Free propagation phase-contrast breast CT provides higher image quality than cone-beam breast-CT at low radiation doses: a feasibility study on human mastectomies.

In this study we demonstrate the first direct comparison between synchrotron x-ray propagation-based CT (PB-CT) and cone-beam breast-CT (CB-CT) on human mastectomy specimens (N = 12) including different benign and malignant lesions. The image quality and diagnostic power of the obtained data sets were compared and judged by two independent expert radiologists. Two cases are presented in detail in this paper including a comparison with the corresponding histological evaluation. Results indicate that with PB-CT it is possible to increase the level of contrast-to-noise ratio (CNR) keeping the same level of dose used for the CB-CT or achieve the same level of CNR reached by CB-CT at a lower level of dose. In other words, PB-CT can achieve a higher diagnostic potential compared to the commercial breast-CT system while also delivering a considerably lower mean glandular dose. Therefore, we believe that PB-CT technique, if translated to a clinical setting, could have a significant impact in improving breast cancer diagnosis.

[Imaging findings of intramammary malignant lymphoproliferative disease]. / Bildgebende Diagnostik maligner lymphoproliferativer Erkrankungen der Brust.

Intramammary manifestation of lymphoproliferative disease is rare. The radiological evaluation follows in most cases the clinical suspicion and therefore the radiologist takes an important place in diagnostics. The aim of this work is to demonstrate typical radiological patterns of this rare entity with multimodal cases and to sensitize for it. The differential diagnosis to other breast tumors, especially primary breast carcinoma, can be radiologically difficult, so the suspicious lesion must be histologically verified by biopsy.

[Imaging diagnostics of breast metastases from extramammary tumors]. / Bildgebende Diagnostik bei Brustmetastasen extramammärer Tumoren.

Breast metastases of solid extramammary tumors are very rare in comparison to primary malignancies of the breast and account for only 0.33-6.3% of all malignant neoplasms of the breast. The most common primary tumors are malignant melanoma, distant sarcomas, lung cancer, ovarian cancer, renal cell cancer and thyroid cancer in decreasing order of frequency. This review article summarizes the clinical features and the different imaging findings of breast metastases from different extramammary solid tumors. Breast metastases are often incidental findings in computed tomography (CT) or positron emission tomography CT (PET-CT) imaging. Mammography shows two different imaging patterns, namely focal lesions and diffuse architectural distortion with skin thickening. Breast metastases presenting as focal masses usually occur as solitary and more rarely as multiple round lesions with a smooth edge boundary. Associated calcifications are rare findings. Diffuse architectural distortion with skin thickening is more common in breast metastases from most gastric tumors, ovarian cancer and rhabdomyosarcoma. Using ultrasound most lesions are hypoechoic, oval or round with smooth boundaries and posterior acoustic enhancement. The magnetic resonance imaging (MRI) criteria of breast metastases show an inconstant signal behavior that cannot be safely classified as benign or malignant. In summary, in patients with known malignancies the presence of breast metastases should be considered even with imposing clinically and radiologically benign findings.

[Long-term results of thrust plate prostheses: comparison of patients younger than and older than 50 years]. / Langfristige Analyse der Druckscheibenendoprothese: Vergleich von Patienten unter und über 50 Jahren.

BACKGROUND: Hip replacement in patients younger than 50 years old is no longer an exception in view of the increasing necessity for care. The aim of the present study was to analyze whether the results after implantation of thrust plate prosthesis (TPP) with metaphyseal anchorage are equal for patients below 50 years compared to older patients. PATIENTS AND METHODS: The investigation comprised 465 TPP implantations. In 149 TPP the patient age was below 50 years (group A) und in 316 TPP cases above 50 years (group B). Clinical and radiological evaluation of the results for both groups was carried out as well as a differentiated survival analysis with defined endpoints. RESULTS: Survival analysis of group A (96%/13.2 years) showed a significantly improved survival rate compared to group B (86%/12.5 years). Additionally, the risk of prosthesis and/or radiological signs loosening of was significantly lower in group A than in group B (p <0.05). CONCLUSION: Comparison of long-term results of prostheses with intramedullary fixation shows that the anchorage principle of TPP with bone-saving implantation to the proximal femur is justified especially for patients below 50 years of age.

[Eight-year results of the femoral neck prosthesis ESKA-CUT]. / 8-Jahres-Resultate der Schenkelhalsprothese ESKA-CUT.

AIM: With the help of a clinical and radiological follow-up evaluation 8 years after implantation of the femoral neck prosthesis CUT (ESKA Implants, Lübeck Germany), the question of whether this metaphyseal anchoring implant is recommendable in young patients will be answered. METHOD: Between 2000 and 2001 82 CUT-prosthesis procedures were performed in 79 patients (38 female, 41 male patients; average age 51.3 years) and evaluated prospectively. The clinical investigation was carried out according to the criteria of the Harris Hip and Merle d'Aubigné scores. Radiological periprosthetic bone changes were registered and a measurement of the CCD angle and femoral offset was performed. The survival rate was calculated according to both the Kaplan-Meier and the life-table analyses. RESULTS: During the 12-month follow-up examination the HHS (48.4 preop.) as well as the Merle d'Aubigné score (10 preop.) increased significantly to an average value of 85.1 and 15.8, respectively (p < 0.000). Cumulative survival with replacement of the prosthesis as an end point at 8 years was 49.6 %. Due to 25 aseptic loosenings, three periprosthetic infections and three cases of persisting thigh pains, 31 replacements of the femoral neck prosthesis became necessary up to June 2008. The implantation of the CUT prosthesis led to a significant valgisation (p < 0.001) of 17.4 degrees degrees with a consecutive reduction of the femoral offset of 5 mm. Radiologically periprosthetic progressive radiolucencies, hypertrophic cortical bone changes as well as atrophy of the calcar femoris were often evaluated and interpretated as a sign of a stress shielding and migration process. CONCLUSION: The analysis of the eight-year follow-up of 82 CUT prostheses shows that the implant does not fulfil our expectations of a femoral neck prosthesis, in spite of the possibility of a less invasive and bone-saving implantation technique. In view of unacceptable survival rates, valgisation changes of the joint geometry and critical changing procedures, from our point of view the femoral neck prosthesis CUT does not represent a recommendable alternative implant in young, active patients.

[Results after replacement of femoral neck prostheses - thrust plate prosthesis (TPP) versus ESKA cut prosthesis]. / Ergebnisse nach Wechsel von Schenkelhalsprothesen - Druckscheibenprothese versus ESKA-Cut-Prothese.

AIM: The aim of this study was to analyse and evaluate comparatively loosening mechanisms, failure frequency, surgical changing strategies and results after replacement of thrust plate prostheses (TPP) and ESKA Cut prostheses. METHOD: Between 1993 und 2007, 465 TPP and in the years 2000 and 2001 82 ESKA Cut prostheses were performed and evaluated prospectively. Until 2007 46 change interventions of the TPP and 35 of the CUT prosthesis became necessary. All patients who received a stem revision procedure in our hospital were included within this study. Besides the evaluation of clinical results according to the criteria of the Harris Hip Score on the average at 15.6 months (+/- 14.4) postoperatively, radiological loosening processes and surgical difficulties were registered. Furthermore, an analysis of perioperative data was performed according to some criteria of the German Federal Office of Quality Assurance (BQS), such as duration of the surgery, intraoperative blood loss and complications. Statistical investigations for comparative analysis as well as survival analysis of both groups were calculated using SPSS for Windows 13.0. RESULTS: The mean age of the 46 patients who had to undergo revision surgery after TPP was 60.1 years, that of 35 patients in whom revision surgery was necessary after receiving an ESKA Cut femoral neck stem was 56.6 years. The survival rate analysis according to Kaplan-Meier at 13 years was 89.4 % (TPP) and 53.6 % at 66 months (ESKA Cut). In all cases the partial osteointegration of the tripod surface of the loosened Cut prosthesis complicated the explantation. It led on the one hand to a significant difference of the surgery duration and on the other hand to an increased frequency of fractures of the trochanteric region. The conversion of the TPP on standard type stems was usually free of problems. The HHS increased significantly to the averages of 86.6 (TPP) or, respectively, 91.69 (ESKA Cut) after revision. CONCLUSION: In comparison with the usually problem-free changing procedure of the TPP to a standard type stem, the revision surgery of the Cut prosthesis becomes substantially more complex and leads frequently to complications. In view of unacceptable survival rates, the Cut prosthesis does not represent an alternative implant in young patients. Except for the implantation technique, which does not allow a less invasive surgical procedure, the TPP fulfils the requirements of femoral neck prosthesis due to acceptable survival rates and good convertibility.

Automatic selection of optimal systolic and diastolic reconstruction windows for dual-source CT coronary angiography.

The aim of this study was to assess the performance of a motion-map algorithm that automatically determines optimal reconstruction windows for dual-source coronary CT angiography. In datasets from 50 consecutive patients, optimal systolic and diastolic reconstruction windows were determined using the motion-map algorithm. For manual determination of the optimal reconstruction window, datasets were reconstructed in 5% steps throughout the RR interval. Motion artifacts were rated for each major coronary vessel using a five-point scale. Mean motion scores using the motion-map algorithm were 2.4 +/- 0.8 for systolic reconstructions and 1.9 +/- 0.8 for diastolic reconstructions. Using the manual approach, overall motion scores were significantly better (1.9 +/- 0.5 and 1.7 +/- 0.6, p < 0.05), but diagnostic image quality was reached in >90% of cases using either approach. Using the automated approach, there was a negative correlation between heart rate and motion scores for systolic reconstructions (rho = -0.26, p < 0.05) and a positive correlation for diastolic reconstructions (rho = 0.46, p < 0.01). For the manual approach, no significant correlation was found for systolic reconstructions (rho = -0.1, p = 0.52), while there was a positive correlation for diastolic reconstructions (rho = 0.48, p < 0.01). Thus, the motion-map algorithm is a useful tool to save time in finding an appropriate reconstruction window in patients with heart rates <70 bpm (diastolic reconstruction) and >80 bpm (systolic reconstruction).

[Clinical and radiological results of the thrust plate prosthesis in patients with aseptic necrosis of the femoral head]. / Klinische und Radiologische Ergebnisse nach Implantation der Druckscheibenendoprothese (DSP) bei Patienten mit Femurkopfnekrose.

AIM: In this study, we investigated the results after implantation of the thrust plate prosthesis (TPP) in patients with femoral head necrosis. We intended to answer the question if the femoral neck prosthesis, inaugurated by Huggler and Jacob in Switzerland, which needs a good bone stock for a successful implantation, is a recommendable alternative to other cementless intramedullary fixed prostheses. METHOD: In a prospective study, 62 patients who had received 70 TPP because of femoral head necrosis as a result of various aetiologies between 1993 and 2004 were examined clinically and radiologically. The follow-up examinations were carried out 3 and 6 months postoperatively and subsequently once a year. The mean follow-up interval was 6.0 +/- 1.9 years (1.0-10.2 years). Clinical examination was carried out using the Harris hip score; the radiological examination was performed according to predefined criteria in an exact a.-p.-view. Four sectors can be distinguished: A corresponds to the femoral neck stump, B to the bony stock cranial (= 1) and caudal (= 2) to the mandrel of the prosthesis, C is the region above and under the bolt and D is the cortical area around the lateral plate. Furthermore, we performed a Kaplan-Meier survival rate analysis. RESULTS: We found excellent clinical results. The preoperative Harris score increased from 48.3 to 91.6 +/- 6.6 at 24 months after the operation. Radiolucencies of various relevancies were detected depending on the localisation. We often saw bony atrophy under the thrust plate (sector A: A 1 21.4%, A 2 9.9%) and small radiolucencies along the bolt (sector C 30 % in general). As a pathological finding we interpreted progressive radiolucencies of sector B, which was considered to be a sign of loosening, when they showed a thickness of > or = 2 mm. Therefore, we had to change one TPP. In two additional cases we saw an extended atrophy under the lateral plate, which was also interpreted to be a sign of loosening. The Kaplan-Meier survivorship analysis for 5 and 10 years was 95.1% (95% - 0.95 +/- 0.05). Our study suggests that, in spite of a slightly higher aseptic loosening rate in comparison with cementless stem prosthesis, the thrust plate prosthesis proved worthwhile. On account of our previous experience we consider the TPP to be a good alternative implant, especially for young patients. CONCLUSION: Due to excellent clinical results and nearly identical findings in the survivorship analysis in comparison to cementless stem prostheses, the TPP is also a good alternative implant for total hip arthroplasty in patients with femoral head necrosis. For a successful implantation of the TPP a good bone quality of the proximal femur is necessary. Therefore we cannot recommend the use of a thrust plate prosthesis in patients with femoral head necrosis and simultaneous osteopeny.

[Radiological analysis of the thrust plate prosthesis (TPP)]. / Radiologische Verlaufsanalyse der Druckscheibenendoprothese (DSP).

AIM: The various radiological changes after implantation of the thrust plate prosthesis (TPP) are demonstrated and, with the help of a standardized radiological classification, divided in pathological and non-pathological findings. METHOD: The radiological follow-ups of 167 TPP implanted between 1993 and 1998 was analyzed in this study. The follow-up examination was carried out postoperatively, after 6 months and subsequently every year. The radiological assessment was carried out in an exact a.p. view. We subdivided the images into four sectors: A corresponds to the femoral neck stump, B to the bony stock cranial (=1) and caudal (=2) to the mandrel of the prosthesis, C is the region above and under the bolt and D the cortical area around the lateral plate. RESULTS: Radiolucencies were especially seen in sector A (A 1 = 34.7 %; A 2 = 18%) and sector C (44 %). As a pathological finding, we saw progressive radiolucencies of sector B (6 %), which were interpreted to be a sign of loosening, when they showed a thickness of = 2 mm. Furthermore, in some cases we observed extended atrophy under the lateral plate, which was also judged to be a sign of loosening. CONCLUSION: The radiological changes of the bony stock of the TPP can be divided into physiological adaptation processes because of changed biomechanics and signs of loosening. As a stress-shielding phenomenon we see a progressive atrophy under the thrust plate and simultaneously a sclerosis of the spongious bone above the calcar femoris. An indication for a loosening of the prosthesis is a progressive radiolucency of sector B.

[Midterm results and revisions of the thrust plate prosthesis (TPP)]. / Mittelfristige Ergebnisse und Wechseloperationen nach Druckscheibenendoprothesen (DSP).

AIM: Although already in use for 20 years, the concept of the metaphyseal anchored thrust plate prosthesis has not yet gained general acceptance. Clinical and radiological follow-up examinations were carried out 5 to 8 years after implantation of a TPP. We tried to answer the question if the metaphyseal anchorage of the cement-less TPP is equal to a diaphyseal anchorage of a cement-less stem prosthesis and to define the advantages of the TPP. METHODS: We included 170 of the patients from our clinic with an implanted TPP in this study. Furthermore we reviewed the results of 30 revision hip arthroplasties of the TPP. The clinical examination were carried out using the Harris hip score while the radiological examinations were performed on the basis of predefined criteria. RESULTS: We found good clinical results. The preoperative Harris score of 48.7 increased to 93.7 at 24 months postoperatively. Radiolucencies were detected and were of varying relevance in dependence on their localization. The Kaplan-Meier survival analysis at 8 years was 90.5 %. The clinical results after changing the TPP were also good to excellent. The mean Harris hip score was 87.3. CONCLUSION: Our study suggests that in spite of a slightly higher aseptic loosening rate in comparison to the cement-less stem prosthesis, the thrust plate prosthesis proved to be worthwhile. On the basis of previous experience we assume that the TPP is a good alternative implant especially for young patients.