Imaging in cystic renal disease.
Explore the source record for details and available documents.
Child↗
Biomedical subjects
I Gordon
Publications and source records attributed to I Gordon.
Comparative histopathology of radial artery versus internal thoracic artery and risk factors for development of intimal hyperplasia and atherosclerosis.
BACKGROUND: In this study, we examined the comparative histopathology, morphometry, and risk factors for the development of intimal hyperplasia and atherosclerosis in the radial artery (RA) and the internal thoracic artery (ITA). METHODS AND RESULTS: Paired specimens of RAs and ITAs, obtained from 150 patients who underwent CABG, were evaluated with histopathology; 110 pairs of arteries were suitable for morphometric analysis. The severity of disease was evaluated on the basis of percentage of luminal narrowing, intimal thickness index, and intima-to-media ratio. Risk factors were determined with stepwise linear regression. Intimal hyperplasia was seen in 141 RAs (94%) and 103 ITAs (69%) (P<0.001). Atherosclerosis was seen in 5% of RAs and 0.7% of ITAs (P=0.04). Medial calcification was found only in RAs (20 of 150, 13.3%) (P<0.001). Morphometric analysis showed that compared with ITAs, RAs had a significantly higher intimal area, medial area, percentage of luminal narrowing, intimal thickness index, and intima-to-media ratio (all P<0.001) Factors found to be significant (P<0.05) predictors of the 3 severity indices of intimal hyperplasia, including atherosclerosis, in RAs were peripheral vascular disease, smoking, age, and diabetes. Risk factors for intimal hyperplasia in ITAs were age and smoking. CONCLUSIONS: The RA is more likely to have atherosclerosis, intimal hyperplasia, and medial calcification than the ITA. Morphometric analysis indices showed marked differences between the RA and the ITA. Care should be taken when selecting the RA as a conduit in CABG, particularly in patients who are elderly, diabetic, smoke, or have peripheral vascular disease.
Adult↗
The relationship between magnetic resonance diffusion imaging and autoradiographic markers of cerebral blood flow and hypoxia in an animal stroke model.
This study examined the relationship between magnetic resonance diffusion imaging and autoradiographic markers of cerebral blood flow (99mTc-hexamethylpropylene amine oxime) and cerebral hypoxia (125I-iodoazomycin arabinoside) in a rat model of stroke. Middle cerebral artery occlusion in the rat was performed using an intraluminal suture approach. Diffusion, hypoxia, and blood flow maps were acquired 2 hr following occlusion, and were compared with T2 images and histology at 7 hr. Two hours following middle cerebral artery occlusion the lesion distributions from the diffusion maps and hypoxic autoradiographs were similar. The blood flow threshold for increased uptake of the hypoxic marker was approximately 34 +/- 7% of the normal flow. The combination of diffusion or hypoxic images with perfusion maps allowed differentiation between four regions: 1) normal tissue; 2) a region of decreased perfusion but normal diffusion and normal uptake of hypoxic marker; 3) a region of decreased perfusion, decreased diffusion and increased uptake of hypoxic marker; 4) a region of decreased perfusion, decreased diffusion and low uptake of hypoxic marker. The areas for increased uptake of hypoxic marker and decreased diffusion are equivalent, indicating similar blood flow thresholds. Regions of oligaemic misery perfusion, ischaemic misery perfusion and lesion core may be delineated with the combination of diffusion or hypoxic images and perfusion maps.
Animals↗
Assessment of various parameters in the estimation of differential renal function using technetium-99m mercaptoacetyltriglycine.
Differential renal function (DRF) is an important parameter that should be assessed from virtually every dynamic renogram. With the introduction of technetium-99m mercaptoacetyltriglycine (99mTc-MAG3), a tracer with a high renal extraction, the estimation of DRF might hopefully become accurate and reproducible both between observers in the same institution and also between institutions. The aim of this study was to assess the effect of different parameters on the estimation of DRF. To this end we investigated two groups of children: group A, comprising 35 children with a single kidney (27 of whom had poor renal function), and group B, comprising 20 children with two kidneys and normal global function who also had an associated 99mTc-dimercaptosuccinic acid scan (99mTc-DMSA). The variables assessed for their effect on the estimation of DRF were: different operators, the choice of renal regions of interest (ROIs), the applied background subtraction, and six different techniques for analysis of the renogram. The six techniques were based on: linear regression of the slopes in the Rutland-Patlak plot, matrix deconvolution, differential method, integral method, linear regression of the slope of the renograms, and the area under the curve of the renogram. The estimation of DRF was less dependent upon both observer and method in patients with two normally functioning kidneys than in patients with a single kidney. The inter-observer comparison among children in either group was not dependent on either ROI or background subtraction. However, in patients with poor renal function the method of choice for the estimation of DRF was dependent on background subtraction, though not ROI. In children with two kidneys and normal renal function, the estimation of DRF from the 24 techniques gave similar results. Methods that produced DRF values closest to expected results, from either group of children, were the Rutland-Patlak plot and matrix deconvolution methods.
Area Under Curve↗
Normal appearances of technetium-99m dimercaptosuccinic acid in children on planar imaging.
Thirty-two children who underwent renal arteriography with normal results also underwent technetium-99m dimercaptosuccinic acid (DMSA) imaging. Variations in the normal appearance of 99mTc-DMSA images are described in these children. Criteria for high-quality 99mTc DMSA images are defined in terms of kidney outline and contrast between the inner and the outer part of the kidney. Most of the images in this study were of high quality. The two most common features of normal 99mTc-DMSA images were a round-shaped (50%) or flat (either lateral or medial aspect) (24.8%) contour. A small number of unusual appearances were observed and these have been illustrated. The mean differential function of the left kidney was 51% with a range of 45%-57%.
Child↗
Improved imaging of carotid artery bifurcation using helical computed tomographic angiography.
Although duplex scan and magnetic resonance angiography (MRA) provide reliable and noninvasive tests for detecting extracranial carotid artery disease, they sometimes fail to differentiate between high-grade stenosis and total carotid occlusion. Helical computed tomographic angiography (CTA) is a safe, noninvasive technique that allows the rapid acquisition of data that can be reconstructed into two- and three-dimensional images. Axial images can be magnified and provide a cross-sectional view of the carotid vessel and the atherosclerotic plaque. Maximal intensity projection technique allows data to be reconstructed into images that closely resemble conventional arteriograms. Helical CTA has previously been shown to have a diagnostic accuracy approaching 90%. We present two case reports demonstrating the utility of helical CTA in carotid artery imaging when duplex scan and MRA results are ambiguous. These cases illustrate improved carotid imaging with helical CTA. Duplex scan results are unreliable in the presence of thick calcified plaques, and severe stenoses can be misread as occlusion by duplex and MRA due to low blood flow. Thus, helical CT angiography should be considered as a confirmatory test, before arteriography, when duplex scan or MRA results are equivocal.
Carotid Artery, Internal↗
Consensus on renal cortical scintigraphy in children with urinary tract infection. Scientific Committee of Radionuclides in Nephrourology.
A questionnaire related to cortical scintigraphy in children with urinary tract infection was submitted to 30 experts. A wide consensus was reached on several issues related to planar images: 99mTc dimercapto succinic acid (DMSA) appears as the most appropriate tracer for renal imaging; dynamic tracers are considered to be inferior, in particular 99mTc diethylenetriaminepentaacetate, which is not recommended. The general opinion is that DMSA scintigraphy is not feasible with a minimal dose below 15 MBq, whereas the maximum dose should not be higher than 110 MBq. The dose schedule generally is based on body surface area, and sedation is only exceptionally given to children. Images are obtained 2 to 3 hours after injection, preferably with high resolution collimators; pinhole images are used by only half of the experts. Posterior and posterior oblique views are used by most of the experts, and the posterior view is acquired in supine positions. At least 200.000 kcounts or 5 minute acquisition is required for nonzoomed images. As a quality control, experts check the presence of blurred or double outlines on the DMSA images. Color images are not used and experts report on film or directly on the computer screen. As far as normal DMSA images are concerned, most experts agree on several normal variants. Hydronephrosis is not a contraindication for DMSA scintigraphy but constitutes a pitfall. Differential renal function generally is measured, but no consensus is reached whether or not background should be subtracted. Most of the experts consider 45% as the lowest normal value. A consensus is reached on some scintigraphic aspects that are likely to improve and on some others that probably represent persistent sequelae. There is a wide consensus for the systematic use of DMSA scintigraphy for detection of renal sequelae, whereas only 58% of the experts are systematically performing this examination during the acute phase of infection.
Child↗
Childhood leukaemia and TV towers revisited.
Explore the source record for details and available documents.
Child, Preschool↗
Quantitative 99mTc-DMSA uptake in experimental pyelonephritis.
UNLABELLED: Quantitative 99mTc-dimercaptosuccinic acid (DMSA) renal uptake was studied in unilateral reflux-related pyelonephritis in pigs. The changes to absolute % dose uptake and differential uptake occurring with induction and after treatment of pyelonephritis were correlated with the DMSA images and renal pathology. METHODS: Quantitative uptake in 53 young pigs was obtained from planar images acquired 6 h after injecting the dose. Baseline studies were made (Q1), and studies were made again after urinary infection was established (Q2), when 8 pigs had normal (no defect) renal images (group A), 23 had photon-deficient (reversible) focal defects (group B) and 22 had photon absent (irreversible) focal defects (group C). Q3 studies were made in 21 animals from groups B and C after 3-wk antimicrobial treatment. RESULTS: At Q2 the affected kidney differential uptake was unchanged for group A and reduced for groups B and C (respective mean changes -1.7%, P < 0.01; and -5.5%, P < 0.01). The absolute % dose uptake was unchanged in pyelonephritic kidneys, but increased in the contralateral nondiseased kidneys in groups B and C (respective mean increases +1.4%, P < 0.05; and +5.4%, P < 0.01), while remaining unchanged for group A. In group C, global renal accumulation was actually increased above the Q1 values. After treatment (Q3) the reduced pyelonephritic kidney differential uptake persisted in groups B and C. In group C, however, the increased absolute % dose uptake by the contralateral kidney was less marked and not significantly different from Q1 values in this small group. CONCLUSION: Induction of unilateral pyelonephritis produced a small reduction in diseased kidney differential uptake that was greatest in the group with irreversible imaging defects. The method did not discriminate individuals with reversible and irreversible imaging defects. The decrease in pyelonephritic kidney differential uptake resulted from increased DMSA accumulation (absolute % dose uptake) by the nondiseased contralateral kidney, while that in pyelonephritic kidneys remained unchanged. After treatment, the reduced pyelonephritic kidney differential uptake persisted, but the elevated global DMSA accumulation seen for group C (with irreversible imaging defects) was not sustained and was variable.
Animals↗
[Recommendations for the performance of DMSA scintigraphy in children].
Explore the source record for details and available documents.
Child↗
The value of renal scintigraphy during controlled diuresis.
Explore the source record for details and available documents.
Child↗
Bilateral internal thoracic artery grafting may improve outcome of coronary artery surgery. Risk-adjusted survival.
BACKGROUND: Excellent clinical results of the patients with single left internal thoracic artery (ITA) grafting compared with saphenous vein grafting have prompted surgeons to use both ITAs. However, long-term benefits of the bilateral ITA grafting have not been proven. METHODS AND RESULTS: We reviewed our experience of 2826 patients (age 62 +/- 9 years [mean +/- 1 SD], 2350 men, mean follow-up 52 months) who underwent surgery with ITAs, supplemented by saphenous vein grafts when required, between 1985 and 1995. Single ITA grafting (n = 1557) was compared with double (n = 1269), by means of the Cox proportional hazards model. Significant predictors of all-cause mortality were as follows: (1) peripheral vascular disease, rate ratio (RR) = 2.4 (1.7 to 3.4 [95% CI]); (2) prior myocardial infarction, RR = 2.1 (1.5 to 3.1); (3) severe left ventricular dysfunction, RR = 3.9 (2.6 to 5.9) and moderate left ventricular dysfunction, RR = 2.0 (1.5 to 2.6); (4) age > or = 70 years, RR = 3.4 (2.4 to 4.8), and age 60 to 69 years, RR = 1.7 (1.3 to 2.4); (5) diabetes mellitus, RR = 1.7 (1.3 to 2.4); (6) carotid disease, RR = 1.7 (1.2 to 2.4); and (7) single ITA (versus bilateral ITA), RR = 1.4 (1.1 to 1.8). Number of vessels diseased, surgical status (i.e., urgent versus elective), hypertension, and sex were not significant predictors. Unadjusted actuarial survival rates at 10 years were 86 +/- 3% (mean +/- 95% CI) for bilateral ITA group and 71 +/- 5% for single ITA. Single ITA was also a predictor of all-cause mortality, late myocardial infarction, or late reoperation (RR = 1.3 [1.1 to 1.6]). CONCLUSIONS: Bilateral ITA grafting may improve long-term survival and freedom from late myocardial infarction or reoperation after coronary artery surgery. Mathematical modeling may assist in developing a strategy for use of bilateral ITA grafts.
Arteries↗
Phosmet induces up-regulation of surface levels of the cellular prion protein.
Chronic (2 day) exposure of human neuroblastoma cells to the organophosphate pesticide phosmet induced a marked concentration-dependent increase in the levels of PrP present on the cell surface as assessed by biotin labelling and immunoprecipitation. Levels of both phospholipase C (PIPLC)-releasable and non-releasable forms of PrP were increased on the plasma membrane. These increases appear to be due to post-transcriptional mechanisms, since PrP mRNA levels as assessed by Northern blotting were unaffected by phosmet treatment. These data raise the possibility that phosmet exposure could increase the susceptibility to the prion agent by altering the levels of accessible PrP.
Cell Membrane↗
Re: "Cancer incidence near radio and television transmitters in Great Britain. I. Sutton Coldfield transmitter. II. All high power transmitters".
Explore the source record for details and available documents.
Adolescent↗
Estimation and relevance of depth correction in paediatric renal studies.
Measurement of absolute renal function by gamma camera techniques requires knowledge of kidney depth to correct for soft tissue attenuation, there is debate about the need to take depth into account when only relative renal function is estimated. The aim of this study was to derive a formula for renal depth in children and to assess the importance of depth correction when relative renal function is assessed with dimercaptosuccinic acid (DMSA) on the gamma camera. In this study, kidney depths were derived from measurements on abdominal computerised tomography (CT) images in 57 children in the supine position with two normally located kidneys. Using best-subset regression analysis, one formula for both left and right kidney depth (KD, cm) was developed based on the easily measured parameters of height (H, cm) and body weight (W, kg). The inclusion of extra variables was found to significantly improve the model compared with a model using weight alone (P<0.005). A second group of 19 children who underwent technetium-99m DMSA scans, had differential function estimated from both anterior and posterior views and the geometric mean method. The mean difference in differential renal function calculated by the geometric mean method versus the posterior image was only 1.2%. In conclusion, we present a new formula for the estimation of paediatric kidney depth for the absolute quantitation of kidney uptake. Further, for normally located kidneys it appears unnecessary to use the geometric mean method or to correct for individual renal depth when calculating differential function.
Adolescent↗
Helical CT angiography in the preoperative evaluation of carotid artery stenosis.
PURPOSE: To determine the utility and accuracy of helical CT angiography (CTA) in the evaluation of carotid artery stenosis. METHODS: A comparison of CTA and conventional arteriogram was performed in 53 patients undergoing evaluation for carotid artery stenosis. Ninety-six carotid systems were evaluable. CTA stenosis was determined by the percent of area reduction seen on axial images through the level of greatest narrowing. MIP images were used to identify the point of maximal stenosis and to visualize overall vascular anatomy. The percent diameter stenosis was measured on conventional arteriograms using strict North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) criteria. RESULTS: Significant correlation was found between CTA and arteriography (NASCET method R=0.87, ECST method R=0.87, p < 0.001). Using NASCET >60% as an indicator for disease, CTA had a sensitivity of 87%, specificity of 90%, accuracy of 89%, negative predictive value of 88%, and positive predictive value of 89%. CTA identified plaque characteristics such as ulcerations (8), occlusion (10), fatty plaques (22), calcifications (48), and fibrosis (2). CTA underestimated 2 cases of short segment stenoses because of volume averaging, but this discrepancy was detected by duplex scan. No complications or renal dysfunction occurred with CTA; 1 patient became symptomatic during arteriography, necessitating termination of the procedure. CONCLUSION: CTA is a safe, non-invasive technique that precisely measures carotid artery area reduction and highly correlates to conventional arteriography. With this new technology, the current standards for carotid artery imaging may need to be reevaluated, and the precise role for helical CTA more clearly defined.
Aged↗
Proteinuria, hypertension and chronic renal failure in X-linked Kallmann's syndrome, a defined genetic cause of solitary functioning kidney.
BACKGROUND: Anosmia and hypogonadotrophic hypogonadism are the classic features of X-linked Kallmann's syndrome, a disorder caused by mutations of KAL, a gene expressed during kidney and brain development. About a third of patients have a solitary functioning kidney, but little is known about their renal morbidity. METHODS: We studied seven patients aged 22-35 years with X-linked Kallmann's syndrome and a solitary functioning kidney. RESULTS: Two patients developed significant proteinuria associated with mild to moderate arterial hypertension in the second to third decades of life. In one, proteinuria and renal impairment preceded the appearance of hypertension, and the disorder progressed to chronic renal failure. The remaining five patients had normal plasma creatinine concentrations and no significant proteinuria although four had borderline systolic and/or diastolic hypertension. In two sets of patients from the same kindreds, there was a striking discordance for the occurrence of renal morbidity. CONCLUSIONS: All patients with X-linked Kallmann's syndrome should be screened for renal malformations, and those with solitary kidneys require life-long follow-up to detect hypertension, proteinuria and renal failure.
Adult↗
Use of tracheobronchography as a diagnostic tool in ventilator-dependent infants.
OBJECTIVE: Comparison of investigations of the airway in ventilator-dependent infants. DESIGN: Consecutive infants with suspected upper airway abnormalities were investigated using rigid bronchoscopy and tracheobronchography. SETTING: Tertiary pediatric and neonatal intensive care units. PATIENTS: Eight infants with suspected airway abnormalities. INTERVENTIONS: Rigid bronchoscopy and tracheobronchography. MEASUREMENTS AND MAIN RESULTS: Structural abnormalities, segmental narrowing of the airways and the effect of various levels of positive-end expiratory pressures on the narrowings were documented. In six of the eight cases, additional airway abnormalities were diagnosed with tracheobronchography compared with rigid bronchoscopy. CONCLUSIONS: In cases of suspected abnormalities of the upper airway in small infants unable to be weaned from ventilatory support, tracheobronchography may be a more reliable investigation method than rigid bronchoscopy. The ability to assess the structural and dynamic components of the airway accurately and safely allows a correct and long-term treatment plan to be established in this group of patients.
Airway Obstruction↗