Search

Background:  Considering radiological examinations not as mere images, but as a source of data, has become the key paradigm in the diagnostic imaging field. This change of perspective is particularly popular in breast imaging. It allows breast radiologists to apply algorithms derived from computer science, to realize innovative clinical applications, and to refine already established methods. In this context, the terminology "imaging biomarker", "radiomics", and "artificial intelligence" are of pivotal importance. These methods promise noninvasive, low-cost (e. g., in comparison to multigene arrays), and workflow-friendly (automated, only one examination, instantaneous results, etc.) delivery of clinically relevant information., Methods and Results:  This paper is designed as a narrative review on the previously mentioned paradigm. The focus is on key concepts in breast imaging and important buzzwords are explained. For all areas of breast imaging, exemplary studies and potential clinical use cases are discussed., Conclusion:  Considering radiological examination as a source of data may optimize patient management by guiding individualized breast cancer diagnosis and oncologic treatment in the age of precision medicine., Key Points:   · In conventional breast imaging, examinations are interpreted based on patterns perceivable by visual inspection.. · The radiomics paradigm treats breast images as a source of data, containing information beyond what is visible to our eyes.. · This results in radiomic signatures that may be considered as imaging biomarkers, as they provide diagnostic, predictive, and prognostic information.. · Radiomics derived imaging biomarkers may be used to individualize breast cancer treatment in the era of precision medicine.. · The concept and key research of radiomics in the field of breast imaging will be discussed in this narrative review.., Citation Format: · Dietzel M, Clauser P, Kapetas P et al. Images Are Data: A Breast Imaging Perspective on a Contemporary Paradigm. Fortschr Röntgenstr 2021; 193: 898 - 908., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Purpose: The general gap in the BIRADS lexicon between lesion description and categorization leads to very different recommendations in clinical breast radiology. This is particularly true for breast MRI. The third consensus meeting of course directors in breast imaging aimed at an increase in standardization of breast MRI., Materials and Methods: Between 166 and 344 participants in the audience (A) and 9 and 13 expert panel participants (P) took part in an electronic wireless voting system. The audience consisted of 98% radiologists and 2% gynecologists (A: n=295; P: n=12: radiologists 92%/gynecologists 8%). Of all participants, 62% had more than 10 years of experience in breast imaging and only 9% had less than 3 years of experience (P: 100%>10 years of experience). The day before 44, clinically relevant, though unresolved questions were formulated by the expert panel. For the evaluation a distinction was made between answers with a great majority (>75%), simple majority (50-<75%) and no majority (<50%) as well as answers from the expert panel and answers from the audience., Results: Of 44 questions, all but two were answered with simple or great majority., Conclusion: Technique, reporting and clinical use are becoming more and more accurately defined in MRI of the breast and MR-guided interventions. The third consensus meeting of this kind gained numerous answers and thus enables recommendations for didactic as well as clinical routine work., (© Georg Thieme Verlag KG Stuttgart · New York.)

Fourteen directors of breast imaging courses met on behalf of the German Society of Radiology to discuss the actual standards of the diagnosis of masses. Open questions on the fields of mammography, breast ultrasound and breast MRI were elucidated by a presentation of one of the 14 panel members, followed by an electronic anonymous voting. Beside of the panel members, more than 300 participants of the consensus meeting contributed their opinions by electronic voting. Answers with definite majorities (> 75 %), answers with narrow majorities and those with missing majorities were discriminated from each other. The opinions of the plenum were compared to the majorities of the podium and showed only a few critical differences. Due to unequivocal majorities seven answers to important questions concerning the diagnosis of masses can lead to a further standardization of breast cancer diagnosis., (Georg Thieme Verlag KG Stuttgart, New York.)

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.

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.

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.

Purpose: To compare the sensitivity of conventional two-dimensional (2D) projection imaging with tomosynthesis with respect to the detectability of mammographic phantom lesions., Materials and Methods: Using a breast tomosynthesis prototype based on a commercial FFDM system (Siemens MAMMOMAT Novation), but modified for a wide angle tube motion and equipped with a fast read-out amorphous selenium detector, we acquired standard 2D images and tomosynthesis series of projection views. We used the Wisconsin mammographic random phantom, model RMI 152A. The anode filter combinations Mo/Mo and W/Rh at two different doses were used as typical radiographic techniques. Slice images through the phantom parallel to the detector were reconstructed with a distance of 1 mm employing a filtered back-projection algorithm. The image data sets were read by five radiologists and evaluated with respect to the detectability of the phantom details., Results: For all studied radiographic techniques, the detection rate in the tomosynthesis mode was 100 %, i. e. 75 true positive findings out of 75 possible hits. In contrast, the conventional projection mode yielded a detection rate between 80 and 93 % (corresponding to 60 and 70 detected details) depending on the dose and X-ray spectrum., Conclusion: Tomosynthesis has the potential to increase the sensitivity of digital mammography. Overlapping structures from out-of-plane tissue can be removed in the tomosynthesis reconstruction process, thereby enhancing the diagnostic accuracy.

Purpose: The NMR-MOUSE is an open and mobile sensor for measuring NMR relaxation parameters in organic matters. T1-measurements of the subcutaneous fatty tissue and the skin are reported., Material and Method: For the first time, the NMR-MOUSE was employed to measure the signal recovery following saturation of the skin and the subcutaneous fatty tissue of three patients, before and after administering a contrast agent., Results: Despite a low signal-to-noise ratio, changes in the relaxation behaviour of the skin could be detected. Malignant tissue exhibits faster signal recovery than scar tissue and healthy tissue, which only show a small difference., Conclusions: Changes in the relaxation behavior can be monitored with the NMR-MOUSE. Before the clinical use of the NMR-MOUSE, sensitivity, sensor mounting device, and sensor tuning must be improved. Further investigations need to be performed on a statistically relevant number of patients.

Purpose: To determine the diagnostic accuracy of microcalcifications and focal lesions in a retrospective clinical-histological study using high-resolution digital phosphor storage plates (hard copy) and full-field digital mammography (hard copy)., Materials and Methods: From May 2003 to September 2003, 102 patients underwent digital storage plate mammography (CR), using a mammography unit (Mammomat 3000 N, Siemens) in combination with a high resolution (9 lp/mm) digital storage phosphor plate system (pixel size 50 microm) (Fuji/Siemens). After diagnosis and preoperative wire localization, full-field digital mammography (CCD) (DR) was performed with the same exposure parameters. The full-field digital mammography used a CCD-detector (SenoScan) (Fisher Imaging) with a resolution of 10 Ip/mm and a pixel size of 50 microm. Five investigators determined the diagnosis (BI-RADS I - V) retrospectively after the operation from randomly distributed mediolateral views (hard copy reading). These results were correlated with the final histology., Results: The diagnostic accuracy of digital storage plate mammography (CR) and full-field digital mammography (CCD) (DR) was 73 % and 71 % for all findings (n = 102), 73 % and 71 % for microcalcifications (n = 51), and 72 % and 70 % for focal lesions (n = 51). The overall results showed no difference., Conclusion: Our findings indicate the equivalence of high-resolution digital phosphor storage plate mammography (CR) and full-field digital mammography (CCD) (DR).

Purpose: Experimental phantom study for the detection of simulated lesions with five different digital and one conventional screen-film mammography system., Materials and Methods: Three radiographs were obtained at various configurations of the phantom with one conventional screen-film system (Mammomat 3000 N) (Siemens), five digital systems (high resolution computed radiography system [Fuji/Siemens], one a-Si detector [GE Medical Systems], two a-Se detectors [Siemens; Hologic / Lorad] and one CCD detector [Fischer Imaging]), applying the same exposure parameters. The Wisconsin Mammographic Random Phantom, Model 152 A, was used. Five investigators with different experience in mammography (3 months to more than 4 years) evaluated the 18 randomly selected radiographs., Results: No significant differences were found in the detection rate of simulated breast lesions for conventional screen-film mammography (84.9 %), high resolution computed radiography (86.7 %) and digital mammography with an a-Si detector (89.8 %). Highly significantly better results (p < 0.001) were found with the two a-Se systems (97.3 %) and the CCD system (100 %)., Conclusion: Conventional screen-film mammography can be replaced by high resolution computed radiography and digital mammography with a-Si-, a-Se- and CCD-detectors. This has to be confirmed in further clinical studies.

Purpose: Experimental investigations of a new digital mammography system., Materials and Methods: The digital mammography system SenoScan (Fischer Imaging) is based on 4 charged coupled devices (CCD) (slot detector). The pixel size is 50 micro m, field of view 21 x 29 cm (2), effective quantum efficiency (DQE) (0) 50 %, spatial resolution 10 lp/mm, and memory depth 12 bit. The object of investigation was the Wisconsin Mammographic Random Phantom, Model 152 A (Radiation Measurements Inc., Wisconsin). The radiograms were acquired using the digital mammography system., Results: The digital mammography detected 225 of 225 possible details. The surface dose was 6.95 mGy., Conclusions: These experimental results support the use of the digital mammography in practice. This has to be confirmed in further clinical trials.

Objective and Methods: Stereotaxic and sonographically guided vacuum biopsies are standard methods in interventional breast procedures. We report about the newly developed sonographically guided and vacuum-assisted VacuFlash (VF) method for breast biopsy. In comparison to the Mammotome system, all components for vacuum biopsy are integrated in the hand-held gun of the VF biopsy system. Our first preliminary results in 5 patients are reported., Results: VF was performed in five patients with a nonpalpable, sonographically detectable lesion. The histopathological examination diagnosed a fibroadenoma in 4 patients and established unremarkable breast parenchyma in 1 patient. Subsequent sonography immediately after the biopsy revealed that 3 of the 5 lesions were completely removed., Conclusion: The VF biopsy system is a new, technically perfected and applicable diagnostic method. Its costs, risks and accuracy have to be compared with high-speed core cut biopsy, hand-held Mammotome system and open surgical biopsy. Indications for the VF-biopsy are lesions that are too small, superficial or deep for conventional core biopsy as well as abnormalities where wide sampling is considered important. Complete removal can only be expected when the lesion is small and plays a secondary role in a diagnostic process. High-speed core cut biopsy remains the standard procedure in percutaneous breast interventions to clarify sonographically detected breast lesions.

Purpose: A retrospective clinical-histological study to determine the diagnostic accuracy of mammography using conventional screen-film cassettes (hard copy), high-resolution digital phosphor storage plates (hard copy) and monitor display (soft copy) for microcalcifications and focal lesions (BI-RADS (TM) category 4 or 5)., Materials and Methods: From April to November 2001, 76 patients underwent conventional film-screen mammography and, after diagnosis and preoperative wire localization, digital mammography with the same exposure parameters. Five investigators retrospectively determined the diagnosis after the operation from randomly distributed mediolateral views (hard-copy reading) and from the monitor display (soft-copy reading). These results were correlated with the final histology., Results: The accuracy of conventional screen-film mammography, digital mammography and monitor-displayed mammography was 67%, 65% and 68% for all findings, (n = 76), 59%, 59% and 68% for microcalcifications (n = 44) and 75%, 72% and 63% for focal lesions (n = 32). The overall results showed no difference., Conclusion: Our findings indicate equivalence of conventional screen-film mammography, high-resolution digital phosphor storage plate mammography and monitor-displayed mammography.

Purpose: Determination of image quality of a new digital mammography system with an a-Se-detector., Material and Method: Radiograms of the Wisconsin Mammographic Random Phantom, Modell 152 A (Radiation Measurements Inc., Wisconsin) were acquired using a conventional film screen and a digital system., Results: With the conventional film screen system there were detected 191/a 38.2 and with the digital mammography 219/a 43.8 of 225 possible details., Conclusion: Based on these results there is the possibility to replace the conventional film screen system by the digital mammography with a-Se-detector--this has to be confirmed in further clinical trials.

Purpose: To determine the optimum number of specimens of a sonographically guided core biopsy of the breast., Materials and Methods: From January 2001 to April 2001, sonographically guided core biopsies (coaxial needle: 11 G; core needle: 12 G) were performed on 106 patients with 115 BI-RADS trade mark 4-5 lesions that had corresponding sonographic findings. Five specimens were obtained in anteroposterior direction parallel to the chest wall and each specimen examined histologically., Results: A total of 575 core biopsies produced 545 specimens (94.8 %), with no material obtained in 30 biopsies (5.2 %). The first and second specimen confirmed the diagnosis in 99 of 115 lesions (86 %), with subsequent specimens confirming the diagnosis in 87 % (3 rd specimen), 88 % (4 th specimen) and 82 % (5 th specimen). The additive accuracy of the five core breast specimens was 86 %, 96 %, 98 %, 99 % and 100 %. The possible volume of 78.9 mm 3 as determined by the sample notch of the core needle only furnished an average volume of 38.1 mm 3 (41.1 mm 3 for the 1 st, 40.1 mm 3 for the 2 nd, 37.5 mm 3 for the 3 rd, 36.7 mm 3 for the 4 th and 35.0 mm 3 for 5 th core specimen)., Conclusion: Sonographically guided core breast biopsy (coaxial needle: 11 G; core needle: 12 G) may require five passes to achieve a diagnostic accuracy of more than 99 %.

Purpose: MRI is the most reliable method to differentiate scar and recurrent carcinoma of the breast after surgical treatment. This study compares MRI and color-coded ultrasound with and without echo signal amplifier (ESA)., Materials and Methods: Forty-two patients with suspected recurrent tumors were enrolled in this prospective study, with 38 patients after breast conserving therapy and 4 after mastectomy. All patients had a clinical examination, mammography (n = 38), real time ultrasound (US), color-coded ultrasound without and with ESA (Levovist(R), Schering, Berlin), and dynamic MRI. The criteria used for duplex ultrasound were tumor vascularisation and flow pattern. The results were compared with histologic findings or the results of follow-up examinations for at least 12 months., Results: The detection of penetrating or central vessels proved to be an accurate sign of malignancy in duplex ultrasound. With the application of ESA, additional vessels were detected within the lesions, increasing the diagnostic accuracy (83 % with ESA versus 79 % without ESA). The sensitivity of color-coded ultrasound improved from 64 % to 86 % with echo signal amplifier. The specificity was 86 % without and 82 % with echo signal amplifier. MRI was found to have a sensitivity of 100 % and a specificity of 82 %. The same 5 lesions were false positive on MRI and color-coded US after Levovist(R). No lesion without signs of vascularity within or in its vicinity was malignant., Conclusion: Color-coded ultrasound seems to be a promising method in the differentiation between scar and recurrence. Lesions with penetrating or central vessels have a high probability of being malignant, whereas lesions without any signs of vascularity inside or nearby have a high probability of being benign. Advantage of contrast-enhanced US is its ubiquitous availability.

Purpose: Determination of image quality between conventional film screen system, digital phosphor storage plate mammography (high resolution) and digital mammography., Materials and Methods: Mammograms of the Wisconsin Mammographic Random Phantom, Model 152 A (Radiation Measurements Inc., Wisconsin) were acquired using a conventional film-screen system, a digital storage phosphor plate system and a digital system., Results: Of 225 possible details, 191/a 38.2, 193/a 38.6, and 202/a 40.4 details were detected with conventional film-screen system, digital phosphor storage plate mammography and digital mammography, respectively. There was no significant difference (p < 0,058). The entrance surface air kerma was 9.64 mGy, 7.60 mGy and 7.02 mGy, respectively., Conclusions: Based on these results, conventional film-screen system can be replaced with both digital phosphor storage plate mammography and digital mammography, to be confirmed with further clinical trials.

Based on experimental studies with animals we examined 22 patients with pathological (bloody) nipple discharge by cytology, ultrasonography, galactography and the newly developed galactoscopy [Endoscopic-System EndoGnost(R) (Polydiagnost)]. The duct's cannula has an outer/inner diameter of 0.45 mm/0.36 mm and a working length of 30 mm, the endoscope a length of 1200 mm, adapted to a CCD-camera (2500 pixel). All patients underwent surgery and histo-pathological diagnosis. The best diagnostic results were received with galactoscopy (21/22). By using an additional cutter it is possible to obtain a histological sample for diagnosis endoscopically. Galactoscopy is an emerging technique and will expand the spectrum of interventional methods in breast diagnosis.

Purpose: We wanted to determine if tissue marker clips after sonographically or stereotactically guided breast biopsy improve the follow-up of small breast lesions classified BI-RADS 4/5 and the localisation of breast cancer (TNM stage 2 or 3) after neoadjuvant chemotherapy., Material and Methods: Prospective analysis was performed of 108 breast lesions 1 cm or smaller mammographically classified as BI-RADS 4/5 and 14 breast lesions larger than 2 cm mammographically classified as BI-RADS 5. 33 of the 108 breast lesions 1 cm or smaller underwent sonographic core cut breast biopsy (group 1) and 75 stereotactic vacuum-assisted breast biopsy (group 2). All 14 lesions greater than 2 cm were stereotactically vacuum-assisted breast biopsied (group 3). The centre of the lesion was marked by a clip after the biopsy. Mammographies were performed in all patients of group 1 and 2 with a histologically benign finding (n = 31, n = 69, respectively) and in all patients of group 3 directly after clip placement and after 6 and 12 months. Clip localisation and possible divergence from the original position were verified by a grid., Results: Two patients of group 1 and 6 patients of group 2 had breast conservative surgery (BET) because of the histological diagnosis of a ductal carcinoma in situ or invasive breast cancer. The tissue marker clips of the remaining 31 patients of group 1 and 69 patients of group 2 diverged with a mean value of 0.4 cm (standard deviation +/- 0.23 cm; range 0.1 cm to 0.9 cm) from their placement position after 6 months. After 12 months the marker clips deviated with a mean value of 0.4 cm (standard deviation +/- 0.21 cm; range 0.1 cm to 0.9 cm) in 94 patients and 0.8 cm (standard deviation +/- 0.25 cm; range 0.1 cm to 0.9 cm) in 6 patients from their original location. No tumour progression of the benign lesions in group 1 and 2 was diagnosed in follow-up mammograms. In all patients of group 3 the tissue marker clips were the only possibility to localize the tumour after neoadjuvant chemotherapy as all other diagnostic methods showed inconsistent results., Conclusion: Positioning a tissue marker clip in the tumour centre seems to be reasonable after interventional biopsy of breast lesions of 1.0 cm or smaller and before neoadjuvant chemotherapy.

Purpose: To describe the procedure of percutaneous vertebroplasty and to present our first clinical results of patients treated for benign or malignant painful vertebral body disease., Material and Methods: We performed percutaneous vertebroplasty in 31 painful lesions of the spine. Liquid bone cement was injected into the affected vertebral body using fluoroscopic guidance through a bilateral transpedicular approach. Etiology of the bone disease was assessed by biopsy. Pain intensity was assessed before and 1 week after the procedure by standardized catalogue., Results: Percutaneous vertebroplasty was performed in 17 thoracic and in 14 lumbar spine bodies of benign (n = 23) or malignant (n = 8) disease; no clinically relevant complications occurred. All patients reported significant pain relief 1 week after the intervention. One week after treatment, patients were pain-free in 15/31 vertebral bodies, and reported mild residual pain not necessitating narcotic medication in 16/31 cases., Conclusion: In accordance with the literature, percutaneous vertebroplasty proved to be a highly effective, minimal invasive interventional procedure to treat severely painful bone lesions of benign and malignant origin.

When discussing the radiation risk of X-ray mammography, the magnitude of the dose applied has decisive importance. The radiation exposure of the breast is the predominant factor in risk considerations, since it contributes more than 98% to the effective dose of this examination. At present, it is generally assumed that, with regard to cancer induction by ionizing radiation, the glandular tissue is the most vulnerable part in the breast. Therefore, the average glandular dose, i.e., the mean value of the absorbed dose in the glandular tissue, is used for a description of the radiation risk. The average glandular dose cannot be measured directly, but is calculated under certain assumptions from the experimentally determined entrance surface air kerma or entrance surface dose by the use of a so-called conversion factors. During the seventies, i.e., in the era of the industrial type X-ray film, the mean value of the average glandular dose per exposure for a larger sample of patients (n > 100) was about 20 mGy. Due to the progress in radiographic technique such as, for example, the use of sensitive film-screen systems, optimized radiation qualities and modern automatic exposure control units this value has now decreased to about 1 mGy. Further dose reductions seem possible by the introduction of digital image receptors.

Unlabelled: Comparison of image quality between conventional film screen system, digital phosphor storage plate mammography in magnification technique and digital mammography in CCD-technique., Materials and Methods: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system, two digital storage plate systems and two digital systems in CCD-technique. Additionally, the radiograms of one digital phosphor storage plate system were postprocessed emphasizing contrast and included in the comparison., Results: The detectability of details was the best with the digital mammography in CCD-technique in comparison with the conventional film screen technique resp. digital phosphor storage plate in magnification technique., Conclusions: Based on these results there is the possibility to replace the conventional film screen system by further studies--this has to be confirmed.

Purpose: Comparison of image quality between digital phosphor storage plate mammography in magnification technique and a conventional film screen system regarding the special aspect of radiation exposure., Materials and Methods: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system and two digital storage plate systems. Additionally, the radiograms of one digital system were post-processed emphasizing contrast and included in the comparison., Results: The detectability of details in storage plate mammographies with magnification technique is almost equal to that of film screen mammographies. Thereby, lower radiation exposures were necessary using the digital systems., Conclusions: Based on these results, storage plate mammography in magnification technique is used in clinical routine at our institution. The correct parameters in image postprocessing are of elementary importance for detail detectability. Future studies must show, whether the lower radiation exposure in digital radiograms of the breast, revealing much higher background noise, will allow the same detail detectability as film screen mammographies.

Between November 1987 and May 1991 217 stereotactic examinations of the breast were performed in the Breast Clinic of the University of Freiburg, including 136 stereotactic biopsies and 81 localisations. Indications were localisation of lesions which were only visible in one plane on mammography, preoperative definition of lesions which could be recognised only by mammography, cytological confirmation of benign lesions and preoperative cytological confirmation of malignant lesions before carrying out conservative resections. Cytological diagnosis was possible in 81 patients (59%) (1988-26%, 1989-67%, 1990-74% and up to May 1991-80%). All carcinomas diagnosed cytologically were confirmed histologically (8 cases with a diameter up to 5 mm). Comparison of the preoperative diagnosis (81 cases) with histological findings showed a high proportion of grade 2 and 3 proliferative mastopathies and papillomatoses (45 patients = 81%).