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Biomedical subjects

N M Hickey

Publications and source records attributed to N M Hickey.

15 recordsLinked to original sources

Integrated radiologic information system: a radiology multimedia communication system.

A multimedia radiologic communication system has been developed that achieves the system design goal of providing a clinical communication service that is an efficient improvement over present methods of communication. The system allows users to access, through a workstation, digitized radiographic images, voice reports, and other patient data. Physicians can consult with each other while simultaneously accessing this information through a shared visual workspace, even though they are in different places. The system was designed by a multidisciplinary team including radiologists, clinicians, engineers, user-interface specialists, and psychologists from hospital, university, and research settings in an effort to maximize system performance and clinical utility.

Computer Communication Networks

Percutaneous embolotherapy in life-threatening hemoptysis.

Percutaneous embolization of the bronchial arteries to control massive or recurrent hemoptysis has become an accepted procedure, especially in treating patients with chronic pulmonary disease who are poor candidates for lung resection. Nonbronchial systemic collateral arteries and pulmonary arteries may contribute significantly to pulmonary hemorrhage, but embolization of these vessels has not been stressed in recent literature. When embolization of the bronchial artery fails to control hemoptysis, nonbronchial systemic collateral arteries should be embolized. If no systemic collaterals are present, then embolization of segmental pulmonary arteries may prove helpful.

Acute Disease

Dual-energy digital radiographic quantification of calcium in simulated pulmonary nodules.

The presence or absence of calcium in solitary pulmonary nodules may indicate whether a nodule is benign or malignant. Because current techniques for measuring the amount of calcium in these nodules are unsatisfactory, a study was carried out to assess the capability of dual-energy digital chest radiography to identify and quantify the calcium content of simulated pulmonary nodules of known calcium content. Measurements were carried out on 280 nodules of various sizes and calcium content that were placed within the lungs of a frozen human-chest phantom. A new calcium quantification technique that uses a parallelogram was developed to eliminate the problem of nodule superimposition over ribs. Nodules containing more than 35 mg of calcium per square centimeter (i.e., 7, 30, 60, and 110 mg of calcium for spherical nodules 0.5, 1.0, 1.5, and 2.0 cm in diameter) were measured with a high degree of accuracy and reasonable precision. Dual-energy digital radiography is a simple and accurate method of measuring the calcium content of solitary pulmonary nodules in humans.

Calcium

Simulated pulmonary nodules: detection with dual-energy digital versus conventional radiography.

Performance of a prototype dual-energy digital chest radiography unit in detecting calcified and noncalcified simulated pulmonary nodules was compared with that of a highly optimized, conventional system. Nodules ranging in size (0.5, 1.0, and 1.6 cm), in number (five to 11), and in calcium content (0-25 mg) were superimposed over the lungs of a frozen, unembalmed, human chest phantom. For each technique, six observers examined 50 posteroanterior projections with different randomized nodule locations. Detection consisted of locating and assigning a level of confidence to each perceived nodular opacity. The resulting plots of the true-positive fraction versus the mean number of false-positive calls per projection indicate that for both calcified and noncalcified nodules, the digital unit performed significantly better (P less than .01).

Cadaver

Calcification in pulmonary nodules: detection with dual-energy digital radiography.

The authors undertook a clinical study to determine the accuracy of dual-energy digital radiography in revealing nodule calcification because calcification in a pulmonary nodule almost excludes the possibility of malignancy. Over a 6-month period, 61 patients with pulmonary nodules (less than or equal to 3 cm) or masses (greater than 3 cm) were examined on a prototype scanned projection unit using a dual-energy detector. In 49 of 61 patients, nodules were noncalcified, and in 12, they were calcified. In 57 patients, the benignancy or malignancy of nodules was established beyond reasonable doubt by pathologic confirmation in 38 and by strong inference in 19 (four patients with noncalcified solitary pulmonary nodules either refused further investigation or surgery or their follow-up was too short to permit exclusion of malignancy). Dual-energy radiography was found to be highly accurate in assessing the presence or absence of calcification in pulmonary nodules and thus in determining their benignancy or possible malignancy.

Adult

A modified procedure for percutaneous abscess and fluid drainage using the Malecot catheter-Stamey needle technique.

Percutaneous abscess and fluid drainage (PAFD) of various intraabdominal collections with computed tomographic and ultrasonic guidance is well established. Current techniques use a catheter of pigtail design introduced either by multiple step dilatations or a separate trocar insertion, and are subject to complications which can be avoided by use of a new catheter-needle system we propose. This system uses a straight, winged, Malecot catheter which is introduced in one step with a Stamey needle. We report upon our experience with the Malecot catheter/Stamey needle system for PAFD in 13 patients with good results. This method ensures a single step introduction of a large bore catheter, accurate catheter placement, a stable catheter position with good function, and easy drainage of multiloculated or multiple abscesses.

Abscess

"Salmon".

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Midwifery

One for one.

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Clothing

A quantitative comparison of light and electron microscopic diagnoses in specimens obtained by fine-needle aspiration biopsy.

Because fine-needle aspiration biopsy (FNAB) is being increasingly used as a primary diagnostic tool, it is essential to obtain the maximum information from the aspirate. Electron microscopy is an adjunctive procedure that is readily applied to FNAB specimens. The value of electron microscopy to the cytopathologist was assessed by comparing the initial, tentative, or interim diagnosis based on light microscopic features with the diagnosis resulting from the ultrastructural characteristics of needle rinse material. Over a 3-year period, 279 FNAB specimens obtained under radiologic control were examined ultrastructurally; of these, 57 (20.4%) were considered inadequate specimens for diagnostic purposes. The remaining 222 FNAB specimens were segregated into four groups: 17 cases (7.7%) in which electron microscopy played a major role because the final diagnosis was unsuspected from light microscopy; 43 cases (19.4%) in which electron microscopy selected a specific diagnosis from a set of differential diagnoses or provided additional information that was clinically relevant; 45 cases (20.3%) in which additional diagnostic information was obtained by electron microscopy but was not clinically relevant; and 117 cases (52.6%) in which electron microscopy was not helpful because the light and electron microscopic diagnoses were the same. In this comparative study, electron microscopy provided a major contribution to the final cytologic diagnosis in 27.1% of the cases (groups 1 and 2). Descriptive examples illustrate how the architectural and cytologic features revealed by electron microscopy assist in establishing the final diagnosis. Examination of needle rinse specimens, particularly aspirates from lung and liver, indicates that most FNABs provide mini-surgical biopsy specimens that are well suited to ultrastructural examination.

Adult

Thoracic fine needle aspiration biopsy versus fine needle cutting biopsy. A comparative study of 40 patients.

The fine needle aspiration (FNA) biopsy findings were compared with the results of fine needle cutting (FNC) biopsy in 40 patients. The lesions (38 pulmonary nodules, 1 mediastinal mass and one lytic rib lesion) were biopsied with 22-gauge Greene and 21-gauge E-Z-EM needles through a 19-gauge needle guide. The FNA biopsy findings were based on smears and cell blocks of material obtained with the Greene needles while the FNC biopsy findings were based on tissue cores obtained by the E-Z-EM needles. In 83% of the cases, both techniques yielded specimens with similar cellularity; in seven cases, the FNA samples were more cellular. Malignancy was diagnosed in 80% of the patients: by both techniques in 26 patients, by FNA biopsy only in 5 patients and by FNC biopsy only in 1 patient. The sensitivity of FNA biopsy was higher than that of FNC biopsy (96.8% vs. 84.3%). The specificity and predictive value of positive results were 100% for both techniques. The predictive value of negative results was higher for FNA biopsy (88.8% vs. 54.5%). The majority of FNC biopsy tissue cores consisted mostly of clotted blood, lung tissue and/or fibrous tissue and did not facilitate or improve the diagnosis. Those data suggest that the contribution of FNC biopsy to the diagnosis of thoracic neoplasms is very limited and that the performance of FNC biopsy with an E-Z-EM needle in addition to or instead of FNA biopsy is not justified.

Adenocarcinoma