ABSTRACT: HintergrundDie anatomische Darstellung und Erfassung möglicher Anomalien der Nierengefäße und Ureteren ist für die Planung einer Lebendnierenspende
von essenzieller Bedeutung. Die vorliegende Untersuchung soll die Wertigkeit der nichtinvasiven Evaluation mit der 64-Zeilen-Multidetektor-CT
Material und MethodenIn die Auswertung wurden 63 Lebendnierenspender (LNS) eingeschlossen, die im Zeitraum 12.2004 bis 01.2007 mit der CT präoperativ
untersucht wurden. Die Untersuchungen erfolgten mit einem Somatom-Sensation-Cardiac-64 (Siemens Medical Solutions, Deutschland).
Neben einer CT-Angiographie (CTA) wurden eine venöse Phase des Abdomens und eine Spätphase nach 15min in Low-dose-Technik
für die CT-Urographie (CTU) durchgeführt. Die radiologischen Befunde wurden mit dem intraoperativen Befund oder in 2 Fällen
mit der konventionellen Angiographie verglichen, außerdem wurden Sensitivität, Spezifität, negativer und positiver Vorhersagewert
ErgebnisseBei den ausgewerteten 63 LNS (31 weibliche, 32 männliche) erreichte die CTA eine Sensitivität von 100% für die Arterien und
Polarterien und 98,3% für die Nierenvenenanatomie. Die Low-dose-CTU erreichte ebenfalls eine Sensitivität von 100%.
SchlussfolgerungDie Ergebnisse zeigen, dass eine nichtinvasive präoperative Planung bei potenziellen Lebendnierenspendern anhand einer 64-Zeilen-Multidetektor-CT
im Sinne des „On-stop-Shopping“ zuverlässig möglich ist.
BackgroundAnatomical imaging and the ascertainment of any anomalies in the renal vessels and the ureters are essential in the planning
of a kidney donation. The aim of the present study was to assess the value of 64-row multidetector CT in noninvasive examination
of the renal vessels and ureters of potential living kidney donors.
MethodsThe evaluation embraced 63 living renal donors (LNS) who underwent preoperative CT examination from December 2004 to January
2007. The examinations were all carried out using a Somatom Sensation –Cardiac 64 (Siemens Medical Solutions, Germany). As
well as CT angiography (CTA), a venous phase of the abdomen and a late phase after 15min using low-dose technique were performed
for CT urography (CTU). The radiological findings were compared with the surgical results, or with the angiograms in 2 cases.
Sensitivity, specificity and both negative and positive predictive value were calculated.
ResultsIn the 63 (31 female, 32 male) donors CTA had a sensitivity of 100% in examination of the main and accessory renal arteries
and of 98.3% when the venous and ureteric anatomy were assessed. The sensitivity of low-dose CTU was also 100%.
ConclusionThe findings recorded in this study indicate that noninvasive preoperative planning with 64-row multidetector CTA and CTU
is a reliable “one-stop shopping” method of examination for potential living kidney donors.
Der Radiologe 04/2012; 48(7):673-680. · 0.61 Impact Factor
ABSTRACT: Evaluation of subjective image quality in dose-reduced multi-detector CT (MDCT) of paranasal sinuses using a 2D non-linear adaptive post-processing filter (2D-NLAF).
MDCT of paranasal sinuses was simulated using a human head phantom at a Somatom Sensation Cardiac 64 (Siemens, Erlangen). At constant collimation (64 × 0.6 mm) und pitch (p = 1), the tube current (50, 100, 200 mAs) and tube potential (80, 100, 120 kVp) were modified. The radiation exposure was represented by CTDIvol. Four independent blinded radiologists evaluated the image quality of axial 2 mm images and coronal reformations concerning the assessment of "fractures" and "soft tissue processes". The subjective image quality of original and post-processed images using a 2D-NLAF (SharpViewCT®, Sweden) was graded on a 5-point scale ("1" excellent - "5" not adequate) and compared.
Compared to the protocol with the best image quality (120kVp/ 200 mAs) 2D-NLAF led to a significant improvement in the subjective image quality at 100 kVp/ 100 mAs (score "1.4" with filter versus "2.2" without) and 120 kVp/ 50 mAs ("1.6" versus "2.0") (p < 0.03) particularly for high contrasts ("fractures", p < 0.001). In "soft tissue processes", 2D-NLAF provided improved quality from "2.1" to "1.4" (p < 0.04) at 100 kVp/ 100 mAs. Down to a CTDIvol of 8 mGy, the image quality was rated "good", and down to 5 mGy "diagnostic".
The phantom study indicates a dose reduction potential in MDCT of paranasal sinuses up to 58% compared to a standard dose protocol using a 2D-NLAF without an essential loss of image quality. 2D-NLAF is particularly effective at 100 kVp/ 100 mAs and 120 kVp/ 50 mAs.
RöFo - Fortschritte auf dem Gebiet der R 11/2010; 182(11):973-8. · 2.76 Impact Factor
ABSTRACT: Anatomical imaging and the ascertainment of any anomalies in the renal vessels and the ureters are essential in the planning of a kidney donation. The aim of the present study was to assess the value of 64-row multidetector CT in noninvasive examination of the renal vessels and ureters of potential living kidney donors.
The evaluation embraced 63 living renal donors (LNS) who underwent preoperative CT examination from December 2004 to January 2007. The examinations were all carried out using a Somatom Sensation -Cardiac 64 (Siemens Medical Solutions, Germany). As well as CT angiography (CTA), a venous phase of the abdomen and a late phase after 15 min using low-dose technique were performed for CT urography (CTU). The radiological findings were compared with the surgical results, or with the angiograms in 2 cases. Sensitivity, specificity and both negative and positive predictive value were calculated.
In the 63 (31 female, 32 male) donors CTA had a sensitivity of 100% in examination of the main and accessory renal arteries and of 98.3% when the venous and ureteric anatomy were assessed. The sensitivity of low-dose CTU was also 100%.
The findings recorded in this study indicate that noninvasive preoperative planning with 64-row multidetector CTA and CTU is a reliable "one-stop shopping" method of examination for potential living kidney donors.
Der Radiologe 08/2008; 48(7):673-80. · 0.61 Impact Factor
ABSTRACT: In acute ischemic stroke MR-imaging typically shows diffusion abnormalities surrounded by reduced perfusion signifying the so-called ischemic penumbra. Mismatch between diffusion and perfusion abnormalities gives indication for thrombolysis. But is there an indication for thrombolytic treatment, if there is no diffusion abnormality but pathologic perfusion combined with acute stroke symptoms?.
MR-imaging of 1465 patients treated on our Stroke Unit between June 2004 and May 2007 retrospectively are analyzed. 6 patients met the inclusion criteria of severe neurological symptoms, large territorial perfusion disturbances, lack of diffusion abnormalities and complete neurological recovery after treatment.
In all six patients MTT measurements showed a significantly depressed perfusion in the symptomatic hemisphere (p<0.02). Time-to-peak delay correlated with the mean transit time delay (0.949, p<0.01). Indication for thrombolysis was based on perfusion abnormalities and clinical symptoms. Stroke symptoms could be reversed in all patients without any complication.
Whereas diffusion imaging could not reveal any abnormality, perfusion analysis legitimated therapy with systemic thrombolysis in heavily affected patients. This work underlines the importance of multimodal MR imaging for guiding treatment decisions in acute stroke patients.
European journal of radiology 05/2008; 71(1):1-10. · 2.65 Impact Factor
ABSTRACT: Postrenal reasons of renal transplant failure can be assessed by magnetic resonance urography. This study was designed to retrospectively compare the diagnostic accuracy of static fluid (T2-)MRU compared to contrast enhanced (CE-)MRU in patients with renal transplant failure.
Thirty-five consecutive patients (14 female, 21 men; mean age 48.6 years) with renal transplant failure and sonographically detected hydronephrosis were examined both with T2-MRU as well as CE-MRU resulting in 39 MRU examinations. MRU was performed both using T2-weighted HASTE-sequence (T2-MRU) as well as Gadolinium-enhanced 3D-FLASH-sequence (CE-MRU) on a 1.5-T clinical MRI scanner (Magnetom Vision, Siemens Medical Solutions). Subjective image quality of resulting maximum intensity projection was assessed in consensus by two readers blinded to the final diagnosis, using a five point scale. MRU findings were correlated to sonography, operative results or clinical follow up.
CE-MRU yielded a sensitivity of 85.7% (T2-MRU 76.2%), and a specificity of 83.3% (T2-MRU: 73.7%), however statistical significance was not reached. The subjective image quality was significantly better in CE-MRU.
Only concerning subjective image quality CE-MRU proved superior to T2-MRU. Yet, there was no significant difference in diagnostic accuracy between T2- and CE-MRU. Thinking of incipient nephrogenic systemic fibrosis, T2-MRU can be used as reliable alternative in patients with decreased renal transplant function due to urological complications.
European journal of radiology 01/2008; 69(2):324-30. · 2.65 Impact Factor
ABSTRACT: To compare a commercial CT colonography software ("Colonography", Siemens, Forchheim) with a non-commercial post-processing system ("Colotux", Department of Informatics).
Identical data sets of 10 patients, who underwent an ultra-low-dose multi-detector CT colonography (ULD-MDCTC) (4x1 mm collimation, 8 mm pitch, 120 kVp, 10 mAs) were analyzed retrospectively. Assessment was performed using both software solutions by two resident radiologists, who did not have any experience with any colonography software tool before and who did not know the clinical symptoms of the patients or the results of the conventional colonoscopy. Both systems were analyzed using several subjective quality criteria including workflow, handling, image quality, endoluminal navigation and analysis of lesions with grading on a 5-point-scale. Results concerning polyps were compared between the two systems as well as with conventional colonoscopy.
Both colonography systems detected the same number of polyps. Although both showed some advantages for single criteria, no relevant difference was noted in general for subjective assessment. The time for calculation of three dimensional interactive volumes was three times longer for "Colotux" compared to "Colonography." Linux-based "Colotux" showed a trend towards better subjective image quality and easier measurement of polyp size. An intuitive desktop and "Syngo"-workflow integration were advantages of "Colonography."
The analysis of CT colonographies (4-detector-row-CT-scanner, ultra low dose technique, supine position) can adequately be achieved by both software solutions. There was no significant subjective or objective difference of quality between a "stand-alone" individual system and a commercial workflow-integrated solution. A relevant factor for decision between the two systems may be the difference in time needed for the 3D volume calculation, especially in institutes with a high frequency of examinations.
RöFo - Fortschritte auf dem Gebiet der R 10/2005; 177(9):1227-34. · 2.76 Impact Factor
RöFo - Fortschritte auf dem Gebiet der R 06/2004; 176(5):764-5. · 2.76 Impact Factor
Clinical imaging 34(1):78. · 0.73 Impact Factor