Rofo-fortschritte Auf Dem Gebiet Der Rontgenstrahlen Und Der Bildgebenden Verfahren最新文献

Augmented reality (AR) projects additional information into the user's field of view during interventions. The aim was to evaluate the acceptance and clinical feasibility of an AR system and to compare users with different levels of experience. A system was examined that projects a CT-generated 3D model of a phantom into the field of view using a HoloLens 2, whereby the tracked needle is displayed and navigated live. A projected ultrasound image is used for live control of the needle positioning. This should minimize radiation exposure and improve orientation.The acceptance and usability of the AR navigation system was evaluated by 10 physicians and medical students with different levels of experience by performing punctures with the system in a phantom. The required time was then compared and a questionnaire was completed to assess clinical acceptance and feasibility. For statistical analysis, frequencies for qualitative characteristics, location and dispersion measures for quantitative characteristics and Spearman rank correlations for correlations were calculated.9 out of 10 subjects hit all 5 target regions in the first attempt, taking an average of 29:39 minutes for all punctures. There was a significant correlation between previous experience in interventional radiology, years in the profession, and the time required. Overall, the time varied from an average of 43:00 min. for medical students to 15:00 min. for chief physicians. All test subjects showed high acceptance of the system and rated especially the potential clinical feasibility, the simplification of the puncture, and the image quality positively. However, the majority require further training for sufficient safety in use.The system offers distinct advantages for navigation and orientation, facilitates percutaneous interventions during training and enables professionally experienced physicians to achieve short intervention times. In addition, the system improves ergonomics during the procedure by making important information always directly available in the field of view and has the potential to reduce the radiation exposure of staff in particular by combining AR and sonography and thus shortening CT-fluoroscopy times. · AR navigation offers advantages for orientation during percutaneous radiological interventions.. · The subjects would like to use the AR system in everyday clinical practice on patients.. · AR improves ergonomics by making important information directly available in the field of view.. · The combination of AR and sonography can significantly reduce radiation exposure for staff.. · Rohmer K, Becker M, Georgiades M et al. Acceptance and feasibility of an augmented reality-based navigation system with optical tracking for percutaneous procedures in interventional radiology - a simulation-based phantom study. Fortschr Röntgenstr 2024; DOI 10.1055/a-2416-1080.

Background:  Perivascular spaces (synonym: Virchow-Robin spaces) were first described over 150 years ago. They are defined as the fluid-filled spaces surrounding the small penetrating cerebral vessels. They gained growing scientific interest especially with the postulation of the so-called glymphatic system and their possible role in neurodegenerative and neuroinflammatory diseases.

Methods:  PubMed was used for a systematic search with a focus on literature regarding MRI imaging and evaluation methods of perivascular spaces. Studies on human in-vivo imaging were included with a focus on studies involving healthy populations. No time frame was set. The nomenclature in the literature is very heterogeneous with terms like "large", "dilated", "enlarged" perivascular spaces whereas borders and definitions often remain unclear. This work generally talks about perivascular spaces.

Results:  This review article discusses the morphologic MRI characteristics in different sequences. With the continual improvement of image quality, more and tinier structures can be depicted in detail. Visual analysis and semi or fully automated segmentation methods are briefly discussed.

Conclusion:  If they are looked for, perivascular spaces are apparent in basically every cranial MRI examination. Their physiologic or pathologic value is still under debate.

Key points:   · Perivascular spaces can be seen in basically every cranial MRI examination.. · Primarily T2-weighend sequences are used for visual analysis. Additional sequences are helpful for distinction from their differential diagnoses.. · There are promising approaches for the semi or fully automated segmentation of perivascular spaces with the possibility to collect more quantitative parameters..

Citation format: · Seehafer S, Larsen N, Aludin S et al. Perivascular spaces and where to find them - MRI imaging and evaluation methods. Fortschr Röntgenstr 2024; 196: 1029 - 1036.

The TFCC consists of several components whose functional significance has been recognized in detail in recent years. Existing classifications are partly incomplete. In addition, the TFCC requires specific and dedicated imaging techniques.This review describes the anatomy and pathoanatomy of the TFCC. The different types of TFCC lesions on MRI as well as MR and CT arthrography are explained and compared with the current literature. In addition, the novel CUP classification is presented and illustrated with image examples.Anatomically and functionally, the articular disc and radioulnar ligaments with their ulnar insertions and the inhomogeneously structured TFCC periphery must be differentiated. For accurate imaging, thin slices with high in-plane resolution and techniques to optimize contrast are required. Plain MRI is exclusively dependent on T2 contrast, while gadolinium-enhanced MRI offers the additional benefit of focal contrast enhancement, e.g., of fibrovascular repair tissue at the lesion site. However, the reference standard continues to be MR and CT arthrography, which should be used for focused indications. The CUP classification, which allows a comprehensive description and categorization of TFCC lesions, is presented and illustrated. · Anatomically, the TFCC consists of the central ulnocarpal disc, the dorsal and palmar radioulnar ligaments, and the ulnocarpal joint capsule including intracapsular ligaments and the meniscus homologue.. · The most important restraining structure of the TFCC is the lamina fovealis, which stabilizes the DRUJ. This structure constitutes the proximal (deep) continuation of the radioulnar ligaments at the ulnar insertion.. · Imaging of the TFCC requires high spatial and contrast resolution due to its minute structures. MR and CT arthrography are the reference standard in imaging.. · The CUP classification clearly describes all structures of the TFCC with the categorization of individual or combined lesion patterns.. · Schmitt R, Kunz AS, Reidler P et al. Triangular Fibrocartilage Complex (TFCC) - Anatomy, Imaging, and Classifications with Special Focus on the CUP Classification. Fortschr Röntgenstr 2024; DOI 10.1055/a-2411-8444.

Background:  Partial pancreatic resections are among the most complex surgical procedures in visceral tumor medicine and are associated with a high postoperative morbidity with a complication rate of 40-50 % of patients even in specialized centers.

Methods:  Description of typical surgical resection procedures and the resulting postoperative anatomy, typical normal postoperative findings, common postoperative complications, and radiological findings.

Results and conclusion:  CT is the most appropriate imaging technique for rapid and standardized visualization of postoperative anatomy and detection of clinically suspected complications after partial pancreatic resections. The most common complications are delayed gastric emptying, pancreatic fistula, acute pancreatitis, bile leakage, abscess, and hemorrhage. Radiologists must identify the typical surgical procedures, the postoperative anatomy, and normal postoperative findings as well as possible postoperative complications and know interventional treatment methods for common complications.

Key points:   · Morbidity after pancreatic surgery remains high.. · CT is the best method for visualizing postoperative anatomy and is used for early detection of complications.. · Pancreatic fistula is the most common relevant complication after pancreatic resection.. · The ability of a center to manage complications is crucial to ensure the success of therapy..

Citation format: · Fischbach R, Peller M, Perez D et al. The postsurgical pancreas. Fortschr Röntgenstr 2024; 196: 1037 - 1045.

Purpose:  With an incidence between 1-9/100 000 per year, Langerhans cell histiocytosis (LCH) is a rather rare disease from the hemato-oncologic disease spectrum (Hayes et al. 2009). The tumorlike disease with proliferation of histiocytic cells may manifest as localized to one organ or disseminated with infiltration of a wide variety of organs. Approximately 25-30 % of these cases show involvement of the temporal bone (Ni et al. 2017).

Case description:  With vertigo persisting for three years, chronic mastoiditis, and acute progressive hearing loss bilaterally (r > l) for three weeks, a 41-year-old woman presented at an emergency department. The DVT showed extensive bony destruction of large parts of the temporal bone on both sides, involving the vestibular organ, the cochlea, and the internal auditory canal. To confirm the suspicion of a systemic inflammatory process, a PE was performed from the mastoid with bioptic confirmation of an LCH. Systemic therapy was initiated. Post-therapeutic imaging showed almost complete remission with reossification of the preexisting defect zones and the internal auditory canal and labyrinth structures again showed bony margins. Clinically, there was an improvement of the vegetative symptoms with remaining bilateral sensorineural hearing loss.

Discussion:  LCH of the temporal bone is a rare and often misdiagnosed disease due to its nonspecific clinical presentation. Awareness of temporal bone LCH and its occurrence in adults is essential for accurate and consistent diagnosis.

Key points:   · LCH is a rather rare disease from the hemato-oncological spectrum. · Affection of the temporal bone, especially such an extensive one (as in this case report), is rather atypical in adulthood. · Use of systemic therapy resulted in remission. · There was complete reossification of the osseous structures post-therapy. · A cochlear implant was able to be implanted to compensate for hearing loss.