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Background: The aim of this study was to optimize computed tomography pulmonary angiography (CTPA) protocols with regard to improve vascular attenuation without increasing contrast media (CM) volumes. Therefore, we compared the standard CTPA protocol to an individualized contrast media injection protocols adjusted for the patient's body mass index (BMI). Materials and Methods: Two groups of 295 patients with suspected pulmonary embolism (PE) have been receiving CTPA. Group 1 received a standard protocol without taking patient's BMI into account. Group 2 received a CTPA scan, where dose and flow rate of CM injections were adjusted for the patient's BMI. Images were retrospectively analyzed by drawing regions of interests in defined positions in the superior vena cava, descending aorta, the pulmonary main trunk as well as the left and right lower lobe arteries. Intravascular attenuation, contrast volumes, and flow rates were compared using unpaired t-tests. Furthermore, a qualitative image analysis was performed by two experienced readers blinded for the protocol used for image acquisition to evaluate the image quality and arterial attenuation. Results: Patient's BMI was similar in both the groups (27.5 ± 1.5 kg/m2 vs. 28.4 ± 2.1 kg/m2; P = 0.67). Contrast volumes were lower (54.2 ± 4.8 ml vs. 55 ml; P < 0.05), and flow rates (4.1 ± 0.3 ml/s vs. 3.5 ml/s; P < 0.05) were significantly higher in the individualized protocol. The qualitative image analysis yielded an agreement on diagnostic interpretability in the individualized and standard group of 49% and 51% (95% Wilson confidence interval for mean), respectively. Conclusion: An individualized CTPA protocol based on the patient's BMI reduced the contrast media volume and led to an increased pulmonary artery enhancement improving image quality, particularly in the evaluation of the peripheral pulmonary arteries. Thus, contrast media volumes in CTPA should be adjusted for the patient's BMI.

We report a rare case of fatal intoxication in a 40-year-old man caused by injection of a fluid containing organic mercury, allegedly in an attack with a syringe fixed to the tip of an umbrella. The man suffered from severe neurological symptoms and progressive multiorgan failure and died 10 months later in refractory status epilepticus. Autopsy revealed severe brain atrophy and non-specific kidney damage. Neuropathological examination showed neuronal loss especially in the occipital lobe, distinct granule cell necrosis in the cerebellum and Wallerian degeneration in the brainstem. Postmortem toxicological analysis revealed extremely increased levels of mercury in liver and kidney tissue as well as methylmercury levels in peripheral blood.

Purpose To determine the clinical impact of CT dose management team on radiation exposure and image quality. Methods 2026 clinical routine CT examinations of 1315 patients were evaluated retrospectively. A CT dose management team was established as an integral part of the radiological department. It identified 5 CT protocols (A–E), where national reference values were exceeded the most. Those reference values included specifically the mean volumetric CT dose index (CTDIvol) and the mean dose-length product (DLP). Baseline data (period 1) and follow up data (period 2) were obtained after reduction of tube voltage and increase of pitch or noise index. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated to compare image quality. Two-sided t-tests were performed. Results Mean CTDIvol and mean DLP of the chest protocol (A) decreased after reduction of tube voltage (P 0.05). SNR (protocol A) was significantly higher in period 2 (P Conclusions Establishing an operating dose management team as a standard for good clinical practice helps to considerably reduce CT radiation dose while preserving image quality.

Objectives: To evaluate frequency and severity of complications after CT-guided lung biopsy using the Society of Interventional Radiology (SIR) classification, and to assess risk factors for overall and major complications. Methods: 311 consecutive biopsies with a non-coaxial semi-automated 18 gauge biopsy system were retrospectively evaluated. Complications after biopsy were classified into minor SIR1-2 and major SIR3-6. Studied risk factors for complications were patient-related (age, sex and underlying emphysema), lesion-related (size, location, morphologic characteristics, depth from the pleura and histopathology), and technique-related (patient position during procedure, thoracic wall thickness at needle path, procedure time length and number of procedural CT images, number of pleural passes, fissure penetration and needle-to-blood vessel angle). Data were analyzed using logistic and ordinal regression. Results: Complications were pneumothorax and pulmonary hemorrhage. The complications were minor SIR1-2 in 142 patients (45.6%), and major SIR3-4 in 25 patients (8%). SIR5-6 complications were not present. Emphysema, smaller deeply located lesion, increased puncture time length and number of procedural CT images, multiple pleural passes and fissure puncture were significant risk factors for complications severity in univariate analysis. Emphysema (OR=8.8, p

To assess digital patient briefing as an alternative to conventional paper documentation. 502 patients with a planned computed tomography (CT) examination were selected for digital patient briefing using the E-ConsentPro software from Thieme Compliance on an iPad by Apple (Cupertino, California, USA). For the analysis, three age groups were formed. The time required for the patient briefing, the number of open questions as well as the time needed for discussion with physicians were determined. Student's t-test was performed to assess statistical significance. There was no significant difference between patient age and briefing time which was about 20 minutes on average. The number of open or unclear questions increased with patient age. While patients younger than 30 years of age had about 2 open questions, patients over 30 and 60 years had about 4 and 5 questions, respectively. The total time needed for discussion with physicians was less than 2 minutes on average. A significant difference in the time required for discussion with physicians could not be observed between the individual age groups. Tablet-based digital briefing allows the storage of patient documents with reasonable time and effort. Furthermore, it minimizes the risk of data loss. · Tablet-based digital patient briefing in computed tomography can be performed with reasonable time and effort.. · The time required for tablet-based patient briefing is independent of patient age.. · The cost-benefit analysis presents a significant improvement in digital patient briefing compared to the paper-based process..· Alikhani B, Hensen B, Grosser A et al. Initial Experience with Digital Patient Briefing in Computed Tomography. Fortschr Röntgenstr 2019; 191: 540 - 546.ZIEL: Die Möglichkeit der digitalen Aufklärung von Patienten wurde im Rahmen eines Pilotprojekts evaluiert. Für die vorliegende Arbeit wurden 502 konsekutive Patienten ausgewählt, die in der Computertomografie (CT) untersucht werden sollten. Die digitale Aufklärung erfolgte mit der Software E-ConsentPro der Firma Thieme Compliance auf einem iPad. Die Patienten wurden in 3 Altersgruppen unterteilt. Die Auswertung beschränkte sich auf die Ermittlung der Gesamtdauer der Patientenaufklärung, der offenen oder unklaren Fragen sowie des Zeitaufwands für ein Aufklärungsgespräch mit dem Arzt. Zur Prüfung von signifikanten Unterschieden wurde der t-Test durchgeführt. Unabhängig vom Alter bearbeiteten die Patienten den digitalen Aufklärungsbogen im Mittel ca. 20 Minuten. Die Anzahl der offenen oder unklaren, noch mit dem aufklärenden Arzt zu besprechenden Fragen nahm nicht signifikant mit dem Patientenalter zu. Während Patienten unter 30 Jahren vor dem Arztgespräch ca. 2 offene Fragen hatten, hatten Patienten über 60 Jahre ca. 5 offene Fragen. Patienten zwischen 30 und 60 Jahren hatten noch ca. 4 Fragen, die mit dem Arzt besprochen werden sollten. Die Gesamtdauer eines Aufklärungsgesprächs mit dem Arzt betrug im Mittel unter 2 Minuten. Signifikante Unterschiede im Zeitaufwand für das ärztliche Aufklärungsgespräch konnten zwischen den einzelnen Altersgruppen nicht festgestellt werden. Die Tablet-basierte digitale Aufklärung ermöglicht unabhängig vom Patientenalter und der Anzahl der offenen Fragen vor dem Arztgespräch eine mit vertretbarem Zeit- und Arbeitsaufwand zu realisierende rechtssichere Ablage der Dokumente, bei der das Risiko des Datenverlusts durch die Logistik und Archivierung von Patientenunterlagen reduziert werden kann. · Die digitale, Tablet-basierte Patientenaufklärung kann mit vertretbarem Zeit- und Arbeitsaufwand durchgeführt werden.. · Die Tablet-basierte Aufklärungsdauer ist vom Alter der Patienten unabhängig.. · Die digitale Aufklärung leistet einen wesentlichen Beitrag zur Verbesserung der Arbeitsabläufe in der Radiologie..· Alikhani B, Hensen B, Grosser A et al. Initial Experience with Digital Patient Briefing in Computed Tomography. Fortschr Röntgenstr 2019; 191: 540 – 546.

Background Radiofrequency (RFA) and microwave ablation (MWA) are established minimally invasive techniques for treatment of hepatic tumors. Purpose To compare technical success and accuracy of hepatic thermoablation using computed tomography (CT) and magnetic resonance imaging (MRI) acquired 24 h after ablation with regard to evaluation of the post-interventional ablation zone and local tumor recurrence (LTR), and to assess whether additional MRI within 24 h is beneficial. Material and Methods Thirty-two patients (23 men, 9 women; mean age, 60 years) with 48 lesions were included in this retrospective study. CT was performed immediately and MRI was performed 24 h after ablation. Diameter and volume calculations of the ablation zone were compared (T-Test). Technical success and ablation margin distinction, shape, and configuration were evaluated (κ-statistic). Local effectiveness was calculated based on follow-up imaging. Technical success and ablation margin features were correlated with LTR (log-rank test, Fisher's exact test). Results Ablation zone volumes were significantly higher with MRI compared to CT ( P Conclusion CT and MRI are suited for early evaluation of technical success after thermoablation. Within 24 h a significant increase of the ablation volume is observed, which has to be taken into account when interpreting immediate postprocedural imaging and treating lesions near critical structures. Additional MRI 24 h after ablation seems of limited value regarding prognosis of LTR, especially with regards to evaluation of ablation margin shape and conspicuity.

Purpose The aim of this investigation is to establish the relationship between the size-dependent conversion factor (fsize) and the body-mass-index (BMI) and to test whether BMI can be substituted for the conventionally used patients’ anterior-posterior (AP) and lateral (LAT) dimensions for calculation of fsize. By calculating fsize on the basis of BMI instead of the AP and LAT measurements, size-specific dose estimates (SSDE) could be determined prior to image acquisition. Methods Our institute utilizes a dose monitoring software to record radiation exposure during CT examinations. The datasets gathered during each examination contain information regarding the scan protocol, the volumetric computed tomography dose index (CTDIvol), SSDE and BMI. fsize is traditionally calculated through measurement of AP and LAT dimensions. In this work, the dose monitoring system calculates AP and LAT diameters at the middle of scout views. For purpose of this investigation, we used data from 13544 patients who underwent CT examinations of the torso, head or knee (both) to compare fsize as calculated from the AP and LAT dimensions to fsize calculated as a function of BMI. Results In the examinations of the torso, we observed an exponentially decreasing correlation between fsize and BMI. In the examinations of the head and knee (both), fsize reflected an almost independent behavior to BMI. Conclusion This study demonstrates that it is possible to estimate fsize by using the patients’ BMI for the torso as well as the head and knee CT, thereby enabling calculation of the probable SSDE prior to image acquisition on the basis of the presumed CTDIvol provided by the scanner. By providing information on the expected patient dose prior to image acquisition, this method is advantageous over the traditional calculation of fsize via the AP and LAT dimensions.

Purpose To evaluate transient severe respiratory motion artifacts (TSM) at gadoxetate disodium-enhanced MRI dependent on the mode of contrast agent application. Methods 200 patients (71f, 129m; mean 51y) were included in this retrospective IRB-approved study. Contrast application protocols (n = 4) differed with regards to injection rate (2ml or 1ml/sec), dose (weight-based or fixed 10ml) and supplemental oxygen administration (yes/no). SNR measurements were performed in the aorta and portal vein. Qualitatively, three readers assessed arterial phase image quality and TSM independently (4- and 5-point scale, respectively). Quantitative and qualitative results were compared (Kruskal-Wallis test, Dunn’s multiple comparison test). The influence of different contrast agent application parameters on the occurrence of respiratory motion artifacts was assessed (univariate analysis). Interrater agreement and reliability were calculated (intraclass correlation coefficient, ICC)). Results Use of a lower contrast injection rate resulted in significantly higher arterial SNR in the aorta and portal vein (p

Introduction To evaluate the image quality provided by MDCT scanners using an ACR phantom an to find out the relationship between CT parameters and physical quantities related to image quality. Methods A GE Lightspeed VCT and a GE Lightspeed Pro 16 are used. The ACR phantom consists of four modules for evaluating physical parameters. The image quality parameters, such as CT number, linearity, CNR, image uniformity, SNR and at least spatial resolution using MTF, by different sets of image acquisition protocols (IAPs) are characterized. The influences of the IAPs on the physical quantities are also discussed. Results The CT numbers behaved linearly relative to material density for all tube voltages. The impact of the tube current on the CT numbers is neglectable. However, the variation of the tube current reflects in the CT number uncertainties. The CNR are altered by changing the IAPs. 50% MTF decreases from 6.2 to 3.6 lp/cm and from 6.5 to 3.7 lp/cm using Lung and Soft kernel for the Lightspeed VCT and Lightspeed Pro 16 scanner, respectively. Conclusion The dependence of the image quality parameters on reconstruction kernels, tube peak voltages, tube currents and the slice thicknesses has been discussed. The tube peak voltage has the most influence on the CT numbers. The results indicate that the reconstruction kernel has the main impact on the spatial resolution. The spatial resolution dependence on the tube voltages, tube currents and slice thicknesses can be ignored.

Background Desmoid-type fibromatosis (DF) is a rare disease, which often occurs in young adults. Medical treatment is an important option in the treatment algorithm of DF. Different chemotherapeutic regimens showed clinical activity in DF, but overall treatment tolerability remains poor for this patient cohort. Novel approaches investigated tyrosine kinase inhibitors in DF, but tolerability remained an issue. Case presentation We treated a patient with progressive DF after failure of chemotherapy for 1 year with singe agent bevacizumab. He achieved a symptomatic and radiologic response while attainning excellent tolerability. Conclusions This is the first report on single agent bevacizumab in DF, which showed both, good tolerability and efficacy in our patient, thereby warranting future trials in DF.

and the smaller-diameter stents would have been more likely to cause obstruction and would have been more difficult to exchange in the future (1). A three-staged combined procedure (2) involving placement of an antegrade nephrostomy catheter/nephroureterostomy catheter, conversion to a retrograde nephroureteral catheter, and, finally, transileal exchange of the retrograde nephroureteral stent and removal of the antegrade nephrostomy tube was also not considered appropriate despite a success rate greater than 90% because, again, this would involve positioning the patient prone to initially insert the antegrade nephrostomy. In most cases of ileal conduit obstruction and urosepsis, we would advocate percutaneous nephrostomy to decompress the system and antibiotic treatment with retrograde exchange of ureteroileal stents via the ileal conduit at a later date. However, in the present case, positioning the patient prone to perform nephrostomy insertion was considered more difficult as a result of recent laparotomy and large parastomal hernia. A retrograde transileal approach reduced the risk associated with the performance of percutaneous nephrostomy and

We present an electromechanically coupled Finite Element model for cardiac tissue. It bases on the mechanical model for cardiac tissue of Hunter et al. that we couple to the McAllister-Noble-Tsien electrophysiological model of purkinje fibre cells. The corresponding system of ordinary differential equations is implemented on the level of the constitutive equations in a geometrically and physically nonlinear version of the so-called edge-based smoothed FEM for plates. Mechanical material parameters are determined from our own pressure-deflection experimental setup. The main purpose of the model is to further examine the experimental results not only on mechanical but also on electrophysiological level down to ion channel gates. Moreover, we present first drug treatment simulations and validate the model with respect to the experiments.

The rationale and objectives were to define the MRI tumor-characterizing potential of a new protein-avid contrast agent, Gd-GlyMe-DOTA-perfluorooctyl-mannose-conjugate (Gadofluorine M™; Schering AG, Berlin, Germany) in a chemically induced tumor model of varying malignancy. Because of the tendency for this agent to form large micelles in water and to bind strongly to hydrophobic sites on proteins, it was hypothesized that patterns of dynamic tumor enhancement could be used to differentiate benign from malignant lesions, to grade the severity of malignancies and to define areas of tumor necrosis. Gadofluorine M, 0.05 mmol Gd kg−1, was administered intravenously to 28 anesthetized rats that had developed over 10 months mammary tumors of varying degrees of malignancy as a consequence of intraperitoneal administration of N-ethyl-N-nitrosourea (ENU), 45–250 mg kg−1. These tumors ranged histologically from benign fibroadenomas to highly undifferentiated adenocarcinomas. Dynamic enhancement data were analyzed kinetically using a two-compartment tumor model to generate estimates of fractional plasma volume (fPV), apparent fractional extracellular volume (fEV*) and an endothelial transfer coefficient (KPS) for this contrast agent. Tumors were examined microscopically for tumor type, degree of malignancy (Scarff–Bloom–Richardson score) and location of necrosis. Eighteen tumor-bearing rats were successfully imaged. MRI data showed an immediate strong and gradually increasing tumor enhancement. KPS and fEV*, but not fPV obtained from tumors correlated significantly (p

Background Continuous use of anabolic androgenic steroid in high-doses is associated with substantial health risks, including hepatocellular adenoma. Malignant transformation from hepatocellular adenoma to hepatocellular carcinoma after anabolic androgenic steroid abuse has been rarely reported. The morphological distinction of adenoma from well-differentiated hepatocellular carcinoma is challenging and requires elaborated imaging techniques and histology. Case presentation We report about a 29-year old male professional bodybuilder who presented with mid-epigastric pain at the emergency unit. Ultrasound showed a severe hepatomegaly with multiple lesions. Contrast-enhanced ultrasound revealed a heterogeneous pattern with signs of hepatocellular carcinoma. CT scan of the abdomen confirmed multiple hypervascular lesions and central areas of necrosis without contrast enhancement. Subsequent diagnostics included fine needle aspiration (FNA) of suspicious lesions and mini-laparoscopy to establish the diagnosis of a β-catenin and testosterone-receptor positive hepatocellular carcinoma embedded in multiple adenomas. The patient was subsequently treated by liver transplantation and remains tumor-free 27 month after surgery. Conclusion Hepatocellular carcinoma occurring in association with anabolic androgenic steroid abuse should sensitize physicians and especially professional bodybuilders for the harmful use of high doses of steroids.