S O Schoenberg

Publications of S O Schoenberg

• [Current oncologic concepts and emerging techniques for imaging of head and neck squamous cell cancer].

  Authors: M Sadick, S O Schoenberg, K Hoermann, H Sadick

  Laryngo- rhino- otologie. 03/2012; 91 Suppl 1:S27-47.

  The incidence of head and neck squamous cell carcinoma (HNSCC) is increasing and currently they account for 5% of all malignancies worldwide. Inspite of ongoing developments in diagnostic imaging andThe incidence of head and neck squamous cell carcinoma (HNSCC) is increasing and currently they account for 5% of all malignancies worldwide. Inspite of ongoing developments in diagnostic imaging and new therapeutic facilities, HNSCC still represents a multidisciplinary challenge.One of the most important prognostic factors in HNSCC is the presence of lymph node metastases. Patients with confirmed nodal involvement have a considerable reduction of their 5-year overall survival rate. In the era of individually optimised surgery, chemotherapy and intensity modulated radiotherapy, the main role of pre- and posttherapeutic imaging remains cancer detection at an early stage and accurate follow-up. The combined effort of early diagnosis and close patient monitoring after surgery and/or radio-chemotherapy influences disease progression and outcome prediction in patients with HNSCC.This review article focuses on currrent oncologic concepts and emerging tools in imaging of head and neck squamous cell cancer. Besides the diagnostic spectrum of the individual imaging modalities, their limitations are also discussed. One main part of this article is dedicated to PET-CT which combines functional and morphological imaging. Furthermore latest developments in MRT are presented with regard to lymph node staging and response prediction. Last but not least, a clinical contribution in this review explains, which information the head and neck surgeon requires from the multimodality imaging and its impact on operation planning.

• [Functional magnetic resonance imaging for evaluation of radiation-induced renal damage].

  Authors: S Haneder, J Boda-Heggemann, S O Schoenberg, H J Michaely

  Der Radiologe. 03/2012; 52(3):243-51.

  The diagnosis of radiation-induced (especially chronic) renal alterations/damage is difficult and currently relies primarily on clinical evaluation. The importance of renal diagnostic evaluation willThe diagnosis of radiation-induced (especially chronic) renal alterations/damage is difficult and currently relies primarily on clinical evaluation. The importance of renal diagnostic evaluation will increase continuously due to the increasing number of long-term survivors after radiotherapy. This article evaluates the potentia diagnostic contribution of magnetic resonance (MR) imaging with a focus on functional MRI. The following functional MRI approaches are briefly presented and evaluated: blood oxygenation level-dependent imaging (BOLD), diffusion-weighted imaging (DWI) or diffusion tensor imaging (DTI), MR perfusion measurements and (23)Na imaging. In summary, only DWI and contrast-enhanced MR perfusion currently seem to be suitable approaches for a broader, clinical implementation. However, up to now valid data from larger patient studies are lacking for both techniques in regard to radiation-induced renal alterations. The BOLD and (23)Na imaging procedures have a huge potential but are currently neither sufficiently evaluated with regard to radiation-induced renal alterations nor technically simple and reliable for implementation into the clinical routine.

• Imaging of Tumor Viability in Lung Cancer: Initial Results Using 23Na-MRI.

  Authors: T Henzler, S Konstandin, G Schmid-Bindert, P Apfaltrer, S Haneder, F Wenz, L Schad, C Manegold, S O Schoenberg, C Fink

  RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin. 02/2012; 184(4):340-344.

  Purpose: 23Na-MRI has been proposed as a potential imaging biomarker for the assessment of tumor viability and the evaluation of therapy response but has not yet been evaluated in patients with lungPurpose: 23Na-MRI has been proposed as a potential imaging biomarker for the assessment of tumor viability and the evaluation of therapy response but has not yet been evaluated in patients with lung cancer. We aimed to assess the feasibility of 23Na-MRI in patients with lung cancer. Materials and Methods: Three patients with stage IV adenocarcinoma of the lung were examined on a clinical 3 Tesla MRI system (Magnetom TimTrio, Siemens Healthcare, Erlangen, Germany). Feasibility of 23Na-MRI images was proven by comparison and fusion of 23Na-MRI with 1H-MR, CT and FDG-PET-CT images. 23Na signal intensities (SI) of tumor and cerebrospinal fluid (CSF) of the spinal canal were measured and the SI ratio in tumor and CSF was calculated. One chemonaive patient was examined before and after the initiation of combination therapy (Carboplatin, Gemcitabin, Cetuximab). Results: All 23Na-MRI examinations were successfully completed and were of diagnostic quality. Fusion of 23Na-MRI images with 1H-MRI, CT and FDG-PET-CT was feasible in all patients and showed differences in solid and necrotic tumor areas. The mean tumor SI and the tumor/CSF SI ratio were 13.3 ± 1.8 × 103 and 0.83 ± 0.14, respectively. In necrotic tumors, as suggested by central non-FDG-avid areas, the mean tumor SI and the tumor/CSF ratio were 19.4 × 103 and 1.10, respectively. Conclusion: 23Na-MRI is feasible in patients with lung cancer and could provide valuable functional molecular information regarding tumor viability, and potentially treatment response.

• [Multiparametric prostate MRI for follow-up monitoring after radiation therapy].

  Authors: A M Weidner, D J Dinter, M Bohrer, M Sertdemir, D Hausmann, F Wenz, S O Schoenberg

  Der Radiologe. 02/2012; 52(3):235-42.

  CLINICAL/METHODICAL ISSUE: Radiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the currentCLINICAL/METHODICAL ISSUE: Radiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the current standard of care in the follow-up. Imaging is recommended only for symptomatic patients and/or for further therapeutic options. STANDARD RADIOLOGICAL METHODS: For detection of local recurrence magnetic resonance imaging (MRI) of the prostate is acknowledged as the method of choice. PERFORMANCE: Good results for primary diagnosis were found especially in combination with functional techniques, whereas in recurrent prostate cancer only few studies with heterogeneous study design are available for prostate MRI. Furthermore, changes in different MRI modalities due to radiation therapy have been insufficiently investigated to date. PRACTICAL RECOMMENDATIONS: As the initial results were promising prostate MRI and available therapeutic options for detection of local recurrence should be considered in patients with increased PSA.

• CT Angiography of the Aorta Is Superior to Transesophageal Echocardiography for Determining Stroke Subtypes in Patients with Cryptogenic Ischemic Stroke.

  Authors: A Chatzikonstantinou, R Krissak, S Flüchter, D Artemis, A Schaefer, S O Schoenberg, M G Hennerici, C Fink

  Cerebrovascular diseases (Basel, Switzerland). 02/2012; 33(4):322-328.

  Background: The etiology of ischemic strokes remains cryptogenic in about one third of patients, even after extensive workup in specialized centers. Atherosclerotic plaques in the aorta can causeBackground: The etiology of ischemic strokes remains cryptogenic in about one third of patients, even after extensive workup in specialized centers. Atherosclerotic plaques in the aorta can cause thromboembolic events but are often overlooked. They can elude standard identification by transesophageal echocardiography (TEE), which is invasive or at best uncomfortable for many patients. CT angiography (CTA) can be used as an alternative or in addition to TEE if this technique fails to visualize every part of the aorta and in particular the aortic arch. Methods: We prospectively studied 64 patients (47 men, age 60 ± 13 years) classified as having cryptogenic stroke after standard and full workup [including brain MRI and 24-hour electrocardiogram (ECG)] with ECG-triggered CTA of the aorta in search of plaques and compared the results with those of TEE. Investigators were blinded to the results of both techniques. Plaques were graded on CTA according to their presence (0 = not present; 1 = mild; 2 = severe) and degree of calcification (1a or 2a = noncalcified; 1b or 2b = calcified). Associations with risk factors and infarct localization were also assessed. Results: Only 21 of 64 patients (32.8%) had aortic plaques identified by TEE, compared to 43 of 64 (67.2%) with CTA (p < 0.05). The plaque localization was as follows (TEE vs. CTA): ascending aorta, 10 vs. 20 (p < 0.05); aortic arch, 10 vs. 40 (p < 0.05), and descending aorta, 20 vs. 34 (p < 0.05). Grade 1 plaques were most commonly found in the aortic arch (25; 39%), while grade 2 plaques were most often detected in the aortic arch (15; 23.4%) and the descending aorta (14; 21.9%). There was no significant correlation between plaque location, infarct territory or vascular risk profile, except for hypertension (p = 0.003), which was significantly associated with the presence of plaques. Conclusions: CTA identifies more plaques throughout the aortic arch and around the origins of the major cerebral arteries in particular compared to TEE. These may represent potential embolic sources of acute ischemic stroke. Better plaque detection may have an impact on the best available secondary prevention regimen in individual patients if proximal embolic sources are suspected.

• Insights into the location of type I ECG in patients with Brugada syndrome: Correlation of ECG and cardiovascular magnetic resonance imaging.

  Authors: C Veltmann, T Papavassiliu, T Konrad, C Doesch, J Kuschyk, F Streitner, D Haghi, H J Michaely, S O Schoenberg, M Borggrefe, C Wolpert, R Schimpf

  Heart rhythm : the official journal of the Heart Rhythm Society. 11/2011; 9(3):414-21.

  Brugada syndrome is characterized by ST-segment abnormalities in V1-V3. Electrocardiogram (ECG) leads placed in the 3rd and 2nd intercostal spaces (ICSs) increased the sensitivity for the detectionBrugada syndrome is characterized by ST-segment abnormalities in V1-V3. Electrocardiogram (ECG) leads placed in the 3rd and 2nd intercostal spaces (ICSs) increased the sensitivity for the detection of a type I ECG pattern. The anatomic explanation for this finding is pending. The purpose of the study was to correlate the location of the Brugada type I ECG with the anatomic location of the right ventricular outflow tract (RVOT). Twenty patients with positive ajmaline challenge and 10 patients with spontaneous Brugada type I ECG performed by using 12 right precordial leads underwent cardiovascular magnetic resonance imaging (CMRI). The craniocaudal and lateral extent of the RVOT and maximal RVOT area were determined. Type I ECG pattern and maximal ST-segment elevation were correlated to extent and maximal RVOT area, respectively. In all patients, Brugada type I pattern was found in the 3rd ICS in sternal and left-parasternal positions. RVOT extent determined by using CMRI included the 3rd ICS in all patients. Maximal RVOT area was found in 3 patients in the 2nd ICS, in 5 patients in the 4th ICS, and in 22 patients in the 3rd ICS. CMRI predicted type I pattern with a sensitivity of 97.2%, specificity of 91.7%, positive predictive value of 88.6%, and negative predictive value of 98.0%. Maximal RVOT area coincided with maximal ST-segment elevation in 29 of 30 patients. RVOT localization determined by using CMRI correlates highly with the type I Brugada pattern. Lead positioning according to RVOT location improves the diagnosis of Brugada syndrome.

• Pulmonary embolism: ct signs and cardiac biomarkers for predicting right ventricular dysfunction.

  Authors: T Henzler, S Roeger, M Meyer, U J Schoepf, J W Nance, D Haghi, W E Kaminski, M Neumaier, S O Schoenberg, C Fink

  The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology. 09/2011;

  To prospectively evaluate the accuracy of quantitative cardiac CT parameters and two cardiac biomarkers (NT-pro-Brain Natriuretic Peptide (NT-pro-BNP); troponin I), alone and in combination, forTo prospectively evaluate the accuracy of quantitative cardiac CT parameters and two cardiac biomarkers (NT-pro-Brain Natriuretic Peptide (NT-pro-BNP); troponin I), alone and in combination, for predicting right ventricular dysfunction (RVD) in patients with acute pulmonary embolism (PE).557 consecutive patients with suspected PE underwent pulmonary CTA. Patients with PE also underwent echocardiography and NT-pro-BNP/troponin I serum level measurements. 3 different CT measurements were obtained (RV/LVaxial, RV/LV4-CH), and RV/LVvolume). CT measurements and NT-pro-BNP/troponin I serum levels were correlated with RVD at echocardiography.Patients with RVD (n=77) showed significantly higher RV/LV ratios and NT-pro-BNP/troponin I levels compared to those without RVD (RV/LVaxial 1.68±0.84 vs. 1.00±0.21; RV/LV4ch 1.52±0.45 vs. 1.01±0.21; RV/LVvolume 1.97±0.53 vs. 1.07±0.52; serum NT-pro-BNP 6372±2319 vs. 1032±1559 ng·L(-1); troponin I 0.18±0.41 vs. 0.06±0.18). The area under the curve for the detection of RVD of RV/LVaxial, RV/LV4Ch, RV/LVvolume, NT-pro-BNP and troponin I were 0.84, 0.87, 0.93, 0.83 and 0.70 respectively. The combination of biomarkers and RV/LVvolume increased the AUC to 0.95 (RV/LVvolume with NT-pro-BNP) and 0.93 (RV/LVvolume with troponin I).RV/LVvolume is the most accurate CT parameter for identifying patients with RVD. A combination of RV/LVvolume with NT-pro-BNP or troponin I measurements improves the diagnostic accuracy of either test alone.

• Correlation of CT angiographic pulmonary artery obstruction scores with right ventricular dysfunction and clinical outcome in patients with acute pulmonary embolism.

  Authors: P Apfaltrer, T Henzler, M Meyer, S Roeger, D Haghi, J Gruettner, T Süselbeck, R B Wilson, U J Schoepf, S O Schoenberg, C Fink

  European journal of radiology. 09/2011;

  OBJECTIVE: To correlate CTA pulmonary artery obstruction scores (OS) with right ventricular dysfunction (RVD) and clinical outcome in patients with acute pulmonary embolism (PE). MATERIALS ANDOBJECTIVE: To correlate CTA pulmonary artery obstruction scores (OS) with right ventricular dysfunction (RVD) and clinical outcome in patients with acute pulmonary embolism (PE). MATERIALS AND METHODS: In a prospective study of 50 patients (66±12.9 years) with PE pulmonary artery OS (Qanadli, Mastora, and Mastora central) were assessed by two radiologists. To assess RVD all patients underwent echocardiography within 24h. Furthermore, RVD on CT was assessed by calculating the right ventricular/left ventricular (RV/LV) diameter ratios on transverse (RV/LVtrans) and four-chamber views (RV/LV4ch) as well as the RV/LV volume ratio (RV/LVvol). OS were correlated with RVD and the occurrence of adverse clinical outcomes (defined as death, need for intensive care treatment, or cardiac insufficiency ≥NYHA III). RESULTS: Mean Mastora, Qanadli, and Mastora central OS were 26.4±17.7, 12.6±9.9 and 7.5±9, respectively. Echocardiography demonstrated moderate and severe RVD in 10 and 5 patients, respectively. Patients with moderate and severe RVD showed significantly higher Mastora central scores than patients without RVD (14±10.8 vs. 5.9±7.8 [p=0.05]; 17.6±13.2 vs. 5.9±7.8 [p=0.038]). A relevant correlation (i.e. r≥0.6) between OS and CT parameters for RVD were only found for the Mastora score and the Mastora central score (RV/LV4ch: r=0.61 and 0.68, RV/LVvol: r=0.61 and 0.6). 18 patients experienced an adverse clinical outcome. None of the OS differed significantly between patients with and without adverse clinical outcome. CONCLUSION: Pulmonary artery obstruction scores can differentiate between patients with and without RVD. However, in this study, obstruction scores were not correlated to adverse clinical outcome.

• Functional imaging of lung cancer using dual energy CT: how does iodine related attenuation correlate with standardized uptake value of 18FDG-PET-CT?

  Authors: G Schmid-Bindert, Thomas Henzler, T Q Chu, M Meyer, J W Nance, U J Schoepf, D J Dinter, P Apfaltrer, R Krissak, C Manegold, S O Schoenberg, C Fink

  European radiology. 08/2011; 22(1):93-103.

  To investigate the correlation between maximum standardized uptake value (SUV(max)) of (18)FDG PET-CT and iodine-related attenuation (IRA) of dual energy CT (DECT) of primary tumours and (18)FDGTo investigate the correlation between maximum standardized uptake value (SUV(max)) of (18)FDG PET-CT and iodine-related attenuation (IRA) of dual energy CT (DECT) of primary tumours and (18)FDG PET-CT positive thoracic lymph nodes (LN) in patients with lung cancer. 37 patients with lung cancer (27 NSCLC, 10 SCLC, 86 (18)FDG PET-CT positive thoracic LN) who underwent both (18)FDG PET-CT and DECT were analyzed. The mean study interval between (18)FDG PET-CT and DECT was ≤21 days in 17 patients. The mean and maximum IRA of DECT as well as of virtual unenhanced and virtual 120 kV images of DECT was analyzed and correlated to the SUV(max) of (18)FDG PET-CT in all tumours and (18)FDG PET-CT positive thoracic lymph nodes. Further subgroup analysis was performed for histological subtypes in all groups. A moderate correlation was found between SUV(max) and maximum IRA in all tumours (n = 37;r = 0.507;p = 0.025) whereas only weak or no correlation were found between SUV(max) and all other DECT measurements. A strong correlation was found in patients with study intervals ≤21 days (n = 17; r = 0.768;p = 0.017). Analysis of histological subtypes of lung cancer showed a strong correlation between SUV(max) and maximum IRA in the analysis of all patients with NSCLC (r = 0.785;p = 0.001) and in patients with NSCLC and study intervals ≤21 days (r = 0.876;p = 0.024). Thoracic LN showed moderate correlation between SUV(max) and maximum IRA in patients with study intervals ≤21 days (r = 0.654; p = 0.010) whereas a weak correlation was found between SUV(max) and maximum IRA in patients with study intervals >21 days (r = 0.299; p = 0.035). DECT could serve as a valuable functional imaging test for patients with NSCLC as the IRA of DECT correlates with SUV(max) of (18)FDG PET-CT.

• Do structural changes in the tumour bed after intraoperative radiotherapy (IORT) of breast cancer complicate the evaluation of mammograms in a long-term follow-up?

  Authors: K Wasser, M Ruch, J Brade, C Schoeber, U Kraus-Tiefenbacher, A Schnitzer, D Engel, F Wenz, M Sütterlin, S O Schoenberg, K A Buesing

  European journal of radiology. 03/2011; 81(3):e255-9.

  The purpose of the study was to assess whether postoperative changes in the tumour bed after intraoperative radiotherapy (IORT) with low-energy X-rays complicate the mammographic evaluation. 54The purpose of the study was to assess whether postoperative changes in the tumour bed after intraoperative radiotherapy (IORT) with low-energy X-rays complicate the mammographic evaluation. 54 patients receiving breast-conserving surgery and IORT were compared to a control group of 48 patients with conventional breast-conserving treatment. All patients were included in routine follow-ups (≥3 years) with mammography accompanied by ultrasound. By retrospective consensus reading the mammographic changes in the tumour bed were classified as absent, low or distinct. Using the same grading it was classified whether mammographic evaluation was complicated due to postoperative changes. Focusing the yearly follow-ups within a period of four years, distinct changes were found significantly more often after IORT (52-62% vs. 7-30%). After IORT the evaluation was significantly more often distinctly complicated in each follow-up, except for year 1 (16-21% vs. 0-8%). In the IORT group the distribution of findings was nearly stable over time. In the control group it changed over time and a distinctly complicated evaluation was no longer seen in the follow-ups of years 3 and 4. Overall, further non-routine diagnostic procedures due to unclear findings in the tumour bed became necessary in 7% (IORT) vs. 8% (control group) of the patients (p=0.86). Evaluation of mammograms is complicated after IORT. In contrast to conventionally treated patients postoperative changes and difficulties of evaluation do not decrease over time. Overall, after IORT the diagnostic uncertainty does not seem to be increased in ultrasound supported mammographic follow-ups. The topic needs further evaluation with larger study samples.

• Oxygen-enhanced MRI of the lungs: intraindividual comparison between 1.5 and 3 tesla.

  Authors: S F Thieme, O Dietrich, D Maxien, K Nikolaou, S O Schoenberg, M Reiser, C Fink

  RöFo : Fortschritte auf dem Gebiete der Röntgenstrahlen und der Nuklearmedizin. 02/2011; 183(4):358-64.

  To assess the feasibility of oxygen-enhanced MRI of the lung at 3 Tesla and to compare signal characteristics with 1.5 Tesla. 13 volunteers underwent oxygen-enhanced lung MRI at 1.5 and 3 T with a TTo assess the feasibility of oxygen-enhanced MRI of the lung at 3 Tesla and to compare signal characteristics with 1.5 Tesla. 13 volunteers underwent oxygen-enhanced lung MRI at 1.5 and 3 T with a T 1-weighted single-slice non-selective inversion-recovery single-shot half-Fourier fast-spin-echo sequence with simultaneous respiratory and cardiac triggering in coronal orientation. 40 measurements were acquired during room air breathing and subsequently during oxygen breathing (15 L/min, close-fitting face-mask). The signal-to-noise ratio (SNR) of the lung tissue was determined with a difference image method. The image quality of all acquisitions was visually assessed. The mean values of the oxygen-induced relative signal enhancement and its regional coefficient of variation were calculated and the signal enhancement was displayed as color-coded parameter maps. Oxygen-enhancement maps were visually assessed with respect to the distribution and heterogeneity of the oxygen-related signal enhancement at both field strengths. The mean relative signal enhancement due to oxygen breathing was 13 % (± 5.6 %) at 1.5 T and of 9.0 % (± 8.0 %) at 3 T. The regional coefficient of variation was significantly higher at 3 T. Visual and quantitative assessment of the enhancement maps showed considerably less homogeneous distribution of the signal enhancement at 3 T. The SNR was not significantly different but showed a trend to slightly higher values (increase of about 10 %) at 3 T. Oxygen-enhanced pulmonary MRI is feasible at 3 Tesla. However, signal enhancement is currently more heterogeneous and slightly lower at 3 T.

• Comparison of a new whole-body continuous-table-movement protocol versus a standard whole-body MR protocol for the assessment of multiple myeloma.

  Authors: S Weckbach, H J Michaely, A Stemmer, S O Schoenberg, D J Dinter

  European radiology. 12/2010; 20(12):2907-16.

  To evaluate a whole body (WB) continuous-table-movement (CTM) MR protocol for the assessment of multiple myeloma (MM) in comparison to a step-by-step WB protocol. Eighteen patients with MM wereTo evaluate a whole body (WB) continuous-table-movement (CTM) MR protocol for the assessment of multiple myeloma (MM) in comparison to a step-by-step WB protocol. Eighteen patients with MM were examined at 1.5T using a WB CTM protocol (axial T2-w fs BLADE, T1-w GRE sequence) and a step-by-step WB protocol including coronal/sagittal T1-w SE and STIR sequences as reference. Protocol time was assessed. Image quality, artefacts, liver/spleen assessability, and the ability to depict bone marrow lesions less than or greater than 1 cm as well as diffuse infiltration and soft tissue lesions were rated. Potential changes in the Durie and Salmon Plus stage and the detectability of complications were assessed. Mean protocol time was 6:38 min (CTM) compared to 24:32 min (standard). Image quality was comparable. Artefacts were more prominent using the CTM protocol (P = 0.0039). Organ assessability was better using the CTM protocol (P < 0.001). Depiction of bone marrow and soft tissue lesions was identical without a staging shift. Vertebral fractures were not detected using the CTM protocol. The new protocol allows a higher patient throughput and facilitates the depiction of extramedullary lesions. However, as long as vertebral fractures are not detectable, the protocol cannot be safely used for clinical routine without the acquisition of an additional sagittal sequence.

• [Non-invasive imaging modalities for preoperative axillary lymph node staging in patients with breast cancer].

  Authors: K Wasser, A Schnitzer, J Brade, S O Schoenberg

  Der Radiologe. 11/2010; 50(11):1022-9.

  In the last decade sentinel lymph node biopsy has become a well-established method for axillary lymph node staging in patients with breast cancer. Using preoperative imaging modalities it can beIn the last decade sentinel lymph node biopsy has become a well-established method for axillary lymph node staging in patients with breast cancer. Using preoperative imaging modalities it can be tested whether patients are suitable for sentinel node biopsy or if they should directly undergo an axillary dissection. The imaging modalities used must be mainly characterized by a high positive predictive value (PPV). For this question B-mode ultrasound is the best evaluated method and provides clear morphological signs for a high PPV (>90%) but the sensitivity barely exceeds 50%. It has not yet been proven whether other modalities such as duplex sonography, magnetic resonance imaging, computed tomography (CT) or scintigraphy might achieve a higher sensitivity while still maintaining a high PPV. There is only some evidence that positron emission tomography (PET) might achieve a higher sensitivity. This should be confirmed by further studies because PET or PET/CT will play an increasing role for an initial whole body staging in patients with breast cancer in the near future.

• "Number needed to read"--how to facilitate clinical trials in MR-angiography.

  Authors: M Voth, U I Attenberger, A Luckscheiter, S Haneder, T Henzler, S O Schoenberg, C Schwenke, H J Michaely

  European radiology. 10/2010; 21(5):1034-42.

  To evaluate the effect of the number of readers on the statistical results in peripheral MRA. 40 patients with peripheral arterial occlusive disease were included as a sample dataset in this study,To evaluate the effect of the number of readers on the statistical results in peripheral MRA. 40 patients with peripheral arterial occlusive disease were included as a sample dataset in this study, randomly separated into two matched groups with n = 20 patients (group 1--gadobutrol, group 2--gadoterate meglumine) who underwent a continuous table movement MRA of the peripheral vessels at 3 T. Image quality (IQ) of 17 vessel segments was evaluated by 5 independent readers. The effect of the number of readers on significance and statistical power was statistically analyzed. Image quality in group 1 (gadobutrol) ranks significantly higher compared to group 2 (gadoterade meglumine) with a diagnostic IQ in 97% vs. 78% (p < 0.0001). For the diagnostic/non-diagnostic IQ assessment significance was reached with one reader 1/5 times (20%), with two readers in 4/10 (40%), with three readers in 6/10 (60%), with four readers in 4/5 (80%), with five readers in 1/1 (100%). Power considerations showed considerable gain when increasing the number of readers. Increasing the number of readers in a diagnostic MRA-study can be used to achieve a higher power or to decrease the number of subjects included with maintained statistical validity.

• [Imaging diagnostics of the prostate].

  Authors: D J Dinter, A M Weidner, F Wenz, A E Pelzer, M S Michel, S O Schoenberg

  Der Urologe. Ausg. A. 08/2010; 49(8):963-75.

  Prostate cancer is the most common malignancy of men with approximately 32,000 new cases of prostate cancer in Germany and approximately 11,000 men who would die of the disease each year. For earlyProstate cancer is the most common malignancy of men with approximately 32,000 new cases of prostate cancer in Germany and approximately 11,000 men who would die of the disease each year. For early diagnosis of prostate cancer PSA testing is used, whereas at present screening cannot be recommended due to the lack of confirmed medical and economic benefits. Regarding the imaging modalities, ultrasound of the prostate, currently performed in combination with elastography and histoscanning, magnetic resonance imaging of the prostate in combination with endorectal coils and positron emission tomography combined with computed tomography (PET-CT) are the methods of choice. Using these methods benign prostatitis can be differentiated from prostate cancer and staging of the tumor can be accomplished. On the other hand using these imaging methods it is possible to define the dominant intraprostatic lesion with different sensitivities and specificities, which is important for minimally invasive therapeutic strategies.

• [Diagnostically relevant craniocervical vascular injury in trauma room CT : Results of an inter-observer comparison.]

  Authors: S Jochum, C Brockmann, S J Diehl, D Baake, U Obertacke, S O Schoenberg, D J Dinter

  Der Unfallchirurg. 04/2010;

  PURPOSE: Injuries of the craniocervical vessels in multi-traumatized patients are rare but devastating and can lead to stroke and death; nevertheless the diagnostic assessment of these injuries isPURPOSE: Injuries of the craniocervical vessels in multi-traumatized patients are rare but devastating and can lead to stroke and death; nevertheless the diagnostic assessment of these injuries is often not part of the CT trauma examination protocol. MATERIALS AND METHODS: A total of 44 out of 315 multi-traumatized patients were defined to be at high risk for vessel injuries. Two readers analyzed the CT angiography (CTA) with respect to 1.) type and extent of fractures and 2.) trauma-associated pathologies of the vessels from the aortic arch to the cerebrum. The CTs were presented as original scans with the possibility to view the multiplanar reconstructions. RESULTS: The two readers could detect 12 out of 14 and 14 out of 14 cervical fractures, respectively. Both readers could demonstrate 28 out of 28 fractures of the skull, skull base and extended facial fractures. The diagnostic evaluation of vessel diseases showed correct classification of the type of pathology in 8 out of 12 and 7 out of 12 cases for the two readers, respectively. CONCLUSIONS: CTA of the craniocervical vessels is an important tool for rapid detection of vessel injuries and diseases in trauma patients. Different types of fractures may indicate the need for focused attention to vessel injuries, but even if there are no fractures present dissection of internal carotid and vertebral arteries can occur.

• First multimodal embolization particles being visible in MRI and CT

  Authors: S.H. Bartling, J. Budjan, H. Aviv, H.J. Michaely, W. Semmler, S.O. Schoenberg, S. Diehl, S. Margel, M. Sadick

  ECR 2010, Vienna; 03/2010

  Purpose: To develop and test the first multimodal embolization particles being visible within CT and MRI. Its usage might be beneficial within multimodality angiography setups, therapy control,Purpose: To develop and test the first multimodal embolization particles being visible within CT and MRI. Its usage might be beneficial within multimodality angiography setups, therapy control, long-term follow-up of embolization therapy, future transition to interventional MRI and research of novel embolization concepts. Methods and Materials: CT visible iodine was combined with MRI visible iron in a macroparticle (diameter 50-250 µm). Its core - consisting of copolymerized monomer MAOETIB [2-methacryloyloxyethyl(2,3,5-triiodobenzoate)] - was coated with paramagnetic iron oxide nanoparticles (USPIO). After ex-vivo testing, including SNR measurements (n=5), its ability to embolize tissue was tested in an established tumor embolization model in rats (2) and rabbits (5). X-ray angiography, CT and MR imaging was performed on clinical scanners (Dual-source Definition CT, 3 Tesla Magnetom Tim Trio MRI, Siemens) before, during and after application of particles to the catheterized renal artery. Histology was prepared. Results: The particles provided a sufficient image contrast in both CT (SNR: 14±4) and MRI (SNR: 14±1). Successful embolization of renal tissue was confirmed by particles residing within the kidney as seen in corresponding areas in MRI and CT. Histology allowed a direct visualization of the residing particles as well as associated thrombosis in kidney arteries. Successful embolization was confirmed by inflammation and necrosis in treated kidneys while the control kidneys were unaltered. Conclusion: A multimodality embolization material was successfully developed and tested in animal models. Its consistence of clinically used substances might ease approval.

• Image quality of T2w-TSE of the abdomen and pelvis with Cartesian or BLADE-type k-space sampling: a retrospective interindividual comparison study.

  Authors: S Haneder, D Dinter, A Gutfleisch, S O Schoenberg, H J Michaely

  European journal of radiology. 02/2010; 79(2):177-82.

  The purpose of this study was to evaluate the image quality of T2-weighted (T2w) imaging of the abdomen and pelvis based on the acquisition of rotating rectangular stripes of k-space data afterThe purpose of this study was to evaluate the image quality of T2-weighted (T2w) imaging of the abdomen and pelvis based on the acquisition of rotating rectangular stripes of k-space data after successive radiofrequency excitation (BLADE technique) in comparison to T2w turbo-spin-echo (TSE) sequences with Cartesian k-space sampling. A total number of 107 patients with MR imaging of the abdomen or the pelvis were included in this retrospective interindividual study. All exams were performed in the clinical routine at 1.5T. The T2w images were randomly performed in BLADE technique or as TSE sequences. Two blinded radiologists assessed the images, presented in a random order, concerning the delineation of the abdominal and the musculoskeletal structures, the artifacts of these structures, and the overall image qualities. For the abdomen the mean overall image quality of the T2w-BLADE was rated 3.2 vs. 3.1 for T2w-TSE (p=0.871). The mean musculoskeletal/visceral artifacts of the T2w-BLADE were scored as 2.9/3.0 vs. 3.2/2.6 for the T2w-TSE (p=0.101/p=0.051). The delineation of the musculoskeletal, respectively of the visceral structures was assessed for the T2w-BLADE as 3.0/3.4 vs. 3.2/3.1 for the T2w-TSE (p=0.263; p=0.185). For the pelvis the mean overall image quality of the T2w-BLADE was 3.4 vs. 2.9 for the T2w-TSE (p=0.005). Furthermore the musculoskeletal/visceral artifacts were assessed with a mean of 3.6/3.3 for the T2w-BLADE vs. 3.0/2.8 for the T2w-TSE (p=0.005; p=0.011). The musculoskeletal/visceral delineation of the T2w-BLADE was rated 3.6/3.4 vs. 3.0/2.8 for the T2w-TSE sequence (p<0.001; p=0.008). In imaging of the pelvis the overall quality of T2w sequences with k-space sampling in BLADE technique was rated significantly superior compared with the standard Cartesian sampling. Similar results were assessed for the reduction of the amount of artifacts and blurring. By contrast, no significant benefit could be demonstrated for the T2w-BLADE in the abdomen.

• Non-invasive measurement of cardiac output during atrial fibrillation: comparison between cardiac magnetic resonance imaging and inert gas rebreathing.

  Authors: J Saur, F Trinkmann, C Doesch, J Weissmann, K Hamm, S O Schoenberg, M Borggrefe, D Haghi, J J Kaden

  Cardiology. 02/2010; 115(3):212-6.

  Atrial fibrillation (AF) is one of the most frequent heart rhythm disorders. It potentially influences cardiac function and its measurement. Cardiac magnetic resonance imaging (CMR) has become theAtrial fibrillation (AF) is one of the most frequent heart rhythm disorders. It potentially influences cardiac function and its measurement. Cardiac magnetic resonance imaging (CMR) has become the new gold standard for non-invasive assessment of cardiac output (CO). A novel inert gas rebreathing (IGR) device based on the Fick Principle also proved promising in patients in sinus rhythm (SR). The aim of our study was to compare the agreement of non-invasive CO measurements between CMR and IGR in AF patients. A total of 68 patients, 34 with AF and 34 pair-matched controls in SR, were included. Bland-Altman analysis showed good agreement between both methods, with an average deviation of 0.2 +/-1.2 l/min in the AF group versus 0.3 +/-1.0 l/min in the SR group (p = 0.77). IGR demonstrated good agreement for CO between 2.0 and 5.4 l/min. However, in hyperdynamic circulatory conditions (CO >5.5 l/min), the increasing disagreement of IGR and CMR measurements reached statistical significance. Non-invasive CO measurements using CMR and IGR are feasible in patients suffering from AF. Good agreement was found between the two methods in an unselected cohort. Hyperdynamic circulatory conditions can lead to significant measurement differences which, however, do not affect the reproducibility of IGR.

• Graph-Matching Based CTA

  Authors: D. Maksimov, J. Hesser, C. Brockmann, S. Jochum, T. Dietz, A. Schnitzer, C. Duber, S.O. Schoenberg, S. Diehl

  Medical Imaging, IEEE Transactions on. 01/2010;

  Separating bone, calcification, and vessels in computer tomography angiography (CTA) allows for a detailed diagnosis of vessel stenosis. This paper presents a new, graph-based technique that solvesSeparating bone, calcification, and vessels in computer tomography angiography (CTA) allows for a detailed diagnosis of vessel stenosis. This paper presents a new, graph-based technique that solves this difficult problem with high accuracy. The approach requires one native data set and one that is contrast enhanced. On each data set, an attributed level-graph is derived and both graphs are matched by dynamic programming to differentiate between bone, on one hand side, and vessel/calcification on the other hand side. Lumen and calcified regions are then separated by a profile technique. Evaluation is based on data from vessels of pelvis and lower extremities of elderly patients. Due to substantial calcification and motion of patients between and during the acquisitions, the underlying approach is tested on a class of difficult cases. Analysis requires 3-5 min on a Pentium IV 3 GHz for a 700 MByte data set. Among 37 patients, our approach correctly identifies all three components in 80% of cases correctly compared to visual control. Critical inconsistencies with visual inspection were found in 6% of all cases; 70% of these inconsistencies are due to small vessels that have 1) a diameter near the resolution of the CT and 2) are passing next to bony structures. All other remaining deviations are found in an incorrect handling of the iliac artery since the slice thickness is near the diameter of this vessel and since the orientation is not in cranio-caudal direction. Increasing resolution is thus expected to solve many the aforementioned difficulties.