Biomedical subjects
Publications and source records attributed to D R Kirks.
Fluoroscopic catheter removal of blunt esophageal foreign bodies is a safe, efficacious, time-effective, and cost-effective technique.
Nephroblastomatosis is an abnormality of nephrogenesis characterized by incomplete maturation of primitive nephrogenic cells. The resultant individual lesions have variable histologic findings and distribution in the kidney. There is wide acceptance of nephroblastomatosis as a precursor lesion to Wilms tumor. Consequently, the role of imaging in assessing patients for neoplastic transformation of nephroblastomatosis should be emphasized. Computed tomography (CT) has been shown to be superior to ultrasound (US) in this regard. Nonetheless, the low cost and lack of radiation of US make it attractive for serial screening studies. Although magnetic resonance imaging shows promise in assessment of the kidney for nephrogenic rests, experience is limited in its use in evaluating patients for nephroblastomatosis. The authors present protocols for assessing patients identified as being at either high or low risk for the development of Wilms tumor due to nephroblastomatosis. These protocols take into account the advantages of CT and US. Scanning intervals are determined from epidemiologic data on the occurrence of Wilms tumor; the most intense screening occurs during the younger ages of life, when the likelihood of Wilms tumor development is highest.
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Ten cases of traumatic atlanto-occipital disruption in pediatric patients are reported. All injuries resulted from motor vehicle accidents, the majority of which were pedestrian/automobile. Three patients survived their injury for a period greater than one year. The importance of recognizing atlanto-occipital disruption is stressed because of its relative frequency in severely traumatized pediatric patients, particularly pedestrian/vehicle incidents, and because of the potential for survival. Diagnosis, in most instances, is based on the lateral cervical spine radiograph. The most applicable diagnostic features in children, as demonstrated on the lateral cervical spine radiograph, are reviewed.
Esophagitis in children with immunodeficiency is most commonly due to opportunistic infection. The authors describe three patients with chronic granulomatous disease (CGD) of childhood who developed esophageal strictures that were believed to be complications of the primary disease. At radiologic examination, all three patients initially had a focal narrowing of the upper thoracic esophagus. Endoscopy showed no signs of opportunistic infection or Barrett esophagus. Biopsy of the strictures in two patients revealed findings consistent with CGD. In two of the three patients, inflammation extended to involve the middle and distal esophagus. Long-term response to balloon dilation was poor in the first two patients. The third patient was lost to follow-up after a partial clinical and radiographic response to dilation.
Air enema was used for exclusion, diagnosis, initial movement, and complete reduction of intussusception in 186 pediatric patients. Average pressure needed for initial movement of intussusception was 56.5 mm Hg; average maximum pressure of 97.8 mm Hg was required for complete reduction. Average fluoroscopy time required for intussusception reduction was 94.8 seconds; an average of 41.8 seconds was required to exclude intussusception. Intussusception was diagnosed in 75 patients, and reduction was accomplished in 65 (87%). Of 100 consecutive patients that underwent hydrostatic reduction of intussusception at the authors' institution, reduction was successful in 55. Compared with hydrostatic enema, air enema involves shorter fluoroscopy time and lower radiation dose to the patient. Air enema is safe and effective for diagnosis and treatment of intussusception in infants and children and has replaced hydrostatic enema for such procedures at the authors' institution.
A new device has been developed for pneumatic reduction of childhood intussusception. The device consists of a reusable, hand-held pressure gauge and insufflator connected to a disposable enema tip and tubing system. The assembled device permits one-handed operation which maximizes operator control of the air reduction procedure. The system has been used to evaluate 50 cases of suspected intussusception. Reduction was successful in 19 of 22 confirmed intussusceptions. This device provides a practical, simple and safe method for diagnosis and treatment of intussusception.
The members of the Society for Pediatric Radiology were surveyed in 1989 about their involvement with newer imaging modalities. Results were compared with those obtained in a similar study performed 10 years earlier. The performance and monitoring of imaging studies increased dramatically, with most respondents now being involved with ultrasound (US) and computed tomography (CT), and almost one-half involved with magnetic resonance (MR) imaging. When equipment became available, pediatric radiologists were quicker to assume control of MR imaging than US and CT. In most large pediatric centers, imaging with all current modalities and of all organ systems has become the responsibility of pediatric radiologists. These findings are in contrast to those obtained in 1979, when pediatric imaging practices primarily consisted of conventional radiography and fluoroscopy.
Chest radiographs are often considered an essential part of the workup of the febrile infant. Anteroposterior and lateral radiographs of the chest are frequently obtained in this group of patients, irrespective of respiratory tract symptoms and/or signs. A total of 226 children (less than or equal to 2 years old) with and without signs and symptoms of lower respiratory tract infections were examined to assess the yield of chest radiographs. The radiograph was considered positive only if a focal parenchymal infiltrate was present. Hyperinflation or bronchial thickening was not included as a positive finding because these children usually do not receive antibiotics despite the fact that viral illness or reactive airway disease may be present. In a retrospective study of 105 infants, confidence intervals for yield were established for children with (95% Cl = 12%, 32%) and without (95% Cl = 0%, 14%) symptoms or signs of lower respiratory tract infection. In a prospective study of 121 infants without chest symptoms or signs, confidence levels for positive yield were better defined (95% Cl = 0%, 3%). The data suggest that obtaining chest radiographs to look for parenchymal infiltrates treatable with antibiotics in infants less than 2 years old is necessary only in those infants who have clinical evidence of lower respiratory tract illness.
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Congenital mesoblastic nephroma is the only primary renal neoplasm with radiographically demonstrable function. Renal function within two typical congenital mesoblastic nephromas was demonstrated by computed tomography in one case and renal scintigraphy in the other. Excretion of contrast medium and radionuclide was due to functioning nephrons trapped within the tumor.
This retrospective study documents the findings on nuclear cystography and renal sonography of 455 girls who had urologic imaging for a proved urinary tract infection (UTI). Nuclear cystograms were normal in 313 (69%) of 455 patients. Vesicoureteral reflux was seen in 142 patients (31%): six with grade I, 90 with grade II, 43 with grade III, and three with grade IV. Twelve percent of patients with vesicoureteral reflux had renal parenchymal scars. Increasing grades of reflux were associated with an increase in the severity and number of parenchymal scars. Normal renal sonograms were seen in 83% of patients. Abnormalities noted on sonograms included parenchymal scarring in 31 (7%) of the 455 patients, anomalies in 19 patients (4%), mild to moderate dilatation of the renal pelvis and or ureters in 45 patients (10%), and bladder wall thickening in 45 patients (10%).
We have described a newborn who had rapid resolution of cholelithiasis after a gallstone was incidentally discovered during sonographic evaluation of a renal mass. This case emphasizes the importance of conservative management and serial sonograms in infants with tumefacient sludge or gallstones without clinical or imaging evidence of biliary tract disease.
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Intussusception represents the most common abdominal emergency of early childhood. Despite its prevalence, there is controversy concerning diagnosis and therapy. The authors discuss their approach to the diagnosis of suspected intussusception and the radiologist's role in therapy.
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A new low-dose chest radiographic system for use in the neonatal nursery was evaluated. This test system, composed of a Du Pont Kevlar fiber-front cassette, Quanta fast-detail screen, Cronex 4L film (wide latitude), and additional yttrium filtration (0.1 mm), reduced the radiation dose in neonatal chest radiography by 69% (0.9 vs 2.9 mrad [0.009 vs 0.029 mGy]) as compared with a conventional system without added yttrium filtration; the thyroid dose was reduced by 76% (0.9 vs 3.7 mrad [0.009 vs 0.037 mGy]). The cumulative dose reduction was achieved through a combination of factors, including (1) beam hardening by the added yttrium filter, (2) increased X-ray transmission through the Kevlar cassette, and (3) a fast film-screen combination. Scatter radiation at distances of 1 and 6 ft. (0.3 and 1.8 m) was negligible for both systems. Image sharpness was compared for the conventional system with and without added yttrium filtration and for the Kevlar system with yttrium. Although sharpness of bony detail was unchanged by adding yttrium filtration to the conventional system, a decrease in sharpness was noted with the Kevlar system. Because image sharpness was affected in the test system, we are not using the Kevlar-Cronex 4L system for mobile chest radiography in the neonatal intensive care unit, despite dose reductions. However, further study is recommended to determine if there is a slower film-screen combination with yttrium filtration that will not degrade image sharpness.
A retrospective analysis of pediatric admissions over 10 years revealed 29 patients with cervical spine injuries. Eleven patients were below 12 years of age, and 10 of these had injuries involving C1, C2, or the occipitoatlantal articulation. Eighteen patients were between 12 and 16 years of age with injuries distributed throughout the cervical spine similar to injuries in the adult population. Our results suggest that teenagers with suspected cervical injuries are best evaluated by an adult radiographic series including trauma oblique views. In younger patients, careful evaluation of occipitoatlantoaxial alignment and the prevertebral soft tissues is required for diagnosis and selection of additional imaging evaluation.