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Biomedical subjects

H A Shaffer

Publications and source records attributed to H A Shaffer.

At least 37 records · Page 2Linked to original sources
PubMed1990

Videofluoroscopic assessment of muscle fiber shortening in the in situ canine diaphragm.

We tested the hypothesis that dynamic shortening of the costal diaphragm can be accurately estimated from measurements of the radiographic width of the zone of apposition (WZapp) by studying seven supine anesthetized dogs. Both muscle fiber length, represented by the distance between implanted radiopaque markers, and WZapp were measured from digitized recordings of fluoroscopic images utilizing interactive computer software. The WZapp was highly correlated with the length of costal fibers during active respiration in all animals (mean R2 = 0.94). The accuracy in the prediction of fiber length and shortening during breathing is enhanced by inclusion of additional variables describing the displacement of the abdominal wall and the resting geometric orientation of the fibers. We conclude that dynamic fluoroscopic measurement of WZapp is a valuable technique for estimating dynamic diaphragm fiber length and shortening. Depending on the experimental circumstances, WZapp may be a more easily acquired indicator of diaphragm shortening than other variables that have been previously utilized. As such, it may provide a suitable approach to assess active shortening of the diaphragm in humans.

Animals↗
PubMed1988

Allergy to barium sulfate suspension with angioedema of the stomach and small bowel.

Hypersensitivity reactions occurring during barium studies of the gastrointestinal tract are rare. A case is presented with radiographically demonstrated angioedema in the stomach and small bowel accompanied by allergic rhinitis, which was apparently an allergic response to the barium sulfate suspension. The reaction was documented twice during separate challenges to the barium suspension performed several months apart.

Adult↗
PubMed1988

Anastomotic strictures of the upper gastrointestinal tract: results of balloon dilation.

Enteroenteric anastomotic strictures of the upper gastrointestinal tract are common and require treatment if significant obstruction occurs. The authors performed 44 fluoroscopically guided balloon dilations in 19 patients with symptomatic anastomotic strictures. The anastomoses were esophagoesophageal (n = 5), esophagogastric (n = 8), esophagoileocolonic (n = 4), and gastrojejunal (n = 2). Nine patients required only one balloon dilation for stricture lysis and relief of clinical symptoms. Recurrent symptoms developed in the remaining ten patients, who required two to eight dilations. Radiographically, stenoses made up 40%-90% of the anastomotic lumen before dilation (mean, 72%). Complete resolution of the stricture was achieved during the procedure in 24 instances. Residual stenosis in 18 instances varied from 7% to 45% (mean, 21%). Two complications, a mucosal tear and a perforation, were immediately recognized and successfully treated non-operatively. The authors conclude that fluoroscopically guided balloon dilation has an important role in the treatment of anastomotic strictures of the upper gastrointestinal tract.

Anastomosis, Surgical↗
PubMed1988

Duplication of the colon: varied presentations of a rare congenital anomaly.

Duplication of the colon is a rare congenital anomaly which may produce diagnostic difficulties for both clinician and radiologist. We report three patients who illustrate the spectrum of clinical and radiographic features which may be encountered. Radiology is essential in assessing the full extent of this condition including its various presentations, associated congenital anomalies, and anticipated complications.

Barium Sulfate↗
PubMed1988

Choledochocele: a rare form of choledochal cyst.

Choledochocele is the least common form of cystic dilatation of the biliary tree. Whether this condition is a congenital abnormality or the result of inflammation at the papilla of Vater is not clear. In most cases, the clinical presentation is that of intermittent abdominal pain, nausea, and vomiting, with biliary colic and/or jaundice. As described in our case, choledochocele has characteristic radiologic features, but the lesion can be easily overlooked if one is not aware of its distinctive appearance.

Aged↗
PubMed1987

Esophageal anastomotic leaks: preliminary results of treatment with balloon dilation.

Disruption of a cervical esophagogastric or esophagocolonic anastomosis shortly after surgery is a common complication, and fistula drainage from the leaking anastomosis may be prolonged. Narrowing of the anastomosis apparently contributes to the development and maintenance of the fistula. Fluoroscopically guided balloon dilation of anastomotic strictures was performed in three patients with anastomotic leaks. Preliminary results suggest that the procedure is safe and promotes healing of the fistula.

Adult↗
PubMed1985

Familial visceral myopathy: the role of surgery.

Familial visceral myopathy is a form of chronic intestinal pseudoobstruction in which fibrosis of the smooth muscle of the alimentary tract causes protean symptoms of disordered visceral motility. Based on our 8 year observation of six members of one family with familial visceral myopathy and review of the few well-documented case reports of this disease, we have confirmed a role for surgeons in tissue diagnosis, case identification, and palliation of incapacitating symptoms of familial visceral myopathy after obtaining dynamic radiographic assessment of the entire alimentary canal. Because the duodenum and colon are the usual sources of major dysmotility symptoms, patients incapacitated by duodenal or colonic pseudoobstruction may benefit from bypass or resective operations.

Adult↗
PubMed1985

Barium suspension formulation for use with the bubbly barium method.

A new medium density barium suspension is described for the biphasic contrast examinations of the upper gastrointestinal tract. It is designed for the bubbly barium method, and combines good mucosal coating properties in the double contrast phase of the examination with transparency in the single contrast graded-compression phase.

Administration, Oral↗
PubMed1984

Bull's-eye lesions: a new gastrointestinal presentation of mastocytosis.

Systemic mastocytosis is a rare disorder that infrequently affects the GI tract. Bowel involvement in mastocytosis is characterized by thickened folds and small mucosal nodules, and there is an increased incidence of peptic ulcer disease and malabsorption. This paper describes a new case of mastocytosis that presented radiographically as 1.0-1.5 cm gastric and duodenal nodules. Some of the duodenal nodules were bull's-eye lesions with central collections of barium. Mastocytosis, along with primary neoplasms, aberrant pancreas, eosinophilic granuloma, and metastases should be included in the differential for bull's-eye lesions of the GI tract.

Adult↗
PubMed1981

Limitations of ultrasonography in evaluating patients with jaundice or cholecystectomy.

Abdominal ultrasonography has been shown to accurately distinguish medical (nonobstructive) jaundice from surgical (obstructive) jaundice. As occurs commonly with a new diagnostic procedure, initial evaluations are enthusiastic and emphasize the positive features of the technic. When further experience with the procedure is acquired, its negative features are recognised and reported. We review our experience and that of others to stress the limitations of ultrasonography and the potential for misinterpretation of its findings when evaluating the biliary tract in patients with jaundice or postcholecystectomy biliary colic. The applications of computed tomography and cholescintigraphy are briefly and critically evaluated in this same patient population. The role of sonography as a screening procedure and the findings that indicate the need to proceed to other imaging technics are examined. Finally, we describe our criteria for choosing the next step in the diagnostic evaluation--intravenous, percutaneous transhepatic, or endoscopic retrograde cholangiography.

Cholangiography↗
PubMed1980

Tarsal pseudo-coalition--a positional artifact.

Pseudo-coalition of the talocalcaneal joint is a positional artifact which is created by either slight abduction or inversion of the foot on the lateral radiograph. This apparent bony bridge is due to overlap of normal structures on opposite sides of the hindfoot. It may be distinguished from a true coalition by the following features: 1) it disappears in a truly lateral radiograph, 2) there is no associated talar spur, and 3) there are no clinical findings of spastic flat foot. In addition, the true medial talocalcaneal bridge requires special views for its demonstration and cannot be seen in a lateral radiograph.

Adolescent↗