Ronald L. Arenson

Hepatic and biliary tract abnormalities in patients with AIDS. Sonographic-pathologic correlation.

A retrospective evaluation of hepatobiliary sonograms in 22 patients with AIDS was performed and the sonographic abnormalities were correlated with pathologic findings in 10 patients. Hepatic parenchymal abnormalities noted on ultrasound include a hyperechoic parenchymal echo pattern in 45.5%, hepatomegaly in 41%, and focal masses in 9% of patients. Etiologies for the diffuse hyperechoic pattern based on pathologic correlation in eight cases were hepatic steatosis and granulomatous hepatitis. Biliary tract abnormalities identified included gallbladder wall thickening in 55% of patients, dilated gallbladder in 18%, biliary sludge in 23%, and gallstones in 5% of patients. Extrahepatic ductal dilation was seen in 23% of patients, but the intrahepatic ducts were dilated in only 5% of patients. Possible etiologies for biliary tract abnormalities suggested by pathologic correlation in five patients and literature review were cytomegalovirus and cryptosporidial infection, although constitutional factors may have played a role. Hepatobiliary ultrasound is, therefore, an effective screening tool for directing further diagnostic and therapeutic procedures in AIDS patients presenting with clinical evidence of hepatobiliary dysfunction.

The Digital Imaging Workstation

Picture archiving and communication systems (PACS) are expected to convert film-based radiology into a computer-based digital environment, with associated cost savings and improved physician communication. The digital workstation will be used by physicians to display these “soft-copy” images; however, difficult technical challenges must be met for the workstation to compete successfully with the familiar viewbox. Issues relating to image perception and the impact on physicians’ practice must be carefully considered. The spatial and contrast resolutions required vary according to imaging modality, type of procedure, and class of user. Rule-based software allows simple physician interaction and speeds image display. A consensus appears to be emerging concerning the requirements for the PACS workstation. Standards such as the American College of Radiology/National Electrical Manufacturers’ Association Digital Imaging and Communication Standard are facilitating commercial applications. Yet much careful study is needed before PACS workstations will be fully integrated into radiology departments.

Development Of A Physician-Friendly Digital Image Display Console

A high speed fiber optic network for the transmission of digital images has been under development for the last three years at our Hospital. This network utilizes a ring architecture with token passing contention handling. Radiographs are digitized with a high resolution camera. Images can be viewed at either high or low resolution. The software for this four node Medical Image Management System (MIMS) is now complete and is undergoing trial runs. Clinical tests begin on March 1, 1986. This paper will focus on the philosophy, evolution and the present state of the interfaces that exist between the system and the physician. Care has been taken to develop an interface that is fast, powerful and error-free. Though simple to use, it presents the physician with a number of powerful options to manipulate the image to facilitate effective interpretation. An effort has been made to incorporate those functions that are useful to the physician. We tried to avoid cluttering the user menu with an array of less-used options.

Clinical experience with PACS at the University of Pennsylvania

A Picture Archiving and Communication System (PACS) was installed in the Medical Intensive Care Unit of the Hospital of the University of Pennsylvania. For one year, 8 week periods of FILM ONLY usage were alternated with 8 week periods of PACS OR FILM usage. The time interval between obtaining portable chest images and taking image dependent actions decreased when the PACS was used, however, about 40% of the action decisions were made without a radiologists consultation. Only 5% of action decisions were made without consultation during the FILM ONLY periods. A new clinical study for measuring diagnostic accuracy and efficiency as well as communication patterns is described.

PACS at Penn

History: Our experience with Medical Image Management Systems (MIMS, also called PACS) began in 1982 with the creation of a digital subtraction angiography (DSA) unit. This DSA system was built utilizing a DeAnza image array processor with boards fabricated by our staff to interface with a Siemens angiography room. Because of the need to transmit and eventually store very large image files on a remote computer, we designed and fabricated a point-to-point fiber-optic link [82-ARENA. This device was later marketed by Canoga Systems and was an important contribution to the design of commercial fiber-optic networks. Recognizing the importance of a versatile Radiology Information System (RIS) and its critical inter-relationship to a MIMS, some very early work on RIS design was carried out [79-ARENA, [79.B-AREN ], [84-AREN ].

Abruptio placentae: apparent thickening of the placenta caused by hyperechoic retroplacental clot.

Antepartum bleeding occurs in approximately 3.5 per cent of third trimester pregnancies, with placental abruption being the causative factor in up to 32 per cent of cases. 1 Although the diagnosis of abruptio placentae is often based solely on the clinical examination, sonographic studies may confirm the condition. Primary sonographic findings are visualization of a retroplacental mass of varying echogenicity and/or bulging of the chorionic plate. This mass effect has commonly been described as hypoechoic or anechoic and is related to bleeding or infarction. 2·3 In this report, two unusual cases are presented of abruptio placentae which initially presented as homogenously enlarged placentas. In the proper clinical setting, this finding should heighten suspicion of abruptio placentae.

Design of a medical image management system: a practical cost-effective approach.

The impact of technology and economics is driving radiology departments into a digital era. There have been significant developments in the design of Medical Image Management System components. However, many important design criteria have been neglected, leading to an ineffective end product. This paper will discuss the more important design criteria. The design will be considered from the users point of view. The implementation of a prototype Medical Image Management System (MIMS) serving a Medical Intensive Care Unit in our Institution will be presented. The structure and very preliminary results of a clinical evaluation will be discussed. Plans to expand the MIMS beyond the Department and the Hospital will also be briefly discussed. The role of the personal computer in the design of a MIMS will be reviewed.

Fiber Optic Communication System For Medical Images

This paper discusses a fiber optic communication system linking ultrasound devices, Computerized tomography scanners, Nuclear Medicine computer system, and a digital fluoro-graphic system to a central radiology research computer. These centrally archived images are available for near instantaneous recall at various display consoles. When a suitable laser optical disk is available for mass storage, more extensive image archiving will be added to the network including digitized images of standard radiographs for comparison purposes and for remote display in such areas as the intensive care units, the operating room, and selected outpatient departments. This fiber optic system allows for a transfer of high resolution images in less than a second over distances exceeding 2,000 feet. The advantages of using fiber optic cables instead of typical parallel or serial communication techniques will be described. The switching methodology and communication protocols will also be discussed.

Prototype Medical Image Management System (MIMS) at the University of Pennsylvania: Software Design Considerations

A 10 Mbits/second fiber-optic network for the transmission of chest x-ray images has been designed and implemented at our Hospital. Images are acquired with a high-resolution laser scanner. The viewing consoles display images at spatial resolutions of either 512 square or 1024 square. User interfaces have been designed to simplify the digitization and display processes. The applications level networking software and all the image processing software has been developed in-house. The system is now serving a 11-bed critical care facility on a day-to-day basis. This paper will focus on the software design issues. The software will be presented from a systems perspective. The importance of the user in the design process will be stressed and exemplified. The role of intelligent, rule-based software will be demonstrated. Selected clinical results will be discussed.

Clinical evaluation of PACS: modeling diagnostic value

A model is presented for evaluating the diagnostic value of an imaging system in clinical use. It is site-specific and includes thedistribution of diagnostic findings, diagnostic accuracy, the importance of the test outcomes to the physician, and the timeliness of information delivery.