Steven C. Horii

Evaluation of malignant invasion of the carotid artery by CT scan and ultrasound

Carcinoma adherent to the carotid artery may be present in advanced head and neck cancers. Angiography, ultrasound, computerized tomography (CT), and magnetic resonance imaging (MRI) are available for the preoperative evaluation of the carotid artery. This study demonstrates that CT is not accurate in demonstrating malignant invasion of the carotid artery. Ultrasonography appears to be the best modality for assessing carotid artery invasion. Magnetic resonance imaging may prove helpful in this determination.

Unified Digital Image Display And Processing System

Our institution like many others, is faced with a proliferation of medical imaging techniques. Many of these methods give rise to digital images (e.g. digital radiography, computerized tomography (CT) , nuclear medicine and ultrasound). We feel that a unified, digital system approach to image management (storage, transmission and retrieval), image processing and image display will help in integrating these new modalities into the present diagnostic radiology operations. Future techniques are likely to employ digital images, so such a system could readily be expanded to include other image sources. We presently have the core of such a system. We can both view and process digital nuclear medicine (conventional gamma camera) images, positron emission tomography (PET) and CT images on a single system. Images from our recently installed digital radiographic unit can be added. Our paper describes our present system, explains the rationale for its configuration, and describes the directions in which it will expand.

Overview Of ACR-NEMA Digital Imaging And Communication Standard

This presentation is to outline the American College of Radiology (ACR) and National Electrical Manufacturers Associa-tion (NEMA) Digital Imaging and Communica-tion Standard (ACR-NEMA Digital Imaging and Communication), which is a creation of joint effort of many fine knowledgeable people on the ACR-NEMA Digital Imaging and Communication Standards Committee, especially Allen Edwin and Gwilym Lodwick, Co-Chairman and Laura Murphy, Executive of the Committee. We hope that the ACR-NEMA Standard will be useful in the development of digital diagnostic imaging and medical information.

Message Protocols For Radiologic Consultations Over A Local Area Network

There has been much discussion of the hardware associated with local area networks (LAN), but little discussion of the practical impact such a system will have on the practice of radiology as we know it today. This paper will address the problems associated with conducting consultations in a networked environment. The first consideration is what messages must be formulated. Questions such as the following arise: can one or more physicians communicate with a digital image source at the time a study is being done to instruct the technologist to obtain another view or to change the window width and level before the film is made; how can the surgeon viewing an image consult with the radiologist to obtain information concerning tumor localization; once the image is on the network in a standard format, what might be the best way to distribute it to two or more different locations in such a manner that consulting can occur effectively; if two physicians are consulting how can a third person either be included in the conversation or prevented from listening in. This paper will focus on the messages which must be exchanged to communicate the necessary information and to control the sharing and cooperative use of this information.

Image Processing Requirements In Hospitals And An Integrated Systems Approach

The full capabilities of digital image producing modalities are rarely utilized routinely. Only a small fraction of the available information may be used in the initial diagnosis, and subsequent review is often severely limited by the use of film recordings which may display less than 5% of the original data. An alternative is presented, as a unified digital image distribution and processing system, linking various digital image sources through a high speed data link and a common image format. The system allows for viewing and processing of all images produced within the complex, from viewing stations at any number of convenient locations. The physical handling of storage media is totally eliminated. Complete archiving, file maintenance, and large scale processing capabilities are provided by a central file server. Provisions for hard copy, and the input and output of external image data are also included. The cost of such a system and its operation for ten years is shown to be approximately

A distribution system for digital images from diverse image sources : Incorporating a local area network in an imaging environment

0.20 per image.

Multimodality image display: desirable frame characteristics

This paper proposes a unified image-processing and viewing system as a viewing station and initially as the central file server in a unified digital image distribution and processing network, linking various digital image sources through a high speed data link and a common image format. The network allows for viewing and processing of all images produced within the complex and for locating viewing stations in any number of convenient areas. The system proposed can be slowly expanded to include all the digital images produced within the department or institution.

Display Preferences For Viewing CT Scans

The intent of this paper is to understand the characteristics of those frame buffers currently used to display images, versus more ideal frame buffers for medical image display purposes. This study is based on current needs and what characteristics might be desirable. Two case examples are presented: (1) a system developed for high quality computer graphics and (2) a system developed for nuclear medicine and radiation therapy treatment planning. Our study considers: (1) defining a pixel depth sufficient to hold data, (2) the desirability of multiple color look-up tables, (3) how cine loops are managed, and (4) display memory size.

PACS User Level Requirements

During our design of a workstation for diagnostic radiology, and having studied other designs being produced either commercially or institutionally, it became evident that a number of questions existed regarding the number and physical arrangement of CT images which a radiologist likes to have during interpretation. We wished to answer the questions about number and physical arrangement, and at the same time, determine how much difference there was concerning these parameters among the subspecialty sections. We approached this problem by using different numbers and arrangements of CT scan images presented to the radiologist on film. This paper will discuss the findings of this study, and explain some of the reasons given by the radiologists for their answers. The implications for workstation designs will also be discussed.

Broadband Coaxial Cable Image Viewing And Processing For Radiology

We discuss the requirements of a Picture Archiving and Communication System (PACS) for medical, from the user level. Based on the current requirements and current inadequacies with film file rooms, and anticipated future requirements, we suggest a minimal set of operation classes that a working PACS must support. No specific command set is proposed; each class is discussed purely in terms of what functions it provides to the user.