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PURPOSE To investigate if the assessment of spinal fracture stability according to the Magerl classification permits a better therapy decision than using the Denis 3-column model. MATERIAL AND METHODS The X-ray and CT images of 99 consecutive patients treated for thoracolumbar spine fractures were analysed and the fractures were classified according to the above mentioned classifications. Using the 3-column model, the involvement of two or more columns was considered as unstable, whereas the fracture types A3.2, A3.3, B and C of the Magerl classification were defined as unstable. The stability evaluation was compared with the therapy decision and outcome. RESULTS According to the 3-column model, 23 of 53 fractures which were classified as unstable were operated. Only five of the 30 conservatively treated unstable fractures showed a reduced healing process. The 46 stable fractures were treated conservatively with good results. Using the Magerl classification, 21 of the 28 unstable fractures were operated and 4 of the remaining 7 cases showed a reduced healing process. Of the 71 stable fractures only 2 were operated and in one patient minimal neurological symptoms occurred. CONCLUSION The Magerl classification enables a more exact definition of stable and unstable spinal fractures.

Background Although modern chemotherapy of stage IV advanced colorectal cancer (CRC) has impressively improved overall survival, the response of the primary tumor has not been studied because surgical resection of the primary continues to be the standard procedure in stage IV CRC. Aim Long-term follow-up of the primary in patients with stage IV CRC under chemotherapy. Methods and results Here we report on the histological changes in the primary tumor in four patients suffering from stage IV CRC. Systemic chemotherapy was started immediately after endoscopic tumor debulking in three cases. In one case no endoscopic intervention was performed before chemotherapy. Neither macroscopic nor histological evidence for malignant tumor growth was found at the former site of the primary after 6, 23, 26 or 48 months, respectively. Two patients had a complete suppression of the primary, two patients had an adenoma at the former site of the primary. To date, three patients have died because of progression of liver metastases and one patient is still alive with no signs of tumor growth. Conclusion The four cases illustrate that today's chemotherapy may effectively induces suppression of the primary in CRC. The development of CRC may follow different pathways.

After cystectomy two principal types of urinary diversion are used for the surgical reconstruction of the urinary tract: incontinent and continent. In the continent type of urinary diversion, a differentiation must be made between those with and without catheterization for voiding. Besides urothelial cancer other reasons for urinary diversion include neurogenic bladder palsy (connatal or acquired) due to meningomyelocele or connatal diseases like bladder exstrophy. The main objective of the clinical urologist when selecting urinary diversion are to achieve continence and to preserve upper urinary tract function. Knowledge of the different forms of urinary diversion is critical for the exact interpretation of the images. This review presents the typical imaging techniques after a description of the basic surgical features of urinary diversion. CT urography and MR urography are becoming increasingly important as further imaging tools for controlling urinary diversions.

Objectives The aim of this study was to compare the image performance of silicon-based flat-panel-detector-based volumetric computed tomography (fpVCT) to multislice spiral computed tomography (MSCT) for the visualization and detail detectability of skeletal structures in rodents of different development stages. Materials and Methods Rodents of different development stages were imaged with fpVCT (GE prototype with circular gantry with two 1024×1024, 200-μm pixel size, amorphous silicon/Cesium lodid (Csl) flat-panel detector) and eight-slice MSCT (LightSpeed Ultra). Imaging parameters (80 kVp, 100 mA) and the position of the rodents were identical in both techniques. Image quality, detail detectability, and contour of skeletal structures were judged by two observers in consensus using a 4-point scale (1=unsatisfactory…4=good). Findings were displayed and evaluated in axial slices, multiplanar reconstructions (MPR), maximum intensity projections (MIP) and volume rendering technique (VRT) in both modalities. Mean and standard of error of mean were calculated. Results In axial slices, visualization and detail detectability of very subtle skeletal structures, e.g., the basis of the skull was better in fpVCT than in MSCT (4 vs. 2 points). The MPRs of fpVCT showed less artifacts and more details than those of the MSCT. The MIPs and VRTs of the fpVCT demonstrated best image quality in all rodents of different development stages, whereas MSCT showed significant artifacts. Conclusion fpVCT outperformed MSCT in imaging of small rodents. Due to the truly isotropic volume data set with high spatial resolution, fpVCT is a powerful tool in evaluating detailed skeletal structures.

Intervertebral spacers for anterior spine fusion are made of different materials, such as titanium and cobalt chromium alloys and carbon fiber-reinforced polymers. Implant-related susceptibility artifacts can decrease the quality of MRI scans. The aim of this cadaveric study was to demonstrate the extent that implant-related MRI artifacting affects the postfusion differentiation of determined regions of interest (ROIs). In six cadaveric porcine spines, we evaluated the postimplantation MRI scans of a titanium, cobalt-chromium and carbon spacer that differed in shape and surface qualities. A spacer made of human cortical bone was used as a control. A defined evaluation unit was divided into ROIs to characterize the spinal canal as well as the intervertebral disc space. Considering 15 different MRI sequences read independently by an interobserver-validated team of specialists the artifact-affected image quality of the median MRI slice was rated on a score of 0–3. A maximum score of 18 points (100%) for the determined ROIs was possible. Turbo spin echo sequences produced the best scores for all spacers and the control. Only the control achieved a score of 100%. For the determined ROI maximum scores for the cobalt-chromium, titanium and carbon spacers were 24%, 32% and 84%, respectively. By using favored T1 TSE sequences the carbon spacer showed a clear advantage in postfusion spinal imaging. Independent of artifact dimensions, the scoring system used allowed us to create an implant-related ranking of MRI scan quality in reference to the bone control.

The flat panel-based volume computed tomography (fpVCT) is a new CT device applicable for experimental, three-dimensional evaluation of teeth at a resolution of about 150 microm in the high contrast region. The aim of this study was to investigate whether fpVCT was suitable for quantification of the volumes of dental hard tissues and the root canal system to establish a new method for morphological studies. Fifty-two extracted third molars (maxillary: 31, mandibular: 21) were examined with a prototype of an fpVCT using a volumetry algorithm at different levels according to the radiographic density of enamel and dentine. Volumetry of the root canal system was performed after "region growing segmentation": starting from a voxel in the centre of the root canal, this algorithm searches voxels of same density in the surrounding. The volumetry of the root canal system was stopped by the investigator at the apical constriction. Results showed that dentine, enamel and root canal system could be well distinguished in three-dimensional images. Volumetry yielded the following data (cm(3), mean+/-SD): dentine 0.438+/-0.111, enamel 0.227+/-0.051, root canal system 0.052+/-0.017 and total volume 0.753+/-0.159. In conclusion, the fpVCT is appropriate for non-destructive volumetry of large numbers of teeth in experimental laboratory studies.

PURPOSE Successful endodontic diagnostics and therapy call for adequate depiction of the root canal anatomy with multimodal diagnostic imaging. The aim of the present study is to evaluate visualization of the endodont with flat-panel detector volume CT (FD-VCT). MATERIALS AND METHODS 13 human teeth were examined with the prototype of a FD-VCT. After data acquisition and generation of volume data sets in volume rendering technology (VRT), the findings obtained were compared to conventional X-rays and cross-section preparations of the teeth. RESULTS The anatomical structures of the endodont such as root canals, side canals and communications between different root canals as well as denticles could be detected precisely with FD-VCT. The length of curved root canals was also determined accurately. The spatial resolution of the system is around 140 microm. Only around 73 % of the main root canals detected with FD-VCT and 87 % of the roots could be visualized with conventional dental X-rays. None of the side canals, shown with FD-VCT, was detectable on conventional X-rays. In all cases the enamel and dentin of the teeth could be well delineated. No differences in image quality could be discerned between stored and freshly extracted teeth, or between primary and adult teeth. CONCLUSION FD-VCT is an innovative diagnostic modality in preclinical and experimental use for non-destructive three-dimensional analysis of teeth. Thanks to the high isotropic spatial resolution compared with conventional X-rays, even the minutest structures, such as side canals, can be detected and evaluated. Potential applications in endodontics include diagnostics and evaluation of all steps of root canal treatment, ranging from trepanation through determination of the length of the root canal to obturation.

Purpose To evaluate the usefulness of a computer-aided detection (CAD) system in full-field digital mammography in correlation to tumor histology. Material and methods A total of 476 patients (226 patients with histologically proven malignant tumors, 250 healthy women) took part in this study. The mammograms were studied retrospectively, using the CAD system Image Checker. For 226 patients digital mammograms in MLO-projection were available. For 186 of these patients the CC-projection was also available. CAD markers that correlated with histologically proven carcinomas were considered to be true-positive markers. All other CAD markers were considered to be false-positive. Histologically proven carcinomas without markers were false-negative results. The dependence of the CAD markers placement upon the different carcinoma histologies was studied using the Chi-square test. Results No significant difference could be proven for the detectability of malignant breast lesions of different histologic types. For the detectability of ductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), lobular carcinoma in situ (LCIS), tubular carcinoma and ductulo-lobular carcinoma, the true positives were 71.1 %, 75 %, 70.7 %, 70 %, 60 % and 80 %, respectively, in the MLO projection and 83.9 %, 75.9 %, 81.8 %, 77.8 %, 87.5 % and 33.3 %, respectively, in the CC projection. There was an average of 0.5 false-positive markers per mammographic image. Conclusion The histologic type of carcinoma seems to have no influence on detectability when using the CAD system. The high rate of false-positive markers shows, however, the limited specificity of the CAD system and that improvements are necessary.

PURPOSE To compare image quality of single-slice spiral CT (SSCT) and multislice spiral CT (MSCT) in the diagnosis and classification of calcaneal fractures and to present a rapid and precise algorithm for the classification system of Stuermer. MATERIALS AND METHODS In 102 patients with 124 calcaneal fractures, spiral CT was performed, in 82 cases as SSCT with a slice thickness (SD) of 3 mm, a table speed (TS) of 3 - 4 mm/rot and an increment of 1.5 mm. In 42 cases, patients were scanned using MSCT (SD of 1.25 mm, increment 0.8 mm). For these examinations, 2 different scan protocols were used, with a TS of 3.75 mm/rot in one group (n = 21) and a TS of 7.5 mm/rot in the other group (n = 21). The image quality of axial sections and reconstructed images was assessed on a scale from 1 to 5 (1 = very good; 5 = insufficient). The fractures were evaluated using a classification system according to Stuermer, which assigns three main groups (A/B/C) and three subtypes (1/2/3). RESULTS MSCT had substantial advantages over SSCT with respect to scan time and image quality, especially for multiplanar reformatting (median 1.5 versus 4.0). TS showed no significant influence on the image quality. The standardized evaluation of the images enabled a classification of fractures within 5 minutes. All fractures could be assigned to the different types and subtypes. This classification system takes into account the severity of the fracture and the therapeutic approach. The most common type (90 of 124 fractures) were "joint depression" fractures (type C), which were treated by surgery in 92 %. Type A fractures were treated conservatively in 72 %. CONCLUSION Spiral CT, especially MSCT, allows rapid diagnosis and precise classification of calcaneal fractures, achieved with high quality multiplanar reformatting. The presented classification in different fracture types and subtypes allows an adequate planning of therapy.

PURPOSE: To determine the performance of an a-Si/CsJ flat-panel detector-based volumetric computed tomography (VCT) prototype in volumetry of synthetic nodules in a pulmonary phantom, and to assess VCT accuracy in the assessment of hypothetic tumor growth rates based on predefined tumor doubling times. METHODS: The true volumes of 50 synthetic nodules (diameter range = 1.36 - 5.34 mm) were determined and VCT volumetry was performed before and after isovolumetric deformation of the nodules. The percent measurement error (PMF) was calculated as the percent difference of the measured from the true volume. Based on the PMF, the minimum interval between two scans was determined that would be needed to depict tumor growth corresponding to the minimum number of required follow-up days (FUDs). Based on predefined tumor doubling times (VDT) FUDs were determined before and after nodule deformation. RESULTS: Measured volumes of undeformed and deformed nodules of 0.99 - 20.05 mm (3) differed significantly from corresponding true volumes (p = 0.002 - 0.004). The PMFs of these nodules significantly exceeded the values measured in larger nodules (p = 0.0001 - 0.0029). In addition, PMFs were significantly lower before than after deformation (1.33 - 7.14 % and 0.61 - 11.09 %, respectively; p = 0.002). For theoretical VDTs of 177 and 396 days, the calculated FUDs for detection of tumor growth were 19.1 and 42.7 days before deformation, and 30.2 and 67.6 days after deformation for nodules < 2 mm, respectively. CONCLUSION: VCT allows for accurate volumetry of smallest pulmonary nodules and may become a valuable clinical tool for depiction of tumor growth of even small lesions within very short scan intervals.

Several mechanisms of development of hepatocellular carcinoma (HCC) in patients with liver cirrhosis have been discussed. One hypothesis suggests that the somatic stem cells of the liver, the so-called oval cells, may undergo malignant transformation. Oval cells are derived from the biliary cells of the canal of Hering and are characterized by c-kit-positivity, the transmembrane receptor of stem cell factor. Constitutively activated tyrosine kinases have been identified as major pathogenetic mechanisms in the development of malignant diseases like gastrointestinal stromal tumors (c-kit) and chronic myelogenous leukemia (bcr-abl). The prognosis of these diseases improved enormously since the drug imatinib, a tyrosine kinase inhibitor of c-kit and bcr-abl, was introduced. Here we report the successful cure of a patient with liver cancer by this tyrosine kinase inhibitor.

Einleitung: Es wurde der Nutzen einer retrospektiven EKG-Triggerung fur die Mehrschicht-Spiral CT (MSCT) bei Patienten mit Verdacht auf akute Lungenembolie (LE) untersucht. Methode: 45 Patienten mit Verdacht auf akute LE wurden mittels retrospektiv EKG-getriggerter (Gruppe 1, n = 23) oder 8-Zeilen-MSCT ohne EKG-Triggerung (Gruppe 2, n = 22) untersucht. Die interaktive Auswertung durch drei unabhangige Befunder bezog sich auf das Vorliegen einer LE in den verschiedenen Gefasabschnitten und den Nachweis kardialer Pulsationsartefakte. Eine Konsensusauswertung durch zwei erfahrene Thoraxradiologen diente als diagnostischer Standard. Die Ergebnisse wurden mit einer ROC-Analyse fur die unterschiedlichen Gefasabschnittte ermittelt. Ergebnisse: Bei 25 Patienten (56 %, n = 13 in Gruppe 1, n = 12 in Gruppe 2) lag eine akute LE vor. Kardiale Pulsationsartefakte traten in Gruppe 2 signifikant haufiger als in Gruppe 1 auf (70 % ggu. 13 %, p < 0,05). Es lagen keine signifikanten Unterschiede in beiden Gruppen bezuglich der Sensitivitat (0,92 vs. 0,95) und Spezifitat (0,92 vs. 0,98) insgesamt bzw. bei Auswertung der unterschiedlichen Gefasabschnitte vor. Schlussfolgerung: Die retrospektive EKG-Triggerung zeigt keinen eindeutigen diagnostischen Vorteil im Vergleich zur MSCT der Pulmonalarterien ohne EKG-Triggerung und wird deshalb fur die klinische Routinediagnostik nicht empfohlen. Aim: This study determined the diagnostic performance of ECG-gated MSCT in comparison with conventional MSCT. Materials and Methods: Forty-five consecutive patients prospectively underwent ECG-gated (group 1, n = 23) or non-ECG-gated (group 2, n = 22) 8-slice MSCT of the pulmonary arteries. Image data were interactively evaluated by three independent chest radiologists with respect to the presence of emboli at different arterial levels, and with regard to cardiac motion artefacts. Consensus reading by two experienced chest radiologists served as diagnostic gold standard. ROC analysis was carried out for the different vascular sections. Results: Twenty-five patients (56 %) were diagnosed to have pulmonary embolism (13 from group 1, 12 from group 2). Cardiac motion artefacts were significantly more frequent in group 2 (70 % in group 2 versus 13 % in group 1, p < 0.05). There was no significant difference between the two groups in the overall sensitivities (0.92 vs. 0.95) and specificities (0.92 vs. 0.98) or in sensitivities and specificities at any assessed pulmonary arterial level. Conclusion: ECG-gated MSCT pulmonary angiography does not significantly influence the diagnostic performance of MSCT in these patients. Therefore no recommendation for routine clinical practice can be given.

Purpose: To evaluate the diagnostic value of a higher concentrated contrast medium (gadobutrol) for contrast-enhanced MRA of the hepatic arteries and portovenous system. Materials and Methods: The examinations were performed on a 1.5-Tesla whole body imaging system (Magnetom Symphony Quantum, Siemens) with a 30-mTesla/m gradient field strength using a phased-array body coil. A 3D FLASH sequence (TR/TE/FA 3.88 ms/1.44 ms/25°) was used imaging the hepatic arteries and portovenous system after determination of the circulation time. The study included 50 patients, with 25 patients (group 1) injected with 0.2 mmol Gd-GTPA/kg body weight and 25 patients (group 2) injected with 0.1 mmol gadobutrol/kg body weight. The signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) were calculated for both groups. The image quality was graded by three radiologists on a 5-point scale. Results: The highest SNR was measured in group 1, with no statistically significant differences of the SNR in the abdominal aortal, coeliac trunk and common hepatic artery. CNR was also similar in both groups. Likewise, portal, superior mesenteric and splenic veins showed no statistically significant differences. All cases were found to have a good image quality. Conclusion: For MRA of the hepatic arteries and the portal veins, the higher concentrated Gd-DTPA contrast medium gadobutrol can be used at half the dosage recommended for the standard Gd-DTPA contrast medium.

Summary Background and Aim: In recent years, much research interest has been rightfully directed towards modelling human disease. The increasing demand of laboratory animals has led to a major impetus in small animal imaging. We evaluated the feasibility of using multislice spiral CT (MSCT) technology in a severe combined immunodeficiency (SCID) mouse model for non-small cell lung cancer. Materials and Methods: Mice (n = 14) were implanted orthotopically with the human non-small cell lung adenocarcinoma cell line A 549. Mice were scanned with MSCT and sacrificed 7 days (n = 3), 14 days (n = 3), and 21 days (n = 5) after tumor cell implantation, respectively. Histopathology was performed. Tumor size as revealed by imaging and pathology was correlated. A group of animals (n = 3) received anti-cancer treatment with seco-CBI-Q-galatoside. Those mice were scanned with MSCT 21 days after tumor implantation and sacrificed, and histopathologic work-up was performed. Results: A total of 14 mice with 14 macroscopically visible and 5 microscopically appreciable adenocarcinomas of the lung were examined. All macroscopically visible tumors were readily depicted with MSCT except from 2 lesions of 1 mm in diameter. MSCT accurately displayed the different tumor sizes in treated vs. non-treated animals. Discussion: MSCT proved to be a valuable tool for imaging of a murine lung cancer model. This evidences a potential use of this technology in small animal lung cancer imaging.

The aim of this study was to evaluate the potential for radiation dose reduction by using other beam qualities in full-field digital mammography (FFDM) compared with screen-film mammography (SFM). FFDM was performed using an amorphous silicon detector with a caesium iodide scintillator layer (Senographe 2000D, GE, Milwaukee, USA). SFM was performed using a state-of-the-art conventional system (Senographe DMR, GE, Milwaukee, USA) with a dedicated screen-film combination. An anthropomorphic breast phantom with superimposed microcalcifications (50-200 microm) was used to evaluate the detectability of microcalcifications. Contact mammograms and magnification views (m=1.8) performed with both the digital and the screen-film system were compared. Images were exposed automatically. Molybdenum/Molybdenum (Mo/Mo) anode-filter combination, 28 kVp and 63 mAs were selected by the automatic optimization of parameters (AOP) of the conventional system. This exposure protocol (protocol A) was also used as baseline for the digital system. Dose reduction in digital mammography was achieved by using protocol B with Mo/Rh and 31 kVp and protocol C with Rh/Rh and 32 kVp. The detectability of microcalcifications was assessed by 3 experienced readers with a confidence level ranging from 1 to 5. A receiver operating characteristic (ROC) analysis was performed. In protocol A the area under the ROC-curve (A(z)) for contact views performed by the screen-film system was 0.64 and for those performed with the FFDM system 0.68. The A(z) values were 0.74 in protocol B and 0.65 in protocol C for the digital system. For the conventional and digital magnification views A(z) values were 0.71 and 0.79, respectively. For protocol B the A(z) value was 0.81 and for protocol C it was 0.76. There is no statistically significant difference in the A(z) values for the different protocols in digital mammography and no significant difference from the screen-film system. A potential for dose reduction by using other beam qualities seems to be possible with this digital system.

The advent of fast multiscale computed tomography (MSCT) technology has sparked new interest in the noninvasive assessment of the solitary pulmonary nodule (SPN). Fast scanning within a single breath-hold period, simultaneous acquisition of multiple thin slices with subsequent morphologic characterization of the nodule, determination of perfusion patterns as well as growth rates has led to unprecedented improvements in this emerging field. This article reviews the capabilities of MSCT in the diagnostic assessment of the SPN.

PURPOSE: To investigate the value of different postprocessing algorithms for multislice spiral CT (MSCT) in diagnosing acute pulmonary embolism. MATERIALS AND METHODS: Forty-eight patients with suspected pulmonary embolism prospectively underwent MSCT using an 8-slice spiral CT. Using a confidence level on a three-point scale, three radiologists reviewed 2-mm and 5-mm axial slices, 5-mm and 10-mm axial maximum intensity projections (MIP) and 2-mm coronal slices as well as interactively generated multiplanar reformatted images. A subsequent consensus reading of the primary 1.25-mm axial slices served as gold standard. ROC analysis was applied to the various vascular sections. RESULTS: The ROC analysis revealed a higher diagnostic accuracy of the 2-mm axial sections as compared to the 5-mm axial slices (Az = [0.988;0.976] vs. Az = [0.988;0.802]). Coronal and multiplanar reformations also showed excellent diagnostic accuracy (Az = [0.972;0.949] and Az = [0.997;0.951], respectively) and were significantly superior to the 5-mm axial slices through the segmental and subsegmental arteries (p=0.05). MIP showed the weakest diagnostic accuracy (Az = [0.967;0.802] for 5-mm MIP; Az = [0.879;0.781] for 10-mm MIP). CONCLUSION: Thin axial slices as well as coronal and multiplanar reformations are superior to thick axial slices in the diagnosis of acute pulmonary embolism. MIP is not suited for accurate diagnosis of pulmonary embolic disease.

Hintergrund: Die extramedullare Homatopoese ist eine kompensatorische Antwort des Organismus auf eine defizitare Produktion von Zellen im Blut bildenden Knochenmark. Sie kann in Zusammenhang mit einer Reihe von hamatologischen Erkrankungen beobachtet werden. Es werden zwei Patienten vorgestellt, bei denen paravertebrale Raumforderungen als Korrelat einer extramedullaren Blutbildung nachgewiesen wurden. Hierauf basierend werden die charakteristischen Befunde der extramedullaren Blutbildung prasentiert. Fallberichte: Ein 76-jahriger Patient mit bekanntem myelodysplastischen Syndrom stellte sich mit einer Unterlappenpneumonie links vor. Zudem waren die Symptome eines Cauda-equina-Syndroms mit Schmerzen und Hypasthesien beider Beine sowie einer Blasenentleerungsstorung nachweisbar. Eine 63-jahrige Patientin wurde mit langer bestehenden, progredienten gurtelformigen Beschwerden am unteren Brustkorb sowie im Kreuz-Darmbein-Bereich mit Ausstrahlung in das linke Bein und Dysasthesien beider Fuse stationar aufgenommen. Anamnestisch waren eine Polycythaemia vera und ein Status nach Splenektomie bekannt. Beide Patienten wiesen paravertebrale und intraspinale Raumforderungen in thorakalen bzw. lumbosakralen Lokalisationen auf die anhand der magnetresonanz- und computertomographischen Untersuchung als Korrelat einer extramedullaren Hamatopoese gewertet wurden. Eine Radiatio der Raumforderungen fuhrte bei beiden Patienten nach wenigen Fraktionen zu einer Besserung der klinischen Beschwerdesymptomatik. Schlussfolgerung: In der Diagnostik einer extramedullaren Blutbildung ist fur eine korrekte differentialdiagnostische Interpretation die Kenntnis von Grunderkrankung, klinischer Prasentation sowie radiologischen Befunden essentiell. In der primaren Diagnostik der extramedullaren Blutbildung ist die Magnetresonanztomographie (MRT) das bildgebende Verfahren der Wahl, da auch die etwaige Ausdehnung auf den intraspinalen Raum besser erfasst werden kann und differentialdiagnostische Uberlegungen erleichtert werden. Sie dient des Weiteren der exakten Planung der Bestrahlungsfelder sowie der Kontrolle im Rahmen der Nachsorge.

Purpose: To determine the optimal scan parameters in multi-slice helical CT (MSCT) of the facial bone complex for both axial scanning and multiplanar reconstructions. Material and Methods: An anthropomorphic skull phantom was examined with a MSCT. Axial scans were performed with continuously increasing collimations (4 x 1.25 - 4 x 2.5 mm), tube current (20 -200 mA) and table speeds (3.75 mm/rot. and 7.5 mm/rot.). Multiplanar reconstructions in coronal and parasagittal planes with different reconstruction increment and slice thickness were evaluated in terms of image noise, contour artifacts and visualisation of anatomical structures. Results: The best image quality was obtained with a collimation of 4 x 1.25 mm and a -table speed of 3.75mm/rot. A reconstruction increment of 0.6 mm achieved the best time to image quality relation. With these parameters the bone structures were depicted in an optimal way without artifacts. The tube current could be reduced to 50 mA without significant loss of image quality. The optimized protocol was used for regular routine examinations in patients with facial trauma (n = 66). Conclusions: Low-dose MSCT using thin collimation, low table speed and small reconstruction increments provides excellent data for both axial images and multiplanar reconstructions in patients with facial trauma. An additional examination in coronal orientation is therefore no longer necessary.

PURPOSE Determination of average glandular dose with a full-field digital mammography system using a flat-panel X-ray detector based on amorphous silicon technology for a large group of patients. MATERIAL AND METHODS The patient group includes women who were examined in a 4-month period with the digital mammographic system Senographe 2000D. The number of women was 591 and the number of exposures was 1116; only cranio-caudal projections were considered. Various quantities, including entrance surface air kerma, tube loading, and compressed breast thickness, were determined during actual mammography. Average glandular dose was determined using conversion factors g for standard breast composition. RESULTS The mean average glandular dose was 1.51 mGy (0.66 - 4.05 mGy) for a single view. The mean compressed breast thickness was 55.7 mm. The mean age of patients was 55 years (34 - 81 years). CONCLUSION The results demonstrate that full-field digital mammography with a flat-panel detector based on amorphous silicon needs about 25 % less dose in comparison with conventional screen-film mammography.

Objective: To evaluate the diagnostic advantages of high in-plane resolution contrast-enhanced (CE) magnetic resonance imaging (MRI) of the breast in comparison to standard CE-MRI. Methods: Forty-one patients with 51 hypervascularized lesions were selected prospectively after undergoing bilateral standard CE MRI (slice thickness 4 mm, in-plane resolution 1.52×1.25 mm2, temporal resolution 81 s). Patients underwent high in-plane resolution CE MRI, either (n=21) a two-dimensional fast-low-angle-shot sequence (slice thickness 4 mm, in-plane resolution 0.76×0.63 mm2, temporal resolution 96 s) or (n=20) a SE sequence being used (slice thickness 4 mm, in-plane resolution 0.8×0.63 mm2, temporal resolution 115 s). Results: Histopathology revealed 33 malignant and 18 benign lesions (0.2–2.2 cm). Morphologic characteristics were much better visualized with high in-plane resolution. Additional diagnostic information, however, resulted only in one patient with fibroadenoma due to a better visualization of smooth contours. Conclusions: High in-plane resolution provides better visualization of morphologic patterns in comparison to standard dynamic MRI. However, a diagnostic advantage is only rare.

Ziel. Umsetzung qualitatsverbessernder Masnahmen in der rontgendiagnostischen Abteilung einer universitaren Einrichtung zur Verbesserung der internen Handlungsablaufe sowie der Kontakte im Bereich von Schnittstellen (Patient, Zuweiser, MTRA, Radiologe). Methodik. Nach der Durchfuhrung von Vorgesprachen und Vorstudien erfolgten durch einen Berater moderierte halbtagige Workshops zu den Themen “Verhalten gegenuber Patienten”, “Befunderstellung und Verhaltnis zu den Uberweisern” sowie “Forschung und Ausbildung”. Es wurden Veranderungsmasnahmen zum Abbau der wichtigsten Qualitatshemmnisse in verschiedenen Handlungsfeldern definiert und noch im Workshop durch den Abteilungsleiter entschieden. Ergebnisse. In 8 Behandlungsfeldern wurden insgesamt 53 Masnahmen beschlossen, die jeweils von einem Verantwortlichen innerhalb einer definierten Frist umzusetzen waren. Nach 6 Monaten waren 46 (86%) dieser Masnahmen komplett realisiert und weitere 4 (8%) innerhalb noch laufender Fristen in Bearbeitung. Anhand einer Patienten- und Zuweiserumfrage konnte die Zufriedenheit z. B. im Hinblick auf den Umgang mit Wartezeit bzw. Befunderstellung partiell gesteigert werden. Schlussfolgerungen. Die Durchfuhrung qualitatsverbessernder Masnahmen in einer radiologischen Abteilung fuhrt zu einer deutlichen Verbesserung der internen Betriebsablaufe und z. T. auch der externen Kommunikation. Essentielle Bestandteile einer solchen Optimierung sind die Unterstutzung durch einen abteilungsexternen Berater sowie eine konsequente Kontrolle der Umsetzungserfolge.

Fragestellung. Es soll geklart werden, ob und inwieweit das Zooming einer primar digital gewonnenen Rontgenmammographie die zusatzliche Anfertigung einer direkten Vergroserungsmammographie entbehrlich macht. Methodik. Im Rahmen einer intraindividuellen Vergleichsstudie wurde bei 55 Patientinnen mit 57 Mikroverkalkungen die Aussagekraft der direkten Vergroserungsmammographie (Faktor 1,8 [MAG1,8]) mit der nachtraglich vom Monitorbild gezoomten Aufnahme (Faktor 1,8 [ZOOM1,8]) verglichen. Vier Auswerter stuften die Bildqualitat ein und fuhrten eine Charakterisierung der Verkalkungen nach der BI-RADS-Kategorisierung des American College of Radiology (ACR) durch. Ergebnisse. Histopathologisch fanden sich 16 benigne (sklerosierende Adenose, Hyperplasie, Hamartom, radiare Narbe) und 21 maligne Veranderungen (DCIS, invasive Karzinome). Bei den restlichen 20 Patienten lagen gutartige Veranderungen vor, die im Verlauf uber mehr als 2 Jahre befundkonstant waren. Die Bildqualitat der direkten Vergroserungsmammographie wurde besser eingeschatzt als die der gezoomten Aufnahme. Auch die Sensitivitat der MAG1,8 war mit 97,5% der gezoomten Aufnahme (ZOOM1,8: 96,3%) geringfugig uberlegen. Im Gegensatz hierzu zeigten die nachbearbeiteten Monitorbilder eine hohere Spezifitat (MAG1,8: 34,3%, ZOOM1,8: 40%), einen besseren PPV (MAG1,8: 47,5%, ZOOM1,8: 49,8%) und eine gunstigere Treffsicherheit (MAG1,8: 58,1%, ZOOM1,8: 61,2%). Die durchschnittliche Abweichung der BI-RADS-Kategorien lag bei 0,45 fur MAG1,8 und bei 0,44 fur ZOOM1,8. Schlussfolgerungen. Die digitale Aufnahmetechnik erlaubt aufgrund der Option des Monitorzoomings in aller Regel den Verzicht auf eine zusatzliche direkte Vergroserungsmammographie. Hieraus resultieren eine weitere Verbesserung des Work-flows und ein Potenzial zur Dosisreduktion.

Aufgrund der besonderen Anforderungen an die Abbildungsqualitat eines Mammographiesystems vollzieht sich der Ubergang zu digitalen Systemen in diesem Bereich nur zogerlich. Dieser Artikel gibt einen Uberblick uber die physikalisch-technischen Grundlagen fur eine digitale Mammographie mit hoher Bildqualitat bei moglichst niedriger Strahlenexposition. Der haufig erhobenen Forderung nach einer hohen Ortsauflosung bzw. nach einer moglichst geringen Pixelgrose wird die Kontrastauflosung und die effektive Quantenausnutzung des Abbildungssystems als masgebliche Kenngrose der Abbildungseigenschaften gegenuber gestellt. Der gegenwartige Stand der fur die Mammographie zur Verfugung stehenden digitalen Detektortechnologie wird erlautert. Bisherige Erfahrungen zeigen, dass die auf dem Markt befindlichen digitalen Systeme bzgl. der Kontrastauflosung der konventionellen Film-Folien-Mammographie uberlegen sind. Auf in der Entwicklung befindliche neue digitale Mammographiesysteme wird hingewiesen.

Die Vorteile der digitalen Mammographie liegen in der exzellenten Bildqualitat und hohen Bildkonstanz, in einer Reduktion der Strahlenexposition sowie in den Moglichkeiten der modernen Informationstechnologie. Durch die Entkopplung von Bildakquisition und Bilddarstellung ist eine unabhangige Optimierung dieser Teilschritte moglich. Digitale Mammogramme konnen entweder auf Laserfilme ausgedruckt oder am Computermonitor visualisiert werden. Dabei werden aufgrund der grosen Datenmengen hohe Anforderungen an Hard- und Software gestellt. Mit hochauflosenden Laserdruckern und leistungsfahigen Workstations mit hochauflosenden Graustufenmonitoren lassen sich vergleichbare diagnostische Resultate bei der Befundung digitaler Mammogramme erzielen. Beim Filmausdruck gehen jedoch die Moglichkeiten zur interaktiven Bildbearbeitung verloren. Die weiteren Vorteile der digitalen Aufnahmetechnik wie z. B. die computerassistierte Diagnose (CAD) oder die Telemammographie konnen nur durch die Softcopybefundung sinnvoll erschlossen werden.

Durch den zunehmenden Einsatz der Mammographie bei asymptomatischen Frauen werden immer haufiger unsuspekte Befunde erhoben. Zur weiteren Abklarung stehen diverse perkutane Biopsieverfahren zur Verfugung, die im Vergleich mit einem operativen Eingriff kostengunstiger, zeitsparender und mit geringerer Morbiditat belastet sind. Hierzu zahlen in erster Linie die Feinnadelpunktion und die Hochgeschwindigkeitsstanzbiopsie. Seit 1995 wird zudem die sog. Vakuumbiopsie eingesetzt, die mittels Unterdruck eine kontinuierliche Gewebeabtragung eines mammographisch suspekten Areals uber einen solitaren Zugangsweg erlaubt. In der Literatur wird der Einsatz dieser Methode kontrovers diskutiert. In der vorliegenden Arbeit werden zunachst die Technik der perkutanen, stereotaktisch gezielten Vakuumbiopsie und die BI-RADS™(Breast-Imaging-Reporting-and-Data-System)-Kategorisierung des American College of Radiology (ACR) prasentiert. Anschliesend sollen die Indikationen zur Vakuumbiopsie mit Blick auf die BI-RADS™-Terminologie vorgestellt werden. Anhand einer Literaturubersicht erfolgt schlieslich eine kritische Darstellung der Vor- und Nachteile dieser Methodik im Vergleich zu den alternativen Biopsieverfahren.

Purpose: To evaluate the detection rate of vascular stenosis in contrast-enhanced 3D MR angiography using a flow phantom. Material and methods: The examinations were performed on a 1.5 T whole body imaging system (Magnetom Symphony/Quantum) with 30 mT/m gradient field strength using a body-phased-array coil. Different 3D sequences (TR/TE/FA < 5 ms/

Purpose: Evaluation of stereotactic vacuum core biopsy of clustered microcalcifications categorized as BI-RADS 3. Material and Methods: 86 patients with microcalcifications BI-RADS 3 (probably benign

Intramural hematomas (IMH) are regarded as a hemorrhage into the aortic wall. In general a traumatic form can de differentiated from a spontaneous non-traumatic. There is a predisposition of IMH with arterial hypertension and mesoectodermal dysplastic syndromes. The diagnosis is established with the clinical presentation in combination with the findings of different imaging modalities. Acute and subacute discomfort associated with a tendency of collaps are considered as typical presenting complaints. A semicircular or concentric thickening of the aortic wall with the absence of blood flow or a dissection membrane are typical findings in transesophageal echocardiography, computed tomography and magnetic resonance tomography. From a differential diagnostic point of view a distinction from atherosclerotic wall changes, intraluminal thrombi and inflammatory aortic diseases is essential. The IMH is considered as an early presentation of aortic dissection, put into and treated according to the Stanford classification. In the course of natural history an IMH can disappear, rupture or progress into a classic aortic dissection.

Aim: To determine the value of multi-slice CT for the diagnosis of acute pulmonary embolism and an underlying venous thrombosis. Methods: 70 patients with clinically suspected acute pulmonary embolism were examined. Using multi-slice CT a combined examination of the pulmonary arteries and the veins of the lower limb, pelvis and abdomen was performed. Only one single bolus of 150 ml iopromid 300 was injected into a cubital vein with a flow of 4 ml/s. First, the pulmonary arteries were scanned with a slice thickness of 2.5 mm and a pitch of 1.5. On arrival of the contrast medium at the popliteal veins, indicated by bolus trakking, the veins of the lower limbs up to the end of the inferior vena cava were imaged using a slice thickness of 3.75 mm and a pitch of 1.5. The results could be compared with a ventilation-perfusion scan in 48 cases, with a Doppler ultrasound examination in 46 cases, and with a venography in 10 cases. Furthermore, the image quality of all arterial and venous regions was subjectively assessed. Results: In all patients who underwent multi-slice CT the pulmonary arteries as well as the veins of the lower half of the body could be recorded completely. Regarding, the pulmonary arteries the image quality showed excellent results for the central and segmental arteries. The region up to the 3rd division in subsegmental branches could be sufficiently judged. More peripherally, a diagnostic assessment was not possible. The image quality of the veins was excellent in all sections, except the calf, where a reliable diagnosis could not be made. The comparison with the other techniques confirmed the superiority of multi-slice CT concerning the central and segmental pulmonary arteries and the veins from the popliteal vein to the inferior vena cava. In contrast, peripheral pulmonary emboli can be detected more certainly in ventilation/perfusion scans. The veins of the calf can be evaluated more reliably with venography. Conclusion: Multi-slice CT proved to be an outstanding tool in the diagnosis of acute pulmonary embolism. The clinically suspected disease and a causing venous thrombosis can be detected in a fast and reliable way. At present, multi-slice CT is not suitable for the recognition of peripheral emboli. However, expected technical developments hold promise for future improvements.

Um den Wert der digitalen Technik fur ein Screening-Programm zu uberprufen, wurden zahlreiche experimentelle Studien und klinische Untersuchungen an einem Gerat zur direkten digitalen Vollfeldmammographie (FFDM) durchgefuhrt. Die Befunde im Hinblick auf die Detektion und die Charakterisierung von Mikrokalk und von soliden Tumoren sowie den Dosisbedarf der FFDM wurden mit der konventionellen Film-Folien-Mammographie (FFM) verglichen. Die Ergebnisse dieser Studien belegen eine zumindest gleich hohe Bildqualitat der digitalen Technik fur Ubersichtsaufnahmen sowie eine signifikant hohere Detektionsrate speziell von Mikrokalk fur Vergroserungsaufnahmen. Dies trifft insbesondere zu, wenn man die vielfaltigen Optionen zur Bildnachbearbeitung nutzt. Ferner ergibt sich die Moglichkeit, die Sensitivitat der digitalen Technik durch die Einfuhrung einer Software zur Mustererkennung (CAD) zu erhohen. Daruber hinaus besteht ein relevantes Potenzial zur Reduktion der Dosis. Weitere Vorteile sind u. a. die einfache und schnelle Handhabung des Systems, der rasche Datentransfer und die digitale Archivierung. Daher kann man davon ausgehen, dass die FFDM mittelfristig einen wichtigen Beitrag fur die Durchfuhrung eines Mammographie-Screenings leisten wird.

Objectives: The study compares contrast-detail and microcalcification detectability of a full-field digital mammography (FFDM) to a state-of-the-art conventional screen-film mammography (SFM) by using different doses in the digital system. Materials and Methods: The investigations were performed with an FFDM (Senographe 2000 D, GEMS) and an SFM system (Senographe DMR, GEMS) using a contrast-detail mammography phantom (CDMAM) and an anthropomorphic breast phantom with superimposed microcalcifications. The digital detector was exposed with standard dose of SFM and with a dose reduction of up to 75%. Contrast-detail curves and correct observation ratio (COR) were performed for the CDMAM phantom. ROG analysis with a confidence level ranging from 1 to 5 was done with the results of the anthropomorphic phantom. Results: Digital mammography with the same dose revealed at least an equivalent or even higher detectability rate than conventional mammography, COR could be increased at about 10-25%. The ROC analysis yielded better results for the FFDM system. The same lesion detectability in digital mammography as in the conventional method was reached at a dose reduction of about 25 %, concerning spot views even at higher reduction. Dose reduction in the anthropomorphic phantom resulted in a linear loss of detectability. The same detectability as in conventional mammography was reached, however, by a dose reduction of about 50 %. Conclusion: The results suggest that FFDM is at least equivalent to or - as far as spot views are concerned - superior to conventional SFM concerning the detectability of simulated lesions. Thus, a potential of dose reduction is suggested.

Purpose: Comparison of radiation exposure between a digital amorphous silicon and a screen-film based mammography system. Evaluation of a possible potential of full-field digital mammography in order to decrease the radiation dose. Methods: The average glandular dose for phantom thicknesses from 30 to 60 mm was calculated from experimentally determined entrance surface air kerma for a digital and a conventional mammography system. The effect of reducing the detector dose and of changing the radiation quality on radiation exposure and on image quality were investigated. Results: By using the delivered settings of the automatic exposure control (AEC) devices, both mammographic systems needed nearly the same doses. Regulations and guidelines on radiation doses were complied. With the digital system, a reduction of radiation exposure of up to 40% by using a higher radiation quality and decreasing slightly the detector dose without loss of diagnostic image quality, might be possible. Conclusion: The potential of full-field digital mammography for radiation dose reduction, as shown in the present phantom study, needs however, a careful examination under clinical conditions.

Purpose The aim of this study is to determine the optimal scan parameters for the evaluation of experimental vascular stenoses with a multislice-helical CT. Material and methods A vascular phantom consisting of four tubes with an inner diameter of 8 mm and with experimental stenoses of 50%, 75% and 90% was scanned in different tube orientations using a multislice-CT scanner (LightSpeed QX/i, GE, Milwaukee, USA). Examinations were performed with increasing collimations (1.25-5 mm), tube currents (100-300 mA) and two different table speeds (0.75 HQ mode and 1.5 HS mode). Results The most exact measurements were obtained in tubes angulated parallel to the scan direction with a collimation of 2.5 mm in the HQ mode (7.5 mm/rot.). An almost equivalent accuracy was obtained in the HS mode (15 mm/rot.) with a collimation of 2.5 mm when higher tube currents (300 mA) were employed. The degree of stenoses was overestimated when the tube was angulated perpendicular to the z-axis. Conclusion Multislice-CT provides a good detection rate of vascular stenoses especially at 0 degree and also at 45 degrees angulation in the HQ mode. The use of the HS mode with higher tube currents allows scanning of longer distances with almost identical accuracy.

Introduction: In patients with the mammographic findings of a radial scar, contrast enhanced (CE) MR mammography was evaluated in a retrospective study. Material and methods: In 24 women with radial opacities and black star configurations, CE MR mammography was performed. Examinations were done on a 1.5T system using bilateral superficial coil (2D technique, T 1 -weighted FLASH-sequence, T R 336ms, T E 5 ms, FA 90°). Findings in mammography and MR mammography were compared with the histological results. Results: 15 radial scars (including 4 with additional ADH) and 9 carcinomas (6 in coexistence with a radial scar) presenting with a diameter of 3 mm to 13 mm were evaluated. There was no evidence of malignancy in MRI in 12 of 15 radial scars. In MR mammography 6 of the carcinomas fulfilled the criteria for malignant tumors. There were 3 borderline cases (scored 3 points) corresponding histologically to 1 radial scar, and to 2 carcinomas. Within the results found in MRI there were 2 false positives and 1 false negative. Conclusion: CE MR mammography is superior to other imaging modalities in the differentiation between radial scars and carcinomas. However, lesions suggestive of radial scars have to be removed surgically.

Objectif: The study compares direct full-field digital mammography (FFDM) to the state-of-the-art conventional screen-film mammography (SFM) concerning the detectability of simulated microcalcifications. Materials and Methods: The investigations were performed with a FFDM system (Senographe 2000D, GEMS) and a SFM system (Senographe DMR, GEMS, Fuji UM MA film with Fuji UM MAMMO FINE screen). An anthropomorphic breast phantom with superimposed microcalcifications (50-200 μm) was used to evaluate the detectability of microcalcifications with a confidence level ranging from 1 to 5. Contact mammograms and magnification spot views (m = 1.8) of the FFDM and SFM systems were compared. A receiver operating characteristic (ROC) analysis was performed by three well-experienced readers. Results: The ROC analysis revealed a higher performance of the digital images compared to the conventional screen-film mammograms. The area under the ROC-curve (A z ) in the digital contact mammograms was 0.68 versus 0.63 in the conventional technique. The results were not significantly different. In digital spot views, A z was 0.79 versus 0.70 in the conventional spot views. Conclusions: The results suggest that FFDM is at least equivalent or - as far as spot views are concerned - may be superior to conventional SFM in the detection of microcalcifications.

Ziel: Die technischen Voraussetzungen, die optimierten Untersuchungsprotokolle und die diagnostischen Moglichkeiten der Virtuellen Endoskopie (VE) der oberen Luftwege werden in einer Ubersicht vorgestellt. Methode: Phantomstudien konnten nachweisen, dass fur ein 1-Zeilen-Spiral-CT-Gerat eine Kollimation von 3,0 mm kombiniert mit einem Tischvorschubsfaktor von 1,5 ein optimierter Kompromiss zwischen der Bildqualitat und der tolerablen Untersuchungsdauer pro Atemanhaltephase ist. Ein Mehrzeilen-Spiral-CT der neuesten Generation benotigt bei einer vergleichbaren raumlichen Auflosung nur noch einen Teil der Akquisitionszeit, was insbesondere bei Patienten mit Dyspnoe die Durchfuhrung der Untersuchung vereinfacht. Ergebnisse: Die schwellenwertabhangige virtuell endoskopische Oberflachendarstellung (surface rendering) ist fur die Abbildung der oberen Luftwege ein verlasslicher und schnell einsetzbarer Rekonstruktionsalgorithmus. Schlussfolgerungen: Die VE bietet sich fur die Darstellung raumfordernder Prozesse und umschriebener Stenosen an. Verlaufs- und Therapiekontrollen konnen mit der VE nichtinvasiv durchgefuhrt und interventionelle Masnahmen optimal geplant werden. Aufgrund der computertomographischen Datenakquisition kann die Struktur der Mukosa nicht beurteilt werden. Ferner fehlt die Moglichkeit zur bioptischen Probeentnahme.

Purpose: The purpose of this phantom study was to evaluate the visualization of vascular stents by using contrast-enhanced (CE) 3D MR angiography (MRA). Methods: The measurements were performed on a Magnetom Vision operating at 1.5 T with 25 mT/m gradients by using a head coil; a 3D FISP sequence (TR/TE/FA 4.6 ms/1.8 ms/30°) was used. A phantom was designed with a length of 20 cm and consisted of a plastic cylinder filled with hydrogel. Tubes were used to install 7 different stents (Strecker, Boston Scientific; Cragg, Mintec; Wall, Schneider; Memotherm, Angiomed; St-Come, Trigon-MTS; Sinus, Optimed; Palmaz, Johnson & Johnson) with different metal components. The tubes were perfused with a solution of water and Gd-DTPA. Four radiologists evaluated the image quality. The measurements of the endoluminal stent diameters were compared with the findings obtained by digital subtraction angiography. The signal intensities were measured before (inflow), within (stent) and after (outflow) the different stent types. Results: The endoluminal diameter of the Cragg stent and the strecker graft were easily detectable. The signal loss within the lumen of the Wall stent was approx. 10% in relation to the inflow and outflow measurements. The result was an only slightly reduced image quality. The other grafts (St-Come, Sinus, Palmaz, Memotherm) showed significant signal losses ranging from 65% to 96%. A correct diagnosis was not possible within these graft lumina. Conclusion: Contrast-enhanced MR angiography can be used to evalute vascular stents. A prerequisite is the application of particular commercially available grafts.

PURPOSE To improve the image quality of magnetic resonance cholangiopancreatography (MRCP) by modification of examination conditions. MATERIALS AND METHODS MRCP of 72 patients was performed with a 1.5 T system (Magnetom Vision, Siemens, 25 mT/m) using two breath-hold techniques, half-fourier acquisition with multislice T2-WI HASTE in MIP technique, and single shot T2-WI turbo-spin-echo (RARE) with different slice thicknesses. The effects of n-butylscopolamine were assessed. Furthermore, oral contrast agents [barium sulfate, Fe(II)-gluconate, Fe(II,III)-oxide] in various concentrations were used. The slice thickness was varied for the RARE sequence (3-7 cm). RESULTS N-butylscopolamine had no influence on image quality. Improvements could be attained by variation of the slice thickness. A significant reduction of disturbing background noise was obtained by oral application of iron gluconate, or iron oxide-containing contrast media. Similar improvements were achieved with barium sulfate. CONCLUSIONS Variation of slice thickness allows an improvement of MRCP quality. Oral contrast media improve the image quality of MRCP. The expense of contrast media may be a determinant of choice.

PURPOSE: To compare digital X-ray, CT, and MRI in the evaluation of ligamentous and osseous lesions in upper cervical spine specimens after artificial craniocervical injury with the findings of macroscopic preparation. MATERIALS AND METHODS: A rotation trauma of defined severity was applied to 19 human corpses. After dissection of the neck specimens, digital X-ray (DIMA Soft P41, Feinfocus), conventional and helical CT (CTi, High Speed, GE, collimation 1 mm; pitch 1.0), and MRI were performed from the skull base to C3. The findings were correlated with the macroscopic results of preparation. MR (Magnetom Vision, Siemens) imaging was obtained with a 1.5 T system using 2D- and 3D-sequences. RESULTS: Preparation revealed 6 fractures of the vertebral bodies, 5 fractures of the dens axis, 1 fracture of the arcus anterior of the atlas, 4 osseous flakes at the occipital condylus, and 6 lesions of the alar ligaments. Digital radiography showed all fractures and 4 osseous flakes at the occipital condylus. With conventional and helical CT, all fractures and all ruptured alar ligaments could be detected. 2D MRI depicted 9 of the fractures and 3D MRI showed fractures. With 2D MRI, 2 of the 4 osseous flakes at the condylus could be detected and with 3D MRI one occipital condylus fracture could be depicted. Ligamentous injuries were visualized by 2D MRI in 2 of 6 cases and by 3D MRI in one case. CONCLUSIONS: In post-mortem studies, CT was superior to MRI in the visualization of osseous and ligamentous injuries after trauma of the upper cervical spine. However, these results are not transferable to patients with rotation injury in general.

To determine if magnetic resonance (MR) imaging can help determine the therapeutic approach in women with breast cancer.Preoperative contrast-enhanced MR imaging of the breast was performed in 463 patients with probably benign lesions (n = 63), suspicious lesions (n = 230), or lesions highly suggestive of malignancy (n = 170) per established clinical, mammographic, and/or ultrasonographic (US) criteria. T1-weighted fast low-angle shot MR imaging was performed before and after administration of gadopenetetate dimeglumine. MR imaging findings were correlated with other imaging results and histopathologic findings. Special attention was paid to multifocality and multicentricity.Histopathologic analysis revealed 143 benign and 405 malignant lesions. The sensitivity, specificity, and accuracy were 58%, 76%, and 62% for clinical examination; 86%, 32%, and 72% for conventional mammography; 75%, 80%, and 76% for US; and 93%, 65%, and 85% for contrast-enhanced MR imaging. Multifocality in 30 of 42 patients, multicentricity in 24 of 50 patients, and additional contralateral carcinomas in 15 of 19 patients were depicted with MR imaging alone. Due to the MR imaging findings, therapy was changed correctly in 66 patients (14.3%); unnecessary open biopsy was performed in 16 patients (3.5%).Contrast-enhanced MR imaging of the breast is highly sensitive for invasive breast cancer. MR imaging may reveal unsuspected multifocal, multicentric, or contralateral breast carcinoma and result in therapy changes.

Akute Erkrankungen der Aorta im Korperstamm stellen eine lebensbedrohliche Situation fur den betroffenen Patienten dar, so das ein rasches Handeln zwingend erforderlich ist. Voraussetzung hierfur ist eine leistungsfahige, schnelle und zuverlassige Diagostik, die von der neuen CT-Technik in nahezu idealer Weise realisiert werden kann. Methoden: Bei klinischem Verdacht auf eine Aortenerkrankung wurden Untersuchungen mit einer neuen Mehrzeilen-Spiral-CT (MZ-SCT) durchgefuhrt. Die Aorta thoracalis, die Aorta abdominalis oder der gesamte Gefasbaum von den supraaortalen Asten bis zu den Inguinalarterien wurden mit verschiedenen Protokollen untersucht. In den ersten beiden Gruppen wurden bei konstanter Untersuchungszeit die Schichtdicke und die Tischvorschubgeschwindigkeit variiert. In der dritten Gruppe wurde eine monophasische mit einer biphasischen Untersuchung verglichen. Ergebnisse: In der Diagnostik von aortalen Erkrankungen erwies sich die MZ-SCT als schnelle und verlasliche Methode mit allen Protokollen. Die objektive Messung der Kontrasthomogenitat und die subjektiven Abbildungsqualitaten waren in den ersten beiden Gruppen vergleichbar. Das monophasische Vorgehen war der biphasischen Untersuchung uberlegen. Schlusfolgerung: Die MZ-SCT ist bei Anwendung geeigneter Untersuchungsprotokolle heute der Goldstandard in der Diagnostik akuter Aortenerkrankungen.