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A Helck,
M Wessely,
M Notohamiprodjo,
U Schönermarck,
E Klotz,
M Fischereder,
F Schön,
K Nikolaou, D A Clevert,
M Reiser,
C Becker
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ABSTRACT: OBJECTIVES: To assess the benefit of quantitative computed tomography (CT) perfusion for differentiating acute tubular necrosis (ATN) and acute rejection (AR) in kidney allografts. METHODS: Twenty-two patients with acute kidney allograft dysfunction caused by either AR (n = 6) or ATN (n = 16) were retrospectively included in the study. All patients initially underwent a multiphase CT angiography (CTA) protocol (12 phases, one phase every 3.5 s) covering the whole graft to exclude acute postoperative complications. Multiphase CT dataset and dedicated software were used to calculate renal blood flow. Renal biopsy or clinical course of disease served as the standard of reference. Mean effective radiation dose and mean amount of contrast media were calculated. RESULTS: Renal blood flow values were significantly lower (P = 0.001) in allografts undergoing AR (48.3 ± 21 ml/100 ml/min) compared with those with ATN (77.5 ± 21 ml/100 ml/min). No significant difference (P = 0.71) was observed regarding creatinine level with 5.65 ± 3.1 mg/dl in AR and 5.3 ± 1.9 mg/dl in ATN. The mean effective radiation dose of the CT perfusion protocol was 13.6 ± 5.2 mSv; the mean amount of contrast media applied was 34.5 ± 5.1 ml. All examinations were performed without complications. CONCLUSION: CT perfusion of kidney allografts may help to differentiate between ATN and rejection. KEY POINTS: • Quantitative CT perfusion of renal transplants is feasible. • CT perfusion could help to non-invasively differentiate AR from ATN. • CT perfusion might make some renal biopsies unnecessary.
European Radiology 05/2013; · 3.22 Impact Factor
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ABSTRACT: If a renal mass is suspected on clinical examination or ultrasound the finding has to be confirmed by cross-sectional imaging. Methods that are used include multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Also contrast-enhanced ultrasound has been successfully implemented in renal imaging and now plays a major role in the differentiation of benign from malignant renal masses. In expert hands it can be used to show very faint vascularization and subtle enhancement. The MDCT technique benefits from the recently introduced dual energy technology that allows superior characterization of renal masses in a single-phase examination, thereby greatly reducing radiation exposure. For young patients and persons allergic to iodine MRI should be used and it provides excellent soft tissue contrast and visualizes contrast enhancement kinetics in multiphase examinations.This article aims at giving a comprehensive overview of these different imaging modalities, their clinical indications and contraindications, as well as a description of imaging findings of various renal masses.
Der Urologe 04/2013; 52(4):515-26. · 0.50 Impact Factor
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ABSTRACT: STANDARD RADIOLOGICAL METHODS: High-intensity focused ultrasound (synonyms FUS and HIFU) under magnetic resonance imaging (MRI) guidance (synonyms MRgFUS and MR-HIFU) is a completely non-invasive technology for accurate thermal ablation of a target tissue while neighboring tissues and organs are preserved. METHODICAL INNOVATIONS: The combination of FUS with MRI for planning, (near) real-time monitoring and outcome assessment of treatment markedly enhances the safety of the procedure. ACHIEVEMENTS: The MRgFUS procedure is clinically established in particular for the treatment of symptomatic uterine fibroids, followed by palliative ablation of painful bone metastases. Furthermore, promising results have been shown for the treatment of adenomyosis, malignant tumors of the prostate, breast and liver and for various intracranial applications, such as thermal ablation of brain tumors, functional neurosurgery and transient disruption of the blood-brain barrier.
Der Radiologe 03/2013; · 0.61 Impact Factor
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ABSTRACT: PURPOSE: To evaluate the feasibility of the classification of endoleaks following endovascular aortic aneurysm repair using the time-to-peak of the contrast agent in CEUS examinations. MATERIAL AND METHODS: In this retrospective study, a cohort of 171 patients with a total of 489 CEUS follow-up examinations after EVAR were included. In 254 of the 489 examinations, an endoleak was seen and the time-to-peak was measured in seconds. Existence of an endoleak was confirmed by CT as the gold standard. RESULTS: We evaluated 254 CEUS video sequences showing an endoleak out of a total of 489 examinations. Kruskal-Wallis test revealed with p = 0.00 differences between the single endoleak types based on the time to peak. Correction after Bonferroni showed significant differences between type Ia compared to Ib and to IIa over inferior mesenteric artery (IMA) and IIa over lumbar artery (LA). There are also disparities between type Ib and type IIa IMA and type III, furthermore between type IIa IMA compared to IIa LA and type III as well as type IIa LA matched to type III. CONCLUSION: CEUS is an important method for the follow-up after EVAR. The time to peak does not seem to be a useful additional feature in classifying endoleaks, although there are differences between time-to-peak of the single endoleak types and it is possible to make an order of the different endoleak types referring to the mean values.
Clinical hemorheology and microcirculation 03/2013; · 3.40 Impact Factor
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M Claudon,
C F Dietrich,
B I Choi,
D O Cosgrove,
M Kudo,
C P Nolsøe,
F Piscaglia,
S R Wilson,
R G Barr,
M C Chammas, [......],
J B Fowlkes,
R N Gibson,
B B Goldberg,
N Lassau,
E L S Leen,
R F Mattrey,
F Moriyasu,
L Solbiati,
H-P Weskott,
H-X Xu
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ABSTRACT: Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.
Ultraschall in der Medizin 11/2012; · 2.40 Impact Factor
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ABSTRACT: Ultrasound is often the first imaging modality used in the diagnosis of abdominal vascular as well as parenchymal organ pathologies. Contrast-enhanced ultrasound (CEUS) enables the dynamic assessment and quantification of microvascularisation up to capillary perfusion. Current clinical applications of CEUS are mainly in detection and characterization of lesions, particularly benign and malignant hepatic and renal lesions, based on differences between lesion and organ perfusion. Multifrequency high-resolution transducers are being increasingly used, including intra-operatively. Dynamic 3D techniques and ultrasound image fusion with CT or MRI may assist the diagnosis and therapy control after interventional procedures. Our own studies have demonstrated the excellent diagnostic performance of CEUS with perfusion-analysis in the characterization of hepatic and renal lesions as well as the assessment of tissue transplant macro- and microvascularisation. CEUS opens up new possibilities in the characterization of the microvasculature with perfusion analysis, even during the course of interventions, thereby providing new possibilities for modified therapeutic strategies. In this review, the different new ultrasound techniques with their potential applications are described and illustrated.
Clinical hemorheology and microcirculation 09/2012; · 3.40 Impact Factor
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ABSTRACT: Purpose: To evaluate the feasibility of US image fusion in the clinical routine and to discuss potential benefits for follow-up after renal transplantation. Materials and methods: 15 patients with a renal transplant were prospectively included in the study. For all of them, a previously performed CT- or MRI-scan covering the renal transplant was available. Each patient was investigated using ultrasound image fusion. Time needed for sucessful implementation of image fusion was registered. Subsequently, quality of image fusion was assessed by two experienced radiologists (10 and 5 years of experience) in consensus using a subjective 5 point rank scale (1 = best). Results: Image fusion was successfully performed in all patients. Time needed for setup of image fusion varied from 45-120 sec (85 ± 5 sec). The score for quality of US image fusion was 1.9 ± 0.7. Conclusion: Assessment of renal transplants using USimage fusion is feasible and provides several potential benefits for the follow-up of renal transplants.
Clinical hemorheology and microcirculation 09/2012; · 3.40 Impact Factor
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ABSTRACT: Purpose: To evaluate "bolus-tracking" (BT) and "flash-replenishment" (FR) for the assessment of tissue hemodynamics by contrast-enhanced ultrasound (CEUS) in an experimental small-animal-squamous-cell-carcinoma-model. Since the underlying tissue is the same, strong correlations between parameter outcomes of both techniques are expected. Methods and materials: Human hypopharynx-carcinoma-cells were subcutaneously injected into the left flank of 18 female athymic-nude-rats. After 10 days of subcutaneous tumour growth, bolus tracking and flash-replenishment measurements were performed consecutively in the same imaging plane in each rat after bolus-injection of SonoVue via the lateral tail vein using a high-end ultrasound system with a 15 MHz probe. Video-sequences were analysed with dedicated software (VueBox®, Bracco-Suisse®). From BT measurements, the parameters peak enhancement (PEBT), wash-in area-under-the-curve (Wi-AUCBT), mean transit time (MTTBT), wash-in-rate (WiRBT) and perfusion-index (Wi-PIBT) were derived; FR yielded estimates of relative-blood-volume (rBVFR), mean transit time MTTFR, relative blood flow rBFFR and wash-in rate Wi-RFR. Results: In all rats, BT and FR measurements could be completed successfully. Highly significant correlations were observed between rBVFR and PEBT, rBVFR and Wi-AUCBT, rBVFR and MTTBT, rBVFR and WiPIBT, MTTFR and MTTBT, rBFFR and PEBT, rBFFR and Wi-AUCBT, rBFFR and WiRBT, rBFFR and WiPIBT, WiRFR and PEBT, WiRFR and Wi-AUCBT, WiRFR and WiRBT and WiRFR and WiPIBT. Conclusion: Whereas bolus tracking can be used in a wide range of modalities including CEUS, CT and MR, FR as a technique for the assessment of tissue hemodynamics is unique to CEUS. Although BT and FR yield different parameters, the underlying tissue hemodynamics are equal. In this work, we were able to demonstrate strong correlations between different parameters of both modalities in a small-animal-tumor-model, indicating that flash-replenishment is a valid alternative to the more established bolus-tracking technique. Although the lack of absolute, quantitative parameters hinders a direct comparison of both modalities, FR and BT should both be suitable for a relative comparison, e.g. between baseline and follow-up examinations.
Clinical hemorheology and microcirculation 09/2012; · 3.40 Impact Factor
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ABSTRACT: Purpose: The purpose of this study was to evaluate whether image fusion with contrast enhanced ultrasound (CEUS) and CT is effective in the pre-, intra- and post-interventional management of liver lesions during microwave or radiofrequency ablation. Methods and materials: Fifteen patients with a single hepatocellular carcinoma (HCC) up to 3 cm diameter, identified on both contrast-enhanced CT (Siemens Somatom Definition AS and Definition Edge, Siemens Healthcare, Erlangen, Germany) and ultrasound (Siemens ACUSON S2000™ or S3000™, Siemens Healthcare, Erlangen, Germany) were retrospectively enrolled between July 2011 and May 2012. Either automatic registration or plane match registration was chosen on CT and ultrasound for the pre-, intra- and postinterventional management of all treated liver lesions during microwave or radiofrequency ablation. Using conventional ultrasound B-mode, CEUS and image fusion including B-mode and CEUS the detectability of the liver lesions was evaluated semi-quantitatively by comparing the image sequences in a consensus reading. Eight patients underwent radiofrequency ablation and seven patients underwent microwave ablation. Results: All patients were examined using all diagnostic ultrasound tools of the study. The results show that the procedure is easy and convenient to perform, as well as efficient. The co-registration procedure took approximately 5 to 10 minutes depending on the amount of DICOM volume-data and the habitus of the patient. The results show that the use of image fusion with CT and contrast-enhanced ultrasound could improve the diagnostic assessment capabilities in comparison to the examination without image fusion in the pre-, intra- and postinterventional management of malignant liver lesions during thermal ablation. Conclusion: Percutaneous thermal ablation guided by contrast-enhanced ultrasound and image fusion seems to be an efficient approach for malignant liver lesions especially if these are not clearly demarcated by B-mode. The use of the image fusion technique in the pre-, intra- and postinterventional management can increase operator confidence, the accuracy of the procedure, and technical success in real time.
Clinical hemorheology and microcirculation 09/2012; · 3.40 Impact Factor
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RöFo - Fortschritte auf dem Gebiet der R 09/2012; 184(9):835-6. · 2.76 Impact Factor
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ABSTRACT: The current improvements in modern high resolution ultrasound technology, like Tissue Harmonic Imaging (THI), Speckle Reduction Imaging (SRI), partial color coding of B-mode (Color Coded Imaging), and also the advent of ultrasound based elastography as well as contrast-enhanced ultrasound (CEUS) offer fundamentally new ways to characterize diffuse alterations of the liver parenchyma. Besides metabolic disease, disorders of liver fat distribution, infectious and malignant diseases can cause diffuse alterations of the liver parenchyma. In case of liver fibrosis, only a combination of different ultrasound techniques including CEUS, allows the differentiation between benign dysplastic and malignant lesions. Ultrasound elastography allows assessing the extent of the fibrosis. This article focuses on the different ultrasound based diagnostic possibilities in case of diffuse liver disease.
Der Radiologe 07/2012; 52(8):706-16. · 0.61 Impact Factor
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ABSTRACT: Im Rahmen der Diagnostik fokaler Leberläsionen wird die Sonographie meist als erstes bildgebendes Verfahren eingesetzt. Neben
der primären grundlegenden B-Bild-Optimierung wie „tissue harmonic imaging“ (THI), Spatial-compounding- und Speckle-reduction-Technik
hat die Sonographie v.a. mit der Einführung von Ultraschallkontrastmitteln sowohl beim Nachweis als auch der Charakterisierung
von Lebermetastasen zu den anderen Schnittbildverfahren aufgeschlossen. Zusätzlich können Volumendarstellungen und die sonographisch
gestützte Bildfusion mittels CT oder MRT die Diagnostik und Therapiekontrolle nach Interventionen erleichtern.
In diesem Beitrag sollen die unterschiedlichen neuen Techniken mit ihren Einsatzmöglichkeiten dargestellt und anhand von Bildbeispielen
erläutert werden.
Abdominal ultrasound (US) is often the first-line imaging modality used to assess focal liver lesions. Due to various new
gray-scaled US techniques, such as tissue harmonic imaging (THI), spatial compounding technique and speckle reduction technique,
as well as contrast-enhanced techniques, abdominal ultrasound nowadays has great potential regarding detection and characterization
of focal liver lesions. Furthermore, image fusion with computed tomography (CT), magnetic resonance imaging (MRI) and 3D ultrasound
will most likely help to improve clinical management before and after interventional procedures.
This article illustrates the principles and clinical impact of recently developed techniques in the field of ultrasound.
Schlüsselwörter„Tissue harmonic imaging“ (THI)–Spatial-compounding-Technik–Speckle-reduction-Technik–Bildfusion–Kontrastmittelgestützte Ultraschalluntersuchungen
KeywordsTissue harmonic imaging (THI)–Spatial compounding–Speckle reduction imaging–Image fusion–Contrast-enhanced ultrasound (CEUS)
Der Radiologe 05/2012; 51(8):661-670. · 0.61 Impact Factor
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ABSTRACT: Zystische Nierenläsionen können unterteilt werden in einfache oder komplizierte Zysten, die sowohl solitär als auch multifokal
auftreten können. Die Bosniak-Klassifikation (I–IV) unterteilt die Nierenzysten anhand von sonographischen oder computertomographischen
Kriterien. Aufgrund dieser Charaktersierung kann eine Entscheidung über das weitere therapeutische Vorgehen getroffen werden.
Das Standardverfahren zur Diagnose von Nierenzysten ist die Sonographie. Neben der primären konventionellen B-Bild-Sonographie
stellt der kontrastmittelverstärkte Ultraschall mit SonoVue® eine neue, vielversprechende Methode für die Einteilung der Zysten
nach Bosniak dar. Dieser Review beschreibt zystische Nierenveränderungen mit dem Schwerpunkt auf Ätiologie und Bedeutung dieser
Pathologien im Methodenvergleich zum konventionellen B-Bild, dem kontrastmittelverstärkten Ultraschall und der Computertomographie.
Cystic renal lesions can be classified as either simple or complicated cysts, which might occur as solitary as well as multifocal
lesions. The Bosniak classification (I-IV), which characterizes renal cysts on the basis of ultrasound or computer tomographic
criteria, is very useful for further decision-making about the therapeutic approach. The method of choice for diagnosis of
renal cysts is ultrasound. Besides the conventional B-mode ultrasound, contrast enhanced ultrasound with SonoVue® provides
a promising new technique for distinguishing cysts according to the Bosniak classification. This review describes cystic renal
lesions with emphasis on the etiology and significance of these pathologies in a methodological comparison of conventional
B-mode, contrast enhanced ultrasound and computer tomography.
SchlüsselwörterNierenzysten-Bosniak-Klassifikation-B-Bild-Sonographie-Kontrastmittelverstärkter Ultraschall-Computertomographie
KeywordsRenal cysts-Bosniak classification-B-mode ultrasound-Contrast enhanced ultrasound-Computer tomography
Der Urologe 05/2012; 49(3):421-432. · 0.50 Impact Factor
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ABSTRACT: Obstruktive Erkrankungen der Speicheldrüse sind ein häufiges Problem in der Hals-, Nasen- und Ohrenheilkunde. Die Sialolithiasis
ist in ca. 60% der Fälle ursächlich, gefolgt von Gangstenosen und selteneren Ursachen. Trotz einer Vielzahl diagnostischer
Möglichkeiten bleibt bei 5–10% der Patienten die Ursache unklar. Die Ultraschalluntersuchung mit intraduktal appliziertem
Kontrastmittel (IA-CEUS, „contrast-enhanced ultrasound“) stellt eine nebenwirkungsarme, kostengünstige und schnell durchzuführende
Methode dar, um konventionelle Untersuchungstechniken zu ergänzen und obstruktive Speicheldrüsenerkrankungen besser klassifizieren
und behandeln zu können.
Obstructive diseases of the salivary glands are a common problem in otorhinolaryngology. They are mostly due to sialolithiasis
followed by duct stenosis and other rarer causes. Several diagnostic modalities exist which allow classification of the disease;
however, in 5–10% of all cases ultrasound and conventional radiological imaging do not provide a clear diagnosis. Ultrasound
examination with contrast material injected into the duct (IA-CEUS, intraductal administered contrast-enhanced ultrasound)
enables improved evaluation of obstructive diseases of the salivary glands and at the same time an evaluation of the parenchyma
of the glands is possible. As a complementary method to conventional investigation techniques IA-CEUS is an economic and rapid
method with low side-effects which improves the diagnostic assessment of ultrasound and results in a better treatment for
patients.
SchlüsselwörterObstruktive Speicheldrüsenerkrankungen–Intraduktale Applikation (IA)–„Contrast-enhanced ultrasound“ (CEUS)–Sialolithiasis–Gangstenosen
KeywordsObstructive disease of salivary glands–Intraductal administration (IA)–Contrast-enhanced ultrasound (CEUS)–Sialolithiasis–Duct stenosis
Der Radiologe 05/2012; 51(6):490-496. · 0.61 Impact Factor
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ABSTRACT: In der Vergangenheit war die Darstellung der Tumorperfusion ausschließlich mit Hilfe invasiver Verfahren wie etwa der intravitalen
Mikroskopie oder aber apparativ aufwendiger Großgeräte wie z.B. bei der Multidetektorcomputertomographie (MDCT), der Magnetresonanztomographie
(MRT) oder dem gemeinsamen Einsatz der Positronenemissionstomographie und der Computertomographie (PET/CT) möglich. Ein Vorteil
der Sonographie ist die nichtinvasive Darstellung des Körperinneren mit einer hohen räumlichen und zeitlichen Auflösung ohne
Anwendung ionisierender Strahlung. Durch die Anwendung der farbkodierten Duplexsonographie (FKDS) sowie des Powerdopplers
lässt sich jedoch keine Tumorvaskularität detektieren. Die Einführung des kontrastverstärkten Ultraschalls („contrast-enhanced
ultrasound“, CEUS) sowie die Entwicklung neuer hochfrequenter Ultraschallköpfe ermöglichen es, die Mikrozirkulation in Tumoren
zeitlich hochaufgelöst zu detektieren und zu quantifizieren. Der CEUS wird in der Klinik bereits seit über 10Jahren am Menschen
eingesetzt. In letzter Zeit wird er auch für tierexperimentelle Untersuchungen, z.B. bei Tumormodellen an Mäusen, Hamstern
oder Ratten genutzt. Durch die Analyse der individuellen Kontrastmittelkinetik vor und nach Therapie können funktionelle Informationen
über den angiogenetisch-metabolischen Status des Gewebes gewonnen werden. Weitere Forschungsprojekte sind nötig, um eine absolute
Quantifizierung der Perfusionsparameter zu erreichen und die wünschenswerte Vergleichbarkeit mit anderen Untersuchungsmodalitäten
(MRT, CT) herstellen zu können.
In the past the detection of tumor perfusion was achieved solely via invasive procedures, such as intravital microscopy or
with the help of costly modalities, such as multidetector computed tomography (MDCT), magnetic resonance tomography (MRT)
or the combined use of positron emission tomography and computed tomography (PET/CT). Ultrasound offers the non-invasive display
of organs without usage of ionizing radiation and it is widely available. However, colour-coded ultrasound and power Doppler
do not allow the detection of tumor microcirculation. The introduction of contrast-enhanced ultrasound (CEUS) as well as new
high-frequency ultrasound probes made it possible to detect and quantify tumor microcirculation with high resolution. CEUS
has been used clinically on human beings for more than 10 years. During the last years different tumor models in experimental
animals were used for the establishment of this new technique, e.g. in rats, hamsters and mice. CEUS allows the detection
of functional parameters, such as the angiogenetic metabolic status of tissue pretreatment and posttreatment. Further research
is required to solve the problems of absolute quantification of these perfusion parameters to allow the comparison of CEUS
with other modalities (e.g. MRT and CT).
SchlüsselwörterKontrastverstärkter Ultraschall–Tumorresponse–Wiederauffüllungskinetik–Kontrastmittelquantifizierung–Tierexperimentell
KeywordsContrast-enhanced ultrasound (CEUS)–Tumor response–Flash replenishment method–Absolute quantification–Animal experiments
Der Radiologe 05/2012; 51(6):506-513. · 0.61 Impact Factor
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ABSTRACT: Mit der Einführung von Ultraschallkontrastmitteln der zweiten Generation bietet sich die Kontrastmittelsonographie des Abdomens
als zusätzlicher Untersuchungsschritt bei hämodynamisch stabilen Patienten nach stumpfem Bauchtrauma an. Bezüglich klinisch
relevanter Organverletzungen bewies die Kontrastmittelsonographie dabei zumindest unter Studienbedingungen eine ausgezeichnete
diagnostische Genauigkeit. Gerade bei jüngeren, hämodynamisch stabilen Patienten nach Niederrasanztrauma könnte diese Modalität
zu einem zuverlässigen Ausschluss von Parenchymverletzungen beitragen, ohne den Patienten ionisierender Strahlung zu exponieren.
Der vorliegende Beitrag erläutert die technische Durchführung dieses Verfahrens, zeigt typische Befunde traumatisch geschädigter
Parenchymorgane und fasst die derzeitige Studienlage bzgl. des Einsatzes der Kontrastmittelsonographie nach stumpfem Bauchtrauma
zusammen.
With the introduction of second generation ultrasound contrast agents, contrast-enhanced ultrasound (CEUS) has become available
as an adjunct to the conventional FAST (focused assessment with sonography in trauma) protocol and B-mode sonography of the
abdomen after blunt force abdominal trauma. Results from several controlled studies indicate excellent diagnostic accuracy
of CEUS for the exclusion of clinically relevant parenchymal injuries after blunt force abdominal trauma. Particularly in
younger, hemodynamically stable patients this technique could contribute to a reliable exclusion of parenchymal injuries without
the use of ionizing radiation. This report provides details on the technical performance of CEUS, shows examples of typical
CEUS findings after blunt abdominal trauma and summarizes the current clinical evidence regarding the use of CEUS after blunt
abdominal trauma.
SchlüsselwörterFAST-Algorithmus (Focused Assessment with Sonography in Trauma)–Kontrastmittelsonographie–Kontrastmittelverstärkter Ultraschall („contrast-enhanced ultrasound“, CEUS)–Bauchtrauma–Freie Flüssigkeit
KeywordsFAST algorithm (focused assessment with sonography in trauma)–Contrast medium sonography–Contrast-enhanced ultrasound (CEUS)–Abdominal injuries–Free fluid
Der Radiologe 04/2012; 51(6):475-482. · 0.61 Impact Factor
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ABSTRACT: Die Methode der automatisierten Ultraschalldiagnostik der Mamma ist schon lange bekannt, spielte jedoch bisher keine ernsthafte
diagnostische Rolle, da zum einen die Sensitivität für kleine solide Herdbefunde mit niedrigfrequenten Schallköpfen zu gering,
zum anderen der Komfort der Patientinnen bei der Untersuchung in Bauchlage mit in Wasser getauchten Mammae unzureichend war.
Der Acuson S2000 Automated-breast-volume-Scanner (AVBS) ist ein High-end-Ultraschallgerät mit einer Frequenz von 5–14MHz.
Die Untersuchungseinheit besteht aus einem flexiblen Arm mit dem Ultraschallscanner, einem Touchscreen und einer 3D-Workstation.
Die Untersuchung erfolgt in Rückenlage, und in Abhängigkeit von der gewählten Brustgröße werden automatisch verschiedene Presets
vorgeschlagen, die individuell angepasst werden können. Als besondere Vorteile der Methode gelten: Unabhängigkeit von der
Erfahrung des Untersuchers, Konstanz der Ergebnisse und Reproduzierbarkeit der Aufnahmen sowie erstmals die Möglichkeit, die
gesamte Mamma auch in der koronaren Ebene darzustellen.
In diesem Beitrag sollen die Technik des ABVS und die praktische Anwendung anhand von Bildbeispielen erläutert werden.
The automated breast ultrasound technique has been known for a long time but did not play an important role in diagnostics
due to its inferior sensitivity for small solid lesions with low frequency transducers and its uncomfortable examination technique
with the patients in a supine position and the breast immersed in water.
The automated breast volume scanner (AVBS) is a high-end ultrasound scanner which employs frequencies of 5-14MHz and consists
of a flexible arm with the transducer at the end, a touchscreen and a 3D workstation. The scan is performed with the patient
in the prone position. Depending on the breast size, various presettings are available from which the examiner may select
the most appropriate. AVBS has various major advantages, such as being independent from the experience of the operator as
well as supplying consistent and reproducible results. Additionally, for the first time it became possible to obtain coronal
images of the complete breast, which greatly assists the planning of surgical interventions.
In this article the ABVS technique will be described and results will be illustrated by means of clinical examples.
SchlüsselwörterAutomatisierter Brustvolumenscan (ABVS)-Mammasonographie-3D-Bildgebung-Multiplanare Rekonstruktion-Mammatumoren
KeywordsAutomated breast volume scan (ABVS)-Breast sonography-3D imaging-Multiplanar reconstruction-Breast lesions
Der Radiologe 04/2012; 50(11):973-981. · 0.61 Impact Factor
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ABSTRACT: Der vaskuläre Ultraschall ist eine etablierte Technik in der Shuntdiagnostik und ermöglicht eine nichtinvasive Diagnostik
der Gefäßmorphologie und Hämodynamik. Möglichst frühzeitig sollen stenosierende Gefäßwandveränderungen eines Dialyseshunts
erkannt werden, um einen thrombotischen Verschluss zu vermeiden. Das sichere Erkennen auch echoarmer Wandveränderungen und
die Beurteilung des lokalen Stenosegrades erleichtern eine Interventionsentscheidung. Hierbei rechtfertigen hohe Verschlussraten
bei vermindertem Durchflussvolumen von bis zu 45% innerhalb eines Jahres eine sonographische Verlaufsuntersuchung. Das Risiko
hämodynamisch relevanter Shuntstenosen wird durch häufige Punktionen im Rahmen perkutaner Interventionen gesteigert. Durch
die Einführung neuer Ultraschallverfahren wie B-Flow und Advanced Dynamic Flow (ADF) kann eine direkte Darstellung des Flusses
im Anastomosenbereich erleichtert werden. Darüber hinaus eröffnen sich durch eine hochauflösende Ultraschalldiagnostik neue
Möglichkeiten einer verbesserten Flussdetektion ohne Gefäßüberzeichung oder Aliasing. In der vorliegenden Arbeit wird auch
auf Untersuchungsstrategien, mögliche Komplikationen und deren Behandlungsmöglichkeit durch die perkutane Interventionstechnik
eingegangen.
Vascular ultrasound has been proven to be effective in the assessment of hemodialysis fistulas providing noninvasive diagnostic
work-up of vascular morphology and hemodynamics. The most common reason for hemodialysis fistula failure is thrombosis due
to stenosis. Therefore, early identification of stenosis is essential to avoid complications. Ultrasound-based identification
of hypoechoic plaques and intimal proliferation helps to reach therapeutic decisions. An estimation of the grade of stenosis
is also feasible. An occlusion rate of up to 45% due to reduced blood flow justifies follow-up examinations. Due to frequent
puncture of the fistula the risk of hemodynamically relevant stenoses is increased. Establishment of new ultrasound methods
like B-flow and advanced dynamic flow (ADF) enable direct visualization of the flow in the area of the anastomosis. In addition,
high-resolution ultrasound techniques allow improved flow detection without aliasing. Our report addresses the topics of examination
strategy, possible complications, and treatment like percutaneous intervention techniques.
Der Radiologe 04/2012; 48(3):272-280. · 0.61 Impact Factor
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ABSTRACT: Der Nachweis oder Ausschluss von Endoleaks nach endovaskulärer Aneurysmaoperation (EVAR) der infrarenalen Aorta stellt eine
schwierige diagnostische Herausforderung dar. Die kontrastmittelverstärkte Sonographie (CEUS) ist eine neue und viel versprechende
Methode für die Diagnose und die Verlaufskontrolle von Endoleaks. Die CEUS mit dem Kontrastmittel SonoVue® ermöglicht eine
schnelle, nichtinvasive Diagnostik im Follow-up nach endovaskulärer Therapie des infrarenalen Bauchaortenaneurysmas. Sensitivität
und Spezifität des konventionellen Ultraschalls im Vergleich zur Multislice-CT-Angiographie (MS-CTA) werden mit 33–63 bzw.
63–93% angegeben. Diese Werte können durch den Einsatz der CEUS auf 98–100% (Sensitivität) bzw. 82–93% (Spezifität) gesteigert
werden. Dieser Beitrag beschreibt die Ätiologien, die Klassifikation und Bedeutung von Endoleaks und deren Auffindbarkeit
mit Hilfe von CEUS.
Endoleaks following endovascular aneurysm repair (EVAR) are common and present a diagnostic challenge in the follow-up after
EVAR. Contrast-enhanced ultrasound (CEUS) is a promising new method for the diagnosis and follow-up of endoleaks. CEUS with
SonoVue® allows a rapid and non-invasive diagnosis in the follow-up after EVAR. The sensitivity and specificity of conventional
ultrasound compared to the multislice CT angiography is estimated to be 33–63% and 63–93%, respectively. These values can
be increased through the use of CEUS in up to 98–100% (sensitivity) and 82–93% (specificity). This article describes the etiology,
classification and importance of different types of endoleaks. The value of CEUS in this clinical scenario will be discussed.
Der Radiologe 04/2012; 49(11):1033-1039. · 0.61 Impact Factor
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ABSTRACT: Die Ultraschalluntersuchung der extrakraniellen hirnversorgenden Arterien ermöglicht die gleichzeitige Erfassung morphologischer
und hämodynamischer Befunde in hoher örtlicher und zeitlicher Auflösung. Für die Stenosedetektion und -quantifizierung an
der A.carotis und A.vertebralis ist die intrastenotische systolische Maximalgeschwindigkeit von mehr als 120cm/s der Schwellenwert
für eine >50%ige Diameterreduktion. Daneben existieren weitere direkte und indirekte Stenoseparameter (intra- und poststenotische
Strömungsstörungen, erhöhte Pulsatilität in der prästenotischen A.carotis communis [ACC], intra- oder extrakranielle Umgehungskreisläufe),
die in der Zusammenschau mit der Durchmesser- und Flächenreduktion im B-Bild zu einer hohen Zuverlässigkeit der Farbduplexsonographie
(FKDS) bei Stenosen der A.carotis interna (ACI) führen. Sonographisch-pathoanatomische Vergleichsstudien haben bei gleichzeitiger
Verwendung mehrerer Ultraschallkriterien eine hohe Übereinstimmung gezeigt (r >0,9). Nach Stenting der ACI sind die Flussgeschwindigkeiten
im Stent generell erhöht, sodass erst ab einer systolischen Flussbeschleunigung von 300–450cm/s von einer ≥70%igen In-stent-Restenose
gesprochen wird. Bei der Beschreibung arteriosklerotischen Plaques im B-Bild sollten keine histologischen Begriffe, sondern
vielmehr die Ultraschallterminologie zur Beschreibung der Plaquebinnenstruktur, -oberfläche und -bewegung sowie Schallschattenbildung
verwendet werden.
Ultrasound examination of extracranial blood-supplying arteries allows the simultaneous acquisition of morphologic and hemodynamic
information with high spatial and temporal resolution. For detection and quantification of stenoses in the carotid and vertebral
arteries, an intrastenotic peak systolic velocity of more than 120cm/s is the threshold value for a diameter reduction of
>50%. In addition there are further direct and indirect stenosis parameters (intrastenotic and poststenotic circulation disturbance,
increased pulsatility in the prestenotic common carotid artery, intracranial or extracranial collateral pathways) which together
with diameter and area reduction in the B-scan, lead to a high reliability of color duplex sonography for stenoses of the
internal carotid artery (ICA). Sonographic and patho-anatomic comparative studies have shown a high agreement (r >0.9) by
using a battery of several ultrasound criteria. Following stenting of the ICA the blood flow velocity in the stent is generally
increased so that a ≥70% in-stent restenosis is present in case of a peak systolic velocity of 300-450cm/s. For the description
of arteriosclerotic plaques in the B-scan, ultrasound terminology but not histological terms should be used to describe the
internal, surface and motion structure of plaques as well as the sonic shadow formation.
Der Radiologe 04/2012; 49(11):1016-1023. · 0.61 Impact Factor
