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Biomedical subjects

M S Frank

Publications and source records attributed to M S Frank.

At least 19 recordsLinked to original sources
PubMed1995

Opinion: a prototype for a computerized national mammography registry and tracking system using telecommunications and the Internet.

In this report, we analyze the feasability and discuss the potential benefits of using currently available technology for the wide-area registration and tracking of mammography patients. In our prototype, three dissimilar computer systems transmitted mammographic data (demographics and the results of mammograms) in a standardized format to a central data repository. Two of the three systems were dedicated computerized mammography systems and one was a general-purpose radiology information system. High-speed modems and the Internet were used to connect with the central repository, which could be queried in real time by remote users. Our results indicated that a busy mammography practice, using the slowest transmission method we tested (14-kilobaud modem), could transmit several days of mammographic data to a central repository in a matter of minutes. To implement systems that provide nation-wide mammographic tracking and follow up, more in-depth planning, development, and testing are necessary.

Computer Communication Networks↗
PubMed1995

CT of the lungs in patients with pulmonary emphysema.

Pulmonary emphysema is a pathological diagnosis. The clinical diagnosis of emphysema can be difficult because correlations between results of lung function tests and the extent of emphysema are poor. Features of chronic bronchitis or asthma may overlap with emphysema, making the clinical diagnosis more challenging. Nonetheless, the diagnosis of pulmonary emphysema can be made with relative confidence on the basis of clinical and radiological criteria. Despite not detecting mild emphysema and underestimating the severity of disease, CT--and high-resolution CT in particular--is the best noninvasive modality for detecting or corroborating pulmonary emphysema. This review focuses on several important aspects of pulmonary emphysema: (1) the definition and pathological characterization, (2) techniques of CT imaging, (3) CT findings and their correlation with pathophysiological data, and (4) quantification with CT.

Humans↗
PubMed1995

Chest computed tomography display preferences. Survey of thoracic radiologists.

RATIONALE AND OBJECTIVES: The authors conducted a survey of dedicated thoracic radiologists and tabulated their preferences for reconstruction algorithm, display, and photography of computed tomography (CT) scans of the chest. METHODS: Data were derived from a mail survey of 343 active members of the Society of Thoracic Radiology and based on a set of 20 questions about the display and photography of chest CT scans. The response rate was 35.4%. RESULTS: There were 119 usable replies from 31 states and 8 countries. Although there was considerable variation, the questionnaire indicates that the "typical" dedicated thoracic radiologist, regardless of practice setting, uses a standard reconstruction algorithm for chest CT and prints images on a laser imager using the "sharp" setting with a 12-on-1 format. Window settings for evaluating the lung are window-width 1500 HU and window-level -600 HU. Window settings for evaluating the mediastinum are window-width 350 HU and window-level 40 HU. CONCLUSIONS: Although there is wide variation in the preferences used to display and photograph chest CT scans, most thoracic radiologists have similar display preferences.

Algorithms↗
PubMed1995

Use of data in a radiology information system for labeling computed radiographs: an interface to connect the two systems.

Computers have greatly facilitated the processing and storage of radiologic information. Manufacturers of radiology information systems (RISs) are gradually incorporating options for interfacing their products with other computers (e.g., hospital information systems). However, a growing need exists to also interface RISs with digital radiologic equipment so that images (e.g., computed radiographs of the chest and skeleton) are automatically labeled with identification data. Such connectivity would eliminate redundant work by technologists, decrease errors in the labeling of images, and increase the consistency of patients' data within a radiology department. Unfortunately, the rapid advances in digital technology, combined with the lack of a well-defined standard for the transfer of demographic information between dissimilar systems, have delayed development of these interfaces. We have developed a widely applicable method to automatically transfer patients' demographic data from an RIS to a commercially available computed radiography system. A personal computer is configured with inexpensive programmable telecommunications software to create an interactive gateway, which eliminates the need for redundant data entry (compared with entering data once on the RIS and again on the stand-alone computed radiography system), and thus also decreases errors in the labeling of images.

Local Area Networks↗
PubMed1995

Value of on-line informational databases in a radiology department.

Radiologists and ancillary personnel in a radiology department frequently access a variety of paper-based information during their workday to facilitate decision making. This information can be as mundane as telephone numbers and work schedules or as important as a detailed emergency procedure for treating a patient with a severe contrast reaction. We have installed some hierarchical, textual database systems on the same computer that runs our radiology information system. Several different databases are maintained, including protocol manuals, emergency procedures, and a directory of telephone and pager numbers. This information is accessible from any terminal connected to our radiology information system and from any personal computer connected to our department's local area network or terminal server. Advantages include decreased costs from the photocopying, consumption, and distribution of paper; ubiquitous access for all users to a single source of information; faster and more powerful ways to access data than paper-based media provide; decreased risk of inadvertently using information from an obsolete document; and convenience in maintaining computerized versus paper-based information. Because we use software that is either free or that came with our computer's operating system, no additional software costs were involved.

Online Systems↗
PubMed1995

CT mosaic pattern of lung attenuation: distinguishing different causes.

Areas of variable lung attenuation in a lobular or multilobular distribution are occasionally seen on CT or high-resolution CT scans of the lungs [1], although never as a normal finding. This mosaic pattern of lung attenuation presents a challenge to the radiologist when deciding which are the abnormal regions of lung--those of low attenuation, those of high attenuation, or both. We have observed three categories of disease known to cause a CT mosaic pattern of lung attenuation: small-airway disease, vascular lung disease, and infiltrative disease. Diseases from each of these categories can cause similar patterns of mosaic lung attenuation on CT scans. However, it is sometimes possible to distinguish among these categories by using additional CT findings. We illustrate the known causes of a CT mosaic pattern of lung attenuation and highlight distinguishing features.

Aged↗
PubMed1994

Integrating a digital dictation system with a network data base for creating and managing radiologic teaching files.

RATIONALE AND OBJECTIVES: A method for facilitating the creation and management of radiologic teaching files is described. METHODS: A digital dictation system was integrated with a personal computer data base. The data base is maintained with user-friendly, graphically oriented software. Radiologists can dictate any examination for the teaching file from any dictation station in the department with minimal interruption of their clinical activities. The data base resides on a file server, thus providing department-wide access for radiologists and students. RESULTS: Attending radiologists and residents have responded favorably to the system. Maintenance and retrieval of teaching files are facilitated by using a computer for otherwise tedious aspects of information management. Data are stored in a well-organized manner, thus increasing the value of the teaching file while reducing redundant data entry. CONCLUSION: Computer technology can facilitate the maintenance of radiologic teaching files. Radiology departments that have a convenient, department-wide method for entering cases--such as a digital dictation system and existing computer network--are ideal for the technique that we describe.

Humans↗
PubMed1994

Evaluation of a combined two- and three-dimensional compression method using human visual characteristics to yield high-quality 10:1 compression of cranial computed tomography scans.

RATIONALE AND OBJECTIVES: The compression of cranial computed tomography scans was improved by using independent intra- and interframe compression techniques. METHODS: For intraframe compression, an image was decomposed into four subimages, one subimage was chosen as a reference subimage, and three of the subimages were predicted from the reference subimage. The prediction error was encoded with a classified vector quantizer (CVQ) based on human visual perception characteristics. Interframe redundancy is exploited by a displacement estimated interslice (DEI) algorithm that encodes the differences between reference subimages from adjacent slices. This combined DEI/CVQ method was subjectively evaluated by 13 radiologists under a blinded protocol, and was compared to the CVQ method alone, the DEI method alone, the original images, and to a standard intraframe discrete cosine transform (DCT) compression method. RESULTS: Only the combined DEI/CVQ method at 10:1 compression was not scored significantly different from the original images. At 15:1 compression, the DEI/CVQ method was scored significantly better than the 10:1 DCT and any other 15:1 compression methods. CONCLUSIONS: Compressed image quality is enhanced by exploiting inter- and intraframe redundancy, and by modeling some characteristics of human visual perception. The DEI/CVQ method is well-suited for progressive transmission, and thus, holds potential in teleradiology as well as picture archiving and communications systems.

Analysis of Variance↗
PubMed1994

Hemidiaphragm paralysis: CT diagnosis.

We describe the use of computed tomography (CT) in diagnosing and documenting diaphragmatic paralysis in a patient with right lung cancer that invaded the mediastinum. The patient was unable to breath hold during CT scanning, and the images were degraded by motion artifact. Motion artifact, however, was noted only in the left lung. In patients with suspected phrenic nerve dysfunction who are having chest CT for any reason, we suggest obtaining several dynamic images at the lung bases during forced exhalation. The lack of motion artifact in the lung parenchyma may be useful for diagnosing phrenic nerve injury and hemidiaphragm paralysis.

Artifacts↗
PubMed1994

Panlobular pulmonary emphysema caused by i.v. injection of methylphenidate (Ritalin): findings on chest radiographs and CT scans.

OBJECTIVE: Recent reports have described severe precocious pulmonary emphysema in persons who inject methylphenidate (crushed Ritalin tablets) i.v. We retrospectively evaluated the plain radiographic and CT features in 21 such patients. MATERIALS AND METHODS: The chest radiographs, available CT scans, and clinical and pathologic data were reviewed in 21 cases of i.v. Ritalin use. The patients were from 35 to 54 years old. Twelve patients were men, and nine were women. Emphysema was graded on the basis of findings on chest radiographs, by consensus, on a four-point scale as absent, mild, moderate, or severe. CT scans were available for three patients, including one imaged after a single lung transplantation. Autopsy results were available for four patients. Fixed inflated lung specimens and corresponding high-resolution CT scans were available in three cases. RESULTS: Radiographs showed pulmonary emphysema in all cases. The distribution of disease was basilar and symmetric. Small apical bullae were suggested in only one case. Basilar emphysema was rated as mild in four patients, moderate in three patients, and severe in 14 patients. In 11 patients who had serial chest radiographs, the basilar emphysema was noted to progress over a 2- to 7-year period. No evidence of progressive massive fibrosis was seen in any patient. CT scans confirmed emphysema, most severe at the lung bases. CONCLUSION: The plain radiographic and CT findings in patients who inject Ritalin are similar to those found in patients with alpha 1-antitrypsin deficiency and different from the findings seen in other types of i.v. drug use. The finding of basilar pulmonary emphysema should alert the radiologist to the possibility of i.v. injection of Ritalin.

Adult↗
PubMed1994

Integrating a personal-computer local-area network with a radiology information system: value as a tool for clinical research.

We investigated a method for increasing the utility of a radiology information system by connecting it to a personal-computer network and transferring radiologic data to a more user-friendly, familiar computing environment. We have developed a personal-computer local-area network that is linked to our radiology information system. Our software periodically transfers data from the radiology information system to a file server on our network that supports cross-platform access for Macintosh and IBM PC--compatible computers. Data are stored in formats compatible with inexpensive personal-computer software. These capabilities facilitate any research that requires a tailored, retrospective analysis of radiologic data. The need for ancillary personnel to perform paper-based searches or redundant data entry is decreased. Radiologists and administrators also have user-friendly access to information that might facilitate other projects dealing with education or analysis of clinical efficacy. The ever-growing power of personal computers, combined with inexpensive yet sophisticated software for these machines, frequently provides a more useful method for retrospective analysis of radiologic data than does a proprietary radiology information system running on a minicomputer.

Local Area Networks↗
PubMed1994

CT of the lung in patients with pulmonary emphysema: diagnosis, quantification, and correlation with pathologic and physiologic findings.

Pulmonary emphysema is a pathologic diagnosis. However, the diagnosis can be made with relative certainty on the basis of clinical and radiologic criteria. The clinical diagnosis of emphysema can be difficult because correlations between results of lung function tests and the extent of emphysema are poor. Additionally, features of other obstructive lung diseases may overlap. From the clinician's standpoint, the main value of differentiating between emphysema and other obstructive diseases of the airways (e.g., asthma and chronic bronchitis) is to (1) establish a prognosis and (2) guide the use of corticosteroid therapy by defining the degree of reversibility that can be expected in patients with limitation in air flow.

Female↗
PubMed1994

Small-airway diseases of the lungs: findings at expiratory CT.

CT performed in patients during suspended full expiration has recently been used to reveal a major physiologic consequence of airway diseases, particularly diseases of those smaller airways beyond the segmental branches: air trapping. Lung regions that retain air during exhalation (air trapping) remain more lucent than normal lung regions do. Detection of air trapping can provide clues to an otherwise unsuspected or underappreciated small-airway disease.

Adult↗