Technical aspects of catheter-related interventions in the liver of the rabbit.

PURPOSE: On the basis of 89 different vascular interventions performed in the livers of 39 rabbits, we attempted to establish the feasibility and technical limitations of these procedures. MATERIAL AND METHODS: Forty-five selective hepatic artery catheterizations were carried out using 0.66-mm and 1.0-mm catheters, including superselective proper hepatic catheterizations (n = 14) using a specially designed 0.66-mm introducer/catheter system. The portal system was investigated with both direct (n = 5) and indirect (arterial) (n = 4) portography. Hepatic, vein catheterizations were performed in 22 cases. RESULTS: With the 0.66-mm system, spasm occurred in one of 11 cases in the proper hepatic artery, and no spasm was observed in the common hepatic and celiac arteries. Both arterial portography and hepatic venography were easily performed and were a precise and repeatable method. CONCLUSION: The 0.66-mm system has proved to be advantageous over the 1.0-mm catheterization in avoiding arterial spasm. Direct portography as well as catheterization of the hepatic vein from a jugular approach are hazardous, leading to serious complications including the death of the animal.

Antiinflammatory agents protect opossum esophagus during radiotherapy.

Eighteen opossums received 2250 rad 60Co to the entire esophagus and lower esophageal sphincter. Animals received treatment with 600 mg aspirin, 25 mg/kg hydrocortisone, or saline before irradiation and twice daily for 1 week after irradiation. At 10 days postirradiation, animals were evaluated for signs of acute esophagitis by esophagoscopy and barium esophagram. Each animal was then killed and the esophagus removed and evaluated histologically. Animals treated with either aspirin or hydrocortisone had significantly milder esophagitis than control irradiated animals.

The radiology research technologists: who are they?

Over the years, radiology research has expanded its application due to the tremendous advances in imaging technology and the expanding role of the radiologist in the care and management of the patient. This paper is intended to provide insight into the activities and role of the radiologic technologist in radiology research today.

Improved image quality and examination procedures in xeroradiographic peripheral angiography: an experimental study.

Ten dogs were used to compare conventional peripheral angiography and xeroradiographic angiography using three different concentrations of contrast material. Serial angiograms were produced in order to determine maximum arterial filling time, and a xeroradiograph was made at the predetermined maximal arterial phase. Xeroradiographic angiography consistently provided better imaging of the peripheral vessels and soft tissue. Reduction of the concentration of contrast material resulted in the loss of an image of diagnostic quality using conventional angiography, but vascular definition was maintained using xeroradiography. These studies indicate that xeroradiographic angiography not only improved peripheral vascular imaging, but is also successful at a lower concentration of contrast material, thus reducing toxic systemic effects and pain associated with the procedure.

Radiation esophagitis in the opossum: radioprotection with indomethacin.

Twenty-five opossums (Didelphis virginiana) were evaluated before irradiation by fiberoptic endoscopy and air-contrast barium esophagram examination. All animals received 2250 rad 60Co-irradiation in a single exposure to the entire esophagus and lower exophageal sphincter. Animals received treatment with indomethacin before and daily for 1 wk postirradiation of 16, 16-dimethylprostaglandin E2 before irradiation and every 4 hr for 24 hr postirradiation. Control animals received only injection vehicle. Acute esophagitis occurred 7--10 days postirradiation in control animals and was characterized by erythema, ulceration, and sloughing of esophageal mucosa as determined by air-contrast barium esophagram, endoscopy, and histology. Prostaglandin-treated animals showed more severe evidence of esophagitis than control animals. Indomethacin-treated animals showed no signs or only mild esophagitis posttreatment. It is concluded that indomethacin treatment may significantly reduce the severity of radiation esophagitis perhaps by blockade of prostaglandin synthesis.

A technique for barium esophagram in the opossum.

Single and double contrast barium esophagram examinations were performed on 42 opossums. Each animal was anesthetized with pentabarbital sodium, a catheter was placed in the esophagus, and barium or barium and air were injected into the esophagus. Two radiographs per second for 7 seconds were taken. The radiographs were reproducible and of high quality.

The opossum as an animal model for studying radiation esophagitis.

Six opossums were evaluated as a possible animal model of radiation esophagitis. In a single exposure to the esophagus, four animals received 60Co radiation of various doses; two served as controls. Pre- and postirradiation evaluations using fiberoptic endoscopy, mucosal biopsy, barium esophagography, and manometry were performed. Esophagitis developed at one week in irradiated animals. Opossums receiving 17.5, 20, and 22.5 Gy (1,750; 2,000; and 2,250 rad) became anorexic one week postirradiation, and abnormal motility subsequently developed. The controls and the animal receiving 15 Gy (1,500 rad) remained normal. Histological changes in the irradiated opossum esophagus resembled those found in humans.