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Clinical/methodical Issue: In view of the diagnostic complexity and the large number of examinations, modern radiology is challenged to identify clinically significant prostate cancer (PCa) with high sensitivity and specificity. Meanwhile overdiagnosis and overtreatment of clinically nonsignificant carcinomas need to be avoided., Standard Radiological Methods: Increasingly, international guidelines recommend multiparametric magnetic resonance imaging (mpMRI) as first-line investigation in patients with suspected PCa., Methodical Innovations: Image interpretation according to the PI-RADS criteria is limited by interobserver variability. Thus, rapid developments in the field of automated image analysis tools, including radiomics and artificial intelligence (AI; machine learning, deep learning), give hope for further improvement in patient care., Performance: AI focuses on the automated detection and classification of PCa, but it also attempts to stratify tumor aggressiveness according to the Gleason score. Recent studies present good to very good results in radiomics or AI-supported mpMRI diagnosis. Nevertheless, these systems are not widely used in clinical practice., Achievements and Practical Recommendations: In order to apply these innovative technologies, a growing awareness for the need of structured data acquisition, development of robust systems and an increased acceptance of AI as diagnostic support are needed. If AI overcomes these obstacles, it may play a key role in the quantitative and reproducible image-based diagnosis of ever-increasing prostate MRI examination volumes.

Background: A revised version of the PI-RADS scoring system has been introduced and score-related variability between version 1 and 2 may be suspected. This study aimed to assess the PI-RADS scores derived from version 1 (v1) and the updated version 2 (v2)., Material and Methods: 61 patients with biopsy-proven prostate cancer (PCa) and 90 lesions detected on pre-biopsy 3-Tesla multiparametric MRI were included in this retrospective analysis. 2 experienced radiologists scored all lesions in consensus. Lesion scores differing between PI-RADS v1 and v2 were further analyzed. Histology data from radical prostatectomy (RP) were included when available., Results: The PI-RADS v1 and v2 score differed in 52% of patients (32/61) and in 39% of lesions (35/90). On a lesion basis, the reason for the differences were related to sum score in v1 vs. categorical system in v2 in 51% (18/35) of lesions, cutoff between PI-RADS 4 and 5 based on lesion size in v2 as opposed to the sum score in v1 in 31% (11/35) and were inconclusive in 17% (6/35). The RP subgroup indicates enhanced detection of PCas with GS 3+3 and GS 3+4 in v2., Conclusion: PI-RADS scores of prostatic lesions frequently differed between v1 and v2, the major reasons for these differences being score-related. In men undergoing RP, PI-RADS v2 improved detection of low risk PCa, but did not increase accuracy for discrimination of GS 3+4 vs. GS≥4+3 compared to v1. Urologists should be aware of the system-related differences when interpreting PI-RADS scores., (© Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: To quantitatively analyze differences in mechanical properties, needle design including signs of wear, subjective handling and specimen quality of bone biopsy needles., Materials and Methods: In this study 19 different bone biopsy systems (total 38; 2 /type) were examined. With each biopsy needle five consecutive samples were obtained from vertebral bodies of swine. During puncture a force-torques sensor measured the mechanical properties and subjective handling was assessed. Before and after each biopsy the needles were investigated using a profile projector and signs of wear were recorded. Afterwards, a pathologist semi-quantitatively examined the specimen regarding sample quality. The overall evaluation considered mechanical properties, needle wear, subjective handling and sample quality. Differences were assessed for statistical significance using ANOVA and t-test., Results: Needle diameter (p = 0.003) as well as needle design (p = 0.008) affect the mechanical properties significantly. Franseen design is significantly superior to other needle designs. Besides, length reduction recorded by the profile projector, as a quality criterion showed notable distinctions in between the needle designs., Conclusion: Bone biopsy needles vary significantly in performance. Needle design has an important influence on mechanical properties, handling and specimen quality. Detailed knowledge of those parameters would improve selecting the appropriate bone biopsy needle., (© Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: Evaluation of the enhancing or protecting effects of different fluids during microwave ablation (MWA)., Materials and Methods: 3 samples of 17 different fluids (each 20 ml) were heated using MWA at power levels of 10, 20, 30, 40 and 45 watts. Energy was applied until the temperature reached 80 degrees C or the duration of heating exceeded 10 minutes. The cooling-down process was then observed until the temperature reached 30 degrees C., Results: Gastrografin needed the shortest time to be heated up to 80 degrees C (370 sec), followed by Magnograf (410 sec) and HES 10 % (420 sec). The least heatable fluids were Lipiodol (10 min -54.5 +/- 2.43 degrees C), distilled water (10 min -56 +/- 2.42 degrees C) and Glucose 5 % solution (10 min -56.6 +/- 1.69 degrees C). Fluids which could not be heated well, such as distilled water, Lipiodol or Glucose 5 % solution, had a small slope of the temperature curve as a function of the power level used (m = 0.60 - 0.73), whereas fluids which could be heated well, such as Gastrografin, Magnograf and HES 10 %, had a much steeper slope of the temperature curve as a function of the power level (m = 0.99 - 1.20). With respect to the maximum temperature, the above mentioned groups differed significantly (p < 0.05). The temperature slope correlated strongly with maximum temperatures reached (Pearson correlation coefficient: 0.97)., Conclusion: By additionally administering a carefully chosen fluid, enhancing or protecting effects during microwave ablation can be observed. Especially Gastrografin, Magnograf and HES 10 % can be used to enhance ablation effects, whereas protective effects can be observed particularly when using Lipiodol, distilled water and Glucose 5 %-solution., (Georg Thieme Verlag KG Stuttgart New York.)

Purpose: Osteoid osteoma is a benign primary bone tumor that typically occurs in children and young adults. Besides local pain, which is often worse at night, prompt relief due to medication with acetylsalicylic acid (ASS) is characteristic for this bone lesion. Because long-term medication with ASS does not represent an alternative treatment strategy due to its potentially severe side effects, different minimally invasive image-guided techniques for the therapy of osteoid osteoma have been developed. In this context radiofrequency (RF) ablation in particular has become part of the clinical routine. The technique and results of image-guided RF ablation are compared to alternative treatment strategies., Materials and Methods: Using this technique, an often needle-shaped RF applicator is percutaneously placed into the tumor under image guidance. Then a high-frequency alternating current is applied by the tip of the applicator which leads to ionic motion within the tissue resulting in local heat development and thus in thermal destruction of the surrounding tissue including the tumor., Results: The published primary and secondary success rates of this technique are 87 and 83 %, respectively. Surgical resection and open curettage show comparable success rates but are associated with higher complication rates. In addition image-guided RF ablation of osteoid osteomas is associated with low costs., Conclusion: In conclusion image-guided RF ablation can be considered the gold standard for the treatment of osteoid osteoma.