Image quality of opportunistic breast examinations in photon-counting computed tomography: A phantom study.

PURPOSE: To compare the breast imaging performance of a clinical whole-body photon-counting CT (PCCT) to that of a dedicated breast CT (BCT) to determine the image quality of opportunistic breast examinations in clinical PCCT. MATERIALS AND METHODS: To quantify image quality for breast cancer applications, acquisitions of a breast phantom including representations of calcifications, fibers, and masses were performed using a clinical PCCT and a dedicated BCT. When imaging with the PCCT, the phantom was also combined with a thorax phantom to simulate realistic patient positioning, while only the breast phantom was imaged in the BCT. Images in BCT were acquired at 7.0 mGy (CTDI16cm) and using 2.6 mGy-25.0 mGy in the PCCT. Spatial resolution between the BCT and PCCT images was matched and data were reconstructed using the default methods of each system. The dose-normalized contrast-to-noise ratio (CNRD) of masses and the structural visibility of fibers and calcifications were evaluated as figures of merit for all reconstructions. RESULTS: CNRD between masses and background was 0.56 mGy-½, on average with BCT and varied between 0.39 mGy-½ to 1.46 mGy-½ with PCCT over all dose levels, phantom configurations, and reconstruction algorithms. Calcifications down to a size of 0.29 mm and fibers down to a size of 0.23 mm could be reliably identified in the images of both systems. CONCLUSIONS: Clinical PCCT provides an image quality superior to that obtained with BCT in terms of CNRD and allows for the identification of calcifications and fibers at comparable dose levels.

Structured reporting in fetal magnetic resonance imaging with congenital diaphragmatic hernia.

OBJECTIVE: We aim to provide a template structured report of fetal Magnetic Resonance Imaging in congenital diaphragmatic hernia (CDH) that was locally validated by the CDH study group in Mannheim. METHODS: A selection of 50 fetal MRIs of patients with an isolated diaphragmatic hernia and associated radiology reports from five different senior radiologists from a single center resulted in a primary structured report, which was put into practice by using dedicated software. A questionnaire survey of the interdisciplinary CDH study group Mannheim was used to adapt the report to the clinical requirements. RESULTS: There was a huge variability in how deep the free text reports go into detail. The side of the hernia was named in 94% of cases. In 58%, both the lung volume and the total lung volume were reported. A comparison with the expected lung volume was reported in 66% of cases. Additional findings, such as herniated organs, were reported in 96% of cases. Overall satisfaction with the newly established structured report was high within the CDH study group with a mean of 4.7. CONCLUSIONS: The use of the structured report of this study can optimize the interdisciplinary dialog, the standardization of report content, increase report completeness and improve quality.

[Sports injuries in children and adolescents]. / Sportverletzungen im Kindesalter.

CLINICAL/METHODOLOGICAL ISSUE: Due to active participation of children and adolescents in school sports as well as in club sports, sporting injuries in childhood are common. Because skeletal maturity is not yet complete, injury patterns in children differ from sporting injuries in adults. Knowledge of the pathophysiologic characteristics, as well as knowledge of typical injury sequelae, is of great relevance to radiologists. This review article therefore deals with common acute and chronic sporting injuries in children. STANDARD RADIOLOGICAL METHODS: Basic diagnostic imaging comprises conventional X­ray imaging in two planes. In addition, sonography, magnetic resonance imaging (MRI) and computed tomography (CT) are used. PRACTICAL RECOMMENDATIONS: Close consultation with clinical colleagues and knowledge of childhood-specific injuries help identify sports-associated trauma sequelae.

[Relevant incidental findings and iatrogenic injuries : A retrospective analysis of 1165 resuscitation room patients]. / Relevante Zufallsbefunde und iatrogene Verletzungen : Eine retrospektive Analyse von 1165 Schockraumpatienten.

BACKGROUND: Whole-body computed tomography (CT) is increasingly being used as the diagnostic modality of choice in patients admitted to the resuscitation room. Beyond findings related to the suspected diagnosis it often additionally reveals incidental findings. The aim of this investigation was the evaluation of these findings in patients admitted via the emergency room after suffering potential major trauma or life-threatening medical conditions. Furthermore, the number of iatrogenic injuries as well as misplaced catheters and endotracheal tubes was investigated. METHODS: All patients admitted from 1 February 2012 to 31 January 2014 via the resuscitation area of the Mannheim University Medical Center, a tertiary care hospital and level 1 trauma center, were included in this study if they had undergone a whole-body CT scan at admission. Data from 1362 patients were collected retrospectively and 197 patients were excluded because of missing data so that the final cohort consisted of 1165 patients (1038 trauma and 127 internal neurological patients). Reports from the whole-body CT scans were screened for incidental findings. These findings were then classified as either clinically relevant or not. Furthermore, the reports were checked for iatrogenic injuries as well as misplaced catheters and endotracheal tubes. RESULTS: A total of 465 incidental findings were reported in 293 patients (25.1%) of the final cohort. In the synopsis of the radiological and clinical findings, 72 were rated as clinically relevant. In one patient two relevant incidental findings were reported and one patient presented with three incidental findings. In total, relevant incidental findings could be detected in 5.8% of the study patients (68/1165). In the discharge letters and/or the radiological report 16.2% of the incidental findings rated as clinically relevant were reported to be previously known, 66.2% were reported to be unknown and 17.6% could not be unequivocally classified as known or unknown due to missing references in the discharge letters. The group of internal neurological patients were clearly older than the trauma patients (61.6 years vs. 45.5 years). The rate of relevant incidental findings in the internal neurological group was more than twice as high as in the trauma group (11.0% vs. 5.2%); however, in the relatively young trauma group 1 in 20 patients showed an incidental finding classified as clinically relevant. In 43 (3.7%) patients a total of 46 iatrogenic injuries or misplaced catheters were reported. The most common finding was a too deeply placed endotracheal tube and five transurethral catheters placed in the emergency room were found to be blocked within the urethra. CONCLUSION: In addition to the main diagnosis, clinically relevant incidental findings were reported in nearly 25% of whole-body CT scans of patients admitted to the resuscitation room. Approximately 6% of patients had incidental findings rated as clinically relevant. In the internal neurological group of patients the rate of incidental findings was doubled compared to the trauma group; however, the latter were significantly younger. Whole-body CT was also useful for diagnosing iatrogenic injuries and misplaced catheters in approximately 4% of the study patients.

[Infectious diseases and injuries of bladder and urinary tract]. / Infektionskrankheiten und Verletzungen der Harnblase und der ableitenden Harnwege.

Urinary tract infections are the most common infectious diseases in Germany. In most cases clarification does not rely on imaging techniques other than sonography and is made mostly based on clinical symptoms. Computed tomography (CT) and magnetic resonance imaging (MRI) can be used in selected cases to find the cause and detection or exclusion of complications, e.g. recurrent or atypical and complicated courses. The method of choice for clarification of urolithiasis is CT. Using low-dose techniques, detection or exclusion of urinary stones can be achieved with a high sensitivity and specificity as well as an acceptable level of radiation exposure. Native stone CT supplies additional fundamental information that can substantially influence further therapy planning. The diagnosis of ureteral injuries is clinically and radiologically not trivial and clarification is aided by urographic contrast media. The method of CT cystography has an important role in the diagnostics of urinary bladder injuries.

[Oncological diseases and postoperative alterations of the bladder and urinary tract]. / Onkologische Erkrankungen und postoperative Veränderungen der Harnblase und der ableitenden Harnwege.

In the challenging evaluation of upper urinary tract malignancies multidetector computed tomography (CT) has become the standard imaging method. Cross sectional imaging not only allows the detection and visualization of the tumor itself but also provides nodal and metastasis staging in one examination (one-stop-shop). The majority of urothelial carcinomas are located in the urinary bladder. In this case, CT and more recently magnetic resonance imaging (MRI) can also deliver decisive information regarding TNM classification. A combination of clinical, histological, morphological and functional parameters allows both risk stratification and a targeted therapy based on the individual tumor stage.

[Value of galactography for the diagnostic work-up of pathological nipple discharge in multimodal breast diagnostics. Part 2: a systematic review of the literature]. / Stellenwert der Galaktographie zur Abklärung pathologischer Sekretion in der komplementären Mammadiagnostik. Teil 2: Eine systematische Literaturanalyse.

BACKGROUND: The survey results of a previous study showed that galactography is now rarely used in Germany and newer methods are applied. The evidential value of galactography should be established and opposed to the evidential value of ultrasound (US) and magnetic resonance mammography (MRM). MATERIALS AND METHODS: A search was carried out in PubMed and Cochrane involving studies written in English or German. The level of evidence was measured according to the Oxford Centre for Evidence-based Medicine. RESULTS: A total of 19 studies were included, 14 with results on galactography, 10 on US and 5 on MRM. Almost all studies were retrospective with an evidence assigned to level 3b or lower. The results on the diagnostic values showed a very wide range. Because of very variable numbers of cases and consideration of various pathologies, the studies are only comparable to a limited extent. CONCLUSION: Galactography, US and MRM all show a weak level of evidence and no superiority of a particular method can be derived. Therefore, galactography can no longer be considered as a mandatory standard in modern multimodal imaging of the breast. Recommendations for the diagnostic work-up of pathological nipple discharge have to be included in current guidelines and must consider these facts.

The Urological Dyna-CT: ex vivo feasibility study of interventional cross-sectional imaging in the endourological operation room.

BACKGROUND: Imaging of the urinary tract and its surrounding tissue still remains challenging, since standard imaging in the urological operation room consists of fluoroscopy and plain X-rays. The combination of a ceiling-mounted X-ray system and a new urological intervention table now allows cross-sectional imaging and 3D reconstruction to be performed in the endourological operation room (Urological Dyna-CT). MATERIALS AND METHODS: The imaging quality of the Artis Zee Ceiling (Siemens Medical Solutions, Erlangen, Germany) was assessed using slice images of an ex vivo pig kidney model prepared with artificial stones (plaster of Paris). We compared the image quality of three different examination protocols with this model. 3D reconstruction quality was illustrated by means of retrograde filling of one pig`s urinary tract with a diluted contrast medium. RESULTS: Interventional stone detection and localization is possible with a 5 s low-dose Urological Dyna-CT. Detailed imaging of the collecting system by retrograde pyelography is possible with a high image quality. CONCLUSION: The combination of an Artis Zee(®) Ceiling (Siemens Medical Solutions, Erlangen, Germany) with our newly developed urological intervention table we call the Urological Dyna-CT. In addition to such standard procedures as fluoroscopy or plain X-rays, cross-sectional imaging and 3D reconstruction of the urinary tract are possible and provide fast and excellent urological imaging.

[Value of galactography for the diagnostic work-up of pathological nipple discharge in multimodal breast diagnostics : Part 1: An online survey among German breast care centers.] / Stellenwert der Galaktographie zur Abklärung pathologischer Sekretion in der komplementären Mammadiagnostik : Teil 1: Eine Onlineumfrage an den deutschen Brustzentren.

PURPOSE: Galactography has been used in cases of pathological discharge for decades. Meanwhile other methods, such as high-resolution ultrasound (US) and magnetic resonance mammography (MRM) have been established for modern multimodal breast imaging. A survey among certified German breast care centers aimed to investigate to what extent galactography is currently used and whether newer techniques in multimodal imaging are preferred. MATERIALS AND METHODS: An anonymous online survey was carried out nationwide and open to 342 radiology units in certified German breast care centers. RESULTS: A total of 177 units (52 %) participated in the survey of which 13 % generally do not provide galactography, 33 % conduct a maximum of 5 galactographies per year, 24 % conduct 6-10, 18 % 11-20, 8 % 21-50 and 5 % 51-100. Of the participants 53 % give first priority to US and prefer galactography to MRM in stepwise diagnosis and 32 % prefer MRM to galactography. Only 4 % use galactography initially. CONCLUSION: Currently galactography is no longer a mandatory standard and newer methods are preferred. The evidential value of galactography in comparison to other techniques should be established on the basis of the literature. The second part of this paper will deal with this question.

Predictive value of zero calcium score and low-end percentiles for the presence of significant coronary artery stenosis in stable patients with suspected coronary artery disease.

PURPOSE: To prospectively investigate the predictive value of a zero calcium score (CS) value as well as age- and sex-adjusted low-end CS percentiles for the presence of significant coronary artery stenosis in stable patients with suspected coronary artery disease (CAD). MATERIALS AND METHODS: In total, 87 consecutive stable patients with suspected CAD were prospectively enrolled in this study (33 women; 66 ± 10 years). All patients underwent non-enhanced CT for calcium scoring (CSCT) and contrast-enhanced coronary CT angiography (cCTA). Invasive coronary angiography (ICA) served as the reference standard in all patients. Diagnostic performance for the presence of significant stenosis (≥ 50% diameter) was calculated separately for CS in comparison to cCTA and ICA. RESULTS: ICA identified significant stenosis in 56/87 patients (64%). The mean CS was 571 ± 599. On a per patient based analysis, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for patients with a zero CS were 98.5%, 18.2%, 78.0% and 80.0%, respectively, compared to cCTA and 100%, 16.1%, 68.3% and 100%, respectively, compared to ICA. Low-end age- and sex-adjusted percentiles derived from asymptomatic Caucasian populations showed results comparable to a CS of zero. CONCLUSION: The prevalence of significant coronary artery stenosis is low in stable patients with suspected CAD and a CS of zero but also in patients below certain low-end age- and sex-adjusted percentile ranks. Thus, CS should be used as a gatekeeper prior to further diagnostic procedures in these patients. A CS value below certain age- and sex-adjusted percentile ranks seems to be of identical diagnostic value to a CS of zero in stable patients.

[The urological Dyna-CT. Urological cross-sectional imaging on a newly developed urological intervention table]. / Das urologische Dyna-CT. Urologische Schnittbildgebung auf einem neu entwickelten urologischen Interventionstisch.

BACKGROUND: The development of a new urological intervention table now enables the application of an Artis zee ceiling Dyna-CT (Siemens, Erlangen, Germany) for interventional cross-sectional imaging and 3-D reconstruction of the urinary tract in the prone and supine positions (urological Dyna-CT). MATERIALS AND METHODS: We tested the feasibility of the urological Dyna-CT with the newly developed urological intervention table. The system was moved five times to enable 3-D reconstruction of the urinary tract of a test person in the prone and in supine positions. RESULTS: Handling of the free floating table is easily possible during the intervention. We found no limitation of imaging system movement in any position of the test person. CONCLUSION: Apart from standard urological imaging such as fluoroscopy, intravenous pyelography or plain abdominal X-ray the urological Dyna-CT enables further imaging of the urinary tract. Fluoroscopy sequences can be stored as videos, and 3-D reconstructions of the urinary tract are possible with permanent patient access for any intervention. Extensive tests led to the technical approval of the system in urology.

[Image-guided radiation therapy. Paradigm change in radiation therapy]. / Bildgestützte Strahlentherapie. Paradigmenwechsel in der Strahlentherapie.

CLINICAL ISSUE: The introduction of image-guided radiotherapy (IGRT) has changed the workflow in radiation oncology more dramatically than any other innovation in the last decades. STANDARD TREATMENT: Imaging for treatment planning before the initiation of the radiotherapy series does not take alterations in patient anatomy and organ movement into account. TREATMENT INNOVATIONS: The principle of IGRT is the temporal and spatial connection of imaging in the treatment position immediately before radiation treatment. DIAGNOSTIC ASSESSMENT: The actual position and the target position are compared using cone-beam computed tomography (CT) or stereotactic ultrasound. PERFORMANCE: The IGRT procedure allows a reduction of the safety margins and dose to normal tissue without an increase in risk of local recurrence. ACHIEVEMENTS: In the future the linear treatment chain in radiation oncology will be developed based on the closed-loop feedback principle. PRACTICAL RECOMMENDATIONS: The IGRT procedure is increasingly being used especially for high precision radiotherapy, e.g. for prostate or brain tumors.

[Whole-body MRI in preoperative diagnostics of breast cancer--a comparison with [corrected] staging methods according to the S 3 guidelines]. / Ganzkörper-MRT in der präoperativen Diagnostik des Mammakarzinoms--ein Vergleich mit den Stagingmethoden in der S 3-Leitlinie.

PURPOSE: The German Society of Senology (step-3 guidelines for the early recognition of breast cancer in Germany) recommends whole-body staging including chest X-ray, ultrasound of the liver and bone scintigraphy before systemic therapy in patients with breast cancer. The performance of these three examinations is time-consuming and involves radiation exposure. Whole-body MR imaging (WB-MRI) allows staging in a single examination without radiation exposure. The purpose of this study was to compare the diagnostic accuracy of WB-MRI with staging according to the guidelines. MATERIALS AND METHODS: During 04/07 and 06/09, the initial staging in 51 patients (56 ± 12 yrs) with breast cancer (24 patients with lymph node metastases) was performed according to the S 3-guidelines. Additionally, all patients underwent contrast-enhanced WB-MRI (1.5-Tesla-Magnetom Avanto, Siemens, Erlangen). The findings of the different modalities were compared after correlation of the lesions by follow-up. The detection of suspicious findings and the accuracy of prediction of malignancy of the detected lesions were evaluated. RESULTS: Overall, 14 metastases were detected in 4 of 51 patients after completion of the follow-up. By means of WB-MRI, all 14 metastases could be detected, while just 4 of these metastases were identified by the conventional methods. CONCLUSION: The detection of distant metastases has an important impact on patient management. In this study WB-MRI in breast cancer staging has shown promising results in regard to possible clinical implementation as a matter of routine staging.

[Complications of venous port systems : Radiological diagnostics and minimally invasive therapy]. / Komplikationen venöser Portsysteme : Radiologische Diagnostik und minimalinvasive Therapie.

INTRODUCTION: Documentation of a correct port placement is a routine investigation in radiology. This article describes typical complications of port catheters and minimally invasive treatment options which can guarantee further use without complications. MATERIAL AND METHODS: From January 2009 to May 2010 a surgical port placement was carried out on 174 patients at the University Clinic in Mannheim and of these, 52 patients were admitted to our institute for radiological imaging of the port. Minimally invasive treatment options are presented based on the observed port complications. RESULTS: Of the 52 patients 7 (13.5%) received a port catheter lysis. A successful port position correction was carried out in 3 (5.8%) patients with a malpositioned port catheter and port removal was recommended in 2 patients (3.8%) due to extensive arm venous thrombosis. A minimally invasive port catheter treatment allowed further use of the port system without operative revision in the corresponding patients. The measures were tolerated very well by the patients without postinterventional complications.

[Shoulder injuries in overhead athletes: utility of MR arthrography]. / Schulterverletzungen des Uberkopfsportlers: Wertigkeit der MR-Arthrografie.

INTRODUCTION: The goal of this work was to assess the accuracy of the MR-Arthrografie in the evaluation of over head athletes injuries in comparison with athroscopy. MATERIAL AND METHODS: In 29 patients (middle age: 30 years, 21 male, 8 female, age 16 - 53 years) with persistent pain after conservative therapy an Arthro-MRI with intraarticular application of gadolinum was performed prior to arthroscopic surgery. The MRI was retrospectivly analysed of three examiners independently from one another. The result were compared to the results of the Arthroscopy. Interrater Reliability was calculated by using of Cohens Kappa. RESULTS: The MR-Arthrography could demonstrate 8 of 9 (88.9 %) partial tears of he rotator cuff. All SLAP (Superiores Labrum from Anterior to Posterior) Lesions as well as all bankart type Lesions were recognized through the MR-Arthrography. However, dependent upon the experience of the examiner in a span between 33.3 % (fellow radiologist) and 93.3 % (consultant radiologist). We found a high agreement between consultant radiologist and shoulder surgeon with Kappa of 0.79 for rotator cuff tear-, 0.86 for Bankart- and 0.82 for SLAP-Läsionen.

[Interdisciplinary diagnosis of and therapy for cholangiocarcinoma]. / Interdisziplinäre Diagnostik und Therapie von Gallengangskarzinomen.

The diagnosis of and therapy for cholangiocarcinomas still remains an interdisciplinary challenge. For diagnostic and therapeutic purposes intra- and extrahepatic cholangiocarcinomas need to be distinguished. Multiple imaging tools such as sonography, multidetector computer tomography, magnetic resonance tomography as well as endoscopic ultrasound and endoscopic retrograde cholangiography for the diagnosis and localisation of these tumours are available. To date, surgical resection is the only curative treatment. At the time of diagnosis, most of the tumours are advanced. Therefore, only a small percentage of patients are suitable for curative surgery. Infiltration of the portal vein no longer constitutes a contraindication for surgery. Liver transplantation is not a reasonable option for intrahepatic cholangiocarcinomas but may be of advantage for perihilar Klatskin tumours. Severe cholangitis is the main cause of death of patients with obstructive cholangiocarcinomas. Drainage of the biliary tree system or surgery with construction of a biliary-digestive anastomosis is often necessary. If possible, a photodynamic therapy (PDT) should be performed in addition to biliary drainage. PDT has been shown to facilitate biliary drainage and to improve survival. The value of radiologist-assisted interventional procedures as well as percutaneous ablation and radiochemotherapy is not well established. In addition, so far, there is no standardised chemotherapy in a palliative situation established but there is some evidence for a benefit of gemcitabine-based chemotherapy. For the best care and treatment of patients with cholangiocarcinomas an interdisciplinary approach is required and to achieve progress in the therapy patients should be included in prospective clinical trials to test new approaches.

[Magnetic resonance imaging for the assessment of myocardial perfusion: value of various semiquantitative perfusion parameters]. / MRT zur Beurteilung der Myokardperfusion: Aussagekraft verschiedener semiquantitativer Perfusionsparameter.

PURPOSE: The aim of this study was to determine the diagnostic accuracy of various semiquantitative perfusion parameters of the magnetic resonance perfusion examination of the myocardium compared to conventional coronary angiography. PATIENTS, MATERIAL AND METHODS: Twenty patients with suspicion of coronary artery disease who underwent coronary angiography were examined by MR imaging within 14 days before or after coronary angiography. A perfusion examination during adenosine application (140 microg/kg/min) and at rest was performed using a saturation recovery turboFLASH sequence. The semi-quantitative parameters maximum signal intensity (SIM), time-to-peak (TTP), area under the curve (AUC) and upslope (US) were determined using dedicated software (Dynamic Signal Analysis, ARGUS, Siemens Medical Solutions) for the evaluation of the signal-intensity-time curves. In addition, the ratio of these parameters (MPRI: myocardial perfusion reserve index) were determined by dividing the values of the stress examination by the values of the rest examination. RESULTS: Accuracy was 78.4% (SIM), 64.9% (TTP), 64.2% (AUC) and 70.4% (US) for the evaluation of the stress examination. Accuracy for the MPRI of the semi-quantitative parameters was 72.2% (SIM), 50.9% (TTP), 72.2% (AUC) und 89.1% (US). CONCLUSION: A combined semi-quantitative evaluation of the MPRI values using the ratio of the upslope values of the stress and rest examination was shown to be the most accurate method. MPRI (US(Stress)/US(Rest)) is superior to an evaluation of the stress examination alone.

[Quantification of right ventricular function in congenital heart disease: correlation of 3D echocardiography and MRI as complementary methods]. / Quantifizierung der rechtsventrikulären Funktion bei angeborenen Herzfehlern: Korrelation von 3D-Echokardiographie und MRT als sich ergänzende Methoden.

PURPOSE: In congenital heart disease, the exact determination of the right ventricular function is of high importance for therapeutic and especially surgical planning. The aim of this study was to correlate the parameters of the right ventricular function in MRI and 3D echocardiography to determine the agreement of both modalities. MATERIALS AND METHODS: In 18 patients suffering from congenital heart disease, 3D echocardiography was performed using a Philips Sonos 7500 system. In MRI short axis slices with a 4-mm distance were acquired using an SSFP sequence on a Siemens Sonata or Symphony System. Volumetry for both modalities was performed on an external workstation (Tomtec) using the EchoView software. RESULTS: Enddiastolic and endsystolic volumes showed a highly significant correlation with coefficients of 0.996 and 0.990, respectively. In echocardiography there was a systematic slight underestimation of enddiastolic volumes and overestimation of endsystolic volumes. The Wilcoxon test did not show significant differences between the volumes and ejection fractions assessed by both modalities. CONCLUSION: There is an excellent correlation in the quantification of right ventricular volumes in MRI and 3D echocardiography, which allows a comparison of acquired volumes in clinical follow-up.