Karl Ludwig

CT-guided radiofrequency ablation of osteoid osteoma and osteoblastoma: Clinical success and long-term follow up in 77 patients

The purpose of this study was to retrospectively evaluate long-term success of CT-guided radiofrequency ablation (RFA) in patients with osteoid osteoma (OO) and osteoblastoma (OB) including tumors in critical locations. Eighty-one CT-guided RFA procedures were performed in 77 patients with OO (65 patients) and OB (12) including 6 spinal and 15 intra/periarticular tumors. Procedural techniques included multiple needle positions, three-dimensional access planning, as well as, thermal protection techniques. Long-term success was assessed using a questionnaire including, among others, several VAS (visual analogue scale) scores. All patients completed 3-6 months follow-up, overall response to the questionnaire was 64/77 (83.1%). Primary success rate was 74/77 (96.1%) of all patients. Retreatment with RFA in 3 patients resulted in a secondary success rate of 77/77 (100%). Long-term follow-up (mean, 38.5 months; range, 3-92) revealed a highly significant (p<0.001) reduction of all assessed limitation scores reaching normal or almost normal values. One major complication, a cannula break leading to a secondary short hospital stay, occurred. In conclusion, RFA is a safe and effective long-lasting treatment of OO and OB. Advanced procedural techniques aid treating tumors in critical locations and in the coverage of larger tumors. Besides night pain, RFA also greatly improves other factors negatively affecting the quality of life.

CT-guided radiofrequency ablation of osteoid osteoma: correlation of clinical outcome and imaging features

PURPOSE We aimed to retrospectively evaluate the computed tomography (CT) and magnetic resonance imaging (MRI) findings of patients with osteoid osteoma treated with CT-guided radiofrequency ablation (RFA) along with the clinical outcome and long-term success. MATERIALS AND METHODS Seventy-three CT-guided RFA procedures were performed in 72 patients. The long-term success was assessed using a questionnaire including several visual analog scale scores. The CT evaluation included pre- and immediate postprocedural imaging of all 72 patients, and MRI was performed in 18 patients with follow-up imaging (mean, 3.4±2.2 months). The evaluation criteria included nidus morphology and a correlation with markers of clinical success. RESULTS The primary technique effectiveness rate was 71/72 (99%). One relapse was successfully retreated, leading to a secondary technique effectiveness rate of 72/72 (100%). The long-term follow-up (mean, 51.2±31.2 months; range, 3-109 months) revealed a highly significant reduction of all assessed limitation scores (P < 0.001). The CT morphology was typical in all cases and did not change during the short-term follow-up. The follow-up MRI patterns varied considerably, including persistent nidus contrast enhancement in one-third (6/18) and persistent marrow edema in half (9/18) of the patients. None of the investigated MRI and CT patterns correlated with the clinical outcome. CONCLUSION The long-term outcome of CT-guided RFA of osteoid osteoma is excellent. There is no correlation of the CT and MRI patterns with the clinical outcome. Thus, the treatment decisions should not be solely based on the imaging findings. Investigators should also be aware of the variety of imaging patterns after RFA.

Depiction of the triangular fibro-cartilage in patients with ulnar-sided wrist pain: comparison of direct multi-slice CT arthrography and direct MR arthrography

To compare direct multi-slice CT arthrography (MSCT-AG) and direct MR arthrography (MR-AG) of the wrist with regard to the depiction of the triangular fibro-cartilage (TFC). Fifteen consecutive patients with ulnar-sided wrist pain suspicious for TFC tear underwent both MSCT-AG and MR-AG of the wrist. Images obtained were evaluated by two radiologists in a blinded fashion for the depiction of six anatomical areas (radial, central and ulnar portion on the proximal and distal side) of the TFC by means of a five-point scoring system (1 = excellent visibility to 5 = not visible). Scores for MSCT-AG and MR-AG were compared using the Students t-test. Mean scores for MSCT-AG and MR-AG, respectively, were 2.5/2.0, 3.2/2.5 and 2.8/2.4 for the radial, central and ulnar portion of the TFC on its proximal side, and 2.7/2.0, 3.1/2.3 and 2.9/2.4 for the radial, central and ulnar portion on its distal side (n = 15). Paired Students t-test showed no significant difference between MSCT-AG and MR-AG (P > 0.05). In a first, small series, depiction of the TFC with MSCT-AG is comparable to that of MR-AG. Further evaluation of direct multi-slice CT arthrography of the wrist in a larger patient population would be promising.

Diagnostic performance of a flat-panel detector at low tube voltage in chest radiography: a phantom study.

Rationale and Objectives:To evaluate a large area, cesium iodide amorphous silicon flat-panel detector (CsI/a-Si) at 3 tube voltages to detect simulated interstitial lung disease, nodules, and catheters. Methods:Simulated interstitial lung disease, nodules, and catheters were superimposed over a chest phantom. Images were generated at 125 kVp, 90 kVp, and 70 kVp at the same surface dose and reduced effective dose equivalent for 90 kVp and 70 kVp and printed on hard copies. Fifty-four thousand observations were analyzed by receiver operating characteristic (ROC). Results:Detectability of linear, miliary, reticular pattern, and nodules over lucent lung as well as of catheters and nodules over obscured chest areas increased at 90 and/or 70 kVp with higher Az values; however, only it was statistically significant for reticular pattern at 70 kVp and nodules at 90 kVp compared with 125 kVp (P <0.05). The detection of ground-glass pattern was worse at lower kVp (P >0.05). Conclusion:For most simulated patterns, differences in diagnostic performance at 70 kVp/90 kVp and 125 kVp were not significant, except for reticular pattern and nodules over lucent lung.

Mikropaläontologische Hinweise für die autochthone Entstehung der miozänen Braunkohle im Becken von Teruel-Ademuz (NE-Spanien)

The Miocene of the basin of Teruel-Ademuz (NE-Spain) is characterized by extreme lateral and vertical facies changes. An example is the genesis of the brown coal deposit and the interbedded calcareous marls near Mas del Olmo in the southern part of the basin. Seeds of the subaquaceous, carnivorous water plantAldrovandia praevesiculosa occur in the brown coal. This plant is restricted to warmswampy environments with extremely low calcium content. The rocks surrounding the basin of TeruelAdemuz are predominately limestones and marls; thus, any water supply from the general area to the swamp would have changed the conditions indicated byAldrovandia. This shows that the lake basin had no freshwater influx during the formation of the peat which is therefore autochthonous. A different situation existed during the deposition of the interbedded and underlying marly clays. They contain teeth of carp, freshwater ostracods(Candona-Cypridopsis-Potamocypris assemblage) and charophytes. The fossils indicate a deposition of these layers in a shallow, oligotrophic Stillwater area sporadically or permanently connected with a fluvial system.KurzfassungZur Klärung der Bildung des miozänen Braunkohlevorkommens im neogenen Bekken von Teruel-Ademuz (NE-Spanien) werden mikropaläontologische Hinweise herangezogen. Das Vorkommen von Samenresten der submers lebenden, fleischfressenden WasserpflanzeAIdrovandia praevesiculosa in der Kohle beweist neben dem Fehlen von Hölzern die Entstehung in einem von Süßwasserzufuhr abgetrennten, kalkfreien, sumpfigen Milieu unter warmen klimatischen Verhältnissen und unterstreicht den autochthonen Ursprung der Kohle. Die in den Zwischenschichten gefundenen Floren- und Faunenelemente (Charophyten, Schlundzähnchen von Karpfen, Süßwasser-Ostracoden wie z. B.Candona sp.,Cypridopsis sp.,Potamocypris sp.) geben dagegen Anhaltspunkte für die Ablagerung dieser Zwischenschichten in einem flachen, oligotrophen Stillwasserbereich mit höherem Kalkgehak, der sporadisch oder permanent mit einem Flußsystem in Verbindung stand.