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J J Conway

Publications and source records attributed to J J Conway.

At least 19 recordsLinked to original sources
PubMed1992

"Well-tempered" diuresis renography: its historical development, physiological and technical pitfalls, and standardized technique protocol.

Differentiating the various causes of hydronephrosis from that of obstruction can be very difficult. Diuretic renography has been adopted as a noninvasive clinical management tool to assist in this differentiation. However, the correlation of the results of diuresis renography, the Whitaker test, and the surgical results has only been between 40% and 85%. This is believed to be due to the many physiological factors and technical pitfalls of the technique. These include variable renal function, variable compliance of the collecting system, the effect of back pressure from a full bladder, the state of hydration, the choice of radiopharmaceutical, and the timing of the diuretic injection. Even the technique of measuring the clearance half-time (T 1/2) is controversial, with at least eight different methods defined. In order to diminish the effect of these variables, a standardized protocol for diuretic renography has been proposed by a consortium of members of the Society for Fetal Urology and the Pediatric Nuclear Medicine Club of the Society of Nuclear Medicine. These include a standardized hydration with a dilute glucose solution, bladder catheterization and measurement of urine output response, uniform radiopharmaceutical choice, and diuretic dose with specific timing of the diuretic injection. The various methods for T 1/2 calculation are illustrated, and various stereotypical renogram and diuresis response curves are offered as aids in the interpretation of the study. Diuresis renography is one of the most complex functional studies in nuclear medicine today. A thorough understanding of the physiological basis for diuresis renography and the pitfalls of the technique is required for its appropriate use in the management of patients suspected of urinary tract obstruction.

Diuretics↗
PubMed1992

Grading nephroureteral dilatation detected in the first year of life: correlation with obstruction.

To understand better the significance of pediatric idiopathic nephroureteral dilatation the renal ultrasound images of patients less than 1 year old with hydronephrosis or hydroureteronephrosis were graded and compared to the radiological diagnosis of obstruction as determined by diuresis renography and/or urography. The study included 73 boys and 30 girls with hydronephrosis (76 patients) or hydroureteronephrosis (27). For hydronephrosis obstruction was diagnosed in 56 children (74%) and involved 61 of 97 kidneys (63%). For obstructed kidneys the mean grade of hydronephrosis (3.4 +/- 0.7 standard deviation) was statistically different from that of nonobstructed kidneys (1.6 +/- 0.8 standard deviation) (p less than 0.05). When the value to predict obstruction was set at grade 3 hydronephrosis or greater there was an 88% sensitivity and 95% specificity. For hydroureteronephrosis obstruction was diagnosed in 15 of 27 children (56%) and involved 17 of 34 kidneys (50%). The degree of dilatation was weighted as a score to assess the grades of hydronephrosis and ureteral dilatation, namely hydroureteronephrosis score equals grade of hydronephrosis plus grade of ureteral dilatation. In obstructed megaureters the mean hydroureteronephrosis score (5.8 +/- 1.0) was statistically different from that for nonobstructed megaureters (mean hydroureteronephrosis score 2.7 +/- 1.9) (p less than 0.001). When the value to predict obstruction was set at hydroureteronephrosis score of 5 or greater there was a 94% sensitivity and 80% specificity. Although ultrasound examination alone cannot be used to diagnose urinary obstruction, the radiological diagnosis of obstruction is linked with the grade of hydronephrosis or score of hydroureteronephrosis.

Age Factors↗
PubMed1992

Communicating risk information in medical practice.

The public's preceptions about the risks of radiation are adversely influenced by the many negative reports by the media on the hazards of all radiation. As a result, patients express concern about the risks of radiation from radiologic examinations. Radiologists are well positioned to dispel these fears because of their training and their access to and ability to interpret information from scientific organizations specifically concerned with the determination of radiation risk. To do this, radiologists must be willing to communicate with patients and be accessible. Pamphlets and handouts can be given to anxious patients before examinations. In direct interaction with patients, the radiologist must listen to them and be prepared to address their concerns, especially those about repeat examinations, exposure during pregnancy, inadvertent exposure of the fetus, exposure of children, use of radiation in research, and misadministration of radionuclides. In addition, radiologists can help patients by educating referring physicians, other medical staff, and nurses. They can also reach the public by being a spokesperson at meetings of local organizations or by accepting opportunities to speak to the media. All these efforts help counteract negative perceptions aroused by the media.

Child↗
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↗
PubMed1979

The cystometric nuclear cystogram.

Vesicoureteral reflux is a common clinical problem that we monitor by interval nuclear cystography. Of the children having nuclear cystograms 40% also have voiding abnormalities, including incontinence (damp pants), urgency and infrequent micturition. We have evaluated these symptoms by recording the intravesical pressure during the nuclear cystogram. This combined examination, the cystometric nuclear cystogram, has been done on 46 children. An abnormal cystometrogram was found in 61% of the children with a voiding abnormality and helped to establish a basis for successful therapy. The cystometric nuclear cystogram aids in the diagnosis and rational therapy of childhood voiding abnormalities. It is a practical method to obtain a cystometrogram in children with voiding abnormalities who are being evaluated for ureteral reflux and it has facilitated the management of childhood ureteral reflux.

Child↗
PubMed1978

Quantitative nuclear cystogram. Aid in determining spontaneous resolution of vesicoureteral reflux.

The quantatitative data derived from serial nuclear cystograms over a five-year period in 37 children were compared with the clinical course. A direct correlation (92 per cent) between an increasing bladder volume at which reflux occurs was observed in the clinically stable group. In the clinically unstable group, there was a 75-per cent correlation of an unchanged or decreasing bladder volume at which reflux occurs. The quantitative nuclear cystogram provides an objective as opposed to subjective data base for management of patients with vesicoureteral reflux.

Child↗
PubMed1978

Methotrexate encephalopathy. A neuropathologic study.

The present report is a neuropathologic study of three patients who died from a severe form of necrotizing encephalopathy following intrathecal methotrexate therapy and craniospinal irradiation for acute lymphoblastic leukemia. During the early phase the lesion presented as multifocal coalescing areas of coagulation necrosis in the deep white matter. In the diseased areas the myelin was lost and the axons were severely swollen and fragmented. During the late stage the white matter was reduced to a thin gliotic calcified layer. The pathogenesis of this lesion is unclear, but the preferential involvement of the white matter with sparing of the cortical gray matter and basal ganglia makes it unlikely that direct chemical injury is the cause. The distribution of the lesion suggests a vascular disturbance due to endothelial injury caused by interaction of the methotrexate with tissue infiltrated by leukemic cells and altered by irradiation.

Brain↗