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Biomedical subjects

G N Bender

Publications and source records attributed to G N Bender.

At least 19 recordsLinked to original sources
PubMed2001

Malignant melanoma: patterns of metastasis to the small bowel, reliability of imaging studies, and clinical relevance.

OBJECTIVES: The aims of this study were to determine the frequency of different patterns of melanoma metastases to small bowel on radiological examination, and to assess the reliability of the most commonly used radiological methods for detecting these lesions. METHODS: The records of cases archived as melanoma metastatic to the small bowel of the Armed Forces Institute of Pathology were reviewed. The clinical information, type of imaging procedure performed, and radiological features were analyzed and compared to the findings at surgery and at autopsy. RESULTS: A total of 32 patients had clinical and surgical data with pathological confirmation. Seven patients had metastasis involving the duodenum, 22 had jejunal involvement, and 11 had ileal involvement. Metastases were categorized as polypoid, cavitary, infiltrating, or exoenteric. The polypoid pattern was seen in 20 patients (63%), six of whom showed multiple polypoid lesions (>10), referred to as polyposis. The "target lesion," a discrete polypoid mass with a central ulceration, was observed in only three (9%) of the 32 patients. Eight patients (25%) demonstrated a cavitary pattern, a circumferential mass with inner marginal necrosis, and five (16%) showed an infiltrating pattern. One patient (3%) had an exoenteric lesion with a fistulous tract. The small bowel follow-through demonstrated 32 of 55 metastases (sensitivity 58%). Contrast-enhanced CT demonstrated 32 of 48 masses (sensitivity 66%). Of the six cases of malignant polyposis, none were identified using CT, and only two were diagnosed by small bowel follow-through. CONCLUSIONS: The polypoid pattern, equally distributed between the jejunum and ileum, is the most common manifestation of metastatic melanoma to the small bowel. The target lesion was infrequently seen in this series. Small bowel follow-through and conventional CT seem to be unreliable in demonstrating melanoma metastases to the small bowel.

Adult↗
PubMed2001

Small-bowel obstruction: optimizing radiologic investigation and nonsurgical management.

Small-bowel obstruction is an old and common problem. Like most illnesses, its diagnosis and treatment continue to evolve. The radiologic approach to the investigation of small-bowel obstruction and the timing of surgical intervention have undergone considerable changes during the past decade. In this review, the authors analyze the recently described radiologic techniques used in the examination of patients with suspected mechanical small-bowel obstruction, revisit the controversy of the short versus long decompression tube, and provide insights on how to optimize the radiologic investigation and nonsurgical management of small-bowel obstruction.

Algorithms↗
PubMed2000

Imaging findings in pancreatic lymphoma: differential aspects.

When the radiologist is faced with a well-circumscribed tumoral mass in the pancreas, knowing when to direct the patient toward nonsurgical biopsy instead of surgical biopsy and staging is critical. Lymphoma does not require surgical staging or a palliative Whipple's procedure before chemotherapy or radiation therapy. A better overall prognosis with nonsurgical treatment is additional impetus to search for secondary signs of primary pancreatic lymphoma. In patients with primary pancreatic lymphoma, no marked pancreatic ductal dilatation is present even with ductal invasion. Adenocarcinoma commonly dilates the more distal pancreatic duct when more proximal ductal invasion has taken place. Lymph node involvement below the level of the renal veins was another finding not seen with adenocarcinoma. Clinical and imaging findings are otherwise not specific in the differentiation of pancreatic lymphoma and pancreatic cancer, but a bulky homogeneous tumoral mass without alteration of Wirsung's duct or the peripancreatic vessels should suggest the diagnosis. In patients with diffuse infiltration of the pancreatic gland without clinical signs of pancreatitis, the radiologist should be alert to the possibility of pancreatic lymphoma.

Adenocarcinoma↗
PubMed1999

The need for using fluoroscopic guidance to obtain gastric biopsies when in search of Helicobacter pylori with a nonendoscopic method.

PURPOSE: Nonendoscopic, fluoroscopic biopsy of the gastric mucosa, following barium examination of the stomach, has gained attention with its ease of performance and cost savings potential over endoscopy. Endoscopic research concerning the efficacy of biopsy sites has revealed an increased sensitivity of antral biopsies over greater curvature biopsies for the detection of Helicobacter pylori. Fluoroscopically guided biopsies of the gastric mucosal are studied to determine whether such a difference between site sensitivity held true. If not, blind biopsy through a nasogastric tube, which traditionally samples only the greater curvature, might prove an even less expensive alternative. MATERIALS AND METHODS: Seventy-two patients underwent nonendoscopic, fluoroscopically guided, mucosal biopsy of both the gastric antrum and the greater curvature of the stomach. Pathologic reports from both sites, using each patient as their own control, are compared to assess site sensitivity in the diagnosis of H. pylori gastritis. RESULTS: The sensitivity for the detection of H. pylori gastritis by antral biopsy is 89%, whereas the sensitivity of greater curvature biopsy is 62%, The difference is considered clinically significant at P < or = 0.05. CONCLUSIONS: This study confirms the need for antral biopsies when desiring a nonendoscopic approach to gastric mucosal sampling, in order to obtain a reasonable yield of data in dyspeptic patients with H. pylori gastritis. Blind techniques cannot reliably reach the antrum. Fluoroscopy can, and remains a less expensive alternative to endoscopy.

Adult↗
PubMed1999

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1996

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↗
PubMed1995

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↗
PubMed1995

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↗
PubMed1995

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↗
PubMed1994

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↗
PubMed1994

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↗
PubMed1994

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↗