Hepatic and pancreatic fat as imaging biomarkers of metabolic syndrome. / Valoración de la grasa hepática y pancreática como biomarcadores de imagen en el síndrome metabólico.

OBJECTIVE: To objectively evaluate hepatic and pancreatic involvement in metabolic syndrome through magnetic resonance imaging (MRI) biomarkers. MATERIAL AND METHODS: From an initial retrospective sample of 407 patients diagnosed with metabolic syndrome studied by MRI in a single center during a 2-year period, 154 were excluded because of a lack of clinical and/or laboratory data, pancreatic abnormalities, or inadequate quality of MRI studies. To measure hepatic and pancreatic fat, we used chemical shift imaging (in-phase and out-of-phase), measuring the fat fraction (%) in regions of interest in the pancreas and liver. Associations between the fat fraction and selected clinical and laboratory variables were assessed with beta regression models. RESULTS: In the end, 253 patients were included. The hepatic fat fraction was 4.9% and the pancreatic fat fraction was 7.9%. We found no significant associations between the hepatic fat fraction and any of the clinical or laboratory variables. However, the pancreatic fat fraction was positively associated with age (OR=1.025, p<0.001) and baseline glucose (OR=1.005, p<0.001). Patients with diabetes had higher values of pancreatic fat fraction (OR=2.64, p=0.038). Pancreatic fat fraction and hepatic fat fraction were positively associated (OR=69.44, p<0.001). CONCLUSIONS: Pancreatic steatosis can be considered a marker of metabolic syndrome and diabetes. Quantitative MRI enables the diagnosis and grading of fatty pancreas through simple chemical shift techniques.

Magnetic resonance imaging: Proton density fat fraction for assessment of pancreatic fatty infiltration during progression of T2DM bama minipigs.

BACKGROUND: Recent studies have highlighted the correlation between diabetes and pancreatic fat infiltration. However, pancreatic fat content (PFC) is rarely confirmed by pathological results, and a change of PFC during progression of type 2 diabetes (T2DM) is currently controversial. PURPOSE: To evaluate the relationship of MRI-pancreatic proton density fat fraction to serologic changes and histology in an experimental model of diabetes. STUDY TYPE: Prospective animal study. ANIMAL MODEL: Thirteen Bama pigs were randomly assigned to diabetes (n = 7) or control (n = 6) groups. Pigs in the diabetic group received high-fat/high-sugar feed, combined with three doses of streptozotocin injections. FIELD STRENGTH/SEQUENCE: 3.0T, IDEAL-IQ sequence. ASSESSMENT: Starting in the fifth month, biochemical changes were evaluated; all pigs underwent axial MRI with the IDEAL-IQ sequence to measured pancreatic fat fraction (PFF). PFC was measured by the Soxhlet extraction method. Pancreatic fat distribution and pancreas islet morphology were observed by histopathology. STATISTICAL TESTS: A Mann-Whitney U-test, independent-samples t-test, Pearson correlation, Spearman correlation, single-measure intraclass correlation coefficient (ICC) were performed. RESULTS: During the development of T2DM, the PFF, weight, fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TCHO), low-density lipoprotein (LDL), and HOMA-IR (insulin resistance) of the experimental group showed an upward trend; fasting insulin (INS), high-density lipoprotein (HDL), and HOMA-ß showed decreasing trends. At the end of the fifteenth month, FBG (mmol/L) was 18.06 ± 6.03 and 5.06 ± 1.41 (P < 0.001), PFF (%) was 36.52 ± 4.07 and 27.75 ± 3.73 (P = 0.002), INS (mU/L) was 21.59 ± 2.93 and 29.32 ± 3.27 (P = 0.001), HOMA-IR was 16.83 ± 4.22 and 6.70 ± 2.45 (P < 0.001), HOMA-ß was 1.50 ± 0.24 and 2.77 ± 0.45 (P < 0.001), between the experimental and control groups. There were strong and moderate positive correlations between PFF and PFC (r = 0.968, P < 0.001), and FBG (r = 0.657, P = 0.015), and HOMA-IR (r = 0.608, P = 0.028). DATA CONCLUSION: MRI-proton density fat fraction can measure the fat content of the pancreas with great accuracy and repeatability; PFF is a potential biomarker that can reflect the different stages of diabetes development. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1905-1913.

Abbreviated MRI Protocols for the Abdomen.

Technical advances in MRI have improved image quality and have led to expanding clinical indications for its use. However, long examination and interpretation times, as well as higher costs, still represent barriers to use of MRI. Abbreviated MRI protocols have emerged as an alternative to standard MRI protocols. These abbreviated MRI protocols seek to reduce longer MRI protocols by eliminating unnecessary or redundant sequences that negatively affect cost, MRI table time, patient comfort, image quality, and image interpretation time. However, the diagnostic information is generally not compromised. Abbreviated MRI protocols have already been used successfully for hepatocellular carcinoma screening, for prostate cancer detection, and for screening for nonalcoholic fatty liver disease as well as monitoring patients with this disease. It has been reported that image acquisition time and costs can be considerably reduced with abbreviated MRI protocols, compared with standard MRI protocols, while maintaining a similar sensitivity and accuracy. Nevertheless, multiple applications still need to be explored in the abdomen and pelvis (eg, surveillance of metastases to the liver; follow-up of cystic pancreatic lesions, adrenal incidentalomas, and small renal masses; evaluation of ovarian cysts in postmenopausal women; staging of cervical and uterine corpus neoplasms; evaluation of müllerian duct anomalies). This article describes some successful applications of abbreviated MRI protocols, demonstrates how they can help in improving the MRI workflow, and explores potential future directions. ©RSNA, 2019.

One-day diagnosis for hepatobiliary and pancreatic lesions: An innovative patient-centered care pathway organization.

OBJECTIVE: Reducing the time required for diagnosis is one of the major challenges to improving and accelerating the management of patients. The aim of this work is to describe an organizational innovation in the management of patients with hepatobiliary or pancreatic diseases, and to report the initial results. MATERIALS AND METHODS: A multidisciplinary and multi-professional working group designed and instituted a patient-centered organizational system that optimizes the investigation of liver and pancreatic diseases, in order to achieve diagnosis in one day. From January 2017 to June 2017, all patients referred for consultation for hepatobiliary or pancreatic pathology were included in this new management pathway. Data were collected prospectively in a standardized form. RESULTS: Fifty-six patients with hepatobiliary or pancreatic disease were evaluated in the program during dedicated slots over a total of 20 days. Of these, four patients underwent evaluation in the program twice. The average number of patient slots in the program was three per day (range: 1-5). An additional computed tomography (CT) and/or magnetic resonance imaging (MRI) was required in 23 (41.7%) of the visits. These imaging studies were performed the same day, including nine patients who required both types of imaging (16.7% of cases). "One-day diagnosis" established an accurate diagnosis by the end of the day in 49 patient encounters (81.7%). Overall assessment of this organization was considered excellent by 46 (83%) of patients. CONCLUSION: An organizational innovation has made it possible to effectively diagnose hepatobiliary or pancreatic pathology within one day in the majority of cases, with good patient satisfaction. It is now necessary to evaluate the medico-economic aspect of this organization, and more generally to develop a methodology for multidimensional evaluation of organizational innovations.

Ultrasonographic Quantitative Analysis of Fatty Pancreas in Obese Children: Its Correlation with Metabolic Syndrome and Homeostasis Model Assessment of Insulin Resistance.

OBJECTIVES: To evaluate pancreatic echogenicity on transabdominal ultrasonography and the correlation of fatty pancreas with metabolic syndrome (MetS), as well as insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]). STUDY DESIGN: This retrospective study included 135 obese children and adolescents who underwent transabdominal ultrasonography from January 2015 to December 2015. Fatty pancreas was quantitatively analyzed using the pancreato-perihepatic fat index (PPHFI). The correlation between the PPHFI and HOMA-IR was analyzed, and multivariate logistic regression analysis was used to determine factors that were independently correlated with MetS. Receiver operating characteristic curve analysis was performed to determine the best cut-off value of the PPHFI for diagnosing MetS. RESULTS: The PPHFI and the HOMA-IR value were significantly higher in subjects with MetS than in those without MetS (P < .0001). The PPHFI also showed an association with the HOMA-IR value (r = 0.70; P <.0001). The PPHFI was an independent factor for diagnosing MetS (OR 4.36; P = .032). The best cut-off value for the PPHFI for a diagnosis of MetS was 2.34 with a sensitivity of 0.96 and specificity 0.70. CONCLUSIONS: These results suggest that an increased PPHFI is significantly correlated with MetS and insulin resistance, and that the PPHFI may be a useful indicator for diagnosing MetS in obese children and adolescents. The impact of the presence of fatty pancreas in obese children and adolescents must be evaluated.

The clinical value of secretin-enhanced MRCP in the functional and morphological assessment of pancreatic diseases.

Secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) provides a non-invasive way, with which, to evaluate pancreatic duct (PD) anatomy and exocrine pancreatic function. S-MRCP can be added to the routine pancreas MR examination in equivocal cases. Moreover, it can detect subtle PD involvement, allowing diagnosis of early, rather than end-stage, pancreatic diseases. Although S-MRCP is a valuable non-invasive diagnostic method, it is only performed in a few centres due to relative high cost. Furthermore, less familiarity with its indications, the examination technique, and image interpretation also contribute to its limited use. Thus, the purpose of this article is to explain secretin's mechanism of action, the examination technique, the clinically relevant indications, the advantages, and limitations. Finally, we will focus on image analysis and its role in achieving an early and accurate diagnosis of specific pancreatic and PD diseases.

Focal Cystic Pancreatic Lesion Follow-up Recommendations After Publication of ACR White Paper on Managing Incidental Findings.

PURPOSE: To describe the variation in radiologists' follow-up recommendations for focal cystic pancreatic lesions (FCPL) after publication of the 2010 ACR incidental findings White Paper and determine adherence to guidance of the ACR Incidental Findings Committee. METHODS: Institutional Review Board approval was obtained for this retrospective, HIPAA-compliant observational study. Patients with FCPL were identified from abdominal CT and MRI reports generated in 2013 using natural language processing software. Patient-, lesion-, and radiologist-specific variables were recorded. Primary outcome was whether a follow-up recommendation was made, and if it included a specific study or intervention and recommended time for follow-up. χ2 and logistic regression models were used to identify predictors and controlled for recommendation. These data were compared with 2009 data obtained before the White Paper's publication. Secondary outcome was adherence to the ACR's guidance. RESULTS: During calendar year 2013, 1,377 reports describing FCPLs were identified in 1,038 patients. After excluding examinations from low-volume readers (n = 80), radiologists recommended follow-up imaging in 13.5% (175/1,297) of cases, a decrease from 2009 when it was recommended in 23.7% (221/933) of cases (P < .001). Findings were consistent across radiologists after controlling for patient- and lesion-specific variables. Variability in follow-up recommendations persists between radiologists (2.4-fold difference in 2013 versus 2.8-fold difference in 2009). Radiologists adhered to ACR guidance principles 47.4% of the time. CONCLUSIONS: Despite published guidance recommendations and reported awareness of them, fewer than half of follow-up recommendations for FCPL are consistent with the guidance and considerable variability persists among radiologists.

[Assessment of amylase and lipase levels following puncture biopsy and fine needle aspiration guided by endoscopic ultrasound in pancreatic lesions]. / Evaluación de los niveles de amilasa y lipasa posterior a la realización de biopsia por aspiración con aguja fina guiada por ultrasonido endoscópico en lesiones del páncreas.

BACKGROUND: Puncture biopsy and fine needle aspiration guided by endoscopic ultrasound has been used as an effective technique and is quickly becoming the procedure of choice for diagnosis and staging in patients suspected of having pancreatic cancer. This procedure has replaced retrograde cholangiopancreatography and brush cytology due to its higher sensitivity for diagnosis, and lower risk of complications. OBJECTIVE: To assess the levels of pancreatic enzymes amylase and lipase, after the puncture biopsy and fine needle aspiration guided by endoscopic ultrasound in pancreatic lesions and the frequency of post-puncture acute pancreatitis. MATERIAL AND METHODS: A longitudinal and descriptive study of consecutive cases was performed on outpatients submitted to puncture biopsy and fine needle aspiration guided by endoscopic ultrasound in pancreatic lesions. Levels of pancreatic enzymes such as amylase and lipase were measured before and after the pancreatic puncture. Finally we documented post-puncture pancreatitis cases. RESULTS: A total of 100 patients who had been diagnosed with solid and cystic lesions were included in the study. Significant elevation was found at twice the reference value for lipase in 5 cases (5%) and for amylase in 2 cases (2%), none had clinical symptoms of acute pancreatitis. Eight (8%) of patients presented with mild nonspecific pain with no enzyme elevation compatible with pancreatitis. CONCLUSION: Pancreatic biopsy needle aspiration guided by endoscopic ultrasound was associated with a low rate of elevated pancreatic enzymes and there were no cases of post-puncture pancreatitis.

Pancreaticobiliary Juice Reflux in Patients With a Morphologically Normal Ductal System: Assessment Using Unenhanced MRI With Spin Labeling.

OBJECTIVE: The purpose of this article is to evaluate pancreaticobiliary reflux and to assess its correlation with clinical findings in patients without morphologic pancreaticobiliary maljunction by using a new MRI technique. MATERIALS AND METHODS: A total of 320 consecutive patients with suspected pancreaticobiliary diseases underwent MRCP and flow analysis by MRI. MRI flow analysis, clinical, and laboratory findings of each patient were retrospectively reviewed. The visible pancreaticobiliary reflux was graded on a 5-point confidence scale. RESULTS: Among all 320 patients with pancreatic juice reflux, 14.1% had reflux scored as grades 4 and 5 combined, and 5.0% had reflux scored as grade 5. By univariate analysis and multivariate analysis, a relatively long common channel was found to be the only significant causal factor for pancreatic juice reflux. Of patients with pancreatic juice reflux of grade 4 or 5, 11.1% (5/45) also had biliary malignancies; 18.8% (3/16) of those with pancreatic juice reflux of grade 5 had biliary malignancies. Conversely, pancreatic juice reflux of grade 4 or 5 occurred in 35.7% (5/14) of patients with biliary malignancies, and reflux of grade 5 occurred in 21.4% (3/14) of those patients. CONCLUSION: It was possible to evaluate pancreaticobiliary reflux using an MRI technique that may be suitable as a screening tool. Our results revealed that pancreaticobiliary reflux is relatively frequent in individuals without pancreaticobiliary maljunction.

Quantitative assessment of pancreatic fat by using unenhanced CT: pathologic correlation and clinical implications.

PURPOSE: To assess the relationship between computed tomographic (CT) indexes and histologically measured pancreatic fat in surgical specimens and to evaluate patients with impaired glucose metabolism in a clinical setting. MATERIALS AND METHODS: This retrospective study was institutional review board approved and informed consent was waived. The hospital database was searched for records from November 2008 to April 2009, and 62 patients (42 men and 20 women; mean age, 61.4 years; age range, 21-81 years) who underwent CT within 1 month before pancreatectomy were identified. The histologic pancreatic fat fraction (area ratio of fat to total tissue times 100%) was measured in nontumorous pancreatic tissue. Attenuation was measured in three regions of interest in the pancreas and the spleen on nonenhanced CT images. The difference between pancreatic and splenic attenuation and the pancreas-to-spleen attenuation ratio were calculated. Visceral fat area at the level of the umbilicus was measured on the CT images. Spearman correlation coefficients (ρ) were calculated to examine the correlation between the CT indexes or visceral fat area and the histologic pancreatic fat fraction. A multivariate logistic regression model was used to determine whether CT attenuation indexes and patient age, sex, and visceral fat correlated with impaired glucose metabolism (ie, impaired glucose tolerance, impaired fasting glucose, or presence of diabetes). RESULTS: The histologic pancreatic fat fraction ranged from 0% to 65.3% and was significantly correlated with the difference between pancreatic and splenic attenuation (ρ = -0.622, P < .01) and the pancreas-to-spleen attenuation ratio (ρ = -0.616, P < .01). The visceral fat area was not correlated with the histologic pancreatic fat fraction (ρ = 0.09, P = .50). The CT attenuation indexes were significant and independent variables predictive of impaired glucose metabolism after adjusting for age, sex, and visceral fat. CONCLUSION: Pancreatic fat can be quantified by using CT, and CT attenuation indexes that are applied to the quantification of pancreatic fat are significantly associated with clinical assessment of impaired glucose metabolism.

Pancreatic surgery: a multidisciplinary assessment of the value of intraoperative US.

PURPOSE: To assess the value of intraoperative ultrasonography (US) for different types of pancreatic surgery. MATERIALS AND METHODS: An institutional review board-approved, HIPAA-compliant retrospective review with waiver of informed consent was performed to evaluate all cases of pancreatic surgery with intraoperative US or laparoscopic US that occurred at a single institution during a 10-year period. Surgical notes, radiologic images, and clinical data for each surgical procedure and subsequent clinical course were reviewed by pancreatic surgeons and radiologists. Presumptive diagnosis, type of surgical procedure performed, and final pathologic data were recorded. A relative value score was established by consensus and assigned to each case with a grade of 0-3, which indicated the value of the intraoperative or laparoscopic US. The type of operation and pathologic data were compared in each of the value score groups. Categoric variables were compared by using either χ(2) or Fisher exact test. RESULTS: One hundred ninety-three intraoperative or laparoscopic US procedures were performed in 189 patients. Of the patients, there were 102 men and 87 women. The mean age was 57.8 years (range, 18-86 years). Intraoperative or laparoscopic US value scores were as follows: value score 0, 3.6%; value score 1, 11.9%; value score 2, 31.1%; and value score 3, 53.4%. The most common contribution that resulted in a high score (value score 3) was facilitation of technical performance of the surgery (n = 60). High value score was significantly associated with performance of pancreatitis-related surgery (P < .001). The surgical indication that most commonly resulted in a low value score of 0 or 1 was staging of pancreatic cancers. All cases that received a score of 0 occurred in the laparoscopic adenocarcinoma surgical setting (staging or pancreatic biopsy). CONCLUSION: Intraoperative or laparoscopic US can be a valuable procedure in multiple types of surgical procedures that involve the pancreas and shows clear patterns of value in the different types of surgery.

Tissue perfusion in pathologies of the pancreas: assessment using 128-slice computed tomography.

PURPOSE: Perfusion CT can provide information regarding blood perfusion and permeability in (tumor) tissues in a non-invasive manner. In this study, values of CT perfusion parameters in several pancreas pathologies were determined and compared to a control population. MATERIALS AND METHODS: Dynamic 128-slice perfusion CT was performed in patients admitted to the radiology department between June 2010 and March 2011. Included pathologies were pancreatic adenocarcinoma, acute and chronic pancreatitis, neuroendocrine tumors, and (pseudo)cystic lesions. Parametric mappings of blood flow, blood volume, and permeability surface area product were generated. RESULTS: Blood flow and blood volume were significantly lower in acute and chronic pancreatitis compared to the control group. In the center of adenocarcinoma tumors, low blood flow and blood volume was observed, gradually increasing toward the tumor rim; perfusion values in pancreatic parenchyma adjacent to the tumor were not significantly different from the control population. In neuroendocrine tumors, significantly increased perfusion values were observed. CONCLUSION: Compared to the control population, significant decreases in perfusion values were observed in all pancreatic pathologies under study, except in neuroendocrine tumors. Perfusion CT values can be used as an additional parameter to differentiate pancreatic pathologies.

Endoscopic ultrasound in the assessment of solid and cystic pancreatic lesions.

Pancreatic masses can be solid or cystic, benign or malignant. Rapid and accurate diagnosis is essential for optimal management. Clinical presentation and radiological appearance are often inadequate for a definitive diagnosis. Endoscopic ultrasound allows more detailed assessment of the pancreas than traditional imaging techniques.

Preoperative multidetector row computed tomography for evaluation and assessment of resection criteria in patients with pancreatic masses.

BACKGROUND: preoperative assessment of pancreatic masses is still challenging as regards the characterization and assessment of irresectability. The opportunities of modern multidetector computed tomography (MDCT) with image postprocessing can be expected to enhance the diagnostic performance if accurate criteria are elaborated. PURPOSE: to estimate the accuracy of MDCT and multiplanar image reconstructions with the use of standardized imaging criteria for preoperative evaluation of pancreatic masses with respect to irresectability. MATERIAL AND METHODS: a total of 105 consecutive patients who underwent exploratory laparoscopy or pancreatic resection and had preoperative 3-phase MDCT (4-64 rows) were enrolled retrospectively. First, transverse sections and secondly additional 3Ds were reviewed by two independent blinded observers (O1/O2). Preoperative imaging findings were correlated with intraoperative and histopathologic results. RESULTS: among all 105 patients, 70 malignant pancreatic tumors and 35 benign pancreatic diseases were found (accuracy of 93% for O1 and 91% for O2). For arterial tumor invasion, receiver operator characteristic (ROC) analysis (values averaged from the results of O1 and O2) revealed an area under the curve (AUC) of 0.931 for transverse sections and 0.986 for 3Ds. Regarding irresectability, positive predictive values were 97% (with 3Ds, 97%) for O1/O2; negative predictive values were 84% (with 3Ds, 89%) for O1 and 86% (with 3Ds, 91%) for O2. CONCLUSION: MDCT with 3Ds was highly accurate for evaluation and assessment of irresectability criteria in patients with pancreatic masses. However, due to the limited specificity regarding arterial tumor infiltration, the indication for surgical exploration should be made generously in case of inconclusive findings.

Pancreatic involvement in hereditary hemorrhagic telangiectasia: assessment with multidetector helical CT.

PURPOSE: To evaluate and describe pancreatic involvement by using multidetector computed tomography (CT) in patients with a diagnosis of hereditary hemorrhagic telangiectasia (HHT). MATERIALS AND METHODS: Institutional review board approval was obtained, and all patients provided informed consent. Across 12 months, all consecutive adult patients with a confirmed diagnosis of HHT referred to our pluridisciplinary HHT center for evaluation were enrolled prospectively in the study and underwent contrast material-enhanced multidetector CT of the abdomen. Pancreatic telangiectases and arteriovenous fistulas were noted, and their characteristics were described. Genetic mutation was also investigated. RESULTS: Thirty-five patients (19 women, 16 men; mean age, 48.4 years) were included. All patients were asymptomatic. A genetic mutation was identified in 28 (80%) patients, including endoglin in 16 (57%), activin type-II-like receptor kinase 1 (ALK1) in 11 (39%), and SMAD4 in one (4%). Eleven (31%) patients exhibited pancreatic involvement. Fifty-four percent of patients with ALK1 mutation had pancreatic involvement. Twenty-three pancreatic telangiectases were identified during the arterial phase in nine patients. Seven pancreatic arteriovenous malformations (AVMs) were identified in four patients. CONCLUSION: Pancreatic involvement commonly is found in patients with HHT (31% in our study), mainly in patients with ALK1 mutation; pancreatic telangiectases or AVMs are only diagnosed duringthe arterial phase at multidetector CT.

Clinicians' attitudes towards endoscopic ultrasound: a survey of four European countries.

OBJECTIVE: Despite the documented effectiveness of endoscopic ultrasound (EUS) in research studies, data on the utilization of this technology in clinical practice are scarce. The aim of this study was to assess EUS availability and accessibility as well as EUS utilization among clinicians from different European countries. MATERIAL AND METHODS: A direct mail survey was sent to members of the national gastroenterological associations in Sweden, Norway, Greece, and the United Kingdom. RESULTS: Out of 2361 clinicians with valid addresses, 593 (25.1%) responded. Overall, EUS was available to 43% of clinicians within their practice but availability varied from 23% in Greece to 56% in the United Kingdom. More than 50% of respondents evaluating patients with esophageal cancer, rectal cancer, or pancreaticobiliary disorders had utilized EUS during the previous year, but utilization varied considerably among different countries, being more frequent in the United Kingdom. In logistic regression analyses, factors independently related to EUS utilization were mainly EUS availability and accessibility as well as perceived utility of EUS (p <0.05 for all). Respondents considered the lack of trained endosonographers (79%) and high cost (52%) as the main barriers to wider EUS use. CONCLUSIONS: The majority of responding clinicians use EUS but overall utilization varies considerably among different countries. There is considerable variation in EUS service availability and accessibility among countries which, together with perceived usefulness of EUS, is a major determinant of EUS utilization. A shortage of trained endosonographers and the high cost are major barriers to wider EUS use. The findings of this study might help to define policies aimed at development of EUS services.

Prospective, randomized comparison of mechanical and electronic radial endoscopic ultrasound systems: assessment of performance parameters and image quality.

OBJECTIVE: Implementation of electronic image technology in endoscopic ultrasonography (EUS) should improve image quality, but systematic data are scarce. The purpose of this study was to compare the image quality and performance of an electronic and a mechanical radial echoendoscope. MATERIAL AND METHODS: Eighty consecutive patients (42 M, mean age 56 years) in a tertiary referral center, without gross pathology (advanced tumors excluded), were prospectively randomized to EUS with the mechanical or electronic echoendoscope. Images from five standardized positions (pancreatobiliary and upper gastrointestinal (GI) tract) were taken by two examiners of differing experience. Time to acquire images was noted. Penetration depth was also measured. Image quality variables (overall quality, contrast, and structure discrimination) were assessed blindly on the basis of randomly shuffled images during three independent evaluations by the same experienced examiner (mean values were taken), using a visual analogue scale (VAS) from 1 (excellent) to 10 (inadequate). RESULTS: Time needed to achieve visualization of the distal common bile duct (CBD) was significantly shorter with the electronic scope (49.7+/-8.6 versus 97.4+/-8.5 s; p<0.001). Image quality with the electronic scope was rated significantly better for all variables assessed, whereas EUS penetration depth was similar in both groups. There were no differences in examiner experience. CONCLUSIONS: Electronic EUS provided better quality images according to the examiner's subjective assessment. An objective advantage was faster identification of the distal CBD.

Intraductal ultrasonography for the assessment of preoperative biliary and pancreatic strictures.

Diseases of the biliary and pancreatic ducts are often difficult to diagnose. Although transcutaneous ultrasonography, computer tomography and magnetic resonance greatly improved in performance, two major problems have not been completely solved yet: first, the differentiation of malignant and benign bile duct strictures, and, second, the assessment of the resectability of carcinomas underlying biliary strictures. Ultrasound probes can be inserted through the working channel of the duodenoscope and passed selectively both into the biliary and pancreatic ducts. Ultrasound frequencies of 20 or 30 MHz enable a penetration of up to 2 cm and a resolution of 0.07 to 0.18 mm. The main clinical indication for intraductal ultrasonography of the biliary tract is obstructive jaundice, which requires assessment of bile duct strictures and local tumor staging. Miniprobes can contribute to the differential diagnosis of strictures localized in the main pancreatic duct, and also to localizing small endocrine tumors. Small tumors of the papilla of Vater can be staged before a possible endoscopic resection. Feasibility of the method is excellent in expert hands with almost no added morbidity.

Focal inflammation in the embryological ventral pancreas: assessment using CT and MRI.

AIM: To identify the characteristic computed tomography (CT) and magnetic resonance imaging (MRI) findings of nonuniform inflammation between the posterior aspect of the head and the remainder of the pancreas. MATERIALS AND METHODS: Two radiologists retrospectively evaluated images of 19 patients in whom the degree of attenuation in the CT images and/or the signal intensity in the MRI images differed between the posterior aspect of the head (ventral primordium) and the remainder of the pancreas (dorsal primordium) due to benign disorders other than uneven fatty replacement. Multiphase, contrast-enhanced CT examinations were performed in 17 patients. In five, T1- and T2-weighted images with and without fat suppression were obtained using a 1.5 T superconducting MRI system. RESULTS: The lesions were localized in the posterior aspect of the head in 17 patients. In two patients, the lesions occupied the posterior aspect of the head and extended to the neck. The lesions exhibited the following findings: inhomogeneous hypoattenuation (with spotty areas of relatively well-maintained contrast enhancement) during the pancreatic phase (17/17) and no intense peripheral enhancement or central necrotic areas (17/17) in CT images, hypointensity in T1-weighed images (5/5), hyperintensity in T2-weighed images (4/5), no vascular invasion (19/19), failure to depict the entire course of Wirsung's duct (17/19), and calcification (13/19). Santorini's ducts were depicted in all but three patients. CONCLUSION: Focal inflammation in the embryological ventral pancreas exhibits a unique anatomical distribution and characteristic findings.

A clinical algorithm for the assessment of pancreatic lesions: utilization of 16- and 64-section multidetector CT and endoscopic ultrasound.

Pancreatic masses may be solid or cystic, benign or malignant, and their characterization can often be difficult as there is considerable overlap in their imaging features. Multidetector computed tomography (MDCT) with multiplanar reconstructions offers improved resolution and optimum visualization of the peripancreatic vasculature, which has improved the accuracy in predicting surgical resectability. Endoscopic ultrasound (EUS) is valuable in the detection of tumours not identified on CT. It is also accurate in identifying vascular involvement, which complements MDCT in predicting resectability. In cases of diagnostic uncertainty, EUS-guided fine-needle aspiration (FNA) can be used to obtain tissue samples from solid lesions and fluid aspirates from cystic lesions, allowing histological, cytological, and biochemical analysis to determine the nature of the lesion. This article focuses on the MDCT and EUS appearances of common pancreatic malignancies, highlighting their relative advantages and their complementary role in detecting and characterizing pancreatic masses. A clinical algorithm for the assessment of pancreatic malignancy, as practised in our institution, is outlined.