Arterial spin labelling perfusion MRI of breast cancer using FAIR TrueFISP: initial results.

AIM: To assess the feasibility of an unenhanced, flow-sensitive, alternating inversion recovery-balanced steady-state free precession (FAIR TrueFISP) arterial spin labelling (ASL) magnetic resonance imaging (MRI) technique for quantification of breast cancer perfusion. MATERIALS AND METHODS: Eighteen untreated breast tumour patients (mean age 53 ± 17 years, range 30-68 years) and four healthy controls (mean age 51 ± 14 years, range 33-68 years) were enrolled in this study and were imaged using a clinical 1.5 T MRI machine. Perfusion measurements were performed using a coronal single-section ASL FAIR TrueFISP technique in addition to a routine breast MRI examination. T1 relaxation time of normal breast parenchyma was determined in four healthy volunteers using the variable flip angle approach. The definitive diagnosis was obtained at histology after biopsy or surgery and was available for all patients. RESULTS: ASL perfusion was successfully acquired in 13 of 18 tumour patients and in all healthy controls. The mean ASL perfusion of invasive ductal carcinoma tissue was significantly higher (88.2 ± 39.5 ml/100 g/min) compared to ASL perfusion of normal breast parenchyma (24.9 ± 12.7 ml/100 g/min; p < 0.05) and invasive lobular carcinoma (30.5 ± 4.3 ml/100 g/min; p < 0.05). No significant difference was found between the mean ASL perfusion of normal breast parenchyma and invasive lobular carcinoma tissue (p = 0.97). CONCLUSION: ASL MRI enables quantification of breast cancer perfusion without the use of contrast material. However, its impact on diagnosis and therapy management of breast tumours has to be evaluated in larger patient studies.

[Forms of urinary diversion--methods and imaging findings]. / Formen der operativen Harnableitung: Methoden und bildgebende Diagnostik.

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.

[Determination of renal carcinoma progression in small animals by means of flat-panel volumetric computer tomography]. / Die Erfassung der Progression des Nierenzellkarzinoms in Kleintieren mittels Flachdetektor-Volumen-CT.

PURPOSE: We investigated the feasibility of using flat panel volumetric computer tomography (fpVCT) for the detection of orthotopically implanted renal carcinomas in nude mice. MATERIALS AND METHODS: One million renal cell carcinoma cells [A-498 line (Braunschweig, Germany), in 0.2 ml phosphate-buffered solution (PBS), pH 7.4] were injected into the left kidney of each of the eight nude mice. Each mouse was imaged twice (12 and 16 weeks after implantation) with fpVCT (GE prototype with circular gantry with two 1024 x 1024, 200 microm pixel size, aSi/CsI flat panel detector) after injection of 200 microl contrast medium to check for tumour spread. After 16 weeks the mice were killed and dissected, and the imaging findings in liver, kidneys and lung were compared with the macroscopic findings. RESULTS: No local evidence of tumour or of metastatic spread was seen on fpVCT after 12 weeks in any of the mice. After 16 weeks fpVCT revealed tumour growth in 6 of the 16 kidneys. Two mice had each developed a multifocal renal cell carcinoma and one mouse, a bilateral renal tumour manifestation. In one mouse liver metastases were seen. The fpVCT findings correlated well with the observations recorded in the pathological examination. CONCLUSION: fpVCT is an innovative and noninvasive imaging procedure that can be used for longitudinal investigation of tumour progression following orthotopic implantation of renal cell carcinoma to small animals. The use of a system of this kind will make a decisive contribution to reducing the number of animals used in experimental test projects.

[Value of MR-guided localization and biopsy in breast lesions]. / Stellenwert der MR-gestützten Lokalisation und Biopsie von Brustläsionen.

Contrast-enhanced dynamic MR mammography can provide important additional diagnostic information when performed for certain indications. When suspicious lesions are identified on MR mammography and cannot be reproduced using other imaging modalities, a decision must be made as to its management, i. e. further diagnostic work-up. One possibility is the short-term follow-up of such findings, resulting in higher costs and a possible delay in the start of treatment of a malignant lesion. An alternative to a follow-up is an MR-guided intervention. MR-compatible equipment has been developed for this purpose. This includes equipment specialized for percutaneous biopsy and preoperative localization. The following is an overview of the diagnostic value of MR-guided biopsy and preoperative localization including the relevant literature.

[Characteristics and applications of a flat panel computer tomography system]. / Eigenschaften und Anwendungen der Flächendetektor-basierten Volumen-Computertomographie.

PURPOSE: To assess a new flat panel volume computed tomography (FP-VCT) with very high isotropic spatial resolution as well as high Z-axis coverage. MATERIALS AND METHODS: The prototype of an FP-VCT scanner with a detector cell size of 0.2 mm was used for numerous phantom studies, specimen examinations, and animal research projects. RESULTS: The high spatial resolution of the new system can be used to accurately determine solid tumor volume, thus allowing for earlier assessment of the therapeutic response. In animal experimentation, whole-body perfusion mapping of mice is feasible. The high spatial resolution also improves the classification of coronary artery atherosclerotic plaques in the isolated post mortem human heart. With the depiction of intramyocardial segments of the coronary arteries, investigations of myocardial collateral circulation are feasible. In skeletal applications, an accurate analysis of the smallest bony structures, e. g., petrous bone and dental preparations, can be successfully performed, as well as investigations of repetitive studies of fracture healing and the treatment of osteoporosis. CONCLUSION: The introduction of FP-VCT opens up new applications for CT, including the field of molecular imaging, which are highly attractive for future clinical applications. Present limitations include limited temporal resolution and necessitate further improvement of the system.

[Retrospective analysis of a computer-aided detection (CAD) system in full-field digital mammography in correlation to tumor histology]. / Retrospektive Analyse eines computerassistierten Detektions-Systems (CAD) in der digitalen Vollfeldmammographie in Abhängigkeit von der Histologie.

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.

Dose reduction in full-field digital mammography: an anthropomorphic breast phantom study.

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.

[Contrast-enhanced MR angiography of the arterial and portovenous system of the liver with varying concentrations of contrast medium]. / Kontrastmittel-gestützte 3D-MR-Angiographie des arteriellen und portalvenösen Gefässsystems der Leber mit unterschiedlicher KM-Konzentration.

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(3)) 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.

[Radiation exposure in full-field digital mammography with a flat-panel x-ray detector based on amorphous silicon in comparison with conventional screen-film mammography]. / Strahlenexposition bei der digitalen Vollfeldmammographie mit einem Flachdetektor aus amorphem Silizium im Vergleich zur konventionellen Film-Folien-Mammographie.

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.

[The contribution of different postprocessing methods for multislice spiral CT in acute pulmonary embolism]. / Stellenwert unterschiedlicher Nachverarbeitungsverfahren in der Mehrschicht-Spiral-CT der akuten Lungenembolie.

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.

[Full-field digital mammography: dose-dependent detectability of breast lesions and microcalcinosis]. / Digitale Vollfeldmammographie: Dosisabhängige Detektion von simulierten Herdbefunden und Mikrokalzifikationen.

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. ROC 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.

[The optimization of MR cholangiopancreatography]. / Optimierung der MR-Cholangiopankreatikographie.

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.

[Diagnostic performance of retrospectively ECG-gated multislice CT of acute pulmonary embolism]. / Diagnostischer Stellenwert der retrospektiven EKG-Triggerung in der Mehrschicht-Spiral-CT der akuten Lungenembolie.

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.

[Slice sensitivity profile and image pixel noise of multi-slice spiral CT in comparison with single slice spiral CT]. / Schichtempfindlichkeitsprofile und Bildpunktrauschen einer Mehrschicht Spiral-CT im Vergleich zu einer Einzelschicht Spiral-CT.

PURPOSE: Presentation and evaluation of slice sensitivity profile and pixel noise of multi-slice CT in comparison to single-slice CT. METHODS: Slice sensitivity profiles and pixel noise of a multi-slice CT equipped with a 2D matrix detector array and of a single-slice CT were evaluated in phantom studies. RESULTS: For the single-slice CT the width of the slice sensitivity profiles increased with increasing pitch. In spite of a much higher table speed the slice sensitivity profiles of multi-slice CT were narrower and did not increase with higher pitch. Noise in single-slice CT was independent of pitch. For multi-slice CT noise increased with higher pitch and for the higher pitch decreased slightly with higher detector row collimation. CONCLUSIONS: Multi-slice CT provides superior z-resolution and higher volume coverage speed. These qualities fulfill one of the prerequisites for improvement of 3D postprocessing.

[Stereotactic vacuum core biopsy of clustered microcalcifications classified as B1-RADS 3]. / Stereotaktische Vakuumstanzbiopsie zur Abklärung von gruppiertem Mikrokalk der Kategorie BI-RADS 3.

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, < 3% malignant) underwent a stereotactic vacuum core biopsy (Mammotome, Fa. Ethicon Endo-Surgery Breast Care) using a digital stereotactic unit (Mammotest, Fa. Fischer Imaging). The removal of the calcifications was judged by two radiologists in consensus and classified as complete (100%), major (55-99%) or incomplete (< 50%). RESULTS: 4/86 patients could not be evaluated by vacuum core biopsy due to the localization of the microcalcifications close to the skin or lack of detection. In 40/82 cases a complete, in 38/82 a major, and in 4/82 a incomplete removal was achieved. Histology revealed 67 cases of fibrocystic changes, 4 papillomas, 4 fibroadenomas, 4 cases of atypical ductal hyperplasia (ADH), and 3 ductal carcinomas in situ (DCIS), one of these with a minimal-invasive tumor component. Patient with ADH were advised to undergo surgical biopsy. Histology revealed complete removal. 7 patients had complications or side-effects. CONCLUSIONS: Percutaneous vacuum core biopsy is a reliable minimal-invasive diagnostic method to come to the final diagnosis in patients with clustered microcalcifications categorized BI-RADS 3. However, if malignancy is proven (about 4% of our cases) an open biopsy is necessary.

Average glandular dose with amorphous silicon full-field digital mammography - Clinical results.

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.

[The evaluation of experimentally induced injuries to the upper cervical spine with a digital x-ray technic, computed tomography and magnetic resonance tomography]. / Evaluation experimentell erzeugter Verletzungen der oberen Halswirbelsäule mit digitaler Röntgentechnik, Computertomographie und Magnetresonanztomographie.

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.

[Full-field digital mammography: a phantom study for detection of microcalcification]. / Digitale Vollfeldmammographie: Phantomstudie zur Detektion von Mikrokalk.

OBJECTIVES: 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 microns) 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 (Az) 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, Az 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.

[The radial scar in contrast media-enhanced MR mammography]. / Die radiäre Narbe in der KM-gestützten MR-Mammographie.

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 1.5 T system using bilateral superficial coil (2D technique, T1-weighted FLASH-sequence, TR 336 ms, TE 5 ms, FA 90 degrees). 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.

Neurosarcoidosis: findings in MRI.

Sarcoidosis is a multisystemic granulomatous disease of unknown etiology. Neurologic manifestations occur usually as a part of the spectrum of the systemic disease. The aim of this retrospective study was to evaluate the role of magnetic resonance imaging (MRI) in the diagnosis of patients with neurosarcoidosis (NS). Seven patients with sarcoidosis could be included into the study. All patients had neurological symptoms and were evaluated with MRI revealing a wide spectrum of findings: periventricular and white matter lesions, multiple or solitary supra- and infratentorial brain lesions, leptomeningeal enhancement, involvement of brain nerves and intramedullar lesions. These findings are not specific for sarcoidosis and must be considered with the clinical course of the patient in arriving at the correct diagnosis.