Biomedical subjects
Publications and source records attributed to Y L Wan.
Antral web is a rare cause of gastric-outlet obstruction. We report a case of gastric antral web with intermittent vomiting in a 10-year-old girl who received medical treatment for 6 months. The literature on this anomaly is reviewed with respect to differential diagnosis on the basis of upper gastrointestinal radiographic series, gastroscopy, and treatment planning.
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The purpose of this study was to analyse the sonographic findings of focal splenic lesions with an attempt to differentiate benign lesions from malignancies. The sonographic findings of 53 cases of verified focal splenic lesions, excluding post-traumatic haematomas and phleboliths, were retrospectively analysed. Of the 53 cases, 30 cases (57%) were benign and 23 cases (43%) were malignant. The malignancies included lymphoma (n=13), metastases (n=10); while the benign lesions included cysts (n=17), infarcts (n=3), and abscesses (n=5), and one case each of haemangioma, hamartoma, spontaneous rupture, tuberculosis, and lymphangioma. Significant differences were noted between the benign and malignant groups with respect to the presence of solitary lesions (p<0.0001), anechoic mass (p<0. 0001), lesions with highly echogenic foci due to gas or calcification (p = 0.0303), hyperechoic/mixed echoic lesions (p<0. 0001), presence of extrasplenic abdominal masses (p<0.0001), and nodules with the target sign (p<0.0001). Solitary lesions, anechoic mass, and lesions with highly echogenic foci due to gas or calcification each had a positive predictive value of 85%, 100%, and 100%, respectively, for the lesions to be benign. The multifocal/diffuse lesions, presence of extrasplenic abdominal masses, hyperechoic/mixed echoic lesions, and nodules with the target sign each had a positive predictive value of 70%, 100%, 70%, and 100%, respectively, for the lesions to be malignant. In summary, focal lesions with anechoic pattern or echogenic foci due to gas or calcification are suggestive signs of benign process. The sonographic observations of multifocal or diffuse solid lesions, especially those associated with target sign or extrasplenic abdominal masses are suggestive of malignancy.
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Transarterial embolization with detachable coils is a technique commonly used for the treatment of intracranial aneurysms. We report on a patient with a pulmonary arteriovenous fistula (PAVF) treated successfully with this technique. The patient presented with a history of intermittent hemoptysis, nasal bleeding, numbness of the upper extremities, and seizures. Computed tomographic angiography and magnetic resonance angiography demonstrated a single-hole arteriovenous fistular lesion in the left lower lung. Pre-embolization superselective pulmonary angiography revealed multiple fistulae communicating to the venous sac of the lesion. Eleven detachable coils were deployed into the venous sac, with resultant total occlusion of the pulmonary arteriovenous fistula. We conclude that venous sac embolization in treating this kind of patients is effective. The combined use of a microcatheter system and electrolytic detachable coils may be an excellent technique for achieving this kind of embolization. Superselective angiographic evaluation is essential before embolization, because many occult feeders can be present in cases of high-flow PAVF.
In this study, we retrospectively reviewed the MRI features of recurrent nasopharyngeal carcinoma (NPC) in 72 patients who underwent MRI before and after gadolinium injection. Recurrent NPC exhibited a high degree of regional spread and a variety of signal intensities and contours. MRI showed a nasopharyngeal mass in 50 patients (69.4 %); other sites of involvement included the parapharyngeal space (44.4 %), nasal cavity (12.5 %), paranasal sinuses (27.8 %), oropharynx (4.2 %), orbit (8.3 %), infratemporal fossa (18.1 %), skull base (59.8 %), intracranial area (51.4 %) and regional lymph nodes (15.3 %). On T2-weighted images, the nasopharyngeal mass gave high signal in 9 of 50 cases (18 %), intermediate in 27 (54 %), mixed in 8 (16 %) and low signal in 6 (12 %). Contrast enhancement was strong in 12 cases (24 %), moderate in 29 (58 %) and heterogeneous in 9 (18 %). The lesion was convex in 31 cases (62 %) and concave or straight in 19 (38 %). Recognition of the distribution and the appearance of recurrent NPC on MRI is essential for timely diagnosis and appropriate treatment.
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We describe a rare case of splenic arteriovenous fistula and venous aneurysm which developed after splenectomy in a 40-year-old woman who presented with epigastralgia, watery diarrhoea, repeated haematemesis and melaena caused by hyperkinetic status of the portal system and bleeding of oesophageal varices. It was diagnosed by computed tomography and angiography, and obliterated with giant Gianturco steel coils.
We report MRI findings in a 56-year-old woman with Balo's concentric sclerosis (BCS) who initially presented with a progressive hemiparesis. MRI showed two lesions with a concentric pattern in the left frontoparietal region and a laminated, arcuate pattern in the right frontal region. These patterns were best seen in post-contrast images and were consistent with BCS. In addition, there were several small cerebral multiple sclerosis-like plaques. The clinical symptoms improved and the MR findings regressed after corticosteroid therapy. The patient had completely recovered 12 months later, except for mild right hand numbness. MRI showed further regression of the lesions, but the concentric pattern was still present. This case demonstrated that BCS can run a benign prolonged course and may persist for a long time. Concentric or laminated contrast enhancement in the acute phase may suggest that bands of demyelination in BCS occur synchronously rather than successively.
MRI is a valuable method for evaluating thoracic vascular lesions by virtue of its non-invasiveness and multiplanar capability. In addition, ionizing radiation and iodinated contrast medium are not required. Electrocardiographically gated T1 weighted spin echo MRI remains the principal technique for demonstrating the anatomy and morphology of thoracic vascular diseases. Cine MRI allows dynamic evaluation of vascular flow, whereas MR angiography is particularly useful in the two-dimensional (2D) or three-dimensional (3D) display of vascular anatomy. This pictorial review illustrates the use of 2D time-of-flight MR angiography in the assessment of various thoracic vascular conditions including aortic arch and great vessel anomalies, heterotaxic syndromes, aortic dissection, aortic or arch vessel aneurysms, pulmonary embolism, pulmonary sequestration, axillofemoral bypass and tumour/vessel relationships.
OBJECTIVE: The objective of this study was to evaluate the spectrum of sonographic and CT findings in adult ovarian granulosa cell tumors with pathologic correlation. MATERIALS AND METHODS: Transabdominal sonograms and CT scans in 13 patients with pathologically proven adult ovarian granulosa cell tumors were retrospectively reviewed. Morphologic characteristics of the lesions shown on sonography and CT were correlated with the histopathologic findings. RESULTS: On the basis of sonographic and CT findings, 13 cases of adult ovarian granulosa cell tumor were categorized into five morphologic patterns: multilocular cystic (n = 6), thick-walled unilocular cystic (n = 2), thin-walled unilocular cystic (n = 1), homogeneously solid (n = 2), and heterogeneously solid (n = 2) masses. Histopathologically, the multilocular cystic masses were characterized by a predominately macrofollicular pattern of granulosa cells and multiple cystic spaces with watery fluid or hemorrhage. Unilocular central cystic masses seen on CT correlated pathologically with confluence and expansion of the cystic spaces. Homogeneously solid masses seen on sonography and CT were correlated with evenly distributed trabecular or diffuse patterns in the tumor cells. Intratumoral bleeding, infarcts, fibrous degeneration, and irregularly arranged tumor cells yielded heterogeneously solid tumors. CONCLUSION: Adult ovarian granulosa cell tumors have a varied histologic appearance and a varied arrangement of tumor cells, both of which can create a spectrum of imaging manifestations. Appreciation of these manifestations is helpful in the diagnosis of this tumor.
Burkitt's lymphoma, the most common childhood non-Hodgkin's lymphoma, usually presents with abdominal tumors. Central nervous system (CNS) involvement in Burkitt's lymphoma is mostly secondary to advanced systemic disease, rarely with brain parenchymal lesions, and was previously recalcitrant to treatment. We report an unusual case of CNS Burkitt's lymphoma with minimal extraneural disease. This 10-year-old immunocompetent boy presented with increased intracranial pressure and seizures and was found to have multifocal intracerebral lesions on brain imaging studies. Cerebrospinal fluid studies confirmed the presence of Burkitt's lymphoma cells. Abdominal computed tomography showed bilateral nephromegaly with left intrarenal lesions that disappeared after three doses of intravenous dexamethasone. The patient was treated for 6.5 months according to the LMB 89 group C protocol of the French Pediatric Oncology Society. The response was brisk and complete. The patient has been disease free for more than 4 years, and is believed to be cured.
Due to the elimination of intermediate hosts and the improvement of clinical care, most parasitic infections have been effectively controlled in developing countries. Recently, the increase of the worldwide tourism, especially to Mainland China, and the migration of overseas workers from endemic countries have led to more parasitic infections that should not be overlooked by physicians. Assessment of diffuse liver disease with physical examination and laboratory findings is notoriously inaccurate. Thus, physicians use liver biopsy for accurate diagnoses. We present 4 patients with hepatic schistosomiasis japonica which were diagnosed using imaging before liver biopsy. Hepatic schistosomiais japonica has a tendency to cause dystrophic calcification and fibrosis in the liver. According to the results, a combination of ultrasonography and computed tomography (CT), used to recognize characteristic calcification patterns, seem useful to physicians for accurate diagnoses. Thus, unnecessary biopsy procedures can be avoided.
AIM: To investigate the antitumor effects of cytosine deaminase (CD) gene in combination with prodrug flucytosine (Flu, 5-fluorocytosine) on human hepatocellular carcinoma. METHODS: CD gene was transduced into human hepatocellular carcinoma cell line SMMC7721 with retroviral method and the cytotoxicity of Flu on the tumor cells was assayed in vitro with clonogenic techniques. The xenograft tumor model in nude mice was used to study in vivo therapeutic effects of CD gene/Flu system against human hepatocellular carcinoma. RESULTS: CD gene/Flu system had significant antitumor activities on human hepatocellular carcinoma cells in vitro and in nude mice. The antitumor activities of Flu 500 mg.kg-1 on hepatocellular carcinoma xenografts in nude mice were more potent than those of 5-fluouracil 10 mg.kg-1. CD gene/Flu system possessed bystander killing effects on hepatocellular carcinoma xenografts in nude mice. CONCLUSION: The experiment demonstrates the potential value of the CD gene/Flu system in the treatment of human hepatocellular carcinoma.
PURPOSE: We identified and quantified prognostic factors for emphysematous pyelonephritis. MATERIALS AND METHODS: The clinical information, laboratory data and radiological findings from 38 patients with emphysematous pyelonephritis were retrospectively analyzed. RESULTS: There were no significant differences between the nonsurvivor and survivor groups with respect to age, gender, diabetes mellitus history, presence of bacteremia, identity of infecting organisms, blood glucose level, leukocyte count, urinary white blood count, presence or absence of urinary tract obstruction or urolithiasis, and modes of treatment. There were significant differences between the nonsurvivor and survivor groups, however, with respect to platelet count (84,300 +/- 119,500 versus 220,400 +/- 161,800/mm.3, p = 0.001), serum creatinine level (3.61 +/- 1.25 versus 2.19 +/- 1.32 mg./dl., p = 0.003) and urinary red blood counts (56.47 +/- 41.86 versus 27.65 +/- 36.14, p = 0.028). Patients with radiological type I emphysematous pyelonephritis were significantly more likely to die than those with type II (69 versus 18%, p = 0.002). CONCLUSIONS: Serum creatinine level is the most reliable predictor of outcome in patients with emphysematous pyelonephritis. By calculating likelihood ratios, patients with creatinine levels greater than 1.4 mg./dl. and platelet counts 60,000/mm.3 or less were at high risk. The posttest probability of death increased from 69 and 18% to 92 and 53% for type I and II emphysematous pyelonephritis, respectively. Patients with creatinine levels 1.4 mg./dl. or less and platelet counts greater than 60,000/mm.3 were at much lower risk. Posttest mortality risk in these patients dropped from 69 and 18% to 27 and 4% for type I and II emphysematous pyelonephritis, respectively.
A rare case of cecal lymphangioma which presented as intussusception was reported. The patient was a 28-year-old female who suffered from vomiting, abdominal pain and mass for 6 days. Ultrasonography revealed a multilocular cyst that measured 7 cm in maximal diameter, and an adjacent target-like mass with concentric layering in the right abdomen. Computed tomography confirmed the sonographic findings with fatty component in the target-like mass. Intussusception in adults is a diagnostic challenge to a physician due to its vague and nonspecific presentations. Laparatomy is indicated because of underlying pathology in a vast majority of cases. Diagnosis can be established by the characteristic findings mentioned above.