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Clinical/methodical Issue: In daily routine, every radiologist is confronted with a variety of questions concerning the biliary tract and pancreatic system., Standard Radiological Methods: Today, besides sonography, magnetic resonance cholangiopancreatography (MRCP) is considered the method of choice in the investigation of many disorders of the hepatobiliary and pancreatic system and is commonly preferred over invasive ERCP in a mere diagnostic setting., Methodical Innovations: Since its introduction in 1991, MRCP has constantly evolved. Major innovations have been the reduction of acquisition time by using fast spin echo (FSE) sequences, the use of respiratory gating and contrast-enhanced imaging of the bile ducts with hepatobiliary-specific MRI contrast agents., Performance: Many diagnoses may already be made with noncontrast enhanced images. By supplemental administration of a hepatobiliary-specific contrast agent, it is also possible to evaluate the flow dynamics of the bile. This is of additional value especially in patients who underwent surgery of the biliodigestive system or endoscopic interventions., Achievements: Aside from robustness and reproducibility, a major advantage of this technique is the modular design of imaging protocols, which can easily be adapted to the clinical question., Practical Recommendations: MRCP is a reliable and low-risk imaging method for primary diagnosis and follow-up of biliary and pancreatic pathologies.

Clinical/methodical Issue: Both computed tomography (CT) and magnetic resonance imaging (MRI) constitute the gold standard in radiological imaging of hepatocellular carcinoma (HCC). In cases of typical contrast behavior each modality as a single dynamic technique allows the diagnosis of HCC. There is still a challenge in detection of small HCCs < 2 cm, in differentiating HCC and high-grade dysplasia from other benign liver lesions as well as the evaluation of hypovascular liver lesions in the cirrhotic liver., Performance: Nowadays, both modalities achieve high detection rates of 90-100 % for lesions > 2 cm. Regarding lesions between 1 and 2 cm there is a higher sensitivity for MRI ranging between 80 and 90 % compared to 60-75 % with CT. Besides the multimodal diagnostic criteria, MRI provides significant benefits with the use of hepatobiliary contrast. Especially in combination with diffusion- weighted imaging (DWI) increased sensitivity and diagnostic accuracy compared to CT has been described for lesions sized < 2 cm. Regarding the differentiation from other hepatic nodules in the cirrhotic liver there is strong evidence that the coexistence of arterial enhancement and hypointensity on hepatobiliary imaging is specific for HCC. Moreover, hypointensity on hepatobiliary imaging is associated with a high positive predictive value (PPV) of up to 100 % for the presence of high-grade dysplasia and HCC., Achievements: The use of MRI including hepatobiliary imaging and DWI has to be regarded as the best non-invasive imaging modality for the detection of HCC and for the characterization of nodules in patients with liver cirrhosis. In comparison to CT there are benefits regarding detection of small lesions < 2 cm and evaluation of hypovascular liver lesions in the context of the hepatocarcinogenesis including prognostic values of premalignant lesions., Practical Recommendations: Both MRI and CT provide a high diagnostic performance in evaluation of HCC in liver cirrhosis. With MRI there are considerable advantages regarding the detection rate and specificity. For daily clinical routine, CT offers a fast, reliable and easy available modality with benefits for patients in reduced general state of health and restricted compliance.

Clinical Problem: Diffuse liver diseases show an increasing prevalence. The diagnostic gold standard of liver biopsy has several disadvantages. There is a clinical demand for non-invasive imaging-based techniques to qualitatively and quantitatively evaluate the entire liver., Standard Radiological Methods: Ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) are routinely used., Methodical Innovations: Steatosis: chemical shift and frequency selective imaging, MR spectroscopy (MRS). Hemochromatosis: MR-based iron quantification. Fibrosis: MR elastography, diffusion, intravoxel incoherent motion (IVIM) and MR perfusion. PERFORMANCE/ACHIEVEMENTS/PRACTICAL RECOMMENDATIONS: T1-weighted in and opposed phase imaging is the clinically most frequently used MR technique to noninvasively detect and quantify steatosis. New methods for quantification that are not influenced by confounders like iron overload are under investigation. The most sensitive method to measure the fat content of the liver is MRS. As data acquisition and analysis remain complex and there is no whole organ coverage, MRS of the liver is not a routine method. With an optimized protocol incorporating T2* sequences, MRI is the modality of choice to quantify iron overload in hemochromatosis. Standard MR sequences cannot depict early stages of liver fibrosis. Advanced MR techniques (e.g. elastography, diffusion, IVIM and perfusion) for noninvasive assessment of liver fibrosis appear promising but their role has to be further investigated.

This article describes the architecture of a project aiming to implement a DIN EN ISO 9001 quality management system in a radiological department. It is intended to be a practical guide to demonstrate each step of the project leading to certification of the system. In a planning phase resources for the implementation of the project have to be identified and a quality management (QM) group as core team has to be formed. In the first project phase all available documents have to be checked and compiled in the QM manual. Moreover all relevant processes of the department have to be described in so-called process descriptions. In a second step responsibilities for the project are identified. Customer and employee surveys have to be carried out and a nonconformity management system has to be implemented. In this phase internal audits are also needed to check the new QM system, which is finally tested in the external certification audit with reference to its conformity with the standards.

Diffusion-weighted magnetic resonance imaging (DW-MRI) provides qualitative and quantitative information of tissue cellularity and the integrity of cellular membranes. Since DW-MRI can be performed without ionizing radiation exposure and contrast media application, DW-MRI is a particularly attractive tool for patients with allergies for gadolinium-based contrast agents or renal failure. Recent technical developments have made DW-MRI a robust and feasible technique for abdominal imaging. DW-MRI provides information on the detection and characterization of focal liver lesions and can also visualize treatment effects and early changes in chronic liver disease. In addition DW-MRI is a promising tool for the detection of inflammatory changes in patients with Crohn's disease.

Acute intestinal inflammation is common. In most cases the medical history, clinical investigations and laboratory parameters alone are not sufficient for a conclusive diagnosis because of the wide variety of differential diagnoses and the striking similarity of symptoms. Modern imaging methods can help to clarify the diagnosis and multi-slice CT (MSCT) is highly useful in this diagnostic dilemma. It is widely available, employs standardized protocols, is cost-effective and can be performed within an acceptable examination time. MSCT enables the location and extension of the underlying pathology to be assessed and detection of complications which require immediate therapeutic intervention.

Purpose: To determine the value of MR enteroclysis (MRE) in the localization and characterization of primary carcinoid tumors of the small bowel and to describe typical imaging features., Material and Methods: Twenty patients with suspicion of primary small bowel carcinoid tumors (pCT) were recruited to undergo MRE following nasojejunal intubation and small bowel filling with 2.5 l of 0.5% methylcellulose solution under MR fluoroscopic guidance. MRE was performed on a 1.5 T MR scanner including T2w SSFSE, SSFP and contrast enhanced T1w GRE sequences with fat saturation. Fifteen patients, who subsequently had surgery for resection of their pCT, were retrospectively included in the study. All MRE were analyzed as for the presence, location, number, size, multiplicity and morphologic appearance of the pCT by two board certified radiologists in consensus. The conspicuity of the tumors was rated for each sequence type separately, according to a 4-point rating scale. Signal intensity measurements were performed in tumor and muscle. The presence of desmoplastic reaction, vascular involvement and lymph node metastases was also analyzed., Results: pCT were correctly identified and localized in 14/15 patients. Due to their hyperenhancement tumors was best detected on contrast-enhanced T1w fat saturated GRE sequences. SSFSE was clearly inferior with the tumors being either hyperintense or isointense to muscle. pCT appeared as nodular intraluminal masses in 40% of the cases, as focal wall thickening in 33.3% and in 20% with both. Mean size was 25 (7-46 mm) with a tendency to smaller size for ileal tumors. MRE failed to depict superficial micronodular peritoneal spread in one patient. Desmoplastic reaction was observed in 73.3% of the cases with mesenteric masses exhibiting lower signal than the pCT due to fibrotic changes., Conclusion: MRE is a valuable method for the detection and localization of primary carcinoid tumors, provided that appropriate bowel distension is achieved. Various characteristic morphologic features could be identified which may contribute to characterize pCT and their loco-regional metastases.

Objective: The aim of this study was to describe the imaging findings for inflammatory pseudotumors in patients with chronic pancreatitis as detected in computed tomography (CT)., Materials and Methods: In this retrospective study 20 patients with chronic pancreatitis were included, who underwent an abdominal CT scan. In all patients the diagnosis was confirmed by surgery and histopathology. Imaging findings which have previously been described as typical for chronic pancreatitis and for inflammatory pseudotumors were assessed by two radiologists in consensus. Values of tissue density (HU) at CT were measured within the lesions and in the surrounding pancreatic tissue., Results: In 90% of patients with histologically proven chronic pancreatitis, CT showed corresponding indicative findings. In 10 patients the resected specimen revealed an inflammatory pseudotumor, which was located in all cases within the pancreatic head. Using CT these 10 patients presented with calcifications within the lesion in 50% of the cases, an irregular dilatation of the main pancreatic duct in 90%, a "double duct sign" in 70%, an interrupted main pancreatic duct in the area of the lesion in 50%, a "duct penetrating sign" in 30%, an infiltration of adjacent structures in 10% and pathologically enlarged lymph nodes in 100% of the cases. In the venous contrasting phase six tumors were hypodense and four isodense compared to the surrounding pancreatic tissue. In six patients biphasic CT was performed and the mean difference in attenuation between inflammatory pseudotumors and surrounding parenchyma was significantly higher in the pancreatic phase than in the venous phase., Discussion: Differentiation between inflammatory pseudotumors and adenocarcinoma remains difficult or even impossible. Typical signs indicative of an adenocarcinoma of the pancreatic head, such as dilatation of the common bile duct and/or the main pancreatic duct as well as enlarged lymph nodes, were also found in patients with inflammatory pseudotumors. Inflammatory pseudotumors showed low contrast between lesions and parenchyma in the venous phase and calcifications within the solid part of the tumor.

Solid pseudopapillary tumors of the pancreas (SPTP) are rare tumors of the pancreas with low malignancy potential and a very good prognostic outcome after surgery. They typically occur in young women or adolescents and consist of solid, cystic and cystic-hemorrhagic components.Imaging findings in these tumors are characteristic and include a fibrotic capsule with a clear delineation and exhibit solid and cystic-hemorrhagic signal and density characteristics. Calcifications may be present in the periphery of the tumor. The tumor capsule shows contrast enhancement, the solid components in the periphery enhance in the early phase and gradually and inhomogeneously in late phases. MRI is superior to CT and other imaging modalities for characterization of SPTP. Awareness and knowledge of this tumor entity with an excellent prognosis is crucial to guide the patient towards effective, predominantly organ-sparing surgical treatment.

Background: Percutaneous vertebroplasty (PVP) represents a minimally invasive option which is gaining in importance for the treatment of vertebral compression fractures (VCF) and osteolysis of the spine. This article describes the indications for its use, peri-interventional imaging, technique, and results of PVP., Material and Methods: The current guidelines for performance of PVP are explained in accordance with the "Interdisciplinary Consensus Paper on Vertebroplasty and Kyphoplasty" of the German Professional Associations and the 2005 CIRSE Guidelines. The results of our own study carried out in 2002 are compared to the complication rates and clinical outcomes reported in the literature., Results: Painful osteoporotic VCF and osteolysis within the vertebral body due to metastases and multiple myeloma are indications for PVP. Absolute contraindications are, in particular, asymptomatic VCF, alleviation of pain by drug treatment, therapy-refractory coagulopathies, allergies to cement components, and active infections. MRI or CT is indicated before undertaking PVP to assess the fracture age, to exclude other causes of pain, and to evaluate the posterior edge of the vertebral body. High-quality mono- or biplanar fluoroscopy--preferably in combination with CT (fluoroscopy)--is necessary for PVP to minimize the risk of cement leakage. A clear reduction in pain [mean reduction of 6.1 points (VAS)] is achieved in 86-92% of the patients with PVP. Our own study treating 58 patients (mean follow-up 323+/-99 days) revealed a clear alleviation of pain in 77% [-5.7 points (VAS)]., Conclusion: PVP constitutes a safe and effective minimally invasive treatment approach to stabilize and reduce acute and chronic back pain due to osteoporotic VCF and tumor-associated osteolysis.

Magnetic resonance cholangio-pancreaticograpy (MRCP) is a non-invasive imaging modality of the pancreatico-biliary system which plays an increasingly important role in the clinical and diagnostic workup of patients with biliary or pancreatic diseases. The present review is designed to give an overview of the currently available and appropriate sequences, their technical background, as well as new developments and their relevance to the various clinical issues and challenges. The impact of the latest technical innovations, such as integrated parallel imaging techniques and navigator-based respiratory triggering, on the diagnostic capacities of MRCP is discussed. In this context, the individual value of RARE, T2w single shot turbo/fast spin echo (SSFSE) and the recently introduced 3D T2w turbo/fast spin echo sequences (T2w 3D-T/FSE) is reviewed. RARE imaging may be preferred in severely ill patients with limitations in cooperation, SSFSE is particularly effective in differentiating benign and malignant stenosis, and 3D-FSE offers additional advantages in the detection of small biliary concrements.

This contribution provides an overview and imparts basic knowledge on pertinent technical developments in magnetic resonance imaging (MRI) of the liver: 3D sequences, respiratory triggering, parallel imaging, and 3 Tesla (3T). 3D sequences can be used as T1-weighted (T1w) sequences for analyzing dynamics of contrast enhancement or as T2w sequences for MR cholangiography. Consistent improvements in respiratory triggering make it possible to obtain good image quality on T2w scans even in patients unable to hold their breath. Parallel imaging as a universal technique to accelerate image acquisition is particularly appropriate for MRI of the liver, and it has been shown that the reduced acquisition time is not achieved at the expense of image quality. Further progress in MRI of the liver can be expected with use of the 3T systems, but hitherto irrelevant problems must still be solved. Overall the innovations presented here, applied alone or in combination, facilitate rapid, robust, and high-quality MRI diagnostic assessment of the liver.

Objective: To compare the value of the various imaging modalities in the detection of pancreatic islet cell tumors., Methods: Analysis of the literature to compare the value of ultrasound, CT, MRI, angiography, venous sampling, scintigraphy and PET in the detection of neuroendocrine tumors of the pancreas., Results: For transabdominal ultrasound a sensitivity of 60% has been reported; for endoscopic ultrasound a sensitivity of more than 90%. MRI with a sensitivity of 75-100% is more sensitive compared to CT with a sensitivity of 64-82%. Angiography and venous sampling have a reported sensitivity of 66% and 76%. Somatostatin receptor scintigraphy has a sensitivity of 81-88% with significant differences between the various histological subtypes of the pancreatic islet cell tumors. PET does not play an important role in the detection of neuroendocrine tumors of the pancreas., Conclusion: None of the various modalities is superior alone, so that it is often necessary to combine them for diagnostic imaging of pancreatic islet cell tumors.

Objective: This paper describes the value of various imaging modalities for diagnostic work-up of tumors of the adrenal gland., Methods: Results of the literature are reviewed. An optimized examination protocol for computed tomography (CT) and magnetic resonance imaging (MRI) is shown for assessment and differentiation of unclear lesions of the adrenal gland., Results: Measurements of attenuation in the native examination as well as delayed enhancement are the cornerstones in the CT diagnostics of tumors of the adrenal gland. In MRI, chemical-shift imaging and evaluation of signal characteristics in T1- and T2-weighted images are most important for characterization even in unclear cases., Conclusion: CT and MRI play the major role in imaging of adrenal gland tumors. Whereas CT is less expensive and widely available,MRI provides advantages in unclear cases because of the excellent tissue contrast and the superior characterization.