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Biomedical subjects

D L Mueller

Publications and source records attributed to D L Mueller.

44 records · Page 3Linked to original sources

Removal of esophageal foreign bodies with a Foley balloon catheter under fluoroscopic control.

Between 1982 and 1985 removal of a nonorganic, smooth, radiopaque foreign body in the esophagus with a Foley balloon catheter under fluoroscopic control without sedation was attempted in 38 children. An ultra-low-dose fluoroscopic unit was used. In 35 children the foreign body (a coin) was either easily removed (in 29 cases) or advanced into the stomach (in 6). No complications of the procedure were observed. In three children the foreign body could not be removed by this means; it was subsequently removed by endoscopy (in two cases, both of coins) or esophagotomy (in two cases, both of coins) or esophagotomy (in one, of a stone). When carefully performed, removal of blunt, recently ingested esophageal foreign bodies with a Foley catheter under fluoroscopic control is a safe mode of treatment.

Catheterization↗

Neuroblastoma: a specific sonographic tissue pattern.

Previous attempts to determine a sonographic appearance characteristic of neuroblastoma have had diverse results. Sonograms of 53 abdominal tumors, including 10 neuroblastomas, imaged during 1982-1986 were reviewed. Four of the patients with neuroblastoma had a distinctive sonographic "lobule" of increased echogenicity in a part of the larger tumor mass. This sonographic appearance was secondary to the growth pattern of the tumor and was not cell specific. Correlative CT scans in two of the four patients did not differentiate this lobule. Histologically, the lobule was an aggregate of uniform neuroblastoma cells (marginated by reticulin and collagen) without hemorrhage, necrosis, or calcification. This tissue pattern was not seen in any of the other 43 neoplasms, including 12 Wilms' tumors. When identified sonographically, the lobule identified in this study seems specific for neuroblastoma and is a valuable diagnostic sign in children with an abdominal mass.

Abdominal Neoplasms↗

Ultra-low-dose routine pediatric radiography utilizing a rare-earth filter.

Clinical evaluation of the usefulness of primary beam filtration with erbium to achieve marked reductions in radiation exposure and dosage was undertaken. We evaluated 250 routine pediatric radiographic and 100 contrast examinations. An additional 52,727 radiographic and 4745 fluoroscopic examinations were analyzed prospectively by evaluation of subjective film quality. Radiation exposure and dosage reductions ranged from 57% at 50 kVp to 36% at 80 kVp and 39% at 120 kVp. These reductions were obtained in addition to those previously attained by using a 600-speed gadolinium oxysulphide screen/film system (Trimax 12, XDL). The erbium filter requires that the tube current be increased to approximately double that without the filter (in the most commonly used range of 60-100 kVp). However, tube loading is already so low with the 600 system that this effect on wear is considered inconsequential. This ultra-low-dose rare-earth beam filter and screen/film combination results in films with no demonstrable loss of overall quality, plus a subjective slight improvement in contrast definition for iodine and barium contrast studies. The addition of erbium foil beam filtration to existing rare-earth screen/film technology results in what is currently the ultimate in low-dose conventional radiographic imaging.

Child↗

Ultrasonography and the impalpable testis.

The accuracy of inguinal ultrasonography in the pre-operative localization of the maldescended testis was assessed in 51 patients with 57 maldescended testes. Pre-operative sonographic results were compared with the clinical assessment and the operative findings. Testes located in the inguinal canal or at the internal ring, which were occasionally impalpable, were readily demonstrated by sonography. The management of children with an impalpable maldescended testis should include a sonographic examination as the investigative procedure of choice.

Adolescent↗

Pediatric digital subtraction angiography.

Experience with intravenous digital subtraction angiography (DSA) in infants and children is limited, although its relative ease of performance, low complication rate, and diagnostic accuracy indicate great potential. We performed 87 DSA examinations (74 patients) and obtained sufficient detail to facilitate diagnosis in most cases. The major problems of patient movement and overlapping vessels can be minimized by judicious use of sedation and strict attention to technique. Exposure of patients to radiation has not been a limiting factor since our system uses low exposure factors (2-38 mR [.51-9.76 mu C/kg]/frame). Our results demonstrate that DSA has wide applicability to many organ systems and is especially useful in intracranial disease and for preoperative evaluation of neoplasms. More specific indications for its use in children must await further correlative studies.

Adolescent↗

Rapid automated turbidimetric assay for chlortetracycline hydrochloride, using Leuconostoc mesenteroides as the test organism.

A rapid turbidimetric assay has been developed for chlortetracycline hydrochloride (CTC-HCl) in finished animal feeds and feed supplements, using Leuconostoc mesenteroides as the test organism. Two modifications are presented: The incubation period of modification 1 is 2.5 hr and the sensitivity of the assay is 0.03 microgram CTC-HCl/assay tube. Modification 2 has a sensitivty of 0.01 microgram CTC-HCl/assay tube and requires an incubation period of 3.5 hr. For 21 feed formulations, the turbidimetric method recovered 95.7% of label claim. Recoveries of CTC-HCl standards from the same feeds ranged from 93.4 to 134% with a mean of 103%. The relative standard deviation among day-to-day duplicates is 3.50% for the faster modification and 1.63% for the more sensitive modification.

Animal Feed↗

The application of i.v. digital subtraction angiography to cranial disease in children.

All intracranial IV digital subtraction angiographic examinations performed over the past 2 years were reviewed retrospectively to ascertain the uses and limitations of this technique for the evaluation of pediatric intracranial disease. Of the various abnormalities studied, this imaging technique was particularly useful in diagnosing venous and dural sinus abnormalities; in screening for suspected large aneurysms, vascular malformations, and major arterial occlusive disease; and in preoperative vascular mapping. IV digital subtraction angiography has selected usefulness in confirming brain death, in evaluating cerebral ischemia, in identifying vascular abnormalities underlying intracranial hemorrhage, and in evaluating vascularity and sinus extension of masses. The IV route for digital subtraction angiography is not useful in diagnosing segmental arterial occlusive or small-vessel disease, nor is it useful in preoperative localization of specific arterial supply to arterial venous malformations, aneurysms, or neoplasms. IV digital subtraction angiography can be performed successfully in children of all ages with minimal patient morbidity. For most patients, the diagnostic information obtained was adequate without the need for standard cerebral arteriography.

Adolescent↗