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J J Gisvold

Publications and source records attributed to J J Gisvold.

11 recordsLinked to original sources
PubMed1992

A comparison of mammography screen-film combinations.

A comparison study was performed to evaluate the image quality and radiation dose of six mammographic screen-film combinations: a Min-R screen with OM-1, SO-155, and SO-177 films (Eastman Kodak); a Min-R medium screen (Eastman Kodak) with OM-1 film; an HR Mammo medium screen (Fuji Medical Systems USA) with OM-1 film; and a Min-R fast screen with T-Mat M II film (Eastman Kodak). SO-177 films were processed with an extended cycle. Exposures of an acrylic test object with embedded masses, fibers, and specks and of a preserved breast specimen were made, for two paired image comparison tests in which the visibility of diagnostic features, contrast, and noise were judged. In most areas of image quality evaluated, a Min-R screen with OM-1, SO-155, and SO-177 films was superior. These three screen-film combinations had similar imaging characteristics, even though OM-1 film requires a higher radiation exposure. Images produced with a Min-R fast screen and T-Mat M II film were significantly lower in quality.

Breast Neoplasms↗
PubMed1990

Imaging of the breast: techniques and results.

Procedures for imaging of the breast have increased in number substantially in the past 30 years. Mammography, currently the most important breast imaging technique, was introduced at the Mayo Clinic in 1961. In 1988, more than 36,000 mammographic procedures were done. Breast ultrasonography is also a valuable examination, particularly for determining whether mass lesions are cystic or solid. The use of mammography for screening is increasing. Screening mammography allows the detection of breast cancer before it is palpable and while it is still in a stage known as minimal breast cancer. Lesions metastatic to axillary lymph nodes are less common in women with nonpalpable breast cancers than in women with palpable lesions. Nondiagnostic mammography should not delay the biopsy of a mass that is suspicious on physical examination. A special breast imaging center for performance of screening studies and evaluation of breast problems has been established at the Mayo Clinic.

Aged↗
PubMed1979

Computed tomographic mammography (CTM).

Breasts of 724 patients were studied by physical examination, mammography, and computed tomographic mammography (CTM) using a scanner designed for evaluation of the breast. Among cases in which CTM was not accompanied by use of contrast material, there were 60 malignant lesions, of which 10% were missed by mammography, 32% by CTM, and 8% by both. Among cases where CTM was supplemented by a 50 ml injection of 75% contrast material, there were 63 malignant lesions, of which 14% were missed by mammography, 16% by CTM, and 3% by both. Among cases where CTM was supplemented by a 300 ml infusion of 30% contrast material, there were 41 malignant lesions, of which 7% were missed by mammography and 5% by CTM, but none by both. Clinically, 22% of the malignant lesions in the infusion series were occult. There were 44 benign lesions in patients studied with the infusion technique. With mammography 68% were suspicious for malignancy, and with CTM, 56%.

Adenocarcinoma↗
PubMed1977

Secondary neoplasms of the small bowel.

Patterns of small bowel involvement from primary neoplasms elsewhere in the body were studied in order to determine whether the location of the lesions or their radiological appearance could provide criteria for distinguishing secondary from primary lesions. Multiplicity of lesions and the finding of "transverse stretch" were found to be highly indicative of secondary neoplastic involvement of the small bowel.

Humans↗
PubMed1977

Clinical evaluation of computerized tomographic mammography.

This is an initial report of the first clinical study using computerized tomographic mammography (CTM). A study is being conducted comparing CTM and conventional mammographic techniques in patients who subsequently undergo breast biopsy. This report analyzes the experience with 160 breast lesions found in patients who were examined using CTM without contrast material. One hundred lesions were benign and 60 were malignant. Mammography correctly identified 54 of the malignant lesions while CTM identified 41. Five lesions were missed by both modalities. The report also analyzes results experienced with 79 lesions found in patients who were examined with CTM both before and after the intravenous injection of contrast material. Forty-six of these lesions were benign and 33 were malignant. Mammography correctly identified 28 of the malignant lesions while CTM identified 27. Only one lesion was missed by both modalities. It is planned to continue this study, especially to enlarge our experience with the use of contrast material in breast scanning.

Breast Neoplasms↗
PubMed1976

Tomography of the gallbladder in oral cholecystography.

Tomography was used to supplement 327 oral cholecystograms in which the findings, including nonvisualized gallbladder, were inconclusive. In 136 cases, operative and tomographic findings were correlated. In 286 cases (87%), tomography provided conclusive diagnostic information. A diagnosis was possible in 108 of 111 cases in which the gallbladder had been visualized on conventional films and in 179 of 216 cases in which the gallbladder had not been visualized. Tomography of the gallbladder is an easily accomplished procedure that usually adds enough information to the inconclusive cholecystogram to permit accurate diagnosis and eliminate the need for reexamination.

Adult↗
PubMed1976

Computerized reconstructive tomography applied to breast pathology.

Breast tumors can be clearly defined from the surrounding breast parenchyma by the use of computerized reconstructive tomography. Certain types of fibrocystic mastitis also can be distinguished from tumors, but other types of fibrous mastitis and probably fibroadenomas may not be distinguishable from tumors unless contrast material is used.

Adenocarcinoma↗
PubMed1975

Breast cancer detection today: an opinion.

The family physician, more than most other physicians, is faced with rapidly increasing demands for breast cancer screening. The old standby, physical examination, is now accompanied by mammography, xeromammography, and, more recently, thermography. In this paper, we present our opinion, based on the collective experience at the Mayo Clinic, regarding the use and effectiveness of the several modalities, including mammography, xeromammography, and thermography, available for detection of breast cancer today.

Adult↗
PubMedDate not supplied

Improvement in specificity of ultrasonography for diagnosis of breast tumors by means of artificial intelligence.

A set of ultrasonograms of lesions from 200 patients between the ages of 14 and 93 years who underwent mammography followed by ultrasonographic examination and excisional biopsy has been studied with computer vision techniques to improve the ultrasonographic specificity of the diagnosis. Selected features representing the texture of the lesion were calculated and then classified by an artificial neural network. This network was biased toward correctly classifying all the malignant cases at the expense of some misclassification of the benign cases. The network diagnosed the malignant cases with 100% sensitivity and 40% specificity (compared with 0% specificity for the radiologists diagnosing the same set of cases in the breast imaging setting), and tests performed with a leave-one-out technique indicate that the network will generalize well to new cases. This suggests that methods based on neural network classification of texture features show promise for potentially decreasing the number of unnecessary biopsies by a significant amount in patients with sonographically identifiable lesions.

Adolescent↗