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S Odegaard

Publications and source records attributed to S Odegaard.

At least 37 records · Page 2Linked to original sources
PubMed1998

Imaging studies in dyspepsia.

Patients with functional dyspepsia have discomfort centred in the upper abdomen in the absence of oesophagitis, ulcer, cancer or other pathology which could have explained the dyspepsia. It is generally accepted that neither endoscopy, nor other imaging modalities give any positive findings supporting the diagnosis. However, recent investigations have shown that both endoscopic and ultrasonographic imaging show changes: erosive prepyloric changes (EPC) and accommodation abnormalities, respectively, in a high percentage of the patients. The diagnostic sensitivity and specificity of the changes are not yet known, but the fact that they are also seen in several other conditions characterised by dyspepsia, for instance in gallstone disease, may simply indicate that they are linked to epigastric discomfort in general, and not to a specific dyspeptic condition. Ultrasonographic imaging is a non-invasive, widely available, convenient, and reliable method for evaluation of gastric emptying, gastric motility, transpyloric flow and accommodation disturbances, which may play a crucial role in the pathogenesis of dyspepsia.

Dyspepsia↗
PubMed1998

Endoscopic ultrasound: a new look at achalasia?

Achalasia is a relatively infrequent disorder of oesophageal motility, and is most often easily diagnosed by stationary manometry showing absence of peristalsis and incomplete lower oesophageal sphincter (LOS) relaxation. In rare cases manometric findings may be inconclusive or a malignant underlying disease is suspected. In such cases direct visualization of the LOS by endoscopic ultrasound (EUS) could contribute to securing the diagnosis and possibly lead to earlier diagnosis and treatment. With lower frequency EUS, increased thickness of the inner circular layer of the muscularis propria may be difficult to detect. Available data suggest that high frequency (20 MHz) and 3-D EUS has a potential to reliably discriminate between achalasia patients and normal subjects, and thereby be of diagnostic value.

Endosonography↗
PubMed1997

Common pathogenetic mechanisms in symptomatic, uncomplicated gallstone disease and functional dyspepsia: volume measurement of gallbladder and antrum using three-dimensional ultrasonography.

Following cholecystectomy for uncomplicated gallstone disease (GS) some patients experience persistent symptoms suggesting an underlying functional disorder. To study this phenomenon, we have compared symptomatic GS with functional dyspepsia (FD) patients and healthy individuals (C) with respect to putative pathogenetic mechanisms. Gallbladder and gastric antrum volumes were estimated with three-dimensional (3D) ultrasonography before and 10 min after ingestion of 500 ml meat soup in 18 patients with GS. Volume estimation was performed digitally after interactive manual tracing and organ reconstruction in three dimensions. Respiratory sinus arrhythmia (RSA) was calculated to index vagal tone. Abdominal symptoms were assessed by interview. The results were compared to previously published data in patients with FD and C investigated with the exact same methods. No significant differences were found between groups with respect to fasting gallbladder or gallbladder emptying. Antral volumes both fasting (P < 0.05) and postprandially (P < 0.01) were larger in GS and FD than in C. The soup meal induced dyspeptic symptoms in 2/18 (11%) of C, 12/18 (67%) of GS and 15/17 (88%) of FD patients (P < 0.001). Compared with C, both GS and FD patients had significantly decreased vagal tone (P < 0.001). There was no significant difference between GS and FD patients with respect to antral volume, vagal tone, or symptoms. We concluded that both gallstone and functional dyspepsia patients are characterized by dyspeptic symptoms in response to ingestion of 500 ml of meat soup, a wide gastric antrum, low vagal tone, but normal gallbladder size and emptying. Thus, patients with symptomatic, uncomplicated gallstone disease and functional dyspepsia seem to have common pathogenetic mechanisms.

Adolescent↗
PubMed1997

Transendoscopic ultrasonography during conventional upper gastrointestinal endoscopy. Clinical evaluation of a linear 20-MHz probe system.

BACKGROUND: Endoluminal ultrasonography provides detailed images of the gastrointestinal wall and surrounding tissue. Miniature ultrasound probes can be applied during conventional endoscopy. METHODS: The supplementary diagnostic information obtained during endoscopy with a linear 20-MHz ultrasound probe system was independently assessed by two observers applying a general rating system on 188 consecutive examinations in 173 patients. RESULTS: On average, 70% of the examinations were found to contribute conclusive or important supplementary information that could potentially influence treatment or further patient evaluation (substantial diagnostic yield). Substantial diagnostic yield was most often obtained in patients with known malignancy (92%), stenoses (81%), or subepithelial masses (80%) and more often in patients with malignant (85%) than in those with benign (61%) conditions (P < 0.001). CONCLUSIONS: Transendoscopic ultrasonography using a 20-MHz linear miniature ultrasound probe may provide substantial supplementary diagnostic information during upper gastrointestinal endoscopy, especially in patients with malignant disease and with stenotic or subepithelial lesions.

Adolescent↗
PubMed1997

Virtual reality in surgical practice in vitro and in vivo evaluations.

This paper describes a method for the acquisition and integrative processing of laparoscopic and endoluminal ultrasound images. We used a stepping motor attached to a stabilizing rig, interfaced to the laparoscope, or the ultrasound probe. 360 degrees laparoscopic scenes were constructed during minimally invasive surgery, and three-dimensional reconstructions were made of related ultrasound data. Integration of 360 degrees panoramas with geometric ultrasound models could be displayed as interactive scenes. This resulted in a better demonstration of the surgical field and topographic anatomy. In conclusion, this type of visualizations may be used in virtual reality simulations for documentation, education and in operative planning.

Computer Simulation↗
PubMed1996

[High frequency ultrasonography of the gastrointestinal wall].

If an ultrasound probe comes close to the area of interest, high ultrasound frequencies can be applied. Endoscopic ultrasonography is performed by means of echoendoscopes or miniature probes using ultrasound frequencies between 7 and 30 MHz. A high frequency ultrasound image of the normal gastrointestinal wall usually shows five layers corresponding closely to the histological layers of the wall. Corrections have to be made, however, for interface echoes between layers with different acoustic impedances. We describe studies performed with the aim of correlating ultrasound images of the normal and diseased gastrointestinal wall with the histology. Ultrasound images of the normal gastrointestinal wall and pathological changes like ischemia, ulcers, tumours and inflammation are presented.

Gastric Mucosa↗
PubMed1996

[Mini-probe ultrasound of the upper gastrointestinal tract--1995 state of the art and perspectives. Workshop on Mini-Probe Ultrasound in Gastroenterology, Münster, 28 October 1995].

Endoscopic ultrasound (EUS) allows for intraluminal sonographic imaging of the oesophagus, stomach, pancreatobiliary duct system, the papilla of Vater, as well as the colon and rectum. EUS has proved valuable for diagnosis and staging of tumours of the upper intestinal tract. EUS can also provide valuable additional information concerning lesions that cannot be immediately classified. As doing this involves, first, removal of the conventional endoscope and, second, insertion of the echo endoscope, EUS is not suitable for routine examinations. Therefore EUS has remained an independent endoscopic diagnostic modality. Moreover, due to their diameter conventional echoendoscopes cannot be inserted into the pancreatobiliary duct system. Fine calibre high frequency ultrasound probes promise a resolution of less than 2 mm in diameter. The following report is a summary of a one-day workshop which took place in Muenster, Germany on Oct. 28, 1995. Its goal was to define the current state of the art of miniaturised endoscopic ultrasound probes in the field of gastroenterology. During this workshop, possible clinical applications for diagnosis, therapy, as well as follow-up were described and discussed. The potential of miniaturised endoscopic ultrasound probes was explored in terms of possible future technical developments.

Endoscopy, Gastrointestinal↗
PubMed1996

Three-dimensional ultrasonography of the gastric antrum in patients with functional dyspepsia.

BACKGROUND: We have developed and validated a three-dimensional ultrasound system for transabdominal imaging. The aims of this study was to evaluate its applicability in scanning and volume estimation of the gastric antrum in humans. METHODS: Twenty patients with functional dyspepsia and 20 healthy controls, comparable with regard to gender, age, and smoking habits, agreed to be scanned while ingesting 500 ml of meat soup. A mechanical scanner with a 3.25-MHz transducer coupled to a tilting motor provided in 3 sec multiple images of the antrum during fasting and 1, 10, and 30 min postprandially. On a Unix work station planar contours of the antrum were selected and drawn manually before organ reconstruction and volume computation. RESULTS: Two volume scans of 160 could not be analyzed due to air in the antrum. Up to 5 cm proximal to the pylorus, volumes could be computed in 95% of fasting samples and in 98% of postprandial samples, versus 8% and 75%, respectively, up to 7 cm proximal to the pylorus. We found no significant differences in antral volumes between dyspeptic patients and controls, either fasting or postprandially. Fasting antral volumes in Helicobacter pylori-positive dyspeptics were smaller than in H. pylori-negative patients (P = 0.02). CONCLUSIONS: Three-dimensional ultrasonography by use of a tilting motor makes non-invasive volume estimation of the gastric antrum possible without making assumptions about its geometry. In the present material no difference was found in antral volumes between patients with functional dyspepsia and controls. It is possible that fasting antral volumes in dyspeptic patients are dependent on H. pylori status.

Adolescent↗
PubMed1996

Ultrasonography of the human stomach.

UNLABELLED: Improved technology and new systems have expanded the possibilities of using ultrasound in clinical gastroenterology. METHODS: Conventional real-time ultrasound was applied to the stomach in order to study motor activity and accommodation to meals. The antrum was imaged by various modalities of two- and three-dimensional ultrasonography, while duplex sonography was used for studying transpyloric flow. Miniature ultrasound probes and echo-endoscopes were employed for endoscopic ultrasound RESULTS: The examinations provided new information about contractions, distension, co-ordination of movements, and flow. Patients with functional dyspepsia were characterized by rapid emptying of the proximal stomach, wide gastric antrum, early commencement of transpyloric flow, and epigastric discomfort following ingestion of a meat soup. Endoscopic ultrasonography exposed detailed images of the gastric wall and adjacent structures of great importance in clinical decision-making. CONCLUSIONS: The new ultrasound methods have improved our diagnostic capabilities and opened new promising possibilities for further research in the field of motility.

Endosonography↗
PubMed1995

In vivo comparison of 3D ultrasonography and magnetic resonance imaging in volume estimation of human kidneys.

The objective of this study was to evaluate the accuracy of a three-dimensional ultrasound system (3D-US) compared with Magnetic Resonance Imaging (MRI) in volume estimation of human kidneys in vivo. Twenty healthy volunteers were scanned fasting in supine position with MRI and with a 3D-US. An ultrasound sector scanner with a mechanical transducer coupled to a tilting motor provided images of multiple sections of kidneys. A 3.25-MHz transducer was tilted through 88 degrees yielding 81 frames, and volume estimation was performed on a Unix workstation after manual contour indication. Data acquisition with MRI was performed by using a 1-T magnet. Eighteen included kidneys [mean +/- standard deviation (SD)] measured 155.7 +/- 26.4 mL (range 110.0-205.0 mL) by 3D ultrasound and 171.8 +/- 24.6 mL (range 127.5-211.0 mL) by MRI, yielding a good correlation (r = 0.82, p < 0.001) between the two methods. The mean difference was -16.1 +/- 15.6 mL (SD) and the limits of agreement were -49.0 mL. We conclude that this 3D-US is accurate in volume estimation of human kidneys in vivo.

Adult↗
PubMed1995

Monitoring postprandial size of the proximal stomach by ultrasonography.

The purpose of this study was to develop a sonographic method to monitor postprandial size of the proximal stomach. Twenty-three healthy persons were scanned in a sitting position with a 3.25 MHz transducer after ingestion of 500 ml meat soup. The area in a sagittal section and the maximal diameter in an oblique frontal section were chosen as standard measurements. The soup emptied from the proximal stomach in a linear manner (r = 0.99) and at a rate of 2.0 +/- 1.3%/min. Intraobserver error of the scans (mean +/- SD) was 5.6% +/- 2.3% and 9.5% +/- 4.5% for sagittal area and frontal diameter, respectively, and the corresponding interobserver error was 5.3% +/- 4.0% and 8.3% +/- 5.3%, respectively. This sonographic method demonstrated a moderate day-to-day variation, had low intra- and interobserver error, and allowed estimation of initial emptying fractions of the proximal stomach.

Adult↗
PubMed1994

[Endoscopic ultrasonography in the diagnosis and follow-up of gastrointestinal diseases].

Endoscopic ultrasonography provides detailed images of gastrointestinal structures by means of high frequency ultrasound transducers placed within the gastrointestinal tract. In this paper, the authors describe various systems and discuss their clinical potential and indications for use. Endoscopic ultrasonography allows imaging of various small pathological lesions in the visceral wall and adjacent structures, such as the mediastinum, pancreas and distal parts of the bile duct. Experience in endoscopy and ultrasonography is necessary for a proper management of the technique.

Endoscopes, Gastrointestinal↗
PubMed1994

Volume measurements of gastric antrum by 3-D ultrasonography and flow measurements through the pylorus by duplex technique.

We present a method for estimating volumes of abdominal organs using 3-D ultrasonography. In vitro validation experiments demonstrated excellent agreement between estimated and true volumes. In vivo estimations after ingestion of 500 ml meat soup showed greater antral filling and poorer emptying of the gallbladder in patients with functional dyspepsia (FD) than in healthy controls. Abnormal antral filling was associated with dyspeptic symptoms. The relationship between motility and transpyloric movements of luminal contents after ingestion of 500 ml meat soup was studied in healthy subjects by duplex technique. Accurate timing of antegrade and retrograde flow were recorded using bidirectional velocity curves. Mid-cycle and end-cycle reflux were often observed; end-cycle reflux was more frequent in conjunction with coordinated than with uncoordinated antroduodenal contractions. The peristaltic closure of the pylorus was normally preceded by a short gush of duodenogastric reflux.

Dyspepsia↗
PubMed1994

In vitro evaluation of three-dimensional ultrasonography in volume estimation of abdominal organs.

The purpose of this study was to evaluate the accuracy and precision of a three-dimensional (3D) ultrasound system in volume estimation of abdominal organs in vitro. A mechanical sector scanner coupled to a stepping motor recorded images of porcine stomach and kidneys. The transducer was tilted through 88 degrees yielding 81 frames, and volume estimation was performed digitally after interactive manual contour indication and organ reconstruction in 3 dimensions. This 3D system showed good correlation (r = 0.998) between estimated and true volumes. Volume estimation of stomach and kidneys using 3.25 MHz probe demonstrated limits of agreement of 0.877 to 1.146 and 1.007 to 1.125, respectively, depicting estimated volumes as a proportion of true volumes in 95% of the examinations. Intra- and interobserver variation of the tracing procedure revealed low values. We conclude that this 3D ultrasound system performs high accuracy and precision in volume estimation.

Abdomen↗