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The attributable proportion of occupation-related influences on airway and lung diseases is 10-30%. In patients with obstructive airway diseases it is extremely important to sufficiently document findings during the period of activities burdening the airway as compared to periods off work. Chronic obstructive pulmonary disease (COPD) can have a work-related (partial) cause even in smokers. Regarding occupational infectious diseases, the main cause up to 2019 was tuberculosis but the corona pandemic has led to coronavirus disease 2019 (COVID-19) being the most frequent occupational disease. For the occupational medical assessment of interstitial and malignant pulmonary diseases, checklists can be helpful to support the medical history.Die attributablen Anteile berufsbedingter Einflüsse auf Atemwegs- und Lungenerkrankungen betragen 10–30 %. Bei obstruktiven Atemwegserkrankungen ist eine medizinische Dokumentation insbesondere noch zu Zeiten der atemwegsbelastenden Tätigkeit im Vergleich zu arbeitsfreien Zeiten erforderlich. Auch bei Rauchern kann eine chronisch obstruktive Lungenerkrankung (COPD) berufsbedingte (Teil‑)Ursachen haben. Bei berufsbedingten Infektionskrankheiten stand bis 2019 die Tuberkulose im Vordergrund, die Coronapandemie hat die „coronavirus disease 2019“ (COVID-19) zur häufigsten Berufskrankheit gemacht. Für die arbeitsmedizinische Beurteilung interstitieller und maligner Lungenerkrankungen können anamneseunterstützende Checklisten hilfreich sein.

Da Arbeitsplatzeinflusse zu etwa 10–30 % der Lungenerkrankungen ursachlich beitragen, gilt es, diese moglichst fruh vorbeugend zu erkennen und abzuklaren. Der Leitthemenbeitrag soll radiologische Untersuchungen und Befunde im Zusammenhang von Erkennen und Begutachtung vermuteter oder gesicherter berufsbedingter Lungenerkrankungen durch Staube, Rauche oder Dampfe (Staublungen, Pneumokoniosen) erklaren. In einer Ubersichtsarbeit werden der Ablauf der arbeitsmedizinischen Abklarung, die Verfahren der radiologischen Untersuchung und Befunderstellung und die typischen Befunde von in Deutschland besonders bedeutsamen, als Berufskrankheiten anerkannten Pneumokoniosen dargestellt. Arbeitsanamnese, Expositionsbestimmung und Lungenfunktionsuntersuchung fuhren zu Vermutungen uber Ursachen-Wirkungs-Beziehungen. In international standardisierter, epidemiologisch erfassbarer Weise durchgefuhrte und semiquantitativ beurteilte Rontgenaufnahmen (mit ILO[International Labour Office]-Klassifikation) und qualifizierte Low-Dose-Volumen-HR-CT [hochauflosende Computertomographie] des Thorax, Computertomographieaufnahmen (mit ICOERD[International Classification of Occupational and Environmental Respiratory Diseases]-Klassifikation) dienen der Zusammenhangs- und Verlaufsbegutachtung insbesondere bei anorganischen und organischen Pneumokoniosen und dem Erkennen moglicher berufsbedingter Ausloser von Lungenkarzinomen und Pleuramesotheliomen. International standardisiert durchgefuhrte und begutachtete Rontgen- und HR-CT-Aufnahmen des Thorax unterstutzen das Erkennen von Zusammenhangen zwischen Arbeitsplatzexposition und Lungenerkrankungen durch anorganische und organische Staube sowie durch Rauche oder Dampfe.

Annemarie Klingenstein,1 Aylin Garip-Kuebler,1 Siegfried Priglinger,1 Christoph Hintschich,1 Ullrich G Mueller-Lisse2 1Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany; 2Department of Radiology, Ludwig-Maximilians-University, Munich, GermanyCorrespondence: Annemarie KlingensteinLudwig-Maximilians-University, Department of Ophthalmology, Klinikum der Universität München, Campus Innenstadt, Mathildenstraße 8, Munich, D-80336, GermanyTel +49 89 44005 3811Fax +49 89 44005 5160Email Annemarie.Klingenstein@med.uni-muenchen.deAim: To detect radiological features that, in addition to clinical findings, may aid in correct differentiation between IgG4-related ophthalmic disease (IgG4-ROD) and ocular adnexal lymphoma (OAL).Methods: In this retrospective, single-center, comparative analysis, we compared cross-sectional imaging findings of 13 consecutive patients with histologically proven IgG4-ROD and a control group of 29 consecutive OAL-patients diagnosed between 10/2014 and 09/2019. Statistical significance was accepted at a p< 0.05 significance level.Results: IgG4-ROD-patients had longer time-to-diagnosis, higher orbital recurrence rates, but smaller lesions compared to OAL-patients (p=0.002; p=0.006 and p=0.006; Mann–Whitney U-test). Frequent cross-sectional imaging findings in both IgG4-ROD-patients and OAL-patients included extraocular muscle enlargement (92% and 93%, respectively; most often in the lateral rectus muscles and the levator-complex), and lacrimal-gland enlargement (85% and 83%, respectively). Other imaging findings comprised infraorbital nerve-involvement (IgG4-ROD, 23%, OAL, 17%) and orbital fat inflammation (IgG4-ROD, 23%, OAL, 28%). Bony infiltration and remodeling, heterogenous contrast-media distribution, and infiltration of the lacrimal system were seen slightly more often in IgG4-ROD (23%, 38%, 15% and 15% versus 17%, 14%, 3% and 7%). However, cross-sectional imaging features did not differ significantly between patient subgroups. Clinical symptoms predominantly occurred unilaterally (IgG4-ROD, 9/13, 69%, OAL, 24/29, 83%), while imaging findings were most often bilateral (IgG4-ROD, 11/13, 85%, OAL, 23/29, 79%, p< 0.001, McNemar test).Conclusion: No morphological cross-sectional imaging sign could reliably distinguish between IgG4-ROD and OAL, leaving histopathology indispensable for definite diagnosis. Yet, importantly, for both IgG4-ROD and OAL, cross-sectional imaging frequently detected bilateral orbital disease when only one eye was clinically affected.Keywords: IgG4, idiopathic orbital inflammation, CT, ocular adnexal lymphoma

Several studies proposed a loss of neural structures (such as hair cells or neurons within the spiral ganglion) in Menière’s disease (MD). It has been shown that VIIth and VIIIth cranial nerves are enlarged within MD patients compared to normal controls. We now aimed to investigate potential differences in these two nerves in patients with MD. Etiology of endolymphatic hydrops, central pathological hallmark of MD, includes genetic predisposition, autoimmune processes, viral infections, cellular apoptosis and oxidative stress. We evaluated morphometric properties (long and short diameter, cross-sectional area) of the VIIth and VIIIth cranial nerves passing from the cerebellopontine angle to the inner ear modiolus, acquired on a clinical 3T magnetic resonance imaging scanner. 71 patients with MD were included, 53 of whom clinically showed a unilateral affection. Our data showed no differences in nerve morphometry between the clinically non-affected and the clinically affected side in patients with clinically unilateral MD. There was also no correlation to duration of symptoms, in contrast to previously demonstrated correlations between clinical features and the extent of endolymphatic hydrops. A disease process starting before the onset of clinical symptoms could be a potential explanation.

The Working Group Uroradiology and Urogenital Diagnosis of the German Roentgen Society (DRG) revised and updated the recommendations for preparation and scanning protocol of the multiparametric MRI of the Prostate in a consensus process and harmonized it with the managing board of German Roentgen Society and Professional Association of the German Radiologist (BDR e. V.). These detailed recommendation define the referenced "validated quality standards" of the German S3-Guideline Prostate Cancer and describe in detail the topic 1. anamnestic datas, 2. termination of examinations and preparation of examinations, 3. examination protocol and 4. MRI-(in-bore)-biopsy. KEY POINTS:: · The recommendations for preparation and scanning protocol of the multiparametric MRI of the Prostate were revised and updated in a consensus process and harmonized with the managing board of German Roentgen Society (DRG) and Professional Asssociation of the German Radiologist (BDR).. · Detailed recommendations are given for topic 1. anamnestic datas, 2. termination and preparation of examinations, 3. examination protocoll and 4. MRI-(in-bore)-biopsy.. · These recommendations define the referenced "validated quality standards" of the German S3-Guideline Prostate Cancer.. CITATION FORMAT: · Franiel T, Asbach P, Beyersdorff D et al. mpMRI of the Prostate (MR-Prostatography): Updated Recommendations of the DRG and BDR on Patient Preparation and Examination Protocol. Fortschr Röntgenstr 2021; 193: 763 - 776.Die AG Uroradiologie und Urogenitaldiagnostik der Deutschen Röntgengesellschaft hat die Empfehlungen zur Vorbereitung und Durchführung der multiparametrischen MRT der Prostata im Konsensusverfahren und in Abstimmung mit den Vorständen der Deutschen Röntgengesellschaft und des Berufsverbandes der Deutschen Radiologen überarbeitet und aktualisiert. Diese aktualisierten Empfehlungen definieren die in der deutschen S3-Leitlinie Prostatakarzinom referenzierten „geltenden Qualitätsstandards“ und gehen detailliert auf die Themen 1. Anamnestische Angaben, 2. Untersuchungsterminierung und -vorbereitung, 3. Untersuchungsprotokoll und 4. MRT- (in-bore) -Biopsie ein. KERNAUSSAGEN:: · Die Empfehlungen zur Vorbereitung und Durchführung der multiparametrischen MRT der Prostata wurden von der AG Uroradiologie und Urogenitaldiagnostik der Deutschen Röntgengesellschaft in Abstimmung mit den Vorständen der Deutschen Röntgengesellschaft und des Berufsverbandes der Deutschen Radiologen überarbeitet und aktualisiert.. · Es werden detailiert Empfehlungen zu 1. Anamnestische Angaben, 2. Untersuchungsterminierung und -vorbereitung, 3. Untersuchungsprotokoll und 4. MRT-(in-bore)-Biopsie gegeben.. · Diese Empfehlungen definieren die in der S3-Leitlinie Prostatakarzinom referenzierten „geltenden Qualitätsstandards“.. ZITIERWEISE: · Franiel T, Asbach P, Beyersdorff D et al. mpMRI of the Prostate (MR-Prostatography): Updated Recommendations of the DRG and BDR on Patient Preparation and Examination Protocol. Fortschr Röntgenstr 2021; 193: 763 – 777.

This information provided by the Thoracic Imaging Section of the German Radiological Society is intended to give physicians recommendations on the use of thoracic imaging procedures in the context of the current COVID-19 pandemic. It represents the consensus of the authors based on the previous scientific knowledge and is intended to provide guidance for unified, structured CT reporting if COVID-19 pneumonia is suspected. The recommendations presented correspond to state of knowledge at the time of print and will be updated according to the results of ongoing and future scientific studies. KEY POINTS:: · COVID-19. · chest imaging. · German Radiological Society. CITATION FORMAT: · Vogel-Claussen J, Ley-Zaporozhan J, Agarwal P et al. Recommendations of the Thoracic Imaging Section of the German Radiological Society for clinical application of chest imaging and structured CT reporting in the COVID-19 pandemic. Fortschr Röntgenstr 2020; DOI: 10.1055/a-1174-8378.Diese Information der AG Thoraxdiagnostik der Deutschen Röntgengesellschaft soll Ärztinnen und Ärzten Empfehlungen zur Anwendung thoraxradiologischer Verfahren im Rahmen der aktuellen COVID-19-Pandemie geben. Sie repräsentiert den Konsensus der Autoren basierend auf den bisherigen wissenschaftlichen Erkenntnissen und soll zur einheitlichen und strukturierten CT-Befundung bei COVID-19 anleiten. Die vorgestellten Empfehlungen entsprechen dem Wissensstand zum Zeitpunkt der Drucklegung und werden entsprechend den Ergebnissen laufender und zukünftiger wissenschaftlicher Untersuchungen bei Bedarf aktualisiert. KERNAUSSAGEN:: · COVID-19. · Thoraxbildgebung. · Deutsche Röntgengesellschaft. ZITIERWEISE: · Vogel-Claussen J, Ley-Zaporozhan J, Agarwal P et al. Recommendations of the Thoracic Imaging Section of the German Radiological Society for clinical application of chest imaging and structured CT reporting in the COVID-19 pandemic. Fortschr Röntgenstr 2020; DOI: 10.1055/a-1174-8378.

PURPOSE Combined whole-body F-18-fluoro-2-deoxyglucose positron emission tomography / computed tomography ([18F]FDG-PET/CT) gives precise information about tumour morphology and metabolism. The standardized uptake value (SUV) allows quantification of tumour metabolism. The diagnostic value of PET/CT in patients with suspected orbital adnexal lymphoma (OAL) was evaluated. METHODS Of 21 patients with suspected OAL who underwent combined whole-body PET/CT between 07/2002 and 11/2016, 16 were scanned before and five after orbital biopsy. Histological tumour determination was performed in all cases via biopsy. Correlation between SUVmax and therapeutic status, lymphoma stage (Ann Arbor classification) and histological grading was tested. RESULTS All lesions could be depicted by combined whole-body PET/CT. Histology confirmed two malignant T-cell and 18 malignant B cell non-Hodgkin lymphomas as well as one patient suffering from systemic lymphoma with chronic polypoid sinusitis. SUVmax levels of orbital findings were significantly lower after therapy (p

Mediastinal, hilar, and peripheral pulmonary lymphadenopathy is a hallmark sign of different benign and malignant diseases of the chest. Contrast-enhanced (CE) chest CT is a test frequently applied to examine thoracic lymph node zones. We attempted to find out whether mediastinal, hilar, and peripheral lymph nodes delineate equally in CE chest CT with reduced dose (CE-LDCT, about 1 mSv) when compared with accepted standard CE chest CT (CE-SDCT). In this ethics committee-approved, mono-institutional, retrospective (20 months) matched case–control study, two independent, blinded observers compared measurable lymph node delineation (yes–no) in six different International Association for the Study of Lung Cancer (IASLC) zones (upper mediastinal, aortopulmonary, subcarinal, lower mediastinal, hilar, peripheral) between 62 CE-LDCT cases and 124 CE-SDCT controls (respective tube charge, 100, 120 KVp, computed tomography dose index, 1.66 ± 0.51, 5.36 ± 2.24 mGy, automatic exposure control-modulated 64-row multi-detector chest CT with iterative image reconstruction). Individual matching for gender (53% female), age (53 ± 19 years), body height, weight, anterior–posterior and transverse diameters of chest and lung ruled out pre-test confounders. Lymph node size (cut-off value, 1 cm) was a potential post-test confounder. Two-tailed T test and Chi-square test were significant for p

Electrical impedance tomography (EIT) attempts to reveal the conductivity distribution of a domain based on the electrical boundary condition. This is an ill-posed inverse problem; its solution is very unstable. Total variation (TV) regularization is one of the techniques commonly employed to stabilize reconstructions. However, it is well known that TV regularization induces staircase effects, which are not realistic in clinical applications. To reduce such artifacts, modified TV regularization terms considering a higher order differential operator were developed in several previous studies. One of them is called total generalized variation (TGV) regularization. TGV regularization has been successively applied in image processing in a regular grid context. In this study, we adapted TGV regularization to the finite element model (FEM) framework for EIT reconstruction. Reconstructions using simulation and clinical data were performed. First results indicate that, in comparison to TV regularization, TGV regularization promotes more realistic images. Graphical abstract Reconstructed conductivity changes located on selected vertical lines. For each of the reconstructed images as well as the ground truth image, conductivity changes located along the selected left and right vertical lines are plotted. In these plots, the notation GT in the legend stands for ground truth, TV stands for total variation method, and TGV stands for total generalized variation method. Reconstructed conductivity distributions from the GREIT algorithm are also demonstrated.

Electrical impedance tomography (EIT) has mostly been used in the Intensive Care Unit (ICU) to monitor ventilation distribution but is also promising for the diagnosis in spontaneously breathing patients with obstructive lung diseases. Beside tomographic images, several numerical measures have been proposed to quantitatively assess the lung state. In this study two common measures, the 'Global Inhomogeneity Index' and the 'Coefficient of Variation' were compared regarding their capability to reflect the severity of lung obstruction. A three-dimensional simulation model was used to simulate obstructed lungs, whereby images were reconstructed on a two-dimensional domain. Simulations revealed that minor obstructions are not adequately recognized in the reconstructed images and that obstruction above and below the electrode plane may result in misleading values of inhomogeneity measures. EIT measurements on several electrode planes are necessary to apply these measures in patients with obstructive lung diseases in a promising manner.

Purpose: Electrical Impedance Tomography (EIT) is an imaging modality used to generate two-dimensional cross-sectional images representing impedance change in the thorax. The impedance of lung tissue changes with change in air content of the lungs;hence, EIT can be used to examine regional lung ventilation in patients with abnormal lungs. In lung EIT, electrodes are attached around the circumference of the thorax to inject small alternating currents and measure resulting voltages. In contrast to X-ray computed tomography (CT), EIT images do not depict a thorax slice of well defined thickness, but instead visualize a lens-shaped region around the electrode plane, which results from diffuse current propagation in the thorax. Usually, this is considered a drawback, since image interpretation is impeded if 'off-plane' conductivity changes are projected onto the reconstructed two-dimensional image. In this paper we describe an approach that takes advantage of current propagation below and above the electrode plane. The approach enables estimation of the individual conductivity change in each lung lobe from boundary voltage measurements. This could be used to monitor disease progression in patients with obstructive lung diseases, such as chronic obstructive pulmonary disease (COPD) or cystic fibrosis (CF) and to obtain a more comprehensive insight into the pathophysiology of the lung. Methods: Electrode voltages resulting from different conductivities in each lung lobe were simulated utilizing a realistic 3D finite element model (FEM) of the human thorax and the lungs. Overall 200 different patterns of conductivity change were simulated. A 'lobe reconstruction' algorithm was developed, applying patient-specific anatomical information in the reconstruction process. A standard EIT image reconstruction algorithm and the proposed 'lobe reconstruction' algorithm were used to estimate conductivity change in the lobes. The agreement between simulated and reconstructed conductivity change in particular lobes were compared using Bland-Altman plots, correlation plots and linear regression. To test the applicability of the approach in a realistic scenario, EIT measurements of a patient suffering from cystic fibrosis (CF) were carried out. Results: Conductivity changes in each lobe generate specific patterns of voltage change. These can be used to estimate the conductivity change in lobes from measured boundary voltage. The correlation coefficient between simulated and reconstructed conductivity change in particular lobes is r > 0.89 for all lobes. Unknown position of the electrode plane leads to over-or underestimation of reconstructed conductivity change. Slight mismatches (+/- 5% of the forward model height) between the actual position of the electrode plane and the position used in the reconstruction model lead to regression coefficients of 0.7 to 1.3 between simulated and reconstructed conductivity change in the lobes. Conclusion: The presented approach enhances common reconstruction methods by providing information about anatomically assignable units and thus facilitates image interpretation, since impedance change and thus ventilation of each lobe is directly determined in the reconstructions. (C) 2016 American Association of Physicists in Medicine

To apply an easy-to-assemble phantom substitute for human prostates in T2-weighted magnetic resonance imaging (T2WI), diffusion-weighted imaging (DWI) and 3D magnetic resonance spectroscopy (MRS).Kiwi fruit were fixed with gel hot and cold compress packs on two plastic nursery pots, separated by a plastic plate, and submerged in tap water inside a 1-L open-spout plastic watering can for T2WI (TR/TE 7500/101 ms), DWI (5500/61 ms, ADC b50-800 s/mmMean contrast between central placenta (CP) and outer pericarp (OP, 0.346-0.349) or peripheral placenta (PP, 0.364-0.393) of kiwi fruit was similar to Gleason 7b-9 prostate cancer and PZ (0.308) in T2WI. ADC values of OP and PP (1.27 ± 0.07-1.37 ± 0.08 mmThe kiwi fruit phantom reproducibly showed zones similar to PZ, TZ and cancer in human prostates in T2WI and DWI and two metabolite peaks in MRS and appears suitable to compare different MR protocols, coil systems and scanners.• Kiwi fruit appear suitable as phantoms for human prostate in MR examinations. • Kiwi fruit show zonal anatomy like human prostates in T2-weighted MRI and DWI. • MR spectroscopy reliably shows peaks in kiwi fruit (citrate/inositol) and human prostates (citrate/choline+creatine). • The kiwi fruit phantom works both with and without an endorectal coil. • EU regulation No. 543/2011 specifies physical and biochemical properties of kiwi fruit.

The Working Group Uroradiology and Urogenital Diagnosis of the German Roentgen Society has developed uniform recommendations for the preparation and implementation of prostate MRI. In the first part detailed recommendations are given in tabular form regarding 1. anamnestic data before prostate MRI, 2. termination of examinations and preparation of examinations, 3. examination protocol and 4. MRI-guided in-bore biopsy. In the second part, the recommendations are discussed in detail and relevant background information is provided. Key Points: Citation Format

Treatment of advanced EML4-ALK-translocation-positive non-small-cell lung cancer (NSCLC) with an ALK tyrosine kinase inhibitor (TKI) is now standard of care. Since EML4-ALK gene fusion is rare in NSCLC and testing depletes both tissue samples and health care funds, deciding who to screen is critical. CT features associated with EML4-ALK-positive cases may help prioritize individual patients for ALK testing in settings where biopsy size or health care factors make ubiquitous testing difficult. We used well-described computed tomography (CT) lung tumor features to distinguish EML4-ALK-translocation-positive from ALK-negative European patients with advanced NSCLC. CT scans were evaluated for lung tumor location (either central or peripheral versus combined), growth pattern (focal versus diffuse), array (single versus multiple lesions), delineation (infiltrative versus circumscribed), composition (solid only versus nonsolid parts), site-specific blood vessel appearance (normal versus altered), and air inclusions (present versus absent). Two-tailed statistical tests (Fisher exact/Student-T) were used to compare ALK-positive and ALK-negative tumors. The analyses took potential confounders into account including patient age, gender, previous NSCLC therapy, UICC stage, and smoking status. Ten of 39 adult European Caucasian patients (age 57 ± 10 years, 17 female) were ALK positive. Diffuse tumor growth (ALK positive 9, ALK negative 7/5, p < 0.0005/p < 0.0001, agreement 95%), multiple lung lesion arrays (ALK positive 9, ALK negative 6, p < 0.0002, agreement 82%), and combined central/peripheral tumor location (ALK positive 9, ALK negative 12/7, p < 0.01/p < 0.0005, agreement 82%) each were associated with ALK-positive cases. Diffuse tumor growth, multiple lung lesion arrays, and combined central/peripheral tumor location are CT features that may prove useful in prioritizing NSCLC samples for ALK testing in this setting.

Besides the application of EIT in the intensive care unit it has recently also been used in spontaneously breathing patients suffering from asthma bronchiole, cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD). In these cases large thorax excursions during deep inspiration, e.g. during lung function testing, lead to artifacts in the reconstructed images. In this paper we introduce a new approach to compensate for image artifacts resulting from excursion induced changes in boundary voltages. It is shown in a simulation study that boundary voltage change due to thorax excursion on a homogeneous model can be used to modify the measured voltages and thus reduce the impact of thorax excursion on the reconstructed images. The applicability of the method on human subjects is demonstrated utilizing a motion-tracking-system. The proposed technique leads to fewer artifacts in the reconstructed images and improves image quality without substantial increase in computational effort, making the approach suitable for real-time imaging of lung ventilation. This might help to establish EIT as a supplemental tool for lung function tests in spontaneously breathing patients to support clinicians in diagnosis and monitoring of disease progression.

Diagnosis and treatment of many lung diseases like cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD) could benefit from 3D ventilation information. Applying two EIT systems concurrently is a simple approach without specialized hardware that allows monitoring of regional changes of ventilation distribution inside the thorax at different planes with the high temporal resolution much valued in common single plane EIT. Effects of two simultaneously operated EIT devices on one subject were investigated to monitor rapid processes inside the thorax with a multi-plane approach. Results obtained by simulations with a virtual phantom and measurements with a phantom tank reveal that the distance of electrode planes has an important influence on the signal quality. Band-pass filters adapted according to the distance of the planes, can be used to reduce the crosstalk of the concurrent EIT systems. Besides simulations and phantom tank experiments measurements were also taken from a lung healthy volunteer to demonstrate the operation under realistic conditions. Reconstructed images indicate that it is possible to simultaneously visualize regional ventilation at different planes if settings of the EIT devices are chosen appropriately.

Electrical Impedance Tomography (EIT) is a medical imaging technique which can be used to monitor the regional ventilation in patients utilizing voltage measurements made at the thorax. Several reconstruction algorithms have been developed during the last few years. In this manuscript we compare a well-established algorithm and a re-cently developed method for image reconstruction regarding EIT indices derived from the differently reconstructed images.

The objective of electrical impedance tomographic reconstruction is to identify the distribution of tissue conductivity from electrical boundary conditions. This is an ill-posed inverse problem usually solved under the finite-element method framework. In previous studies, standard sparse regularization was used for difference electrical impedance tomography to achieve a sparse solution. However, regarding elementwise sparsity, standard sparse regularization interferes with the smoothness of conductivity distribution between neighboring elements and is sensitive to noise. As an effect, the reconstructed images are spiky and depict a lack of smoothness. Such unexpected artifacts are not realistic and may lead to misinterpretation in clinical applications. To eliminate such artifacts, we present a novel sparse regularization method that uses spectral graph wavelet transforms. Single-scale or multiscale graph wavelet transforms are employed to introduce local smoothness on different scales into the reconstructed images. The proposed approach relies on viewing finite-element meshes as undirected graphs and applying wavelet transforms derived from spectral graph theory. Reconstruction results from simulations, a phantom experiment, and patient data suggest that our algorithm is more robust to noise and produces more reliable images.

Purpose: The semi-quantitative Brody score measures the severity of cystic fibrosis (CF)-related lung disease. We investigated the short-term (28 – 60 days) and long-term (2 – 7 years) intra- and inter-observer reproducibility of the Brody score in low-dose multidetector row computed tomography examinations performed in inspiration (LDCTs) of adult CF patients. Materials and Methods: Composite Brody scores and respective underlying bronchiectasis, mucus plugging, peribronchial thickening, parenchymal opacity, and hyperinflation subscores were evaluated twice (time interval, 1 – 84 months) by each of 3 independent radiologists (1 – 20 years of professional diagnostic radiology experience) in LDCTs (4 – 64 rows, 120 KVp, 10 – 15 mAs/slice, CTDIw approx. 1.0 mGy, effective dose approx. 0.5 mSv) of 15 adult patients with CF-related lung disease (8 female, 7 male, age, 18 – 50 years, mean, 33 years). Results: The average reproducibility of the Brody score was within +/–7 % (range, 2 – 30 %) between radiologists, and +/–6 % (3 – 12 %) within radiologists (short-term, 28 – 60 days, 4 %, 0 – 12 %, long-term, 2 – 7 years, 12 %, 1 – 36 %). For the different subscores, the reproducibility was within +/–25 % (15 – 41 %) between radiologists and +/–23 % (12 – 46 %) within radiologists. Conclusion: The Brody score shows high average inter-observer reproducibility in LDCTs of adult CF patients. The Brody score also demonstrates high average intra-observer reproducibility if subsequent assessments are made within 28 – 61 days. With time intervals of 2 – 7 years between subsequent evaluations, however, intra-observer reproducibility decreases. Respective subscores each demonstrate lower intra- and inter-observer reproducibility than does the composite Brody score. Citation Format

Electrical impedance tomography (EIT) reconstructs the conductivity distribution of a domain using electrical data on its boundary. This is an ill-posed inverse problem usually solved on a finite element mesh. For this article, a special regularization method incorporating structural information of the targeted domain is proposed and evaluated. Structural information was obtained either from computed tomography images or from preliminary EIT reconstructions by a modified k-means clustering. The proposed regularization method integrates this structural information into the reconstruction as a soft constraint preferring sparsity in group level. A first evaluation with Monte Carlo simulations indicated that the proposed solver is more robust to noise and the resulting images show fewer artifacts. This finding is supported by real data analysis. The structure based regularization has the potential to balance structural a priori information with data driven reconstruction. It is robust to noise, reduces artifacts and produces images that reflect anatomy and are thus easier to interpret for physicians.

To compare contrast-enhanced low-dose multidetector-row computed tomography (CE-LDCT) of the chest with unenhanced (UN-) LDCT and contrast-enhanced standard-dose CT (CE-SDCT) in regard to the delineation of intrathoracic lymph nodes.Based on the international association for the study of lung cancer (IASLC) grouping of thoracic lymph nodes, two independent radiologists retrospectively assessed lymph node delineation in 9 CE-LDCTs (64 rows, 120 KV, p 30 mAs/slice) and in 2 control groups of 36 UN-LDCTs and 36 CE-SDCTs, each matched for gender, age, chest/lung diameters, and clinical history. At a significance level of p 0.025 (Bonferroni-correction for two control groups), two-tailed Chi-square and Fisher's exact tests were applied. For the evaluation of the inter-observer agreement, Cohen's kappa statistics were used.CE-LDCT delineated lymph node groups significantly more often than UN-LDCT, in general (p 0.001) and individually in the subcarinal (p 0.025), the hilar (p 0.001), and the peripheral lung (p 0.001) zones. There were no significant differences in lymph node delineation between CE-LDCT and CE-SDCT. Inter-observer agreement was substantial to perfect for all lymph node zones (κ 0.64-1.0). Measurable lymph nodes did not significantly differ in size between cases and controls.At CE-LDCT of the chest, delineation of mediastinal and hilar lymph node groups was superior to UN-LDCT and similar to CE-SDCT. CE-LDCT may be a promising alternative for patients with non-malignant lung disease, unclear chest X-ray findings, or the need for follow-up.

Maligne Beckentumoren stellen 12–13% aller neu diagnostizierten soliden Neoplasien bei Frauen in den USA und in Deutschland dar. Deutsche Leitlinien befurworten bildgebende Untersuchungen bei Lokalrezidiven und Metastasen; fur Primartumoren gibt es keine einschlagigen Empfehlungen. Da das Ausscheidungsurogramm durch die Ausscheidungsaufnahme der CT-Urographie (CTU) weitgehend abgelost ist, wurde bei weiblichen Beckentumoren oder deren Rezidive der Zusammenhang zwischen CTU-Befunden und nachfolgenden operativen urologischen Masnahmen retrospektiv von 2 unabhangigen Auswertern gepruft. Bei 31 CTUs von 27 Frauen (Alter 29–84, Median 57 Jahre) mit 15 Primartumoren und 13 Rezidiven waren 83–100% der unauffalligen oberen, mittleren und unteren Harnleitersegmente in der Ausscheidungsaufnahme (Delay 16 min, Streubreite 6–29) vollstandig abgrenzbar. Haufige pathologische Veranderungen waren Obstruktionen der unteren Harnleiter (19-mal, 61%), Harnblasenkompressionen (13-mal, 42%) und Harnblaseninvasionen (8-mal, 26%). Acht von 20 pathologisch veranderten, jedoch keiner von 10 unauffalligen Harnwegen wurden nachfolgend urologisch operativ versorgt (zweiseitiger Fisher-Exact-Test, p=0,0215). Daher scheint die CTU eine sinnvolle diagnostische Masnahme vor der Weiterbehandlung weiblicher Beckentumoren oder deren Rezidive darzustellen.

Diffusion-weighted magnetic resonance imaging (DWI) can complement MRI of the prostate in the detection and localization of prostate cancer, particularly after previous negative biopsy. A total of 13 original reports and 2 reviews published in 2010 demonstrate that prostate cancer can be detected by DWI due to its increased cell density and decreased diffusiveness, either qualitatively in DWI images or quantitatively by means of the apparent diffusion coefficient (ADC). In the prostate, the ADC is influenced by the strength of diffusion weighting, localization (peripheral or transitional zone), presence of prostatitis or hemorrhage and density and differentiation of prostate cancer cells. Mean differences between healthy tissue of the peripheral zone and prostate cancer appear to be smaller for ADC than for the (choline + creatine)/citrate ratio in MR spectroscopy. Test quality parameters vary greatly between different studies but appear to be slightly better for combined MRI and DWI than for MRI of the prostate alone. Clinical validation of DWI of the prostate requires both increased technical conformity and increased numbers of patients in clinical studies.

An extensive spectrum of differential diagnoses has to be considered when a patient presents with enophthalmos. The most common causes of this presentation include orbital trauma or contraction and atrophy of the orbital contents secondary to scleroderma or radiotherapy. However radiologists also have to consider less common causes of enophthalmos, such as the imploding antrum syndrome or the ethmoid silent sinus syndrome. The latter involves the ethmoidal cells and results in medial orbital wall implosion. Along with the case presentation the pathogenesis, incidence and differential diagnoses of ethmoid silent sinus syndrome are elucidated. In particular the differentiation from normal anatomical variants, such as dehiscent lamina papyracea is discussed.

Excretory-phase CT urography (CTU) may replace excretory urography in patients without urinary tumors. However, radiation exposure is a concern. We retrospectively compared upper urinary tract (UUT) delineation in low-dose and standard CTU. CTU (1-2 phases, 120 KV, 4 × 2.5 mm, pitch 0.875, i.v. non-ionic contrast media, iodine 36 g) was obtained with standard (14 patients, n = 27 UUTs, average 175.6 mAs/slice, average delay 16.8 min) or low-dose (26 patients, n = 86 UUTs, 29 mAs/slice, average delay 19.6 min) protocols. UUT was segmented into intrarenal collecting system (IRCS), upper, middle, and lower ureter (UU,MU,LU). Two independent readers (R1,R2) graded UUT segments as 1-not delineated, 2-partially delineated, 3-completely delineated (noisy margins), 4-completely delineated (clear margins). Chi-square statistics were calculated for partial versus complete delineation and complete delineation (clear margins), respectively. Complete delineation of UUT was similar in standard and low-dose CTU (R1, p > 0.15; R2, p > 0.2). IRCS, UU, and MU clearly delineated similarly often in standard and low-dose CTU (R1, p > 0.25; R2, p > 0.1). LU clearly delineated more often in standard protocols (R1, 18/6 standard, 38/31 low-dose, p > 0.1; R2 18/6 standard, 21/48 low-dose, p

To describe current radiological cross-sectional imaging in the detection and staging of advanced renal cell carcinoma (RCC), defined here as RCC reaching beyond the renal capsule, whether by immediate extension or by metastasis. Review and summary of current radiological and urological literature, including original articles and reviews, retrieved from the medical data base “PubMed”. Multi-detector-row computed tomography (MDCT) shows a sensitivity of up to 100% and specificity of about 90% for retroperitoneal disease, venous tumour thrombus, and metastasis, but limited accuracy for lymphadenopathy in RCC. Magnetic resonance imaging (MRI) is applied as a problem-solving modality, with particular strength in imaging metastasis to brain and bone. However, dynamic, contrast-enhanced- (DCE-) and arterial-spin-labelling (ASL-) MRI may help to monitor early response to angiogenesis inhibitor drugs. Ultrasonography (US) shows limited capability of identifying retroperitoneal disease, venous tumour thrombus extension, and metastasis. Positron Emission Tomography with 18-fluoro-desoxy-glucose (FDG-PET) demonstrates modest accuracy for metastasis of RCC, with positive studies being suspicious, while negative studies cannot reliably exclude disease. MDCT represents the diagnostic mainstay for the detection and staging of RCC. In the wake of new systemic therapies for advanced RCC, including angiogenesis inhibitor drugs, monitoring treatment response may become a new task for cross-sectional imaging.

Diagnostic imaging of the upper urinary tract is a cumbersome process that involves a multitude of different imaging modalities, including ultrasonography, conventional radiography, X-ray fluoroscopy (retrograde and antegrade ureteropyelography), endoscopy (cystoscopy and ureterorenoscopy) without or with biopsy, multi-detector-row computed tomography (MDCT), and magnetic resonance imaging (MRI). However, these modalities leave a diagnostic gap because they cannot demonstrate different layers of the wall of the upper urinary tract. Recent research shows that catheter-based, intraluminal probes for optical coherence tomography (OCT) with near-infrared light provide cross-sectional images from within the lumen of the upper urinary tract that distinguish between the urothelium, lamina propria, and muscle layer at spatial resolutions of about 10–15 μm in axial and about 20–25 μm in lateral directions respectively. The feasibility of in vivo imaging and the superiority of OCT to endoluminal ultrasonography (ELUS) have been demonstrated. However, OCT has yet to show that it is capable of characterizing pathologic lesions, e.g., urothelial cancer. The present paper summarizes the basic principles and initial results of catheter-based, time-domain intraluminal OCT in the upper urinary tract.

PURPOSE: For nonsuperimposed and three-dimensional imaging of jaws and teeth, multislice computer tomography (MSCT) can be performed, or alternatively digital volume tomography as a cone beam technique can be applied. The radiation dose of both procedures should be evaluated with different methods of dose assessment. MATERIALS AND METHODS: A 4-row MSCT (Volume Zoom Siemens®) and a cone beam CT (NewTom QR-DVT 9000®) were compared regarding the radiation exposure of the patient during a dental examination. Organ dose and effective dose were estimated by thermoluminescence dosimetry (TLD) using an Alderson-Rando phantom for both devices. In addition the effective dose of MSCT was calculated from the CTDI vol -value at scanner display and by CT-Expo® program. RESULTS: The effective dose of MSCT was 0.33 mSv for women (w) and 0.32 mSv for men (m) measured with TLD in the Alderson-Rando phantom, 0.39 / 0.35 mSv (w/m) by CTDI calculation and 0.39 / 0.33 mSv by CT-Expo® program. The effective dose of NewTom® QR-DVT 9000 from TLD measurement was 0.095 / 0.093 mSv (w/m). CONCLUSION: The radiation exposure of a typical dental examination with a NewTom® cone beam DVT is about one third of the MSCT dose. Both techniques, however, moderate patient doses. Dosimetry methods as routinely used for MSCT cannot be applied to cone beam DVT.

The presence and extent of lymph node metastasis and primary tumor are among the most important prognostic factors in penile cancer. While inguinal lymphadenectomy is currently the most accurate means of staging, it is associated with severe morbidity and even mortality. Recent literature was reviewed for alternative means of staging.Functional imaging modalities distinguish between inguinal lymph nodes with and without metastasis. The false-negative rate of dynamic sentinel lymph node biopsy has recently improved from approximately 20 to 5% in one study. In 13 patients with penile cancer, (18)F-fluorodeoxyglucose-PET/computed tomography was 80% sensitive and 100% specific for lymph node metastasis, but missed micro-metastasis. In seven patients with penile cancer, MRI with lymphotrophic nanoparticles was 100% sensitive and 97% specific for lymph node metastasis.Combined PET/computed tomography and sentinel lymph node biopsy may help to detect both inguinal micrometastasis and pelvic and abdominal metastasis. Since MRI is highly accurate for staging of both primary penile cancer and its lymph node metastasis, however, it may turn out to be a powerful tool for a one-stop modality in the staging of penile cancer.

The aim was to develop clinical guidelines for multidetector computed tomography urography (CTU) by a group of experts from the European Society of Urogenital Radiology (ESUR). Peer-reviewed papers and reviews were systematically scrutinized. A summary document was produced and discussed at the ESUR 2006 and ECR 2007 meetings with the goal to reach consensus. True evidence-based guidelines could not be formulated, but expert guidelines on indications and CTU examination technique were produced. CTU is justified as a first-line test for patients with macroscopic haematuria, at high-risk for urothelial cancer. Otherwise, CTU may be used as a problem-solving examination. A differential approach using a one-, two- or three-phase protocol is proposed, whereby the clinical indication and the patient population will determine which CTU protocol is employed. Either a combined nephrographic-excretory phase following a split-bolus intravenous injection of contrast medium, or separate nephrographic and excretory phases following a single-bolus injection can be used. Lower dose (CTDIvol 5-6 mGy) is used for benign conditions and normal dose (CTDIvol 9-12 mGy) for potential malignant disease. A low-dose (CTDIvol 2-3 mGy) unenhanced series can be added on indication. The expert-based CTU guidelines provide recommendations to optimize techniques and to unify the radiologist's approach to CTU.

The sensitivity and specificity of MDCT for depiction and localization of urothelial carcinoma (UC) was determined retrospectively. Axial and coronal four-row MDCT of the urinary tract (unenhanced, contrast-enhanced nephrographic, CT urography) was independently reviewed for UC by a radiologist (R1) and a urologist (R2), without other patient information, in 27 patients (22 male, five female; age, 72 +/- 11 years) with previous UC and/or painless macroscopic haematuria. Urinary tract segments included bladder, right and left upper, middle, and lower caliceal groups, renal pelvis, uretero-pelvic junction, upper, middle, and lower ureter. MDCT findings were corroborated by surgery, other invasive procedures, and 1-year follow-up, including MDCT, intravenous urography, and cystoscopy. Receiver-operating characteristic analysis was undertaken and the the area under the curve (AUC) calculated. Eighteen of 27 patients had evidence of UC (pTa, n = 3; pT1-pT3, n = 15; TNM 2002). Tumor was correctly located by both R1 and R2 in 17 patients (sensitivity, 94%; 95% confidence interval, 84-100%) and ruled out in seven (specificity, 78%; 95% confidence interval, 51-100%), with complete agreement. Each detected ten of 11 upper urinary tracts affected by UC. For 35 urinary tract segments with UC and 308 without, the AUC was 0.910 +/- 0.035 (R1) and 0.74 +/- 0.055 (R2), z = 2.4772, Bonferroni-corrected P = 0.022. MDCT depicts urinary tracts affected by UC with high sensitivity and substantial agreement between readers with different training.

Background A 53-year-old man presented with left-sided flank pains to the Gastroenterology department of our clinic in September 2004. A left adrenal mass of 6.5 cm by 7.5 cm was detected by a CT scan. The patient showed no evidence of Cushing's syndrome, and had normal blood pressure and potassium levels. Endocrine tests ruled out excess levels of aldosterone or catecholamines. The patient underwent laparoscopic surgery to remove the tumor mass; histologic work-up revealed an adrenocortical carcinoma. A fluorodeoxyglucose (FDG)-PET scan 1 month, and a CT scan 8 months postoperatively showed no pathologic findings. The patient, however, again presented with left-sided flank pain to our Endocrinology department in August 2005. Investigations In our department, laboratory work-up for endocrine activity was performed, as well as CT scans of the adrenal region, and FDG-PET scans in order to determine the extension of disease. Histologic work-up of the removed tumor tissue was performed. Diagnosis Recurrent adrenocortical carcinoma after laparoscopic adrenalectomy. Management In our department, 10 months after initial laparoscopic surgery, local tumor recurrence was treated by repeated extensive surgery, tumor-bed radiation therapy, and mitotane treatment. A year later, a large lymph-node metastasis was surgically removed from the lower abdomen and mitotane treatment was again started postoperatively. The patient is now scheduled for polychemotherapy because of progressive metastatic disease revealed by follow-up CT and FDG-PET scanning in June 2006.

To assess structural, technical, and communicative aspects of dedicated MR examinations of the prostate (MRP) offered by radiologists in Germany.We conducted an eight-item online survey among members of the German Radiology Society (DRG). Radiological institutions were asked about their structure, i.e., either hospital department (HD) or private practice (PP), number of board-certified radiologists, postal regions, number of MRPs in 2011, MR technology and MR sequences applied, ways to communicate results, and feedback from referring physicians on results of subsequent tests and procedures. Submissions were cleared of redundancies and anonymized. Differences in the number of positive replies to each item were statistically significant at p0.05 for two-tailed testing in 2 x 2 tables.The survey represented board-certified radiologists in 128 institutions (63 HDs and 65 PPs) in 67/95 German postal regions (71%). Almost two-thirds of institutions performed 11 to 50 MRPs in 2011, more often at 1.5 T (116/128, 91%) than at 3.0 T (36/128, 28%), and most frequently with surface coils (1.5 T, 88/116, 76%; 3.0 T, 34/36, 94%; chi-square, 1.9736, 0.1p0.25). About two-thirds of 1.5 T users and 90% of 3.0 T users applied at least one functional MR modality (diffusion-weighted imaging, dynamic contrast-enhanced imaging, or MR spectroscopy) for MRP. Reports including graphic representations of the prostate were applied by 21/128 institutions (16%). Clinical feedback after MRP to radiologists other than upon their own request was infrequent (HDs, 32-45%, PPs, 18-32%).MRP was a widely available, small-volume examination among radiologists in Germany in 2011. The technology mainstay was a 1.5 T surface coil examination including at least one functional MR modality. Dedicated reporting and feedback mechanisms for quality control were underdeveloped.MRI of the prostate was available in at least 67 of 95 German postal regions (71%) in 2011. MRI of the prostate was most often performed at 1.5 T without an endorectal coil in Germany in 2011. At least two thirds of MRI-examinations of the prostate included both T2WI and at least one functional MR test (mostly DWI, less frequently MRS or DCE) in Germany in 2011. Structured reporting including graphic elements was offered by less than 20% of participating radiological institutions. Feedback to radiologists from referring physicians on subsequent test results in patients with MRI of the prostate most frequently came only upon special request by the radiologist.

Background: Motion artifacts that degrade image quality of coronary CT angiography (CCTA) in patients with high heart rates may be reduced with specific automatic motion correction algorithms (AMC). Objectives: We compared coronary-artery delineation between AMC and conventional CCTA reconstruction (CR). Patients and Methods: CCTA images (clinical single-source-64-slice-CT system) of 17 consecutive patients with heart rates exceeding 55 bpm were reconstructed with both CR and AMC during the individually best-suited phase of the cardiac cycle. Two independent readers who were blinded to the reconstruction algorithm scored image quality of each coronary artery segment (AHA 15-segment-model; 1: non-diagnostic 4: excellent). In case of disagreement a third blinded reader assigned a final score. Two-tailed statistical tests (Wilcoxonmatched-pairs, Pearson-correlation) were significant at P 70 bpm; P = 0.021). Inter-reader agreement was good. (inter-class-correlation, 0.762). Conclusions: CCTA image quality improves significantly with AMC in patients with high heart rates and reduces the proportion of nondiagnostic examinations.

Objectives: The tumor Gleason score is an important prognostic factor in prostate cancer (PCA). This retrospective study analyzes whether serum prostate-specific antigen (PSA), or magnetic resonance imaging (MRI)-based PSA density of the entire prostate (PSAD) or the prostatic transitional zone (PSAT) distinguishes between PCA of Gleason scores 6 or lower (G6-) and 7 or higher (G7+). Materials and Methods: Total prostate and transitional zone volumes were planimetrically determined in axial, T2-weighted fast spin echo (FSE) MRI images of the prostate in 61 patients with previously untreated PCA. Automated standardized microparticle enzyme immuno-assay (EIAs) measured PSA. Results: Thirty patients had G6- and 31 patients had G7+. PSA values ranged from 1.0 to 57.2 ng/mL. Assignment to G6 - or G7+, respectively, was correct in 49 of 61 (80%) cases (odds ratio [OR], 17.1; 95% confidence interval [CI], 4.8-61.5) for PSA above the optimal cutoff level of 10.35 ng/mL, 48 cases (79%; OR, 13.7; 95% CI, 4.0-46.8) for PSAD above the optimal cutoff level of 0.23 ng/ mL/cm 3 , and 45 cases (74%; OR, 6.9; 95% CI, 2.2-21.3) for PSAT above the optimal cutoff level of 0.38 ng/mL/cm 3 (no significant differences, McNemar test). Conclusions: In patients with biopsy-proven PCA, serum PSA level alone and MRI-based PSAD and PSAT help distinguish between G6- and G7+. PSAD and PSAT do not improve the level of confidence at which this discrimination is made.

A novel ureter phantom was developed for investigations of image quality and dose in CT urography. The ureter phantom consisted of a water box (14 cm x 32 cm x 42 cm) with five parallel plastic tubes (diameter 2.7 mm) filled with different concentrations of contrast media (1.88-30 mg iodine/ml). CT density of the tubes and noise of the surrounding water were determined using two multidetector scanners (Philips MX8000 with four rows, Siemens Sensation 16 with 16 rows) with varying tube current-time product (15-100 mAs per slice), voltage (90 kV, 100 kV, 120 kV), pitch (0.875-1.75), and slice thickness (1 mm, 2 mm, 3.2 mm). Contrast-to-noise ratio as a parameter of image quality was correlated with dose (CTDI) and was compared with image evaluation by two radiologists. The CT densities of different concentrations of contrast media and contrast-to-noise ratio were significantly higher when low voltages (90 kV versus 120 kV, 100 kV versus 120 kV) were applied. Smaller slice thickness (1 mm versus 2 mm) did not change CT density but decreased contrast-to-noise ratio due to increased noise. Contrast phantom studies showed favourable effects of low tube voltage on image quality in the low dose range. This may facilitate substantial dose reduction in CT urography.

Prostate cancer is difficult to visualise in its early stages and after definitive therapy (radiation, prostatectomy) and PSA-failure using current imaging technology. The present update aims to clarify the utility of PET (positron emission tomography) and magnetic resonance imaging (MRI) combined with proton MR spectroscopy (MRS). Past and current literature of both metabolic imaging modalities are reviewed. Although still under investigation, PET as well as MRI/MRS already have relative indications in staging and restaging of patients diagnosed with prostate cancer.

PURPOSE Intravascular optical coherence tomography (OCT) is a new technique based on infrared light that visualizes the arteries with a resolution of 10-20 microm. Intravascular ultrasound (IVUS) is the current in vivo reference standard and provides a resolution of 100-150 microm. This study compared OCT to IVUS and histopathology with respect to the ability to differentiate atherosclerotic plaques and quantify vascular dimensions in peripheral crural arteries ex vivo. MATERIALS AND METHODS 50 segments of atherosclerotic arteries derived from five amputated human lower extremities were examined. The different plaque types (fibrous, high-lipid content, calcified) were assigned by two independent examiners, and the sensitivity and specificity of OCT in comparison with histopathology as well as intra- and interobserver consensus were calculated. A comparison of OCT with IVUS addressed the parameters: luminal area (LA), vascular wall area (VA) and plaque area (PA). RESULTS When comparing OCT and histopathology with respect to the differentiation of various plaque types, sensitivities of 81 % and specificities of 89 % for fibrous plaques, of 100 % and 93 % for lipid-rich plaques and of 80 % and 89 % for calcified plaques were achieved (overall correlation 83 %). Intra- and interobserver consensus was very high (kappa = 0.86 and kappa = 0.89, p < 0.001, respectively). There was also a high correlation between quantitative measurements (Bland-Altman plot [LA]: mean bias, 0.1 mm(2) accuracy +/- 1.8 mm(2), r = 0.95 [p < 0.001] Bland-Altman plot [VA]: mean bias, 0.3 mm(2) accuracy +/- 2.3 mm(2), r = 0.94 [p < 0.001] Bland-Altman plot [PA]: mean bias, 0.4 mm(2) accuracy +/- 2.3 mm(2), r = 0.80 [p < 0.01]. CONCLUSION OCT allows the differentiation of atherosclerotic plaque types in crural arteries with high accuracy compared to histopathology. Quantitative measurements show a high correlation with IVUS, the current reference standard.

The aim of this study was to reproduce prostate cancer (PCA) localization by MRI based on prostatic sextants (right and left base, middle, and apex) with minimal systematic error. Combined endorectal/body-phased-array-coil MRI of the prostate at 1.5 T was retrospectively evaluated twice, with an interval of more than 1 month, by each of two independent radiologists (R1 readings R11 and R12, and R2 readings R21 and R22) in 23 patients (age 51-75 years) who had radical prostatectomy within 1 month of MRI. PCA stage was pT2 in 14 patients, and pT3 in nine. Median Gleason score was 7 (range 5-9). Histopathology showed 83 sextants with PCA and 55 without. Reproducibility of sextant positions was within one MRI slice (3 mm) in over 80% of cases. For PCA localization, ROC analysis (AUC=0.584+/-0.048-0.724+/-0.043) yielded no significant intra-reader differences. R11 and R21 differed slightly (P=0.035). Intra-observer agreement (kappa=0.52-0.58) exceeded inter-observer agreement (kappa=0.35-0.45). Intra-observer Spearman correlation (r=0.72-0.74) exceeded inter-observer correlation (r=0.43-0.51) for sextants with PCA, but not for sextants without (r=0.69-0.74). Per-sextant localization and reporting provides a highly reliable framework in MRI of the prostate. MRI of the prostate should be followed up by the same radiologists to minimize systematic error of interpretation.

Purpose To assess image quality of chest CT with an 80 to 90 percent dose reduction in follow-up studies of patients with lung disease, dose and image quality of a low-dose protocol was investigated. Materials and methods A follow-up low-dose CT (ND-CT, 120 kV, 10 mAs/slice, 3 mm slice thickness) was performed on 35 patients with non-malignant lung disease and compared with the initial standard dose CT (= SD-CT, 100 mAs/slice, 3 or 5 mm slice thickness). The dose was measured by thermo-luminescence in an Alderson phantom. Image quality was assessed by four independent radiologists in six perihilar, central and peripheral lung regions using a 4-point-scale ("very good", "good", "moderate", and "poor"). Results Effective dose was 0.5 mSv for ND-CT and 4.0 - 5.0 mSv for SD-CT. The ratings "very good"/"good" were given in the perihilar regions in ND-CT 97.5 % versus SD-CT 99.3 % (n. s.), in the central regions in ND-CT 96.4 % versus SD-CT 94.6 % (n. s.), and in the peripheral regions in ND-CT 70.0 % versus SD-CT 88.2 % (p Conclusion Follow-up CT of pulmonary structures in patients with chronic lung disease can be performed with substantial dose reduction. A decrease of image quality may result in peripheral lung regions.

OBJECTIVE As a screening test for prostate cancer (PCA), prostate-specific antigen (PSA) may induce unnecessary prostate biopsy in patients with PSA 4.1-10.0 ng/ml. PCA detection may be delayed in patients with PSA < or =4.0 ng/ml. MRI-based PSA density of the prostate (PSAD) and of the prostatic transitional zone (PSAT) could improve differentiation of PCA and benign prostatic hyperplasia. MATERIAL AND METHODS Total prostate and transitional zone volumes were planimetrically determined in axial, T2-weighted fast spin echo MR images of the prostate. Serum PSA concentration was measured with an automated standardized microparticle enzyme immune assay. PSAD and PSAT were calculated in 17 patients with clinically significant PCA and 42 patients with benign prostatic hypertrophy (BPH) (66 +/- 6 versus 64 +/- 8 years, p = 0.2410, t test) who had PSA levels < or =10.0 ng/ml. RESULTS For differentiation of BPH and PCA, PSA alone above the optimal cutoff level of 4.2 ng/ml showed an odds ratio for PCA of 6.7 (95% confidence interval [CI], 1.9-23.2). PSAD showed an odds ratio for PCA of 71.3 (95% CI, 11.8-430.9) above the optimal cutoff level of 0.07 ng/ml/cc. PSAT demonstrated an odds ratio for PCA of 320.0 (95% CI, 27.1-3781.4) above the optimal cutoff level of 0.15 ng/ml/cc. CONCLUSIONS In patients with PSA < or =10.0 ng/ml, MRI-based PSAD and PSAT appear to improve differentiation of prostate cancer and BPH and are feasible to reduce the frequency of unnecessary prostate biopsy.

The purpose of our study was to evaluate the use of 2D-selective, parallel-transmit excitation magnetic resonance imaging (MRI) for diffusion-weighted echo-planar imaging (pTX-EPI) of the prostate, and to compare it to conventional, single-shot EPI (c-EPI).The MRI examinations of 35 patients were evaluated in this prospective study. PTX-EPI was performed with a TX-acceleration factor of 1.7 and a field of view (FOV) of 150 × 90 mm(2), whereas c-EPI used a full FOV of 380 × 297 mm(2). Two readers evaluated three different aspects of image quality on 5-point Likert scales. To quantify distortion artefacts, maximum diameters and prostate volume were determined for both techniques and compared to T2-weighted imaging.The zoomed pTX-EPI was superior to c-EPI with respect to overall image quality (3.39 ± 0.62 vs 2.45 ± 0.67) and anatomic differentiability (3.29 ± 0.65 vs 2.41 ± 0.65), each with p 0.0001. Artefacts were significantly less severe in pTX-EPI (0.93 ± 0.73 vs 1.49 ± 1.08), p 0.001. The quantitative analysis yielded a higher agreement of pTX-EPI with T2-weighted imaging than c-EPI with respect to coronal (ICCs: 0.95 vs 0.93) and sagittal (0.86 vs 0.73) diameters as well as prostate volume (0.94 vs 0.92). Apparent diffusion coefficient (ADC) values did not differ significantly between the two techniques (p 0.05).Zoomed pTX-EPI leads to substantial improvements in diffusion-weighted imaging (DWI) of the prostate with respect to different aspects of image quality and severity of artefacts.Recent technical developments in MRI allow the use of accelerated, spatially-selective excitation (parallel-transmit, pTX). pTX can be used for zoomed echo-planar prostate imaging (pTX-EPI). pTX-EPI improves different aspects of image quality in prostate MRI. Distortion artefacts are reduced by the use of pTX-EPI in prostate MRI. Further studies should aim at assessing the diagnostic accuracy of pTX-EPI.

To determine the accuracy of combined magnetic resonance (MR) imaging and three-dimensional (3D) proton MR spectroscopic imaging in localizing prostate cancer to a sextant of the gland in patients receiving hormone deprivation therapy.Combined MR imaging/3D MR spectroscopic imaging examinations were performed in 16 hormone-treated patients and 48 nontreated matched control patients before radical prostatectomy and step-section histopathologic analysis. At MR imaging, cancer presence within the peripheral zone was assessed on a per sextant basis by two readers. At 3D MR spectroscopic imaging, cancer was identified by using (choline plus creatine)-to-citrate ratios at cutoff values of 2 and 3 SDs above mean normal peripheral zone values. Data were compared by using receiver operating characteristic analysis.There was no significant difference in the ability of combined MR imaging/3D MR spectroscopic imaging to localize prostate cancer in treated versus control patients. For MR imaging alone, the sensitivity and specificity were 91% and 48% (reader 1) and 75% and 60% (reader 2) in treated patients versus 79% and 60% (reader 1) and 84% and 43% (reader 2) in control patients. For 3D MR spectroscopic imaging alone (3 SDs cutoff), higher specificity (treated, 80%; controls, 73%) but lower sensitivity (treated, 56%; controls, 53%) was attained. In treated patients, high sensitivity or specificity (up to 92%) was achieved when either or both modalities indicated cancer.When performed within 4 months after initiating hormone deprivation therapy, combined MR imaging/3D MR spectroscopic imaging had the same accuracy in localizing prostate cancer as in nontreated patients.

Purpose: We compared the accuracy of endorectal magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging with that of sextant biopsy for the sextant localization of prostate cancer.Materials and Methods: Sextant biopsy, MRI, magnetic resonance spectroscopic imaging and radical prostatectomy with step section histology were done in 47 patients with prostate cancer. For each sextant we categorized biopsy and imaging results as positive or negative for cancer. Step section histology was used as the standard of reference.Results: For sextant localization of prostate cancer MRI and magnetic resonance spectroscopic imaging were more sensitive but less specific than biopsy (67% and 76% versus 50%, and 69% and 68% versus 82%, respectively). The sensitivity of sextant biopsy was significantly less in the prostate apex than in the mid prostate or prostate base (38% versus 52% and 62%, respectively). MRI and magnetic resonance spectroscopic imaging had similar efficacy throughout the prostate co...

The purpose of our study was to determine relative values of rapid acquisition relaxation enhancement (RARE) and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences in breathhold magnetic resonance (MR) urography in healthy volunteers under nonobstructive conditions of the urinary tract. A total of 20 healthy volunteers underwent MR urography with breathhold RARE and HASTE sequences at 1.5 T. For evaluation, the urinary tract was divided into nine segments on each side. Visualization of segments and artifacts was scored and the intensity ratios (InR) were determined. The upper five urinary segments were sufficiently visualized with RARE and significantly better with HASTE (renal calices, p = 0.002-0.037). The middle and lower ureter was sufficiently delineated both with RARE and HASTE, but HASTE images were statistically superior (p = 0.009-0.041). Both in RARE and HASTE images, the lower ureter was frequently superimposed by bowel contents and bowel motion. Superimposition of genital organs degraded image quality in eight of ten female volunteers. InRs were superior with HASTE in the kidney and ureter (p = 0.0003-0.0125). RARE InRs were higher in the bladder (p = 0.0008-0.014). We concluded that neither the RARE nor the HASTE sequences allowed the evaluation of the entire urinary tract under nonobstructive conditions. Although it cannot entirely replace intravenous urography, MR urography seems to lend itself to combination with other MR techniques, particularly in the investigation of pelvic or retroperitoneal disease.

The purpose of this study was to predict diameters of lesions induced by laser-induced thermotherapy (LITT) of benign prostatic hyperplasia (BPH) from MRI signal/tissue temperature correlations during on-line monitoring with a temperature-sensitive fast low-angle shot (FLASH) sequence. Twenty LITT procedures with Nd:YAG (1,064 nm) and diode (830 nm) lasers were monitored on line with a T1-weighted FLASH sequence at 1.5 Tesla. Interstitial prostate temperature (T) was measured on line in 10 LITT procedures and laser energy deposition in 12. Slopes of linear regression curves for signal intensity (SI) over T were applied to determine SI at 60 degrees C to estimate diameters of intraprostatic LITT lesions. Diameters of unperfused LITT lesion cores in contrast-enhanced T1-weighted images served as gold standards. Linear regression curves with an average slope of -.54% SI/degrees C were obtained in 17 LITT procedures. Correlation coefficients were r = .92-.95 for SI/T and SI/energy deposition. Baseline variation of SI at body temperature was +/-3.9%, corresponding to +/-7 degrees C. Prediction of size (13 lesions) from on-line FLASH imaging was correct in 10 of 13, whereas 3 lesions were overestimated. Prediction of LITT lesion diameters from on-line MRI monitoring is possible with a temperature-sensitive FLASH sequence in the prostate. Accuracy may suffice to assign target regions of interest to tissue locations to be protected from coagulation.