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Dive into the research topics where Lars Schimmöller is active.

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Featured researches published by Lars Schimmöller.


European Urology | 2015

Prospective Randomized Trial Comparing Magnetic Resonance Imaging (MRI)-guided In-bore Biopsy to MRI-ultrasound Fusion and Transrectal Ultrasound-guided Prostate Biopsy in Patients with Prior Negative Biopsies

Christian Arsov; Robert Rabenalt; Dirk Blondin; Michael Quentin; Andreas Hiester; Erhard Godehardt; Helmut E. Gabbert; Nikolaus Becker; Gerald Antoch; Peter Albers; Lars Schimmöller

BACKGROUND A significant proportion of prostate cancers (PCas) are missed by conventional transrectal ultrasound-guided biopsy (TRUS-GB). It remains unclear whether the combined approach using targeted magnetic resonance imaging (MRI)-ultrasound fusion-guided biopsy (FUS-GB) and systematic TRUS-GB is superior to targeted MRI-guided in-bore biopsy (IB-GB) for PCa detection. OBJECTIVE To compare PCa detection between IB-GB alone and FUS-GB + TRUS-GB in patients with at least one negative TRUS-GB and prostate-specific antigen ≥4 ng/ml. DESIGN, SETTING, AND PARTICIPANTS Patients were prospectively randomized after multiparametric prostate MRI to IB-GB (arm A) or FUS-GB + TRUS-GB (arm B) from November 2011 to July 2014. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The study was powered at 80% to demonstrate an overall PCa detection rate of ≥60% in arm B compared to 40% in arm A. Secondary endpoints were the distribution of highest Gleason scores, the rate of detection of significant PCa (Gleason ≥7), the number of biopsy cores to detect one (significant) PCa, the positivity rate for biopsy cores, and tumor involvement per biopsy core. RESULTS AND LIMITATIONS The study was halted after interim analysis because the primary endpoint was not met. The trial enrolled 267 patients, of whom 210 were analyzed (106 randomized to arm A and 104 to arm B). PCa detection was 37% in arm A and 39% in arm B (95% confidence interval for difference, -16% to 11%; p=0.7). Detection rates for significant PCa (29% vs 32%; p=0.7) and the highest percentage tumor involvement per biopsy core (48% vs 42%; p=0.4) were similar between the arms. The mean number of cores was 5.6 versus 17 (p<0.001). A limitation is the limited number of patients because of early cessation of accrual. CONCLUSIONS This trial failed to identify an important improvement in detection rate for the combined biopsy approach over MRI-targeted biopsy alone. A prospective comparison between MRI-targeted biopsy alone and systematic TRUS-GB is justified. PATIENT SUMMARY Our randomized study showed similar prostate cancer detection rates between targeted prostate biopsy guided by magnetic resonance imaging and the combination of targeted biopsy and systematic transrectal ultrasound-guided prostate biopsy. An important improvement in detection rates using the combined biopsy approach can be excluded.


Magnetic Resonance Imaging | 2014

Feasibility of diffusional kurtosis tensor imaging in prostate MRI for the assessment of prostate cancer: preliminary results.

Michael Quentin; Gael Pentang; Lars Schimmöller; Olga Kott; Anja Müller-Lutz; Dirk Blondin; Christian Arsov; Andreas Hiester; Robert Rabenalt; Hans-Jörg Wittsack

PURPOSE To assess the feasibility of full diffusional kurtosis tensor imaging (DKI) in prostate MRI in clinical routine. Histopathological correlation was achieved by targeted biopsy. MATERIALS AND METHODS Thirty-one men were prospectively included in the study. Twenty-one were referred to our hospital with increased prostate specific antigen (PSA) values (>4ng/ml) and suspicion of prostate cancer. The other 10 men were volunteers without any history of prostate disease. DKI applying diffusion gradients in 20 different spatial directions with four b-values (0, 300, 600, 1000s/mm(2)) was performed additionally to standard functional prostate MRI. Region of interest (ROI)-based measurements were performed in all histopathologically verified lesions of every patient, as well as in the peripheral zone, and the central gland of each volunteer. RESULTS DKI showed a substantially better fit to the diffusion-weighted signal than the monoexponential apparent diffusion coefficient (ADC). Altogether, 29 lesions were biopsied in 14 different patients with the following results: Gleason score 3+3=6 (n=1), 3+4=7 (n=7), 4+3=7 (n=6), 4+4=8 (n=1), and 4+5=9 (n=2), and prostatitis (n=12). Values of axial (Kax) and mean kurtosis (Kmean) were significantly different in the tumor (Kax 1.78±0.39, Kmean 1.84±0.43) compared with the normal peripheral zone (Kax 1.09±0.12, Kmean 1.16±0.13; p<0.001) or the central gland (Kax 1.40±0.12, Kmean 1.44±0.17; p=0.01 respectively). There was a minor correlation between axial kurtosis (r=0.19) and the Gleason score. CONCLUSION Full DKI is feasible to utilize in a routine clinical setting. Although there is some overlap some DKI parameters can significantly distinguish prostate cancer from the central gland or the normal peripheral zone. Nevertheless, the additional value of DKI compared with conventional monoexponential ADC calculation remains questionable and requires further research.


American Journal of Roentgenology | 2016

MRI-Guided In-Bore Biopsy: Differences Between Prostate Cancer Detection and Localization in Primary and Secondary Biopsy Settings

Lars Schimmöller; Dirk Blondin; Christian Arsov; Robert Rabenalt; Peter Albers; Gerald Antoch; Michael Quentin

OBJECTIVE The objective of our study was to evaluate transrectal MRI-guided in-bore biopsy in patients who either were biopsy-naive (primary biopsy) or had undergone at least one previous negative transrectal ultrasound-guided biopsy (secondary biopsy) with regard to cancer detection rate, tumor localization, and lesion size. MATERIALS AND METHODS In total, 1602 biopsy cores from 297 consecutive patients (mean ± SD, 66.1 ± 7.8 years; median prostate-specific antigen value, 8.2 ng/mL) in primary (n = 160) and secondary (n = 137) prostate biopsy settings were evaluated in this retrospective study. All patients previously underwent prostate MRI (T2-weighted imaging, DWI, dynamic contrast-enhanced imaging) at 3 T. All described lesions were biopsied with MRI-guided in-bore biopsy and were examined histologically. RESULTS In 148 patients, overall 511 cores were positive for prostate cancer. Clinically significant prostate cancer (any Gleason pattern ≥ 4) was found in 82.4% of patients. The prostate cancer detection rate for patients who underwent primary biopsies was 55.6% and was 43.1% for patients who underwent secondary biopsies. In patients with primary versus secondary biopsies, prostate cancer was located peripherally in 62.9% versus 49.5% (p = 0.04), in the transition zone in 27.4% versus 27.5% (p = 1.0), and in the anterior stroma in 10.3% versus 22.9% (p < 0.01), respectively. The prostate cancer detection rates for patients with smaller prostate volumes (< 30 vs 30-50 vs > 50 mL; p < 0.01) or for patients with larger lesions (> 0.5 vs 0.25-0.5 vs < 0.25 cm(3); p < 0.01) were significantly higher. CONCLUSION MRI-guided in-bore biopsy led to high detection rates in primary and secondary prostate biopsies. Prostate cancer detection rates were significantly higher for patients with larger lesions and smaller prostate glands. In patients who underwent secondary biopsies, prostate cancer was located in the anterior stroma at a significantly more frequent rate.


European Radiology | 2014

Increased signal intensity of prostate lesions on high b-value diffusion-weighted images as a predictive sign of malignancy

Michael Quentin; Lars Schimmöller; Christian Arsov; Robert Rabenalt; Gerald Antoch; Peter Albers; Dirk Blondin

AbstractObjectivesThe evaluation of lesions detected in prostate magnetic resonance imaging (MRI) with increased signal intensity (SI) on high b-value diffusion-weighted images as a sign of malignancy.MethodsOne hundred and three consecutive patients with prostate MRI examination and MRI-guided in-bore biopsy were retrospectively included in the study. MRI-guided in-bore biopsy histologically confirmed prostate cancer in 50 patients (n = 92 lesions). The other 53 patients (n = 122 lesions) had negative bioptical results.ResultsIn patients with histologically confirmed prostate cancer, 46 of the 92 lesions had visually increased SI on the high b-value images compared with the peripheral zone (SI = +27 ± 16%) or the central gland (SI = +37 ± 19%, P < 0.001 respectively). In patients with a negative biopsy, ten of the 122 lesions had visually increased SI (compared with the peripheral zone, SI = +29 ± 18%, and with the central gland, SI = +41 ± 15%, P < 0.001 respectively). Neither the apparent diffusion coefficient (ADC) values nor the Gleason Score of lesions with increased SI were significantly different from lesions without increased SI.ConclusionsVisually increased SI on the high b-value images of diffusion-weighted imaging using standard b-values is a sign of malignancy but can occasionally also be a feature of benign lesions. However, it does not indicate more aggressive tumours.Key points• Diffusion weighted magnetic resonance imaging is increasingly used to diagnose prostatic cancer • Reduced signal intensity (SI) on apparent diffusion coefficient (ADC) mapping is characteristic • Prostatic tumours usually exhibit increased SI on high b-value images • But benign lesions can also yield increased SI on high b-value images


Journal of Thoracic Imaging | 2014

Evaluation of a high iodine delivery rate in combination with low tube current for dose reduction in pulmonary computed tomography angiography.

Philipp Heusch; Rs Lanzman; J Aissa; Lars Schimmöller; Gerald Antoch; Martin Krix; Patric Kröpil

Purpose: The present study evaluates the combination of a high iodine delivery rate with a low tube current-time product for pulmonary computed tomography angiography (CTA). Materials and Methods: One-hundred nineteen consecutive patients undergoing pulmonary CTA for suspected pulmonary embolism were included and imaged on a 128-row computed tomography scanner at 100 kVp using highly concentrated contrast material (85 mL Iomeprol; 400 mg iodine/mL). The protocol entailed a flow rate of 5 mL/s and 90 mAs for group A, 3.5 mL/s and 135 mAs for group B, 5 mL/s and 135 mAs for group C, and 3.5 mL/s and 90 mAs for group D. Signal-to-noise ratio and contrast-to-noise ratio (CNR) were determined for the pulmonary artery. Subjective image quality (IQ) was rated on a 5-point scale (1=nondiagnostic IQ to 5=excellent IQ). Results: CNR did not differ significantly between groups A (43.7±27.7), B (34.5±17.9), and C (38.9±13.8), as well as between groups B and D (29.9±11.2). CNR was higher in groups A and C than in group D (P<0.02). Subjective IQ was higher in group A than in groups B and D (P<0.05). Subjective IQ was significantly higher in group A compared with group D (P=0.026) and in group C compared with group D (P=0.007). Conclusions: A high iodine delivery rate permits dose reduction in pulmonary CTA and can be recommended in patients with suspected pulmonary embolism.


Acta Radiologica | 2013

3-T in-bore MR-guided prostate biopsy based on a scoring system for target lesions characterization.

Michael Quentin; Lars Schimmöller; Christian Arsov; Robert Rabenalt; Gerald Antoch; Peter Albers; Dirk Blondin

Background To estimate potential malignant lesions within the prostate gland, the usage of a scoring system has recently been proposed by a European consensus meeting. Purpose To prospectively investigate a scoring system for functional prostate magnetic resonance imaging (MRI) using in-bore MR-guided prostate biopsy at 3-T. Material and Methods Prostate MRI examinations of 59 patients (between February 2011 and May 2012) with no known prostate cancer, elevated prostate specific antigen (PSA) level, and unsuspicious digital rectal examination were included in the study. In each patient up to three lesions were defined and scored using a 5-point scoring system for each MR sequence (T2-weighted images, diffusion-weighted imaging, dynamic contrast-enhanced imaging). Following MRI-guided in-bore biopsy these lesions were correlated to the histopathological findings. Results A total number of 144 lesions were defined in 59 patients. In 28 patients (51 lesions) MR-guided in-bore biopsy was positive for tumor (Gleason grade 6 or higher). A cut-off limit of 10 or more points in summation of the individual scores of all three sequences was used, leading to a 90% sensitivity, 63% specificity, 58% positive predictive value, and 92% negative predictive value. Conclusion A simple 5-point scoring system of functional prostate MRI achieves excellent sensitivity and moderate specificity for directing 3-T-guided prostate biopsy relative to the histopathological findings.


Journal of Medical Imaging and Radiation Oncology | 2016

CT angiography of the aorta using 80 kVp in combination with sinogram‐affirmed iterative reconstruction and automated tube current modulation: Effects on image quality and radiation dose

Johannes Boos; J Aissa; Rs Lanzman; Philipp Heusch; Lars Schimmöller; Christoph Schleich; Christoph Thomas; Gerald Antoch; Patric Kröpil

The objective of this study was to evaluate image quality and radiation dose of a CT angiography (CTA) protocol using 80 kVp in combination with iterative reconstruction and automated tube current modulation.


Radiologe | 2012

Polyostotische Knochenveränderungen mit assoziierten intramuskulären Weichteiltumoren

Lars Schimmöller; N. Lehwald; Gerald Antoch; Patric Kröpil

A 40-year-old female patient presented with progressive painful soft tissue lesions in the left upper arm. Conventional radiography showed multicystic bone tumors of the left humerus, radius and ulna. The computed tomography (CT) scan showed no paraosteal spread. Magnetic resonance imaging (MRI) detected intramuscular tumors in the deltoid muscle, biceps humeri muscle and triceps humeri muscle which were T2-weighted hyperintense and T1-weighted hypointense. Postcontrast images showed a marginal enhancement. The findings corresponded to the rare Mazabrauds syndrome in which polyostotic fibrous dysplasia is associated with intramuscular myxomas.


Radiologe | 2012

[Polyostotic fibro-osseus lesions associated with intramuscular soft tissue neoplasms].

Lars Schimmöller; N. Lehwald; Gerald Antoch; Patric Kröpil

A 40-year-old female patient presented with progressive painful soft tissue lesions in the left upper arm. Conventional radiography showed multicystic bone tumors of the left humerus, radius and ulna. The computed tomography (CT) scan showed no paraosteal spread. Magnetic resonance imaging (MRI) detected intramuscular tumors in the deltoid muscle, biceps humeri muscle and triceps humeri muscle which were T2-weighted hyperintense and T1-weighted hypointense. Postcontrast images showed a marginal enhancement. The findings corresponded to the rare Mazabrauds syndrome in which polyostotic fibrous dysplasia is associated with intramuscular myxomas.


The Journal of Urology | 2017

Risk Stratification of Equivocal Lesions on Multiparametric Magnetic Resonance Imaging of the Prostate

T Ullrich; Michael Quentin; Christian Arsov; Anna Katharina Schmaltz; Alexander Tschischka; Nina Laqua; Andreas Hiester; Dirk Blondin; Robert Rabenalt; Peter Albers; Gerald Antoch; Lars Schimmöller

Purpose We systematically analyzed the records of patients with PI‐RADS™ (Prostate Imaging Reporting and Data System) 3 lesions, which are called equivocal according to PI‐RADS version 2, using prostate multiparametric magnetic resonance imaging and magnetic resonance imaging targeted biopsies. Systematic transrectal ultrasound guided biopsies served as the reference standard. Materials and Methods A total of 120 consecutive patients were retrospectively included in the study. In these patients the overall PI‐RADS score was 3 after 3 Tesla T2‐weighted imaging, diffusion weighted imaging and dynamic contrast enhanced multiparametric magnetic resonance imaging as well as subsequent targeted magnetic resonance imaging/ultrasound fusion guided biopsies plus systematic 12‐core transrectal ultrasound guided biopsies. The study end points were the prostate cancer detection rate, the Gleason score distribution, the prostate cancer location and risk stratification by subgroup analyses. Results Prostate cancer was detected in 13 of 118 patients for a detection rate of 11%, including 5 patients (4.2%) with a Gleason score of 3 + 4 = 7 or greater. Three of the 212 lesions (1.4%) in the transition zone and 6 of the 64 (9.4%) in the peripheral zone were positive for prostate cancer. Multiparametric magnetic resonance imaging revealed patterns of peripheral prostatitis combined with diffuse stromal hyperplasia in 54% of the patients with prostate cancer. Prostate volume was significantly lower in patients with prostate cancer (p = 0.015) but differences in prostate specific antigen levels were not statistically significant (p = 0.87). Prostate specific antigen density was higher in patients with prostate cancer (0.19 vs 0.12 ng/ml/ml). Conclusions Low grade prostate cancer (Gleason score 3 + 3 = 6) can develop in patients with an overall PI‐RADS score of 3. Prostate cancer with a Gleason score of 3 + 4 = 7 or greater can be detected by multiparametric magnetic resonance imaging with a high degree of certainty. Gleason score 4 + 3 = 7 or greater prostate cancer is unlikely in PI‐RADS 3 lesions. Therefore, these patients should primarily undergo followup multiparametric magnetic resonance imaging. In patients with a combination of multiparametric magnetic resonance imaging aspects of extensive prostatitis and diffuse stromal hyperplasia low prostate volume and/or high prostate specific antigen density biopsy might be considered.DISCLAIMER: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our subscribers we are providing this early version of the article. The paper will be copy edited and typeset, and proof will be reviewed before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to The Journal pertain.

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Gerald Antoch

University of Düsseldorf

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Christian Arsov

University of Düsseldorf

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Michael Quentin

University of Düsseldorf

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Robert Rabenalt

University of Düsseldorf

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Peter Albers

University of Düsseldorf

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Dirk Blondin

University of Düsseldorf

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Patric Kröpil

University of Düsseldorf

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Andreas Hiester

University of Düsseldorf

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D Blondin

University of Düsseldorf

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Rs Lanzman

University of Düsseldorf

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