Differentiation of Metastatic and Non-Metastatic Mesenteric Lymph Nodes by Strain Elastography in Surgical Specimens.

PURPOSE: To investigate if strain elastography could differentiate between metastatic and non-metastatic mesenteric lymph nodes ex-vivo. MATERIALS AND METHODS: 90 mesenteric lymph nodes were examined shortly after resection from 25 patients including 17 patients with colorectal cancer and 8 patients with Crohn's disease. Ultrasound-based strain elastography was performed with a linear probe. Tissue hardness in lymph nodes was assessed using visual scales and measuring the strain ratio. B-mode characteristics were also recorded. Pathological diagnosis with grading of fibrosis served as the reference standard. RESULTS: 20 lymph nodes were metastatic and 70 lymph nodes were non-metastatic. The strain ratios of metastatic and non-metastatic lymph nodes were significantly different (1.83 vs. 1.42, p = 0.021). The VAS scale (0 - 100) for tissue hardness gave higher mean values for metastatic than non-metastatic nodes, but the difference was not significant (65.5 vs. 55.0, p = 0.055). There was no difference between lymph nodes in Crohn's and non-metastatic cancer specimens. The metastatic lymph nodes were significantly more fibrotic than the non-metastatic lymph nodes by the ordinal fibrosis score (0 - 3). In an ROC analysis, quantitative strain imaging was not superior to the measurement of the short-axis diameter of lymph nodes in differentiating metastatic from non-metastatic mesenteric lymph nodes ex-vivo. CONCLUSION: Strain elastography is correlated to fibrosis in lymph nodes and a significant difference was observed on a group level using the strain ratio. Due to measurement overlap, individual mesenteric lymph nodes could not be identified accurately as metastatic or not in this ex-vivo model by strain imaging alone.

Strain assessment in surgically resected inflammatory and neoplastic bowel lesions.

PURPOSE: To investigate whether ultrasound-based strain imaging can discriminate between colorectal adenocarcinomas and stenotic Crohn's lesions in newly resected surgical specimens. MATERIALS AND METHODS: Resected surgical specimens from 27 patients electively operated for colorectal tumors or stenotic lesions from Crohn's disease were prospectively examined with ultrasonography using a Hitachi HV 900 US scanner with real-time elastography (RTE). Three different methods were applied to assess tissue strain: A four-level categorical visual classification, a continuous visual analog scale (VAS, 0 - 100) and a strain ratio (SR) measurement between the lesion and surrounding reference tissue. The imaged sections were marked and subsequently examined by a pathologist. Results from RTE were evaluated according to diagnosis, degree of fibrosis, inflammatory parameters, tumor stage and grade. RESULTS: 16 sections from Crohn's lesions, 18 sections from adenocarcinomas and 4 sections from adenomas were examined. Both adenocarcinomas and Crohn's lesions were found to be harder than the surrounding tissue, but they could not be discriminated from each other by any of the strain imaging evaluation methods. All adenocarcinomas had significantly higher strain ratios than adenomas. The categorical classification differentiated poorly between Crohn's lesions, adenocarcinomas and adenomas. Categorical evaluation and VAS score showed fair interobserver agreement. SR measurements provided semi-quantitative strain data and added improved information about elasticity properties, despite substantial intra-observer variation. CONCLUSION: Sonoelastography with SR measurements and visual evaluation of strain differences could not differentiate stenotic Crohn's lesions from adenocarcinomas in resected bowel specimens. A small number of adenomas were found to be significantly softer than adenocarcinomas using the same evaluation methods. The tumor stage or grade did not have a significant impact on the elastography results.

Real-Time Elastography: Strain Ratio Measurements Are Influenced by the Position of the Reference Area.

PURPOSE: Real-time elastography (RTE) is an ultrasound-based method for the visualization of relative strain distribution in soft tissues. Strain ratio is a semi-quantitative measurement of strain differences between two user-defined areas in an elastogram. The aim of this study was to evaluate the impact of the size and location of a reference area when measuring the strain ratio of focal lesions in a tissue-mimicking phantom and in normal liver tissue. We also investigated whether the strain ratio was affected by changing the scanner parameter: elasticity dynamic range (E-dyn). MATERIALS AND METHODS: Two investigators individually collected data by scanning 4 spherical inclusions with different elasticity in a phantom in which the elastic modulus was known in both the lesions and the background. Subsequently, a liver scan was performed in-vivo using the same scanning protocol. Five different setups with changes in reference area position or size were tested. All eight levels of the scanner setting Edyn were recorded for each setup and the strain ratio was measured in 3 different representative elastograms for each recording situation. RESULTS: The four inclusions had significantly different mean strain ratio levels (p < 0.01) when compared to the surrounding material. Changing the position of the reference area to a deeper position influenced the strain ratio measurements significantly for all phantom lesions and in the liver. Changing the size of the reference area, while keeping the center depth unchanged, did not influence the mean strain ratio levels significantly. The strain ratio was independent of the E-dyn parameter setting. The intraand interobserver reliability was high when measuring the strain ratio with a free-hand technique. CONCLUSION: Strain ratio provides reproducible measurements of inclusions representing different elastic contrasts using a free-hand technique in vitro. Changes in the distance of the reference areas to the ultrasound probe, representing the stress source, seem to have a significant impact on strain ratio measurements.

A multimodal laser Doppler and endosonographic distension device for studying mechanosensation and mucosal blood flow in the oesophagus.

We describe the development of a multimodal device combining bag distension, manometry, high frequency intraluminal ultrasound, laser Doppler flowmetry and symptom registration. Bench tests showed that the different modalities did not influence each other. During bag distension we obtained high quality images of the oesophageal wall for computing biomechanical parameters, and laser Doppler signals showing variation in mucosal perfusion. We conclude that the principle of measurement is sound and that the device can provide a basis for further studies.

Endoscopic ultrasonography for preoperative diagnosis and localization of insulinomas.

BACKGROUND: Endoscopic ultrasonography (EUS) is generally accepted as a sensitive method for the detection of small pancreatic tumors. We report our experience with EUS for preoperative imaging of insulinomas. METHODS: Nine patients with clinical and biochemical signs of insulinoma were examined by EUS using a 7.5/12 MHz radial-scanning ultrasound endoscope prior to surgery. EUS outcome was evaluated on the basis of surgery (open or laparoscopic) and examination of the resected specimens. RESULTS: Two EUS-negative patients appeared, by reassessment of clinical and biochemical data, not to have an insulinoma and were not operated on. EUS correctly imaged and localized five of seven insulinomas that were surgically removed. One isoechoic tumor in the pancreatic head and one pedunculated tumor connected to the caudal side of the pancreatic body were missed by EUS. EUS could demonstrate the size and shape of the imaged tumors, as well as their relationship to adjacent structures, such as the pancreatic duct, bile duct, and large vessels. CONCLUSIONS: Our experience with seven insulinomas accords with previous reports claiming EUS to be the method of choice for preoperative imaging and localization of pancreatic islet cell tumors.

Endosonography-guided endoscopic band ligation of Dieulafoy's malformation: a case report.

Dieulafoy's vascular malformation may cause serious upper gastrointestinal hemorrhage. The mucosal lesion is usually small, and precise location of the lesion may therefore be difficult. We report a case of Dieulafoy's lesion successfully treated by endoscopic band ligation (EBL) where endoscopic ultrasonography (EUS), including Doppler examination, was applied for accurate diagnosis, guiding EBL and control of treatment.

Comparison of a linear miniature ultrasound probe and a radial-scanning echoendoscope in TN staging of esophageal cancer.

BACKGROUND: Endoscopic ultrasonography is a precise method for TN staging of esophageal cancer. We explored the staging properties of a linear miniprobe as compared with a radial-scanning echoendoscope. METHODS: Sixty-eight patients with esophageal cancer underwent preoperative TN staging using a 20-MHz linear miniprobe and a 7.5/12-MHz radial-scanning echoendoscope. Tumor stage was verified by surgery and/or histology. RESULTS: T and N stages were verified in 53 and 54 patients, respectively. T-staging accuracy using the echoendoscope was 70%. The high-frequency miniprobe could not differentiate between T3 and T4 tumors, but both systems had an accuracy of 87% in discriminating between T1, T2, and T3/4 stages. With traversable tumors, the accuracy of N staging was significantly better with the echoendoscope than with the miniprobe (90% vs. 48%, P = 0.008). CONCLUSIONS: The two endosonographic systems had similar accuracy for assessing transmural tumor growth, but the echoendoscope was superior in staging advanced transmural tumors and in predicting lymph node metastasis with traversable tumors.

[Intraluminal sonography in the diagnosis of gastrointestinal diseases]. / Intraluminale Sonographie in der Diagnostik von gastrointestinalen Krankheiten.

Endosonography is an imaging method whereby a high frequency ultrasound probe is inserted into a body cavity with or without under endoscopic control. Examination of the gastrointestinal tract is performed using special echo-endoscopes or trans-endoscopic mini-probes. The gastrointestinal wall, mediastinum, pancreas, bile ducts, retroperitoneum, and other structures surrounding the gastrointestinal tract are target organs for endosonography. A detailed image of pathological processes can thus be obtained. The method can be used both for primary diagnosis of lesions and in follow-up of gastrointestinal diseases. It is accurate in local staging of cancer and in detecting small lesions. There are some limitations for optimal examination like stenoses or other factors prohibiting a precise positioning of the ultrasound transducer. The clinical importance of endo-sonographic examinations must be continuously evaluated on the basis of new technical modalities and changes in therapeutic procedures.

Prophylaxis of postoperative relapse in Crohn's disease with mesalamine: European Cooperative Crohn's Disease Study VI.

BACKGROUND & AIMS: This study investigated if long-term treatment with high-dose mesalamine reduces the risk of clinical relapse of Crohn's disease after surgical resection. METHODS: In a prospective, randomized, double-blind, multicenter study, 4 g of mesalamine (Pentasa; Ferring A/S, Vanlose, Denmark) daily was compared with placebo in 318 patients. Treatment was started within 10 days after resective surgery and continued for 18 months. Primary outcome parameter was clinical relapse as defined by an increase in Crohn's Disease Activity Index, reoperation, septic complication, or newly developed fistula. Risk factors for recurrence were prospectively defined to be analyzed in a stepwise proportional hazards model. RESULTS: Cumulative relapse rates (+/-SE) after 18 months were 24.5% +/- 3.6% and 31.4% +/- 3.7% in the mesalamine (n = 152) and placebo (n = 166) groups, respectively (P = 0.10, log-rank test, 1-sided). Retrospective analysis showed a significantly reduced relapse rate with mesalamine only in a subgroup of patients with isolated small bowel disease (n = 124; 21.8% +/- 5.6% vs. 39.7% +/- 6.1%; P = 0.02, log-rank test). Probability of relapse was predominantly influenced by the duration of disease (P = 0.0006) and steroid intake before surgery (additional risk, P = 0.0003). CONCLUSIONS: Eighteen months of mesalamine, 4 g daily, did not significantly affect the postoperative course of Crohn's disease. Some relapse-preventing effect was found in patients with isolated small bowel disease.

3D-endosonography in gastroenterology: methodology and clinical applications.

Endoluminal ultrasonography allows detailed imaging of the gastrointestinal wall and adjacent structures. Three-dimensional (3D) imaging may improve visualisation of topographic relations and the nature of pathologic lesions. The objective of this report is to summarise current status of 3D-endosonography and to discuss the possible clinical impact of this new modality. 3D ultrasonographic images are usually generated from a series of digitised two-dimensional ultrasound pictures acquired in a manner that enables registration of their relative spatial position. Such acquisition can be accomplished with different ultrasound probes, but in most cases of endosonography, a controlled pullback of radial-scanning probes has been applied. Digital ultrasound images are obtained by frame grabbing of analogue video recordings or by direct transmission from digital scanners. Dedicated software programs have been developed for 3D reconstruction and visualisation, allowing interactive display and measurements. 3D endosonography provides new possibilities for clinical imaging, but the impact on therapeutic strategies and clinical outcome has yet to be established.

Dieulafoy's vascular malformation: role of endoscopic ultrasonography in therapeutic decision-making.

BACKGROUND: Dieulafoy's vascular malformation may cause severe, potentially life-threatening gastrointestinal bleeding. Endoscopic diagnosis may be difficult because of minute mucosal lesions, and additional intramural abnormalities are usually not encountered. Endoluminal high-frequency ultrasonography is a new modality for imaging intramural and perivisceral structures. METHODS: We report two cases of recurrent severe gastric bleeding in which different endosonographic modalities were used in the diagnosis of Dieulafoy's malformation, and the impact of endosonography on therapeutic strategy is discussed. In the first case a radial-scanning 7.5/12-MHz echoendoscope and a linear 20-MHz miniature probe were applied for B-mode imaging in a stable-state patient who had undergone previous endoscopic sclerotherapy, and arterial flow signals from the small intramural lesion were recorded using a 10-MHz transendoscopic pulsed Doppler probe. In the other case urgent endosonography was performed shortly after a bleeding episode, disclosing an aberrant large-calibre artery entering the gastric wall with a long submucosal branch. RESULTS: Both patients were successfully operated on with a transabdominal approach. CONCLUSION: Endosonography is a quick and safe diagnostic method and should be considered when vascular malformations are suspected as the cause of gastric bleeding.

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.

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.

Bismuth-based combination therapy for Helicobacter pylori-associated peptic ulcer disease (metronidazole for eradication, ranitidine for pain).

OBJECTIVES: 180 Helicobacter pylori-positive patients with peptic ulcer disease were randomly allocated to double-blind placebo-controlled treatment with one of four anti-H. pylori regimens consisting of bismuth subnitrate suspension (B), oxytetracycline (OT), metronidazole (M)/metronidazole placebo, or ranitidine (R)/ranitidine placebo. METHODS: Regimen 1: B 150 mg q.i.d., OT 500 mg q.i.d., M 400 mg t.i.d. for 10 days and R 300 mg b.i.d. for 4 wk. Regimen 2: same as regimen 1 except ranitidine. Regimen 3: same as regimen 1 except metronidazole. Regimen 4: same as regimen 1 except metronidazole and ranitidine. Gastroscopy and 14C-urea breath test were performed 4 wk after cessation of therapy, and breath test six months after cessation. RESULTS: According to intention-to-treat analysis, H. pylori eradication rates were 96%, 91%, 20%, and 9% with regimens 1, 2, 3, and 4, respectively. Comparing regimens 1+2 and 3+4, the eradication rates with and without metronidazole were 93% and 14%, respectively (p < 0.0001). Metronidazole increased the occurrence of diarrhea and abdominal pain. Comparing regimens 1+3 with 2+4 ranitidine did not influence H. pylori eradication (58% with and 50% without ranitidine; p = 0.37) or ulcer healing (93% with and 90% without ranitidine; p = 0.72) significantly, but reduced the occurrence of pain (p < 0.01). Six months after treatment, three patients who were H. pylori negative at 4 wk had become positive. These three had all received metronidazole placebo. H. pylori status remained negative in the other 85 patients. CONCLUSIONS: H. pylori eradication with this triple therapy is critically dependent on metronidazole. Adding ranitidine reduces the occurrence of abdominal pain during such therapy.

[High frequency ultrasonography of the gastrointestinal wall]. / Høyfrekvent ultrasonografi av gastrointestinalkanalens vegg.

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.

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.

Lansoprazole capsules and amoxicillin oral suspension in the treatment of peptic ulcer disease.

BACKGROUND: Lansoprazole is a potent antisecretory drug also possessing anti-Helicobacter pylori activity in vitro. It is a candidate drug for combination regimens with antibiotics for treating H. pylori infections. METHODS: In a semiblind study, 65 patients with duodenal and/or gastric ulcer and pathologic 14C urea breath test results were treated with either 60 mg lansoprazole every morning only for 14 days or combined with 500 mg amoxicillin oral suspension four times daily between meals, given for 11 days. Endoscopy and breath test were repeated after 6 weeks and 6 months. Patients with unhealed ulcers were withdrawn. RESULTS: Eradication of H. pylori infection was attained in 46% of patients receiving lansoprazole and amoxicillin but in no patient receiving lansoprazole alone. Ulcers healed significantly more often in those who were H. pylori-negative (18 of 19 (95%)) than in those who were H. pylori-positive (20 of 41 (49%)). Adverse events, particularly stomatitis/sore throat and diarrhea, occurred significantly more often when amoxicillin was combined with lansoprazole. CONCLUSIONS: Lansoprazole eradicated H. pylori infection only when combined with amoxicillin. Eradication rates in this study are hardly acceptable, and further studies are necessary to define optimal doses and duration of treatment. Using amoxicillin as an oral suspension may not be of any substantial benefit and may cause stomatitis and sore throat.