Als Teil der multiparametrischen MRT der Prostata ist die Akquisition von diffusionsgewichteten Sequenzen mit b-Werten von über 1500 s/mm2 zeitaufwändig und artefaktanfällig, hier stellt die Berechnung auf der Grundlage mehrere Datensätzen mit geringeren b-Werten eine Alternative dar, von der berichtet wird, dass die Tumordetektion verbessert und gesundes Gewebe besser supprimiert wird. Wir untersuchten anhand von MR-geführten Prostatabiopsien, welchen Einfluss die in der Berechnung gewählten b-Werte und die räumliche Auflösung auf den positiven prädiktiven Wert hat.

Purpose To assess the apparent diffusion coefficient (ADC) derived from diffusion‐weighted (DW) magnetic resonance imaging (MRI) as a specific marker of renal fibrosis in rats with unilateral ureteral obstruction (UUO). Materials and Methods Thirteen rats were analyzed in group 1 ( n = 4), group 2 ( n = 3), and group 3 ( n = 6) and measured using a clinical 3.0T MR scanner. Groups 1 and 2 were used to establish the final imaging protocols for group 3. DW imaging with four b‐values (0, 50, 300, 800 s/mm 2 ) was conducted before UUO, at days 3 and 5 after UUO, after release of the obstruction, and after sacrifice. Renal cortical ADCs were correlated with histological and ultrastructural analyses. Results ADC values of group 3 are shown as mean ± standard deviation of [10 −3 mm 2 /s]. On day 5, in vivo cortical ADC of obstructed fibrotic kidneys was significantly reduced compared to unobstructed kidneys (1.4 ± 0.086 vs. 1.535 ± 0.087, P = 0.0018). Postmortem ADC dropped by 50% and was significantly increased in obstructed vs. unobstructed kidneys (0.711 ± 0.094 vs. 0.566 ± 0.049, P = 0.0046). Histopathology of obstructed kidneys showed tubular dilation, tubular cell atrophy, and expansion of the interstitial space. Postmortem ADC correlated tightly with tubular lumen area ( r = 0.9, P < 0.001), fibronectin ( r = 0.8, P = 0.003), collagen type I ( r = 0.73, P = 0.007), and interstitial expansion ( r = 0.69, P = 0.013). Conclusion Compared to the in vivo measurements, postmortem renal ADCs were considerably reduced and, unlike in vivo, fibrotic kidneys exhibited consistently higher ADC compared to healthy kidney parenchyma. Our data suggest that in vivo ADC is unlikely to be a direct measure of renal fibrosis. J. Magn. Reson. Imaging 2015;42:990–998.

Background: Myocardial deformation analysis by speckle-tracking echocardiography (STE) has been shown to accurately predict viability in patients with chronic ischemic left ventricular (LV) dysfunction. The aim of this study was to evaluate two-dimensional STE for the prediction of global and segmental LV functional changes after acute myocardial infarction (AMI) in comparison with late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR).Methods: In 93 patients (mean age, 60 +/- 11 years) with first AMIs (55 with ST-segment elevation myocardial infarctions and 38 with non-ST-segment elevation myocardial infarctions) treated with acute percutaneous coronary intervention, global peak longitudinal strain was determined to describe global function by STE, and peak systolic circumferential and longitudinal strain was determined for segmental function analysis. LGE CMR was performed to define the amounts of global and segmental myocardial scar. STE and LGE CMR were performed within 48 hours of AMI. At 6-month follow-up, transthoracic echocardiography was repeated to determine global and segmental LV recovery and adverse LV remodeling (increase in end-systolic volume > 15%).Results: Accuracy to predict global functional improvement as well as LV remodeling at 6-month follow-up after AMI was similar for STE and LGE CMR (areas under the curve, 0.715 vs 0.729 [P = .8830] and 0.806 vs 0.824 [P = .7141], respectively). Peak systolic circumferential strain < -14.2% had sensitivity of 71.6% and specificity of 58.1% to predict segmental functional improvement. Compared with LGE CMR, the predictive accuracy of transmural STE for segmental functional improvement at 6-month follow-up was lower (area under the curve, 0.788 vs 0.668; P = .0001). Predictive accuracy for segmental functional improvement could be improved by analysis of endocardial circumferential strain (area under the curve, 0.700 vs 0.668 for transmural speckle-tracking echocardiographic analysis; P = .0023).Conclusions: Two-dimensional STE allows the prediction of global functional recovery as well as LV remodeling after AMI with accuracy comparable with that of LGE CMR. Accuracy to predict segmental functional recovery using transmural deformation analysis by two-dimensional STE is inferior compared with LGE CMR but can be improved by a layer-specific analysis of endocardial deformation.

Purpose: To assess physiological spinal cord motion during the cardiac cycle compared with the influence of respiration based on magnetic resonance imaging (MRI) measurements.Materials and Methods: Anterior-posterior spinal cord motion within the spinal canal was assessed in 16 healthy volunteers (median age, 25 years) by cardiac-triggered and cardiac-gated gradient echo pulse sequence MRI. Image acquisition was performed during breath-holding, normal breathing, and forced breathing. Normal spinal cord motion values were computed using descriptive statistics. Breathing-dependent differences were assessed using the Wilcoxon signed-rank test and compared with the cardiac-based cord motion.Results: A normal value table was set up for the spinal cord motion of each vertebral cervico-thoracic-lumbar segment. Significant differences in cord motion were found between cardiac-based motion while breath-holding and the two breathing modalities (P < 0.01 each). Spinal cord motion was found to be highest during forced breathing, with a maximum in the lower cervical spinal segments (C5; mean, 2.1 mm +/- 1.17). Image acquisition during breath-holding revealed the lowest motion.Conclusion: MRI permits the demonstration and evaluation of cardiac and respiration-dependent spinal cord motion within the spinal canal from the cervical to lumbar segments. Breathing conditions have a considerably greater impact than cardiac activity on spinal cord motion.Key points:Cardiac-triggered and ECG-gated MRI allows for demonstration of the smallest spinal cord motions.Respiratory influences seem to have the highest impact on spine motion.In contrast, the influence of the cardiac cycle seems to be small.The smallest spinal cord motions were measured during breath-hold.

AIMS:Separate analysis of endocardial and epicardial myocardial layer deformation has become possible using strain-encoded cardiovascular magnetic resonance (SENC) and 2D-dimensional speckle tracking echocardiography (Echo). This study evaluated and compared both modalities for the assessment of infarct transmurality as defined by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR).METHODS AND RESULTS:In 29 patients (age 62.4 ± 11.7 years, 23 male) with ischaemic cardiomyopathy, SENC using 1.5 T CMR and Echo were performed. Peak circumferential systolic strain of the endocardial and the epicardial layer of 304 myocardial segments was assessed by SENC and by Echo. The segmental transmurality of myocardial infarction was determined as relative amount of LGE (0%: no infarction; 1-50%: non-transmural infarction; 51-100%: transmural infarction). Endocardial and epicardial strain defined by SENC and by Echo differed significantly between segments of different infarct transmurality determined by CMR. Endocardial layer circumferential strain analysis by Echo and by SENC allowed distinction of segments with non-transmural infarction from non-infarcted segments with similar accuracy [area under the curve (AUC) 0.699 vs. 0.649, respectively, P = 0.239]. Epicardial layer circumferential strain analysis by Echo and by SENC allowed distinction of transmural from non-transmural myocardial infarction defined by LGE CMR with similar accuracy (AUC 0.721 vs. 0.664, respectively, P = 0.401). Endocardial strain by SENC correlated moderately with endocardial strain by Echo (r = 0.50; standard error of estimate = 5.2%).CONCLUSION:Layer-specific analysis of myocardial deformation by Echo and by SENC allows discrimination between different transmurality categories of myocardial infarction with similar accuracy. However, accuracy of both methods is non-optimal, indicating that further tools for improvement should be evaluated in the future.

In this work, a finite element model was created using MRI scans of the main author to analyze sources of the dynamic thoracic bioimpedance. This model can be used to identify limitations of impedance cardiography (ICG) in practice. Heart beat (8.3 ms temporal resolution) and aortic wave propagation (2.6 ms temporal resolution) were implemented. The static volume contains all major organs of the thorax in high spatial resolution. Simulations were successfully conducted and a high correlation (r = 0.9) between the simulated aortic ICG signal and a measured signal of the same subject was obtained.

Ziele: Wir untersuchten die Bildgebungscharakteristik von Regionen, die für eine MRT-geführte Prostatabiopsie ausgewählt wurden und verglichen diese mit der Histologie der hier gewonnenen Biopsate. Methode: Die Einschlusskriterien waren Serum PSA >4µg/l und mindestens 2 TRUS-geführte Prostatabiopsien ohne Karzinomnachweis. Bei 13 Patienten (mittleres Alter 66 Jahre) wurden eine diagnostische MRT der Prostata und eine MRT-geführte Prostatabiopsie in einem 3 Tesla System (Achieva, Philips Medical Systems, Best, the Netherlands) durchgeführt. Die anatomische Bildgebung der Prostata erfolgte mit einem standardisierten Protokoll, welches multiplanare hochauflösende T2-gewichtete Sequenzen, dynamische kontrastanreichernde Sequenzen und diffusionsgewichtete Sequenzen einschloss und mittels Sechskanal-Oberflächenspule aufgenommen wurde. An einem zweiten Termin innerhalb 1–4 Wochen erfolgte die MRT-geführte Prostatabiopsie der identifizierten karzinomverdächtigen Regionen mit dem Invio DynaTRIM Gerät (Invivo, Orlando, USA). Mit der Histologie als Goldstandard wurden der prädiktive Wert der Bildgebung bezüglich T2-, ADC- (Apparent Diffusion Coefficient), T0- und TTP- (time to peak) Parametern verglichen. Ergebnis: Histologisch wurde ein Prostatakarzinom in 11 Biopsien von 7 Patienten nachgewiesen. Ein signifikant geringerer ADC (p<0.01) wurde in den Regionen mit high grade Tumoren (Gleason 8 oder 9, G89 Gruppe, ADC=0.609 ± 0.104mm2/s) im Vergleich zu den mittelgradigen Tumoren (Gleason 6 oder 7, G67 Gruppe, ADC=0.878 ± 0.120mm2/s) gefunden. Zudem zeigte sich ein signifikant geringerer ADC (p<0.01) beim Vergleich der mittelgradigen Tumoren mit den tumorfreien Regionen (NoPCa Gruppe, ADC=1.209 ± 0.345mm2/s). Schlussfolgerung: Der ADC-Wert in suspekten Regionen hat unter den untersuchten Parametern den besten prädiktiven Wert zur Detektion eines Prostatakarzinomes bei der MRT-geführten Biosie von Patienten nach mehrfacher negativer Ultraschall-geführter Biopsie.

Definitive radiation therapy is a well-recognized curative treatment option for localized prostate cancer. A suitable technique, dose, target volume and the option of a combination with androgen deprivation therapy need to be considered. An optimal standard external beam radiotherapy currently includes intensity-modulated and image-guided radiotherapy techniques with total doses of ≥76–78 Gy in conventional fractionation. Protons or carbon ions are alternatives available only in specific centers. Data from several randomized studies increasingly support the rationale for hypofractionated radiotherapy. A simultaneous integrated boost with dose escalation focused on a computed tomography/PET- or MRI/magnetic resonance spectroscopy-detected malignant lesion is one option to increase tumor control, with potentially no additional toxicity. The application of a spacer is a promising concept for optimal protection of the rectal wall.

The purpose of this paper was to evaluate computed tomography (CT) based electromagnetically tip-tracked (EMT) interventions in various clinical applications. An EMT system was utilized to perform percutaneous interventions based on CT datasets. Procedure times and spatial accuracy of needle placement were analyzed using logging data in combination with periprocedurally acquired CT control scans. Dose estimations in comparison to a set of standard CT-guided interventions were carried out. Reasons for non-completion of planned interventions were analyzed. Twenty-five procedures scheduled for EMT were analyzed, 23 of which were successfully completed using EMT. The average time for performing the procedure was 23.7 ± 17.2 min. Time for preparation was 5.8 ± 7.3 min while the interventional (skin-to-target) time was 2.7 ± 2.4 min. The average puncture length was 7.2 ± 2.5 cm. Spatial accuracy was 3.1 ± 2.1 mm. Non-completed procedures were due to patient movement and reference fixation problems. Radiation doses (dosis-length-product) were significantly lower (p = 0.012) for EMT-based interventions (732 ± 481 mGy x cm) in comparison to the control group of standard CT-guided interventions (1343 ± 1054 mGy x cm). Electromagnetic navigation can accurately guide percutaneous interventions in a variety of indications. Accuracy and time usage permit the routine use of the utilized system. Lower radiation exposure for EMT-based punctures provides a relevant potential for dose saving.

Background and purpose The aim was to evaluate the impact of a spacer gel on the dose distribution, applying three-dimensional conformal (3D CRT) and intensity modulated radiotherapy (IMRT) planning techniques. Material and methods The injection of a spacer gel (10 ml SpaceOAR™) was performed between the prostate and rectum under transrectal ultrasound guidance in 18 patients with prostate cancer. 3D CRT and IMRT treatment plans were compared based on CT before and after injection (78 Gy prescription dose). Results In contrast to the PTV and bladder, significant advantages (p < 0.01) resulted in respect of all analysed rectal dose values comparing pre spacer with post spacer plans for both techniques. Rectal NTCP (normal tissue complication probability) reached the lowest percentage after spacer injection irrespective of the technique, with a mean reduction of >50% for both IMRT and 3D CRT. Significantly (p < 0.01) higher Dmean, and V78 for the PTV were reached with IMRT vs. 3D CRT plans, with a smaller rectum V76 but larger rectum V50. Conclusions The injection of a spacer gel between the prostate and anterior rectal wall is associated with considerably lower doses to the rectum and consequentially lower NTCP values irrespective of the radiotherapy technique.

During the past years, magnetic resonance imaging (MRI) has been established as a reliable method for examination of the kidneys. Modern MRI systems enable to visualize renal masses with a high spatial resolution. This enables not only to differentiate between benign lesions and renal cancer but also to define the tumor stage with high accuracy. The impact of a precise preoperative staging has increased significantly due to stage adapted therapy approaches such as nephron sparing surgery or local ablative techniques (e.g. radiofrequency ablation). Tumor-related infiltration of the renal pelvis, infiltration of the perinephric fat or a tumor thrombus within the inferior caval vein has to be diagnosed with high accuracy to enable these stage adapted treatment regimens. This article introduces into clinically established "morphologic" MRI techniques for diagnosis and staging of renal cell carcinoma (RCC). Besides detection and staging of kidney cancer, the recent development of molecularly targeted therapies in patients with metastatic or non-operable tumors has led to novel diagnostic demands. To evaluate treatment efficiency, more information than just tumor morphology should be provided. Functional imaging techniques including dynamic contrast enhanced (DCE) MRI, diffusion weighted imaging (DWI), arterial spin labeling (ASL) and MR-spectroscopy are being investigated in preclinical and clinical trials. While some new techniques have shown promising results for a broad clinical application, others seem to be suited for dedicated questions only.

Ziele: Wir untersuchten die Durchführbarkeit einer Hochdruckinjektion via ein dafür zugelassenes Port-System zur kontrastangehobenen Spiral-CT versus eine Injektion über einen üblichen peripheren Venenzugang. Das Augenmerk wurde hierbei insbesondere auf den erzielten Kontrast sowohl auf Gefäßebene als auch auf Parenchymebene gesetzt. Methode: 43 onkologische Patienten (Durchschnittsalter 63±6J) wurden im Rahmen des Stagings zwei kontrastangehobene Spiral-CTs ausgesetzt. Für die erste Untersuchung erfolgte die Kontrastmittelinjektion über einem peripheren 18-G Venenzugang. Nach zwischenzeitlicher Port-Anlage (PowerPort, Bard Access System, UT, USA) erfolgte im Rahmen der zweiten CT-graphischen Untersuchung die Kontrastmittelinjektion über das Port-System. Beide Untersuchungen erfolgten unter identischen Bedingungen und identischen Injektionsprotokollen. Das zeitliche Intervall zwischen beiden Untersuchungen lag bei 142±56 Tagen. Die Dichtewertemessungen in unterschiedlichen arteriellen Gefäßen und im Leberparenchym erfolgten im intraindividuellen Vergleich. Zur statistischen Analyse wurden ein ANOVA-Test und ein gepaarter t-Test berechnet. Ergebnis: Alle Untersuchungen erfolgten ohne jegliche Komplikation. Die Dichtewertemessungen ergaben einen signifikant höheren Kontrast auf allen gemessenen Ebenen zugunsten der Kontrastmittelinjektion über das Port-System (p<0.01). Schlussfolgerung: Die Hochdruckinjektion über ein dafür zugelassenes Port-System zur kontrastangehobenen Spiral-CT ist ein sicheres Verfahren, welches in Hinblick auf den häufig desaströsen peripheren Venenzustand onkologischer Patienten von Vorteil ist. Ferner bietet sie den Vorteil eines signifikant höheren Gefäßkontrastes.

Purpose: In this study we assessed the effect of an interactive breath-hold control system on procedure time and technical success in transthoracic CT-guided lung biopsies.Materials and Methods: In 36 patients (4 female, 32 male, mean age 65 years; range 33 - 88) with a pulmonary nodule, we performed CT-guided biopsy using a 18G Tru-cut needle (Cardinal Health, Dublin, UK) in a 64 row dual-source CT scanner (Somatom Definition, Siemens, Forchheim, Germany) using intermittent imaging of the needle. In half of the patients (2 female, 16 male, mean age 67 years), an interactive breath-hold control system (IBC) (Mayo Clinic Medical Devices, USA) was applied. No additional device was used in the control group.Results: The biopsy was visually successful in all patients. The diameter of the target lesion was comparable in both groups (IBC: 30 +/- 19 mm; control: 28 +/- 15 mm). The number of imaging steps was significantly smaller (p < 0.05) and the intervention time was significantly shorter (p < 0.05) in the IBC group (IBC: 9 +/- 5 steps 17 +/- 10 min; control: 13 +/- 5 steps 26 +/- 12 min).Conclusion: Application of the IBC unit reduced the intervention time and radiation exposure in CT-guided Tru-cut biopsy of pulmonary nodules.

Purpose: To determine the safest and most tolerable method for totally implantable access ports (TIAPs) particularly in regard to patient's pain perception and catheter-related complications.Materials and methods: From January 2007 to October 2008 a subcutaneous TIAP (Bardport, Bard Access System, UT, USA) was implanted in 138 oncological patients (60 male, 78 female; 18-85 years old; mean age of 56 +/- 6 years) by experienced interventional radiologists. 94 TIAP were implanted through the subclavian vein (subclavian group) and 44 TIAP were implanted through the internal jugular vein (jugular group). Intrainterventional pain perception (visual analogue scale from 1 to 10), postinterventional catheter tip migration and radiation dose were documented for each method and implantation side and differences were compared with Wilcoxon t-test. For ordinal variables, comparison of two groups was performed with the Fisher's exact test.Results: No severe periinterventional complication occurred. Inadvertent arterial punctures without serious consequences were reported in one case for the jugular group versus four cases in the subclavian group. Significantly (p < 0.05) lower pain perception, radiation dose and tip migration rate were observed in the jugular group. Catheter occlusions occurred in 4% (n = 4) of the subclavian group versus 2% (n = 1) of the jugular group. The corresponding values for vein thrombosis and catheter dislocation were 3% (n = 3) and 1% (n = 1) in the subclavian group, while none of those complications occurred in the jugular group.Conclusion: Both techniques, the TIAP implantation via fluoroscopy-guided subclavian vein puncture and via ultrasound-guided jugular vein puncture, are feasible and safe. Regarding intrainterventional pain perception, radiation dose, postinterventional catheter tip position and port function the jugular vein puncture under ultrasound guidance seems to be advantageous. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

OBJECTIVE:To compare image quality and accuracy of left ventricular function of cine SSFP (steady-state free precession) images before and after injection of Gd-DTPA.METHODS:In 30 patients T1 times of LV blood and myocardium were measured before and after injection of 0.2 mmol/kg body weight Gd-DTPA. Signal intensity of myocardium and left ventricular blood were measured on SSFP images and the contrast calculated. In 20 additional patients short axis images completely covering the left ventricle were acquired before and after injection of Gd-DTPA and parameters of left ventricular function compared. Image quality and regional function were assessed using the 17-segment model.RESULTS:Image quality after injection of contrast medium did not significantly change compared with unenhanced images. Contrast between myocardium and LV blood decreased from 0.6 ± 0.01 to 0.4 ± 0.03 after injection while the T1 value of myocardium decreased from 1121 ± 21 ms to 389 ± 14 ms (blood 1413 ± 48 ms to 222 ± 8 ms). Assessment of regional and global left ventricular function revealed similar results before and after the injection of contrast medium.CONCLUSION:Cine SSFP can be obtained after injection of contrast medium without loss of accuracy for regional and global LV ventricular function. This protocol can be used to decrease imaging time for thorough cardiac examination.

Ziele: Die klinische Effizienz und Genauigkeit von auf computertomographischen Daten basierter elektromagnetischer Navigation (EMT) in verschiedenen klinischen Anwendungen zu evaluieren. Methode: Ein klinisch zugelassenes EMT System (iGuide Cappa, Siemens Medical, Forchheim, Deutschland) wurde für CT-basierte Interventionen im klinischen Einsatz verwendet. Prozedurzeit und Genauigkeit wurden anhand aufgezeichneter Logdaten zusammen mit während der Prozedur aufgenommenen CT-Kontrollen analysiert. Gründe für einen Abbruch der Intervention wurden analysiert. Ergebnis: 26 Prozeduren wurden für eine elektromagnetische Navigation vorgesehen (13 Drainageanlagen, 5 Biopsien, 3 Sympathicolysen, eine Radiofrequenzablation, eine Facettengelenkspunktion, eine Kyphoplastie, eine Drahtmarkierung und eine Diskographie) von denen 23 erfolgreich durchgeführt werden konnten. Die durchschnittliche Zeit für die Durchführung der Intervention betrug 23,7±17min. Die Vorbereitungszeit lag im Mittel bei 5,8±7,2min und die Interventionszeit (skin-to-target) lag bei 2,6±2,4min. Die Punktionslänge war durchschnittlich 7,2±2,5cm. Die örtliche Genauigkeit lag bei 3,1±2,1mm. Gründe für den Abbruch von Interventionen waren starke Patientenbewegung, Probleme bei der Fixierung der Referenzierung und das Fehlen einer drainierbaren Formation. Schlussfolgerung: CT-basiert, elektromagnetisch geführte Interventionen können im klinischen Einsatz in verschiedenen Fragestellungen präzise und mit vertretbarem Zeitaufwand durchgeführt werden. Das System erleichtert besonders bei schwierigen, doppelt-angulierten Zugängen die Punktion.

Cardiac magnetic resonance imaging (MRI) is an important tool for the diagnosis of cardiac masses. Various cardiac tumors are predisposed to occurring in atrial structures. The aim of this review article is the description of atrial tumors and their morphological features in MRI. In general, cardiac tumors are rare: approximately 0.001 - 0.03 % in autopsy studies. About 75 % of them are benign. The most common cardiac tumor is the myxoma. They are predisposed to occur in the atria and show a characteristically strong hyperintense signal on T 2-wieghted images in MRI. In other sequences a heterogeneous pattern reflects its variable histological appearance. Lipomas exhibit a signal behavior identical to fatty tissue with a typical passive movement in cine imaging. Fibroelastomas are the most common tumors of the cardiac valves. Consisting of avascular fibrous tissue, they often present with hypointense signal intensities. Thrombi attached to their surface can cause severe emboli even in small tumors. Amongst primary cardiac malignancies, sarcomas are most common and favor the atria. Secondary malignancies of the heart are far more common than primary ones (20 - 40 times). In case of known malignancies, approximately 10 % of patients develop cardiac metastasis at the end of their disease. Lymphogenic metastases favor the pericardium, while hematogenic spread prefers the myocardium. Since they are not real atrial tumors, thrombi and anatomical structures of the atria have to be differentiated from other pathologies.

In der Differenzialdiagnostik kardialer Raumforderungen spielt die Magnetresonanztomografie (MRT) neben der Echokardiografie eine bedeutende Rolle. Verschiedene kardiale Tumoren zeigen ein gehäuftes Auftreten in den Vorhöfen. Ziel dieser Übersichtsarbeit ist die Beschreibung dieser verschiedenen Vorhoftumoren, ihrer Eigenschaften und Klinik sowie ihrer kernspintomografischen Morphologie. Allgemein sind Herztumoren mit einer Prävalenz von ca. 0,001– 0,03% in Autopsiestudien eine sehr seltene Erkrankung und mit ca. 75% überwiegend benigner Natur. Das Myxom ist der häufigste Herztumor, der die Vorhöfe bevorzugt. Charakteristisch ist eine starke T2-Hyperintensität bei ansonsten inhomogenem, teils hyper-, teils hypointensem Signalverhalten, das mit dem uneinheitlichen histologischen Erscheinen korreliert. Lipome liegen subendokardial und zeigen ein fettisointenses Signalverhalten, das sich durch Fettsuppressionstechniken minimieren lässt. Fibroelastome sind die häufigsten Tumoren der Herzklappen und bestehen aus avaskulärem Bindegewebe, das sich relativ signalarm darstellt. Auf ihrer faserigen Oberfläche lagern sich leicht Thromben auf, sodass auch sehr kleine Tumoren früh durch Embolien symptomatisch werden können. Bei den selteneren malignen Tumoren überwiegen Sarkome, wobei vor allem Angiosarkome und Rhabdomyosarkome kardial am häufigsten auftreten und eine Präferenz für die Vorhöfe aufweisen. Sekundäre Malignome des Herzens sind ca. 20bis 40fach häufiger als primäre und treten bei einer bestehenden Malignomerkrankung in ca. 10% der Fälle im späten Krankheitsverlauf auf. Lymphogene Metastasen bevorzugen das Perikard, die hämatogene Metastasierung befällt vor allem das Myokard. Von den eigentlichen Vorhoftumoren müssen zudem auch Thromben oder anatomische Normvarianten unterschieden werden. Abstract !

Gadobenate (Gd-BOPTA), injected at a dose of 0.1 mmol/kg body weight, was compared with gadopentetate (Gd-DTPA), injected at a dose of 0.2 mmol/kg body weight, for delineation of myocardial infarction interindividually in two groups of 26 patients each. Delayed enhancement images were assessed subjectively for image quality, and measured for regional T1 values before, 3 min after and 25 min after the injection of each contrast agent. In the 26 patients who received Gd-BOPTA, T1 values of remote myocardium were 1,070 +/- 125 ms, 358 +/- 78 ms and 562 +/- 108 ms before, 3 min after and 25 min after injection, respectively. Infarcted myocardium values were 1,097 +/- 148 ms, 246 +/- 68 ms and 373 +/- 84 ms and left ventricular blood pool 1,238 +/- 95 ms, 194 +/- 47 ms and 373 +/- 72 ms. In the 26 patients who received Gd-DTPA, T1 values were 1,087 +/- 96 ms, 325 +/- 60 ms and 555 +/- 108 ms for remote myocardium; 1,134 +/- 109, 210 +/- 43 ms and 304 +/- 57 ms for infarcted myocardium; and 1,258 +/- 104 ms, 166 +/- 27 ms and 351 +/- 73 ms for left ventricular blood pool. Delayed enhancement image quality showing myocardial infarction was rated good (54%) and excellent (46%) after Gd-BOPTA, and good (58%) and excellent (42%) after Gd-DTPA (no significant differences). A single dose of Gd-BOPTA compared with a double dose of Gd-DTPA causes similar changes of T1 values in infarcted and remote myocardium and provides fairly similar contrast between infarcted and remote myocardium (0.64 +/- 14 versus 0.71 +/- 11) and slightly higher contrast between left ventricular blood and infarcted myocardium (0.22 +/- 17 versus 0.14 +/- 6; p < 0.05). Administration of 0.1 mmol/kg body weight Gd-BOPTA can provide similar late enhancement images compared with the standard 0.2 mmol/kg body weight dose of Gd-DTPA due to the higher T1 relaxivity associated with the former.