D Roggenland

CT Angiography in Suspected Pulmonary Embolism: Impact of Patient Characteristics and Different Venous Lines on Vessel Enhancement and Image Quality

OBJECTIVE The objective of our study was to compare image quality, patient characteristics, and different catheters in pulmonary CT angiography (CTA) performed with bolus tracking and z-axis automated tube current modulation (ATCM) in patients with suspected pulmonary embolism. SUBJECTS AND METHODS One hundred twenty-six patients were referred to undergo pulmonary CTA with bolus tracking and ATCM. Besides patient characteristics, the type, position, size, and side of venous catheters were documented. Pulmonary vessel enhancement and image noise were quantified; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective vessel contrast was assessed by two radiologists in consensus. RESULTS Patient age showed a moderate but significant positive correlation to vessel enhancement (r = 0.244, p = 0.006), CNR (r = 0.178, p = 0.046), and subjective image quality (r = 0.344, p < 0.001). Patient weight revealed a significant negative correlation to vessel enhancement (r = -0.496, p < 0.001), SNR (r = -0.446, p < 0.001), CNR (r = -0.425, p < 0.001), and subjective image quality (r = -0.422, p < 0.001). In univariate analysis, SNR and CNR were significantly higher in patients who received contrast medium through peripheral catheters (30 +/- 13 and 27 +/- 13, respectively) than in those in whom central catheters were used (22 +/- 8 and 19 +/- 7, p = 0.041 and p = 0.029, respectively). Neither patient sex nor catheter size, position, or side had any significant impact on image quality. CONCLUSION Patient age and weight showed significant impact on vascular attenuation and image quality in pulmonary CTA with bolus tracking and ATCM, whereas patient sex and different peripheral catheters did not significantly influence image parameters.

Cumulative Effective Dose Associated With Radiography and CT of Adolescents With Spinal Injuries

OBJECTIVE The purpose of this study was to analyze the quantity and distribution of cumulative effective doses in diagnostic imaging of adolescents with spinal injuries. MATERIAL AND METHODS At a level 1 trauma center from July 2003 through June 2009, imaging procedures during initial evaluation and hospitalization and after discharge of all patients 10-20 years old with spinal fractures were retrospectively analyzed. The cumulative effective doses for all imaging studies were calculated, and the doses to patients with spinal injuries who had multiple traumatic injuries were compared with the doses to patients with spinal injuries but without multiple injuries. The significance level was set at 5%. RESULTS Imaging studies of 72 patients (32 with multiple injuries; average age, 17.5 years) entailed a median cumulative effective dose of 18.89 mSv. Patients with multiple injuries had a significantly higher total cumulative effective dose (29.70 versus 10.86 mSv, p < 0.001) mainly owing to the significantly higher CT-related cumulative effective dose to multiple injury patients during the initial evaluation (18.39 versus 2.83 mSv, p < 0.001). Overall, CT accounted for 86% of the total cumulative effective dose. CONCLUSION Adolescents with spinal injuries receive a cumulative effective dose equal to that of adult trauma patients and nearly three times that of pediatric trauma patients. Areas of focus in lowering cumulative effective dose should be appropriate initial estimation of trauma severity and careful selection of CT scan parameters.

Endosonographie—eine zusätzliche diagnostische Möglichkeit bei der Differenzierung der beiden häufigsten Formen des primären Hyperaldosteronismus

ZusammenfassungHintergrund:Der primäre Hyperaldosteronismus hat in der Abklärung sekundärer Hypertonieursachen eine bedeutende Rolle. Bei der Diagnostik ist die Unterscheidung zwischen den beiden häufigsten Ursachen einer Mineralokortikoidhypertonie, dem aldosteronproduzierenden Adenom (APA) und dem idiopathischen Hyperaldosteronismus (beidseitige Nebennierenrindenhyperplasie; IHA), wichtig, da beide Formen prinzipiell unterschiedlich behandelt werden.Fallbeschreibung:Berichtet wird über den Fall eines 65-jährigen Patienten mit langjährig bekannter arterieller Hypertonie, bei dem eine suffiziente Blutdruckeinstellung nicht gelang und daher nach sekundären Hypertonieursachen gesucht wurde. In der Diagnostik fielen ein deutlich erhöhter Aldosteron/Renin-Quotient im Serum und erhöhte Werte für Aldosteron und dessen Metaboliten im 24-h-Sammelurin auf. Der daraufhin durchgeführte Salzbelastungstest ergab eine nicht ausreichende Suppression des Aldosterons, der zur differentialdiagnostischen Abklärung durchgeführte Orthostasetest zeigte einen Anstieg des Aldosterons, so dass von einem IHA ausgegangen werden musste. In der Bildgebung mittels MRT ließ sich kein pathologischer Befund der Nebennieren darstellen. Aufgrund der unklaren Konstellation der laborchemischen Tests und der Bildgebung wurde eine Endosonographie durchgeführt, mit welcher sich ein einseitiges Adenom darstellen ließ. Daraufhin konnte der Patient kurativ adrenalektomiert werden.Schlussfolgerung:Die Endosonographie spielt in der Differentialdiagnostik der beiden häufigsten Formen des primären Hyperaldosteronismus eine bedeutendere Rolle als bislang angenommen. Sie bietet eine Hilfestellung bei einer unklaren Konstellation von laborchemischen Tests und der Bildgebung mittels CT oder MRT. Anhand des Fallberichts wird das gegenwärtige diagnostische Vorgehen dargestellt.AbstractBackground:Primary aldosteronism is an important and one of the few potentially curable forms of secondary hypertension. The distinction between aldosterone-producing adenoma (APA) and idiopathic adrenal hyperplasia (IHA) may be difficult, but establishing the correct diagnosis is essential because surgery is only effective in patients with adrenal adenoma.Case Report:The case of a 65-year-old man with long-term hypertension due to an APA is reported. The routine laboratory tests displayed an elevated plasma aldosterone/renin quotient as well as an elevated 24-h urinary excretion of aldosterone and its metabolites. The serum aldosterone concentration did not decrease normally in the saline suppression test. The posture testing demonstrated an increase in aldosterone. These facts might lead to the conclusion of an IHA. Magnetic resonance imaging (MRI) of the adrenal glands revealed no abnormalities. Because of the unusual combination of laboratory findings and radiologic results an endosonographic examination of the adrenal glands was performed which yielded a unilateral adrenal adenoma. With establishing this diagnosis, curative surgery became possible.Conclusion:This case demonstrates that in the differential diagnosis of primary aldosteronism, endosonography is more important than previously discussed. It may be helpful in the differentiation of an unusual constellation of laboratory and radiologic findings.

Transient Simulation of the Blood Flow in the thoracic Aorta based on MRI-Data by Fluid-Structure-Interaction

High-grade heart valve stenoses and insufficiencies are supplied with prosthetic heart valves. In 2006, heart valve operations in Germany increased to 20,000.

Lagebeurteilung transpedikulärer Schrauben nach dorsaler Spondylodese mittels konventioneller Röntgenaufnahmen: ein Vergleich zur Mehrzeilen-Computertomografie

PURPOSE To evaluate the performance of conventional radiographs (CR) for the assessment of pedicle screws in comparison with CT including MPR. MATERIALS AND METHODS Comparison of CR and CT for the evaluation of screw length, extracorporal perforation (grade A: 0 - 2 mm, B: 3 - 4 mm, C: 5 - 6 mm, D: > 6 mm, relevant: grade C and D), screw contact/loosening, and subjective image quality (1: excellent to 4: non-diagnostic). The sensitivity (SE), specificity (SP), positive (PPV) and negative predictive value (NPV), and overall accuracy (OA) were calculated with 4x4 contingency tables. The subjective image quality was evaluated using the Wilcoxon test (p < 0.05). RESULTS 411 screws were evaluated. The relevant medial perforation was diagnosed with CR/CT in 53(13 %)/ 11(3 %) screws, while the relevant lateral perforation was found in 3(1 %)/ 43(11 %) screws. Pedicle screw contact was diagnosed by CR/CT in 10(2 %)/ 18(4 %) cases and incorrect length was confirmed in 80(20 %)/ 90(22 %) screws. A diagnosis of loosening was established in 10(2 %) screws by CR and in 7(2 %) screws by MDCT. In summary, CR demonstrated SE, SP, PPV, NPV, and OA for the following variables: relevant medial perforation = 64 / 89 / 13 / 99 / 88 %, relevant lateral perforation = 4 / 99 / 67 / 90 / 90 %, screw contact = 11 / 98 / 20 / 96 / 94 %, incorrect screw length = 86 / 58 / 89 / 51 / 81 %, and screw loosening = 71 %/ 99 %/ 50 %/ 100 %/ 98 %. The subjective image quality of CR was significantly lower compared to CT (2.19 A + or - 0.84 and 1.11 A + or - 0.31; p < 0.001). CONCLUSION CR evaluation of pedicle screws following dorsal instrumentation of the spine demonstrated an OA < or = 90 % for relevant medial and lateral perforation and for incorrect screw length compared to CT. Thus, reliable evaluation of pedicle screws based solely on CR does not seem feasible.

[Endosonography -- an additional diagnostic possibility in the differentiation between the two common types of primary hyperaldosteronism].

ZusammenfassungHintergrund:Der primäre Hyperaldosteronismus hat in der Abklärung sekundärer Hypertonieursachen eine bedeutende Rolle. Bei der Diagnostik ist die Unterscheidung zwischen den beiden häufigsten Ursachen einer Mineralokortikoidhypertonie, dem aldosteronproduzierenden Adenom (APA) und dem idiopathischen Hyperaldosteronismus (beidseitige Nebennierenrindenhyperplasie; IHA), wichtig, da beide Formen prinzipiell unterschiedlich behandelt werden.Fallbeschreibung:Berichtet wird über den Fall eines 65-jährigen Patienten mit langjährig bekannter arterieller Hypertonie, bei dem eine suffiziente Blutdruckeinstellung nicht gelang und daher nach sekundären Hypertonieursachen gesucht wurde. In der Diagnostik fielen ein deutlich erhöhter Aldosteron/Renin-Quotient im Serum und erhöhte Werte für Aldosteron und dessen Metaboliten im 24-h-Sammelurin auf. Der daraufhin durchgeführte Salzbelastungstest ergab eine nicht ausreichende Suppression des Aldosterons, der zur differentialdiagnostischen Abklärung durchgeführte Orthostasetest zeigte einen Anstieg des Aldosterons, so dass von einem IHA ausgegangen werden musste. In der Bildgebung mittels MRT ließ sich kein pathologischer Befund der Nebennieren darstellen. Aufgrund der unklaren Konstellation der laborchemischen Tests und der Bildgebung wurde eine Endosonographie durchgeführt, mit welcher sich ein einseitiges Adenom darstellen ließ. Daraufhin konnte der Patient kurativ adrenalektomiert werden.Schlussfolgerung:Die Endosonographie spielt in der Differentialdiagnostik der beiden häufigsten Formen des primären Hyperaldosteronismus eine bedeutendere Rolle als bislang angenommen. Sie bietet eine Hilfestellung bei einer unklaren Konstellation von laborchemischen Tests und der Bildgebung mittels CT oder MRT. Anhand des Fallberichts wird das gegenwärtige diagnostische Vorgehen dargestellt.AbstractBackground:Primary aldosteronism is an important and one of the few potentially curable forms of secondary hypertension. The distinction between aldosterone-producing adenoma (APA) and idiopathic adrenal hyperplasia (IHA) may be difficult, but establishing the correct diagnosis is essential because surgery is only effective in patients with adrenal adenoma.Case Report:The case of a 65-year-old man with long-term hypertension due to an APA is reported. The routine laboratory tests displayed an elevated plasma aldosterone/renin quotient as well as an elevated 24-h urinary excretion of aldosterone and its metabolites. The serum aldosterone concentration did not decrease normally in the saline suppression test. The posture testing demonstrated an increase in aldosterone. These facts might lead to the conclusion of an IHA. Magnetic resonance imaging (MRI) of the adrenal glands revealed no abnormalities. Because of the unusual combination of laboratory findings and radiologic results an endosonographic examination of the adrenal glands was performed which yielded a unilateral adrenal adenoma. With establishing this diagnosis, curative surgery became possible.Conclusion:This case demonstrates that in the differential diagnosis of primary aldosteronism, endosonography is more important than previously discussed. It may be helpful in the differentiation of an unusual constellation of laboratory and radiologic findings.

[Analysis of image acquisition, post-processing and documentation in adolescents with spine injuries - comparison before and after referral to a university hospital].

PURPOSE Systematic evaluation of imaging situation and standards in acute spinal injuries of adolescents. MATERIALS AND METHODS Retrospective analysis of imaging studies of transferred adolescents with spinal injuries and survey of transferring hospitals (TH) with respect to the availability of modalities and radiological expertise and post-processing and documentation of CT studies were performed. Repetitions of imaging studies and cumulative effective dose (CED) were noted. RESULTS 33 of 43 patients (77 %) treated in our hospital (MA 17.2 years, 52 % male) and 25 of 32 TH (78 %) were evaluated. 24-hr availability of conventional radiography and CT was present in 96 % and 92 % of TH, whereas MRI was available in only 36 %. In 64 % of TH, imaging expertise was guaranteed by an on-staff radiologist. During off-hours radiological service was provided on an on-call basis in 56 % of TH. Neuroradiologic and pediatric radiology expertise was not available in 44 % and 60 % of TH, respectively. CT imaging including post-processing and documentation matched our standards in 36 % and 32 % of cases. The repetition rate of CT studies was 39 % (CED 116.08 mSv). CONCLUSION With frequent CT repetitions, two-thirds of re-examined patients revealed a different clinical estimation of trauma severity and insufficient CT quality as possible causes for re-examination. A standardization of initial clinical evaluation and CT imaging could possibly reduce the need for repeat examinations.

Interventional radiology at the meetings of the German Radiological Society from 1998 to 2008: evaluation of structural changes and radiation issues

AbstractObjectivesEvaluation of structural changes and the weight given to radiation exposure of interventional radiology (IR) contributions at the Congress of the German Radiological Association from 1998 to 2008.MethodsAll IR abstracts were evaluated for type of contribution, design, imaging modality, and anatomic region. Weight given to radiation exposure was recorded as general statement, main topic and/or dose reduction. Statistical analysis included calculation of absolute/relative proportions of subgroups and ANOVA regression analyses.ResultsOut of 9,436 abstracts, 1,728 (18%) were IR-related. IR abstracts significantly rose to a maximum of 200 (20%) in 2005 (P = 0.048). While absolute numbers of scientific contributions declined, educational contributions significantly increased (P = 0.003). Computed tomography (CT) and magnetic resonance imaging (MRI) were the main IR imaging modalities, with growing use of CT (P = 0.021). The main body regions were vessels (45%) and abdomen (31%). Radiation exposure was addressed as a general statement in 3% of abstracts, as a main topic in 2%, and for dose reduction in 1%, respectively. During the study interval a significant growth of dose reduction abstracts was observed (P = 0.016).ConclusionsIR emerged as a growing specialty of radiology, with a significant increase in educational contributions. Radiation exposure was rarely in the focus of interest but contributions relating to dose reduction demonstrated a significant growth during the study period. Main MessagesInterventional radiology emerged as a growing specialty at the German radiological congress.Significant increments of educational and prospective research contributions could be observed.Despite a significant trend towards computed tomography, radiation exposure of IR was rarely in the focus of interest.Contributions related to dose reduction demonstrated a significant growth during the study period.

Atrioösophageale Fistel nach Ablation – kann der Radiologe helfen?

Die Zahl der Katheterablationen steigt in den letzten Jahren kontinuierlich an (18 in 1995, 5050 in 2002 und aktuell >23000 Falle in der medizinischen Literatur). Durch die steigende Anzahl der Interventionen gewinnnen jedoch auch die Komplikationen zunehmend an Bedeutung. Bei der Katheterablation handelt es sich mittlerweile in der Kardiologie um eine ubliche Technik und Therapie bei therapierefraktarem Vorhofflimmern, zusammen mit einer Pulmonalvenenisolation (uni- oder bipolare Sonden). Die Erfolgsrate liegt nach dem 1. Versuch bei ca.70–80%, beim 2. Versuch bei ca.90%, bei chronischem VHF bei ca.50%. Durch die Sonden resultiert eine Temperaturerhohung, auch im Osophagus. Komplikationsfordernd weist der Osophagus manchmal einen langstreckigen Verlauf mit direktem Kontakt zur dorsalen Wand des linken Vorhofs auf und ist haufig lediglich durch eine inkonstante periosophageale Fettschicht umgeben. Insgesamt sind atrioosophageale Fisteln als Komplikation nach einer Ablation sehr selten, die Inzidenz liegt bei 0,05–1%, sie haben aber eine extrem hohe Mortalitat. Die Komplikation tritt 1–5 Wochen nach der Intervention auf, wobei zur Diagnsotik die Echokardiographie und die CT geeignet sind. Am wichtigsten erscheint jedoch, dass daran gedacht werden sollte. Eine Gastroskopie und eine transosophageale Echokardiographie sind wegen todlicher systemischer Luftembolien kontraindiziert. Lernziele: Die atrioosophageale Fistel ist eine haufig todliche Komplikation, die mit der Echokardiographie und der CT diagnostiziert werden kann. Wichtiger erscheint aber die Sensibilisierung aller beteiligten Arzte fruh daran zu denken, da eine Gastroskopie und eine transosophageale Echo wegen Luftembolisationen kontraindiziert sind. Anhand des Posters soll diese seltene Komplikation anschaulich dargestellt werden. Keywords: Fistel, atrioosophageale Fistel, CT, Ablation, Komplikation Korrespondierender Autor: Roggenland D Berufsgenossenschaftliches Universitatsklinikum Bergmannsheil GmbH, Institut fur Diagnostische Radiologie, Interventionelle Radiologie und Nuklearmedizin, Burkle-de-la-Camp Platz 1, 44789 Bochum E-Mail: daniela.roggenland@rub.de

PATIENT-SPECIFIC SIMULATION MODEL TO RESEARCH THE IMPACT OF AORTIC VALVE PROSTHESES ON BLOOD FLOW

Between 1998 and 2004, approximately 400,000 people died in Germany from cardiovascular disease, with heart valve disease playing a significant role. Heart valve disease can lead to stenoses or insufficiency. In 2004, heart valve operations nationwide reached over 18,500 [German Association for cardiovascular Research, 2005]. Numerous medical questions demand precise knowledge of the effect on blood flow of aorta prosthetic valves and patient-specific aortic anatomy [Pennekamp, 2004]. On this topic use of Computational Fluid Dynamics (CFD) is recommend. However, numerical simulation in biomedical applications is challenged by formulating the extremely complex material properties, local influences and especially patient geometries for the virtual model.