The aim of this study is the clinical establishment of a native and contrast-enhanced computer tomography of the breast. The early detection of breast cancer is still a great challenge. Even though the implementation of the digital mammography combined with the mandatory screening-programs lead to significant improvements, sensitivity and specificity of these examinations need to be clearly classified as improvable. Generally, it is stated that the necessary transit from 2-D projected images to 3-D tomography will be crucially advantageous as magnetic resonance imaging has already shown. Similar or even major advantages can be expected by new approaches regarding CT with very high local resolution, better than 100µm in 3D and lower dose, under 5 Milligray (mGy), as demanded for a screening. A device that meets these demands and is also applicable for dynamic scans after intravenous administration of a contrast agent, has been developed with the support by the European Union (EU), German Research Foundation (DFG) and Federal Ministry of Education and Research (BMBF). Publications on technical and experimental results are already available. An evaluation in the clinical use is missing yet. The primary aim of this study is to evaluate systematically the performance of the native and dynamic, contrast-enhanced CT of the breast.

Inclusion Criteria:

Sub Study 1:

• patients with mammographic or sonographic validated Breast Imaging Reporting and Data System (BI-RADS)-4 or BI-RADS-5-result or in BI-RADS-6-situation, i.e. with an already reliable carcinoma by punch biopsy, for which a clinical indication for a mamma-MRI consists.
• Age >= 40
• maintained renal function (MDRD with GFR >= 60 ml/min/1,73m²)
• normal thyroid function, no clinical indication for an endocrine autonomy, normal TSH (not older than 8 weeks)
• Persons which are able to give written consent and are aware of the nature, meaning and extent of the study
• signed informed consent

Substudy 2:

• patients with a doubtful and suspect clinical or mammographic or sonographic result (BI-RADS 3, 4a, 4b, 4c, 5) as well as patients with a reliable carcinoma by punch biopsy (BI-RADS 6), patients with high risk of breast cancer for which a clinical indication for a mamma-MRI consists.
• Age >= 40
• maintained renal function (MDRD with GFR >= 60 ml/min/1,73m²)
• normal thyroid function, no clinical indication for an endocrine autonomy, normal TSH (not older than 8 weeks)
• Persons which are able to give written consent and are aware of the nature, meaning and extent of the study
• signed informed consent

Exclusion Criteria:

Substudy 1:

• Pregnancy or lactation
• Women with child-bearing potential without sufficient contraception
• Age <40 years
• Women with proven pathogenic Breast Cancer (BRCA) 1-mutation or heterozygote risk (>= 25%)
• Hospitalization of patient ordered by the court or local authorities
• Relationship of dependence or employment to sponsor or investigator

additionally the following criteria apply, if conducting the dynamic contrast-enhanced breast-CT

• signs of a renal insufficiency (GFR < 60ml/min/1,73m²)
• clinical signs or signs of the labor chemistry for endocrine autonomy (increase of TSH)
• Patients with known allergies or intolerance reactions grade II or higher to contrast medium containing iodine

Substudy 2:

• Pregnancy or lactation
• Women with child-bearing potential without sufficient contraception
• Age <40 years
• Women with proven pathogenic BRCA 1-mutation or heterozygote risk (>= 25%)
• Hospitalization of patient ordered by the court or local authorities
• Relationship of dependence or employment to sponsor or investigator

additionally the following criteria apply, if conducting the dynamic contrast-enhanced breast-CT:

• end stage or advanced renal insufficiency
• clinical signs or signs of the labor chemistry for endocrine autonomy (increase of TSH)
• Patients with known allergies or intolerance reactions grade II or higher to contrast medium containing iodine