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Biomedical subjects

W M Thompson

Publications and source records attributed to W M Thompson.

174 records · Page 10Linked to original sources
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Gallbladder density and iodine concentration in humans during oral cholecystography. A comparison of iopanoic acid and iopronic acid.

A comparison of two oral cholecystopaques, iopanoic acid (Telepaque) and iopronic acid (Oravue), was performed using normal volunteers. Using a double-blind crossover design, comparisons were made between the degree of gallbladder opacification and the amount of iodine recovered from the gallbladder. Bile was collected via a double lumen intestinal tube before, during, and after stimulating gallbladder contraction. There were no differences between the two agents in terms of opacification or iodine concentration. Only 19% of the administered dose of either agent was recovered, and the maximum iodine concentration in bile was 10 mg I/ml. The results suggest that this technique has merit for future comparative studies of agents concentrated in the gallbladder.

Administration, Oral↗
PubMedDate not supplied

High-resolution multiplanar CT images of the larynx.

The standard technique for computed tomographic evaluation of the larynx utilizes 5-mm contiguous transaxial sections. Multiplanar images reformatted with these sections have not been of clinical use. We have evaluated the practicality of utilizing coronal and sagittal reformatted images produced from contiguous 1.5-mm transaxial sections. The technique of rapid sequential scanning with automatic table incrementation allows 36 contiguous thin section scans to be acquired in less than 9 minutes. Phantom studies showed a marked improvement in spatial resolution with thin section reconstructions. Preliminary clinical evaluation shows visualization of smaller structures with improved edge definition of both low- and high-contrast structures.

Humans↗
PubMedDate not supplied

The mechanism of transcatheter electrocoagulation (TCEC).

This study was performed to evaluate the temperature, pH change, and electrolysis products at the anode during transcatheter electrocoagulation (TCEC). Stainless steel and platinum anodes insulated by standard angiographic catheters were placed in renal dialysis tubing. The tubing, filled with either saline solution or plasma, was placed in a water bath (25 degrees C) containing a cathode. Temperature was recorded at the tip of the anode, placed in saline solution, using 15 ma for 20 minutes (n = 5 for each wire and current). pH was measured during applications of 15, 30, and 60 ma for 20 minutes (n = 6 for each current, anode, and solution). The solutions were analyzed for products of electrolysis. The temperature remained constant. The pH declined to 1.5 +/- .3 (mean +/- SEM) with the platinum electrode and to 2.5 +/- .5 with the stainless steel anode. Metallic elements and oxygen were the electrolysis products recovered from the stainless steel experiments. Chlorine gas was the major product recovered from the platinum studies. These results confirm that during TCEC there is no thermal injury. The pH change at the anode is probably a major mechanism in TCEC. Different types of reactions take place at platinum and stainless steel anodes, which may account for differences between TCEC with these two electrodes.

Catheterization↗
PubMedDate not supplied

Evaluation of embolization distal to arterial occlusion by transcatheter electrocoagulation (TCEC) and Gianturco coils.

A technique was developed to evaluate the degree of embolization distal to arterial occlusion by transcatheter electrocoagulation (TCEC) and Gianturco coils. The kidneys of mongrel dogs were used to collect emboli distal to conventional TCEC or Gianturco coil occlusion of the renal arteries. TCEC controls (TCEC setup without current), normal kidneys, kidneys embolized with autologous clot, and kidneys whose renal arteries were surgically ligated were evaluated for comparison. The renal vasculature was flushed and then fixed by glutaraldehyde infusion. The kidneys were filled with a barium gelatin mixture and examined both radiographically and pathologically. The four normal kidneys and the four ligated kidneys gave a characteristic complete filling of the vascular web, while filling defects were evident in the following conditions: 3/12 TCEC controls; 26/34 with TCEC occlusion; 6/10 with Gianturco coils; and 11/11 with autologous clot. An excellent correlation existed between radiographic intraluminal filling defects and grossly and microscopically identified emboli.

Animals↗
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Computed tomographic evaluation of an experimental model for pyogenic liver abscesses.

Computed tomography (CT) was used to evaluate 15 rabbits with experimentally induced liver abscesses. The animals were examined both before and after intravenous contrast injection. After sacrificing the animals, postfreeze CT scans were made to mark the abdomen for 1-cm thick whole body sections for correlating the gross pathology with the results of the CT scans. CT detected 15 abscesses in 13 of the 14 rabbits with true positive lesions. Ten abscesses less than 1.4 cm in diameter were not detected by CT. Contrast agent enhancement was helpful in 70% of the studies. These abscesses have characteristics similar to human liver abscesses, but there was more gas and calcium in the experimentally induced abscesses than is encountered in humans with hepatic abscesses. The model and its CT characteristics appear well suited for future studies in the diagnosis and treatment of liver abscesses.

Animals↗
PubMedDate not supplied

The aortogram and gastrointestinal bleeding.

Three cases of gastrointestinal hemorrhage are reported which illustrate that the bleeding site may be missed angiographically if the study is limited to celiac and mesenteric angiograms. An abdominal angiogram must be performed as part of the radiological investigation of gastrointestinal bleeding.

Aged↗
PubMedDate not supplied

Aortic and iliac graft fistulae.

Sixteen patients with aortic and iliac graft fistulae were diagnosed from a series of over 886 abdominal aortic reconstructive operations. A preoperative diagnosis was established in 12, eleven by radiographic studies. Angiography and barium intestinal studies were the most helpful. The two most important features in diagnosis are a high index of suspicion and an aggressive radiographic approach.

Aged↗
PubMedDate not supplied

Experimental pulmonary infarction in dogs: a comparison of chest radiography and computed tomography.

Transcatheter electrocoagulation of the pulmonary artery was used to successfully create experimental pulmonary infarcts in 15 to 16 dogs. The animals were evaluated from one to 13 weeks by chest radiography, computed tomography (CT), angiography, and pathologic examination. The abnormal densities in the dogs' lungs cleared in two to three weeks. The majority of the chest radiographs were normal in two weeks, and all were normal after three weeks. Prior to sacrifice, CT showed abnormal densities in the lungs in only two of eight animals. CT proved to be more sensitive than chest radiography for showing the densities in the lungs due to pulmonary infarction.

Angiography↗