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Biomedical subjects

K Shaffer

Publications and source records attributed to K Shaffer.

15 recordsLinked to original sources
PubMed1992

Image-guided aspiration of solitary occult breast 'cysts'.

During the 30-month period from March 1, 1988, through August 31, 1990, image-guided aspirations of 183 solitary occult breast masses, which were considered possible cysts, were performed. Indications for aspiration included (1) mass on mammography, either invisible on ultrasonography or with features atypical of a cyst, in 111 patients; (2) enlarging solitary mass on mammography with ultrasonic features suggesting a cyst in 45 patients; and (3) mammographic mass with features typical of a cyst in 27 patients, with confirmation requested by the referring physician. Of the group, 151 (83%) lesions were fluid-filled and 32 (17%) were solid. All aspirates had normal cytologic features. Of the 32 aspirates found to be solid, 19 were subsequently removed after wire localization and 13 were unchanged on mammography for a minimum of 6 months after aspiration. This is a simple and safe procedure, confirming the innocuous nature of an occult solitary breast cyst, and obviates the need for surgical biopsy.

Adult↗
PubMed1992

Enlarging occult fibroadenomas.

From July 1, 1989, through June 30, 1991, 1,218 preoperative wire-localization breast biopsies were performed at one institution. In this group, 254 (21%) of the abnormalities were fibroadenomas, 26 of which had enlarged or developed in the interval between routine or short-interval follow-up mammography. This interval growth was noted in 21 premenopausal women and in five who were postmenopausal and receiving oral estrogen supplementation.

Adenofibroma↗
PubMed1992

Malignant pleural mesothelioma: value of CT and MR imaging in predicting resectability.

OBJECTIVE: Our objective was to determine if CT or MR imaging findings could be used to accurately predict resectability in patients with biopsy-proved malignant pleural mesotheliomas. SUBJECTS AND METHODS: CT and MR findings in 41 consecutive patients with malignant mesotheliomas who were referred to the thoracic surgery clinic for extrapleural pneumonectomy were studied by thoracic radiologists before surgery. Review of radiologic studies focused on local invasion of three separate regions: the diaphragm, chest wall, and mediastinum. Results of all imaging examinations were carefully correlated with intraoperative, gross, and microscopic pathologic findings. RESULTS: After radiologic and clinical evaluation, 34 patients (83%) had thoracotomy; 24 of these had tumors that were resectable. The sensitivity was high (> 90%) for both CT and MR in each region. Specificity, however, was low, probably because of the small number of patients with unresectable tumors. CONCLUSION: CT and MR provided similar information on resectability in most cases. Sensitivity was high for both procedures. Because CT is more widely available and used, we suggest it as the initial study when determining resectability. In difficult cases, important complementary anatomic information can be derived from MR images obtained before surgical intervention.

Asbestos↗
PubMed1992

Standard imaging in silicosis and coal worker's pneumoconiosis.

Silicosis and coal worker's pneumoconiosis (CWP) are two relatively common occupational diseases. Silicosis is the most common pneumoconiosis in the United States. It results from inhalation of the particulate form of quartz or other crystalline forms of silicon dioxide with a diameter of less than 5 micrograms. CWP is the result of inhalation of carbon particles. Pathologic features of the two diseases differ, yet their radiologic features are identical. Simple pneumoconiosis is characterized by multiple small rounded opacities of 1 to 5 mm in diameter and with a bias for the upper lung zones. Complicated pneumoconiosis results from confluence of small opacities into large opacities that form conglomerate masses or progressive massive fibrosis.

Coal Mining↗
PubMed1990

Primary mediastinal leiomyoma.

An elderly woman was seen with a left mediastinal mass in the region of the aortic arch on chest roentgenography. Further imaging with computed tomography, angiography, and magnetic resonance demonstrated a highly vascular neoplasm adjacent to the aortic arch. Pathological analysis of the resected specimen showed a leiomyoma. A brief review of the 10 previous reported cases of primary mediastinal leiomyoma is provided.

Aged↗
PubMed1989

Small pulmonary nodules: dynamic CT with a single-breath technique.

Small pulmonary nodules can be difficult to examine with routine computed tomographic techniques, primarily because of inconsistent levels of inspiration on sequential scans. However, with the patient performing a breathing technique that involves three rapid maximal inspirations and expirations followed by a final maximal inspiration, an average of six images that cover a 12-mm section of lung can be obtained during a single breath. The technique has been used in 10 patients, with encouraging results.

Humans↗
PubMed1988

Radiology reports: assessment of a 5,000-word speech recognizer.

A prototype 5,000-word recognizer for the generation of radiologic reports by voice entry was evaluated. The system had a capacity sufficient enough to include all radiologic examinations and all desired words in one lexicon. The lack of such a capacity had been identified as a major limitation of a 1,000-word system previously evaluated. Overall reliability in word recognition was 98%. The device may be widely applicable for use in any radiology practice.

Hospital Information Systems↗
PubMed1987

Speech-controlled generation of radiology reports.

Voice entry has been successfully employed to generate radiology reports with a word recognizer with a 1,000-word lexicon capacity. About 50% of reports were able to be dictated with a single 900-word lexicon. This was split into five sections by anatomic or subspecialty application. Each was augmented to 900 words. By switching from one lexicon to another, it was possible to dictate more than 70% of reports. With exclusive use of three lexicons in subspecialty areas (gastrointestinal radiology, neuroradiology, and mammography), and with further modification of the respective vocabulary, it has been possible to employ the system 88% of the time. Twelve percent of cases included wording that was beyond the scope of the lexicon. Computer subsets that allow different translations of some words when used in different contexts have been used. Some of these are used as triggers that will print whole lines, sentences, or even complete reports. Dictation times with voice entry take about 20% longer. Recognition reliability has been greater than 95%.

Computers↗
PubMed1985

Aging and memory in skilled language performance.

The issue of irreversible decrements versus developmental plasticity with aging was explored for skilled language users. Fifteen English teachers (22 to 31 years of age) and 15 retired English teachers (50 to 83 years of age) were tested for language memory, using a 2 X 2 X 2 (Recall vs. Recognition X Meaningful vs. Nonmeaningful X Incidental vs. Intentional) design, and for overall grammar-skill memory, using speed and error measures. On the language-memory test, experimental variables (but not the age variable) were related to performance. On the grammar-skill test, the older subjects showed longer completion times but no decrements in accuracy. The results provided support for developmental plasticity in language memory and suggested an optimistic view of memory for skilled content areas.

Aged↗
PubMed1978

Pitfalls in the radiographic diagnosis of angiofibroma.

Radiographic findings previously thought pathognomonic for juvenile nasopharyngeal angiofibroma are anterior bowing of the posterior wall of the maxillary antrum on plain films or tomography, and a dense homogeneous blush on angiography. Two patients presented with nasopharyngeal masses which mimicked angiofibroma radiographically: one mass was a lymphoepithelioma and the other was a fibrous tumor. Constitutional symptoms and atypical physical findings should alert the physician to a diagnosis other than juvenile nasopharyngeal angiofibroma.

Adolescent↗
PubMed1977

The radiologic diagnosis of pneumocele of the maxillary sinus.

Pneumocele of the maxillary sinus is a recently described disease, first noted in 1974. Three subsequent cases have been encountered. Pneumocele refers to an expansile cystic air-containing mass, occupying the entire maxillary sinus, and lined by the original attenuated mucous membrane. It is analogous to mucocele, but containing air rather than fluid content. Radiologic signs are diagnostic, and it is the purpose of this presentation to enumerate these radiologic findings.

Adolescent↗
PubMedDate not supplied

Otosclerosis: comparison of complex-motion tomography and computed tomography.

A prospective computed tomographic and complex-motion tomographic evaluation was performed in 18 suspected or proven cases of otosclerosis. Although there was good agreement between both methods, there was no greater diagnostic accuracy with computed tomography. However, computed tomography demonstrated the changes better than complex-motion tomography.

Evaluation Studies as Topic↗