Açai juice as contrast agent in MRCP exams: qualitative and quantitative image evaluation

Abstract This works aims to assess images obtained with administration of açai juice as compared to a manufactured standard iron oxide-based contrast employed as negative oral agents in Magnetic Resonance Cholangiopancreatography (MRCP), employing qualitative and quantitative evaluation. The research was developed with 64 patients submitted to MRCP exams (on 2 days) in a clinic of Curitiba city (Brazil). First (day 1), a manufactured iron oxide-based contrast (A) was offered and later (day 2), açai juice (contrast B) was given to patients. Radiologists (R1 and R2) evaluated the images, classifying them by a score (1-4). In order to have a quantitative assessment, Image J free software was employed generating plots of gray levels against distance of a chosen area of the bile duct interest region. Evaluating images for contrast A, R1 furnished an average score of 3.52 and R2 of 3.27. For contrast B, R1 provided 3.44 and R2 3.38. Both evaluators considered image quality with contrast A adequate for 62 patients. R1 considered adequate for 62 and R2 for 60 patients when using açai juice. By taking same images for all patients with Image J, a quantitative analysis was obtained, resulting correlation coefficient of 0.986 between average curves of contrasts A and B. Thus, açai juice is an adequate alternative as contrast agent in MRCP exams. Image J was employed as a new method for quantitative investigation of image quality, presenting good agreement with medical opinion.

Genetics in idiopathic pancreatitis and acute recurrent pancreatitis

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Empleo de clip y endoloop para canular una papila difícilmente accesible debido a cambios anatómicos posquirúrgicos / Clip and endoloop lifting technique to assist cannulation of a hardly reachable papilla because of anatomical changes due to surgery

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Acute cholangitis: an unexpected cause of fever of unknown origin diagnosed by 18F-FDG PET/CT / Colangitis aguda: causa imprevista de fiebre de origen desconocido diagnosticada mediante 18F-FDG PET/TC

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Interventional MRI-guided local delivery of agents into swine bile duct walls using MR-compatible needle-integrated balloon catheter system.

The purpose of this study was to investigate the feasibility of interventional MRI-guided local agent delivery into pig common bile duct (CBD) walls using a newly designed MR-compatible, needle-integrated balloon catheter system. We first designed a needle-integrated balloon catheter system that comprised of a 22 G MR-compatible Chiba biopsy needle and a conventional 12 mm × 2 cm balloon catheter. Under fluoroscopy guidance, a custom needle-balloon system was positioned in the target CBD via a transcholecystic access. T1-weighted MRI was used to localize and reposition the needle-balloon system in the target. A 0.5 mL mixture of motexafin gadolinium (MGd) and trypan blue dye as well as 5-fluorouracil was delivered into the CBD wall through the needle-balloon system. Post-infusion T1-weighted MRI was obtained and contrast-to-noise ratios (CNRs) of CBD walls of pre- and post-MGd-blue infusions were compared by a paired t-test. In addition, post-infusion x-ray cholangiography was achieved to evaluate the potential injuries of CBDs by the needle-balloon system. Subsequent histologic analysis was performed to correlate and confirm the imaging findings. A post-infusion cholangiogram did not show any extravasation of contrast agent, indicating no procedure-related damage to the CBDs. MRI demonstrated clear enhancement of the target bile duct walls infused with MGd-trypan blue dye with average penetration depth of 4.7 ± 1.2 mm and an average MGd perfusion length of 21 ± 1.5 mm in the bile ducts and their surrounding tissues. The average CNR of the post-infusion bile ducts was significant higher than that of the pre-infusion bile ducts (110.6 ± 22 versus 5.7 ± 2.8, p < 0.0001). Histology depicted the blue dye staining and red fluorescence of MGd through the target CBD walls, which was well correlated with the imaging findings. It is feasible to use the new MR-compatible, needle-integrated balloon catheter system for intrabiliary local agent delivery into CBD walls under MRI guidance, which may open new avenues for efficient management of pancreatobiliary malignancies using MR-guided interventional oncology.

Evaluation of date syrup as an oral negative contrast agent for MRCP.

OBJECTIVE: The purpose of this study was to compare the in vitro effects of date syrup with those of other contrast agents by qualitative and quantitative analysis and in vivo evaluation of the use of date syrup to improve the quality of MRCP images. MATERIALS AND METHODS: Phantoms containing date syrup, ferumoxsil, pineapple juice, and water were imaged by 1.5-T MRI with T2-weighted and MRCP sequences, and signal-to-noise ratios were calculated. Biochemical analysis of date syrup was performed to find the nature of iron in it, and the iron content was quantified by energy-dispersive x-ray spectroscopy. Sixty patients underwent MRCP before and 30 minutes after ingestion of 100 mL of date syrup. Unenhanced and contrast-enhanced images were scored for gastrointestinal tract signal suppression and visualization of various pancreaticobiliary structures. RESULTS: In vitro evaluation showed that images obtained with date syrup had a signal-to-noise ratio comparable to that of images obtained with ferumoxsil in T2-weighted and MRCP sequences. The iron concentration in date syrup was 2.6 mg/dL, and it was in ferric form. Images obtained after oral contrast administration had statistically significant improvement in gastrointestinal tract signal suppression (p < 0.001) and an increase in visibility of the common bile duct, cystic duct, and pancreatic duct (all p < 0.001). No adverse effects were noted in any of the patients. CONCLUSION: Date syrup can be used as a negative oral contrast agent for gastrointestinal tract signal suppression during MRCP and for improving visualization of various pancreaticobiliary structures.

Quantification of pancreatic exocrine function of chronic pancreatitis with secretin-enhanced MRCP.

AIM: To obtain reference values for pancreatic flow output rate (PFR) and peak time (PT) in healthy volunteers and chronic pancreatitis (CP); to correlate quantification of secretin enhanced magnetic resonance cholangiopancreatography (SMRCP) of pancreatic fluid output following secretin with fecal elastase-1 (FE-1) tests. METHODS: The present study includes 53 subjects comprised of 17 healthy individuals and 36 patients with CP from April 2011 to January 2013. The 36 patients with CP were divided into three groups of mild CP (n = 14), moderate CP (n = 19) and advanced CP (n = 3) by M-ANNHEIM classification for CP.. Fifty-three cases underwent FE-1 test and magnetic resonance imaging using 3.0 T-device (Signa EXCITE, GE Healthcare). Coronal T2-weighted single-shot turbo spin-echo, spiratory triggered, covering the papillae, duodenum and small bowel. MRCP was performed with a heavily T2-weighted fat-suppressed long TE HASTE sequence (thick slab 2D MRCP sequence), repeated every 2 min up to 11 min after 0.1 mL/kg secretin injection (Secrelux, Sanochemia(®), Germany). FE-1 test used sandwich enzyme-linked immunosorbent assay (ELISA) test (ScheBo. Tech(®), Germany). RESULTS: A good linear correlation showed between the calculated volume and the actual volume by Phantom experiments. Fifty-three paired Quantification of secretin enhanced magnetic resonance cholangiopancreatography (MRCPQ) and FE-1 data sets were analyzed. The mean FE-1 of 53 cases was 525.41 ± 94.44 µg/g for 17 healthy volunteers, 464.95 ± 136.13 µg/g for mild CP, 301.55 ± 181.55 µg/g for moderate CP, 229.30 ± 146.60 µg/g for advanced CP. Also, there was statistically significant difference in FE-1 (P = 0.0001) between health and CP. The mean values of PFR and PT were 8.18 ± 1.11 mL/min, 5.76 ± 1.71 min for normal; 7.27 ± 2.04 mL/min, 7.71 ± 2.55 min for mild CP; 4.98 ± 2.57 mL/min, 9.10 ± 3.00 min for moderate CP; 4.13 ± 1.83 mL/min, 12.33 ± 1.55 min for advanced CP. Further, statistically significant difference in PFR (P = 0.0001) and PT (P = 0.0001) was observed between health and CP. Besides, there was correlation (r = 0.79) and consistency (K = 0.6) between MRCPQ and ELISA Test. It was related between M-ANNHEIM classification and PFR (r = 0.55), FE-1 (r = 0.57). CONCLUSION: SMRCP can provide a safe, non-invasive and efficient method to evaluate the exocrine function of the pancreas.

Preoperative evaluation of the cystic duct for laparoscopic cholecystectomy: comparison of navigator-gated prospective acquisition correction- and conventional respiratory-triggered techniques at free-breathing 3D MR cholangiopancreatography.

OBJECTIVE: To evaluate the quality of magnetic resonance cholangiopancreatography (MRCP) images obtained with a three-dimensional navigator-gated (NG) technique and compare findings with conventional respiratory-triggered (RT) images in pre-laparoscopic cholecystectomy patients. METHODS: Turbo-spin-echo (TSE) RT-MRCP (average 242 s) and balanced turbo-field-echo (bTFE) NG-MRCP (average 263 s) were acquired at 1.5-T MRI for 49 pre-laparoscopic cholecystectomy patients. Two radiologists independently assessed image quality, visibility of anatomical structures, common bile duct (CBD) stones, and signal-to-noise ratios (SNRs). Interobserver agreement was also evaluated. RESULTS: The anatomical details of the cystic duct were clearly demonstrated in 33 (67.3 %, reader A) and 35 (71.4 %, reader B) patients on RT-MRCP, and in 45 (91.8 %) and 44 (89.7 %) patients on NG-MRCP. On NG-MRCP, visualisation of the cystic duct (3.22/3.12), its origin (3.57/3.55), and the gallbladder(3.61/3.59) was statistically better than on RT-MRCP (2.90/2.78, 3.29/3.12, 2.98/2.88, respectively). The overall image quality was statistically better on NG-MRCP than RT-MRCP. Each technique identified the presence of CBD stones in all affected patients. The SNR was significantly higher on NG-MRCP (CHD 22.40, gallbladder 17.13) than RT-MRCP (CHD 17.05, gallbladder 9.30). Interobserver agreement was fair to perfect. CONCLUSION: Navigator-gated MRCP is more useful than respiratory-triggered MRCP for evaluating the gallbladder and cystic duct in patients scheduled for laparoscopic cholecystectomy. KEY POINTS: • Magnetic resonance cholangiopancreatography (MRCP) provides important cystic duct information before laparoscopic cholecystectomy. • Navigator-gated (NG) MRCP images were better than conventional respiratory-triggered (RT) MRCP. • The signal-to-noise ratio was significantly higher for NG-MRCP than for conventional RT-MRCP. • Balanced turbo-field-echo NG-MRCP is useful for evaluating the gallbladder and cystic duct.

[New developments in MRI of the liver]. / Neuere Entwicklungen der Leber-MRT.

Radiology has gained an exceptional position in medicine because a correct diagnosis is the most crucial issue in determining an accurate and personalized therapeutic strategy. This has a direct influence not only on the individual patient but also on the socio-economic aspects of healthcare services in terms of shortening the time interval to establish a diagnosis and to avoid risk-associated invasive diagnostic methods or long-term, cost-intensive follow-up. Magnetic resonance imaging (MRI) is an excellent example of this which due to continuous technological developments and emerging techniques allows a non-invasive diagnosis of the different hepatic diseases. In this article, we illustrate the direct correlation between the recent technical advances in MRI, such as 3.0 T, diffusion-weighted imaging, perfusion imaging, spectroscopy, texture analysis and MR elastography and obtaining a confident non-invasive diagnosis of focal and diffuse liver diseases.

Rigidez de descerebración transitoria en el contexto de hipoxemia y administración de propofol, midazolamflumacenilo y remifentanilo-naloxona / No disponible

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Congenital anomalies and variations of the bile and pancreatic ducts: magnetic resonance cholangiopancreatography findings, epidemiology and clinical significance.

PURPOSE: The objective of this paper is to document the magnetic resonance cholangiopancreatography (MRCP) findings and the epidemiology of congenital anomalies and variations of the bile and pancreatic ducts and to discuss their clinical significance. MATERIALS AND METHODS: Three-hundred and fifty patients of both sexes (150 females, 200 males, age range 0-76 years, average age 38 years) underwent MRCP for clinically suspected lithiasic, neoplastic or inflammatory disease of the bile and pancreatic ducts. Patients were imaged with a 1.5-T superconductive magnet (Magnetom Vision, Siemens, Erlangen, Germany), a four-channel phased-array body coil, breath-hold technique, with multislice T2-weighted half-Fourier acquisition single-shot turbo spin echo (HASTE), MIP reconstructions, and a single-shot T2-weighted turbo-spin-echo sequence rapid acquisition with relaxation enhancement (RARE) with different slice thicknesses. Studies in oncological patients were completed with fat saturation 3D T1 gradient-echo sequences during the intravenous injection of gadolinium diethylene triamine pentaacetate acid (DTPA) (0.2 ml/kg). RESULTS: MRCP demonstrated recurrent and therefore normal bile and pancreatic ducts in 57% of patients. In the remaining 42.3%, it documented anatomical variants (41%) and congenital anomalies (1.3%). Variants of the intrahepatic bile duct were seen in 21% of cases: crossover anomaly (6.7%), anterior branch of the right hepatic duct draining the IV and VII segments that flow together with the left bile duct (3.1%) and anterior and posterior branches of the right hepatic duct that flow together with the common hepatic duct (3.3%). Variants of the extrahepatic bile ducts were present in 8.8% of patients: low insertion of the cystic duct into the common hepatic duct (4.5%), emptying of the cystic duct into the right hepatic duct (2.7%) and a second-order large branch draining into the cystic duct (1.6%). MRCP identified a double gall bladder in 3% of patients and anatomical variants of the biliopancreatic system in 8.2%: pancreas divisum (5.2%) and a long sphincter of Oddi (3%). Finally, congenital anomalies were diagnosed in 1.3% of cases: bile duct cysts (0.3%), atresia of the bile ducts (0.3%) and multiple biliary hamartomatosis (0.7%). CONCLUSIONS: The congenital anomalies and anatomical variants of the bile and pancreatic ducts present a complex spectrum of frequent alterations, which are worthy of attention in both the clinical and surgical settings and are readily identified by MRCP.

Aplicaciones clínicas de la colangiopancreatografía por resonancia magnética / Clinical applications of magnetic resonance cholangiopancreatography

La colangiopancreatografía por resonancia magnética (CPRM) es la alternativa diagnóstica más importante que ha surgido en los últimos años para la evaluación de las vías biliar y pancreática. Las ventajas de este método son: no utiliza medio de contraste ni radiación ionizante, no es invasivo y está exento de complicaciones y el tiempo de estudio es relativamente corto (aproximadamente entre 20 y 30 minutos). Tiene alta sensibilidad y especificidad para diagnosticar la dilatación biliar y para demostrar el sitio y la causa de la estenosis. Para los cálculos biliares y pancreáticos su exactitud diagnóstica es similar a la de la colangiopancreatografía endoscópica retrógrada (CPRE). En variantes anatómicas biliopancreáticas ha reemplazado a la CPRE como método diagnóstico. En la CPRE fallida, la CPRM es casi la única modalidad diagnóstica para la evaluación de los conductos biliares. Otras aplicaciones son la colangitis esclerosante primaria, la estenosis post tranplante hepático y la valoración de las anastomosis bilioentéricas. Este artículo es una revisión de las aplicaciones clínicas de la CPRM en la evaluación de las enfermedades biliopancreáticas (AU)

Magnetic resonance cholangiopancreatography (MRCP) is the most important diagnostic alternative that has been developed in recent years for the evaluation of the biliary and pancreatic ducts. The advantages of this technique are: it does not use contrast media or ionizing radiation; it is noninvasive and complication free; and, the examination is relatively short (approximately 20 to 30 minutes). MRCP has high sensitivity and specificity for diagnosing biliary dilatation and for determining the site and cause of stenosis. Its diagnostic precision for biliary and pancreatic stones is similar to that of endoscopic retrograde cholangiopancreatography (ERCP). MRCP has replaced ERCP in biliary and pancreatic anatomic variants. In unsuccessful ERCP, MRCP is nearly the only diagnostic modality for the evaluation of the biliary tract. Other applications include primary sclerosing cholangitis, stenosis after liver transplantation, and the evaluation of bilioenteric anastomoses. This article reviews the clinical applications of MRCP in the evaluation of biliopancreatic diseases (AU)

Quantitative secretin MRCP (MRCPQ): results in 215 patients with known or suspected pancreatic pathology.

Secretin magnetic resonance cholangiopancreatography quantification (MRCPQ) of pancreatic exocrine function correlates well with steatorrhoea and conventional, non-invasive function tests. We report MRCPQ results in a variety of pancreatic conditions. A total of 215 patients [107 male, mean age 46 years (14-78)] were studied. A multi-slice MRCP sequence was performed before and at 2-min intervals after 0.1 ml/kg IV secretin. Change in small intestinal water volume was plotted against time and the flow rate derived from the gradient. Patients were classified using clinical history, MRCP, MR imaging, computed tomography (CT) [150/215 (70%)] and endoscopic retrograde cholangiopancreatography (ERCP) [56/215 (26%)] findings but not MRCPQ results. Mean, standard deviation and 95% confidence intervals were calculated. The one way ANOVA and Student's t-test were used for statistical analysis. Seventy-six patients had chronic pancreatitis, 26 were post-surgical, 34 post-acute pancreatitis, six atrophic pancreatopathy, eight with obstruction, 15 divisum, ten sphincter of Oddi dysfunction, 26 normal and 14 miscellaneous. Significant differences were observed between normals (mean+/-SD; 7.4 +/- 2.9 ml/min) and severe chronic pancreatitis (5.3 +/- 2.4) (P = 0.018), pancreatic atrophy (3.8 +/- 3.1) (P = 0.013) or duct obstruction (5.3 +/- 2.4) (P = 0.047)) and between moderate (7.0 +/- 3.0) (P = 0.03) and severe chronic pancreatitis. MRCPQ can be used to quantify function across the spectrum of pancreatic disease and showed significant differences between several different pathologies.

[Role of MR cholangiopancreatography in the evaluation of biliary disease]. / II ruolo della colangiopancreatografia a risonanza magnetica nello studio della patologia biliare.

PURPOSE: To evaluate the diagnostic accuracy of MR cholangiopancreatography (MRCP) in biliary tree patology in comparison with percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiopancreatography (ERCP) and surgical findings. MATERIALS AND METHODS: Forty-six patients , with clinical and laboratory findings suggestive of biliary tree pathology, and after an abdominal US, underwent MRCP with a 1.5 T superconductive magnet equipped with a phased-array body coil. MR exam was performed with baseline sequences for the examination of the upper abdomen, followed by specific MRCP sequences and, in cases of suspected neoplastic disease, completed with abdominal sequences after a bolus injection of paramagnetic contrast. RESULTS: MRCP showed normal findings in 16/46 patients, biliary duct dilatation in 25/46 patients (7 choledocolithiasis, 10 benign obstructions and 8 neoplastic stenoses) and stenoses without dilatation of biliary tree in 5/46 patients. In 25 patients with biliary duct dilatation, CPRM correctly identified the level of in 100% of patients (25/25) and the nature in 88% of patients (22/25). In 5 patients with stenosis without dilatation of biliary tree, CPRM identified 2 true positives (sclerosing cholangitis), 2 false positives and 1 patient is still in follow-up. CONCLUSIONS: In our experience MRCP proved to be highly accurate as fundamental diagnostic step in patients with clinical and laboratory findings suggestive of biliary disease. The workload of ERCP, invasive method with risk of complications, in the diagnosis stage could therefore be reduced and its use be reserved for therapeutic indications.

[Magnetic resonance imaging: technical aspects and recent developments]. / Magnetresonanztomographie-technische Grundlagen und aktuelle Entwicklungen.

Magnetic resonance imaging (MR) is based on electromagnetic effects of rotating protons in hydrogen of water and organic materials. With a magnetic field and high frequency electromagnetic pulses, MRI generates data sets to be reconstructed as two-dimensional cross-sectional images or three-dimensional volumes of anatomic structures with excellent soft-tissue contrast. Since modern MR techniques have dramatically reduced acquisition times and motion artifacts, breathhold studies of moving organs such as the stomach and intestinum or heart and lung have become part of the daily routine. MRI does not apply ionizing radiation, therefore dynamic studies and repeated controls may be performed. Original contraindications such as metallic implants or electronic devices (pacemakers) have become relative in many cases. Since MR contrast media are considered not nephrotoxic when applied in regular dose, MRI provides a most valuable alter native for imaging studies and angiography in patients with renal insufficiency. The recent developments in the field of internal medicine include functional imaging of stomach, intestinum, heart and lung. Based on these experiences, protocols for whole-body MRI within reasonable acquisition time and at acceptable costs have been developed. In particular for screening and staging, such MRI proto cols might cover an even broader spectrum of applications in the near future. Based on the knowledge of recent trends and technical backgrounds, many perspectives are opened up for the further development of the method in interdisciplinary cooperation.