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Biomedical subjects

E V Staab

Publications and source records attributed to E V Staab.

At least 19 recordsLinked to original sources
PubMed1992

Screening test for detection of metallic foreign objects in the orbit before magnetic resonance imaging.

RATIONALE AND OBJECTIVES: A study was designed to determine whether plain films, used as a screening modality for magnetic resonance imaging (MRI), could reliably detect intraorbital metallic foreign objects. METHODS: In the first experiment, 20 metal particles were placed in five human cadaver orbits. Routine orbital plain film series and computed tomography (CT) were obtained, randomized, and interpreted blinded by three experienced radiologists. RESULTS: The threshold size of particle detection for CT (0.07 mm3) was lower than for plain films (0.12 mm3). Placing metal particles in artificial and true vitreous demonstrated that all particles moved under a magnetic field at 1.5 T. When human globes were exposed to industrial tools (grinder, bandsaw, air hose, etc.), no metal objects penetrated the sclera. CONCLUSIONS: Plain films can be used as a low-cost, low-radiation screening procedure for high-risk patients with occupations involving metal work. CT should be used for patients with a history of eye trauma from other causes.

Costs and Cost Analysis↗
PubMed1992

Evaluation of requirements and planning for picture archiving and communication systems.

Successful implementation of a picture archiving and communication system (PACS) requires extensive planning and the input of the users in the planning and evaluation stages. System design is conducted in nine stages: systems analysis, stages 1-4; system design, stages 5 and 6; and system implementation, stages 7-9. Users of the PACS are actively involved in systems analysis. At stage 1, problems are identified, project scope is defined, and whether the problems can be successfully addressed with a PACS is determined. If the project is feasible, current systems are studied at stage 2. Data are collected on the volume of image data to be transmitted, stored, retrieved, and displayed; distribution of imaging through the day; radiologists' reading patterns and volumes; job functions of technologists; characteristics of images to be included; types of equipment to be interfaced; physical placement of cables, connections, and equipment; and operational restrictions. All these data and more are used in stage 3 to specify requirements of the PACS. Rigorous specifications are needed to ensure that the final system performs at the desired level. At stage 4, users evaluate alternative solutions to problems. Although consultants and equipment manufacturers do much of the design, implementation, and installation, users must understand project scope and limitations of the technology and must ultimately be responsible for planning a system that meets their needs.

Cluster Analysis↗
PubMed1992

Image archival technologies.

A typical radiology department can create many gigabytes of image data per day and as much as 1 terabyte of data per year. Archiving and accessing this much data are substantial problems. One solution is data compression, which decreases data storage requirements and increases the rate of data transfer; however, standards are not yet available. Other solutions involve improvements in archival media. Jukebox subsystems allow automated access to multiple units. Digital magnetic tape, the standard medium, can store large amounts of information and enables easy updates or replacements; more practical technologies have been introduced in recent years. Digital videotape allows storage of digital video data and features a high rate of data transfer. Optical disks, now the preferred permanent archival medium, have a large storage capacity and provide excellent long-term stability. Optical tape is also being investigated as a solution to the archiving dilemma. Which technology to choose depends on many factors, including needs of the institution and the cost, stability, transfer time, and storage capacity of the system.

Computer Storage Devices↗
PubMed1992

Understanding and using teleradiology.

In 1972, Webber and his coauthors closed their landmark paper with some visionary remarks that have proved to be remarkably perceptive. They hypothesized that special telephone circuits or radiofrequency channels could be used to yield "images whose grey scale and resolution are satisfactory enough to be virtually indistinguishable from the original." Speaking of transmitting still-frame images in a reasonable length of time and at a reasonable cost, they were limited by the current state of technology, but not by failing to use available technology creatively. We now have the tools they lacked; we must analyze alternatives and apply them. First, define the clinical problem. Determine the minimum acceptable function level of the proposed teleradiology system. Then use your best judgement to sort our convenience, reliability, cost, and various other considerations in light of the needs of your practice. As you develop the scenario, frequently refocus on the problem to be solved. Very likely you will find, as you look closer at current options, that by using teleradiology you could increase the quality of service to your patients by extending your presence electronically to areas where constant physical presence is simply not possible, affordable, or convenient.

Medical Informatics Applications↗
PubMed1991

Magnetic resonance imaging in the evaluation of knee injuries.

To better define the role of magnetic resonance imaging (MRI) in the evaluation of knee injuries, we analyzed 10 recently published articles comparing MRI and arthroscopy in the detection of meniscal and anterior cruciate ligament tears. Sensitivity (SN), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) for medial meniscus (MM) tears, lateral meniscus (LM) tears, and anterior cruciate ligament (ACL) tears were either obtained or calculated from data contained in each article. The medians of measurements for MM tears were 97% SN, 89% SP, 88% PPV, and 96% NPV. Measurement medians for LM tears were 85% SN, 94% SP, 86% PPV, and 95% NPV. ACL tear measurement medians were 100% SN, 96% SP, 80% PPV, and 98% NPV. High NPVs were found in several studies, many of which were 100%. The high NPV of MR imaging suggests that diagnostic arthroscopic surgery is not necessary in the evaluation of patients with negative MRI studies. The superior sensitivity of MRI in detecting frank posterior horn tears, intrasubstance meniscal tears, and significant incidental findings also suggests that screening MRI scans can facilitate preoperative planning.

Arthroscopy↗
PubMed1990

Electronic imaging in a teaching hospital intensive care unit: evaluation of the clinical review system.

An intrahospital image-communication and display system was installed and is in continuous use. All images obtained in the medical intensive care unit (MICU) are digitized in the radiology department, then transmitted, stored and retrieved at the nurses' station in the MICU. This unit was easy to install, required minimal user training, and has been in continuous use for 1 year with negligible down time. The details of this system are provided in this report.

Computer Communication Networks↗
PubMed1990

Lymphoma of the solid abdominal viscera.

Lymphomas of the solid abdominal viscera include hepatic (both primary and secondary), splenic, and pancreatic lymphomas. The use of the various diagnostic imaging modalities in each of these lymphomas is discussed, and the imaging appearance of each is described.

Hodgkin Disease↗
PubMed1979

Computerized tomography applied to gynecologic oncology.

Forty patients on the gynecologic oncology service at the University of North Carolina were evaluated with CT scans. Accuracy and clinical benefit of these scans were compared to those of manual clinical examinations. The CT scans were generally superior and had fewer (9) verified errors in the regions of the pelvic wall and para-aortic area than did the manual examinations (17). Both the CT and bimanual examinations had the same number of verified errors (3) in the central pelvic region. The authors found the CT scans to be beneficial in evaluation of pelvic wall and para-aortic regions for treatment planning of either primary or recurrent cancer.

Diagnosis, Differential↗
PubMed1979

Thrombosis: a study of coagulation parameters and mechanisms during allograft rejection.

Thrombosis of the microvasculature has been recognized at the end product of organ rejection, but the exact biological pathway through which this occurs has not been clarified. Normal, factor VII deficient and heterozygous hemophilic (factor VIII) dogs were grouped to study the intrinsic and extrinsic clotting and platelet mechanisms during unmodified renal allograft rejection. The observed alterations of the hemostatic mechanisms are related to the changes observed in the microvasculature. Six groups of donor-recipient animals were studied: Group I -autografts (control); Group II - normal to normal allografts with bilateral nephrectomy; Group III - heterozygotes for factor VIII deficiency; Group IV - normal to normal allografts with unilateral nephrectomy; Group V - normal to factor VII deficiency without nephrectomy; and Group VI - normal to normal allografts with unilateral nephrectomy and dipyridamole. Each engrafted animal was followed pre- and posttransplantation for change in the blood clotting factors, fibrin split products, platelets, white blood cells, renal function and microvasculature. The animals with factor VII deficiency rejected in a similar fashion as the control animals. The group with impaired factor VIII synthesis and platelet function had longer survival times. These data suggest that the intrinsic clotting pathway and platelets are the primary mechanism through which thrombosis occurs secondary to immune injury.

Animals↗
PubMed1979

Computed tomography and spinal dysraphism: clinical and phantom studies.

Two cases illustrating the value of CT in the assessment of spinal dysraphic tissue are presented. In one case, the configuration and origins of two osseous diastematomyelic spurs were shown well; in the second case, the CT recognition of a sacral lipoma led to air myelographic confirmation of the tumor and tethered cord. CT phantom studies indicated that dysraphic tissues, such as fat, cartilage, and fibrous tissue, are better identified and quantitated in the spinal canal when surrounded by air. Varying degrees of image degradation occur with water (simulating CSF) or metrizamide.

Adult↗
PubMed1979

Computed tomography: a three-dimensional study of the nasal airway.

1. Accurate volume measurement of the nasal airway based upon computed tomography images sequentially generated along the length of the airway is possible. 2. The cross-sectional area of the airway at any position along its length can be determined. 3. The most constricted part of the airway is not necessarily at the location of the turbinates. 4. Details of hard- and soft-tissue anatomy not otherwise discernible can be detected with computed tomography imaging.

Cephalometry↗
PubMed1979

Multiple imaging modalities for the study of pancreatic disease.

Gray scale ultrasonography (US) and computed tomography (CT) have enhanced the role of various imaging modalities in the evaluation of patients with suspected pancreatic disease. When these anatomical studies are normal or equivocal, a functional, radionuclide pancreas scan may be useful. Pancreatic imaging can be achieved using ultrasound, transmission CT, single photon radionuclide imaging, and positron emission CT. A diagnostic imaging decision chart for the evaluation of patients with possible pancreatic disease is useful in choosing the correct imaging modality in a specific situation. Such a chart and its theoretic basis are described in this review. The need to optimize the pancreatic work-up with respect to cost-benefit decisions and diagnostic accuracy, sensitivity, and specificity are of particular concern to the physician. Of all the potential areas for disease, the pancreas has been and remains a particularly difficult diagnostic problem.

Humans↗
PubMed1979

Technical note. Optimal computed tomography technique for bone evaluation.

Various combinations of window settings and displays were evaluated to determine the optimal photographic reproduction of images obtained from the Ohio-Nuclear Delta scanner to best demonstrate bony structure by computed tomography. A combination of wide window and negative images will produce better bony structure detail than various other settings. The physical basis of this technique will be described along with several cases to illustrate the conclusion. Although no one combination was universally adequate, the best in our experience was a wide window with negative images.

Adolescent↗