Biomedical subjects

Zhen J Wang

Publications and source records attributed to Zhen J Wang.

6 recordsLinked to original sources

PubMed2005

Living donor candidates for right hepatic lobe transplantation: evaluation at CT cholangiography--initial experience.

PURPOSE: To retrospectively evaluate computed tomographic (CT) cholangiography in the depiction of second-order biliary tract anatomy in living donor candidates for right hepatic lobe transplantation. MATERIALS AND METHODS: Human research committee approval was obtained, informed consent was not required, and the study was compliant with the Health Insurance Portability and Accountability Act. The authors identified all living right-lobe liver donor candidates who underwent CT cholangiography at their institution between October 2001 (when CT cholangiography was introduced at the institution) and March 2003 (n = 62). There were 41 men (mean age, 36 years; range, 18-55 years) and 21 women (mean age, 40 years; range, 22-55 years). Two readers in consensus rated quality of second-order bile duct visualization at CT cholangiography on a four-point scale (0, not seen; 3, excellent visualization) and noted the presence of variant second-order biliary tract branching anatomy. CT cholangiography findings were compared with those at surgery in subjects who underwent right hepatic lobe retrieval (n = 24). In addition, adult donors who underwent right hepatic lobe retrieval between January 2000 and March 2003 (29 men, mean age, 35 years [range, 20-52 years]; 18 women, mean age, 38 years [range, 23-54 years]) were identified. Numbers of donors who underwent intraoperative cholangiography before and after the introduction of CT cholangiography were compared by using the Fisher exact test. RESULTS: The mean second-order bile duct score at CT cholangiography was 2.9 (range, 2-3). Of 24 subjects who underwent right lobe retrieval, biliary tract anatomy determined at CT cholangiography was concordant with findings at surgery in 23 (96%). Variant second-order branching anatomy was seen in 13 subjects (54%) at surgery; one variant branch was missed at CT cholangiography. Of 47 subjects who underwent right hepatic lobe retrieval, significantly fewer subjects required conventional intraoperative cholangiography after the introduction of CT cholangiography (three of 24 subjects [12%]) than before (23 of 23 subjects; P < .0001). CONCLUSION: CT cholangiography accurately depicts biliary tract anatomy in living donor candidates for right hepatic lobe transplantation, and donors who undergo preoperative CT cholangiography are unlikely to need conventional intraoperative cholangiography.

Adolescent↗

PubMed2005

Concordance of second-order portal venous and biliary tract anatomies on MDCT angiography and MDCT cholangiography.

OBJECTIVE: We sought to investigate the concordance between second-order portal venous and biliary tract anatomies using MDCT angiography and MDCT cholangiography. MATERIALS AND METHODS: We retrospectively identified 56 living related potential liver donors who underwent both MDCT angiography and MDCT cholangiography. Two reviewers independently rated axial images and 3D reconstructions of MDCT angiograms and cholangiograms as diagnostic or nondiagnostic with respect to depiction of second-order portal venous and biliary tract anatomies. In images rated as diagnostic, second-order portal venous and biliary tract anatomies were categorized as conventional or variant. The concordance between portal venous and biliary tract anatomies was analyzed using McNemar exact chi-square test. RESULTS: All examinations were diagnostic. Second-order portal venous variants were seen in 10 (18%) and biliary branch variants were seen in 23 (41%) of the 56 patients. Patients with variant portal venous anatomy (6/10, 60%) were more likely to have variant biliary tract anatomy than patients with conventional portal venous anatomy (17/46, 37%; p < 0.01). The sensitivity of variant portal venous anatomy as a marker for variant biliary anatomy was 26% (6/23 patients). CONCLUSION: Concordance between second-order portal venous and biliary tract anatomies is statistically significant. However, in our series, a number of patients with conventional portal venous anatomy had variant biliary anatomy; therefore, the finding of conventional portal venous anatomy does not obviate preoperative biliary tract imaging in patients before liver donation.

Adolescent↗

PubMed2003

Cardiovascular shunts: MR imaging evaluation.

Magnetic resonance (MR) imaging has become an important tool for the accurate and noninvasive assessment of congenital heart disease. Because more precise delineation of anatomy and evaluation of function can be obtained with MR imaging than with either echocardiography or angiography, MR imaging is frequently used to evaluate cardiovascular shunt lesions. It is essential that imaging specialists be able to recognize the MR imaging features of various kinds of shunts, including supracristal ventricular septal defect, atrioventricular septal defect, and partial anomalous pulmonary venous connection. MR imaging is particularly useful for evaluating shunt severity, which can be expressed quantitatively as the ratio of pulmonary flow to systemic flow. This ratio can be estimated accurately with the use of either volumetric cine MR imaging or velocity-encoded cine MR imaging.

Adult↗

PubMed2003

CT and MR imaging of pericardial disease.

In the evaluation of pericardial disease, computed tomography (CT) and magnetic resonance (MR) imaging traditionally have been used as adjuncts to echocardiography. However, CT and MR imaging are particularly useful as sensitive and noninvasive methods for evaluating loculated or hemorrhagic pericardial effusion, constrictive pericarditis, and pericardial masses. Both CT and MR imaging provide excellent delineation of the pericardial anatomy and can aid in the precise localization and characterization of various pericardial lesions, including effusion, constrictive pericarditis and pericardial thickening, pericardial masses, and congenital anomalies such as partial or complete absence of the pericardium. Both modalities provide a larger field of view than does echocardiography, allowing the examination of the entire chest and detection of associated abnormalities in the mediastinum and lungs. Soft-tissue contrast on CT scans and MR images also is superior to that on echocardiograms. Given the many potential applications of these modalities in the evaluation of pericardial diseases, familiarity with the CT and MR imaging features of these diseases is important.

Adult↗

PubMedDate not supplied

CT and MRI of hepatic pseudotumor in long-standing biliary atresia.

Two patients who developed a hepatic pseudotumor in long-standing biliary atresia treated by hepatoportoenterostomy are presented. Both masses were detected during routine imaging surveillance prior to liver transplantation. The CT, MR, and pathologic appearances are described. Accurate radiologic identification of this entity is important for appropriate clinical management.

Adolescent↗

PubMedDate not supplied

Malignant pleural mesothelioma: evaluation with CT, MR imaging, and PET.

Imaging plays an essential role in the evaluation of malignant pleural mesothelioma (MPM). Computed tomography is the primary imaging modality used for the diagnosis and staging of MPM. Magnetic resonance (MR) imaging and, more recently, positron emission tomography (PET) have emerged as modalities that can provide additional important diagnostic and prognostic information to help further delineate the extent of disease, especially in surgical candidates. Use of MR imaging performed with different pulse sequences and gadolinium-based contrast material can improve the detection of tumor extension, especially to the chest wall and diaphragm. PET can provide both anatomic and metabolic information, especially in cases of extrathoracic and mediastinal nodal metastasis. Each imaging modality has its advantages and limitations, but their combined use is crucial in determining the most appropriate treatment options for patients with MPM.

Aged↗