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International audience; In the latest update of the European Society of Cardiology (ESC) guidelines for the management of infective endocarditis (IE), imaging is positioned at the centre of the diagnostic work-up so that an early and accurate diagnosis can be reached. Besides echocardiography, contrast-enhanced CT (ce-CT), radiolabelled leucocyte (white blood cell, WBC) SPECT/CT and [F-18]FDG PET/CT are included as diagnostic tools in the diagnostic flow chart for IE. Following the clinical guidelines that provided a straightforward message on the role of multimodality imaging, we believe that it is highly relevant to produce specific recommendations on nuclear multimodality imaging in IE and cardiac implantable electronic device infections. In these procedural recommendations we therefore describe in detail the technical and practical aspects of WBC SPECT/CT and [F-18]FDG PET/CT, including ce-CT acquisition protocols. We also discuss the advantages and limitations of each procedure, specific pitfalls when interpreting images, and the most important results from the literature, and also provide recommendations on the appropriate use of multimodality imaging.

Worldwide breast cancer has the highest incidence of all malignancies in women. Although the incidence has increased, mortality has decreased during the last two decades [1]. This reduction in mortality is largely due to early detection of malignancies in screening and to better and more personalized therapies [2]. Mammography is the primary screening imaging modality. This technique, however, has limitations in terms of sensitivity (39–86 %) and specificity (88–94 %), depending on age and breast density [3, 4]. Therefore, ultrasound is used in addition to mammography to increase diagnostic accuracy [5]. Mammography is scored in five categories according to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS): category 1, negative; 2, benign finding; 3, probably benign; 4, suspicious finding (chance of malignancy 2–95 %); and 5, highly suggestive of malignancy (chance of malignancy >95 %) [6]. The guideline for non-invasive diagnostic tests for breast abnormalities of the Agency for Healthcare Research and Quality (AHRQ) in the USA states that for BI-RADS 1 and 2 no further work-up is required. The work-up for BI-RADS 4 and 5 requires an invasive procedure (biopsy). The diagnostic work-up of a BIRADS 3 lesion (chance of malignancy 5 cm), clinical symptoms or laboratory values suggesting the presence of metastases [9, 10]. In the case of proven breast cancer, imaging modalities can have an added value not only to determine the extent of the disease but also to characterize the primary and metastatic breast lesions. Non-invasive modalities are increasingly implemented in standard care to support breast cancer diagnosis, staging and evaluation. However, the role of several potential imaging investigations has not yet been fully established and existing international guidelines are lagging behind these developments. The purpose of this editorial is to provide guidance for the application of (developing) imaging techniques in (1) the non-invasive work-up of breast lesions and (2) staging and characterization of advanced breast cancer. M. D. Dorrius Department of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands

The diagnosis of infection is often based on clinical, pathological and microbiological results. However, these investigations lack specificity. White blood cell (WBC) scintigraphy is considered the gold standard nuclear imaging technique for diagnosing infections in bone and soft tissues (except spondylodiscitis). However, image acquisition and interpretation criteria differ amongst centres throughout the world, leading to differences in reported results. The aim of this study was to identify the most accurate WBC scintigraphy acquisition and interpretation protocols for diagnosis of bone and soft tissue infections.Included in this retrospective study were 297 patients with suspected bone or soft tissue infection who underwent WBC scintigraphy with Tc-99m-HMPAO-labelled leucocytes between 2009 and 2012. Sensitivity, specificity, accuracy, and positive and negative predictive values of WBC scintigraphy were determined for two different dual time point acquisition protocols (fixed-time acquisition and time decay-corrected acquisition) and five image interpretation methods (visual and semiquantitative with four different reference regions of interest). Final diagnosis was based on pathological and microbiological reports, and when these were not available, on clinical follow-up of at least 6 months.The best acquisition protocol was 4 h and 20 - 24 h dual time-point acquisition with time decay-corrected acquisition. When using this acquisition protocol, visual qualitative interpretation led to a sensitivity of 85.1 %, a specificity of 97.1 %, a diagnostic accuracy of 94.5 %, a positive predictive value of 88.8 % and a negative predictive value of 95.9 %. For semiquantitative analysis, the best results were found when lesion-to-reference ratios were calculated with the contralateral side as the reference tissue, except for osteomyelitis and infected osteosynthesis, for which the contralateral bone marrow was found to be the best reference tissue. Results of the semiquantitative analyses per se were not better than for visual analysis. In the optimal analysis protocol, scans are first visually evaluated, and if this gives equivocal results, semiquantitative analysis is performed. This strategy resulted in an improved sensitivity of 97.9 %, a specificity of 91.8 % and a diagnostic accuracy of 93.1 %.WBC scintigraphy for bone and soft-tissue infection is best performed using a dual acquisition protocol at 4 h and at 20-24 h after injection, in which the acquisition time of the scans is corrected for decay. In most patients, visual analysis is sufficient and leads to high diagnostic accuracy. When interpretation by visual analysis is inconclusive, semiquantitative analysis adds accuracy. Based on our results, we propose a flow chart for analysing WBC scintigraphy in musculoskeletal infections.

The aim of this study was to determine the yield of attenuation correction in myocardial perfusion imaging (MPI), before and after a 1-year experience period. In 48 consecutive patients referred for MPI, both non-corrected (NC) and attenuation-corrected (AC) images were analysed by three independent readers shortly after implementation of attenuation correction. The same images were re-analysed 1 year later, after having obtained experience in attenuation correction on a routine basis in >500 patients with clinical feedback. Results were compared with gold standards for ischaemia and infarction based on coronary angiography, follow-up, ultrasound and gated blood pool imaging. Sensitivity and specificity for the detection of coronary artery disease were 95% and 45% respectively for NC images and 77% and 70% respectively for AC images at first readings. After 1 year of AC experience, NC sensitivity/specificity was 100%/61%, and AC results were 89%/92%. It is concluded that attenuation correction improves the performance of MPI interpretation. With attenuation correction, specificity is increased and sensitivity is similar as compared with NC images. However, attenuation correction requires experience and is associated with a learning curve.