Biomedical subjects

C Macedonia

Publications and source records attributed to C Macedonia.

8 recordsLinked to original sources

PubMed2001

The fetus at term: in utero volume-selected proton MR spectroscopy with a breath-hold technique--a feasibility study.

In three healthy gravidas at 38 and 39 weeks gestation, fetal MR spectroscopy was performed with a breath-hold technique by using the following pulse sequences: single voxel point-resolved spectroscopy, or PRESS, for liver and heart studies and stimulated-echo acquisition mode, or STEAM, for brain studies. Signal peaks of lipid from heart and liver were detected, as were the signal peaks of choline, creatine, and N-acetylaspartate from fetal brain. Findings demonstrated the feasibility of performing proton MR spectroscopy to assess mobile fetal structures.

Adult↗

PubMed2000

Magnetic resonance spectroscopy to detect lecithin in amniotic fluid and fetal lung.

BACKGROUND: Proton magnetic resonance spectroscopy is a noninvasive technique that detects molecules within a specified region in vivo. Lecithin, the major component of surfactant, has a characteristic magnetic resonance signal, but to our knowledge, it has never been reported in fetal lung or amniotic fluid (AF). The objective of this study was to characterize the lecithin signal in utero, which could lead to a noninvasive fetal lung maturity test. METHOD: Human fetal lung and AF pockets can be identified and studied with magnetic resonance spectroscopy with the use of a 1.5-tesla Vision whole-body magnetic resonance scanner (Siemens Medical Systems; Erlangen, Germany). Spectroscopy data are collected with a single-voxel-point-resolved spectroscopy sequence. After identification of fetal anatomy with the use of scout magnetic resonance images, magnetic resonance spectroscopy of human fetal lung and AF identifies a lecithin peak. EXPERIENCE: Three healthy gravidas near term were studied and lecithin peaks were identified in all. CONCLUSION: Lecithin can be identified in vivo with the use of volume-selected proton magnetic resonance spectroscopy. Patient comfort and extremely short scan times suggest that refined magnetic resonance spectroscopy might be a safe, quick, and comfortable test of fetal lung maturity.

Amniotic Fluid↗

PubMed2000

The physiologic cipher at altitude: telemedicine and real-time monitoring of climbers on Mount Everest.

Advanced wearable biosensors for vital-signs monitoring (physiologic cipher) are available to improve quality of healthcare in hospital, nursing home, and remote environments. The objective of this study was to determine reliability of vital-signs monitoring systems in extreme environments. Three climbers were monitored 24 hours while climbing through Khumbu Icefall. Data were transmitted to Everest Base Camp (elevation 17,800 feet) and retransmitted to Yale University via telemedicine. Main outcome measures (location, heart rate, skin temperature, core body temperature, and activity level) all correlated through time-stamped identification. Two of three location devices functioned 100% of the time, and one device failed after initial acquisition of location 75% of the time. Vital-signs monitors functioned from 95%-100% of the time, with the exception of one climber whose heart-rate monitor functioned 78% of the time. Due to architecture of automatic polling and data acquisition of biosensors, no climber was ever without a full set of data for more than 25 minutes. Climbers were monitored continuously in real-time from Mount Everest to Yale University for more than 45 minutes. Heart rate varied from 76 to 164 beats per minute, skin temperature varied from 5 to 10 degrees C, and core body temperature varied only 1-3 degrees C. No direct correlation was observed among heart rate, activity level, and body temperature, though numerous periods suggested intense and arduous activity. Field testing in the extreme environment of Mount Everest demonstrated an ability to track in real time both vital signs and position of climbers. However, these systems must be more reliable and robust. As technology transitions to commercial products, benefits of remote monitoring will become available for routine healthcare purposes.

Altitude Sickness↗

PubMed2000

Uterine perforation resulting in bowel infarction: sharp traumatic bowel and mesenteric injury at the time of pregnancy termination.

BACKGROUND: By law, elective terminations of pregnancy are not performed in U.S. military institutions. However, in the civilian sector, more than a million abortions are performed each year, some of which are on military beneficiaries. Although complications are relatively rare, patients not uncommonly present for follow-up care to their military installation. We report the case of a patient who presented after a second-trimester elective abortion and was found to have suffered uterine perforation with mesenteric and bowel injury that required bowel resection. CASE: An 18-year-old gravida 1 para 0 female presented from an outlying facility 1 week after elective termination at 18 weeks of gestation with complaints of severe abdominal pain, nausea, and vomiting. Exploratory laparotomy for presumed bowel obstruction revealed uterine perforation and bowel devitalization and necrosis, which required small bowel resection. Fetal bones were discovered within the surgical specimen. CONCLUSION: Morbid, even potentially fatal, complications can occur as a result of pregnancy termination. With second-trimester procedures, perforation can result in injury to abdominal viscera from the perforating instruments or even from sharp fetal bony structures. Military gynecologic surgeons, who are not in abortion practice, must nevertheless be cognizant of the potential for perforation leading to serious visceral injury.

Abortion, Induced↗

PubMed1998

Lecithin can be detected by volume-selected proton MR spectroscopy using a 1.5 T whole body scanner: a potentially non-invasive method for the prenatal assessment of fetal lung maturity.

The prenatal determination of fetal lung maturity is currently assessed by chemical analysis of surfactant associated lipids from aminotic fluid obtained by amniocentesis. This is an invasive procedure with rare but occasionally serious morbidity. Magnetic resonance spectroscopy (MRS) is a non-invasive method for the in vivo localization and identification of molecules with known resonance peaks at specified chemical shifts. In this report we examine the in vitro MRS of a lecithin/saline solution as well as term and preterm amniotic fluid samples with the use of a 1.5 T whole body scanner and a flexible surface coil. We found that amniotic fluid at term demonstrates a resonance peak at 3.2 ppm which was the same as the chemical shift of lecithin in saline. The lecithin peak is not observed in preterm amniotic fluid. This demonstrates the feasibility of using MRS with a whole body scanner to detect lecithin, one of the markers for fetal lung maturity.

Adult↗

PubMed1997

TeleInViVo: a collaborative volume visualization application.

Converging technologies in the areas of networks, volume visualization algorithms, and computer performance have made possible the development of a new tool for collaboration, which extends the reach of health professionals, and other consumers of volumetric data around the world. TeleInViVo(tm) is a three-dimensional (3D) collaborative volume visualization tool for medical applications. It extends the capabilities of InViVo(tm), a fast volume visualization tool developed at the Fraunhofer IGD, Darmstadt, Germany [1-3], with efficient and intuitive network collaboration features for remote consultation and new modes of interaction. The software runs on both UNIX and Windows NT platforms. TeleInViVo provides a high degree of interactivity for the medical professional when interacting with the patient data, facilitates explanation and communication between field personnel and medical experts located far from the field, and permits viewing of the data in a multitude of ways designed to support rapid and accurate diagnosis. Current efforts involve architectural enhancements to support multiuser, distributed telemedical scenarios. The application includes the following features: Volume and subvolume data transmission at user specified resolution, Synchronization cues, Integration of Immersion Probe(tm), a 6 degree-of-freedom input device, for ergonomic 3D data exploration, Tools for measuring distances, Tools for planning instrument path, Arbitrary cutting planes in real time, Interactive segmentation tools, Virtual video recorder and playback (cine loops), 3D stereo mode. TeleInViVo is an essential part of the MUSTPAC-1 portable 3D ultrasound system developed by Battelle Pacific Northwest Labs, Richland, WA.

Computer Communication Networks↗

PubMed1997

Three-dimensional ultrasound and image-directed surgery: implications for operating room personnel.

The proliferation of new imaging technologies is having a profound impact on all surgical specialties. New means of surgical visualization are allowing more surgeries to be performed less invasively. Three-dimensional ultrasound is a technology that has potential as a diagnostic tool, as a presurgical planning simulator, and as an adjunct to image-directed surgery. This article describes how three-dimensional ultrasound is being used by the United States Department of Defense and how it may change the role of the perioperative nurse in the near future.

Humans↗

PubMedDate not supplied

Cytogenetic analysis using telemedicine consultation: an improved means of providing expert cross-coverage.

PURPOSE: We used telemedicine in providing cross-coverage for a clinical cytogenetics laboratory. A genetic teleconsultation system was used to provide expert cross-coverage for a laboratory in a neighboring metropolitan region for a 6 month period while the usual provider of these services was on military reserve duty. METHODS: The teleconsultation system was a commercially available Perceptive Scientific Instruments (PSI) workstation. Five hundred thirty-nine cytogenetic cases were performed during the study period in the home laboratory in Baltimore, Maryland. RESULTS: Karyotypes and supporting metaphase spreads were transmitted by modem to the covering director, whereas work sheets and reports were faxed. Physical transfer of data was not necessary, and turn-around-time was not increased. CONCLUSION: This ability to employ a remote part time director has significant benefits for the laboratory with an absentee director for short or even extended periods of time. We conclude that the use of telemedicine in clinical cytogenetics proved to be an efficient and a cost effective means of providing genetics services to a region during a time of cross-coverage need.

Chromosome Aberrations↗