[Differential diagnoses of biliary tract diseases : Computed tomography and magnetic resonance imaging]. / Differenzialdiagnosen von Gallenwegerkrankungen : Computertomographie und Magnetresonanztomographie.

CLINICAL/METHODICAL ISSUE: Bile duct diseases can be found in all age groups and show an increased prevalence in northern Europe. Pathologies range from benign diseases to malignant tumors with very poor survival. STANDARD RADIOLOGICAL METHODS: Magnetic resonance imaging (MRI) and computed tomography (CT) are the radiological methods of choice for a detailed evaluation of the bile duct system in addition to sonography. By assessing the lumen and the wall of the bile ducts as well as the surrounding structures, both obstructive and nonobstructive pathologies can be diagnosed and differentiated with high sensitivity and specificity. METHODICAL INNOVATIONS: Technical developments with postprocessing modalities as well as the use of biliary-excreted liver-specific MR contrast agents improve the diagnosis of bile duct diseases and enable morphological and functional assessment. PERFORMANCE: Due to high patient tolerance, minimal procedural risk in contrast to invasive endoscopic methods and the possibility of three-dimensional post-processing, beside CT, MRI with magnetic resonance cholangiography (MRC) represents the method of choice in patients with sonographically or clinically suspected bile duct disease and has significantly reduced the indications of diagnostic endoscopic retrograde cholangiopancreatography (ERCP). A complementary multimodality and multiparametric imaging approach is particularly helpful for preoperative assessment. PRACTICAL RECOMMENDATIONS: Rapidly evolving technology for both MRI and CT represent opportunities and challenges. By understanding the advantages and limitations of modern MR and CT techniques and by knowing the spectrum of bile duct pathologies, improved diagnosis and narrowing of possible differential diagnosis can be achieved.

Simultaneous Radiological and Fiberendoscopic Evaluation of Swallowing ("SIRFES") in Patients After Surgery of Oropharyngeal/Laryngeal Cancer and Postoperative Dysphagia.

To compare the results of a simultaneously performed videofluoroscopic swallowing study and fiberendoscopic evaluation of swallowing in patients with dysphagia after surgery and radiotherapy for oropharyngeal or laryngeal cancer. This prospective study included 31 patients who were examined simultaneously with a standardized protocol. The fiberendoscopic and videofluoroscopic swallowing loops were independently scored by two otorhinolaryngologists/phoniatricians and two radiologists. The presence of penetration/aspiration, the amount of pharyngeal residues and the position of the bolus head when triggering of pharyngeal swallow begins were evaluated. Generalized linear models were used to model the impact of rater, method, bolus and quantities as well as specified moderation effects on scorings. In addition, post hoc Wilcoxon tests were used. Rater agreement was assessed using weighted kappas and their 95% confidence intervals. A total of 202 swallow sequences in 29 patients was evaluated. Interrater agreement was substantial to excellent for both methods (weighted k = 0.979-0.613). Significant differences between both methods were found when assessing the penetration-aspiration scale (p = 0.001, tendency of higher scores by videofluoroscopic (median = 2.59) as opposed to fiberendoscopic (median = 2.14) and the residue severity scores in the valleculae (p = 0.029) and the sinus piriformes (p = 0.002) with larger residues scored by fiberendoscopic evaluation of swallowing. No significant differences were found regarding the time point of triggering (p = 0.273). Simultaneous evaluation of swallowing with FEES and VFSS showed significantly different results in symptomatic patients after tumor operation and radiotherapy.

[Imaging of gastrointestinal inflammation : Characteristic patterns and signs]. / Bildgebung gastrointestinaler Entzündungen : Charakteristische Muster und Zeichen.

CLINICAL PROBLEM: Pathological conditions of the gastrointestinal tract can result from various disorders, including inflammatory, infectious, neoplastic, and ischemic diseases. RADIOLOGICAL STANDARD PROCEDURES: Cross-sectional imaging techniques have largely replaced many of the conventional fluoroscopic examinations, such as small bowel follow-through and double-contrast barium enema. The former allow for time-efficient, accurate, and minimally invasive diagnostics. Therefore, they have become important diagnostic tools for the evaluation of inflammatory diseases of the gastrointestinal tract. The distension of the intestinal lumen with orally administered neutral contrast media improves not only the evaluation of the intraluminal aspect, but also of the cross-sectional appearance. Furthermore, with cross-sectional imaging techniques, the additional assessment of the extraintestinal structures and organs is also possible. METHODICAL INNOVATIONS AND ASSESSMENT: With the ongoing development of scanner and software technology, pathologic conditions of the gastrointestinal wall can be characterized in more detail by both computed tomography and magnetic resonance imaging. A structured approach, based on the analysis of typical radiological signs and patterns, combined with the evaluation of extraintestinal findings may help to assign the observed imaging findings to specific disease groups. RECOMMENDATIONS: This article summarizes common signs and typical patterns frequently seen in inflammatory conditions of the gastrointestinal tract. A systematic approach for structured analysis of specific and nonspecific imaging features and common pitfalls may aid in the interpretation and help to narrow the spectrum of potential differential diagnoses.

[Incidental findings of liver, biliary system, pancreas and spleen in asymptomatic patients : Assessment and management recommendations]. / Zufallsbefunde von Leber, Gallensystem, Pankreas und Milz bei asymptomatischen Patienten : Bewertung und Managementempfehlung.

CLINICAL ISSUE: The increased use of highly developed imaging procedures, such as multidetector-row computed tomography and magnetic resonance imaging has led to a substantial increase of asymptomatic and unexpected findings. STANDARD RADIOLOGICAL METHODS: Abdominal CT investigations are particularly affected with a large number of incidental findings. This valuable diagnostic procedure also entails the risk of complex and cost-intensive subsequent investigations with partly invasive procedures. ACHIEVEMENTS: For this reason radiologists are more often confronted with the difficult task of correctly assessing these lesions, to decide on the need for additional investigations and to inform the patient in detail about the clinical relevance. PRACTICAL RECOMMENDATIONS: The aims of this article are to describe the most common abdominal incidentalomas, to assist with the interpretation and differential diagnosis and to give recommendations for further management.

[Incidental findings of the kidneys, adrenal glands, adnexa uteri, gastrointestinal tract, mesentery and lymph nodes : Assessment and management recommendations]. / Zufallsbefunde von Niere, Nebenniere, Adnexen, Gastrointestinaltrakt, Mesenterium und Lymphknoten : Bewertung und Managementempfehlung.

CLINICAL ISSUE: Besides the upper abdominal parenchymal organs, the increasing application of cross-sectional imaging has also led to a rising number of incidental findings in the kidneys, adrenal glands, adnexa uteri, the gastrointestinal tract, mesentery and abdominal lymph nodes. STANDARD RADIOLOGICAL METHODS: Abdominal computed tomography investigations often show unexpected findings without any correlating symptoms. The growing clinical relevance is due to the large number of incidental findings as well as an increasing awareness of ethical and socioeconomic factors. ACHIEVEMENTS: When interpreting radiological findings not only morphological criteria but also individual risk factors of the patient and the clinical context are of great importance. PRACTICAL RECOMMENDATIONS: The aims of this article are the description and evaluation of frequent incidental findings detected by computed tomography and to provide information about management recommendations.

[Swallowing Disorders]. / Schluckstörungen.

Swallowing disorders are a common disease in all ages. The spectrum of diseases in patients with swallowing disorders has significantly changed in the last decades. Often complexe clinical pictures require a multidisciplinary approach including various different professionals. Videofluoroscopy is the method of choice for evaluation of the entire swallowing tract within one investigation. Functional as well as morphological changes can be diagnosed and as a therapeutic study, it helps guide decisions regarding further swallow therapy based on those findings.

[Modern MRI of the small bowell]. / Moderne MRT des Dünndarms.

CLINICAL METHODOLOGICAL ISSUES: The radiological diagnostics of diseases of the small intestine have undergone a great change in the last two decades. Through rapid progress with new treatments and an increasing therapeutic focus on transmural healing, a complete evaluation of the gastrointestinal tract is now crucial. STANDARD RADIOLOGICAL METHODS: With the introduction of endoscopy, gastrointestinal imaging with a relatively high radiation exposure had only limited applications. The development of cross-sectional imaging allowed a much broader radiological evaluation of abdominal diseases. Due to rapid investigation techniques, excellent soft tissue contrast and the distinct advantage of eliminating exposure to radiation, magnetic resonance imaging (MRI) of the gastrointestinal tract has gained increasing importance. With sufficient filling of the intestinal lumen, simultaneous imaging of all the intestinal wall layers, the perienteric structures and associated abdominal pathologies is now possible. METHODOLOGICAL INNOVATIONS: New MR sequences, such as diffusion-weighted sequences, dynamic contrast-enhanced sequences and MR fluoroscopy, enable the detection of morphological changes, with additional characterization of affected bowel loops as well as the assessment of functional pathologies with dynamic information about intestinal motility disturbances. ACHIEVEMENTS: Recent guidelines of European radiological and gastroenterological organizations have confirmed the importance of cross-sectional imaging and particularly of MRI for diagnostics and follow-up in patients with Crohn's disease. Due to the possibility of assessment of all the layers of the intestinal wall and the presence of extramural complications, MRI has a significant impact on further therapeutic treatment in patients with inflammatory bowel disease. PRACTICAL RECOMMENDATIONS: Especially in patients with inflammatory bowel disease, MR enterography and MR enteroclysis should be the methods of choice for the evaluation of small bowel pathologies because of radiation issues and the great diagnostic value they provide. A variety of MR sequences has enabled not only the detection but also the characterization of pathological changes of the small intestine, which are vital for further treatment of these patients.

Preoperative evaluation of colorectal liver metastases: comparison between gadoxetic acid-enhanced 3.0-T MRI and contrast-enhanced MDCT with histopathological correlation.

OBJECTIVES: The aim of this prospective study was to compare the diagnostic performance of 64-row MDCT and gadoxetic-acid-enhanced MRI at 3.0 T in patients with colorectal liver metastases in correlation with histopathological findings. METHODS: Lesions detected at MDCT and MRI were interpreted by three blinded readers and compared with histopathological workup as the term of reference. Two subgroups of lesions were additionally evaluated: (1) metastases smaller than 10 mm and (2) lesions in patients with and without steatosis of the liver, assessed histopathologically. RESULTS: Surgery and histopathological workup revealed 81 colorectal liver metastases in 35 patients and diffuse metastatic involvement in 3 patients. In a lesion-by-lesion analysis, significant sensitivity differences could only be found for reader 1 (P = 0.035) and reader 3 (P = 0.003). For segment-based evaluation, MRI was more sensitive only for reader 3 (P = 0.012). The number of false-positive results ranged from 3 to 12 for MDCT and 8 to 11 for MRI evaluation. In the group of small lesions, the sensitivity differed significantly between both methods (P = 0.003). In patients with hepatic steatosis, MRI showed a trend toward better performance than MDCT, but without statistical performance. CONCLUSIONS: The 3.0-T MRI with liver-specific contrast agents is the preferred investigation in the preoperative setting, especially for the assessment of small colorectal liver metastases. KEY POINTS: • Potential surgical treatment requires accurate radiological assessment of colorectal liver metastases • Magnetic resonance imaging with gadoxetic acid is the preferred imaging investigation. • MRI is better than multidetector CT for detecting small liver metastases.

Quantification of axial alignment of the lower extremity on conventional and digital total leg radiographs.

The purpose was to assess axial alignment of the lower limb using mechanical axis measurements on conventional and digital radiographs. Total-leg radiographs of 24 patients, 8 male and 16 female, with a mean age of 68.6+/-10.2 years, were performed in a standardized anterior-posterior projection and standing position using a conventional and digital phosphor storage film screen radiography system. Knee joint angulation was assessed by measuring the angle between a line drawn from the center of the femoral head to the middle of the femoral condyles and a line drawn from the middle of the tibial condyles to the midpoint of the malleolus. On conventional leg radiographs, line drawing and angle measurement were performed manually with a transparent goniometer. Angle measurement on digital leg radiographs was performed on a PACS workstation using computer-assisted measurement software (IMPAX, AGFA-GEVAERT, Belgium). Evaluation time for both measurements was recorded. We diagnosed 14 varus and 10 valgus angulations of the knee joint. The mean individual difference between axis deviation of conventional digital leg radiographs was 0.93+0.6 degrees (min 0 degrees, max 2 degrees), the mean difference in varus angulation was 1.13+/-0.45 degrees (min 0.3 degrees, max 2 degrees), and the mean difference in valgus angulation was 0.65+/-0.71 degrees (min 0 degrees, max 2 degrees). Angle measurements on conventional and digital radiographs did not show any statistically significant difference. Mean time exposure was 4.9 min/patient for manual and 1.08 min/patient for computer-assisted angle measurement (P<0.001). Computer-assisted angle measurement on digital total-leg radiographs represents a reliable method with no significant angle differences compared to conventional radiographic systems and offers a significantly lower evaluation time.

Effects of gastric acid on euro coins: chemical reaction and radiographic appearance after ingestion by infants and children.

OBJECTIVES: This study investigated whether coins of the new European currency (euro) corrode when they are exposed to gastric acid, and whether this change can be detected radiographically. METHODS: The eight different denominations of coins were immersed for seven days in 0.15 N hydrochloride acid (HCl), which corresponds to the level of post-prandial gastric acid. A Swedish crown coin and three different Austrian schilling coins were used as controls. The coins were weighed and radiographed daily to evaluate visible corrosions and HCl was analysed daily for possible dissolved substances. RESULTS: All coins lost weight within 24 hours after exposure to HCl. The 1, 2, and 5 euro cent coins developed changes that were visible on radiographs. The weights of all coins decreased by 0.43% to 11.30% during one week. The dissolved substances measured in the HCl corresponded to the different metals and alloys of the coins, except for copper, which does not dissolve in HCl. The highest absolute weight loss was observed in the Swedish crown coin (0.67 g), and the highest relative weight loss in the 1 Austrian schilling coin (11.30%). The two coins that showed the highest absolute and relative weight losses were the 2 euro (0.54 g or 6.35%) and the 1 euro (0.48 g or 6.39%) coin. CONCLUSIONS: A higher rate of toxicity for the new European coins compared with coins of other currencies is not expected, unless a massive coin ingestion occurs.

[MR imaging in congenital complicated anterior body wall defects]. / MRT von komplizierten angeborenen Bauchwanddefekten.

INTRODUCTION: Aim of this study was to estimate the value of postmortem MR imaging in evaluation of specimen with congenital anterior body wall defects of the museum of pathologic-anatomy. MATERIAL AND METHODS: We examined 19 specimen with a 1.5 Tesla unit by using T 1 - and T 2 -weighted sagittal and coronal sequences. In some specimen additional axial T 2 -weighted images were obtained. We evaluated the site of the bowel, the liver, the heart and presence of associated disorders. RESULTS: The bowels were completely intraabdominal, in two specimen, completely extraabdominal in 12 specimen and in 5 specimen intra- and extraabdominal. The liver was in two specimen completely extraabdominal/ in 12 completely intracorporal, and in 5 specimen intra- and extraabdominal. In 5 cases the heart was located extraanatomically. In 12 specimen we found disorders of the spine and the extremities. Congenital disorders of the kidneys were found in 6 specimen. CONCLUSION: MR imaging is of great value in the assessment of congenital anterior body wall defects. In the light of ultrafast sequences the role of fetal MR imaging in the evaluation of congenital body wall defects may be mandatory in the future.

Significant symptomatic relief after transoral endoscopic staple-assisted treatment of Zenker's diverticulum.

BACKGROUND: Zenker's diverticulum is associated with characteristic symptoms of progressive dysphagia and regurgitation. As most patients are elderly, the perioperative risk is usually high. We report our clinical experience with the transoral endoscopic staple-assisted method, including a thorough assessment of the symptomatic relief achieved by the procedure. METHODS: 46 consecutive patients (29 m, 17 f) with a median age of 61 years (range, 37-96 years) were treated between 1997 and 2002. The symptoms and their frequency were registered. The follow-up consisted of clinical and radiographic investigations. RESULTS: The median size of the diverticulum was 4 cm (range, 2-12 cm). Transoral treatment was successful in 39 patients; in 7 cases (15.2%) a switch to open surgery was required. The median operating time was 30 min (range, 10-150 min). Mortality rate was nil, while morbidity was 7.7%. The median duration of the postoperative hospital stay was 5 days (range, 1-65 days). After a median follow-up of 11 months (range, 1-40 months), 5 patients had been reoperated on endoscopically due to clinical recurrence. Clinical symptoms were significantly reduced (dysphagia of liquids p

Videofluoroscopy of deglutition in children after repair of esophageal atresia.

PURPOSE: To evaluate the functional disorders of the oral and pharyngeal phases of deglutition after repair of esophageal atresia in children. MATERIAL AND METHODS: 19 children (10 girls, 9 boys, mean age 22 months) underwent videofluoroscopy of deglutition after repair of esophageal atresia. The videofluoroscopic studies were assessed according to functional and morphological changes in the oral, pharyngeal and esophageal phases. The persistence of radiologic findings on videofluoroscopy was determined. RESULTS: The oral phase was normal in all patients. The main functional disorder of the pharyngeal phase was aspiration in 7 (37%) children. A completely normal deglutition in the pharyngeal and esophageal phases was not seen in any patient. CONCLUSION: Videofluoroscopy after repair of esophageal atresia is helpful in differentiation of functional and morphological disorders that can lead to prandial aspiration and have an influence on the decision about continued therapy.

[Imaging techniques and examination protocols in the pediatric emergency]. / Aufnahmetechnik und Untersuchungsprotokolle beim pädiatrischen Notfall.

Paediatric emergencies demand a quick and efficient radiological investigation with special attention to specific adjustments related to patient age and radiation protection. Imaging modalities are improving rapidly and enable to diagnose childhood diseases and injuries more quickly, accurately and safely. This article provides an overview of imaging techniques adjusted to the age of the child and an overview of imaging strategies of common paediatric emergencies. Optimising the imaging parameters (digital radiography, different screen-film systems, exposure specifications) allows for substantial reduction of radiation dose. Spiral- and multislice-CT reduce scan time and enable a considerable reduction of radiation exposure if scanning parameters (pitch setting, tube current) are properly adjusted. MRI is still mainly used for neurological or spinal emergencies despite the advent of fast imaging sequences. The radiologist's task is to select an appropriate imaging strategy according to expected differential diagnosis and to adjust the imaging techniques to the individual patient.

[Acute abdomen in the child]. / Das akute Abdomen beim Kind.

The acute abdomen in childhood demands early diagnosis for the sake of appropriate and early therapy. A high number of differential diagnosis in the assessment of acute abdominal pain and problems, as well as different causes of diseases in different age of the children, make a partition with respect to the age of the children considerable. A partition in diseases, which are leading to acute abdominal pain in neonates, in toddlers and small infants and in schoolchildren makes sense. In older schoolchildren and adolescents also diseases of the grown up generation are possible as a cause of acute abdominal pain. The lack of compliance (cooperation and communication) in small children obstructs clinical and radiological assessment and elucidates the necessity of knowledge of causes of acute abdominal pain as much as possible. A lot of patience and experience are mandatory in the evaluation of small children and therefore make a dedicated, trained and experienced stuff necessary. A dedicated paediatric radiologist will find a safe and proper technique, and in cooperation with the referring clinician the necessary decision for therapy will be made.

[Diagnostic imaging of giant cell tumors]. / Riesenzelltumoren in der Bildgebung.

Although classified as benign neoplasms, giant cell tumors are locally aggressive with a high recurrence rate of 30-50%. The histological appearance include osteoclast-like, multinucleated giant cells and round to spindle-shaped mono-nuclear stromal cells. These neoplasms predominately affect adults in the third and forth decades of life (70-80%). Giant cell tumors predominately arise in long tubular bones (75-95%) with the majority occurring around the knee (50%). The next most common site being the distal radius (10%). The epicenter of giant cell tumors is in the epiphysis. The radiographic signs of giant cell tumors are a geographical radiolucency with no internal mineralization, a thinning of the cortex, eccentric in the epiphysis of long bones. MRI signs of giant cell tumors are high signal intensity in T2-weighted images, high contrast media enhancement, fluid levels, signs according to haemorrhage and haemosiderin deposition. CT shows the expanded and thinned cortex. Plain radiographs remain the mainstay of diagnosis of giant cell tumors. MRI and CT are important for staging and therefore for surgical planning.