Das Thoraxröntgen mit den Vorteilen der schnellen Verfügbarkeit, geringen Strahlendosis und geringen Kosten ist unverändert die häufigste radiologische Untersuchung. Es wurde jedoch vielfach publiziert, dass primär im Thoraxröntgen übersehene Lungenrundherde retrospektiv sichtbar waren.

Chest radiography still represents the most commonly performed X-ray examination because it is readily available, requires low radiation doses and is relatively inexpensive. However, as previously published, many initially undetected lung nodules are retrospectively visible in chest radiographs.The great improvements in detector technology with the increasing dose efficiency and improved contrast resolution provide a better image quality and reduced dose needs.The dual energy acquisition technique and advanced image processing methods (e.g. digital bone subtraction and temporal subtraction) reduce the anatomical background noise by reduction of overlapping structures in chest radiography. Computer-aided detection (CAD) schemes increase the awareness of radiologists for suspicious areas.The advanced image processing methods show clear improvements for the detection of pulmonary lung nodules in chest radiography and strengthen the role of this method in comparison to 3D acquisition techniques, such as computed tomography (CT).Many of these methods will probably be integrated into standard clinical treatment in the near future. Digital software solutions offer advantages as they can be easily incorporated into radiology departments and are often more affordable as compared to hardware solutions.

Purpose: To compare image quality of standard-dose computed radiography and dose reduced needle-technology CR for supine CXR in a clinical setting.Materials and methods: We prospectively evaluated 128 radiographs of 32 immunocompromised patients. For each patient four clinical CXR were performed within one week, two with powder image plates (PIP; Fuji ST-V) and two with needle image plates (NIP; Agfa DXS) at standard and half dose, respectively. One experienced radiologist and two residents blinded to dose level and kind of imaging system rated different anatomical structures, image noise, tubes/lines and abnormalities on a image quality scale from 1 to 10 (1 = poor, 10 = excellent). The rating scores were tested for statistical differences using analysis of variance with repeated measures.Results: A statistical difference (p < 0.05) was found for the two systems as well as for the two dose levels. Overall rating scores were 6.5 for PIP with full dose, 6.2 for PIP with half dose, 7.6 for NIP with full dose and 7.4 for NIP with half dose. There was a significant difference in favour of the NIP system at the same dose level. Also the NIP images obtained at half dose were ranked significantly better compared to the PIP images at standard dose. The differences in ranking of anatomical structures and abnormalities were more pronounced in low absorption areas (pulmonary vessels, parenchyma) than in high absorption areas (mediastinum, spine).Conclusion: For supine chest radiograms the NIP technology allows for a dose reduction of 50% while providing higher image quality. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Dosisreduktion und adäquate Bildqualität in der digitalen Radiographie – ein Widerspruch?

We report the case of a 35-years-old renal transplant patient known to have familial Mediterranean fever with serum amyloid A (SAA)-amyloidosis, who presented with his second episode of bilateral pneumonia. As antimicrobials failed to control the first episode of pneumonia and all studies done were non-contributory, we attributed the condition to the highly active Mediterranean fever presumably resistant to colchicine and treated the patient with the interleukin-1 receptor antagonist anakinra: the patient substantially improved by clinical symptoms, chemistry and radiological evidence within no more than 2 days and was discharged in good health after 4 days.

To test a digital imaging X-ray device based on the direct capture of X-ray photons with pixel detectors, which are coupled with photon-counting readout electronics.

OBJECTIVE A newly developed computed radiography (CR) detector that uses a storage phosphor plate made of needle-shaped crystals provides improved dose efficiency. The aim of our study was to compare the image quality of standard-dose CR and dose-reduced CR achieved using needle technology for knee imaging in a clinical setting. MATERIALS AND METHODS We compared standard CR images obtained using a powder-structured image plate (PIP) (ADC Compact Plus) with images obtained using the new needle-structured image plate (NIP) (DX-S). In 30 consecutive patients with knee pain willing to participate in this study, anteroposterior knee radiographs were acquired with both systems at a standard dose. In addition, NIP images were obtained with approximately 75% and 50% of the standard dose (corresponding incident doses: 300, 235, and 154 μGy, respectively). Images were evaluated in a blinded, side-by-side comparison. Six radiologists determined whether there was an appreciable difference in image quality at five anatomic landmarks in regions with high and low differences of attenuation. They also assessed the delineation of selected abnormalities and ranked them using a 10-point scale. The rating scores were tested for statistical differences using an analysis of variance with repeated measures. RESULTS The mean overall rating scores for the evaluation of anatomic landmarks were 6.97 for NIP images obtained at full dose, 6.48 for NIP images obtained at about 75% dose, 5.47 for NIP images obtained at half dose, and 6.01 for PIP images. There was a significant difference in favor of the CR system with an NIP at the same dose level (p < 0.05). The NIP images obtained at a dose of about 75% were also ranked significantly better than the PIP images with regard to the depiction of both anatomic landmarks and abnormalities. The readers ranked half-dose NIP images inferior to the PIP images with regard to abnormalities and anatomic landmarks in areas with high attenuation, whereas in areas with low attenuation, the image quality was regarded as equivalent to the standard technique. CONCLUSION NIP technology allows a dose reduction of approximately 25% compared with PIP while still providing higher image quality. Even at the half-dose level, there was no relevant loss of image quality with regard to the delineation of anatomic landmarks in areas with low attenuation in anteroposterior knee images. The higher dose efficiency of the needle-detector CR technology compared with conventional CR can be used either for dose reduction or for improved image quality.

Peptide receptor radionuclide therapy (PRRT) has recently been established as an important treatment modality for somatostatin receptor (SSTR)-positive tumors. The purpose of this study was to evaluate the clinical response, side-effects as well as the quality of life following 90 Y-DOTA-lanreotide (DOTALAN) and/or 90 Y-DOTA-Tyr 3 -DPhe 1 -octreotide (DOTATOC) therapy in patients with progressive metastatic disease during a 6-year follow-up period. Following dosimetric evaluation with 111 In-DOTALAN and 111 In-DOTATOC, 13 patients with estimated absorbed tumor doses of >5 Gy/GBq (carcinoid, n = 5; radioiodine-negative thyroid cancer, n = 4; gastrinoma, n = 1; insulinoma, n = 1; glucagonoma, n = 1; glomus jugularis tumor, n = 1) were assigned for PRRT. A dose of 925 MBq of 90 Y-DOTALAN (four patients) or 1.85-3.7 GBq of 90 Y-DOTATOC (10 patients) was administered intravenously and repeated every 4-8 weeks. Tumor dosimetry was performed prior to and under therapy, re-staging every 2-3 months. Pain intensity, Karnofsky score and general symptoms were evaluated in order to determine quality of life. Patients were followed until death. Altogether, 53 infusions of PRRT (1.85-14.1 GBq) were administered. After the first follow-up of 3 months of 90 Y-DOTALAN therapy, stable disease (SD) was observed in one patient and progressive disease (PD) in three patients. With 90 Y-DOTATOC therapy, SD was found in all 10 patients. During the re-evaluation period (4-27 months), one patient had to be shifted from 90 Y-DOTALAN to 90 Y-DOTATOC therapy due to reduced 111 In-DOTALAN uptake after 5.5 GBq. In the first 6 months after PRRT with DOTATOC, SD was found in nine of 10 patients and PD in one patient. Thereafter, SD was observed in two patients and PD in eight patients. Nine of 13 patients after PRRT with either DOTALAN or DOTATOC died. None of the patients had experienced severe acute hematological side-effects. Transient thrombocytopenia or lymphocytopenia was seen in 10 patients after 3.7 GBq, and a skin reaction in one patient. Total accumulated kidney dose ranged between 4 and 64 Gy, with reduced creatinine clearance in two patients. Pain relief was achieved in three of three patients after ~3.7 GBq ERT within 4-6 months. Appetite, weight, Karnofsky score and general well-being had improved in patients with SD during and after therapy. Based on the results of this study conducted on a small group of patients, we conclude that PRRT may offer an alternative treatment option for SSTR-positive tumors, with only mild transient side-effects and a marked improvement in the quality of life.

OBJECTIVE. The purpose of this article is to evaluate the impact of gray-scale reversal on the detection of small pulmonary nodules in two-view chest radiography.MATERIALS AND METHODS. One hundred twenty-eight patients (mean age, 62 years) who underwent CT and chest radiography within 6 weeks were retrospectively selected for this study. Seventy-three percent of patients showed variable degrees of radiographic findings of a "dirty lung." A total of 129 solid pulmonary nodules were present in 74 patients (nodule diameter range, 5-30 mm; mean diameter, 13 mm). The remaining 54 patients served as negative control subjects. Six readers with varying experience levels evaluated the images without and with the availability of gray-scale reversal in two separate reading sessions. Figure of merit (FOM), sensitivity per lesion, mean number of false-positive marks per image, and accuracy were calculated.RESULTS. Five of the six readers showed a slight increase in sensitivity with the use of gray-scale reversal, but on average, the difference was not significant (48% vs 50%; p > 0.05). The mean number of false-positive marks per image also nonsignificantly increased from 0.20 to 0.23. The increases in both sensitivity and the mean number of false-positive marks per image translated into nonsignificant decreases in average FOM (0.79 vs 0.77) and accuracy (72% vs 71%). Data analysis of subgroups of nodules or different reader groups, depending on level of experience, did not reveal significant differences.CONCLUSION. Using PACS display of digital chest radiographs, gray-scale reversal does not help the radiologists in detecting pulmonary nodules.

To evaluate the impact of computer-aided detection (CAD, IQQA-Chest; EDDA Technology, Princeton Junction, NJ) used as second reader on the detection of small pulmonary nodules in chest radiography (CXR).A total of 113 patients (mean age 62 years) with CT and CXR within 6 weeks were selected. Fifty-nine patients showed 101 pulmonary nodules (diameter 5-15mm); the remaining 54 patients served as negative controls. Six readers of varying experience individually evaluated the CXR without and with CAD as second reader in two separate reading sessions. The sensitivity per lesion, figure of merit (FOM), and mean false positive per image (mFP) were calculated. Institutional review board approval was waived.With CAD, the sensitivity increased for inexperienced readers (39% vs. 45%, P < .05) and remained unchanged for experienced readers (50% vs. 51%). The mFP nonsignificantly increased for both inexperienced and experienced readers (0.27 vs. 0.34 and 0.16 vs. 0.21). The mean FOM did not significantly differ for readings without and with CAD irrespective of reader experience (0.71 vs. 0.71 and 0.84 vs. 0.87). All readers together dismissed 33% of true-positive CAD candidates. False-positive candidates by CAD provoked 40% of all false-positive marks made by the readers.CAD improves the sensitivity of inexperienced readers for the detection of small nodules at the expense of loss of specificity. Overall performance by means of FOM was therefore not affected. To use CAD more beneficial, readers need to improve their ability to differentiate true from false-positive CAD candidates.

We used nonpegylated liposomal doxorubicin (NPLD) in cytostatic drug combinations to treat 37 patients with non-Hodgkin's lymphoma and pre-existing cardiac disorder or elderly patients with reduced physical state who were ineligible for conventional anthracycline-containing therapy. High remission rates were observed in this poor-risk population: Complete remission rates were 75% for diffuse large B cell lymphoma (DLBCL) and 55% for T/NK cell neoplasm (overall response rate of 80% and 89%, respectively). Twenty-seven patients (73%) are still alive after a median observation time of 14 months. No major cardiac or gastrointestinal toxicity was observed. Extravasation of NPLD in two patients resulted in mild inflammation without tissue damage. Hematologic toxicity was comparable to that of conventional anthracycline-containing regimens. We conclude that NPLD is highly active in combination chemotherapy for lymphoma with low cardiac toxicity in patients with pre-existing cardiac disorders or higher age. Moreover, we also observed remarkable efficacy in T/NK cell lymphomas.

Peritoneale Erkrankungen können sich in den verschiedenen Bildgebungsmodalitäten entweder als Gas-/Flüssigkeitsansammlung oder als weichteildichte Gewebevermehrung entlang der verschiedenen Ligamente und Mesenterien der Peritonealhöhle manifestieren. Dieses breite Spektrum der pathologischen Veränderungen beinhaltet entzündliche, infektiöse, neoplastische und verschiedenste Erkrankungen anderer Genese. In vorliegendem Artikel wird ein großes Spektrum dieser Pathologien wie Aszites, Peritonitis, intraabdominelle Blutung und verschiedene primäre und sekundäre peritoneale Tumoren vorgestellt. Des Weiteren wird der Einsatz der verschiedenen radiologischen Untersuchungsmodalitäten, v. a. der Computertomographie (CT) als wichtigster Untersuchungsmethode, erläutert. Die charakteristischen Bildgebungsmerkmale und die typischen anatomischen Ausbreitungswege werden erklärt.

This issue of European Journal of Radiology presents an update of Digital Radiography. We are grateful to a group of internationally renowned authors for their outstanding contributions that cover new trends in the field of acquisition technology and processing for various clinical applications. Since its introduction more than almost 3 decades ago, digital radiography has matured considerably. After some initial reluctance, the vast majority of institutions has nowadays made the transition from conventional analogue radiography to digital techniques. The eventual triumph of digital over conventional technique is related to superior image quality and logistic reasons. The latter are probably the most important argument: only digital radiography systems make it possible to run a picture archiving and communication system (PACS) efficiently. With respect to digital detector technology, there is a constant trend towards higher dose efficiency, faster readout and more integrated systems (Schaefer-Prokop et al.). Control of radiation dose is an important topic because image density and contrast are de-coupled from the exposure parameters. Techniques that control the dose in digital radiography and avoid a slow but constant dose creep are described (Uffmann et al., Veldkamp et al.). Dedicated articles describe new trends in digital mammography (Schulz-Wendtland et al.) and feature optimisation of image acquisition and image quality for paediatric patients (Willis et al.). Monitor reading is an integral part of working with PACS technology. This has made it possible to introduce new advanced acquisition and processing techniques, such as tomosynthesis, dual energy subtraction and temporal subtraction that have the goal to reduce the overlying anatomic noise and improve detection of subtle pathology (McAdams et al., Vock et al. and MacMahon et al.). Such algorithms may or may not require modification of data acquisition but they have in common that advanced image processing is performed in the background and the results are available on the monitor display as soon as the radiologist reads the case. CAD is an increasingly important topic in digital radiography. The abbreviation refers to either computer-aided diagnosis or computer-aided detection. Detection schemes do not alter the anatomic noise but aim at improving human perception by alerting the reader to suspicious areas (DeBoo et al., van Ginneken et al.). Other CAD schemes are designed to support the radiologist in time-consuming reading tasks such as quantification of skeletal changes in rheumatoid arthritis (Peloschek et al.). Some of these new processing options have already made their way into the routine application, others are still in the state of being evaluated and optimised under study conditions. We thank the editor, Professor Imhof for giving us the opportunity to compose this issue as guest editors and hope that these articles will help the readers to understand new techniques in digital radiography and to implement them in their daily clinical practice.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

After some initial reluctance, nowadays transition from conventional analogue-to-digital radiographic technique is realized in the vast majority of institutions. The eventual triumph of digital over conventional technique is related to its undoubted advantages with respect to image quality and improved image handling in the context of a picture archiving and communication system. CR represents the older system, which matured over decades and experienced some important recent improvements with respect to dose efficiency and work-flow efficiency that strengthened its position. It represents a very versatile, economically attractive system that is equally suited for integrated systems as well as for cassette-based imaging at the bedside. DR systems offer superb image quality and realistic options for dose reduction based on their high dose efficiency. While for a long time only integrated systems were on the market suited for a large patient throughput, also mobile DR systems became recently available. While for the next years, it is likely that DR and CR systems will coexist, the long term perspective of CR will depend on further innovations with respect to dose efficiency and signal-to-noise characteristics while for DR economical aspects and broader availability of mobile systems will play a role.

Screening of the liver for hepatic lesion detection and characterization is usually performed with either ultrasound or CT. However, both techniques are suboptimal for liver lesion characterization and magnetic resonance (MR) imaging has emerged as the preferred radiological investigation. In addition to unenhanced MR imaging techniques, contrast-enhanced MR imaging can demonstrate tissue-specific physiological information, thereby facilitating liver lesion characterization. Currently, the classes of contrast agents available for MR imaging of the liver include non-tissue-specific extracellular gadolinium chelates and tissue-specific hepatobiliary or reticuloendothelial agents. In this review, we describe the MR features of the more common focal hepatic lesions, as well as appropriate imaging protocols. A special emphasis is placed on the clinical use of non-specific and liver-specific contrast agents for differentiation of focal liver lesions. This may aid in the accurate diagnostic workup of patients in order to avoid invasive procedures, such as biopsy, for lesion characterization. A diagnostic strategy that considers the clinical situation is also presented.

Peritoneal diseases can be seen in the different imaging modalities either as fluid collections or solid tumors along the ligaments, mesenteries, and spaces of the peritoneal cavity. The broad spectrum of different abnormalities includes inflammatory, infectious, traumatic, and neoplastic diseases. In this article, a large variety of peritoneal abnormalities such as ascites, peritonitis, intraperitoneal hemorrhage, and both primary and secondary peritoneal tumors are discussed. The different imaging modalities, characteristic radiological features, and typical pathways of anatomic spread are explained.

Detection of focal pulmonary lesions is limited by quantum and anatomic noise and highly influenced by variable perception capacity of the reader. Multiple studies have proven that lesions – missed at time of primary interpretation – were visible on the chest radiographs in retrospect. Computer-aided diagnosis (CAD) schemes do not alter the anatomic noise but aim at decreasing the intrinsic limitations and variations of human perception by alerting the reader to suspicious areas in a chest radiograph when used as a ‘second reader’.