Estimation of the tissue composition of the tumour mass in neuroblastoma using segmented CT images.

Neuroblastoma is the most common extra-cranial, solid, malignant tumour in children. Advances in radiology have made possible the detection and staging of the disease. Nevertheless, there is no method available at present that can go beyond detection and qualitative analysis, towards quantitative assessment of the tissue composition of the primary tumour mass in neuroblastoma. Such quantitative analysis could provide important information and serve as a decision-support tool to the radiologist and the oncologist, result in better treatment and follow-up and even lead to the avoidance of delayed surgery. The problem investigated was the improvement of the analysis of the primary tumour mass, in patients with neuroblastoma, using X-ray computed tomography (CT) images. A methodology was proposed for the estimation of the tissue content of the mass: it comprised a Gaussian mixture model for estimation, from segmented CT images, of the tissue composition of the primary tumour. To demonstrate the potential of the method, the results are presented of its application to ten CT examinations of four patients. The method provides quantitative information, and it was observed that the tumour in one of the patients reduced from 523 cm3 to 81 cm3 in volume, with an increase in calcification from about 20% to about 88% of the tumour volume, in response to chemotherapy over a period of five months. Results indicate that the proposed technique may be of considerable value in assessing the response to therapy of patients with neuroblastoma.

Common Pediatric Urological Disorders: Clinical and radiological evaluation.

The clinical and radiological presentations of 12 pediatric urological disorders are described. The described disorders include pyelonephritis, vesicoureteral reflux, ureteropelvic obstruction, ureterovesical obstruction, ectopic ureterocele, posterior urethral valves, multicystic dysplastic kidney, polycystic kidney disease, ectopic kidney, staghorn calculi, urethral diverticulum, and urethral meatal stenosis.

Genital edema in children on continuous ambulatory peritoneal dialysis.

Genital edema is a recognized complication of continuous ambulatory peritoneal dialysis (CAPD) in adults. Two children who developed genital edema while on CAPD are reported. The edema developed in both children as a consequence of a peritoneal leak in the inguinal region. A computerized tomogram (CT) scan of the abdomen is an excellent method to identify the site of the peritoneal leak. The literature is reviewed and the pathophysiology of the development of genital swelling and edema is discussed.

Sonographic features of urinary bladder involvement in regional enteritis.

Three cases of regional enteritis (Crohn disease) with secondary involvement of the urinary bladder diagnosed by ultrasound are presented. The ability of ultrasound to simultaneously and noninvasively demonstrate the changes in bladder and adjacent bowel, unlike other radiologic or urologic investigations, is emphasized.

CT visualization of medullary sponge kidney.

Recognizing the changes of medullary sponge kidney (MSK) on computed tomographic (CT) scans may be of value in both diagnosis and in differentiating this from other disease states. The appearance on CT of MSK has not previously been well described. A case is reported that demonstrates ectatic renal collecting tubules visualized by CT, and techniques are suggested to optimize visualization of these changes.