Hans-Jürgen Raatschen

Radiofrequency Ablation of a Rare Case of an Intraosseous Hibernoma Causing Therapy-refractory Pain

and the smaller-diameter stents would have been more likely to cause obstruction and would have been more difficult to exchange in the future (1). A three-staged combined procedure (2) involving placement of an antegrade nephrostomy catheter/nephroureterostomy catheter, conversion to a retrograde nephroureteral catheter, and, finally, transileal exchange of the retrograde nephroureteral stent and removal of the antegrade nephrostomy tube was also not considered appropriate despite a success rate greater than 90% because, again, this would involve positioning the patient prone to initially insert the antegrade nephrostomy. In most cases of ileal conduit obstruction and urosepsis, we would advocate percutaneous nephrostomy to decompress the system and antibiotic treatment with retrograde exchange of ureteroileal stents via the ileal conduit at a later date. However, in the present case, positioning the patient prone to perform nephrostomy insertion was considered more difficult as a result of recent laparotomy and large parastomal hernia. A retrograde transileal approach reduced the risk associated with the performance of percutaneous nephrostomy and

Is there a need for MRI within 24 hours after CT-guided percutaneous thermoablation of the liver?

Background Radiofrequency (RFA) and microwave ablation (MWA) are established minimally invasive techniques for treatment of hepatic tumors. Purpose To compare technical success and accuracy of hepatic thermoablation using computed tomography (CT) and magnetic resonance imaging (MRI) acquired 24 h after ablation with regard to evaluation of the post-interventional ablation zone and local tumor recurrence (LTR), and to assess whether additional MRI within 24 h is beneficial. Material and Methods Thirty-two patients (23 men, 9 women; mean age, 60 years) with 48 lesions were included in this retrospective study. CT was performed immediately and MRI was performed 24 h after ablation. Diameter and volume calculations of the ablation zone were compared (T-Test). Technical success and ablation margin distinction, shape, and configuration were evaluated (κ-statistic). Local effectiveness was calculated based on follow-up imaging. Technical success and ablation margin features were correlated with LTR (log-rank test, Fishers exact test). Results Ablation zone volumes were significantly higher with MRI compared to CT (P < 0.05; mean volume, 55.19 and 45.97 mL). Agreement between CT and MRI for technical success was good (κ = 0.801) and for margin conspicuity fair (κ = 0.289). LTR was 26.1% (mean follow-up, 11.7 months). LTR showed no correlation with technical success or margin conspicuity. Conclusion CT and MRI are suited for early evaluation of technical success after thermoablation. Within 24 h a significant increase of the ablation volume is observed, which has to be taken into account when interpreting immediate postprocedural imaging and treating lesions near critical structures. Additional MRI 24 h after ablation seems of limited value regarding prognosis of LTR, especially with regards to evaluation of ablation margin shape and conspicuity.

CT angiography for pulmonary embolism detection: the effect of breathing on pulmonary artery enhancement using a 64-row detector system.

Background Computed tomography pulmonary angiography (CTPA) is used most often in routine clinical practice for the assessment of a suspected pulmonary embolism. The diagnostic accuracy relies on sufficient contrast enhancement. Purpose: To evaluate whether image acquisition during shallow breathing can improve the image quality in patients with insufficient contrast enhancement during breath-hold examinations. Material and Methods A total of 2786 CT pulmonary angiographies, acquired on a 64-row CT during deep-inspiration breath-hold, were reviewed. Twenty-four examinations were considered non-diagnostic due to poor contrast enhancement in the pulmonary arteries (PA), although they showed preserved vascular enhancement of the superior vena cava (SVC) and the ascending aorta (AO). Eleven flawed CTPA examinations, including severe breathing artifacts and incorrect triggering were excluded. In 13 of the remaining patients, the examination was repeated during shallow breathing. Vascular contrast enhancement was compared between both scans by measuring the relative enhancement within the SVC, the main PA, and the AO. Image quality was scored by two, clinically experienced radiologists. The values are given as median and [25th;75th] quartile. Results There was a significant difference in the CT values for the PA between the repeated scans (P = 0.0002, Wilcoxon test), and with the CTPA in deep-inspiration showing a median enhancement of 97 HU (59–173), compared with 303 HU (239–385) in the CTPA acquired during free breathing. The differences for both the AO (P = 0.54) and the SVC (P = 0.78) were not significant. Scoring for the attenuation quality rose significantly (P = 0.0002) and no severe motion artifacts were detected on either scans. Conclusion If there is insufficient pulmonary artery enhancement during CTPA, attenuation of the pulmonary arteries can be improved by acquisition during shallow breathing and is without significant loss of the overall diagnostic image quality.

Proof of principle for bevacizumab activity in desmoid-type fibromatosis

BackgroundDesmoid-type fibromatosis (DF) is a rare disease, which often occurs in young adults. Medical treatment is an important option in the treatment algorithm of DF. Different chemotherapeutic regimens showed clinical activity in DF, but overall treatment tolerability remains poor for this patient cohort. Novel approaches investigated tyrosine kinase inhibitors in DF, but tolerability remained an issue.Case presentationWe treated a patient with progressive DF after failure of chemotherapy for 1 year with singe agent bevacizumab. He achieved a symptomatic and radiologic response while attainning excellent tolerability.ConclusionsThis is the first report on single agent bevacizumab in DF, which showed both, good tolerability and efficacy in our patient, thereby warranting future trials in DF.

Initial Experience with Digital Patient Briefing in Computed Tomography

PURPOSE  To assess digital patient briefing as an alternative to conventional paper documentation. MATERIALS AND METHODS  502 patients with a planned computed tomography (CT) examination were selected for digital patient briefing using the E-ConsentPro software from Thieme Compliance on an iPad by Apple (Cupertino, California, USA). For the analysis, three age groups were formed. The time required for the patient briefing, the number of open questions as well as the time needed for discussion with physicians were determined. Students t-test was performed to assess statistical significance. RESULTS  There was no significant difference between patient age and briefing time which was about 20 minutes on average. The number of open or unclear questions increased with patient age. While patients younger than 30 years of age had about 2 open questions, patients over 30 and 60 years had about 4 and 5 questions, respectively. The total time needed for discussion with physicians was less than 2 minutes on average. A significant difference in the time required for discussion with physicians could not be observed between the individual age groups. CONCLUSION  Tablet-based digital briefing allows the storage of patient documents with reasonable time and effort. Furthermore, it minimizes the risk of data loss. KEY POINTS   · Tablet-based digital patient briefing in computed tomography can be performed with reasonable time and effort.. · The time required for tablet-based patient briefing is independent of patient age.. · The cost-benefit analysis presents a significant improvement in digital patient briefing compared to the paper-based process.. CITATION FORMAT · Alikhani B, Hensen B, Grosser A et al. Initial Experience with Digital Patient Briefing in Computed Tomography. Fortschr Röntgenstr 2019; 191: 540 - 546.

Evaluation of transient respiratory motion artifact at gadoxetate disodium-enhanced MRI—Influence of different contrast agent application protocols

Purpose To evaluate transient severe respiratory motion artifacts (TSM) at gadoxetate disodium-enhanced MRI dependent on the mode of contrast agent application. Methods 200 patients (71f, 129m; mean 51y) were included in this retrospective IRB-approved study. Contrast application protocols (n = 4) differed with regards to injection rate (2ml or 1ml/sec), dose (weight-based or fixed 10ml) and supplemental oxygen administration (yes/no). SNR measurements were performed in the aorta and portal vein. Qualitatively, three readers assessed arterial phase image quality and TSM independently (4- and 5-point scale, respectively). Quantitative and qualitative results were compared (Kruskal-Wallis test, Dunn’s multiple comparison test). The influence of different contrast agent application parameters on the occurrence of respiratory motion artifacts was assessed (univariate analysis). Interrater agreement and reliability were calculated (intraclass correlation coefficient, ICC)). Results Use of a lower contrast injection rate resulted in significantly higher arterial SNR in the aorta and portal vein (p<0.05). TSM was observed in 12% of examinations. Neither injection rate, contrast dose, nor oxygen had a significant influence. Interrater agreement and reliability for evaluation of image quality and respiratory motion were substantial/ almost perfect (ICC = 0.640–0.915). Conclusions Technical factors regarding the specific mode of contrast application do not seem to significantly reduce the incidence of severe transient respiratory motion artifacts.