Christian Zechmann
Research interests
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InterestsProstate Cancer, Breast Cancer, MRI, MRSI
Publications
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2.09Impact points
Automated vs. Manual Pattern Recognition of 3D (1)H MRSI Data of Patients with Prostate Cancer.
Academic radiology. 06/2012; 19(6):675-84.
The aim of this study was to assess (1) automated analysis methods versus manual evaluation by human experts of three-dimensional proton magnetic resonance spectroscopic imaging (MRSI) data from patients with prostate cancer and (2) the contribution of spatial information to decision making. Three-d... [more] The aim of this study was to assess (1) automated analysis methods versus manual evaluation by human experts of three-dimensional proton magnetic resonance spectroscopic imaging (MRSI) data from patients with prostate cancer and (2) the contribution of spatial information to decision making. Three-dimensional proton MRSI was applied at 1.5 T. MRSI data from 10 patients with histologically proven prostate adenocarcinoma, scheduled either for prostatectomy or intensity-modulated radiation therapy, were evaluated. First, two readers manually labeled spectra using spatial information to identify the localization of spectra and neighborhood information, establishing the reference set of this study. Then, spectra were labeled again manually in a blinded and randomized manner and evaluated automatically using software that applied spectral line fitting as well as pattern recognition routines. Statistical analysis of the results of the different approaches was performed. Altogether, 1018 spectra were evaluable by all methods. Numbers of evaluable spectra differed significantly depending on patient and evaluation method. Compared to automated analysis, the readers made rather binary decisions, using information from neighboring spectra in ambiguous cases, when evaluating MRSI data as a whole. Differences between anatomically blinded and unblinded evaluation were larger than differences between evaluations using blinded data and automated techniques. An automated approach, which evaluates each spectrum individually, can be as good as an anatomy-blinded human reader. Spatial information is routinely used by human experts to support their final decisions. Automated procedures that consider anatomic information for spectral evaluation will enhance the diagnostic impact of MRSI of the human prostate.
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Cancer with unknown primary: finding a needle in a hay stack.
Experimental oncology. 03/2012; 34(1):64-5.
Detection and resection of small neuroendocrine tumours (NET) is like finding a needle in a hay stack. Use of specific tracers such as 68Ga-DOTATOC in a PET/CT study has been proven to have a high sensitivity and specificity to cells expressing somatostatin-SSR receptors. The use of 99mTc-Octreotide... [more] Detection and resection of small neuroendocrine tumours (NET) is like finding a needle in a hay stack. Use of specific tracers such as 68Ga-DOTATOC in a PET/CT study has been proven to have a high sensitivity and specificity to cells expressing somatostatin-SSR receptors. The use of 99mTc-Octreotide to detect neuroendocrine tumours during surgery is an effective adjunct for therapy. We here present a clinical case of patient with NET where these modalities help in both diagnostic and therapeutic surgery.
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2.65Impact points
Comparison of neuroendocrine tumor detection and characterization using DOTATOC-PET in correlation with contrast enhanced CT and delayed contrast enhanced MRI.
European journal of radiology. 01/2012;
PURPOSE: We evaluated the rate of successful characterization of gastroenteropancreatic neuroendocrine tumors (NETs) present with an increased somatostatin receptor, comparing CE-CT with CE-MRI, each in correlation with DOTATOC-PET. METHODS AND MATERIALS: 8 patients with GEP-NET were imaged using CE... [more] PURPOSE: We evaluated the rate of successful characterization of gastroenteropancreatic neuroendocrine tumors (NETs) present with an increased somatostatin receptor, comparing CE-CT with CE-MRI, each in correlation with DOTATOC-PET. METHODS AND MATERIALS: 8 patients with GEP-NET were imaged using CE-MRI (Gd-EOB-DTPA), CE-CT (Imeron 400) and DOTATOC-PET. Contrast-enhancement of normal liver-tissue and metastasis was quantified with ROI-technique. Tumor delineation was assessed with visual-score in blind-read-analysis by two experienced radiologists. RESULTS: Out of 40 liver metastases in patients with NETs, all were detected by CE-MRI and the lesion extent could be adequately assessed, whereas CT failed to detect 20% of all metastases. The blind-read-score of CT in arterial and portal phase was median -0.65 and -1.4, respectively, and 2.7 for delayed-MRI. The quantitative ROI-analysis presented an improved contrast-enhancement-ratio with a median of 1.2, 1.6 and 3.3 for CE-CT arterial, portal-phase and delayed-MRI respectively. CONCLUSION: Late CE-MRI was superior to CE-CT in providing additionally morphologic characterization and exact lesion extension of hepatic metastases from neuroendocrine tumor detected with DOTATOC-PET. Therefore, late enhanced Gd-EOB-DTPA-MRI seems to be the adequate imaging modality for combination with DOTATOC-PET to provide complementary (macroscopic and molecular) tumor characterization in hepatic metastasized NETs.
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2.09Impact points
Parametric histogram analysis of dynamic contrast-enhanced MRI in multiple myeloma: a technique to evaluate angiogenic response to therapy?
Academic radiology. 01/2012; 19(1):100-8.
From dynamic contrast-enhanced magnetic resonance imaging, it is known that microcirculation patterns in multiple myeloma differ depending on the infiltration pattern. The purpose of this study was to evaluate histogram analysis of dynamic contrast-enhanced magnetic resonance imaging in MM to monito... [more] From dynamic contrast-enhanced magnetic resonance imaging, it is known that microcirculation patterns in multiple myeloma differ depending on the infiltration pattern. The purpose of this study was to evaluate histogram analysis of dynamic contrast-enhanced magnetic resonance imaging in MM to monitor early treatment response on the basis of microcirculation patterns. A total of 51 patients with multiple myeloma requiring therapy were examined. Dynamic contrast-enhanced magnetic resonance imaging of the lumbar spine was performed before and after conventional or high-dose chemotherapy with autologous stem cell transplantation. Statistical analysis included 245 vertebrae and dynamic microcirculation parameters as displayed in histograms. Resulting parameters (amplitude, exchange rate constant, skewness, kurtosis, and left shift) were correlated with therapeutic response. More than 70% of histograms derived from the microcirculation parameters showed a difference between the maximum peak before and after therapy (left shift). However, there was no significant difference between the particular treatment. Significantly different skewness of amplitude in 98% and kurtosis of exchange rate constant (94.1% and 98%) were seen in the patients who responded to treatment (P for each < .05). Histogram analysis revealed early changes after therapy resulting in a shift toward more (kurtosis) and lower values (skewness) of microcirculation parameters. Therefore, histogram analysis can determine and describe if a chosen therapy works at all. However, there were no differences between the chosen therapies. This needs to be reevaluated in a larger number of treated patients. Histogram analysis can also be an adjunct to a subjective visual analysis but is hampered by heterogeneous infiltration pattern seen in multiple myeloma.
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2.77Impact points
Reproducibility of 3D 1H MR spectroscopic imaging of the prostate at 1.5T.
Journal of magnetic resonance imaging : JMRI. 09/2011; 35(1):166-73.
To determine the reproducibility of 3D proton magnetic resonance spectroscopic imaging ((1)H-MRSI) of the human prostate in a multicenter setting at 1.5T. Fourteen subjects were measured twice with 3D point-resolved spectroscopy (PRESS) (1)H-MRSI using an endorectal coil. MRSI voxels were selected i... [more] To determine the reproducibility of 3D proton magnetic resonance spectroscopic imaging ((1)H-MRSI) of the human prostate in a multicenter setting at 1.5T. Fourteen subjects were measured twice with 3D point-resolved spectroscopy (PRESS) (1)H-MRSI using an endorectal coil. MRSI voxels were selected in the peripheral zone and combined central gland at the same location in the prostate in both measurements. Voxels with approved spectral quality were included to calculate Bland-Altman parameters for reproducibility from the choline plus creatine to citrate ratio (CC/C). The repeated spectroscopic data were also evaluated with a standardized clinical scoring system. A total of 74 voxels were included for reproducibility analysis. The complete range of biologically interesting CC/C ratios was covered. The overall within-voxel standard deviation (SD) of the CC/C ratio of the repeated measurements was 0.13. This value is equal to the between-subject SD of noncancer prostate tissue. In >90% of the voxels the standardized clinical score did not differ relevantly between the measurements. Repeated measurements of in vivo 3D (1)H-MRSI of the complete prostate at 1.5T produce equal and quantitative results. The reproducibility of the technique is high enough to provide it as a reliable tool in assessing tumor presence in the prostate.
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3.78Impact points
Respiratory-induced prostate motion: characterization and quantification in dynamic MRI.
Strahlentherapie und Onkologie : Organ der Deutschen Röntgengesellschaft ... [et al]. 06/2011; 187(7):426-32.
To investigate prostate movement during deep breathing and contraction of abdominal musculature by means of dynamic MRI and analyze implications for image-guided radiotherapy of prostate cancer. A total of 43 patients and 8 healthy volunteers were examined with MRI. Images during deep respiration an... [more] To investigate prostate movement during deep breathing and contraction of abdominal musculature by means of dynamic MRI and analyze implications for image-guided radiotherapy of prostate cancer. A total of 43 patients and 8 healthy volunteers were examined with MRI. Images during deep respiration and during contraction of abdominal musculature (via a coughing maneuver) were obtained with dynamic two-dimensional (2D) balanced SSFP; 3 frames/s were obtained over an acquisition time of 15 s. Images were acquired in sagittal orientation to evaluate motion along both the craniocaudal (cc)-axis and anteroposterior (ap)-axis. Prostate motion was quantified semi-automatically using dedicated software tools. Respiratory induced mean cc-axis displacement of the prostate was 2.7 ± 1.9 (SD) mm (range, 0.5-10.6 mm) and mean ap-axis displacement 1.8 ± 1.0 (SD) mm (range, 0.3-10 mm). In 69% of the subjects, breathing-related prostate movements were found to be negligible (< 3 mm). The prostate displacement for abdominal contraction was significantly higher: mean cc-axis displacement was max. 8.4 ± 6.7 (SD) mm (range, 0.6-27 mm); mean anteroposterior movement was 8.3 ± 7.7 (SD) mm (range, 0.7-26 mm). Dynamic MRI is an excellent tool for noninvasive real-time imaging of prostate movement. Further investigations regarding possible applications in image-guided radiotherapy, e.g., for individualized planning and in integrated linac/MRI systems, are warranted.
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1.27Impact points
Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging of bone marrow in healthy individuals.
Acta radiologica (Stockholm, Sweden : 1987). 04/2011; 52(3):324-30.
Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) displays microcirculation and permeability by application of contrast-media and diffusion-weighted imaging (DWI) is a tool for quantification of cellularity in the investigated area. Recently published examples cover breast cancer, CNS t... [more] Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) displays microcirculation and permeability by application of contrast-media and diffusion-weighted imaging (DWI) is a tool for quantification of cellularity in the investigated area. Recently published examples cover breast cancer, CNS tumors, head and neck cancer, gastrointestinal cancer, prostate cancer as well as hematologic malignancies. To investigated the influence of age, sex, and localization of the investigated region on findings of DCE-MRI and DWI. DCE-MRI-parameters amplitude A and exchange rate constant kep as well as the DWI-parameter ADC of the bone marrow of the lumbar vertebral column of 30 healthy individuals covering the typical range of age of tumor patients were evaluated. ADC was calculated using b=0 and a maximal b value of either 400 or 750 s/mm(2). Amplitude A of DCE-MRI decreased with age (P = 0.01) and amplitude A, exchange rate constant kep as well as ADC based on b = 400 s/mm(2) and b = 750 s/mm(2,) respectively, decreased significantly from the first to the fifth lumbar vertebra with P = 0.02, P = 0.05, P = 0.003, and P = 0.002, respectively. Quantitative parameters of functional imaging techniques in bone marrow are influenced by the age of the examined individual and the anatomical location of the investigated region.
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Impact of geometric mean imaging in the accurate determination of partial function in MAG3 renal scanning in a patient with retroperitoneal mass.
Journal of radiology case reports. 01/2011; 5(6):9-17.
Liposarcoma frequently occurs in the retroperitoneum and lower extremities, accounting for 20% of all mesenchymal malignancies. Liposarcomas vary by histology and can be classified into four types. Those four types are well differentiated, myxoid/round cell, pleomorphic and dedifferentiated. Due to ... [more] Liposarcoma frequently occurs in the retroperitoneum and lower extremities, accounting for 20% of all mesenchymal malignancies. Liposarcomas vary by histology and can be classified into four types. Those four types are well differentiated, myxoid/round cell, pleomorphic and dedifferentiated. Due to retroperitoneal location of this tumor, it is expected to affect the kidney position. Renography has provided a unique tool for noninvasive evaluation of various functional parameters e.g. relative renal function. Most renography studies are carried out using the posterior view, under the assumption that the depths of both kidneys are similar so that the radiotracer counts in the region of interest will be attenuated to the same extent. Errors in estimation of the relative renal function may arise if the kidneys are at different depths e.g. secondary to a pushing tumor. Geometric mean imaging from combined anterior and posterior views helps to overcome this issue. This case shows the impact of geometric mean imaging in the truthful determination of partial function in patients with retroperitoneal liposarcoma.
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3D printing based on imaging data: review of medical applications.
International journal of computer assisted radiology and surgery. 07/2010; 5(4):335-41.
Generation of graspable three-dimensional objects applied for surgical planning, prosthetics and related applications using 3D printing or rapid prototyping is summarized and evaluated. Graspable 3D objects overcome the limitations of 3D visualizations which can only be displayed on flat screens. 3D... [more] Generation of graspable three-dimensional objects applied for surgical planning, prosthetics and related applications using 3D printing or rapid prototyping is summarized and evaluated. Graspable 3D objects overcome the limitations of 3D visualizations which can only be displayed on flat screens. 3D objects can be produced based on CT or MRI volumetric medical images. Using dedicated post-processing algorithms, a spatial model can be extracted from image data sets and exported to machine-readable data. That spatial model data is utilized by special printers for generating the final rapid prototype model. Patient-clinician interaction, surgical training, medical research and education may require graspable 3D objects. The limitations of rapid prototyping include cost and complexity, as well as the need for specialized equipment and consumables such as photoresist resins. Medical application of rapid prototyping is feasible for specialized surgical planning and prosthetics applications and has significant potential for development of new medical applications.
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3D printing based on imaging data: review of medical applications.
Int. J. Computer Assisted Radiology and Surgery. 01/2010; 5:335-341.
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3.54Impact points
Estimating Kinetic Parameter Maps From Dynamic Contrast-Enhanced MRI Using Spatial Prior Knowledge
Medical Imaging, IEEE Transactions on. 11/2009;
Dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging can be used to study microvascular structure in vivo by monitoring the abundance of an injected diffusible contrast agent over time. The resulting spatially resolved intensity-time curves are usually interpreted in terms of kinetic parame... [more] Dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging can be used to study microvascular structure in vivo by monitoring the abundance of an injected diffusible contrast agent over time. The resulting spatially resolved intensity-time curves are usually interpreted in terms of kinetic parameters obtained by fitting a pharmacokinetic model to the observed data. Least squares estimates of the highly nonlinear model parameters, however, can exhibit high variance and can be severely biased. As a remedy, we bring to bear spatial prior knowledge by means of a generalized Gaussian Markov random field (GGMRF). By using information from neighboring voxels and computing the maximum a posteriori solution for entire parameter maps at once, both bias and variance of the parameter estimates can be reduced thus leading to smaller root mean square error (RMSE). Since the number of variables gets very big for common image resolutions, sparse solvers have to be employed. To this end, we propose a generalized iterated conditional modes (ICM) algorithm operating on blocks instead of sites which is shown to converge considerably faster than the conventional ICM algorithm. Results on simulated DCE-MR images show a clear reduction of RMSE and variance as well as, in some cases, reduced estimation bias. The mean residual bias (MRB) is reduced on the simulated data as well as for all 37 patients of a prostate DCE-MRI dataset. Using the proposed algorithm, average computation times only increase by a factor of 1.18 (871 ms per voxel) for a Gaussian prior and 1.51 (1.12 s per voxel) for an edge-preserving prior compared to the single voxel approach (740 ms per voxel).
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6.34Impact points
Multiple myeloma and monoclonal gammopathy of undetermined significance: importance of whole-body versus spinal MR imaging.
Radiology. 09/2009; 252(2):477-85.
PURPOSE: To examine if standard magnetic resonance (MR) imaging of the axial skeleton is sufficient for evaluation of patients with multiple myeloma (MM) or monoclonal gammopathy of undetermined significance (MGUS) or if whole-body MR is necessary. MATERIALS AND METHODS: A total of 100 untreated pat... [more] PURPOSE: To examine if standard magnetic resonance (MR) imaging of the axial skeleton is sufficient for evaluation of patients with multiple myeloma (MM) or monoclonal gammopathy of undetermined significance (MGUS) or if whole-body MR is necessary. MATERIALS AND METHODS: A total of 100 untreated patients with MGUS (n = 27) or any stages of MM (n = 73) were examined with whole-body MR imaging and MR imaging of the axial skeleton. The study was approved by the institutional ethics committee, and written informed consent was given. Spinal pattern ("no diffuse involvement" or "diffuse involvement" as assessed from the signal intensity of the spinal bone marrow), serum parameters, and stage of disease were correlated with the probability of detecting extra-axial lesions with and without destruction of cortical bone by using a multiple logistic regression model. RESULTS: Of 100 patients, 39 had lesions in the axial skeleton and 37 had lesions in the extra-axial skeleton. Of the latter group, nine patients had no axial lesions and 13 patients had lesions that violated cortical bone, which implied an increased fracture risk. Because of the extraaxial location, lesions in these patients could be diagnosed with whole-body MR only. In addition, no single or combination of clinical factors observed (stage of disease, serum parameters, and spinal pattern) allowed investigators to identify patients with a significantly increased probability of having extra-axial lesions or lesions violating cortical bone. CONCLUSION: Whole-body MR imaging has potential for use in the initial work-up of patients with MGUS or MM, since almost one-half of all observed lesions would have been missed by using spinal MR imaging only and clinical parameters could not exclude the presence of extra-axial lesions.
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Comparison of diagnostic quality and accuracy in color-coded versus gray-scale DCE-MR imaging display.
International journal of computer assisted radiology and surgery. 09/2009; 4(5):457-62.
The purpose of this study was to evaluate the diagnostic value and tumor-vascular display properties (microcirculation) of two different functional MRI post-processing and display (color and gray-scale display) techniques used in oncology. The study protocol was approved by the IRB and written infor... [more] The purpose of this study was to evaluate the diagnostic value and tumor-vascular display properties (microcirculation) of two different functional MRI post-processing and display (color and gray-scale display) techniques used in oncology. The study protocol was approved by the IRB and written informed consent was obtained from all patients. 38 dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) data sets of patients with malignant pleural-mesothelioma were acquired and post-processed. DCE-MRI was performed at 1.5 tesla with a T1-weighted 2D gradient-echo-sequence (TR 7.0 ms, TE 3.9 ms, 15 axial slices, 22 sequential repetitions), prior and during chemotherapy. Subtracting first image of contrast-enhanced-dynamic series from the last, produced gray-scale images. Color images were produced using a pharmacokinetic two-compartment model. Eight raters, blinded to diagnosis, by visual assessment of post-processed images evaluated both diagnostic quality of the images and vasculature of the tumor using a rating scale ranging from -5 to +5. The scores for vasculature were assessed by correlating with the maximum amplitude of the total-tumor-ROI for accuracy. Color coded images were rated as significantly higher in diagnostic quality and tumor vascular score than gray-scale images (p < 0.001, 0.005). ROI signal amplitude analysis and vascular ratings on color coded images were better correlated compared to gray-scale images rating (p < 0.05). Color coded images were shown to have higher diagnostic quality and accuracy with respect to tumor vasculature in DCE-MRI, therefore their implementation in clinical assessment and follow-up should be considered for wider application.
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2.39Impact points
B-Cell Lymphoma of the Female Breast: Comparison of Mammography, Ultrasound and Dynamic MRI.
Ultraschall in der Medizin (Stuttgart, Germany : 1980). 05/2009;
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2.09Impact points
3D reconstructions of the cerebral ventricles and volume quantification in children with brain malformations.
Academic radiology. 05/2009; 16(5):610-7.
RATIONALE AND OBJECTIVES: The aim of this study was to assess the ability of a semiautomated process to produce three-dimensional reconstructions of the ventricles and calculate ventricular volumes from magnetic resonance (MR) imaging data in children with structural brain abnormalities. MATERIALS A... [more] RATIONALE AND OBJECTIVES: The aim of this study was to assess the ability of a semiautomated process to produce three-dimensional reconstructions of the ventricles and calculate ventricular volumes from magnetic resonance (MR) imaging data in children with structural brain abnormalities. MATERIALS AND METHODS: Fourteen children referred for MR imaging of the brain for neurologic symptoms were selected. Seven participants had structural brain abnormalities on MR imaging; seven further participants were age-matched controls with normal brain morphology. MR imaging included T1-weighted volumetric images in all cases. Semiautomated postprocessing techniques were performed on the MR imaging data to generate three-dimensional reconstructions of the ventricles. These were analyzed for morphologic changes, and volumes were calculated. Inter- and intrarater agreement of ventricular volumes were calculated. RESULTS: This technique produced detailed three-dimensional reconstructions of the ventricles, even in children with grossly abnormal ventricular morphology. All MR imaging data were successfully postprocessed in <5 minutes. Inter- and intrarater reliability was excellent, with correlation coefficients of 0.99 and 0.92, respectively. CONCLUSION: This methodology can create detailed three-dimensional visualizations and volumetric measurements of morphologically abnormal ventricles. This technique could help physicians and parents comprehend abnormal ventricular anatomy better and may have future clinical uses in monitoring disease progression or neurosurgical planning.
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1.23Impact points
Can dynamic MR imaging predict response in patients with rectal cancer undergoing cetuximab-based neoadjuvant chemoradiation?
Onkologie. 04/2009; 32(3):86-93.
BACKGROUND: The aim of this study was to evaluate therapy response in patients undergoing cetuximab-CapIri-based chemoradiation for rectal cancer using dynamic magnetic resonance imaging (dMRI). PATIENTS AND METHODS: The volumetric degree of tumor regression and contrast media perfusion were compare... [more] BACKGROUND: The aim of this study was to evaluate therapy response in patients undergoing cetuximab-CapIri-based chemoradiation for rectal cancer using dynamic magnetic resonance imaging (dMRI). PATIENTS AND METHODS: The volumetric degree of tumor regression and contrast media perfusion were compared to the results of the histopathologic ypTN staging. 33 patients were examined using a 1.5-T scanner with repetitive 2D FLASH sequences after contrast media application. All patients were examined twice - before therapy and immediately before surgery. RESULTS: In all patients, the tumor volume decreased (mean 72 +/- 16%). In 25/33 patients, the slope of the contrast media enhancement curve decreased (mean 31 +/- 20%). In histopathologically proven downstaging after therapy, the decrease in slope was significantly higher than in the group without downstaging, and the decrease in slope was better for distinguishing between 'responder' and 'non-responder' than the decrease in volume. CONCLUSION: Using dMRI helps to identify responders undergoing cetuximab-based chemoradiation better than volume decrease alone.
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6.75Impact points
Dynamic Contrast-Enhanced Magnetic Resonance Imaging Identifies a Subgroup of Patients with Asymptomatic Monoclonal Plasma Cell Disease and Pathologic Microcirculation.
Clinical cancer research : an official journal of the American Association for Cancer Research. 04/2009;
PURPOSE: The aim of our study was to investigate whether dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) allows visualization of changes in microcirculation between healthy controls on the one side and early/advanced stages of plasma cell disease on the other.EXPERIMENTAL DESIGN: We e... [more] PURPOSE: The aim of our study was to investigate whether dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) allows visualization of changes in microcirculation between healthy controls on the one side and early/advanced stages of plasma cell disease on the other.EXPERIMENTAL DESIGN: We examined a group of 222 individuals consisting of 60 patients with monoclonal gammopathy of undetermined significance (MGUS), 65 patients with asymptomatic multiple myeloma (aMM), 75 patients with newly diagnosed symptomatic MM (sMM), and 22 healthy controls with DCE-MRI of the lumbar spine.RESULTS: A continuous increase in microcirculation parameters amplitude A and exchange rate constant kep reflecting vascular volume and permeability, respectively, was detected from normal controls over MGUS and aMM to sMM. For A and kep, significant differences were found between controls and aMM (P = 0.03 and P = 0.004, respectively) as well as controls and sMM (P = 0.001 and P < 0.001, respectively). Although diffuse microcirculation patterns were found in healthy controls as well as MGUS and MM, a pattern with focal hotspots was exclusively detected in 42.6% of sMM and in 3 MGUS and 3 aMM patients. MGUS and aMM patients with increased microcirculation patterns showed significantly higher bone marrow plasmocytosis compared with patients with a low microcirculation pattern.CONCLUSIONS: Our investigations substantiate the concept of an angiogenic switch from early plasma cell disorders to sMM. Pathologic DCE-MRI findings correlate with adverse prognostic factors and DCE-MRI identifies a distinct group of patients with increased microcirculation parameters in aMM and MGUS patients.
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1.27Impact points
Intraindividual Comparison between Gadopentetate Dimeglumine and Gadobutrol for Magnetic Resonance Perfusion in Normal Brain and Intracranial Tumors at 3 Tesla.
Acta radiologica (Stockholm, Sweden : 1987). 03/2009;
Background: In vitro studies have shown that the 3-Tesla (T) magnetic resonance (MR) characteristics of high- and standard-molar gadolinium-based contrast agents differ. Such differences may indicate that high-molar (1.0 M) agents offer advantages for perfusion-weighted imaging (PWI) at 3T, as has b... [more] Background: In vitro studies have shown that the 3-Tesla (T) magnetic resonance (MR) characteristics of high- and standard-molar gadolinium-based contrast agents differ. Such differences may indicate that high-molar (1.0 M) agents offer advantages for perfusion-weighted imaging (PWI) at 3T, as has been previously reported at 1.5T. Purpose: To investigate possible intraindividual differences of high- versus low-molar contrast agents on PWI at 3T in patients with intracranial space-occupying lesions. Material and Methods: Six patients with intraaxial and five patients with extraaxial tumors underwent two MR examinations at 3T, separated by at least 48 hours. On each occasion, an exogenous contrast-based, T2*-weighted, gradient-recalled echo-planar imaging (EPI) technique was used to determine the intracranial perfusion characteristics using one of two intravenous contrast agents: either 5 ml of 1.0 M gadobutrol or 10 ml of 0.5 M gadopentetate dimeglumine. The primary PWI outcome measure was region-of-interest maximal signal change (C(max)). Results: The difference in C(max) for gray and white matter (triangle upC(max)) was significantly higher for gadobutrol compared to gadopentetate dimeglumine (P<0.01). The ratio of C(max) between gray and white matter (rC(max) = C(maxGray)/C(maxWhite)) was also significantly higher (median 24.6%, range 13.7-36.5%) for gadobutrol (P<0.01). The ratio of C(max) between the whole tumor and whole normal side hemisphere was higher in five out of the six intraaxial tumor cases. A significantly higher ratio (triangle upC(max)/C(max)) in the difference between C(max) of gray and white matter (from hemisphere without brain lesion) compared to C(max) for the hemisphere containing the neoplasm (hemisphere with brain lesion) was demonstrated for gadobutrol in intraaxial tumors (P<0.05). Conclusion: Higher-concentration 1.0 M gadobutrol can offer advantages over standard 0.5 M gadopentetate dimeglumine, particularly with respect to delineation between gray and white matter and for the demarcation of highly vascularized tumor tissue on brain PWI performed at 3T.
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0.48Impact points
[Bony space-occupying lesion at the lumbosacral junction with malignant primary disease].
Der Radiologe. 02/2009; 49(2):154-8.
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Comparison of diagnostic quality and accuracy in color-coded versus gray-scale DCE-MR imaging display.
Int. J. Computer Assisted Radiology and Surgery. 01/2009; 4:457-462.
Following (12)
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Moritz Palmowski
Deutsches Krebsforschungszentrum -
Wolfhard Semmler
Deutsches Krebsforschungszentrum -
Amit Mehndiratta
Univeristy of Oxford -
Marc Lemort
Institut Jules Bordet -
Soenke Bartling
German Cancer Research Center / UMC Mannheim
