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Biomedical subjects

James G Smirniotopoulos

Publications and source records attributed to James G Smirniotopoulos.

7 recordsLinked to original sources

MR and CT imaging of 24 pleomorphic xanthoastrocytomas (PXA) and a review of the literature.

INTRODUCTION: The aim of our study was to review the imaging appearance of PXA, a rare and usually low-grade, astrocytic tumor that typically occurs in young adults. METHODS: The clinical presentation, location and imaging findings on CT (n = 15) and MR (n = 18) of 24 pathologically confirmed PXA were retrospectively reviewed. Two morphologic patterns were defined according to imaging features. The Mann-Whitney U-test was used for statistical analysis of the data. RESULTS: All the neoplasms were supratentorial and superficial in location with obvious leptomeningeal contact in 22 patients, although leptomeningeal enhancement was demonstrated in only 3. Common locations were temporal (42%), frontal (33%) and parietal (21%), and more than one lobe was involved in 21% of patients. On CT without contrast enhancement, PXA was an iso- or hypoattenuating mass, and calcification was seen in six tumors and inner table remodeling was seen in three patients younger than 12 years. On MR, the solid component of PXA was isointense relative to gray matter on T1-weighted images, hyperintense on T2-weighted images in more than 90% and enhanced intensely following intravenous contrast material administration. Cystic areas showed hyperintensity relative to CSF. Two imaging patterns were differentiated: first a cystic mass containing a mural nodule (70%) and second a predominantly solid mass that may show cystic changes (30%). CONCLUSION: The most consistent imaging features of PXA were a superficial location, leptomeningeal contact, and enhancement of the solid component. Apart from the classical PXA appearance of a cystic lesion with an enhancing mural nodule, a second pattern consisting of a predominantly solid mass was recognized.

Adolescent↗

Internet-accessible radiographic database of Vietnam War casualties for medical student education.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the feasibility of archiving radiographic images from Vietnam era conflict casualties into a personal computer-based electronic database of text and images and displaying the data using an Internet-accessible database for preservation and educational purposes. MATERIALS AND METHODS: Thirty-two patient cases were selected at random from a pool of 1,000 autopsy reports in which radiographs were available. A total of 74 radiographs from these cases were digitized using a commercial image scanner and then uploaded into an Internet accessible database. The quality of the digitized images was assessed by administering an image-based test to a group of 12 medical students. RESULTS: No statistically significant (p > 0.05) differences were found between test scores when using the original radiographs versus using the digitized radiographs on the Internet-accessible database. CONCLUSION: An Internet-accessible database is capable of effectively archiving Vietnam era casualty radiographs for educational purposes.

Databases, Factual↗

Retention of radiographic anatomy of the chest by 4th-year medical students.

RATIONALE AND OBJECTIVES: The authors performed this study to assess the ability of medical students to retain their knowledge of radiographic anatomy into the 4th year. MATERIALS AND METHODS: One hundred ninety-four 4th-year medical students were quizzed on their ability to (a) identify 10 anatomic structures on chest radiographs and (b) search an abnormal radiograph to identify two important findings. Frontal and lateral views were used. The students had learned about radiographic anatomy of the chest and plain radiography search techniques in 1st- and 2nd-year courses and had proved their ability to perform these tasks, during their 2nd year of medical school, by achieving grades of 84% or more (average grade, 90%) on individual oral examinations administered by radiologists. RESULTS: The mean test score was 4.47 out of 12. Only 10 students (5%) were able to identify the main pulmonary artery on the frontal view, and only nine (4%) identified the main bronchi on the lateral view. Of the 194 students, 192 failed to detect a collapsed vertebral body on the lateral view of a patient who had previously undergone a mastectomy. CONCLUSION: Specific radiologic anatomy facts and search techniques are poorly retained by 4th-year medical students. Preclinical teaching of imaging probably should stress principles rather than specific details.

Anatomy↗

Hemangioma from head to toe: MR imaging with pathologic correlation.

Hemangioma is a common benign vascular neoplasm that closely resembles normal vessels and can be found in all organs of the human body. Vascular lesions can be classified as infantile hemangiomas or vascular malformations on the basis of their natural history, location, cellular turnover, and histologic characteristics. The magnetic resonance (MR) imaging features of vascular malformations of the central nervous system depend on the pathologic subtype. Soft-tissue vascular malformations can be categorized with combined MR imaging and MR angiography as either high- or low-flow. Osseous vascular malformations commonly demonstrate a high-signal-intensity trabecular pattern at both T1- and T2-weighted MR imaging. A group of more aggressive vascular neoplasms, including hemangioendothelioma, hemangiopericytoma, and glomus tumor, have a nonspecific appearance at MR imaging. In the liver and spleen, hemangiomas are typically hyperintense at T2-weighted MR imaging, with a centripetal filling pattern after administration of gadopentetate dimeglumine. Vascular lesions can involve several organs or systems in angiomatous syndromes. MR imaging allows characterization of a hemangioma with typical features, which vary depending on anatomic location. Familiarity with these features facilitates diagnosis and management of these anomalies.

Angiomatosis↗