A comparison between digital fluoroscopic hard copies and 105-mm spot films in evaluating vesicoureteric reflux in children.

OBJECTIVE: To compare fluoroscopic freeze-frame digital images with conventional 105-mm spot films during voiding cystourethrography (VCUG) with regard to diagnostic quality and radiation dose. MATERIALS AND METHODS: VCUG was performed on 57 consecutive children by a commercially available fluoroscopic digital system. Both freeze-frame digital images and conventional 105-mm spot films were obtained during 90 s of fluoroscopy. Skin radiation dose was assessed separately for spot films and for both fluoroscopy and spot films, employing thermoluminescent crystals on the anterior surface of the body. Patients were classified into three age groups: group A younger than 12 months, group B 1-5 years old and group C 5-12 years of age. RESULTS: Digital and conventional images provided diagnostically identical results in 108 out of 114 ureters examined (94.7%). Percentage reductions in skin radiation dose due to the fluoroscopic hard copies compared with the four 105-mm radiographs were 53.8%, 50.5% and 57.1% for groups A, B and C, respectively. CONCLUSION: Substitution of conventional 105-mm spot films during VCUG with digital fluoroscopic hard copies resulted in a substantial reduction in radiation dose. Digital images were as accurate as the conventional films in excluding vesicoureteric reflux (VUR). The two methods correlated well in diagnosing and grading VUR.

Relationship of gallbladder contour, fasting volume and emptying to body size indices in normal subjects and patients with gallstones.

Fasting gallbladder volume and fasting gallbladder roundness index (ratio of anteroposterior diameter to gallbladder length) were estimated by ultrasonography in 182 normal subjects and 43 patients with gallstones and correlated to body size indices. In 20 of the normal subjects, gallbladder emptying was assessed and correlated to gallbladder roundness index. Gallstone patients had a larger fasting gallbladder volume as compared to normals (42 +/- 10 vs 22 +/- 7 (SD) ml, p < 0.001). Gallbladder fasting volume was found to be significantly related to roundness index (p < 0.001) and body surface area (p < 0.0001) in normals, but not in patients with cholelithiasis. Subjects with a roundness index > 0.3 showed a less-complete gallbladder emptying as compared to those with a roundness index < 0.3 (p < 0.01). It is concluded that increased body size, but not obesity alone, is associated with an increased gallbladder fasting volume, and that a rounder gallbladder tends to empty less completely.

Ultrasound attenuation of the calcaneus in the female population: normative data.

Broadband ultrasound attenuation (BUA) on the os calcis has been proposed as a safe and reliable technique for evaluating skeleted status. The present study provides preliminary normative BUA results on 93 female subjects divided into five age groups. These data can be used as a guide for comparing the results of individual studies. The diagnosis of osteoporosis was determined from lateral calcaneus and spine radiographs. Postmenopausal osteoporotic female subjects had significantly lower BUA values than normal women (P less than 0.001). There was a significant negative linear relationship between BUA and age in the postmenopausal subjects. No correlation was found between body size parameters (weight, height, and body mass index) and ultrasound attenuation. These results indicate that BUA may be a useful technique for detection of persons at risk.

Optimal CT settings for head imaging in the paediatric patient. An analysis of absorbed dose.

The absorbed dose at CT was measured at nine points in a 16 cm diameter phantom. The effect of different reconstruction algorithms and scan settings on the quality of head CT images was studied in children and phantoms. Two low-dose CT techniques for head imaging can be selected for children, depending on differences in the image quality necessary for the diagnostic information required.