Imaging of Pathologies of the Temporal Bone and Middle Ear: Inflammatory Diseases, Their Mimics and Potential Complications-Pictorial Review.

Imaging of the temporal bone and middle ear is challenging for radiologists due to the abundance of distinct anatomical structures and the plethora of possible pathologies. The basis for a precise diagnosis is knowledge of the underlying anatomy as well as the clinical presentation and the individual patient's otological status. In this article, we aimed to summarize the most common inflammatory lesions of the temporal bone and middle ear, describe their specific imaging characteristics, and highlight their differential diagnoses. First, we introduce anatomical and imaging fundamentals. Additionally, a point-to-point comparison of the radiological and histological features of the wide spectrum of inflammatory diseases of the temporal bone and middle ear in context with a review of the current literature and current trends is given.

Retroperitoneal Fibrosis and its Differential Diagnoses: The Role of Radiological Imaging. / Retroperitoneale Fibrose und ihre Differenzialdiagnosen: Die Rolle der radiologischen Bildgebung.

BACKGROUND: Retroperitoneal fibrosis is a rare disease with an incidence of 0-1/100 000 inhabitants per year and is associated with chronic inflammatory fibrosis of the retroperitoneum and the abdominal aorta. This article sheds light on the role of radiological imaging in retroperitoneal fibrosis, names various differential diagnoses and provides an overview of drug and surgical treatment options. METHODS: A literature search for the keywords "retroperitoneal fibrosis" and "Ormond's disease" was carried out in the PubMed database between January 1, 1995 and December 31, 2019 (n = 1806). Mainly original papers were selected, but also reviews, in English and German language, with a focus on publications in the last 10 years, without excluding older publications that the authors believe are relevant to the topic discussed in the review (n = 40). RESULTS AND CONCLUSION: Ormond's disease is a rare but important differential diagnosis for nonspecific back and flank pain. Imaging diagnostics using CT or MRI show a retroperitoneal mass, which must be differentiated from lymphoma, sarcoma, multiple myeloma and Erdheim-Chester disease. Patients have an excellent prognosis under adequate therapy. FDG-PET/CT or FDG-PET/MRT should be considered as potential modalities, as hybrid imaging can evaluate both the morphological changes and the inflammation. KEY POINTS: · Ormond's disease is a differential diagnosis for nonspecific back and flank pain.. · Radiological imaging is essential and the gold standard in the diagnosis and follow-up of RPF.. · Patients have an excellent prognosis under adequate therapy.. CITATION FORMAT: · Peisen F, Thaiss WM, Ekert K et al. Retroperitoneal Fibrosis and its Differential Diagnoses: The Role of Radiological Imaging. Fortschr Röntgenstr 2020; 192: 929 - 936.

CT-response patterns and the role of CT-textural features in inoperable abdominal/retroperitoneal soft tissue sarcomas treated with trabectedin.

PURPOSE: To evaluate CT patterns and textural features of soft tissue sarcomas following trabectedin therapy as well as their suitability for predicting therapeutic response. MATERIAL AND METHODS: A total of 31 patients (18 female, 13 male; mean age, 58.0years; range, 38-79years) with sarcoma under trabectedin as a third-line therapy between October 2008 and July 2017 underwent baseline and follow-up contrast-enhanced CT. Response evaluation was based on modifiedCHOI-criteria and RECIST1.1, classified as partial response(PR), stable disease(SD), progressive disease(PD). For CT-texture analysis (CTTA), mean, entropy and uniformity of intensity/skewness/entropy of co-occurrence matrix (COM) and contrast of neighboring-grey-level-dependence-matrix (NGLDM) were calculated. RESULTS: Following CHOI-criteria, 9 patients achieved PR, 10 SD and 12 PD. RECIST1.1. classified patients into 5 PR, 15 SD and 11 PD. A frequent (n = 6/31; 19.3%) pattern of response was tumor liquefaction. In responders differences in entropy of entropy-NGLDM(p = 0.028) and uniformity-NGLDM(p = 0.021), in non-responders entropy of average(p = 0.039), deviation(p = 0.04) and uniformity of deviation(p = 0.013) occured between baseline and follow-up. Mean intensity and average were higher when liquefication occured(p = 0.03; p = 0.02), whereas mean deviation was lower(p = 0.02) at baseline compared to other response patterns. Differences in mean(p = 0.023), entropy(p = 0.049) and uniformity(p = 0.023) of entropy-NGLDM were found between responders and non-responders at follow-up. For the mean of heterogeneity a cut-off value was calculated for prediction of response in baseline CTTA (0.12; sensitivity 89%; specificity 77%). CONCLUSION: A frequent pattern of response to trabectedin was tumor liquefication being responsible for pseudoprogression, therefore modifiedCHOI should be preferred. Single CT-textural features can be used complementarily for prediction and monitoring response to trabectedin.

Longitudinal Computed Tomography Monitoring of Pelvic Bones in Patients With Breast Cancer Using Automated Bone Subtraction Software.

OBJECTIVE: The aim of this study was to optimize computed tomography (CT) surveillance of skeletal metastases in patients with breast cancer through the use of osseous subtraction maps between baseline and follow-up examinations created by a novel software algorithm. The new postprocessing algorithm segments the original bone followed by image intensity-based rigid alignment creating gray-shaded maps that highlight focal or diffuse loss or increase in bone attenuation. MATERIALS AND METHODS: Institutional review board was obtained for this retrospective data evaluation. A total of 33 consecutive patients (31 female; 2 male; mean age, 59.13 ± 12.68 years; range, 32-81 years) with breast cancer were included, who underwent 143 standardized baseline and follow-up CT examinations between February 2014 and June 2016. We classified bone metastases into lytic, sclerotic, and mixed osseous lesions. Any new osteolysis inside a known sclerotic lesion and enlargement of pre-existing sclerotic lesions were considered to represent progressive disease (PD), whereas no change was classified as stable disease (SD). Results were compared additionally with the course of the disease considering the entire skeleton and other involved organs. Software-created automated bone subtraction maps were compared with conventional CT interpretations of axial 5-mm and coronal 1-mm reformatted images. Region of interest measurements were used to quantify new lesions. Results were validated by clinical and CT follow-up. Reading time was evaluated. RESULTS: Skeletal metastases were present in 17/33 (51%) patients (9 sclerotic, 2 lytic, 6 mixed) at baseline. The use of bone subtraction maps resulted in an overall change of response classification into PD in 9/33 (8.1%) patients. Compared with conventional CT evaluation, the bone subtraction maps disclosed 123 new or enlarging sclerotic and 32 new lytic metastases in 23/33 (30.9%) examinations. Mean attenuation of new bone lesions (sclerotic or lytic) significantly increased or decreased (P < 0.01) in all patients. Bone attenuation in pelvic areas without evident metastatic disease significantly increased in patients with PD (P = 0.019), whereas there was no change in SD (P = 0.076). Lesion-based sensitivity, specificity, accuracy, positive predictive values, and negative predictive values were 98.7%, 79.5%, 94.5%, 95.1%, and 94.5%, respectively. Interobserver agreement was good (κ = 0.80; P = 0.077). Reading time was significantly faster for the bone subtraction maps versus 5-mm axial images (P < 0.001). CONCLUSIONS: Longitudinal bone subtraction maps increase the accuracy and efficiency of CT diagnosis of skeletal metastases in patients with breast cancer.