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Biomedical subjects

S T Treves

Publications and source records attributed to S T Treves.

At least 37 records · Page 2Linked to original sources
PubMed1999

Registration of three-dimensional magnetic resonance and radionuclide skeletal images.

PURPOSE: To apply postprocessing techniques to register three-dimensional TI-201 bone SPECT datasets with MRI. This may provide more accurate anatomic-functional correlation when localizing active tumors. MATERIALS AND METHODS: Three-dimensional datasets were constructed from previously acquired MRIs using routine imaging protocols. Registration software was used to coregister the TI-201 SPECT studies and the MRIs in three dimensions. RESULTS: Adequate TI-201 uptake in muscles and soft tissues along with relatively low accumulation in tendons and joint spaces provided adequate landmarks for visually aligning SPECT and MRI datasets. MR abnormalities were more extensive because of surrounding reactive tissue, and more focal TI-201 uptake could be demonstrated within the region of MR signal abnormality, allowing the focal metabolically active tissue to be distinguished from adjacent edema. CONCLUSIONS: Image registration of SPECT and anatomic imaging (CT or MRI) is used routinely to evaluate functional abnormalities within the brain. This technique has now been applied to the combination of TI-201 SPECT and MR data for evaluating bone lesions and may provide additional anatomic information for localizing functional abnormalities. This may be valuable for defining targets for biopsy, planning surgical treatment, and using minimally invasive therapies.

Bone Neoplasms↗
PubMed1999

Radioaerosol scintigraphy in infants and children born to mothers with HIV disease. Pediatric Pulmonary and Cardiovascular Complications (of Vertically Transmitted Human Immunodeficiency Virus) Study Group.

PURPOSE: To determine the usefulness of technetium 99m diethyltriaminepentacetic acid (DTPA) radioaerosol inhalation-clearance scintigraphy for early detection of pulmonary complications of human immunodeficiency virus (HIV) disease in children. MATERIALS AND METHODS: A total of 301 studies were performed in 132 HIV-positive children (group 1; mean age, 46.6 months). In children born to HIV-positive mothers (group 2), 273 studies were performed in 160 children who eventually were proved to be HIV negative (mean age, 10.3 months), and 80 studies were performed in 47 HIV-positive children (mean age, 15.6 months). Radioaerosol studies were performed by using commercially available radioaerosol nebulizers. Pulmonary clearance half-time was measured by using conventional gamma camera computer systems. Radioaerosol results were correlated with indexes of pulmonary health and function. RESULTS: The HIV-negative, group 2 children had a mean radioaerosol clearance half-time (58.1 minutes; 162 studies in 108 children) similar to that reported in healthy adults. Group 1 children with pulmonary involvement exhibited a faster mean clearance half-time (28.6 minutes) than did children without evidence of pulmonary involvement from either group 1 or group 2 (P < .05). A faster pulmonary clearance rate did not simply reflect the presence of chest disease that also was detectable on radiographs (P = .3). CONCLUSION: Quantitative DTPA radioaerosol clearance studies may provide useful information about pulmonary involvement in selected children with HIV disease.

Administration, Inhalation↗
PubMed1999

Pediatric applications of pinhole magnification imaging.

Pinhole magnification imaging is an important technique for practitioners of pediatric nuclear medicine. This article reviews basic principles of pinhole magnification imaging and ways for optimizing image acquisition with this technique. Applications to skeletal scintigraphy, scrotal scintigraphy and renal cortical scintigraphy are discussed and illustrated.

Bone Diseases↗
PubMed1998

Long-term effect of perfluorocarbon distension on the lung.

BACKGROUND/PURPOSE: We have demonstrated previously that postnatal lung growth can be accelerated by continuous intrapulmonary distension with perfluorocarbon (PFC). The purpose of this study was to examine the effect of PFC distension on long-term lung function and to determine if shorter periods of lung distension would be sufficient to stimulate growth. METHODS: Eight neonatal lambs underwent a right thoracotomy. The superior segment of the right upper lobe of the experimental group (n = 5) was isolated and distended with PFC to an intrabronchial pressure of 7 to 10 mm Hg. The inferior segment was removed. After a 7-day distension period (the maximum period of exposure currently allowed for humans), the experimental animals underwent removal of the intrabronchial catheter and surgical closure of the bronchial stump. Control animals (n = 3) underwent right upper lobe inferior segmentectomy alone. Animals were allowed to breathe spontaneously and reach 3 to 6 months of age. Before death, all animals were evaluated by chest radiographs and ventilation-perfusion scans. Pulmonary venous blood gas levels were obtained. Lungs were harvested and airway fixed for morphometric analysis. RESULTS: Chest radiographs of the experimental group showed variable amounts of intrapleural and interstitial PFC but were otherwise normal. Results of ventilation/perfusion (VQ) scans of all experimental animals were normal. On retrieval, the right upper lobe of experimental animals appeared slightly hyperinflated compared with controls. Right upper lobe pulmonary vein PaO2 to left pulmonary vein PaO2 ratio was comparable in experimental and control animals (1.2 +/- .41 v 0.92 +/- .15). DNA to protein ratios were slightly higher in the right upper lobes of experimental animals, however, the difference was not statistically significant (.64 +/- .11 v .42 +/- .03). On histological evaluation, the airway epithelium and alveoli of the right upper lobe of experimental animals appeared normal. Lung morphometry results showed no statistically significant differences in alveolar number between experimental and control animals. CONCLUSIONS: From these preliminary data we conclude that (1) lung architecture is preserved in juvenile animals subjected to intrapulmonary PFC distension as neonates, (2) lung function is preserved in the lobar segment after PFC distension, and (3) intrapulmonary PFC distension appears to be safe at 3 to 6 months follow-up. However, 7 days of PFC distension is insufficient to promote lung growth.

Animals↗
PubMed1998

Childhood brain tumor: neuroimaging correlated with disease outcome.

The authors explored the hypothesis that functional behavior of childhood brain tumors can be estimated by serial analysis of imaging (thallium-201 [201Tl] single-photon emission computed tomography and magnetic resonance imaging [MRI]) examinations. Seventy-five patients diagnosed on clinical or histologic grounds were monitored for a period of 1 day to 3.9 years (mean +/- S.D. = 1.39 +/- 1.10 years). Abnormal 201Tl uptake appeared to denote a subgroup of lesions with distinctly greater mortality and morbidity. Of 201Tl-positive patients, 17% died within the course of this study; no deaths occurred among the 201Tl-negative group. Other parameters of disease outcome also clearly separated the 201Tl-positive and 201Tl-negative groups, with the former demonstrating a 50% shorter period of recurrence-free survival from the time of diagnosis (two-tailed t test, P < 0.01). Significant enhancement with paramagnetic contrast agents paralleled 201Tl positivity in correlating with greater mortality but failed to predict duration of recurrence-free survival. The authors conclude that 201Tl activity provides significant predictive information of the expected biologic behavior of childhood brain tumors, both for duration of recurrence-free survival and for estimated life expectancy. This information complements and extends data provided by MRI enhancement patterns.

Adolescent↗
PubMed1998

Synthesis and biodistribution of 64Cu-labeled monocationic diiminedioxime copper(II) complexes.

Monocationic copper(II) complexes of three derivatives of the diiminedioxime ligand 2,10-dioximino-3,9-dimethyl-4,8-diazaundeca-3,8-diene were labeled with 64Cu in high radiochemical yield, and the biodistribution of the complexes was measured in mice. The concentration of the complexes in the heart was low, but the partition coefficients of the complexes are less than optimal for a myocardial perfusion agent. All three complexes are resistant to reduction by glutathione in vitro. This suggests that more lipophilic derivatives of these compounds merit further investigation as possible myocardial perfusion agents.

Animals↗
PubMed1998

Acute scrotal symptoms in boys with an indeterminate clinical presentation: comparison of color Doppler sonography and scintigraphy.

PURPOSE: To compare the performance of color Doppler ultrasonography (US) and scintigraphy in assessing testicular perfusion in boys with clinically equivocal presentations. MATERIALS AND METHODS: Forty-one boys with clinically equivocal testicular perfusion underwent color Doppler US and scintigraphy. Studies were retrospectively classified as consistent with torsion, consistent with nontorsion, or indeterminate. Sensitivity and specificity were determined with alternate positivity criteria (indeterminate studies first considered positive and then negative for torsion). RESULTS: Color Doppler US demonstrated nine of 11 cases of torsion and 23 of 30 cases of nontorsion, with one false-positive and eight indeterminate studies. Scintigraphy demonstrated 10 of 11 cases of torsion and 29 of 30 cases of nontorsion, with two indeterminate studies (both in patients with inguinal testis). When indeterminate studies were considered positive for torsion, specificity was 77% for color Doppler US versus 97% for scintigraphy (P = .05). There were no other statistically significant differences between the sensitivities and specificities. CONCLUSION: Color Doppler US and scintigraphy demonstrate no statistically significant difference in ability to demonstrate testicular torsion in boys with acute scrotal symptoms and indeterminate clinical presentations. Owing to its greater specificity, scintigraphy may help prevent unnecessary surgery when color Doppler US shows equivocal flow.

Acute Disease↗
PubMed1998

Hypoplastic dysplastic kidney with a vaginal ectopic ureter identified by technetium-99m-DMSA scintigraphy.

Ectopic insertion of a ureter draining a hypoplastic dysplastic kidney is a significant cause of urinary incontinence in girls. In this case, such a kidney was detected with 99mTc-DMSA scintigraphy but not by intravenous pyelography. Scintigraphy facilitated further delineation of the anatomy with CT prior to nephrectomy. Based on this case and a literature review, we suggest that 99mTc-DMSA scintigraphy be performed early when evaluating girls with urinary incontinence.

Child↗
PubMed1998

Assessing the limping child with skeletal scintigraphy.

Skeletal scintigraphy is frequently used in the clinical investigation of young children who present with limping as their only or predominant symptom. This article reviews techniques used for pediatric skeletal scintigraphy, skeletal tracer distribution in the immature skeleton and scintigraphic manifestations of relatively common conditions that can produce limping in children 1-6 yr old. Acute osteomyelitis, vertebral infections, transient synovitis, septic arthritis, Legg-Calvé-Perthes disease, lower extremity injuries in toddlers and osteoid osteoma are emphasized.

Acute Disease↗
PubMed1998

Three dimensional image alignment, registration and fusion.

Combined assessment of three dimensional anatomical and functional images (SPECT, PET, MRI, CT) is useful to determine the nature and extent of lesions in many parts of the body. Physicians principally rely on their spatial sense to mentally re-orient and overlap images obtained with different imaging modalities. Objective methods that enable easy and intuitive image registration can help the physician arrive at more optimal diagnoses and better treatment decisions. This review describes a simple, intuitive and robust image registration approach developed in our laboratory. It differs from most other registration techniques in that it allows the user to incorporate all of the available information within the images in the registration process. This method takes full advantage of the ability of knowledgeable operators to achieve image registration and fusion using an intuitive interactive visual approach. It can register images accurately and quickly without the use of elaborate mathematical modeling or optimization techniques. The method provides the operator with tools to manipulate images in three dimensions, including visual feedback techniques to assess the accuracy of registration (grids, overlays, masks, and fusion of images in different colors). Its application is not limited to brain imaging and can be applied to images from any region in the body. The overall effect is a registration algorithm that is easy to implement and can achieve accuracy on the order of one pixel.

Algorithms↗
PubMed1998

Meckel's diverticulum: demonstration of heterotopic gastric mucosa with technetium-99m-pertechnetate SPECT.

Demonstration of functioning heterotopic gastric mucosa with 99mTc-pertechnetate SPECT is reported. Abnormal tracer uptake was shown conclusively with SPECT but not with planar imaging. When a Meckel's diverticulum is suspected, we suggest SPECT be performed if the results of planar scintigraphy are equivocal and that it be considered if there is a high clinical suspicion and planar imaging is normal.

Adolescent↗
PubMed1997

Childhood moyamoya disease: hemodynamic MRI.

BACKGROUND: Childhood moyamoya disease is a rare progressive cerebrovascular disease. OBJECTIVE: To evaluate cerebral hemodynamics using dynamic Gd-DTPA-enhanced imaging in children with moyamoya disease. MATERIALS AND METHODS: Eight children (2-11 years of age) with the clinical and angiographic findings typical of moyamoya disease, before and/or after surgical intervention (pial synangiosis), underwent conventional MR imaging (MRI) and hemodynamic MR imaging (HMRI). HMRI used a spoiled gradient-echo with low flip angle (10 deg) and long TE (TR/TE = 24/15 ms) to minimize T 1 effects and emphasize T 2* weighting. Raw and calculated hemodynamic images were reviewed. Three-dimensional time-of-flight MR angiography (MRA) and perfusion brain single photon emission computed tomography (SPECT) were also performed. RESULTS: Abnormal hemodynamic maps resulting from vascular stenosis or occlusion and basal collaterals were observed in six patient studies. HMRI depicted perfusion dynamics of affected cerebrovascular territories, detected cortical perfusion deficits, and complemented conventional MRI and MRA. HMRI findings were consistent with those of catheter angiography and perfusion SPECT. CONCLUSION: Our preliminary experience suggests that HMRI may be of value in the preoperative and postoperative evaluation of surgical interventions in moyamoya disease.

Brain↗
PubMed1997

Vesicoureteral reflux in children: incidence and severity in siblings.

PURPOSE: We attempted to determine the incidence of vesicoureteral reflux in asymptomatic siblings of children with reflux at different ages and assess the incidence of renal damage in asymptomatic siblings with reflux. MATERIALS AND METHODS: We reviewed radionuclide cystograms of 482 consecutively referred siblings of children with vesicoureteral reflux, including 295 girls and 187 boys 2 weeks to 12.8 years old (mean age 2.8 years). Ultrasonograms and renal cortical scintigrams of children with reflux were evaluated. All siblings were considered asymptomatic by the referring physicians. RESULTS: The overall incidence of vesicoureteral reflux was 36.5%, and the incidence in girls and boys was 39.3 and 32.1%, respectively. Children 24 months old or younger had the highest incidence (45.7%) and the highest risk of bilateral reflux. From ages 25 to 72 months the incidence of reflux was 33.1% and in siblings older than 72 months it was 7%. Reflux of urine to the level of the renal pelvis was detected in 28.6% of all referred siblings. Renal damage was observed on sonography or scintigraphy in 4.7% of the siblings with reflux. CONCLUSIONS: The high incidence of vesicoureteral reflux through age 72 months indicates that it is important to screen siblings of children with reflux at an early age to prevent renal damage, which can occur in the absence of symptomatic urinary tract infection.

Age Distribution↗
PubMed1997

Estimating normal bladder capacity in children.

PURPOSE: An accurate estimation of normal bladder capacity can be helpful in evaluating the patient with genitourinary disease and in interpreting urodynamic data. Prior studies have provided initial estimates. We propose 2 new equations that are practical, easy to use and more accurate than those previously published. MATERIALS AND METHODS: We retrospectively reviewed the records of more than 5,000 children undergoing radionuclide cystography at our institution. Radionuclide cystography was conducted by instilling (99m)technetium pertechnetate via gravity drip in awake children. Bladder capacity was believed to be achieved when rate of inflow diminished to a minimal rate, initiation of voiding occurred or significant discomfort was indicated. Patients with vesicoureteral reflux, infravesical obstruction, urinary tract infection, dysfunctional voiding or other lower urinary tract pathology were excluded from the study. Linear and nonlinear regression modeling established the relationship between age and bladder capacity. RESULTS: A total of 2,066 children (598 boys and 1,468 girls) had normal radionuclide cystography and were included in the analysis. Analysis of variance demonstrated that increasing age was strongly predictive of bladder capacity (p <0.0001). Because a nonlinear model was the most accurate formula for all ages (4.5 x age(0.40) = capacity [ounces]), 2 practical linear equations were determined: 2 x age (years) + 2 = capacity (ounces) for children less than 2 years old, and age (years) divided by 2 + 6 = capacity (ounces) for those 2 years old or older. Although girls had larger capacities than boys, the rate of increase was not significantly different between them. CONCLUSIONS: The relationship between normal bladder capacity and age in children follows a nonlinear curve. This nonlinear relationship can be approximated by 2 practical linear formulas that are easy to remember and are derived from a larger population than any prior study. These formulas provided accurate estimations of bladder capacity when prospectively applied to normal patients.

Adolescent↗
PubMed1997

Scintigraphy of lower extremity cadaveric bone allografts in osteosarcoma patients.

PURPOSE: To describe scintigraphic characteristics of bone allografts used in limb salvage reconstruction after resection of lower extremity osteosarcoma. MATERIALS AND METHODS: The authors reviewed 85 skeletal scintigrams of 20 pediatric patients followed up for 0.5-5.7 years after resection of lower extremity osteosarcoma and allograft reconstruction. Uptake in the allograft and adjacent host tissues was assessed visually. RESULTS: Lack of tracer uptake in the allografts was seen in 99% of the studies and a faint rim of tracer localization outlining the allograft's periphery was seen in 95% of the studies. Increased uptake was noted at the allograft-host bone junction in 78% of the studies. Uptake was increased in the joint surfaces of native bones articulating with allografts (97% of studies), including the patella (93% of studies) when the knee was involved. These findings were stabilized as time passed. CONCLUSION: Cadaveric bone allografts have a characteristic scintigraphic appearance in this selected patient group that reflects the physiology of their incorporation process.

Adolescent↗
PubMed1997

A prospective comparison of high-resolution planar, pinhole, and triple-detector SPECT for the detection of renal cortical defects.

To compare the detection rate of renal cortical defects with Tc-99m dimercaptosuccinic acid (DMSA) using triple-detector SPECT, pinhole, and planar cortical scintigraphy, the authors prospectively studied 80 kidneys in 40 patients (26 males, 14 females) who ranged in age from 3 months to 26 years (mean: 7.5 years). They found single or multiple definite defects in 30 kidneys using SPECT, 23 using pinhole imaging, and 17 using planar imaging (McNemar's test, two-tailed, P < 0.001 and P = 0.03, respectively). SPECT was significantly better than pinhole imaging at demonstrating definite defects (P = 0.008). This study indicates that SPECT, and to a lesser extent pinhole, are superior to planar imaging for conclusively demonstrating renal cortical defects.

Adolescent↗