PubMed Health⌕ Search

Biomedical subjects

C A Gooding

Publications and source records attributed to C A Gooding.

At least 37 records · Page 2Linked to original sources
PubMed1994

Role of MRI in the evaluation of ambiguous genitalia.

Diagnostic accuracy of magnetic resonance imaging (MRI) interpretation was assessed prospectively in patients with ambiguous genitalia or intersex problems. MRI depiction of the uterus was possible in 93%, the vagina in 95%, the penis in 100%, the testis in 88%, and the ovary in 74% of patients. The strength of MRI lies in the multiplanar capability and tissue characterization by means of T1- and T2-weighted sequences. MRI contributes to accurate morphologic evaluation of müllerian duct structures, the gonads, and the development of the phallus, all of which are essential for appropriate gender assignment and planning of surgical reconstruction.

Adolescent↗
PubMed1989

Quantitative density-time measurements in the lungs of children with suspected airway obstruction using ultrafast CT.

Fourteen children under 3 years of age with possible airway obstruction were evaluated with an ultrafast CT scanner, Imatron C-100. Serial 0.05-second multilevel scans were obtained through the chest at rates of 17 images per second. No patient sedation or contrast medium was used. Time-density curves generated over each lung and specific pulmonary zones were compared to characterize the normal variation of density during inspiration and expiration and to determine abnormal patterns associated with airway obstruction. There was a high, positive correlation value (r greater than 0.79) between time/density curves over those pulmonary regions in which there was no focal bronchial obstruction and a low, negative correlation value (r = less than -0.58) with bronchial obstruction. Three studies with reconstruction artifacts were excluded. Furthermore, the results indicate that young children generally have denser lungs, particularly in expiration, than older children or adults. This preliminary study suggests that ultrafast CT offers a promising, unique, rapid and noninvasive approach for diagnosing airway obstruction in childhood.

Airway Obstruction↗
PubMed1989

Metabolic and anatomic development of the chick embryo as studied by phosphorus-31 magnetic resonance spectroscopy and proton MRI.

Thirty fertilized chick eggs were studied sequentially over the 22-day maturation period of the egg by phosphorous-31 (P-31) magnetic resonance spectroscopy (MRS) and proton (H-1) magnetic resonance imaging (MRI) at 2.0 Tesla. The total MR observable P-31 volume in the egg decreased by nearly 80% from day 4 through day 22, suggesting P-31 uptake into tissues in which the P-31 signal is not visible by MR, such as phospholipid bilayers, membranes, cellular structures, and bone mineral phosphates. Of the remaining visible phosphates, the relative phospholipid peak area decreased and the relative peak areas of the phosphocreatine and nucleoside di- and triphosphate metabolites increased. Inorganic phosphate also showed an increase in peak area during maturation. The metabolic development correlated with the anatomic development of visible structures such as brain, eyes, spine and organs in the chick as seen by MRI. In-vivo MR techniques offers the potential to follow changes in prenatal development and maturation.

Adenosine Triphosphate↗
PubMed1988

Preservation of sickle cell blood-flow patterns during MR imaging: an in vivo study.

Magnetic fields and RF energy have been shown to affect sickle erythrocytes in vitro. Because both strong magnetic fields and RF energy are used in MR imaging, it has been suggested that capillary blood flow in patients with sickle cell disease may be altered during MR imaging. In order to examine sickle cell blood flow during MR imaging in vivo, laser-Doppler velocimetry was performed in normal control subjects and in sickle cell subjects before, during, and after MR imaging at 0.35 and 1.5 T. Mean blood flow and patterns of blood-flow variability were compared by two hematologists. No differences were found on the recordings from each subject made before, during, and after MR imaging were compared. Blood-flow patterns generally differed between control and sickle cell subjects. Periodic oscillatory blood flow, reportedly a specific finding in sickle cell subjects, was observed in one control subject and was not consistently found in sickle cell subjects. Although energies employed during MR imaging have effects on sickle erythrocytes in vitro, our data show no changes in sickle cell blood flow during MR imaging in vivo.

Anemia, Sickle Cell↗
PubMed1987

31P magnetic resonance spectroscopy of mesenteric ischemia.

31P magnetic resonance spectroscopy (MRS) was performed in vivo on normal and ischemic rat intestine. Within 3 min after induction of ischemia, there is a dramatic fall in adenosine triphosphate (ATP) and rise in inorganic phosphate (Pi). Our results suggest that MRS may prove useful in the early detection of mesenteric ischemia.

Adenosine Triphosphate↗
PubMed1987

Upper airway obstruction in infants and children: evaluation with ultrafast CT.

The diagnostic accuracy of ultrafast computed tomography (CT) was evaluated prospectively in 25 infants and children with suspected airway obstruction. All examinations were conducted in spontaneously breathing, nonsedated children. Scan acquisition times were 0.05 or 0.1 second. CT examinations, completed in an average of 10 minutes, routinely included localizing, contiguous sections through the trachea followed by serial images obtained at a rate of 17 per second through regions of interest. Imaging results were correct in 24 of 25 examinations as judged from clinical and surgical data. Ultrafast CT data permitted diagnosis of dynamic changes in airway caliber, small intraluminal polyps, focal tracheal atresia, compressive mediastinal masses, and foreign body obstructions of the major bronchi. Dose measurements showed a maximum skin exposure of 245 mR (0.06 mC/kg) per 0.05-second image. Ultrafast CT provides an accurate, minimally invasive method for dynamic imaging of the airway in nonsedated children.

Adolescent↗
PubMed1986

Comparison of in vivo 31P-MR spectra of the brain, liver, and kidney of adult and infant animals.

In vivo 31P-magnetic resonance spectroscopy (MRS) was used to determine the phosphorus metabolite levels in the brain and kidney of infant rabbits and adult rats and in the liver of infant rabbits and adult and infant rats. For 31P-MRS of the brain, a surface, radiofrequency coil was placed on the anterosuperior region of the head; for 31P-MRS of the liver and kidney, a radiofrequency coil was chronically implanted either between the hepatic lobes or around the kidney. 31P-MR spectra were found to show large variations in the levels of the phosphorus metabolites depending on the species, the organ, and the age of the animal. The phosphate monoester (MP)/adenosine triphosphate (ATP) ratio was significantly higher and the phosphocreatine (PCr)/ATP ratio was significantly lower in the brains of infant rabbits than in the brains of adult rats. Comparison of these data with data reported for humans and other animals suggests that these differences are due mainly to differences in age and not to differences among species. The phosphodiester (PD)/ATP ratio was found to be significantly higher in the livers of infant rabbits than in the livers of adult and infant rats - a difference more likely related to the species than to age. The kidneys of the infant rabbits showed a higher PCr/ATP radio than the kidneys of the adult rats, but this difference might be due to the influence of PCr in the surrounding muscle.

Adenosine Triphosphate↗
PubMed1986

Magnetic resonance imaging in pediatric hematology/oncology. Part I. Basic technology.

Magnetic resonance imaging (MRI) is a promising new diagnostic modality that is well suited for the evaluation of children with hematological or oncological diagnosis. The side effects of ionizing radiation are avoided, the tomographic pathological anatomy in three orthogonal planes can be obtained, and differences between normal and abnormal tissues are often present. In order to present our preliminary clinical experience with MRI in pediatric hematology and oncology, the historical background of MRI, the technique, and possibilities for tissue characterization are reviewed.

Child↗
PubMed1986

Magnetic resonance imaging in pediatric hematology/oncology. Part II. Illustrative cases and assessment of technique.

Preliminary clinical experience with magnetic resonance imaging (MRI) in 28 pediatric patients with 20 different hematological diseases, benign tumors, or malignant neoplasms is presented. The clinical results are presented in the form of case presentations that are discussed in the context of alternative diagnostic imaging modalities. Also discussed are the known biological effects, or lack thereof, the need for sedation, the effect of motion, the effect of MRI on foreign metallic objects, the financial considerations, and the trends for the future of MRI. This imaging modality has many unique merits. Present difficulties should be overcome by future innovations, making MRI even more efficacious for the diagnosis of blood diseases and cancer in children.

Adolescent↗
PubMed1986

In vivo 31P-MR spectroscopy of the liver in the infant rabbit to study the effect of hypoxia on the phosphorus metabolites and intracellular pH.

In vivo 31P-magnetic resonance spectroscopy (MRS) with a chronically implanted detection coil was used to study the effect of hypoxia on the phosphorus metabolites and intracellular pH in the liver of infant rabbits. A two-turn 10-mm radiofrequency coil was placed between the hepatic lobes in each of four infant New Zealand white rabbits (10-16 days old). Two days later, the rabbits were anesthetized and mechanically ventilated with 1.5% isoflurane in 98.5% O2. Blood gases, heart rate, and mean arterial pressure were monitored. 31P-MR spectra were continuously obtained every 5 minutes during 15 minutes of hyperoxia (PaO2 greater than 250 torr), 15 minutes normoxia (PaO2 approximately equal to 100 torr), 60 minutes hypoxia (PaO2 = 24 torr +/- 4 S.D.), and 15 minutes recovery (hyperoxia). In addition, 31P-MR spectra of perchloric-acid extracts of the liver of an adult and of an infant rabbit, removed under normoxic conditions, were examined. The 31P-MR spectra of liver of the normoxic adult (in vitro) and infant rabbits (in vitro and in vivo) revealed a high level of phosphodiesters, namely glycerol-3-phosphorylethanolamine, glycerol-3-phosphorylcholine, and phosphoenolpyruvate, compared with that reported for adult rat and adult mouse liver. The inorganic phosphate (Pi)-to-adenosine triphosphate (ATP) ratio was about 0.90 during hyperoxia and during normoxia. Within 15 minutes after induction of hypoxia, the level of phosphorus metabolites changed markedly: The ATP decreased 41% +/- 18 S.D. (P less than .01) and the Pi increased 206% +/- 29 S.D. (P less than .01); the Pi/ATP ratio was 5.0.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1986

Bone marrow in children with acute lymphocytic leukemia: MR relaxation times.

Magnetic resonance imaging of the lumbar spine was performed in 17 children with acute lymphocytic leukemia (ALL): eight with newly diagnosed ALL, four with ALL in relapse, and five with ALL in remission. Eleven age-matched children were also imaged as controls. The T1 and T2 relaxation times of the bone marrow in the lumbar spine were calculated for all the children. The T1 relaxation times of the bone marrow were as follows (mean +/- standard deviation): newly diagnosed ALL, 968 msec +/- 68; ALL in relapse, 765 msec +/- 19; ALL in remission, 404 msec +/- 135; and age-matched controls, 441 msec +/- 82. T1 relaxation time was statistically significant in differentiating children with newly diagnosed ALL from normal children and from children with ALL in remission. In addition, T1 may be useful in differentiating children with ALL in relapse from children with ALL in remission and from healthy children. T2 was not significantly different among the four groups.

Adolescent↗
PubMed1985

Artifacts, variants, and factors degrading image quality in pediatric magnetic resonance imaging.

The experience from 123 pediatric MRI examinations disclosed several different types of artifacts and age-related variants that could have caused pitfalls in MRI interpretation. Artifacts were caused by metallic objects, patient touching the RF coil, and patient motion. The potential pitfalls are caused by the MRI variant appearances of anatomical structures specific to the growing body. Recommendations concerning preparation and immobilization of children prior to and during MRI examinations to minimize artifacts are given.

Adolescent↗
PubMed1985

Effects of hypoxic hypoxia on cerebral phosphate metabolites and pH in the anesthetized infant rabbit.

The effects of hypoxic hypoxia on high-energy phosphate metabolites and intracellular pH (pHi) in the brain of the anesthetized infant rabbit were studied in vivo using 31P nuclear magnetic resonance spectroscopy. Five 10- to 16-day-old rabbits were anesthetized with 1.5% halothane. Ventilation was controlled to maintain normocarbia. Inspired O2 fraction was adjusted to produce three states of arterial oxygenation: hyperoxia (PaO2 greater than 250 mm Hg), normoxia (PaO2 approximately 100 mm Hg), and hypoxia (PaO2 25-30 mm Hg). During hypoxia, blood pressure was kept within 20% of control values with a venous infusion of epinephrine. During hyperoxia, the phosphocreatine-to-ATP ratio was 0.86, a value that is 2-2.5 times less than that reported for adults. During normoxia, ATP decreased by 20% and Pi increased by 90% from hyperoxia values. During 60 min of hypoxia, the concentrations of high-energy phosphate metabolites did not change, but intracellular and arterial blood pH (pHa) decreased significantly. When hyperoxia was reestablished, pHi returned to normal and pHa remained low. These results suggest that during periods of hypoxemia, the normotensive infant rabbit maintains intracellular concentrations of cerebral high-energy phosphates better than has been reported for adult animals.

Adenosine Triphosphate↗