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Biomedical subjects

Samson Munn

Publications and source records attributed to Samson Munn.

7 recordsLinked to original sources
PubMed2004

The way to a man's heart is through his stomach: much 'diaphragmatic' attenuation is likely gastric, and effervescent granules enhance cardiac imaging.

Avoidance of falsely positive results depends on distinguishing reality from artifact, in turn depending on images of highest quality. In radionuclide cardiac imaging, an inferior wall artifactual defect, so called "diaphragmatic attenuation", is particularly common and vexing. Despite the historically held view, analysis and review of the literature suggest the defect is likely not diaphragmatic but rather primarily due to attenuation by nearby stomach wall. The explanation is based on gravity and anatomy. With this improved understanding, effervescent granules were given as a clinical, nonresearch measure to nine patients during myocardial scanning. It was observed that two-thirds demonstrated moderate or marked lessening of attenuation. An additional benefit is lessening of artifact by extracardiac activity. These benefits may also apply to other sorts of cardiac radionuclide imaging. The significance of this new imaging method is discussed and various avenues of research are proposed.

Adult↗
PubMed2004

Diagnostic accuracy of chest X-rays acquired using a digital camera for low-cost teleradiology.

Store-and-forward telemedicine, using e-mail to send clinical data and digital images, offers a low-cost alternative for physicians in developing countries to obtain second opinions from specialists. To explore the potential usefulness of this technique, 91 chest X-ray images were photographed using a digital camera and a view box. Four independent readers (three radiologists and one pulmonologist) read two types of digital (JPEG and JPEG2000) and original film images and indicated their confidence in the presence of eight features known to be radiological indicators of tuberculosis (TB). The results were compared to a "gold standard" established by two different radiologists, and assessed using receiver operating characteristic (ROC) curve analysis. There was no statistical difference in the overall performance between the readings from the original films and both types of digital images. The size of JPEG2000 images was approximately 120KB, making this technique feasible for slow internet connections. Our preliminary results show the potential usefulness of this technique particularly for tuberculosis and lung disease, but further studies are required to refine its potential.

Data Compression↗
PubMed2003

Imaging HIV/AIDS. Body cavity-based lymphoma.

Non-Hodgkin's lymphoma (NHL) is an important and common AIDS-related neoplasm. AIDS-related NHL can be defined by its anatomic distribution as systemic (nodal and extranodal masses), primary central nervous system, and occasionally body cavity-based lymphomas (BCBL). Radiologic imaging plays an important role in differentiating the varied appearances of AIDS-related NHL, particularly regarding BCBL: patients' images demonstrate only fluid in the pleural, pericardial, and/or peritoneal spaces. Imaging of a case of BCBL is presented, including simultaneous pericardial, pleural, and peritoneal effusions.

Humans↗
PubMed2002

Imaging HIV/AIDS. Burkitt's lymphoma.

Imaging is often vital in the diagnosis and staging of acquired immune deficiency syndrome (AIDS) patients with regard to infections and malignancies. Non-Hodgkin's lymphoma is an AIDS-defining illness and a common AIDS-related malignancy. These lymphomas are usually high-grade immunoblastic, primary central nervous system (CNS) or Burkitt's, and occasionally Hodgkin's. In Europe and North America, Burkitt's lymphoma occurs vastly more often in AIDS. Images of three widely varied cases of AIDS-related Burkitt's lymphoma reflect its radiologic features.

AIDS-Related Opportunistic Infections↗
PubMed2002

Pseudoazygos lobe caused by lymph node pneumatocele.

In patients with AIDS, the relatively high incidence of pulmonary tuberculosis places them at risk for more severe esophageal tuberculosis (including fistula formation), and tuberculous esophagitis in the setting of AIDS may be more common than had been thought. Tuberculous esophageal fistulae have long been described and are well known. Air tracking from the esophagus into a mediastinal lymph node is very rare and reported previously to collect in small pockets in either of two patterns: irregular (or "amorphous") or peripheral and curvilinear. Complete filling of a large lymph node by air has not previously been reported. Reported here is a case of tuberculous mediastinal lymphadenopathy in an AIDS patient in whom CT scans demonstrated fistula development between a large lymph node and adjacent esophagus; this was accompanied by total replacement of the apparently necrotic content of the node with air, surrounded by the relatively thin, smooth, residual wall of the node. A lymph nodal pneumatocele was thereby created, which has not been previously described, and is the first feature of this case. On frontal chest radiography, the lateral wall of the lymph nodal pneumatocele produced an appearance falsely akin to an azygos fissure, creating the second feature: a previously unreported cause of false appearance of an azygos lobe. It is important to consider tuberculosis when a fistula to the esophagus is demonstrated in an AIDS patient, to be aware that even a large lymph node may "shell out" entirely in that setting, and not to confuse the final resulting appearance with the normal variant it may resemble.

Acquired Immunodeficiency Syndrome↗