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Biomedical subjects

J J Conway

Publications and source records attributed to J J Conway.

At least 37 records · Page 2Linked to original sources
PubMed1992

The "well tempered" diuretic renogram: a standard method to examine the asymptomatic neonate with hydronephrosis or hydroureteronephrosis. A report from combined meetings of The Society for Fetal Urology and members of The Pediatric Nuclear Medicine Council--The Society of Nuclear Medicine.

Perinatal hydronephrosis (HN) and hydroureteronephrosis (HUN) are recognized more frequently as the routine use of prenatal ultrasonography increases. The decision-making process for those instances of urinary tract dilatation that require surgical correction and those that do not is based in part on the findings of diuresis renography. The methodology for performing this test has differed among nuclear medicine practitioners and the surgical findings are occasionally discrepant from the diuretic renogram interpretation. Consequently, the Society of Fetal Urology (SFU) and the Pediatric Nuclear Medicine Council (PNMC) of the Society of Nuclear Medicine met to develop by consensus a more uniform methodology. A standard method has been agreed upon for the following facets of diuretic renography: patient preparation (hydration and bladder catheterization), diuresis renography technique (radiopharmaceutical used, patient position during examination, data acquisition parameters, diuretic pharmaceutical and dosage, time of injection and regions of interest to monitor diuretic effect), and data analysis (percent differential renal function, curve pattern analysis and methods of measuring diuretic response). Pooled diuresis renogram data are being collected for analysis for correlation with surgical results and clinical outcomes to determine the most appropriate information to be derived from the diuretic renogram in neonates with HN and HUN.

Data Interpretation, Statistical↗
PubMed1988

The role of scintigraphy in urinary tract infection.

There is controversy regarding the role of radiological imaging for urinary tract infection (UTI). The "gold standard" has been the intravenous pyelogram (IVP). Yet, the IVP has a very limited value with only about 25% of children with pyelonephritis demonstrating abnormalities. Ultrasound (US) has recently been advocated as a replacement for the poorly sensitive and poorly specific IVP. However, comparative studies between US and IVP indicate only an equivalent sensitivity and specificity. Cortical scintigraphy with Technetium-99m glucoheptonate (99mTc GH) or 99mTc dimercaptosuccinic acid (99mTc DMSA) has also been advocated as a means of differentiating parenchymal (pyelonephritis) from nonparenchymal (lower UTI) involvement in UTI. The clinical presentation may be misleading especially in the infant and child in whom an elevated temperature, flank pain, shaking chills, or an elevated sedimentation rate are often lacking. The clinician attempts to localize the site of infection for it has a direct bearing upon the therapy. A collecting system infection can often be eradicated with a single oral dose of an appropriate antibiotic, whereas renal parenchymal involvement requires IV therapy for an extended interval. Cortical scintigraphy can localize the site of infection with a high degree of accuracy. Recent studies report a sensitivity of 86% and specificity of 81% of pyelonephritis. This is in contrast to the IVP with a sensitivity of only 24% and US with a sensitivity of only 42%. The scintigraphic appearance of parenchymal infection of the kidney is a spectrum of minimal to gross defects reflecting the degree of histologic involvement that spans from a mild infection to frank abscess. Cortical scintigraphy can be used to monitor the evolution of scarring following infection. Cortical scintigraphy with 99mTc DMSA or 99mTc GH is the method of choice for the initial evaluation of UTI. Not only does it have a very high sensitivity and specificity for differentiating parenchymal from collecting system disease, but it also provides an accurate quantitative measurement of function and in combination with radioiodinated orthoiodohippurate renography and Lasix (furosemide; Abbott Laboratories, North Chicago) diuresis will also differentiate significant obstruction from stasis. The use of radionuclide techniques opens new vistas for the investigation of UTI. Cortical scintigraphy should become the gold standard by which other technologies, therapy, and theoretical considerations of pyelonephritis are measured.

Child↗
PubMed1987

The evolving uroradiographic evaluation of the lower urinary tract in neonates with myelomeningocele.

Radiographic cystography (VCUG) has been advocated to detect dynamic and anatomic abnormalities of the lower urinary tract in the neonate with myelomeningocele (MM). We reviewed the VCUG in 120 neonates and the radionuclide cystograms (RNC) or cystometrograms (RNCMG) in 30 neonates to reevaluate the role of cystography in this population. Surgery was not required to treat the anatomic abnormalities detected by VCUG. The absence/presence of reflux and a bladder residual volume of greater than 15 cc were the two most important criteria in determining the neonatal voiding regimen. Because RNC provides this information equally well with a much smaller radiation dose and because of the additional functional information available from RNCMG, we now recommend that RNC or RNCMG be used to evaluate the lower urinary tract of neonates with MM.

Humans↗
PubMed1987

Radiological approaches in the evaluation of joint disease in children.

In summary, the newer technologies in radiology have allowed us to visualize more clearly the manifestation of joint disease in children. The presence of small erosions and cartilage damage can be seen much better with magnetic resonance imaging than with any other modality short of arthrography, a much more invasive examination. Joint effusion, although sometimes visualized with conventional radiography, is probably best recognized with ultrasound or magnetic resonance imaging, although it can be detected with computed tomography as well. For the evaluation of avascular necrosis that can be associated with steroid use in joint disease, bone scintigraphy is a simple, sensitive method. Magnetic resonance may be as or more sensitive and gives additional information as well. In the detection of change with time, conventional radiography probably will remain the standard as it is still the simplest, least expensive examination; however, it has many limitations in specific cases. Bone scintigraphy may be of value in selected cases. Although we have still not had enough experience with magnetic resonance imaging to use it as a way of evaluating progress of joint disease, it promises to be the most sensitive radiologic measure of evaluating progress as small anatomical changes can be detected within the cartilage, which cannot be done easily with other means.

Arthritis, Juvenile↗
PubMed1986

The localization of urinary tract infection with 99mTc glucoheptonate scintigraphy.

A retrospective study was performed of 39 children at the Children's Memorial Hospital, Chicago, Illinois, who underwent technetium-99m glucoheptonate (99mTcGH) scintigraphy for evaluation of possible urinary tract infection. Clinical and laboratory criteria classified the children as having pyelonephritis, cystitis, or no urinary tract infection. Of 28 children classified as having pyelonephritis, 24 (86%) children had abnormalities on 99mTcGH scintigraphy. Only 8 of 19 (42%) renal ultrasound scans and 4 of 17 (24%) intravenous pyelography studies performed in these children demonstrated findings consistent with parenchymal disease. Only 9 of 19 (47%) cystograms demonstrated vesicoureteral reflux. Three children who underwent gallium-67 citrate scintigraphy had localization at the sites of focal defects with 99mTcGH scintigraphy. 99mTcGH scintigraphy is a sensitive and specific indicator of renal parenchymal involvement that helps localize urinary tract infection to the kidney.

Child↗
PubMed1986

Radionuclide bone scintigraphy in pediatric orthopedics.

Radionuclide bone scintigraphy is highly sensitive and specific for diagnosing the musculoskeletal disorders of childhood. Conditions such as neonatal osteomyelitis, septic arthritis, diskitis of childhood, Legg-Calvé-Perthes disease, the osteochondroses, the "toddler's fracture," sports injuries, spondylolysis, myositis ossificians, and reflex sympathetic dystrophy are readily defined. High-quality state-of-the-art scintigraphy is essential in infants and young children.

Adolescent↗
PubMed1985

Scintigraphic localization of bone lesions during surgery.

Nuclear medicine provides several methods for increasing the accuracy of surgical removal of bone lesions with focally increased uptake. In this paper, three intraoperative procedures are discussed: remote control by imaging, intraoperative control by imaging, and intraoperative control by scintillation probe. All techniques require preoperative injection of bone imaging tracer. Remote operative control calls for a gamma camera to mark the skin over the lesion prior to surgery, providing optimal preoperative localization and imaging of the excised lesion to ensure complete removal. Intraoperative control procedures require that a portable camera or a scintillation probe be used in the operating room; these permit direct monitoring of localization and resection. Our experience with 18 procedures performed on 15 patients suggests that these techniques are worthy of continued use.

Adolescent↗
PubMed1985

The spleen: development and functional evaluation.

Despite the fact that the spleen has multiple functions, only one has been widely used for evaluation of the organ by imaging techniques (phagocytosis of 99mTc sulfur colloid). The usual splenic uptake of this radiocolloid can by used to determine the size, location, and integrity of the organ. A major use of splenic radiocolloid imaging has been in the study of congenital defects. Thus, eventration of the diaphragm, accessory spleens, splenogonadal fusion, the asplenia and polysplenia syndromes, and the wandering spleen are amenable to study by means of intravenously administered radiocolloid. Interference with the splenic uptake of radiocolloid can be either focal or generalized (as in functional asplenia). Imaging of the spleen has a major role in evaluating suspected trauma of the organ and in following its clinical course. The return of splenic function after splenectomy (splenosis or accessory spleens) can be documented by radionuclide imaging, and likely by hematologic techniques when the volume of tissue is sufficiently large. The detection of intrasplenic lesions is important in tumor staging and as an alerting sign to an ongoing process.

Abscess↗
PubMed1985

Gallium scintigraphy in American Burkitt lymphoma: accurate assessment of tumor load and prognosis.

The radiographic evaluation of 18 children with American Burkitt lymphoma was analyzed retrospectively. Pretreatment gallium-67 (67Ga) scintigraphy, done in 12 children, was interpreted as normal in only three children. In the other nine children, 67Ga scans demonstrated more sites of tumor involvement than any other method. Pretreatment abdominal computed tomography and sonography were valuable for evaluating ascites, density and size of the liver and spleen, renal involvement, and the presence of lymphomatous soft-tissue masses. Sonography was less accurate at localizing tumor deposits, but more sensitive to small amounts of ascites. Any of these methods is an effective way of following response to chemotherapy. However, it appears that sequential 67Ga scintigraphy may have significant prognostic value, as those children whose scintigrams reverted to normal within 6 months have survived.

Adolescent↗
PubMed1984

Neonatal osteomyelitis examined by bone scintigraphy.

Thirty-three infants less than six weeks of age and suspected of having osteomyelitis were examined by bone scintigraphy. Each of the 25 sites of proved osteomyelitis in 15 individuals demonstrated abnormal radionuclide localization. Ten additional scintigraphically positive but radiographically normal sites were detected. Optimal quality scintigrams of the growth plate complex and osteomyelitis in neonates appeared similar to those in older children. All neonates suspected of having osteomyelitis should be studied with bone scintigraphy following initial radiographs.

Bone and Bones↗
PubMed1983

Bladder capacity (ounces) equals age (years) plus 2 predicts normal bladder capacity and aids in diagnosis of abnormal voiding patterns.

Standardization of the bladder capacities of children will improve the precision of urodynamic evaluation. In an attempt to develop a practical guide to predict the normal bladder capacity during childhood the bladder capacities of 132 children without a clinically abnormal pattern of voiding were measured. When the bladder capacities are correlated by age the following linear relationship exists: normal bladder capacity (ounces) equals age (years) plus 2. The bladder capacities of 68 children with primary enuresis, frequency or infrequent voiding were then measured. Children with clinically infrequent voiding demonstrated large bladder capacities and those with frequency or enuresis demonstrated small bladder capacities compared to normal children. The formula appears to be a useful guide to predict normal bladder capacity by age and also to aid in the diagnosis of abnormal voiding patterns.

Adolescent↗
PubMed1981

Detection of ectopic gastric mucosa in Meckel's diverticulum and in other aberrations by scintigraphy: I. Pathophysiology and 10-year clinical experience.

Ten years of clinical experience with pertechnetate (Tc-99m) scintigraphy has proven its validity for the diagnosis of ectopic gastric mucosa in bleeding Meckel's diverticulum and other congenital anomalies. Careful patient preparation and a standardized technique based on sequential gamma imaging has resulted in an overall sensitivity of 85%. Experience in differentiating "nonspecific" accumulations of pertechnetate from true ectopic gastric mucosa had increased the specificity to 95%. When we consider all the studies reported (954) with a surgical or clinical diagnosis, the accuracy of the method is calculated at 98%. When only surgically proven cases are analyzed, the calculated accuracy is 90%. Pertechnetate excretion by the mucoid cells of gastric mucosa is the basis of this test. The effect of drugs and hormones on the test has been studied in animals and in patients. The findings suggest that an improvement can be achieved by the use of cimetidine, pentagastrin, or glucagon.

Animals↗
PubMed1981

Detection of ectopic gastric mucosa in Meckel's diverticulum and in other aberrations by scintigraphy: ii. indications and methods--a 10-year experience.

Ten years' experience with pertechnetate (Tc-99m) abdominal scintigraphy has shown that the method is specifically indicated for the diagnosis and location of ectopic gastric mucosa in a Meckel's diverticulum, in enteric or gastric duplications and cysts, and in Barrett's esophagus. Careful patient preparation is essential, and sequential gamma camera imaging for 1 hr in the anterior projection is advisable, with complementary lateral, upright, and postvoiding views. Nonspecific accumulations of the tracer within tumours, intestinal obstructions, arteriovenous malformations, and the urinary tract can be recognized with the help of the clinical history and can be investigated by other tests. This approach has raised the accuracy of the method above 90%.

Abdomen↗