PubMed Health⌕ Search

Biomedical subjects

R G Evens

Publications and source records attributed to R G Evens.

At least 19 recordsLinked to original sources
PubMed1979

Utilization of head computed tomography units: in installations with greater than two-and-a-half years' experience.

Utilization and economic data from head computed tomography (HCT) units providing more than 2 1/2 years' experience are compared with data from installations in 1976. The average unit operates 60 hr/wk, examining 63 patients. Nearly half the examinations are "double" studies, requiring about 53 minutes. The annual total technical cost is approximately $383,000. Charges have been reduced since 1976. While technical charges are lower in high-volume institutions, professional charges are higher. Usual charges and expected net revenues are above Medicare maximum allowable charges. Most units meet the national guidelines. There is considerable variation in data from individual facilities; a "typical" HCT unit cannot be defined.

Cost-Benefit Analysis↗
PubMed1979

Utilization of body computed tomography units: in installations with greater than one-and-a-half years' experience.

Utilization and economic data from body computed tomography (BCT) units with more than 1 1/2 years' experience are compared to data in 1977. The average unit operates 52 hr./wk., examining 34 patients. Head studies constitute 55% of examinations, abdominal and pelvic 38%. The total technical cost of examining 35 patients/wk. is approximately $384,000. Charges have been reduced since 1977 by approximately 5%; the average annual loss is about $77,000. Technical and professional charges are lower in high-volume institutions. Current Medicare maximum allowable charges are below BCT costs and charges. Only 17% of installations meet the National Guidelines of 2,500 patient examinations per year.

Cost-Benefit Analysis↗
PubMed1979

Iosefamate meglumine: an iodinated contrast agent for hepatic computed tomography scanning.

Iosefamate meglumine, a water-soluble, iodinated compound which is chemically and pharmacologically similar to iodipamide, was studied as a contrast agent for hepatic CT scanning in dogs. The difference between the CT attenuation number of liver and blood increased by 16 EMI units after intravenous injection of iosefamate 150 mg l/kg. The agent may prove useful in improving the CT detection of isodense tumors within the liver.

Animals↗
PubMed1978

Complementary use of ultrasound and computed tomography in studies of the pancreas and kidney.

113 cases of pancreatic and renal disease studied by both ultrasound and computed tomography (CT) were analyzed retrospectively. CT provided a diagnosis when pancreatic ultrasound was unsuccessful due to overlying bowel gas or obesity and when renal ultrasound was unsuccessful due to obesity, reverberations from ribs, small lesions, or multiple lesions. Conversely, ultrasound provided a diagnosis when CT was unsuccessful due to lack of fat planes or respiratory motion. CT usualy distinguished carcinoma from pancreatitis when ultrasound showed a focal echogenic mass. CT resolved renal cyst from neoplasm when ultrasound showed a mixed echo pattern mass.

Diagnosis, Differential↗
PubMed1978

Economic analysis of body computed tomography units including data on utilization.

All operating body computed tomography installations in the United States were surveyed in May 1977; data were obtained from 74 of 118 installations. Utilization and economic data from this survey are compared to similar data from January 1976. Scheduling delay data indicate that computed tomography availability is closer to meeting the clinical demand for CT studies than in January 1976; however, CT demand (as indicated by scheduling delay) is rising at installations with greater than 5 months BCT experience. The estimated annual technical cost of BCT is $359,000--$392,000 with a patient volume of 25--50 patients per week and is higher than the current net technical revenue.

Costs and Cost Analysis↗
PubMed1977

The clinical efficacy and cost analysis of cranial computed tomography and the radionuclide brain scan.

Cranial computed tomography (CCT) has already been demonstrated to provide significant diagnostic information in patients with neurologic disease and to reduce the need for special neuroradiologic procedures. The important question remaining is: Should CCT replace the radionuclide brain scan (RBS) as the first diagnostic study in most patients with suspected intracranial pathology? Data are now available to define the costs and benefits of this substitution. The technical costs of CCT have been determined by a national survey and have shown to be $130 per patient at a volume of 50 patients per week. The costs of RBS at the Mallinckrodt Institute have been estimated at $51 per patient. Data from the literature indicate that CCT is slightly more sensitive and considerably more accurate than RBS. Eighteen to twenty-eight percent of patients studied by CCT and RBS have abnormalities (e.g. cerebral atrophy and ventricular dilatation) that are only detected by CCT, and the overall accuracy of CCT is 95%, while the accuracy of RBS is approximately 70%. Substituting CCT for RBS is cost-beneficial. Although CCT is more costly, it increases overall accuracy by approximately 25%. The cost benefit is further increased by the reduction of complicated diagnostic procedures (and associated hospitalization and morbidity) and improvement in diagnostic information for the individual patient. Substituting CCT for RBS may not be more costly because a positive RBS will be followed by CCT (because of increased diagnostic information), and a negative RBS may be followed by CCT (because of increased accuracy), whereas a positive or negative CCT is unlikely to be followed by RBS.

Brain Diseases↗
PubMed1977

Body computed tomography: a clinically important and efficacious radiologic procedure.

In the institutions represented by the authors, more than 7,500 body CT examinations have been performed. Body CT has been found to be particularly useful in solving specific problems, especially when other diagnostic procedures yield confusiing results. Radiologists and their collegues, and not governmental agencies and insurance companies, should define the experimental, research and clinical usefulness of computed tomography.

Humans↗
PubMed1977

Utilization, reliability, and cost effectiveness of cranial computed tomography in evaluating pseudotumor cerebri.

Cranial computed tomography (CT) has reduced the frequency of cerebral angiography from 95% to 32% and pneumoencephalography from 71% to 11% in patients with pseudotumor cerebri. Total hospital stay has been significantly reduced from a mean of 19.6 to 13.3 days and the hospital days required for diagnosis from a mean of 5.8 to 3.4. The diagnostic reliability of CT in pseudotumor cerebri was estimated using Bayes's decision theorem. The combination of CT and radionuclide brain scans provide diagnostic accuracy similar to radiologic contrast studies. The diagnosis of pseudotumor cerebri can be adequately established without cerebral angiography and air studies. CT has significantly reduced the morbidity, time, and cost of diagnostic evaluation in these patients.

Brain↗
PubMed1976

New frontier for radiology: computed tomography. 40th Annual Preston M. Hickey Memorial Lecture.

The basic principles of computed tomography (CT) and their application are discussed. The impact of this method on neuroradiologic diagnosis is reviewed, including economic considerations and the effect on nuclear medicine and other diagnostic procedures. The initial experiences of the Mallinckrodt Institute with whole body scanning are illustrated, and failure possibilities for CT are predicted.

Aged↗
PubMed1976

Economic analysis of computed tomography units.

All operating CT installations in the United States were surveyed in January 1976; data were obtained from 98 of 140 installations. Although the respondents represented 80 head units and 18 head and body units, the overwhelming experience was with head CT studies. CT equipment was installed in an average of 1.3 months, operated 64 hr per week and examined 50-55 patients per week. A downtime of 7 hr per week was reported. Radiologists are responsible for 92 of 98 installations, and 90% of installations are in a hospital. The scheduling delay averages 1.6 days for inpatients and 11.5 days for outpatients. The delay is increasing in many installations. The estimated total yearly technical cost is +325,000-+371,000 per installation, depending upon patient volume. The estimated technical cost per patient (when 50 patients per week are studied) compares favorably with the estimated net revenue per patient from the average basic technical charge (+130 compared to +138). A separate billing method is used by 59% of installations, and 76% have an extra charge for contrast injection and additional studies; 60% of patients receive contrast. The reported total charges during the last 3 months were higher in installations that (1) charged additionally for contrast, (2) were located in outpatient settings, and (3) had nonradiologists as the responsible physician. It should be emphasized that most CT installations are not independent activities and should be considered an integral part of a diagnostic radiology department or office.

Ambulatory Care↗