Perivascular mast cells and expression of vascular endothelial growth factor, laminin-332 and matrix metalloproteinase-9 in human colorectal neoplasms.

INTRODUCTION AND AIMS: Colorectal cancer (CRC) is one of the most prevalent cancers worldwide, and significantly contributes to cancer-related deaths. Most cases arise from adenomatous polyps. Biomarkers currently play an important role in tumor progression. Our aim was to identify perivascular mast cells and analyze the expression of laminin-332, MMP-9, and VEGF in cases of adenoma and CRC in humans. MATERIALS AND METHODS: Patients were selected at the Coloproctology Service and samples were obtained through biopsies. Adenoma and CRC slides were examined, utilizing immunohistochemistry to detect molecules, and were processed, using 1% Alcian Blue (pH 0.5) for mast cell staining. RESULTS: Higher density of perivascular mast cells was observed in adenomas. Laminin-332 expression revealed basement membrane discontinuity associated with tumor invasion in CRC. MMP-9 immunostaining in adenoma was detected in glandular epithelium and lining epithelium, in areas close to the basement membrane, whereas in CRC, the enzyme was found in the cytoplasm of invasive clusters. VEGF expression was associated with cell atypia in adenoma and in areas of disorganization of the epithelium-connective tissue interface in CRC. VEGF has also been detected in endothelial cells from microvessels. CONCLUSIONS: We demonstrated the different patterns of perivascular mast cells and molecular expression in colorectal neoplasms. Those analyses favor the recognition of the predisposition to the disease, or its early stage, and have the potential to define the molecular profile of the lesions.

Could formaldehyde induce mutagenic and cytotoxic effects in buccal epithelial cells during anatomy classes?

BACKGROUND: Due to increased formaldehyde exposure, carcinogenic to humans, several researches have been studying the potential toxicity and the safe levels for human beings. The aim of this study was to investigate mutagenicity and cytotoxicity in buccal epithelial exfoliated cells (BEC) of students subjected to formaldehyde (FA) during anatomy classes. MATERIAL AND METHODS: BEC were collected periodically from 17 volunteers of undergraduate programs, who had participated in practical anatomy classes, before and after FA exposure. Cells were stained according to Feulgen method and then micronucleus test was applied. A total of 1,500 cells were assessed per individual in this study for the micronucleus frequency and other parameters of cytotoxicity. RESULTS: There was statistically significant increase in number of micronucleated BEC after FA exposure (after 1 month p=.034 and after 3.5 months p=.017). However, FA exposure caused no significant increase in other nuclear alterations closely related to cytotoxicity (p≥.05). CONCLUSIONS: FA induced mutagenicity during anatomy classes. Cell death increased, but it was not statistically significant. Efforts have to be made to improve air quality and reduce exposures during anatomy classes.

Structural and ultra-structural features of the first mandibular molars of young rats submitted to pre and postnatal protein deficiencies.

The effects of protein malnutrition, both in utero and prior to weaning, on formation of the first mandibular molars were evaluated by phase-contrast and electron microscopy in rats. The nourished group (GI) received a diet that included 20% casein, while the malnourished group (GII) received 5% casein. The first mandibular molars from GII exhibited low density of cells and odontoblasts, which lacked regular organization compared with molars from GI. In addition, a difference in collagen type was observed between the groups, with a prevalence of Type III collagen fibers detected in the dentin, periodontal ligament, and alveolar bone of GII, and a prevalence of Type I collagen fibers in GI. Finally, examination of surface area in molar sagittal sections indicated 30% less dentin in GII, compared with GI. Our results suggest that structural and ultra-structural features of the dentin-pulp complex and periodontal components of rat molars are affected by protein deficiency.

[Oropharyngeal pathologies]. / Oropharynxpathologie.

The oropharynx is an interface between the airway and the digestive tract. Clinical evaluation and endoscopy suffice for the diagnosis of a variety of lesions, but tumors require cross-sectional imaging to assess local infiltration depth and lymphatic spread. This article discusses different lesions of the oropharynx with respect to imaging characteristics of CT and MRI, with a focus on resectability issues and decision-making.

Experimental model to evaluate in vivo and in vitro cartilage MR imaging by means of histological analyses.

OBJECTIVES: Implementation of an experimental model to compare cartilage MR imaging by means of histological analyses. MATERIAL AND METHODS: MRI was obtained from 4 patients expecting total knee replacement at 1.5 and/or 3T prior surgery. The timeframe between pre-op MRI and knee replacement was within two days. Resected cartilage-bone samples were tagged with Ethi-pins to reproduce the histological cutting course. Pre-operative scanning at 1.5 T included following parameters for fast low angle shot (FLASH: TR/TE/FA=33 ms/6 ms/30 degrees, BW=110 kHz, 120 mm x 120 mm FOV, 256 x 256 matrix, 0.65 mm slice-thickness) and double echo steady state (DESS: TR/TE/FA=23.7 ms/6.9 ms/40 degrees, BW=130 kHz, 120 x 120 mm FOV, 256 x 256 matrix, 0.65 mm slice-thickness). At 3T, scan parameters were: FLASH (TR/TE/FA=12.2 ms/5.1 ms/10 degrees, BW=130 kHz, 170 x 170 mm FOV, 320 x 320, 0.5mm slice-thickness) and DESS (TR/TE/FA=15.6 ms/4.5 ms/25 degrees, BW=200 kHz, 135 mm x 150 mm FOV, 288 x 320 matrix, 0.5mm slice-thickness). Imaging of the specimens was done the same day at 1.5 T. MRI (Noyes) and histological (Mankin) score scales were correlated using the paired t-test. Sensitivity and specificity for the detection of different grades of cartilage degeneration were assessed. Inter-reader and intra-reader reliability was determined using Kappa analysis. RESULTS: Low correlation (sensitivity, specificity) was found for both sequences in normal to mild Mankin grades. Only moderate to severe changes were diagnosed with higher significance and specificity. The use of higher field-strengths was advantageous for both protocols with sensitivity values ranging from 13.6% to 93.3% (FLASH) and 20.5% to 96.2% (DESS). Kappa values ranged from 0.488 to 0.944. CONCLUSIONS: Correlating MR images with continuous histological slices was feasible by using three-dimensional imaging, multi-planar-reformat and marker pins. The capability of diagnosing early cartilage changes with high accuracy could not be proven for both FLASH and DESS.

Automated breast ultrasound: lesion detection and BI-RADS classification--a pilot study.

PURPOSE: Evaluation of an automated breast ultrasound system (ABUS) regarding the detection and classification of breast lesions according to BI-RADS. MATERIALS AND METHODS: Women were selected for the study who had unclear findings in breast diagnosis performed elsewhere (palpation, sonography or mammography) and who were referred for further work-up. All patients received a hand-held ultrasonography (HHUS) with a 13 MHz transducer, clinical examination and mammography of both breasts. Additionally, the affected breast received the ABUS (SomoVuTM, U-Systems, Inc., San Jose, CA, USA; EC Representative: Siemens, Erlangen, Germany) which was performed with an 8 MHz transducer. Five radiologists independently evaluated the ABUS images regarding lesion detectability. All detected lesions were classified according to BI-RADS assessment. The examiners had no knowledge of the patients' clinical examination or of the result of the mammography or the HHUS. Results of the ABUS were compared to HHUS. RESULTS: 35 women were included in the study. 25 BI-RADS 4 or 5 lesions had further histological (n = 23) or cytological (n = 2) work-up which revealed 13 malignant and 12 benign findings. The size of all lesions ranged from 6 to 32 mm (median 14 mm). With the ABUS all examiners detected 29 to 30 lesions while HHUS revealed 30 lesions. One suspicious area in HHUS was not reported by any of the five examiners with the ABUS. Histology of this area revealed mastopathic disease. No benign lesion was classified as BI-RADS 5 with the ABUS or HHUS. All breast cancers were found with the ABUS by all examiners and correctly classified as BI-RADS 4 or 5. There was good agreement regarding BI-RADS classification of HHUS and ABUS for the five different examiners with Kappa values between 0.83 and 0.87. CONCLUSION: These preliminary results show that the ABUS allows detection of solid and cystic lesions and their BI-RADS classification with a high reliability in a selected patient group.

MR imaging: influence of imaging technique and postprocessing on measurement of internal carotid artery stenosis.

BACKGROUND AND PURPOSE: MR angiography (MRA) is increasingly used as an alternative to digital subtraction angiography (DSA) to evaluate internal carotid artery (ICA) stenosis. Because MRA is not standardized in data acquisition and postprocessing, we sought to evaluate the effects of different acquisition techniques (time-of-flight MRA [TOF-MRA]) and contrast-enhanced MRA [CE-MRA]) and postprocessing methods (maximum intensity projection [MIP], multiplanar reformation [MPR], and volume-rendering on stenosis grading. MATERIALS AND METHODS: Fifty patients (33 men, 17 women) with symptomatic ICA stenosis were examined at 1.5T. Two imaging techniques and 3 postprocessing methods resulted in 6 image datasets per patient. Two readers independently evaluated ICA stenosis according to the North American Symptomatic Carotid Endarterectomy Trial criteria. Interobserver variability was calculated with the Pearson correlation coefficient and simultaneous confidence intervals (CI). The relationship of the values of ICA stenosis between the techniques was assessed by means of simultaneous 95% Tukey CI. RESULTS: Interobserver agreement was high. Higher concordance was found for postprocessing techniques with TOF- than with CE-MRA; the mean difference between TOF-MPR and TOF-MIP was 0.4% (95% CI, -2.9%-3.8%). Stenosis values for CE-MPR differed significantly from those of CE volume-rendering (7.2%; 95% CI, 3.9%-10.6%). CONCLUSION: Stenosis grading was found to be independent of the postprocessing technique except for comparison of CE-MPR with CE volume-rendering, with the volume-rendering technique resulting in higher stenosis values. MPR seems to be best-suited for measurement of ICA stenosis. Parameter setting is critical with volume-rendering, in which stenosis values were consistently higher compared with the other methods.

[Computer-assisted navigation system for interventional CT-guided procedures: results of phantom and clinical studies]. / Computergestütztes Navigationssystem für CT-gesteuerte Interventionen: Ergebnisse am Phantom und im klinischen Einsatz.

PURPOSE: To evaluate the technical applicability and accuracy of a navigation system for CT-guided interventional procedures in a phantom and a patient study. MATERIALS AND METHODS: A novel navigation tool (CAPPA IRAD, CAS innovations AG, Erlangen, Germany) was employed for CT-guided biopsies in a phantom and in patients. The entire system consists of a PC, navigation software, an optical tracking system and a patient frame. For the phantom study, a spine phantom in wax was used. The phantom as well as the patients were placed on the CT table in a stable position and fixed within a double vacuum device. The patient frame equipped with optical and CT markers was placed above the target region, followed by acquisition of a planning scan. All data were transferred to the navigation system inside the scanning room, and with the aid of the above mentioned navigation software, the biopsy pathway was planned. Hereafter, the needle holder was aligned accordingly, and a coaxial biopsy needle was pushed forward to the planned target. An additional control scan confirmed needle position, and the navigation software was used to evaluate the distance between the target and needle tip. RESULTS: In the phantom study (n = 60) the average deviation between the planned and documented needle tip position was 1.1 mm. In the clinical study (n = 15), we performed biopsies of the lung, the mediastinal area, the pancreas and liver and some bone biopsies as well as a therapeutic nerve root infiltration. 12 of 15 cases required oblique needle access. In 9 / 15 cases merely a single planning and control scan were required, whereas in 5 / 15 cases additional safety or correction scans were performed. In the case of pancreas biopsy, the lesion (diameter 1 centimeter) visible during the arterial phase only could not be punctured even following repeated corrections due to severe breathing artifacts and pronounced peristaltic movement of the adjacent bowel. The time between planning CT and correct needle position was about 30 minutes. CONCLUSION: The navigation system allows for safe interventions in case of angulated needle access with high accuracy and little tissue trauma. However, insufficient corrections for respiration movement constitute a substantial limitation of the tool.

Cutaneous application of local anaesthetic--a useful help in galactography.

Galactography is an important step in the diagnostic workup of abnormal nipple discharge. At times it is impossible to insert the cannula in the secreting duct and galactography cannot be performed. In such cases we tried applying local anaesthetic spray (LA) cutaneously to the nipple followed by a further insertion attempt. LA has enabled us to insert the galactography cannula in all patients so far. We concluded that after previous unsuccessful attempts, the presented technique may relax the duct orifice and therefore permit insertion of the galactography cannula into the secreting duct.

[Current situation and future perspectives of digital mammography]. / Aktueller Stand und weitere Perspektiven der digitalen Mammographie.

Digital mammography has extensively replaced conventional film screen mammography and is now the standard in combination with soft copy reading in clinical as well as screening mammography. Large international multicenter studies demonstrate an equivalent or superior detection rate of breast cancers by digital in comparison to conventional mammography especially in dense breasts, premenopausal and perimenopausal women and women less than 50 years old. Computer-aided detection (CAD) is important for the experienced investigator (increased specificity). Digital mammography also offers further options, such as tomosynthesis, digital contrast-enhanced mammography and the combination of digital mammography and ultrasound. The future in breast diagnosis will be the fusion of images from different digital systems.

Unusual subcutaneous localisation of a dermatofibrosarcoma protuberans of the female breast: a case report.

Dermatofibrosarcoma protuberans (DFSP) is a slow growing soft tissue neoplasm of dermal fibroblastic origin characterised by local invasion and a high propensity for local recurrence. We report a 31-year-old woman with subcutaneous DFSP of the breast, which is an unusual localisation. Diagnostic work-up comprised clinical examination, mammography and ultrasound. Definitive diagnosis was not possible prior to histological analysis of the lesion. Wide excision of the tumour was performed, which is the therapy of choice in DFSP. Ultrasound played an important role in histological diagnosis before definitive surgery and might be helpful in follow-up of patients with DFSP of the breast.

[Tolerance of magnetic resonance imaging in children and adolescents performed in a 1.5 Tesla MR scanner with an open design]. / Untersuchungstoleranz von Kindern und Adoleszenten in einem 1,5 Tesla MR-Tomografen mit offenem Magnetdesign.

PURPOSE: To investigate the tolerance of MR examinations in children and adolescents performed in a 1.5 Tesla MR scanner with an expanded bore diameter. METHOD AND MATERIALS: 163 patients, ages 4 to 25, underwent MR examinations in a 1.5 Tesla MR scanner with an open design (MAGNETOM Espree, Siemens, Erlangen, Germany), characterized by a compact length of 125 cm and an expanded 70 cm bore diameter. MR imaging of the brain was carried out in most cases (78.5 %), followed by examinations of the spinal canal (9.8 %), the extremities (9.2 %) and the neck (2.5 %). The patients were divided into four age groups and the success rate, motion artifacts and diagnostic quality of the MR examinations were assessed using a 3-grade scale. RESULTS: In 119 of 163 patients (73.0 %), MR examination was possible without any motion artifacts. With respect to the different age groups, 41.7 % of the 4 - 7-year-old children, 67.6 % of the 8 - 10-year-old children, 84.1 % of the 11 - 16-year-old children and 95.8 % of the patients older than 17 showed tolerance grade I without motion artifacts and excellent diagnostic image quality. In 39 of 163 children (23.9 %), the MR images showed moderate motion artifacts but had sufficient diagnostic quality. With regard to the different age groups, 52.8 % of the 4 - 7-year-old children, 26.5 % of the 8 - 10-year-old children, 15.9 % of the 11 - 16-year-old children and none of the patients older than 17 showed tolerance grade II with moderate motion artifacts and sufficient diagnostic image quality. In only 4 of 124 children < 10 years old and 1 child > 10 years old, the MR examination was not feasible and had to be repeated under sedation. CONCLUSION: Pediatric MR imaging using a 1.5 Tesla MR scanner with an open design can be conducted in children and adolescents with excellent acceptance. The failure rate of 3.0 % of cases for pediatric MR imaging is comparable to that of a conventional low-field open MR scanner.

[Experimental investigations for dose reduction by optimizing the radiation quality for digital mammography with an a-Se detector]. / Experimentelle Untersuchungen zur Dosisreduktion durch Optimierung der Strahlungsqualität bei digitaler Vollfeldmammografie mit einem Detektor auf Selenbasis.

PURPOSE: Reduction of radiation exposure at an adequate image quality by optimizing the radiation quality for a new system of full-field digital mammography using a digital detector (a-Se). MATERIALS AND METHODS: The investigations were performed using a digital mammography system Novation (Siemens, Erlangen). The system was constructed with a bimetal anode (molybdenum and tungsten) and the possibility of changing the filter (molybdenum/rhodium). The test object was the Wisconsin Mammography Random Phantom Model 152 A (Radiation Measurements Inc.) of which images were acquired using the digital technique with the tungsten anode and rhodium filter at different tube voltages (26-35 kV) and tube loads (40-100 mAs) and compared to images in the molybdan/molybdan molybdenum/molybdenum technique. To quantify the image quality, we used the detection rate of the simulated lesions in the phantom. RESULTS: Increasing the tube voltage significantly decreases the average glandular dose when using AEC (Automatic Exposure Control), i. e., constant detector dose. At the same time, the image quality decreases significantly with respect to the detection rate (26 kV, 1 mGy, 95.1 %; 35 kV, 0.7 mGy, 82.7 %). As a good compromise between the necessary diagnostic image quality and the lowest dose exposition, 28 kV and 60 mAs were selected for imaging with the tungsten/rhodium anode/filter combination. A further change to the tube load did not make sense because a decrease of 10 % resulted in a significant decrease in the detection rate while only a 2 % increase in detection rate was achieved for a 65 % increase in radiation exposure. CONCLUSION: The results of this phantom study demonstrate that the routine use of the tungsten anode in combination with a rhodium filter for full-field digital mammography with an a-Se detector in contrast to a molybdan/molybdan molybdenum/molybdenum anode/filter combination results in a reduction of the average glandular dose of up to 30 % without loss of diagnostic image quality.

[Comparing the clinical value of spot view mammography with reduced pixel size to monitor zooming by reporting microcalcifications in digital mammography]. / Vergleich der klinischen Wertigkeit von Zielaufnahmen mit reduzierter Pixelgrösse des Detektors und digitalem Monitorzooming bei der Beurteilung von Mikrokalzifikationen in der digitalen Mammografie.

PURPOSE: Evaluation of the diagnostic value of breast specimen imaging with a digital mammographic system using a detector system with changeable pixel size compared to standard mode imaging in different monitor display modes. MATERIALS AND METHODS: Using the digital mammographic system SenoScan (Fischer Imaging, Denver, USA), 50 diagnostic breast specimens with microcalcifications were visualized in both standard mode (pixel size 54 microm) and high resolution mode (pixel size 27 microm). The resulting radiographs were displayed 1:1 on a monitor. Standard mode images (pixel size 54 microm) were additionally displayed in a 2:1 mode. A total of 5 readers with different mammographic experience analyzed the type of the microcalcifications on the basis of the different display modes. The images were presented randomly. The findings were subsequently compared to the histology. RESULTS: The high resolution mode yielded slightly but not significantly better results than the standard mode on average for all 5 readers. Compared to a sensitivity of 80 % and a specificity of 72 % (PPV = 74 %, NPV = 78 %) in the standard mode, the high resolution mode provided a sensitivity of 86 % and a specificity of 74 % (PPV = 77 %, NPV = 83 %). The standard mode images on a 2:1 monitor display yielded 84 % and 74 % (PPV = 76 %, NPV = 82 %). CONCLUSION: The high resolution mode did not significantly increase the sensitivity and specificity of the microcalcification reading. A similar improvement was achieved by the 2:1 display mode, i. e. digital monitor zooming. For the clinical situation this means that there is no diagnostic advantage from using a high resolution target view with this mammographic system.

[Mammography screening]. / Mammographiescreening.

Exclusive biannual mammography screening for women ages 50-69 years reduces the mortality from breast cancer among participants by 35%. Compared with 50% of clinically detected cancers, only 20% of carcinomas detected in screening have nodal metastases, and up to 55% of screening carcinomas are in the T1 stage of "minimal cancer." In many European countries (including Sweden, Norway, the Netherlands, and Great Britain), mammography screening programmes have been established for more than 10 years. In Germany, the aim is to establish, by 2008, a nationwide organised programme on the basis of the European Guidelines for Quality Assurance. This goal requires 80-100 mammography screening units. The first screening units went into use in 2005. Women between 50 and 69 years are invited to participate in 2-year intervals.

Effect of CT-based attenuation correction on uptake ratios in skeletal SPECT.

UNLABELLED: The AIM of this study was to determine the clinical relevance of compensating SPECT data for patient specific attenuation by the use of CT data simultaneously acquired with SPECT/CT when analyzing the skeletal uptake of polyphosphonates (DPD). Furthermore, the influence of misregistration between SPECT and CT data on uptake ratios was investigated. METHODS: Thirty-six data sets from bone SPECTs performed on a hybrid SPECT/CT system were retrospectively analyzed. Using regions of interest (ROIs), raw counts were determined in the fifth lumbar vertebral body, its facet joints, both anterior iliacal spinae, and of the whole transversal slice. ROI measurements were performed in uncorrected (NAC) and attenuation-corrected (AC) images. Furthermore, the ROI measurements were also performed in AC scans in which SPECT and CT images had been misaligned by 1 cm in one dimension beforehand (ACX, ACY, ACZ). RESULTS: After AC, DPD uptake ratios differed significantly from the NAC values in all regions studied ranging from 32% for the left facet joint to 39% for the vertebral body. AC using misaligned pairs of patient data sets led to a significant change of whole-slice uptake ratios whose differences ranged from 3,5 to 25%. For ACX, the average left-to-right ratio of the facet joints was by 8% and for the superior iliacal spines by 31% lower than the values determined for the matched images (p < 0.05). CONCLUSIONS: AC significantly affects DPD uptake ratios. Furthermore, misalignment between SPECT and CT may introduce significant errors in quantification, potentially also affecting left-to-right ratios. Therefore, at clinical evaluation of attenuation-corrected scans special attention should be given to possible misalignments between SPECT and CT.

Anatomical accuracy of interactive and automated rigid registration between X-ray CT and FDG-PET.

AIM: Comparison of anatomical accuracy of software-based interactive (IRR) and automated rigid registration (ARR) of separately acquired CT and FDG-PET data sets. PATIENTS, METHODS: Independently acquired PET and helical CT data from 22 tumour patients were registered manually using the Syngo advanced Fusion VC20H tool. IRR was performed separately for the thorax and the abdomen using physiological FDG uptake in several organs as a reference. In addition, ARR was performed with the commercially available software tool Mirada 7D on all of the patients. For both methods, the distances between the representation of 53 malignant lesions on PET and CT were measured in X-, Y-, and Z-direction with reference to a common coordinate system (X-, Y-, Z-distances). RESULTS: The percentage of lesions misregistered by less than 1.5 cm was in X-direction 91% for IRR and 89% for ARR; in Y-direction 85% and 68%; in Z-direction 72% and 51%, respectively. The average X-, Y- and Z-distances for IRR ranged from 0.58 +/- 0.55 cm (X-direction) to 1.17 +/- 1.66 cm (Z-direction). For ARR, the average X-, Y- and Z-distances varied between 0.66 +/- 0.61 cm (X-direction) and 1.81 +/- 1.37 cm (Z-direction). Mixed effects analysis of the absolute X-, Y- and Z-distances revealed a significantly better alignment for IRR compared to ARR in Z-direction (p < 0.01). Lesion size and localization either in thorax or abdomen had no significant influence on the accuracy of registration. CONCLUSION: For the majority of malignant lesions, manual image registration with the possibility to separately align different body segments was more accurate than the automated approach. Current software for ARR does not reach the anatomical accuracy reported for PET/CT hybrid scanners.

Evaluation of carotid artery stenosis with multisection CT and MR imaging: influence of imaging modality and postprocessing.

BACKGROUND AND PURPOSE: We prospectively evaluated the influence of different imaging techniques (time-of-flight MR angiography [TOF-MRA], contrast-enhanced MR angiography [CE-MRA], multisection CT angiography [CTA]) and postprocessing methods (maximum intensity projection [MIP], multiplanar reformation [MPR]) on carotid artery stenosis grading. MATERIALS AND METHODS: Fifty patients (34 men, 16 women) with symptomatic stenosis of the internal carotid artery were examined with a 16-section spiral CT and a 1.5T MR unit. Two MRA techniques were applied: 3D-TOF and CE-MRA. MPR was used for postprocessing with all modalities; MIP was used only with MRA. Four readers measured and calculated the percentage diameter stenosis independently according to NASCET criteria. The Wilcoxon test was used to measure interobserver variability, and the Friedman test was used to test the null-hypothesis of equality of the modalities. RESULTS: The hypothesis for global equality was rejected (P < .001). TOF-MRA and CTA assessed with MPR showed the highest concordance (difference, 0.6%; confidence interval [CI], -3.0, 4.3%), and CE-MRA with MIP and CTA showed the lowest concordance in stenosis grading (difference, 7.0%; CI, 3.4, 10.6%). MPR resulted in lower degrees of stenosis than MIP for both MRA sequences, although not statistically significant (CE, -3.0%; CI, -6.6, 0.6%; TOF, -2.2%; CI, -5.8, 1.4%). When only studies with good or excellent image quality were considered, the differences decreased, but the trends remained. CONCLUSION: Stenosis grading is dependent on the examination method and postprocessing technique. CTA and TOF-MRA evaluated with MPR revealed highest concordance.

[How to cope with the demands of the new "Approbation Regulation" (AR) by radiology-related interdisciplinary courses. The Erlangen model]. / Wie wir die Herausforderungen der neuen Approbationsordnung (AO) durch neue computergestützte radiologisch-interdisziplinäre Programme bewältigen können. Das Erlanger Modell.

BACKGROUND: To create radiology-related interdisciplinary programs for the undergraduate education in terms of the new "Approbation Regulation". MATERIAL AND METHODS: Medical students developed in collaboration with radiologists and clinical partners virtual, radiology-related interdisciplinary training courses for different fields. Students and teachers evaluated the acceptance of the programs' structure and content as well as the possibility to replace the radiologist partly during interdisciplinary lessons. RESULTS: Six target group oriented virtual, radiology-related interdisciplinary training courses were developed which will relieve the implementation of the new AR's demands for more interdisciplinary education in small groups and the dreaded shortage of personnel. CONCLUSION: By the use of web- and CDRom-based interdisciplinary course models different fields of medicine and diagnostic radiology can be bridged in the sense of the new AR's demands as well as manpower in radiology can be saved.