Search PubMed⌕ Search

Biomedical subjects

R T Davis

Publications and source records attributed to R T Davis.

13 recordsLinked to original sources
PubMed1987

Normal hepatic and splenic size in children: scintigraphic determination.

Measurements were made on sulfur colloid scintigrams of normal pediatric livers and spleens by analyzing 131 scans from 116 patients referred for liver or spleen trauma. Studies were used only if scans were normal, there was no history of malignancy or hepatic or splenic disease either prior to of after the study. Linear correlation was made with age, weight and both age and weight. All measured parameters correlated better with weight than with age, with vertical liver dimension exhibiting the best correlation (r = 0.848). Multivariate analysis demonstrated uniformly better correlation of all measurements with both age and weight. Spleen and liver volumes were calculated assuming simple geometry, and showed excellent correlations. Graphical presentation of data will be useful in the clinical determination of hepatomegaly or splenomegaly in routine scintigraphy.

Adolescent↗
PubMed1987

Vesicoureteral reflux in asymptomatic siblings of patients with known reflux: radionuclide cystography.

The familial nature of vesicoureteral reflux among siblings of patients with vesicoureteral reflux has been reported to be from 8% to 32%. These included both symptomatic and asymptomatic siblings. The incidence of vesicoureteral reflux in asymptomatic siblings, however, has not been studied extensively. Sixty asymptomatic siblings of patients known to have vesicoureteral reflux were studied with radionuclide voiding cystography. Their ages ranged from 2 months to 15 years (mean, 4.2 years). Vesicoureteral reflux was detected in 27 of 60 (45%) of the siblings. Vesicoureteral reflux was unilateral in 15 and bilateral in 12 of the siblings. Radionuclide cystography is more sensitive than radiographic cystography and results in a very low radiation dose to the patient. The gonadal dose with radionuclide cystography is only 1.0 to 2.0 mrads. Because of these features, radionuclide cystography is a nearly ideal technique for the diagnosis of vesicoureteral reflux in siblings of patients with known vesicoureteral reflux. All siblings (symptomatic or asymptomatic) of patients with known vesicoureteral reflux should have a screening radionuclide cystography.

Child↗
PubMed1986

Comparison of ultrashort-lived iridium-191m with technetium-99m for first pass radionuclide angiocardiographic evaluation of right and left ventricular function in adults.

Ultrashort-lived iridium-191m (Ir-191m, physical half-life = 5.0 seconds) has been used in angiocardiography, primarily in pediatric patients. A theoretical obstacle to more widespread use of Ir-191m is the belief that its physical half-life is too short to permit evaluation of left ventricular function in adult patients. To evaluate its usefulness in adults, first pass ejection fractions of the left and right ventricles determined with use of Ir-191m and technetium-99m (Tc-99m) were compared in 33 adult patients. An osmium-191m----iridium-191m (Os-191----Ir-191m) generator was employed to deliver doses of 150 to 250 mCi (5.5 to 9.2 GBq) of Ir-191m for intravenous injection. The whole body radiation absorbed dose with Ir-191m was 15 to 25 mrad. High quality angiocardiograms were obtained with both Tc-99m and Ir-191m. Total counts per image for the right ventricle were 51,000 +/- 8,000 (mean +/- SD) for Ir-191m and 30,000 +/- 8,000 for Tc-99m. The left ventricular counts were comparable for both radiotracers (25,000 +/- 7,000 for Ir-191m and 25,000 +/- 8,000 for Tc-99m). Right ventricular ejection fractions were similar: 44 +/- 8% for Ir-191m and 47 +/- 9% for Tc-99m. The correlation coefficient was 0.93 with a standard deviation of the regression of 3.1% ejection fraction units. The left ventricular ejection fractions were also similar: 45 +/- 14% for Ir-191m and 46 +/- 13% for Tc-99m. The left ventricular ejection fraction correlation coefficient was 0.96 with a standard deviation of the regression of 3.7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Variations on the family resemblance hypothesis as applied to personality disorders.

Diagnosis and classification of the personality disorders is controversial and problematic. Diagnostic reliability is uneven because of overlapping of traits and the lack of clear boundaries between categories. This study demonstrates that personality disorder diagnosis is dependent on the total number of defining features. Clinicians tend to ignore the presence of conflicting features when making a diagnosis. A new research instrument, artificially created case histories that allow the specific manipulation of defining features (i.e., diagnostic criteria), is described.

Diagnosis, Differential↗