[Bone marrow edema-differential diagnosis of the femoral head necrosis]. / Das Knochenmarködem ­ Differenzialdiagnose zur aseptischen Hüftkopfnekrose.

In patients with hip pain, clinical examination is of only restricted value in the differential diagnosis. Besides a patient's age, their medical history is often helpful in finding the correct diagnosis. Additionally, imaging can give valuable hints for excluding or validating a differential diagnosis. Nowadays, magnetic resonance imaging (MRI) is often used as a primary imaging modality in Germany. These MRIs show a bone marrow edema (BME) in many different pathologies. BME occurs in transitory bone marrow edema and outside of the atraumatic femoral head necrosis, concomitant with coxarthrosis, arthritis, herniation pit, and osteoid osteoma, amongst other conditions. This article describes several frequent differential diagnoses and gives hints on how to find the correct diagnosis.

White Paper: Radiological Curriculum for Undergraduate Medical Education in Germany.

Purpose: Radiology represents a highly relevant part of undergraduate medical education from preclinical studies to subinternship training. It is therefore important to establish a content base for teaching radiology in German Medical Faculties. Materials and Methods: The German Society of Radiology (DRG) developed a model curriculum for radiological teaching at German medical universities, which is presented in this article. There is also a European model curriculum for undergraduate teaching (U-level curriculum of the European Society of Radiology). In a modular concept, the students shall learn important radiological core principles in the realms of knowledge, skills and competences as well as core scientific competences in the imaging sciences. Results: The curriculum is divided into two modules. Module 1 includes principles of radiation biology, radiation protection and imaging technology, imaging anatomy as well as the risks and side effects of radiological methods, procedures and contrast media. This module is modality-oriented. Module 2 comprises radiological diagnostic decision-making and imaging-based interventional techniques for various disease entities. This module is organ system-oriented. Conclusion: The curriculum is meant as a living document to be amended and revised at regular intervals. The curriculum can be used as a basis for individual curricular development at German Medical Faculties. It can be integrated into traditional or reformed medical teaching curricula. Key Points: • Radiology is an integral and important part of medical education.• The German Society of Radiology (DRG) developed a model curriculum for teaching radiology at German Medical Faculties to help students develop the ability to make medical decisions based on scientific knowledge and act accordingly.• This curriculum can be used for individual curricular development at medical departments. It is divided into two modules with several chapters. Citation Format: • Ertl-Wagner B, Barkhausen J, Mahnken AH et al. White Paper: Radiological Curriculum for Undergraduate Medical Education in Germany. Fortschr Röntgenstr 2016; 188: 1017 - 1023.

[Molecular imaging of head and neck cancers : Perspectives of PET/MRI]. / Molekulare Bildgebung bei Kopf-Hals-Tumoren : Perspektive der PET-MRT.

BACKGROUND: The (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG-PET/CT) procedure is a cornerstone in the diagnostics of head and neck cancers. Several years ago PET-magnetic resonance imaging (PET/MRI) also became available as an alternative hybrid multimodal imaging method. OBJECTIVE: Does PET/MRI have advantages over PET/CT in the diagnostics of head and neck cancers? MATERIAL AND METHODS: The diagnostic accuracy of the standard imaging methods CT, MRI and PET/CT is depicted according to currently available meta-analyses and studies concerning the use of PET/MRI for these indications are summarized. RESULTS: In all studies published up to now PET/MRI did not show superiority regarding the diagnostic accuracy in head and neck cancers; however, there is some evidence that in the future PET/MRI can contribute to tumor characterization and possibly be used to predict tumor response to therapy with the use of multiparametric imaging. CONCLUSION: Currently, (18)F-FDG-PET/CT is not outperformed by PET/MRI in the diagnostics of head and neck cancers. The additive value of PET/MRI due to the use of multiparametric imaging needs to be investigated in future research.

Simultaneous [18F]FDG-PET/MRI: Correlation of Apparent Diffusion Coefficient (ADC) and Standardized Uptake Value (SUV) in Primary and Recurrent Cervical Cancer.

OBJECTIVES: Previous non-simultaneous PET/MR studies have shown heterogeneous results about the correlation between standardized uptake values (SUVs) and apparent diffusion coefficients (ADCs). The aim of this study was to investigate correlations in patients with primary and recurrent tumors using a simultaneous PET/MRI system which could lead to a better understanding of tumor biology and might play a role in early response assessment. METHODS: We included 31 patients with histologically confirmed primary (n = 14) or recurrent cervical cancer (n = 17) who underwent simultaneous whole-body 18F-FDG-PET/MRI comprising DWI. Image analysis was performed by a radiologist and a nuclear physician who identified tumor margins and quantified ADC and SUV. Pearson correlations were calculated to investigate the association between ADC and SUV. RESULTS: 92 lesions were detected. We found a significant inverse correlation between SUVmax and ADCmin (r = -0.532, p = 0.05) in primary tumors as well as in primary metastases (r = -0.362, p = 0.05) and between SUVmean and ADCmin (r = -0.403, p = 0.03). In recurrent local tumors we found correlations for SUVmax and ADCmin (r = -0.747, p = 0.002) and SUVmean and ADCmin (r = -0.773, p = 0.001). Associations for recurrent metastases were not significant (p>0.05). CONCLUSIONS: Our study demonstrates the feasibility of fast and reliable measurement of SUV and ADC with simultaneous PET/MRI. In patients with cervical cancer we found significant inverse correlations for SUV and ADC which could play a major role for further tumor characterization and therapy decisions.

Validating New Software for Semiautomated Liver Volumetry--Better than Manual Measurement?

PURPOSE: This prospective study compared a manual program for liver volumetry with semiautomated software. The hypothesis was that the semiautomated software would be faster, more accurate and less dependent on the evaluator's experience. MATERIALS AND METHODS: Ten patients undergoing hemihepatectomy were included in this IRB approved study after written informed consent. All patients underwent a preoperative abdominal 3-phase CT scan, which was used for whole liver volumetry and volume prediction for the liver part to be resected. Two different types of software were used: 1) manual method: borders of the liver had to be defined per slice by the user; 2) semiautomated software: automatic identification of liver volume with manual assistance for definition of Couinaud segments. Measurements were done by six observers with different experience levels. Water displacement volumetry immediately after partial liver resection served as the gold standard. The resected part was examined with a CT scan after displacement volumetry. RESULTS: Volumetry of the resected liver scan showed excellent correlation to water displacement volumetry (manual: ρ = 0.997; semiautomated software: ρ = 0.995). The difference between the predicted volume and the real volume was significantly smaller with the semiautomated software than with the manual method (33% vs. 57%, p = 0.002). The semiautomated software was almost four times faster for volumetry of the whole liver (manual: 6:59 ± 3:04 min; semiautomated: 1:47 ± 1:11 min). CONCLUSION: Both methods for liver volumetry give an estimated liver volume close to the real one. The tested semiautomated software is faster, more accurate in predicting the volume of the resected liver part, gives more reproducible results and is less dependent on the user's experience. KEY POINTS: Both tested types of software allow exact volumetry of resected liver parts. Preoperative prediction can be performed more accurately with the semiautomated software. The semiautomated software is nearly four times faster than the tested manual program and less dependent on the user's experience.

Initial clinical results of simultaneous 18F-FDG PET/MRI in comparison to 18F-FDG PET/CT in patients with head and neck cancer.

PURPOSE: The aim of this study was to evaluate the diagnostic capability of simultaneous (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/MRI compared to (18)F-FDG PET/CT as well as their single components in head and neck cancer patients. METHODS: In a prospective study 17 patients underwent (18)F-FDG PET/CT for staging or follow-up and an additional (18)F-FDG PET/MRI scan with whole-body imaging and dedicated examination of the neck. MRI, CT and PET images as well as PET/MRI and PET/CT examinations were evaluated independently and in a blinded fashion by two reader groups. Results were compared with the reference standard (final diagnosis determined in consensus using all available data including histology and follow-up). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. RESULTS: A total of 23 malignant tumours were found with the reference standard. PET/CT showed a sensitivity of 82.7%, a specificity of 87.3%, a PPV of 73.2% and a NPV of 92.4%. Corresponding values for PET/MRI were 80.5, 88.2, 75.6 and 92.5%. No statistically significant difference in diagnostic capability could be found between PET/CT and PET/MRI. Evaluation of the PET part from PET/CT revealed highest sensitivity of 95.7%, and MRI showed best specificity of 96.4%. There was a high inter-rater agreement in all modalities (Cohen's kappa 0.61-0.82). CONCLUSION: PET/MRI of patients with head and neck cancer yielded good diagnostic capability, similar to PET/CT. Further studies on larger cohorts to prove these first results seem justified.

Performance of an automatic dose control system for CT: patient studies.

PURPOSE: To study the effect of an automatic dose control (ADC) system with adequate noise characteristic on the individual perception of image noise and diagnostic acceptance compared to objectively measured image noise and the dose reductions achieved in a representative group of patients. MATERIALS AND METHODS: In a retrospective study two matched cohorts of 20 patients each were identified: a manual cohort with exposure settings according to body size (small - regular - large) and an ADC cohort with exposure settings calculated by the ADC system (DoseRight 2.0™, Philips Healthcare). For each patient, 12 images from 6 defined anatomic levels from contrast-enhanced scans of chest and abdomen/pelvis were analyzed by 4 independent readers concerning image noise and diagnostic acceptance on a five-point Likert scale and evaluated for objectively measured image noise. Radiation exposure was calculated from recorded exposure data. RESULTS: Use of the ADC system reduced the average effective dose for patients by 36 % in chest scans (3.2 vs. 4.9 mSv) and by 17 % in abdomen/pelvis scans (7.6 vs. 8.3 mSv). Average objective noise was slightly lower in the manual cohort (11.1 vs. 12.8 HU), correlating with a slightly better rating in subjective noise score (4.4 vs. 4.2). However, diagnostic acceptance was rated almost equal in both cohorts with excellent image quality (4.6 vs. 4.5). CONCLUSION: Use of an ADC system with adequate noise characteristic leads to significant reductions in radiation exposure for patients while maintaining excellent image quality.

[CT-guided marking of pulmonary nodules with a special lung marking wire before video-assisted thoracoscopic surgery - review of 184 cases]. / CT-gestützte Drahtmarkierung vor videoassistierter thorakoskopischer OP von pulmonalen Rundherden - eine Auswertung von 184 Fällen.

PURPOSE: Minimally invasive techniques like video-assisted thoracoscopic surgery (VATS) are currently the method of choice for the resection of small pulmonary nodules, when they are located in the periphery of the lungs. To guarantee quick and safe intraoperative identification of the nodule, preoperative marking is necessary and sensible. We report about our experiences in 184 markings with a special lung marking wire, which is placed in or around the pulmonary nodule using CT guidance. MATERIALS AND METHODS: In 184 patients (97 m, 87f, mean age: 58.1 ± 13.7 years) with pulmonary nodules, scheduled for resection with VATS, a special lung marking wire was placed preoperatively under CT guidance. We evaluated the technical success, safety, necessity of conversion to thoracotomy and histology in all patients. RESULTS: The marking wire could be positioned successfully in 181 cases (98.4 %). There was one major complication (uncontrollable pneumothorax). Minor adverse events like small pneumothorax (53.3 %) or a perifocal bleeding (30.4 %) did not necessitate treatment. Complete resection of the marked nodule was successful in 98.4 % of the patients. Conversion to thoracotomy was necessary in 29 patients (15.9 %) due to bleeding, adhesions, malignancy or wire dislocation. Histology revealed a benign nodule in 96 cases (54.4 %) and a malignant lesion in 78 cases (45.6 %), of which only 21 nodules (11.5 %) turned out to present a primary pulmonary carcinoma. CONCLUSION: CT-guided marking of pulmonary nodules using a special marking wire followed by thoracoscopic resection is an efficient and safe method for diagnosing suspicious nodules in the periphery of the lung.

Performance of an automatic dose control system for CT: specifications and basic phantom tests.

PURPOSE: To assess the performance and to provide more detailed insight into the characteristics and limitations of devices for automatic dose control (ADC) in CT. MATERIALS AND METHODS: A comprehensive study on DoseRight 2.0, the ADC system provided by Philips for its Brilliance CT scanners, was conducted. Phantom tests were carried out on a 64-slice scanner (Brilliance 64) using assorted quality control (QC) phantoms that allowed verification of the basic specifications. If feasible, the findings were verified by model calculations based on known specifications. RESULTS: For all tests, the dose reductions and modulation characteristics fully met the values expected from the specifications. Adverse effects due to increased image noise were only moderate as a result of the "adequate noise system" design that employs comparatively gentle modulation, and the additional use of adaptive filtration. CONCLUSION: Simple tests with QC phantoms allow evaluation of the most relevant characteristics of devices for ADC in CT.

Performance of an automatic dose control system for CT: anthropomorphic phantom studies.

PURPOSE: To assess the performance and to provide more detailed insight into characteristics and limitations of devices for automatic dose control (ADC) in CT. MATERIALS AND METHODS: A comprehensive study on DoseRight 2.0, the ADC system provided by Philips for its Brilliance CT scanners, was conducted with assorted tests using an anthropomorphic phantom that allowed simulation of the operation of the system under almost realistic conditions. The scan protocol settings for the neck, chest and abdomen with pelvis were identical to those applied in the clinical routine. RESULTS: Using the appropriate ADC functionalities, dose reductions equal 40% for the neck, 20% for the chest and 10% for the abdomen with pelvis. Larger dose reductions can be expected for average patients, since their attenuating properties differ significantly from the anthropomorphic phantom. Adverse effects due to increased image noise were only moderate as a consequence of the "adequate noise system" design and the complementary use of adaptive filtration. The results of specific tests also provided deeper insight into the operation of the ADC system that helps to identify the causes of suspected malfunctions and to prevent potential pitfalls. CONCLUSION: Tests with anthropomorphic phantoms allow verification of the characteristics of devices for ADC in CT under almost realistic conditions. However, differences in phantom shape and material composition require supplementary patient studies on representative patient groups.

[Therapeutic options in sinunasal adenoid cystic carcinomas--a case report and review]. / Behandlungsstrategie bei sinunasalen adenoidzystischen Karzinomen--Ein Fall mit Literaturübersicht.

BACKGROUND: Adenoid cystic carcinomas (ACC) in sinunasal compartments are often not completely resectable. We discuss both, surgical margins and functional results preoperatively and postoperative options for adjuvant therapy. The former opinion of a resistance of ACC towards chemotherapy or irradiation seems to be outdated, even though consensus about therapeutic strategies is still missing. MATERIAL AND METHODS: We discuss therapeutic options and compare data from literature regarding the best adjuvant therapy with the case of a 25-year-old patient with an advanced ACC of the left fossa pterygopalatina. Further we discuss alternative therapeutic options like neutron irradiation, chemotherapy or targeted therapy. Following the advice from literature, we performed an eye saving tumor resection by a left transmaxilloethmoidale sphenoidectomy via combined trans- und extranasal approach. We accepted close surgical margins for the benefit of the abandonment of dismembering measures and performed an adjuvant radiochemotherapy with taxol and carboplatin. RESULTS: With the described therapeutic strategy we reached an optimal local tumor control with unlimited visus and without functional and cosmetic restrictions up to now. Periodic staging did not show any local tumor progress or metastatic spread hitherto. CONCLUSION: Organ preserving surgery and adjuvant radiochemotherapy even in combination with taxol and carboplatin seems to be a sufficient therapeutic option in treating advanced sinunasal ACC, and might not have any prognostic disadvantages to radical surgery.

Giant ovarian cysts: is a pre- and intraoperative drainage an advisable procedure?

There has been a considerable debate over the merits of a pre- or intraoperative drainage of giant ovarian cysts, which represented a very frequent approach before definitive surgery in the past. Including our presented case of a 57-year-old woman with a 49 kg mucinous cystadenoma, 19 patients with giant ovarian cysts weighing more than 40 kg were reported in the literature since 1970. An incidence of 37% of malignant and low malignant potential tumors was found. Based on a critical evaluation of the medical courses and the discussed miscellaneous advantages and complications, we conclude that a pre- and intraoperative drainage should be avoided.