49 research outputs found
MR spectroscopy in the breast clinic is improving
No full textCarolyn E. Mountford, Christian Schuster, Pascal A.T. Baltzer, Peter Malycha and Werner A. Kaise
Assignment of the Biological Identity of Breast Masses in Contrast-enhanced Spectral Computed Tomography Examinations of Chest Carried Out in Clinical Routine Diagnostics
No full textBackground: Focal breast lesions are observed in up to 5.8% of CT examinations performed in female patients for a wide variety of indications not affecting the breast. To simplify and standardize the further procedure in the case of breast masses visualized by computed tomography (CT), an easy and robust diagnostic approach in assigning surely benign findings, uncertain findings and probably malignant findings is warranted. Objective: We aimed (1) to determine the diagnostic gain of quantitative measurements of the iodine content in breast masses visualized in contrast-enhanced dual energy (DE) CT examinations additional to the assessment of qualitative image features; and (2) to generate an interactive hierarchical decision tree allowing to assess the individual probability of benign or malignant findings. Materials and Methods: All contrast-enhanced DECT examinations performed in adult females from January 2018 to December 2020 were retrospectively screened for solid breast masses. Subsequently, the DECT images with confirmed breast masses were evaluated independently by 3 radiologists experienced in breast imaging using a structured questionnaire. First, the image characteristics of the ACR-BIRADS atlas on MRI were queried, and an assessment of the probability of benignancy or malignancy was requested. Second, the iodine content in the breast masses was interactively measured, and the readers were asked to provide a further assessment of the biological identity. Third, a decision tree was developed using a nonparametric supervised (machine) learning algorithm. Results: During the survey period, 5.591 contrast-enhanced DECT examinations of the chest were carried out in adult female patients. Six hundred eighty-seven DECTs (12.3%) displayed breast masses. The study group comprised 415 female patients (7.4%) with a benign or malignant breast mass confirmed by histology (155, 37.4%), a constant CT-course of ≥2 years without interfering therapy (202, 48.8%) and/or noninvasive breast imaging (57, 13.8%). Neither in the first step nor in the second step of the evaluations a cancer confirmed in the reference standard was classified as certainly benign. Subgroup analyses showed that the combined qualitative and quantitative approach was diagnostically superior compared with the sole descriptor-based assessments in 757 assessments of DECT evaluations with ACR 1+2 breast densities (AUC = 0.961 vs 0.924, lower bound 0.940 vs 0.893, upper bounds 0.982 vs 0.956, P = 0.001) and for the 541 assessments of DECT examinations visualizing masses in denser ACR 3+4 parenchyma (AUC = 0.972 vs 0.948, lower bound 0.953 vs 0.923, upper bound 0.991 vs 0.974, P = 0.043). Including iodine content into the descriptive image evaluations proved to be superior to the solely descriptor-based assessments in 456 assessments of lesions with >5 to 10 mm diameter and in 370 assessments of lesions with >10 to 20 mm ( P = 0.002, 0.002 and 0.018, respectively). Mass contour proved to be the first hierarchical decision level of the interactive classification tree for the differentiation of benign and malignant lesions developed in step 3. In the second hierarchical level, automatically generated classifications of the iodine content allowed to generate 3 diagnostic predictors analogous to the BIRADS classification with a depth of 2 ramifications. Conclusions: Information on the iodine content of breast masses detected by DECT increases diagnostic certainty in the assessment of the biological significance of the lesions. The presented nonparametric decision tree may be helpful in interactively combining semantic and quantitative image data in clinical routine diagnostics of breast masses in spectral CT examinations
Assessing the degree of collinearity among the lesion features of the MRI BI-RADS lexicon
No full textBenndorf M, Baltzer PAT, Kaiser WA. Assessing the degree of collinearity among the lesion features of the MRI BI-RADS lexicon. European Journal of Radiology. 2011;80(3):e322-e324.Purpose: To retrospectively assess collinearity among lesion feature of the MRI BI-RADS lexicon. Collinear-
ity denotes a situation in which two or more (independent) variables are correlated to some degree, thus
partly conveying the same information. Collinearity may cause problems in the interpretation of logistic
regression models.
Materials and methods: We analysed the BI-RADS features of 351 lesions in 325 consecutive patients.
Patients with biopsy proven breast disease or treated with chemotherapy were excluded. All lesion fea-
tures were dichotomised into “present” or “not present”. Correlation matrices were generated for mass
and non-mass lesions separately, focus lesions were omitted. The phi coefficient was used as measure
for correlation.
Results: There were 253 mass (175 malignant, 78 benign), 66 non-mass (21 malignant, 45 benign) and 32
focus (5 malignant, 27 benign) lesions among the study population. The strongest inter-subgroup corre-
lations among mass lesion features were: slow initial enhancement with persistent kinetics, phi = 0.64
(0.56–0.71), rapid initial enhancement with washout kinetics, phi = 0.52 (0.43–0.61) and rapid initial
enhancement with persistent kinetics, phi = −0.43 (−0.53 to −0.32). The strongest inter-subgroup corre-
lation among non-mass lesion features were: rapid initial enhancement with washout kinetics, phi = 0.51
(0.30–0.67), slow initial enhancement with persistent kinetics, phi = 0.43 (0.21–0.61) and rapid initial
enhancement with persistent kinetics, phi = −0.41 (−0.18 to −0.60).
Conclusion: There is a noticeable overlap of information, especially between kinetic features and initial
enhancement types for both, mass and non-mass lesions. This should be considered when generating
logistic regression models with the MRI BI-RADS lesion features
Diagnosis of focal liver lesions suspected of metastases by diffusion-weighted imaging (DWI): systematic comparison favors free-breathing technique
No full textBaltzer PAT, Schelhorn J, Benndorf M, Dietzel M, Kaiser WA. Diagnosis of focal liver lesions suspected of metastases by diffusion-weighted imaging (DWI): systematic comparison favors free-breathing technique. Clinical Imaging. 2013;37(1):97-103.Two echo planar imaging diffusion-weighted imaging (DWI) techniques [one breath hold (DWIbh), repetition time/echo time (TR/TE) 2100/62 ms; one at free breathing (DWIfb), TR/TE 2000/65 ms] were compared regarding diagnosis of focal liver lesions (FLLs) in 45 patients with suspected liver metastasis without prior treatment. Apparent diffusion coefficient values of 46 benign and 67 malignant FLLs were analyzed by receiver operating characteristics (ROC) analysis. DWIfb detected more malignant lesions than DWIbh (P=.002). Lesion size ≤10 mm was associated with FLLs missed by DWIbh (P=.018). Area under the ROC curve of DWIfb (0.801) was higher compared to that of DWIbh (0.669, P<.0113), demonstrating the diagnostic superiority of DWIfb
Diffusion weighted imaging of liver lesions suspect for metastases: Apparent diffusion coefficient (ADC) values and lesion contrast are independent from Gd-EOB-DTPA administration
No full textBenndorf M, Schelhorn J, Dietzel M, Kaiser WA, Baltzer PAT. Diffusion weighted imaging of liver lesions suspect for metastases: Apparent diffusion coefficient (ADC) values and lesion contrast are independent from Gd-EOB-DTPA administration. European Journal of Radiology. 2012;81(8):e849-e853.Purpose: Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced liver
MRI is widely used for detection and differentiation of focal liver lesions. Diffusion weighted imaging
(DWI) including apparent diffusion coefficient (ADC) measurements is increasingly utilised as a fast
and, with limitations, quantitative method for liver lesion detection and characterisation. Herein we
investigate whether the administration of Gd-EOB-DTPA affects DWI.
Materials and methods: 31 consecutive patients referred to standardised liver MRI (1.5 T, Gd-EOB-DTPA,
0.025 mmol/kg) were retrospectively reviewed. All underwent a breathhold DWI sequence before and
after contrast agent administration (EPI-DWI, TR/TE (effective): 2100/62 ms, b-values: 0 and 800 s/mm2 ).
Patients with previously treated liver lesions were excluded. Signal intensity of lesion, parenchyma and
noise on DWI images as well as the ADC value were measured after identification by two observers
in consensus using manually placed regions of interest. The reference standard was imaging follow-
up determined separately by two radiologists. Data analysis included signal-to-noise (SNR) ratio and
contrast-to-noise ratio (CNR) calculations, comparisons were drawn by employing multiple Bonferroni
corrected Wilcoxon signed-rank tests.
Results: 50 malignant and 39 benign lesions were identified. Neither SNR, CNR nor ADC values showed sig-
nificant differences between pre- and postcontrast DWI. Both pre- and postcontrast ADC values differed
significantly between benign and malignant lesions (P < 0.001).
Conclusion: We did not identify a significant influence of Gd-EOB-DTPA on DWI of liver lesions. This allows
for individual tailoring of imaging protocols according to clinical need
A new method to reduce false positive results in breast MRI by evaluation of multiple spectral regions in proton MR-spectroscopy
No full textIs breast MRI a helpful additional diagnostic test in suspicious mammographic microcalcifications?
No full textActa Radiologica Open / Density and tailored breast cancer screening: practice and prediction an overview
No full textMammography, as the primary screening modality, has facilitated a substantial decrease in breast cancer-related mortality in the general population. However, the sensitivity of mammography for breast cancer detection is decreased in women with higher breast densities, which is an independent risk factor for breast cancer. With increasing public awareness of the implications of a high breast density, there is an increasing demand for supplemental screening in these patients. Yet, improvements in breast cancer detection with supplemental screening methods come at the expense of increased false-positives, recall rates, patient anxiety, and costs. Therefore, breast cancer screening practice must change from a general one-size-fits-all approach to a more personalized, risk-based one that is tailored to the individual womans risk, personal beliefs, and preferences, while accounting for cost, potential harm, and benefits.
This overview will provide an overview of the available breast density assessment modalities, the current breast density screening recommendations for women at average risk of breast cancer, and supplemental methods for breast cancer screening. In addition, we will provide a look at the possibilities for a risk-adapted breast cancer screening.(VLID)479970
Table_1_Economic evaluation of breast MRI in screening - a systematic review and basic approach to cost-effectiveness analyses.docx
No full textBackgroundEconomic evaluations have become an accepted methodology for decision makers to allocate resources in healthcare systems. Particularly in screening, where short-term costs are associated with long-term benefits, and adverse effects of screening intermingle, cost-effectiveness analyses provide a means to estimate the economic value of screening.PurposeTo introduce the methodology of economic evaluations and to review the existing evidence on cost-effectiveness of MR-based breast cancer screening.Materials and methodsThe various concepts and techniques of economic evaluations critical to the interpretation of cost-effectiveness analyses are briefly introduced. In a systematic review of the literature, economic evaluations from the years 2000-2022 are reviewed.ResultsDespite a considerable heterogeneity in the reported input variables, outcome categories and methodological approaches, cost-effectiveness analyses report favorably on the economic value of breast MRI screening for different risk groups, including both short- and long-term costs and outcomes.ConclusionEconomic evaluations indicate a strongly favorable economic value of breast MRI screening for women at high risk and for women with dense breast tissue.</p
