Monica A. Rossleigh

Evaluation of acute urinary tract infection in children by dimercaptosuccinic acid scintigraphy: a prospective study.

A prospective study examining the incidence of dimercaptosuccinic acid (DMSA) abnormalities in children at the time of acute urinary tract infection, the progression of these abnormalities following treatment and their correlation with the presence of vesicoureteral reflux is reported. DMSA scans performed within 72 hours of presentation in 65 previously healthy children with acute urinary tract infection were abnormal in 34 (52%). The scan appearances of 30 of 36 (83%) initially abnormal kidneys improved or became normal on the repeat DMSA study performed at 3 to 6 months after the acute urinary tract infection. A cystogram demonstrated significant vesicoureteral reflux in 11 of 45 cases (24%). Of these 11 cases 10 had abnormal DMSA studies and 1 had dilated upper tracts on ultrasound. Several conclusions may be drawn from our study. The incidence of DMSA abnormalities at the time of acute urinary tract infection is high but these abnormalities tend to resolve with time. An abnormal DMSA study at the time of urinary tract infection identifies most children with significant vesicoureteral reflux, and in our series a combination of ultrasound and DMSA identified all cases. This study may have major implications for the clinical investigation of children with urinary tract infection.

The Detection of Reflux Nephropathy in Infants by 99 mtechnetium Dimercaptosuccinic Acid Studies

Dimercaptosuccinic acid (DMSA) studies were performed in 113 infants less than 1 year old at risk of renal scarring. Of these patients 86 presented with urinary tract infection and 27 were asymptomatic. A voiding cystourethrogram was performed in all cases and excretory urography (IVP) was done in 99. More abnormalities were detected by DMSA study when compared to scars on IVP. When both studies were abnormal there was an excellent correlation on a site by site basis. Fever or systemic disorder was not a reliable sign to determine whether there was upper tract involvement with infection. The incidence of DMSA abnormalities in infants increased with high grade vesicoureteral reflux and decreased with low grade reflux. There was no significant difference in the incidence of abnormal kidneys between the infected and noninfected groups, suggesting that renal scarring may occur with sterile reflux.

Low incidence of new renal scars after ureteral reimplantation for vesicoureteral reflux in children: a prospective study.

PURPOSE The major aim of treating vesicoureteral reflux in children is the prevention of renal scars. Dimercapto-succinic acid (DMSA) is the modality of choice for detecting renal scars. We documented the incidence of new renal scarring and measured changes in differential renal function after ureteral reimplantation using DMSA studies. MATERIALS AND METHODS We evaluated 45 boys and 98 girls with a median age of 2 years who had vesicoureteral reflux and underwent ureteral reimplantation. DMSA scans were done preoperatively and at a median of 3.4 years postoperatively. Maximal reflux grade was III in 84 children (59%), IV in 27 (19%) and V in 6 (4%). RESULTS Preoperatively DMSA studies showed scarred or contracted kidneys in 106 of the 143 patients (74%). After reimplantation mean change in differential function was 2.5%. New scars developed in 3 children (2%). We noted greater than 6% decrease in relative differential function without new scarring in 7 cases (5%). CONCLUSIONS The incidence of new renal scars in our study using DMSA was lower than that in previous series using excretory urography and imaging. Surgical correction of vesicoureteral reflux may offer better protection of kidneys in childhood than previously believed.

Diuresis renography : the need for an additional view after gravity-assisted drainage

The role of diuresis renography (DR) in the evaluation of pelvi-ureteric junction obstruction is well established. However, problems may be encountered when applying this technique to patients after pyeloplasty because of the role of gravity-assisted drainage (GAD) in this post-operative group. Twenty-three radionuclide studies that were performed in 21 children were reviewed. All children underwent standard DR and all then had an additional view performed after GAD. In 12 children evaluated in a preoperative assessment for possible obstruction, 5 were obstructed on both DR and after GAD, 1 was equivocal on DR but drained after GAD, and 6 were not obstructed in either part of the study. In 11 children assessed after pyeloplasty, 5 were obstructed on DR but not obstructed on GAD, 3 were not obstructed in both studies, 1 was obstructed in both, and 2 were equivocal on DR but not obstructed after GAD. It can be concluded that when assessing patients, particularly those who have undergone pyeloplasty, DR should be supplemented with an additional view acquired after gravity-assisted drainage.

Osteonecrosis in patients with malignant lymphoma. A review of 31 cases

Osteonecrosis of the femoral and humeral heads is a serious complication of therapy for Hodgkins disease and non‐Hodgkins lymphoma. Twenty‐five patients were reassessed 5 years after being initially reported, in order to study the further progress and natural history of this complication. In addition, six recent patients who have also developed this condition are presented. With 5‐year additional follow‐up, no patient had developed symptoms of osteonecrosis in any bone other than those initially involved. Five patients developed severe complications thought to arise from their therapy suggesting that this group of patients were more sensitive to radiation injury than other patients treated with this modality. During the relatively short follow‐up 5‐year period, a surprising finding was the fact that 31% of the patients with Hodgkins disease and 50% with non‐Hodgkins lymphoma had died. It is recommended that patients treated for lymphoma with steroid containing chemotherapy and radiotherapy be observed carefully for the occurrence of joint pain. Early diagnosis should lead to attempts to prevent total joint destruction. Cancer 58:1112‐1116, 1986.

Reliability of DMSA for the diagnosis of renal parenchymal abnormality in children

Abstract The objective of this study was to evaluate the variability of technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy interpretation by four nuclear medicine physicians for the diagnosis of renal parenchymal abnormality in children, and to compare variability among three different DMSA methods in clinical use: planar alone, single-photon emission tomography (SPET) alone, and planar with SPET. One hundred consecutive DMSA studies were independently interpreted 3 times by four participating nuclear medicine specialists from different departments and in random order. All scans were classified by the presence or absence of renal parenchymal abnormality using the modified four-level grading system of Goldraich. Indices of agreement were the percentage of agreement and the kappa statistic. Disagreement was analysed using children, kidneys and kidney zones (three zones per kidney). Using patients as the unit of analysis, agreement for planar and planar with SPET methods was 87%–88% (kappa 0.74) for the normal-abnormal scan classification. The corresponding agreement value for the SPET alone method was 78% (kappa 0.56). Similarly, substantial disagreement (disagreement ≥2 categories) occurred in 2.5% and 1.3% of comparisons between observers for planar alone and planar with SPET, respectively, but in 5.2% of comparisons for SPET alone. These results did not vary appreciably whether interpretation of patients, kidneys or kidney zones was compared. It is concluded that the four experienced nuclear medicine physicians showed substantial agreement in the interpretation of planar alone and planar with SPET DMSA scintigraphic images. Interpretation of SPET DMSA images, without planar images, was significantly more variable than interpretation using the two other methods, disagreement occurring in more than 20% of comparisons. SPET DMSA scintigraphy, when used without planar images, does not provide a firm basis for clinical decision making in the care of children who may have renal damage. There is no apparent benefit of reduced variability from the extra provision of SPET data to nuclear medicine physicians who already have planar images.

2-deoxy-2-(~(18)F)fluoro-D-glucose positron emission tomography/computed tomography imaging in paediatric oncology

Positron emission tomography (PET) is a minimally invasive technique which has been well validated for the diagnosis, staging, monitoring of response to therapy, and disease surveillance of adult oncology patients. Traditionally the value of PET and PET/computed tomography (CT) hybrid imaging has been less clearly defined for paediatric oncology. However recent evidence has emerged regarding the diagnostic utility of these modalities, and they are becoming increasingly important tools in the evaluation and monitoring of children with known or suspected malignant disease. Important indications for 2-deoxy-2-((18)F)fluoro-D-glucose (FDG) PET in paediatric oncology include lymphoma, brain tumours, sarcoma, neuroblastoma, Langerhans cell histiocytosis, urogenital tumours and neurofibromatosis type I. This article aims to review current evidence for the use of FDG PET and PET/CT in these indications. Attention will also be given to technical and logistical issues, the description of common imaging pitfalls, and dosimetric concerns as they relate to paediatric oncology.

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 had normal hepatobiliary scans. The authors conclude that intrahepatic bile duct dilatation with cholestasis (Carolls 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.

Determination of the normal range of furosemide half-clearance times when using Tc-99m MAG3.

In radionuclide diuresis renography, furosemide half-clearance times have been established using Tc-99m DTPA but have not been verified when Tc-99m MAG3 is used. One hundred and six consecutive diuretic renograms using Tc-99m MAG3 for the evaluation of unilateral renal abnormalities were assessed. The furosemide half-clearance times of the normal kidneys were all less than 9.8 minutes, with a mean of 3.4 minutes. In 18 patients, the half-clearance times of the normal kidney were artificially prolonged because urine had drained before the administration of the diuretic. The normal furosemide half-clearance time values obtained using Tc-99m MAG3 were found to be similar to those established for Tc-99m DTPA. Prolonged half-clearance times of Tc-99m MAG3 must be confirmed by visual evidence of obstruction.

Nomograms of renal length in children obtained from DMSA scintigraphy

The aim of this study was to establish nomograms of renal length in children comparing age, body weight, and height. Renal lengths were obtained from data derived from Tc-99m DMSA scintigraphy in 266 patients with 532 kidneys that appeared normal on DMSA studies. The childrens ages ranged from 6 days to 19 years. Renal length appeared to have nonlinear relationships with patient weight and age, but was found to correlate linearly with patient height. On average, scintigraphic renal length exceeded sonographic renal length by approximately 1 cm. The most likely explanation for this is the effect of respiration causing renal motion during the acquisition of the scintigraphic images. It is hoped that the nomograms derived from these data will be of use in routine clinical practice for nuclear medicine departments performing DMSA scintigraphy in children.