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Biomedical subjects

G N Bender

Publications and source records attributed to G N Bender.

18 recordsLinked to original sources

Using sector endoluminal ultrasound to identify the normal pancreas when axial computed tomography is falsely positive.

RATIONALE AND OBJECTIVES: Little has been reported on the ability of endoluminal ultrasound (EUS) to identify a normal pancreas after an abnormal axial computed tomogram (CT). Many clinicians still use axial technology, as opposed to helical or spiral CT, which differ in scanning speed. Spiral CT and EUS are considered equal in their ability to diagnose pancreatic tumors. Although this is not the case with axial CT, the complementary role by EUS has not been defined. This study reports on the ability of EUS to identify the "true-negative" pancreas deemed abnormal by axial CT. METHODS: Sixty-five consecutive patients suspected of having a small pancreatic lesion were studied by comparing axial CT and EUS examinations, using each patient as his or her own control. Identification of a normal pancreas was reviewed using surgery, biopsy, and long-term clinical follow-up as the standard of truth. RESULTS: Thirty-three patients were documented as having small pancreatic lesions; the remaining 32 were normal. The sensitivity and specificity, respectively, were 91% and 41% for axial CT and 88% and 88% for EUS. The positive and negative predictive values, respectively, were 61% and 82% for CT and 88% and 88% for EUS. The statistical differences between axial CT and EUS were significant. CONCLUSION: An axial CT positive for a small pancreatic mass requires confirmation with additional imaging before invasive management. The specificity of EUS--twice that of CT--is strong evidence that EUS can fulfill this role. Review of the literature supports the conclusion that EUS should be required in the workup of small pancreatic lesions identified at axial CT.

Chronic Disease

Radiographic examination of the small bowel. An application of odds ratio analysis to help attain an appropriate mix of small bowel follow through and enteroclysis in a working-clinical environment.

RATIONALE AND OBJECTIVES: Simplifying data collection and analysis should promote utilization management in review of examinations of the small bowel in the general practice. METHODS: A case control format with the generation of an odds ratio to answer sets of binary questions derived from annual examination data is shown. The positive examination results applied were compared with the literature as a cross-checking mechanism. The examination identified as most likely to be positive was recommended prospectively in a protocol for the following year. Two of 5 years are illustrated to emphasize the development of the methodology. RESULTS: Application of this model in testing its validity, since 1990 at Madigan Army Medical Center, allows for the generation of a new protocol each year to prospectively improve clinical definition. CONCLUSIONS: A 5-year analysis of small bowel examination protocols, subdivisions, and odds ratios, will be forthcoming. The 2 years illustrated show how strongly our practice was influenced in using enteroclysis or in using the small bowel follow through as the examination of choice in the various clinical categories of small bowel disease: (1) practice was influenced by protocol and (2) outcome was steered toward positive examinations.

Barium Sulfate

Fluoroscopic-guided in vivo gastric mapping for assessment of gastric carcinoma.

RATIONALE AND OBJECTIVES: The authors seek to determine if a new method of combining fluoroscopy and nasogastric biopsy can demonstrate the existence and boundary limits of a known gastric carcinoma or its premalignant conditions. The study is performed in hopes of avoiding unnecessary surgery or limiting resection. METHODS: Two cases are presented to illustrate the technique. The first had a known gastric carcinoma; the other had adenomatous change in the antrum. After topical anesthesia was applied, a nasogastric tube with a coaxial biopsy forceps was inserted. Multiple biopsies were taken in a designed geographic pattern and sent to pathology. The patient with known carcinoma received a total gastrectomy. The specimen was sectioned in the same regions as the biopsies to validate mapping technique. RESULTS: Pathology results for sectioned stomach were nearly identical to the biopsies showing the technique can accurately map the stomach. No adenomatous change in the antrum or other sections of the stomach was observed in the second case. This resulted in the patient being spared gastric resection. CONCLUSIONS: Fluoroscopic-guided gastric mapping can aid in determining the boundaries of a known carcinoma or premalignant conditions. Additional cases and follow-up are necessary.

Adenocarcinoma

Double-contrast barium examination of the upper gastrointestinal tract with nonendoscopic biopsy: findings in 100 patients.

PURPOSE: To evaluate the performance of double-contrast barium examination of the upper gastrointestinal tract augmented with nonendoscopic gastric mucosal biopsy. MATERIALS AND METHODS: One hundred twenty-six patients (aged 9-81 years) underwent double-contrast barium examination of the upper gastrointestinal tract and nasogastric biopsy. Pathology reports were recovered for 100 patients. These patients' records were searched for procedural complications, sufficiency of biopsy tissue, diagnoses among various age groups, and radiographic findings. RESULTS: Forty-nine (49%) of the 100 patients had biopsy-proved Helicobacter pylori infection with chronic active gastritis. Twenty-one patients (21%) with H pylori-negative biopsy specimens had chronic gastritis. One patient with eosinophilic gastritis and one with granulomatous gastritis were identified. Twenty-nine patients (29%) had negative biopsy results. Nineteen (30%) of the patients with negative barium studies had a positive biopsy specimen, and four (6%) of the patients with positive barium studies had negative biopsy specimens. Eight patients (8%) had a second diagnosis of intestinal metaplasia. CONCLUSION: Use of double-contrast barium examination of the upper gastrointestinal tract combined with nonendoscopic biopsy is quick and safe and can provide reliable histologic information to the primary care physician.

Adolescent

Computed tomographic enteroclysis: one methodology.

RATIONALE AND OBJECTIVES: Computed tomography (CT) is limited in the assessment of partial small bowel obstruction (SBO). Enteroclysis is preferred but gives little direct information about the bowel wall, mesentery, or remote findings. Preliminary results of a combined CT enteroclysis (CT-E) methodology are reported. METHODS: Forty-eight patients with suspected partial SBO underwent a water soluble contrast enteroclysis followed immediately by CT. Pump rates at fluoroscopy and CT were 75 to 100 cc/min unless a high-grade obstruction was encountered at fluoroscopy. Shrake's criteria for complete, high-grade or low-grade partial SBO were used. RESULTS: The calculated dose per patient was 27 rad for CT-E as opposed to 32 rad with traditional enteroclysis. Site specific sensitivity and specificity for low-grade partial SBO, were 82.1% and 87.5%. One death was encountered in a patient with diffuse abdominal metastatic disease and complete obstruction. This was caused by vomiting and aspiration secondary to tube placement alone, CT-enteroclysis having been aborted. CONCLUSIONS: Computed tomographic enteroclysis is a diagnostic option for evaluation of low-grade partial SBOs. Pitfalls with this technique are encountered in decompressed torsions and hernias.

Abdominal Neoplasms

Evaluation of the medical diagnostic imaging support system based on 2 years of clinical experience.

The Medical Diagnostic Imaging Support (MDIS) system at Madigan Army Medical Center (MAMC) has been operational in a phased approach since March 1992. Since then, nearly all image acquisition has been digital with progressively increasing primary softcopy diagnosis used. More than 375,000 computed radiography (CR) images as well as other modality images have been archived. Considerable experience in installation and implementation phasing has been gained. The location and ergonomic aspects of equipment placement were refined with time. The original clinical scenario was insufficiently detailed and additions were made to facilitate smoother and more complete transition toward a filmless environment. The MDIS system effectiveness and performance have been good in terms of operational workload throughout, background operations, and reliability. The important areas regarding reliability are image acquisition, output, display, database operations, storage, and the local area network. Fail-safe strategies have been continually improved to maintain continuous clinical image availability during the times when the MDIS system or components malfunction. Many invaluable lessons have been learned for effective quality assurance in a hospital-wide picture archiving and communication system. These issues include training, operational quality control, practical aspects of CR image quality, and increased timeliness in the generation and distribution of radiographic reports. Clinical acceptability has been a continuous process as each phase has been implemented. Clinical physicians quickly used the workstations soon after the start of MDIS at MAMC. The major advantage for clinicians has been the amount of time saved when retrieving multimodality images for review. On the other hand, the radiologists have been slower in their acceptance of the workstation for routine use.(ABSTRACT TRUNCATED AT 250 WORDS)

Computers

Double contrast upper gastrointestinal barium examination with biopsy versus endoscopy with biopsy in dyspeptic patients.

RATIONALE AND OBJECTIVES: The financial restrictions of the managed care environment require reconsideration of the barium upper gastrointestinal examination as a diagnostic tool for gastritis patients. However, a greater sensitivity and specificity for gastritis is needed. A prospective study was performed comparing barium examinations with gastric biopsies to endoscopy with biopsy. METHODS: Forty adult patients underwent upper gastrointestinal barium examination with gastric biopsies obtained under fluoroscopy through a nasogastric tube. Twenty-seven patients gave consent for subsequent endoscopy with biopsy. Both sets of biopsies were compared, as were the interpretations of the radiographs and visual appearances. RESULTS: For barium examinations with gastric biopsies, sensitivity for gastritis was 94% and specificity was 100%, using endoscopic biopsies as the gold standard. CONCLUSIONS: In addition to endoscopy with biopsy, the upper gastrointestinal barium examination with biopsy is another option of sufficient sensitivity and specificity for consideration by clinicians in their workup of patients with gastritis.

Adult

Antral nodularity, fold thickness, and narrowing. Signs on the upper gastrointestinal series that may indicate chronic active gastritis secondary to Helicobacter pylori.

RATIONALE AND OBJECTIVES: The purpose of this retrospective study was to investigate any association between the classic radiographic findings of nonerosive gastritis on the upper gastrointestinal (GI) series (antral nodularity, fold thickening, and narrowing) and histologically proven gastritis secondary to Helicobacter pylori. METHODS: The authors reviewed the histopathologic results of 31 patients who had upper GI barium examinations with the findings listed above who presented with dyspepsia. These patients were compared with 30 dyspeptic patients who had radiographically normal antrums. RESULTS: Twenty (64.5%) patients had chronic active gastritis and tested positive for H pylori organism, 5 (16.1%) were normal, 5 (16.1%) had inflammation but were negative for H pylori, and 1 (3.2%) had an insufficient amount of tissue. The barium upper GI series was 66.7% sensitive and 69.4% specific for chronic active gastritis secondary to H pylori (P = 0.0002 Fisher's exact test), with a positive predictive value of 64.5% and a negative predictive value of 83.3%. CONCLUSIONS: The differential diagnosis for antral nodularity, fold thickening, and narrowing is extensive. However, because of the common histopathologic diagnosis of chronic active gastritis secondary to H pylori in patients with these radiographic findings, the radiologist must remember to include this infectious cause of gastritis in the interpretive report. If the antrum is normal on the upper GI series, other causes should be considered.

Adult

Case report: peri-anal episiotomy scar endometrioma imaged by CT and sector endoluminal ultrasound.

Endometriosis is a common clinical entity, and is found in approximately 15% of menstruating females. An endometrioma is somewhat less common, and is defined as functioning endometrial tissue outside the uterus. Endometriomas have been reported in a variety of different locations, including the rectus abdominis muscle following Caesarean section, skin and tissues adjacent to surgical scars, and even abdominal wall endometrial implants at the site of needle passage for amniocentesis. We present a case of a solitary endometrioma located in the peri-anal region beneath the site of an episiotomy scar. Sector endoluminal ultrasound was utilized in imaging this thick-walled, cystic mass. Episiotomy scar endometriomas have thus far only been reported in the surgical literature, without reference to radiologic imaging. Our case is illustrated with CT and sector endoluminal ultrasonography.

Adult

Nonendoscopic gastric mucosal biopsy to augment double-contrast upper gastrointestinal barium examination.

The authors present a gastric mucosal biopsy technique with use of a nasogastric catheter and biopsy forceps after double-contrast upper gastrointestinal fluoroscopy in patients with clinical symptoms of dyspepsia. In 51 patients (18 men and 33 women, aged 27-73 years [mean, 46 years]), 136 aggregates (specimens composed of the two pieces of mucosal tissue obtained in each region) ranged from 0.1 to 0.6 cm in diameter. All but three specimens were of adequate mucosal depth. No complications secondary to bleeding resulted.

Adult

Small bowel biopsy through an enteroclysis catheter to augment findings at enteroclysis and hypotonic duodenography.

Proximal jejunal mucosal biopsy was performed by a radiologist through the nasojejunal catheter at the time of enteroclysis. Seventeen patients (10 men and seven women, aged 23-73 years [mean, 46 years]) were studied with enteroclysis because of clinical signs of malabsorption with suspected small bowel disease. In seven (41%) patients, results at biopsy were positive, and results in another seven (41%) were positive at enteroclysis. In 10 (59%) patients, results were positive at one or both tests. Performance of both small bowel biopsy and enteroclysis at the same session is feasible and offers additional clinically pertinent information than can be obtained at enteroclysis alone.

Barium Sulfate

Colonic pseudo-obstruction: decompression with a tricomponent coaxial system under fluoroscopic guidance.

A tricomponent coaxial system (TAS) suitable for colonic decompression with fluoroscopic guidance is described. The TAS was successfully used in four of four patients, two with acute pseudo-obstruction, one with sigmoid volvulus, and one with recurrent colonic pseudo-obstruction. All patients had acute abdominal distention with cecal diameter of at least 12 cm, and nonsurgical management was unsuccessful. Complete colonic decompression was observed in all four patients, with no recurrence in three of three patients after removal of the decompression catheter. The decompression catheter was left in place in one patient for her comfort until she died of hepatic failure 4 days later. There was no associated colonic bleeding or perforation in any of the four cases. The procedure lasted approximately 20-90 minutes. The TAS promises to be a useful and inexpensive tool with which to perform colonic decompression in selected patients.

Adolescent

The radiographic preauricular groove: its non-relationship to past parity.

Deep preauricular sulci were identified on abdominal radiographs in 29 of 190 (15%) adult females and in none of 110 adult males. To assess the value of the deep preauricular sulcus as an index of past pregnancy, we examined gravidity and parity records of 190 women, using standard films that included the sacroiliac region. Deep, radiographic preauricular grooves were identified in 4 of 41 (10%) nulliparous women and in 25 of 149 (17%) women with positive pregnancy histories. We also examined radiographs obtained before and after pregnancy in six primigravidas. No evidence of radiographic changes in the preauricular grooves was seen in any of the six women. We conclude that the presence of a deep, radiographic preauricular sulcus is not necessarily an indication of past pregnancy.

Adult