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Biomedical subjects

D L Gilday

Publications and source records attributed to D L Gilday.

At least 19 recordsLinked to original sources

Detection of silent coronary artery disease in adolescents and young adults with familial hypercholesterolemia by single-photon emission computed tomography thallium-201 scanning.

Familial hypercholesterolemia (FH), a genetic disease characterized by increased levels of total and low-density lipoprotein cholesterol in the blood, results in a markedly increased incidence of atherosclerosis and coronary artery disease in homozygotes and to a lesser extent in heterozygotes. The purpose of this study was to detect the presence of myocardial ischemia, particularly in heterozygotes, with stress single-photon emission computed tomography thallium-201 scanning and to determine if there were any differentiating variables between heterozygotes with normal and abnormal thallium-201 scans. Fifty-four patients (mean age 16 years; range 8 to 24) with FH were analyzed (4 homozygotes and 50 heterozygotes). Eleven heterozygotes and 3 homozygotes had abnormal thallium-201 scans. Family history, lipid profile, age and sex of heterozygotes with FH did not predict the presence of myocardial ischemia. The mean total cholesterol level in heterozygotes with normal thallium-201 scans was 7.68 +/- 2.29 mmol/liter (297 mg/dl), which was not significantly different from that in heterozygotes with abnormal scans (7.63 +/- 1.07 mmol/liter [295 mg/dl]; p = 0.91). The coronary angiography of 1 homozygote who had an abnormal thallium-201 scan demonstrated a 50% stenosis of the left anterior descending artery. Aggressive, repetitive plasma exchange was then instituted. The 11 heterozygotes with abnormal thallium-201 scans underwent more rigorous dietary and drug therapy. It is concluded that myocardial ischemia with stress in heterozygotes with FH can occur at a young age and that thallium-201 scanning should be performed early as a screening test and to guide patient management.

Adolescent

Ventricular performance before and after Fontan repair for univentricular atrioventricular connection: angiographic and radionuclide assessment.

OBJECTIVES: This study was designed to evaluate changes in ventricular volume, mass and cardiac function before and after creation of an atrial to pulmonary connection in patients with a univentricular atrioventricular connection. BACKGROUND: Intact systolic and diastolic performance is critical for successful establishment of an atrial dependent circulation, and few studies are available comparing cardiac performance before and after creation. METHODS: With the use of radionuclide blood pool imaging and ventricular cineangiography, 54 patients (mean age 6.4 +/- 3.4 years) were studied. Twenty-eight patients were investigated preoperatively and 36 greater than 1 year after repair and compared with a control population. RESULTS: Before operation, end-diastolic volume and wall mass were significantly increased compared with those of control subjects; however, the mass/volume ratio was normal (1.08 +/- 0.31 g/ml for the preoperative group; 0.97 +/- 0.19 for control subjects). Although end-diastolic volume returned to normal after the procedure, wall mass remained elevated and contributed to an elevated mass/volume ratio (1.20 +/- 0.38 g/ml). After the procedure, systemic vascular resistance index was significantly elevated compared with that before surgery or with that of control subjects (1,199 +/- 373, 2,120 +/- 645, 1,556 +/- 275 dynes.s.cm-5.m2: pre- and postrepair and control subjects, respectively). Radionuclide studies demonstrated that preoperative ejection fraction (52 +/- 9, 50 +/- 9, 60 +/- 8%), peak ejection (2.58 +/- 0.66, 2.95 +/- 0.81, 3.73 +/- 0.70 EDV/s) and peak filling rates (2.84 +/- 0.75, 2.75 +/- 0.79, 3.84 +/- 0.51 end-diastolic volumes [EDV/s]) were significantly reduced compared with those of control subjects and remained so after surgery. CONCLUSIONS: These data suggest that systolic and diastolic function is depressed preoperatively in these patients, remains unchanged after the creation of an atrial-dependent circulation and is associated with an increased systemic vascular resistance. Long-term issues addressing preservation of cardiac function need to be prospectively studied.

Child

Decrease in gastric emptying time and episodes of regurgitation in children with spastic quadriplegia fed a whey-based formula.

The gastric emptying times associated with three whey-based formulas were significantly shorter than that associated with a casein-based formula in nine gastrostomy-fed patients with spastic quadriplegia (p less than 0.001). Patients fed whey-based formulas had significantly fewer episodes of emesis than when they were fed casein-based formula (p less than 0.001). We conclude that whey-based formulas reduce the frequency of emesis by improving the rate of gastric emptying.

Adolescent

Evaluation of ventricular diastolic function in normal children using equilibrium radionuclide angiography.

Twenty children, aged 10.3 +/- 4.5 (3.3 to 17.5) years, were studied by equilibrium radionuclide angiography to establish a normal range for diastolic parameters. Ejection fraction (EF), peak ejection rate (PER) and time to peak ejection rate (TPER), peak filling rate (PFR) and time to peak filling rate (TPFR) were obtained from ventricular time-activity curves and their first derivative curves, and PFR and TPFR were considered as the diastolic parameters. Normal ranges obtained were as follows: EF, 60 +/- 8%; PER, 3.73 +/- 0.70 EDV-1; TPER, 109 +/- 25 ms; PFR, 3.84 +/- 0.51 EDVs-1; TPFR, 136 +/- 21 ms. There were significant correlations between PER and EF (P less than 0.001), PFR and EF (P less than 0.05), while age and heart rate had no influence upon these variables. Such normal ranges will be useful for evaluation of systolic and diastolic function in children with heart disease.

Adolescent

Ventricular function during supine bicycle exercise in univentricular connection with absent right atrioventricular connection.

Fourteen patients with univentricular connection, absent right connection (tricuspid valve atresia) and normally related great arteries underwent rest and supine bicycle exercise equilibrium radionuclide blood pool studies. Ejection fraction, heart rate, systemic blood pressure and oxygen saturation (ear oximetry) were measured. There were 6 male and 8 female patients. Mean age +/- standard error of the mean was 14.5 +/- 1.1 years (range 6.3 to 21.1). Eight patients (group 1) had systemic to pulmonary shunts placed as palliation 8.2 +/- 2.2 years before study and 6 patients (group II) had caval to pulmonary shunts placed 11.8 +/- 1.6 years previously. Ejection fraction at rest was 54 +/- 2% and an abnormal response to exercise (failure of ejection fraction to increase greater than or equal to 5% from rest to peak exercise) was found in 9 of 14 patients. When analyzed separately, ejection fraction at rest in group I was higher than in group II; however, this difference disappeared at peak exercise. There was a significant negative correlation between ejection fraction at peak exercise and the interval since palliative surgery, although it was not apparent at rest. These data suggest that ventricular function is compromised during exercise and that abnormal performance is influenced by long-standing volume overload. Importantly, this abnormal state is concealed at rest and the choice of palliative shunting procedure appears to have little effect on normalizing pump performance.

Adolescent

Pediatric cerebrovascular disease. Alterations of regional cerebral blood flow detected by TC 99m-HMPAO SPECT.

Regional cerebral blood flow (rCBF) alterations, as determined by single photon emission computed tomography (SPECT) using technetium Tc 99m hexamethyl propylenamine oxime (Tc 99m-HM-PAO), were studied in 15 infants and children presenting with cerebrovascular disorders between the ages of 2 weeks and 16 years. The rCBF patterns were correlated with clinical presentation, electroencephalographic patterns, radiologic studies, including computed tomography and magnetic resonance imaging of the head, and cerebral angiography. All patients presented with motor weakness that was accompanied in some with dysphasia, defects in visual fields, obtundation, seizures, and high temperature. Perturbations of rCBF with Tc 99m-HMPAO SPECT brain scanning were detected in all patients investigated, with no adverse effects related to the radiotracer. All patients had a focal area of decreased rCBF, with adjacent hyperemia in 3 patients. In 7 patients, there was an rCBF decrease in a vascular distribution, mainly that of the middle cerebral artery, that correlated with the clinical findings and a focal electroencephalogram, as well as computed tomography and magnetic resonance imaging of the head. Impairment of rCBF was more extensive in 3 children, while early abnormal SPECT findings preceded abnormal computed tomographic findings in another 2 children. In 2 patients, Tc 99m-HMPAO SPECT was the only positive radiologic test to correlate with focal clinical and electroencephalographic abnormalities, in view of repeated normal computed tomographic scans. We conclude that Tc 99m-HMPAO SPECT brain scanning is a sensitive, complementary diagnostic measure in the early detection, localization, and estimation of rCBF alterations in pediatric cerebrovascular disease.

Cerebrovascular Circulation

99mtechnetium-dimercapto-succinic acid renal scanning and excretory urography in diagnosis of renal scars in children.

We compared the ability of excretory urography (without tomography) and 99mtechnetium-dimercapto-succinic acid renal scanning to detect renal scars in 32 children with primary vesicoureteral reflux. These children did not have hydronephrosis, renal failure or urinary tract obstruction. In all cases both studies were conducted within a 10-month period. The findings from both modalities were in agreement for 51 of the 64 renal units evaluated (80 per cent). Evaluation of the excretory urogram indicated 6 cases of diffuse and 2 of focal scarring that were not detected by evaluation of the renal scan. The sensitivity of excretory urography to detect renal scars was 84 per cent and the specificity was 83 per cent. The 99mtechnetium-dimercapto-succinic acid renal scan showed 5 cases of focal renal scarring not detected by excretory urography. The sensitivity of the renal scan to detect renal scars was 77 per cent and the specificity was 75 per cent. We conclude that neither study alone could effectively replace the other for the detection of renal scars, and recommend that both be included in the initial evaluation and followup of patients with renal scars.

Adolescent

Transient myocardial ischemia of the newborn infant demonstrated by thallium myocardial imaging.

Five term and two premature newborn infants were referred for respiratory distress and congestive heart failure, and were found to have electrocardiographic Q or ST-T abnormalities suggesting ischemia. Echocardiographic and/or hemodynamic assessment excluded anatomic heart disease in six infants. In three infants, moderate or severe hemodynamic impairment within 36 hours of age was suggested by these studies. Myocardial perfusion images in all patients showed very poor myocardial uptake of thallium 201, compatible with global myocardial ischemia. Infants of similar age with myocarditis, or with congenital heart disease and congestive failure, had normal myocardial uptake. Rapid clinical improvement occurred within three to seven days. Two to five months later, all infants were well. Two had persistent electrocardiographic abnormalities but repeat thallium 201 imaging in six demonstrated almost normal myocardial uptake. These data provide further evidence that perinatal respiratory distress may be associated with myocardial dysfunction and congestive heart failure in some infants without anatomic heart disease, and suggest that myocardial dysfunction in these infants is associated with global myocardial ischemia, most of which is transient. The timing and nature of the insult causing the ischemia are unclear.

Coronary Disease

Radionuclide skeletal survey in neuroblastoma.

Of 63 99mTc-phosphate bone images in 49 patients with neuroblastoma, 41 were abnormal, 17 showed tracer uptake within the primary tumor, 29 showed evidence of skeletal metastatic disease, and 17 demonstrated renal/urinary tract involvement. The metastases were asymmetric in 24 patients and symmetrical in 9, in whom they involved the metaphyses and epiphyses of the long bones. Except for one patient with multiple "cold" areas, all metastases were seen as focal hyperactive regions. Eleven of 42 skeletal radiographic surveys were abnormal. The radionuclide study appears to be more accurate than skeletal radiography in estimating bone involvement in neuroblastoma. Primary tumor concentration of the tracer is almost pathognomonic of neural crest neoplasms in childhood.

Abdominal Neoplasms

Craniosynostosis: correlation of bone scans, radiographs, and surgical findings.

Skull scintigraphy was performed in 68 children with suspected craniosynostosis after injection of technetium-99m methylene diphosphonate. The scans demonstrated four patterns of sutural activity: normal, absent, increased, and wide. When correlated with surgical findings, "absent" indicated fused sutures, "increased" indicated fusing hyperactive sutures or sutures reacting to fusion elsewhere, and "wide" indicated splite sutures. Upon correlation with the radiographs, it was found that when the radiograph was normal, the scan contributed little; when the radiograph was abnormal or equivocal, the scan was often of great assistance in confirming fused sutures and detecting other abnormal sutures.

Child, Preschool

Radiopharmaceutical bone scanning in pediatric neurosurgery.

Radionuclide bone scanning is an extremely sensitive, safe and widely applicable investigative aid. In most circumstances it cannot be employed to the exclusion of plain radiography as the two procedures--one dynamic and the other static--complement each other. In children, bone imaging demonstrates physiologic characteristics of bone growth and early suture closure, delineates obscure tumors and infection, recent or old trauma not always visible on orthodox radiography and may solve the diagnostic dilemma of a child with heretofore undiagnosed head, neck or back pain.

Back Pain

Fourier multiaperture emission tomography (FMET).

We describe a new emission tomographic technique, using an Anger scintillation camera and a new family of coded apertures, in which a noniterative computer algorithm is used to reconstruct multiplanar images. The novel feature is a set of spatial narrow band filters that allow the depth information to be separated in the frequency domain. The position of the reconstructed planes can be selected at will. Using this technique, a planar resolution of 0.75 cm and a depth resolution of 1.6 cm have been measured at a depth of 10 cm and a magnification of 1. To demonstrate the potential of this system, the results of a phantom study are reported.

Fourier Analysis

Thallium-201 myocardial imaging in anomalous left coronary artery arising from the pulmonary artery. Applications before and after medical and surgical treatment.

Thallium-201 myocardial imaging was performed on six patients with an anomalous left coronary artery arising from the pulmonary artery. Initial images in three children (aged 4 months, 12 months and 2 1/2 years, respectively) demonstrated anterolateral perfusion defects in agreement with the electrocardiographic localization of infarction. Repeat imaging in two patients 2 to 3 months later, after clinical improvement with anticongestive therapy, demonstrated a reduction in the perfusion defect. In 3 other patients (aged 16, 16 and 20 years, respectively) thallium-201 scans performed during exercise stress demonstrated normal myocardial perfusion 7 to 15 years after operation (ligation of anomalous left coronary in two, ligation plus bypass graft in one). Thallium-201 imaging appears to be helpful in monitoring changes in myocardial perfusion before and after medical or surgical treatment of an anomalous left coronary artery, and may shed light on the pathophysiology of the defect. A possible practical limitation of thallium-201 imaging in this condition is the difficulty of imaging subendocardial infarction.

Adolescent

Splenic trauma--nonoperative management and long-term follow-up by scintiscan.

1972 TO April, 1977, 28 children with splenic rupture were managed nonoperatively. The diagnosis was confirmed by splenic scintigraphy with 99mTechnetium-sulfide colloid. Those patients whose condition was stable and satisfactory or maintained stable with intravenous fluids or blood transfusions were not operated upon. All patients sustained their ruptured spleens as a result of trauma, except for one spontaneous rupture in a patients with infectious mononucleosis. Emergency laparotomy for deterioration of clinical condition or late complications was never necessary. Splenic scans were repeated in 22 patients to assess resolution. Fourteen patients had minimal residual defects but there were no late complications detected.

Abdominal Injuries

The spectrum of intervertebral disc-space infection in children.

Discitis, intervertebral disc-space infection, and vertebral osteomyelitis form a spectrum of disorders with a probably common bacterial etiology. We studied forty-one children who had symptomatic narrowing of the disc space associated with fever and an elevated erythrocyte sedimentation rate and found that the diagnosis of infection in the spine was usually delayed. Technetium 99m polyphosphate bone-scanning proved to be an accurate, rapid, and safe method of establishing an early diagnosis of infection. A positive culture of blood or biopsy material was found in 34 per cent of all the patients (half of the patients for whom cultures were obtained). The clinical and roentgenographic picture that develops is determined both by the virulence and extent of infection and by the resistance and regenerative capacity of the host. Discitis in children is a vertebral osteomyelitis with disc involvement.

Abdomen