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Background Synchronous metastases are considered a negative prognostic factor in patients with metastatic colorectal cancer (CRC). We investigated the outcomes of stage IV CRC patients undergoing complete gross resection (R0/1) of both the primary tumor and the metastases under the guidance of a multidisciplinary team (MDT). Methods All CRC patients with synchronous metastases were retrieved from a prospective database. Patients treated from 2006 to 2017 who underwent complete resection were analyzed. Various factors, including multiple metastatic sites and complex procedures, were investigated. Univariate and multivariate overall survival (OS) calculations were performed. Results Of 330 consecutive patients with synchronous metastases, 101 (30.6%) achieved an R0/1 status including 12 (11.9%) patients with multiple metastatic sites. Complex procedures were necessary in 45 (44.6%) patients. Five-year OS was 53.0% for the R0/1 patient group. Multivariate analysis could not detect factors associated with prognosis. Conclusions With modern treatment, the prognosis of patients with synchronous CRC metastases can be improved. Decisions made by a MDT offered one-third of patients a potentially curative approach to their stage IV disease. Despite the treatment of a high rate of patients with complex metastases necessitating complex procedures, we achieved a favorable 5-year OS rate.

Background: Very few studies have investigated whether unilateral choanal atresia is associated with permanent olfactory deficits. Objective: This study aimed to evaluate the olfactory performance of patients with unilateral choanal atresia postsurgically. Methods: Three patients with unilateral atresia were examined in terms of olfactory performance with the Sniffin’ Sticks test (odor identification, threshold, and discrimination), size of the olfactory bulb, and volumetric brain changes. Results: All patients demonstrated significantly lower olfactory performance in terms of odor threshold on the same side with the choanal atresia. Grey matter reductions were found ipsilaterally in the hippocampus. Conclusions: This pilot study indicates that persistent olfactory deficits and volumetric brain changes are present in patients with unilateral choanal atresia.

Olfactory loss impacts around 20% of the population and is associated with the reduction of pleasure from eating and drinking, sex and depression (1). Encouragingly, research findings have consistently demonstrated that olfactory training (OT) can improve olfactory function in people with olfactory loss due to various aetiologies (2). The most commonly used method for OT involves smelling four different odours (lemon, eucalyptus, rose and cloves), twice daily, for 12 weeks.

Purpose The identification of a brain tumor imaged with PET or SPECT is usually performed with visual inspection of an expert medical clinician. However an automated diagnostic of such images hasn't been established or applied. In this study, we explored the possibility of establishing an automated statistical analysis for the diagnosis of glioma by means of IPA-SPECT data. Methods On the basis of a dataset of 100 patients that have undergone MRI and IPA-SPECT acquisition, in this work, we identify an automated workflow. Three different approaches were explored: I. statistical non-parametric mapping analysis (SnPM), II. statistical non-parametric analysis with an increased number of permutations due to sign-flipping function (PALM) and III. statistical parametric analysis (SPM). The automated methods were compared with the visual inspection. Results The study proved PALM and SPM approaches to have a high diagnostic power. Compared to the parametric methods, the non-parametric method is the mathematically correct approach for the problem in question. If we take the high resolution structural MRI information into account, the diagnostic power of PALM was not significantly inferior to the visual inspection (P = 0.5150), showing an area under the ROC curve (AUC) smaller only by less than 3%. Conclusions The automated diagnostic method based on statistical inference, here applied to diagnose glioma tumors in IPA-SPECT data, seems to be a promising tool that can support the visual investigation in nuclear medicine. Moreover in the foreseeable future, the presented methodology has a big potential in various application like localization of active tumor tissues in surgical resection or stereotactic radiosurgery.

Purpose Annotation of meaningful landmark ground truth on DCE-MRI is difficult and laborious. Motion correction methods applied to DCE-MRI of the liver are thus mostly evaluated using qualitative or indirect measures. We propose a novel landmark annotation scheme that facilitates the generation of landmark ground truth on larger clinical datasets. Methods In our annotation scheme, landmarks are equally distributed over all time points of all available dataset cases and annotated by multiple observers on a per-pair basis. The scheme is used to annotate 26 DCE-MRI of the liver. A subset of the ground truth is used to optimize parameters of a deformable motion correction. Several variants of the motion correction are evaluated on the remaining cases with respect to distances of corresponding landmarks after registration, deformation field properties, and qualitative measures. Results A landmark ground truth on 26 cases could be generated in under 12 h per observer with a mean inter-observer distance below the mean voxel diagonal. Furthermore, the landmarks are spatially well distributed within the liver. Parameter optimization significantly improves the performance of the motion correction, and landmark distance after registration is 2 mm. Qualitative evaluation of the motion correction reflects the quantitative results. Conclusions The annotation scheme makes a landmark-based evaluation of motion corrections for hepatic DCE-MRI practically feasible for larger clinical datasets. The comparably large number of cases enables both optimization and evaluation of motion correction methods. Electronic supplementary material The online version of this article (10.1007/s11548-018-1710-1) contains supplementary material, which is available to authorized users.

Background and purpose: Magnetic resonance imaging (MRI) plays an important role in the field of MR-guided radiotherapy or personalised radiation oncology. The application of quantitative image analyses like radiomics as well as automated tissue characterisation is frequently disturbed by the effect of intensity non-uniformity. We present a novel fully automated physical correction model (PCM) for the reduction of intensity non-uniformity. Materials and methods: The proposed algorithm is based on a 3D physically motivated correction model, which maximises the image information expressed by the Shannon entropy. The PCM was evaluated using the coefficient of variation (cv) on 176 MRI datasets of the human brain and abdomen acquired on 1.5 Tesla and 3 Tesla MR scanners. The resulting cv was compared to the cv of the original images and to the results of the established N4 algorithm. Results: The PCM algorithm significantly improved the image quality of all considered 1.5 and 3.0 Tesla MR scans compared to the original images (p

Purpose: Multimodal imaging plays a key role in patient assessment and treatment planning in liver radioembolization. It will reach its full potential for convenient use in combination with deformable image registration methods. A registration framework is proposed for multimodal liver image registration of multi-phase CT, contrast-enhanced late-phase T1, T2, and DWI MRI sequences. Methods: A chain of four pair-wise image registrations based on a variational registration framework using normalized gradient fields as distance measure and curvature regularization is introduced. A total of 103 cases of 35 patients was evaluated based on anatomical landmarks and deformation characteristics. Results: Good anatomical correspondence and physical plausibility of the deformation fields were attained. The global mean landmark errors vary from 3.20 to 5.36 mm, strongly influenced by low resolved images in z-direction. Moderate volume changes are indicated by mean minimum and maximum Jacobian determinants of 0.44 up to 1.88. No deformation foldings were detected. The mean average divergence of the deformation fields range from 0.08 to 0.16 and the mean harmonic energies vary from 0.08 to 0.58. Conclusion: The proposed registration solutions enable the combined use of information from multimodal imaging and provide an excellent basis for patient assessment and primary planning for liver radioembolization.

Background. Tumour hypoxia can be measured by FMISO-PET and negatively impacts local tumour control in patients with head and neck squamous cell carcinoma (HNSCC) undergoing radiotherapy. The aim of this post hoc analysis of a prospective clinical trial was to investigate the spatial variability of FMISO hypoxic subvolumes during radio-chemotherapy and the co-localisation of these volumes with later recurrences as a basis for individualised dose prescription trials with dose escalation defined by FMISO-PET. Methods. Sequential FMISO scans of 12 (of 25) patients presenting residual hypoxia taken before (FMISOpre) and during (FMISOw1–FMISOw5) radio-chemotherapy were analysed regarding the stability of the FMISO subvolumes and, in case of local failure, their correlation to local relapse. Results. Consecutive FMISO-PET positive volumes could be classified as moderately stable with Dice conformity indices of 62% and 58% up to the second week of treatment. Substantial volumetric variation during treatment was observed, with more than 20% geographic miss in all patients and more than 40% in half of the patients. The localisation of the maximum standardised uptake value (SUVmax) differed with a mean distance of 7.0 mm and 13.5 mm between the pre-therapeutic and first or second FMISO-PET during treatment. A stable hypoxic consensual volume (i.e. overlap of pre-therapeutic FMISO and intra-treatment FMISO subvolumes up to week two, generated by different contouring methods) was determined for six patients with imaging information of local recurrence. Three of these six local recurrences were located within this consensual volume. Conclusions. Our data suggest that selective dose painting to hypoxic tumour subvolumes requires adaptation during treatment and sufficient margins. An alternative strategy is to escalate the dose to the gross tumour volume, accepting lesser escalation of dose outside hypoxic areas if indicated by constraints for organs at risk.

Background To investigate vascular-related pathophysiological characteristics of two human lung cancers with modifiable vascularisation using MRI and CT. Methods Tumour xenografts with modifiable vascularisation were established in 71 rats (approval by the Animal Care Committee was obtained) by subcutaneous transplantation of two human non-small-cell lung cancer (NSCLC) cells (A549, H1299) either alone or co-transplanted with vascular growth promoters. The vascularity of the tumours was assessed noninvasively by MRI diffusion-weighted-imaging (DWI), T2-weighted, and time-of-flight (TOF) sequences) as well as contrast-enhanced CT (CE-CT), using clinical scanners. As a reference standard, histological examinations (CD-31, fluorescent beads) were done after explantation. Results Microvessel density (MVD) was higher in co-transplanted tumours (171 ± 19 number/mm2) than in non-co-transplanted tumours (111 ± 11 number/mm2; p = 0.002). Co-transplanted tumours showed higher growth rates and larger tumour vessels at TOF-MRI as well as larger necrotic areas at CE-CT. In co-transplanted tumours, DWI revealed higher cellularity (lower minimal ADCdiff 166 ± 15 versus 346 ± 27 mm2/s × 10−6; p

Olfactory dysfunction is a common disorder, especially in elderly people. From the etiological point of view a differentiation is made between sinunasal, traumatic and non-sinunasal causes of dysosmia. Olfactory disorders are often observed in neurodegenerative diseases, especially in patients with Parkinson's disease or Alzheimer's disease. Apart from an extensive medical history important diagnostic tools are a complete ear nose and throat (ENT) examination including nasal endoscopy and olfactory testing, for example, with "sniffin' sticks". For diagnostic purposes modern imaging procedures, such as magnetic resonance imaging (MRI) are becoming more and more important. For testing children, olfactory testing needs to be adapted and depending on the etiology, olfactory training, antiphlogistic and surgical procedures are the most promising therapeutic approaches. In cases of intracranial causes of dysosmia neurosurgeons should know and respect the anatomical structures of the olfactory signal pathway, not least for the long-term prognosis.

Die Rontgen-Computertomografie ist ein Schnittbildverfahren, mit dem die raumliche Verteilung von Rontgen-Schwachungskoeffizienten ermittelt und in Hounsfield-Einheiten umskaliert wird. Hierfur bewegt sich eine Rontgenrohre als externe Strahlenquelle auf einer Kreisbahn um den Patienten. Fur die Bildrekonstruktion wird traditionell die gefilterte Ruckprojektion benutzt. Iterative Verfahren erlangen gegenwartig zunehmende Bedeutung mit dem Ziel, ein gewisses Kontrast-Rausch-Verhaltnis mit niedrigerer Dosis zu erlangen. Eine schnelle Datenaufnahme wird durch Spiral-CT (gleichzeitiger Umlauf der Rohre um den Patienten und Vorschub der Patientenliege) und/oder Mehrschicht-CT (Einsatz mehrerer parallel angeordneter Detektorringsegmente) erreicht. Verbesserungen in der Unterscheidbarkeit von Materialien (Knochen vs. Kontrastmittel, Plaquezusammensetzung usw.), aber auch die Reduktion von Artefakten, z. B. durch metallische Implantate, werden gegenwartig durch die Kombination von Messungen bei verschiedenen Rontgenspektren angestrebt. Weitere klinisch relevante Information wird durch die meist i. v.-Gabe von Kontrastmittel erlangt, durch das in gewissen Geweben und in den Blutgefasen der Schwachungskoeffizient erhoht wird. Haufige Bildartefakte werden dargestellt. Die Computertomografie ist eines der dosisintensivsten Verfahren der radiologischen Diagnostik. Parameter zur Dosisbeschreibung und Qualitatskontrolle sowie verschiedene technische Masnahmen zur Dosisoptimierung werden beschrieben.

Die Computertomografie ist das bildgebende Verfahren, das die hochste Strahlenexposition fur Patienten aufweist. Seit einigen Jahren werden intensiv dosissparende Techniken entwickelt, erforscht und zum Einsatz gebracht. Die wichtigsten dieser Entwicklungen und ihr Potenzial werden in diesem Artikel vorgestellt. Unter Berucksichtigung der aktuellen Literatur wird gezeigt, dass die klinische Relevanz der korrekt indizierten und durchgefuhrten Computertomografie das sehr kleine Risiko fur den einzelnen Patienten aufwiegt.

This study was conducted to determine the temporal pattern of lateralized congestion of the nasal mucosa. Thirteen female and 15 male healthy subjects (median age, 27 years) were examined using magnetic resonance imaging (MRI) at a 0.2-T system every 30 min. Contiguous coronal T1-weighted imaging was performed covering the entire nasal cavity. Subjects were investigated over periods of up to 4 h (n = 28) or up to 14 h (n = 6), respectively. Nasal cavity volumes were measured by manual segmentation of the acquired images and summation of areas. Additionally, olfactory testing was performed. All subjects exhibited normal olfactory function. The minimum unilateral volume of the nasal cavity during congestion was 2.2 cm3, and maximum volume during decongestion was 17.0 cm3 (mean, 7.7 cm3). Seven subjects exhibited minor fluctuation of their nasal volumes. In contrast, 21 subjects showed nasal cyclicity. Maximum fluctuation of the volume of the nasal cavity was found in the vicinity of the turbinates in the central and posterior nasal cavity. The length of the nasal cycle showed high variability and was in the range of 180 to 280 min. No correlation was found between nasal volumes and olfactory scores. Using MRI, the present study is the first to report differences with regard to both the presence of a nasal cycle in an individual subject and the length of the nasal cycle. Considering that nasal congestion is of significance to human well-being, the present observations may influence clinical decisions.

Integrated scanners capable of simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) data acquisition are now available for human use. Although the scanners' manufacturers have made substantial efforts to understand and minimize the mutual electromagnetic interference between the 2 modalities, the potential physiological inference has not been evaluated. In this study, we have studied the influence of the acoustic noise produced by the magnetic resonance (MR) gradients on brain fludeoxyglucose (FDG) uptake in the Siemens MR-BrainPET prototype. Although particular attention was paid to the primary auditory cortex (PAC), a brain-wide analysis was also performed.The effects of the MR on the PET count rate and image quantification were first investigated in phantoms. Next, 10 healthy volunteers underwent 2 simultaneous FDG-PET/MR scans in the supine position with the FDG injection occurring inside the MR-BrainPET, alternating between a "quiet" (control) environment in which no MR sequences were run during the FDG uptake phase (the first 40 minutes after radiotracer administration) and a "noisy" (test) environment in which MR sequences were run for the entire time. Cortical and subcortical regions of interest were derived from the high-resolution morphological MR data using FreeSurfer. The changes in the FDG uptake in the FreeSurfer-derived regions of interest between the 2 conditions were analyzed from parametric and static PET images, and on a voxel-by-voxel basis using SPM8 and FreeSurfer.Only minimal to no electromagnetic interference was observed for most of the MR sequences tested, with a maximum drop in count rate of 1.5% and a maximum change in the measured activity of 1.1% in the corresponding images. The region of interest-based analysis showed statistically significant increases in the right PAC in both the parametric (9.13% [4.73%]) and static (4.18% [2.87%]) images. The SPM8 analysis showed no statistically significant clusters in any images when a P0.05 (corrected) was used; however, a P0.001 (uncorrected) resolved bilateral statistically significant clusters of increased FDG uptake in the area of the PAC for the parametric image (left, 8.37% [1.55%]; right, 8.20% [1.17%]) but only unilateral increase in the static image (left, 8.68% [3.89%]).Although the operation of the BrainPET prototype is virtually unaffected by the MR scanner, the acoustic noise produced by the MR gradients causes a focal increase in the FDG uptake in the PAC, which could affect the interpretation of pathological (or brain-activation-related) changes in the FDG uptake in this region if the expected effects are of comparable amplitude.

BACKGROUND AND PURPOSE: Reliable tumor staging is a fundamental pre-requisite for efficient tumor therapy and further prognosis. The aim of this study was to compare head and neck cancer (HNC) staging before and after FDG-PET/CT, evaluating the stage modifications for radiotherapy (RT) planning. PATIENTS AND METHODS: A total of 102 patients with untreated primary HNC, who underwent conventional staging and staging including FDG-PET/CT before RT, were enrolled in this retrospective study. Blinded pre-FDG-PET/CT and post-FDG-PET/CT staging data were compared. The impact on patient management was tested by comparing the intention before and after FDG-PET/CT. RESULTS: Significant modifications of T, N, and M stage as well as clinical stage were detected after inclusion of FDG-PET/CT data (p = 0.002, 0.0006, 0.001, 0.03, respectively). Overall, the implementation of FDG-PET/CT led to modification of RT intention decision in 14 patients. CONCLUSIONS: FDG-PET/CT demonstrates essential influence on tumor staging in HNC patients scheduled for irradiation. Implementation of FDG-PET/CT in imaging protocol improves selection of candidates for curative and palliative RT and allows further optimization of treatment management and therapy intention.

Hypoxia is a marker of poor prognosis in malignant tumors independent from the selected therapeutic method and the therapy should be intensified in such tumors. Hypoxia imaging with positron emission tomography (PET) is limited by low contrast to noise ratios with every available tracer. In radiation oncology appropriate delineation is required to allow therapy and intensification. While manual segmentation results are highly dependent from experience and observers condition (high inter- and intra observer variability), threshold- and gradient-based algorithms for automatic segmentation frequently fail in low contrast data sets. Likewise, calibration of these algorithms using phantoms is not useful. Complex computational models such as swarm intelligence-based algorithms are promising tools for optimized segmentation results and allow observer independent interpretation of multimodal and multidimensional imaging data.

Hypoxia is a marker of poor prognosis in malignant tumors independent from the selected therapeutic method and the therapy should be intensified in such tumors. Hypoxia imaging with positron emission tomography (PET) is limited by low contrast to noise ratios with every available tracer. In radiation oncology appropriate delineation is required to allow therapy and intensification. While manual segmentation results are highly dependent from experience and observers condition (high inter- and intra observer variability), threshold- and gradient-based algorithms for automatic segmentation frequently fail in low contrast data sets. Likewise, calibration of these algorithms using phantoms is not useful. Complex computational models such as swarm intelligence-based algorithms are promising tools for optimized segmentation results and allow observer independent interpretation of multimodal and multidimensional imaging data.

Purpose: To explore in a prospective trial the prognostic value of hypoxia imaging before and during radiochemotherapy in patients with locally advanced head and neck cancer. Patients and methods: Twenty-five patients with stage III/IV head and neck cancer were investigated with [18F]-fluoromisonidazole (FMISO) PET/CT at four time points during radiochemotherapy (baseline, 8–10 Gy, 18–20 Gy,50–60 Gy). FMISO PET/CT image parameters were extracted including maximumtumour-to-background (TBRmax) and thresholded volume at different TBR ratios. CT volume and baseline FDG-PET/CT image parameters were also included. Parameters at all time points were investigated for their prognostic value with the local-progression-free-survival endpoint (LPFS). Significance was evaluated with multivariate Cox (including clinical parameters) and Log-rank tests. Results: FMISO-image parameters were found to have a strong association with the LPFS endpoint, and were strongest at the week 1 and 2 time points (p = 0.023–0.048 and 0.042–0.061 respectively on multivariate Cox). Parameters measured at baseline were only significant on univariate analysis. None of the clinical parameters, and also FDG- or CT-delineated volumes, were significantly associated with LPFS. Conclusion: This prospective, exploratory study demonstrated that FMISO-PET/CT imaging during the initial phase of treatment carries strong prognostic value. FMISO-PET/CT imaging at 1 or 2 weeks during treatment could be promising way to select patients that would benefit from hypoxia modification or dose-escalated treatment. A validation study is on-going.

Summary[18F]Fluoromisonidazole positron emission tomography (FMISO-PET) is a non invasive imaging technique that can assist detecting intra tumour regions of hypoxia. FMISO-PET evinces comparatively low signal-to-noise-ratio (SNR) and may be acquired dynamically or after different uptake times post injection (p. i.). The aim of this study was to identify, if static images acquired two hours (MISO2) or four hours (MISO4) p. i. reveal higher contrast. Patients, methods: As part of a prospective trial, 23 patients with cancers of the head and neck underwent [18F]fluoro deoxyglucose (FDG) PET before and during curative radiochemotherapy. Additionally, FMISO-PET studies 2 h and 4 h p. i. were done before treatment and after a mean dose of 11 Gy, 23 Gy and 57 Gy during RCT. After coregistration, a dedicated software was used to define the gross tumour volume (GTV) by FDG PET for the primary tumour. This volume was overlaid to the FMISO images and hypoxia within the GTV was determined. The contrast between hypoxia determined by MISO2 and by MISO4 was investigated and analysed with the Wilcoxon-matched-pairs test. Results: Mean SUVmax in tumours of all examinations was 2.2 (stdev: 0.4, min: 1.3, max: 3.4) after 2 h and 2.4 (stdev: 0.7, min: 1.1, max: 4.4) after 4 h. In the neck musculature the mean SUVmax was 1.5 at both time points and the mean SUVmean decreased from 1.2 after 2 h to 1.1 after 4 h, respectively. These effects resulted in significantly rising contrast ratios from MISO2 to MISO4. The differently defined contrasts revealed significantly higher values for examinations 4 h p. i. (p < 0.002). Conclusion: Data acquisition of [18F]FMISO should be done 4 h p. i. to gather the optimal contrast, preferably allowing further analysis, e. g. hypoxic sub volume definition for therapy planning.

Background: Recently published data show some controversy concerning the impact of [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in predicting head and neck tumors (HNT) outcome. Assessment of tumor blood supply parameters using dynamic contrast-enhanced CT (DCE-CT) may deliver additional information concerning this important question. Purpose: To evaluate the contribution of DCE-CT implemented in pretherapeutic FDG-PET/CT protocol for prognosis prediction in patients with HNT. Material and Methods: Ten consecutive patients (median age 50 years, range 47–74 years) with histologically proven HNT underwent FDG-PET/CT with DCE-CT before treatment. FDG uptake was measured by maximum standardized uptake value (SUVmax). Relative tumor blood volume (rTBV) was determined from DCE-CT using Patlak analysis. Intratumoral heterogeneity was assessed by means of lacunarity analysis. Obtained values were compared with time-to-progression and overall survival. PET and DCE-CT images were compared on a pixel-by-pixel basis using Pearson coefficient of correlation. Results: Three patients with lower FDG uptake (SUVmax: 8±1) and five patients with higher FDG uptake (SUVmax: 15±4, P=0.004) were free of local recurrence for 24 months. Two groups of patients with significantly differing lower (group A: 0.37±0.02, n=6) and higher (group B: 0.52±0.01, n=4; P2=0.1). Conclusion: FDG-PET/CT and DCT-CT are complementary methods for surveillance assessment in patients with HNT. Implementation of DCE-CT in the pretreatment FDG-PET/CT protocol may improve tumor outcome prediction.

Purpose Perfusion computed tomography is increasingly being used in diagnostic radiology. Axial coverage of the traditional approach is limited to the width of the detector. Using continuous periodic table movement coverage can be increased beyond this limit. In this study, we compared tissue flow values determined from scans with a periodic spiral implementation with variable pitch with ones determined from standard dynamic scan modes. Methods A flow phantom (preserved porcine kidney) was scanned with 2 settings of a periodic spiral (Adaptive 4D Spiral) with a range of 100 and 148 mm and a temporal sampling of 1.5 seconds. Additionally, the whole phantom was scanned with the standard dynamic mode (detector width 38.4 mm, temporal sampling 1.0 seconds) at various overlapping positions as a reference. Scan parameters (80 kV, 140 mAs, 40s scan time) were selected similar to a typical brain perfusion study. All scans were repeated 5 times. Tissue flow was calculated with a dedicated deconvolution algorithm. In a center slice and 3 additional slices at various off center positions flow values were recorded in a total of 126 regions of interest (ROI). Reproducibility was determined from the variation of the repeat scans. Agreement between periodic spirals and standard mode was determined by Bland Altman plots and correlation analysis. Results The reproducibility of the tissue flow determination ranged from 2.7 to 4.4 mL/100 mL/min and was similar for all scan modes. The coefficient of variation ranged from 3.9% to 6.1%. Mean tissue flow in the 126 ROIs ranged from 35 to 121 mL/100 mL/min. There was excellent correlation between both periodic spiral ranges and the standard dynamic mode with a Pearson correlation coefficient of r = 0.97. The regression slope (intercept 0) for the 100 mm range was 1.01, for the 148 mm range it was 0.97. The absolute differences per ROI varied between 1.5 and 4.1 mL/100 mL/min, the relative differences between 1.9% and 6.5%. Differences did not depend on the slice location. Conclusions Periodic spiral scan modes with variable pitch and a sampling rate of 1.5 seconds can be used for the quantitative determination of tissue flow. Their performance is equivalent to equidistant sampling with standard dynamic scan modes. The ranges of 100 and 148 mm investigated allow coverage of the whole brain or an entire organ for perfusion imaging.

Diffusion-weighted magnetic resonance imaging (dwMRI) is sensitive to tissue microstructure on the cellular level and may therefore help to define biological tumour subvolumes and add complementary information to morphology-based cancer treatment protocols and therapy monitoring. The purpose of this study was therefore to evaluate the potential of dwMRI as compared with morphological MRI (mMRI) for tumour volume delineation using a nude rat human tumour xenograft model. Sixteen tumour-bearing rats (10 H1299, six FaDu) were examined with mMRI (T2-weighted true fast imaging with steady precession (TrueFISP), T1-weighted fast low angle shot (FLASH), T2-weighted dual echo steady state (DESS)) and echo-planar dwMRI in a clinical scanner at 1.5 T. For each method, we compared tumour volume and intra- and inter-observer variability of tumour outer edge delineation (disregarding intra-tumoural structure) as well as tumour signal-to-noise ratio (SNR) and tumour-to-muscle contrast-to-noise ratio (CNR). Tumours were visualised with significantly higher SNR and CNR in dwMRI. Median tumour volumes as measured by dwMRI (3.5 cm(3)) and mMRI (TrueFISP: 3.3 cm(3); FLASH: 3.3 cm(3); DESS: 3.2 cm(3)) were not significantly different and significantly correlated. Related to partial volume effects, the intra- and inter-observer variability of dwMRI (intra/inter: 12%/12%) was larger than for mMRI (TrueFISP: 4%/4%; FLASH: 5%/5%; DESS: 5%/5%). In conclusion, dwMRI allows tumour delineation with overall volume estimation comparable with mMRI approaches but slightly higher observer variability. Thus, besides tumour outline, it may potentially supplement morphology-based therapy planning and monitoring with additional biological information.

To compare MRI-based functional pulmonary and cardiac measurements in the long-term follow-up of children operated on for left-sided congenital diaphragmatic hernia (CDH) with age- and body size-matched healthy controls. Twelve children who received immediate postnatal surgery for closure of isolated left-sided CDH were included and received basic medical examinations, pulmonary function testing and echocardiography. MRI included measurement of lung volume, ventricular function assessment and velocity-encoded imaging of the pulmonary arteries and was compared with the data for 12 healthy children matched for age and body size. While patients’ clinical test results were not suspicious, comparison between the MRI data for patients and those for healthy controls revealed significant differences. In patients, the volumes of the left lungs were increased and the tidal volume was larger on the right side. While the stroke volumes of both ventricles were reduced, heart rate and ejection fraction were increased. Flow, acceleration time and cross-sectional area of the left pulmonary artery were reduced. Functional MRI detected pulmonary and cardiac findings in the late follow-up of CDH children which may be missed by standard clinical methods and might be relevant for decisions regarding late outcome and treatment.

The aim of this study is to examine the dose-response relationships between age, "lifestyle factors" (body mass index, tobacco smoking, sports), and symptomatic knee osteoarthritis in a population-based case-control study. Additionally, the study aims to investigate the mode of interaction between body mass index (BMI) and physical workload (occupational kneeling/squatting and lifting/carrying of loads) with respect to the risk of symptomatic knee osteoarthritis.In five orthopedic clinics and five practices, 295 male patients aged 25-70 with radiographically confirmed knee osteoarthritis associated with chronic complaints were recruited. The control group comprised 327 male control subjects. In a structured personal interview, body weight at different ages, body height, cumulative amount of smoking, and cumulative duration of different sports activities until the date of first diagnosis of knee osteoarthritis were elicited. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis. An interaction analysis for the parameters BMI and kneeling/squatting respective lifting/carrying of loads was performed. Population attributable risks (PAR) for knee osteoarthritis were determined for BMI solely and for the combination of BMI with occupational kneeling/squatting and lifting/carrying of loads, respectively.Age and overweight were strongly associated with the diagnosis of knee osteoarthritis. Compared with persons less than 35 years old, persons who were at least 65 years old had an odds ratio (OR) of 19.0 (95% CI 6.1-58.7) for knee osteoarthritis. Persons with a BMIor = 28.41 kg/m2 had a strongly elevated risk of knee osteoarthritis (OR 10.8; 95% CI 4.8-24.3) compared to persons with a BMI22.86 kg/m2. Heavy tobacco smoking (or = 55.5 pack years) was associated with a decreased knee osteoarthritis risk in comparison with never-smoking (OR 0.2; 95% CI 0.1-0.5). Ball games (handball, volleyball, basketball) and cycling were associated with symptomatic knee osteoarthritis (OR 4.0; 95% CI 1.8-8.9 and OR 3.7; 95% CI 1.7-7.8 in the highest category of cumulative duration, respectively); to a weaker degree jogging, swimming, and soccer also were positively related to symptomatic knee osteoarthritis. Combining the two parameters, BMI and kneeling/squatting into one variable led to a multiplicative interaction mode for symptomatic knee osteoarthritis. For persons with elevated BMI in combination with moderate to high exposure to occupational kneeling/squatting, the population attributable risk (PAR) was 4%. The PAR for elevated BMI in combination with moderate to high exposure to occupational lifting/carrying of loads was 7%.In accordance with the literature, we find a strong association between BMI and knee osteoarthritis risk. Considering the relatively high prevalence of occupational manual materials handling, prevention of knee osteoarthritis should not only focus on body weight reduction, but should also take into account work organizational measures particularly aiming to reduce occupational lifting and carrying of loads.

We investigated the capability of small animal imaging in clinical scanners for cancer research focusing on positron emission tomography (PET), computed tomography (CT) and magnetic resonance imaging (MRI).We summarise basic principles, benefits and drawbacks of imaging modalities and discuss issues associated with animal welfare during imaging and its related effects on imaging results based on data from literature supplemented by own experiences.MRI of tumour-bearing mice and rats in the clinical scanner is well-established for morphological and functional imaging in oncology. Clinical PET/CT did not yet establish as a research tool due to limited resolution and sensitivity, but its feasibility for tumour imaging has been demonstrated in mice. Anesthesia, animal handling and application of substances (e.g., contrast media) may alter animal physiology and, thus, also influence imaging results.Small animal imaging in clinical scanners offers good image quality and presents an alternative to dedicated small animal scanners for numerous applications in cancer research. Successful and meaningful small animal imaging in clinical as well as dedicated scanners prerequisites a thorough knowledge of animal morphology and physiology, a deep understanding of likely influences of animal manipulation on imaging and an adequate care for animal welfare.

To assess possible consequences for radiotherapy (RT) planning, e.g., reduction of treatment volume by a decreased tumour volume in Fluor-18-fluoro-deoxy-glucose-Positron emission tomography (FDG-PET) based on a close-meshed evaluation of FDG uptake in primary head and neck cancer (HNC) during RT.PET data were analysed using a source-to-background based algorithm. The following parameters were obtained: max. standardised uptake value (SUVmax), PET-based gross tumour volume (GTV-PET) and metabolic volume (MV).While the median SUVmax decreased (initial: 15.2, 1st/2nd week: 10.2, 3rd/4th week: 6.5, 5th/6th week: 6.4), the median values of GTV-PET (9.3 cm(3), 12.4 cm(3), 14.0 cm(3), 17.9 cm(3)) and MV (92.2 cm(3), 61.7 cm(3), 60.0 cm(3), 71.3 cm(3)) seemed to increase during radiotherapy. The intra-individual development of SUVmax could be divided into two groups: group A having continuously decreasing values of SUVmax (n = 10 patients), and group B having a temporary increase of SUVmax (n = 13).Data suggest that a reduction of treatment volume is not possible by an adaptive re-planning based on FDG-PET, e.g., at 50 Gy. This may be caused by a consecutive therapy associated inflammation. This limitation is probably related to the use of a source-to-background based algorithm.

The aim of this study was to assess the effect of eye and testicle shielding on radiation dose to the lens and the testes of patients undergoing CT examinations. Fifty-one male patients underwent CT twice with identical protocols initially without, the second time with protective garments. Doses to the testes and the lenses were recorded with beryllium oxide-based dosimeters. The dose to the testes and lenses from CT exposure was reduced by 96.2% +/- 1.7% and 28.2% +/- 18.5%, when testicle and eye shielding was used, respectively. The effect of the eye shielding on the eye lens dose was found to depend on the x-ray tube position when the eye is primarily exposed during the scan. The maximum eye lens dose reduction achieved was found to be 43.2% +/- 6.5% corresponding to the anterior position of the tube. A significant correlation between the patient's body mass index and dose exposure could not be found. Eye and testicle shields, apart from being inexpensive and easy to use, were proven to be effective in reducing eye lens and testicle radiation dose burden from CT exposures.

Olfactory dysfunction is a frequent diagnosis. This overview describes recent standards in structural imaging related to olfactory dysfunction, with magnetic resonance imaging being the most significant imaging tool both quantitatively and qualitatively. Relevant MRI-techniques to be applied in patients during routine clinical workup and the consecutive imaging evaluation are presented and discussed.

Background and purpose Loco-regional failure after radiotherapy with total doses of 60–70 Gy for non-small cell lung cancer (NSCLC) remains a major clinical problem. Escalation of radiation dose is often limited because of exceeding normal tissue constraints. The present study was designed to test the hypothesis that a reduction in disease volume during radiotherapy detected by FDG PET/CT would facilitate radiation dose escalation, whilst remaining within normal tissue constraints. Materials and methods Ten patients with localised inoperable NSCLC were prospectively enrolled. Each received standard 3D-conformally planned radiotherapy to a dose of 66 Gy in 33 fractions over 6.5 weeks. FDG PET/CT imaging in the treatment position was performed prior to treatment and repeated following 50 or 60 Gy. CT and PET-delineated gross tumour volumes were generated and a composite created. A margin of 15mm was added in all planes to form the planning target volume (PTV). Treatment planning was performed to compare two dose escalation strategies: 78 Gy delivered to the initial PTV with treatment in two phases (shrinking field), i.e., 66 Gy to the initial PTV with a 12 Gy-boost to the PTV after 50/60 Gy. As an alternative planning approach the maximal dose without exceeding normal tissue constraints was evaluated for each patient (individualized dose prescription). Results There was a median PTV reduction after 50/60 Gy of 20%. Delivering 78 Gy to the initial PTV could have been achieved in 4/10 patients. Of the remaining 6, delivering 78 Gy to the initial PTV would have exceeded normal tissue constraints and no benefit was seen when delivered in two phases. The results from the individualized dose prescription indicated a higher median maximal dose when treatment would be given in two phases compared to one phase resulting in a modest increase of calculated tumour control probability. Conclusions Our data suggest that despite tumour shrinkage determined by subsequent FDG PET/CT during treatment the tested adaptive targeting strategy would result only in a modest improvement in the context of dose escalation. Further studies on the optimal use of FDG PET/CT and other approaches for dose escalation in loco-regionally advanced NSCLC are warranted.

The olfactory bulb (OB) is considered to be the most important relay station in odor processing. Involving 125 randomly selected subjects (58 men, 67 women; age range: 19 to 79 years), the present study aimed to investigate a possible correlation between OB volume and specific olfactory functions including odor threshold, odor discrimination, and odor identification. The history of all participants was taken in great detail to exclude possible causes of smell dysfunction. All participants received an otolaryngological investigation including a volumetric scan of the brain (MRI), lateralized olfactory tests and a screen for cognitive impairment. Volumetric measurements of the right and left OB were performed by manual segmentation of the coronal slices through the OB. Significant correlations between OB volumes in relation to olfactory function were observed, independent of the subjects' age. Additionally, OB volumes decreased with age. In agreement with previous research the present study confirmed the correlation between OB volume and specific olfactory functions. Furthermore, the correlation between OB volume and olfactory function was not mediated by the subjects' age. In conclusion, the present data obtained from a relatively large group of subjects forms the basis for age-related normative values of OB volumes.

PURPOSE Determination of the influence of tube currents varying during a CT scan on organ doses and on the effective dose as a function of patient constitution. Evaluation of the accuracy of effective dose calculations based on summarizing parameters (effective mAs, dose length product [DLP]) compared to calculations based on slice-specific tube currents. MATERIALS AND METHODS Investigation of the CT datasets of 806 patients acquired from the skull base to the proximal thigh with respect to the body mass index (BMI). The effective dose was calculated by means of slice-specific as well as region-specific conversion factors. RESULTS Dose optimization by means of variable tube current resulted in a reduction of the gonad dose in patients with BMI < or = 20 ... 21 kg/m (2) and of the effective dose in patients with BMI < or = 26 kg/m (2). Effective dose values calculated with the DLP for 90 % of the patients are within an interval of +/- 20 % of the values calculated using slice-specific tube currents. CONCLUSION If tube current optimization during the CT scan was applied, for the scan region under investigation, at a BMI already below the German mean value, an increased effective dose was observed. Calculations of the effective dose on the basis of summarizing values such as DLP or effective mAs are of sufficient accuracy.