P Apfaltrer

Publications of P Apfaltrer

• 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.

• Coronary computed tomography--present status and future directions.

  Authors: P Apfaltrer, U J Schoepf, R Vliegenthart, G W Rowe, J R Spears, C Fink, J W Nance

  International journal of clinical practice. Supplement. 10/2011;

  The use of coronary computed tomography angiography (cCTA) is growing rapidly, in large part because of fast-paced technical innovations that have increased diagnostic accuracy while providing newThe use of coronary computed tomography angiography (cCTA) is growing rapidly, in large part because of fast-paced technical innovations that have increased diagnostic accuracy while providing new opportunities for radiation dose reduction. cCTA using recent generation CT scanners has been repeatedly shown to have excellent negative predictive value for ruling out significant coronary stenosis in comparison with invasive coronary angiography (ICA) and is now accepted for this use in selected populations. Current work is increasingly focused on evaluating and optimising radiation dose reduction techniques, the cost-effectiveness of cCTA implementation, and the impact of cCTA on patient management and outcomes. In addition, the potential value of emerging applications, such as atherosclerotic plaque characterisation and myocardial perfusion and viability assessment, are undergoing intense investigation.

• 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.

• Coronary computed tomography--present status and future directions

  Authors: P. Apfaltrer, U. J. Schoepf, R. Vliegenthart, G. W. Rowe, J. R. Spears, C. Fink, J. W. Nance

  Int J Clin Pract Suppl.

  The use of coronary computed tomography angiography (cCTA) is growing rapidly, in large part because of fast-paced technical innovations that have increased diagnostic accuracy while providing newThe use of coronary computed tomography angiography (cCTA) is growing rapidly, in large part because of fast-paced technical innovations that have increased diagnostic accuracy while providing new opportunities for radiation dose reduction. cCTA using recent generation CT scanners has been repeatedly shown to have excellent negative predictive value for ruling out significant coronary stenosis in comparison with invasive coronary angiography (ICA) and is now accepted for this use in selected populations. Current work is increasingly focused on evaluating and optimising radiation dose reduction techniques, the cost-effectiveness of cCTA implementation, and the impact of cCTA on patient management and outcomes. In addition, the potential value of emerging applications, such as atherosclerotic plaque characterisation and myocardial perfusion and viability assessment, are undergoing intense investigation.

• 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. Suselbeck, R. B. Wilson, U. J. Schoepf, S. O. Schoenberg, C. Fink

  Eur J Radiol.

  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.

• Contrast-enhanced dual-energy CT of gastrointestinal stromal tumors: is iodine-related attenuation a potential indicator of tumor response?

  Authors: P. Apfaltrer, M. Meyer, C. Meier, T. Henzler, J. M. Barraza, D. J. Dinter, P. Hohenberger, U. J. Schoepf, S. O. Schoenberg, C. Fink

  Invest Radiol. 47(1):65-70.

  OBJECTIVES: To assess the correlation of true nonenhanced (TNE) and virtually nonenhanced (VNE) images of abdominal dual-energy computed tomography (DECT) in patients with metastatic gastrointestinalOBJECTIVES: To assess the correlation of true nonenhanced (TNE) and virtually nonenhanced (VNE) images of abdominal dual-energy computed tomography (DECT) in patients with metastatic gastrointestinal stromal tumors (GIST), and further to investigate the correlation of iodine-related attenuation (IRA) of DECT with the Choi criteria. MATERIAL AND METHODS: Twenty-four consecutive patients (5 women aged 61 +/- 10 years) with metastatic GIST underwent DECT of the abdomen (80 kV, 140 kV) using first-generation dual-source computed tomography (CT). All patients had at least one or more liver lesions (median, 4; maximum, 9). Image data were processed with a dedicated DECT software algorithm designed for evaluation of iodine distribution in soft tissue lesions, and VNE CT images were generated. The tumor density (according to Choi criteria) and the maximum transverse diameter of the lesions (according to Response Evaluation Criteria in Solid Tumors [RECIST]) were determined. TNE and VNE lesion attenuation and Choi criteria and IRA were correlated with each other. RESULTS: A total of 291 liver lesions were evaluated, of which 220 were cystic and 71 were solid. The mean lesion size was 4.5 +/- 3.2 cm (1.1-18.7 cm). The mean attenuation of all lesions was significantly higher in the TNE images than in the VNE images (P=0.0001). Pearson statistics revealed an excellent correlation of r=0.843 (P=0.0001) between IRA and Choi criteria for all lesions. DECT showed significantly higher IRA in progressive (23.3 +/- 9.5 HU) lesions compared with stable or regressive (17.8 +/- 9.1 HU) lesions (P=0.0185). Similarly, the Choi criteria differed significantly between progressive (39.9 +/- 12.8 HU) and stable/regressive (31.1 +/- 10.3 HU) lesions (P=0.0003). CONCLUSIONS: DECT is a promising imaging method for the assessment of treatment response in GIST, as IRA might be a more robust response parameter than the Choi criteria. VNE CT data calculated from DECT may eliminate the need for acquisition of a separate unenhanced data set.

• Contrast-enhanced dual-energy CT of gastrointestinal stromal tumors: is iodine-related attenuation a potential indicator of tumor response?

  Authors: P. Apfaltrer, M. Meyer, C. Meier, T. Henzler, J. M. Barraza, D. J. Dinter, P. Hohenberger, U. J. Schoepf, S. O. Schoenberg, C. Fink

  Invest Radiol. 47(1):65-70.

  OBJECTIVES: To assess the correlation of true nonenhanced (TNE) and virtually nonenhanced (VNE) images of abdominal dual-energy computed tomography (DECT) in patients with metastatic gastrointestinalOBJECTIVES: To assess the correlation of true nonenhanced (TNE) and virtually nonenhanced (VNE) images of abdominal dual-energy computed tomography (DECT) in patients with metastatic gastrointestinal stromal tumors (GIST), and further to investigate the correlation of iodine-related attenuation (IRA) of DECT with the Choi criteria. MATERIAL AND METHODS: Twenty-four consecutive patients (5 women aged 61 +/- 10 years) with metastatic GIST underwent DECT of the abdomen (80 kV, 140 kV) using first-generation dual-source computed tomography (CT). All patients had at least one or more liver lesions (median, 4; maximum, 9). Image data were processed with a dedicated DECT software algorithm designed for evaluation of iodine distribution in soft tissue lesions, and VNE CT images were generated. The tumor density (according to Choi criteria) and the maximum transverse diameter of the lesions (according to Response Evaluation Criteria in Solid Tumors [RECIST]) were determined. TNE and VNE lesion attenuation and Choi criteria and IRA were correlated with each other. RESULTS: A total of 291 liver lesions were evaluated, of which 220 were cystic and 71 were solid. The mean lesion size was 4.5 +/- 3.2 cm (1.1-18.7 cm). The mean attenuation of all lesions was significantly higher in the TNE images than in the VNE images (P=0.0001). Pearson statistics revealed an excellent correlation of r=0.843 (P=0.0001) between IRA and Choi criteria for all lesions. DECT showed significantly higher IRA in progressive (23.3 +/- 9.5 HU) lesions compared with stable or regressive (17.8 +/- 9.1 HU) lesions (P=0.0185). Similarly, the Choi criteria differed significantly between progressive (39.9 +/- 12.8 HU) and stable/regressive (31.1 +/- 10.3 HU) lesions (P=0.0003). CONCLUSIONS: DECT is a promising imaging method for the assessment of treatment response in GIST, as IRA might be a more robust response parameter than the Choi criteria. VNE CT data calculated from DECT may eliminate the need for acquisition of a separate unenhanced data set.

• 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. Suselbeck, R. B. Wilson, U. J. Schoepf, S. O. Schoenberg, C. Fink

  Eur J Radiol.

  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.

• Coronary computed tomography--present status and future directions

  Authors: P. Apfaltrer, U. J. Schoepf, R. Vliegenthart, G. W. Rowe, J. R. Spears, C. Fink, J. W. Nance

  Int J Clin Pract Suppl.

  The use of coronary computed tomography angiography (cCTA) is growing rapidly, in large part because of fast-paced technical innovations that have increased diagnostic accuracy while providing newThe use of coronary computed tomography angiography (cCTA) is growing rapidly, in large part because of fast-paced technical innovations that have increased diagnostic accuracy while providing new opportunities for radiation dose reduction. cCTA using recent generation CT scanners has been repeatedly shown to have excellent negative predictive value for ruling out significant coronary stenosis in comparison with invasive coronary angiography (ICA) and is now accepted for this use in selected populations. Current work is increasingly focused on evaluating and optimising radiation dose reduction techniques, the cost-effectiveness of cCTA implementation, and the impact of cCTA on patient management and outcomes. In addition, the potential value of emerging applications, such as atherosclerotic plaque characterisation and myocardial perfusion and viability assessment, are undergoing intense investigation.