Endoscopic Ultrasound Elastography Research Articles

Endoscopic Ultrasound Elastography in the Assessment of Rectal Tumors: How Well Does It Work in Clinical Practice?

Endorectal ultrasound applications in the evaluation of rectal tumors could be a useful tool in achieving proper staging of rectal cancer. The purpose of this study was to compare the efficacy of rectal tumor staging by flexible endoscopic ultrasound (EUS) with real-time elastography (RTE) using the gold standard post-surgery histological analysis of the resected tissue as the control. The second aim of our research was to establish cutoff values for the EUS-RTE strain ratio corresponding to stages by independently comparing the stiffness values obtained with histology and EUS-RTE staging in order to minimize observation bias. We evaluated the records of 130 patients with a rectal tumor confirmed by biopsy. EUS was used in 70 patients, EUS-RTE—in the other 60. We found no statistically significant differences in staging accuracy when comparing EUS to EUS-RTE. Through a correspondence method between staging assessment and the EUS-RTE stain ratio, we identified cutoff intervals for T2, T3, and T4 staging that were nonoverlapping and proved to be statistically significant in terms of EUS-RTE values (significantly different ascending values from one interval to the other). We found that EUS-RTE offers slightly better, although not statistically significant sensitivity and specificity for T and N stage predictions compared to 2D EUS. Our results showed that EUS-RTE offers slightly higher sensitivity and specificity compared to EUS. Reliable cutoff intervals were found for strain rate elastography, previously available only for shear wave elastography (SWE) which is currently unavailable on any EUS system. Thus, these commonly available EUS-RTE systems can serve as a complementary tool in the staging of rectal tumors.

The evolving role of EUS-guided tissue acquisition.

The introduction of endoscopic ultrasound-guided fine-needle aspiration into clinical practice was a pivotal moment for diagnostic gastrointestinal endoscopy. It facilitates the ease of tissue acquisition from previously inaccessible sites. The performance characteristics of cytological diagnosis are excellent. However, there remain areas of inadequacies. These include procedural inefficiencies such as the need for rapid on-site cytological evaluation or macroscopic on-site evaluation, the crucial role of histology for diagnosis in specific conditions, the issue of sampling errors and the need for repeat procedures, and the shift towards personalized medicine, which requires histology, immunohistochemical studies, and molecular analysis. The original Trucut biopsy needle had been cumbersome to use, but the recent introduction of newer-generation biopsy needles has transformed the landscape, such that there is now a greater focus on tissue acquisition for histological assessment. Concomitant technological advances of endoscopic ultrasound processors enabled higher-resolution imaging, and facilitated image enhancement using contrast harmonic endoscopic ultrasound and endoscopic ultrasound elastography. These techniques can be used as an adjunct to guide tissue acquisition in challenging situations. There is ongoing research on the use of artificial intelligence to complement diagnostic endoscopic ultrasound and the early data are promising. Artificial intelligence may be especially important to guide clinical decision-making if biopsy results are nondiagnostic.

Endoscopic Ultrasound (EUS) Elastography and Contrast EnhancedEUS for Discrimination of Pancreatic Masses

AbstractBackground: Investigate the clinical utility of contrast-enhanced endoscopic ultrasound (CEEUS) and endoscopicultrasound elastography (EUS-E) in diagnosis of pancreaticmasses.Patients and Methods: 30 patients with solid pancreaticfocal lesions were included. All patients were subjected tolaboratory investigations, conventional ultrasound, triphasiccomputed tomography (CT) scan, EUS-E, CEEUS, and EUSFNA. Diagnostic accuracy of EUS-E and CEEUS were com-pared and correlated to the pathology for pancreatic lesions.Results: Malignant lesions were larger in size (32.2±10.3), and had greater SR-E-EUS and more hypovascular pattern. The mean strain ratio was 16.4±8.14 for benign and 67.76 ± 72.45 for malignant lesions (p=0.001). Hypovascular pattern after contrast injection was present in 76% of malignant and 60% of benign lesions (p=0.66). ROC analysis for the mean SR-E-EUS of the region of interest yielded an optimal cutoff of 74.4 with an AUC of 0.91 (95% CI: 0.74-0.98) for the best power distinction for malignancy. It provided a sensitivity and specificity of 75% and 80%, respectively.Conclusion: EUS based novel modalities (CE-EUS andEUS-E) could distinguish between benign and malignantlesions and improve the identification of the vascular patternrespectively. Both techniques could be considered a comple-mentary imaging modality in the characterization of pancreatictumors.

Role of Endoscopic Ultrasonography and Endoscopic Retrograde Cholangiopancreatography in the Diagnosis of Pancreatic Cancer.

Pancreatic cancer has the poorest prognosis among all cancers, and early diagnosis is essential for improving the prognosis. Along with radiologic modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), endoscopic modalities play an important role in the diagnosis of pancreatic cancer. This review evaluates the roles of two of those modalities, endoscopic ultrasonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP), in the diagnosis of pancreatic cancer. EUS can detect pancreatic cancer with higher sensitivity and has excellent sensitivity for the diagnosis of small pancreatic cancer that cannot be detected by other imaging modalities. EUS may be useful for the surveillance of pancreatic cancer in high-risk individuals. Contrast-enhanced EUS and EUS elastography are also useful for differentiating solid pancreatic tumors. In addition, EUS-guided fine needle aspiration shows excellent sensitivity and specificity, even for small pancreatic cancer, and is an essential examination method for the definitive pathological diagnosis and treatment decision strategy. On the other hand, ERCP is invasive and performed less frequently for the purpose of diagnosing pancreatic cancer. However, ERCP is essential in cases that require evaluation of pancreatic duct stricture that may be early pancreatic cancer or those that require differentiation from focal autoimmune pancreatitis.

Endoscopic ultrasound elastography for small solid pancreatic lesions with or without main pancreatic duct dilatation

Background/Objectives: Endoscopic ultrasound elastography (EUS-EG) is useful for diagnosis of small solid pancreatic lesions (SPLs), particularly in excluding pancreatic cancer (PC), but its dependence on main pancreatic duct dilatation (MPDD) has not been examined. We aimed to investigate EUS-EG for diagnosis of small SPLs with and without MPDD. MethodsPatients with pathologically diagnosed SPLs of ≤20 mm were included and retrospectively analyzed. Using the blue:green ratio, an EUS-EG image was classified as blue-dominant, equivalent, or green-dominant. Using multiple EUS-EG images per patient, a lesion with a greater number of blue-dominant than green-dominant images was classified as stiff, and the others as soft. EUS-EG images in random order were judged by three raters. Considering stiff SPLs as PC, diagnostic performance of EUS-EG was examined for SPLs with and without MPDD. ResultsOf 126 cases analyzed, 65 (52%) were diagnosed as PC, and 63 (50%) had MPDD. A total of 1077 EUS-EG images were examined (kappa coefficient = 0.783). Lesions were classified as stiff in 91 cases and soft in 35 (kappa coefficient = 0.932). The ratio of stiff to soft lesions was significantly higher in PC than in non-PC (62:3 vs. 29:32, P < 0.001). The sensitivity, specificity, and negative predictive value of a stiff lesion with vs. without MPDD for diagnosis of PC were 94%, 23%, and 50% vs. 100%, 60%, and 100%, respectively. ConclusionsUsing the EUS-EG stiffness classification for small SPLs, PC can be excluded with high confidence and concordance for a soft lesion without MPDD.

Efficacy of Endoscopic Ultrasound Elastography in Differential Diagnosis of Gastrointestinal Stromal Tumor Versus Gastrointestinal Leiomyoma.

BackgroundThe diagnostic efficacy of endoscopic ultrasound (EUS) elastography for alimentary tract diseases remains uncertain. The aim of this study was to evaluate the utility of EUS elastography in differential diagnosis between the 2 most common subepithelium tumors of the digestive tract – gastrointestinal stromal tumors (GISTs) and gastrointestinal leiomyomas (GILs) – which cannot be differentiated by conventional EUS imaging.Material/MethodsElectronic records were retrospectively reviewed from Jan 2015 to Jul 2019. Patients accepting EUS elastography with histopathological diagnosis of GISTs or GILs were included. The images of EUS elastography were analyzed by hue histogram in Photoshop. Hue values of RGB, R, G, and B channels of each group were acquired. We used the t test, ROC curve analysis, and binary logistic regression analysis for data post-processing.ResultsWe included 47 patients with GISTs and 14 with GILs. The mean±standard deviations (SD) of hue values were 20.25±0.72, −0.79±0.78, 20.79±1.68, 39.72±1.30 for GISTs and 20.80±0.46, 1.80±1.05, 28.39±2.15, and 31.95±2.60 for GILs of RGB, R, G, and B channels, respectively. The t test showed statistically significant differences in mean hue values between GISTs and GILs in B and G channels, but not in RGB and R channels. The area under the ROC curve combining B and G values was 0.723. Binary logistic regression analysis suggested no statistically significant difference in ability to differentiate between GISTs and GILs with B and G values (P>0.05).ConclusionsThere was insufficient evidence to support the application of quantitative EUS elastography for differential diagnosis of GISTs and GILs in this study.

Endoscopic Ultrasound Elastography as a Novel Diagnostic Method for the Assessment of Hardness and Depth of Invasion in Colorectal Neoplasms

Introduction: We aimed to compare the efficacy of endoscopic ultrasound elastography (EUS-EG) with that of magnifying chromoendoscopy (MCE) and endoscopic ultrasonography (EUS) for the diagnosis of the depth of invasion in colorectal neoplasms. This is an important clinical issue as the depth of invasion is associated with the risk of metastasis. Methods: Consecutive patients with suspected superficial colorectal neoplasms, evaluated by MCE, EUS, and EUS-EG, for whom endoscopic submucosal dissection was considered, were enrolled in 2018 (derivation study) and in 2019–2020 (validation study). The primary clinical endpoint was the diagnostic yield differentiating intramucosal and shallow submucosal neoplasms from deep submucosal (dSM) and advanced colorectal cancers. In addition, inter- and intra-observer agreements of the elastic score of colorectal neoplasm (ES-CRN) were evaluated by 2 expert and 2 non-expert endoscopists. Results: Thirty-one (33 lesions) and 50 (55 lesions) patients were enrolled in the derivation and validation studies, respectively. Sensitivity, specificity, positive, and negative predictive values, and accuracy of assessment of the depth of submucosal or deeper invasion in the derivation and validation groups were as follows: EUS-EG, 100/88.2/86.7/100/93.3% and 77.8/86.1/73.7/88.6/83.3%; MCE, 66.7/94.4/90.9/77.3/81.8% and 84.2/91.4/84.2/91.4/88.9%; and EUS, 93.3/77.8/77.8/93.3/84.8% and 89.5/65.7/58.6/92.0/74.1%, respectively. For the 2 expert endoscopists, interobserver agreement for the ES-CRN (first and second assessments) in the derivation group was 0.84 and 0.78, respectively; these values were 0.73 and 0.49, respectively, for the 2 non-expert endoscopists. Discussion/Conclusion: All 3 modalities presented similar diagnostic yield. Inter- and intra-observer agreements of the ES-CRN were substantial, even for non-expert endoscopists. Therefore, EUS-EG may be a useful modality in determining the depth of invasion in colorectal neoplasms.

Results of liver and spleen endoscopic ultrasonographic elastography predict portal hypertension secondary to chronic liver disease.

Background and study aims Assessment of endoscopic ultrasonography (EUS)-elastography of the liver and spleen may identify patients with portal hypertension secondary to chronic liver disease. We aimed to evaluate use of EUS-elastography of the liver and spleen in identification of portal hypertension in patients with chronic liver disease. Patients and methods This was a single-center, diagnostic cohort study. Consecutive patients with liver cirrhosis and portal hypertension underwent EUS-elastography of the liver and spleen. Patients without a history of liver disease were enrolled as controls. The primary outcome was diagnostic yield of liver and spleen stiffness measurement via EUS-elastography in prediction of portal hypertension secondary to chronic liver cirrhosis. Cutoff values were defined through Youden’s index. Overall accuracy was calculated for parameters with an area under the receiver operating characteristic (AUROC) curve ≥ 80 %. Results Among the 61 patients included, 32 had cirrhosis of the liver. Liver and spleen stiffness was measured by the strain ratio and strain histogram, with sensitivity/(1 − specificity) AUROC values ≥ 80 %. For identification of patients with cirrhosis and portal hypertension, the liver strain ratio (SR) had a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 84.3 %, 82.8 %, 84.4 %, and 82.8 %, respectively; the liver strain histogram (SH) had values of 87.5 %, 69.0 %, 75.7 %, and 83.3 %, respectively. EUS elastography of the spleen via the SR reached a sensitivity, specificity, PPV, and NPV of 87.5 %, 69.0 %, 75.7 %, and 83.3 %, respectively, whereas the values of SH were 56.3 %, 89.7 %, 85.7 %, and 65.0 %, respectively. Conclusion Endoscopic ultrasonographic elastography of the liver and spleen is useful for diagnosis of portal hypertension in patients with cirrhosis.

S0975 EUS Elastography: Initial Experience at the Safety Net Hospital

INTRODUCTION: Endoscopic Ultrasound Elastography (EUS-E) is increasingly used to augment EUS imaging and to direct EUS-guided tissue acquisition. The experience with EUS-E using new generation EUS processors is limited. We aimed to evaluate the diagnostic utility of EUS-E in a variety of gastrointestinal lesions in a diverse safety net patient population. METHODS: The EUS database was retrospectively queried for EUS-E procedures performed from 08/15/2019, when EUS-E first became available at our institution, to 06/15/2020. EUS-E was performed with a linear echoendoscope (GF-UCT180, Olympus USA) and Hitachi Aloka ProSound F75 processor (Olympus USA). The queried data included EUS-E strain ratios (SR), final pathologic diagnosis, EUS findings, and patient demographics. Where multiple SR obtained, the mean was reported. Previously reported SR cutoff of 18 was used to define high risk lesions. RESULTS: EUS-E was performed in 19 patients (mean age 55 y; 28–77; 9 men and 10 women); mean lesion size 3.3 cm ± 1.3 cm. Pancreatic masses, lymph node, thyroid mass, hepatic mass, gastric mass were among lesions analyzed. High risk lesions based on EUS-E were confirmed by cytology/tissue pathology to be five pancreatic adenocarcinomas, one pancreatic intraepithelial neoplasia, and one intraductal papillary mucinous neoplasia with mean SR 41.5 ± 22.8 (0.48–81.0). EUS-E with EUS-FNA/B as a diagnostic standard had the sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of 87.5%, 71.4%, 77.8%, 83.3%, and 80.0%, respectively (Table 1). One heterogeneous lesion with SR 0.48 was later determined to be pancreatic adenocarcinomaTable 1. Benign pathology was found in a peri-pancreatic mass, SR 3.8, a pancreatic head mass, SR 13.7, a pancreatic body mass, SR 0.75, a gastric subepithelial lesion, SR 0.71, and a hepatic lesion, SR 0.33. Two pancreatic lesions with benign pathology, SR 22.7 and 42.8, are now pending repeat EUS-FNB. Pathology was non-diagnostic on a thyroid mass with SR 9.5 and a pancreatic body mass with SR 1.4. Biopsy was not performed on two lesions, a peri-pancreatic lymph node with SR 25.3 and a peri-pancreatic splenule with SR 45.3. CONCLUSION: Our initial experience suggests that EUS-E could be a useful adjunct to EUS imaging and EUS-guided tissue acquisition. Lesions with benign pathology and high strain ratios should be considered for repeat sampling and closely followed.

S3244 EUS Elastography in Prediction of Lymph Node Metastases in Suspected GI Cancer: A Pilot Study

INTRODUCTION: Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (EUS-FNA) are the most accurate techniques for local staging of malignant gastrointestinal (GI) cancers. Four features are used to predict metastatic lymph nodes (LNs) with 80% accuracy if all are present: hypoechogenicity, well-defined margins, round shape, and size >1 cm. Despite near 100% specificity, the challenges of obtaining a sample limits the use of FNA. EUS elastography is a real-time technology (EUS-RTE) with the potential to differentiate malignant and benign tissue via color histogram. Investigators have speculated that the subjectivity of color interpretation leads to variable results. Image J is a processing software that can be used to help minimize bias. Our goal is to establish a quantitative EUS criterion for assessment of LNs. METHODS: At least 3 EUS-RTE images of each LN were obtained. The endoscopist recorded his assessment of the LN based on the four criteria described above (“endoscopist’s impression”). If at least 3 of the 4 criteria were present, the LN was considered malignant. FNA was performed if feasible. All images were from a linear echoendoscope. Images without adequate transducer pressure as measured by the strain graph display or cytology were excluded. A stylus was used to outline the entire LN in B-mode, which was considered the region of interest (ROI). This outline was superimposed on the corresponding color histogram for processing. The number of red, green and blue pixels and total area of each ROI were quantified using Image J. RESULTS: Twenty-one LNs from 19 patients were included in the final analysis. Ten LNs were malignant (45%). Most procedures were performed for suspected esophageal or pancreatic cancer (14/19). A comparison of the endoscopist’s impression, blue pixels as a predictor of malignancy and red pixels as a predictor of benign LN is depicted in Figure 1. Sensitivity and specificity of the endoscopist’s impression was 90% and 67% respectively; accuracy was 80%. The endoscopist’s impression performed the best (95% CI, 0.63-0.98), but the difference was not statistically significant. CONCLUSION: Our study was limited by a small sample size and selection of the ROI may be another source of subjectivity. While Image J did not outperform current EUS criteria, firm conclusions cannot be drawn. Further study with a larger cohort is necessary to refine our interpretation of elastography and determine if post-procedure processing of elastography images is a useful adjunct.Figure 1

Diagnostic performance of endoscopic ultrasonography-guided elastography for solid pancreatic lesions: Shear-wave measurements versus strain elastography with histogram analysis.

Endoscopic ultrasound (EUS) elastography (EUS-EG) is a minimally invasive diagnostic method for evaluating tissue elasticity. The aim of this study was to evaluate the feasibility of newly developed EUS shear-wave measurement (EUS-SWM) and to compare diagnostic performance between EUS-SWM and the conventional strain elastography (SE) for the measurement of elasticity of solid pancreatic lesions (SPLs). From December 2017 until August 2019, we retrospectively reviewed 64 consecutive cases with SPLs who underwent both EUS-SWM and SE. EUS-SWM was used to measure the shear-wave velocity, Vs (m/s), and the unique measurement reliability index, VsN (%), in the target lesion. SE images were assessed by strain histogram (SH) analysis, and the mean strain value of the elasticity index was measured. We evaluated the diagnostic performance of EUS-SWM and SE with SH to characterize the SPLs. The Vs (m/s) values of SPLs were 2.19 for pancreatic cancer (PC), 1.31 for pancreatic neuroendocrine neoplasm (PanNEN), 2.56 for mass-forming pancreatitis (MFP) and 1.58 for metastatic tumors. Vs showed no significant difference based on the disease. The mean strain values were 45.5 for PC, 47.3 for PanNEN, and 74.5 for MFP. In the comparison of tissue elasticity between PC and MFP, Vs showed no significant difference (P=0.5687); however, the mean strain value was significantly lower in PC cases (45.4 vs 74.5: P=0.0007). Endoscopic ultrasound SWM tended to be unstable for the measurement of elasticity of SPLs, and conventional SE with SH was superior for their characterization.

Experimental model standardizing polyvinyl alcohol hydrogel to simulate endoscopic ultrasound and endoscopic ultrasound-elastography.

BACKGROUNDEndoscopic ultrasound (EUS) and endoscopic ultrasound elastography (EUS-E) simulation lessens the learning curve; however, models lack realism, diminishing competitiveness.AIMTo standardize the mechanical properties of polyvinyl alcohol (PVA) hydrogel for simulating organs and digestive lesions.METHODSPVA hydrogel (Sigma Aldrich, degree of hydrolysis 99%) for simulating EUS/EUS-E lesions was investigated in Unidad de Investigación y Desarrollo Tecnológico at Hospital General de México “Dr. Eduardo Liceaga”, Mexico City. We evaluated physical, contrast, elasticity and deformation coefficient characteristics in lesions, applying Kappa’s concordance and satisfaction questionnaire (Likert 4-points).RESULTSPVA hydrogel showed stable mechanical properties. Density depended on molecular weight (MW) and concentration (C). PVA bblocks with the greatest density showed lowest tensile strength (r = -0.8, P = 0.01). Lesions were EUS-graphically visible. Homogeneous and heterogeneous examples were created from PVA blocks or PVA phantoms, exceeding (MW2 = 146000-186000, C9 = 15% and C10 = 20%) with a density under (MW1 = 85000-124000, C1 = 7% and C2 = 9%). We calculated elasticity and deformation parameters of solid (blue) areas, contrasting with the norm (Kappa = 0.8; high degree of satisfaction).CONCLUSIONPVA hydrogels were appropriate for simulating organs and digestive lesions using EUS/EUS-E, facilitating practice and reducing risk. Repetition amplified skills, while reducing the learning curve.

Mo1637 NOVEL METHOD TO DETERMINE THE DEPTH OF INVASION IN COLORECTAL NEOPLASMS WITH ULTRASOUND ELASTOGRAPHY USING A FORWARD-VIEWING RADIAL-ARRAY ECHOENDOSCOPE

With the increasing use of endoscopy for treating colorectal cancer, accurate diagnosis of the depth of invasion in colorectal neoplasms has become an important clinical issue. Our study aimed to compare the diagnostic ability and clinical efficacy of endoscopic ultrasound elastography (EUS-EG) with those of magnifying chromoendoscopy (MCE) and EUS in diagnosing the depth of invasion in colorectal neoplasms. Patients with superficial colorectal neoplasms evaluated by MCE, EUS, and EUS-EG were enrolled. The primary clinical endpoint was the diagnostic yield differentiating intramucosal and shallow submucosal cancers from deep submucosal and advanced colorectal neoplasms, using the elastic score of colorectal neoplasms (ES-CRN). In addition, validation of ES-CRN was performed using inter- and intra-observer agreement from two expert and two non-expert endoscopists. We examined the diagnostic yield of additional patients prospectively due to these results. Thirty-one patients (33 lesions) with colorectal neoplasms were enrolled. The diagnostic yields (sensitivity, specificity, positive predictive value, negative predictive value and accuracy) of deeply submucosal cancers or advanced colorectal neoplasms, respectively, were as follows: EUS-EG:100%/88.2%/86.7%/100%/93.3%, MCE: 66.7%/94.4%/90.9%/77.3%/81.8% and EUS: 93.3%/77.8%/77.8%/93.3%/84.8%. Interobserver agreement for the ES-CRN was 0.70/0.80 and 0.45/0.40 for the first/second assessment, for the two expert endoscopists and two non-expert endoscopists. Furthermore, we examined additional 33 patients (34 lesions) prospectively. The diagnostic yields of prospective study were as follows, respectively: EUS-EG:83.3%/81.5%/50.0%/95.7%/81.8%, MCE: 75.0%/92.0%/75.0%/92.0%/87.9% and EUS: 85.7%/61.5%/37.5%/94.1%/66.7%. The diagnostic yield was from equal to higher for EUS-EG than for MCE and EUS, with moderate inter and intra-observer agreement, even for non-expert endoscopists. Therefore, EUS-EG may be a useful modality to determine the depth of invasion in colorectal neoplasms.

Sa1447 ESTIMATING THE STIFFNESS OF THE PANCREATIC PARENCHYMA WITH A STRAIN RATIO USING ENDOSCOPIC ULTRASOUND ELASTOGRAPHY

Non-invasive quantitative evaluation of pancreas is extremely difficult. Recently, endoscopic ultrasound elastography (EUS-EG) was developed, but the measuring method remains to be established. To establish EUS-EG methods, and score the stiffness of pancreatic. We enrolled 200 patients (112 males and the mean age, 65.8 years old) from 2015 to 2017. All EUS procedures were performed using UCT-260 attached to EU-ME2 premier plus. We measured the strain ratio from the stomach when of the color pattern of EG between the parenchyma and the mesentery was most clear, and set the ROI of the parenchyma as A and the mesentery as B. We measured 5 times and calculated the mean value of the median three ratios, which was defined as PM (parenchyma/mesentery) score. We estimated the cut-off value of chronic pancreatitis (CP), and correlation between the scores and other EUS findings. The median score of all case was 3.81 [0.76-89.33]. Sixteen cases were diagnosed as CP and the median score was 5.84, which was significantly higher than non-CP of 3.66 (p<0.001). Based on ROC analysis, the cut-off value was 4.91, and AUC was 0.810. Hyperechoic appearance (median score, 4.44), heterogenous echo (4.36), early CP (4.36), and fatty change (4.45) tended to result with higher scores (p<0.05). Because of high PM score in CP patients, the harder parenchyma would suggest higher score. Our measuring method might enable us non-invasive quantitative evaluation. However, limitations still exist to use this scoring as golden standard.

Diagnosis of vascular invasion in pancreatic ductal adenocarcinoma using endoscopic ultrasound elastography

BackgroundVascular invasion is an important criterion for resectability and deciding the therapeutic strategy for pancreatic ductal adenocarcinoma (PDAC), but imaging diagnosis is currently difficult. Endoscopic ultrasound (EUS) elastography (EG) images have band-like artifacts on the border between tumor and vessel due to different movement if the tumor is not connected to the vessel, i.e., no invasion. Based on this phenomenon, we assessed the usefulness of EUS-EG in the diagnosis of vascular invasion in PDAC.MethodsThe subjects were 44 out of 313 patients with PDAC who underwent EUS between January 2015 and November 2018, followed by surgery, no chemotherapy or radiotherapy, and pathological evaluation. Diagnostic accuracies of vascular invasion using dynamic computed tomography (CT), EUS B-mode and EUS-EG were compared with histopathological diagnosis.ResultsIn 44 subjects (48 sites) who underwent both dynamic CT and EUS-B mode, the sensitivity, specificity and accuracy were 0.733, 0.697 and 0.708 on dynamic CT (48 sites); 0.733, 0.606 and 0.646 in EUS B-mode (48 sites); and 0.917, 0.900 and 0.906 in EUS-EG (32 sites). In 27 subjects (29 sites) with a tumor contacting a vessel with no vascular obstruction or stenosis on dynamic CT, the sensitivity, specificity and accuracy were 0.556, 0.750 and 0.690 on dynamic CT; 0.667, 0.700 and 0.690 in EUS B-mode; and 0.889, 0.850 and 0.862 in EUS-EG.ConclusionsThese results suggest that EUS combined with EG improves diagnostic performance of vascular invasion in PDAC, especially in cases of which vascular invasion cannot be clearly assessed by dynamic CT.

Noninvasive assesment in differentiating benign and malign pancreatic lesions with endosonographic elastography score and strain ratio

Background: We aimed to evaluate the diagnostic capability of endoscopic ultrasound elastography (EUS-EG) and strain ratio (SR) for differentiating benign pancreatic lesions from the malign lesions Material and Method: We retrospectively evaluated well collected data of patients who undergone EUS-EG in a single centre during the period of January 2016-June 2019. Patients who had pancreatic disorders were further evaluated for the study. The final diagnosis of solid pancreatic lesions (SPL) was made by histopathologic examination. Control group consisted of patients with chronic pancreatitis (CP) who diagnosed according to Rosemont criteria. Elastography was evaluated by a qualitative (elastography scores) and a quantitative method SR. Results: A total of 66 patients (42 (63.6%)female/42 (63.6%)male) with mean age of 58.88±15.32 (19- 80) were included in the study. Thirty-eight patients had SLP, remain 28 patients were CP. In SPL group, 32 (84.2%) had adenocarcinomas and 6 (15.8%) had neuroendocrine tumors. Among 28 patients with benign pancreatic lessions, 23 (82.1%) had CP while five (17.9%) had autoimmune pancreatitis. Median SR values were significantly higher in patients with SPL than those with CP (44.0 (10.0-110.0) vs 7.0 (2.6-14.6), p&amp;lt;0.001). Elasticity scores were also significantly different between patients with SLP and CP (p&amp;lt;0.001). Elasticity scores were significantly different between adenocarcinomas and CP (p&amp;lt;0.001). A 14 cut-off value of SR had 97% sensitive and 100% specificity for SPL and receiver-operating characteristic curves showed an area under the curve of 0.99.6. Likelihood Ratio test revealed that SR appears as the best parameter in discrimination of lesion type either as benign or malignant (X2 = 54.031, p&amp;lt;0.001). Conclusion: Our study suggested that EUS-elastography and SR scores are highly effective in differentiating malign-benign pancreatitis lesions

Clinical analysis on the differential diagnosis of gastrointestinal neoplasms by real-time endoscopic ultrasonography

Abstract: objective: to study and analyze the effect of real-time endoscopic ultrasonography in the differential diagnosis of gastrointestinal tumors.Selection methods: between January 2014 and January 2015 xinyang 53 cases of digestive system cancer patients admitted in hospital, a total of 79 substantial tumor of the digestive system lesions, all patients were diagnosed by endoscopic ultrasonography real-time tissue elastography, use elastic imaging score, for patients with lesions and their surrounding structures control the elastic strain rate ratio of measure and comparison analysis.Results: compared with the malignant lesion group, the difference between the benign lesion group and the benign lesion group was statistically significant (P&lt;0.05).The ratio of elastic strain rate in benign lesion group was lower than that in malignant lesion group (P&lt;0.05).The diagnostic accuracy, sensitivity and specificity were 91.14%, 94.74% and 81.82% respectively.Conclusion: endoscopic ultrasound real-time tissue elastography is effective in the differential diagnosis of digestive system tumors, and can effectively determine the benign and malignant tumors and improve the diagnostic accuracy.

The Strain Ratio as Obtained by Endoscopic Ultrasonography Elastography Correlates With the Stroma Proportion and the Prognosis of Local Pancreatic Cancer.

The aim of this study was to investigate the association of the strain ratio (SR) with clinicopathologic features and the prognostic value of the SR in local pancreatic cancer. The SR as obtained by endoscopic ultrasonography elastography is useful in the differential diagnosis of pancreatic diseases. However, its role in the prognostic prediction of pancreatic cancer remains unknown. A total of 78 resected pancreatic cancer patients and 93 locally advanced pancreatic cancer (LAPC) patients were enrolled in this study according to the inclusion criteria. Masson trichrome staining was used to evaluate the stromal proportion. Survival rates were calculated according to the Kaplan-Meier method and were compared using the log rank test. Multivariate analysis was performed with a Cox regression model. The SR was positively associated with the stromal proportion of resected pancreatic cancer (R = 0.768, P < 0.001). High SR was more likely in males (P = 0.039) and was related to perineural invasion (P = 0.022). High SR predicted unfavorable overall survival (OS) relative to low SR (15.4 vs. 25.8 mo, P = 0.017). SR was confirmed as an independent prognostic factor for resected pancreatic cancer based on multivariate analysis (hazard ratio = 1.939, P = 0.020). For LAPC patients who received nab-paclitaxel and gemcitabine, high SR was associated with improved prognosis (OS: 14.9 vs. 11.6 mo, P = 0.045), but this positive association was not observed in patients treated with other gemcitabine-based regimens (OS: 10.7 vs. 12.4 mo, P = 0.478). A high SR as obtained by endoscopic ultrasonography elastography was associated with poor prognosis of resected pancreatic cancer but predicted improved survival for LAPC patients treated with the nab-paclitaxel and gemcitabine regimen.

Surgical resection of pancreatic tumors: review of 70 cases

Background: Endoscopic ultrasound (EUS) has gradually become the main stream method of the diagnosis and local treatment of pancreatic tumors. Endoscopic ultrasound (EUS) is frequently used in making the cytological diagnosis of pancreatic cancer and its great role in the pre-operative staging of pancreatic tumors.Objective: To evaluate the role of EUS in diagnosis and treatment of pancreatic tumors prospectively for 2 years study 2014-2015.Patients and methods: Prospective study including 70 patients who presented with pancreatic tumors underwent EUS at the endoscopy unit at Faculty of Medicine Cairo University and National Cancer Institute, Cairo University.Results: Out of 70 patients; median age was 55 years (range 32_73 years). Males were 32 (46%) and females were 38 (54%). Jaundice was the main symptom 47 (67%), clay colored stool 46 (65.7%), dark urine 47 (67%) and abdominal pain 50 (71%). There were 20 patients with benign disease and 50 patients with malignant disease. The following results showing the accuracy of the EUS in detecting malignant pancreatic tumors; Sensitivity: 96.0%, specificity: 75%, PPV: 90.6%, NPV: 88.2%, accuracy: 90.0%.Conclusion: EUS can clarify locoregional spread when CT/MR are equivocal. EUS Elastography is a new application in the field of the endosonography and seems to be able to differentiate fibrous and benign tissue from malignant lesions. The combination of superior detection, good staging, tissue diagnosis and potential therapy makes EUS guided FNA a cost-effective modality.

Clinical impact of strain histogram EUS elastography and contrast-enhanced EUS for the differential diagnosis of focal pancreatic masses: A prospective multicentric study.

Background:Recent advances in EUS techniques (real-time EUS elastography and contrast-enhanced EUS) have allowed a better characterization of focal pancreatic masses. Mean strain histograms (SHs) are considered a good parameter for the semi-quantitative evaluation of focal pancreatic masses, alongside complementary contrast-enhanced EUS parameters which can be quantified during both the early arterial and late venous phase.Materials and Methods:The study design was prospective, blinded, and multicentric, assessing real-time EUS elastography and contrast-enhanced EUS results for the characterization of focal pancreatic masses using parametric measurements, in comparison with pathology which is the gold standard. SHs were performed based on the embedded software of the ultrasound system, with the values being reversed as opposed to our initially published data on hue histograms. Consequently, a cutoff of 80 was derived from previous multicentric trials. Contrast-enhanced EUS also allowed the focal masses to be classified as hyper-, iso-, or hypoenhanced in comparison with the normal pancreatic parenchyma. EUS-FNA was then performed for all patients, with a positive cytological diagnosis taken as a final proof of malignancy for the pancreatic masses. The diagnoses obtained by EUS-FNA were verified further either by surgery or during a clinical follow-up of at least 6 months.Results:A total number of 97 consecutive patients with focal pancreatic masses were included in the study. Based on previously defined cutoffs of 80, the values of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the mean SHs for the diagnosis of pancreatic cancer were 100%, 29.63%, 78.65%, 100%, and 80.41%, respectively. Corresponding values for contrast-enhanced EUS (taking into consideration hypoenhencement as a predictive factor of malignancy) were 98.57%, 77.78%, 92%, 95.45%, and 92.78%, respectively. Combining contrast enhancement-EUS (hypoenhencement) and semi-quantitative EUS elastography (SH cutoffs <80), the resulting values corresponding for sensitivity, specificity, and accuracy were 98.57%, 81.48%, and 93.81%, respectively.Conclusion:The current study using objective parametric tools for both EUS elastography and contrast-enhanced EUS confirmed the results of previous studies and meta-analyses that indicated a complementary role for the differential diagnosis of focal pancreatic masses. Moreover, the best values for the receiver operating curves were obtained using a sequential clinical algorithm based on the initial use of elastography, followed by contrast enhancement.