Video time lapse endoscopy

Video time lapse endoscopy Daniel Jaspersen, MD Rainer Keerl, MD Rainer Weber, MD Andreas Huppmann, MD Carl-Heinz Hammar, MD Wolfgang Draf, MD T h e r e is as yet no satisfactory m e t h o d for displaying mucosal healing as a dynamic process. Continuous (time lapse) video endoscopy for d e m o n s t r a t i o n of the changing mucosal a p p e a r a n c e fails for several reasons. Major problems include p a t i e n t noncompliance and the inconstancy of image cuts due to the phenomenon of wobbling. The l a t t e r picture disturbance is a n i n h e r e n t problem w h e n time lapse segments of videotape are sequenced in a n effort to d e m o n s t r a t e a n evolving process such as mucosal healing. Wobbling diminishes the ability to depict a dynamic process by m e a n s of videotape. It would be useful if certain biologic events, such as mucosal healing, could be displayed as the smooth, transitional process t h a t actually takes place over the course of time. This can be accomplished by m e a n s of a c o m p u t e r assisted t e c h n i q u e called morphing. Instead of simply sequencing interval segments of videotape, "snap shots" of the evolving process are obtained. The c o m p u t e r assisted technique o f m o r p h i n g t h e n g e n e r a t e s i n t e r m e d i a t e snap shots so t h a t an actual dynamic process becomes observable as a n orderly sequence of change t h a t has the a p p e a r a n c e of being compressed into a relatively brief period of time. We refer to this t e c h n i q u e as video time lapse endoscopy. To d e t e r m i n e w h e t h e r m o r p h i n g can be used in gastrointestinal endoscopy, we chose to test these m e t h o d s by studying a p a t i e n t with esophagitis due to gastroesophageal reflux disease who was t r e a t e d with omeprazo]e. 1

Figure 1. Monitor foil with endoscopic image.

Figure 2. Image separator (Colour-Quad-System).

Video Machine = digital video processing

I ILightSourceI |

I Endo,cope I

Monitor .

&

MATERIALS AND METHODS

I

I ~ 1 Colour-Quad-Systern

The subject is a 47-year-old man with Savary grade 3 esophagitis at endoscopy.2 He was treated with omeprazole, 20 mg twice a day, for 3 weeks. Video endoscopy was performed every 4 days. The endpoint of this study was reached at 3 weeks, at which time there was no macroscopic evidence of esophagitis. Short endoscopic video sequences

Camera

Video Recoiler

Received March 26, 1996. For revision August 30, 1996. Accepted February 7, 1997. From the Department of Gastroenterology, and the Department of ENT, Head, Neck and Facial Plastic Surgery, Communication Disorders, Academic Hospital Fulda, Germany. Reprint requests: Daniel Jaspersen, MD, Medizinische Klinik II, Pacelliallee 4 - 6, Postfach 1380, D-36043 Fulda, Germany. 0016-5107/97/4500-051655.00 + 0 GASTROINTESTINAL ENDOSCOPY Copyright © 1997 by the American Society for Gastrointestinal Endoscopy

37/69/81016 516 G A S T R O I N T E S T I N A L E N D O S C O P Y

Photo Morph = production of missing interjacent stills

I Computer

Figure 3. Complete system for video time lapse endoscopy. were recorded at definite time intervals (4 days). The best shot, several seconds in length, was selected from each video sequence and stored in the computer as a single take (termed an original). The intermediate "missing" pictures between original takes were produced by means of a special computer technique that is based on the mathematical concept of interpolation. The time interval between original video takes must be selected in such a way that significant information is not lost. Furthermore, the time course of the final presentation must not be too slow or excessively fast. In either case, the viewer's perception of the changing proVOLUME 45, NO. 6, 1997

Figure 4. Sequence of endoscopic images at 4-day intervals demonstrating healing of esophagitis. A, Before therapy. B, Day 5. cess will be unsatisfactory. We selected a time course of 60 seconds as convenient and manageable. The central problem in video time lapse endoscopy is the assurance of constancy of the picture cut out. This means that the endoscopic view with respect to distance from a lesion and endoscopic viewing angle must be nearly identical in every original video sequence. The problem is compounded if there is the slightest movement of the patient or the endoscope. In either case, the wobbling phenomenon becomes more pronounced. Our method of ensuring that the position of the endoscope and hence the picture cut out was exactly the same in each original video segment is as follows: The most favorable position was determined at the first session. Based on the images from the first recording session, a foil was constructed that can be fastened to the video monitor screen (Fig. 1). Fixed anatomic reference points (e.g., the cardia) were marked on the foil. As a further aid to f~ing the position of the endoscope, an image separator (Colour-Quad-System) was used to place original single takes from the video sequences adjacent and parallel to the real-time mucosal images (Fig. 2). With the assistance of the computer, the real-time and previous single takes can be made congruent with three prior takes. Endoscopy was performed with an Olympus GIF-100 video gastroscope (Olympus, Hamburg, Germany). The video recordings were made with an Olympus video processor (CV-100), a Sony UMatic videocassette recorder (model V0-5630), and a Sony color video monitor (model PVM 2130 QM) (Sony, Frankfurt am Main, Germany). The specifications of the computer used to process the images are as folVOLUME 45, NO. 6, 1997

Figure 4. C, Day 10. D, Day 15. E, Healing. lows: 33 MHz, 486DX CP'U, supplemented with 16 MB main storage (RAM), and 1 gigabyte hard disc storage. Further essential elements are the Targa+ Graphic and Digitalization card (Truevision, Indianapolis, Ind.) and the Speedstar 24X - graphic card (Diamond, Sunnyvale, Calif.). Software used for processing of the original pictures and production of the intermediate images was the Video and Maker program (version 2.0, T~evision) and the Photo Morph program (North Coast Software, Barrington, N.H.). The complete system is shown in Figure 3. Jumps between successive original takes were minimized by morphing with the Photo Morph program so that they are nearly invisible to the viewer. The number of morph images needed depended on the real time interval between the original pictures. In this way it is possible to exactly reproduce the dynamic process of mucosal healing.

RESULTS Resolution of g a s t r o e s o p h a g e a l reflux disease as achieved within the f r a m e w o r k of this s t u d y (Fig. 4) GASTROINTESTINAL ENDOSCOPY

517

was documented by time lapse video endoscopy at 20 days of therapy with omeprazole. This technique disclosed that healing proceeded symmetrically from the edges of the erosion toward the center, and that the rate of healing was steady in that the edges of the erosion closed with constant velocity. DISCUSSION

Flexible endoscopy has been an invaluable diagnostic and therapeutic technique for many years for the management of patients with digestive diseases. The advent of video endoscopy greatly simplified the process of documentation of endoscopic findings. 3 Video endoscopy and electronic data processing can be combined to create a time lapse video. This technique was developed by Weber et al. 4 to demonstrate wound healing after paranasal sinus surgery. Video time lapse, which we used for the first time in gastrointestinal endoscopy, compresses a sequence of changes so that it becomes possible to observe and analyze processes that actually occur over relatively long periods of time. With time lapse video endoscopy, endoscopic images taken at short time intervals can be integrated with computer generated images to create a dynamic sequence of images that accurately depict the flow of changes that occur with biologic events such as injury and healing of the gastrointestinal mucosa. Video time lapse endoscopy may be especially useful for research. Observation of change over the course of time is a standard method of scientific investigation. Morphing techniques can therefore provide new insights into the physiology and pathophysiology of the gastrointestinal tract. Whereas the researcher has hitherto been unable to watch a dynamic portrayal of events, time-dependent detailed changes can now be observed without haste and repeated for analysis. Morphing allows an investigator to analyze processes that were previously inaccessible to the naked eye or to visual depiction. For example, the relative efficacy

An esophageal foreign body impaction from a Tums E-X tablet Ralph M. Wisniewski, MD David D. Stone, MD John C. Fang, MD From the Department of Gastroenterology and Hepatology, University of Virginia Health Sciences Center, Charlottesville, Virginia. Reprint requests: Ralph M. Wisniewski, MD, University of Virginia Health Sciences Center, Gastroenterology and Hepatology, Box 10013, Charlottesville, VA 22906-0013. 0016-5107/97/4506-051855.00 + 0 GASTROINTESTINAL ENDOSCOPY Copyright © 1997 by the American Society for Gastrointestinal Endoscopy 37/4/81019

518 G A S T R O I N T E S T I N A L E N D O S C O P Y

of different therapeutic agents can be compared, or the effects of potentially injurious pharmacologic drugs such as nonsteroidal anti-inflammatory drugs can be observed. A major limitation of video time lapse endoscopy is that endoscopic examinations must be repeated at short time intervals. Thus, its use for patient care is unlikely to be feasible. However, it is ideal for education and teaching purposes. When we presented the process of healing of esophagitis to medical students in video time lapse, they found the process to be readily comprehensible and they much preferred the video illustration to descriptions based on projection of 35 mm slides. We therefore produced a similar time lapse video on gastric ulcer; a further subject is the documentation of healing in ulcerative colitis. The observation and documentation of mucosal healing in one patient is of course insufficient reason to proclaim video time lapse endoscopy as a new and useful technique. However, this work forms the basis for further systematic exploration of its potential uses, especially in the area of mucosal healing. It may be concluded that computer assisted morphing enables dynamic analysis of mucosal processes in a more natural way that may enhance our understanding and treatment of various conditions. Video time lapse endoscopy provides an almost natural, highly realistic portrayal of mucosal healing that may enhance teaching and research. REFERENCES 1. Jaspersen D, Schwacha H, Schorr W, Brennenstuhl M, Raschka C, Hammar CH. Omeprazole in the treatment of patients with complicated gastro-oesophageal reflux disease. J Gastroenterol Hepatol 1996;11:900-2. 2. Savary M. Grading of esophagitis. In: Savary M, Miller G, editors. The esophagus. Solothurn, Switzerland: Gassmann, 1977: 87-92. 3. Sivak MV. Video endoscopy. Ann Gastrointest Endosc 1988;1: 115-21. 4. Weber R, Keerl R, Huppmann A, DrafW, Saha A. Wound healing after paranasal sinus surgery by video time lapse sequences. Op Tech Oto Laryngol Head Neck Surg 1995;6:237-40.

An esophageal foreign body in the adult patient is most commonly caused by an impacted food bolus and is due to an underlying structural abnormality of the esophagus. 1,2 Although pill-induced esophagitis is well described, esophageal foreign body impaction is a rare complication of pill ingestion. 2, 3 We report the first case of a patient with an esophageal foreign body impaction caused by a Turns Extra Strength (Turns E-X) tablet. CASE REPORT

An 81-year-old woman with corticosteroid-dependent chronic obstructive pulmonary disease presented with retrosternal chest discomfort of 4 hours duration. There was no VOLUME 45, NO. 6, 1997