F K W Schäfer

University Medical Center Schleswig-Holstein, Kiel, Schleswig-Holstein, Germany

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Publications (65)133.81 Total impact

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    ABSTRACT: Ultrasound elastography is an established method for characterization of focal lesions in the breast. Different techniques and analyses of the images may be used for the characterization. This article addresses the use of ultrasound elastography in breast cancer diagnosis. In the first part of the article the techniques behind both strain- and shear-wave-elastography are explained and followed by a section on how to obtain adequate elastography images and measurements. In the second part of the article the application of elastography as an adjunct to B-mode ultrasound in clinical practice is described, and the potential diagnostic gains and limitations of elastography are discussed. © Georg Thieme Verlag KG Stuttgart · New York.
    Full-text · Article · Aug 2015 · Ultraschall in der Medizin
  • A. Strauss · V. Günther · D. Freytag · F. Schäfer · L. Sanders
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    ABSTRACT: Unter der Begrifflichkeit „benigne Erkrankung der weiblichen Brust“ ist eine Vielzahl sehr unterschiedlicher Veränderungen des Brustgewebes zu verstehen. Bezogen auf übergeordnete Kategorien lassen sich diese in Architekturstörungen der weiblichen Brust, symptomorientierte Brusterkrankungen und umschriebene Tumoren im engeren Sinn einteilen. Konkret ist dabei der Formenkreis Mastopathie von den Symptomkomplexen Mastodynie und Mamillensekretion wie auch einer Anzahl nodulärer Neubildungen abzugrenzen. Die Mehrzahl dieser gutartigen Brusterkrankungen wird als klinischer, mammographischer oder sonographischer Befund diagnostiziert. Eine möglichst exakte diagnostische Klassifizierung spielt insbesondere in Abgrenzung zum Malignom eine wichtige Rolle. Nur aus der exakten Kenntnis der unterschiedlichen Entitäten mit ihrem klinischen Erscheinungsbild, diagnostischen Optionen und nicht zuletzt ihren therapeutischen und prognostischen Konsequenzen erwächst eine befundadaptierte, häufig nur minimal eingreifende ärztliche Begleitung. Abstract A heterogeneous group of breast tissue changes is encompassed by the term of benign breast disease. Superordinate classes are architectural disorders of the breast tissue (e.g., mastopathy), symptom-oriented breast disease (e.g., mastalgia), and circumscribed tumors (e.g., fibroadenoma, papilloma). The majority of benign breast diseases appear either as a clinical or mammographic finding. A precise diagnosis is imperative to differentiate and exclude breast cancer from benign conditions. Only exact knowledge of the wide range of benign breast diseases including clinical appearance, imaging, and prognosis allows for appropriate treatment selection, which can often be a minimally invasive procedure.
    No preview · Article · Dec 2013 · Der Gynäkologe
  • F.K.W. Schäfer · C. Eckmann-Scholz · A. Strauss · P.J. Schäfer
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    ABSTRACT: Besides mammography breast ultrasound is the most important modality for diagnosing breast cancer: to differentiate between solid and cystic lesions, and to characterize lesions in terms of benign versus malignant. Additionally, ultrasound may be used as an excellent tool for guiding interventions. Elastography is currently focussed in clinical research, with promising preliminary results. Overall, recent technical developments and standardized examination, documentation and assessment according to the guidelines have had a considerably positive impact on the diagnostic accuracy of breast ultrasound. The crucial variables are as follows training, expertise of radiologist/ gynaecologist, high-end technique, standardized examination, standardized documentation, standardized assessment according to BI-RADS.
    No preview · Article · Oct 2013 · Chirurgische Praxis
  • I Alkatout · B Order · W Klapper · M T Weigel · W Jonat · F K W Schaefer · C Mundhenke · A Wenners
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    ABSTRACT: Local treatment of breast cancer with tumor-free surgical margins is the standard procedure in the treatment of T1 and small T2 breast cancers. Surgery is followed by radiation therapy, and adjuvant systemic therapy is offered depending on primary tumor characteristics, such as tumor size, grade of differentiation, number of involved axillary lymph nodes, the status of estrogen (ER) and progesterone (PR) receptors, and the expression of the human epidermal growth factor 2 (HER2) receptor. Although this approach implies a higher risk of ipsilateral breast tumor recurrence, the total risk of recurrence is low (1% per year), with rates of overall survival similar to that after radical procedures. The most peripheral part of epithelial tumors, the tumor margin, is the part which is most likely to remain in loco after surgical resection. Thus, understanding the biology of the invasion front is important as these tumor cells have been reported to lose epithelial properties, such as cohesiveness and keratin expression, and to acquire features of mesenchymal cells. The parallel appearance of tumor cells in different states of cell dedifferentiation implicates a dynamic equilibrium that is determined by the induction of epithelial-mesenchymal transition (EMT). EMT has been suggested to be of prime importance for tissue and vessel invasion. Furthermore, features of EMT are associated with the activity of tumor stem cells (TSC). TSC exist in breast cancer and their appearance varies depending on the used marker profile. Consequently, intratumoral heterogeneity is reflected by the grade of EMT activation. A specific function at the invasion front is hypothesized but has not yet been proven. Nevertheless, the molecular differentiation between the tumor center and the invasion front enhances the importance of tumor-free surgical margins.
    No preview · Article · Aug 2013 · Minerva ginecologica
  • P J Schaefer · J Pfarr · J Trentmann · A M Wulff · C Langer · M Siggelkow · J Groß · H Knabe · F K W Schaefer
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    ABSTRACT: Objective: To prospectively analyze duplex sonography, CTA, and MRA with respect to stenosis grading of the celiac trunk (TC) and the superior mesenteric artery (SMA), with DSA as the reference. Materials and methods: 52 subjects were enrolled (mean age: 71). The image quality was graded: 1-insufficient, 2-bad, 3-moderate, 4-good or 5-excellent. Stenosis was graded: 1 (< 25 %), 2 (25 - < 50 %), 3 (50 - 75 %) or 4 (75 %). Two-sided chi-square tests were used to check for correlation of stenosis grading between modalities. The weighted Cohen's kappa was calculated to assess the strength of correlation. With a threshold of 50 % for non-relevant stenosis vs. relevant stenosis, the sensitivity, specificity, PPV, NPV, and accuracy were calculated. Results: The mean image quality was 3.8 ± 0.7, 3.1 ± 1.0, 4.4 ± 0.7, and 3.8 ± 0.9 for DSA, duplex sonography, CTA, and MRA, respectively. For both TC and SMA, stenosis grading reached a significant level of correlation between each noninvasive modality with DSA (p < 0.001, each). The weighted Cohen's kappa for duplex sonography/CTA/MRA was 0.94/0.93/0.74, respectively, for the TC and 0.64/0.91/0.56, respectively, for the SMA. Highest sensitivity/specificity/NPV/PPV/accuracy were found for CTA with 100 %/95 %/85 %/100 %/96 % for the TC and with na/98 %/na/100 %/98 %, respectively, for the SMA. Conclusion: CTA provided the best image quality, reached the highest level of agreement and significance in correlation in stenosis grading, and offered the best diagnostic accuracy.
    No preview · Article · Jun 2013 · RöFo - Fortschritte auf dem Gebiet der R
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    ABSTRACT: Purpose: To determine the benefit of ShearWave™ Elastography (SWE™) in the ultrasound characterization of BI-RADS® 3 breast lesions in a diagnostic population. Materials and methods: 303 BI-RADS® 3 lesions (mean size: 13.2 mm, SD: 7.5 mm) from the multicenter BE1 prospective study population were analyzed: 201 (66%) had cytology or core biopsy, and the remaining 102 had a minimum follow-up of one year; 8 (2.6%) were malignant. 7 SWE features were evaluated with regard to their ability to downgrade benign BI-RADS® 3 masses. The performance of each SWE feature was assessed by evaluating the number of lesions correctly reclassified and the impact on cancer rates within the new BI-RADS® 3' lesion group. Results: No malignancies were found with an E-color "black to dark blue", which allowed the downgrading of 110/303 benign masses (p < 0.0001), with a non-significant increase in BI-RADS® 3' malignancy rate from 2.6% to 4.1%. E-max ≤ 20 kPa (2.6 m/s) was able to downgrade 48/303 (p < 0.0001) lesions with a lower increase in BI-RADS® 3' malignancy rate (3.1%). No other SWE features were useful for reclassifying benign BI-RADS® 3 lesions. Conclusion: Applying simple reclassification rules, SWE assessment of the maximum stiffness of lesions allowed the downgrading of a sub-group of benign BI-RADS® 3 lesions. This was accompanied by a non-significant increase in the malignancy rate in the new BI-RADS® 3 class.
    Full-text · Article · Jun 2013 · Ultraschall in der Medizin
  • F.K.W. Schäfer · C. Eckmann-Scholz · A. Strauss · P.J. Schäfer
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    ABSTRACT: Besides mammography breast ultrasound is the most important modality for diagnosing breast cancer: to differentiate between solid and cystic lesions, and to characterize lesions in terms of benign versus malignant. Additionally, ultrasound may be used as an excellent tool for guiding interventions. Elastography is currently focussed in clinical research, with promising preliminary results. Overall, recent technical developments and standardized examination, documentation and assessment according to the guidelines have had a considerably positive impact on the diagnostic accuracy of breast ultrasound. The crucial variables are as follows training, expertise of radiologist/ gynaecologist, high-end technique, standardized examination, standardized documentation, standardized assessment according to BI-RADS.
    No preview · Article · Jun 2013
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    ABSTRACT: The clinical part of these Guidelines and Recommendations produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology EFSUMB assesses the clinically used applications of all forms of elastography, stressing the evidence from meta-analyses and giving practical advice for their uses and interpretation. Diffuse liver disease forms the largest section, reflecting the wide experience with transient and shear wave elastography . Then follow the breast, thyroid, gastro-intestinal tract, endoscopic elastography, the prostate and the musculo-skeletal system using strain and shear wave elastography as appropriate. The document is intended to form a reference and to guide clinical users in a practical way.
    Full-text · Article · Apr 2013 · Ultraschall in der Medizin
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    ABSTRACT: The technical part of these Guidelines and Recommendations, produced under the auspices of EFSUMB, provides an introduction to the physical principles and technology on which all forms of current commercially available ultrasound elastography are based. A difference in shear modulus is the common underlying physical mechanism that provides tissue contrast in all elastograms. The relationship between the alternative technologies is considered in terms of the method used to take advantage of this. The practical advantages and disadvantages associated with each of the techniques are described, and guidance is provided on optimisation of scanning technique, image display, image interpretation and some of the known image artefacts.
    Full-text · Article · Apr 2013 · Ultraschall in der Medizin
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    Full-text · Dataset · Mar 2013
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    Full-text · Dataset · Mar 2013
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    Full-text · Dataset · Mar 2013
  • F Schäfer

    No preview · Article · Dec 2012 · European journal of radiology
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    ABSTRACT: Purpose: To analyze the efficacy of interventions in acute dysfunctional hemodialysis fistulas, if intervention is performed immediately as recommended by European Best Practice Guidelines for Hemodialysis. Materials and methods: Over 3 years, all (n = 280) patients with an acute dysfunctional hemodialysis fistula were immediately referred to angiography, irrespective of the time of day. Angiography and, if possible, interventional revision (n = 241) were performed. Three groups of interest were established: interventionalist's experience (high/low), time of day (routine hours: 7 am-4 pm/emergency hours: 4 pm-7 am), lesion type (stenosis/fibrosclerotic occlusion/thrombotic occlusion/combined stenosis+thrombotic occlusion). For statistical analysis corresponding success rates, chi-square tests (p < 0.025) and logistic regression analysis (p < 0.05) were calculated. Results: The total success rate was 62 % (149/241). The success rates were: interventionalist experience high/low 71 % (79/111)/54 % (70/130), p = 0.022; time of day routine/emergency hours 68 % (93/136)/53 % (56/105), p = 0.017; lesion type stenosis/fibrosclerotic occlusion/thrombotic occlusion/combined stenosis+occlusion 82 % (94/104)/39 % (13/33)/18 % (6/33)/59 % (36/61), p < 0.001. Relevant variables due to logistic regression analysis were high experience and the lesion types stenosis and combined stenosis+occlusion with odds ratios 2.300 (p = 0.012), 12.053 (p < 0.001), 3.189 (p = 0.003). Conclusion: Unrestricted implementation of immediate interventions in acute dysfunctional hemodialysis fistulas requires permanent availability of experienced interventionalists. The lesion types fibrosclerotic occlusion and thrombotic occlusion offer poor success rates for interventional revision.
    No preview · Article · Dec 2012 · RöFo - Fortschritte auf dem Gebiet der R
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    ABSTRACT: PURPOSE To determine potential impact of shear-wave elastography (SWE) on reclassification of sonographic BI-RADS 3 breast masses to BI-RADS 2. Previous reports indicate that upgrading BI-RADS 3 masses suspicious on SWE to biopsy (BI-RADS 4a) is appropriate. METHOD AND MATERIALS From 9/2008 to 9/2010, across 16 centers in Europe and USA, 1647 women with breast masses consented to repeat ultrasound and quantitative SWE imaging (SuperSonic Imagine, Aix, France). 1562 women/masses had acceptable reference standard (biopsy or 1-year follow-up imaging). 440 (28.2%) masses were BI-RADS 3 based on B-mode imaging, of which 310 (70.5%) had biopsy. Quantitative maximum elasticity (Emax) across three acquisitions was determined, with range set 0 (very soft) to 180 kPa (very stiff). Shape and homogeneity of the mass and surrounding tissue on SWE were also recorded. A nonparametric test for trend was performed across ordered categories. RESULTS Among 440 BI-RADS 3 masses, 11 (2.5%) were malignant (1 borderline phyllodes, 1 DCIS, 9 invasive; median invasive tumor size 9 mm). There were 72 (16%) BI-RADS 3 masses with Emax ≤ 20 kPa, all of which were benign; increasing Emax predicted increasing likelihood of malignancy, with 5/323 (1.6%) malignant among masses with 20<Emax<160 kPa, and 6/45 (13%) of masses with Emax 160 kPa or higher malignant (p<.001 across Emax categories). No other subset was reliably benign, with 4/318 (1.3%) BI-RADS 3 masses oval on SWE malignant, compared to 1/28 (4%) of round and 6/94 (6%) of irregular masses (p=.005). When the mass and surrounding tissue were homogeneous on SWE, 5/235 (2.1%) were malignant, compared to 1/149 (0.7%) of those reasonably homogeneous, and 5/56 (9%) of masses heterogeneous on SWE (p=.05). CONCLUSION Confirming earlier reports, it is possible to identify a subset of BI-RADS 3 masses which require biopsy, based on suspicious features on SWE, with malignancy rates of 5 to 13%; however, the vast majority can be safely followed. While very soft lesions on SWE were unlikely to be malignant, only a small percentage of BI-RADS 3 masses could be considered for downgrade to BI-RADS 2, and they would still require diagnostic follow-up: it is not clear that SWE should be used reduce short-term follow-up of probably benign lesions. CLINICAL RELEVANCE/APPLICATION BI-RADS 3 masses are common on breast ultrasound. Understanding the appropriate role of SWE for such masses is important for appropriate patient management.
    No preview · Conference Paper · Nov 2012

  • No preview · Article · May 2012 · RöFo - Fortschritte auf dem Gebiet der R

  • No preview · Article · May 2012 · RöFo - Fortschritte auf dem Gebiet der R
  • PD Dr. C. Schem · F.K.W. Schäfer
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    ABSTRACT: Die konventionelle Mammographie ist derzeit die einzige für die Erkennung von Brustkrebsvorstufen oder frühen Tumorstadien allgemein anerkannte Methode (1a LoE, Leitlinienadaptation). Sie ist die am besten erprobte und evaluierte diagnostische Untersuchungsmethode der Brust und wird eingesetzt zur Abklärung und Charakterisierung von Tastbefunden, zum lokalen Staging und zur Brustkrebsfrüherkennung. Dabei erweist sie sich als besonders effektiv. Prospektiv randomisierte Studien zeigen, dass mit der Einführung der Screeningmammographie als Röntgenreihenuntersuchung eine altersabhängige Brustkrebssterblichkeitsreduktion möglich ist (1b-1a LoE, Leitlinienadaptation). Die Mammographie hat sich auch technisch deutlich weiterentwickelt. Die Digitaltechnik einerseits und die ergänzenden Darstellungsmethoden, wie Sonographie, Tomosynthese und Magnetresonanztomographie komplettieren heute die diagnostischen Möglichkeiten. In dieser Übersichtsarbeit sollen der derzeitige Goldstandard und mögliche zukünftige Entwicklungen bei der Diagnostik des duktalen Carcinoma in situ dargestellt werden.
    No preview · Article · Apr 2012 · Der Gynäkologe
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    Full-text · Conference Paper · Mar 2012
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    ABSTRACT: To evaluate prospectively the correlation of scar-formations after vacuum-assisted biopsy with different systems and needle-sizes and interventional bleeding/post-interventional hematoma. Between 01/2008 and 12/2009, 479 patients underwent vacuum-assisted biopsy under stereotactic-guidance, using the Mammotome(®)-system with 11/8-gauge and ATEC(®)-system with 12/9-gauge, whereas in 178 cases with representative benign histology no surgical-biopsy after vacuum-assisted biopsy was performed and at least a 2-plane-follow-up-mammogram after 6 month post-vacuum-assisted biopsy was available. Bleeding during intervention, hematoma post-intervention and scar-tissue was scored as minimal and moderate/severe. Statistical analysis included Chi-Square-trend-test, p-value <0.05 was considered to be significant. Significantly more bleedings and post-interventional hematomas for 8-gauge-Mammotome(®)-system vs. 11-gauge-Mammotome(®)-system (41.9% vs. 8.4%, p<0.001/35.5% vs. 16.7%, p=0.029), no significant-differences for the ATEC(®)-systems 9-gauge vs. 12-gauge (26.9% vs. 29.7%, p=0.799/42.3% vs. 43.2%, p=0.596). 11-gauge-Mammotome(®)-system vs. ATEC(®)-12-gauge-system revealed significantly less bleedings/hematomas (8.4% vs. 29.7%, p=0.015/16.7% vs. 43.2%, p=0.001), no significant differences for the large-systems (p=0.135/p=0.352). Follow-up of Mammotome(®)-11/8-gauge-system system has shown 13.1/16.1% minimal scar-formation and 1.2/3.2% moderate/severe scars, whereas ATEC(®)-12/9-gauge-system has shown 10.8/3.8% minimal scar-formation and 0/11.5% moderate/severe scars, no significant differences. No significant difference was found when comparing Mammotome(®)-11/8-g-systems vs. ATEC(®)-12/9-g-systems (p=0.609/p=0.823). There was also no correlation between risk of scar-formation after occurrence of bleeding or hematoma with any examined VAB-system or any needle size in this study (p=0.800). Using larger needle-sizes significantly (Mammotome(®))/not significant for ATEC(®)) more interventional bleedings and post-interventional hematomas were detected, only a tendency concerning scar-formation.
    No preview · Article · Feb 2012 · European journal of radiology

Publication Stats

1k Citations
133.81 Total Impact Points

Institutions

  • 2005-2013
    • University Medical Center Schleswig-Holstein
      • Department of Pediatrics
      Kiel, Schleswig-Holstein, Germany
  • 2001-2013
    • Christian-Albrechts-Universität zu Kiel
      • UKSH Klinik für Diagnostische Radiologie
      Kiel, Schleswig-Holstein, Germany
  • 2012
    • Universitätsklinikum Schleswig - Holstein
      • Klinik für Gynäkologie und Geburtshilfe (Kiel)
      Kiel, Schleswig-Holstein, Germany