Diagnostic Endoscopic Ultrasound in Pancreatology: Focus on Normal Variants and Pancreatic Masses.

Background: Endoscopic ultrasound (EUS) is a main tool in gastroenterology for both diagnosis and exclusion of pancreatic pathology. It allows minimally invasive assessment of various diseases or anatomic variations affecting the pancreas also with the help of new Doppler technologies, elastography, contrast-enhanced imaging including post hoc image processing with quantification analyses, three-dimensional reconstruction, and artificial intelligence. EUS also allows interventional direct access to the pancreatic parenchyma and the retroperitoneal space, to the pancreatic duct, pancreatic masses, cysts, and vascular structures. Summary: This review aimed to summarize new developments of EUS in the field of pancreatology. We highlight the role of EUS in evaluating pancreatic pathology by describing normal anatomic variants like pancreas divisum, pancreatic lipomatosis, pancreatic fibrosis in the elderly and characterizing pancreatic masses, both in the context of chronic pancreatitis and within healthy pancreatic parenchyma. EUS is considered the optimal imaging modality for pancreatic masses of uncertain dignity and allows both cytological diagnosis and histology, which is essential not only for neoplastic conditions but also for tailoring therapy for benign inflammatory conditions. Key Messages: EUS plays an indispensable role in pancreatology and the development of new diagnostic and interventional approaches to the retroperitoneal space and the pancreas exponentially increased over the last years. The development of computer-aided diagnosis and artificial intelligence algorithms hold the potential to overcome the obstacles associated with interobserver variability and will most likely support decision-making in the management of pancreatic disease.

Endoscopic Ultrasound in Pancreatology: Focus on Inflammatory Diseases and Interventions.

Background: Endoscopic ultrasound (EUS) is a main tool in pancreatology for both diagnosis and therapy. It allows minimally invasive differentiation of various diseases, with a minimal degree of inflammation or anatomic variations. EUS also enables interventional direct access to the pancreatic parenchyma and the retroperitoneal space, the pancreatic duct, the pancreatic masses, cysts, vascular structures for diagnostic and therapeutic purposes. Summary: This review aimed to summarize the new developments of EUS in the field of pancreatology, with special interest on inflammation and interventions. EUS enables way to perform pseudocyst drainage, necrosectomy, transenteral drainage and transenteric access of the main pancreatic duct, or the direct visualization or therapy of vascular structures adjacent to the pancreas. Key Messages: EUS has a deep impact on pancreatology, and the development of new diagnostic and interventional approaches to the retroperitoneal space and the pancreas has increased in the last years exponentially, allowing minimal invasive diagnostics and therapy and avoiding surgery and percutaneous therapy.

[Contrast-Enhanced Ultrasound of Fibrolamellar Hepatocellular Carcinoma]. / Kontrastmittelsonografie eines fibrolamellären hepatozellulären Karzinoms.

We present the case of a 24-year-old male patient, who was admitted for endoscopy due to sustained pain in the upper abdomen with nausea and postprandial fullness without vomiting for more than 5 months. In the physical examination, an epigastric induration was found. Endoscopy revealed an external impression of the proximal duodenum. Beyond that, normal findings could be ascertained in gastroscopy and ileo-colonoscopy. Abdominal ultrasound identified a large hypoechoic lesion in the left liver lobe with a sharp delineation. Along the upper mesenteric vessels, enlarged lymphnodes were visible with contact to the proximal duodenum. Contrast-enhanced ultrasound (CE-US) was conducted and revealed the typical perfusion pattern of hepatocellular carcinoma. For further assessment, an ultrasound-guided core-biopsy of the lesion was performed. The histopathological evaluations resulted in the diagnosis of a hepatocellular carcinoma of fibrolamellar subtype.With the present case, we want to illustrate the perfusion pattern of a fibrolamellar hepatocellular carcinoma in contrast-enhanced ultrasound. Even though the tumor tissue is surrounded by lamellar bands of fibrosis with collagen-rich fibers, the perfusion pattern is consistent with the previously known appearance of HCC in CE-US.

Transabdominal ultrasonography for confirmation of accurate percutaneous endoscopic gastrostomy tube placement: analysis of patient- and procedure-related complications.

AIMS: Technique-related factors, patient-related factors, and localization determine the risk for complications in percutaneous endoscopic gastrostomy (PEG) tube placement. The objective of this study was to identify patient characteristics and ultrasonographic parameters after PEG tube placement concerning localization, which correlate with complications. MATERIAL AND METHODS: Patients undergoing PEG-tube placement were examined by abdominal ultrasound after dismissal from the endoscopic recovery room. Patient demographics, PEG characteristics, ultrasonographic parameters and complications were retrospectively analyzed. RESULTS: Of 64 enrolled patients, 59.4% were male and the mean age was 62.3 years. A significant negative correlation between complications at PEG placement and Body-Mass-Index (BMI; kg/m2) was observed (Spearman's Rho: -0.382; p=0.002). A low BMI <18 tended to be more frequent in the group with complication-related PEG removal compared to patients without (18.2% vs. 1.9%). Further descriptive analysis revealed that 4 patients (36.4% of N=11) with and 5 patients (9.4% of N=53) without PEG removal due to complications already had complications at the time of PEG placement. Of the patients with complications during follow-up, those with a peritoneal course (N=10) in ultrasound tended to have a lower BMI (mean ± standard deviation: 22.5±6.5 vs. 26.8±5.9) compared to those without (N=5). In all 4 patients with a triad of follow-up complications, peritoneal course, and complications at PEG placement, the tube was removed due to complications. CONCLUSIONS: Post-PEG-placement ultrasonography can help to determine complications in specific procedure-related conditions. A low BMI was found to be a relevant predictor of PEG-related complications, substantiating the need for early intervention in potentially PEG-relevant indications.

Assessment of sorafenib induced changes in tumor perfusion of uveal melanoma metastases with dynamic contrast-enhanced ultrasound (DCE-US).

PURPOSE: Dynamic contrast-enhanced ultrasound (DCE-US) was used to monitor early response to sorafenib therapy in patients with liver metastases from uveal melanoma. METHODS: In total, 21 patients with liver metastases were recruited within a prospective trial and underwent daily sorafenib therapy. DCE-US of a target lesion was performed before initiation of treatment, on day 15 and 56. Two independent blinded investigators performed software analysis for DCE-US parameters and inter-observer-correlation was calculated. Response to treatment was evaluated on day 56. DCE-US parameters were correlated with clinical response and RECIST1.1 criteria. RESULTS: Inter-observer-correlation (r) of DCE-US parameters [time-to-peak (TTP), mean-transit-time (MTT), peak intensity (PI), regional blood volume (RBV), regional blood flow (RBF)] at baseline, day 15, and day 56 was highly significant (r-range 0.73-0.97, all p < 0.001). Out of 17 evaluable patients, 12 patients survived day 56 (clinical responders, cRE), whereas, five patients died before day 56 and were classified as non-responders (cNR). TTP values significantly increased in the cRE group 15 days after initiation of treatment for investigator 1 (p = 0.034) and at day 56 for both investigators (p = 0.028/0.028). MTT had increased significantly in the cRE group on day 56 (p = 0.037/0.022). In the cNR group changes for TTP and MTT remained insignificant. Thus, increase of the DCE-US parameters TTP and MTT are associated with response to treatment and prognosis. CONCLUSION: An increase of TTP and MTT at frequent intervals could serve as a surrogate marker for early response evaluation to anti-angiogenic treatment of metastatic uveal melanoma.

Bowel wall thickening and hyperemia assessed by high-frequency ultrasound indicate histological inflammation in Crohn's ileitis.

PURPOSE: We evaluated ileal bowel wall thickness and semiquantitative vascularization by ultrasound in correlation with the presence or absence of histopathological inflammation in patients with Crohn's disease (CD). METHODS: We conducted a retrospective analysis of 221 ultrasound examinations of the terminal ileum or neoterminal ileum in CD patients with biopsies of the ileum during colonoscopies within 8 weeks of the ultrasound. Ultrasound data were obtained from an inflammatory bowel disease ultrasound register from 2011 to 2017. Bowel wall ultrasound was performed by a high-frequency, linear transducer (7-12 MHz). Presence of bowel wall thickening (> 3 mm), vascularization by the Limberg score, and presence of ileal histopathological inflammation were analyzed. RESULTS: In 221 bowel wall ultrasound examinations of CD patients (128 female, 93 male, mean age 37.5 years), a thickened bowel wall was found in 140 (63.3%) and hypervascularization (corresponding to a Limberg score ≥ 2) in 96 (43.4%) cases. In 187 (84.6%) cases, ileal inflammation was confirmed by histopathology and in 34 (15.4%) cases no inflammation was shown. Bowel wall thickening showed a sensitivity of 70.1%, a negative predictive value (NPV) of 30.9%, a specificity of 73.5% and a positive predictive value (PPV) of 93.6% for the detection of histopathological ileal inflammation. Hypervasularization had a low sensitivity (49.7%) and NPV (24.8%), but high specificity (91.2%) and PPV (96.9%). CONCLUSION: In this CD subcohort of an ultrasound register, pathologic ultrasound findings were quite common. Bowel wall thickening (> 3 mm) and hypervascularization are good predictors of histopathological inflammation within the terminal ileum or neoterminal ileum. Normal ultrasound findings without bowel wall thickening and without hypervascularization do not rule out histopathological inflammation.

Acoustic Radiation Force Impulse (ARFI) Elastography in Autoimmune and Cholestatic Liver Diseases.

INTRODUCTION: Acoustic Radiation Force Impulse (ARFI) elastography evaluates hepatic fibrosis non-invasively and has been mainly validated in viral hepatitis. Data on rare liver diseases such as autoimmune hepatitis (AIH), overlap syndrome, primary biliary cholangitis (PBC) or primary sclerosing cholangitis (PSC) are sparse. MATERIAL AND METHODS: 85 patients (including 31 AIH, 26 PBC, 16 PSC and 3 PSC-and 9 PBC-AIH-overlap syndromes) were retrospectively analysed pointing at ARFI elastography of the liver and the correlation with histologic Ishak fibrosis score (F0-6). Results of shear wave velocities (m/s) were expressed as mean ± standard deviation. RESULTS: The mean shear wave velocity of all 85 patients showed 1.80 ± 0.84 m/s (0.74-3.98). The ARFI elastography values correlated with the degree of fibrosis in all patients overall and in patients with AIH, overlap syndrome and PSC, respectively. The subgroup of 26 patients with PBC (only with Ishak F > 3) revealed no correlation between ARFI and these early fibrosis stages (r = 0.019, p = 0.927). ARFI elastography correlated with bilirubin, AST, but not with patient age, body mass index or measurement depth. The cut-off of 2.04 m/s for detecting cirrhosis (Ishak F > 5) leads to a sensitivity of 90.0% and specificity of 74.7% (AUROC 87.2%). CONCLUSION: ARFI elastography can evaluate fibrosis in AIH, PSC and PSC-/PBC-AIH-overlap syndrome with good accuracy for the detection of hepatic cirrhosis. Shear wave velocities in PBC should be interpreted with caution in early stages of fibrosis.

Acoustic radiation force impulse (ARFI) shear wave elastography of the bowel wall in healthy volunteers and in ulcerative colitis.

BACKGROUND: Acoustic radiation force impulse (ARFI) elastography is a non-invasive, ultrasound-based approach of evaluation of tissue elasticity. It has not yet been systematically applied to the bowel wall. PURPOSE: To perform ARFI elastography of the bowel wall in healthy volunteers and patients with ulcerative colitis (UC). MATERIAL AND METHODS: A high-frequency ultrasound (with bowel wall thickness and vascularization score) and an ARFI elastography of the bowel wall were performed in 20 patients with UC and 13 healthy volunteers. At least 10 ARFI measurements were obtained within the terminal ileum and the ascending, transverse, descending, and sigmoid colon and correlated with results of high-frequency ultrasound. RESULTS: The UC group had mostly moderate disease activity. All patients had signs of inflammation upon B-mode ultrasound. Eight patients showed an ulcerative (ileo)pancolitis. Overall, ARFI elastography values and wall thickness were higher in the UC group than in the group of healthy volunteers (P = 0.021 and P < 0.001, respectively). ARFI velocities of the separate segments were significantly higher in the transverse (P = 0.045) and sigmoid colon (P = 0.032) in case of UC. CONCLUSION: ARFI elastography of the bowel wall of the colonic frame and the terminal ileum is feasible but shows high standard deviation. ARFI shear wave velocities appear to be slightly higher in patients with UC than in healthy volunteers, particularly in the sigmoid and transverse colon. Further studies are needed.

Differentiation of malignant liver tumors by software-based perfusion quantification with dynamic contrast-enhanced ultrasound (DCEUS).

BACKGROUNDEnhancement patterns on contrast-enhanced ultrasound (CEUS) help to distinguish different liver tumors. OBJECTIVE: Assessing the diagnostic value of dynamic contrast-enhanced ultrasound (DCEUS) for the discrimination of different malignant liver lesions. METHODS: 148 malignant focal liver lesions were assessed prospectively with DCEUS (hepatocellular carcinoma = HCC; cholangiocellular carcinoma = CCC; pancreatic adenocarcinoma = PCA; breast cancer = BC; colorectal cancer = CRC; melanoma = MM). Focal-nodular-hyperplasias (FNH) served as a reference for benign lesions. DCEUS-clips were recorded continuously over three minutes. DCEUS-values were compared between the tumor entities. For better inter-individual comparability, perfusion kinetics were analyzed considering the perfusion characteristics of the surrounding liver parenchyma (Relative Signal Intensity = RSI: lesion-liver tissue/liver tissue) at different points in time. RESULTS: Absolute signal intensity in FNH showed a tendency towards higher values compared with malignant liver lesions [Peak Enhancement(a.u.): FNH 7111.4; HCC 549.9; CCC -6654.3; PCA -7307.9; BC -4562.4; CRC -10672.9; MM -3034.1]. Washout was significantly less in FNH versus PCA and CRC, and more pronounced and earlier in PCA and CRC versus HCC [RSI 30 seconds after PE-lesion(%): FNH +52; PCA -65; CRC -76; HCC -26]. Rise Time, Fall Time and mean-Transit-Time did not differ significantly. CONCLUSIONS: DCEUS-values reflect significant differences between malignant liver lesions, especially at peak enhancement and during the washout phases.

The importance of pancreatic inflammation in endosonographic diagnostics of solid pancreatic masses.

AIMS: Endosonography (EUS) is one of the main diagnostic tools for the differential diagnosis of pancreatic masses. The aim of our study was to describe the value of this technique in the work-up of solid pancreatic lesions, considering the influence of the morphological evidence of pancreatic inflammation in the diagnostic process. MATERIAL AND METHODS: Retrospective analysis of prospectively collected data in our tertiary University center. From March 2007 to October 2015, 218 patients underwent EUS for a suspected solid pancreatic neoplasm (based on previous cross-sectional imaging results, idiopatic acute pancreatitis, weight loss, pancreatic hyperenzymemia, painless jaundice or elevated Ca 19-9 values). RESULTS: Malignant lesions were diagnosed in 98 (45%) patients. Sensitivity of EUS for malignancy was 91% and specificity 89.2%. Signs of pancreatic inflammation in the surrounding pancreatic parenchyma around the focal lesion were present in 97 patients (44.4%)(more often in men, smokers and drinkers, and the most common etiology was focal chronic pancreatitis) and in these patients the sensitivity and sensibility dropped to 44% and 87.1%, respectively. In patients without signs of pancreatic inflammation, the pancreatic focal lesions were adenocarcinoma, neuroendocrine tumor, ventral/dorsal split, non-pancreatic pathology, pancreatic lipomatosis and autoimmune pancreatitis. CONCLUSION: Pancreatic inflammation (either focal or involving the whole gland) lowers the diagnostic sensibility of EUS in the work- up of pancreatic masses suspected for cancer, requiring further invasive diagnostic methods. Focal autoimmune pancreatitis and paraduodenal pancreatitis are still confused with pancreatic cancer, even in the absence of pancreatic inflammation.

Quantitative contrast-enhanced ultrasound for monitoring vedolizumab therapy in inflammatory bowel disease patients: a pilot study.

Background Microvascularization of the bowel wall can be visualized and quantified non-invasively by software-assisted analysis of derived time-intensity curves. Purpose To perform software-based quantification of bowel wall perfusion using quantitative contrast-enhanced ultrasound (CEUS) according to clinical response in patients with inflammatory bowel disease treated with vedolizumab. Material and Methods In a prospective study, in 18 out of 34 patients, high-frequency ultrasound of bowel wall thickness using color Doppler flow combined with CEUS was performed at baseline and after 14 weeks of treatment with vedolizumab. Clinical activity scores at week 14 were used to differentiate between responders and non-responders. CEUS parameters were calculated by software analysis of the video loops. Results Nine of 18 patients (11 with Crohn's disease and seven with ulcerative colitis) showed response to treatment with vedolizumab. Overall, the responder group showed a significant decrease in the semi-quantitative color Doppler vascularization score. Amplitude-derived CEUS parameters of mural microvascularization such as peak enhancement or wash-in rate decreased in responders, in contrast with non-responders. Time-derived parameters remained stable or increased during treatment in all patients. Conclusion Analysis of bowel microvascularization by CEUS shows statistically significant changes in the wash-in-rate related to response of vedolizumab therapy.

Contrast-Enhanced Ultrasound as a New Investigative Tool in Diagnostic Imaging of Muscle Injuries-A Pilot Study Evaluating Conventional Ultrasound, CEUS, and Findings in MRI.

OBJECTIVE: To emphasize the diagnostic value of contrast-enhanced ultrasound (CEUS) in the imaging of muscle injuries with different degrees of severity by comparing findings to established imaging modalities such as conventional ultrasound and magnetic resonance imaging (MRI). DESIGN: Case series. SETTING: Institutional study. Conventional ultrasound and CEUS were performed in the Department of Internal Medicine. Magnetic resonance imaging was carried out in the Department of Radiology within the Magnetom Avanto 1.5T and Magnetom Skyra fit 3T (Siemens Healthineers, Erlangen, Germany) and in the Institution of Imaging Diagnostics and Therapy (Magnetom Avanto 1.5T; Siemens, Erlangen, Germany). PATIENTS: Fifteen patients who underwent an acute muscle injury were recruited. MAIN OUTCOME MEASURES: The appearance and detectable size of muscle injuries were compared between each imaging modality. The injuries were assessed by 3 independent observers and blinded between imaging modalities. RESULTS: All 15 injuries were identified on MRI and CEUS, whereas 10 injuries showed abnormalities in conventional ultrasound. The determination and measurement revealed significant differences between conventional ultrasound and CEUS depending on injury severity. Contrast-enhanced ultrasound revealed an impairment of microcirculation in grade I lesions (corresponding to intramuscular edema observed in MRI), which was not detectable using conventional ultrasound. CONCLUSIONS: Our results indicate that performing CEUS seems to be a sensitive additional diagnostic modality in the early assessment of muscle injuries. Our results highlight the advantages of CEUS in the imaging of low-grade lesions when compared with conventional ultrasound, as this was the more accurate modality for identifying intramuscular edema.

Application of Acoustic Radiation Force Impulse Elastography in Imaging of Delayed Onset Muscle Soreness: A Comparative Analysis With 3T MRI.

CONTEXT: Delayed onset muscle soreness is one of the most common reasons for impaired muscle performance in sports and is associated with reduced muscle strength and frequently observed both in professional and recreational athletes. OBJECTIVE: To emphasize the diagnostic value of acoustic radiation force impulse (ARFI) in imaging of delayed onset muscle soreness by comparing findings with high-resolution 3T magnetic resonance imaging T2-weighted sequences. DESIGN: Case series. SETTING: Laboratory environment. PARTICIPANTS: Fifteen healthy students (7 females and 8 males; mean [SD]: age 24 [4] y, height 178 [10] cm, body weight 67 [12] kg). MAIN OUTCOME MEASURES: ARFI values, represented as shear wave velocities of the gastrocnemius muscle and soleus muscle, as well as conventional ultrasound, high-resolution 3T magnetic resonance imaging, creatine kinase activity, extension range of the ankle joint, calf circumference, and muscle soreness were assessed before (baseline) and 60 hours after (postintervention) a standardized eccentric exercise. RESULTS: ARFI shear wave velocity values of the gastrocnemius muscle revealed a statistically significant decrease of 19.1% between baseline (2.2 [0.26] m/s) and postintervention (1.78 [0.24] m/s); P = .01. At follow-up, the magnetic resonance imaging investigations showed intramuscular edema for the gastrocnemius muscle in all participants corresponding to a significant raise in T2 signal intensity (P = .001) and in T2-time values (P = .004). CONCLUSIONS: ARFI elastography seems to be an additional sensitive diagnostic modality in the diagnostic workup of delayed onset muscle soreness. Intramuscular shear wave velocities could represent an additional imaging marker for the assessment and monitoring of ultrastructural muscle injuries and therefore be helpful for individual training composition in elite sports.

Intramuscular Perfusion Response in Delayed Onset Muscle Soreness (DOMS): A Quantitative Analysis with Contrast-Enhanced Ultrasound (CEUS).

The purpose of this study was to analyse intramuscular perfusion response in ultrastructural muscle lesions, by applying contrast-enhanced ultrasound (CEUS) to a delayed onset muscle soreness (DOMS) model. Results of this analysis were compared to high-resolution 3 Tesla MRI T2-weighted sequences. 14 healthy participants were recruited. Average perfusion parameters, represented as Peak enhancement (contrast agent inflow) and wash-in area under curve (WiAUC) of the gastrocnemius (GM) and soleus muscle (SM) were assessed before (baseline) and 60 h after inducing DOMS by eccentric exercise. Additionally, conventional ultrasound, high-resolution 3T MRI, creatine kinase level, range of motion (ROM) of the ankle joint, calf circumference and muscle soreness data were collected. Perfusion quantification revealed a statistically significant increase of intramuscular perfusion, corresponding to an increase in peak enhancement of 129.6% (p=0.0031) and in WiAUC of 115.2% (p=0.0107) in the gastrocnemius muscle at post-intervention. At follow-up, the MRI investigations showed intramuscular oedema for GM in all participants corresponding to a significant rise in T2 signal intensity (p=0.001) and in T2 time value (p=0.005). CEUS seems to be able to detect intramuscular perfusion changes and therefore may contribute to gaining deeper insight into the histopathology, inflammatory reactions and regeneration processes of ultrastructural muscle lesions.

Pancreatic Panniculitis and Polyarthritis.

PURPOSE OF REVIEW: Polyarthritis can have numerous reasons and may thus constitute a challenge for differential diagnosis. One rare potential reason for sterile polyarthritis is underlying pancreatic disease with systemic hyperlipasemia, most often accompanied by painful skin lesions caused by a subcutaneous inflammatory process known as panniculitis. Systematic evidence on pancreatic panniculitis and polyarthritis is limited, particularly regarding its feature as facultative paraneoplasia with underlying intra- or even extra-pancreatic malignancy. Therefore, we will summarize the current knowledge about this orphan disease including epidemiological, pathophysiological, diagnostic, and treatment aspects in the present review. RECENT FINDINGS: Although direct evidence is lacking, it is highly probable that pancreatic polyarthritis and panniculitis are caused by peripheral lipolytic activity of lipase systemically circulating due to benign (e.g., acute or chronic pancreatitis) or malign (e.g., acinar cell carcinoma (ACC) or adenocarcinoma) pancreatic disease. In the latter case, pancreatic polyarthritis and panniculitis are associated with poor outcome. Pancreatic polyarthritis and panniculitis should always be included into diagnostic considerations, and once suspected, a thorough work-up to identify the underlying disease has to be performed.

Dynamics of Fukuoka Criteria and Patient Management in Pancreatic Intraductal Papillary Mucinous Neoplasms (IPMNs) During Follow-Up.

BACKGROUND Pancreatic intraductal papillary mucinous neoplasms (IPMNs) present a clinical challenge. Evidence-based guidelines are lacking. The so-called "Fukuoka criteria" were developed to assess the risk of malignancy in IPMNs upon imaging. However, little is known about their diagnostic value and the natural course of IPMNs. Thus, the aim of this study was the assessment of Fukuoka criteria and patient management in pancreatic IPMNs -during follow-up. MATERIAL AND METHODS IPMNs were identified via retrospective survey of endoscopic ultrasound (EUS) examinations. Fukuoka criteria were assessed on EUS findings and additional imaging (CT, MRI, ultrasound). Patients' symptoms and comorbidities were recorded. Dynamics of Fukuoka criteria and patient management were compared at first presentation and during follow-up. RESULTS We screened 1324 EUS examinations. Sixty-five patients (male/female, 14/37; mean age, 68.8 years; range, 48-85 years) with IPMNs were identified (57 branch duct (BD-)IPMNs, 3 main duct (MD-) IPMNs, 5 mixed-type (MT)-IPMNs). Seven patients received surgical resection (4 BD-IPMNs, 2 MD-IPMNs, 1 MT-IPMN). Nine BD-IPMNs had neither surgery nor follow-up. Fifty-one patients (44 BD-IPMNs, 2 MD-IPMNs, 5 MT-IPMNs) underwent follow-up (mean duration, 18.7 months; range, 3-139 months). There were 15/51 patients who were initially Fukuoka-positive. One MD-IPMN, 4/5 MT-IPMNs, and 13/44 BD-IPMNs showed progressive changes but were not resected due to patients' refusal or comorbidities. Four BD-IPMNs converted to Fukuoka-positive. CONCLUSIONS Evidence-based guidelines for non-invasive dignity assessment of IPMNs are lacking. In our study, MD-IPMNs displayed greater dynamics than BD-IPMNs and MT-IPMNs concerning Fukuoka criteria. Prospective long-term studies are needed to clarify prognostic significance of the single Fukuoka criteria and sensible duration of follow-up.

Two-dimensional shear-wave elastography: a new method comparable to acoustic radiation force impulse imaging?

OBJECTIVES: Two-dimensional shear-wave elastography (2D-SWE) is an ultrasound-based technique for the noninvasive assessment of tissue stiffness. In contrast to the well-established point-shear-wave elastography (pSWE) method acoustic radiation force impulse imaging, there is little evidence on the performance and usefulness of 2D-SWE in the assessment of liver stiffness. Thus, the aim of our study was to compare 2D-SWE versus pSWE. MATERIALS AND METHODS: 2D-SWE and pSWE were performed in 20 cirrhotic patients, 20 healthy individuals and an elasticity phantom. Stiffness values, examination time and number of measurements were compared. For 2D-SWE, the influence of size of the region of interest (ROI) was assessed. RESULTS: Elastography values in healthy individuals were slightly higher for 2D-SWE versus pSWE (1.4 m/s, range: 1.21-1.68 vs. 1.23 m/s, range: 1.07-1.39). In cirrhotic patients, there were no significant differences (3.06 m/s, range: 1.83-5.35 vs. 3 m/s, range: 1.67-4.37 m/s). Examination times were significantly longer for 2D-SWE in both patient groups (mean values for healthy/cirrhotic patients: 129.6/157.1 vs. 75/71.6 s). For 2D-SWE, variation of ROI size (5, 10, 20 mm) produced comparable results. After eight measurements, 90% of cirrhotic patients showed less than 5% of deviation from the results after the gold standard of 10 measurements; for healthy individuals, this was observed after six measurements. CONCLUSION: 2D-SWE seems to be comparable to pSWE (acoustic radiation force impulse-imaging) in cirrhotic patients, with slightly higher values in healthy individuals. 2D-SWE measurements require considerably more time. For 2D-SWE, ROI size seems to be of minor importance; multiple measurements should be obtained as single measurements differ. These preliminary results should be confirmed in larger patient collectives with histology as the reference standard.

Acoustic radiation force impulse elastography: comparison and combination with other noninvasive tests for the diagnosis of compensated liver cirrhosis.

BACKGROUND AND AIMS: The aim of this study was to compare acoustic radiation force impulse (ARFI) elastography with other noninvasive tests and to develop a new score for the assessment of liver fibrosis/cirrhosis. MATERIALS AND METHODS: B-mode ultrasound (including high-frequency liver surface evaluation), routine blood tests, ARFI quantification, and mini-laparoscopic liver evaluation were obtained in compensated patients scheduled for mini-laparoscopic biopsy. Our new cirrhosis score (CS) for the assessment of liver cirrhosis, based on a linear combination of ARFI, platelet (PLT), liver surface, and prothrombin index (PI), was calculated by linear discriminant analysis. Its performance was compared with ARFI-elastography, APRI, FIB-4, alanine aminotransferase (ALT)/aspartate aminotransferase (AST)-ratio, PLT, and PI. For the diagnosis of cirrhosis, a combined gold standard (cirrhosis at histology and/or at macroscopic liver evaluation) was used. RESULTS: In total, 171 patients, of whom 38 had compensated cirrhosis, were included. The CS was significantly better for the diagnosis of cirrhosis compared with ARFI (P=0.028), APRI (P=0.012), PLTs (P=0.013), PI (P=0.025), and ALT/AST ratio (P=0.001), but not the FIB-4 score (P=0.207), with an area under the receiver operating characteristic curve of 0.92 [95% confidence interval (CI): 0.87-0.97], 0.86 (95% CI:0.79-0.93), 0.80 (95% CI: 0.72-0.87), 0.79 (95% CI: 0.7-0.87), 0.81 (95% CI: 0.73-0.89), 0.72 (95% CI:0.64-0.81), and 0.86 (95% CI: 0.8-0.93), respectively. Sensitivity, specificity, positive predictive value, and negative predictive value for CS were 87%, 86%, 63%, and 96%, respectively. The FIB-4 score was significantly superior to the APRI score (P=0.041) and the ALT/AST ratio (P=0.011), with no significant difference from ARFI elastography (P=0.88) for the diagnosis of cirrhosis. CONCLUSION: Combining ARFI elastography with other noninvasive tests that are used routinely in the workup of patients with suspected liver disease can improve diagnostic accuracy for compensated liver cirrhosis as compared with ARFI elastography alone. The FIB-4 score showed an overall comparable diagnostic accuracy to ARFI-elastography for compensated cirrhosis.

Acoustic radiation force impulse shear wave elastography (ARFI) of acute and chronic pancreatitis and pancreatic tumor.

INTRODUCTION: Acoustic Radiation Force Impulse (ARFI) elastography evaluates tissue stiffness non-invasively and has rarely been applied to pancreas examinations so far. In a prospective and retrospective analysis, ARFI shear wave velocities of healthy parenchyma, pancreatic lipomatosis, acute and chronic pancreatitis, adenocarcinoma and neuroendocrine tumor (NET) of the pancreas were evaluated and compared. MATERIAL AND METHODS: In 95 patients ARFI elastography of the pancreatic head, and also of the tail for a specific group, was analysed retrospectively. Additionally, prospectively in 100 patients ARFI was performed in the head and tail of the pancreas. RESULTS: A total of 195 patients were included in the study. Healthy parenchyma (n=21) and lipomatosis (n=30) showed similar shear wave velocities of about 1.3m/s. Acute pancreatitis (n=35), chronic pancreatitis (n=53) and adenocarcinoma (n=52) showed consecutively increasing ARFI values, respectively. NET (n=4) revealed the highest shear wave velocities amounting to 3.62m/s. ARFI elastography showed relevant differences between acute pancreatitis and chronic pancreatitis or adenocarcinoma. With a cut-off value of 1.74m/s for the diagnosis of a malignant disease the sensitivity was 91.1% whereas the specificity amounted to 60.4%. CONCLUSION: ARFI shear wave velocities present differences in various pathologies of the pancreas. Acute and chronic pancreatitis as well as neoplastic lesions show high ARFI values. Very high elasticity values may indicate malignant disease of the pancreas. However, there is a considerable overlap between the entities.