| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Clinical Investigation |
1 Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland; and 2 Division of Gastroenterology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland
Correspondence: For correspondence or reprints contact: Harvey A. Ziessman, MD, Johns Hopkins Outpatient Center, 601 N. Caroline St., Suite 3231, Baltimore, MD 21278. E-mail: hziessm1{at}jhmi.edu
Gastric-emptying studies have no accepted standard methodology or reference values. A simplified standardized protocol with a large reference database has been proposed, with imaging obtained at only 0, 1, 2, and 4 h. The rationale for its 4-h length is data suggesting that delayed emptying is detected with higher sensitivity at 4 h than at 2 h. The purpose of the current investigation was to review our 2-y experience using this protocol, to determine the added value of 4-h imaging, and to determine whether the lag phase can predict delayed emptying. Methods: After ingesting a sandwich made with 99mTc-sulfur colloid egg substitute, 175 patients were imaged immediately, every 10 min for 1 h, and then at 2, 3, and 4 h. Percentage retention was calculated for each interval. Sensitivities, specificities, predictive values, and receiver operating characteristic (ROC) curves were computed for the 1-, 2-, and 3-h intervals on the basis of normal 4-h values. Data were analyzed to determine the added value of the 4-h study. Thresholds were sought that optimized accuracy. ROC analysis was used to determine the predictive value of the lag phase. Results: Gastric emptying was delayed in 20% of patients at 2 h and in 26% at 4 h, a 29% increase in abnormal studies (P < 0.02). Of those normal at 2 h, 13% became abnormal at 4 h. Of those with delayed emptying at 2 h, 24% normalized at 4 h. Compared with the study at 4 h, the study at 2 h had a 59% sensitivity, 94% specificity, 76% PPV, and 87% NPV. ROC analysis showed that the areas under the ROC curve (AUC) were 0.75, 0.93, and 0.97 at 1, 2, and 3 h, respectively. The threshold for optimal accuracy for 3-h data was estimated to be greater than 30% retention. The accuracy of this threshold was 91%. The lag phase AUC for predicting delayed emptying at 4 h was 0.60. Conclusion: This first investigation of a large referral patient population using a standardized protocol found that abnormal emptying is detected with greater sensitivity at 4 h than at 2 h and that the lag phase is not predictive of delayed emptying.
Key Words: gastric emptying • lag phase • stomach • gastroparesis • standardization
COPYRIGHT © 2007 by the Society of Nuclear Medicine, Inc.
This article has been cited by other articles:
|
|
 |
|
  H. A. Ziessman, A. Chander, J. O. Clarke, A. Ramos, and R. L.Wahl The Added Diagnostic Value of Liquid Gastric Emptying Compared with Solid Emptying Alone J. Nucl. Med., May 1, 2009; 50(5): 726 - 731. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. C. Klingensmith III and S. P. Lawrence The Gastric Emptying Study: Protocol Design Considerations J. Nucl. Med. Technol., December 1, 2008; 36(4): 195 - 199. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Abell, M. Camilleri, K. Donohoe, W. L. Hasler, H. C. Lin, A. H. Maurer, R. W. McCallum, T. Nowak, M. L. Nusynowitz, H. P. Parkman, et al. Consensus Recommendations for Gastric Emptying Scintigraphy: A Joint Report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine J. Nucl. Med. Technol., March 1, 2008; 36(1): 44 - 54. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| JOURNAL OF NUCLEAR MEDICINE TECHNOLOGY | THE JOURNAL OF NUCLEAR MEDICINE |
