Radiologe最新文献

Clinical problem: Due to the widespread use of computed tomography (CT) and magnetic resonance imaging (MRI) asymptomatic incidental findings of the gastrointestinal tract (GI) are increasingly being recognized. Incidental findings are frequently not part of the primary inquiry from referring physicians but it is obligatory to make a diagnosis and to stipulate the need for further clarification.

Radiological standard procedures: A multitude of incidental findings in the intestinal lumen, in the intestinal wall and in the adjacent mesenterium or subperitoneal space are shown in CT and MRI.

Methodological innovations and assessment: The first part of the two-part overview addresses the intestinal incidental findings in the lumen, such as coproliths, invaginations, mucoceles and chronic dilatations. In the intestinal wall, thickenings of neoplastic and nonneoplastic origins are discussed. Many of the findings can be classified as benign and as "leave me alone lesions" do not necessitate any further clarification but in contrast others need a definitive clarification. The most important incidental findings in the GI tract are systematically classified, illustrated and evaluated with respect to the clinical relevance, depending on the localization (e.g. stomach, small and large intestines).

Background: Ultrasound (US)-guided biopsy is widely used for the diagnostic confirmation of focal lesions. For sampling of prostate tissue, magnetic resonance imaging (MRI)/US fusion-guided biopsy has already been implemented in routine clinical practice and has shown a superior detection rate of significant prostate cancer in risk assessment compared with standard systematic biopsy. Newer three-dimensional software tools with volumetric mapping of the prostate and biopsy core channels provide a better overview of systematic biopsy and thus contribute to more accurate treatment planning. Automatic fusion is a time-saver and can reduce potential examiner errors through greater standardization of the fusion process itself.

Methodical innovations: In abdominal pathologies, US fusion biopsy can improve the rate of successful tissue sampling by using fused imaging to target lesions that are barely visible or difficult to delineate on B‑mode US scans. In addition, solid portions within larger tumors with enhancement on contrast-enhanced US can be targeted selectively, thereby avoiding sampling of necrotic areas and improving the quality of tissue cores for histopathological work-up.

Conclusion: Especially in complex situations, use of US fusion not only saves time but also improves sampling accuracy, which in turn reduces the rate of insufficient tissue specimens that necessitate repeat biopsy.

The main granulomatous diseases of the musculoskeletal system are Langerhans cell histiocytosis, sarcoidosis, Erdheim-Chester disease (lipoidgranulomatosis) and mastocytosis. In most cases the patients have only a few symptoms, and the disease is detected coincidentally. The diagnosis is usually made by a synopsis of topographical presentation, clinical appearance and the radiological pattern (destruction, reactive new bone formation).

Background: Due to our ageing population, the number of elderly patients who are treated in the emergency department due to low-energy trauma (e.g., tripping) continues to rise. These minor accidents often result in fragility fractures classically located in the proximal humerus, distal radius, spine, pelvis, and near the hip joint. Pre-existing conditions, polypharmacy, and general frailty increase the risk of fragility fractures in this patient population.

Methods: Geriatric trauma fractures and especially insufficiency fractures of the posterior pelvic ring are often difficult to diagnose by plain X‑ray. Therefore, in geriatric trauma patients, cross-sectional imaging, e.g., computed tomography (CT), dual-energy CT (DECT), or magnetic resonance imaging (MRI), should be considered early for reliable evaluation of a suspected fracture. This also allows for the identification of older fractures. Particularly in cognitively impaired elderly patients, difficult examination conditions or an unclear fall event, cross-sectional imaging is often indicated. However, this may also involve risks, e.g., use of contrast medium in patients with impaired renal function, so that each case must be considered individually. Furthermore, the diagnosis and treatment of osteoporosis, which is an underlying disease that leads to fragility fractures, is of particular importance. In the diagnostic workup, measurement of bone density using dual energy X‑ray absorptiometry (DXA) is the standard method according to guidelines. In specific situations, high-resolution peripheral quantitative CT (HR-pQCT) may also be used.

Conclusion: Due to the special challenges of correctly detecting fragility fractures and being able to quickly initiate adequate therapy, good cooperation between radiologists and trauma surgeons is necessary.

Background: Bone marrow consists of connective tissue and stem cells, which generate blood cells. This includes erythropoiesis, leukopoiesis and thrombopoiesis. Thus, hematologic disorders first affect the bone marrow and secondarily the blood.

Methods: Bone marrow changes can be sensitively detected using magnetic resonance imaging (MRI) and often represent the initial manifestation of the underlying disease. With longer duration of disease, changes can also be found on X‑ray or computed tomography (CT).

Results: The findings on MRI and X‑ray/CT are often nonspecific and can only be interpreted in the context of clinical information.

Conclusion: In the following article, we provide a brief overview of the clinical manifestations and imaging changes to be expected in leukemia, anemia, and chronic myeloproliferative disorders.

Background: Plasma cell dyscrasias are a spectrum of diseases characterized by clonal plasma cell proliferation. Important entities within this group are monoclonal gammopathy of unknown significance, smoldering multiple myeloma, and symptomatic multiple myeloma.

Purpose: The goal of this review is to illustrate plasma cell dyscrasia imaging findings of bone and bone marrow as seen on whole-body computed tomography (CT) and magnetic resonance imaging (MRI) and to discuss the relevance of imaging for management of patients with plasma cell dyscrasias.

Materials and methods: Selective literature search with analysis of dedicated original research articles and reviews and discussion of clinical guidelines.

Results: Diagnostic classification of plasma cell dyscrasias is based on the SLiM-CRAB criteria. CT primarily represents imaging of mineralized bone to show osseous end organ damage by detecting osteodestruction. MRI is primarily used for bone marrow imaging to detect diffuse or focal bone marrow infiltration, even in the absence of bone destruction. Different patterns of bone marrow infiltration can be distinguished. Treatment response is associated with characteristic imaging signs of lesion regression.

Conclusion: Imaging plays a prominent role in treatment stratification of patients with plasma cell dyscrasia at first diagnosis and during follow-up.

In multimodal radiologic imaging, contrast-enhanced ultrasound (CEUS) is increasingly used. One of the advantages of CEUS is the possibility of repeated application of contrast media without decreasing renal function or affecting the thyroid gland. Small solid liver lesions can be diagnosed and detected with high accuracy. Moreover, solid lesions in other abdominal organs can also be characterized. Frequent applications for solid lesions in the near field concern thyroid tumors and lymph nodes. For prostate diagnostics, CEUS can be used with an endorectal probe and perfusion imaging. This review explains how the additional (semi-)quantitative perfusion analysis, especially time-intensity curve (TIC) analyses, and wash-in/wash-out kinetics of integrated or external perfusion software programs facilitate new options in dynamic assessment of microvascularization during tumor follow-up care and even minimally invasive tumor therapy.

Neuroendocrine tumors (NET), or more generally neuroendocrine neoplasms (NEN), represent a very heterogeneous group of rare tumors with varying location which are only defined by their endocrine biology and secretion of synaptophysin and chromogranin A. They originate from mesoderm-derived stem cells. In the last few years, the incidence and prevalence of NEN have been steadily increasing. Classification is based on the affected organ, the proliferation rate and presence or absence of hormone production with typical symptoms. Diagnosis and treatment of these tumors is therefore very specific and requires an interdisciplinary approach. Treatment options include endoscopic or surgical resection, drug therapy for control of symptoms and proliferation, locoregional therapy and radionuclide therapy. Guidelines with algorithms for diagnostic workup and treatment are constantly updated.