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The barium meal with plain X-ray films of the small intestine has for decades been the undisputed gold standard in imaging of the small intestine. More recently, X-rays and fluoroscopy with an overall accuracy of 73% have been replaced by multislice computed tomography (MSCT) or modern magnetic resonance imaging (MRI). Ultrasound is suitable for the orienting investigation of the small intestine in the context of general abdominal sonography as well as for dedicated examinations with a sensitivity of 67-96% and a specificity up to 97%. The endoscopic examinations of the small bowel, such as video capsule endoscopy and double-balloon enteroscopy are expensive and time-consuming techniques, which provide valuable information in special indications. Other than with the stomach or colon, the diagnostics of primary small intestine tumors plays a relatively subordinate role due to the low incidence of 3-5% of all gastrointestinal (GI) neoplasms but with a high sensitivity of 84% and a specificity of up to 97% for computed tomography (CT) and MRI. Predominant questions are those concerning ileus or the diagnostics of passage disturbances after preceding operations, to depict bowel obstructions, adhesions or the involvement of the small bowel in peritoneal carcinomatosis. The sensitivity per lesion in the initial evaluation of Crohn's disease (CD) is 47-68% for capsule endoscopy, 43% for MRI and 21% for CT enterography. In cases of known CD, the sensitivity is 70% for capsule endoscopy and 79% for MRI. A further indication is the evaluation of acute or occult gastrointestinal bleeding.

CT, and multi-detector row computed tomography in particular, play a very important role in staging malignant tumors of the stomach. The optimized technique of so called "Hydro-CT", including distension to the gastric wall with 1-1.5 l oral contrast media, mainly water, has fostered the diagnostic value of CT in the diagnosis of diseases of the stomach. By using the "Hydro-CT" technique, the detection rate for gastric carcinoma is now between 89% and 94%, and for liver metastasis between 85% and 92%. For overall T staging, the sensitivity is rather low at between 43% and 65%, and for the lymph nodes between 64 and 88%. Depending on tumor type, multislice computed tomography (MSCT) supplies morphological details for defining the type of lesion (polyps, gastritis, lymphoma, gastrointestinal stromal tumours, carcinoma). Nevertheless, a definite differential diagnosis remains difficult. In addition, multiplanar reconstruction (MPR), derived from multi-detector row computed tomography data sets, is very helpful in localizing these pathologies and demonstrating their anatomic relationship to adjacent organs and vascular structures. MRI plays no major part in the diagnostic evaluation of the upper GI-tract.

In the diagnosis of diseases of the esophagus, conventional x-ray evaluation still plays a more important role than endoscopy in the visualization of stenoses. CT plays a major role in the staging of malignancies of the esophagus, while MRI plays does not play a major part in the diagnostic evaluation of the upper GI-tract but is equal to CT for the staging and evaluation of the extent of local infiltration. The main indication for the radiological examination of the esophagus by barium studies is dysphagia. The use of barium allows a functional examination of esophageal motility. Swallow motility disorders can be diagnosed by videofluorography using high frame rate imaging. Zenker's diverticulum and other pulsion diverticula should also be investigated by functional esophageal imaging. Candida esophagitis can be identified by its characteristic ulcerations using barium swallow. The extension of gastroesophageal hernias are more accurately evaluated with barium studies than with endoscopy. The diagnosis of gastroesophageal reflux disease should be made by barium studies, but discrete inflammation as well as epithelial dysplasia are best investigated by classic endoscopy and modern endoscopic techniques. In cases of esophageal carcinoma, radiology adds to the findings of endoscopy and endosonography.

Purpose: Evaluation of typical MRI-findings in patients with Crohn's disease receiving therapy. Correlation with the course of disease., Patients and Methods: 81 follow-up MRI-studies in 25 patients conducted within a period of 3 weeks to 4 years were evaluated retrospectively. Therapy consisted in various combinations of antibiotics and immunosuppressive agents and if necessary operation. The findings of the MRI-studies were correlated with clinical data (e.g.operation of Crohn's complications) and the subjective perception during therapy., Results: The morphological substrate of Crohn's disease in the Hydro-MRI images is reliably detected. Especially in a delineation of extraluminal changes MRI is superior to endoscopy and enteroclysis. Independent from clinical symptoms short- and mid-term follow-up showed inflammatory changes of the intestinal wall in all 25 patients. In 24/81 studies there was persistence or even progression of Crohn's disease in the MRI-studies, although patients were free of symptoms by the time of image acquisition., Conclusion: Hydro-MRI is a modality for the evaluation of inflammatory changes in patients with Crohn's disease. Independent from clinical symptoms persistence of Crohn's disease is detectable.

Goal: To demonstrate the Heidelberg results of the previous 2 years in patients referred for acute aortic dissection., Material and Methods: 93 patients referred for acute aortic dissection were treated by cardiac surgery, vascular surgery and interventional radiology according to a novel therapeutic algorithm including stent-grafts and combined open and interventional procedures and conservative medical therapy when no malperfusion syndrome was present or patients were considered prohibitive for even minor surgical procedures. Stent-graft placements were done assisted by short term cardiac arrest to facilitate correct device deployment., Results: 36 patients presented with type A and the other 57 with type B dissection. 32 of the A patients were operated and 20 of the B patients, respectively. 12 patients with B dissection were treated with stent-grafts. 3 required additional interventional therapy for organ malperfusion. The mortality was 0% in these 12 patients The overall mortality rate in the A group was close to 40% mainly as a result of postoperative organ malperfusion while it was 15% in the B group. In both groups mortality was highest in the respective untreated patient subgroup (3/4 and 8/37, respectively). The main mortality factor was visceral (mesenteric or liver) ischemia. Paraplegic complications occured in neither group. In 4 patients a combined approach applying cardiac surgery of the ascending aorta and endluminal stent-graft placement for the residual B dissection was successfully performed. In one patient this was done simultaneously., Discussion: Acute aortic dissection of type A with or without valve involvement, coronary artery ischemia can be treated with high technical success rates. However, remaining distal aortic dissection associated with true lumen collapse and organ malperfusion is the main causative factor for clinical failures. Successful combination of open proximal aortic surgery with endoluminal treatment of residual B dissection encourages further use of this novel approach. Acute B type dissection appears to be effectively and safely treated by endoluminal approach in selected cases. Unsolved questions of this less invasive therapeutic approach focus mainly on the design of the proximal anchoring part of the devices.

Purpose: To investigate the value of multiphase breath-hold 3D gadolinium (Gd)-enhanced MR angiography (MRA) for lesion detection and characterization of focal liver lesions., Materials and Methods: Breath-hold 3D Gd-enhanced MRA was performed in 25 patients with benign and malignant hepatic lesions on a 1.5-T MR system using an ultrafast 3D spoiled gradient echo sequence (TR/TE =5/2 ms, FOV=300-450 mm, matrix=256x168, voxel volume=1.8x2.3 x2.5 mm, 64 partitions, central k-space reordering; acquisition time=27 s). Three measurements were done in the arterial, portal venous, and late venous phase., Results: The analysis of the spatial and temporal evolution of contrast enhancement of the 3D-MRA improved significantly (P<0.01) lesion detection and characterization if compared with T1 precontrast, T2-weighted, and T1 postcontrast images., Conclusion: Multiphase breath-hold 3D Gd-enhanced MRA imaging is a robust new technique to significantly improve morphological detection of benign and malignant lesions during the early arterial phase and further improves functional characterization of liver lesions by a combination of an arterial, a portal venous, and a late venous phase. Schlüssselwörter Multiphasisch. MR-Angiographie. Leberläsionen

For imaging of renal pathology a broad spectrum of radiologic diagnostic procedures are available which are, sometimes and particularly more recently, competing among each other in their diagnostic yield and relevance. For tumorous lesions ultrasound, computed tomography and magnetic resonance imaging are performed predominantly. Angiography is no longer required with the exception of highly selected cases and in some specific preoperative workup requirements. Until recently, catheter based digital subtraction angiography has been considered as gold standard. However, non-invasive techniques such as CT-angiography and MR-angiography are evolving parallel to their quantum leap of resolutions and readiness to use. Nevertheless, well accepted criteria for quality assessement of these new modalities are still lacking. More comparison studies are urgently warranted. Despite the availability of ultrashort pulse sequences applying the T1 relaxation reduction effect of gadolinium enhanced MR techniques overestimation of renal artery stenosis still poses a substantial problem. Renal intervention implies a variety of procedures such as plain angioplasty, stent placement, embolization of traumatic and both benign and malignant tumors. These methods have emerged over the last two decades from a more experimental nature to a fully accepted treatment option. When renal artery angioplasty is embedded in an aggressive approach including stenting as an adjunct for more complex cases, renal ostial lesions and a well organized follow-up regimen its therapeutic potential for treatment of renal insufficiency, malignant hypertension, for organ preservation bears a very high potential. Provided adequat periinterventional drug regimen restenosis rates may be as low as 10%. In highly selected cases capillary embolization might be used as an alternative to nephrectomy with a similar clinical outcome. Particularly the development of superselective small caliber embolization catheters parallel to further refinement of embolization material has aided to use superselective occlusion techniques in benign vascular lesions and renal trauma.

Diagnostic imaging after renal transplantation is of high importance in the differential diagnosis of peri- and postoperative complications. Sonography with color duplex imaging is the method of choice in the diagnosis of acute transplant rejection. MRI is an additional method in the diagnosis of transplant dysfunction especially in diagnosis of perirenal fluid collections. MR angiography and MR urography are noninvasive diagnostic modalities with the potential to replace angiography and pyelography. Angiography, complemented by carbon dioxide angiography, still is the gold standard in the diagnosis of transplant artery stenosis.

Purpose: To evaluate the feasibility of determining patency of the transjugular intrahepatic portosystemic shunt (TIPSS) by non-invasive CT angiography (CTA)., Materials and Methods: (1) Non-enhanced scanning of the shunt. (2) Bolus tracking by injecting 20 ml of non-ionic contrast material through a cubital vein access to determine the time to maximal shunt enhancement. (3) Contrast-enhanced spiral CT study applying a delay according to the time to peak of the shunt, 3 mm collimation, 5 mm table feed and 3 mm reconstruction interval. (4) 3D and multiplanar reconstructions. (5) Evaluation of the questions: intrahepatic shunt patent or not; evidence of intimal hyperplasia; evidence of stenosis and potential location. (6) Transjugular portography via the stent. (7) Comparison of angiographic findings and CT morphology., Results: Eight patients had inconspicuous CTA. Four of them had a normal shunt at angiography, four had slight intimal hyperplasia. No intervention was necessary in these patients. CTA of three patients showed intimal hyperplasia (lumen reduction between 10% and 50%). The diagnosis was angiographically confirmed in all cases. Due to a high portosystemic gradient intervention was required in all. In five patients CTA and angiography showed a stenosis (reduction of shunt lumen > 50%). All required a revision including stent placement or PTA of the shunt tract. Four shunts were occluded; all occlusions were shown both in CTA and angiography., Conclusions: None of the shunts with normal findings at CTA required revision. All shunts conspicuous on CTA resulted in revision. In this study, CTA turned out to be an accurate, non-invasive method to evaluate the patency of TIPSS.

The indications or ultrasound in the evaluation of pulmonary disorders are described. Clinical applications are several lung diseases in adults and especially in children. In specific, well-defined applications, the feasibilities of ultrasound are promising. Sonography provides important additional information to chest X-ray and is even superior to CT under special circumstances. Pulmonary sonography is a useful link between conventional X-ray and more expensive cross-sectional imaging. In the evaluation of pulmonary diseases at present the potential of ultrasound is not optimally used.