S. H. Duda

[CT-guided radiofrequency (RF) ablation of osteoid osteoma: clinical long-term results].

PURPOSE To evaluate CT-guided radiofrequency (RF) ablation of osteoid osteoma using internally cooled monopolar RF electrodes for technical success, complications and clinical long-term success. MATERIALS AND METHODS Between April 1999 and July 2006, 23 patients were treated under general anesthesia with CT-guided RF ablation using an internally cooled monopolar single RF electrode (Cool-tip, Valleylab, TycoHealthcare, Boulder, USA; active tip: 10 mm). For the removal of the nidus, we used either a manual or an automated drill. The technical success was evaluated by a CT scan (MSCT, Siemens Medical Solutions, Forchheim). The clinical long-term success was investigated by questioning patients prior to discharge, and after 6, 12 and 18 months. After 18 months, patients were interviewed on an annual basis. RESULTS The technical success rate was 100 %. The nidus was located in n = 19 cases at the lower extremity and in n = 4 cases at the upper extremity. Minor complications were observed for n = 2 patients. The mean hospitalization time was 1.5 d (1-2 d). The mean follow-up was 75.9 months (18-120 months) for n = 23 patients. No local recurrence was observed. One patient had intermediate pain one week after RF ablation without recurrent symptoms. CONCLUSION CT-guided RF ablation using an internally cooled monopolar single RF electrode is an effective and safe minimally invasive method for the treatment of osteoid osteoma with excellent clinical long-term success.

Verschlußikterus – palliative Drainage aus der Sicht des Radiologen

The technical success rates of percutaneous transhepatic biliary drainage (PTBD) in patients with malignant biliary obstructions range between 95 and 100%. There is a reocclusion rate of 30% after percutaneous implantation of Wallstents. The median survival of these patients is 180 days. For management of stent occlusions we prefer overstenting. Patients after surgery of the upper gastrointestinal tract should receive a PTBD as first-line therapy. The same applies for proximal occlusions and obstructions in the very distal choledochal duct with invasion of the papilla of Vateri or duodenal stenosis. Another advantage of the percutaneous route is a simplified technique for afterloading therapy of biliary carcinoma.

Nichtinvasive Diagnostik von Gallenwegstenosen mit der Magnetresonanz-Cholangiopankreatikographie

Magnetic resonance cholangiopancreatography (MRCP) is a noninvasive technique for evaluation of the biliary system without need of contrast agents. Heavily T2-weighted projection acquisitions and tomographic images are performed in a single breath-hold period. Choledocholithiasis and bile duct obstruction can be ruled out consistently. PSC-related intrahepatic cholestasis is well demonstrated. However, diagnostic accuracy in the differentiation of benign and malignant disease is limited, particularly in the papillary segment. Currently, MRCP should be performed when endoscopic retrograde CP was unsuccessful, in the follow-up of PSC and for complete staging of obstructing tumors in addition to MRI and MR angiography.