Search PubMed⌕ Search

Biomedical subjects

L H Nelson

Publications and source records attributed to L H Nelson.

49 records · Page 3Linked to original sources
PubMed1981

Comparison of methods for determining crown-rump measurement by real-time ultrasound.

Determination of gestational age without an accurate last menstrual period is difficult. In the later stages of pregnancy, the correlation between fetal biparietal diameter (BPD), as determined by ultrasound, and gestational age is compromised by normal biologic variation in fetal growth rates. The fetal crown-rump measurement (CRM) by gray-scale sonography has been described but has not been evaluated using real-time ultrasound. Currently available tables for determining gestational age from the fetal CRM were evaluated using a linear array real-time ultrasound system. A normal obstetric population with known menstrual histories, delivery dates, and Dubowitz scores at delivery was used for evaluation. On the basis of this study, Robinson's data listed as "regression analysis values" are suggested for application to real-time ultrasound. Alternatively, the equation generated from data on the above 86 patients could be used and further evaluated. The fetal CRM appears to be a valid and accurate assessment of gestational age.

Anthropometry↗
PubMed1980

Sonolucencies in fetal and infant abdomen: implications for management.

The increased use of prenatal and antenatal ultrasonography will detect predictably abnormalities of fetal and infant anatomy not assessed or suspected previously. Three cases are presented illustrating similar ultrasonographic findings with different diagnoses and prognoses, and comparisons are made with other cases reported in the literature. Caution should be used in interpreting sonolucencies in fetal and infant abdomen to be diagnostic of a particular defect since further studies are required to define properly the specific abnormality so that proper treatment can be instituted.

Abnormalities, Multiple↗
PubMed1979

Real-time ultrasound in locating intrauterine contraceptive devices.

Roentgenography and ultrasonography have been recommended for location of an intrauterine contraceptive device (IUCD) when the strings are not visible at the cervical os. Real-time ultrasound may have limited application compared to gray-scale B-scanning in certain clinical applications. Because of previous difficulty in locating an IUCD in 2 gravid and 2 nongravid patients, a blind study of 68 women was conducted. Seven patients were eliminated from the study because of inadequately filled bladders and failure to return for follow-up visits. There were 37 patients with IUCDs and 24 patients in the control group who used other forms of contraception. An incorrect diagnosis was made in 12 of 61 patients. Ten of 37 patients with an IUCD were identified as having no IUCD and 2 of 24 patients without an IUCD were identified as having an IUCD present. The accuracy of correctly identifying the presence or absence of an IUCD appears to be related to the type of device used. All of the 20 patients with a Copper-7 were correctly identified as having an IUCD, although the type was in error in 11 of the 20. Five of 7 patients with a Lippes Loop and none of the patients with a Saf-T-Coil were correctly identified as having an IUCD. Prior literature is reviewed, and possible sources of error are discussed.

False Negative Reactions↗
PubMed1978

Use of professional patients in teaching pelvic examinations.

Learning proper techniques in physical examinations is mandatory for a physician. Although students may examine each other in early training, examination of the female pelvis does not readily conform to this reciprocity. A randomized study was conducted, comparing teaching methods utilizing professional patients or plastic models. Training on a professional patient significantly increased a student's chance of palpating one or both ovaries, reduced the student's anxiety about performing a pelvic examination, and may have improved the student's gentleness. Costs of the professional patient method were minimal. It is recommended that teaching pelvic examinations with the professional patient replace teaching on the plastic model.

Female↗
PubMed1977

Ultrasonographic description of succenturiate placenta.

Postpartum hemorrhage may occur in cases of a retained succenturiate lobe. More catastrophic is rupture of the fetal vessels connecting the lobe to the placenta. A case is presented demonstrating the sonographic description of a large succenturiate lobe.

Adult↗
PubMed1977

Ultrasonography preceding diagnostic amniocentesis and its effect on amniotic fluid cell growth.

Experience with 107 consecutive patients with and without ultrasonography preceding diagnostic amniocentesis is presented. Cell cultures and alpha-fetoprotein levels were obtained on all specimens. Adequate cell growth was found in both groups. The frequency of bloody taps was reduced from 15 to 6.9% and of repeat taps from 6.3 to 0%. Possible complications of amniocentesis which might be avoided by prior ultrasonography are discussed. The use of gray scale or real time ultrasonography prior to diagnostic amniocentesis is stressed.

Adult↗