Imaging of Fibrosis in Chronic Pancreatitis

Chronic pancreatitis (CP) describes long-standing inflammation of the pancreas, which leads to irreversible and progressive inflammation of the pancreas with fibrosis. CP also leads to abdominal pain, malnutrition, and permanent impairment of exocrine/endocrine functions. However, it is difficult to assess CP pathologically, and imaging modalities therefore play an important role in the diagnosis and assessment of CP. There are four modalities typically used to assess CP. Pancreatic duct features are assessed with magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP). However, ERCP is a rather invasive diagnostic modality for CP, and can result in adverse events such as post-ERCP pancreatitis. Computed tomography (CT) is often the most appropriate initial imaging modality for patients with suspected CP, and has high diagnostic specificity. However, CT findings typically only appear in advanced stages of CP, and it is difficult to detect early CP. Endoscopic ultrasonography (EUS) provides superior spatial resolution compared with other imaging modalities such as CT and magnetic resonance imaging (MRI), and is considered the most reliable and efficient diagnostic modality for pancreatic diseases. The EUS-based Rosemont classification plays an important role in diagnosing CP in clinical practice. Evaluation of tissue stiffness can be another option to assess the diagnosis and progression of CP, and MRI and EUS can be used to assess CP not only with imaging, but also with elasticity measurement. MR and EUS elastography are expected to provide new alternative diagnostic tools for assessment of fibrosis in CP, which is difficult to evaluate pathologically.

Role of endoscopic ultrasound elastography in differential diagnosis of pancreatic solid masses

Introduction: Endoscopic ultrasound (EUS) elastography is another technique that measures the stiffness of tissue and adds more diagnostic value to EUS. Objective: This study aimed to assess the ability of qualitative and quantitative EUS elastography in differentiating malignant from benign solid pancreatic masses. Methods: This 2-year cross-sectional study enrolled 80 patients with solid pancreatic masses in the department of endoscopy in Alassad University Hospital who underwent conventional and elastography-assisted EUS and then followed for pathology through EUS-guided or CT-guided biopsy or surgery. Results: Qualitative elastography using a 5-point scoring system was able to recognize malignant pathology (obtained by EUS-guided biopsy, CT-guided biopsy, or surgery) with a sensitivity, specificity, and accuracy rates of 100%, 28.6%, and 81.3%, respectively. A quantitative method using hue histogram had a sensitivity of 71.2%–86.4% and specificity of 71.4%–81% with the best accuracy for histogram mean ratio (area under the curve, 0.867). Conclusion: EUS elastography is a simple and good alternative method in differentiating malignant from benign pancreatic solid masses.

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-Guided Fine-Needle Aspiration (EUS-FNA) with Image Enhancement

Although endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is useful in the differential diagnosis of solid pancreatic lesions, lymph nodes, and liver lesions, inadequate sampling may result in an incorrect pathological diagnosis. The accuracy of EUS for the evaluation of pancreatobiliary lesions may be increased by image enhancement technologies, including contrast-enhanced harmonic (CH)-EUS and EUS-elastography. These methods can provide information that complement EUS-FNA for the diagnosis and staging of pancreatobiliary cancer, and can help to identify the EUS-FNA target, reducing the requirement for repeat FNA.

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.