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Biomedical subjects

C C Jaffe

Publications and source records attributed to C C Jaffe.

At least 73 records · Page 4Linked to original sources
PubMed1979

Lack of an acoustic shadow on scans of gallstones: a possible artifact.

The high attenuation of gallstones results in the formation of an acoustic shadow on the ultrasound scan. Such shadows are best seen when the stone lies within the focal zone of the transducer and is large in comparison to the beam width or wavelength employed. Inadequecies in the dynamic range of available TV display units necessitate the use of compression-amplification signal processing which may preclude perception of such a shadow and seriously interfere with diagnostic accuracy.

Cholelithiasis↗
PubMed1979

The clinical impact of ultrasonic beam focusing patterns.

Previous clinical ultrasound investigations have been adversely affected by inadequate knowledge of the focusing characteristics of the transducer. Precise knowledge of the beam width profile has substantial impact on routine diagnostic procedures and is essential for proper display of the anechoic nature of small cysts, tissue textures, and particularly the distal shadow which characterizes gallstones. In vitro and in vivo tests using transducers with various beam focusing profiles clearly demonstrate that optimal imaging performance occurs within a very narrow range at a critical distance from the transducer face.

Cholelithiasis↗
PubMed1979

A new computed tomographic sign of pancreatitis.

Computed body tomography has become useful in the diagnosis of pancreatic disease. Pancreatitis frequently results in lateral and posterior extension of inflammatory tissue into the pararenal fat planes, which can be visualized by CT. In our series it was associated with clinically diagnosed pancreatitis. Of 100 cases studied for abdominal pathology where pancreatic visualization was optimum, 10 had enlargement of the pancreas with destruction of soft tissue planes extending into the left pararenal space and clinical findings of pancreatitis. Carcinoma of the pancreas was identified in 12; no abnormality was identified in 49; the remaining cases were mixed intraabdominal and retroperitoneal pathology. The value of this sign lies in separating inflammatory processes from neoplastic disease; the sign was not found in normals.

Acute Disease↗
PubMed1978

Prospective comparison of ultrasound and computed tomography in the evaluation of gynecologic pelvic masses.

A prospective evaluation of computed tomography and ultrasound was performed on 24 consecutive patients with suspected pelvic masses. Of the 24 patients, 22 had subsequent surgical identification of abnormalities; two were considered normal on clinical follow-up. Ultrasound provided important clinical information in 17 of 24 patients; CT in 15 of 24 patients. There were three false negative examinations with each method and no false positives. Differentiation between benign and malignant disease could not be made in four of 24 patients by ultrasound and five of 24 patients by CT. Because both imaging techniques depict similar pathology and use similar diagnostic criteria, the two methods tend not to be complementary.

Diagnostic Errors↗
PubMed1978

Computerized tomography in the assessment of diseases of the thorax: a critical review.

Many diseases of the chest wall, heart, mediastinum, pleura, and lungs can be successfully imaged by CT. Radiotherapy ports can be calculated and transcutaneous biopsies can be monitored. In future, it is conceivable that by studying the numerical data within these areas of diseased and healthy lung it may be possible to more closely correlate pulmonary function with radiographic images. It is hoped that lung volumes extravascular lung water, blood flow patterns, and many more physiological parameters may become open to elucidation by CT.

Adult↗
PubMedDate not supplied

Medical image collection indexing: shape-based retrieval using KD-trees.

The capacity to retrieve images containing objects with shapes similar to a query shape is desirable in medical image databases. We propose a similarity measure and an indexing mechanism for non-rigid comparison of shape which adds this capability to image databases. The (dis-)similarity measure is based on the observations that: (1) the geometry of the same organ in different subjects is not related by a strictly rigid transformation; and (2) the orientation of the organ plays a key role in comparing shape. We propose a similarity measure that computes a non-rigid mapping between curves and uses this mapping to compare oriented shape. We also show how KD-trees can index curves so that retrieval with our similarity measure is efficient. Experiments with real-world data from a database of magnetic resonance images are provided.

Abstracting and Indexing↗
PubMedDate not supplied

Physical parameters affecting the visibility of small ventricular septal defects using two-dimensional echocardiography.

We report a study showing that two-dimensional echocardiography is capable of visualizing a ventricular septal defect as small as 3 mm. The physical parameters which determine the visibility of an aperture in the myocardium include the presence of anterior refractile tissue, the amount of ultrasound beam focusing and range over which this occurs, the angle of incidence of the ultrasound beam on the septum, and the number of lines of information per degree of sector sweep. These factors are illustrated by in vitro tests. The influence of operator controllable variables in two-dimensional sector scanning echocardiography is discussed.

Child, Preschool↗
PubMedDate not supplied

Why an image?

Explore the source record for details and available documents.

Humans↗
PubMedDate not supplied

Medical image databases: a content-based retrieval approach.

Information contained in medical images differs considerably from that residing in alphanumeric format. The difference can be attributed to four characteristics: (1) the semantics of medical knowledge extractable from images is imprecise; (2) image information contains form and spatial data, which are not expressible in conventional language; (3) a large part of image information is geometric; (4) diagnostic inferences derived from images rest on an incomplete, continuously evolving model of normality. This paper explores the differentiating characteristics of text versus images and their impact on design of a medical image database intended to allow content-based indexing and retrieval. One strategy for implementing medical image databases is presented, which employs object-oriented iconic queries, semantics by association with prototypes, and a generic schema.

Abstracting and Indexing↗