Search PubMed⌕ Search

Biomedical subjects

R Uren

Publications and source records attributed to R Uren.

At least 19 recordsLinked to original sources
PubMed2000

Response of Charcot's arthropathy to contact casting: assessment by quantitative techniques.

AIMS/HYPOTHESIS: This study used two different methods of quantitative bone scanning to study the relation between activity of Charcot's arthropathy and clinical variables over 12 months. METHODS: Skin temperature of affected and unaffected feet was measured at baseline and every 3 months for 12 months in 17 subjects. Eight subjects underwent a three-phase quantitative bone scan at baseline and 3 monthly for 12 months. Bone isotope uptake in a standard rectangular area over the foot and tibia was analysed by the bilateral scan method (the ratio of isotope uptake of affected and unaffected feet) and the unilateral scan method (the ratio of isotope uptake of affected foot and ipsilateral tibia). The affected foot was placed in a contact cast for an average of 8 months. RESULTS: At presentation the affected foot was hotter than the unaffected foot but the temperature became progressively cooler over 12 months. Median isotope uptake in the affected foot was 2.1% of the injected dose (interquartile range, IQR 1.9-3.0). In both scanning methods the ratio of uptake decreased after casting but at 12 months the affected foot still had more isotope uptake. There was a strong correlation between temperature difference and the ratio of uptake in the bilateral scan method (r = 0.90; p < 0.0001) but when using the unilateral scan method this relation was not significant (r = 0.1;p = 0.6). A strong relation existed between perfusion of the affected foot in the dynamic phase and isotope uptake in the delayed phase of the scans (r = 0.92; p < 0.0001). CONCLUSION/INTERPRETATION: Bone activity and skin temperature of Charcot's arthropathy can be measured quantitatively and both improve over 12 months with contact casting. There is a strong relation between perfusion and disease activity in this condition.

Aged↗
PubMed2000

An unusual white blood cell scan in a child with inflammatory bowel disease: a case report.

Technetium-99m-labeled leukocyte (WBC) imaging is a valuable screening method for inflammatory bowel disease, especially in children, because of its high rate of sensitivity, low cost, and ease of preparation. A 14-year-old girl is described who had juvenile arthritis and iritis complicated by inflammatory bowel disease. She was examined for recurrent abdominal pain. A Tc-99m stannous colloid WBC scan was performed, and tracer accumulation was seen in the small bowel in the region of the distal ileum on the initial 1-hour image. Delayed imaging at 3 hours also revealed tracer accumulation in the cecum and ascending colon, which was not seen on the early image. A biopsy of the colon during endoscopy showed no evidence of active inflammation in the colon. The small bowel was not seen. Computed tomography revealed changes suggestive of inflammatory bowel disease in the distal ileum. The appearance on the WBC study was most likely a result of inflammatory bowel disease involving the distal ileum, with transit of luminal activity into the large bowel.

Adolescent↗
PubMed1997

Pediatric nuclear oncology.

Nuclear medicine plays an important and increasing role in the management of childhood malignancy. This is particularly true in the solid tumours of childhood. It is also helpful in the management of the complications of cancer treatment such as the infections which often accompany immune suppression in oncology patients. Scintigraphy is a complementary investigation to other radiological techniques and adds the functional dimension to anatomical investigations such as CT, MRI and ultrasound. Scintigraphy is used in the initial diagnosis, staging, assessment of tumour response to treatment, detection of recurrence and the diagnosis of complications. In selected malignancies radionuclides are also used in treatment. This review discusses the technical considerations relating to children and the specific techniques relating to pediatric oncology. Specific tumours and the various applications of radionuclides are discussed in particular lymphoma, primary bone tumours, soft tissue sarcomas, neuroblastoma, Iangerhan's cell histiocytosis, Wilms' tumour, brain tumours and leukemia. Uncommon tumours are also discussed and how radionuclides are useful in the investigation of various complications which occur in oncology patients.

Child↗
PubMed1995

Intrahepatic bile duct dilatation and cholestasis in autosomal recessive polycystic kidney disease. Demonstration with hepatobiliary scintigraphy.

Fifteen patients with the clinical and radiologic features of autosomal recessive polycystic kidney disease were investigated with radionuclide hepatobiliary scintigraphy. In nine patients (60%), cholestasis and intrahepatic bile duct dilatation were demonstrated. A 10th child had scintigraphic evidence of cholestasis, but the bile ducts were not dilated. The other five children has normal h hepatobiliary scans. The authors conclude that intrahepatic bile duct dilatation with cholestasis (Caroli's disease) is part of the clinical spectrum of autosomal recessive polycystic kidney disease and that hepatobiliary scintigraphy can be of value in determining the extent of hepatobiliary disease in this group of patients.

Bile Ducts↗
PubMed1995

Clinical and diagnostic features of osteomyelitis occurring in the first three months of life.

We report a retrospective study of 94 infants, ages < 4 months, who underwent investigation for possible osteomyelitis during a 9-year period. Of the 30 babies with proven osteomyelitis (radiographic changes or positive bone cultures or positive blood cultures plus a compatible clinical picture), 17 were preterm artificially ventilated babies and 4 were full term infants receiving intensive care. An etiologic organism was isolated from 28: methicillin-susceptible Staphylococcus aureus, 16; methicillin-resistant S. aureus (MRSA), 7; Escherichia coli, 3; and group B Streptococcus, 2. MRSA occurred exclusively in the preterm group. Osteomyelitis was multifocal in 40% and associated with septic arthritis in 47%. The long bones were frequently affected (80%) whereas the flat bones were often sites of clinically silent disease. Twenty-five (83.3%) of the 30 babies with proven osteomyelitis had focal clinical signs or evidence of disseminated staphylococcal disease. Only 10 were febrile. Four of 27 babies investigated because of positive blood cultures for S. aureus but no focal signs had osteomyelitis, as did only 1 of 27 babies with suspected sepsis but no focal signs. The sensitivity of 99mTc bone scanning was 84%, specificity 89%, positive predictive value 79% and negative predictive value 92%. The addition of gallium scanning (in 39 of the 94 infants) improved the respective figures to 90, 97, 93 and 95% and was useful in interpreting equivocal bone scans.

Arthritis, Infectious↗
PubMed1993

Ga-67 scintigraphy in pulmonary blastoma in a child.

Pulmonary blastoma is a rare primary malignancy of the lung with a small number of cases reported in children. The primary treatment is surgery, however radiotherapy and chemotherapy are also used. The ability to determine whether the tumor has been fully removed and when recurrence occurs is important for appropriate treatment and prognosis. A case of a 7-year-old girl with pulmonary blastoma is reported in which the primary tumor is extremely Ga-67-avid and in which the gallium scans were helpful in determining early recurrence and metastatic disease to the brain.

Brain Neoplasms↗
PubMed1993

Ga-67 scintigraphy in a child with adrenocortical carcinoma.

Adrenocortical carcinoma is a rare malignancy in childhood and often presents with a large abdominal mass and precocious puberty. The tumor is often advanced at the time of diagnosis. Radiological techniques are the main imaging modalities for assessment of the primary tumor. Ga-67 scintigraphy has been used in other pediatric solid tumors, however, no data were available for this tumor in childhood. A case of a 2.5-year-old male with a Ga-67 avid adrenocortical carcinoma is reported in which Ga-67 scintigraphy was very useful in detecting recurrence of the tumor and in assessing response to therapy.

Adrenal Cortex Neoplasms↗
PubMed1993

Hepatobiliary scintigraphy in a pediatric population: determination of hepatic extraction fraction by deconvolution analysis.

A study was performed to assess the feasibility of measuring the hepatic extraction fraction (HEF) and hepatic half clearance time (HCT) in pediatric patients with a variety of hepatobiliary diseases. There were 45 children categorized into four groups: normal 12; obstruction 9; hepatocellular disease (HCD) 16 and miscellaneous 8. In the normal patients, the mean HEF was 99% +/- 3.6% and the HCT was 23.6 +/- 7.7 min. In the two disease categories, hepatocellular disease and obstruction, there was a wide range of HEF 15%-84% and 25%-100%, respectively. This reflected the varying degrees of liver dysfunction and/or cholestasis. The average results of HEF for the HCD group was significantly lower than controls, and the greatest difference of the HCD group and other disease groups was with the miscellaneous group. This was not, however, different from the obstructive group. There was, however, a large overlap of results, and differentiation between the disease groups was not possible. HCT from the disease groups also showed a prolonged average clearance when compared to normals, although this was not significant when the p value was adjusted for multiple comparisons. The normal HCT was 23.6 +/- 7.7 min, whereas the hepatobiliary disease groups ranged from 20 to 714 min. Again, there was considerable overlap of results in the disease groups. These functional parameters are feasible and applicable in the pediatric population.

Adolescent↗
PubMed1992

Multifocal osteomyelitis in childhood. Review by radionuclide bone scan.

Multifocal osteomyelitis is considered an uncommon complication of acute osteomyelitis. Over a 3-year period, 136 infants and children who had a final diagnosis of acute osteomyelitis were reviewed, and multifocal osteomyelitis was detected in 27 (19%) patients. The major age peak of acute osteomyelitis was between 6 weeks and 3 years (46%). Two age peaks were found for multifocal disease-less than 6 weeks (38%), and 9 to 12 years (44%). Three patients with multifocal disease had septicemia and photon-deficient areas on bone scans. Another adolescent group had nonspecific bone and joint pain that in some cases persisted for more than 3 months and were finally diagnosed as multifocal osteomyelitis. Organisms were isolated in 15/27 (56%). Multifocal osteomyelitis is well recognized in the neonatel age group. However, it occurs more commonly than previously described in older patients. This higher incidence can most likely be attributed to the higher use of the radionuclide bone scan early in the disease and the high sensitivity of the scan for the detection of osteomyelitis.

Acute Disease↗
PubMed1987

Volume expansion diuretic renal scan in urinary tract obstruction.

The diuretic renal scan is used to differentiate the obstructed dilated urinary system from the nonobstructed dilated system. The technique, however, has a false-positive and indeterminate rate of 10%-15%. This usually is due to variables such as the degree of dilatation of the pelvicalyceal system or ureter, the degree of bladder distention, the diuretic dose, and the state of hydration. We developed the volume expansion diuretic renal scan (VEDRS) to overcome these variables and to improve the accuracy of the technique. Twelve patients who had obstructive patterns on the diuretic renal scan were evaluated. Ten patients were shown to be dilated but not obstructed. Two patients were confirmed as obstructed. This technique improves the accuracy of the diuretic renal scan.

Adolescent↗
PubMed1982

Comparison of N-isopropyl (I-123) p-iodoamphetamine brain scans using Anger camera scintigraphy and single-photon emission tomography.

N-isopropyl (I-123) p-iodoamphetamine (IMP), which is extracted by the brain in proportion to regional blood flow, has been shown to be useful with single-photon emission tomography (SPECT) in the assessment of pathologic states related to blood flow. Because emission tomographic equipment is not yet available at most hospitals, the authors compared IMP brain images obtained with an Anger camera with those obtained by SPECT to determine the usefulness of IMP scintigraphy. Thirty-nine pairs of studies were performed on 12 control patients, 14 patients with stroke, three patients with tumors, and a miscellaneous group of eight patients. Planar scintigraphy showed good correlation with SPECT in determining the presence or absence of abnormality in all patients except one with a very small brain stem infarction that was not detected by planar imaging. Anger images showed poor contrast resolution compared with SPECT images. It is thus expected that SPECT will result in better lesion detection when smaller lesions are studied. Planar scintigraphy is not capable of providing quantitative measurement of regional cerebral blood flow.

Amphetamines↗