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Biomedical subjects

J Rosenman

Publications and source records attributed to J Rosenman.

At least 19 recordsLinked to original sources
PubMed1998

[Recurrent tuberculosis in a psychiatric hospital, recurrent outbreaks during 1987-1996].

During 1987-1996, 39 of 720 patients hospitalized (most for severe schizophrenia) were diagnosed as having active pulmonary tuberculosis (5.4%, 975 per 105 per year). In 1992-1993, after a cluster of 5 cases was found, all patients were screened by PPD skin test and chest X-ray and 16 more cases were identified. Diagnosis was confirmed bacteriologically in only 10 of them but there were typical radiological findings in the others. 39 were treated with a multi-drug regimen. In addition, 333 exposed patients and 21% who had converted their skin tests were given isoniazid preventive therapy. A small increase in levels of liver enzymes was common, but significant abnormality (over 4 times the upper limit of normal) was found in only 7 patients, in whom therapy was therefore stopped or changed. During a follow-up period of 4 years, 2 more developed tuberculosis and 33 converted their PPD reactivity status. We conclude that an outbreak of tuberculosis in a psychiatric hospital can be controlled with a relatively low rate of side-effects by using systematic diagnostic and therapeutic measures. However, single step screening is not sufficient. Routine screening of all new patients, a high index of suspicion and contact investigation are needed.

Antitubercular Agents↗
PubMed1997

Methods for displaying intracerebral vascular anatomy.

We are developing three-dimensional imaging methods to portray vascular anatomy better, including noise-free display of vessels extracted from 3-D data sets, tree-based display, and reconstruction of angiographic data (preliminary work has resulted in the successful reconstruction of aneurysms from angiographic data). Fast, interactive display permits real-time manipulation of viewing orientation.

Computer Systems↗
PubMed1996

Three-dimensional reconstruction of intracranial vessels from biplane projection views.

The three-dimensional (3D) reconstruction of intracerebral vessels from two-dimensional (2D) projection views is an important clinical problem that, so far, has eluded solution. This report describes a new approach that uses projection images to build arterial trees progressively from an underlying 3D network, using a new method to pair shadow images on widely separated projection views. As a test of our general methodology, we have reconstructed a middle cerebral arterial tree from two projection views of a magnetic resonance dataset and have tested the accuracy of reconstruction against the original 3D dataset. This report describes the general approach to 3D vascular reconstruction and the computer program used to perform the final reconstruction step. The results suggest that accurate, 3D reconstruction of intracranial vessels is indeed possible from as few as two projection views.

Cerebral Arteries↗
PubMed1995

Tumor and target delineation: current research and future challenges.

In the past decade, significant progress has been made in the imaging of tumors, three dimensional (3D) treatment planning, and radiation treatment delivery. At this time one of the greatest challenges for conformal radiation therapy is the accurate delineation of tumor and target volumes. The physician encounters many uncertainties in the process of defining both tumor and target. The sources of these uncertainties are discussed, as well as the issues requiring study to reduce these uncertainties.

Forecasting↗
PubMed1995

Three-dimensional reconstruction of a bullet path: validation by computed radiography.

Three-dimensional visualization is an important tool in the evaluation and demonstration of injury. Creating convincing graphics, however, requires strict distinction between illustrative and reconstructive visualizations and a method of validation. We present a case in which we used a radiation-planning tool to provide a 3-dimensional illustrative visualization of a contact gunshot wound to the head, and validated the result by comparing computed radiographs with radiographs taken at autopsy. We discuss the use of visualization tools for data exploration in forensic pathology.

Adult↗
PubMed1994

A feasibility study of extended chemotherapy for locally advanced non-small cell lung cancer: a phase II trial of cancer and leukemia group B.

The purpose of this study was to determine the feasibility of additional chemotherapy beyond 5 weeks of vinblastine-cisplatin followed by radiation therapy for patients with stage III non-small cell lung cancer. In this randomized phase II trial, the goal was to determine, in a similar population of patients, the toxicity of either of two additional chemotherapy programs. Ninety-one patients with stage III non-small cell lung cancer received the same induction regime of vinblastine/cisplatin/radiotherapy. In patients randomized to regime 1, an additional four cycles of vinblastine/cisplatin were given after the radiotherapy. In regimen 2, six weekly doses of carboplatin were given concurrent with the radiotherapy. The additional four cycles of vinblastine and cisplatin were completed by 34% of patients; the concurrent carboplatin program was completed by 70% of patients. Grade 3 or 4 granulocytopenia occurred in 53% of patients on regime 1 versus 17% on regime 2 (p < 0.003); grade 3 or 4 nausea/vomiting occurred in 20% of those on regime 1 versus 7% on regimen 2 (p = 0.175). Response rates and survival were similar for the two regimens, with approximately 30% of patients surviving at 2 years. Given the reduced toxicity and the improved capacity to complete the planned therapy with the concurrent carboplatin treatment, this regimen will be further examined in a phase III trial.

Adult↗
PubMed1993

Portal film enhancement: technique and clinical utility.

We report on the results a 3-year project which had as its goal the development of methods to enhance radiation portal films to improve their readability. We had previously reported on a portal film enhancement technique, contrast limited adaptive histogram equalization, which could enhance low contrast detail, but degraded sharply contrasted edges. A new method, unsharp masking followed by contrast limited adaptive histogram equalization, now appears to overcome this problem. A clinical trial to test whether enhanced portal films could be read more accurately than standard ones was undertaken. The trial involved 12 readers from two institutions doing 276 readings. In this trial the enhanced films were judged to be of higher quality than the non-enhanced films (p < .001) and were read more accurately (p = .026). The usefulness and difficulties of routinely performing portal film enhancement in a busy radiation therapy department are discussed.

Humans↗
PubMed1993

Future directions in 3-dimensional radiation treatment planning.

In recent years, computed tomography data have been used to build three-dimensional (3D) patient models for radiation treatment planning. The strength of 3D treatment planning systems lies in their ability to substantially improve the precision of radiation therapy and provide some of the tools needed to improve dose conformation. This article describes the V2 virtual simulation system used at the University of North Carolina at Chapel Hill. The virtual simulator allows the patient model to be rotated to determine the best beam angles and calculates the positions of the table, gantry, and collimator necessary to achieve desired beam orientations. Considerable disagreement remains as to how to produce an optimal radiation treatment plan using 3D systems. The University of North Carolina's VISTAnet project provides real-time 3D radiation dose calculation and display, allowing the user to search for the optimal plan.

Humans↗
PubMed1992

An electronic medical record system with direct data-entry and research capabilities.

The transfer of medical records from a paper system to a computer-based system is inevitable. However, the widespread acceptance of electronic medical records has been delayed by problems such as high cost, inefficiency, data entry errors and poor physician acceptance. We have developed a database system that has overcome these difficulties and now serves as an electronic medical record. Our system has been in use for a year and a half, and currently contains information on over two thousand patients. The database provides an electronic radiation oncology chart containing patients' demographic information, technical treatment data and dictated reports. All dictated notes are captured, including consultation notes, treatment summaries, on-treatment visits, letters and follow up reports. The system provides data validation upon entry, required few additional software or hardware purchases, and allows for efficient retrieval of data. Unlike other database systems which require the hiring of data entry clerks to input the data, ours combines transcription and data entry. The database runs on a local area network of computers and uses a commercially available relational database package. It makes extensive use of mouse interface features such as pull-down menus, pop-up lists, buttons, multi-page forms, and scrolling fields, making the system easy to use with minimal training. Many custom features are built in, such as help screens, control functions, audit trails, and a system that keeps track of each patient's referring and other relevant physicians. For research purposes, the system has the capability to perform survival analyses on arbitrary user-defined subsets of patients. Data may also be exported transparently to statistical packages for other types of analyses.

Data Display↗
PubMed1992

High-performance computing in radiation cancer treatment.

In 1989 a consortium of the Radiation Oncology and Computer Science Departments at the University of North Carolina, BellSouth Corporation, GTE, and the MCNC was formed in response to the high-speed network initiative proposed by the National Science Foundation and the Defense Advanced Research Projects Agency. One of the purposes of this effort has been to demonstrate that applications exist that require gigabit per second networks. Our consortium, known as VISTAnet, proposed to use real-time radiation therapy treatment planning as the application that would require the use of a gigabit network. The plan was to develop a system that could rapidly calculate and display a three-dimensional radiation dose distribution for any configuration of radiation beams. The gigabit network would be used to tie the dose calculations done with the Cray Y-MP at the Research Triangle to the graphics engine at the Department of Computer Science (Pixel-Planes 5) and the medical workstation at Radiation Oncology. The system would then provide the radiation physician with the capability of considering hundreds of potential treatment plans, instead of the usual two or three, with the goal of arriving at a highly optimized plan within a few minutes.

Computer Communication Networks↗
PubMed1992

Penetrating thoracic wounds caused by plastic bullets.

Thoracic penetrating injuries caused by a new plastic bullet were studied to determine the nature of the wounds and the appropriate management. Twenty-six casualties from the Israeli-Palestinian conflict (Intifada) were included. The organs most commonly involved were lung (n = 21), bony chest wall (n = 9), heart (n = 3), and diaphragm. Bleeding was at least moderate in 20 patients, amounting in all patients to an average of 975 ml. Thoracotomy was required in 11 patients (42%) mainly because of cardiac injury (n = 3) and aortic or other arterial bleeding (n = 3). Simple oversewing of severed organs (n = 8) or ligation of bleeding vessels (n = 3) was satisfactory. Two patients died (7.7% mortality); one after major liver resection; the other was dead on arrival. We conclude that plastic bullets have a linear course unless displaced by the bony chest wall, when they tend to fragment and cause simple fractures. Fired from a presumed range of at least 70 m, plastic bullets behave like low-velocity missiles, and tissue destruction is minimal. Management should be similar to that of civilian thoracic penetrating trauma.

Adolescent↗
PubMed1991

Virtual simulation: initial clinical results.

We have developed a graphics-based three-dimensional treatment design system that permits the physician to easily understand which anatomy will be treated for any arbitrary beam orientation. Our implementation of this system differs from others in that the software (the Virtual Simulator) simulates the full functionality of a (physical) radiation therapy simulator allowing it to be easily used by physicians. The details of the of our initial clinical experience with virtual simulation are presented in this paper. Virtual simulation was attempted in 71 patients and completed in 65. In 41/71 patients (58%), the beam orientations chosen differed significantly from those traditionally used in our department. Although virtual simulation lead to traditional radiation portals in the remaining patients, in 23/71 (32%) secondary blocking was designed which was different from that which would have been conventionally employed. Thus, overall, virtual simulation lead to treatment changes in 64/71 (90%) of the patients in whom it was attempted. In 78% of evaluable patients the treatment designed with virtual simulation could be implemented on the physical simulator with a precision of +/- 5 mm (+/- 3 mm for brain and head and neck). Thus virtual simulation allowed both accurate planning and execution of treatment plans that would be difficult to achieve with conventional methods.

Brain Neoplasms↗
PubMed1991

Recent advances in radiotherapy treatment planning.

Radiation treatment planning is currently in a state of rapid change. Dissatisfaction with past planning technology stems from the growing realization that: (1) Increases in the local regional tumor control rate will increase the cure rate in many malignancies. (2) Even at the best treatment centers geometric tumor misses are commonplace. (3) Traditional constraints on treatment techniques, originally imposed for simplicity and reproducibility, are no longer necessary, and can result in suboptimal treatment. (4) Treatment plans judged "optimal" in two dimensions may be far from optimal when viewed over the entire treatment volume. (5) Lack of treatment reproducibility is also commonplace, and can be demonstrated to adversely affect treatment outcome. On the positive side, recent developments in computer graphics, image processing, radiation physics, and radiation biology are now making it possible to define, design, and deliver sophisticated 3D radiation treatments. However, because many of these technologies are being developed for other disciplines, their applicability to radiation therapy treatment planning is not widely appreciated. We outline the current status and new developments in radiation therapy treatment planning.

Artificial Intelligence↗
PubMed1989

Three-dimensional display techniques in radiation therapy treatment planning.

Good radiation treatment planning requires that the target volume be treated with a high and uniform dose of radiation while irradiating normal tissue as little as possible. Even if the merits of a given treatment plan are judged only on the appearance of isodose lines in one or a few planes it can sometimes be difficult for the experienced radiation oncologist to select the best of several alternative plans. If consideration is given to the entire spatial distribution of dose, however, the problem becomes far more difficult because of the enormous amount of data that must be evaluated. We believe that the lack of suitable methods to display these data has greatly contributed to the slow incorporation of 3D considerations into routine radiation treatment planning. In the past few years there have been great advances in both the theory of how to produce effective 3D displays and in the display hardware itself. In this paper we survey some of the methods used at the University of North Carolina, and show specific examples of how these displays can be used in radiation therapy treatment planning.

Computer Graphics↗