Gastrointestinal endoscopy, although highly useful, is limited because only the mucosal lining of the intestinal wall is seen. Endoscopic ultrasound provides a method to view tissue beneath the mucosa, but the existing equipment is expensive and difficult to use. We have developed a simpler method of applying ultrasound that uses a probe passed through the biopsy channel of conventional endoscopes. With this new endoscopic echo probe (EEP) we have obtained ultrasound images of normal animal and excised normal and abnormal human gastrointestinal wall and identified areas needing further study. We will pursue further EEP development with 3 types of ultrasound probes designed to investigate specific questions about the gastrointestinal wall. EEP-1: We will refine our current EEP (20 MHz probe) and investigate its use in imaging mucosal gastrointestinal lesions. Nonsteroidal anti-inflammatory drug-induced (NSAID) gastroduodenal injury and peptic ulcer relapse will be studied to determine lesion depth and character. NSAID induced gastric erosions in normal subjects and patients will be followed to determine whether ultrasound characteristics can distinguish which erosions eventually deepen to form ulcers. Duodenal ulcers will be imaged with EEP-l in the healing phase to determine whether there are characteristics of the tissue under the ulcer predicting relapse. EEP-2: Lower frequency probes (10-18 MHz) and a multiples frequency system will be developed to study staging of esophageal and colonic neoplasia which require a deeper penetrating ultrasonic energy than the 20 MHz EEP.l. Neoplastic invasion in esophageal and colonic lesions will be investigated to determine if more accurate nonoperative staging with EEP-2 can contribute to the outcome of therapy. M-mode: We will develop probes that attach to the gut wall, and generate M- mode signals, which shows muscle thickening during contraction and thinning during relaxation. This new methodology will be used to study muscle physiology in animals and humans and provide pathophysiologic insight into gastrointestinal problems associated with abnormal intestinal mobility. Finally, each of these devices as developed, will be studied in vitro and then tested for safety and efficacy in animals. Initial clinical trials will be conducted cc identify specific problems if they exist. Formal clinical trials will follow to establish the value of these devices and to provide new understanding of the important pathophysiologic processes discussed above.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
2R01DK034814-04A1
Application #
3233061
Study Section
Surgery and Bioengineering Study Section (SB)
Project Start
1984-12-01
Project End
1993-11-30
Budget Start
1988-12-01
Budget End
1989-11-30
Support Year
4
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of Washington
Department
Type
Schools of Medicine
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Taniguchi, D K; Martin, R W; Trowers, E A et al. (1995) Simultaneous M-mode echoesophagram and manometry in the sheep esophagus. Gastrointest Endosc 41:582-6
Taniguchi, D K; Martin, R W; Myers, J et al. (1994) Measurement of the ultrasonic attenuation of fat at high frequency. Acad Radiol 1:114-20
Taniguchi, D K; Martin, R W; Trowers, E A et al. (1993) Changes in esophageal wall layers during motility: measurements with a new miniature ultrasound suction device. Gastrointest Endosc 39:146-52
Cheung, A H; Ferguson, D C; Jiranek, G C et al. (1993) Experimental use of high-frequency ultrasound to image bowel wall after porcine intestinal transplantation. J Pediatr Surg 28:591-6
Cheung, A H; Jiranek, G C; Haggitt, R C et al. (1992) Use of ultrasound to detect intestinal wall ischemia in piglets. Ultrasound Med Biol 18:843-9
Cheung, A H; Ferguson, D C; Jiranek, G C et al. (1992) High-frequency ultrasound detects abnormal bowel wall after porcine small bowel transplantation. Transplant Proc 24:1069-70
Odegaard, S; Kimmey, M B; Martin, R W et al. (1992) The effects of applied pressure on the thickness, layers, and echogenicity of gastrointestinal wall ultrasound images. Gastrointest Endosc 38:351-6
Cheung, A H; Wang, K Y; Jiranek, G C et al. (1992) Evaluation of a 20-MHz ultrasound transducer used in diagnosing porcine small bowl ischemia. Invest Radiol 27:217-23
Thiagarajan, S; Jayawardena, I; Martin, R W (1991) Design of 20 MHz wideband piezoelectric transducers for close proximity imaging. Biomed Sci Instrum 27:57-65
Kimmey, M B; Wang, K Y; Haggitt, R C et al. (1990) Diagnosis of inflammatory bowel disease with ultrasound. An in vitro study. Invest Radiol 25:1085-90

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