Biomedical subjects
Publications and source records attributed to P M Krook.
Alterations from the standard conditions under which measurements of fetal femurs are made may alter the estimate of gestational age by up to four weeks. We describe and quantify the errors induced by variations in depth, gain settings, and angle of the femur relative to the US beam. We describe a simple phantom that may be used to help eliminate these sources of possible error.
A prospective study of 70 adult patients was undertaken to determine whether lumbar metrizamide myelography can be performed as an outpatient procedure without an increased incidence of side effects and without undue risk. In selected patients and with a specific protocol, the incidence of common sequelae was similar to that in previous studies of inpatients either in bed with the head elevated or ambulatory after lumbar metrizamide myelography. No patient in this series experienced seizures or other severe complications. This approach provided increased cost effectiveness without increased risk.
The Wolfe Classification System of evaluating risk of developing breast cancer from analysis of mammographic parenchymal patterns (MPP) has received worldwide attention. In addition to confirming its validity, it is necessary to establish the ability of radiologists to apply the classification of mammograms consistently and reproducibly. This paper reports the results of 12 radiologists associated with the former Breast Cancer Detection Demonstration Projects (BCDDP) in Ann Arbor, Honolulu, Seattle, and Tucson. The participating radiologists had all had some experience with classifying mammograms, then were exposed to more intensive instruction, and finally worked with atlases developed at each institution. The results reported here show the comparisons of the radiologists' readings with Dr. Wolfe in a series of three separate exercises and also three tests of intraobserver consistency. Two of the participating institutions used xeromammograms and two, film mammograms. The study was designed and supervised by an independent data coordinating center with masking of mammograms, without benefit of information of previous readings and no information available except age. The results indicate that this group of radiologists could classify mammograms in the method of Wolfe at an acceptable level compared to other similar exercises.
To evaluate the efficacy of real-time ultrasonography in detecting cholelithiasis, a series of outpatients and inpatients was examined by oral cholecystography and real-time cholecystosonography. In 163 patients, real-time cholecystosonography achieved a sensitivity of 0.91 and a specificity of 0.99. These values are equal to or better than those usually obtained in current B-mode cholecystosonography or some reported series of oral cholecystography. However, technically excellent and meticulously performed oral cholecystography achieves slightly better sensitivity and specificity than real-time cholecystosonography. The latter is suggested as the initial examination for hospitalized patients, those with abnormal liver function studies or gastric outlet obstruction, and pregnant women. Real-time ultrasonography should also be used when the gallbladder is not adequately opacified on initial oral cholecystography if a sequential dose examination cannot be readily accomplished.
Megacystis-microcolon-intestinal hypoperistalsis syndrome was observed in a male infant. Review of the literature failed to turn up any other cases involving males. The sonogram revealed megacystis, hydronephrosis, and a normal amount of amniotic fluid. The hypoperistalsis failed to respond to several pharmacological agents, including metoclopramide and caerulein.
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Different mammographic parenchymal patterns have been found to be associated with significantly different rates for the development of breast cancer in a screening program of self-referred women. These differences are qualitatively similar but of lesser magnitude than those in previous reports by Wolfe which were based on symptomatic women who had had a previous negative mammogram. In addition, this report indicates a small difference in the rate of breast cancer at first mammographic examination, using the same parenchymal classifications. These findings, coupled with other risk factors, may permit the concentration of mammographic screening on a smaller segment of the population at risk, thus improving the benefit to risk ratio.
The routine use of single dose oral cholecystography is suggested for the examination of outpatients. A diagnosis is more quickly obtained for the great majority of patients and there is a lower incidence of side effects. An effective method of contrast administration and filming is discussed. The medical, personal, and economic impact of single dose oral cholecystography is contrasted with that for routine consecutive dose examinations in an outpatient population.
In a screening program of self-referred women, different mammographic parenchymal patterns were related to significantly different rates for developing breast cancer. The risk of cancer detection subsequent to a negative mammographic examination was 7.6 times greater for women in the highest parenchymal risk class compared with the lowest, an increase in risk comparable to that of a personal history of breast cancer and greater than that reported for any other combination of historical risk factors. These differences are qualitatively similar to, but of a lesser magnitude than, those in previous reports which were based on symptomatic women with previous negative mammograms. Data suggest this difference in risk is inherent between parenchymal patterns, rather than indicating difficulty in identifying small cancers in dense breasts. Findings of differential parenchymal risk, coupled with other risk factors, may lead to concentrating mammographic screening on a smaller segment of the population, thus improving the benefit-to-cost ratio.