in three patients, and esophageal varices were found in three others, yet both conditions were found only in patients with positive hepatitis-B-surface antigen (HBsAg). Doppler flowmetry of the portal veins in HSJ patients showed a mean flow rate of 15.34 +/- 6.82 cm/sec, and a mean flow volume of 993.21 +/- 290.63 ml/min, both showed no significant difference from those in normal adults (p > 0.5). HSJ can be confidently diagnosed in patients with hepatic fibrosis when the hepatic pathology is presented as a coarse reticular pattern. The portal hemodynamics in HSJ patients who have been isolated from the infection site (for more than 35 years) are significantly different from portal hemodynamics in cirrhotic patients and are similar to those in healthy volunteers.

Aged↗
PubMed2003

Hypertrophic pulmonary osteoarthropathy associated with disease progression in renal cell carcinoma.

Hypertrophic osteoarthropathy (HOA) is a paraneoplastic syndrome characterized by periosteal formation and arthritis and usually accompanied by clubbing ofthe digits. Many malignancies have been associated with HOA/clubbing, most being lung cancer and lung metastatic cancer. We herein present a 53-year-old man with lung metastasis from renal cell carcinoma (RCC). HOA occurred one year after the metastasis. Reviewing the literature, only five cases of RCC with HOA have been reported. If their clinical history was traceable, they consistently had disease progression. We reviewed the pathogenesis of HOA/clubbing and linked the prognosis of RCC to relevant cytokines. Therefore, HOA not only heralds a progression of disease but suggests a probable therapeutic choice by targeting some cytokines.

Carcinoma, Renal Cell↗
PubMed2002

Solitary metastasis from renal cell carcinoma presenting as diffuse pancreatic enlargement.

Late metastasis of renal cell carcinoma (RCC) to the pancreas is uncommon. Diffuse pancreatic metastasis of any carcinoma rarely causes global enlargement of the pancreas. We present the case of a 73-year-old man diagnosed with metastatic RCC of the pancreas 9 years after radical nephrectomy had been performed and describe our radiologic findings. The disease involved the entire pancreas, which was hypoechoic on sonography, hypodense on CT without contrast enhancement, and markedly hyperdense after intravenous administration of a contrast agent. Color Doppler sonography showed that the involved areas of the pancreas had increased color flow signals, indicating that the metastatic tumor was characteristically hypervascular. In patients with a history of RCC, color or power Doppler sonographic demonstration of diffuse enlargement of the pancreas with evidence of hypervascularity may indicate metastasis of RCC to the pancreas.

Aged↗
PubMed2002

Colonic diverticulitis diagnosed by computed tomography in the ED.

The purpose of this study is to evaluate the application of computed tomography (CT) in the diagnosis of colonic diverticulitis in the emergency department (ED). Clinical information and CT images of 38 proved cases of colonic diverticulitis were reviewed retrospectively. The most common CT findings were pericolic fat infiltration (100%), thickened fascia (78.9%), muscular hypertrophy (26.3%), and arrowhead sign (23.7%). The CT findings were correlated with clinical prognosis and 3 parameters were found to be indicators for poor prognosis: older age, abscess formation, and presence of free air. The patients with diverticulitis on right side colon were found to be younger in age and the lesions were shorter in involved length with higher incidence of muscular hypertrophy and less incidence of perforation, as compared with the left side group.

Adult↗
PubMed2002

Boerhaave syndrome with atypical clinical presentations diagnosed by computed tomography.

Spontaneous rupture of esophagus (Boerhaave syndrome) is a life-threatening emergency requiring immediate surgical management. The diagnosis is often delayed and results in high mortality and morbidity. Typical clinical presentations are postprandial vomiting and subsequent chest or back pain, which alert the clinicians to take chest film and esophagogram for diagnosis. We presented a case of Boerhaave syndrome with atypical presentation mimicking dissecting aortic aneurysm, which was diagnosed by computed tomography.

Aged↗
PubMed2002

Mycotic aneurysm of thoracic aorta with aortoesophageal fistula mimicking the esophageal tumor with bleeding--a case report.

An aortoesophageal fistula is a rare but fatal disease, most commonly associated with thoracic aortic aneurysm. Early diagnosis and emergency surgical intervention are mandatory for survival. We reported a case of mycotic aneurysm of thoracic aorta with aortoesophageal fistula, presenting with intermittent hematemesis, tarry stool and sepsis. Initially, misdiagnosis of esophageal submucosal tumor with bleeding was made clinically and endoscopically. With contrast-enhanced spiral computed tomography (CT) scan the diagnosis was confirmed. The pathogenesis, clinical presentation, endoscopic feature and imaging findings were reviewed.

Aged↗
PubMedDate not supplied

Epiploic appendagitis of the rectosigmoid junction: demonstration with transrectal sonography.

A 24-year-old man presented with lower abdominal pain that had been present for 18 hours. Physical examination revealed mild tenderness in the lower abdomen. Digital rectal examination revealed a tender point approximately 9 cm above the anal verge. Transrectal sonographic examination demonstrated an ovoid echogenic noncompressible mass surrounded by a hypoechoic halo attached to the wall of the rectosigmoid junction. A diagnosis of epiploic appendagitis was made on the basis of sonographic findings and was subsequently confirmed with contrast-enhanced CT.

Abdominal Pain↗
PubMedDate not supplied

Gray-scale and color Doppler ultrasonographic manifestations of papillary thyroid carcinoma: analysis of 51 cases.

UNLABELLED: The purpose of this study is to assess the specific ultrasonic characteristics of papillary thyroid carcinoma and to determine the relative frequency of various patterns of papillary carcinoma on gray-scale ultrasonography (US) and color Doppler ultrasonography (CDU). METHODS: We retrospectively reviewed US features in 51 patients with confirmed papillary thyroid carcinoma. The features were analyzed based on tumor size, echogenicity, echotexture, boundary, margin, shape, and calcification pattern on gray-scale US imaging, and on patterns of vascularity on CDU. We obtained the relative frequency of features and classified these features into three categories: common (> or =50% of lesions), less common (>10% but <50%), and uncommon (< or =10%). Individual differences and combinations of features were also analyzed. RESULTS: In total, 67 nodules were enrolled in our study. The sizes of 76% of nodular lesions were <20.0 mm. Common US features of papillary carcinoma included: a homogeneous hypoechoic solid picture; a poorly defined boundary; an irregular margin; the absence of halo; the absence of calcifications or microcalcifications; and mixed perinodular and intranodular blood flow patterns. Less common features included: a heterogeneous hypoechoic or very hypoechoic picture; microcalcifications; a well-defined boundary; a regular margin; a halo with uneven thickness or an incomplete halo; and a taller-than-wide shape. Uncommon features included: an isoechoic picture; solid with cystic components; coarse calcifications; mixed coarse calcifications and microcalcifications; "inferno"-type blood flow; and absence of blood flow. On average, each nodule had 4.9 US features considered common, 1.8 US features considered less common, and 0.4 US feature considered uncommon. Features such as predominantly cystic composition, hyperechoic texture, and hypoechoic halo with even thickness were never found in our study. The top two common manifestations of papillary carcinoma were solid architecture and mixed perinodular and intranodular blood flow signals. CONCLUSION: All lesions in our series had a predominantly solid characteristic on gray-scale US.

Adult↗
PubMedDate not supplied

Tumor and tumor-like lesions of duodenum: CT and barium imaging features.

Neoplasms of the duodenum, either primary or secondary, are uncommon. However, imaging diagnosis for presurgical evaluation is extremely important due to complex regional anatomy. Computed tomography (CT) and barium-based double contrast examination (UGI series) are most frequently employed to evaluate the tumor invasion and intraluminal mucosal pattern. In this pictorial review, the CT and UGI series imaging features of benign and malignant duodenal tumors and tumor-like lesions are demonstrated and discussed.

Barium Sulfate↗
PubMedDate not supplied

Fibrous dysplasia of mandible with chronic osteomyelitis in a child: report of one case.

We report here a 6-year-old girl with fibrous dysplasia (FD) of the mandibular bone. She had a growing mass with local pain over right chin after a severe trauma, which was thought to be chronic osteomyelitis (OM). After failure of antibiotic treatment, malignant bone tumor was suspected from imaging studies including magnetic resonance imaging (MRI). FD of the mandible with chronic OM was confirmed one year after its onset by repeated biopsy performed at our hospital. Causes of delayed diagnosis may include (1) FD of the mandibular bone and chronic OM have similar characteristics clinically and radiographically, (2) the previous biopsy was not performed at appropriate site, and (3) failure to include fibrous dysplasia in the differential diagnosis. In this report, we also review the features in radiology and MRI of OM and FD, which may help differentiate the diagnosis. When a patient with mandibular FD has acute symptoms, the possibility of superimposed OM or malignant change should be considered.

Child↗
PubMedDate not supplied

Megacystis-microcolon-intestinal hypoperistalsis syndrome: report of one case.

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a very rare congenital disease characterized by abdominal distension due to a dilated urinary bladder, microcolon and decreased or absent intestinal peristalsis. Most patients die at an early age. We report on a female baby with this syndrome which was associated with duodenal web and tracheobronchial malacia. The literature on this syndrome is also reviewed.

Abnormalities, Multiple↗