Radiologe最新文献

Clinical problem: Neurofibromatosis type 1 (NF1) and tuberous sclerosis (TS) are among the most common genetic diseases. Bone and soft tissue manifestations are common disease manifestations.

Standard radiological procedure and evaluation: The standard radiological procedure is magnetic resonance imaging (MRI). All macroscopic disease manifestations can be diagnosed radiologically and observed during the course. Specific complications such as plexiform neurofibromas and malignant peripheral nerve sheath tumors (MPNST) in NF1 are readily visible on MRI. Differentiation of plexiform neurofibromas and MPNST is uncertain and requires follow-up.

Recommendation for practice: MRI is the most important procedure for the investigation of soft tissue and bone manifestations of NF1 and TS.

Clinical/methodical issue: Diagnosis of sclerosing and hyperostotic bone disorders (SHS) is challenging. The correct and early identification of SHS can have therapeutic, prognostic and, in case of genetic SHS with regard to the risk of inheritance, advisory consequences.

Standard radiological methods: For diagnosis, radiographic examinations and supplementary computed tomography (CT) and magnetic resonance imaging (MRI) are used. These are of indicative nature. Definitive diagnosis is usually made by genetic differentiation.

Methodical innovations: In combination with the age of the affected person and the location of the osseous changes the characteristic image criteria are important. These are summarized in groups in this overview.

Practical recommendations: Projection radiography in two planes is the imaging modality of choice. CT and MR can detect additional differential diagnostic criteria and should be indicated when needed.

Introduction: Hybrid magnetic resonance (MR) linear accelerators (MR-Linacs) for radiotherapy allow for the visualization and tracking of moving target volumes during the entire treatment. This makes gated treatments possible, decreasing the irradiated volumes and thus sparing healthy tissue from unnecessary radiation dose. Conventionally, tumors that are subject to respiration motion are treated by irradiating the entire area of potential target presence (internal target volume, ITV). This study presents three patient cases (lung, adrenal gland, and liver tumors) treated with gated MR-guided radiotherapy and compares the treatment plans retrospectively with conventional ITV plans.

Materials and methods: The gross tumor volume was delineated on MR and computed tomography (CT) images of the patients, and MR-Linac treatment plans were generated using additional clinical and planning target volume margins. The motion of the gross tumor volume was evaluated on two-dimensional cine-MRI images during the entire MR-Linac treatment. Based on the motion analysis, standard ITV-based plans were retrospectively created and compared by means of irradiated target volumes and dose-volume parameters.

Results: For the MR-Linac plans, the irradiated treatment volumes were reduced by an average of 62% across the three cases, and for one case the ITV-based target volume would have overlapped with a critical organ. Target volume coverage was much better and the lung and adrenal MR-Linac plans revealed superior sparing of the organs at risks thanks to gated treatments.

Conclusion: Dosimetrically beneficial treatment plans with promising clinical outcomes can be applied when using gated MR-guided radiotherapy. Future studies will reveal which patients will benefit most from this technique. To utilize the full potential of online adaptive, individualized MR-guided therapy, the close collaboration of radio-oncology and radiology is needed.

Over the last decade, a fundamentally new type of computed tomography (CT) detectors has proved its superior capabilities in both physical and preclinical evaluations and is now approaching the stage of clinical practice. These detectors are able to discriminate single photons and quantify their energy and are hence called photon-counting detectors. Among the promising benefits of this technology are improved radiation dose efficiency, increased contrast-to-noise ratio, reduced metal artifacts, improved spatial resolution, simultaneous multi-energy acquisitions, and the prospect of multi-phase imaging within a single acquisition using multiple contrast agents. Taking the conventional energy-integrating detectors as a reference, the authors demonstrate the technical principles of this new technology and provide phantom and patient images acquired by a whole-body photon-counting CT. These images serve as a basis for discussing the potential future of clinical CT.

Background: The detection or exclusion of bone metastases is one of the most frequent tasks faced by the radiologist. The decision has significant and long-term consequences for the patient, therapeutic decisions and prognosis. For these reasons, specialized knowledge of the morphology, diagnostics and differential diagnoses of skeletal metastases is essential for the radiologist.

Objective: The various manifestations of skeletal metastases are elaborated and some representative nonmetastatic differential diagnoses are presented.

Imaging: The way in which metastases are radiologically depicted depends on the primary tumor, the localization of a metastasis, the interaction between metastasis and host bone, concomitant diseases, already initiated treatment and the individual circumstances of the patient. The basis of radiological diagnostics is still projection radiography, albeit with limitations. Computed tomography (CT) and magnetic resonance imaging (MRI) are firmly established methods in diagnostic imaging. Invasive diagnostics, preferably a CT-guided biopsy, are frequently unavoidable.

Conclusion: Various radiological procedures form the basis of the diagnostics of bone metastases. In many cases a definite diagnosis, i.e. presence or absence of bone metastases, is possible. In cases in which a suspected diagnosis with justified differential diagnoses arises, the radiologist, referring physician and other specialists to be consulted should advise on the benefits, risks and therapeutic consequences of an invasive procedure, usually by CT-guided biopsy.

Background: The fascia thoracolumbalis (FTL) is an important component for stabilization and motion control of the lumbar spine. It coordinates the traction forces of the autochthonous muscles of the back (AM) and connects them to the muscles of the abdominal wall, shoulder, and buttocks.

Objectives: The aim of our study was to describe the assessment of the normal FTL and epimysium of the AM in MRI and to identify patterns associated with pathological changes in the lumbar spine.

Material and methods: A total of 33 patients were retrospectively evaluated: 15 patients had no pathology at the lumbar spine; six patients had previous hemilaminectomy, three had spondylodesis, two had ventrolisthesis, and seven had scoliosis. The thickness of the FTL and EM was measured, and the adhesion of both structures was assessed.

Results: The fascial thickness at the levels of the lumbar vertebral bodies LVB 3 was 1.8, of LVB 4 it was 2.0, of LVB 5 it was 2.1, and at the sacral vertebra SVB 1 it was 1.8 mm. Fascial adhesions together with thickening of the EM occurred at the level of LVB 4 in 36% of the cases independently of the underlying disorder. Only thickening of the EM was seen in 48% of cases at the level of SVB 1. By contrast, adhesion of the FTL without epimysial changes occurred in 36% of cases at the level of LVB 3.

Conclusion: Thickening and adhesions at the EM and FTL occurred both postoperatively and in the case of scoliosis. Furthermore, lipomatous and muscular herniation could be detected in the FTL postoperatively. Epimysial and fascial alterations may be imaging manifestations of chronic myofascial back pain and should be included in radiological assessments.

Background: Emergency radiology (ER) is an important part of radiology. But what exactly is ER? How can the required competencies be acquired in a good and feasible way? Who should be in charge of this?

Objectives: Discussion of ER contents and suggestions for the improvement of the acquisition of respective competencies during radiology training.

Materials and methods: General literature review, in particular the current German blueprint for medical specialist training regulations (Weiterbildungsordnung, WBO 2020), publications by the German Radiological Society (DRG), the European Society of Radiology (ESR), the European Society of Emergency Radiology (ESER) and the American Society of Emergency Radiology (ASER).

Results and conclusions: As proof of competence in ER in Germany, confirmation from the authorised residency training supervisor as to whether there is 'competence to act' either 'independently' or 'under supervision' in the case of 'radiology in an emergency situation …, e.g. in the case of polytrauma, stroke, intensive care patients' is sufficient. The ESER refers to all acute emergencies with clinical constellations requiring an immediate diagnosis 24/7 and, if necessary, acute therapy. The ESER and ASER offer, among other things, practical fellowships in specialised institutions, while the ESER complements this with a European Diploma in Emergency Radiology (EDER). On a national level, it would be advisable to use existing definitions, offers and concepts, from the ESR, ESER and ASER. Specialised institutions could support the acquisition of ER competencies with fellowships. For Germany, it seems sensible to set up a separate working group (Arbeitsgemeinschaft, AG) on ER within the DRG in order to drive the corresponding further ER development.