Purpose: HRCT is the preferred imaging technique to evaluate Interstitial-Lung-Disease. Optimal Low-Dose-Computed-Tomography protocol for monitoring ILD with lowest radiation dose and optimal diagnostic accuracy and image quality unknown. Methods: 28 Patients underwent HRCT. Image reconstructions with varying combinations of tube current (50mA, 20mA, 15 mA, 10mA) and image-thickness/increment (1/1mm, 2/2mm, 3/2.4mm, 5/4mm) were simulated from raw data. 448 CTs evaluated by 2 readers on image quality and ILD-specific features (ground glass opacification (ggo), honeycombing (hc), reticulation (ret)). Results: Reduced dose settings with 20 mA did not show any significant difference to standard dose settings for all parameters in reader 1, while results were significantly altered in reader 2. Slice thickness did not significantly influence rating of typical ILD features like ggo, hc, ret or total disease extent. The correct differentiation between UIP and NSIP could be made on all dose settings and with all slice thickness. It was even found, that an increased slice thickness can compensate for the noise associated image quality degradation. Overall, for ggo detection a combination of 20 mA and 3 or 5 mm slice thickness was not different to the original evaluation. Conclusions: Assessment of ILD specific CT features down to 20 mA and a slice thickness of 3 or 5 mm is feasible.

Evaluation einer automatisierten 3D-Volumetrie der Pulmonalarterien basierend auf Magnetresonanzangiografien (MRA) zur Prädiktion der pulmonalen Hypertonie (PH) sowie Bestimmung der Auswerter-Übereinstimmung.

Purpose: We evaluated the rate of successful characterization of gastroenteropancreatic neuroendocrine tumors (NETs) present with an increased somatostatin receptor, comparing CE-CT with CE-MRI, each in correlation with DOTATOC-PET.Methods and materials: 8 patients with GEP-NET were imaged using CE-MRI (Gd-EOB-DTPA), CE-CT (Imeron 400) and DOTATOC-PET. Contrast-enhancement of normal liver-tissue and metastasis was quantified with ROI-technique. Tumor delineation was assessed with visual-score in blind-read-analysis by two experienced radiologists.Results: Out of 40 liver metastases in patients with NETs, all were detected by CE-MRI and the lesion extent could be adequately assessed, whereas CT failed to detect 20% of all metastases. The blind-read-score of CT in arterial and portal phase was median -0.65 and -1.4, respectively, and 2.7 for delayed-MRI. The quantitative ROI-analysis presented an improved contrast-enhancement-ratio with a median of 1.2, 1.6 and 3.3 for CE-CT arterial, portal-phase and delayed-MRI respectively.Conclusion: Late CE-MRI was superior to CE-CT in providing additionally morphologic characterization and exact lesion extension of hepatic metastases from neuroendocrine tumor detected with DOTATOC-PET. Therefore, late enhanced Gd-EOB-DTPA-MRI seems to be the adequate imaging modality for combination with DOTATOC-PET to provide complementary (macroscopic and molecular) tumor characterization in hepatic metastasized NETs. (C) 2011 Published by Elsevier Ireland Ltd.

Tissue microcirculation can be quantified by a deconvolution analysis of concentration-time curves measured by dynamic contrast-enhanced magnetic resonance imaging. However, deconvolution is an ill-posed problem, which requires regularization of the solutions. In this work, four algebraic deconvolution/regularization methods were evaluated: truncated singular value decomposition and generalized Tikhonov regularization (GTR) in combination with the L-curve criterion, a modified LCC (GTR-MLCC), and a response function model that takes a-priori knowledge into account. To this end, dynamic contrast-enhanced magnetic resonance imaging data sets were simulated by an established physiologically reference model for different signal-to-noise ratios and measured on a 1.5-T system in the lung of 10 healthy volunteers and 20 patients. Analysis of both the simulated and measured dynamic contrast-enhanced magnetic resonance imaging datasets revealed that GTR in combination with the L-curve criterion does not yield reliable and clinically useful results. The three other deconvolution/regularization algorithms resulted in almost identical microcirculatory parameter estimates for signal-to-noise ratios > 10. At low signal-to-noise ratios levels (<10) typically occurring in pathological lung regions, GTR in combination with a modified L-curve criterion approximates the true response function much more accurately than truncated singular value decomposition and GTR in combination with response function model with a difference in accuracy of up to 76%. In conclusion, GTR in combination with a modified L-curve criterion is recommended for the deconvolution of dynamic contrast-enhanced magnetic resonance imaging curves measured in the lung parenchyma of patients with highly heterogeneous signal-to-noise ratios.

Ziele: Blood oxygenation level dependent (BOLD) MRT bietet die Möglichkeit einer nicht invasiven Messung der Tumor Oxygenierung. Hierbei reflektieren höhere Relaxationsraten einen höheren Hypoxiegrad.

Ziele: Diagnostik und Therapiekontrolle bei COPD und Asthma stützen sich bislang im Wesentlichen auf die Daten der Lungenfunktionsprüfung. Hier können insb. Informationen zu Lungenvolumina und Atemfluss gewonnen werden. Diese Parameter erscheinen jedoch nicht sensitiv genug, um kurzfristige und lokale Veränderungen zu detektieren, die eine individuell optimierte Therapie ermöglichen. Aus diesem Grund liegt die Hoffnung auf neuen Parametern, die sich auf die MRT stützen.

Ten South American sea lions (Otaria flavescens) were presented for clinical evaluation and diagnosis of tuberculosis following known exposure to Mycobacterium pinnipedii. CT was used to determine whether foci of calcification in mediastinal lymph nodes, typically associated with pinniped tuberculosis, could be detected and whether CT was a useful diagnostic modality, in conjunction with other tests, for the diagnosis of tuberculosis in this species. Blood was collected from the caudal gluteal vein of each animal for serological testing using commercially available serological tests (ElephantTB STAT-PAK and DPP Vet; Chembio Diagnostic Systems) and a multiantigen print immunoassay (MAPIA), carried out at Chembio to verify the in-house kits. In four of nine animals that underwent CT scanning, lesions consistent with pinniped tuberculosis were apparent and these were confirmed at subsequent postmortem examination. The five remaining animals did not show any abnormalities on CT, with three being negative on serological tests, which were considered to be normal and potentially used as reference images for healthy sea lions. One animal could not be CT scanned due to its large size and weight (510 kg).

Imaging studies play a critical role in the diagnosis and staging of lung cancer. CT and 18-fluorodeoxyglucose positron emission tomography CT (PET/CT) are widely and routinely used for staging and assessment of treatment response. Many radiologists still use MRI only for the assessment of superior sulcus tumours, and in cases where invasion of the spinal cord canal is suspected. MRI can detect and stage lung cancer, and this method could be an excellent alternative to CT or PET/CT in the investigation of lung malignancies and other diseases. This pictorial essay discusses the use of MRI in the investigation of lung cancer.

Neuroblastoma is an embryonic tumor of the sympathetic nervous system which represents one of the most common malignancies in early childhood. Its clinical and biological behavior show a remarkable heterogeneity, ranging from spontaneous regression to inexorable progression with a fatal outcome. This review summarizes the clinical risk stratification and treatment options. An extensive overview of the role of imaging during the course of the disease and typical imaging findings in all imaging modalities are demonstrated.

Pulmonary embolism (PE) is the third most common acute cardiovascular disease after myocardial infarction and stroke, and results in thousands of deaths each year. Improvements in MRI accuracy are ongoing with the use of parallel imaging for angiography techniques and pulmonary perfusion. This, associated with other potential advantages of MRI (e.g. a radiation free method and better safety profile of MR contrast media), reinforces its use. The aim of this paper is to perform a pictorial review of the principal findings of MRI in acute PE. Acute PE can manifest itself as complete arterial occlusion and the affected artery may be enlarged. We report the main vascular and parenchymal signs, and an overview of current literature regarding accuracy, limitations and technical aspects is provided.

Hintergrund: Die Lunge stellt als Organ aufgrund der geringen Spindichte, der großen Luftgewebegrenzfläche sowie der Bewegungsartefakte eine große Herausforderung für die MRT dar. Die Sauerstoff-verstärkte MRT (O2-MRT) verwendet O2 als inhalatives Kontrastmittel zur Visualisierung der Ventilation. Es wurde die Reproduzierbarkeit der O2-MRT hinsichtlich der diagnostischen Qualität, des Signals und von Ventilationsdefekten bei Bronchialkarzinompatienten (P) im Vergleich zu lungengesunden, altersangepaßten Probanden (F) untersucht.

The 2009 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension have been adopted for Germany. The guidelines contain detailed recommendations for the diagnosis of pulmonary hypertension. However, the practical implementation of the European Guidelines in Germany requires the consideration of several country-specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2010, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to the non-invasive diagnosis of pulmonary hypertension. This manuscript describes in detail the results and recommendations of the working group which were last updated in October 2011.

Die Zahl der Patienten mit angeborenen vaskulären Fehlbildungen, welche erfolgreich therapiert werden, nimmt konstant zu. Die Patienten müssen regelmäßig Verlaufskontrolliert werden, so dass ein besonderes Augenmerk auf einer optimalen Technik liegt. Optimal ist in diesem Fall zu verstehen als a) überlagerungsfrei, b) morphologische und funktionelle Parameter müssen akquiriert werden, und c) Röntgenstrahlen sollten vermieden werden. Je nach Anomalie ist die Initialdiagnostik mittels Echokardiographie ausreichend um Therapieentscheidungen zu treffen.

SummaryMagnetic Resonance Imaging (MRI) of the chest and especially the lung is more and more accepted as a valuable additional imaging modality for several pulmonary diseases. Magnetic Resonance Imaging allows for combined morphological and functional imaging and therefore elucidates perfectly the effect of parenchymal changes and destruction onto pulmonary perfusion and ventilation. This overview presents the current status for the application of pulmonary MRI in chronic obstructive pulmonary disease as well as infectious and neoplastic diseases.

The standard examination technique for the chest in children is an X-ray examination - it is fast, cheap and provides a good overview of anatomy and pathology. In cases with an unclear pathology or if more details are needed (i. e. pre-therapeutically), computed tomography is most often performed with the well known drawbacks of limited soft tissue contrast and radiation. Radiation should be avoided in children, especially if follow-up examinations are needed. Recent magnetic resonance (MR) techniques allow for fast and reliable assessment of pulmonary diseases in children. Due to the inherent soft tissue contrast, diagnosis can be frequently performed without contrast media application. This review provides an exemplary MR examination protocol for routine application in pediatric patients. The diagnostic value of MRI is shown in patients with infectious diseases, patients with immunodeficiency, anatomic abnormalities, acquired chronic diseases, and pulmonary tumors. Since MRI is especially suitable for functional imaging, an MR protocol is provided for the examination of thoracic deformities. This review summarizes the use of thoracic MRI in the clinical pediatric setting with special focus on the clinical indications as a radiation-free method.

Die aktuelle Bildgebung der Aorta hat in den letzten Jahren an Vielfalt und Qualität gewonnen. Neben der Verifizierung und Dokumentation einer klinischen Verdachtsdiagnose stellt sie die Grundlage für die Indikationsstellung, die Wahl des Therapieverfahrens (konservativ, operativ, interventionell), die Therapieplanung und die Nachsorge dar. Neben der B-Mode- und der Duplexsonographie sowie der transösophagealen Echokardiographie (TEE) spielen heute v. a. die kontrastmittelunterstützten Schnittbildverfahren, die Computertomographie (CT) mit der Option zur CT-Angiographie (CTA) und die Magnetresonanztomographie (MRT) mit der Option der MR-Angiographie (MRA) eine wesentliche Rolle. Der folgende Beitrag beschreibt aus Sicht des Radiologen in einer Klinik der Maximalversorgung die Möglichkeiten der CTA und MRA für die Abklärung aortaler Pathologien.