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Biomedical subjects

Y L Wan

Publications and source records attributed to Y L Wan.

At least 73 records · Page 4Linked to original sources
PubMed1997

Unusual imaging presentations in renal transitional cell carcinoma.

PURPOSE: To report on unusual imaging presentations in renal transitional cell carcinoma (TCC). MATERIAL AND METHODS: Imaging studies of 140 cases of pathologically proven renal TCC were retrospectively studied with the focus on unusual presentations. RESULTS: Unusual imaging manifestations were found in 20 cases (14.3%). These findings were classified into 5 categories: perirenal abscesses or perirenal hematomas in 6 cases; parenchymal masses in 5; undue thickening of the hydronephrotic wall in 4; "tuberculoid" pyelograms in 3; and tumors with massive necrosis in 2. CONCLUSION: Deceptive imaging presentations may occur in renal TCC. Recognition of these presentations may help to prevent delay in diagnosis.

Abscess↗
PubMed1997

Peripheral arterial pseudoaneurysm treated by ultrasound-guided compression.

Ultrasound-guided compression repair of a pseudoaneurysm is a simple, safe and effective therapy, and has been proposed as a first-line treatment for pseudoaneurysms caused by catheterization. Herein, we report a case of a pseudoaneurysm arising from a sport injury which was treated by this method. Obliteration of the track of the pseudoaneurysm induced manual thrombosis and successfully converted the pseudoaneurysm to haematoma. Understanding the mechanism and the procedure is the basis of success in the use of this treatment.

Adolescent↗
PubMed1997

MRI of multiple biliary hamartomas.

Multiple biliary hamartomas (MBH) are uncommon benign malformations of the bile ducts. A case of MBH simulating liver metastases is reported, the diagnosis having been ascertained by US-guided biopsy. US and CT showed multiple hepatic nodules scattering in both lobes of the liver. Angiography showed small hypovascular lesions as well as hypervascular nodules. Only two cases with MRI studies have previously been reported. In this case, the finding was of hepatic cysts containing intermediate signal mural nodules. Demonstrating hepatic cysts with mural nodules on imaging will considerably increase the accuracy of diagnosis.

Adult↗
PubMed1997

Three-dimensional magnetic resonance cholangiopancreatography for evaluation of obstructive jaundice.

The purpose of this study was to assess the diagnostic value of magnetic resonance cholangiopancreatography (MRCP) in studying the anatomy, sites, and causes of obstructive jaundice. From September 1994 to May 1996 three-dimensional MRCP was performed on 31 patients with abdominal pain and obstructive jaundice with a fast spin-echo T2-weighted pulse sequence. The images were reconstructed using maximal intensity projection, AVERAGE and SURFACE algorithm processing techniques at a graphics workstation. All the reconstructed images were compared with those obtained using conventional cholangiographic techniques, such as endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography and drainage, and intraoperative cholangiography. The patients' diagnoses included choledochal cyst (13), cholangiocarcinoma (five), choledocholithiasis (four), pancreatic head carcinoma (three), rhabdomyosarcoma (one), papillary Vater carcinoma (one), recurrent gastric carcinoma (one), ascaris (one), and biliary atresia (two). Extrahepatic biliary dilatation was present in all 13 patients with choledochal cyst; the pancreatic ducts and their entrance level to the common bile duct were observed in eight of these patients. The level of obstruction in patients with cholangiocarcinoma was well documented but the biliary tract of one patient with biliary atresia was not identified by MRCP. In one patient with biliary rhabdomyosarcoma, MRCP clearly delineated the extrabiliary extension of the tumor. In a patient with ascaris in the common bile duct an increase in signal intensity inside the digestive tract of the worm denoted fluid in its gut. Lithiasis was shown in all of the four patients with choledocholithiasis. Thus, MRCP is a useful tool in the assessment of biliary tract obstruction and its causes, and is a valuable addition to ultrasonography.

Adolescent↗
PubMed1997

Cyclopia in one of discordant twins: a case report.

Cyclopia is an uncommon congenital anomaly resulting from arrest of the development of the anterior end of the neural plate. It is always associated with abnormalities of the brain. Cyclopia has never been reported in one twin only. In this report, we describe a case of cyclopia in a female infant with normal karyotype who was one of discordant twins. The infant died perinatally. The parents were healthy and not sanguineously related. Prenatal imaging studies revealed cyclopia, holoprosencephaly and hypognathia. Postmortem examinations revealed one orbit, one eyeball and absence of the nose. The central nervous system included rudimentary cerebral hemispheres with fusion of the two lateral ventricles and the third ventricle forming a single large cavity. The superior aspect of each cerebral hemisphere consisted of only a transparent membrane. The olfactory bulb nad tract was absent. The optic nerves were not identified.

Adult↗
PubMed1996

Pneumocephalus due to nasopharyngeal carcinoma: case report.

A 55-year-old man with recurrent nasopharyngeal carcinoma presented with intractable headaches and intermittent rhinorrhoea for 2 weeks. CT showed severe destruction of the skull base by the tumour. The headache persisted despite intraventricular morphine. On the 29th hospital day, sudden onset of neurological deterioration led to coma, and CT revealed tension pneumocephalus due to nasopharyngeal carcinoma breaking through the skull base. The literature on pneumocephalus is reviewed and the aetiology discussed.

Cerebrospinal Fluid Rhinorrhea↗
PubMed1996

Tuberculoma en plaque: CT.

A 35-year-old woman presented with a 6-month history of intermittent headaches, vomiting and dizziness. CT showed a plaque-like mass with tiny calcifications along the surface of the left frontal lobe. The mass exhibited heterogeneous enhancement with a few low-density foci. Underlying sulcal obliteration and enhancement and white matter oedema were also noted. Histopathological examination of excised material was consistent with tuberculoma. Recognition of this unusual presentation of intracranial tuberculoma may facilitate appropriate diagnosis and management.

Adult↗
PubMed1996

Primary cardiac chondrosarcoma.

A case of primary cardiac chondrosarcoma in a 41-year-old woman who presented with cardiac tamponade and cardiac intracavitary obstruction is described. The tumor originated from the right atrium and invaded the adjacent right ventricular wall and interatrial septum. Primary cardiac chondrosarcoma is extremely rare, and its clinical, computed tomographic, echocardiographic, and magnetic resonance imaging findings are described.

Adult↗
PubMed1996

Acute gas-producing bacterial renal infection: correlation between imaging findings and clinical outcome.

PURPOSE: To correlate imaging findings of types I and II emphysematous pyelonephritis (EPN) with clinical course and prognosis. MATERIALS AND METHODS: The imaging studies and clinical outcome in 38 patients with EPN were retrospectively studied. The imaging studies performed included radiography (n = 33), computed tomography (n = 31), and ultrasonography (n = 35). RESULTS: Two types of EPN were identified. Type I EPN was characterized by parenchymal destruction with either absence of fluid collection or presence of streaky or mottled gas. Type II EPN was characterized as either renal or perirenal fluid collections with bubbly or loculated gas or gas in the collecting system. The mortality rate for type I EPN (69%) was higher than that for type II (18%). Type I EPN tended to have a more fulminant course with a significantly shorter interval from clinical onset to death (P < .001). CONCLUSION: Two distinct types of EPN can be seen radiologically, and the differentiation is important due to the prognostic difference.

Acute Disease↗
PubMed1996

Gastric actinomycosis.

A case of actinomycosis of the stomach in a 61-year-old woman is reported. The patient presented to the hospital with a history of epigastric pain, fatigue, poor appetite, constipation and mild fever of 20 days' duration. On physical examination, a tender mass was felt at the epigastrium. Computed tomography (CT) showed a heterogeneously enhanced mass at the posterior wall of the stomach. Upper gastrointestinal series revealed a submucosal mass at the gastric antrum. A malignant tumor was suspected and surgery was recommended. A 5 x 4 x 2 cm mass was found at the posterior wall of the distal gastric antrum. A Billroth II subtotal gastrectomy was performed. Pathologic examination revealed suppuration and sulfur granules in the indurated mass. The patient was subsequently treated with intravenous penicillin-V for 12 days and then with oral penicillin-G for 4 months. She remained well at her last follow-up appointment. Although the initial radiologic findings were nonspecific, CT was of importance in delineating the location and evaluating the extent of the lesion.

Actinomycosis↗
PubMed1995

Evaluation of pectus excavatum with repeated CT scans.

The use of a single CT scan to evaluate the severity of pectus excavatum has been popular since its inception. However, there is no objective data to address the evolution of the deformity. Using repeated CT scans taken an average of 1 year and 3 months apart, eight children with pectus excavatum were prospectively followed. The initial pectus indices ranged from 3.6 to 6.8 (mean 5.4 +/- 1.3) and the follow-up indices, from 3.5 to 6.7 (mean 5.3 +/- 1.0). No progress of pectus excavatum was found during the study period. Our routine five axial chest CT sections also helped to specify a pectus index based on the central section taken through the deepest part of the deformity, and provided useful information for further conservative or surgical management.

Adolescent↗
PubMed1995

Congenital extracranial meningioma.

The authors report a case of congenital meningioma in a newborn. This tumour is extremely rare and only six cases have been reported in the literature. Those reported cases were mainly intracranial. This is the first case of a neonatal extracranial meningioma that was evaluated preoperatively by computed tomography and magnetic resonance imaging.

Humans↗
PubMed1995

Two-stage orchiopexy with laparoscopic clip ligation of the spermatic vessels in prune-belly syndrome.

A 1-year-old boy with prune-belly syndrome underwent unilateral laparoscopic clip ligation of the spermatic vessels with the hope of developing vasal collateral circulation. Six months later, the patient underwent ipsilateral second-stage orchiopexy on the right testis after division if the ligated spermatic vessels and contralateral Fowler-Stephens orchiopexy on the left testis in combination with major urinary tract reconstructions and abdominoplasty. For the following 1-year period, both testes were growing and comparable in size.

Cryptorchidism↗
PubMed1995

"Spoke wheel" sign of small intestinal volvulus.

Radiographic diagnosis of small intestinal volvulus and gangrenous change produced by an adhesive band is presented. A soft-tissue mass with radiating mucosal folds simulating a "spoke wheel" was found in the right mid-abdomen. Expansion of the mass was documented on a follow-up radiograph 3 hours later. A "spoke wheel" sign is reported as an early indication of small intestinal volvulus.

Adult↗
PubMed1995

Tuberculosis presenting as a solitary splenic tumour.

A 48-year-old male had suffered from body weight loss and general malaise for 2 months. Abdominal computed tomography showed a dilated intrahepatic duct with stones and a hypodense nodular mass in the spleen. A splenectomy and distal pancreatectomy were performed under the preoperative impression of a malignancy. Histological examination of the specimens revealed tuberculosis.

Diagnosis, Differential↗
PubMed1995

Pneumatic reduction of intussusception in children.

Over the past decade, pneumatic reduction has been increasingly accepted as the treatment of choice for pediatric intussusception. However the effectiveness of air compared with the more traditional barium reduction of intussusception continues to be a source of concern and debate. From August 1993 to November 1994, pneumatic reduction was used to treat 75 episodes in 73 patients with proven intussusception at Chang Gung Memorial Hospital, Taoyuan. Two patients underwent air reduction twice because of recurrence following an initial successful reduction. The recurrence rate was 3%. Successful reduction was achieved in 65/75 (87%) episodes. None of the patients experienced any complications following the procedure. In two of the 10 patients in whom reduction failed, one was subsequently found to have a Meckel's diverticulum and the other a duplication cyst as a leading point. This prospective study indicates that air enema is a safe and effective form of treatment for intussusception in infants and children. Pneumatic reduction should be the treatment of choice in the initial management of intussusception.

Child↗
PubMed1994

Radiolucent ureterocele calculus. Case report.

In a 30-year-old man a radiolucent stone in an orthoptic, nonobstructing ureterocele was detected by ultrasonography of the bladder. The stone was impacted in the ureteral orifice. Endoscopic ureteral meatotomy was performed in preference to endoscopic incision of the ureterocele, and the stone was disintegrated at ureterorenoscopy via the enlarged orifice.

Adult↗