High-resolution breast tomography at high energy: a feasibility study of phase contrast imaging on a whole breast.

Previous studies on phase contrast imaging (PCI) mammography have demonstrated an enhancement of breast morphology and cancerous tissue visualization compared to conventional imaging. We show here the first results of the PCI analyser-based imaging (ABI) in computed tomography (CT) mode on whole and large (>12 cm) tumour-bearing breast tissues. We demonstrate in this work the capability of the technique of working at high x-ray energies and producing high-contrast images of large and complex specimens. One entire breast of an 80-year-old woman with invasive ductal cancer was imaged using ABI-CT with monochromatic 70 keV x-rays and an area detector of 92×92 µm² pixel size. Sagittal slices were reconstructed from the acquired data, and compared to corresponding histological sections. Comparison with conventional absorption-based CT was also performed. Five blinded radiologists quantitatively evaluated the visual aspects of the ABI-CT images with respect to sharpness, soft tissue contrast, tissue boundaries and the discrimination of different structures/tissues. ABI-CT excellently depicted the entire 3D architecture of the breast volume by providing high-resolution and high-contrast images of the normal and cancerous breast tissues. These results are an important step in the evolution of PCI-CT towards its clinical implementation.

[Importance of mammography, sonography and MRI for surveillance of neoadjuvant chemotherapy for locally advanced breast cancer]. / Wertigkeit von Mammographie, Sonographie und MRT zur Verlaufsbeurteilung der neoadjuvanten Chemotherapie bei lokal fortgeschrittenem Mammakarzinom.

PURPOSE: The aim of this study is to give an overview on the surveillance of response to neoadjuvant chemotherapy in locally advanced breast cancer with mammography, ultrasound and breast MRI. MATERIAL AND METHODS: The results of a recently presented study on surveillance in the course of chemotherapy with contrast-enhanced MRI are compared with ratings based on mammography and ultrasound. RESULTS: Contrast-enhanced MRI correlates best with the histological tumor size when compared with mammography and ultrasound. Tumors with a high HER2 score (2+ with positive FISH test or 3+) show a significantly higher response compared to tumors with a lower HER2 score: size p <0.01, maximum enhancement p <0.01 and area under the curve (AUC) p <0.05. Reduction of tumor size and enhancement are complementary parameters and are not correlated to each other (r=0.22). DISCUSSION: Contrast-enhanced MRI of the breast is a reliable method for quantification of the response to neoadjuvant chemotherapy. The reductions of tumor size and of tumor enhancement are not correlated. Therefore, it may be reasonable to take both aspects for quantification of therapy response into account. Further studies are needed for evaluation of the value of breast MRI as a prognostic factor.

Small lesions evaluation based on unsupervised cluster analysis of signal-intensity time courses in dynamic breast MRI.

An application of an unsupervised neural network-based computer-aided diagnosis (CAD) system is reported for the detection and characterization of small indeterminate breast lesions, average size 1.1 mm, in dynamic contrast-enhanced MRI. This system enables the extraction of spatial and temporal features of dynamic MRI data and additionally provides a segmentation with regard to identification and regional subclassification of pathological breast tissue lesions. Lesions with an initial contrast enhancement >/=50% were selected with semiautomatic segmentation. This conventional segmentation analysis is based on the mean initial signal increase and postinitial course of all voxels included in the lesion. In this paper, we compare the conventional segmentation analysis with unsupervised classification for the evaluation of signal intensity time courses for the differential diagnosis of enhancing lesions in breast MRI. The results suggest that the computerized analysis system based on unsupervised clustering has the potential to increase the diagnostic accuracy of MRI mammography for small lesions and can be used as a basis for computer-aided diagnosis of breast cancer with MR mammography.

Magnetic resonance imaging in early stage charcot arthropathy: correlation of imaging findings and clinical symptoms.

OBJECTIVE: To report on qualitative and quantitative MRI findings in early stage of diabetic osteoarthropathy (CA) and correlation with clinical symptoms. MATERIALS AND METHODS: Clinical data of 13 patients (mean age = 61.2 years) with Charcot arthropathy (CA, Eichenholtz 0) were compared with findings in native and contrast-enhanced MRI. 12 patients had diabetes mellitus (7 type 2, 5 type 1), one had idiopathic polyneuropathy. Evaluation was performed at acute stage of CA and at a 4 months follow-up. After baseline assessment, patients were treated with pressure-relieving means. Mean values of signal-intensity in short T1 inversion recovery (STIR) images of bones of the foot and ankle and corresponding contrast-enhancement were evaluated. Additional MRI-findings (soft tissue edema, varicosis, tenovaginitis, joint effusion) were analyzed. A correlation with symptoms (reddening, swelling, hyperthermia, pain) was performed. RESULTS: Bone marrow edema in affected bones significantly decreased (p<0.001). Soft tissue edema and pain showed a significant correlation with intensity of bone marrow edema (p<0.05). The presence of bone marrow edema in the STIR sequence was strongly associated with a corresponding contrast enhancement (p<0.0001, kappa-coefficients 0.976 at baseline and 0.953 at follow-up). CONCLUSION: MRI in early stage of CA provides valuable diagnostic information on the activity of the disease. A significant correlation of intensity of bone marrow edema in MRI and some clinical parameters (soft tissue edema and pain) was found. Paramagnetic contrast-agent did not provide additional information. This is the first report on quantitative assessment of signal alterations in stage 0 CA before and after treatment.

[Interventional MRI of the breast. Indications, technique, results and perspectives]. / MR-gestützte Interventionen in der Mammadiagnostik. Indikationen, Techniken, Ergebnisse und Perspektiven.

With the use of diagnostic MR imaging of the breast MR guided minimal invasive interventions are increasingly needed to obtain histologic proof of lesions, that are occult at mammography and ultrasound. MR guided interventions are time consuming and expensive. Therefore it is necessary to insure, that the diagnostic MR examination of the referring institution establishing the indication for biopsy is of high quality.Assuming accurate patient selection percutaneous MR vacuum-assisted biopsy is a safe and accurate method for the evaluation of even small enhancing breast lesions. Up to now the imaging of the biopsy procedure itself is not possible due to a lack of compatibility of the biopsy needle. Careful reviewing of imaging and pathologic findings is therefore recommended. Several newly developed MR compatible devices will allow more precise placement and imaging of the biopsy needle. Procedure times will be reduced. For the evaluation of additional enhancing lesions in patients with breast carcinoma referred for operation the preoperative wire localization is remaining a wide-spread safe and simple method.

[Value of breast MRI as supplement to mammography and sonography for high risk breast cancer patients]. / Wertigkeit der Mamma-MRT als Ergänzung zu Mammographie und Sonographie bei Patientinnen mit erhöhtem Mammakarzinomrisiko.

PURPOSE: The aim of this study is to give an overview on early detection of breast cancer in patients with an increased risk of breast cancer. Sensitivities and diagnostic accuracies of breast MRI, mammography and ultrasound were compared. MATERIAL AND METHODS: A systematic literature search of the past 3 years was performed. Studies which compared breast imaging modalities and used image-guided biopsy results as standard of reference were included. Patients included had to have had an increased lifetime risk for breast cancer (>15%). RESULTS: Regarding sensitivity and diagnostic accuracy, breast MRI performed best in comparison to the other modalities within this collective of patients. Sensitivities ranged from 71-100%, 0-78%, and 13-65%, for MRI, mammography, and ultrasound, respectively CONCLUSION: Breast MRI is a well established tool for screening in patients at high risk for developing breast cancer and is a valuable supplement to mammography and ultrasound within this selected cohort of patients.

COMPUTER-AIDED DIAGNOSIS AND VISUALIZATION BASED ON CLUSTERING AND INDEPENDENT COMPONENT ANALYSIS FOR BREAST MRI.

Computer-aided diagnosis and simultaneous visualization based on independent component analysis and clustering are integrated in an intelligent system for the evaluation of small mammographic lesions in breast MRI. These techniques are tested on biomedical time-series representing breast MRI scans and enable the extraction of spatial and temporal features of dynamic MRI data stemming from patients with confirmed lesion diagnosis. By revealing regional properties of contrast-agent uptake characterized by subtle differences of signal amplitude and dynamics, these methods provide both a set of prototypical time-series and a corresponding set of cluster assignment maps which further provide a segmentation with regard to identification and regional subclassification of pathological breast tissue lesions. Both approaches lead to an increase of the diagnostic accuracy of MRI mammography by improving the sensitivity without reduction of specificity.

Pulmonary radiological characteristics in patients with HIV infection at the time of highly active antiretroviral therapy (HAART).

OBJECTIVE: To report on radiological and epidemiological characteristics of pulmonary disease in patients with HIV infection in times of highly active antiretroviral therapy (HAART). METHODS: Clinical data of 130 HIV infected adults with acute pulmonary symptoms were compared with findings in chest radiography (n = 130) and computed tomography (CT, n = 42). Presence and distribution of consolidation, interstitial changes, pleural effusion, and adenopathy were evaluated. Results were compared to findings from sputum, bronchoalveolar lavage, transbronchial biopsy, or empirical therapy results. RESULTS: 48% of patients presented pathologic findings. Overall sensitivity for the detection of pulmonary involvement was 0.87 (chest radiography) vs. 0.97 (CT). Disease specific sensitivity was 0.33 compared to 0.70. Bacterial pneumonia (BP, n = 26, 20%) was the most frequent diagnosis, followed by pneumocystis jiroveci pneumonia (PJP, n = 17, 13%), mycobacterium avium complex (MAC, 6%), Kaposi's sarcoma and lymphoma (KS and NHL, each 4%), fungal pneumonia (2%), and tuberculosis (TBC, 1%). Focal pulmonary infiltration was predominantly present in BP (50%, n = 13). Reticular (35%; n = 6) and micronodular (35%; n = 6) infiltration were predominantly found in PJP. CONCLUSIONS: Despite HAART, lung involvement is still common. Only contrast-enhanced computed tomography shows an acceptable disease-specific sensitivity. In unclear cases, CT should be performed.

[Inflammatory spine disease as a cause of back pain]. / Entzündliche Wirbelsäulenerkrankungen als Ursache für Rückenschmerzen.

PURPOSE: The aim of this review is to evaluate the role of inflammatory spine disease in patients with chronic back pain. The contribution of imaging modalities for the diagnostic evaluation of back pain is discussed. MATERIAL AND METHODS: A systematic literature search based on the classification of seronegative spondyloarthropathies and rheumatoid arthritis was performed. The results of this search and the experiences in a large collective of rheumatological patients are analyzed. RESULTS: The prevalence of rheumatoid arthritis (1-2%) is comparable to that of spondyloarthropathies (1.9%). The etiology of these entities is not fully elucidated. Magnetic resonance imaging is increasingly used for early detection and surveillance of therapy with TNF-alpha antagonists. DISCUSSION: Bone marrow edema, which is only detectable with MRI, represents an early sign of inflammation. Therapy with TNF-alpha antagonists is based on clinical and laboratory criteria, and signs of inflammation in MRI. MRI is useful for assessment of the effectiveness of anti-inflammatory therapy.

[Pulmonary manifestations in rheumatic systemic diseases]. / Pulmonale Manifestationen bei Erkrankungen des rheumatischen Formenkreises.

Collagen based vascular diseases with pulmonary involvement comprise rheumatoid arthritis, systemic lupus erythematosus, progressive systemic sclerosis, dermatomyositis and polymyositis, ankylosing spondylitis, Sjögren's syndrome, and mixed connective tissue diseases. The different characteristics of pulmonary involvement are described. In such circumstances, early recognition of lung involvement is of considerable significance and the relationship to the corresponding disease has to be made. Frequently unrecognised pulmonary involvement ends up as fibrosis with irreversible deficits in respiratory function.