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Biomedical subjects

K K Lindfors

Publications and source records attributed to K K Lindfors.

At least 19 recordsLinked to original sources
PubMed1995

The cost-effectiveness of mammographic screening strategies.

OBJECTIVE: To compare and analyze the cost-effectiveness of different mammographic screening strategies. DESIGN: A computer simulation model was developed to compare mammographic screening with observation without screening. Cost-effectiveness was expressed as marginal cost per year of life saved (MCYLS) and was calculated for the following mammographic screening strategies: (1) annual for ages 40 to 79 years; (2) annual for ages 50 to 79 years; (3) biennial for ages 50 to 79 years; (4) annual for ages 40 to 49 years with biennial for ages 50 to 79 years; (5) annual for ages 40 to 64 years with biennial for ages 65 to 79 years; (6) biennial for ages 40 to 49 years with annual for ages 50 to 79 years; and (7) annual for high-risk and biennial for normal-risk women aged 40 to 49 years with annual for ages 50 to 79 years. DATA SOURCES: The probability and cost of all outcomes were established from previously published data or community experience. RESULTS: The most cost-effective screening strategy is biennial mammography for women aged 50 to 79 years, with an MCYLS of $16,000. Adding annual mammography for women aged 40 to 49 years increases the MCYLS to $20,200, but is more cost-effective than other tested protocols that included women in their 40s; annual mammography for ages 40 to 49 years with biennial for ages 50 to 79 years is also more cost-effective than annual mammography for ages 50 to 79 years. CONCLUSION: Screening programs that include women in their 40s can be as cost-effective as some that exclude such women. Choice of a screening strategy depends on financial resources and desired effectiveness.

Adult↗
PubMed1994

Needle core biopsy guided with mammography: a study of cost-effectiveness.

PURPOSE: To analyze the cost-effectiveness of needle core biopsy (NCB) in a breast cancer screening program. MATERIALS AND METHODS: A computer model was used to compare two hypothetical groups of women: those who undergo annual mammographic screening and those observed without screening. All clinically significant outcomes for each group were included in the model, which reflected the state of a woman's health each year beginning at age 40 years and ending at age 85 years. RESULTS: The marginal cost per year of life saved by screening was reduced a maximum of 23% (from $20,770 to $15,934) with use of NCB instead of surgical biopsy. The cost of NCB had less effect on cost-effectiveness than the number of women who underwent NCB. CONCLUSION: When used for the same indications as surgical biopsy, NCB substantially reduces the cost of a breast cancer screening program.

Adult↗
PubMed1994

Screening mammography in women aged 40-49 years: analysis of cost-effectiveness.

PURPOSE: To evaluate the cost-effectiveness of screening mammography in women 40-49 years old. MATERIALS AND METHODS: A Markov model compared two hypothetical groups; one underwent screening mammography and the other, observation without mammography. Variables tested included frequency of mammography, reduction in breast cancer mortality, and cost-effectiveness by age group. Results were expressed as marginal cost per year of life saved. RESULTS: If the estimated mortality reduction from mammographic screening was 15% or greater, the marginal cost per year of life saved was comparable to that of other generally accepted medical procedures. Annual screening with an assumed 30% reduction in mortality had a cost-effectiveness similar to that of biennial screening with a 20% reduction. Screening mammography was less cost-effective in the 40-49-year-old age group than in women aged 50-79 years but more cost-effective than in those aged 80-84 years. CONCLUSION: Although the parameters for screening mammography in women aged 40-49 years are not known with certainty, the results of this analysis may help establish priorities for utilization of medical resources.

Adult↗
PubMed1993

Diuretic Doppler sonography following successful repair of renal obstruction in children.

The measurement of resistive index (RI = [peak systolic velocity--end diastolic velocity]/peak systolic velocity) by Doppler sonography has demonstrated variable reliability as an indicator of pediatric urinary obstruction. By modifying Doppler studies with the addition of furosemide (diuretic Doppler sonography), we previously found significant differences between 10 nonobstructed and 10 obstructed kidneys in children (median age 7 months). The obstructed kidneys have since undergone surgical repair, and postoperative reevaluation has been performed by diuretic Doppler sonography and diuretic renography. Diuretic Doppler sonography was performed on well hydrated catheterized patients, with resistive index measurement of the renal interlobar and arcuate arteries obtained before and 10 minutes after 1 mg./kg. furosemide infusion. Following surgical repair of obstruction all 10 kidneys had stable glomerular filtration rate with improved pelvic emptying times as demonstrated by half-time. Of 6 kidneys evaluated by diuretic Doppler sonography before 3 months 2 had resistive index levels greater than 75. Of the 9 kidneys measured at 3 months or more postoperatively all had resistive index values of less than 75, even after furosemide infusion (5 kidneys underwent repeat evaluation). In our study the previously demonstrated post-diuretic elevation of resistive index in pediatric urinary obstruction was eventually reversed following surgical repair. Diuretic Doppler sonography appears to be a promising noninvasive method for evaluating pediatric hydronephrosis, providing an alternative physiological parameter with which to measure renal obstruction.

Furosemide↗
PubMed1991

Cytologic interpretation of fine-needle aspiration biopsies from clinically occult breast masses.

Fine-needle aspiration biopsy (FNAB) was performed on 39 occult breast masses of soft tissue density using standard mammographic guidance. All malignant tumors were diagnosed as either positive or suspicious for carcinoma, and there were no false-positive or false-suspicious diagnoses. These excellent results can be attributed to accurate cytologic interpretation based on consideration of problems unique to these lesions and the sampling method, such as scantier cellularity, potentially less confidence in needle placement, and the nature of the occult mass itself. The team approach between pathologist, radiologist, and clinician is emphasized.

Biopsy, Needle↗
PubMed1991

The roles of ultrasonography and amniocentesis in evaluation of elevated maternal serum alpha-fetoprotein.

A total of 681 pregnant women were referred for evaluation of elevated maternal serum alpha-fetoprotein levels. Ultrasonographic examination yielded an explanation for the elevation of maternal serum alpha-fetoprotein in 42% of patients. Diagnoses made by ultrasonography included incorrect fetal dating, multiple gestation, fetal death, open neural tube defect, abdominal wall defect, placental abnormalities, cystic hygroma, renal anomalies, and oligohydramnios. Optimal prenatal diagnosis of fetal anomalies also requires the use of amniocentesis in many patients. Amniocentesis may be obviated if fetal dating is incorrect, if an unsuspected multiple gestation is discovered, or if there is a clear anomaly and the parents do not desire genetic counseling based on karyotype information. If the fetus appears normal, the ultrasonographic results are equivocal, or the parents desire more detailed genetic counseling when an anomaly is found by ultrasonography, then amniocentesis should be performed. Thirteen abnormalities were diagnosed by amniocentesis alone in this group.

Amniocentesis↗
PubMed1991

Diuretic Doppler sonography in postnatal hydronephrosis.

Renal resistive indexes were measured by Doppler sonography in 12 children undergoing other standard diagnostic studies to evaluate hydronephrosis. Measurement of renal resistive indexes was modified by prior placement of a bladder catheter, oral hydration and administration of 1 mg./kg. furosemide after baseline measurement. Renal resistive indexes were again measured at 10 and 30 minutes after diuretic. While diuretic administration had no measurable influence on 10 nonobstructed kidneys, the elevated 10-minute post-diuretic renal resistive indexes recorded in 10 obstructed kidneys differed significantly from the indexes recorded in the nonobstructed group (p less than 0.001). The highest elevations in renal resistive indexes were recorded in nonpaired kidneys, which included 7 of the 10 kidneys in the obstructed group. In the 3 unilaterally obstructed kidneys the 10-minute post-diuretic renal resistive indexes did not differ significantly. However, renal resistive indexes in these kidneys increased at least 15% over baseline readings after diuretic administration. Diuretic Doppler sonography appears to be another useful method for differentiating functionally significant hydronephrosis from nonobstructive hydronephrosis in children.

Child↗
PubMed1990

The rediscovery of infant feeding formula with magnetic resonance imaging.

In six newborns, regular infant feeding formula given approximately one-half hour to four hours prior to MR examination, demonstrated a high intensity signal within the infant's stomach, small bowel, and colon. This effect was observed on both 0.5 Tesla and 1.5 Tesla magnets on T1 (SE TR/TE 433-600/20-25) and on T2 (SE TR/TE 1500/30-80) weighted images. Infant feeding formula has the potential to be used as an oral contrast agent for visualization of the newborn gastrointestinal tract. Chloral hydrate and other agents were also tested.

Digestive System↗
PubMed1989

Medullary carcinoma of the breast: mammographic and US appearance.

Medullary carcinoma of the breast is an uncommon tumor, which may mimic a benign mass at both mammography and ultrasonography (US). A total of 24 medullary carcinomas visible at mammography appeared as round or oval, noncalcified masses with varying degrees of marginal lobulation. In six of the 24 patients, US demonstrated well-defined masses with an inhomogeneous, hypoechoic texture. There was no attenuation of sound, and all lesions showed enhanced through transmission.

Adult↗
PubMed1989

Stab wounds to the neck: role of angiography.

Angiographic findings in 61 stab wounds to the neck were correlated with specific clinical findings. Eighteen of the stab wounds were associated with one or more major physical findings that included (a) pulse deficit, (b) active bleeding or expanding hematoma, (c) bruit or murmur, (d) neurologic deficit, or (e) hypotension. Of these 18 wounds, only two involved significant vascular injuries. The other 43 stab wounds were associated with minor physical findings, with the only indications for angiography being nonexpanding hematoma or proximity of trauma to major vessels. None of these 43 wounds involved significant vascular injury.

Adolescent↗
PubMed1989

Percutaneous cholecystostomy: an alternative to surgical cholecystostomy for acute cholecystitis?

Emergency percutaneous cholecystostomy was successfully performed in 39 of 40 attempted procedures in 37 hospitalized patients with possible acute cholecystitis. All cholecystostomies were performed with ultrasound guidance and preferentially with the transhepatic route, and all but four were performed at the patient's bedside. The patients had been hospitalized an average of 27 days before the procedure. Twenty-two of the 37 patients (59%) eventually died during hospitalization because of other medical or surgical problems. Only minor complications related to percutaneous cholecystostomy placement occurred in this series: catheter dislodgment without sequelae (n = 2) and significant abdominal pain (n = 2). Technical problems included guide-wire buckling during catheter insertion (n = 1) and failed attempted cholecystostomy (n = 1). Percutaneous cholecystostomy is a safe alternative to surgical cholecystostomy in the treatment of patients suspected of having acute cholecystitis.

Acute Disease↗
PubMed1988

Congenital cerebrospinal fluid-containing intracranial abnormalities: a sonographic classification.

Ultrasound is useful as a primary modality for diagnosis of complex nonhydrocephalic intracranial malformations. We present 10 cases of intracranial cerebrospinal fluid containing abnormalities that may be diagnosed by ultrasound. Congenital abnormalities presented include holoprosencephaly, hydranencephaly, agenesis of the corpus callosum with interhemispheric cyst, porencephaly, schizencephaly, and arachnoid cyst. Ultrasound may be used in the fetus or neonate in detecting and separating these abnormalities from hydrocephalus.

Abnormalities, Multiple↗
PubMed1988

Acute cholecystitis: diagnostic accuracy of percutaneous aspiration of the gallbladder.

Results of gallbladder bile aspiration and culture were correlated with presence or absence of acute cholecystitis in 36 patients to test the role of these procedures in hospitalized patients with sepsis. Diagnostic aspiration of the gallbladder was performed in 11 patients, and in the remaining patients a combination of percutaneous aspiration, percutaneous cholecystostomy, or cholecystectomy was used. Bile culture was not helpful in the prediction of acute cholecystitis, since results were not available for a minimum of 24-48 hours after aspiration. In addition, gram-stained smears and bile cultures suffered from low sensitivity (48% and 38%, respectively); consequently, a negative test does not allow the diagnosis of acute cholecystitis to be excluded. Bile aspiration of the gallbladder thus has a limited role in the diagnosis of this condition.

Acute Disease↗